Dissertations / Theses on the topic 'Release animals'

L-DOPA-induced dyskinesia is a common side effect developed after chronic treatment with 3,4-dihydroxyphenyl-L-alanine (L-DOPA) in Parkinson's disease. The biological mechanisms behind this side effect are not fully comprehended although involvement of dopaminergic, serotonergic, and glutamatergic systems has been suggested. The present study utilizes in vivo amperometry to investigate the impact from unilateral 6-hydroxydopamine lesions and L-DOPA (4 mg/kg, including benserazide 15 mg/kg) -induced dyskinetic behavior on striatal basal extracellular glutamate concentration and potassium-evoked glutamate release in urethane-anesthetized rats. Recordings were performed before and after local L-DOPA application in the striatum. In addition, effects from the 5-HT1A receptor agonist (2R)-(+)-8-hydroxy-2-(di-n-propylamino)tetralin hydrobromide (8-OHDPAT; 1 mg/kg) was assessed on glutamate release and on dyskinetic behavior. The results revealed a bilateral similar to 30% reduction of basal extracellular glutamate concentration and attenuated potassium-evoked glutamate release after a unilateral dopamine-depletion in L-DOPA naive animals. In dyskinetic subjects, basal glutamate concentration was comparable to normal controls, although potassium-evoked glutamate release was reduced to similar levels as in drug naive dopamine-lesioned animals. Furthermore, acute striatal L-DOPA administration attenuated glutamate release in all groups, except in the dopamine-lesioned striatum of dyskinetic animals. Co-administration of 8-OHDPAT and L-DOPA decreased dyskinesia in dopamine-lesioned animals, but did not affect potassium-evoked glutamate release, which was seen in normal animals. These findings indicate altered glutamate transmission upon dopamine-depletion and dyskinesia.

O presente relatório refere-se ao estágio curricular realizado no âmbito do Mestrado Integrado em Medicina Veterinária da Universidade de Évora, com o título de Clínica e Comportamento de Animais Selvagens, realizado no Centro de Triagem de Animais Silvestres e no Centro de Medicina e Pesquisa de Animais Selvagens. O relatório está dividido em duas partes. Na primeira é descrita a casuística assistida durante o estágio, enquanto que a segunda é dedicada a uma revisão bibliográfica sobre a criação de órfãos selvagens com expectativa de retorno à natureza, com posterior referência a alguns dos casos acompanhados. Apesar de difícil, é possível manter um órfão selvagem vivo em cativeiro. No entanto, se não forem prestados os devidos cuidados, a cria irá adquirir comportamentos e vínculos não apropriados. Existe recentemente uma maior preocupação para a implementação de novos procedimentos, permitindo que os animais desenvolvam comportamentos típicos e possam ser libertado; Abstract: Wild Animals’ Clinic and Behaviour This dissertation will discuss my placement year as part of my master’s degree in Veterinary Medicine in Universidade de Évora. It will report the training I have gained from working in Centro de Triagem de Animais Silvestres and Centro de Medicina e Pesquisa de Animais Selvagens, whilst reflecting on Wild Animals’ Clinic and Behaviour. This document is divided in two main parts. The first one focuses on the activities I have witnessed and the second one consists on a literature review on the recovery of wild orphans who are intended to return to nature, with reference to some of the cases followed. Although it might be difficult, it is possible to keep a wild orphan alive in captivity. However, proper care must be delivered to prevent them from creating bounds and behaviours that could compromisse their release. New procedures should be regularly implemented in order to allow these animals to continue an ordinary life.

Thesis (Honors)--Ohio State University, 2006.<br>Title from first page of PDF file. Document formatted into pages: contains 50 p.; also includes graphics. Includes bibliographical references (p. 28-37). Available online via Ohio State University's Knowledge Bank.

The angiogenic and cardioprotective effects of basic fibroblast growth factor (FGF-2) and vascular endothelial growth factor (VEGF) in the ischemic myocardium have been studied, but expression and release of endogenous FGF-2 and VEGF during myocardial ischemia are poorly understood. In addition, nitric oxide synthase isoforms eNOS and iNOS may play a role in myocardial ischemia. The purpose of this study was to investigate the release of FGF-2 and expression of FGF-2, VEGF, eNOS, and iNOS in the normal and ischemic heart. In Phase I, serum FGF-2 levels in patients undergoing treadmill stress test were measured to investigate correlation between serum FGF-2 levels and presence of ischemic heart disease. The study found that serum FGF-2 in ischemia-positive and ischemia-negative patients was not significantly elevated after treadmill stress test, and serum FGF-2 levels did not differ significantly between ischemia-positive and ischemia-negative patients. In Phase II, FGF-2 levels in coronary effluent from isolated perfused rabbit hearts subjected to low-flow ischemia was measured. Results suggest that FGF-2 is released into the coronary effluent of isolated perfused hearts over time and that this release may be elevated in ischemic (50% flow) hearts. Furthermore, the present study indicates that FGF-2 is released immediately after surgical isolation and instrumentation of the isolated heart. A linear model was developed to describe the release of FGF-2 from the isolated heart as a function of the coronary flow rate Q : [special characters omitted]where t = time and Q = 1 and 3.01 for normal and 50% flow rates respectively. In Phase III, effect of acute low-flow ischemia on FGF-2, VEGF, eNOS, and iNOS mRNA expression was measured in isolated perfused hearts using RT/PCR. Preliminary results indicate that FGF-2, VEGF, and iNOS mRNA expression is upregulated and eNOS expression is decreased in ischemic hearts suggesting that these growth factors play a role in short-term response of the myocardium to ischemia. The results of this study suggest that FGF-2, VEGF, and iNOS mRNA expression are increased, eNOS expression is decreased, and FGF-2 is released in response to low-flow ischemia in the isolated perfused heart.

O campus da Universidade de São Paulo em Ribeirão Preto consiste em uma área de 450 ha, caracterizada por um mosaico de remanescentes de mata e construções, sendo uma das maiores áreas verdes do município. Para suplementar a população de bugios-pretos (Alouatta caraya) existente no campus, este estudo realizou a soltura de um casal cativo. O grupo residente, composto por quatro bugios, foi rastreado seis dias por mês num período de seis meses para verificação da área de vida com finalidade de definir uma área para a soltura do casal. Um macho adulto e uma fêmea subadulta foram unidos em cativeiro no Parque Municipal Morro de São Bento. A formação do casal foi realizada em três fases (familiarização, junção e pós-junção) com gradativo aumento de aproximação. O padrão de atividades foi registrado pelo método de varredura a cada 5 minutos por 2 horas durante 10 dias (para cada fase). Os valores obtidos ficaram próximos ao relatado para o gênero, com aumento do comportamento social no decorrer das fases: 4,4 16 e 35,2% (p<0,001). O casal foi transferido para um cativeiro na área de soltura, onde permaneceu por 44 dias. Neste período foi realizada a avaliação pré-soltura e a reeducação alimentar. Na avaliação pré-soltura foi verificado que a mudança de área não afetou significativamente o comportamento social do casal, cujo valor obtido foi de 29% (p=0,083 em comparação com o valor obtido na última fase da formação do casal). Na reeducação alimentar, gradativamente a dieta inicial de 2000 g de frutas por dia, teve 1200 g substituídas por folhas de cinco espécies vegetais. A soltura do casal foi realizada no dia 10 de novembro de 2009. O casal foi acompanhado das 6 às 18 h, quatro dias por mês num período de um ano novembro/09 à outubro/10, com exceção de janeiro/10 com total de 528 h de observação. O padrão de atividades foi registrado pelo método de varredura a cada 20 minutos. Durante o ano, o casal dedicou 61,7% do tempo para descanso, 5,9% para locomoção não-direcional, 6,1% para locomoção direcional, 10,9% para alimentação e 15,4% para comportamento social. A locomoção direcional, comportamento que melhor expressa a exploração da área, teve os registros de cada mês comparados com sua média anual (18,6). Os meses dezembro, fevereiro e março apresentaram registros acima da média, sendo o mês de dezembro significativamente maior (p<0,001). Os meses maio, junho, julho, agosto, setembro e outubro, apresentaram registros menores, sendo o mês de julho significativamente menor (p=0,032). A alimentação foi registrada pelo método 1-0 a cada 5 minutos. Durante o ano, o casal utilizou 146 indivíduos (árvores e lianas) de 38 espécies pertencentes a 18 famílias. As seis espécies mais consumidas correspondem a 61,3% do total de registros: Maclura tinctoria (14,8%), Leucaena leucocephala (13,3%), Ficus insipida (11,8%), Handroanthus impetiginosus (7,6%), Poincianella pluviosa (7%) e Terminalia catappa (6,8%). O total de espécies consumidas em cada mês foi comparado com a média anual de 9,8. Os meses de dezembro, fevereiro, março, abril e maio apresentaram mais espécies consumidas que a média. Os meses junho, julho, agosto, setembro e outubro apresentaram menos espécies que a média, sendo o mês de julho significativamente menor (p=0,033). A área de vida foi registrada pelo método de varredura a cada 1 hora. Durante o ano, o casal utilizou 50 quadrantes de 50 x 50 m (0,25 ha), totalizando uma área de 12,5 ha. O total de quadrantes utilizados por mês foi comparado com a média anual de 9. Os meses de dezembro, fevereiro e março apresentaram maior quantidade de quadrantes utilizados que a média, sendo os meses de dezembro e março significativamente maiores (p=0,039 e p=0,025). Os meses junho, julho, agosto, setembro e outubro apresentaram menor quantidade de quadrantes utilizados que a média. Foram encontradas duas áreas centrais (utilização > 10%), ambas correspondem à localização dos recursos alimentares mais utilizados e bambuzais altos e densos utilizados como árvores-dormitório. Com esses resultados, foi possível verificar que o casal explorou a área desconhecida até o 5° - 6° mês de soltura. A partir daí, espécies vegetais e quadrantes foram selecionados, evidenciando que o casal se organizou para atingir o equilíbrio das suas necessidades energéticas. Portanto, podemos concluir que já no primeiro ano o casal de bugios se adaptou ao campus, pois garantiu sua sobrevivência. Com um ano e meio de soltura ocorreu o nascimento do primeiro filhote, acrescentado que, além da sobrevivência o casal também garantiu sua reprodução.<br>The University of São Paulo campus in Ribeirão Preto is an area of 450 hectares, characterized by a mosaic of forest remnants and buildings, one of the largest green areas of the city. For this study a captive couple of black howler monkeys (Alouatta caraya) was released to supplement the existing campus population. In order to define an area for the release of the couple the resident group, composed of four monkeys, was tracked six days per month for a period of six months to determine their home range adult male and a sub-adult female were united in captivity in the Municipal Park Morro de Sao Bento. The couple formation was accomplished in three phases (familiarization, junction and post-junction) with gradual proximity increase. The activity pattern was recorded using the scanning method, every 5 minutes for 2 hours for 10 days (for each phase). Recorded values were close to those reported for the genus, with increased social behavior during the phases: from 4.4 to 16 and 35.2% (p<0.001). The couple was moved to a cage at the release site, where they stayed for 44 days. During this time the pre-release assessment and rehabilitation diet were implemented. During the pre-release it was verified that the change of area did not significantly affect the social behavior of the couple, whose value was 29% (p = 0.083 compared with the value obtained in the last phase of formation the couple). In the rehabilitation diet, of the initial 2000 g of fruit per day, 1200 g were gradually replaced by leaves of five plant species. The couple was release on November 10, 2009. The couple was followed from 6 am to 18 pm, four days per month for a period of one year - November/09 to October/10, except January/10 - a total of 528 observation hours. The activity pattern was recorded by the scanning method every 20 minutes. During the year they spent 61.7% of the time at rest, 5.9% non-directional movement, 6.1%directional movement, 10.9% feeding and 15.4% in social behavior. The directional movement, behavior that best expresses the exploration of the area, monthly records were compared to the annual average (18.6). December, February and March had above-average results with the month of December significantly higher (p<0.001). May, June, July, August, September and October, showed lower results, with the month of July being significantly lower (p=0.032). The feeding was recorded by the method 1-0 every 5 minutes. During the year the couple used 146 individuals (trees and vines) of 38 species belonging to 18 families. The six most consumed species account for 61.3% of total records: Maclura tinctoria (14.8%), Leucaena leucocephala (13.3%), Ficus insipida (11.8%), Handroanthus impetiginosus (7.6%) Poincianella rainfall (7%) and Terminalia catappa (6.8%). The total number of species consumed in each month was compared with the annual average of 9.8. More species than average were consumed during the months of December, February, March, April and May. Fewer species than the average were consumed during the months of June, July, August, September and October, July was significantly lower (p=0.033). The home range was recorded by the scanning method every 1 hour. During the year the couple used 50 quadrants of 50 x 50 m (0.25 ha), totaling an area of 12.5 hectares. The total number of quadrants used per month was compared with the annual average of 9. The months of December, February and March had a higher number of quadrants that the medium used, with December and March significantly higher (p=0.039 and p=0.025). June, July, August, September and October had fewer quadrants used than average. We found two core areas (use > 10%), both correspond to the most used food resources locations and dense tall bamboo ares used as dormitory trees. The results showed that the couple had explored the new area by the 5th - 6th month of release. Thereafter, plant species and quadrants were selected, showing that the couple had organized itself to balance its Therefore, we conclude that in the first year the couple adapted to the campus, ensuring its survival. After a year and a half of release the birth of first infant occurred. Thus, beyond survival, the couple also assured its reproduction.

Thesis (PhD (Molecular Biology and Human Genetics))--University of Stellenbosch, 2010.<br>ENGLISH ABSTRACT: The growing global epidemic of human tuberculosis (TB) results in 8 million new cases of this disease and 2 million deaths annually. Control thereof will require greater insight into the biology of the causative organism, Mycobacterium tuberculosis, and into the pathogenesis of the disease. This will benefit the design of new vaccines and diagnostic assays which may reduce the degree of both disease transmission and progression. Animal models have played a vital role in the understanding of the aetiology, pathogenesis, and treatment of TB. Much of such insight has been obtained from experimental infection models, and the development of new vaccines, for example, is dependant on these. Nonetheless, studies utilising naturally occurring TB in animals, such as those which have investigated the use of interferon-gamma release assays (IGRA) for its diagnosis, have contributed substantially to the body of knowledge in this field. However, there are few such examples, and this study sought to identify and investigate naturally occuring animal TB in South Africa as an opportunity to gain further insight into this disease. During the course of this study, the dassie bacillus, a distinctly less virulent variant of M. tuberculosis, was isolated from a rock hyrax from the Western Cape Province of South Africa. This has provided new insight into the widespread occurrence of this organism in rock hyrax populations, and has given impetus to further exploring the nature of the difference in virulence between these pathogens. Also investigated was M. tuberculosis infection in dogs in contact with human TB patients. In so doing, the first reported case of canine TB in South Africa was described, v a novel canine IGRA was developed, and a high level of M. tuberculosis infection in these animals was identified. This supports human data reflecting high levels of transmission of this pathogen during the course of human disease. Additionally, the fact that infected companion animals may progress to disease and potentially act as a source of human infection was highlighted. However, an attempt to adapt a flow cytometric assay to study cell-mediated immune responses during canine TB revealed the limitations of such studies in species in which the immune system remains poorly characterised. The use of IGRAs to diagnose TB was further explored by adapting a human assay, the QuantiFERON-TB Gold (In-Tube Method), for use in non-human primates. These studies have shown that such an adaption allows for the sensitive detection of TB in baboons (Papio ursinus) and rhesus macaques (Macaca mulatta) and may be suitable for adaption for use in other species. However, they have also evidenced the limitation of this assay to specifically detect infection by M. tuberculosis. Finally, to contextualise the occurrence of the mycobacterial infections described above, and other similar examples, these have been reviewed as an opinion piece. Together, these investigations confirm that animal models will continue to make important contributions to the study of TB. More specifically, they highlight the opportunities that naturally occuring animal TB provides for the discovery of novel insights into this disease.<br>AFRIKAANSE OPSOMMING: Wêreldwye tuberkulose (TB) epidemie veroorsaak agt miljoen nuwe gevalle en twee miljoen sterftes jaarliks. Ingryping by die beheer hiervan vereis begrip van die biologie van die mikroörganisme Mycobacterium tuberculosis, die oorsaak van TB, asook van die patogenese van die siekte self. Hierdie kennis kan lei tot ontwerp van nuwe entstowwe en diagnostiese toetse wat gevolglik beide die oordrag- en vordering van die siekte mag bekamp. Dieremodelle speel lankal 'n rol in ons begrip van die etiologie-, patogenese- en behandeling van TB. Insig is grotendeels verkry vanaf eksperimentele infeksiemodelle, en ontwikkeling van entstowwe, onder andere, is afhanklik van soortgelyke modelle. Desnieteenstaande, studies wat natuurlike TB voorkoms in diere ondersoek, byvoorbeeld dié wat op die ontwikkeling van interferon-gamma vrystellingstoetse (IGVT) fokus, het merkwaardige bydrae gemaak tot kennis en begrip in hierdie studieveld. Daar is slegs enkele soortgelyke voorbeelde. Om hierdie rede is die huidige studie uitgevoer waarbinne natuulike diere-TB geïdentifiseer en ondersoek is in Suid-Afrika om verdere kennis en insig te win aangaande TB. Die "dassie bacillus", bekend om beduidend minder virulent te wees as M. tuberculosis, is tydens hierdie studie geïsoleer vanuit 'n klipdassie (Procavia capensis) in die Wes-Kaapse provinsie, Suid-Afrika. Insig in die wydverspreide voorkoms van hierdie organisme in klipdassie bevolkings is gevolglik verkry en verskaf momentum om die aard van verskil in virulensie tussen dié patogene te bestudeer. vii Voorts is M. tuberculosis infeksie bestudeer in honde wat in kontak is met menslike TB pasiënte en word die eerste geval van honde TB dus in Suid-Afrika beskryf. In hierdie groep diere, is 'n hoë vlak van M. tuberculosis infeksie geïdentifiseer deur gebruik te maak van 'n nuut ontwikkelde IGVT vir die diagnose van honde TB. Gevolglik ondersteun dié studie bevindinge van menslike studies wat toon dat besondere hoë vlakke van M. tuberculosis oordrag voorkom gedurende die verloop van die siekte. Verder toon die studie dat geïnfekteerde troeteldiere 'n bron van menslike infeksie kan wees. 'n Poging om 'n vloeisitometriese toets te ontwikkel om die aard van selgefundeerde immuunreaksies te bestudeer in honde met TB toon die beperkings van dergelike studies in spesies waarin die immuunsisteem gebrekkig gekarakteriseer is. Die gebruik van IGVT'e in die diagnose van TB is verder ondersoek deur 'n menslike toets (QuantiFERON-TB Gold, In-Tube Method) aan te pas vir die gebruik van nie-menslike primaat gevalle. Hierdie studies toon gevolglik dat so 'n aanpassing toepaslik is vir hoogs sensitiewe deteksie van TB in chacma bobbejane (Papio ursinus) en rhesus ape (Macaca mulatta), en mag ook aangepas word vir gebruik in ander spesies. Tog word die beperkings van hierdie toets om infeksie wat spesifiek deur M. tuberculosis veroorsaak uitgelig. Ter afsluiting word hierdie studie in konteks geplaas deur 'n oorsig te gee van bogenoemde- en soortgelyke gevalle van dierlike infeksie deur mikobakterieë in Suid-Afrika. Hierdie studies bevestig dat dieremodelle steeds belangrike toevoegings maak tydens die bestudering van TB en lig veral die moontlikhede uit dat bestudering van natuulike TB in diere kan lei tot die ontdekking van nuwe insigte ten opsigte van die siekte self.

To provide further insight into the relationship between the structure of hydrocolloid solutions and gels and perception of taste and flavour, solutions of gelatin and locust bean gum, and gels prepared from mixtures of (a) high acyl and low acyl gellan (b) carrageenan and locust bean gum were studied. Both solutions contained sodium chloride and the gels were flavoured with ethyl butyrate. The gels were classified from rheological measurements into 3 categories: strong/brittle, intermediate and soft/elastic. Volatile release was measured by monitoring nose space volatile concentration during consumption using Atmospheric Pressure Chemical Ionisation-Mass Spectrometry (APCI-MS). In addition headspace measurements were performed with APCI-MS. The headspace concentrations did not exhibit significant differences between the gels systems but the release of ethyl butyrate in-nose was affected by the matrix, showing a higher intensity for the more brittle gels containing high levels of low acyl gellan. The release of Na' following a two bite compression was monitored by the use of an ion specific electrode. The more brittle gels containing high levels of low acyl gellan and high amount of K-carrageenan exhibited significantly higher release of Na'. Strain at break correlated inversely with salt release (r2=-0.87) and nose space volatile concentration (r2=-0.55). In a later stage gelatin was added (1-5%) in the previous mixtures of HA-Gellan and LA-Gellan (constant polysaccharide concentration of 0.6%). The rheological analysis of the gels yielded different behaviour of the gels. At low levels of LA-Gellan the rheological data can be explained by polymer blending laws. At higher levels of LA-Gellan, development of elastic behaviour from the previous brittle gels observed does not fit polymer blending law theory. Flavour release during diffusion experiment showed that at 37°C the gels containing gelatin exhibited higher salt release. Temperature sweeps have shown that a drop of G' is observed around 27-28° C indicating that the gelatin present in the mixture is melting. However the level of the drop of G' indicates that the continuous phase of the gel composite was the gellan system. Volatile release was measured by monitoring nose space volatile concentration during consumption using Atmospheric Pressure Chemical Ionisation-Mass Spectrometry (APCI-MS) but showed no significant differences between the different gels. Headspace experiments performed at different temperatures showed that the gels containing high amounts of gelatin when compared to control gels that contained 0% gelatin exhibited higher release of ethyl butyrate. To mimic the mixing of gelatin with saliva after melting, gelatin solutions at 50°C containing salt were mixed with water. Even at high concentrations (30%) of gelatin mixing efficiency and release was very efficient. In contrast when locust bean gum solutions containing salt were mixed with distilled water it was found that both salt release and mixing efficiency decreased at polysaccharide concentrations above c*. It is concluded that the intensity of flavour perception in hydrocolloid solutions and gels is dominated by the release of the tastant. In solutions this is favoured by good mixing behaviour between the hydrocolloid solution and saliva and in gels by a low strain at break. A gelatine replacement should not only show melt in the mouth behaviour but good mixing between the melted gelatin and saliva. It was shown that thermal processing at 121°C induced deacetylation of HA-gellan at much lower pH than would normally be needed in a typical deacetylation process. Therefore new textures can be achieved through deacetylation through heat processing. When gels which were prepared by deacetylation by heat processing were compared with blends that had an equivalent acyl content different textures were obtained even though the Young's modulus was very similar at the same total acyl content. The implications of this work for gelled petfood products is discussed.

This thesis examined a variety of factors controlling the storage and release of the catecholamine hormones, adrenaline and noradrenaline, from chromaffin cells in teleost fish. In these fish, chromaffin cells line the walls of the posterior cardinal vein (PCV) in the anterior kidney region (head kidney). To examine the process of catecholamine release, an in situ saline-perfused PCV preparation first was developed and validated in the rainbow trout (Oncorhynchus mykiss). The levels of stored catecholamines were approximately 4X greater in trout than in eel, and trout chromaffin cells released greater quantities of catecholamines in response to both 60 mmol 1$\sp{-1}$ K$\sp+$ and carbachol administration, in situ. Thus trout chromaffin cells appear to exhibit a greater capacity to release catecholamines than do eel chromaffin cells which may explain the different plasma catecholamine levels during acute hypoxia. The proximate stimulus for catecholamine release in rainbow trout, during exposure to acute hypoxia, was examined by acclimating trout to either 5 or 15$\sp\circ$C in order to modify haemoglobin oxygen-affinity. At 15$\sp\circ$C, catecholamines were released into the circulation at a PaO$\sb2$ threshold of 34.5 torr while at 5$\sp\circ$C the threshold was 24.0 torr. Release thresholds, calculated on the basis of arterial blood oxygen-saturation were similar at both temperatures (approximately 60% Hb O$\sb2$-saturation). Thus the lowering of blood oxygen content, rather than PO$\sb2,$ appears to be the proximate stimulus causing catecholamine release in rainbow trout during acute hypoxia. In the rainbow trout, intra-arterial injections of serotonin in vivo caused an increase in both plasma adrenaline and noradrenaline levels. In situ, bolus injections of catecholamines which was attenuated by pre-treatment with the serotonergic receptor antagonist, methysergide but unaffected by hexamethonium. Thus serotonin is capable of causing the release of catecholamines by interacting with serotonergic receptors on the chromaffin cells. The effect of adrenocorticotropic hormone (ACTH), the normal secretagogue of cortisol, on catecholamine release, was investigated in the rainbow trout. Intra-arterial injections of ACTH, in vivo, caused an elevation of plasma adrenaline levels. In situ, adrenocorticotropic hormone (ACTH) caused the release of both catecholamines. ACTH-induced release was unaffected by pre-treatment with hexamethonium or methysergide but abolished in Ca$\sp{2+}$-free media. Injections of cortisol in situ did not elicit catecholamine release. ACTH, therefore, is capable of eliciting catecholamine secretion from the chromaffin cells in rainbow trout. (Abstract shortened by UMI.)

Atrial muscle stretch is widely believed to be the main stimulus for ANF release. However, we demonstrate in this study that although stretch induces an immediate increase in ANF output, this release rapidly decays even though hormone stores are not significantly depleted. In the present work, this phenomenon was studied in an isolated rat atria preparation using double isotope labelling. The tissue was labelled with $\rm\sp C$-leucine for 3 h followed by a 1 h chase, and then with $\rm\sp3H$-leucine for 1 h. A final 1 h chase period was conducted with the tissue under basal (0.2 g load) or stretched (5 g load) conditions. During this final chase period, the $\rm\sp C$-ANF represented ""older", stored ANF and the $\rm\sp3H$-ANF the "newly synthesized" peptide. Following both the $\rm\sp C$- and $\rm\sp3H$-leucine pulses, immunoprecipitable (IP) isotope incorporated into ANF appeared in the chase medium within the first 10 min and stabilized to lower levels after 20 min of chase. Stretch resulted in an immediate significant increase in immunoreactive (ir) ANF release and a decrease in the medium $\rm\sp C$-ANF specific activity (S.A.). However, no change was observed in the medium $\rm\sp3H$-ANF S.A. but the tissue S.A. tended to decrease. It is concluded that, in the basal state, a portion of ANF is immediately and preferentially released upon synthesis, while the remainder is presumably taken up into tissue stores and released from them at a lower rate. The secretory response to stretch was demonstrated to consist of a rapid, short-lived burst of newly synthesized ANF, suggesting an increased translocation of newly synthesized hormone into a stretch-sensitive, rapidly depletable pool. Given the nature of this pool, additional factors yet to be characterized likely come into play to maintain chronically elevated circulating levels of ANF.

The time course of the spontaneous current spikes produced by the release of the catecholamines from individual vesicles was examined in bovine chromaffin cells by using the carbon filament technique in the amperometric mode.<br>Frequency histograms of the rise and decay times of the current spikes showed a paucity of very short duration events. Scatterograms of the rise and decay times consistently showed a positive relation, and the best fitted lines intercepted the ordinate (the axis of the decay time) at: 16.06 $ pm$ 6.45 msec (n = 11).<br>The effect of temperature changes upon the time course of release of content of individual vesicles in chromaffin cells was also examined. The amplitudes of the current spikes did not change significantly, whereas the rise times and the decay times diminished from (23.2 $ pm$ 11.6 to 11.9 $ pm$ 2.7 msec, and from 76.6 $ pm$ 25.4 to 47.3 $ pm$ 9.3 msec respectively) as the temperature was raised from 15$ sp circ$C to 35$ sp circ$C (n = 5). Nevertheless, the Q$ sb{10}$ values of the rise and decay times were surprisingly low.<br>The experimental findings suggest that in bovine chromaffin cells the duration of the release of content of single vesicles is much longer than in synapses. The results also suggest that this mechanism does not involve processes that are strongly temperature sensitive.

The aim of this thesis was to study aspects of the neuronal control of catecholamine secretion in a teleost, the rainbow trout. The development and validation of a nerve stimulation technique made it possible to determine that a portion of the neuronal control of catecholamine release, which prevailed at low frequency stimulation, could be attributed to vasoactive intestinal polypeptide (VIP) and/or pituitary adenylate cyclase activating polypeptide (PACAP). On the other hand, cholinergic stimulation predominated during higher levels of neuronal activity. Fluorescent histochemical techniques in combination with pharmacological approaches provided direct evidence that VIP and PACAP can elicit the secretion of adrenaline, only, from the chromaffin tissue via specific VIP binding sites that exhibited properties of VPAC receptors. Using in situ perfused posterior cardinal vein preparations, evidence was provided that while the nicotinic receptor appears to be the predominant pathway mediating the effects of acetylcholine on catecholamine secretion, muscarinic receptor stimulation may augment the cellular response to nicotinic receptor activation. Under extreme conditions, muscarinic receptors may directly elicit the secretion of catecholamines. The impact of extracellular catecholamines on catecholamine secretion from chromaffin cells was also investigated. Results revealed that the mechanisms of adrenergic inhibition of catecholamine secretion in response to cholinergic stimulation include activation of chromaffin cell membrane beta2-receptors and presynaptic alpha2-adrenergic receptors. However, catecholamine release in response to VIP appears to be insensitive to the adrenergic negative feedback mechanisms. Finally, despite the rapid progress in cDNA cloning, molecular information on the receptors mediating the effects of VIP and PACAP in fish is scant. In this thesis, I report preliminary findings of the cloning of the trout PAC1, VPAC1, and VPAC2 receptors from brain cDNA. In summary, VIP and PACAP appear to function as neurotransmitters in the neuronal regulation of catecholamine release in this species. The apparent complexity of the mechanisms regulating the secretion of catecholamines from trout chromaffin cells may reflect the precise control required for these hormones to play their role in physiological and biochemical homeostasis in these organisms.

This thesis focuses on the effects of adenosine release on neuronal activity in the CA1 region of rat hippocampal slices, especially during energy deprivation, and related events. The overall aim was to find out how brain function is suppressed when metabolism is greatly reduced by the lack of oxygen or glucose, or by cyanide applications, and therefore to provide some insights in the cellular mechanisms underlying these depressant effects. Experiments were carried out on hippocampal slices kept submerged and constantly superfused with oxygenated saline at 33-34$ sp circ$C. Energy deprivation was produced by either removal of oxygen or glucose, or applying cyanide. Extra-/intracellular and whole-cell patch recordings (both in current- and voltage-clamp mode) were used to assess synaptic function and postsynaptic properties.<br>A most interesting phenomenon is the reversible suppression of neuronal function that occurs in the very early phase of energy deprivation. Adenosine receptor antagonists reversibly reduce this suppression. In contrast, neither glibenclamide, a blocker of ATP-sensitive K$ sp+$ channels, nor a nitric oxide synthase inhibitor prevents the suppression of neuronal activity induced by energy deprivation. The depressant effect acts selectively on excitatory synapses, since in the presence of excitatory receptor antagonists, anoxia causes only a small reduction of monosynaptic inhibitory responses. Also adenosine antagonists, but not the K$ rm sb{ATP}$ channel blocker, reversibly attenuate anoxia- and cyanide-induced post-synaptic hyperpolarizations.<br>Furthermore, under normoxic conditions, ongoing adenosine release exerts an inhibitory tone on excitatory synapses but not on inhibitory synapses. The effects of ongoing adenosine release are mainly on synapses, since after blockade of transmitter actions, ongoing adenosine release has no detectable effect on membrane conductance.<br>The evidence presented in this thesis shows that increased adenosine release induced by energy deprivation is a major cause of the reversible loss of synaptic transmission and fall in membrane resistance, and therefore indicates a mechanism by which adenosine release contributes to the reversal depression of neuronal activity seen during energy deprivation.

Mestrado em Biologia Aplicada - Ecologia, Biodiversidade e Gestão de Ecossistemas<br>A dispersão biológica das espécies sempre foi um tema importante em vários estudos em ecologia de populações. Sabe-se que diferentes espécies de borboletas apresentam diferentes tipos de comportamentos: migratório ou sedentário. São conhecidos vários estudos genéticos que dizem respeito à estrutura populacional e aos problemas de isolamento. No entanto, são geralmente desconhecidos estudos de comportamento de dispersão das espécies para a análise populacional. Seleccionaram-se, por isso, dois métodos distintos, microssatélites e marcação e recaptura, para caracterizar a mobilidade de borboletas. Para o método genético foram selecionadas 16 populações (634 indivíduos) de Brenthis ino (Rottemburg, 1775), recolhidas em Rheinland-Pfalz, Alemanha e Alsace, França, a fim de identificar a estrutura genética das populações em estudo. Através da análise por microssatélites de onze loci polimórficos, foi possível identificar a sua variabilidade e a estrutura genética entre populações. A diferenciação genética entre as populações (FST = 0.040) foi significativa. A média da heterozigosidade observada e o erro padrão foi de 0.64±0.013, enquanto a heterozigosidade esperada foi 0.73±0.008. Oito dos onze loci estavam em equilíbrio de Hardy-Weinberg, mas a presença de alelos nulos é provável para três loci. Foi encontrado um sistema de isolamento por distância, que é significativo ao ponto de explicar quase 42% da diversidade genética entre as populações. Nenhum sistema de isolamento por distância foi encontrado nas montanhas de Hunsrück, indicando que ocorre um grande fluxo genético entre populações da região. O segundo método utilizado foi o de marcação e recaptura. Em Trier, Rheinland-Pfalz, Alemanha, foram marcados 1.210 indivíduos de cinco espécies diferentes, Anthocharis cardamines, Pieris napi, Pieris rapae, Leptidea reali e Araschnia levana, a fim de examinar o comportamento de dispersão. A baixa taxa de recaptura indicou que se está perante grandes populações de Pieris napi; Pieris rapae e Leptidea reali. A função exponencial negativa (NEF) mostrou ser o melhor modelo para prever os movimentos de longa distância dos indivíduos por captura/recaptura para as espécies Pieris napi, Pieris rapae e Leptidea reali. Os resultados desta previsão indicam que estas três espécies poderão voar longas distâncias, apresentando uma grande mobilidade. Os resultados obtidos para B. ino são importantes uma vez que esta apresenta um estatuto vulnerável em Rheinland-Pflaz. Programas de monitorização poderão ser aplicados para as cinco espécies do estudo de marcação e recaptura para se caracterizar as tendências populacionais de mobilidade.<br>Biological dispersal has always been an important topic in several studies in population ecology. It is known that different butterfly species present a sedentary or migratory behaviour. While the genetic analysis intends to respond to population structure and isolation issues that are mostly well studied, the effects of different dispersal behaviours of species are widely unknown. Therefore, we selected two different methods, a genetic and an ecological, to characterise butterfly mobility. For the genetic method we selected 16 populations (634 individuals) of Brenthis ino (Rottemburg, 1775), collected in Rhineland-Palatinate, Germany and Alsace, France in order to identify the genetic structure of the study populations. Through analysing eleven polymorphic microsatellite loci, we could identify the genetic variability and structure among populations. The genetic differentiations among populations (FST = 0.040) was highly significant. The mean value of observed heterozygosity and the standard error was 0.64±0.013, while the one of the expected heterozygosity was 0.73±0.008. Eight of the eleven loci were in Hardy-Weinberg equilibrium, but presence of null alleles is likely for three loci. A system of isolation-by-distance was found and it explains almost 42% of the genetic differentiation among populations. No system of isolation-by-distance was found in the Hunsrück mountains leading to a large gene-flow among populations occurring in this region. The mark-release recapture was the second method used. In Trier, Rhineland-Palatinate, Germany, we marked 1.210 individuals of five different species, Anthocharis cardamines, Pieris napi, Pieris rapae, Leptidea reali and Araschnia levana in order to examine their dispersal behaviour. The Negative Exponential Function (NEF) was the best model to predict long distance movements of the capture/recapture individuals for the species Pieris rapae, Pieris napi and Lepdtidea reali. The results of this prediction show that they can move large distances, therefore, we can assume that these three species have a large mobility. The results obtained for the genetic structure seems to guarantee a genetic long-term survival for most of our 16 populations of B. ino. This is an important result once it has a vulnerable status for Rheinland-Pflaz. All five species have a least concern status for the same region, although conservative measures should not be forgotten. Butterfly monitoring programs are an option that describes large-scale population trends.

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2017-10-24T16:27:38Z No. of bitstreams: 1 texto completo.pdf: 1290781 bytes, checksum: 26969e6b4975755e04a6483c8d4906ce (MD5)<br>Made available in DSpace on 2017-10-24T16:27:38Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1290781 bytes, checksum: 26969e6b4975755e04a6483c8d4906ce (MD5) Previous issue date: 2017-07-28<br>Conselho Nacional de Desenvolvimento Científico e Tecnológico<br>Para esta tese foram preparados quatro artigos científicos baseados em estudos de liberação de minerais de alimentos para ruminantes, absorção, metabolismo e equilíbrio de minerais para bovinos de corte, e ingestão de água de bovinos de corte. No primeiro artigo, o objetivo foi quantificar a digestibilidade da matéria seca (MS) e a disponibilidade de cinzas totais (CT) e liberação dos minerais de 12 alimentos concentrados e 12 volumosos comumente adotados em dietas para ruminantes, utilizando métodos in situ e in vitro. Os alimentos foram incubados no rúmen de machos não castrados por 8 deferentes tempos. Foram realizados dois ensaios, um para concentrados e outro para volumosos, com tempo máximo de incubação de 72 e 120 h, respectivamente. O resíduo das amostras incubadas durante 24 h foi tratado com pepsina e ácido clorídrico para simular a digestão no abomaso. As amostras iniciais e residuais após incubação in situ e in vitro foram avaliadas quanto aos teores de MS, CT e minerais. Um modelo assintótico foi adotado para estimar a liberação dos minerais, e as taxas de degradação da MS e CT. Foram avaliadas as correlações entre os teores nos alimentos e a liberação de cada mineral. “Clusteres” foram formados para agrupar os alimentos, em relação à liberação de CT. Observou-se grande variabilidade entre os alimentos concentrados e volumosos para todos os constituintes analisados. Grande variabilidade foi observada para a degradação ruminal efetiva da CT e para a liberação de cada mineral. Quando os alimentos foram agrupados de acordo com as estimativas α β e kd da liberação ruminal de CT, foram identificados 4 grupos. Do grupo "1" para o grupo "4", observou- se um crescimento na fração solúvel e uma redução na fração de liberação lenta e na taxa de liberação. O conteúdo de fibra de detergente neutro apresentou uma correlação negativa com a liberação de mineral no rúmen, enquanto o conteúdo de minerais apresentou correlação positiva. Esses resultados demonstram que a solubilização mineral no trato digestivo não é o fator limitante para a absorção mineral dos alimentos testados. Os objetivos do segundo e terceiro artigos foram medir os efeitos da suplementação mineral sobre ingestão de nutrientes e digestibilidade, desempenho, balanço e exigência de minerais, e concentrações de minerais no corpo de bovinos de corte Nelore alimentados com ou sem cálcio (Ca), fósforo (P ) e fontes suplementares de microminerais (MM) durante as fases de crescimento e terminação. Os animais (n = 51, Nelore, peso corporal inicial = 270,4 ± 36,6 kg, idade = 8 meses) foram atribuídos a um dos três grupos: referência (n = 5), mantença (n = 4) e desempenho (n = 42) . O grupo referência foi abatido no início do experimento para estimar a composição corporal dos demais animais. O grupo mantença foi utilizado para coletar valores de animais com baixos ganho corporal e ingestão de minerais. Os animais do grupo de desempenho foram designados para um dos seis tratamentos: cana-de-açúcar como volumoso e concentrado a base de farelo de soja e casca de soja com (SH100) e sem (SH0) suplementação de Ca, P e MM; Cana-de-açúcar como volumoso e concentrado a base de farelo de soja e milho moído com (SC100) e sem (SC0) suplementação de Ca, P e MM; e silagem de milho como volumoso e concentrado a base de farelo de soja e milho moído com (CS100) e sem (CS0) suplementação de Ca, P e MM. O experimento foi conduzido como um delineamento inteiramente casualizado com um arranjo fatorial 3 × 2, sendo 3 tipos de dietas e presença ou ausência de suplementação inorgânica de minerais. O consumo e digestibilidade de nutrientes, os parâmetros ósseos e séricos relacionados ao metabolismo de Ca e P e as concentrações hepáticas de minerais foram mensurados. Para avaliar a ingestão de cada mineral, a excreção fecal e urinária e a retenção aparente entre os tratamentos, contrastes ortogonais foram adotados. As exigências de mantença e os coeficientes de retenção verdadeiros foram calculados com o auxílio da regressão linear entre o consumo e a retenção de cada mineral. A composição mineral do corpo e as exigências para ganho de peso foram avaliados, utilizando modelos não lineares entre o conteúdo corporal e o consumo de cada mineral. Os consumos, digestibilidade e desempenho de nutrientes não foram afetados pelo fator mineral (P > 0,10). Os consumos de Ca, P, S, Cu, Zn, Mn, Co e Fe foram reduzidas na ausência de suplementação de Ca, P e MM (P < 0,05). A excreção fecal de Ca, Cu, Zn, Mn e Co também foi reduzida em tratamentos sem suplementação (P < 0,01). Em geral, os coeficientes de absorção e retenção aparentes foram reduzidos quando os minerais não foram fornecidos (P < 0,05). A resistência à ruptura dos ossos da costela e a densitometria óssea foram reduzidas (P < 0,04) na ausência de suplementação. Os parâmetros do metatarso não foram afetados (P > 0,10). O conteúdo de Cu no fígado foi reduzido (P < 0,01) em dietas sem suplementação. As exigências totais dos minerais foram menores para P, Cu e Zn e maiores para o Fe quando comparados às recomendações previamente publicadas. Portanto, a ausência de suplementação mineral não influencia o consumo e o desempenho de bovinos Nelore não castrados em confinamento. No entanto, esta ausência pode influenciar parâmetros séricos, hepáticos e ósseos de acordo com o tipo de dieta. Este estudo forneceu informações úteis sobre as exigências minerais e estratégias de fornecimento adequado de minerais para bovinos Nelore em condições tropicais. No quarto artigo, o objetivo foi validar seis equações já publicadas para predição da ingestão de água (IA) para bovinos de corte usando dados coletados em quatro experimentos realizados no Norte do Colorado (n = 1 experimento, novilhos de raça Angus) ou no Sudeste do Brasil (n = 3 experimentos, bovinos de corte Nelore). Características relacionadas ao desempenho animal, à composição da dieta e aos dados ambientais foram coletados em todos os experimentos. A predição de IA usando as equações publicadas atualmente foi testada através da regressão entre os valores previstos e mensurados. Todas as equações testadas diferiram dos dados observados. Vários fatores podem ajudar a explicar o porquê das equações publicadas não predizerem acuradamente a IA. Um dos fatores é que as equações testadas foram desenvolvidas em ambientes de clima temperado usando predominantemente animais Bos taurus taurus. A partir dos dados coletados no presente estudo, foram geradas novas equações baseadas no peso corporal metabólico, consumo de MS, umidade relativa e índice de temperatura e umidade para bovinos Nelore confinados no Sudeste brasileiro e baseadas no peso corporal metabólico, consumo de MS, temperatura máxima diária e nível de inclusão de concentrado na dieta para bovinos mestiços Angus no Norte do Colorado<br>For the thesis composition were prepared four scientific manuscripts based on studies with mineral release, absorption, metabolism and balance, and water intake of beef cattle. In the first manuscript the objective was to quantify the dry matter (DM) digestibility and total ash (TA) and mineral release from 12 concentrate and 12 forage feedstuffs commonly fed to cattle using in situ and in vitro methods. The concentrate and forage feedstuffs were incubated in the rumen of ruminally cannulated beef bulls at 8 different time points. Two different trials were conducted for concentrates and forages, with maximum incubation time of 72 and 120 h, respectively. The residue from samples incubated for 24 h were treated with pepsin and HCl to simulate abomasum digestion. The initial and residual samples after in situ and in vitro incubations were measured. An asymptotic model was adopted for estimating solubility of minerals, degradation rate of DM, and TA. Correlations between feedstuff contents and mineral release were evaluated. Cluster analysis was performed to group feedstuffs, in relation to TA release. Large variability was observed between concentrate and forage feedstuffs for all analyzed constituents. Large variability was observed for the effective ruminal degradation of TA, and individual mineral release. When feedstuffs were clustered according with the α, β and kd estimates of TA ruminal release, 4 groups were identified. From group “1” to group “4” was observed an increase in the soluble fraction, and a reduction in both moderate releasable fraction and release rate. Neutral detergent fiber content has a negative correlation with mineral release in the rumen, while mineral content has positive correlation. These results demonstrate that mineral solubilization in digestive tract is not the limiting factor to mineral absorption from the feedstuffs tested. The objectives of the second and third manuscripts were to measure the effects of mineral supplementation on nutrient intake and digestibility, performance, mineral balance and requirements and mineral concentrations in the body of Nellore beef cattle fed with and without calcium (Ca), phosphorus (P) and micromineral (MM) supplemental sources during the growing and finishing phases. Nellore cattle (n = 51, initial body weight = 270.4 ± 36.6 kg, age = 8 months) were assigned to one of three vigroups: reference (n = 5), maintenance (n = 4), and performance (n = 42). Reference group was slaughtered at the beginning of the experiment to measure initial mineral status. The maintenance group was used to collect values of animals at low gain and reduced mineral intake. Animals of performance group were assigned to one of six treatments: sugarcane as a roughage source and a soybean meal and soybean hull-based concentrate with (SH100) and without (SH0) Ca, P and MM supplementation; sugarcane as the roughage source and a soybean meal and ground corn-based concentrate with (SC100) and without (SC0) Ca, P and MM supplementation; and corn silage as the roughage source with a soybean meal and corn-based concentrate with (CS100) and without (CS0) Ca, P and MM supplementation. The experiment was conducted as a completely randomized design with a 3 × 2 factorial arrangement of treatments. Nutrient intake and digestibility, bone and serum parameters related to Ca and P metabolism, and liver mineral concentrations were measured. Orthogonal contrasts were adopted to compare mineral intake, fecal and urinary excretion and apparent retention among treatments. Maintenance requirements and true retention coefficients were generated with the aid of linear regression between mineral intake and mineral retention. Mineral composition of the body and gain requirements were assessed using non-linear regression between body mineral content and mineral intake. Nutrient intake, digestibility and performance were not affected by mineral factor (P > 0.10). Intakes of Ca, P, S, Cu, Zn, Mn, Co, and Fe were reduced in the absence of Ca, P, and MM supplementation (P < 0.05). Fecal excretion of Ca, Cu, Zn, Mn, and Co were also reduced in treatments without supplementation (P < 0.01). Overall, excretion and apparent absorption and retention coefficients were reduced when minerals were not supplied (P < 0.05). Rib bone breaking strength and densitometry were reduced (P < 0.04) in absence of supplementation. Metatarsus parameters were not affected (P > 0.10). Liver Cu content was reduced (P < 0.01) in diets without supplementation. Dietary mineral requirements were lower for P, Cu, and Zn and greater for Fe when compared to previously published recommendations.Therefore, absence of mineral supplementation does not influence intake and performance of Nellore beef cattle. However, this absence may influence serum, liver and bone parameters according to dietary type. This study provides useful information about mineral requirements and mineral supplementation to obtain adequate dietary mineral supply of Nellore cattle in tropical conditions. In the fourth manuscript, the objective was to validate six current water intake (WI) equations for beef cattle using water intake data from four experiments conducted in North America (n = 1 experiment; crossbred Angus beef steers) and Brazil (n = 3 viiexperiments; Nellore beef cattle). Animal performance, diet composition, and environmental data were collected for all experiments. The prediction of WI using the current published WI equations was tested though the regression between predicted and measured WI values. All tested equations differed from the measured WI data from the four experiments. Several factors can help explain why the published equations did not predict the WI obtained from the three experiments, including that the tested equations were developed in temperate climates using predominantly Bos taurus taurus. From the current data, was generated new WI equations based on metabolic BW, DMI, humidity and temperature-humidity index for Nellore cattle in Brazil and metabolic BW, DMI, maximum daily temperature, and dietary concentrate level for Angus crossbred cattle in North America

In response to i.v. ANF at 175 ng/kg/min, normal dogs increase sodium excretion ($ Delta$UNaV = 150 uEq/min) independent of changes in GFR and RPF. In contrast, when ANF was infused into chronic caval dogs (TIVC) or cirrhotic dogs (Cir) retaining sodium in the presence of ascites, they divided 50:50 into those who had a marked natriuretic response (responders, R) and those who had no natriuretic response (non-responders, NR). Of 46 TIVC dogs, 22 R had UnaV of 185 + 35 uEq/min and 24 NR had $ Delta$UNaV = 2 + 1 uEq/min. In 19 Cir dogs, 9 R had $ Delta$UNaV = 60 + 10 uEq/min and 10 NR had $ Delta$UNaV = 1.3 +.6 uEq/min. R and NR could not be differentiated in terms of atrial content of ANF, plasma iANF, ANF T1/2, plasma levels of renin and aldosterone, systemic hemodynamics, plasma volume, or papillary plasma flow. All dogs generated plasma and urinary cGMP equally. Renal denervation or vasodilitation did not increase sodium excretion in response to ANF in RN. When NR dogs returned to sodium balance in the presence of ascites, the natriuretic response was restored ($ Delta$UNaV = 90-340 uEq/min) and was not different from R dogs in this phase. Cir dogs studied sequentially in the pre-ascitic phase responded normally to ANF infusion when they were in sodium balance but split 50:50 into R and NR at week 4 during a period of sodium retention, plasma volume expansion, elevated plasma iANF and normal renin and aldosterone. We conclude that the blunting of UNaV in response to ANF is a characteristic of the sodium-retaining kidney, is reversible when sodium balance is restored and occurs at a tubular level, most likely in the medulla.

Thesis (M.S.)--University of California, San Diego, 2008.<br>Title from first page of PDF file (viewed June 25, 2008). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 48-51).

The present work was aimed at studying the release of arachidonic acid and formation of lipoxygenase metabolites in rat brain slices maintained in vitro, as well as exploring possible physiological roles for them in the mammalian central nervous system. A particularly active 12-(S)-lipoxygenase activity was found, which could be stimulated by various stimuli including the neurotransmitters norepinephrine and glutamate. Activation of $ alpha$-adrenergic and N-methyl- scD-aspartate (NMDA) receptor subtypes appear responsible for the effect observed in each case. Arachidonic acid on the other hand was found to have profound effects on synaptic transmission, inducing a long-lasting potentiation which appears dependent on the formation of lipoxygenase metabolites. In return, pharmacological conditions which can potentially lead to long-term potentiation (LTP) of synaptic transmission and for most of them activate NMDA receptors also induced arachidonic acid release. As these observations suggest, it is proposed that arachidonic acid and its lipoxygenase metabolites belong to a new group of messengers in the nervous system possibly acting as modulator of synaptic transmission both intra- and transcellularly. This new class of messengers constitutes an essential component of the molecular machinery involved in synaptic plasticity.

Ruminants possess a unique digestive system. Using the high metabolic potential of the symbiotic microflora of the rumen, ruminants are capable of digesting plant material and obtaining nutrients and energy from this process. Because of the ruminal fermentation, the most bioactives are not stable in the harsh ruminal environment. Therefore there is a need to improve the bioavailability of a bioactive by protecting it from the ruminal digestion. The formulation of protected bioactive can be delivered in the rumen in a controlled manner and over a long period of time. In this project the degree of rumen protection was estimated using model substrates (sugar pellets and granules). These materials were coated with the pH-sensitive polymer Eudragit E. The model bioactive (phloridizin) was coated using the coating methodology adopted from exploratory studies with model substrates. The bioavailability of protected (coated) phloridizin was assessed by administering directly into the abomasum of fistulated cows. Formulation of protected phloridizin was used to demonstrate the feasibility of bioactive controlled delivery based on ART ( Active Rumen Technology ). This technology uses an elevated gas pressure created by a hydrogen-producing cell to drive a plunger which extrudes bioactive formulation from an intraruminal controlled-release device. Four groups of devices filled with formulation containing different amounts of protected phloridizin were tested. The bioactive was released in a controlled manner over several days. The formulation release profiles were reproducible suggesting that in principle the technology can be further developed to use in a commercial sense or for research purposes. The limitations of the technology, including formulation issues and gas diffusion through barrel walls, were identified.

Prolonging function of the corpus luteum (CL) is a method of suppressing estrus that maintains secretion of endogenous progesterone to keep mares out of heat naturally. The use of oxytocin to prolong CL function is becoming more popular. In these therapies, upregulation of cyclooxygenase-2 is inhibited, which impairs prostaglandin F2α ( PGF2α) production. Intramuscular (IM) administration of 60 IU of oxytocin once daily from 7 to 14 days after ovulation is currently the most common treatment protocol. Although that protocol is efficacious in ≥70% of treated mares, the need for daily administration is a drawback to its use. A proprietary slow-release oxytocin formulation (SR-OT) with a two-injection protocol to prolong CL function was evaluated in the first experiment. Mares were examined to determine the day of ovulation (day 0) and then randomly assigned either to a non-treated control group or an SR-OT treatment group (n = 8 mares/group). Mares in the treated group received 1.0 mL of SR-OT containing 2,400 IU oxytocin IM once on Day 7 and again on Day 10 after ovulation. Jugular blood samples were collected on day 0 and then every M, W, and F continuously. Serum progesterone concentrations were evaluated to assess CL function, which was prolonged in 0/8 (0%) control mares and 6/8 (75%) of the SR-OT treated mares (p< 0.01). In a second study, the ability of the endometrium to synthesize PGF2α was evaluated in mares in a state of prolonged CL function. Mares were designated into groups 50-59, 60-69, or 70-79 days post-ovulation (50s, 60s, 70s) and 14-day post-ovulation controls. PGF2α synthesis was evaluated by measurement of a prostaglandin metabolite in response to a single 10 IU intravenous oxytocin bolus (0 minutes). Blood samples were collected serially from 30 minutes before until 120 minutes after oxytocin administration. The metabolite response was significantly higher in the 70s versus the 50s and 70s versus the 60s groups (p< 0.001; p< 0.02, respectively); and there was no significant difference between the 70s group and the control group (P>0.36). Luteal function was maintained after oxytocin administration in 4/4, 3/4, and 0/3 mares in the 50s, 60s, and 70s groups, respectively. Collectively, these results indicate that the luteolytic mechanism returns approximately 70 days into the period of prolonged CL function.

Plants require N to complete their life cycle. Without adequate concentration of N, crops will not produce their potential yields. For turfgrass systems, N fertilizer application allows for the maintenance of functional, aesthetic, and recreational properties. However, fertilizer mismanagement is common and leads to N pollution in the environment. Controlled-release and slow-release fertilizers can enhance nitrogen (N)-use efficiency, reduce N pollution, minimize the need for repeated fertilizer applications, and reduce turfgrass shoot growth and associated costs. In order to evaluate the effectiveness of these fertilizers in the Intermountain West, research is needed. The timing of N release was evaluated for seven urea fertilizers: uncoated, sulfur coated (SCU), polymer-sulfur coated (PSCU), and four polymer-coated (PCU) with release timings of 45, 75, 120, and 180 d estimated release. These products were placed on bare soil, a Kentucky bluegrass (Poa pratensis L.) thatch layer, and incorporated into soil. These three placement treatments were replicated to allow for enough samples to be placed in two locations. The first was outside in a field to represent field conditions with diurnal fluctuating temperatures and the second was placed in a storage facility to replicate laboratory conditions with static diurnal temperatures. The PCU prills incorporated into soil under field conditions generally released N over the estimated release period. However, when applied to bare soil or thatch, N from PCU had 80% or greater N release by 35 d after application regardless of expected release time. Fertilizers under laboratory conditions had minimal N release despite having similar average daily temperatures, suggesting that fluctuating temperatures impact N release. The PSCU and SCU treatments were no different from uncoated urea, showing no slow release properties for this particular product. Spring-applied N fertilizer trials were conducted over two years to determine the optimal N rate for Kentucky bluegrass. Similar PCU120 products were applied at 50, 75, and 100% of the recommended full rate, while also being compared to an unfertilized control and urea applied either all at once or split monthly. Spring-applied PCU showed minimal initial N response while urea applied all at once resulted in an initial spike of N uptake. Once PCU began to release N, there was minimal difference for all rates compared to urea split monthly for biomass growth, verdure, and shoot tissue N. Although at the 50% rate, there were a few sampling dates with slower growth and lower verdure. The decrease in verdure at this low rate was slight, and it is recommended that PCU could be applied effectively at a reduced rate between 50 and 75%. Although for better results, additional quick release N is required to compensate for early season lag in N release.

The objective of this research was to investigate the effects of slow release urea on N metabolism in cattle. The ruminal behavior of Optigen®II and the effect of basal diet on the in situ degradability of urea and Optigen®II were evaluated. The effect of slow release urea and its interaction with degradable intake protein (DIP) level in the diet on N retention and excretion was evaluated utilizing 8 Holstein steers in a 4 x 4 Latin square experiment. In addition, the effect of slow release urea and DIP level on ruminal and systemic urea kinetics was evaluated using stable isotope techniques with 8 Holstein steers in a 4 x 4 Latin square experiment. Finally, slow release urea was evaluated under a practical beef production setting. The performance of slow release urea was compared to regular feed grade urea in a 42 day receiving study (288 Angus cross steers) as well as a 70 day growing study (240 Angus cross steers). High forage diets increased the ruminal degradation rate of both urea and slow release urea an increased the extent of degradation of slow release urea when compared to high concentrate diets. Lower DIP concentrations in the diet reduced systemic urea production, ruminal ammonia and plasma urea concentrations and urinary urea excretion under most circumstances but also led to a reduction in N retention, reduced diet digestibility, lower feed intake, lower growth rate and decreased feed efficiency. High DIP intakes increased N retention, growth rate, diet digestibility and improved feed efficiency but also lead to increased excretion on urea N in the urine. Slow release urea improved N retention and efficiency of N retention in high DIP diets when compared to urea and generally reduced plasma urea and ruminal ammonia concentrations. Compared to urea, slow release urea did not significantly improve the production of receiving cattle. However Optigen®II improved the feed efficiency when compared to urea on high concentrate diets but reduced feed efficiency on high forage diets.

Human pleasant touches promote feelings of security, supportiveness, and wellbeing. Conversely, human unpleasant touches promote the body for either “fight or flight” or “short term acute stress” during emergencies, feeling of stress or danger. The promoted stress response is released from the hypothalamus by the sympathetic nerve system further to the spinal cord to reach the signals to the adrenal medulla, where stress hormones adrenaline is released. Adrenaline, which is characterized by a mimic sympathetic nerve system, interacts with α and β receptors on different organs. The aim for this study was to investigate whether the stroker (partner/stranger) touch effects on adrenaline hormone releases. The null hypothesis for this study entails a significant adrenaline reduction in partners’ touches compared with strangers’ touches. Indirect competitive ELISA method was used, and concentration data of a total of sixteen participants was obtained. Whitney-U test was carried out to compare group differences within stroker (stranger/partner) touches and adrenaline releasing level. In addition, correlation in adrenaline with noradrenaline and oxytocin hormones was obtained using Spearman’s correlation test. The significant p-value 0.05 was conducted. The result of this study showed no differences between stroker (partner/stranger) associated with adrenaline hormone release. Correlation between partner maximum (max) concentration data for both oxytocin and adrenaline had significant differences. However, max variables for adrenaline and noradrenaline within stroker did not show significant differences. The conclusion of this study is that the gentle touch stimulus used in this study was not enough to detect stress hormone in adrenaline.

Thesis (MScAgric)--Stellenbosch University, 1999.<br>ENGLISH ABSTRACT: The rate of hydrolysis of urea in the rumen of animals is a major limitation when considering the substitution of natural protein with urea in the formulation of rations. The aim of this study was to evaluate polymer coated urea prills with variable coating thickness and evaluate its potential as a slow-release NPN compound. A new slowrelease urea compound, made by coating prilled feedgrade urea with a co-polymer of urea-formaldehyde resin and a castor-coconut alkyd was initially evaluated for urea-nitrogen concentration in distilled water in order to evaluate its potential as a slow-release urea product for ruminants. Amino/alkyd or polyester blends are among the cheapest of the modern synthetic systems and are considered because it is non-toxic, low-cost, biodegradable and easy to manufacture. A 2 x 2 x 2 x 2 factorial design was used and 16 individual products were made and evaluated. The Wurster method was used to encapsulate urea prills. The slopes of the urea release curves represented the release rate of the encapsulated products and were compared to identify the process variables, which had an effect on release rate. Two of the coating variables, coating weight and alkyd: resin ratio, had a major effect (P = 0.0001) on the release rate of urea. The crushing strength of encapsulated products was significantly (P = 0.0001) higher than that of untreated urea. Results motivated the evaluation of the products in the rumen of sheep in terms of rumen ammonia and blood urea N concentrations. Four slow-release products were made after interpreting results from the first study, and differed on account of the coating weight and the composition of the co-polymer. Fifteen fistulated wethers were randomly allotted into 5 groups and intraruminally received an equivalent of 15g urea. Rumen ammonia and blood ammonia were taken at 0, 1, 2, 4, 6, 8, 12, 16, 20, 24, 36 and 48 h after administration of the various treatments. Slow release urea (SRU) resulted in significantly lower rumen ammonia peaks (P = 0.0001) than untreated urea, while the peaks were also significantly delayed. Untreated urea resulted in the maximum concentration at two hours after administration of the urea (P = 0.0685) while the SRU's reached a maximum at six hours after administration in the rumen. No significant differences between the four different SRU types were found. Responses in blood urea-N was similar to that observed for rumen ammonia nitrogen. The encapsulation was effective in decreasing the rate of ammonia release from the urea for up to six hours after administration. In a third trial four Dehne Merino wethers were used in a 2 x 2 Latin square design. They received a SRU product equivalent to 0.4 g urea per kg body weight orally. Rumen liquor and blood samples were taken at 0, 1, 2, 4, 6, 8, 12, 16, 20, 24, 36 and 48 h after intake. Difficulty was initially experienced with ingestion and palatability of the SRU products due to the strong formaldehyde and butanone odour present in the coating. The maximum rumen ammonia (NH3) concentration for the SRU were lower than that of untreated urea (17.5 mg N/dl vs. 66.9 mg N/dl). The time to reach blood urea levels also differed considerably (6 h vs. 24 h for blood urea nitrogen) between treatments. The encapsulation of urea prills shows potential solutions to reduce the solubility of urea and also reduce the hygroscopic nature of urea and improve the palatability and storage characteristics thereof. Keywords: Slow-release urea, encapsulate, copolymer, urea formaldehyde rumen ammonia, blood urea nitrogen, solubility, palatability, storage characteristics.<br>AFRIKAANSE OPSOMMING: Die vinnige tempo waarteen ureum in die rumen na ammoniak omgesit word, is die grootste beperking in die optimale benutting van ureum, as vervanging van natuurlike protein in herkouerrantsoene. Die doel van hierdie studie was om 'n stadig vrystellende ureumproduk te ontwikkel wat die rumenammoniakvlak gedurende 'n aansienlike periode van die dag bokant 'n sekere vlak kan hou. 'n Nuwe stadig vrystellende ureumproduk, vervaardig deur ureumkorrels met 'n kopolimeer van ureum-formaldehiedhars en 'n kastor-en klapperalkied te bedek, is geevalueer om die potentiaal as stadig vrystellende nie-protein stikstof (NPN)-produk vir herkouers te ondersoek. Die veiligheid, biodegradeerbaarheid, lae koste en maklike vervaardiging van amino/alkied-kopolimere maak dit een van die goedkoopste sintetiese sisteme om vir stadig vrystellende sisteme te oorweeg. 'n 2 x 2 x 2 x 2 Faktoriale antwerp is gebruik om 16 individuele produkte te vervaardig. Die Wurster-metode is gebruik om individuele korrels te enkapsuleer met die polimeer en die potentiaal van die produkte is aanvanklik geevalueer deur die ureumstikstofvrystelling in gedistilleerde water te meet. Die hellings van die vrystellingsgrafieke is vergelyk om die veranderlikes te bepaal wat die grootste invloed op die vrystellingstempo van ureum uit die ge·inkapsuleerde produkte het. Resultate dui dat twee verandelikes 'n betekenisvolle effek het op die vrystellingstempo, nl. dikte van die omhulsel, en die samestelling van die kopolimeer (P = 0.0001 en P = 0.0135, onderskeidelik) het. Die samedrukbaarheid van die ge ·lnkapsuleerde produkte was ook betekenisvol hoer (P = 0.0001) as die van onbehandelde ureumkorrels, wat lei tot verbeterde bergings- en hanteringseienskappe. lnterpetering van resultate lei tot die vorming van vier stadig vrystellende produkte. Vyf groepe van 3 volwasse rumengefistuleerde Dohnemerinohamels is in 'n proef gebruik om die potentiaal van die produkte verder te ondersoek. 'n Ekwivalent van 15 g ureum is direk in die rumen van elke dier geplaas en ammoniak-en bloed monsters is 0, 1, 2, 4, 6, 8, 12, 16, 20, 24, 36 & 48 ure na dosering geneem. Die stadig vrystellende ureumprodukte het 'n betekenisvol laer maksimum waardes vir beide ammoniak-en bloedstikstofureum getoon (P = 0.0001 ). Onbehandelde ureum het 'n maksimum rumenammoniakstikstof konsentrasie reeds twee ure na toediening bereik in vergelyking met ses ure vir die stadig vrysellende produkte. Geen betekenisvolle verskille in hierdie parameters is tussen die ge·lnkapsuleerde produkte gevind nie, terwyl geen interaksie is tussen hoofeffekte voorgekom het nie. In 'n derde proef is vier Dohnemerinohamels gebruik om die vrystellingstempos, in terme van rumenammoniak-en bloedureumstikstof te bepaal waar die stadig vrystellende produk en onbehandelde ureum direk aan die diere gevoer is . 'n Ekwivalent van 0.4 g ureum/kg liggaamsmassa is gevoer. Aanvanklik is inname- en smaakliksheidprobleme ondervind, moontlik as gevolg van die sterk butanoon-en formaldehiedreuk van die omhulsel. Die rumenammoniakstikstof het 'n laer maksimum (17.5 vs. 66.9 mg N/1 00 ml) as die van onbehandelde ureum gehad terwyl die tyd wanneer maksimum konsentrasie bereik word ook aansienlik later was. Die polimeer inkapsulering van ureumkorrels toon potensiaal as 'n stadig vrystellende ureumproduk deurdat dit die oplosbaarheid van ureum in die rumen verlaag. Bykomende voordele is dat die omhulsel die higroskopisiteit verlaag en die samedrukbaarheid verhoog, beide eienskappe wat die hantering-en bergingseienskappe bevorder. Sleutelwoorde: Stadig vrystellende ureum, enkapsulering, kopolimeer, ureumformaldehied, rumenammoniak, bloed ureum stikstof, oplosbaarheid, smaaklikheid, bergingseienskappe.

The final step of paramyxovirus infection requires the assembly of viral structural components at the plasma membrane of infected cells followed by budding of virions. While the matrix (M) protein of some paramyxoviruses has been suggested to play a central role in the assembly and release of virus particles, the specific viral and host protein requirements are still unclear. Using Newcastle disease virus (NDV) as a prototype paramyxovirus, we explored the role of each of the NDV structural proteins in virion assembly and release. For these studies, we established a virus-like particle (VLP) system for NDV. The key viral proteins required for particle formation and the specific viral protein-protein interactions required for assembly and release of particles were explored in chapter 2. First we found that co-expression of all four proteins resulted in the release of VLPs with densities and efficiencies of release (1.18 to 1.16 g/cm3and 83.8%±1.1, respectively) similar to that of authentic virions. Expression of M protein alone, but not NP, F-K115Q or HN proteins individually, resulted in efficient VLP release. No combination of proteins in the absence of M protein resulted in particle release. Expression of any combination of proteins that included M protein yielded VLPs, although with different densities and efficiencies of release. To address the roles of NP, F and HN proteins in VLP assembly, the interactions of proteins in VLPs formed with different combinations of viral proteins were characterized by co-immunoprecipitation. The co-localization of M protein with cell surface F and HN proteins in cells expressing all combinations of viral proteins was characterized. Taken together, the results show that M protein is necessary and sufficient for NDV budding. Furthermore, they suggest that M protein – HN protein and M protein - NP interactions are responsible for incorporation of HN protein and NP proteins into VLPs and that F protein is incorporated indirectly due to interactions with NP and HN protein. Since the vacuolar protein sorting (VPS) system is involved in the release of several enveloped RNA viruses, chapter 3 describes studies which explored the role of the VPS system on NDV particle release. First, we characterized the effects of three dominant negative mutant proteins of the VPS pathway on particle release. Expression of dominant negative mutants of CHMP3, Vps4 and AIP1 proteins inhibited M protein particle release as well as release of complete VLPs. Mutation of a YANL sequence in the NDV M protein to AANA inhibited particle release while replacement of this sequence with either of the classical late domain motifs, PTAP or YPDL, completely restored particle release. The host protein AIP1, which binds YXXL late domain sequences, is incorporated into M protein particles. These results suggest that an intact VPS pathway is necessary for NDV VLP release and that the YANL sequence is an NDV M protein L domain. The sequence and structure of the Newcastle disease virus (NDV) fusion (F) protein are consistent with its classification as a type 1 glycoprotein. We have previously reported, however, that F protein can be detected in at least two topological forms with respect to membranes in both a cell-free protein synthesizing system containing membranes as well as infected COS-7 cells (J. Virol. 2004 77:1951). One form is the classical type 1 glycoprotein while the other is a polytopic form in which approximately 200 amino acids of the amino terminal end as well as the cytoplasmic domain (CT) are translocated across membranes. Furthermore, we detected CT sequences on surfaces of F protein expressing cells and antibodies specific for these sequences inhibited red blood cell fusion to HN and F protein expressing cells suggesting a role for surface expressed CT sequences in cell-cell fusion. In chapter 4, we extended these findings and found that the alternate form of the F protein can also be detected in infected and transfected avian cells, the natural host cells of NDV. Furthermore, the alternate form of F protein was also found in virions released from both infected COS-7 cells and avian cells by Western analysis. Mass spectrometry confirmed its presence in virions released from avian cells. Two different polyclonal antibodies raised against sequences of the CT domain of the F protein slowed plaque formation in both avian and COS-7 cells. Antibody specific for the CT domain also inhibited single cycle infections as detected by immunofluorescence of viral proteins in infected cells. The potential roles of this alternate form of the NDV F protein in infection are discussed. Virus-like particles (VLPs) generated from different viruses have been shown to have potential as good vaccines. Chapter 5 explored the potential of NDV VLPs as a vaccine for NDV or as a vaccine vector for human pathogens. Significant quantities of NDV VLPs can be produced from tissue culture cells. These VLPs are as pure as virions prepared in eggs. In addition, some rules for incorporation of viral proteins into VLPs were also explored. We found that the cytoplasmic domain of the fusion (F) protein is necessary for its incorporation into VLPs. We found that an HN protein with an HA tag at its carboxyl terminus was incorporated into VLPs. We also found that the HN and F proteins of NDV, strain B1, can be incorporated into VLPs with M and NP of strain AV. The demonstration of specific domains required for protein incorporation into particles is important in using NDV VLPs as a vaccine vector for important human pathogens. In conclusion, this dissertation presents results that show that the M protein plays a central role in NDV assembly and release, a finding that is consistent with findings with other paramyxoviruses. More importantly, this work extends the current knowledge of paramyxovirus assembly and release by providing the first direct evidence of interactions between paramyxovirus proteins. These interactions between viral proteins provide a rational basis for incorporation of viral proteins into particles. This work also provides a clearer understanding of the role of the host vacuolar protein sorting machinery in NDV budding. A clear understanding of virus assembly and budding process contributes to the design of strategies for therapeutic intervention and in the development of safer, more economical and effective vaccines.

Foram conduzidos 2 estudos com vacas leiteiras no Departamento de Zootecnia da ESALQ/USP com os objetivos de avaliar a utilização de fonte de uréia de liberação lenta (Optigen ®) e ID (intervalos de desfolhas) fixos ou variáveis em pastagens de capim Elefante. No Experimento 1, foram utilizadas 32 vacas no terço médio de lactação, produzindo 20,8 kg leite dia-1 e pesando 524 kg no início do período experimental. O tratamento controle (C) continha apenas farelo de algodão como suplemento protéico. No tratamento U30, 30 % da PB do farelo de algodão foi substituída por uréia. No tratamento O30, 30% da PB do farelo de algodão foi substituída pela uréia de liberação lenta e no tratamento O60, 60% da PB do farelo de algodão foi substituída pela uréia de liberação lenta. O delineamento experimental adotado foi o quadrado latino 4 x 4 com 8 repetições e as variáveis foram analisadas utilizando o PROC MIXED (SAS). A produção de leite não diferiu (P>0,05) entre os tratamentos C (20,2 kg dia-1), O30 (19,8 kg dia-1) e U30 (19,5 kg dia-1). No tratamento O60 a produção de leite foi reduzida (19,0 kg dia-1) em comparação aos tratamentos C e O30 (P<0,05) e U30 (P<0,06). Não houve diferenças (P>0,05) nos teores de gordura, proteína, lactose, sólidos totais e contagem de células somáticas entre os tratamentos. A concentração de uréia no leite (NUL) foi menor (P<0,05) no tratamento U30 (7,2 mg dL-1) em relação aos tratamentos O30 (9,3 mg dL-1), C (9,1 mg dL-1) e O60 (8,9 mg dL- 1). No Experimento 2 foram utilizadas 32 vacas no terço médio de lactação, produzindo 15 kg de leite dia-1, pesando 466 kg. A área experimental foi composta por 56 piquetes de Pennisetum purpureum cv. Cameroon, com 0,1 ha cada um. Os tratamentos corresponderam a duas estratégias de ID dos pastos de capim Elefante (ID fixos de 27 dias ou ID variáveis determinados pela altura do dossel de 1,0 m) e dois concentrados isoprotéicos com diferentes fontes de N (farelo de algodão e uréia de liberação lenta). Foi adotado o delineamento experimental em blocos aleatorizados e as variáveis foram analisadas utilizando o PROC MIXED (SAS). Não houve efeito (P>0,05) de fonte de N sobre os parâmetros avaliados. Houve diferença estatística (P<0,05) entre os tratamentos com ID fixos de 27 dias e os com ID variáveis para as alturas das pastagens no pré-pastejo (1,20 X 1,03 metros), no pós-pastejo (0,47 e 0,41 metros), nas massas de forragem pré-pastejo (6642 e 6209 kg MS ha-1), pós-pastejo (3666 e 3277 kg MS ha-1) e nas densidades volumétricas (55,04 e 60,06 kg MS ha-1 cm-1) para os tratamentos com ID fixos ou variáveis respectivamente. A produção de leite foi maior para os animais dos tratamentos com ID variáveis (12,59 e 12,06 kg leite dia -1) em relação aos tratamentos com ID fixos de 27 dias (10,94 e 10,66 kg leite dia -1). Os componentes do leite e taxas de ganho diário de peso não foram alterados com os tratamentos (P>0,05).<br>Two studies were conducted with lactating dairy cows at the Animal Sciences Department of the School of Agriculture \"Luiz de Queiroz\", University of São Paulo, to evaluate the use of a slow release urea source (Optigen®) and fixed or variable grazing intervals on Pennisetum purpureum pastures. The objective of Experiment 1 was to evaluate the partial replacement of cotton seed meal (CSM) by urea or by a slow release urea (Optigen®) on the performance of dairy cows fed corn silage. Thirty two mid lactating cows, averaging 20.8 kg of milk day-1 and 524 kg of BW at the beginning of the experimental period were used to compare the 3 treatments. The control treatment (C) contained cotton seed meal (CSM) as protein source, the U30 treatment had 30% of the CSM crude protein replaced by urea, the O30 treatment, had 30% of the CSM crude protein replaced by slow release urea and the O60 treatment, had 60 % of the CSM crude protein replaced by slow release urea. A 4x4 Latin Square design was used and the variables were analyzed using the PROC MIXED (SAS). Replacing 30% of CSM crude protein by urea (U30) or slow release urea (O30) had no effect (P>0.05) on milk yield (20.2, 19.5, and 19.8 kg day-1 respectively). However, replacing 60% of CSM crude protein by slow release urea (O60) (19.0 kg day-1) reduced milk yield compared to C and O30 (P<0.05) and U30 (P<0.06). Milk fat, milk protein, milk lactose, and milk total solids contents, and milk somatic cells counting were not different (P>0.05) among the treatments. The milk urea nitrogen (MUN) was lower (P<0.05) for the U30 treatment (7,2 mg dL-1) compared to the other treatments (9.3 mg dL-1 (O30); 9.1 mg dL-1 (C), and 8.9 mg dL-1 (O60)). On Experiment 2, were used 32 midlactating cows averaging 15 kg of milk day -1 and 466 kg of BW at the beginning of the trial. Experimental area contained 56 paddocks of Pennisetum purpureum cv. Cameroon, averaging 0.1ha each. Treatments were 2 grazing interval (fixed grazing intervals of 27 days or variable grazing intervals based on the dossel height of 1 m), and two protein supplement (CSM x slow release urea). A randomized block design was used and the variables were analyzed using PROC MIXED (SAS). There were no effects (P>0.05) for N source on the evaluated parameters. There were differences (P<0.05) between the fixed and variable grazing intervals (GI). Pre-grazing dossel height (1.03 x 1.2 m), post-grazing stubble height (0.41 e 0.47 meters), pre-grazing (6209 and 6642 kg DM ha-1) and post-grazing forage mass (3277 and 3666 kg DM ha-1) were lower (P<0.05) for variable GI compared to 27 days fixed GI. Volumetric density (55.04 and 60.06 kg DM ha-1 cm-1) was higher for variable GI (P<0.05). Cows grazing pastures managed with variable GI produced more milk (P<0.06) (12.32 and 10.8 kg milk day -1) than cows grazing pastures managed with fixed GI. Milk components and cow average daily gain were not affected by the treatments (P>0.05).

Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2017-05-09T12:45:33Z No. of bitstreams: 1 DissCCTC.pdf: 2703284 bytes, checksum: d6c01b80e9f013e4e3f0004410ab32f9 (MD5)<br>Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-05-10T19:05:03Z (GMT) No. of bitstreams: 1 DissCCTC.pdf: 2703284 bytes, checksum: d6c01b80e9f013e4e3f0004410ab32f9 (MD5)<br>Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-05-10T19:05:10Z (GMT) No. of bitstreams: 1 DissCCTC.pdf: 2703284 bytes, checksum: d6c01b80e9f013e4e3f0004410ab32f9 (MD5)<br>Made available in DSpace on 2017-05-10T19:26:43Z (GMT). No. of bitstreams: 1 DissCCTC.pdf: 2703284 bytes, checksum: d6c01b80e9f013e4e3f0004410ab32f9 (MD5) Previous issue date: 2016-03-29<br>Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)<br>Supplementation with nonprotein nitrogen (NPN) has been widely used in ruminant feeding in diets of low quality forages. This is because these animals have a number of microorganisms in the rumen able to use ammonia for microbial protein production of excellent quality, ammonia is obtained through the action of urease enzyme on the nitrogenous products supplied in food, for example, urea. However, an excessive consumption of urea may result in poisoning by NH3. Thus, a controlled release of urea into the rumen is an essential aspect for ruminants feed, but few studies to control the release of urea in the rumen have been identified to date Thus this paper proposes obtaining nanocomposites montmorillonite and urea, formulated by the extrusion process, as a source of slow-release nonprotein nitrogen on the feed. The materials were characterized by diffraction of X-ray (XRD), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and elemental analysis (CHN). Also was studied the behavior solubilization in an aqueous medium of urea present in the nanocomposites. Characterization results can be observed that the montmorillonite exfoliation suffered in all nanocomposites, urea served as montmorillonite dispersed phase in a matrix. The release results showed that the presence of MMT acts as a barrier to release of urea making all nanocomposites have slower release of urea compared to the pure material In order to assess the effect of the use of such nanocomposites as non-protein nitrogen supplement for sugarcane (bulky), was carried out in vitro digestibility test for dry matter, which simulates the food digestion conditions in the rumen. Different nanocomposite showed gain on the digestibility of sugar cane, which is considered low quality forage, especially for presenting low protein value and be difficult to digest. The nanocomposite MMT/Ur 1:4/HG 2% was the most effective in increasing the digestibility of the sugar cane. The gain on digestibility was not very significant for displaying nanocomposites release kinetics urea very slowly, suggesting that an ideal release rate is required, being synchronized with the power supply supplied from the carbohydrate in the diet. The pH remained within the optimal range for urease activity, the enzyme responsible for metabolizing urea to ammonia and also for maximum microbial synthesis. These results show that the development of nanostructures is a powerful tool for increasing the efficiency of conventional fodder, and can serve as a basis for further in vivo testing.<br>A suplementação com nitrogênio não proteico (NNP) vem sendo muito utilizada na alimentação de ruminantes em dietas com volumosos de baixa qualidade. Isto porque estes animais possuem uma série de microrganismos no rumem capazes de utilizar amônia (NH3) para produção de proteína microbiana de excelente qualidade. Essa amônia utilizada pode ser obtida através da ação da enzima urease sobre os produtos nitrogenados fornecidos na alimentação, como por exemplo, a ureia. No entanto, um consumo excessivo de ureia pode resultar em intoxicação por NH3. Assim, uma liberação controlada de ureia no rúmen é um aspecto essencial na alimentação de ruminantes, porém poucos estudos relacionados ao controle da liberação de ureia no rúmen foram identificados até o momento. Com isso esse trabalho propõe a obtenção de nanocompósitos de montmorilonita e ureia com ou sem a adição de compostos poliméricos (paraformaldeido e hidrogel), formulados pelo processo de extrusão, como fonte de liberação lenta de nitrogênio não proteico sobre a alimentação animal. Os materiais foram caracterizados por Difratometria de raios-X (DRX), Microscopia eletrônica de Varredura (MEV), Análise termogravimétrica (TG) e Análise elementar (CHN). Estudou-se também o comportamento de solubilização em meio aquoso da ureia presente nos nanocompósitos. Dos resultados de caracterização pode-se observar que a montmorillonita sofreu intercalação em todos os nanocompósitos, a ureia atuou como fase dispersa em uma matriz de montmorilonita. Os resultados de liberação mostraram que a presença da MMT atua como barreira na liberação de ureia fazendo com que todos os nanocompositos tenham liberação mais lenta de ureia em relação ao material puro. A fim de avaliar o efeito da utilização desses nanocompósitos como suplemento de nitrogênio não proteico para a cana de açúcar, realizou-se o teste de digestibilidade in vitro da matéria seca, para melhorar a digestibilidade da cana de açúcar. Diferentes nanocompósitos apresentaram ganho sobre a digestibilidade da cana de açúcar, que é considerada uma forragem de baixa qualidade, principalmente por apresentar baixo valor proteico e ser de difícil digestão. O nanocompósito MMT/Ur 1:4/HG foi o mais eficaz no aumento da digestibilidade da cana de açúcar. O incremento sobre a digestibilidade não foi muito expressivo para os nanocompósitos com liberação de ureia muito lenta, o que sugere que uma taxa de liberação ideal é necessária, esta idealidade estaria relacionada a sincronização de energia proveniente dos carboidratos ingeridos na dieta e a concentração de amônia disponível, uma vez que ambos são utilizados na síntese proteica e ambas influenciam na digestão dos alimentos. O valor de pH manteve-se dentro de uma faixa ideal para atividade da urease. Estes resultados mostram que o desenvolvimento de nanoestruturas é uma ferramenta poderosa para incrementar a eficiência de forragens convencionais, e pode servir como base para futuros ensaios in vivo.

Due to the increasing cost of soybean meal and concerns of excess N being excreted into the environment, new protein supplements have been developed. Two products that have shown potential in increasing N utilization efficiency are slow release urea (SRU; Optigen) and ruminal escape protein derived from yeast (YMP; DEMP). The objective of this study was to assess the effects of feeding these 2 supplements in high-forage [(54% of total dietary dry matter (DM)] dairy diets on nutrient utilization, feed efficiency, lactational performance of dairy cows, and their impacts on income-over feed costs. Twelve multiparous dairy cows were used in a triple 4 × 4 Latin square design with one square consisting of ruminally cannulated cows. Treatments included: 1) control, 2) SRU-supplemented total mixed ration (TMR, SRUT), 3) YMP-supplemented TMR (YMPT), and 4) SRU and YMP-supplemented TMR (SYT). The control consisted only of a mixture of soybean meal and canola meal (SBMCM) in a 50:50 ratio. The SRU and the YMP were supplemented at 0.49% and 1.15% DM, respectively. The experiment consisted of 4 periods lasting 28 d each (21 d of adaptation and 7 d of sampling). Cows fed YMPT and SYT had decreased intake of DM, and all supplemented treatments had lower crude protein intake compared to those fed the control. Milk yield tended to have the greatest increase in YMPT compared with the control (41.1 vs. 39.7 kg/d) as well as a tendency for increased milk fat and protein yields. Feed efficiencies based on yields of milk, 3.5% fat-corrected milk, and energy-corrected milk increased at 10-16% due to protein supplementation. Cows fed with protein supplements partitioned less energy toward body weight gain, but tended to partition more energy toward milk production. Efficiency of use of feed N to milk N increased by feeding SRUT and YMPT, and milk N-to-manure N ratio increased in YMPT. Cows fed SRUT or YMPT tended to improve income-over feed costs. Overall results from this experiment indicate that replacing SBMCM with SRU and YMP in high-forage dairy diets can be a good approach to enhance dairy profitability through improved nutrient utilization efficiencies by lactating dairy cows.

Groupers (Epinephelidae: Epinephelinae) are apex predators within many reef communities worldwide. Grouper landings contribute significantly to global fisheries, and many populations are suffering from unsustainable levels of exploitation. The large size, site specificity and catchability of most groupers increase susceptibility to fishing pressure, and a large number of grouper species throughout the world are currently overfished. Multiple species are listed as endangered or threatened, and many have suffered local extirpations across their range. Removal of these upper level predators can significantly alter community structure and result in second order effects that may have critical ecological implications. The economic and ecological value of groupers is significant, and data regarding the abundance, habitat and behavior of these exploited species are necessary in order to implement realistic and effective management strategies. Atlantic Goliath Grouper (Epinephelus itajara) historically occurred in tropical and subtropical waters from the west coast of Africa to the east coast of Florida, south to Brazil, and throughout the Caribbean Sea and Gulf of Mexico. As one of the world's largest groupers, individuals are known to reach at least 37 years of age, and may grow to sizes exceeding 2.5 meters and 400 kilograms. The life history and behavioral characteristics of this species amplify vulnerability to exploitation, and Atlantic Goliath Grouper harvest was banned in U.S. waters in 1990 after a noted sharp decline in population numbers. The species has responded encouragingly to protective measures; however, the population's recovery and present status with U.S. waters should be thoroughly evaluated before altering regulatory guidelines. Traditional fishery-dependent data are not available (i.e., landings data); thus estimates of population demographics and recovery are dependent upon directed, fishery independent research efforts. It was the goal of this project to provide information regarding demographics, movement patterns, effects of catch and release angling, and feeding behavior of Atlantic Goliath Grouper within the central eastern Gulf of Mexico. The majority of research involving Atlantic Goliath Grouper began after the stock was already overfished, resulting in the absence of an existing "baseline" with which to compare current population parameters. Replication of visual surveys over a range of depths and habitat types provided an index of abundance for specific sites, and allowed for quantification of the size distribution of individuals. Atlantic Goliath Grouper were most abundant at high relief, high volume artificial reefs within the study area, and the majority of individuals observed were 80 - 160 cm in total length. Knowledge of fish movement, behavior and habitat associations has been used to exploit many species of fish; thus, this knowledge is critical for the creation of regulatory guidelines regarding conservation. Protection from harvest does not immediately imply that fishing mortality is negligible. As opportunistic ambush predators, Atlantic Goliath Grouper are relatively easy to catch on hook and line, and the species is often targeted for sport or caught incidentally during angling efforts for other reef fish species. Acoustic tracking allowed for continuous monitoring of individuals for several years after catch and release events. Barotrauma severity increased with capture depth, but immediate mortality was not observed during this study. Additionally, the length of total monitoring period was not affected by the severity of barotrauma, which suggests that with proper handling, Atlantic Goliath Grouper are not subject to high levels of release mortality in the study area (at depths < 40 m). However, strong site fidelity of Atlantic Goliath Grouper to artificial reefs increases susceptibility to fishing pressure and amplifies interactions with anglers, so the chronic effects of repeated capture remain unclear. Description and quantification of goliath grouper feeding behavior may allow for innovative suggestions to decrease the probability of catch and release mortality, and potentially offer new tactics to reduce opportunistic predation upon hooked fish. Kinematic analysis of Atlantic Goliath Grouper feeding sequences demonstrated that they are capable of modulating feeding behavior based upon prey activity level and position within the water column. Individuals exhibited larger maximum gapes and more rapid feeding sequences when presented with mobile live food. Immobile (dead) food was primarily consumed through suction, and strikes upon these items were characterized by slower, closer approaches, smaller maximum gapes and longer bite durations. It is hopeful that the information presented herein will provide insight regarding the ecology of Atlantic Goliath Grouper and can be applied to future management efforts involving this protected species.

Atlantic tarpon are sought after because of their fighting ability on various tackle and support a popular, lucrative and predominantly catch-and-release recreational fishery in Florida. They are not commercially harvested or consumed by the general public, therefore assessing effects of catch-and-release angling on tarpon survival is critical to a sustainable fishery. Tarpon caught on artificial breakaway jig and traditional live bait fishing charters in Boca Grande Pass (n=42) and trips from the recreational fishery of Tampa Bay (n=40) were tagged with ultrasonic transmitters and tracked up to 6 hours immediately following release to estimate post-release mortality. Of the 82 tagged tarpon, 11 suffered mortality as inferred from movement patterns (or lack thereof) or visual confirmation (i.e. shark attacks) which yields a combined total estimated catch-and-release mortality rate of 13% (95% confidence interval: 6-21%). There was no significant difference in mortality between the two estuarine systems. Associations between tarpon mortality and angling duration, handling time, fish length, bait type (artificial versus natural), and hook type (circle versus "J") were not significant. Hook location (foul-hooking) and swimming condition at release were significant factors on tarpon mortality (P<0.05). Shark predation was the primary cause of post-release mortality (64%). Excluding predation, the overall mortality rate was estimated at 5% and attributed to poor handling and irreparable physiological damage from angling. Angling events will cause anaerobic activity resulting in physiological disruptions that may have consequences compromising the health and survival of tarpon. Both adult (mature, >70 pounds, 31.8 kg) and sub-adult (sexually immature, <20 pounds, 9 kg) tarpon support Florida's recreational fishery, so maximizing post-release survival and minimizing sub-lethal stress effects of both size classes are critical to their sustainability. In this study, stress responses after exhaustive exercise (angling) were measured using an array of blood chemistry parameters, including hematocrit, hemoglobin, and plasma glucose, lactate, sodium, potassium, chloride, calcium, phosphorus, magnesium and cortisol. Angled, adults (n=45) were compared to large tarpon in a resting state (controls, n=6). Angled, sub-adults (n=28) were compared to those in a resting state (n=9). Adult tarpon were then compared to sub-adults to determine any size-related, intra-species variation in stress responses after angling. Finally, because smaller tarpon are logistically easier to handle and may be subjected to prolonged air exposure by anglers for hook removal or photographs, we evaluated the effect of 60 seconds of air exposure with horizontal (n=9) or vertical (n=9) handling out of the water relative to non-air exposed (n=10) fish in angled sub-adult tarpon. Associations and interactions among the blood chemistry responses of tarpon from each treatment to angling duration, handling time, body size and environmental factors related to each capture event were evaluated using a non-parametric, multivariate redundancy analysis. The duration of the angling event had a positive effect on responses of some parameters, and responses were more extreme in adult tarpon than sub-adults. The exception was cortisol which was significantly higher in sub-adults. Environmental parameters were less influential than angling and handling on observed physiological responses. Sub-adults showed no difference in physiological responses among handling treatments with and without air exposure and exhibited no short term mortality. Using appropriate tackle and gear to reduce fight times and handling should help minimize metabolic and acid-base imbalances. Tagging studies coupled with physiology can be a valuable tool for estimating post-release mortality and secondary stress responses of game fish, especially for large species that might be difficult to maintain in floating pens or tanks. Yet adverse effects of catch-and-release angling could also have population level consequences. Future studies should integrate biology and fish physiology to evaluate post-release recovery windows and establish lethal thresholds to provide potential predictive capability of mortality. In general, it appears that sub-adult and adult Atlantic tarpon along the Gulf coast of Florida can recover from physiological disturbances incurred during routine catch-and-release angling events in the recreational fishery when they are released in the absence of large predators. The anglers themselves can play a key role in tarpon conservation.

Foram realizados 2 experimentos no Departamento de Zootecnia da ESALQ/USP com o intuito de se avaliar o desempenho de tourinhos Nelore em confinamento. No experimento 1 foi avaliada a substituição da uréia (U) convencional por farelo de soja (FS) ou uréia de liberação lenta (ULL) (Optigen®) em rações de bovinos em terminação. Foram utilizados 100 tourinhos da raça Nelore (389 kg), distribuídos em 20 baias por 90 dias. As rações continham 8% de feno de Tifton (% da MS) e 65 a 69% de polpa cítrica no concentrado. Os 5 tratamentos experimentais foram assim designados (%MS): FS - ração com 5% de farelo de soja + 0,9% de uréia; U - ração com 1,7% de uréia; ULL 0,5 - ração com 0,5% de uréia de liberação lenta + 1,2% de uréia; ULL 1,0 - ração com 1,0% de uréia de liberação lenta + 0,8% de uréia; ULL1,5 - ração com 1,5% de uréia de liberação lenta + 0,3% de uréia. A ingestão de MS, o ganho de peso diário, a eficiência alimentar, o rendimento de carcaça, a espessura de gordura subcutânea e a área de olho de lombo não foram afetados pelas fontes de N testadas (P>0,05). Em conclusão, o desempenho de tourinhos Nelore em terminação alimentados com rações ricas em polpa cítrica, não é melhorado com a substituição da uréia convencional por farelo de soja ou uréia de liberação lenta na ração. No experimento 2 foram utilizados 192 animais (403 kg), distribuídos em 32 baias por 99 dias com objetivo de comparar rações contendo milho duro moído fino (M), laminado (L), ensilado (SGU) ou floculado (F), com 2 níveis de inclusão de bagaço de cana-deaçúcar: 12 ou 20% da MS da ração. Não houve interação entre processamentos do grão de milho e os níveis de forragem para nenhum parâmetro avaliado (P>0,05). A IMS foi maior (P<0,05) para o tratamento L comparado como os demais. O GPD foi maior (P<0,05) para os tratamentos F e SGU e a EA foi maior (P<0,05) para os tratamentos F, SGU e M comparados com L e para o tratamento F comparado com M. O rendimento de carcaça (RC) foi maior (P<0,05) para os tratamentos F e M. Os maiores valores (P<0,05) de energia líquida de manutenção e de ganho de peso das rações foram obtidos com os tratamentos F e SGU. A digestibilidade total do amido (DTA) foi maior nas rações contendo milho floculado, intermediária com milho moído fino e com milho ensilado e menor com milho laminado (P<0,05). A IMS foi menor (P<0,05) para os tratamentos contendo rações com 12% bagaço de cana-de-açúcar na MS da ração. O GPD, a EA, e o RC foram maiores nos animais dos tratamentos com 12% de bagaço de cana-de-açúcar na MS da ração (P<0,05). Os valores de energia líquida de manutenção e de ganho de peso das rações foram superiores (P<0,05) para os tratamentos com 12% de bagaço de cana-de-açúcar na MS. A DTA não foi alterada (P<0,05) em função do nível de inclusão do bagaço de cana-de-açúcar nas rações. Com base nos resultados conclui-se que o milho floculado e ensilado úmido são superiores, o milho moído é intermediário e o laminado inferior como fontes energéticas para tourinhos Nelore em terminação. Rações com 12% de bagaço de cana-de-açúcar contêm maior densidade energética e permitem melhor desempenho de tourinhos Nelore na fase de terminação comparadas com rações contendo 20% de bagaço de cana-de-açúcar.<br>Two trials were conducted at the Animal Sciences Department of the University of São Paulo Piracicaba-SP to evaluate the performance of finishing Nellore bulls. In trial 1 soybean meal (FS) and slow release urea (SRU) (Optigen®) replaced urea (U) on diets high in citrus pulp for finishing cattle. One hundred Nellore bulls (389 kg) were grouped in 20 pens for 90 days. Diets contained (%DM) 8% Tifton-85 grass hay and 92% concentrate (65 to 69% citrus pulp). The 5 treatment diets were isonitrogenous as follow (%DM): FS 5% soybean meal + 0.9% urea; U 1.7% urea; SRU 0.5 0.5% slow release urea + 1.2% urea; SRU 1.0 1.0% slow release urea + 0.8% urea; SRU 1.5 1.5% slow release urea + 0.3% urea. Animals were grouped in blocks according to initial BW. DMI, ADG, ADG/DMI, and carcass traits were not affected by N sources (P>0.05). In conclusion, on high citrus pulp diets, replacing soybean meal or slow release urea for urea does not improve performance of finishing Nelore bulls. In trial 2 192 finishing Nellore bulls (403 kg) grouped in 32 pens were fed for 99 days to compare diets containing fine ground, dry rolled, high moisture or steam flaked flint corn and two levels (12 or 20% on DM) of sugar cane bagasse. There was no interaction between corn processing methods and diet forage levels (P>0.05). DMI was higher (P<0.05) for dry rolled corn compared to the other 3 processing methods. ADG was higher (P<0.05) for steam flaked and high moisture corn than for ground or rolled corn. Feed efficiency (ADG/DMI) was higher (P<0.05) for steam flaked corn than for fine ground or dry rolled corn, and higher (P<0.05) for high moisture and ground corn than for dry rolled corn. Dressing was higher (P<0.05) for steam flaked and ground corn than for high moisture and dry rolled corn. The highest (P<0.05) diet energy values were observed for steam flaked and high moisture corn. Total tract starch digestibility was highest for steam flaked, intermediate for high moisture and ground corn and lowest for dry rolled corn (P<0.05). DMI was lower and ADG, feed efficiency, dressing and diet energy values were higher for cattle fed 12% than 20% forage diets (P<0.05). Forage level had no effect on diet starch digestibility (P>0.05). In conclusion, steam flaked and high moisture corn are highest, ground corn is intermediate and dry rolled corn is lowest in energy for finishing Nellore bulls. Performance of finishing Nellore bulls is improved with 12% sugar cane bagasse forage diets compared to 20% forage diets.

The objective of this experiment was to determine if nutrient utilization and energy partitioning by lactating dairy cows would differ in response to dietary corn grain (CG) types [steam-flaked corn (SFC) vs. high-moisture corn (HMC)] and to test if the types of CG would interact with slow-release urea (SRU) on lactational performance and energy utilization. Eight multiparous Holstein cows (32 ± 8.2 days-in-milk) were used in a duplicated 4 × 4 Latin square with one square consisting of ruminally cannulated cows. A 2 × 2 factorial arrangement was used to test 4 dietary treatments: SFC without SRU, SFC with SRU, HMC without SRU, and HMC with SRU. The experimental diets contained 60.5% dry matter (DM) of forages, whereas 12.9% or 14.4% DM of SFC or HMC was added in the diets, respectively. The SRU was supplemented at 0.46% DM, replacing a mixture of soybean meal and canola meal in a 50:50 ratio. Feeding HMC decreased intakes of DM, crude protein, and fiber compared with SFC. Supplementation of SRU did not affect intakes of DM and nutrients, whereas it tended to increase intakes of DM or increased crude protein intake under SFC but no effect under HMC, leading to CG ×SRU interactions on DM and crude protein intakes. Neither type of CG nor SRU supplementation affected milk production except that cows fed HMC-based diets tended to decrease energy-corrected milk yield compared to those fed SFC-based diets. Utilization of HMC in the diet had a tendency to increase dairy efficiency based on milk yield over SFC utilization. Cows fed HMC diets gained more body weight (BW) than those fed SFC diets, whereas supplementing SRU tended to reduce BW gain regardless of type of CG. Cows fed HMC diets shifted more net energy into BW compared with those fed SFC diets, whereas supplementing SRU tended to decrease a portion of net energy partitioned into BW gain under both SFC and HMC diets. Dietary treatments exerted minor impacts on ruminal fermentation profiles. Feeding HMC diets decreased fecal N excretion compared with SFC diets. In addition, supplementing SRU increased fecal N excretion under SFC, but it was decreased by SRU with HMC, leading to an interaction between CG and SRU. These collective results demonstrate that feeding HMC with SRU can be a practical option in high-forage lactation diets to maintain or improve nutrient and energy utilization efficiency and minimize negative environmental impacts.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>The application of organic and mineral fertilizers in agricultural areas, especially, in no-till system and over the years, can promote increased levels of heavy metals and as arsenic (As), cadmium (Cd), lead (Pb), chromium (Cr), copper (Cu), zinc (Zn) and nickel (Ni) in the soil, which may be contaminants and ground water but may also be absorbed and accumulated in plants, and even exported by the grain entering the food chain. The aim of this study was to evaluate how changes of heavy metals in the soil, caused by use of several years of organic and mineral sources, can be reflected in its content in shoots of oat, corn and wheat, and corn and wheat grains. The study was carried in the experimental area of the Department of Soil Science of the Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul (RS). The experiment was installed in 2004 and the treatments were control (without nutrient application) and application of pig slurry (PS), pig deep-litter (PL), cattle slurry (CS), and mineral fertilizers (NPK). August 2014 soil samples were collected and aerial part of black oats (Avena strigosa) (Winter 2013), maize (Zea mays) (2013/14 crop) and wheat (Triticum aestivum) (Winter 2014) and grains of wheat and maize. The elements analyzed were Cd, Cr, Cu, Ni, Pb and Zn and found out that there was an increase of their content in the soil with frequent applications of organic and mineral fertilizers, however, without exceed the maximum set by CONAMA 420. The crops of oat, corn and wheat showed addition of Cr, Cu, Ni and Zn in plant tissue, but the contents of these elements in corn and wheat grains suggest that the use of organic sources do not represent potential risk to the consumption of grains these cash crops.<br>Aplicação de fertilizantes orgânicos e minerais em áreas agrícolas, especialmente, sob plantio direto e ao longo de anos, pode promover o aumento dos teores e metais pesados, como arsênio (As), cádmio (Cd), chumbo (Pb), cromo (Cr), cobre (Cu), zinco (Zn) e níquel (Ni) no solo, que podem ser contaminantes do solo e águas, mas também podem ser absorvidos e acumulados em plantas, e até exportados pelos grãos, ingressando na cadeia alimentar. O objetivo do trabalho foi o de avaliar como as alterações nos os teores de arsênio, cádmio, chumbo, níquel, cromo, zinco e cobre no solo, motivadas pelo uso por vários anos de fontes orgânicas e mineral, podem se refletir no seu conteúdo na parte aérea de plantas de aveia preta, milho e trigo, e nos grãos de milho e trigo. O trabalho foi realizado na área experimental do Departamento de Solos da Universidade Federal de Santa Maria (UFSM), em Santa Maria, Rio Grande do Sul (RS). O experimento foi instalado no ano de 2004 e os tratamentos foram dejetos líquidos de suínos (DLS) e de bovinos (DLB), cama sobreposta de suínos (CSS), adubação mineral (uréia + superfosfato triplo + cloreto de potássio) e testemunha (sem a aplicação de nutrientes). Em agosto de 2014 foram coletadas amostras de solo, dejetos e parte aérea e grãos de aveia-preta (Avena strigosa) (inverno de 2013), milho (Zea mays) (safra 2013/14) e trigo (Triticum aestivum) (inverno de 2014). Foram analisados os elementos As, Cd, Cr, Cu, Ni, Pb e Zn e constatou-se que houve acréscimo de seus teores no solo com as frequentes aplicações de fertilizantes orgânicos e mineral sem, contudo, ultrapassarem os valores máximos estabelecidos pelo CONAMA 420. As culturas de aveia preta, milho e trigo mostraram acréscimo de Cr, Cu, Ni e Zn no tecido vegetal, mas os teores destes elementos nos grãos de milho e trigo sugerem que o uso das fontes orgânicas não representam potencial risco para o consumo de grãos destas culturas comerciais

Parasites may play an important role in biological invasions through two main mechanisms: enemy release and apparent competition. First, alien species may lose part of their parasite fauna during the introduction process and this release from natural enemies may enhance their performances in the new range. Furthermore, parasites may mediate the competition between alien and native species: invaders may transmit alien parasites to naive native species (spillover) or acquire local parasites, increasing their environmental abundance and their impact on native hosts (spillback) and/or altering the pre-existent host-parasite dynamics. In this study, I investigate the above-mentioned processes, using native Eurasian red squirrels (Sciurus vulgaris) and North American Eastern grey squirrels (S. carolinensis) introduced to Italy as a model system. First, I conducted a broad survey of the macroparasite fauna of native red squirrels over a wide geographic area and across different habitats. My results show that the native sciurid has a naturally poor parasite community, likely a consequence of both its arboreal habits and its isolation from other congeners. Both parasite richness and diversity are indeed low, especially for gastro-intestinal helminth fauna, dominated by a single nematode species, the oxyurid Trypanoxyuris sciuri. This finding highlights that the species may be particularly vulnerable to parasite spillover from the alien congener and other invasive species. A parallel survey on the macroparasite fauna of grey squirrels was carried out to detect whether the alien host lost, acquired or introduced to Italy any parasite species. Through this investigation I demonstrated that grey squirrels lost part of their parasite fauna during the introduction process and, although they acquired some European parasites, their number does not compensate the number of species lost, with a resulting parasite richness in Italian populations much lower than in grey squirrels' native range. The helminth community of grey squirrels introduced to Italy is dominated by the North American nematode Strongyloides robustus, whereas the most common arthropod is the flea Ceratophyllus sciurorum, acquired from red squirrels. Hence, this part of the study gives support to the enemy release hypothesis and shows that this biological invasion holds the premises for both spillover and spill-back mechanisms towards native red squirrels to occur. In the following part of the study, grey squirrels and their dominant nematode, S. robustus, were used as a model to assess the performance of indirect parasitological methods and the relationship between helminth fecundity and intensity. My results reveal that, while flotation is a valid method to survey infection status in living hosts, faecal egg counts do not provide a reliable estimate of S. robustus intensity of infection, since density-dependence in nematode fecundity leads to a non-linear relationship between the amount of eggs shed in faeces and parasite load. Next, I investigated prevalence of alien S. robustus and local T. sciuri in living red squirrels to detect whether presence of grey squirrels affects the endo-macroparasite community of the native host. I used indirect methods (flotation and tape-tests) to compare infection status in populations of red squirrels living in presence and absence of the alien congener. Results show that S. robustus infection is linked to grey squirrel presence, thus confirming that red squirrels acquire this North American nematode via spillover from the invader. Interestingly, also prevalence of T. sciuri is significantly higher in red squirrels co-inhabiting with the alien species, suggesting that susceptibility to infection in red squirrels may increase as a consequence of higher stress levels induced by interspecific competition. Finally, infections by Ljungan virus (a potential zoonoses) and adenoviruses (known to cause gastrointestinal disease and mortality in squirrels in Northern Europe) were investigated in both red and grey squirrels to shed some light on the role played by arboreal sciurids in microparasite circulation. I reported for the first time Ljungan virus in red squirrels, indicating that this infection is not limited to small ground-dwelling rodents, and extended the known distribution of adenoviruses in squirrels to Southern Europe. Besides, the low adenovirus prevalence found in grey squirrels confirms that the alien species is not the source of infection in red squirrels as had been previously presumed. Overall, the present thesis highlights the importance of taking into account parasitological aspects when dealing with biological invasions. In particular, the model red-grey squirrel teaches that i) macroparasites have the potential to affect biological invasions as much as microparasites do; ii) an exhaustive knowledge of native species parasite fauna is fundamental to investigate apparent competition; iii) apart from introducing alien parasites, alien species may affect native species parasite communities through other mechanisms; iv) inference of parasitological parameters from indirect methods should always be considered carefully.

Les crocodiliens ont développé des capteurs très précis pour sonder leur environnement jusqu'à atteindre leur position de super prédateur. Ces capacités sensorielles sont primordiales en situation de chasse mais elles sont également nécessaires pour assurer les interactions sociales entre partenaires sexuels ou entre parents et jeunes. Depuis l'intérieur des œufs, les embryons matures utilisent la communication acoustique pour synchroniser l'éclosion. Dans leurs premières années, les jeunes vocalisent en cas de danger pour solliciter la protection de leurs parents et assurer la cohésion du groupe afin de limiter les risques de prédation. Enfin, les vocalisations sont utilisées en parade nuptiale avant l'accouplement. Pour assurer la communication acoustique et pour chasser leurs proies depuis l'interface air-eau, les crocodiliens doivent localiser avec précision les multiples sources sonores de leur environnement. Si la perception acoustique a été un sujet d'intérêt pendant plusieurs années, les capacités de localisation sonore des crocodiliens ont été rapportées comme précises mais n'ont été étudiées que rarement. Les oiseaux, et en particulier les oiseaux vocaux, ont été testés à de nombreuses reprises pour comprendre les processus et les performances de localisation des sons, mais ces caractéristiques restent mal connues chez les espèces apparentées les plus proches : les crocodiliens. Quand ils chassent, les crocodiliens nécessitent une localisation sonore précise de leur proie. La plupart des espèces de crocodiliens sont opportunistes mais une caractéristique commune est leur méthode de chasse à l'affût ne laissant émerger que les yeux, les oreilles et les narines. Une bonne localisation est également nécessaire au cours de leur vie pour assurer leurs interactions sociales.Tout d'abord, nous avons mesuré les indices acoustiques de localisation en plaçant des microphones à l'intérieur des oreilles d'animaux juvéniles. En déplaçant une source sonore autour de l'animal, nous avons pu quantifier les signaux monauraux (fonctions de transfert relative à la tête, HRTF) et binauraux (ILD et ITD). Ensuite, nous avons entraînés des crocodiles du Nil à venir à une source sonore lorsqu'ils émettent un signal spécifique. Nous avons pu quantifier leurs performances de localisation sonore en utilisant séparément l'ILD et l'ITD. Enfin, nous avons mené des expériences de playbacks dans un environnement artificiellement bruyant. Cette dernière partie est basée sur une triple approche, en testant : des caïmans Yacare dans la nature avec des cris de détresse de jeunes individus ; des crocodiles du Nil en diffusant des appels de ses congénères ; des crocodiles du Nil entraînés dans une expérience Go/No-Go, assurant une forte motivation.Nous avons constaté que la morphologie externe de la tête des crocodiliens induit des indices acoustiques pertinents en fonction de la position de la source sonore. En mesurant les indices monauraux lorsque l'animal se reposait sur le sol et dans la position naturelle de chasse à l'interface entre l'air et l'eau - nous avons démontré que ces repères sont conservés même lorsque seulement une petite partie de la tête est émergée. Ce résultat peut suggérer une adaptation potentielle à cette position de chasse spécifique assurant des indices de localisation importants. Les crocodiles testés font preuve d'une très grande précision au cours de tâches de localisation sonore. Nos expériences ont montré que l'ITD et l'ILD sont pertinents pour estimer la position d'une source sonore et nous avons mesuré l'angle minimum audible (MAA) pour la première fois dans l'ordre des crocodiliens. Enfin, en présence d'une source de bruit dans leur environnement, les crocodiliens utilisent le démasquage spatial pour améliorer la détection de signaux acoustiques pertinents<br>Crocodilians developed very accurate sensors to probe their environment until raising their apex predator position. These sensory abilities are primordial in hunting situation but they are also needed to ensure social interactions between sexual partners or between parents and young. Since inside the eggs, the mature embryos use acoustic communication to synchronise the hatch. In their first years, juveniles use to call in case of danger for the help of their parents and ensure the cohesion of the group to limit the predation risks. Finally, acoustic vocalisations are used in courtship before mating. To ensure acoustic communication and to hunt their preys from the air-water interface, crocodilians need to precisely localise the multiple sound sources from their environment.If the acoustic perception was a subject of interest for several years, crocodilians’ sound localisation abilities were noted to be accurate but were studied only a few times. One situation in which crocodilians need to precisely locate a sound source is when they are hunting. Sound localisation is also necessary during their first years when they are subject to predation. When they feel in danger, young crocodilians use distress calls which are relevant to signal their position to their parents when eliciting a protection behaviour from them. Finally, sound localisation may be used to find a partner in the wild when we know that some species are capable of long journeys.To explore sound localisation in crocodilians, we quantified their sound localisation abilities and observed observe how they are able to deal within a noisy environment. First, we measured sound localisation cues by placing microphones inside the ears of juvenile animals. By moving a sound source around the animal, we were able to quantify monaural (Head-Related Transfer Functions, HRTF) and binaural cues (Interaural Level and Time Differences, ILD and ITD). Then, we trained Nile crocodiles to come to a sound source when playing a specific signal. By filtering these signals before playing them to the animal, we were able to quantify their sound localisation performances when using separately ILD and ITD. Finally, we conducted some playbacks experiments in an artificially noisy environment. This last part was constituted by a triple approach, by testing: Yacare caimans in the wild with distress calls of hatchlings; Nile crocodiles hatchlings by simulating a separation from the group and broadcasting calls from its congeners; trained Nile crocodiles in a Go/No-Go experiment, ensuring a high motivation.We evidenced that the external morphology of the crocodilians head induces potentially relevant external acoustic cues depending on the position of the sound source. By measuring the monaural cues in two situation -when the animal was resting on the ground and in the natural hunt position at the interface between air and water- we demonstrated that those cues are conserved even when only a small part of the head is emerged. This result may suggest a potential adaptation to this specific hunting position ensuring strong localisation cues. The tested crocodiles evidence very precise abilities in sound localisation tasks. Our experiments showed that both ITD and ILD are relevant when estimating the position of a sound source and we measured the Minimum Audible Angle (MAA) for the first time in the crocodilians order. Finally, in a presence of a noise source in their environment, crocodilians perform Spatial Release from Masking to increase the detection of relevant acoustic signals

La fragmentation des paysages et des habitats induite par les infrastructures linéaires de transport terrestres est une des principales causes de la perte de biodiversité actuelle. Parmi ces infrastructures, la route est un acteur majeur de fragmentation, d’autant plus qu’elle possède des effets propres dus au trafic circulant qui induit des collisions véhicule-faune et une pollution des paysages. Afin de diminuer ces effets négatifs, des mesures de réduction sont mises en place, notamment des passages à faune permettant de faire traverser la faune de part et d’autre des voies. La route crée aussi de nouveaux habitats potentiels pour les espèces de la petite faune dans des paysages anthropisés et fragmentés. Dans ce mémoire sont démontrées (1) la potentialité d’habitat de différents éléments routiers ; (2) la possibilité de prédire les collisions véhicule-faune afin de positionner au mieux les mesures de réduction ; (3) l’importance de la méthodologie dans l’évaluation de l’efficacité des passages à faune ; et (4) la possibilité d’améliorer les passages à faune existants. Ces résultats permettront d’améliorer les stratégies de défragmentation des paysages<br>Habitats and landscape fragmentation, caused by linear land transports infrastructures, is one of the major cause for the current loss of biodiversity. Among those infrastructures, road is a major cause of fragmentation, especially as it possess specific traffic-linked effects, which induces wildlife-vehicles collisions and landscape pollution. In order to decrease those negative effects, mitigation measures are taken, among which wildlife crossings, enabling wildlife to cross the road. Road also creates new potential habitats for small wildlife species in anthropogenic and fragmented landscapes. In this essay are shown (1) the potential as habitat of different road-linked elements; (2) the possibility to anticipate wildlife-vehicles collisions in order to improve the position of mitigation measures; (3) the importance of methodology in the evaluation of wildlife crossings effectiveness; and (4) the possibility to improve existing wildlife crossings. Those results will allow improving landscape defragmentation strategies