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1

Franco, Georgia Maria de Oliveira. "Zoés, megalopa e estágios juvenis iniciais de Cryptodromiopsis antillensis (Stimpson, 1858) : implicações sobre a monofilia dos Dromiacea (Crustacea : Decapoda : Brachyura)." Universidade Federal do Rio de Janeiro, 1998. http://hdl.handle.net/11422/4003.

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Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2018-05-24T20:44:53Z No. of bitstreams: 1 278422.pdf: 12707060 bytes, checksum: 78bc02382727d7e4b32d7c42959ad395 (MD5)<br>Made available in DSpace on 2018-05-24T20:44:53Z (GMT). No. of bitstreams: 1 278422.pdf: 12707060 bytes, checksum: 78bc02382727d7e4b32d7c42959ad395 (MD5) Previous issue date: 1998-04-23<br>CAPES<br>FUJB<br>A ontogenia de Cryptodromiopsis antillensis (Stimpson, 1858) foi analisada através de dados de literatura (RICE & PROVENZANO, 1966) e observações da megalopa, juvenis e adultos. A megalopa de C. antillensis foi redescrita e Evius ruber Moreira, 1912 foi considerada como sinônimo de C. antillensis por tratar-se da fase megalopa desta espécie. A ontogenia da carapaça e dos apêndices cefálicos, torácicos e abdominais foi acompanhada separadamente. Carapaça, antênulas, antenas, mandíbulas, maxílulas, maxílas, primeiro maxilípede, segundo maxilípede, terceiro maxilípede e pereópodes sofrem mudanças significativas até a fase megalopa, quando adquirem uma forma similar a do adulto. Após a fase megalopa estes apêndices sofrem apenas acréscimo de cerdas. Já o esterno torácico, abdomen, telso, pleópodes e urópodes se modificam até a fase adulta, apresentando dimorfismo sexual. Pl 1 está ausente nas fases zoé e megalopa, surgindo apenas nos juvenis. Foi observada a presença de pleópodes rudimentares (Pl 3-Pl 5) nos espécimens macho de.. C. antillensis. A espécie C. antillensis se encaixa no padrão ontogenético da família Dromiidae. A única espécie que foge ao padrão dromiídeo é Cryptodromia tuberculata, que apresenta desenvolvimento abreviado. Dados ontogenéticos não suportam a monofilia dos Podotremata. A zoé 1 dos Dromiidae e a pré-zoé dos Dynomenidae são similares. A ontogenia do Homolodromiidae apresentou-se bastante diferente daquela dos Dromiidae. O caráter urópodes rudimentares (visíveis ventralmente) na fase megalopa, separa os Homolodromiidae de todos outros Podotremata. Apenas um caráter ontogenético sustenta os Dromiacea sensu GUINOT (1978): exopodito da antena desenvolvido na megalopa. O padrão ontogenético dos Archaeobrachyra sensu GUINOT (1978) também foi estudado. Dados ontogenéticos não fornecem suporte ao agrupamento dos Archaeobrachyura. Os seguintes caracteres ontogenéticos caracterizam os Homoloidea: 4-6 cerdas e estetos no protopodito da antênula na zoé 1; padrão de cerdas na base (2, 2, ,2, 3) e no endopodito (1+0, 1+0, 1+0, 2+0, 4+1) do Mxpl na zoé 1; endopodito do Mxpl divdido em dois artículos na megalopa; padrão de cerdas na base (1, 1, 1, 1) do Mxp2 na zoé 1. Apenas um caráter ontogenético é comum ao Raninidae e Cymonomidae: telso furcado.<br>The ontogeny of Cryptodromiopsis antillensis (Stimpson, 1858) it was analyzed through literature data (RICE & PROVENZANO, 1966) and observations of the megalopa, juveniles and adults. The megalopa of C. antillensis was redescribed and Evius ruber Moreira, 1912 was considered as synonym of C. antillensis by being of the phase megalopa of this species. The ontogeny of the carapace and the cephalic, thoracic and abdominal appendages it was accompanied separately. Carapace, antennule, antenna, mandible, maxillule, maxilla, first maxiliped, second maxiliped, third maxiliped and pereiopods suffer significant changes until the phase megalopa, when they acquire a similar form the one of the adult. After the phase megalopa these appendages just suffer increment of setae. Already the sternum thoracic, abdomen, telson, pleopods and uropods modify until the adult phase, presenting sexual dimorfism. Pl 1 is absent in the phases zoea and megalopa, just appearing in the juveniles ones. The presence of rudimentary pleopods was observed (Pl 3-Pl 5) in the male specimens of C. antillensis. Cryptodromiopsis. Antillensis, has the ontogenetic pattern of the family Dromiidae. The only species that outrange the Dromiidae pattern is Cryptodromia tuberculata, that presents abbreviated development. Ontogenetic data don't support the monophiletism of Podotremata. The zoea 1 of Dromiidae and the pre-zoea of Dynomenidae are similar. The ontogeny of Homolodromiidae came quite different from that of Dromiidae. The character rudimentary uropods (in a ventral view) in the megalopa phase, separates Homolodromiidae from all other Podotremata. Only one ontogenetic character justifies the Dromiacea sensu GUINOT ( 1978): antennal exopod developed in the megalopa. The ontogenetic pattern of the Archaeobrachyura sensu GUINOT ( 1978) was also studied. Ontogenetic data don't support the group of Archaeobrachyura. The following ontogenetic characters diagnoses Homoloidea: 4-6 setae and aesthetasc setae in the protopod of the antennule in the zoea 1; pattern of setae in the base (2, 2, ,2, 3) and in the endopod ( 1+0, 1+0, 1+0, 2+0, 4+1) of the Mxpl in the zoea 1; endopod of the Mxpl dividido in two articles in the megalopa; pattern of setae in the base ( 1, 1, 1, 1) of the Mxp2 in the zoea 1. Only one ontogenetic character is common to Raninidae and Cymonomidae: furcated telson.
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2

Smith, Adam R. "The social biology of the sweat bee Megalopta genalis /." Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/9073.

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3

Kurth, Benjamin Neal. "Trophic Ecology and Habitat Use of Atlantic Tarpon (Megalops atlanticus )." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6531.

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Fish can have complex life histories and use multiple habitats and resources throughout their life span. Consequently, their life histories are often poorly understood. The Atlantic Tarpon, Megalops atlanticus, is a large, typically migratory, elopomorph fish that is both ecologically and economically important. Atlantic Tarpon are under threat due to regional exploitation, loss of natal and juvenile habitat, poor water management, and offshore impacts. In addition, little is known about its lifelong habitat and resource use. In Chapter 1, I used stable isotope analysis of eye lens δ13C and δ15N values to explore patterns in trophic history and habitat use of 16 Atlantic Tarpon from West-Central Florida and Louisiana. The stable isotope chronologies showed 100% use of backcountry habitats during the early life history and an ontogenetic habitat shift to coastal waters at approximately 10 years of age and 140 cm total length. During the coastal phase Atlantic Tarpon displayed among-individual variability and within-individual consistency in basal resource use. In Chapter 2, mark-recapture data from a multi-year genetic tagging program were used to investigate survival and growth rates, ontogenetic habitat use, and migration of juvenile Atlantic Tarpon in Florida. The study found that juvenile Atlantic Tarpon take approximately 10 years to reach the length associated with maturity, and appear to have a high survival rate (~80%), possibly due to effective use of habitats with reduced competition and predation. Atlantic Tarpon underwent several ontogenetic habitat shifts throughout the juvenile phase. In addition, juvenile Atlantic Tarpon did not migrate long distances but instead showed fidelity to systems wherein only short movements were needed to shift habitat types. This work serves to fill critical gaps in our knowledge of Atlantic Tarpon life history and may aid in better management and conservation of the species.
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4

Borba, Susan Caroline Pinto. "Pesquisa de anticorpos anti-megalina em pacientes transplantados renais." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/5/5146/tde-13092010-161121/.

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Introdução: O papel do sistema HLA na evolução do transplante é indiscutível. Dados da literatura internacional e do nosso laboratório têm mostrado que este não é o único sistema envolvido nos processos de RMA (rejeição mediada por anticorpo) Esse fato é comprovado a partir da constatação de que transplantes realizados entre irmãos com total identidade HLA também são alvos da RMA. Entretanto, os alvos antigênicos desses anticorpos permanecem desconhecidos, dificultando assim o diagnostico e tratamento da RMA não-HLA. No transplante renal a presença desses anticorpos têm sido associada com anticorpos anti células endoteliais, células epiteliais tubulares, podocitos, células mesangiais e monócitos. Nosso objetivo neste estudo foi avaliar a presença e a relevância clínica de anticorpos contra a megalina, membro da família de receptores de LDL, expressa na membrana apical dos túbulos proximais, com importante papel na reabsorção de proteínas no rim. Métodos: Soros pré-transplante de 105 pacientes submetidos a transplante renal, realizado no Serviço de Transplante Renal do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (UTR-HC-FMUSP) foram testados por ELISA contra 2 peptídeos da megalina estudados e sintetizados em nosso laboratório. (convencionalmente chamados 18 e 19) Resultado: Não foi detectada a presença de anticorpos do isotipo IgG nas amostras prétransplante dos pacientes estudados. Entretanto, foi detectada a presença de anticorpos do isotipo IgM anti-peptídeo 18 em 33 (31,4%) amostras de soro e anti-peptídeo 19 em 23 (21,9%). Para avaliar a significância clinica desses anticorpos dividimos os pacientes em 2 grupos: pacientes com pelo menos 1 episodio de rejeição aguda (Grupo I) e pacientes sem rejeição (Grupo II) e observamos a distribuição dos pacientes positivos nos 2 grupos. O numero de pacientes com anticorpos anti-peptídeo 18 foi igualmente distribuída nos dois grupos. (12/42, 28,5% no Grupo I e 21/63, 33,3% no Grupo II p=ns). A maioria dos pacientes com anticorpos anti-peptídeo 19 pertenciam ao grupo I (17/42, 40,5% ; 6/63, 9,5% p=0,0003). Esta analise demonstrou uma boa correlação entre presença de anticorpos anti-peptídeo 19 no soro pré-transplante e rejeição. Conclusão: Nossos dados sugerem que anticorpos IgM anti-megalina no pré-transplante podem ser um fator de risco na rejeição do aloenxerto renal. É importante salientar que a nosso conhecimento este é o primeiro estudo envolvendo megalina e rejeição no transplante clínico.<br>Background. Preformed donor-specific human leukocyte antigen (HLA)- antibodies are accountable for the majority of antibody-mediated rejections (AMR). However, recipients of HLA identical kidneys can develop AMR implicating putative pathogenic antibodies that are directed against non-HLA antigens. Unknown immune targets and consecutive lack of detection methods make non-HLA AMR particularly difficult to diagnose and treat. In renal transplant rejection, the presence of antibodies to non-HLA has been associated with antibodies against endothelial cells, tubular epithelial cells, podocytes, mesangial cells and monocytes. The aim of this study was to evaluate the presence and clinical relevance of preformed antibodies against megalin, a member of the LDL receptor family, expressed on the apical membrane of proximal tubules. Megalin performs a central role in renal protein reabsorption. Methods. Pré-transplant sera of 105 recipients of kidney allograft transplanted at Serviço de Transplante Renal do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (STRHCFMUSP) were tested by enzyme-linked immunosorbent assay (ELISA) against 2 megalin-peptides (conventionally named 18 and 19) studied and synthetized in our laboratory. Results. Antibodies were not detected in pretranplant sera when tested for IgG isotype. However, in 33 (31,4%) sera we detected the presence of IgM antibodies to megalin-peptide18 and in 23 (21,9%) to megalin-peptide 19. To evaluate the clinical significance of these antibodies we divided the patients in 2 groups: Group I - 42 patients with at least one rejection episode during the first post-transplant year and Group II - 63 patients without any rejection episode and observed the distribution of positive patients in each of the 2 groups. Patients with megalin-peptide18 antibodies had the same distribution in both groups. (12/42, 28, 5% Group I and 21/63, 33,3% no Group II p=ns). However, patients with megalinpeptide19 antibodies were more frequent in group I. (17/42, 40,5% group I and 6/63, 9,5% group II p=0,0003). This analysis demonstrated a good correlation between preformed anti-megalin-peptide19 antibodies and allograft rejection Conclusion. Our data suggest that presence of IgM megalin antibodies before transplantation might be a risk factor for kidney allograft rejection. To our knowledge, this is the first study involving megalin and rejection in clinical transplantation.
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Olmi, Eugene J. III. "Immigration of blue crab (Callinectes sapidus) megalopae in the York River, Virginia: Patterns and processes." W&M ScholarWorks, 1993. https://scholarworks.wm.edu/etd/1539616798.

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Following larval development in coastal waters, the postlarval stage, the megalopa, of the blue crab enters estuaries and colonizes juvenile/adult habitats. I examined the dynamics of the immigration of blue crab megalopae in the York River, Virginia. Plankton samples were collected nightly during flood tide in the York River Jul-Nov 1987, 1988 and 1989 to quantify variation in abundance of blue crab megalopae during the recruitment season. The abundance of megalopae was highly episodic, and significantly correlated with wind stress to the west (1987, 1988 and 1989), wind stress to the north (1989), and observed tidal range at Gloucester Point (1987 and 1988). These factors accounted for 22-56% of the variation in megalopal abundance. Megalopal abundance was not correlated with current speed, water temperature, salinity, or Chesapeake Bay subtidal volume. While in the estuary, megalopae vertically migrated in response to light and tide. Blue crab megalopae were more abundant during flood than ebb, indicating that megalopae selectively occupy flood waters. Ascent of megalopae into the water column appeared to be light limited. at night, megalopae were concentrated at the surface; during day, they were concentrated near the bottom in deep water, but apparently did not ascend from the bottom in shallow water. Thus, megalopae utilize flood currents for transport up the estuary while reducing the risk of predation to visual predators. Spatial patterns of abundance of megalopal and juvenile blue crabs were not consistent across habitats (plankton, grassbeds, or artificial settlement substrates) or time (days, months). Densities of megalopae and first-stage juveniles in grass beds correlated with megalopal abundance in the plankton; settlement on artificial substrates did not. Total juvenile abundance exhibited lower spatial and temporal variability in grass beds than that of megalopae or first-stage juveniles, suggesting that high variability in settlement is tempered by post-settlement processes. In laboratory studies, sand shrimp, Crangon septemspinosa, consumed &>&99% of available megalopae, while grass shrimp, Palaemonetes pugio, consumed 37% of megalopae in the first trial and 5% in the second trial. Predation by grass shrimp was not related to the rate of metamorphosis of megalopae, but may have been related to water temperature.
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Araiza, Jesús. "Die aristotelischen Ethica megala eine philosophische Interpretation." Berlin Münster Lit, 2007. http://d-nb.info/996034005/04.

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7

Palanisamy, Megala [Verfasser]. "High moisture extrusion of plant proteins / Megala Palanisamy." Hannover : Gottfried Wilhelm Leibniz Universität Hannover, 2019. http://d-nb.info/1198398574/34.

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Marques, Alessandra Resende. "O gênero Squalus no Brasil : caracterização do grupo megalops e determinação do status taxonômico das formas brasileiras." Universidade Federal do Rio de Janeiro, 1999. http://hdl.handle.net/11422/3574.

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Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2018-01-31T00:29:49Z No. of bitstreams: 1 569925.pdf: 15086841 bytes, checksum: 89e5e3ae8d68f6aded9ed24d43c96b31 (MD5)<br>Made available in DSpace on 2018-01-31T00:29:49Z (GMT). No. of bitstreams: 1 569925.pdf: 15086841 bytes, checksum: 89e5e3ae8d68f6aded9ed24d43c96b31 (MD5) Previous issue date: 1999-05-21<br>No presente estudo são definidos três grupos de espécies de Squalus para o litoral brasileiro, e é feita uma caracterização do grupo megalops. A partir da análise da morfologia externa (formato das nadadeiras pélvicas, comprimento do espinho das nadadeiras dorsais em relação a altura das nadadeiras e posição das nadadeiras pélvicas em relação as nadadeiras dorsais), dentículos dérmicos, condrocrânio, coluna vertebral, dentição e mixopterígios, verifica-se que o Squalus megalops do sul do Brasil (sensu Vooren, 1992), o Squalus cubensis do sudeste do Brasil (sensu Figueiredo, 1977) e Squalus sp. do sudeste (sensu Figueiredo, 1981) constituem uma única espécie, que foi denominada Squalus sp. do grupo megalops. Os caracteres que se mostraram mais importantes para a definição da espécie foram: morfologia externa, dentículos dérmicos, condrocrânio e mixopterígios. O estudo indica ainda que outras duas formas ocorrem na costa brasileira: Squalus acanthias e Squalus sp. do grupo blainvillei.<br>Three species groups of Squalus from the Brazilian coast are defined and the megalops group is characterized. According to analysis of external morphology (pectoral fins shape, dorsal fins spines length in comparison with the high of these fins and position of pelvic fins in comparison with dorsal fins), dermal denticles, chondrocranium, vertebral column, dentition and claspers, it is demonstrated that southern species Squalus megalops (sensu Vooren, 1992), southeastern Squalus cubensis (sensu Figueiredo, 1977) and Squalus sp. (sensu Figueiredo, 1981 ), from central and southern Brazil, represents a single species, wherein Squalus sp. of the megalops group. The most important characters to define this species were external morphology, dermal denticles, chondrocranium and claspers. The study also indicated two aditional species occurs in Brazilian waters: Squalus acanthias and Squalus sp. of the blainvillei group.
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Santos, Leandro Mattos. "Análise cladística das abelhas do gênero Megalopta Smith, 1853 (APIDAE: Halictinae, Augochlorini) e revisão taxonômica das espécies brasileiras." reponame:Repositório Institucional da UFPR, 2010. http://hdl.handle.net/1884/25005.

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Resumo: Megalopta (Smith, 1853) é um gênero de abelhas crepusculares e/ou noturnas, com distribuição neotropical. Estas abelhas nidificam em ramos e galhos em decomposição e podem apresentar hábito social facultativo. O gênero possui vinte e sete espécies descritas e na maioria das vezes são consideradas de difícil identificação principalmente por causa de polimorfismos, descobertos após a descrição da maioria das espécies. Além disto, gêneros e subgêneros em sinonímias foram propostos ao longo da história para abrigar as espécies de Megalopta, mas nenhum estudo moderno foi empregado para investigar se constituem agrupamentos monofiléticos. Desta forma, foi realizado um estudo taxonômico das espécies brasileiras bem como uma análise cladística do gênero. Para isto foi obtido empréstimo de indivíduos de Megalopta junto a instituições nacionais e internacionais para realizar o estudo morfológico. Na análise cladística, foram utilizados 73 caracteres e 29 terminais, destes Augochloropsis callichroa, Pseudaugochlora graminea e Xenochlora nigrofemorata como grupo externo. Foi obtida uma árvore de relacionamento filogenético para as espécies de Megalopta. Os subgêneros e gêneros propostos anteriormente foram mantidos em sinonímia sob Megalopta, uma vez que foram considerados parafiléticos ou seu reconhecimento tornava outros grupos parafiléticos dentro do gênero. Foram reconhecidas 24 espécies para a fauna brasileira. Destas, 10 já descritas (Megalopta aegis, M. aeneicollis, M. amoena, M. atlantica, M. cuprea, M. fornix, M. guimaraesi, M. sodalis, M. sulciventris, M. purpurata) e 14 sendo propostas como novas, totalizando 41 espécies no gênero. É apresentada uma chave de identificação, acompanhada com figuras e mapas de distribuição para as espécies brasileiras. Desta maneira, será possível identificar as espécies da nossa fauna o que irá facilitar a realização de novos estudos sobre estas abelhas.
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Biermann, Jeffery Lee. "The distribution of (callinectes sapidus) megalopae at the mouths of Chesapeake and Delaware bays Implications for larval ingress /." College Park, Md.: University of Maryland, 2009. http://hdl.handle.net/1903/9241.

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Thesis (M.S.) -- University of Maryland, College Park, 2009.<br>Thesis research directed by: Marine, Estuarine, Environmental Sciences Graduate Program. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Layman, Bruce Clare. "Role of Habitat Features and Chemical Cues in Substrate Selection by Blue Crab Megalopae: Evidence from Laboratory Experiments." W&M ScholarWorks, 1992. https://scholarworks.wm.edu/etd/1539617647.

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Dias, Rodolfo Liporoni. "Visual ecology of nocturnal bees: how light intensity affects foraging activity in cambuci, a neotropical Myrtaceae." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/41/41134/tde-21082018-082154/.

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The foraging activity of day-active bees often rely on flower availability, light intensity and temperature. However, some bees developed a nocturnal habit and fly during the dusk, dawn and night. We still do not know how these bees cope with environmental factors, especially dimmer light levels, to explore flower earlier than their diurnal relatives. Given that typical bee apposition compound eyes work better in brighter environments and function in their limits in dim-light conditions, we can expect a larger dependence of light intensity for nocturnal groups. Nocturnal and crepuscular bees are frequent visitors of cambuci (Campomanesia phaea, Myrtaceae) in southeastern Brazil. We aimed to investigate how light intensity affects flower visitation of cambuci by nocturnal and crepuscular bees, also controlling for other environmental factors. We counted visits per minute along 30 nights/twilights in 33 cambuci trees from a commercial orchard, measuring the following environmental variables: light intensity, flower availability, temperature, air relative humidity and wind speed. Light intensity is the only variable that explained flower visitation of nocturnal bees in cambuci, which peaks at intermediate light levels that occur around 30 minutes before sunrise. The minimum light intensity threshold to bees start flying is of 0.00024 cd/m2, the first recorded value for nocturnal and crepuscular bees finding flowers in an agro-forest context. Our results highlight for the first time how nocturnal bees rely on light to explore resources and show that the bees light-dependent foraging activity is not always linear, as postulated by previous theoretic models. This is the first step to understand how nocturnal bees react to environmental factors. Our findings also bring concerns about possible negative effects of light pollution at night for cambuci-crepuscular bees interaction<br>O forrageio de abelhas geralmente depende de disponibilidade de flores, intensidade de luz e temperatura. Contudo, algumas abelhas desenvolveram hábitos noturnos e voam durante os crepúsculos e a noite. Não se sabe como essas abelhas lidam com os fatores ambientais, especialmente os reduzidos níveis de luminosidade. Dado que os olhos compostos de aposição de abelhas funcionam melhor em maiores luminosidades, espera-se uma maior dependência da luz para os grupos noturnos. Abelhas noturnas e crepusculares são visitantes frequentes do cambuci (Campomanesia phaea, Myrtaceae) no sudeste do Brasil. Nosso objetivo foi investigar como a intensidade de luz afeta a visitação floral do cambuci por abelhas noturnas e crepusculares, controlada também por outros fatores ambientais. Para isso, contamos as visitas a cada minuto ao longo de 30 noites/crepúsculos em 33 árvores de cambuci em um pomar comercial, medindo as seguintes variáveis ambientais: intensidade de luz, disponibilidade de flores, temperatura, umidade e velocidade do vento. A intensidade de luz foi a única variável que explicou a visitação floral de abelhas noturnas no cambuci, a qual tem um pico em níveis intermediários de luz que ocorrem ao redor de 30 minutos antes do nascer do sol. O limiar mínimo de intensidade de luz para as abelhas começarem a voar foi de 0.00024 cd/m2, o primeiro valor registrado para abelhas noturnas e crepusculares procurando por flores em um contexto agroflorestal. Nossos resultados destacam pela primeira vez como as abelhas noturnas dependem da luz para explorar recursos e mostram que essa dependência, para abelhas em geral, não é sempre linear, como postulado por modelos teóricos prévios. Este é o primeiro passo para entender como abelhas noturnas reagem a fatores ambientais. Nossos dados também trazem alertas para possíveis efeitos negativos da poluição luminosa à noite para a interação entre cambuci e abelhas noturnas
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Tiralongo, Emilia. "Complesso macromolecolare responsabile dell'endocitosi dell'albumina: un ruolo a livello glomerulare? Studio di espressione genica di CLCN5 e megalina in biopsie microdissezionate di nefropatie proteinuriche." Doctoral thesis, Università degli studi di Padova, 2009. http://hdl.handle.net/11577/3426054.

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ClC-5 and Megalin are part of the same macromolecular complex involved in the re-uptake of albumin in the proximal tubuli. To understand the relationship between this mechanism and proteinuric kidney diseases, we have performed gene expression study of CLCN5 and Megalin genes in glomerular (gl) and tubular interstitial (ti) compartments of patients with type 2 diabetes (NIDDM) and IgA nephropathy (IgAN). Gene expression of CLCN5 and Megalin was investigated by Real-Time PCR in microdissected biopsies (mpb) (under a stereomicroscope) from patients with IgAN (n 10) and with NIDDM (n 9). Both groups had similar level of proteinuria. As controls, we used cortical tissues obtained from sites remote from tumor bearing renal tissue (n 9). Moreover, we analyzed human mesangial cells (HMC), endothelial cells (HuVEC), tubular cells (HK-2) and podocytes (HP) in basal conditions. HMC and HK-2 were also examined in high glucose and albumin conditions respectively. We found that: 1) CLCN5 and Megalin were expressed in all mbp both at gl and ti levels, and their expression did not differ between gl and ti of NIDDM and IgAN; 2) CLCN5 and Megalin expression levels were significantly higher in proteinuric nephropathies than in controls both at gl and ti compartment. In order to exclude ti contamination in microdissected glomeruli, we performed gene expression analysis of CLCN5 and Megalin also on laser microdissected glomeruli from 28 NIDDM patients and 14 controls that confirmed our previous results. In these mbp a direct correlation between CLCN5 and Megalin was evidenced (r=0,50 p=0,0039); 3) CLCN5 transcript was evidenced in all cells analyzed, on the contrary, very low levels of Megalin were detected; 4) HK-2 treated with albumin showed the same level of CLCN5 expression as untreated cells; 5) HMC treated with high glucose for 24 and 48 hours showed the same level of CLCN5 expression as untreated cells. Our study reveals, for the first time, that CLCN5 and Megalin genes are expressed in human glomeruli, and that all the cell types constituting the glomerulus express in vitro CLCN5. The overexpression of CLCN5 and Megalin in diabetic and IgA nephropathy biopsies suggests that proteinuria might regulate their expression. The in vitro experiments on HMC exclude the role of glucose in the up-regulation of ClC-5 expression in diabetic glomerulopathy. A role might be hypothesized for podocytes since podocyte endocytosis of proteins does occur in proteinuric patients.<br>ClC-5 e Megalina sono due delle proteine che compongono il complesso macromolecolare coinvolto nel riassorbimento dell’albumina a livello del tubulo prossimale. Per comprendere meglio se ci fosse una relazione tra questo meccanismo e le patologie proteinuriche abbiamo effettuato uno studio di espressione per i geni CLCN5 e Megalina nei compartimenti glomerulare e tubulo interstiziale di pazienti con diabete di tipo II (NIDDM) e nefropatia a depositi di IgA (IgAN). L’espressione di CLCN5 e Megalina è stata investigata mediante Real-Time PCR in biopsie microdissezionate manualmente grazie all’ausilio di uno stereomicroscopio. Queste sono stete ottenute da pazienti con diabete di tipo II (n°9) e nefropatia a depositi di IgA (n°9). Come controllo è stato utilizzato tessuto corticale ottenuto da polo renale indenne in corso di nefrectomia per tumore. Entrambi i gruppi di pazienti analizzati presentavano livelli simili di proteinuria. Abbiamo inoltre analizzato cellule mesangiali umane (HMC), cellule endoteliali umane (HuVEC) cellule tubulari umane (HK-2) e podociti umani (HP) in condizioni basali. HMC e HK-2 sono state anche analizzate rispettivamente in presenza di alte concentrazioni di glucosio e a diverse concentrazioni di albumina. Abbiamo trovato che: 1) CLCN5 e Megalina sono entrambi espressi in tutte le biopsie microdissezionate sia a livello glomerulare che a livello tubulo interstiziale e i loro livelli di espressione erano simili nei due compartimenti in entrambe le patologie; 2) i livelli di espressione sono risultati maggiori nelle nefropatie proteinuriche rispetto ai controlli sia a livello tubulo interstiziale che a livello glomerulare. Per escludere un’eventuale contaminazione del compartimento glomerulare da parte del tubulo prossimale abbiamo chiesto la collaborazione del Dott. J.J.Baelde del Leiden University Medical Center che ha effettuato l’analisi di espressione di CLCN5 e Megalina su glomeruli microdissezionati mediante laser ottenuti da biopsie di pazienti NIDDM (n°28) e su glomeruli sani di controllo (n°14), confermando i nostri precedenti risultati. In queste biopsie microdissezionate è inoltre emersa una correlazione diretta tra CLCN5 e Megalina (r=0,5, p=0,0039); 3) la presenza di CLCN5 è stata evidenziata e quantificata in tutte le cellule analizzate, mentre per Megalina sono stati rilevati livelli molto bassi di espressione; 4) le cellule HK-2 stimolate con albumina hanno mostrato gli stessi livelli di espressione di CLCN5 delle cellule non trattate; 5) le cellule HMC stimolate con glucosio hanno mostrato gli stessi livelli di espressione di CLCN5 delle cellule non trattate. Il nostro studio evidenzia per la prima volta la presenza di CLCN5 e Megalina a livello del compartimento glomerulare nell’uomo ed inoltre che tutti i tipi cellulari costituenti il glomerulo esprimono in vitro CLCN5. La sovrespressione di CLCN5 e Megalina nelle biopsie dei pazienti diabetici e con nefropatia da IgA suggerisce un loro ruolo nella fisiopatologia della proteinuria e la loro correlazione diretta, emersa tra l’espressione genica delle due proteine nel glomerulo, fa ipotizzare un loro meccanismo d’azione coordinato simile a quello presente nel tubulo prossimale. Gli esperimenti in vitro sulle HMC escludono un ruolo del glucosio nella modulazione dell’espressione di CLCN5 nella patologia diabetica. Un ruolo in questo processo potrebbe essere ipotizzato per i podociti in quanto i risultati da noi ottenuti bene si affiancano ai dati in letteratura che mostrano che i podociti, nei pazienti proteinurici, sono in grado di endocitare proteine.
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14

Inoue, Bruna Hitomi. "Bases moleculares da microalbuminúria associada à hipertensão arterial essencial: papel da reabsorção tubular de albumina." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/5/5166/tde-13122012-161119/.

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Evidências epidemiológicas indicam que a presença de microalbuminúria prediz maior freqüência de eventos cardiovasculares e mortalidade em hipertensos essenciais. A microalbuminúria pode ser decorrente do aumento da permeabilidade glomerular e/ou da diminuição da reabsorção desta macromolécula no túbulo proximal. Todavia não é sabido se os mecanismos que regulam a reabsorção de albumina em túbulo proximal renal encontram-se alterados na hipertensão essencial. Este trabalho teve como objetivo investigar as bases moleculares da microalbuminúria associada à hipertensão arterial essencial, focando na reabsorção tubular de albumina. Para tanto, avaliamos a evolução temporal da excreção urinária de albumina em ratos espontaneamente hipertensos (SHR) com 6 semanas de idade (pressão arterial sistólica, PAS, = 105 ± 4 mmHg), 14 semanas de idade (PAS = 180 ± 2 mmHg) e 21 semanas de idade (PAS = 202 ± 2 mmHg). Ratos normotensos Wistar da mesma idade serviram de controle. Observou-se que a excreção urinária diária de albumina aumentou progressivamente com o aumento da pressão arterial em SHR (10,5 ± 1,9; 92 ± 7,0 e 154 ± 27 g/dia, em SHR com PAS média igual a 105, 180 e 202 mmHg respectivamente). Este aumento progressivo não foi observado em ratos normotensos com idade correspondente, indicando que este fenômeno é decorrente do aumento da pressão arterial e não pode ser atribuído ao aumento da idade dos animais durante o período estudado. A análise das proteínas urinárias por eletroforese em gel de poliacrilamida (SDS-PAGE) mostrou que SHR excretam proteínas do tamanho da albumina ou menores (< 70kDa), padrão típico de proteinúria tubular. Adicionalmente, verificou-se que os níveis de expressão dos receptores endocíticos megalina e cubilina, bem como do canal para cloreto ClC-5 diminuem progressivamente no córtex renal de SHR com o aumento da pressão arterial. Observou-se também uma diminuição significativa na expressão de uma outra macromolécula importante no processo de endocitose mediada por receptor em túbulo proximal renal, a v-H+-ATPase. Entretanto, a diminuição da expressão protéica da subunidade B2 desta ATPase foi estatisticamente significante apenas em SHR com 21 semanas comparado aos com 6 semanas de idade. Não foram encontradas alterações no padrão de expressão de componentes estruturais da barreira glomerular como a nefrina e podocina. Em suma, o nosso estudo demonstra que o aumento da excreção urinária de proteínas, especialmente de albumina, está associado com uma menor expressão de componentes essenciais do aparelho endocítico do túbulo proximal renal. É tentador especular que a disfunção da via endocítica no túbulo proximal renal possa ser o principal mecanismo subjacente ao desenvolvimento de microalbuminúria na hipertensão<br>Epidemiological evidences indicate that the presence of microalbuminuria predicts a higher frequency of cardiovascular events and mortality in essential hypertensive patients. Microalbuminuria may arise from increased glomerular permeability and/or reduced proximal tubular reabsorption of albumin. However, it remains to be determined whether the mechanisms that regulate the renal proximal tubular reabsorption of albumin are altered in essential hypertension. The purpose of this work was to investigate the molecular basis of microalbuminuria in essential hypertension, focusing on the renal tubular reabsorption of albumin. To this end, we evaluated the temporal evolution of urinary albumin excretion in spontaneously hypertensive rats (SHR) at 6 weeks of age (systolic arterial pressure, SAP, = 105 ± 4 mmHg), 14 weeks of age (SAP = 180 ± 2 mmHg) and 21 weeks of age (SAP = 202 ± 2 mmHg). Age-matched normotensive Wistar rats were used as controls. It was observed that the daily urinary excretion of albumin progressively increased with blood pressure in SHR from 6 to 21 weeks of age (10.5 ± 1.9, 92 ± 7.0 and 154 ± 27 g in SHR with 105, 180 and 202 mmHg of average SAP, respectively). This progressive increase in microalbuminuria has not been observed in age-matched normotensive Wistar rats, indicating that this phenomenon cannot be attributed to age progression over the studied period. SDS-PAGE analysis of urinary proteins showed that microalbuminuric SHR virtually excreted proteins of the size of albumin or smaller (< 70kDa), typical of tubular proteinuria. Additionally, it was verified that the protein expression levels of the endocytic receptors megalin and cubilin as well as of the chloride channel ClC-5 progressively decreased in the renal cortex of SHR from 6 to 21 weeks of age. Moreover, it was observed reduction of expression of another macromolecule that plays an important role in the process of receptor mediated endocytosis in the renal proximal tubule, the v-H+- ATPase, was reduced. However, reduced cortical expression of the B2 subunit of the v- H+-ATPase, was only statistically significant in 21-wk-old vs. 6-wk-old SHR. Expression levels of structural components of the glomerular barrier such as nephrin and podocin were unchanged. To sum up, our study demonstrates that the increase in urinary protein excretion, especially of albumin, is associated with lower expression of key components of the apical endocytic apparatus in the renal proximal tubule. It is tempting to speculate that dysfunction of the apical endocytic pathway in the renal proximal tubule may be the major mechanism underlying development of microalbuminuria in essential hypertension
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15

Guindon, Kathryn Yvonne. "Evaluating Lethal and Sub-Lethal Effects of Catch-and-Release Angling in Florida's Central Gulf Coast Recreational Atlantic Tarpon (Megalops atlanticus) Fishery." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3134.

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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.
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16

Stein, William III. "Fish and decapod community structure in estuarine habitats of the New Orleans Land Bridge, including a description of the life cycle of tarpon (Megalops atlanticus) in southeastern Louisiana." ScholarWorks@UNO, 2013. http://scholarworks.uno.edu/td/1673.

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Estuarine marshes are generally considered to be productive but not necessarily diverse ecosystems. During 24 consecutive months, I collected 65,000 fishes and decapods comprising over 65 species from the New Orleans Land Bridge, an estuarine salt marsh. My research details the distribution of nekton across five contiguous but geomorphically different regions, which I defined as “Areas”. This factor “Area” was significant in explaining community composition differences in 11 of the 24 months I evaluated. That is, during those 11 months community structure was different among the Areas. Specific “month” was also found to be a significant factor as community structure was found to differ among the months. No consistent abiotic factors were associated with community structure. These observations imply that a different set of factors are associated with community structure at the Area level than at the microhabitat level. Sampling of nekton in shallow estuarine salt marsh habitats was difficult. The cast net is a useful gear type for this type of sampling and can be readily standardized for each operator. Standardization of the area covered by the net allows density of collected nekton to be calculated. Little is known about the life cycle of one important estuarine dependent sport fish, tarpon (Megalops atlanticus), in southeastern Louisiana. This research details the presence of the major life stages of the species in Louisiana and suggests that it is capable of completing its life cycle in State waters. The presence of a spawning capable female and male tarpon is documented.
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17

Erasmus, Christina Petronella. "The concentration of ten metals in the tissues of shark species Squalus megalops and Mustelus mustelus (chondrichthyes) occuring along the Southeastern coast of South Africa." Thesis, University of Port Elizabeth, 2004. http://hdl.handle.net/10948/328.

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The southeastern coast of South Africa is deemed unpolluted and with the exception of a few localized areas, is believed to be pristine. This study aimed to (1) assess the concentration of metals in the water and sharks (Squalus megalops, Mustelus mustelus) from different sites along the southeastern coast, (2) determine the effects that metals have on each other and investigate the accumulation and storage of metals in different shark tissues, (3) determine the effects of length and sex on metal concentration and the presence of metallothioneins in the liver. Metal concentrations in water from seven sites along the southeastern coast revealed concentrations below the detection limit of the extraction method, except for iron at St. Francis Bay which was below the recommended levels as supplied by DWAF. Met al concentrations in S. megalops from the seven sites revealed significantly elevated levels in individuals from Algoa and St. Francis Bay when compared to the other 5 sites. This was observed for all metals except manganese, which had a higher concentration at Cape Agulhas. After comparing the metal levels in muscle tissue (S. megalops) with data from the Department of Health it was concluded that the sharks caught at Algoa and St. Francis Bay were unsuited for human consumption. Liver and vertebral tissues from both S. megalops and M. mustelus were deemed unsuited for human consumption but further research should be conducted especially on vertebral metal concentrations. Comparing the metal concentration in different tissue types of S. megalops and M. mustelus significant difference were observed and attributed to differences in the maturity (thus age) of the two species. Significant differences in the metal concentration of males and females for both the species were observed. A higher number of differences were however observed in M. mustelus than in S. megalops, most probably due to the differences in maturity. Length and weight vs. metal concentration regressions in the males and females of both species revealed more negative than positive trends. This was found to be in accordance with other studies from around the world. Using the life stages of S. megalops, significant differences in the average concentration of metals were observed between the life stages, with embryos usually having the highest concentration. The metal concentration series determined for S. megalops were similar to that which have been reported in the literature in that iron and zinc occupied the highest concentration positions while cadmium, copper and manganese occupied the last three. The spleen usually had the highest metal concentration except for aluminium in skin and arsenic in muscle tissue. Pearson correlation revealed significant negative correlations between cadmium and the mentioned metals suggesting that cadmium replaces essential metals such as manganese, iron and copper as. Negative correlations between essential metals were observed most probably due to the competition for binding positions on ligands. Positive correlations were observed between metals in sp ecific tissue types and may be indicative of synergistic effects, e.g. aluminium may result in the accumulation of other metals such as cadmium. Positive and negative correlations between a specific metal and different tissue types have also been observed and it appears that there are movement of metals between tissue types. Positive correlation for essential metals between yolk and other tissue have been observed, although no correlations for non-essential metals were observed. This could potentially indicate a mechanism that prevents the accumulation of nonessential metals in embryos. Though no metallothioneins were isolated form the liver, the presence of cadmium in other proteins indicate that that cadmium is substituted for essential metals, and as this may result in deleterious physiological effects, further studies should be conducted. In conclusion it can be said that although some of the results were expected there are still quite a few unanswered question and further studies should be conducted.
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18

Zerbi, Alfonso. "Ecologie et biologie des juvéniles de deux groupes de poissons exploités en pêche sportive : le brochet de mer (Centropomus) et le Tarpon (Megalops atlanticus) à Porto Rico." Aix-Marseille 2, 1999. http://www.theses.fr/1999AIX22061.

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L'information disponible sur l'exploitation des brochets de mer et du tarpon a porto rico est limitee, mais pourrait indiquer de faibles niveaux de stocks. Les causes sont de deux natures : 1) ces especes sont soumises a de fortes pressions de peche (commerciale et/ou recreationnelle), et 2) les zones estuariennes servant de nourricerie ont ete profondement perturbees. Des donnees biologiques de base etaient donc necessaires pour correctement evaluer les options de gestion et adopter les strategies appropriees. Dans le chapitre 1, l'importance economique de ces especes et l'etat actuel des ressources a porto rico sont evaluees. Le chapitre 2 presente une synthese des connaissances sur la biologie et l'ecologie de ces deux groupes, en definit les lacunes et justifie les etudes de ce memoire. L'estimation de l'age et de la croissance des juveniles utilisant une technique de marquage-recapture des individus, ainsi que la validation des estimations de l'age par marqueurs fluorescents sont presentees dans le chapitre 3. Ces etudes fournissent des informations sur le recrutement, la saison des pontes, la valeur des habitats et les effets climatiques sur la croissance. Le chapitre 4 est une etude approfondie de la distribution des juveniles et des caracteristiques de l'habitat servant de nourricerie. Dans le chapitre 5, une etude experimentale realisee sur des bassins artificiels vise a etudier l'effet de la profondeur et de la couverture vegetale sur l'installation des populations. Dans le chapitre 6, un modele statistique est defini, identifiant les parametres du milieu les plus a meme de predire la distribution des juveniles, puis valide sur de nouveaux sites d'etude. Enfin, les resultats des differentes etudes sont rassembles dans un dernier chapitre permettant une vue generale de l'etat des ressources et d'etablir des recommandations pour leur gestion.
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19

Ramos, Daniela Maria Justino Alves. "Intraspecific agonistic behaviour during settlement events of a marine invertebrate with a biphasic life cycle." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/16834.

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Mestrado em Ecologia Aplicada<br>Cannibalism is a well-known behaviour among several invertebrate marine species and may play a relevant role in population dynamics and distribution. In this study we tested if this behaviour occurs at key moments of the complex life cycle of a decapod, namely at settlement and early post-metamorphosis. We collected wild megalopae of the brachyuran crab Carcinus maenas at Ria de Aveiro (Portugal) and at laboratory conditions tested the survival of megalopae stocked at different densities and under contrasting conditions of habitat and food availability. We also tested if cannibalism could be observed between megalopae and first, second and third instar juvenile crabs. Our results showed that megalopae only display cannibalism towards conspecifics at the same life stage under high densities scenarios. The occurrence of cannibalism towards megalopae was immediate and more significant with juveniles on the third crab stage (C3) when compared with the first and second juvenile crab stage (C1 and C2). This study allowed to perceived that during high settlement peaks, the performance and survival of megalopae is not affected by possible cannibalistic interactions among other megalopae. However, the structure and number of the adult population may not correspond to the potential settlement of the larvae when conspecifics of previous events, such as juvenile C3 are present in the same place, due to occurrence of cannibalism.<br>O canibalismo é um comportamento intraespecífico observado entre muitas espécies de invertebrados marinhos, introduzindo alterações na dinâmica e distribuição das populações. Neste estudo pretendemos testar se este comportamento pode ser observado durante o assentamento e pós-assentamento de um decápode com um ciclo de vida complexo. Megalopas selvagens do caranguejo braquiúro Carcinus maenas foram recolhidas na Ria de Aveiro (Portugal) e em condições de laboratório, testou-se a sua sobrevivência quando expostas a diferentes densidades, complexidade de habitat e disponibilidade de alimento. Foi também testada a ocorrência de canibalismo dos três primeiros estágios de juvenis para com conspecíficos no estado larvar de megalopa. Os resultados experimentais revelaram que o canibalismo não é comum entre megalopas, sendo apenas influenciado quando estão presentes em grandes densidades. Os juvenis no terceiro estágio de caranguejo (C3) apresentaram comportamentos canibalísticos imediatos e mais significativos quando comparados com os juvenis do primeiro e segundo estágio de caranguejo (C1 e C2). Os resultados apresentados permitiram deste modo perceber que durante elevados picos de assentamento, o desempenho e sobrevivência das megalopas não é afetado por possíveis comportamentos canibalísticos entre estas. No entanto, a estrutura das populações adultas pode não corresponder ao potencial de assentamento das larvas quando coespecíficos de eventos anteriores, como por exemplo, juvenis C3, se encontram presentes no mesmo local, devido à ocorrência de canibalismo.
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20

Webley, James A. C. "The ecology of the mud crab (Scylla serrata): their colonisation of estuaries and role as scavengers in ecosystem processes." Thesis, Griffith University, 2008. http://hdl.handle.net/10072/367091.

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Scylla serrata is a portunid crab which can attain a weight of over 2 kg and a carapace width exceeding 250 mm. It is distributed throughout the Indo-West Pacific extending down the east coast of Africa, and both the east and west coasts of Australia. In Australia it is commonly known as the mud crab because it occurs within muddy, mangrove-lined bays and estuaries. Mud crabs are generalist predators eating most small, slow moving animals which they can catch, but they are also vigorous scavengers. Being scavengers, they are readily caught in baited traps set by commercial and recreational fishers, and are the stock for these popular fisheries. Female crabs spawn offshore and larvae spend a period in the plankton where they develop into postlarvae or megalopae...<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>School of Environment<br>Science, Environment, Engineering and Technology<br>Full Text
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21

Bartilotti, Cátia Alexandra Vieira. "Dinâmica larvar de Pisidia Longicornis (Linnaeus, 1767) na costa ocidental de Portugal continental adjacente à ria de Aveiro." Master's thesis, 2005. http://hdl.handle.net/10400.1/3910.

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Dissertação de mest., Estudos Marinhos e Costeiros, Faculdade de Ciências do Mar e do Ambiente, Univ. do Algarve, 2005<br>Este trabalho pretende descrever os padrões de distribuição horizontal, vertical e temporal dos estádios larvares de Pisidia longicornis e a sua relação com as condições hidrológicas na plataforma continental Portuguesa. Os dados aqui apresentados foram obtidos a partir de uma campanha oceanográfica realizada ao largo da Ria de Aveiro, entre os dias 9-22 de Maio de 2002. Na análise temporal foram também utilizados dados históricos referentes ao período de Outubro de 1986 a Janeiro de 1989. Os resultados permitem concluir que o estádio recém eclodido é transportado da linha de costa até à plataforma continental, conseguindo manter-se durante o seu desenvolvimento entre os 20-25 km da costa, através de migrações verticais favorecidas pela zona de retenção aí existente. As migrações verticais fazem-se pela subida na coluna de água no período nocturno, com ritmos diferentes consoante o estádio de desenvolvimento. O zoé I, sem um ritmo claro de migração vertical, ascende desde os 25 m de profundidade até à camada superficial. O zoé II inicia a sua migração logo após o pôr-do-sol, desde perto do fundo até aos 10-15 m. O megalopa migra verticalmente na coluna de água entre as 0 e as 4h, desde o fundo até à camada de neuston. Espacialmente, comparando com os estádios de zoé, o megalopa encontra-se em maior abundância nas estações mais próximas da costa, evidenciando um transporte efectivo para os locais de assentamento. A evolução mensal de abundâncias larvares ao longo do ano na área em estudo sugere dois picos de emissão larvar (Março- Abril, Julho-Setembro), reflectindo dois picos de abundância do megalopa (Primavera e final do Verão)
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22

Chen, Wen Jou, and 陳溫柔. "Studies on the Taxonomy of the Crab Megalopae collected from Tungkang Coast." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/92474469303464652115.

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碩士<br>國立中山大學<br>海洋生物研究所<br>83<br>From July 1993 to April 1995, crab megalopae were collected from the coast of Tungkang area in south-western part of Taiwan, which included three different kinds of ecological environment : the mouth of Dahperng Bay, the coast of Nanpin and the mouth of the Linpien River. After megalopae were collected, the were sort -ed and reared individually in laboratory until they grew big en -ough to be identified. In this thesis, totally, 2 subsections,6 families, 17 genera and 22 species of crab megalopae were identi -fied and described. Among these, there are 13 genus 17 species crab megalopae were recorded for the first time in Taiwan and 12 genera14 species in the world. The morphological characteristics of these 22 species crab megalopae are described in detail with text and figures. In addition, the main characteristics and keys for each family and genus are included. Among these 22 species, 20 were identified to species, 2 to genus. The crab form of the latter 2 species ~u2;Libystes~u1; sp., and ~u2;Ebalia~u1; sp. u2;Eba~u1; -~u2;lia~u1; (Leach, 1817) are recorded for the first time in
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Shu-Chen, Huang, and 黃淑珍. "Taxonomic studies of crab’s megalopae from Hsiang-Shan wetland--- mtDNA COI sequence as identification tool." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/09899711876966707357.

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碩士<br>國立新竹教育大學<br>人資處應用科學系教學碩士班<br>94<br>From March 2004 to September 2005, adult crabs and their megalopae were collected from the Hsiang-Shan wetland. I use mtDNA COI sequence as genetic marker to identify different species of megalopae. According to the sequence alignment, I have 22 species of megalopae belong to 6 families. There are 1) Portunidae:Portunus pelagicus, Charybdis annulata, Thalamita spinimana; 2) Xanthidae:Leptodius sanguineus; 3) Mictyridae:Mictyris brevidactylus; 4) Ocypodidae:Ocypode stimpsoni, Uca arcuata, Uca vocans borealis, Uca lactea lactea, Scopimera longidactyla, Scopimera bitympana, Macrophthalmus banzai; 5) Grapsidae: Metopograpsus thukuhar, Gaetice depressus, Helice formosensis, Helice subquadrata, Metaplax elegans, Parasesarma plicatum, Parasesarma pictum, Perisesarma bidens, Chiromantes haematocheir; 6) Gecarcinidae:Discoplax hirtipes. For the 22 species of megaplopae, I established a diagnostic key for each species and detail illustrations of morphological characters were given. In addition, after my studies the crab records of Hsiang-Shan wetland are 54 species, Ozius rugulosus, Eriphia sebana, Pinnotheres sinensis, Pinnotheres haiyangensis, and Helice subquadrata are new records. For the crab fauna of 54 species, I established mtDNA COI nucleotide sequences of 41 species belong to 10 families. For the megalopae identification by mtDNA sequence, excluded 22 knowing species, 16 species were unidentified due to lack of adult sequence comparison. More crabs collects in the future will get more mtDNA sequence data, and more megalopae will be identified.
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Chen, Hui-Lun, and 陳慧倫. "Changes in otolith microstructure and microchemistry of Pacific tarpon (Megalops cyprinoides) during the metamorphic stage." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/41291325047812216657.

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碩士<br>國立臺灣大學<br>動物學研究所<br>92<br>The development of Elopomorpha in early stage is characterized by a metamorphosis process from leptocephalus to juvenile. The previous study indicated that the deposition rhythm of the daily growth increments(DGIs)in otoliths of the fishes will be diffusive during metamorphosis. The present study is to use Pacific tarpon (Megalops cyprinoides) as a model animal to validate if DGIs is deposited normally during metamorphosis and their otolith microstructure and microchemistry are also examined. Leptocephali of Pacific tarpon at their Stage I (TL range 25.43 mm~31.26 mm) were collected from Gongshytyan Creek, a tributary to the Tanshui estuary between June and August 2003. The leptocephalus were immersed in a tetracycline (TC) solution with a concentration of 350μg ml-1 to produce a fluorescent TC mark in the otoliths as the onset of the experiment. They were then reared under a constant condition of 25oC, 15psu and light cycle of 10D/14L for 16 days to investigate the ontogenetic somatic and otolith changes during metamorphosis. The results showed that total length of the leptocephali dramatically decreased during the 1st to the 4th day of experiment in the Stage II. In the Stage III(6st ~10th days) the total length of the leptocephali stayed unchanged, the fish body is not transparent any more, organs and systems grew continuously. The juvenile restarted to increase (TL range average 25.66 mm~27.91 mm) after the 10th day. Otoliths remained steadily growing during metamorphoses, the number of otolith DGIs deposited after TC marks as consistant with the rearing days(p<0.01) which validate the daily periodicity of the otolith increment deposition of Pacific tarpon leptocephali during metamorphoses. As for otolith microchemistry, Sr/Ca ratios in otolith of the fish decreased in accompany with metamorphosis, while Na/Ca ratios in otolith changed oppositely as Sr/Ca ratio. Additionally, the effect of salinity and feeding condition on the deposition of DGIs during metamorphosis were also examined, in which the leptocephali were reared in two different salinities (10psu、35psu) and two different feeding condition of feed (+) and starvation (-) for 18 days using a Two-Way ANOVA experimental design. As a result, the ontogenetic changes and the formation of daily growth increments in otolith of Pacific tarpon leptocephali were neither affected by salinity nor starvation during metamorphosis. The Sr/Ca ratios in otoliths were also decreased rapidly at this process. The otolith growth rates were not affected by salinity but significantly affected by the feeding conditions. It also showed that the daily deposition rate of otolith was not changed by either salinity or starvation; here findings are discrepant with previous study.
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Yang, Chun-Sung, and 楊竣菘. "Relationships between water chemistry and otolith elemental concentrations of Pacific tarpon (Megalops cyprinoides) during metamorphosis." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/08065149751787876491.

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碩士<br>國立臺灣大學<br>漁業科學研究所<br>95<br>The Pacific tarpon Megalops cyprinoides are similar with Anguilliformes which has a willow-leaf-shaped larva called leptocephalus. Previous research indicated a drastic ontogenetic change in behavior, habitat, body shape, and recombination of tissue during metamorphosing from leptocephalus to juvenile stages. A maximum otolith increment width (OIW) and sharp decreasing in otolith Sr/Ca ratios resulting from glycosaminoglycan (GAGs) broken–down were observed during metamorphosis. In addition to such physiological factor, otolith microchemistry was affected mostly by ambient concentration rather than salinity and temperature. In order to compare with the affected degree of physiological factors and water chemistry during metamorphosis, we designed a controlled experiment with adding strontium (Sr) and barium (Ba) in rearing water to discuss the relationships between otolith chemistry and life stages in Pacific tarpon. Leptocephali (entering StageⅡ) were collected in the estuary of Gong-shy-tyan Creek, a tributary of the Tanshui river in August to September 2005. After acclimating 1 day, the leptocephali were immersed in a tetracycline solution to mark the otoliths with a fluorescent band as the onset of the experiment (Day 1) and then reared in the treatments spiked with different concentrations (2×、4×、8×) of Sr and Ba. According to the changes of otolith daily growth increments (DGIs), the leptocephalus completed metamorphosis is approximately 14d during rearing conditions. The results of Sr:Ca and Ba:Ca ratios in the rearing water were measured to be 1×、5.3×、13.4×、29.0× and 1.00×、0.99×、1.15×、1.53× respectively after spiking of Sr and Ba. The Sr:Ca ratios of the otoliths were analysed with EPMA and the period of metamorphosis (M-zone) increased times in:1.0×、2.5×、7.4×、16.0× and juvenile (J-zone) in:1.0×、6.5×、20.0×、47.1×, and the phenomenon of Sr:Ca ratios rapid decreasing only presented in control treatment (Sr1×). Other Ba:Ca ratios in the otoliths were analysed with LA-ICPMS and the concentration ratios at M-zone were: 1.00×、1.19×、1.15×、1.16× and J-zone: 1.00×、1.37×、1.60×、1.81×. Although Ba:Ca ratios has less magnification effects than Sr:Ca in the otoliths, both of them reflected the relationships of non-equal times of the element spiked in rearing water. Whether in metamorphasis or juvenile stages, the Sr:Ca ratios in the otoliths were highly related to water chemistry (r=0.99) which indicated that otolith Sr:Ca ratios were mostly influenced by ambient elemental concentrations. Besides, the relationships only appeared within juvenile (r=0.70) in Ba treatments. Sr and Ba belong to alkali metals, but mean partition coefficients DMe in Sr:Ca ratios are around 20 times more than Ba:Ca ratios. In this study the great discovery is the effects of water chemistry are more important than physical factor in metamorphosis, and selective absorption rate from ambient element to otoliths is also existed especially in different life stages.
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"Microhabitat and Movement Assessment for Northern Mexican Gartersnakes (Thamnophis eques megalops) at Bubbling Ponds Hatchery, Arizona." Master's thesis, 2017. http://hdl.handle.net/2286/R.I.43967.

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abstract: Species conservation requires an understanding of the habitats on which that species depends as well as how it moves within and among those habitats. Knowledge of these spatial and temporal patterns is vital for effective management and research study design. Bubbling Ponds Hatchery in Cornville, Arizona, supports a robust population of the northern Mexican gartersnake (Thamnophis eques megalops), which was listed as threatened under the Endangered Species Act in 2014. Natural resource managers are interested in understanding the ecology of gartersnakes at this site to guide hatchery operations and to serve as a model for habitat creation and restoration. My objectives were to identify habitat selection and activity patterns of northern Mexican gartersnakes at the hatchery and how frequency of monitoring affects study results. I deployed transmitters on 42 individual gartersnakes and documented macro- and microhabitat selection, daily and seasonal activity patterns, and movement distances. Habitat selection and movements were similar between males and females and varied seasonally. During the active season (March–October), snakes primarily selected wetland edge habitat with abundant cover and were more active and moved longer distances than during other parts of the year. Gestating females selected similar locations but with less dense cover. During the inactive season (November–February), snakes were less mobile and selected upland habitats, including rocky slopes with abundant vegetation. Snakes displayed diurnal patterns of activity. Estimates of daily distance traveled decreased with less-frequent monitoring; a sampling interval of once every 24 hours yielded only 53–62% of known daily distances moved during the active season. These results can help inform management activities and research design. Conservation of this species should incorporate a landscape-level approach that includes abundant wetland edge habitat with connected upland areas. Resource managers and researchers should carefully assess timing and frequency of activities in order to meet project objectives.<br>Dissertation/Thesis<br>Masters Thesis Applied Biological Sciences 2017
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YUAN, SHI-LI, and 袁世禮. "Reproductive biology of Megalomma sp. (Polychaeta: Sabellidae) in Hsiao-Lin Chiu." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/22422182024311548646.

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Braccini, Juan Matias. "Assessment of ecological risks from effects of fishing to Piked Spurdog ( Squalus megalops ) in South - Eastern Australia." 2006. http://hdl.handle.net/2440/37791.

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Target species in some Australian shark fisheries are adequately managed, but there has been little attention given to non - target shark species and there is limited information on the biology of their local populations. Among this group of non-target species, the piked spurdog - Squalus megalops ) is of special interest because it is a dominant and ecologically important species with high natural abundance. Hence, the main purpose of the present research was to improve knowledge of the basic biology of this species and to provide essential data for its management, sustainable use and conservation. Squalus megalops had a complex population structure, segregating by sex, size and breeding condition. The sex ratio was biased towards females and there was sexual size dimorphism with females attaining a larger maximum size than males. Conversion factors from partial lengths to total length and from partial masses to total mass were determined due to the common commercial fishing practice of eviscerating, beheading and finning sharks. Comparisons of total and partial length - length and mass - length relationships between males and females using different ranges of size showed that there was no effect of size range on measurements reflecting only somatic growth ( fork and carcass lengths ; carcass, pectoral fin and caudal fin masses ). However, for variables reflecting somatic and reproductive growth ( total and liver masses ), different outcomes can be expected when different ranges of size are compared. Examination of dietary composition revealed that S. megalops is an opportunistic predator that consumes a wide range of prey items. High variability was found when overall importance of prey items was estimated. Dietary composition varied in space and time, exhibiting differences among regions, seasons and size classes. Therefore, the intrinsic natural variability in the dietary composition of S. megalops and its spatial and temporal variation in diet suggest that information on the ecological relationships among species is likely to be missed when predator - prey interactions are only inferred from overall diet. Reproductive parameters were determined for population assessment. For both sexes, length - at - maturity differed depending on the criterion adopted for defining maturity. Mature males are capable of mating throughout the year. Females have a continuous asynchronous reproductive cycle. The sex ratio of embryos is 1 : 1 and litter size and nearterm embryo size increase with maternal length. Females have an ovarian cycle and gestation period of two years. Although all females are mature at 600 mm, only 50 % of them are in maternal condition, contributing to annual recruitment each year. Hence, for chondrichthyan species with reproductive cycles of two, three or more years, if maturity ogives are used in population assessments instead of maternity ogives, the models will over - estimate recruitment rates. Age and growth information was also determined for population assessment. Precision estimates, the relationship between spine total length and body length, edge analysis, and agreement between counts on the inner dentine layer and the enameled surface support the use of the first dorsal fin spine for the age estimation of S. megalops. Based on goodness - of - fit criterion, the best growth model for males and females was a two - phase von Bertalanffy function. However, model selection cannot be based on quality of statistical fit only and results should be interpreted with caution. Regardless of the model used, the growth rate of S. megalops, particularly of females, is very low, even within the range of growth rates reported for shark species. A three - levelled hierarchical risk assessment approach was trialed to evaluate the suitability of the approach for S. megalops. Integration of qualitative, semi - quantitative, and quantitative biological and fishing impact data showed that S. megalops is potentially highly susceptible to the effects of fishing. A qualitative assessment indicated that the only fishing related activities to have moderate or high impact on S. megalops were those associated with ' capture fishing ' of the otter trawl, Danish seine, gillnet and automatic longline methods. A semi - quantitative assessment ranked S. megalops at risk because of its low biological productivity and, possibly, its catch susceptibility from cumulative effects across the separate fishing methods. Finally, a quantitative assessment showed that population growth is slow even under the assumption of density - dependent compensation where the fishing mortality rate equals the natural mortality rate. Therefore, conservation and management for sustainable use of S. megalops will require a close control of fishing mortality due to the low capacity of this species to withstand fishing pressure.<br>Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2006.
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Braccini, Juan Matías. "Assessment of ecological risks from effects of fishing to Piked Spurdog (Squalus megalops) in South-Eastern Australia." 2006. http://thesis.library.adelaide.edu.au/public/adt-SUA20060519.153928.

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Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, Discipline of Environmental Biology, 2006.<br>"January 2006" Bibliography: pages 188-209. Also available in print form.
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Biani, Natalia Beatriz. "Alliances and struggles in the miniature ecosystem of a socially flexible bee." 2009. http://hdl.handle.net/2152/6528.

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Cooperation is pervasive in nature but paradoxically also provides opportunity to cheaters. My dissertation involves the study of both cooperation and conflict in two species of Megalopta bees. Megalopta is a Neotropical genus of halictid bees whose biology is characterized by complex life cycles that can range from solitary to eusocial. These bees nest in dead wood and forage under dim light conditions. Megalopta’s nests are inhabited by an extensive array of organisms and each nest therefore constitutes a miniature ecosystem providing opportunities for cooperation and conflict, both within and between species. I first delineate the social structure of M. genalis and M. ecuadoria nests in several Panamanian populations and integrate the factors that play a role in the behavioral decisions of females when joining a social group or not. Within a kin-selection framework, I discuss how genetic relatedness plays a role in the formation of social nests. Second, I investigate the conflict between host bees and a congener social parasite, and I elucidate reproductive structures that are relevant for understanding the evolution of parasitism. Finally, I describe a cleaning mutualism between Megalopta bees and their mite associates. Bee-mite associations encompass a broad spectrum of interspecific interactions. Some bee-mites are thought to perform cleaning services for their hosts in exchange for suitable environments for reproduction and dispersal. Field observations and experimental manipulation reveal a significant correlation between the presence of mites and the absence of fungi inside the brood cells, as well as between the absence of mites and increased bee mortality. This study therefore provides evidence of the sanitary effect of mites in nests of Megalopta bees. This bee-mite association constitutes one of the few examples of terrestrial cleaning mutualisms.<br>text
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Bittler, Kimberly Marie. "The ecology of blue crab (Callinectes sapidus) megalopae in the Mission-Aransas Estuary, Texas : salinity, settlement, and transport." Thesis, 2013. http://hdl.handle.net/2152/23638.

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Blue crabs are a widely distributed estuarine species with broad economic and ecological importance. Several studies have linked blue crabs to freshwater inflows, but the precise nature of this link is still uncertain, as blue crabs have a complex life cycle that utilizes both marine and estuarine environments. One potential link between blue crabs and freshwater inflows is during recruitment, when megalopae developing offshore return to estuaries before molting into juvenile crabs. Megalopae swim during the flood tide to ensure delivery into and farther up estuaries. The behaviors regulating selective tidal stream transport (STST) on the flood tide were originally studied in North Carolina in an estuary with regular freshwater inflows and a strong salinity gradient. The model of STST was re-examined in the Mission-Aransas, an estuary with episodic freshwater inflows and salinity gradients ranging from normal estuarine conditions to hypersaline during droughts. The behavioral responses of megalopae to a range of rates of salinity increase were tested, and then modeled onto rates of salinity change observed in the field to determine the theoretical ecological consequences of STST for blue crab populations in the Mission-Aransas Estuary. To validate the ecological trends predicted by the behavioral model of STST, a simple, long-term data set reflecting changes in megalopae abundance is needed. Hog’s hair collectors are a simple and widely used method of quantifying abundance of brachyuran megalopae, including blue crabs. However, the efficiency of hog’s hair collectors in sampling for megalopae is unknown. Several studies have reported poor correlations between settlement on hog’s hair collectors, transport, and abundance of megalopae in the plankton due to disparate temporal scales and potentially turbulence-driven decoupling. Each of these issues were addressed in field and flume experiments, which were used to develop a model for interpreting settlement on hog’s hair collectors in terms of transport and planktonic abundance.<br>text
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Waap, Silke. "Padrões temporais de fornecimento de Megalopas de Carcinus Maenas na Ria de Aveiro: influência dos ventos e das marés." Master's thesis, 2007. http://hdl.handle.net/10400.1/579.

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Dissertação mest., Biologia marinha - Ecologia e conservação marinha, Universidade do Algarve, 2007<br>Muitos invertebrados marinhos apresentam uma fase planctónica com desenvolvimento larvar no mar, capaz de grande dispersão. Para concluírem o ciclo de vida dependem de correntes favoráveis à migração de regresso das larvas aos locais de maternidade. Este estudo pretendeu investigar os processos envolvidos no transporte de megalopas de Carcinus maenas para a Ria de Aveiro, ao analisar a influência dos ventos que sopram paralelamente à costa (ventos N-S) e das marés na variabilidade intra-anual de fornecimento destas larvas. Para análise, obtiveram-se dados diários entre Março e Junho (2006) de: amplitude de maré (DTR), nível subtidal do mar (SSL), ventos NCEP e abundância de megalopas no Canal de Mira, recolhidas a partir de duas redes de plâncton, à superfície e no fundo da coluna de água. As variações de SSL e predominância dos ventos Norte foram consistentes com a presença de afloramento costeiro na costa noroeste portuguesa. A intensidade de ventos NS apresentou uma correlação positiva com SSL para atrasos de -1 e 0 dias, indicando a presença de uma resposta rápida de divergência e convergência costeira da camada de Ekman. O fornecimento de megalopas apresentou um padrão com pulsos distintos a ocorrerem em períodos quinzenais de marés vivas. As magnitudes de fornecimento estiveram positivamente associadas ao relaxamento e reversão dos ventos Norte, indicando que as larvas foram transportadas em direcção à costa durante convergência costeira da camada de Ekman. O atraso na resposta entre o fornecimento e o forçamento do vento foi de -1 dias. Este encontra-se em conformidade com a possibilidade das larvas ficarem retidas na plataforma continental interior, pela presença de um padrão de migração nictemeral (DVM) durante a circulação de afloramento costeiro. À entrada da Ria, as megalopas parecem ter utilizado o transporte selectivo pelas correntes de maré (STST) para promover a imigração para dentro do estuário.
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Gomes, Joana dos Santos Peixoto. "Expression of megalin in the central nervous system." Master's thesis, 2017. http://hdl.handle.net/1822/54834.

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Dissertação de mestrado em Bioquímica Aplicada<br>The incidence of neurodegenerative diseases is increasing today, so there is an increasing interest and need to better understand the mechanisms involved. Transthyretin (TTR) is a protein that has several physiological functions, being highly involved in the homeostasis of the nervous system. Changes in TTR expression levels are associated with several neurodegenerative pathologies. In addition, TTR plays a crucial role in the preservation and survival of neurons since its internalization through the action of megalin, activates several signalling mechanisms. Megalin has been extensively studied over the years; changes in the levels of this protein are also associated with neurodegenerative pathologies, thus functioning as a biomarker. Furthermore, TTR is regulated by heat shock factor 1 (HSF-1). HSF-1 acts in response to thermal shock, as well as to environmental stress (including ROS presence) and in pathological conditions such as protein misfolding, thus being associated with neuronal stress conditions. Thus, one of the aims of this work was to produce an antibody specific for soluble non membranar megalin and to characterize it so that one could quantify the levels of megalin in mice samples. The anti-megalin antibody was characterized by immunohistochemistry (IHC), by enzymelinked immunosorbent assays (ELISA) and Western blot; it was used to study megalin expression in the brain of wild-type (WT), TTR-knockout (TTR-KO) and HSF-1-deficient mice (with and without TTR), with and without an oxidative diet. The results show that megalin is expressed in the brain, especially in the retrosplenial area of the cortex. Additionally, WT animals present higher levels of megalin in this region than other stains, namely TTR-KOs and HSF-1-deficients. Furthermore, untreated animals presented higher levels of megalin expression in comparison to treated animals. The results suggest that i) the oxidative diet has an impact on the expression of megalin and ii) TTR influences the expression of megalin. The implication of megalin expression and its modulation in the retrosplenial area of the cortex deserves further investigation.<br>A incidência das doenças neurodegenerativas é cada vez mais elevada nos dias de hoje, pelo que cada vez é maior o interesse e a necessidade de se compreender melhor os mecanismos envolventes. A transtirretina (TTR) é uma proteína que apresenta diversas funções fisiológicas, estando altamente envolvida na homeostasia do sistema nervoso. Alterações nos níveis de expressão de TTR estão associadas a diversas patologias neurodegenerativas. Além disso, a TTR desempenha um papel crucial na preservação e sobrevivência dos neurônios uma vez que a sua internalização pela ação da megalina, ativa mecanismos de sinalização. A megalina tem sido um alvo de estudo uma vez que alterações nos níveis desta estão também associadas a patologias neurodegenerativas, funcionando por isso como um biomarcador. A TTR é também regulada pelo fator de transcrição de choque térmico 1 (HSF-1). HSF-1 para além de atuar na resposta ao choque térmico, atua como resposta ao stress (como na presença de espécies reativas de oxigénio) e em condições patológicas como no mau-enrolamento de proteínas, estando associado a condições de stress neuronal. Desta forma, um dos objetivos deste trabalho foi produzir um anticorpo específico para a megalina solúvel e caraterizá-lo para que com ele se pudesse analisar os níveis de megalina em amostras de ratinho. A caraterização do anticorpo foi feita por estudos de imunohistoquímica, por ensaios de imunoabsorção enzimática e Western blot. A expressão da megalina foi estuda em grupos de animais com TTR (WT), sem TTR (TTR-KO) e animais com ausência de HSF-1 (com e sem TTR), na presença e ausência de uma dieta oxidativa. Os resultados obtidos mostram que a megalina é expressa no cérebro nomeadamente na área retrosplenial do córtex. Além disso, verificou-se que os animais WT apresentam níveis mais altos de megalina nesta zona do córtex do que as outras estirpes, nomeadamente em animais com ausência de TTR e com falta de HSF-1 (quer com e sem TTR). Verificou-se também que os animais sujeitos à dieta apresentam menor expressão de megalina que os animais sem sujeitos à dieta. Os resultados sugerem que: i) a dieta oxidativa tem impacto na expressão de megalina e ii) a TTR influencia a expressão de megalina. Estudos sobre a interferência da expressão de megalina e a sua modulação na área retrosplenial do córtex devem ser desenvolvidos.
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Liebenberg, Andre Sarel. "An evaluation of the impact of the Non-ferrous Metals Crime Combating Committee on copper cable theft." Thesis, 2020. http://hdl.handle.net/10500/27467.

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English, Zulu and Northern Sotho summaries<br>This study aims to evaluate the Non-Ferrous Metals Crime Combating Committee's impact on combating copper cable theft in South Africa. Data was collected via in-depth interviews with awaiting trial detainees charged with copper cable theft at the Pollsmoor Correctional Centre in the Western Cape; members of the Mpumalanga and Gauteng Provincial Non-Ferrous Metals Crime Combating Committee; members of Business Against Crime South Africa; and investigators attached to Combined Private Investigations who investigate copper theft nationally. The in-depth interviews provided a comprehensive understanding of participant experiences relating to the impact of the Non-Ferrous Metals Crime Combating Committee on the combating of copper cable theft in South Africa. Moreover, the researcher performed a thorough literature study of the phenomenon locally and internationally. Research findings indicate shortcomings in the Non-Ferrous Metals Crime Combating Committee's effectiveness, limiting its impact on preventing copper cable theft. Based on these findings, the study recommends that the Non-Ferrous Metals Crime Combating Committee be replaced with a specialised South African Police Service Non-Ferrous Metals Theft Unit. Consequently, this study puts forward a set of recommendations proposing a systematic pro-active plan to address and minimise copper cable theft in South Africa. The proposed plan convincingly presents practical solutions to minimise copper cable theft and contributes to the current body of scholarship on copper cable theft in South Africa.<br>Inhloso yalolu cwaningo ukuhlola umthelela wohlelo lwe-Non-Ferrous Metals Crime Combating Committee mayelana nokuqedwa kokutshontshwa kwentambo yogesi (copper cable). Idatha iqoqwe ngokusebenzisa izinhlolovo ezijulile ezenziwa ngokusebenzisa iziboshwa eziboshelwe izintambo zikagesi ezisamele ukugwetshwa ejele lase Pollsmoor Correctional Centre ngaseNtshonalanga Kapa, amalunga eMpumalanga and Gauteng Provincial Non-Ferrous Metals Crime Combating Committee, amalunga eBusiness Against Crime South Africa kanye nabaphenyi abahambisana nophiko lweCombined Private Investigations oluphenya ukutshontshwa kwezintambo zikagesi ezweni lonke. Lezi zinhlolovo ezijulile zinikeze ulwazi olubanzi lwabadlalindima olumayelana nomthelela weNon-Ferrous Metals Crime Combating Committee mayelana nokuqedwa kokutshontshwa kwezintambo zikagesi. Ngaphezu kwalokho, umcwaningi wenze ucwaningo olunzulu lombhalo wobuciko mayelana nokutshontshwa kwezintambo zikagesi lapha ekhaya kanye nasemhlabeni wonke jikelele. Ulwazi olutholakele lukhombisa iziqi ezikhinyabeza ukusebenza kahle kweKomithi mayelana nokuvimbela umthelela walo mayelana nokutshontshwa kwezintambo zikagesi. Ngezizathu ezisuselwa phezu kwalolu lwazi, lolu cwaningo lubeka phambili isethi lezincomo ezinganceda iKomiti ekuqiniseni umthintela walo ngokuhlongoza uhlelo olugqugquzelayo lokunciphisa izinga lokutshontshwa kwezintambo zikagesi eNingizimu Afrika. Lolu hlelo oluhlongoziwe ngaphandle kokungabaza lwethula izixazululo ezenzeka empilweni yangempela ukunciphisa ukwetshiwa kwezintambo zikagesi kanti lokhu kunegalelo kwiziko lamanje futhi luqhubekisa iziko lamanje lwezifundo esimayelana nokwetshiwa kwezintambo zikagesi.<br>Maikemisetso a thutelo ye ke go lekola khuetso ya Komiti ya Twantsho ya Bosenyi bja Dimetale tse di Sego tsa Tshipi ka ga go lwantsha kutso ya megala ya koporo. Datha e kgobokeditswe ka mokgwa wa ditherisano tse di tseneletsego tseo di sepeditswego le mahodu a megala ya koporo ao a golegilwego ao a letetsego go sekiswa Senthareng ya Tshokollo ya Pollsmoor go la Kapa Bodikela, maloko a Diprofense tsa Mpumalanga le Gauteng a Komiti ya Twantsho ya Bosenyi bja Dimetale tse di sego tsa Tshipi, maloko a Dikgwebo tsa Kgahlanong le Bosenyi tsa Afrika Borwa le banyakisisi bao ba dirisanago le Dinyakisiso tsa Praebete tse Kopantswego tseo di nyakisisago kutso ya koporo kemong ya bosetshaba. Ditherisano tse di tseneletsego tse di file kwesiso ka botlalo ya maitemogelo a batseakarolo ye e sepelelanago le khuetso ya Komiti ya Twantsho ya Bosenyi bja Dimetale tse di sego tsa Tshipi ka ga go lwantsha kutso ya megala ya koporo. Gape, monyakisisi o dirile thutelo ya dingwalo ka botebo ya kutso ya megala ya koporo tikologong ya leagong le kemong ya boditshabatshaba. Dikhwetso tsa dinyakisiso di supa mafokodi ao a lebanego bokgoni bja Komiti tshitisong ya khuetso ya yona go kutso ya megala ya koporo. Go ya ka dikhwetso tse, thutelo ye e hlagisa sehlopha sa dikeletso tseo di ka thusago Komiti go tswetsa khuetso ya yona pele ka go sisinya leano la go itokisetsa seemo se ka diregago ka mokgwa wo o beakantswego go fokotsa kutso ya megala ya koporo ka Afrika Borwa. Leano leo le sisintswego le hlagisa ka mo go kgodisago ditharollo tse di ka phethagatswago go fokotsa kutso ya megala ya koporo ka gona la ba la seabe go le go tswetsa pele popego ya bjale ya borutegi ka ga kutso ya megala ya koporo.<br>Criminology and Security Science<br>Ph. D. (Criminal Justice)
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