Dissertations / Theses on the topic 'Production/Reproduction'

Thesis (Ph.D.)--Kent State University, 2009.
Title from OhioLINK ETD abstract webpage (viewed March 12, 2010). Advisor: Christina Haas. Keywords: Scientific writing; rhetoric of science; writing in the disciplines; multimodality; semiotics; visual rhetoric; technical writing; ethnography; workplace literacy. Includes bibliographical references.

This thesis investigates how discourses of mathematical-ability are produced and reproduced by pupils and teachers in the primary classroom and the impacts of these on teaching and learning. Building on a literature base suggesting the often negative and self-fulfilling outcomes of ability labelling and grouping, the thesis embeds this literature strongly in primary mathematics, exploring why these practices not only continue, but form the basis of much Government and school organisational policy. -- Utilising a critical realist meta-theory, the thesis draws pragmatically from multiple traditions. Data were collected from approximately 300 pupils and 14 teachers in two primary schools. Individual and group-interviews and classroom observations explored pupils’ and teachers’ productions of their own and others’ mathematical-ability, with pupil questionnaires and attainment tests used to examine the extent to which these impact on pupil attainment and learning in mathematics. -- The thesis finds that discourses of ability are pervasive, embedded in all aspects of teaching and learning in primary mathematics, and resistant to change. Pupils and teachers are fairly consistent in their understanding of mathematical-ability; this is thought of as a stable, innate quality connected to intelligence and genetics or else conceptualised in terms of, and muddled with, assessment outcomes. Assessment, labelling and inequitable ability practices create pupils from an early age as mathematically able or not, whilst setting places the focus on the mathematics, effectively ignoring the whole-child, raising many of the concerns about setting in secondary mathematics in a primary context. Many teachers recognise the inequity in the practices they engage in, yet reproduce the inequitable practices they experienced.

Le cycle reproducteur de Megathura crenulata a été documenté et la quantification des réserves ovocytaires par des colorants lipospécifiques a été tentée, sans résultats concluants pour cette espèce, ni pour Crassostrea gigas. L'intérêt d'une alimentation des géniteurs femelles C. Gigas au printemps est re-évaluée, car la performance ultérieure des élevages larvaires et post-larvaires n'a pas été affectée par le jeûne imposé lors du conditionnement. L'étude du développement des organes impliqués dans le traitement des particules chez C. Gigas a permis d'identifier des stades critiques associés à l'ontogenèse de chaque organe, ainsi qu'une meilleure compréhension de l'évolution de ces organes si particuliers chez les Ostreidae. L'examen des types ciliaires et la cartographie des mucocytes de la post-larve à l'adulte ont montré que la spécialisation hétérorhabdite précède même la formation anatomique des plis branchiaux caractéristiques de cette condition
The reproductive cycle of Megathura crenulata was documented and quantification of oocyte lipid reserves with lipo-specific stains was explored in both this species and in Crassostrea gigas. The necessity of providing food to female broodstock C. Gigas in spring was re-evaluated, because subsequent larval and post-larval rearing performance was not affected by broodstock starvation during conditioning. Developmental study of the organs responsible of particle processing in C. Gigas allowed the identification of critical stages related to the ontogenesis of each organ, as well as a better understanding of the evolution of these organs,highly-modified in the Ostreidae. Ciliary type identification and mucocyte mapping from post-larval to adult stage showed that the heterorhabdic specialization precedes the anatomic formation of gill plicae specific to this condition

Thesis (Ph. D.)--University of Oregon, 2006.
Typescript. Includes vita and abstract. Includes bibliographical references (leaves 280-290). Also available for download via the World Wide Web; free to University of Oregon users.

Si la formation du conducteur a connu ses débuts en même temps que la naissance de l'automobile, l'éducation routière en tant que phénomène social s'est développée à partir de la deuxième moitié du XXème siècle. Depuis cette période, les évaluations de ces actions de formation ont pointé les difficultés à réduire le nombre et la gravité des accidents de la circulation. Ce constat n'est pas faute d'investissement des pouvoirs publics : en effet, les politiques de sécurité routière n'ont cessé, jusqu'à aujourd'hui, de placer l'éducation routière au centre du dispositif de prévention. Nous avons cherché à identifier la naissance et la persistance de ce paradoxe dans la pratique des acteurs de la sécurité routière, et dans la production et la reproduction d'une culture commune du risque propre à la modernité. Nous avons exercé cette investigation à partir de l'observation et de l'analyse des pratiques d'éducation routière auxquelles nous avons accès à titre d'intervenant en formation du conducteur, d'enseignant de la conduite et de psychologue intervenant en stage de sensibilisation dans le cadre du permis à points. Notre recherche est structurée, par conséquent, autour d'un travail de terrain par immersion dans les centres de formation, alimentée par des lectures en philosophie des techniques (Illich, Canguilhem, Simondon, Stiegler) et en sociologie du risque (Beck, Douglas, Duclos) mises en perspectives avec la théorie psychosociologique de l'homéostasie du risque (Wilde).

Cette recherche porte sur les Raika, éleveurs de moutons et de dromadaires dans la région aride de l'Inde (Rajasthan). Ce travail vise à montrer comment l'organisation de la production pastorale influe sur l'organisation sociale des sociétés pastorales, comment elle contribue à la continuité de la culture pastorale, mais aussi comment elle provoque une marginalisation économique et sociale croissante. Dans une première partie, je présente la caste des Raika dans la société indienne. La partie suivante est consacrée à la pratique sédentaire du mode de la production pastorale avant d'aborder en troisième partie la pratique nomade dans son organisation sociale et économique. La dernière partie est consacrée aux changements qui apparaissent dans la caste du fait de l'urbanisation d'une partie de la caste, au travers de l'institution du mariage et des relations sociales qui unissent les pasteurs et urbains Raika
This research is about the Raika, sheeps and camels herders in the arid zone in India (Rajasthan). This work aims to show how the organization of pastoral production influences the social organization of the pastoral societies, how it contributes to the pastoral culture continuity, but also how it causes an increasing economic and social marginalisation. In a first part, I introduce the caste of Raika in the Indian society. The following part is devoted to the sedentary practice of the pastoral production before approaching in third part the nomadic practice in the social and economic organization. The last part is concentrated to the changes which appear in the caste because of urbanization of a part of the caste, through the institution of the marriage and the social relations between pastors and urban Raika

Aim of this thesis is to explain the role of property relations in the production of urban form. It is assumed that urban form is produced not only as a physical setting but also as a concrete and relatively fixed manifestation of property relations. In this respect, urban form should be considered in a relational conception of space. The study departs from the proposition that property relations are the main determinants of the formation of urban space, and private property constitutes the generator of the dynamics and contradictions of urban formation, through a continuous process of fragmentation. For this reason, in the control of urban formation, property rights are the basic element that city planners have to face. Therefore, this study presents a comprehensive framework that integrates the categories of urban morphology with a structural analysis of urban formation process. As the essential unit of capitalist city, &ldquo
production of the parcel as a commodity&rdquo
is elaborated as the core of urban formation process. In this framework, morphogenesis of Yenisehir&ndash
Ankara is analyzed in order to understand its historical transformation with reference to the context of property relations. Its morphological layers are depicted as a product of the contradictory relation between urban planning and property relations. It is seen that the morphogenesis of Yenisehir includes three distinct layers of formation, which are characterized by the gradual domination of commodity production in the formation process of urban space.

In this thesis I examine the reproductive strategies of the bed bug Cimex lectularius, a traumatically inseminating insect. In Chapter 21 examine the mating behaviour of C. lectularius, including the mating rates of males and females. Remating rates were very high, with females mating with 5 different males during a single reproductive bout. Males copulated for longer with virgin females than non-virgins. Sperm competition was predicted to be an important determinant of male reproductive success, because the ejaculates of an average of 5 males will be concurrent in the female's reproductive tract during a reproductive bout. In Chapter 3 the different gamete allocation strategies used by males were examined. Males allocated more sperm to virgin females than to non-virgins. Sperm migration and storage by females was examined in order to provide a basis from which mechanisms of sperm competition could be predicted. In Chapter 4 the patterns of sperm precedence were examined and a hypothetical mechanism of sperm competition was tested experimentally. Sperm precedence appears to favour the last male to mate due to a positional effect in the spermalege of the last ejaculate inseminated. In Chapter 5 the effect of high mating rates on females was assessed experimentally. Females mating at a high rate were found to die earlier than females mating at an artificially low rate. There was no difference in the rate of egg production of females between these two groups, so females mating at a low rate had a higher lifetime reproductive success. Appendix I investigates the potential benefits females may gain from polyandry. Both direct benefits of mating and a suite of possible fitness traits were assessed. However, no detectable differences in number or quality of offspring were uncovered. Chapter 6 reviews the evidence for a conflict of interest between the sexes over the remating rate and the possible causes of this conflict.

This thesis examines the productive and reproductive experiences of discount department store workers. More specifically, I investigate how female and male Wal-Mart employees reproduce and resist their spatial, social and economic relations, both inside their paid workplace, and outside, in their homes and community. I examine the history of discount department stores and workers; the role of place in influencing workers' experiences; the spatial, social and economic divisions of labor in the paid workplace, home and community; and specific acts of reproduction and resistance on the part of my co-workers. I used covert participant observation and informal interviews in order to learn about Wal-Mart workers paid and unpaid work experiences. I was employed for eight months as a part-time salesclerk by Wal-Mart. This enabled me to observe the various spatial, social and economic relations at work within the store, and it allowed me to hear about my co-workers' experiences outside the paid workplace, in the course of everyday conversations.

Employing a technological approach derived from the ‘Anthropology of Technology’ theoretical literature, this thesis concerns the identification and explanation of change in prehistoric extractive metallurgical behaviour in the Khao Wong Prachan Valley of central Thailand. The ‘Valley’ metallurgical complex, amongst the largest in Eurasia, constitutes Southeast Asia’s only documented industrial-scale copper-smelting evidence. The two smelting sites investigated, Non Pa Wai and Nil Kham Haeng, provide an interrupted but analytically useful sequence of metallurgical consumption and production evidence spanning c. 1450 BCE to c. 300 CE. The enormous quantity of industrial waste at these sites suggests they were probably major copper supply nodes within ancient Southeast Asian metal exchange networks. Excavated samples of mineral, technical ceramic, and slag from Non Pa Wai and Nil Kham Haeng were analysed in hand specimen, microstructurally by reflected-light microscopy and scanning electron microscopy (SEM), and chemically by polarising energy dispersive x-ray fluorescence spectrometry ([P]ED-XRF) and scanning electron microscopy with energy dispersive x-ray fluorescence spectrometry (SEM-EDS). Resulting analytical data were used to generate detailed technological reconstructions of copper smelting behaviour at the two sites, which were refined by a programme of field experimentation. Results indicate a long-term improvement in the technical proficiency of Valley metalworkers, accompanied by an increase in the human effort of copper production. This shift in local ‘metallurgical ethos’ is interpreted as a response to rising regional demand for copper in late prehistory.

Thesis (MScAgric)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Genetic selection for high milk production, type and appearance for the last 50 years has suppressed secondary traits such as reproductive performance, productive life, health and survivability in the pure milk breeds. The economic importance of these secondary traits in dairy production systems is the basis for the interest seen in crossbreeding. The problem of growth rate of heifers, cow fertility, reduced disease resistance and small body frame for beef production in Jerseys can be improved by crossing Jerseys with dual purpose breeds, such as Fleckviehs which possess a more beef potential. Against this background, this study aimed at comparing the production and reproduction of Jersey and Fleckvieh × Jersey cows in a pasture-based system. Milk recording was done according to standard milk recording procedures. Milk production (milk, fat, and protein yield) was adjusted to 305 days of lactation and corrected for age at calving. Effects of breed, parity, month and year were estimated for milk, fat and protein yield as well as fat and protein percentage using general linear models procedure. The fixed effects identified as having significant effects on milk, fat and protein yield were breed, parity and year. F×J cows produced significantly more milk than J cows (6141 ± 102 vs. 5398 ± 95 kg milk). Protein and fat yield were significantly higher in F×J (201 ± 3 and 272 ± 4 kg, respectively) than in J cows (194 ± 2 and 246 ± 3 kg, respectively). There percentages of fat and protein differed slightly between the two breeds with the Jersey recording slightly higher percentages (4.61 ± 0.04 and 3.62 ± 0.03 %, respectively) compared to the F×J cows’ percentages, which were, respectively, 4.47 ± 0.04 and 3.51 ± 0.03 %. It was concluded that F×J crossbred cows were more productive than purebred J cows probably owing to heterotic effects. Heifers were inseminated at 13 months of age and cows 40 days post-calving. Using insemination records and pregnancy check results, fertility traits were analyzed and compared between the two breeds, using analysis of variance for continuous records. Conception age was the same for both breeds resulting in a similar age at first calving. For cows, the interval from calving to first insemination was significantly shorter (P <0.001) in crossbred cows being 76.7 ± 2.2 days compared to 82.4 ± 2.5 days for purebreds. A larger proportion (P < 0.001) of 0.70 for crossbred cows was inseminated within 80 days after calving compared to 0.54 for J cows. Although the absolute number of days between calving and conception (DO) was lower for F×J cows in comparison to J cows (104.8 ± 6.8 vs. 114.8 ± 8.1days, respectively), the difference was not significant. However, the proportion of F×J cows confirmed pregnant by 100 days in milk was 0.79, which was higher (P < 0.001) than the 0.66 for J cows. Results indicate the potential of improving reproductive performance of J cows through crossing with dual-purpose breeds. The beef production of purebred J and Fleckvieh x Jersey (F×J) bull calves was compared, where bull calves were reared similarly for veal, i.e. carcass weight not exceeding 100 kg, or as steers for beef to 21 months of age. In both the veal and steer production systems, the mean birth weight were higher (P < 0.001) for crossbred in comparison to J calves and steers (33.5 ± 1.2 kg vs. 27.9 ± 1.2 kg for veal) and (33.4 ± 0.9 kg vs. 26.9 ± 0.9 kg for steers) respectively. The live weight at 6 months of age was 163.5 ± 3.9 kg for J bull calves, which was lower (P < 0.001) than that for F×J bull calves (180.6 ± 4.0 kg). The F×J bull calves had a significantly higher average daily gain (ADG) of 0.82 ± 0.02 kg/day compared to 0.73 ± 0.02 kg/day for J bulls. Marketing age differed (P < 0.001) in the veal production system with F×J and J bull calves marketed at 7.1 ± 0.1 and 6.3 ± 0.1 months, respectively. End live weight at 21 months of age was significantly higher (P < 0.001) in F×J bulls (441.4 ± 14.9 kg) than the 322.6 ± 13.4 kg in J bulls; while ADG differed (P < 0.001) between the two breeds being 0.64 ± 0.02 and 0.46 ± 0.0 kg/day in F×J and J bull calves, respectively. Crossbred steers had a significantly higher carcass of 206.5 ± 8.9 kg compared to 157.9 ± 8.6 kg for J steers. Results indicate the potential of improving beef production characteristics of the J cattle through crossbreeding.
AFRIKAANSE OPSOMMING: Genetiese seleksie vir hoë melkproduksie, tipe en voorkoms die afgelope 50 jaar het sekondêre eienskappe soos reproduksie, produktiewe lewe, gesondheid en oorlewing onderdruk in die suiwer melk rasse. Die ekonomiese belangrikheid van hierdie sekondêre eienskappe in melkproduksie stelsels is die basis vir kruisteling. Probleme soos groei tempo van verse, koei vrugbaarheid, verlaagde weerstandbiedenheid teen siektes en klein liggaam raam vir vleisproduksie in Jerseys kan verbeter word deur die kruising van Jerseys met ' n dubbele doel rasse, soos Fleckviehs wat beskik oor beter vleis potensiaal. Teen hierdie agtergrond, is hierdie studie daarop gemik om produksie en reproduksie van Jersey en Fleckvieh x Jersey koeie in 'n weiveld - gebaseerde stelsel te vergelyk. Melk opname is gedoen volgens standaard melkaantekening prosedures. Melkproduksie (melk-, veten proteïen opbrengs) was aangepas vir 305 dae van laktasie en gekorrigeer vir kalf ouderdom. ‘n Algemene lineêre model was gebruik om die effekte van ras, pariteit , maand en jaar op melk-, vet- en proteïen opbrengs sowel as vet- en proteïen persentasie te bepaal. Die vaste effekte geïdentifiseer met 'n beduidende effek op melk-, vet- en proteïen opbrengs was ras, pariteit en jaar. F × J koeie het aansienlik meer melk as J koeie (6141 ± 102 teen 5398 ± 95 kg melk) produseer . Vet opbrengs was aansienlik hoër in F × J koeie as in J koeie (272 ± 4 246 teen ± 3 kg vet). Proteïen opbrengs was ook aansienlik hoër in F × J koeie as J koeie (201 ± 3 vs 194 ± 2 kg proteïen). Vet en proteïen persentasies het geneig om effens te verskil met 'n klein effek (4.61 ± 0.04 % vet en 3.62 ± 0.03 % proteïen) vir J koeie en (4.47 ± 0.04 % vet en 3.51 ± 0.03 % proteïen) vir F × J koeie. Daar is tot die gevolgtrekking gekom dat F × J gekruisde koeie kan meer produktief wees as suiwer J koeie weens heterotiese effekte. Verse kunsmatig geïnsemineer was op 13 maande ouderdom en koeie 40 dae na- kalwing aangehou was. Met behulp van bevrugting en swangerskap rekords, is vrugbaarheid eienskappe ontleed en vergelyk tussen die twee rasse, met behulp van ontleding van variansie vir deurlopende rekords. Ouderdom van bevrugting was dieselfde vir beide rasse wat in 'n soortgelyke ouderdomsgroep was by eerste kalwing. Vir koeie was die interval van kalf tot eerste inseminasie aansienlik korter (P < 0.001) vir kruisgeteelde koeie wat 76.7 ± 2.2 dae in vergelyking met 82.4 ± 2.5 dae suiwerrasse is. ‘n Groter proporsie ( P < 0.001) van 0.70 vir gekruisteelde koeie is binne 80 dae na kalwing geïnsemineer in vergelyking met 0.54 vir J koeie. Alhoewel die absolute aantal dae tussen kalwing en opvatting (DO) laer was vir F × J koeie in vergelyking met J koeie (104.8 ± 6.8 teen 114.8 ± 8.1dae, onderskeidelik), is die verskil nie betekenisvol nie. Maar die verhouding van F × J koeie wat swanger bevestig is met 100 dae in melk was 0.79, wat hoër was (P < 0.001) is as die 0.66 vir J koeie. Resultate dui daarop dat daar potensiaal is reproduktiewe prestasie te verbeter van J koeie deur kruisteling met 'n dubbel- doel rasse. Die vleisproduksie van suiwer J en Fleckvieh x Jersey (F × J) bulkalwers vergelyk. Die bul kalwers is soortgelyk grootgemaak vir kalfsvleis, d.w.s karkas gewig mag nie 100 kg oorskry as bulkalwers nie, en as osse vir vleis tot 21 maande oud. In die kalwers- en os produksie stelsels, was die gemiddelde geboorte gewig hoër (P < 0.001) vir die kruise in vergelyking met J kalwers en osse (33.5 ± 1.2 kg teen 27.9 ± 1.2 kg vir kalwers) en (33.4 ± 0.9 kg vs . 26.9 ± 0.9 kg vir osse) onderskeidelik . Die lewendige gewig op 6 maande ouderdom was 163.5 ± 3.9 kg vir J bulkalwers en was hoër (P < 0.001) vir F × J bulkalwers 180.6 ± 4.0 kg. Die F × J bul kalwers het 'n aansienlik ‘n hoër gemiddelde daaglikse toename (GDT) van 0.82 ± 0.02 kg/dag in vergelyking met 0.73 ± 0.02 kg/dag vir J bulle. Bemarkingsouderdom verskil (P < 0.001) in die kalf produksie stelsel met F × J en J bulkalwers bemark op 7.1 ± 0.1 en 6.3 ± 0.1 maande , onderskeidelik. Finale lewendige gewig van 21 maande oud was aansienlik hoër 441.4 ± 14.9 kg in F × J bulle as 322.6 ± 13.4 kg in J bulle , terwyl GDT hoër was (P < 0.001), met 0.64 ± 0.02 kg/dag en 0.46 ± 0.0 kg/dag in F × J en J bulkalwers, onderskeidelik. Gekruisde osse het 'n aansienlik hoër karkasgewig 206.5 ± 8.9 kg in vergelyking met 157.9 ± 8.6 kg van J osse. Resultate dui daarop dat daar potensiaal is om die beesvleis produksie-eienskappe van die J beeste te verbeter d.m.v. kruisteling.

L'alimentation andine peruvienne est connue par sa persistance et ses grandes transformations. Neanmoins, elle n'a pas ete etudiee dans son integrite; notamment, les mecanismes de ses changements et sa dimension sociale demeurent mal connus. Cette etude s'appuie sur une approche systemique et sur une analyse sociologique de l'alimentation, centres sur trois communautes paysannes du haut bassin du canete (andes centrales). Elle cherche a montrer (a) le role de l'etat et de la bourgeoisie "agroalimentaire" nationale dans des mecanismes contradictoires d'exclusion et d'integration des communautes andines, par l'introduction d'aliments; (b) l'action de ces dernieres dans la restructurations de leur systemes alimentaires (autosubsistance et integration au marche). Cette action interne, aussi importante et diversifiee que les changements observes dans chaque groupe, subit toutefois l'action hegemonique des produits de consommation d'origine industrielle via le marche. L'acces a ces produits differencie les familles paysannes, tandis que l'approvisionnement non monetarise (autoconsommation et troc) diminue leurs differenciations; ce dernier se ressent, mais il assure encore plus de la moitie de la consommation domestique paysanne. L'etude des pratiques de consommation a revelee que l'alimentation andine persiste grace a (a) sa place dans l'organisation sociale, les rapports et les valeurs sociaux de chaque groupe etudie; (b) l'incorporation selective d'aliments nouveaux au sein des pratiques et des representations propres aux styles alimentaires etudies. Enfin, l'objectif des strategies alimentaires paysannes dans la conjoncture de crise economique et sociale, les changements de la consommation alimentaire dans le contexte socio-culturel andin, et l'avenir des valeurs alimentaires andines face a leur integration forcee a la societe nationale via la consommation sont discutes.

In the first study, non-genetic influences on pre- and post-weaning growth traits of a tropically adapted beef breed in the arid sub-tropical environment of Southern Africa were investigated. Production data of Santa Gertrudis cattle for a ten-year period were analysed. The herds were managed extensively under harsh arid environmental conditions in the northern thornveld region of Namibia. The cattle were divided into summer and winter breeding seasons, which were limited to 90 days for each group. The effect of sex, herd, season, calf birth year and cow parity group on birth weight, pre-weaning average daily gain, weaning weight, yearling weight, eighteen month weight and post-weaning growth rate were analysed. Sex was a highly significant (p < 0.001) source of variation for birth weight, weaning weight, 12 month weight, 18 month weight and significantly influenced (p < 0.05) pre and post-weaning weight gain. Bull calves were 3.05, 13.75, 123.37 and 238.99 kg heavier than the heifer calves at birth, weaning, yearling and eighteen months respectively and grew faster by 0.07 kg/day from birth to weaning and 0.65 kg/day from weaning to 12 months of age. The effect of season on birth weight, weaning weight, 18-month weight and pre-weaning growth rate was highly significant (p < 0.001). Calves born in the summer season had a lower birth weight compared to calves born in the winter season. However, the summer season calves were heavier by 17.67 kg at weaning but only by 1.7 kg at 12 months of age. They grew faster by 0.16 kg/day from birth to weaning. Calf birth year significantly influenced (p < 0.001) all traits measured with no fixed trend over time for the traits. Herd effects were highly significant (p < 0.001) for birth weight and 12-month weights and significantly influenced (p < 0.05) weaning weight, 18-month weight and growth rate from weaning to 12 months of age. The effect of cow parity was not significant on birth weight, 12-month weights, 18-month weights and post-weaning growth rates, but was significant (p < 0.05) for weaning weight and pre-weaning growth rates. Sex, herd, season of calving, calf birth year and herd x season x calf birth year significantly influenced growth traits and should be taken into consideration when evaluating the genetic merit of cattle during selection. The second study was conducted to determine the associations between lifetime cow fertility and cow frame size, also between lifetime cow fertility and pre-weaning as well as post-weaning calf growth in tropically adapted Santa Gertrudis cattle. A total of 2 506 Santa Gertrudis cows were divided according to their average lifetime calving interval (CI) into short calving interval (SCI, < 400 days, n = 914 cows) and long calving interval (LCI, > 400 days, n = 1 592 cows) groups. Calves were weighed at weaning at approximately 7 months of age. Hip height of cows and pre-weaning gain of calves of the SCI cows (135 cm and 1.01 kg/day) were significantly (p < 0.05) lower than those of the LCI cows (141 cm and 1.25 kg/day). Calves from SCI cows were born significantly earlier in the calving season than calves from LCI cows as measured by age at weaning (221 versus 189 days). As a result of compensatory growth there was no significant difference for yearling weight between progeny of SCI and LCI cows (348 kg versus 349 kg). It is concluded that SCI cows are smaller in size, with significantly lighter calves at weaning. A negative correlation exists between fertility and pre-weaning calf growth. High post-weaning calf growth is compatible with high cow fertility. In the third study, the effects of heifer frame size (FS) on their subsequent performance and the pre-weaning growth of their calves were evaluated using records collected from 1989 to 1998 from the Waterburg Estates at Otjiwarongo, Namibia. Based on hip height at 18 months of age, heifers were assigned to three different frame size (FS) groups: small (< 124 cm), medium (125 to 135 cm), or large (>136 cm). Calving rate (CR), calving date (CD), calf survival rate (CSR), reproductive efficiency (SANDEX), weaning rate (WR), birth weight (BW), weaning weight (WWT), pre-weaning ADG (P-ADG), and kilograms of calf produced per cow bred (KCB) were collected from first –(n = 830), second (n = 623) and third and greater-parity (n = 571) cows. Frame size of heifers significantly influenced (p < 0.001) their calving rate as second-parity cows with small and medium FS cows having higher CR than large FS cows. In spite of heavy culling of cows that had large FS as heifers, calving rates of second parity cows in this category were 41% less than that of second parity cows that had small and medium FS as heifers. In third or greater-parity cows, CR was greater (p < 0.05) for small FS than for medium and large FS. CSR was similar for heifers with a small, medium and large FS for the first, second and third and greater parity groups. Weaning rates of large FS (34.2 ± 11.27), second-parity cows were less (p < 0.001) than those of small (82.9 ± 5.58) and medium (79.0 ± 4.67) FS animals. Among all parity groups, BW of calves born to large FS were significantly higher (p < 0.05) than those of small and medium FS cows. Calves weaned by small FS animals as first parity cows, had lower (p < 0.05) WWT than those weaned by medium and larger FS, but large FS weaned heavier calves (p < 0.05) than small and medium FS in the third and greater-parity group. In first parity cows, calves of large FS had greater P-ADG (p < 0.05) than those from small FS, but in second parity cows the calves from medium FS (p < 0.05) out performed those of small and large FS, while calves from third and greater parity cows of medium and larger FS had greater (p < 0.05) P-ADG than cows with a small FS. Male calves were heavier (p < 0.05) at birth, at weaning and grew faster (P-ADG) than their female counterparts. KCB was similar among small and medium FS cows, but both tended to be greater (p < 0.05) than KCB of large FS cows and as second parity cows the small and medium FS cows had an even greater (p < 0.001) advantage over the large FS animals. Small and medium FS females calved earlier, and had greater calving rates and weaning rates, as well as greater kilogram of calf produced per cow exposed than the large FS females. The performance (fertility and the growth performance of their calves to weaning) traits of the large FS were generally similar to those of smaller cows in the third and greater parity group. The reproductive efficiency (SANDEX) of large FS at first, second, third and greater parity were lower (p < 0.001) compared to the small and medium FS, due to the later calving dates. Therefore, selecting cattle for the hot and dry climatic regions of Southern Africa, under extensive management conditions and with limited supplementary feeding, the recommended cow frame size should be a medium frame. These animals have similar levels of fertility compared to small framed cows, but with similar or even better growth performances than large framed cows. In the fourth study, the objective was to determine the effect of traits such as age, sex, body weight, body length and height, body condition score (BCS), coat score (CS), skin thickness and average skin surface temperature on tick burdens of a tropically adapted beef breed. Bonsmara cattle (n= 143) were used to measure visible tick counts, body condition score, coat score, skin thickness, body height and length, body weight, body surface temperature, gender and inter calving period. Measurements were taken for a period of eight months from April to December. All animals were managed extensively on natural and cultivated pastures near George in the Southern Cape. Female animals had significantly (p<0.05) greater tick infestation (37.9±2.7) compared to male animals (16.5±1.2). Age was a significant factor p<0.001) with the younger animals below two years having (46.4±5.26) more ticks than those of two years and older (20.1±2.44). A significant negative correlation (r = -0.29; p<0.001) was reported between the infestation of ticks on the animals and the age of the animal. Animals with an average body weight below 250kg had 42% (p<0.05) more ticks compared to animals with a body weight above 250kg. Age of the animal and weight were highly correlated (r = 0.70; p<0.001), while the correlation between the number of ticks per cow and the mean weight was negatively correlated (r = -0.37; p<0.001). Skin surface temperature significantly influenced tick infestation on the animals (p<0.001). The degree of infestation increased as body surface temperature exceeded 30º Celsius. Coat score, skin thickness, body condition score and inter calving period did not significantly influence tick infestation on the animals. The infestation of ticks on the animals was significantly influenced by body height (p<0.019) and body length (p<0.001). Animals smaller than a 130cm in height had a significantly (p<0.05) greater tick infestation (36.5±5.0) compared to animals taller than 130cm (21.2±1.5). This trend was also observed for body length. Animals with a body length shorter than 145cm had a greater (p<0.05) average tick infestation of 41.3±4.5 compared to 23.2±1.3 for animals longer than 145cm, indicating a 44% greater tick infestation for the shorter animals. The selection of cattle for adaptability and thus increased production under tropical conditions, through resistance to ticks should be for animals of medium frame sizes having smoother coats that are able to dissipate heat effectively. In the fifth study, the relationship between growth parameters, scrotal circumference and sheath area in tropically adapted beef bulls was investigated. The relationship between growth parameters such as initial weight at the start of the trial, average daily gain for the trial period (ADG), average daily gain per day of age (ADA), feed conversion ratio (FCR), final weight at the end of the trial, scrotal circumference (SC) and age and sheath area in Santa Gertrudis bulls were examined. To investigate the relationship between growth parameters and scrotal circumference, growth test data of 97 on-station performance tested Santa Gertrudis bulls were used while growth results of 55 Santa Gertrudis bulls tested under semi-intensive conditions were used to investigate the relationship of sheath area with growth performance. Bulls were divided into two groups according to their average sheath area (470 cm2). 28 Bulls were assigned to the small sheath group (SSA) below 470 cm2 while 27 bulls were assigned to the large sheath group (LSA) above 470 cm2. The LSA group possessed a 15% (66 kg; p < 0.05)heavier final weight than that of the SSA group. The LSA group had a 64% (241 cm2; p < 0.05) larger sheath area (378 ± 60 vs 619 ± 161 cm2) than the SSA group. A significant phenotypic correlation between ADG (r = 0.31, p < 0.05) and sheath area was found. The correlations between sheath area and initial weight (r = 0.42, p < 0.001) and between sheath area and final weight (r = 0.45, p < 0.001) were also highly significant. A highly significant correlation (p < 0.001) was observed between initial weight and SC and between final weight and SC, while significant correlations (p < 0.05) were also observed between SC and age and between SC and ADA for bulls tested intensively on station. It appears that SC and faster growth rate are compatible in young bulls. In addition, giving careful attention to sheath area in bulls, selected as yearlings is possible without necessarily sacrificing growth performance. In the sixth study, associations among growth and quantitative testicular traits of tropically adapted yearling bulls fed different dietary energy levels were investigated. High energy (HE), medium energy (ME) and low energy (LE) diets were fed to young Bonsmara bulls post-weaning and the subsequent effects on scrotal circumference (SC), average daily gain over an 84 day performance test trial period (ADG), average daily gain per day of age (ADA), body condition score (BCS), testicular histology and seminal traits were examined. Bulls fed the HE diet were significantly heavier and had a greater ADA, with the HE bulls (999.1 ± 7.13 g) out-performing the ME (804.1 ± 12.61 g) and LE (713.2 ± 12.95 g) bulls in terms of growth rate over the duration of the experimental period. Diet influenced (p < 0.001) BCS with the HE bulls (3.9 ± 0.05) having more body fat compared to the ME (3.3 ± 0.06) and LE (3.0 ± 0.08) bulls with the same effect (p < 0.001) observed in the carcass dressing percentage of the bulls fed different levels of energy. SC did not differ significantly between HE, ME and LE fed bulls. Seminal traits, such as semen concentration were significantly (p < 0.001) lower in bulls fed the HE diet (1.3 ± 0.134) compared to those fed the ME diet (2.4 ± 0.18) and LE diet (2.6 ± 0.16). Similarly, linear movement of sperm was also affected by diet and movement was slower (p < 0.05) in bulls fed the HE diet (1.7 ± 0.30) compared to bulls fed the ME diet (2.2 ± 0.31) and LE diet (3.1 ± 0.23). The percentage total major (p < 0.001) and total minor (p < 0.05) sperm defects were also greater in the HE fed bulls (27.1 ± 6.82 and 7.4 ± 0.91% compared to 9.7 ± 1.45 and 5.5 ± 0.87% for the ME fed bulls and 5.4 ± 1.26 and 3.9 ± 6.58% for the LE fed bulls). Dietary energy level significantly (p < 0.001) influenced the percentage inactive seminiferous tubuli, with bulls fed the HE diet having 35% more seminiferous tubules classified as inactive compared to those bulls fed ME and LE diets. Scrotal fat deposits were higher (p < 0.05) in bulls fed the HE diet (243.4 ± 21.59 g) compared to those fed the ME (110.0 ± 12.1 g) and LE (88.4 ± 9.65 g) diets. Correlation coefficients between SC and growth traits were generally favourable for the different dietary treatments. Correlations between live weight and SC were 0.51, 0.45 and 0.52 (p < 0.05) for the HE, ME and LE groups respectively. A negative association was observed between BCS and progressive sperm motility in bulls fed the HE diet (r = -0.54, p < 0.05). The percentage major seminal defects was negatively correlated with live weight in bulls fed the LE diet (r = -0.46, p = 0.008) and ME diet (r = -0.40, p = 0.08), while this characteristic was negatively correlated with mass movement of sperm (r = -0.63; p < 0.05) and percentage live sperm (r = -0.60; p < 0.05) in HE fed bulls. The present results suggest that feeding HE diets to young bulls influenced their testicular development and reduced their reproductive potential. In the seventh and last study, the relationship between scrotal circumference, quantitative testicular traits and growth performance in tropically adapted yearling beef bulls differing in age was investigated. The bulls were fed a high energy diet and the effect on average daily gain (ADG), average daily gain per day of age (ADA), body condition score (BCS), feed conversion efficiency (FCE), scrotal circumference (SC), seminal traits and testicular histology were examined in Bonsmara bulls (n = 34). The high energy diet contained not less than 11 MJ ME / kg DM and 13.8% CP. Bulls were fed the HE diet from an average starting age of either 210 (YB; n = 17) or 257 days (OB; n = 17) for a total of 112 days. Despite the age difference, growth and carcass traits were similar for the bulls irrespective of starting age. Scrotal weight, scrotal skin weight and scrotal skin thickness were greater (p < 0.001) in the YB (2223.4 ± 11.68g; 576.6 ± 25.17g and 4.5 ± 0.15mm) compared to that of the older group (1010.15 ± 50.10g; 255.9 ± 13.55g and 4.0 ± 0.13mm). The weight of the epididymal / spermatic cord (WESC) was heavier (p < 0.05) in the older bulls (70.2 ± 3.53g) compared to that of the younger group (47.2 ± 3.17g) with a similar trend observed when the volume of the epididymal / spermatic cord (VESC) was measured. Scrotal fat deposition was significantly (p < 0.001) increased by initial age (YB = 1164.7 ± 102.20g vs OB = 263.5 ± 27.52g). Age of the bulls also influenced (p < 0.05) the percentage inactive seminiferous tubuli, with the young bulls having 9.7% more seminiferous tubules classified as inactive compared to the older bulls. Seminal quality showed a similar trend and was generally of a lower standard than that of the group tested at an average of 369 days of age. Semen concentration (p < 0.05) and percentage linear sperm motility (p < 0.08) were the traits most affected by age. A negative correlation was evident between BCS and testis weight (r = - 0.51; p = 0.0342), testis volume (r = -0.52; p = 0.0318) and SC of dissected testis (r = -0.49; p = 0.042) in the young bulls. Correlation coefficients between SC and testis traits such as testis weight and testis volume were high (p < 0.05) for both the groups (YB; r = 0.87 and r = 0.87 and OB; r = 0.77 and r = 0.81). The relationship between SC and scrotal fat (r = 0.85) was highly significant (p < 0.001) only in the younger group. The results suggest that when bulls are fed a high energy diet, the age at which such feeding commences is of importance as regards their subsequent fertility. Copyright
Thesis (PhD)--University of Pretoria, 2006.
Animal and Wildlife Sciences
unrestricted

A study was conducted to investigate the effect of supplemental fat from flaxseed (FL) on fatty acid (FA) profile, chemical composition, energy value of colostrum and milk, and litter performance. On day 107 of gestation a total of 59 large white sows were selected, blocked by parity and randomly allotted to one of three diets, 15% flaxseed (FL), 10% fullfat soybean (SB) or a control commercial (CO) diet containing corn and soybean meal. Diets were isocaloric and isonitrogenous but differed in fat content and FA composition. Colostrum and milk were collected soon after farrowing and on day 7, respectively, for fatty acid and chemical analysis. Dietary treatments did not affect sow feed consumption, weight loss, number of live pig born and weaned per litter. Similarly, pig birth weights, and day 7, 14, and 21 weights did not differ among treatment groups. FL significantly (p < 0.05) increased linolenic (LNA C18:3co3) and decreased palmitic (C16:0) and oleic (C18:1) acids in colostrum. FL also significantly (p < 0.001) increased LNA and arachidonic acid (C20:4) in milk, while it decreased myristic (C14:0), palmitic and palmitoleic (C16:1) acids. Chemical analysis showed no significant differences in total solids (TS) and energy value of colostrum while a significant (p < 0.05) increase in TS, fat concentration and energy value was observed in milk from FL. A total of 335 piglets were used in the plasma study of lipid metabolites. Triglyceride (TG), cholesterol, HDL cholesterol and glucose were not affected by dietary treatment (p > 0.05). Feeding FL to sows during late gestation and lactation enriches sow milk and piglets with LNA.

La reproduction naturelle amenagee du brochet (esox lucius l. ) est une methode permettant de produire, en petits etangs et selon une formule extensive, des juveniles destines au milieu naturel ou aux etangs de polyculture. La fiabilite technique globale de cette methode ayant ete prealablement etablie, ce travail en aborde certains aspects biologiques et economiques. Dans une premiere partie, des resultats experimentaux, obtenus de 1985 a 1988 dans les petits etangs de l'esociculture du paraclet (somme), sont rapportes: des taux d'embryonnement eleves (80% en moyenne) sont generalement observes en reproduction naturelle, l'incidence de la temperature de l'eau sur la survie embryonnaire s'avere limitee tandis que celle des macroinvertebres predateurs apparait plus importante (taux de mortalite moyens incombant respectivement a ces deux facteurs: 8% et 34%), aucun des facteurs precedemment mentionnes ne semble en mesure de provoquer l'extinction de la fratrie, le taux de survie du stade ovocyte au stade embryon en fin de resorption est en moyenne de 46%, l'evolution de differents parametres (survie, biomasse, structure de la fratrie et regime alimentaire) a ete etudiee au cours de la phase de pregrossissement jusqu'au stade 15 g (a titre indicatif, les biomasses produites sont de l'ordre de 80 kg/ha au stade 2 g et atteignent 200 kg/ha aux stades 10-15 g). Les differents elements recueillis permettent de decrire la cinetique de la survie du stade ovocyte au stade juvenile de 15 g. Dans une deuxieme partie, une evaluation economique basee sur les donnees de quatre esocicultures montre qu'une rentabilite interessante peut etre escomptee, malgre l'heterogeneite des sites et de comportement des investisseurs (revenu agricole moyen: 20000 f 1986/ha terrain/an). L'ensemble des resultats obtenus conforte la robustesse de la methode et permet d'en expliquer certains points de variabilite

Harvesting of Aloeferox was estimated (in 1996) to bring in an annual income ofR4 million per year to rural communities alone - a vital source of income for full-time tappers who rely solely on Aloe ferox as their only form of financial survival. They are joined on occasion by casual-tappers who rely on tapping to supplement their incomes in times of hardship (Newton and Vaughan 1996). Landowner's also benefit by allowing harvesting on their land in exchange for a percentage of the harvest (Newton and Vaughan 1996). Trade in bitters sap or gel far outweighs that of other plant parts so care is taken by harvesters to keep the plants alive for future tapping. Leaves from only the lower third of the leaf rosette ( 10 - 15 leaves) are harvested, and 2 - 4 cm at the base of the leaves are left to prevent damage to vascular tissues (Newton and Vaughan 1996, Mac Farlane 2004). Populations are only harvested every 18 - 36 months allowing plants to recover from the loss of leaf material. Plants suffering from insect-infestation or disease are not harvested to avoid weakening the plant further and possibly causing death (Newton and Vaughan 1996). Effort is also made by landowners to relocate plants growing in areas they plan to transform and to monitor harvesting activities on their properties (Newton and Vaughan 1996). The vested interest in keeping the plants alive has inadvertently assured the preservation of populations at past harvesting levels although no formal conservation or resource management policy presently exists for A. ferox (Newton and Vaughan 1996). Effects of harvesting, which are not limited to the direct effect of leaf removal on the plant but include indirect effects - such as reduced reproductive output, reduced sap production and even trampling of recruits - have nonetheless raised concern for the long-term survival of populations (Newton and Vaughan 1996). This study addressed some of the indirect effects of harvesting on Aloe ferox on both population and individual plants levels. On the population level plant density, mortality, susceptibility to disease and sizeclass structure was compared between unharvested and harvested populations. On the individual plant level vegetative traits, flower production and sap production were compared between unharvested and harvested plants. One of few other studies on ecology of A. ferox by Hoffman (1988) assessed some of these characteristics for a population in Port Elizabeth, South Africa.

Cette thèse se propose d'analyser les rapports de qualification en milieux ouvriers, notamment au sein des usines gabonaises de transformation du bois. Elle tente de saisir la dynamique des qualifications au regard des processus qui conduisent à leur production et des dispositifs qui sous-tendent leur reconnaissance. Elle interroge les discours et les pratiques autour des régimes de production et de reconnaissance des qualités productives en articulation avec les trajectoires professionnelles. En privilégiant une approche sociétale tenant compte de l'histoire structurelle de l'industrie nationale du bois, l'analyse des processus de production des qualifications ouvrières interroge la place du système scolaire et/ou universitaire, des entreprises et des organisations professionnelles. Les tentatives de professionnalisation des activités industrielles du bois au Gabon depuis les années 50 n'ont pas abouti à la formation de catégories professionnelles qualifiées au sens académique du terme par le diplôme ou tout autre titre. La permanence de ces décalages entre les formations scolaires existantes et les emplois en présence est associée à une longue pratique de production, de reproduction ou de transfert des savoir-faire techniques par l'expérience du travail. Les ouvriers développent ainsi des savoir-faire et des compétences plus ou moins professionnels au gré des trajectoires allant des parcours scolaires généraux ou techniques-professionnels aux expériences d'emplois variées. Les qualités productives construites par la force du travail apparaissent donc comme un caractère dominant des rapports de qualification dans ce secteur industriel. Se pose de fait le problème de leur codification et de leur reconnaissance socioprofessionnelle. De quels dispositifs, de quels espaces et de quelles marges disposent les acteurs alors que les accords, les conventions de travail, bien que « négociés », se révèlent inopérants ? L'intérêt de cette thèse réside moins dans la proposition d'une définition singulière de la notion de qualification que dans la compréhension de ce qui se joue au sein des rapports de qualification dans ces milieux ouvriers. L'étude cherche ainsi à saisir les rapports de qualification sous le prisme des formes et des enjeux de la production, de la reconnaissance, du déni ou du contrôle des rapports salariaux au regard de la structure des trajectoires professionnelles. Elle s'appuie sur la sociologie du travail et emprunte aussi bien à l'histoire, à l'anthropologie, à l'économie qu'au droit du travail
This thesis offers an analysis of the relations of the qualification in workers' environment, more particularly in the Gabonese wood transformation factories. This work attempts to understand the dynamics of the qualifications through the processes leading to their production and the system that underpins their recognition. It will examine the discourses and practices concerning the regimes of production and recognition of productive qualities in articulation with occupational trajectories. This issue will be focused on a societal approach in consideration with the structural history of the national timber industry. The analysis of the production process of workers' qualification will question the role of the educational system (respectively school and university), the firms and occupational organisations. Since the 1950's, the professionalization of the activities in the wood industry in Gabon has failed to create qualified occupational categories in the academic sense of the word, either through the diploma or any other certification. The continuous gap between existing educational trainings and the jobs offered is associated with a long experience of production, reproduction or transfer of technical know-how acquired by the on-the-job experience. The workers thus develop more or less occupational know-how and competences according to the trajectories, going from general or technical/vocational educational paths to various job experiences. The productive qualities built by the force of the work thus appear as a prevailing reference of the qualification relations in the history of the Gabonese timber industry. As a consequence we may wonder about their codification and their socio-occupational recognition. Which system, which spaces and which margins do the actors of the sector have whereas collective labour agreements, albeit "bargained", turn out to be ineffective? The interest of this study is less centred on a single definition of the notion of qualification than on the understanding of what is going on in the qualification system inside the workers' environment. With this objective in mind, this study will try to shed light on the qualification system under the prism of the forms and stakes of the production, recognition, rejection or control of the wage-earner relationships in the factories with regard to the structure of the occupational trajectories. This work is based on the labour sociology but also history, anthropology, economy and labour law

O objetivo deste trabalho foi avaliar a relação entre produção de leite, problemas ao parto e respostas reprodutivas a partir de banco de dados de dois rebanhos de vacas raça Holandês utilizando análise multivariada. Os dados utilizados constaram de número de lactações (NLAC), dias em lactação (DL), produção de leite total (PLT), produção de leite ao pico (PLP), produção de leite ajustada para 305 dias (PL305), período de serviço (PS), número de doses, retenção de placenta (RP), intervalo entre parto e primeira tentativa (IPPT). A PLT foi relacionada positivamente com o número de dias em lactação e negativamente com TP. Não houve associação entre os indicadores reprodutivos, tais como o período de serviço e número de doses com as variáveis PLP e PL305. Houve uma leve associação negativa entre PLP e IPPT. O período de serviço e o número de doses foram positivamente associados com a duração da lactação e, em menor grau, com a produção de leite total. As características retenção de placenta, número de lactações e intervalo entre partos foram positivamente relacionadas. O tipo de parto e retenção de placenta mostraram relação positiva entre si, mas pequena associação positiva com os aspectos produtivos como intervalo último parto e primeira tentativa de cobertura, duração do período serviço e número de doses. Elevadas produções de leite ao pico e ajustadas para 305 dias não mostraram relação negativa consistente com a ocorrência de problemas ao parto e com baixa eficiência reprodutiva. Sendo assim, a hipótese de relação entre alta produção e interferência nas repostas reprodutivas não foi confirmada no presente trabalho.
The objective of this work was to evaluate the relationship between milk production, calving problems and reproductive performance using multivariate analysis from the database of Holstein cows in two herds. The following variables were used: number of lactations (NLAC), days in lactation (DL), total milk production (PLT), milk yield at peak (PLP), milk production adjusted for 305 days (PL305), length of service period (PS), number of semen doses, retention of placenta (RP), interval between delivery and first attempt (IPPT). PLT data were positively correlated with the number of days in lactation and negatively with TP. There was no association between reproductive indicators, such as the period of service and number of doses with PLP and PL305 variables. There was a slight negative association between PLP and IPPT. The service period and number of doses were positively associated with the duration of lactation and, at a lower degree, with the total milk production. The characteristics retained placenta, number of lactations and calving interval were positively associated. The type of delivery and retention of the placenta showed a positive relation between them, but a small positive association with the productive aspects, such as the interval between the last farrowing and the first attempt of breeding, length of service period, and number of doses. High milk yields at peak and adjusted for 305 days showed no consistent negative relation with calving problems and with low reproductive efficiency. Thus, the hypothesis of the relationship between high milk production and interference on reproductive responses was not confirmed in the present study.

Parmi les terrains immédiatement mobilisables pour les opérations foncières de la période de bulle spéculative foncière au Japon (1985-1991), les vastes espaces gagnés sur la mer (umetatechi) dans la baie de Tôkyô ont été d’autant plus la cible de projets de quartiers d’affaires qu’ils offraient des possibilités très avantageuses par rapport au reste de la ville. À proximité du centre (toshin), la structure particulière de la propriété foncière sur ces terrains a permis leur mise à la disposition immédiate pour les promoteurs publics et privés. De vastes opérations urbaines conçues dans les années 1980 sont mises en chantier au milieu des années 1990, après l’éclatement de la Bulle (1991), dans un contexte foncier passé à la déflation. Parmi les plus imposantes, les opérations Rinkaifukutoshin à Tôkyô, Minato Mirai 21 à Yokohama ou encore Makuhari Shintoshin à Chiba. Notre thèse est d’estimer que cette production d’espaces, de territoires, obéit à une logique économique qui revêt des formes géographiques spécifiques dans un cadre sociologique et culturel original. Selon cette approche, le jeu des acteurs impliqués dans la rénovation du front de mer tôkyôte est moins abordé sous l’angle des modalités opératoires de l’aménagement urbain et davantage sous le prisme de leur fonctionnalité systémique. L’identité de ces acteurs révèle quelques surprises, car les principaux, institutions et entreprises, ne correspondent qu’incomplètement à ceux que l’on rencontre habituellement dans la construction de la ville japonaise. Et pour ceux qui sont habituels, leur combinaison et leur rôle respectif diffèrent en partie de ce qui se passe dans les rénovations occidentales des fronts de mer. Les mégaprojets sur terre-pleins ont été le point de départ de la reconversion urbaine des espaces portuaires des mégapoles japonaises. Nous avons choisi de nous appuyer sur l’étude du plus vaste d’entre eux, le Rinkaifukutoshin. Comment, au delà de son développement chaotique, cette opération urbaine a-t-elle initié une reconversion des terre-pleins du port de Tôkyô ? Dans quelle mesure cette reconversion participe-t-elle aujourd’hui à la réorganisation du cœur de la plus grande ville du monde ? Enfin, que peut-on déduire, en termes de produit urbain, de l’avancée de la ville sur les terre-pleins du port ? Sont-ils une simple reproduction de l’espace urbain sur de nouvelles surfaces ou une surface de production de nouveaux espaces urbains ? Après avoir présenté le cadre du terrain, Tôkyô et sa baie, nous montrerons comment le fonctionnement de la mégapole japonaise, ville globale et tête asiatique de la Triade, permet de comprendre la conception du mégaprojet Rinkaifukutoshin. À travers l’histoire chaotique de l’opération, nous proposons une analyse de cette tentative de production d’espace urbain. Dans un deuxième temps, nous nous intéresserons à la reconversion de la zone interne du port de Tôkyô. Nous montrons qu’elle correspond à une véritable avancée de la ville, sur un modèle adapté à la situation foncière de l’après Bulle et selon des principes issus de l’expérience du Rinkaifukutoshin. Cela nous permet d’expliquer comment la reconversion urbaine des terre-pleins du port joue un rôle de premier plan dans les dynamiques sociodémographiques qui remodèlent actuellement les quartiers centraux de la capitale japonaise, au cœur du phénomène de retour au centre, le toshinkaiki. Enfin nous traitons la question de la nature urbaine de ces aménagements et de l’émergence d’un nouvel espace dans la mégapole : le front de mer, ou plutôt, en glocal-language, le wôtâfuronto. Cela nous conduit à traiter la question de l’avenir des terre-pleins du port de la baie ; face aux nouvelles résistances sur fond de débat environnemental, mais surtout face au maintien d’un système de production, et même de surproduction, d’espaces à Tôkyô
During the so-called Bubble Economics in Japan (1985-1991), the large coastal landfills and reclaimed lands in the Tokyo bay area have been particularly affected by huge urban projects. The proximity to the city center (the toshin) and the special property structure of Japanese reclaimed lands (umetatechi) put it at the immediate private and public urban planners’ disposal. These large urban projects (more than 400 ha. For some of these), designed in the 1980s, started to be built only in the middle of the 1990s, after the collapse of the Bubble, which means in a context of land prices deflation while its funding was adapted to the faith of a never-ending land prices growth in Japanese cities. The biggest of these operations are Rinkaifukutoshin in Tôkyô, Minato Mirai 21 in Yokohama and Makuhari Shintoshin in Chiba. These operations were the starting point of the renewal of the Japanese megacities’ port areas. We focused on the most important one, in space and spending, the Rinkaifukutoshin. How, beyond its chaotic development, it started an actual renewal of Tôkyô port’s reclaimed lands. How does this lead today to the reorganization of the urban core of the world largest city? What kinds of urban spaces it produces at the end? After the introduction of our field of work, Tôkyô and its bay, we attempt to demonstrate how the Rinkaifukutoshin operation is to be understood as a result, in its conception, of the globalization of Tôkyô megacity in the 80s. We then analyze the effects of the collapse of the Bubble on the planning and the nowadays urban product due to the successive adaptations of the development method. Second, we show how the redevelopment of the inner part of Tokyo harbor correspond to a real urbanization process, matching with a model resulting in some part of the experience of the Rinkaifukutoshin, but also of the background of more than 15 years of land prices deflation. It enables us to explain clearly how this redevelopment has a key role in the restructuration of the central quarters of the Japanese capital, in the context of the toshinkaiki, the “return to the city center” of urban populations. At least, we deal with the question of the urban nature of all these new constructions and the emergence of a new kind of space in the Japanese megacities: the wôtâfuronto, glocal translation of waterfront. This leads us to tackle the question of the future of newly constructed and planned reclaimed lands in the Tôkyô bay. It faces new resistances, based on environmental protection but more than that, the problem of surproduction of raw space in Tokyo area, while the production system is still in function with the disposal in the sea of urban wastes and refuses

Master of Science
Department of Clinical Sciences
Daniel U. Thomson
Bovine respiratory disease (BRDC) is a multifaceted disease that causes considerable economic loss in both the beef and dairy industry. However, because there may be lingering effects of BRDC in the dairy industry, the full economic costs of the disease may not be realized. These lingering effects may include an increased departure from the herd, decreased milk production, and decreased reproductive performance. All of these outcomes are affected by multiple variables, but proper statistical modeling can control for many of the different influences. Few studies have attempted to look at the long term effects of calfhood BRDC but consistent associations have not been identified. The objective of this observational, retrospective study was to determine the association between calfhood BRDC prior to 120 d of age and departure from the herd, milk production, and reproductive performance. The association between the occurrence of BRDC with departure from the herd prior to first calving depended on the birth year, but for 5 of the 6 years, animals that contracted BRDC were 1.62 to 4.98 times more likely to leave the herd than animals that did not contract BRDC. In addition, animals that contracted BRDC were also 1.28 times more likely to leave the herd between first and second calving than animals that did not contract BRDC. Furthermore, the age at BRDC occurrence was associated with departure from the herd. Animals that contracted BRDC pre-weaning were 2.62 times more likely to leave the herd prior to first calving than animals that contracted BRDC post-weaning. However, age of BRDC occurrence was not significantly associated with departure from the herd between first and second calving. The occurrence of BRDC during the first 120 d of life was associated with a 233 kg decrease in lactation-one production, but was not significantly associated with production in subsequent lactations. Finally, calfhood BRDC was not significantly associated with a decreased reproductive performance measured by calving interval. In conclusion, calfhood BRDC negatively impacts productivity both prior to and after first calving.

Abstract

Author: Annelie Johansson

Year: Spring 2006

Swedish title: Att producera eller reproducera text? En studie av fem gymnasiepojkars arbete

med skrivprocessen i en provsituation.

English title: To produce or reproduce text in essays. A studie of five high school boys’ work

with the writing process in a test situation.

City, university: Växjö, Växjö Universitet, institutionen för humaniora [Växjö, Växjö University, School of the Humanities]

Pages: 53

Content:

The major aim of this study is to investigate how five male high school students in the ages seventeen to eighteen produce or reproduce in their texts during an essay examination. Focus is also put on the five students’ writing processes in a classroom situated writing task and on their own comments to their writing. The main theory used to investigating this problem combines socio-cultural theories and a cognitive approach on writing in the sense that the individual’s thoughts and activities are socially and culturally situated. The methods used to collect information are observations and qualitative individual interviews with five boys from the same class studying the social science program combined with sports at a high school in the south of Sweden. The method used to interpret the boys’ written texts is textual analysis of their writing processes and of behaviour while creating the texts.

The main result is that the two boys who have higher grades plan their texts more carefully than the two boys with lower grades. The boy who got the highest grade on his task had experience from writing reviews, made a written mind map, relied on other texts to illustrate his opinions and did not follow the outline of the questions. The boys with lower or middle high grades on this specific writing task did not make a written text plan. Instead their planning prior to their writing of the text were mental or of an outline-and-develope-type. Two of the boys didn’t explicitly use other texts in their essays and their texts also had a more narrative than analytical approach and didn’t have any reproduction in them either. Typical for four of the boys are that they followed the outline made by the questions put in the task and that they didn’t revise their text in a broad meaning. The three boys who meet or try to meet the task demands also revise their texts at different stages of the writing process. Interesting is that the two boys who revise most in their texts also are the boys who reproduce the most and who lack the experience of this specific type of writing. The boys who reproduce, do it in a way called recreating which means that they use parts of other texts and change the words to synonyms or paraphrase them. The boys think that they are producing original texts when they use this tactic, but they are in fact reproducing.

Swedish keywords: skrivprocess, avskrift, produktion, reproduction, gymnasieelever, textkomposition.

English keywords: writing process, plagiarism, production, reproduction, high school students,

writing composition

O presente relatório tem como objetivo descrever as atividades realizadas no âmbito do estágio curricular do Mestrado Integrado em Medicina Veterinária da Universidade de Évora. Numa primeira parte, será descrita a casuística acompanhada ao longo do estágio, incluindo os procedimentos de profilaxia, sanidade, clínica médica, clínica cirúrgica e assistência reprodutiva. Dentro destas várias componentes, serão descritos com mais detalhe os casos que foram mais frequentes e/ou mais interessantes. Posteriormente, será apresentada uma revisão bibliográfica a propósito da febre Q, com particular abordagem sobre a espécie caprina. Nesta revisão, incluem-se tópicos como: etiologia, sinais clínicos, diagnóstico e tratamento da doença. Por fim, será abordado um estudo de caso sobre a eficácia de uma vacina implementada no âmbito da profilaxia da febre Q, na exploração Barão e Barão Lda. Os resultados demonstraram que, efetivamente, se verificou uma redução na taxa de abortos, após a implementação do protocolo vacinal; Abstract: Clinical medical and surgery in livestock species This report aims to describe the activities carried out within the scope of the curricular internship of the Master degree in Veterinary Medicine of Universidade de Évora. In the first part, will be described the followed activities along the internship, including the procedures of prophylaxis, internal medicine, surgery and reproductive management. Within these several components, will be described in more detail the cases that were more frequent and/or more interesting. Posteriorly, will be presented a bibliographic review about Q fever with particular approach on caprine species. In this review, are included topics like: etiology, clinical signs, diagnostics and treatment of the disease. Lastly, will be described a case study about the efficiency of a vaccine implemented in scope of Q fever profilaxy in Barão e Barão Lda.. The results have demonstrated that, effectively, it was verified a reduction in the abortion rate after the implementation of the vaccine protocol.

La vie au quartier des hommes de la maison d'arrêt constitue un univers de contraintes imposées aux hommes incarcérés. La présence physique dans le cadre spatio-temporel de la prison forme le cadre socialisant de cette expérience. Malgré cette situation de coprésence forcée, les détenus participent à la vie sociale de l'établissement. Ils ne subissent pas passivement leurs conditions de détenu mais deviennent, au cours de leur temps d'incarcération, acteurs à part entière et créateurs de leur identité de prisonnier. Au cours de leur vie quotidienne, ils interagissent entre eux et avec les autres personnes qu'ils rencontrent, notamment les surveillants. Les détenus collaborent avec ces derniers, mais aménagent aussi des espaces de liberté au cours de leur séjour en détention. La rencontre, avec des hommes ordinaires cherchant à préserver leur dignité humaine, permet d'accéder aux pratiques créatrices des détenus et témoigne de cette dynamique, et des multiples compétences acquises au cours de leurs parcours de vie que se soit dans la prison ou en dehors.

The thesis aims to expose the advances achieved in the practices of captive breeding of the European eel (Anguilla anguilla). Aspects investigated concern both approaches livestock (breeding selection, response to hormonal stimulation, reproductive performance, incubation of eggs) and physiological aspects (endocrine plasma profiles of players), as well as engineering aspects. Studies conducted on various populations of wild eel have shown that the main determining factor in the selection of wild females destined to captive breeding must be the Silver Index which may determine the stage of pubertal development. The hormonal induction protocol adopted, with increasing doses of carp pituitary extract, it has proven useful to ovarian development, with a synchronization effect that is positively reflected on egg production. The studies on the effects of photoperiod show how the condition of total darkness can positively influence practices of reproductions in captivity. The effects of photoperiod were also investigated at the physiological level, observing the plasma levels of steroids ( E2, T) and thyroid hormones (T3 and T4) and the expression in the liver of vitellogenin (vtg1 and vtg2) and estradiol membrane receptor (ESR1). From the comparison between spontaneous deposition and insemination techniques through the stripping is inferred as the first ports to a better qualitative and quantitative yield in the production of eggs capable of being fertilized, also the presence of a percentage of oocytes completely transparent can be used to obtain eggs at a good rate of fertility. Finally, the design and implementation of a system for recirculating aquaculture suited to meet the needs of species-specific eel showed how to improve the reproductive results, it would be preferable to adopt low-flow and low density incubation.
L’elaborato presentato si propone di esporre gli avanzamenti conseguiti nelle pratiche di riproduzione in cattività dell’anguilla europea (Anguilla anguilla). Gli aspetti indagati riguardano sia approcci zootecnici (selezione riproduttori, risposta a stimolazione ormonale, performance riproduttive, incubazione di uova) sia aspetti fisiologici (profili endocrini plasmatici dei riproduttori), nonché aspetti ingegneristici. Gli studi condotti sulle diverse popolazioni selvatiche di anguilla hanno evidenziato come il principale fattore discriminante nella selezione delle femmine selvatiche da destinare alla riproduzione in cattività deve essere il Silver Index che ne può determinare, a partire caratteri morfo-metrici e con un chiaro grado di precisione, lo stadio di sviluppo puberale. Il protocollo di induzione ormonale adottato, con dosi crescenti di estratto ipofisario di carpa, si è dimostrato utile allo sviluppo ovarico, con un effetto di sincronizzazione che si è positivamente riflesso sulla produzione di uova. Gli studi sugli effetti del fotoperiodo dimostrano come la condizione di totale buio, nelle vasche di mantenimento dei riproduttori, condizioni positivamente le pratiche di riproduzioni in cattività.. Gli effetti del fotoperiodo sono stati indagati anche a livello fisiologico, osservando i livelli plasmatici di steroidi (E2, T) e ormoni tiroidei (T3 e T4) nonché l’espressione a livello epatico dello vitellogenine (vtg1 e vtg2) e del recettore di membrana dell’estradiolo (esr1). Dalla comparazione fra deposizione spontanea e tecniche di inseminazione attraverso lo stripping si è dedotto come la prima porti ad una migliore resa qualitativa e quantitativa nella produzione di uova atte ad essere fecondate, inoltre la presenza di una percentuale di ovociti completamente trasparenti può essere utilizzato per ottenere le uova ad un buon tasso di fertilità. Infine, il design e la messa in opera di un impianto a ricircolo per l’acquacoltura adatto a soddisfare le necessità specie-specifiche dell’anguilla ha mostrato come per migliorare i risultati riproduttivi, sarebbe preferibile adottare basso flusso e bassa densità incubazione.

Thesis (MScAgric)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: Profitable milk production and genetic improvement in dairy herds are largely dependant on fertile cows capable of calving down on an annual basis. Several studies indicate declines in the reproductive performance of Holstein cows over the last 30 years. Calving interval (CI) and services per conception (SPC) are being used by dairy farmers as indicators of the reproductive performance of dairy cows. However, using these traits as cow fertility indicators is problematic as CI is dependent on subsequent calving dates while SPC is strongly linked to inseminator proficiency. The aim of the study is therefore, firstly, to describe alternative fertility traits derived from insemination and calving dates and pregnancy check results. The effects of some non-genetic factors on these traits are discussed. Means±sd for interval traits from calving to first insemination (CFS) and the interval from calving to conception (DO) were respectively 77±30 and 134±74 days while the number of services per conception (SPC) averaged 2.55±1.79. The percentage of first servics occurring within 80 days post-partum (FS80d) and the proportion of cows being confirmed pregnant within 100 (PD100d) and 200 days post-partum (PD200d) were 0.64±0.48, 0.36±0.48 and 0.71±0.45, respectively. Although fertility traits were affected significantly by lactation number, calving year and month, herds (managers) had the largest effect. Fertility is a complex trait, however, the challenge is finding traits that best describe this trait. Genetic parameters for these traits could give an indication of the response to selection in dairy herds. In the second part of this study, genetic parameters and correlations between fertility traits, sourced from standard reproduction management data bases, are analysed for Holstein cows using bivariate linearlinear and linear-threshold animal models. Insemination events (n = 69 181) from 26 645 lactations of 9 046 Holstein cows from 14 herds, calving down during the period from 1991 to 2007, were available. The outcome of each AI event was known. Insemination records were linked to the calving date of each cow, lactation number as well as dam and sire identification. Fertility traits indicating the ability of cows to show heat early in the breeding period, and to become pregnant, were derived. Data were analysed using bivariate linear-linear and linear-threshold animal models with fixed effects being herd (14 levels), year (17 levels), season (4 levels) and lactation number (6 levels). The model included the random effects of animal and animal permanent environment (PE). Heritability estimates ranged from 0.04±0.01 to 0.10±0.02 for FS80d, from 0.07±0.01 to 0.08±0.02 for PD100d and from 0.06±0.04 to 0.08±0.02 for PD200d depending on the two-trait combination. Although heritability estimates of most fertility traits were below 0.10, they were in close agreement with results published by other researchers using linear models. Genetic correlations between different fertility parameters analyzed in this study indicated that it is unlikely that a single characteristic would serve well for selection purposes; instead, combining different traits could be used in selection programmes to improve fertility. Further research in constructing an optimal fertility index is warranted. In the third part of this study, genetic parameters for South African Holstein cows for fertility and production traits were estimated from 2415 lactation records. Two-trait analysis of fertility and milk yield was investigated as a method to estimate fertility breeding values when culling, or selection based on milk yield in early lactation, determines presence or absence of fertility observations in later lactations. Fertility traits were days from calving to first service (CFS), days from calving to conception (DO), percentage cows inseminated within 80d post-partum (FS80d), number of service per conception (SPC), and the binary traits percentage of cows pregnant within 100d and 200d postpartum (PD100d, Pd200d). Milk production traits were 300 day milk, fat and protein yield. For fertility traits, range of estimates of heritability (h2) was 0.006 to 0.08 for linear traits and 0.05 to 0.12 for binary traits. The range for permanent environmental variance (c2) was 0.016 to 0.032. In this study genetic correlations of fertility with milk production traits were unfavourable ranging between −0.93 to 0.76.
AFRIKAANSE OPSOMMING: Winsgewende melkproduksie en genetiese verbetering in melkkuddes hang grootliks af van vrugbare koeie wat op ‘n jaarlikse basis kalf. Verskeie studies toon dat die reproduksievermoë van Holsteinkoeie oor die afgelope 30 jaar afgeneem het. Melkboere gebruik tussenkalfperiode (TKP) en aantal inseminasies per konsepsie (KIPK) as aanduidings van die reproduksievermoë van melkkoeie. Dit is egter moeilik om hierdie eienskappe as vrugbaarheidseienskappe vir melkkoeie te gebruik omdat TKP afhanklik is van opeenvolgende kalfdatums terwyl KIPK baie sterk gekoppel is aan die inseminasievermoë van die insemineerders. In die eerste gedeelte van die studie word alternatiewe vrugbaarheidseienskappe, wat afgelei is van inseminasie- en kalfdatums en die uitslag van dragtigheidsondersoeke, beskryf. Die invloed van ‘n aantal nie-genetiese faktore op dié eienskappe word ook bespreek. Gemiddeldes±standaard afwykings vir die periode vanaf kalwing tot eerste inseminasie (CFS), die periode van kalwing tot konsepsie (DO) was 77±30 en 134±74 dae onderskeidelik, terwyl die aantal inseminasies per konsepsie (SPC) 2.55±1.79 was. Die persentasie eerste inseminasies wat binne 80 dae na kalwing (FS80d), en die persentasie koeie wat dragtig bevestig is binne 100 (PD100d) en 200 dae na kalwing (PD200d) was 0.64±0.48, 0.36±0.48 en 0.71±0.45, onderskeidelik. Hoewel vrugbaarheidseienskappe betekenisvol beïnvloed is deur laktasienommer, jaar en seisoen van kalwing, het kuddes (bestuurders) die grootste effek op eienskappe gehad. Vrugbaarheid is ‘n ingewikkelde eienskap en die uitdaging is om eienskappe te vind wat dit die beste beskryf. Genetiese parameters vir eienskappe wat oorweeg word sal ‘n aanduiding gee van die seleksieresponse in melkkuddes. In die tweede gedeelte van die studie is genetiese parameters van vrugbaarheidseienskappe en korrelasies tussen dié eienskappe beraam. Eienskappe is bekom vanaf reproduksiebestuursprogramme wat in melkkuddes gebruik word. Al die inseminasierekords (n = 69 181) van 26 645 laktasies van 9 046 Holsteinkoeie van 14 melkkuddes wat tussen 1991 en 2007 gekalf het, was beskikbaar. Die uitslag van elke inseminasie was bekend. Inseminasierekords is met die kalfdatum, laktasienommer, identifkasienommers van die moeder en vader van elke koei, gekoppel. Vrugbaarheidseienskappe wat die vermoë van koeie aandui om vroeg na kalwing op hitte te kom en beset te raak, is verkry. Die data is ontleed deur gebruik te maak van twee-eienskap liniêreliniêr- en liniêr-drempel-diere modelle met vaste effekte kudde (14 vlakke), jaar (17 vlakke), siesoen (4 vlakke) en laktasienommer (6 vlakke). Die modelle het die ewekansige effekte van dier- en dierpermananente omgewingseffkte (PE) ingesluit. Genetiese, diere PE en residuele korrelasies is vervolgens beraam. Oorerflikhede varieer vanaf 0.04±0.01 tot 0.10±0.02 vir FS80d, vanaf 0.07±0.01 tot 0.08±0.02 vir PD100d en vanaf 0.06±0.04 tot 0.08±0.02 vir PD200d, afhangende van die tweeeienskap kombinasie. Ten spyte daarvan dat die oorerflikhede van die meeste vrugbaarseienskappe laer as 0.10 is, is die resultate in ooreenstemming met ander navorsers wat liniëre modelle gebruik het. Genetiese korrelasies tussen verskillende vrugbaarheidseienskappe toon dat daar nie enkel beste eienskap is wat vir seleksiedoeleindes gebruik kan word nie. Dit sou waarskynlik beter wees om verskillende eienskappe te kombineer om die vrugbaarheid in melkkoeie te verbeter. Verdere navorsing is nodig om ‘n optimale vrugbaarheidseienskap te ontwikkel. Dit is belangrik dat die verband tussen reproduksie en melkproduksie vir melkkoeie bepaal word. In die derde gedeelte van die studie is genetiese parameters vir vrugbaarheid- en melkproduksieeienskappe vir Suid Afrikaanse Holsteinkoeie beraam. ‘n Totaal van 2415 laktasierekords was beskikbaar. Vrugbaarheid en melkproduksie is volgens ‘n twee-eienskap analise ontleed as ‘n metode om teelwaardes vir vrugbaarheid te bepaal in gevalle waar die uitskot of seleksie gebaseer op melkproduksie in vroeglaktasie die teenwoordigheid of afwesigheid van vrugbaarheidseienskappe in latere laktasies bepaal. Vrugbaarheidseienskappe was die periode (aantal dae) tussen kalfdatum en eerste inseminasie (CFS), die aantal dae van kalf tot konsepsie (DO), die persentasie koeie wat by 80 dae na kalf vir die eerste keer geïnsemineer was (FS80d), die aantal inseminasies per konsepsie (SPC), en binêre eienskappe van die persentasie koeie wat by 100 dae en 200 dae na kalf beset was (PD100d en PD200d). Melkproduksie-eienskappe was 300-dae melk., vet- en proteïnproduksie. Vir vrugbaarheidseienskappe het die oorerflikheidswaardes (h2) vanaf 0.006 tot 0.08 vir liniêre eienskappe gevarieer en tussen 0.05 tot 0.12 vir binêre eienskappe. Die permanente omgewingsvariansie (c2) het tussen 0.016 tot 0.032 gevarieer. In hierdie studie was die genetiese korrelasies tussen vrugbaarheidseienskappe en melkproduksie-eienskappe ongunstig en het dit tussen −0.93 tot 0.76 gevarieer.

Thesis: Ph. D. in Urban and Regional Planning, Massachusetts Institute of Technology, Department of Urban Studies and Planning, 2014.
Cataloged from PDF version of thesis. Vita.
Includes bibliographical references (pages 237-249).
Rhetorically, people often make a tacit linkage between the spaces of urban informality ("slums"), crime and violence. This occurs in academic circles-as exemplified by the common occurrence that when researchers seek to understand urban crime and violence, they tend to study urban informal spaces (slums, favelas, barriadas, tugurios). However, it is clear that a direct correlation between conflict and informality does not automatically exist. What does exist is evidence that spaces of informality present challenges for formal (state) security actors to assert and maintain their Westphalian monopoly of violence. Conversely, informal settlements present advantages for non-state armed actors to deploy and exhort power and coercive force. This research here argues that, at the core of this contradiction between state disadvantage and non-state armed actor advantage over the control of security and governance, (physical) space clearly emerges as an important variable to study. This study then asks: What roles does physical space play in the conflict-that is, in the production and reproduction of violence-in informal settlements in Medellin? Understanding this would shed light on important phenomena about state and non-state control of informal settlements all over the world. This research looks for ways in which space has played a role in the ongoing urban conflict in the City of Medellin over the last forty years. I look for intersections between two parallel longitudinal studies I have conducted. (1) One study analyzes the physical evolution of Medellfn's informal settlements to map critical inflexion points in the production of urban forms. I also map how these urban forms evolved over time. (2) The second study is an ethnographic study of people's perspectives on their experiences with the evolution of such spaces. I then map their stories of building, rebuilding and urban conflict and merge this with the map of urban forms in the first dimension of my study. The research reveals that time and space in informal settlements do indeed change in prescriptive ways (stages). These stages of development are each marked by singular forms of conflict and violence. Here I argue that physical space plays a fundamental role in the way armed conflict happens in informal settlements. Physical space, which involves all actors in the conflict, impacts armed conflict in two distinct ways. Physical space (1) becomes a form of spatial conditioning that tailors actors and conflict and (2) creates and reinforces conditions unique to informal warfare strategies. This research suggests that we need radical changes in the way urban policy and projects are framed in the context of urban informality. It suggests that we need to consider this framing of informality in nations such as Colombia, in which there is a weak state fighting these types of new wars with asymmetrical adversaries on urban terrain and in which informality and criminal armed groups act. Pro-informal settlement policies and procedures could provide more stable and secure environments in informal settlements than the current tactic of massive expenditures on security in an ongoing asymmetrical warfare.
by José Jaime Samper Escobar.
Ph. D. in Urban and Regional Planning

Le manguier (Mangifera indica L.), cinquième production fruitière mondiale, est une espèce à production irrégulière. L’irrégularité de production a des retombées économiques marquées pour tous les acteurs de la filière fruitière. Il apparait donc important de mieux comprendre les mécanismes qui déclenchent et entretiennent ce phénomène d’irrégularité de production. Le premier objectif de cette thèse est d’apporter un regard nouveau sur l’irrégularité de production du manguier en mobilisant le concept des coûts de la reproduction. Cette étude est effectuée à plusieurs échelles spatiales, unité de croissance (UC), branche charpentière, arbre, et de manière dynamique sur quatre cultivars. Les résultats montrent un effet négatif, ou coût, de la reproduction sur la croissance végétative au cycle suivant, avec des comportements contrastés des cultivars en lien avec leur irrégularité de production. En particulier, un effort reproducteur important diminue la probabilité de débourrement végétatif des UCs porteuses. Le second objectif est d’étudier, chez deux cultivars et à l’échelle de l’UC, les modifications anatomiques et hydrauliques liées à la croissance du fruit, et des mécanismes trophiques et hormonaux contribuant à cet effet négatif de la reproduction sur le débourrement végétatif. Les résultats montrent que la reproduction entraîne une différenciation du cambium de l’UC porteuse principalement en phloème. Les inflorescences et les fruits diffusent de l’auxine qui inhibe le démarrage végétatif des UCs reproductrices. Les fruits en croissance mobilisent les réserves en amidon de l’UC porteuse. Les faibles teneurs en amidon de ces UCs pendant et après la récolte contribuent à réduire leur probabilité de débourrement végétatif, et/ou à le retarder lorsqu’il a lieu. Les résultats diffèrent entre les deux cultivars, et l’implication de ces mécanismes dans l’irrégularité de production est discutée. Nos résultats permettent de mieux comprendre les facteurs qui entretiennent l’irrégularité ou l’alternance de production de différents cultivars de manguiers. De façon appliquée, ils suggèrent que des techniques de taille adaptées à chaque cultivar et nature d’UC pourraient permettre d’obtenir une production plus régulière chaque année
The mango tree (Mangifera indica), the fifth fruit crop production in the world, is characterized by an irregular bearing pattern. Irregular bearing is responsible for economic difficulties for producers and for all actors along the fruit industry chain. A better understanding of mechanisms which trigger and maintain irregular bearing is therefore necessary. The first objective of this study is to provide a new perspective on irregular bearing of the mango tree using a concept developed in ecology and evolutionary biology, the costs of reproduction. The experiment was carried out dynamically at several spatial scales, growth unit (GU), scaffold branch, tree, and on four cultivars. Results show a negative effect, or cost, of reproduction on vegetative growth during the following cycle, with cultivar-specific behaviors related to their bearing pattern. In particular, an important reproductive effort reduces the probability of vegetative burst of the bearing GUs. The second objective is to study, for two cultivars and at the GU scale, the anatomical changes of the bearing axis during fruit growth, and hormonal and trophic mechanisms involved in the negative effects of reproduction on vegetative bud outgrowth. Results show that reproduction leads to cambium differentiation mainly in phloem, favoring nutrients and water supply to the fruit. Inflorescences and growing fruits release auxin, contributing to vegetative bud burst inhibition on fruiting GUs. Growing fruits mobilize starch reserves of bearing GUs. Their low starch content at and after harvest contributes to decrease their probability of vegetative burst, and/or delay it when it occurs. The results reveal a strong cultivar effect, and the involvement of these mechanisms in irregular bearing is discussed. Our results allow to better understand the factors maintaining irregular or alternate bearing of different mango cultivars. From a practical perspective, they suggest that pruning techniques adapted to each cultivar and GU fate may contribute to more regular production each year