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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
451

Análise morfológica e morfométrica do trato reprodutor feminino e masculino de duas espécies de Serracutisoma (Arachnida: Opiliones: Gonyleptidae): evidências de seleção sexual em machos / Morphological and morphometric analysis of the reproductive system of females and males of two species of Serracutisoma harvestmen (Arachnida: Opiliones: Gonyleptidae): evidences of sexual selection among males

Sobral, Marcella 09 September 2010 (has links)
Machos dos opiliões goniosomatíneos Serracutisoma spelaeum e Serracutisoma guaricana, cujas fêmeas copulam com mais de um parceiro em um único período reprodutivo, apresentam uma grande variedade morfológica, especialmente relacionada a caracteres sexuais secundários. Considerando-se que machos menores frequentemente perdem disputas por fêmeas, esta tese objetivou verificar possíveis estratégias reprodutivas alternativas, resultantes de seleção sexual pré e pós-copulatória, adotadas por machos de pequeno porte dessas espécies assim como o papel da fêmea nesses mecanismos. Este trabalho foi, então, dividido em três capítulos, cada um com objetivos específicos. O primeiro deles refere-se à organização do trato reprodutor feminino e caracterização das espermatecas, órgãos de armazenamento de espermatozóides. Imagens de microscopia de luz e de microscopia eletrônica de varredura associadas às obtidas sob estereomicroscópio revelaram a existência de quatro espermatecas inseridas na musculatura da porção distal do ovipositor. Cada uma delas é constituída por quatro sáculos individuais de fundo cego e se comunica com a luz do ovipositor através de um único canal. A complexidade das espermatecas indica que a fêmea pode ser capaz de armazenar separadamente os espermatozóides dos diferentes machos com os quais vier a copular, enquanto a musculatura ao redor dessas estruturas sugere que ela possa determinar a paternidade de sua progênie através de contrações diferenciais. O capítulo 2 abrange observações comportamentais e características morfológicas e morfométricas do trato reprodutor masculino, objetivando identificar possíveis estratégias alternativas utilizadas por machos de pequeno porte na obtenção de sucesso reprodutivo. Para tal, foram efetuados acompanhamento do comportamento sexual e estudos morfométricos de genitália e da gônada. Machos de pequeno porte parecem adotar a estratégia de machos-satélites, copulando com as fêmeas quando machosguardiões estão com a atenção desviada. A ausência de diferenças estatísticas significativas na largura da placa ventral sugere que o pênis de machos grandes e de machos pequenos se ajustam à genitália feminina da mesma maneira e, portanto, sejam vii avaliados pelas fêmeas da mesma forma. Já a semelhança no comprimento da genitália e o menor tamanho corpóreo dos machos pequenos indicam que, durante a cópula, eles poderiam alcançar regiões mais profundas da espermateca, removendo ou deslocando os espermatozóides dos outros machos e, consequentemente, diminuindo o risco de competição espermática. A análise ultraestrutural dos espermatozóides (compostos por núcleo, citoplasma e acrossomo, além de diversas projeções na superfície) mostrou que, provavelmente, todos os machos possuam espermatozóides viáveis, visto que espermatozóides não-férteis, em geral, não possuem acrossomo. As similaridades entre machos de grande e de pequeno porte tanto na morfologia dos gametas como em seu comprimento indicam que tais características possam ter sido objeto de seleção sexual pós-copulatória. O terceiro capítulo propõe uma hipótese para a formação das projeções encontradas nos espermatozóides das duas espécies e que lhes confere uma morfologia peculiar. Para isso foi utilizada a associação de três técnicas de microscopia: microscopia eletrônica de transmissão, de varredura e confocal de varredura a laser. Os resultados obtidos evidenciam que essas estruturas são formadas ao longo do processo de espermatogênese. Uma rede de proteínas situada logo abaixo da membrana plasmática exerceria uma pressão sobre o citoplasma, que extravasaria pelos espaços existentes nessa espécie de malha. Dessa forma, as projeções seriam constituídas de citoplasma envolto por membrana plasmática. Em conclusão, os resultados obtidos na presente tese sugerem que a competição espermática e a escolha críptica da fêmea, componentes da seleção sexual póscopulatória, são pressões seletivas atuantes nessas duas espécies de opilião. / Males of the goniosomatine harvestmen Serracutisoma spelaeum and Serracutisoma guaricana, which females may copulate with more than one partner during the same reproductive season, show a large morphological variation, especially considering secondary sexual features. Since smaller males frequently lose fights against larger males for females, the present thesis aimed at verifying the occurrence of alternative reproductive strategies among these smaller males as a result of pre- and postcopulatory sexual selection, as well as the role of the female in these mechanisms. This study is composed of three chapters, each one with specific objectives, as described as follows. The first chapter describes the general organization of the female reproductive system and the spermathecae, structures for the storage of sperm. Ligth and scanning electronic microscopy images revealed the presence of four spermathecae inserted in the musculature of the distal portion of the ovipositor. Each spermatheca is composed of four individual dead-end sacs and is connected to the ovipositor lumen through a single channel. This complex spermathecae structure indicates that the female is able to store sperm from different males with which she copulates in different places, and that the musculature that involves these structures may be responsible for differential contractions which would result in different paternity for the females descendants. The second chapter includes behavioral observations and morphological and morphometric analysis of the male reproductive system (genitalic and gonadal features), aiming at identifying possible alternative reproductive strategies used by small males to achieve reproductive success. Small males seem to adopt a satellite-male strategy, copulating with females when larger guardian-males are not paying attention. The absence of significant statistic differences in the width of its ventral plate suggests that the penis of both large and small males may adjust to the female genitalia in the same way and, therefore, will be similarly evaluated by the female during copulation. In turn, the smaller length associated to the same sized penis of smaller males in comparison to the larger ones may indicate that they may reach deeper regions of the female genitalia during copulation, possibly removing or displacing the sperm of other males and, in consequence, reducing the risk of sperm competition. The ultrastructure analysis of the spermatozoa (which are composed of a nucleus, cytoplasm and an acrosome, in addition to several surface projections) showed that probably males of different sizes all have viable sperm, since generally non-fertile spermatozoa lack an acrosome. Similarities in the morphology and size of the gametes of both small and large males may indicate that these features have been subjected to postcopulatory sexual selection. The third chapter suggests a new hypothesis for the development of the projections found in the surface of the spermatozoa of the two species here studied. For this study, three microscope techniques were used: transmission electronic microscopy, scanning electronic microscopy, and confocal laser scanning microscopy. The results show that these projections are formed during the spermatogenesis. A net of proteins situated just below the plasmatic membrane restrains the cytoplasm, which flows through the spaces formed in the net, forming the projections, which are externally limited by plasmatic membrane. In conclusion, the results obtained in the present study suggest that sperm competition and female cryptic choice, which are components of the postcopulatory sexual selection process, are selection pressures working on the species studied herein.
452

Intra-operative biomechanical analysis for improvement of intra-articular fracture reduction

Kern, Andrew Martin 01 August 2017 (has links)
Intra-articular fractures (IAFs) often lead to poor outcomes, despite surgeons’ best efforts at reconstructing the fractured articular surface. The objective of articular fracture reduction is to improve joint congruity thereby lower articular contact pressure and minimize the risk of post-traumatic osteoarthritis (PTOA). Surgical fracture reductions performed using less invasive approaches (i.e., percutaneously) rely heavily upon C-arm fluoroscopy to judge articular surface congruity. Based on varied outcomes, it appears that the use of 2D imaging alone for this purpose may prove inadequate. Despite this, there has been little investigation into novel metrics for assessment of reduction quality. This work first explores seven methods for assessment of reduction quality (3 2D, 3 3D, and one biomechanical). The results indicate that metrics which take 3D measurement or joint biomechanics into account when characterizing reduction quality are more strongly correlated with PTOA development. A computer assisted surgery system, which provides up-to-date 3D fracture geometry and contact stress distributions intra-operatively, was developed. Its utility was explored in a series of ten cadaveric tibial plafond fracture reductions, where contact stresses and contact areas were compared in surgeries with vs. without biomechanical guidance. The use of biomechanical guidance caused an increase in surgical time and fluoroscopy usage (39% and 17%, respectively). However, it facilitated decreases in the mean and maximum contact stress by 0.7 and 1.5 MPa, respectively. Contact areas engaged at known deleterious levels (contact stress > 4.5 MPa) were also 44% lower in cases which used guidance. The findings of this work suggest that enhanced visualization of a fracture intra-operatively may facilitate improved long-term outcomes. Further development and study of this system is warranted.
453

Inter- and Intra-sensory Modality Stimulus Scaling: A Method for the Determination of the Relative Salience of Stimuli in Poison-based Aversion Learning by Pigeons

Pounds, David L. 01 May 1981 (has links)
One of the most rapidly expanding areas of research in psychology has been poison-based aversion learning (PBAL). The PBAL paradigm typically involves: exposing an animal to a novel substance; inducing illness following ingestion of that substance; and then providing access to the substance at a later time. The initial reaction to the novel substance is generally to reduce consumption, a finding labeled neophobia. The reduction of substance intake on test day is called learned aversion. Following demonstrations of cue-to-consequence specificity (i.e., the differential associability of some stimuli with certain consequences) in PBAL research with rats, recent research has focused on PBAL by avians. Such research has been instigated by speculation that avians might be specially adapted to better associate visual rather than flavor stimuli with illness. Studies to determine the relative salience of visual or flavor cues in avian PBAL have reported contradictory findings. A number of methodological differences exist between these studies including differences in stimulus intensity and type, duration between conditioning and assessment, and method of assessment. The current series of experiments made several methodological improvements to clarify the issue of cue to consequence specificity in PBAL with avians. Three experiments with pigeons as subjects are reported. The first experiment equated (scaled) stimulus intensity across different sense modalities by equating neophobic responses to various concentrations of salt, sour, and red water. The second experiment determined the extended effects of the illness-inducing stimulus alone on fluid consumption by pigeons in a restricted access to water environment. The third experiment was based upon results from the first two experiments and assessed aversion, at two different post-injection times, to one of two concentrations of either salt, sour, or red water CSs. In addition, a compound (flavor plus color) conditioning group was employed. Aversion was a function of flavor or color stimulus intensity. No differences were observed in degree of aversion demonstrated by groups receiving stimuli equated for initial suppression. Evidence for overshadowing or potentiation was not found. The results support the position that neither flavor or color stimuli are necessarily the most salient in avian PBAL.
454

Approches quantitative et moléculaire pour l’amélioration génétique des aptitudes maternelles des truies sino-européennes Tai Zumu / Quantitative and molecular approach for the genetic improvement of maternal abilities in the Chinese-European Tai Zumu line

Banville, Maxime 07 April 2016 (has links)
Les caractéristiques pondérales de la portée à la naissance et au sevrage sont des caractères importants pour la survie de la portée mais aussi pour la croissance globale des porcs. L’hétérogénéité des poids intra-portée cause régulièrement des difficultés de conduite d’élevage, au moment de l’adoption ainsi qu’au moment de l’allotement des porcs charcutiers. Ce travail de thèse avait pour objectif d’analyser génétiquement la variabilité des caractères associés à la production de porcelets dans la lignée sino-européenne Tai Zumu, constituée à 50% de génétique Meishan et à 50% de génétique Large White, a été créée par l’organisation de sélection porcine GENE+. L’objectif ultime de ce travail de thèse est de proposer des pistes d’amélioration génétique de cette lignée.La première partie de cette thèse a été consacrée à l’étude de la variabilité génétique des caractères pondéraux de la portée et de leur évolution, suite à la sélection génétique menée pour améliorer la prolificité, la croissance et la condition corporelle précoces des truies Tai Zumu. Les héritabilités obtenues en lignée Tai Zumu sont d’une manière générale supérieures à la moyenne de la littérature. Les relations génétiques fortes entre la prolificité et le poids des porcelets, et entre le poids des porcelets et l’écart-type de poids intra-portée, rendent impossible une sélection conjointe sur l’ensemble de ces critères. La stratégie de sélection la plus cohérente avec les objectifs de GENE+ consisterait à intégrer l’écart-type de poids intra-portée à 3 semaines d’âge dans l’évaluation génétique des animaux. En plus de favoriser l’uniformité des porcelets, l’inclusion de ce caractère dans le schéma de sélection entraînera une augmentation du nombre de porcelets sevrés. La prise en compte de ce caractère conduira néanmoins à un léger ralentissement de la croissance des porcelets. Il a également été mis en évidence que la composante génétique directe du porcelet était autant impliquée que la composante génétique maternelle dans la croissance du porcelet en allaitement. Malgré un antagonisme fort et surprenant entre ces deux composantes, nous avons aussi montré que fixer cette corrélation à 0 ne semble pas influencer de façon importante l’évaluation génétique des animaux.Une seconde partie a été orientée sur l’analyse génétique des relations entre la mobilisation des réserves corporelles par la truie allaitante et les caractéristiques de la portée. Cette mobilisation des réserves corporelles pendant la lactation influence davantage les caractéristiques de la portée que les niveaux de réserves corporelles en entrée ou en sortie de maternité. Les truies avec une forte capacité génétique pour la mobilisation des réserves corporelles subissent une diminution de la prolificité mais au bénéfice d’une meilleure croissance de leur portée. Réduire l’adiposité des truies par sélection n’est donc pas une stratégie recommandée en lignée Tai Zumu puisque les truies assurent leur lactation majoritairement par le catabolisme des réserves corporelles.La dernière partie était dédiée à la mise en évidence de QTL pour les caractères numériques et pondéraux de la portée. Un faible nombre de QTL a été mis en évidence pour les caractères utilisés dans l’index de sélection de la lignée. Un seul QTL avec un effet modéré sur le nombre de porcelets nés vivants a été détecté sur le chromosome 14 ; il semble ségréger dans la population. Ce résultat peut être le fait de la pression de sélection forte appliquée sur la prolificité, puisque les QTL de la bibliographie sont majoritairement situés dans des régions du génome où les allèles Meishan sont en partie fixés en lignée Tai Zumu. Dans ce contexte, une sélection de type Sélection Assistée par Marqueur est difficilement envisageable. Si la variabilité génétique des caractères est le fruit de nombreux QTL à effets faibles, la sélection génomique devrait être plus adaptée. / Les caractéristiques pondérales de la portée à la naissance et au sevrage sont des caractères importants pour la survie de la portée mais aussi pour la croissance globale des porcs. L’hétérogénéité des poids intra-portée cause régulièrement des difficultés de conduite d’élevage, au moment de l’adoption ainsi qu’au moment de l’allotement des porcs charcutiers. Ce travail de thèse avait pour objectif d’analyser génétiquement la variabilité des caractères associés à la production de porcelets dans la lignée sino-européenne Tai Zumu, constituée à 50% de génétique Meishan et à 50% de génétique Large White, a été créée par l’organisation de sélection porcine GENE+. L’objectif ultime de ce travail de thèse est de proposer des pistes d’amélioration génétique de cette lignée.La première partie de cette thèse a été consacrée à l’étude de la variabilité génétique des caractères pondéraux de la portée et de leur évolution, suite à la sélection génétique menée pour améliorer la prolificité, la croissance et la condition corporelle précoces des truies Tai Zumu. Les héritabilités obtenues en lignée Tai Zumu sont d’une manière générale supérieures à la moyenne de la littérature. Les relations génétiques fortes entre la prolificité et le poids des porcelets, et entre le poids des porcelets et l’écart-type de poids intra-portée, rendent impossible une sélection conjointe sur l’ensemble de ces critères. La stratégie de sélection la plus cohérente avec les objectifs de GENE+ consisterait à intégrer l’écart-type de poids intra-portée à 3 semaines d’âge dans l’évaluation génétique des animaux. En plus de favoriser l’uniformité des porcelets, l’inclusion de ce caractère dans le schéma de sélection entraînera une augmentation du nombre de porcelets sevrés. La prise en compte de ce caractère conduira néanmoins à un léger ralentissement de la croissance des porcelets. Il a également été mis en évidence que la composante génétique directe du porcelet était autant impliquée que la composante génétique maternelle dans la croissance du porcelet en allaitement. Malgré un antagonisme fort et surprenant entre ces deux composantes, nous avons aussi montré que fixer cette corrélation à 0 ne semble pas influencer de façon importante l’évaluation génétique des animaux.Une seconde partie a été orientée sur l’analyse génétique des relations entre la mobilisation des réserves corporelles par la truie allaitante et les caractéristiques de la portée. Cette mobilisation des réserves corporelles pendant la lactation influence davantage les caractéristiques de la portée que les niveaux de réserves corporelles en entrée ou en sortie de maternité. Les truies avec une forte capacité génétique pour la mobilisation des réserves corporelles subissent une diminution de la prolificité mais au bénéfice d’une meilleure croissance de leur portée. Réduire l’adiposité des truies par sélection n’est donc pas une stratégie recommandée en lignée Tai Zumu puisque les truies assurent leur lactation majoritairement par le catabolisme des réserves corporelles.La dernière partie était dédiée à la mise en évidence de QTL pour les caractères numériques et pondéraux de la portée. Un faible nombre de QTL a été mis en évidence pour les caractères utilisés dans l’index de sélection de la lignée. Un seul QTL avec un effet modéré sur le nombre de porcelets nés vivants a été détecté sur le chromosome 14 ; il semble ségréger dans la population. Ce résultat peut être le fait de la pression de sélection forte appliquée sur la prolificité, puisque les QTL de la bibliographie sont majoritairement situés dans des régions du génome où les allèles Meishan sont en partie fixés en lignée Tai Zumu. Dans ce contexte, une sélection de type Sélection Assistée par Marqueur est difficilement envisageable. Si la variabilité génétique des caractères est le fruit de nombreux QTL à effets faibles, la sélection génomique devrait être plus adaptée.
455

Virtual pre-operative reconstruction planning for comminuted articular fractures

Thomas, Thaddeus Paul 01 January 2010 (has links)
Highly comminuted intra-articular fractures are complex and difficult injuries to treat. Once emergent care is rendered, the definitive treatment objective is to restore the original anatomy while minimizing surgically induced trauma. Operations that use limited or percutaneous approaches help preserve tissue vitality, but reduced visibility makes reconstruction more difficult. A pre-operative plan of how comminuted fragments would best be re-positioned to restore anatomy helps in executing a successful reduction. The objective of this work was to create new virtual fracture reconstruction technologies that would deliver that information for a clinical series of severe intra-articular fractures. As a step toward clinical application, algorithmic development benefits from the availability of more precise and controlled data. Therefore, this work first developed 3D puzzle solving methods in a surrogate platform not confounded by various in vivo complexities. Typical tibial plafond fracture fragmentation/dispersal patterns were generated with five identical replicas of human distal tibia anatomy that were machined from blocks of high-density polyetherurethane foam (bone fragmentation surrogate). Replicas were fractured using an instrumented drop tower and pre- and post-fracture geometries were obtained using laser scans and CT. A semi-automatic virtual reconstruction computer program aligned fragment native surfaces to a pre-fracture template. After effective reconstruction algorithms were created for the surrogate tibias, the next aim was to develop new algorithms that would accommodate confounding biologic factors and puzzle solve clinical fracture cases. First, a novel image analysis technique was developed to segment bone geometries from pre- and post-surgical reduction CT scans using a modified 3D watershed segmentation algorithm. Next, 3D puzzle solving algorithms were advanced to obtain fracture reconstructions in a series of highly comminuted tibial plafond fracture cases. Each tibia was methodically reconstructed by matching fragment native (periosteal and articular) surfaces to an intact template that was created from a mirror image of the healthy contralateral limb. Virtual reconstructions obtained for ten tibial plafond fracture cases had average alignment errors of 0.39±0.5 mm. These novel 3D puzzle solving methods are a significant advancement toward improving treatment by providing a powerful new tool for planning the surgical reconstruction of comminuted articular fractures.
456

Early targeting of knee osteoarthritis : validation of computational methods

Stockman, Tyler Joseph 01 August 2014 (has links)
Osteoarthritis (OA) is the most common type of arthritis, a disease in which inflammation and stiffness of the joints occur. This debilitating disease of the joints currently reigns as the most prevalent among the world's populations. Of particular interest to our group is the study of the biomechanical factors relating to knee OA. Studies have shown that knee OA is related to multiple biomechanical factors, all of which are complexly interrelated. These factors have been seen to produce varied effects on the structures of the knee. This work examines validation of a computational model implementing discrete element analysis, and discusses the potential for large-scale, subject-specific modeling of the knee. In particular, contact stress can be estimated using this technique, and these estimates can potentially be related to OA onset in subjects.
457

Emergence et développement des différences comportementales individuelles chez les souris glaneuse, Mus spicilegus. / Emergence and developpement of individuel behavioural differences in behaviour, a study in the mound-building mouse, Mus spicilegus

Rangassamy, Marylin 08 July 2016 (has links)
Cette thèse comprend cinq manuscrits d'articles. Deux de ces manuscrits sont publiés, l’un est actuellement en révision et deux sont en préparation pour soumission.Les animaux diffèrent de manière stable au cours du temps et dans différents contextes dans leur comportement, un phénomène souvent nommé personnalité animale. Les animaux diffèrent ainsi dans leur niveau d’expression de différents traits de personnalités. Cependant l’étude de la stabilité des traits de personnalité chez les jeunes animaux apporte des résultats controversés. Les deux principaux objectifs de cette thèse ont donc été d’évaluer comment l’environnement précoce des animaux façonnait leur personnalité et si l’expression de leur comportement était stable au cours du développement. Notre modèle d’étude était un petit rongeur d’origine sauvage, la souris glaneuse Mus spicilegus. Cette souris se trouve dans les zones agricoles d’Europe centrale et orientale. Il s'agit d'une espèce monogame et la femelle et le mâle participent aux soins parentaux. Les principaux résultats de cette thèse soulignent la stabilité des réponses comportementales des souris glaneuses dans des contextes sociaux et non-sociaux tôt lors de la période post-natale jusqu’à la maturité. De nombreux traits de personnalité étaient associés à travers différents contextes ; formant ainsi ce qu'il est convenu d'appeler un syndrome comportemental. Cette stabilité dans le comportement était avérée que l'analyse porte sur la totalité de l'échantillon ou qu'elle prenait en compte les différences intra-portées. L’environnement précoce et en particulier la présence du père apparaissent déterminants dans l’émergence et la modulation de la personnalité. Les individus élevés sans père montraient une plus grande réactivité dans deux tests différents par rapport à ceux élevés avec les deux parents. Différentes personnalités étaient associées à des mécanismes physiologiques. Confrontés à un stresseur chronique, les individus exprimant différentes personnalités montraient des différences physiologiques caractérisées par des profils immunologiques et hormonaux distincts. D'autre part les couples possédant des scores similaires d’anxiété, indépendamment du score des deux partenaires du couple, avaient une plus grande probabilité de reproduction durant la période d’observation, que les couples aux scores différents suggérant de potentiels avantages évolutifs. Cette thèse aborde en parallèle les aspects proximaux et ultimes du comportement chez un même modèle biologique ce qui est un but rarement atteint dans une étude éthologique. / This thesis includes five manuscripts. Two are already published, one is currently under review and two others are in preparation for submission.Animals frequently show consistent individual differences in behaviour across time and contexts, a phenomenon called animal personality. Animals have been thus described to differ in the expression level of different specific personality traits. However, consistencies in animal personality traits in young animals are especially controversial. One of the main aims of this thesis was therefore to investigate how the early environment experienced shapes the behavioural phenotype and whether the expression of behaviour remains stable over ontogeny. To this end, we used a small rodent of wild origin, the mound-building mouse Mus spicilegus, as an animal model. This monogamous mouse occurs in a variety of agricultural and steppe-like habitats in Central and South Eastern Europe, and is characterized by bi-parental care. The main results of this thesis highlight the consistency of personality traits in the mound building mouse from the early postnatal period until around maturity, both in social and non-social contexts. Various personality traits were associated across context, thus forming a behavioural syndrome. Such consistencies across time and context were present when looking at the individual level but also when focusing on the relative differences among siblings within a litter. The early developmental environment proved to be decisive in modulating the emergence personality of the individual, via the presence or absence of the father. Pups growing up in absence of the father showed indications of a higher responsiveness in two different tests compared to pups raised by mothers only. We showed how personality differences are related to physiological parameters. Different personality types coped physiologically different with a chronic stressor, apparent by their hormonal and immunological profiles. Pairs with similar anxiety scores, independently of the scores of both partners of the pair, had a higher probability of breeding, and brought forward the onset of breeding during the observation period, which carries along potential fitness benefits. This dissertation brings thus together some insights into the proximate and ultimate aspects underlying consistent individual differences in behaviour, which is seldom the case in a same model species.
458

Perceptions of ethical decision-making : a study of Thai managers and professionals in Bangkok and provincial Thailand

Youngsamart, Daungdauwn January 2009 (has links)
Academics and social commentators have emphasised the importance of religion and specific cultural characteristics in influencing or explaining the perceptions, values and behaviours of cultural groups. The quantitative empirical research into ethical perceptions, intentions and behaviours has used culture and religion to define cultural groups, or compare and contrast two national cultural groups. Little focus has been placed on intra-cultural differences. While there has been some quantitative empirical research into the role of Thai Buddhist religiosity in ethical decision making, there has been no such research that deals with the unique Thai cultural characteristics of greng jai and patron-client relationships or differences between urban and provincial Thai managers and professionals. In the research conducted for this thesis, I explore the relationship between Thai Buddhist religiosity, patron-client relationships and greng jai, and ethical intentions, expectations of other’s behaviour and the nature of ethical dilemmas (ethical or unethical). In addition, intra-cultural differences between ‘Thai managers and professionals in Bangkok and ‘less developed’ provinces on these items are investigated. Survey responses from 522 Thai managers and professionals from Bangkok and provincial Thailand were obtained in the research conducted for this thesis. The instrument used includes five scenarios from previous research, two new scenarios that address greng jai and patron-client relationship dilemmas, demographic and cultural measures, and measures of ethical intentions, behaviour of others, and the nature of the ethical problem. Neither patron-client relationships nor greng jai were found to influence ethical intentions, perception of other’s behaviour or perception of the nature of ethical problems. This suggests that importance of these cultural characteristics has been exaggerated in previous qualitative research, that these previously important characteristics are no longer important, or that Thai managers and professionals insulate their ethical perceptions in business settings from Thai cultural influences. The latter explanation would indicate convergence of Thai business culture with a more modern globalised perception of business ethics. Thai Buddhist religiosity did not consistently play a role in perceptions of ethical intention, behaviour of others or the nature of the problems. In scenarios in which it did play a role, the effect was small. Again, this suggests that the importance of religiosity may have been exaggerated in the past, was once important but is no longer so, or that Thai managers and professionals compartmentalise the role of religion in business and non-business settings. No differences were found between Thai managers and professionals in Bangkok and provincial Thailand. Again, this suggests a convergence with a modern globalised perception of business ethics.
459

Characteristics of Australian edible fungi in the genus Lepista and investigation into factors affecting cultivation

Stott, Karen Gai, University of Western Sydney, Hawkesbury, Faculty of Science and Technology, School of Science, Food and Horticulture January 1998 (has links)
This thesis focuses on the edible fungus Lepista (Pied Bleu or Wood Blewit). Factors affecting its potential commercial cultivation were explored and a contribution to knowledge of the morphology and cultivation of Australian species of Lepista has been made. Australian collections of Lepista were made within a 200 km zone of Sydney. A study of the morphology and taxonomic species of these collections was undertaken. Intra- and inter-fertility crosses were completed with French L. nuda and L. sordida to determine genetic relationships and biological species. Suitable substrates for agar medium, spawn production and cultivation were explored. The response to temperature of French and Australian Lepista in vitro, and Australian Lepista under cultivation, using cold shock, was observed. The effect of modified atmosphere exchanges per hour, CO2 levels, and cold shock during the cultivation cycle and sporophore production were investigated. A genebank of Australian Lepista was established. Three species of Lepista were found in Australia : L. nuda, L. sordida and L. saeva. Two other groups of Lepista were identified. The use of A. bisporus compost appeared to be optimal for experimental and commercial applications. Australian isolates of Lepista tolerate higher temperatures than French isolates, and grew at double the rate of the French at all temperatures except 5 degrees centigrade. The length of the spawn run was reduced from 43-58 days to 12-16 days with introduced CO2 of 9,000-11,000 ppm, but an erratic cyclic pattern of net CO2 production occurred which could only be stabilised by increasing ventilation. This initial cyclic pattern appeared to inhibit subsequent sporophore formation. / Doctor of Philosophy (PhD)
460

Family Size and Relative Need

Bradbury, Bruce William, Economics, Australian School of Business, UNSW January 1997 (has links)
This thesis examines three questions concerned with the relative income needs of families of different sizes - often summarised by indices known as ???equivalence scales???. The first is the extent to which researchers and policy makers should offset the costs of family composition (eg the expenditure costs of children) with the benefits associated with demographic choice (eg the ???joys of parenthood???). Chapter 2 concludes that there are demographic and financial market constraints that will often make a narrow focus on expenditure costs appropriate for distributional research and tax/transfer policies. However, this will not always be the case. One implication of this result is that it may be reasonable for distributional research to use different equivalence scales for adults and children in the same household. Part 2 of the thesis introduces a new method for the estimation of the within-household income distribution and expenditure costs of different family types. This is based upon the household welfare model of Samuelson together with Lau???s method for modelling the joint consumption of household goods. In Chapter 4, this method is applied to the estimation of equivalence scales for older singles and married couples. The estimation is based upon a detailed set of assumptions about the extent of joint consumption for 17 different commodity groups. The main conclusions are that: the theoretical model fits the observed behaviour well (with the exception of some home production effects); that aged couples share their income relatively evenly; and that the relative rate of pension for aged singles in Australia is probably too low. In Part 3, the thesis examines how changes in poverty can be estimated when there is uncertainty about the equivalence scale. The thesis proposes a new method which permits a set of upper and lower bounds for the equivalence scale to be assumed, which in turn determine upper and lower bounds for the increase in poverty. This method is applied to measure the change in poverty in Australia during the 1980s. Equivalence scales can be found that imply either an increase or a decrease in poverty.

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