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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.
121

Exposi??o de embri?es e larvas de zebrafish a compostos bisfen?licos para elucida??o de mecanismos neurotoxicol?gicos

Fonseca, Raphaela Soares 26 February 2018 (has links)
Submitted by PPG Zoologia (zoologia-pg@pucrs.br) on 2018-06-29T17:28:48Z No. of bitstreams: 1 Dissertac?a?o_Mestrado_Raphaela_ (003).pdf: 1487803 bytes, checksum: 85e14999295df94278920f21e8362c4d (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-07-09T11:35:44Z (GMT) No. of bitstreams: 1 Dissertac?a?o_Mestrado_Raphaela_ (003).pdf: 1487803 bytes, checksum: 85e14999295df94278920f21e8362c4d (MD5) / Made available in DSpace on 2018-07-09T11:42:43Z (GMT). No. of bitstreams: 1 Dissertac?a?o_Mestrado_Raphaela_ (003).pdf: 1487803 bytes, checksum: 85e14999295df94278920f21e8362c4d (MD5) Previous issue date: 2018-02-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The increase of environmental pollutants sources directly affects the ecosystem and human health, mainly due to loss of soil and water quality. Among these toxic agents are included endocrine disruptors, which can cause changes in biochemical pathways and physiological changes in organisms. Studies with different forms of bisphenols, compounds present in many products of human consumption and the environment, had already demonstrated extremely adverse effects on behavior and gene expression of targets related to neural and endocrine systems during development. The zebrafish, Danio rerio, is an excellent model organism for studying neurotoxicity, due to its advantages with respect to specific aspects of their development and a low maintenance cost when compared to other vertebrate model organisms. This work proposes the investigation of the effects of bisphenol A (BPA), its chlorinated derivatives and its substitutes (BPS and BPF), toxicological and behavioral parameters combined with characterization of its potential underlying cellular and molecular mechanisms such as cell death and proteins and gene expression in the nervous and endocrine systems. After the embryo and larvae were exposed to different concentrations of BPA and its derivatives, morphological analyzes and embryo survival were carried out, as well as behavioral tests of locomotion and cognitive evaluation of the larvae. In the concentrantion curve of the different bisphenolic compounds, no significant difference was observed in the survival, teratogenesis and hatching of the animals, however, a significant increase was detected in the exploratory parameters of the BPA and BPF groups. When comparing the aversive behavior of the BPA with the DMSO, there was no statistical difference between the groups, whereas in the BPS an improvement in the escape response of the larvae occurred. Additionally, behavioral and locomotor activity analyzes will be performed in adult animals previously treated with the compounds studied during the initial development. In this way, it is expected to contribute to the current knowledge of neurotoxicity mechanisms related to endocrine disruption caused by contaminants of the bisphenol family. / O crescimento das fontes de poluentes ambientais afeta diretamente o ecossistema e a sa?de humana, principalmente devido ? perda da qualidade do solo e da ?gua. Entre estes agentes t?xicos, est?o inclu?dos os disruptores end?crinos, os quais podem acarretar diversas mudan?as em vias bioqu?micas e altera??es fisiol?gicas em organismos. Estudos com diferentes formas de bisfen?is, compostos presentes em diversos produtos de consumo humano e inclusive no ambiente devido ? contamina??o por efluentes industriais, j? apresentaram efeitos extremamente nocivos na regula??o da express?o de genes relacionados ao sistema neural e end?crino durante o desenvolvimento, al?m de altera??es comportamentais severas. O zebrafish, Danio rerio, ? um excelente organismo modelo para estudar neurotoxicidade, uma vez que possui vantagens em rela??o a aspectos espec?ficos do seu desenvolvimento e um custo reduzido de manuten??o quando comparado a outros vertebrados modelos. Este projeto prop?s o estudo dos efeitos do bisfenol A (BPA), seus derivados clorados e substitutivos (BPS e BPF), sobre par?metros de embriotoxicidade e comportamento, buscando tamb?m caracterizar os mecanismos celulares e moleculares dos potenciais efeitos observados avaliando morte celular e n?veis de prote?nas e express?o de genes alvos em embri?es e larvas de zebrafish. Para tanto, ap?s a exposi??o dos embri?es e larvas a diferentes concentra??es de BPA e seus derivados, foram realizadas an?lises morfol?gicas e sobreviv?ncia dos embri?es; ensaios comportamentais de locomo??o e avalia??o cognitiva das larvas. Ao realizar a curva de concentra??o dos diferentes compostos bisfen?licos, n?o foi observada diferen?a significativa na sobreviv?ncia, teratog?nese e eclos?o dos animais, por?m, ao analisar o comportamento explorat?rio dos animais tratados com BPA e BPF foi detectado um aumento significativo nos par?metros explorat?rios das larvas. Ao compararmos o comportamento aversivo do BPA com o controle tratado com o ve?culo DMSO, n?o existiu diferen?a estat?stica entre os grupos, enquanto no BPS ocorreu uma melhora na resposta de escape das larvas. Adicionalmente, ser?o realizadas an?lises comportamentais e de atividade locomotora em animais adultos previamente tratados com os compostos estudados durante o desenvolvimento inicial. Desta forma, espera-se contribuir para o conhecimento atual dos mecanismos de neurotoxicidade relacionados ? disrup??o end?crina causada por contaminantes da fam?lia dos bisfen?is.
122

Contract design for collaborative response to service disruptions

Jansen, Marc Christiaan January 2017 (has links)
This dissertation studies firms' strategic interactions in anticipation of random service disruption following technology failure. In particular it is aimed at understanding how contracting decisions between a vendor and one or multiple clients affect the firms' subsequent decisions to ensure disruption response and recovery are managed as efficiently as possible. This dissertation consists of three studies that were written as standalone papers seeking to contribute to the literature on contract design and technology management in operations management. Together, the three studies justify the importance of structuring the right incentives to mitigate disruption risks. In the first study we contribute to this literature by means of an analytical model which we use to examine how a client and vendor should balance investments in response capacity when both parties' efforts are critical in resolving disruption and each may have different risk preferences. We study the difference in the client's optimal expected utility between a case in which investment in response capacity is observable and a case in which it is not and refer to the difference in outcomes between the two cases as the cost of complexity. Firstly, we show that the cost of complexity to the client is decreasing in the risk aversion of vendor but increasing in her own risk aversion. Secondly, we find that a larger difference in risk aversion between a client and vendor leads to underinvestment in system uptime in case the client's investment is observable, yet the opposite happens when the client’s investment is not observable. In the second study we further examine the context of the first study through a controlled experiment. We examine how differences in risk aversion and access to information on a contracting partner’s risk preferences interact in affecting contracting and investment decisions between the client and vendor. Comparing subject decisions with the conditionally optimal benchmarks we arrive at two observations that highlight possible heuristic decision biases. Firstly, subjects tend to set and hold on to an inefficiently high investment level even though it is theoretically optimal to adjust decisions under changing differences in risk preferences. Secondly, subjects tend to set and hold on to a penalty that is too high when interacting with more risk averse vendors and too low in case the vendor is equally risk averse. Furthermore, cognitive feedback on the vendor’s risk aversion appears to have counterproductive effects on subject’s performance in the experiment, suggesting cognitive overload can have a reinforcing effect on the heuristic decision biases observed. In the third study we construct a new analytical model to examine the effect of contract design on a provider's response capacity allocation in a setting where multiple clients may be disrupted and available response capacity is limited. The results show that while clients may be incentivized to identify and report network disruptions, competition for scarce emergency resources and the required investment in understanding their own exposure may incentivize clients to deliberately miscommunicate with the vendor.
123

The Effect of Superheat on Liquid Droplets in a Supersonic Freestream

Newman, Aaron W. 11 May 1999 (has links)
The effect of superheat on the disruption of liquid droplets in a compressible gas flow was investigated experimentally in a small-scale, supersonic wind tunnel. Aerodynamically generated ethanol droplets of an average diameter of 0.1 mm were injected via a normal sonic jet into a Mach 1.8 freestream. Both nonsuperheated and superheated droplets were injected with initial Weber numbers of approximately 700. The droplets and flow structure were photographed using the shadowgraph method. The relatively high momentum of the liquid droplets typically caused them to pass out of the sonic jet structure. Nonsuperheated droplets showed no signs of disrupting after traveling over 200 mm downstream from the injection point. Only droplets with injection temperatures above the predicted boiling point at tunnel freestream static pressure (48°C) showed signs of disruption, typically after they left the sonic jet structure (30 to 100 mm downstream of the injection point). Droplets in this range of temperatures appeared to begin to boil from the downstream side of the droplet, shedding a vapor cloud before disrupting completely in the chaotic mode. Droplets with temperatures above the boiling point at the exit plane of the sonic jet began to disrupt in the chaotic mode almost instantly (within 1 exit nozzle diameter).
124

Recomendações para o uso de BIM 4D na gestão de empreendimentos habitacionais de retrofit

Souza, Fernanda Justin Chaves de January 2015 (has links)
Os empreendimentos de retrofit vem ganhando destaque dentro do segmento de construção habitacional, dado o aumento de idade do estoque existente. A gestão de empreendimentos de retrofit apresenta muitos desafios, principalmente quando a execução da obra ocorre em edificações ocupadas. Em geral, há muitos desafios ligados às perturbações causadas aos usuários destas edificações. Alguns estudos realizados indicam que o Building Information Modeling (BIM) tem contribuído para a gestão da produção de empreendimentos novos. Entretanto, no âmbito de retrofit, o BIM tem sido pouco explorado, principalmente quanto ao uso de modelagem 4D no processo de produção. O objetivo desta dissertação consiste em propor recomendações para o uso de BIM 4D na gestão da produção de empreendimentos habitacionais de retrofit. Tais recomendações tem como propósito auxiliar tomadores de decisão envolvidos na gestão deste tipo de empreendimento, particularmente no que se refere à identificação e minimização de perturbações que afetam os usuários finais durante a obra. A estratégia de pesquisa adotada neste trabalho foi a Design Science Research, na qual se buscou o desenvolvimento de um conjunto de prescrições para um problema real. Considerando o caráter exploratório desta pesquisa e algumas limitações no estudo empírico, a fase de compreensão do problema teve maior destaque do que a fase de implementação da solução. O estudo empírico foi realizado em uma obra na Irlanda do Norte, sendo que diferentes cenários de execução foram propostos para a execução da obra, utilizando BIM 4D para a identificação e redução das perturbações para os usuários finais. Entre as principais contribuições do trabalho, pode-se destacar a caracterização das perturbações causadas durante as obras de retrofit quando ocupadas pelos usuários, assim como o uso de cenários simulados com o uso de BIM 4D, na análise de planos alternativos nas etapas de projeto e produção. / There has been a growing interest in retrofit projects in the house building sector, given the increasing age of the existing building stock. In general, retrofit projects bring a number of challenges, especially when works are carried out in occupied buildings. Much of these challenges are related to disruptions caused to occupiers. Previous studies have indicated that Building Information Modeling (BIM) has contributed substantially in production management for new projects. However, the application of BIM in retrofit has not been much explored, especially concerning the use of 4D modelling to simulate production processes. The objective of this dissertation is to propose a set of guidelines for using 4D BIM for managing production in housing retrofit projects. Such recommendations were devised to support decision makers involved in the management of this type of project, particularly regarding the identification and minimization of disruptions that affect final users during the construction stage. Design Science Research was the research approach adopted in this investigation, in which a set of prescriptios were proposed for the solution of real problems. In the present study, the solution is a set of guidelines to be adopted by managers. Considering the exploratory character of this research work, and some limitations in the empirical study, the understanding the problem was the more emphasized than the implementation of the solution. The empirical study was developed in a construction project carried out in Nothern Ireland, in which different scenarios for the construction phase were developed using 4D BIM models, in order to identify and reduce disruptions to the end users. The main contributions of this investigation were related to the characterization of different types of disruption, and the use of scenarios simulated in BIM models developed for analyzing alternative plans during the design and production stages.
125

EletroflotaÃÃo nÃo-convencional Aplicada à SeparaÃÃo e Ruptura Celular de Microalgas: um AvanÃo na Viabilidade da GeraÃÃo de Biodiesel / Electroflotation unconventional Applied to Break Mobile and Separation of Microalgae: A Breakthrough in Generation Feasibility of Biodiesel

Anna PatrÃcya Florentino de Souza Silva 31 January 2013 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Embora todas as etapas do processo de produÃÃo de biodiesel a partir de microalgas sejam essenciais, a separaÃÃo e a ruptura celular da biomassa sÃo particularmente importantes, uma vez que as tecnologias disponÃveis para este fim apresentam elevados custos, comprometendo a viabilidade do aproveitamento energÃtico. Este trabalho teve como objetivo apontar um sistema que conseguisse aliar a separaÃÃo da biomassa algal de efluente de sistemas de lagoas de estabilizaÃÃo à ruptura celular, como uma alternativa de prÃ-tratamento para maximizar a extraÃÃo de lipÃdios pelo mÃtodo modificado de Bligh e Dyer; assim como estudar preliminarmente a comunidade fitoplanctÃnica presente para comparaÃÃo dos rendimentos lipÃdicos. Um reator de eletroflotaÃÃo nÃo-convencional foi confeccionado para operar em batelada e em fluxo contÃnuo, utilizando-se eletrodos nÃo consumÃveis e baixa potÃncia elÃtrica. A metodologia proposta foi comparada com tÃcnicas tradicionalmente utilizadas para ruptura celular: autoclave, micro-ondas e ultrassom. Foram selecionadas seis estaÃÃes de tratamento de esgotos (ETE) com diferentes configuraÃÃes de lagoas de estabilizaÃÃo para anÃlise dos gÃneros fitoplanctÃnicos dominantes e do teor lipÃdico. Observou-se a separaÃÃo da biomassa, sendo obtida eficiÃncia de remoÃÃo de turbidez superior a 80% em 20 minutos de operaÃÃo do reator em batelada. Entre os mÃtodos de prÃ-tratamento tradicionais testados, o micro-ondas foi o que apresentou maior rendimento lipÃdico (33,7  5,3%), diferente estatisticamente da autoclave (15,4  2,26%) e ultrassom (13,3  2,96%). Para a eletroflotaÃÃo nÃo-convencional o rendimento lipÃdico foi de 24,8  7,05%, que nÃo apresentou diferenÃa estatÃstica quando comparado ao micro-ondas. Entretanto, quando os custos energÃticos foram considerados, a eletroflotaÃÃo nÃoconvencional apresentou um custo de 5,6 Wh.g-1, sendo menor que o obtido para o micro-ondas. Os gÃneros de microalgas que predominaram nos efluentes analisados pertenciam Ãs classes Chlorophyceae, Cyanophyceae e Euglenophyceae. Em uma anÃlise quantitativa geral, os efluentes de todas as estaÃÃes analisadas apresentaram rendimento lipÃdico entre 8,5 e 34,6%. Os efluentes das ETE Aquiraz e TupÃ-Mirim apresentaram os maiores teores lipÃdicos (28,4  6,3% e 23,1  3,6%, respectivamente), sem diferenÃa estatÃstica (p=0,12). Os efluentes das ETE Araturi e Tabapuà apresentaram os menores potenciais lipÃdicos, sem diferenÃa estatÃstica entre eles (14,3  5,9% e 15,6  4,9%, respectivamente, p=0,68). A eletroflotaÃÃo nÃo-convencional mostrou-se como uma metodologia promissora para separaÃÃo e ruptura das cÃlulas de microalgas de efluentes de lagoas de estabilizaÃÃo, cujos potenciais lipÃdicos assemelharam-se aos obtidos a partir de biomassa microalgal cultivada em processos convencionais. AlÃm disso, a metodologia desenvolvida neste trabalho soma um motivo para a separaÃÃo e utilizaÃÃo da biomassa algal de lagoas de estabilizaÃÃo evitando, com isso, seu lanÃamento nos corpos dÂÃgua e garantindo um ganho econÃmico e ambiental, uma vez que visa o aproveitamento da biomassa para a produÃÃo de biocombustÃvel, ao passo que minimiza impactos ambientais decorrentes da presenÃa elevada desse material no ambiente. / Although all stages on the production of biodiesel from microalgae cells are essential, harvest and cell disruption biomass are particularly important, since the available technologies for this purpose present high cost, compromising energy recovery viability. This study aimed to develop a system that could combine separation of algal biomass from wastewater stabilization pond systems to cell disruption as an alternative of pretreatment to maximize total lipids extraction by the modified method of Bligh and Dyer, as well as perform a preliminary study of the phytoplankton for comparison of lipid content. A non-conventional electroflotation reactor was designed to operate in batch and continuous flow, using non-consumable electrodes and low electrical power. The proposed methodology was compared to traditional techniques used for cell disruption: autoclave, microwave and ultrasound. Six Wastewater Treatment Plant (WTP) with different pond configuration were selected for analysis of the dominant phytoplankton genera and lipid content. Biomass separation was achieved, with turbidity removal efficiency exceeding 70% in 20 minutes of operation with the batch reactor. Among the traditional pretreatment methods tested, the microwave showed the highest lipid yield (33.7  5.3%), followed by autoclave (15.4  2.26%) and ultrasound (13.3  2.96%). For non-conventional electroflotation methodology, lipid yield was 24.8  7.05%, which showed no statistical difference when compared to the microwave method. However, when energy cost was considered, non-conventional electroflotation presented a cost of 5.6 Wh.g-1, which was smaller than that obtained by the microwave method. The predominant microalgae genera in the analyzed effluents belonged to the classes Chlorophyceae, Cyanophyceae and Euglenophyceae. In a general quantitative analysis, the effluents from the analyzed ponds presented lipid yield between 8.5 and 34.6%. Effluents of the WTP Aquiraz and TupÃ-Mirim achieved the highest lipid content (28.4  6.3% and 23.1  3.6%, respectively), with no statistical difference (p = 0.12). Effluents of the WTP Araturi and Tabapuà achieved the lowest lipidic potential, with no statistical difference (14.3  5.9% and 15.6  4.9%, respectively, p = 0.68). Non-conventional electroflotation proved to be a promising methodology for harvesting and cell disruption of microalgae provided by effluent stabilization ponds, whose potential lipid resembled those obtained from microalgal biomass cultivated in conventional processes. Furthermore, the methodology developed in this work adds a reason for the harvesting and utilization of algal biomass from waste stabilization ponds avoiding, thus, its release into water bodies and ensuring an environmental and economic gain, since it aims the use of biomass for biofuel production, while minimizing environmental impacts due to elevated presence of this material on the environment.
126

Efeitos da exposição pré-púbere ao herbicida glifosato no desenvolvimento reprodutivo de ratos Wistar machos / Effects of the prepubertal exposure to glyphosate herbicide on reproductive development of male Wistar rats

Renata Marino Romano 14 December 2007 (has links)
O glifosato-Roundup é um herbicida amplamente utilizado em diversas culturas agrícolas. Sua toxicidade reprodutiva está relacionada com a inibição da proteína StAR e da enzima aromatase, causando in vitro redução significativa da produção de testosterona e estradiol. Este trabalho teve como objetivo verificar esse efeito in vivo, utilizando-se ratos Wistar machos pré-púberes como modelo experimental. Utilizou-se 68 machos tratados dos 23 aos 53 dias de idade com as doses de 0, 5, 50 e 250 mg/kg de peso vivo por gavagem uma vez ao dia. Foram avaliados a progressão da puberdade, o desenvolvimento corporal, a produção hormonal de testosterona, estradiol e corticosterona, morfologia testicular e da glândula adrenal, função renal e hepática e histopatologia renal e hepática. As análises estatísticas utilizadas foram a análise de variâncias de uma via ANOVA, de duas vias MANOVA ou Kruskall-Walis e pós-testes de Tukey-Kramer, Fisher ou de Dun. O herbicida glyphosate-Roundup alterou de forma significativa a progressão da puberdade de forma dose dependente, bem como se observou a redução na produção de testosterona e alterações na morfologia dos túbulos seminíferos. A morfologia da glândula adrenal e a produção de corticosterona não foram afetadas pelas doses utilizadas nesse estudo. Observou-se comprometimento da função renal e alterações patológicas nesse órgão. Não foram evidenciadas alterações hepáticas. O crescimento corporal dos animais não foi influenciado pelo tratamento. Pode-se concluir que esse herbicida é um potente disruptor endócrino in vivo, causando distúrbios no desenvolvimento reprodutivo e na produção hormonal dos animais. / The glyphosate-Roundup is a widely pesticide used in several culturas agrícolas. Its reproductive toxicity is associated to inhibition of StAR protein and aromatase enzime that cause in vitro significantly reduction in testosterone and estradiol production. The objective of this study was to evaluate the in vivo effects of inhibition of StAR protein and aromatase enzyme, using prepubertal male Wistar rats like experimental model. 68 animals were exposed once a day by gavage to glyphosate-Roundup in following doses: 0, 5, 50 or 250 mg/kg of body weight. The end points were puberty progression, body development, testosterone, estradiol and corticosterona productions and testicular and adrenal morphology, renal and liver function and histopatology. The statistical analysis used were one-way ANOVA, multi-way ANOVA or Kruskall-Walis and posthoc tests of Tukey-Kramer, Fisher or Dun. The herbicide glyphosate-Roundup changed significantly the puberty progression in dose-dependent manner, as well reduction in testosterone production and alterations in testicular morphology. There were not observed alterations in adrenal morphology or corticosterone production in the doses used in this study. The renal function and histopatology were altered in treated groups while liver function wasn\'t. The body development was not influenced by the exposure. In conclusion, glyphosate-Roundup is a potent endocrine disruptor in vivo that cause problems in reproductive development and hormonal synthesis in exposure animals.
127

Ontogénèse de l’axe gonadotrope chez le bar européen (Dicentrarchus labrax) et effets des xénoestrogènes sur sa mise en place / Ontogenesis of gonadotropic axis in European sea bass (Dicentrarchus labrax) and effects of xenoestrogenes on its setting up

Nihoul, Florent 19 September 2019 (has links)
Les perturbateurs endocriniens (PE) sont une préoccupation majeure de par leurs effets sur les grandes fonctions physiologiques des organismes etparticulièrement sur la fonction de reproduction. Chez les vertébrés, la reproduction est sous le contrôle d’un axe neuroendocrinien nommé axegonadotrope. Celui-ci comprend différents acteurs cérébraux (gonadolibérines et kisspeptines), hypophysaires (gonadotropines) et gonadiques(stéroïdes sexuels) dont la mise en place et le fonctionnement sont régulés finement. Parmi les mécanismes de régulation, les stéroïdes vont jouer unrôle important en effectuant des boucles de rétrocontrôle. Les PE mimant ces stéroïdes sont donc potentiellement capables d’impacter ces régulations.L’objectif de ce travail était d’évaluer les effets d’un xénooestrogène sur les mises en place des acteurs cérébraux impliqués dans l’axe gonadotrope chezle bar européen (Dicentrarchus labrax). Nous avons d’abord décrit l’ontogénèse des systèmes à kisspeptine, à gonadolibérine et à gonadotropine aucours du développement larvaire. Nous avons mis en évidence une régulation différentielle de ces acteurs suggérant un rôle durant ce processusdéveloppemental. De plus, nous montrons que le 17α-éthinylestradiol (EE2) est capable de perturber l'ontogenèse des systèmes à GnRH2 et à GnRH3au cours des stades précoces du développement larvaire.Ces données constituent une base permettant l’évaluation des effets des PE sur l’ontogénèse des systèmes neuroendocriniens. / Endocrine disruptors (EDs) are a major concern because of their effects on the main physiological functions, particularly on the reproductive function.In vertebrates, reproduction is under the control of a neuroendocrine axis called hypothalamic-pituitary-gonadal (HPG) axis. It includes various actors atthe brain (gonadotropin releasing hormones (GnRH) and kisspeptins), pituitary (gonadotropic hormones) and gonadal (sex steroids) levels. Theirdévelopment and functioning are finely regulated. Among the regulators, steroids play an important role by performing feedback loops. EDs mimickingsteroids are therefore potentially able to impact these regulations. The objective of this work was to evaluate the effects of xenoestrogens on theimplementation of cerebral actors involved in the HPG axis in the European sea bass (Dicentrarchus labrax). We first described the ontogeny of thekisspeptin, GnRH and gonadotropin systems during larval development. We have highlighted a differential regulation of these actors suggesting a roleduring this developmental process. In addition, we show that 17α-ethinylestradiol (EE2) is able to disrupt the ontogeny of GnRH2 and GnRH3 systemsduring the early stages of larval development.These data provide a basis for evaluation of the EDs effects on the ontogeny of neuroendocrine systems.
128

A Phenomenological Exploration of Parent Experiences that Influence Positive Adoption Outcomes

Shelton, Deena 01 January 2018 (has links)
Children who age out of foster care face adjustments and mental health issues at higher rates than their peers, but those who are adopted have the opportunity to heal from previous trauma and experience better outcomes. To create healthy family systems for adopted children, adoptive parents need support and guidance as they personally adjust and help their children adjust to a new family system. Previous research has focused on child identifiers rather than on the broader family system in efforts to understand adoption success and failure. In this transcendental phenomenological study, adoptive parents provided their lived experiences of support during the adoption process. The results were analyzed using Giorgi, Giorgi, and Morley's descriptive phenomenological psychological method and the results were framed using an adapted version of Bronfenbrenner's ecological model. The results offered experiences of support at all 4 levels of the ecological model and provided a framework to use for future research to understand the influences of the sources of support and a guideline for agencies and counselors to use when serving adoptive families. The results can aid in the proactive development of training and support services for adoptive families and provide information for professionals by offering insight into the nontraditional structure of adoptive families. This information may also be used to inform counseling programs accredited by the Council for Accreditation of Counseling and Related Educational Programs that offer the marriage, couples, and families specialization.
129

ACCULTURATIVE STRESS AND IDENTITY NEGOTIATION: A DYADIC EXPERIENCE

de la Serna, Ana X. 01 January 2018 (has links)
Institutions of higher education in the United States have long been attractors for international students from all over the world. The number of international students had been constantly growing until the past couple of years. This is a concerning issue because international students play several important roles in higher education institutions. International students bring different points of view that enhance other students’ learning and institutions gain financial benefits from the presence of international students. Thus, it is important to understand how to improve the experience of international students. For the present study I used a phenomenological approach to explore the experiences of international students and their spouses. Participants in this study included 16.5 dyads from 12 different countries. The sample included both graduate international students and their spouses for various reasons. When studying acculturation, studies have traditionally focused on undergraduate students. The needs and experiences of undergraduate students are different from graduate students because they are usually in a different stage of life. It is also true that graduate students often relocate with their dependents, unlike undergraduate students, and therefore they have different challenges and responsibilities. It is important to include spouses because they are often an invisible population. Dependents have critical limitations such as the prohibition to work or study. This study was conducted through the lens of biographical disruption and participants’ accounts were analyzed to better understand the added communication work that they must manage. The findings showed that there was a relationship between acculturation categories and the amount and type of acculturation work. Finally, the study shows how international students and their dependents reconstruct their biographies by molding their identities. This study should be used to create new policies and services for international students and their dependents.
130

THE INFLUENCE OF DIRECT-TO-CONSUMER GENETIC TEST RESULTS ON THE FINALIZATION OF FOSTER ADOPTION

Hanson, John 01 June 2017 (has links)
ABSTRACT The purpose of the present study was to explore the potential influence of direct-to-consumer genetic test results of a pre-adoptive foster child on the decision of the prospective adoptive foster parents to finalize or disrupt their adoption of the foster child. A quantitative survey was conducted using a sample of foster parents with three distinct statuses as a foster parent. They included, foster parents in the process of adopting their foster child, foster parents awaiting placement of a foster child in their home, and individuals in the process of completing training to become foster parents. The study participants were from a foster family agency that specializes in foster adoptions and all study participants had indicated they wanted to adopt a foster child. The foster family agency has two locations, one in Orange County and the other in San Bernardino County. Study data was collected through the use of a self-report questionnaire at five different foster family agency events. Twelve original survey questions were designed to measure three core areas: knowledge of prospective adoptive foster parents on the information direct-to-consumer genetic testing can provide; attitudes of prospective adoptive foster parents regarding the use of direct-to-consumer genetic testing as a pre-adoption screening tool; and, if direct-to-consumer genetic test results of a foster child influences the decision of prospective adoptive foster parents to finalize or disrupt a foster adoption. Using SPSS software to analyze data, descriptive statistics, Pearson correlation analyses were conducted between the three different foster parent statuses and the four questions designed to measure the core area of if direct-to-consumer genetic test results of a foster child influences the decision of prospective adoptive foster parents to finalize or disrupt a foster adoption. More than half of the survey participants, identified as women (n=39, 54.9%) and 32 (23.9%) identified as men. Results showed that there was a significant relationship found between the direct-to-consumer genetic test results of a foster child to influence the prospective adoptive foster parent to stop adoption proceedings for the child with the status of foster parents awaiting placement of the first foster child into their home.

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