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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.
11

Sebepojetí žáků se specifickou poruchou učení ve skupinové a individuální integraci / Self-concept of pupils with specific learning disability in group and individual integration

Pauková, Barbora January 2014 (has links)
TITLE: "Self-concept of pupils with specific learning disability in group and individual integration" AUTHOR: Bc. Barbora Paukova DEPARTMENT: Special education department THESIS SUPERVISOR: Mgr. Lenka Felcmanova ABSTRACT: The major topic of the diploma thesis named "Self-concept of pupils with specific learning disability in group and individual integration" is the different self-concept of success rate of older school age pupils with specific learning disability who are educated in a form of individual integration and in a form of group integration. The theoretical foundation of the thesis deals with the term of specific learning disability, with its terminology, definition, causes, classification and reeducation. It further focuses on the education of pupils with specific learning disability, on the term of self-concept and on the older school age period. Practical part of the thesis includes the quantitative research made using the standardized SPAS questionnaire. Methodology of the research, research preconditions, targets of the research, analysis of the collected data and evaluation of the research results are described in the thesis. KEY WORDS: Specific learning disability, older school age, self-concept, individual integration, group integration
12

Efeitos de idade na sobrevivência aparente de aves de sub-bosque na floresta Amazônica

Pizarro Muñoz, Jenny Alejandra January 2016 (has links)
A observação de gradientes latitudinais em aspectos da história de vida de aves tem motivado o estudo da evolução e variabilidade das histórias de vida nestes organismos. Um exemplo bem documentado é a variação no tamanho da ninhada, onde aves de latitudes menores tendem a ter ninhadas menores do que os seus homólogos de latitudes altas. Uma hipótese que visa explicar esta variação propõe que a sobrevivência em latitudes tropicais é maior para compensar o tamanho da ninhada menor e evitar a extinção das populações. Esta explicação tem tido grande aceitação e apoio por parte de alguns estudos, mas tem sido questionada por outros que não encontraram taxas de sobrevivência mais elevadas em aves tropicais. De modo implícito, todos estes estudos basearam seus resultados na sobrevivência de indivíduos adultos. As populações com o tamanho da ninhada menor não poderiam crescer da mesma maneira que as populações com ninhadas maiores; portanto, se justifica acreditar que algo deve mudar com a latitude para manter o balanço em tamanho populacional. Na busca por explicações alternativas para a persistência das populações de aves tropicais com relativamente pequenos tamanhos de ninhada, surge outra hipótese que propõe que, se não houver diferenças na sobrevivência de indivíduos adultos entre latitudes, o aspecto fundamental que varia é a sobrevivência juvenil, com sobrevivência maior para os juvenis das zonas tropicais em comparação com os juvenis das zonas temperadas. No entanto, atualmente há pouca evidência que suporta esta conclusão. Os resultados contrastantes desses estudos sugerem a falta de um consenso geral sobre a hipótese de que as aves tropicais têm taxas de sobrevivência mais elevadas do que as aves de regiões temperadas, motivando a formulação de hipóteses alternativas e convidando novos testes de hipótese. Neste estudo, pretendemos a) avaliar o efeito da idade sobre a sobrevivência em aves tropicais, estimando as probabilidades anuais de sobrevivência aparentes idade-específicas para um conjunto de aves passeriformes de sub-bosque na Amazônia central brasileira; e b) contribuir para o debate sobre o gradiente latitudinal na sobrevivência de adultos, comparando nossas estimativas com estimativas de outras latitudes. Para estimar a sobrevivência idade-específica ajustamos aos nossos dados um modelo Cormack-Jolly-Seber (CJS) hierárquico para n espécies, que trata os parâmetros espécie-específicos como efeitos aleatórios, que são estimados e que descrevem todo o conjunto de espécies; para comparação de métodos, ajustamos uma versão de efeitos fixos do modelo. Para a determinação da idade das aves usamos o sistema WRP. Apresentamos uma nova variante do modelo CJS com um parâmetro de mistura para a sobrevivência de aves de idade incerta no momento da primeira captura. Encontramos efeito forte da idade na sobrevivência, com probabilidades de sobrevivência menor para os jovens do que para os adultos; evidência de efeito latitude sobre a sobrevivência, que suporta a hipótese amplamente aceita de variação na sobrevivência com a latitude; e discutimos diferenças metodológicas interessantes entre modelo de efeitos aleatórios e fixos relacionados com a precisão das estimativas e o âmbito de inferência, que nos levam a concluir que os modelos de efeitos aleatórios são os mais adequados para a nossa análise. Concluímos que não é necessário invocar uma hipótese alternativa de maior sobrevivência juvenil nos trópicos a fim de explicar o gradiente latitudinal no tamanho da ninhada. / The observation of latitudinal gradients in bird life history traits has motivated the study of avian life history evolution and variability. A well-documented example is the variation in clutch size, where lower latitude birds tend to have smaller clutches than their higher latitude counterparts. A hypothesis that explains this variation proposes that survival in tropical latitudes is higher to compensate for smaller clutch size and prevent population extinctions. This explanation has had a wide acceptance and support by some studies, but has been questioned by others who have not found such higher survival rates in tropical birds. In an implicit manner, all these studies have based their results on adult survival. Populations with smaller clutch size would not be able to grow as well as populations with larger clutches; therefore one is justified to believe that something else must change with latitude. In the search for alternative explanations to the persistence of tropical bird populations with relatively small clutch sizes it has also been proposed that, if there were no differences in adult survival among latitudes, the fundamental trait that varies is juvenile survival, with higher survival rates for tropical juveniles birds than for temperate ones. However, currently there is little evidence that supports this conclusion. The contrasting results of those studies suggest a lack of a general consensus about the hypothesis that tropical birds have higher survival rates than birds of temperate regions, motivating the formulation of alternative hypotheses, and inviting further tests of the hypothesis. In our study we aim to a) assess the effect of age on survival in a tropical bird community, estimating age-specific annual apparent survival probabilities for a set of passerine understory birds from the central Brazilian Amazon; and b) contribute to the debate about the latitudinal gradient in adult survival by comparing our adult survival estimates to estimates of temperate-zone adult survival probabilities. To estimate the age-specific survival we fit to our data a hierarchical multispecies Cormack-Jolly-Seber (CJS) model for n species, that treats species-specific parameters as random effects that are estimated and that describe the whole assemblage of species; for comparison of methods, we also fit a fixed-effects version of the model. To age birds we use the cycle-based WRP system. We introduce a novel variant of CJS model with a mixture component for the survival of birds of uncertain age at the time of banding. We found strong effect of age on survival, with juveniles surviving less than adults; evidence of latitude effect on survival, that supports the widely accepted hypothesis of variation on survival with latitude; and methodological differences between random and fixed effects model related to precision of estimates and scope of inference, that lead us to conclude that random-effects models are more appropriate for our analysis. We conclude that there is no reason for an alternative latitudinal trend in juvenile survival to account for the general trend in clutch size.
13

"Se mig, för här är jag" : Lärares resonemang kring innebörden av begreppet individanpassad undervisning i skolår 1 / "Notice me, here I am" : Teacher’s dictums of the definition individual tuition in school year 1

Andersson, Ann-Louise, Andersson, Marica January 2009 (has links)
Läroplan för det obligatoriska skolväsendet, fritidshemmet och förskoleklassen, (Lpo94) är tydlig i sin definition att en individanpassad undervisning ska tillämpas i skolan och att undervisningen ska utgå från den enskilde elevens behov. Då forskning pekar på att definitionen och innebörden av begreppet behov inte är tydlig fann vi det intressant att undersöka hur lärare definierar innebörden av begreppet individanpassad undervisning i år 1 med särskilt fokus på aspekten elevers behov. För att studera verksamma lärares resonemang kring detta valdes en kvalitativ metod med intervjuer som hjälpmedel för att samla in data. Det insamlade materialet har analyserats och därefter diskuterats med referens till forskning inom området. Resultatet visar att individanpassad undervisning ses som en förutsättningsfråga. Identifieringen av enskilda elevers behov är det som uppfattas ligga till grund för hur undervisningen ska individanpassas. Svårigheten ligger i att det inte alltid är enkelt att identifiera behoven. Det framkom i resultatet att möjligheten att individanpassa grundar sig i tillgången på resurser samt skolämnets karaktär. Resultatet visar även att åldersintegrerade klasser är en fördel med tanke på tillgången på resurser, då samarbete i arbetslag lättare möjliggör en individanpassad undervisning. / Curriculum for the Compulsory School System, the Pre-School Class and the Leisure-time Centre (Lpo 94) is clear in its definition that individualized tuition shall be applied in the school and that the tuition shall come from the individual pupil’s needs. Since research emphasizes that the definition and meaning of the term needs is not clear we found it interesting to research how teachers define the meaning of the term individualized tuition in school year 1 with special focus on the aspect of pupils’ needs. In order to study active teachers’ reasoning and dictums regarding this we chose a qualitative method with interviews as aid to gather data. The collected material has been analyzed and subsequently discussed with reference to research within the area. The result shows that individualized tuition is regarded as a question of conditions. The identification of individual pupils’ needs is what is perceived to be the basis of how the education should be individualized. The difficulty lies in that it is not always easy to identify the needs. The result showed that the possibility to individualize bases itself in the access of resources and the school subject’s nature. The result also show that age integrated classes is an advantage considering the access of resources, since cooperation between coworkers makes it easier to enable individualized tuition.
14

Dying to make a fresh start : mortality and health transition in a new South Africa

Kahn, Kathleen January 2006 (has links)
Rationale: Vital registration is lacking in developing settings where health and development problems are most pressing. Policy-makers confront an “information paradox”: the critical need for information on which to base priorities and monitor progress, and the profound shortage of such information. Aims: To better understand the dynamics of mortality transition in rural South Africa over a decade of profound socio-political change coupled with emerging HIV/AIDS. Thereby to inform health and development programming, policy formulation, and the research agenda; and contribute to debate on the nature of the ‘health transition’. Methods: The Agincourt health and demographic surveillance system is based on continuous monitoring of the Agincourt sub-district population in rural north-east South Africa. This involves annual recording of all vital events, specifically deaths, births and migrations in 11,700 households comprising some 70,000 persons. A “verbal autopsy” is conducted on every death, and special modules provide additional data. Key findings: A major health transition has occurred over the past decade, with marked changes in population structure and rapidly escalating mortality particularly among children and younger adults. A quadruple burden of disease is evident with persisting infectious disease and malnutrition in children, emerging non-communicable disease in the middle-aged and older, high levels of violence in an apparently peaceful community, and rapidly escalating HIV/AIDS and tuberculosis. There is evidence of sex differences and socio-economic differentials in mortality; vulnerable sub-groups include the children of Mozambican immigrants and recently returned labour migrants. Implications: With respect to health transition, empirical data demonstrate a marked “counter transition” with mortality increasing in children and young adults; “epidemiologic polarization” is evident with the most vulnerable experiencing a higher mortality burden; and a “protracted transition” is reflected in the co-existence of persisting infectious disease and malnutrition, emerging HIV/AIDS, and increasing chronic non-communicable disease. With respect to health policy and practice there is urgent need to: strengthen HIV/AIDS prevention, treatment and care; offer effective long-term care to control the rising burden of chronic illness and related risk; maintain and improve maternal and child health services; and address differential access to care. This poses a substantial challenge to a severely stretched health system.
15

Epidemiologie chronisch entzündlicher Darmerkrankungen bei Kindern und Jugendlichen in Sachsen sowie jungen Erwachsenen in Leipzig

Zurek, Marlen 13 June 2013 (has links) (PDF)
Hintergrund: Angaben zu Inzidenz und Prävalenz von chronisch entzündlichen Darmerkrankungen (CED) bei Kindern und Jugendlichen in Deutschland fehlen bisher, die Daten des im Jahr 2000 gegründeten Sächsischen CED-Registers für Kinder und Jugendliche wurden bisher nicht veröffentlicht. Bei internen Diskussionen der Registerdaten zeigte sich stets eine nicht erklärbare abfallende altersspezifische Inzidenz der CED ab dem 15. Lebensjahr. Es wurde vermutet, dass einige ältere Jugendliche ausschließlich von Erwachsenengastroenterologen betreut wurden und bei einigen Adoleszenten eine längere diagnostische Latenz zur Diagnosestellung nach dem 18. Lebensjahr führte. Patienten und Methoden: Zur Prüfung der Thesen wurden alle gastroenterologisch tätigen Internisten in Leipzig aufgesucht und Patienten eingeschlossen, bei denen bis zum 26. Lebensjahr in den Jahren 2005-2009 eine CED endoskopisch neu diagnostiziert wurde. Die Auswertung des Sächsischen CED-Registers erfolgte hinsichtlich Inzidenz, Prävalenz, Geschlechterverteilung und diagnostischer Latenz im Zehnjahreszeitraum 2000-2009. Ergebnisse: Es wurden tatsächlich einige Jugendliche vor dem 18. Lebensjahr ausschließlich von Internisten betreut und nicht an das Register gemeldet. Die korrigierte Inzidenz von CED bei Patienten bis zum 18. Lebensjahr in Leipzig lag um 37 % höher als im Register angegeben. Nach dem 15. Lebensjahr wurde – ebenfalls in Abweichung zu den Registerdaten – ein kontinuierlicher Anstieg der altersspezifischen Inzidenz bis zum 18. Lebensjahr registriert. Es zeigte sich eine Tendenz zur längeren diagnostischen Latenz bei Adoleszenten, die sich jedoch nicht statistisch sichern ließ. Bis zum 15. Lebensjahr wurden nahezu alle Patienten im CED-Register erfasst.
16

"Se mig, för här är jag" : Lärares resonemang kring innebörden av begreppet individanpassad undervisning i skolår 1 / "Notice me, here I am" : Teacher’s dictums of the definition individual tuition in school year 1

Andersson, Ann-Louise, Andersson, Marica January 2009 (has links)
<p>Läroplan för det obligatoriska skolväsendet, fritidshemmet och förskoleklassen, (Lpo94) är tydlig i sin definition att en individanpassad undervisning ska tillämpas i skolan och att undervisningen ska utgå från den enskilde elevens behov. Då forskning pekar på att definitionen och innebörden av begreppet behov inte är tydlig fann vi det intressant att undersöka hur lärare definierar innebörden av begreppet individanpassad undervisning i år 1 med särskilt fokus på aspekten elevers behov. För att studera verksamma lärares resonemang kring detta valdes en kvalitativ metod med intervjuer som hjälpmedel för att samla in data. Det insamlade materialet har analyserats och därefter diskuterats med referens till forskning inom området. Resultatet visar att individanpassad undervisning ses som en förutsättningsfråga. Identifieringen av enskilda elevers behov är det som uppfattas ligga till grund för hur undervisningen ska individanpassas. Svårigheten ligger i att det inte alltid är enkelt att identifiera behoven. Det framkom i resultatet att möjligheten att individanpassa grundar sig i tillgången på resurser samt skolämnets karaktär. Resultatet visar även att åldersintegrerade klasser är en fördel med tanke på tillgången på resurser, då samarbete i arbetslag lättare möjliggör en individanpassad undervisning.</p> / <p>Curriculum for the Compulsory School System, the Pre-School Class and the Leisure-time Centre (Lpo 94) is clear in its definition that individualized tuition shall be applied in the school and that the tuition shall come from the individual pupil’s needs. Since research emphasizes that the definition and meaning of the term needs is not clear we found it interesting to research how teachers define the meaning of the term individualized tuition in school year 1 with special focus on the aspect of pupils’ needs. In order to study active teachers’ reasoning and dictums regarding this we chose a qualitative method with interviews as aid to gather data. The collected material has been analyzed and subsequently discussed with reference to research within the area. The result shows that individualized tuition is regarded as a question of conditions. The identification of individual pupils’ needs is what is perceived to be the basis of how the education should be individualized. The difficulty lies in that it is not always easy to identify the needs. The result showed that the possibility to individualize bases itself in the access of resources and the school subject’s nature. The result also show that age integrated classes is an advantage considering the access of resources, since cooperation between coworkers makes it easier to enable individualized tuition.</p>
17

Efeitos de idade na sobrevivência aparente de aves de sub-bosque na floresta Amazônica

Pizarro Muñoz, Jenny Alejandra January 2016 (has links)
A observação de gradientes latitudinais em aspectos da história de vida de aves tem motivado o estudo da evolução e variabilidade das histórias de vida nestes organismos. Um exemplo bem documentado é a variação no tamanho da ninhada, onde aves de latitudes menores tendem a ter ninhadas menores do que os seus homólogos de latitudes altas. Uma hipótese que visa explicar esta variação propõe que a sobrevivência em latitudes tropicais é maior para compensar o tamanho da ninhada menor e evitar a extinção das populações. Esta explicação tem tido grande aceitação e apoio por parte de alguns estudos, mas tem sido questionada por outros que não encontraram taxas de sobrevivência mais elevadas em aves tropicais. De modo implícito, todos estes estudos basearam seus resultados na sobrevivência de indivíduos adultos. As populações com o tamanho da ninhada menor não poderiam crescer da mesma maneira que as populações com ninhadas maiores; portanto, se justifica acreditar que algo deve mudar com a latitude para manter o balanço em tamanho populacional. Na busca por explicações alternativas para a persistência das populações de aves tropicais com relativamente pequenos tamanhos de ninhada, surge outra hipótese que propõe que, se não houver diferenças na sobrevivência de indivíduos adultos entre latitudes, o aspecto fundamental que varia é a sobrevivência juvenil, com sobrevivência maior para os juvenis das zonas tropicais em comparação com os juvenis das zonas temperadas. No entanto, atualmente há pouca evidência que suporta esta conclusão. Os resultados contrastantes desses estudos sugerem a falta de um consenso geral sobre a hipótese de que as aves tropicais têm taxas de sobrevivência mais elevadas do que as aves de regiões temperadas, motivando a formulação de hipóteses alternativas e convidando novos testes de hipótese. Neste estudo, pretendemos a) avaliar o efeito da idade sobre a sobrevivência em aves tropicais, estimando as probabilidades anuais de sobrevivência aparentes idade-específicas para um conjunto de aves passeriformes de sub-bosque na Amazônia central brasileira; e b) contribuir para o debate sobre o gradiente latitudinal na sobrevivência de adultos, comparando nossas estimativas com estimativas de outras latitudes. Para estimar a sobrevivência idade-específica ajustamos aos nossos dados um modelo Cormack-Jolly-Seber (CJS) hierárquico para n espécies, que trata os parâmetros espécie-específicos como efeitos aleatórios, que são estimados e que descrevem todo o conjunto de espécies; para comparação de métodos, ajustamos uma versão de efeitos fixos do modelo. Para a determinação da idade das aves usamos o sistema WRP. Apresentamos uma nova variante do modelo CJS com um parâmetro de mistura para a sobrevivência de aves de idade incerta no momento da primeira captura. Encontramos efeito forte da idade na sobrevivência, com probabilidades de sobrevivência menor para os jovens do que para os adultos; evidência de efeito latitude sobre a sobrevivência, que suporta a hipótese amplamente aceita de variação na sobrevivência com a latitude; e discutimos diferenças metodológicas interessantes entre modelo de efeitos aleatórios e fixos relacionados com a precisão das estimativas e o âmbito de inferência, que nos levam a concluir que os modelos de efeitos aleatórios são os mais adequados para a nossa análise. Concluímos que não é necessário invocar uma hipótese alternativa de maior sobrevivência juvenil nos trópicos a fim de explicar o gradiente latitudinal no tamanho da ninhada. / The observation of latitudinal gradients in bird life history traits has motivated the study of avian life history evolution and variability. A well-documented example is the variation in clutch size, where lower latitude birds tend to have smaller clutches than their higher latitude counterparts. A hypothesis that explains this variation proposes that survival in tropical latitudes is higher to compensate for smaller clutch size and prevent population extinctions. This explanation has had a wide acceptance and support by some studies, but has been questioned by others who have not found such higher survival rates in tropical birds. In an implicit manner, all these studies have based their results on adult survival. Populations with smaller clutch size would not be able to grow as well as populations with larger clutches; therefore one is justified to believe that something else must change with latitude. In the search for alternative explanations to the persistence of tropical bird populations with relatively small clutch sizes it has also been proposed that, if there were no differences in adult survival among latitudes, the fundamental trait that varies is juvenile survival, with higher survival rates for tropical juveniles birds than for temperate ones. However, currently there is little evidence that supports this conclusion. The contrasting results of those studies suggest a lack of a general consensus about the hypothesis that tropical birds have higher survival rates than birds of temperate regions, motivating the formulation of alternative hypotheses, and inviting further tests of the hypothesis. In our study we aim to a) assess the effect of age on survival in a tropical bird community, estimating age-specific annual apparent survival probabilities for a set of passerine understory birds from the central Brazilian Amazon; and b) contribute to the debate about the latitudinal gradient in adult survival by comparing our adult survival estimates to estimates of temperate-zone adult survival probabilities. To estimate the age-specific survival we fit to our data a hierarchical multispecies Cormack-Jolly-Seber (CJS) model for n species, that treats species-specific parameters as random effects that are estimated and that describe the whole assemblage of species; for comparison of methods, we also fit a fixed-effects version of the model. To age birds we use the cycle-based WRP system. We introduce a novel variant of CJS model with a mixture component for the survival of birds of uncertain age at the time of banding. We found strong effect of age on survival, with juveniles surviving less than adults; evidence of latitude effect on survival, that supports the widely accepted hypothesis of variation on survival with latitude; and methodological differences between random and fixed effects model related to precision of estimates and scope of inference, that lead us to conclude that random-effects models are more appropriate for our analysis. We conclude that there is no reason for an alternative latitudinal trend in juvenile survival to account for the general trend in clutch size.
18

Efeitos de idade na sobrevivência aparente de aves de sub-bosque na floresta Amazônica

Pizarro Muñoz, Jenny Alejandra January 2016 (has links)
A observação de gradientes latitudinais em aspectos da história de vida de aves tem motivado o estudo da evolução e variabilidade das histórias de vida nestes organismos. Um exemplo bem documentado é a variação no tamanho da ninhada, onde aves de latitudes menores tendem a ter ninhadas menores do que os seus homólogos de latitudes altas. Uma hipótese que visa explicar esta variação propõe que a sobrevivência em latitudes tropicais é maior para compensar o tamanho da ninhada menor e evitar a extinção das populações. Esta explicação tem tido grande aceitação e apoio por parte de alguns estudos, mas tem sido questionada por outros que não encontraram taxas de sobrevivência mais elevadas em aves tropicais. De modo implícito, todos estes estudos basearam seus resultados na sobrevivência de indivíduos adultos. As populações com o tamanho da ninhada menor não poderiam crescer da mesma maneira que as populações com ninhadas maiores; portanto, se justifica acreditar que algo deve mudar com a latitude para manter o balanço em tamanho populacional. Na busca por explicações alternativas para a persistência das populações de aves tropicais com relativamente pequenos tamanhos de ninhada, surge outra hipótese que propõe que, se não houver diferenças na sobrevivência de indivíduos adultos entre latitudes, o aspecto fundamental que varia é a sobrevivência juvenil, com sobrevivência maior para os juvenis das zonas tropicais em comparação com os juvenis das zonas temperadas. No entanto, atualmente há pouca evidência que suporta esta conclusão. Os resultados contrastantes desses estudos sugerem a falta de um consenso geral sobre a hipótese de que as aves tropicais têm taxas de sobrevivência mais elevadas do que as aves de regiões temperadas, motivando a formulação de hipóteses alternativas e convidando novos testes de hipótese. Neste estudo, pretendemos a) avaliar o efeito da idade sobre a sobrevivência em aves tropicais, estimando as probabilidades anuais de sobrevivência aparentes idade-específicas para um conjunto de aves passeriformes de sub-bosque na Amazônia central brasileira; e b) contribuir para o debate sobre o gradiente latitudinal na sobrevivência de adultos, comparando nossas estimativas com estimativas de outras latitudes. Para estimar a sobrevivência idade-específica ajustamos aos nossos dados um modelo Cormack-Jolly-Seber (CJS) hierárquico para n espécies, que trata os parâmetros espécie-específicos como efeitos aleatórios, que são estimados e que descrevem todo o conjunto de espécies; para comparação de métodos, ajustamos uma versão de efeitos fixos do modelo. Para a determinação da idade das aves usamos o sistema WRP. Apresentamos uma nova variante do modelo CJS com um parâmetro de mistura para a sobrevivência de aves de idade incerta no momento da primeira captura. Encontramos efeito forte da idade na sobrevivência, com probabilidades de sobrevivência menor para os jovens do que para os adultos; evidência de efeito latitude sobre a sobrevivência, que suporta a hipótese amplamente aceita de variação na sobrevivência com a latitude; e discutimos diferenças metodológicas interessantes entre modelo de efeitos aleatórios e fixos relacionados com a precisão das estimativas e o âmbito de inferência, que nos levam a concluir que os modelos de efeitos aleatórios são os mais adequados para a nossa análise. Concluímos que não é necessário invocar uma hipótese alternativa de maior sobrevivência juvenil nos trópicos a fim de explicar o gradiente latitudinal no tamanho da ninhada. / The observation of latitudinal gradients in bird life history traits has motivated the study of avian life history evolution and variability. A well-documented example is the variation in clutch size, where lower latitude birds tend to have smaller clutches than their higher latitude counterparts. A hypothesis that explains this variation proposes that survival in tropical latitudes is higher to compensate for smaller clutch size and prevent population extinctions. This explanation has had a wide acceptance and support by some studies, but has been questioned by others who have not found such higher survival rates in tropical birds. In an implicit manner, all these studies have based their results on adult survival. Populations with smaller clutch size would not be able to grow as well as populations with larger clutches; therefore one is justified to believe that something else must change with latitude. In the search for alternative explanations to the persistence of tropical bird populations with relatively small clutch sizes it has also been proposed that, if there were no differences in adult survival among latitudes, the fundamental trait that varies is juvenile survival, with higher survival rates for tropical juveniles birds than for temperate ones. However, currently there is little evidence that supports this conclusion. The contrasting results of those studies suggest a lack of a general consensus about the hypothesis that tropical birds have higher survival rates than birds of temperate regions, motivating the formulation of alternative hypotheses, and inviting further tests of the hypothesis. In our study we aim to a) assess the effect of age on survival in a tropical bird community, estimating age-specific annual apparent survival probabilities for a set of passerine understory birds from the central Brazilian Amazon; and b) contribute to the debate about the latitudinal gradient in adult survival by comparing our adult survival estimates to estimates of temperate-zone adult survival probabilities. To estimate the age-specific survival we fit to our data a hierarchical multispecies Cormack-Jolly-Seber (CJS) model for n species, that treats species-specific parameters as random effects that are estimated and that describe the whole assemblage of species; for comparison of methods, we also fit a fixed-effects version of the model. To age birds we use the cycle-based WRP system. We introduce a novel variant of CJS model with a mixture component for the survival of birds of uncertain age at the time of banding. We found strong effect of age on survival, with juveniles surviving less than adults; evidence of latitude effect on survival, that supports the widely accepted hypothesis of variation on survival with latitude; and methodological differences between random and fixed effects model related to precision of estimates and scope of inference, that lead us to conclude that random-effects models are more appropriate for our analysis. We conclude that there is no reason for an alternative latitudinal trend in juvenile survival to account for the general trend in clutch size.
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Stochastické modelování úmrtnosti pro více populací / Stochastic mortality modeling for multiple populations

Skřivanová, Zuzana January 2016 (has links)
Title: Stochastic mortality modelling for multiple populations Abstract: This thesis deals with the possibilities of modelling and forecasting of age-specific mortality rates. The introductory part summarizes the basic terms from demo- graphy, which are related to mortality, and specifies elementary approaches to the mortality modelling. Subsequently there are in detail described the three most commonly used stochastic mortality models - Lee-Carter, Renshaw-Haberman and Cairns-Blake-Dowd. The fundamental part of this thesis deals with the possi- bilities of using these models for mortality modelling simultaneously in correlated populations. These theoretical bases are in the final part of this thesis numerically illustrated on the mortality models for populations of Czech and Slovak Republic. 1
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A Case-Only Genome-wide Association Study of Gender- and Age-specific Risk Markers for Childhood Leukemia

Singh, Sandeep Kumar 26 March 2015 (has links)
Males and age group 1 to 5 years show a much higher risk for childhood acute lymphoblastic leukemia (ALL). We performed a case-only genome-wide association study (GWAS), using the Illumina Infinium HumanCoreExome Chip, to unmask gender- and age-specific risk variants in 240 non-Hispanic white children with ALL recruited at Texas Children’s Cancer Center, Houston, Texas. Besides statistically most significant results, we also considered results that yielded the highest effect sizes. Existing experimental data and bioinformatic predictions were used to complement results, and to examine the biological significance of statistical results. Our study identified novel risk variants for childhood ALL. The SNP, rs4813720 (RASSF2), showed the statistically most significant gender-specific associations (P < 2 x 10-6). Likewise, rs10505918 (SOX5) yielded the lowest P value (P < 1 x 10-5) for age-specific associations, and also showed the statistically most significant association with age-at-onset (P < 1 x 10-4). Two SNPs, rs12722042 and 12722039, from the HLA-DQA1 region yielded the highest effect sizes (odds ratio (OR) = 15.7; P = 0.002) for gender-specific results, and the SNP, rs17109582 (OR = 12.5; P = 0.006), showed the highest effect size for age-specific results. Sex chromosome variants did not appear to be involved in gender-specific associations. The HLA-DQA1 SNPs belong to DQA1*01:07and confirmed previously reported male-specific association with DQA1*01:07. Twenty one of the SNPs identified as risk markers for gender- or age-specific associations were located in the transcription factor binding sites and 56 SNPs were non-synonymous variants, likely to alter protein function. Although bioinformatic analysis did not implicate a particular mechanism for gender- and age-specific associations, RASSF2 has an estrogen receptor-alpha binding site in its promoter. The unknown mechanisms may be due to lack of interest in gender- and age-specificity in associations. These results provide a foundation for further studies to examine the gender- and age-differential in childhood ALL risk. Following replication and mechanistic studies, risk factors for one gender or age group may have a potential to be used as biomarkers for targeted intervention for prevention and maybe also for treatment.

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