Thesis (Ph.D. in Epidemiology, Dept. of Preventive Medicine and Biometrics) -- University of Colorado Denver, 2008. / Typescript. Includes bibliographical references (leaves 81-92). Free to UCD Anschutz Medical Campus. Online version available via ProQuest Digital Dissertations;

xiii, 198 p. : ill. (some col.) / Whether or not a causal relationship exists between climate and mammal body size is one of the longest-standing and most intractable questions in ecology. The classic model of body size evolution (Bergmann's Rule) holds that body size is driven by temperature, but more recent hypotheses have suggested that other climatic variables or biotic interactions may play a more important role. The use of paleoecological data to address this question allows variables that are tightly correlated in modern ecosystems to be teased apart and allows body size patterns to be observed through time, adding an extra dimension to analyses. This dissertation details the findings of two paleoecological tests of Bergmann's Rule in the Oligo-Miocene (30-5 Ma), one tracking body size and climate through time in the northwestern United States and another tracking geographic body size trends through time along the west coast of North America. In both cases, body size was analyzed in three representative families of mammals: equids, canids, and sciurids. Such large-scale analyses are dependent on fossils that can be placed in a reliable taxonomic, geologic, and temporal context, and this dissertation also focuses on a reevaluation of the canid fauna of Oregon's Juntura Formation that places a critically important Late Miocene carnivore fauna in just such a context. Two genera of canids - Epicyon and Carpocyon - are described from the fauna for the first time, with important implications for regional biostratigraphy. The body size analyses show no consistent relationship between body size and any climatic variable. Further, body size patterns vary widely between taxa at several levels, suggesting that one universal driver of body size evolution does not exist. Not only is there no evidence for Bergmann's Rule in Oligo-Miocene mammals, but comparative analyses of geographic body size patterns in the modern genera Odocoileus, Canis, and Spermophilus fail to show the latitudinal gradients upon which Bergmann's Rule is predicated. The apparent existence of such trends in some taxa may be the result of anthropogenic extirpation at low latitudes, further underscoring the importance of including paleontological data when formulating models predicting the response of biotic variables to environmental change. / Committee in charge: Dr. Samantha Hopkins， Chair； Dr. Gregory Retallack， Member； Dr. Rebecca Dorsey， Member； Dr. Stephen Frost， Outside Member

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-08-31T15:21:18Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertaçao Isabele Góes Nobre (1).pdf: 1399652 bytes, checksum: 5fc0dc11dec680183355feff43c22a5f (MD5) / Made available in DSpace on 2016-08-31T15:21:18Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertaçao Isabele Góes Nobre (1).pdf: 1399652 bytes, checksum: 5fc0dc11dec680183355feff43c22a5f (MD5) Previous issue date: 2016-02-23 / Os objetivos do presente estudo foram: a) analisar estudos que consideram os efeitos do baixo peso ao nascer (BPN) em crianças e sua relação com a antropometria e composição corporal durante o crescimento; b) descrever variáveis antropométricas e de composição corporal e metabolismo energético de acordo com o peso ao nascer; c) verificar a associação entre peso ao nascer, taxa metabólica de repouso (RMR) e gasto energético diário (DEE) com variáveis antropométricas e de composição corporal; d) estabelecer um modelo preditivo para RMR e DEE considerando a influência da antropometria, composição corporal e peso ao nascer em crianças de 7 a 10 anos de idade. Foram avaliadas 464 crianças (241 meninos e 223 meninas) nascidos em Vitória de Santo Antão (Nordeste do Brasil). Variáveis utilizadas: Antropometria (peso, altura, altura do assento, cintura, quadril, braço, perna e perímetro cefálico), composição corporal (dobras cutâneas, área muscular do braço e percentual de gordura corporal [% BF]), RMR e DEE. A noção de que o BPN pode promover um rearranjo no metabolismo energético é plausível. Há uma associação positiva entre o BPN e a redução do peso corporal, estatura, massa livre de gordura e um aumento da massa de gordura. Crianças de 8-10 anos com BPN apresentaram valores médios elevados para a maioria das variáveis quando comparado com crianças de 7 anos de idade, enquanto que para as com BPN, as diferenças estavam entre todas as idades analisadas. O peso ao nascer foi positivamente correlacionado com a circunferência da cabeça (8-10 anos), RMR, DEE, altura e %BF (9-10 anos). Todas as variáveis antropométricos e de composição corporal foram fortemente correlacionadas com RMR e DEE. A partir do modelo de regressão, a altura, circunferência do quadril, % BF, dobras cutâneas tricipital e subescapular foram preditores significativos para RMR e DEE, independentemente da idade. Preditores relevantes da RMR e DEE foram dobra cutânea bicipital aos 8 anos, circunferência da perna aos 9-10 anos, e prega cutânea supra-ilíaca em ambas as idades. O principal determinante da RMR e DEE foi % BF. Crianças com BPN apresentaram um déficit no ganho de medidas antropométricas e de composição corporal em todas as idades. Para o metabolismo energético, a variação na estrutura do corpo das crianças pode ser relacionada com a reestruturação do componente de gordura, uma vez que as diferenças observadas entre as idades estão ligados aos seus indicadores. / The goals of the present study were: a) To analyze studies that consider the effects of low birth weight children and the relationship with anthropometry and body composition during growth; b) To describe anthropometric and body composition variables and energy metabolism according to birth weight; c) to verify the association between birth weight, resting metabolic rate (RMR) and daily energy expenditure (DEE) with anthropometry and body composition variables; d) To stablish a predictive model for RMR and daily energy expenditure (DEE) considering the influence of anthropometry, body composition and birth weight in children at 7 to 10 years old. It was evaluated 464 children (241 boys and 223 girls) born in Vitoria de Santo Antão (Northeast of Brazil). Anthropometry (weight, height, sitting height, waist, hip, arm, leg and head circumferences), body composition (skinfold thickness, arm muscle area and body fat percentage [%BF]), RMR and DEE were evaluated. The notion that the low birth weight can promote an rearrangement in energy metabolism is plausible. There is a positive association between LBW and reduced body weight, body height, fat-free mass and an increase in fat mass. LBW children from 8 to 10y old showed high mean values for the most variables when compared to 7 y old, while for NBW children, the differences were among all ages analyzed. The birth weight was positively correlated with head circumference (8-10y old), RMR, DEE, sitting height and %BF (9-10y old). All anthropometric and body composition variables were strongly positively correlated with RMR and DEE. From the regression model, height, hip circumference, %BF, tricipital and subscapular skinfolds were significant predictors for RMR and DEE regardless age. Relevant predictors of RMR and DEE were bicipital skinfold at age 8y, leg circumference at 9-10y, and suprailiac skinfold in both ages. The major determinant of RMR and DEE was %BF. LBW children showed a deficit in gain of anthropometric and body composition measurements throughout age. For the energy metabolism, variation in body structure of children can be related to restructuring of the fat component, since the differences observed between ages are attached to their predictors.

Fatores ambientais abióticos, como o clima, possuem um efeito profundo sobre a biologia dos organismos e sua distribuição em diferentes habitats. Os insetos, sendo o grupo animal mais abundante do planeta, tem papel importante no entendimento de como as variações climáticas afetam a vida na Terra. Neste estudo, utilizamos as formigas-cortadeiras, da espécie Atta sexdens rubropilosa,, para tratar da importância da umidade na escolha de trilhas de forrageio. As colônias utilizadas foram separadas em dois grupos: um grupo controle, mantido em condições normais de alimentação, e um grupo experimental, alimentado com substrato seco, provocando desidratação da colônia. Os dois grupos foram submetidos a um teste de escolha de trilhas para coleta de água: uma das trilhas foi mantida úmida e a outra mantida seca. As formigas que passaram pelas trilhas, por 24 horas, foram contadas e medidas (estas últimas selecionadas aleatoriamente nas trilhas). Após análise de vídeos, os resultados mostraram que, para o fluxo, houve diferença significativa, tanto entre os grupos quanto entre as trilhas. O fluxo foi sempre maior no grupo experimental, em relação ao controle, e maior na trilha úmida que na trilha seca - sendo assimetricamente maior no grupo experimental. Este resultado demonstra que o estado fisiológico da colônia e das operárias influencia fortemente a saída de forrageadoras e a coleta de água. Além disso, mostra que a escolha da trilha foi influenciada pelo ambiente, com grande preferência das formigas pela trilha úmida. Com relação aos tamanhos, a diferença foi significativa para dois fatores: as formigas nas trilhas do grupo experimental eram, em média, menores do que as formigas do grupo controle. Há relatos de que formigas menores são especializadas em coletar água, o que explica este resultado: no grupo experimental, a dessecação impulsiona as formigas a coletar água de maneira sistemática para reidratação. No grupo experimental, as formigas eram menores na trilha seca do que as da trilha úmida, o que vai contra o esperado se levar em consideração as relações alométricas de perda evaporativa de água. É provável que esse fator esteja ligado ao engajamento na tarefa de coleta de água pelas formigas menores, que é constante nas duas trilhas, dada a necessidade da colônia. Mais estudos, no entanto, são necessários para aprimorar e aprofundar estas questões, especialmente levando em conta a dicotomia entre o comportamento individual e o coletivo / Environmental abiotic factors, such as weather, have a profound impact over the biology of organisms e their distribution on different habitats. Insects, being the most abundant animal group on the planet, play an important role to understand how climatic changes affect life on Earth. In this study, we use leafcutter ants of the species Atta sexdens rubropilosa in order to approach the importance of humidity in the choice of foraging trails. The colonies used were separated in two groups: a control group, kept under normal feeding conditions and an experimental group, fed with dry substrate, which provoked dehydration on the colony. Both groups were submitted to a test of trail choice for water collection: one of the trails was kept humid, while the other was kept dry. Ants that travelled through the trails over 24 hours were counted and measured (in the last case, randomly chosen on the trails). After video analysis, the results show that, regarding to flow, there was a significant difference between groups and between trails. Ants flow were always higher on the experimental group than on the control group, and higher on the humid trail than on the dry trail - being asymmetrically higher on the experimental group. These results show that the physiological state of the colony and the workers strongly influences the exit of foragers and the collection of water. Besides, it shows that trail choice was influenced by the environment, with ants preferring the humid trail. Regarding body size, the difference was significant for two factors: ants on the trails of the experimental group were, on average, smaller than ants from the control group. There are reports that smaller ants are specialized on water collection, which explains that difference: on the experimental group, dehydration pushes ants to collect water systematically for rehydrating. On the experimental group, ants were smaller on the dry trail than the ones on the humid trail, which goes against expected when we consider allometric relations for evaporative water loss. It is likely that this factor is connected to the smaller ant´s engagement to the water collection task, which is constant on both trails due the needs of the colony for water. More studies, however, are necessary to improve and deepen those questions, specially taking onto account the dichotomy between individual and collective behavior

Dans les paysages agricoles, les habitats non cultivés constituent une source importante pour l’entomofaune auxiliaire de cultures. Il est donc important d’adapter la gestion de ces habitats afin de bénéficier au mieux des services fournis par la diversité de ces auxiliaires. L’objectif de cette thèse est de comprendre comment la gestion des bandes enherbées permet d’améliorer le service du contrôle biologique délivré par les carabes. Nous avons d’abord examiné par quels mécanismes, les changements dans la diversité fonctionnelle des carabes augmentent leur capacité de suppression de ravageurs. Ainsi, a été comparée au laboratoire, l’efficience de prédation sur une population de proie, par des assemblages de carabes qui ont différents niveaux de diversité de taille. Par ailleurs, à travers une expérimentation mise en place dans des champs de céréales, nous avons étudié les effets de cinq modes de gestion des bandes enherbées sur la structure végétale de ces habitats non cultivés, et par conséquent sur la structure des communautés carabiques. Nos résultats révèlent l’absence d’une partition de ressources entre les carabes de tailles différentes. La quantité et de la taille de proies consommées augmente avec la taille des carabes. La suppression des proies a ainsi été fortement augmentée par la présence des carabes de grande taille dans les assemblages. Ces résultats suggèrent que l’augmentation de la diversité de taille chez les carabes augmente leur efficience de prédation par l’effet d’échantillonnage. Nous avons mis en évidence une redondance fonctionnelle entre les espèces de carabes. Cette redondance permet de réduire la variabilité spatio-temporelle dans la fonction de régulation exercée sur les populations de ravageurs. L’importance des bandes enherbées en tant qu’habitat pour plusieurs espèces de carabes importantes pour le contrôle biologique, a été mise en évidence. La gestion influence les carabes seulement dans les bandes enherbées. La diversité fonctionnelle des plantes au sein de ces bandes enherbées a été identifiée comme le principal facteur favorisant la richesse spécifique des carabes. L’activité-densité des carabes a, par ailleurs, été favorisée par une végétation peu hétérogène et un pourcentage élevé de sol nu. Les carabes de tailles différentes divergent dans leur réponse à la structure de la végétation. Cette divergence semble être liée aussi à la variation d'autres traits d'histoire de vie des espèces (i.e. régime alimentaire). Les connaissances et les résultats produits dans le cadre de ce travail de thèse, serviront au développement d’indicateurs mesurant l’impact des pratiques de gestion sur le contrôle biologique exercé par les carabes / In the agricultural landscapes, non cropped habitats are an important source for the beneficial entomofauna of crops. It is therefore important to adapt the management of these habitats to best benefit of the services provided by the diversity of this beneficial entomfauna. The objective of this thesis is to understand how field margin management could improve the biological control service delivered by ground beetles. First, we examined by which mechanisms, changes in the functional diversity of ground beetles increases their capacity of pest suppression. Thus, efficiency of predation by ground beetle assemblages, which have different levels of body size diversity, on a prey population was compared in the laboratory. Also, through an experiment installed in cereal fields, we studied the effects of five field margin management on the vegetation structure of these non cropped habitats, and therefore on the structure of ground beetle communities. Our results revealed the absence of resource partitioning among the different-sized ground beetles. The amount and size of prey consumed increased with increasing ground beetle body size. Prey suppression was, therefore, strongly strengthened by the presence of large ground beetles in the assemblages. These results suggest that increasing ground beetles size diversity increases their predation efficiency through the sampling effect. We have showed a functional redundancy among species of ground beetles. This redundancy could reduce the spatial and temporal variability in pest suppression by ground beetles. Our study showed the importance of the field margins as a habitat for many ground beetle species that are important for biological control. Management influenced ground beetles only in the field margin. Plants functional diversity within these field margins has been identified as the main factor promoting the species richness of ground beetles. However, activity-density of ground beetles was promoted by less heterogeneous vegetation and high percentage of bare ground. The responses to the vegetation structure vary between ground beetles with different body sizes. This diversity in ground beetles responses to the vegetation structure appears to be also related to variation in other life history traits (i.e. diet). The knowledge and results produced as part of this thesis will be used in the development of indicators measuring the impact of management on biological control delivered by ground beetles

During human walk, we balance internal muscle forces and external forces outside of the body, while trying to minimize physiological energetic expenditure and mechanical loading on the body. The biomechanics of walking can be affected by various factors, including body size. In individuals with greater body size, the ground reaction force increases, so it is expected that joint moment of the lower limb in individuals with greater body size should increases. However, this relationship is not always true - as documented by previous studies, larger individuals use moderating mechanisms in the form of postural adjustment of the lower limb which decreases the load on joints during walking. The aim of this diploma thesis is to investigate the effect of body size and posture on the biomechanics of walking in the stance phase of walking, and to verify the presence of moderating mechanisms. We obtained kinematic and kinetic data from nineteen probands. The data was collected during three types of walking - during normal walking, walking with extended knees and crouched walking. We used Visual3D software to calculate angles in joints and joints moments of the lower limb. The independent effect of body mass, lower limb length measured in Visual3D, lower limb length measured anthropometrically, biiliac...

Keeping a balanced state in terms of liquids in an organism, especially evaporative water loss regulation, is essential for all terrestial animals, including reptiles. Respiratory water loss and cutaneous water loss account for the highest percentage of total water loss. For this reason, the degree of evaporative water loss in reptiles can be primarily influenced by body dimensions, metabolism intensity and morphology of body surface scales. This thesis focuses on water loss through evaporation in Madagascan Paroedura geckos. The Paroedura are suitable for this research because they represent a monophyletic genus with a strongly supported hypothesis about phylogenetic relationships. The thesis adds some facts to this theory. At the same time, individual Paroedura species differ in body dimensions and habitat preference. The aim of the thesis was to find out whether individual representatives of Paroedura differ in TEWL, to specify the characteristics of the ancestral state of TEWL in this genus and to test which morphological and physiological factors influence TEWL. Further aim was to measure cutaneous water loss. Measuring was carried out by flow- through respirometry. The results show that individual representatives of Paroedura differ remarkably in TEWL figures. The reconstruction of the...

Los insectos saproxílicos, que dependen de la presencia de madera muerta y/o en descomposición, de hongos de la madera, o bien de la presencia de otros organismos saproxílicos, en algún momento de su ciclo vital, desempeñan una función clave para el correcto funcionamiento de los ecosistemas de bosque, actuando como recicladores de los nutrientes contenidos en la madera en descomposición. La diversidad de insectos saproxílicos, y más concretamente de coleópteros, así como la estructura de los ensambles que conforman, se encuentran condicionadas por una serie de variables de carácter físico, químico y biótico. Comprender cómo este amplio conjunto de variables afecta a los patrones espacio-temporales de las comunidades, resulta esencial a la hora de elaborar estrategias de manejo de los ecosistemas, que permitan preservar este tipo de fauna, en muchas ocasiones, amenazada. Con este marco de fondo, el objetivo general de esta tesis doctoral reside en analizar el conjunto de factores ambientales que afectan a la diversidad y a la distribución espacio-temporal de los ensambles de coleópteros saproxílicos que habitan los bosques mediterráneos de roble melojo ubicados en el oeste de la península ibérica para, de este modo, poder proponer una serie de directrices a seguir, a la hora de manejar este tipo de ecosistemas. Este objetivo general se divide en una serie de objetivos específicos, cada uno de los cuales ha derivado en la redacción de un artículo científico y que pueden ser consultados de manera individualizada en los capítulos II, III y IV. En el capítulo II se evaluó la influencia de un total de 24 variables ambientales a nivel de paisaje y a nivel de árbol, muchas de ellas consecuencia del manejo tradicional del bosque en el oeste ibérico por parte del hombre, analizando la riqueza observada de especies y empleando los estimadores de diversidad verdadera. El estudio permitió demostrar que, son muchas las variables que deben ser tenidas en cuenta a la hora de aplicar estrategias de manejo de los ecosistemas forestales y que no todos los métricos empleados para evaluar la diversidad de los ensambles saproxílicos responden de la misma manera frente a esas variables derivadas del manejo. De acuerdo con los resultados obtenidos, es posible establecer una serie de recomendaciones para la gestión forestal de áreas sometidas a técnicas tradicionales de manejo: favorecer en cierta medida la apertura del medio, reducir la carga ganadera y la explotación de madera a nivel vecinal, mantener en el paisaje un elevado volumen de madera en avanzado estado de descomposición, realizar un trasmoche selectivo de cierta cantidad de árboles para acelerar la aparición de oquedades y conservar los denominados “árboles hábitat”, que presenten microhábitats potenciales para este tipo de fauna, ya sean oquedades o tumores. El capítulo III se centró en analizar la posible influencia de los factores abióticos de temperatura y humedad relativa, en los patrones intranuales mostrados por los ensambles de coleópteros saproxílicos que habitan los bosques de roble melojo en la península ibérica, tanto en términos de riqueza como de composición de especies. Además, se abordó el estudio del tamaño corporal, como un rasgo que puede afectar tanto a la fisiología como a la eficacia biológica (fitness) de las especies y que podría explicar, al menos en parte, la dinámica temporal de estos ensambles. Este estudio permitió demostrar que la dinámica temporal de los ensambles de coleópteros saproxílicos que habitan los bosques de roble en el oeste ibérico está condicionada, al menos en gran medida, por las fluctuaciones anuales de las variables abióticas de temperatura y humedad relativa. Considerando el marco actual de calentamiento global, el hecho de conocer cómo ambas variables abióticas afectan a la estructura y diversidad de estos ensambles, permitirá predecir algunas de las consecuencias que el cambio climático puede tener en la distribución temporal de estas comunidades faunísticas. Además, se observó que no todas las especies de coleópteros saproxílicos muestran la misma plasticidad a la hora de adaptarse a esas fluctuaciones de temperatura y que muchas de ellas pueden permanecer activas únicamente bajo un cierto rango térmico. En este sentido, se recomienda profundizar en el estudio de los rangos térmicos de las especies, ya que proporcionará información muy valiosa a la hora de tratar de entender los patrones temporales mostrados por estos ensambles. Finalmente, en el capítulo IV, se estudió la influencia que pueden tener las emisiones de compuestos orgánicos volátiles (COVs) por parte del roble melojo, en los ensambles de coleópteros saproxílicos que emplean esta especie arbórea como planta hospedadora. Para ello, se partió de la premisa de que los árboles añosos (generalmente de mayor tamaño y en un estado de descomposición avanzado) son más visitados por los insectos saproxílicos, que en el caso de los árboles más jóvenes (generalmente de menor porte y en un estado de descomposición nulo o poco avanzado); las emisiones de COVs podrían explicar, al menos en parte, ciertos aspectos de la etología de este grupo de insectos. A pesar de la ausencia de significación estadística, los resultados mostraron una tendencia clara, que indicó que los árboles de mayor porte (árboles añosos, en un estado de descomposición avanzado) emiten este tipo de compuestos con una mayor intensidad que los árboles de menor tamaño. Si tenemos en cuenta, además, que este estudio demostró que los árboles añosos, de mayor perímetro (generalmente en un estado de senescencia más avanzado) albergaron una mayor riqueza de especies de coleópteros saproxílicos, se llega a la conclusión de que la emisión de COVs debe ser tenida en cuenta como una variable más (dentro del amplio conjunto de las ya comentadas en apartados previos), que puede estar condicionando la dinámica espacio-temporal de los ensambles de coleópteros saproxílicos que habitan los bosques de roble melojo en la península ibérica. Este estudio abre una novedosa vía de investigación que permitirá profundizar en el estudio de la relación directa que puede existir entre los compuestos químicos emitidos por los árboles y la fauna saproxílica circundante.

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Body size governs how temperature affects an organism. As temperature vary on different geographical scales, it mediates activity based on size. How does temperature distribute different sized individuals - and what reproductive fitness follow? This study involves the damselfly Enallagma exsulans and field studies at lake Fayetteville, United States. By measuring body length, temperature, copulatory status, and egg counts, I perform regression analysis to determine the fitness implications of varying temperature. Smaller individuals manage to stay active at higher temperatures, they mate at a higher rate, and they generate more eggs. My study contrasts previous research and highlights both the relevance and complexity of specificity when connecting temperature to fitness. / Kroppsstorlek styr hur temperatur påverkar en organism. Eftersom temperatur varierar på olika geografiska nivåer möjliggörs aktivitet baserat på storlek. Hur fördelar temperatur individer av olika storlekar – och vilka reproduktiva konsekvenser medför det? Den här studien involverar flicksländan Enallagma exsulans och fältarbete vid sjön Fayetteville, USA. Genom att mäta kroppslängd, temperatur, kopulationsstatus och antal ägg, utför jag regressionsanalys för att utröna fitness-implikationerna av varierande temperatur. Mindre individer förmår vara aktiva vid högre temperaturer, de parar sig till högre grad och de genererar fler ägg. Min studie står i kontrast till tidigare forskning och belyser både relevansen och komplexiteten i specificitet, när temperatur kopplas till fitness.