National Repository of Grey Literature 11 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Incubation effort in Common Pochard and its determinants
Drekslerová, Šárka ; Hořák, David (advisor) ; Musil, Petr (referee)
Incubation of avian eggs is an energy demanding process. Incubating parent faces a conflict between investment into optimal thermal conditions for developig embryos and meeting of own energy requirements. This applies especially in uniparental incubators such as ducks. During incubation, female utilizes energy from fat storage or actual food intake. The proportion of energy used from food than may reflect the time spent by female on the nest. The utilizing of these both sources ratio plays a role in time spent on nest. The aim of the thesis was to describe an incubation rhythm in females of Common Pochard (Aythya ferina) and relate them to climatic variables and changes in body mass. Data were collecetd for three years in the Poodříí Landscape Protected Area at free-living females. We placed a weighting mechanism under the nest with conected datalogger recording voltage variations, which offered me an information about female body mass and time and duration of recesses. Incubation rhytm of females was described by time spent on time ("incubation constancy"), recess frequency and recess duration. Females left the nest most grequently at night-time and during dawn and dusk. Probable explanation of this pattern is better food availability in the night-time and lower risk of nest predation by predators...
Factors influencing intraspecific scaling of metabolic rate
Trubelová, Zuzana ; Starostová, Zuzana (advisor) ; Storch, David (referee)
The relationship between metabolic rate and animal body size of the animal has been studied for more than hundred years. Recently, attention of scientists moved from the interspecific to the intraspecific level. The work focuses on the intraspecific scaling of metabolism. When plotting the metabolic rate against body mass during ontogeny the resulting line often exhibits one or more breaks. Why these breaks (and thus reduction the metabolic rate) occur hasn't been fully explained. It is assumed that can be due to certain factors that affect an individual during development. Some of these factors came from the most famous of several hypotheses attempting to explain the scaling of metabolic rate. These hypotheses include the Metabolic Theory of Ecology (MTE), the Metabolic Level Boundaries (MLB), the Cell model and the Dynamic Energy Budget (DEB) hypothesis. There are several factors that could affect individuals during ontogeny. These include internal factors, which result from the internal processes within the body. These factors are often interrelated with each other in different ways; therefore, it is unlikely to choose only one particular factor which affects metabolic rate. The most frequently studied factors are changes of cell size and changes in the proportion of metabolically active...
Flight initiation distances and life histories in birds: comparison of intra- and interspecific approaches
Brzobohatá, Tereza ; Albrecht, Tomáš (advisor) ; Klvaňa, Petr (referee)
Information about the distance, in which the birds flee from predators, may help us to better understand avian escape behavior and stress responses. These distances are influenced by many life-history traits and related factors, both on intraspecific and interspecific levels. This bachelor's thesis is trying to summarize the current knowledge of agents influencing flight initiation distances (FID) of birds, in the form of a literary research. The first section deals with antipredator behavior in birds, and explains methods that are used for measuring critical distances. In the second part of thesis, factors affecting flight initiation distances on intraspecific level are described. The main emphasis is on impact of age characteristics, body sizes, reproductive investments and geographical distribution. The last chapter summarizes the information about relationships between FID and life-history traits on interspecific level. The age of the individual, levels of stress hormones, the effect of the season and biotop are described in detail. Powered by TCPDF (www.tcpdf.org)
Muscle force during walking: effect of skeletal morphology
Tomášová, Kateřina ; Hora, Martin (advisor) ; Sedlak, Petr (referee)
The muscle force determines the energy costs of locomotion and the loading of the musculoskeletal system. As the body size increases, the muscle force increases too. The observed less joint flexion in larger individuals could be a moderating mechanism to reduce muscle force when walking. To date, there is a lack of knowledge about the effect of body size and joint angles on muscle force. The aim of this study was to investigate how body size affects muscle force in the stance phase of walking and whether larger individuals can effectively compensate for the increase in muscle force through postural changes. We acquired kinematic, kinetic and electromyographic data for 19 men during normal walking and carrying additional 20 % of body weight. We estimated muscle force using the method of musculoskeletal modeling. We emploeyd the multiple linear regression to asses independent effect of body mass, lower limb length, biiliac breadth and joint flexion angle on total (iF) and maximum (maxF) lower limb muscle force. The body mass had a great positive effect on the gluteus medius muscle force (maxF and iF) but did not affect the iliopsoas muscle force (maxF and iF) nor the vasti muscles force (iF). The lower limb length had a positive effect on the gluteus maximus muscle force (maxF) and a negative effect...
"Putting flesh and fat back onto the bones": A 3D analysis of the influence of body composition and mass on bone architecture
Lacoste Jeanson, Alizé ; Brůžek, Jaroslav (advisor) ; Velemínský, Petr (referee) ; Friedl, Lukáš (referee)
Univerzita Karlova Přírodovědecká fakulta Antropologie a Genetika člověka Alizé Lacoste Jeanson, M.Sc. "NÁVRAT SVALŮ A TUKU ZPĚT NA KOSTI": 3D ANALÝZA VLIVU TĚLESNÉ KOMPOZICE A HMOTNOSTI NA KOSTNÍ ARCHITEKTURU "PUTTING FLESH AND FAT BACK ONTO THE BONES": A 3D ANALYSIS OF THE INFLUENCE OF BODY COMPOSITION AND MASS ON BONE ARCHITECTURE Disertačnn prace Doctoral thesis Školitel Supervisor: Prof. RNDr. Jaroslav Brůžek, CSc, PhD, HDR Praha, 2018 Prague, 2018 Charles University Faculty of Science Department of Anthropology and Human Genetics Abstract The understanding of biomechanics is essential to various studies in bioanthropology. Bone is a living tissue that constantly remodels in order to functionally adapt to biomechanical constrains. Long bones diaphyses in particular have been subjected to various analyses notably because the application of beam engineering principles has rendered possible the evaluation of their resistance to various directional constrains based on their shape. Body mass estimation methods lie on this principle. Body mass is partially used since the nineties as a proxy to control the influence of body size on bone's architecture prior to interpreting variations between populations. More recently, they have been used to estimate physical status (i.e. emaciation, norm, obesity)....
Lower limb proportions and energetic cost of locomotion in Upper Pleistocene humans
Hora, Martin ; Sládek, Vladimír (advisor) ; Jelen, Karel (referee) ; Jandačka, Daniel (referee)
Previous studies proposed that Neandertals had one third higher energetic cost of locomotion than anatomically modern humans. Greater cost of locomotion could disadvantage Neandertals in competition with anatomically modern humans and could be a factor in their extinction. Greater cost of Neandertal locomotion was ascribed to their shorter lower limb and greater body mass. However, Neandertals differed also in other morphological parameters that were not considered in estimation of their locomotor cost. In this dissertation we model locomotor cost of Neandertals and anatomically modern humans using previously described relation between muscle force production and energetic cost of movement. We estimate the key locomotor parameters using a model developed by us from osteometric data from literature (n =50) and from our measurement (n = 21), and from kinematic data of 26 individuals. Further, we analyze the effect of relative lower limb length (in relation to body mass) and crural index on energetic cost of locomotion. Our results suggest that walking of Neandertal males was 9-14% energetically more demanding than walking of anatomically modern males. Nevertheless, the walking cost of Neandertal females was similar to that of anatomically modern females. Inclusion of lower limb proportions into the...
Flight initiation distances and life histories in birds: comparison of intra- and interspecific approaches
Brzobohatá, Tereza ; Albrecht, Tomáš (advisor) ; Klvaňa, Petr (referee)
Information about the distance, in which the birds flee from predators, may help us to better understand avian escape behavior and stress responses. These distances are influenced by many life-history traits and related factors, both on intraspecific and interspecific levels. This bachelor's thesis is trying to summarize the current knowledge of agents influencing flight initiation distances (FID) of birds, in the form of a literary research. The first section deals with antipredator behavior in birds, and explains methods that are used for measuring critical distances. In the second part of thesis, factors affecting flight initiation distances on intraspecific level are described. The main emphasis is on impact of age characteristics, body sizes, reproductive investments and geographical distribution. The last chapter summarizes the information about relationships between FID and life-history traits on interspecific level. The age of the individual, levels of stress hormones, the effect of the season and biotop are described in detail. Powered by TCPDF (www.tcpdf.org)
Factors influencing intraspecific scaling of metabolic rate
Trubelová, Zuzana ; Starostová, Zuzana (advisor) ; Storch, David (referee)
The relationship between metabolic rate and animal body size of the animal has been studied for more than hundred years. Recently, attention of scientists moved from the interspecific to the intraspecific level. The work focuses on the intraspecific scaling of metabolism. When plotting the metabolic rate against body mass during ontogeny the resulting line often exhibits one or more breaks. Why these breaks (and thus reduction the metabolic rate) occur hasn't been fully explained. It is assumed that can be due to certain factors that affect an individual during development. Some of these factors came from the most famous of several hypotheses attempting to explain the scaling of metabolic rate. These hypotheses include the Metabolic Theory of Ecology (MTE), the Metabolic Level Boundaries (MLB), the Cell model and the Dynamic Energy Budget (DEB) hypothesis. There are several factors that could affect individuals during ontogeny. These include internal factors, which result from the internal processes within the body. These factors are often interrelated with each other in different ways; therefore, it is unlikely to choose only one particular factor which affects metabolic rate. The most frequently studied factors are changes of cell size and changes in the proportion of metabolically active...
Incubation effort in Common Pochard and its determinants
Drekslerová, Šárka ; Hořák, David (advisor) ; Musil, Petr (referee)
Incubation of avian eggs is an energy demanding process. Incubating parent faces a conflict between investment into optimal thermal conditions for developig embryos and meeting of own energy requirements. This applies especially in uniparental incubators such as ducks. During incubation, female utilizes energy from fat storage or actual food intake. The proportion of energy used from food than may reflect the time spent by female on the nest. The utilizing of these both sources ratio plays a role in time spent on nest. The aim of the thesis was to describe an incubation rhythm in females of Common Pochard (Aythya ferina) and relate them to climatic variables and changes in body mass. Data were collecetd for three years in the Poodříí Landscape Protected Area at free-living females. We placed a weighting mechanism under the nest with conected datalogger recording voltage variations, which offered me an information about female body mass and time and duration of recesses. Incubation rhytm of females was described by time spent on time ("incubation constancy"), recess frequency and recess duration. Females left the nest most grequently at night-time and during dawn and dusk. Probable explanation of this pattern is better food availability in the night-time and lower risk of nest predation by predators...
Fitness comparison of the European ground squirrel's populations living in different habitats and population density
Novotná, Kristýna ; Matějů, Jan (advisor) ; Pavelková, Věra (referee)
Fitness in ground squirrels is a frequently discussed topic, reported in many publications, although it was rarely the subject of their study. The aim of this study was to determine which factors and find out how they affect the fitness of individuals, and thus the whole population of the European ground squirrel in Czech Republic. For this purpose we collected body mass data at three studied population, which are the main indicator of the fitness in ground squirrels. We also recorded information about injuries, reproduction status, ectoparasites and endoparasites. Moreover we collected all available data on the body mass of European ground squirrel in the central European region, and we compiled overview of body mass changes during the season. This enables us to compare our data with typical/common body mass value in particular sex, age and season. Recorded differences in body mass at three studied sites were related to sex, age, locality and season. We found positive correlation between the body mass and injuries from fights/reproduction activity in adult males. The relationship between body mass and reproduction activity of females was not found. Four species of ectoparasites, mostly occurring in adults, were recorded in studied populations. We also found five species of endoparasites, which...

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