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Effect of temperature on sand fly biology and Leishmania transmission
Charvátová, Lada ; Sádlová, Jovana (advisor) ; Dvořák, Vít (referee)
and keywords The current rise in air temperature causes a range of global changes, affecting many species of organisms and their interactions. Phlebotomine sand flies are small members of Dipteran insects of the family Psychodidae, subfamily Phlebotominae, transmitting Leishmania, parasitic flagellates (Kinetoplastida: Trypanosomatidae) that cause the important human disease leishmaniasis. Based on the literature review, the external temperature significantly affects the biology of sand flies. High temperature accelerates their metabolism and shortens the growth rate of immature stages, also influencing body size and body weight (faster development in higher temperatures makes them smaller). The time needed for blood digestion is also reduced, and female defecation and oviposition are accelerated. On the other hand, cold temperatures prolong growth, and cause lower emergence of adult sand flies, slower digestion of blood, or number of laid eggs. Very high or very low temperatures can cause diapause in the larval stage or eggs. In general, the optimal temperature to cover all of their physiological needs is 24-28 řC. Temperature impacts the development of Leishmania in sand flies as well, it is likely that Leishmania has a lower optimal temperature as opposed to sand flies, and therefore some...
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GDP growth and welfare in developing countries: the case study of Nigeria from 2022-2022
Elias Oluwasegun, Emmanuel
This dissertation sought to assess the impact of economic growth, particularly measured by GDP growth, on various welfare indicators within the framework of Nigeria's economy over the past two decades (2002-2022). A critical literature review laid the groundwork, surveying existing research to establish a comprehensive understanding of the theoretical underpinnings and empirical evidence related to economic growth and welfare. The chosen methodology involved the analysis of trends in GDP growth and welfare indicators using secondary data collected from reputable sources. Multivariate regression analysis, executed with the STATA software, enabled a simultaneous examination of the effects of GDP growth on key indicators such as inequality, poverty, unemployment, and life expectancy. The study aimed to provide valuable insights into Nigeria's economic dynamics and their repercussions on societal well-being. By scrutinizing the nuanced relationships between GDP growth and various welfare metrics, the research contributes not only to academic scholarship but also informs policy formulation. The outcomes of this analysis are expected to guide policymakers and stakeholders in shaping strategies that promote sustainable economic growth, thereby positively impacting inequality, poverty rates, unemployment, and overall life expectancy. In essence, this thesis represents a systematic effort to unravel the complexities of the economic-social nexus in Nigeria, offering a holistic perspective on the ramifications of economic growth on the broader welfare landscape.
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Lipid composition of biological membranes and life-histories in songbirds
Šimonová, Kateřina ; Tomášek, Oldřich (advisor) ; Sam, Kateřina (referee)
Differences in the composition of cell membranes are considered to be the physiological mechanism responsible for different metabolic rates, life span and consequently, different life-histories. The membrane pacemaker theory suggests that higher membrane unsaturation may be an important factor responsible for higher metabolic rate and shorter life span of organisms. The alternative hypothesis, on the other hand, assumes that membranes can function as structural antioxidants, and thus that higher membrane unsaturation may be associated with longer life span. The aim of this work was to test how changes in the fatty acid composition of membranes depends on body size, latitude and altitude, within which different life-histories and metabolic rate were observed. Temperate and tropical lowland songbird species were chosen for the models testing the effect of latitude, and only tropical species of songbirds were chosen for the models testing the effect of altitude. Part of the work was molecular sex determination. Using gas chromatography and mass spectrometry, the amount of individual fatty acids contained in red blood cell phospholipids was obtained from blood samples. The results showed that the composition of the membranes in most cases correlates with body size, which also correlates with almost all...
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Lipid composition of biological membranes and life-histories in songbirds
Šimonová, Kateřina ; Tomášek, Oldřich (advisor) ; Sam, Kateřina (referee)
Differences in the composition of cell membranes are considered to be the physiological mechanism responsible for different metabolic rates, life span and consequently, different life-histories. The membrane pacemaker theory suggests that higher membrane unsaturation may be an important factor responsible for higher metabolic rate and shorter life span of organisms. The alternative hypothesis, on the other hand, assumes that membranes can function as structural antioxidants, and thus that higher membrane unsaturation may be associated with longer life span. The aim of this work was to test how changes in the fatty acid composition of membranes depends on body size, latitude and altitude, within which different life-histories and metabolic rate were observed. Temperate and tropical lowland songbird species were chosen for the models testing the effect of latitude, and only tropical species of songbirds were chosen for the models testing the effect of altitude. Part of the work was molecular sex determination. Using gas chromatography and mass spectrometry, the amount of individual fatty acids contained in red blood cell phospholipids was obtained from blood samples. The results showed that the composition of the membranes in most cases correlates with body size, which also correlates with almost all...
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Lipid composition of biological membranes as a pace-maker of metabolic rate and life-histories
Šimonová, Kateřina ; Tomášek, Oldřich (advisor) ; Vojtek, Libor (referee)
Slože í iologi ký h e rá á zásad í vliv a pol e as e é ast é k seli , jako je apříklad DHA, jsou vel i itlivé k poškoze í vol ý i radikál , oproti o o e as e ý MUFA a as e ý SFA ast ý k seli á . předpokladu, že spolu s e as e ostí e rá se zv šuje o idač í u poškoze í a ásled ě r hlost stár utí, vz ikla a e akerová teorie stár utí Tato h potéza je slože á ze dvou částí. Prv í z týká souvislosti ezi slože í e rá a délkou života, kd živoči hové s ví e e as e ý i e rá a i s v šší pero idač í i de e a počte dvoj ý h vaze ěli ít, dík v šší itlivosti k o idač í u kratší délku života Tato část ašla této rešerši podporu. Druhá část týkají í se slože í e rá a r hlosti eta olis u, la větši ou studií v vrá e a. Me rá ů v šší r hlostí eta olis u spíše é ě e as e é oproti e rá á živoči hů po alejší eta olis e , se e ašla sig ifika t í korela e ož h potézou.
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Physiological adaptations associated with body size and longevity in endothermic vertebrates
Pazdera, Lukáš ; Tomášek, Oldřich (advisor) ; Blažek, Radim (referee)
Abstact Lifespan is related to a number of physiological processes that are interconnected. Longevous species are assumed to have evolved certain physiological adaptations that slow down ageing rate and enable long lifespan. The aim of my thesis was to review physiological traits that has been hypothesised to be associated with lifespan, and to evaluate the empirical support for such hypotheses. Studies testing the association of these traits with body size has also been included in my thesis, as body size is known to be tightly related to lifespan. Traits that are reviewed in my thesis due to their hypothesised coevolution with lifespan are as follows: metabolic rate (i.e., a total amount of energy expended by the organism per unit of body mass and unit of time), oxidative stress resistance, telomere length and rate of telomere shortening and intensity of stress and immune responses. Key words: Lifespan, longevity, survival, reproduction, oxidative stress, free radicals, reactive oxygen and nitrogen species, metabnolic rate, immunity, antioxidants
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Novel roles for the corpus allatum hormone in the cost of sexual interactions in the linden bug Pyrrhocoris apterus
PROVAZNÍK, Jan
The decrease of lifespan by mating is a common, yet poorly understood occurrence. Juvenile hormone (JH) is widely believed to mediate shortened lifespan in insect, caused by mating. In this study we tested the role of JH in the linden bug (Pyrrhocoris apterus) by removal of the corpus allatum gland and thus the JH source. We then proceeded to study the lifespan of mated animals vs. virgin animals. Virgin animals without JH live longer as was expected. The effect on mated animals is however different between males and females. Surprisingly in females, JH seems to lower the cost of mating. In males, on the other hand, the cost of mating seems to be independent on JH levels. Another surprising conclusion is that the level of JH in females affects the lifespan of males that mate with such females.
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The effect of food restriction on longevity in an insect model
BUŘIČOVÁ, Marcela
It is known that the restricted food intake in many species extends lifespan by slowing and/or delaying the aging processes. The underlying biological mechanisms responsible for the lifespan extension are still not known, althought several hypotheses have been proposed. Cost of reproduction, where the lifespan and fecundity are negatively correlated, is of widespread occurrence. In females of the linden bug Pyrrhocoris apterus no evidence for a trade-off between lifespan and fecundity were observed. Restriction of food intake reduces egg production but has no effect on lifespan.
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Ecological comparison of three closely related species from \kur{Myosotis palustris} group
KOUTECKÁ, Eva
The study is focused on comparative ecology of three closely related species from Myosotis palustris group. Importance of various functional traits of individual species was evaluated experimentally in the greenhouse (germination experiments), in the pot experiment and in the reciprocal transplant field experiment. Germination, production of clonal structures and response to various environmental conditions (competition, moisture conditions, etc.) were studied. The experimental data are supplemented with an analysis of phytosociological relationships of the studied species.
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