National Repository of Grey Literature 35 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
Influence of external conditions on egg incubation in lapwings (genus Vanellus) in temperate and subtropical climate
Pešková, Lucie ; Šálek, Miroslav (advisor) ; Hořák, David (referee)
During incubation, most birds require the presence of at least one parent to ensure suitable incubation conditions for embryo development. The main factors that affect the development of the embryo are temperature, humidity and egg turning. In this work, incubation conditions were investigated in two biparental Lapwing species (genus Vanellus), the Northern Lapwing (Vanellus vanellus), which faces the risk of egg cooling in temperate areas, and the Red-wattled Lapwing (Vanellus indicus), which faces the risk of egg overheating in the subtropics. A laboratory experiment testing the thermal properties of the Red-wattled Lapwing nest lining showed that it selects lining material that slows down temperature growth during egg heating, thus ensuring suitable thermal conditions during parental absence at high ambient temperatures. Temperature and egg turning during incubation were recorded by an artificial egg with a built-in sensors placed in the nests of both target species; data collected by the sensors were stored by a base-station located nearby. The average egg temperature was 32.5 řC for the Northern Lapwing, and 35.0 řC for the Red-wattled Lapwing. Egg temperature in both species fluctuated significantly, affected by many factors. Egg temperature increased with increasing ambient temperature, it...
Termoregulace lesních mravenců r. Formica na výškovém gradientu
Kadochová, Štěpánka ; Frouz, Jan (advisor) ; Véle, Adam (referee)
This study examines thermoregulation behavior of wood ant genus Formica on elevation gradient. Two years long dataloger records of inner nest and ambient temperature were combined with detailed spring-summer manual measurement of nest temperature in different depths below nest surface. Results show that inner nest temperature was higher than air temperature in all seasons. Temperature of ant nest is highest in the deepest layer, the heat flows from inside out. We can assume that thermal homeostasis of ant nest in spring and summer i.e. in period of ant highest activity is influenced mainly by inner heat sources - microbial activity and ant metabolism. Insulation seems to have direct effect on nest temperature only in early spring; in summer insulation affects nest temperature indirectly, via ant activity. In winter there is pronounced effect of nest volume which corresponds high isolative properties of nest material. Our results indicate that thermoregulatory behavior of wood ants is driven by endogenous factors, namely colony needs in sense of queen oviposition brood development. Both of these require high temperature. Nests at variable altitude did not differ in average seasonal temperature or seasonal temperature fluctuation. Variability of nest temperature was bigger among nests from one...
Metabolic costs of reproduction in vertebrates, particularly in reptiles
Kukačková, Dominika ; Kratochvíl, Lukáš (advisor) ; Hořák, David (referee)
Animal reproduction involves energy expenditures for gamete formation, support of offspring development, and associated behavioural changes. Due to high variability in reproductive traits, reptiles are the ideal study group for this field. Investment in reproductive organs and gametes represent costs of sex products production. The next phase of reproduction is gestation, when females support their developing offspring, which results in additional metabolic costs. Metabolism of pregnant female can be viewed as a sum of resting metabolism, which is the same as in non-pregnant animal, of increased metabolism to support pregnancy, and of embryonic metabolism. Separation of each component is crucial for assessing energy costs of reproduction and for comparison of different reproductive strategies. Certain behavioural changes during reproduction can influence total energy balance as well. These changes include increased locomotion costs or shifts in the thermoregulatory behaviour. Estimation of the real costs of reproduction is a complex matter since a reproduction is a very dynamic process and there are many issues that influence the overall energy consumption of reproducing individuals.
Influence of external conditions on egg incubation in lapwings (genus Vanellus) in temperate and subtropical climate
Pešková, Lucie ; Šálek, Miroslav (advisor) ; Hořák, David (referee)
During incubation, most birds require the presence of at least one parent to ensure suitable incubation conditions for embryo development. The main factors that affect the development of the embryo are temperature, humidity and egg turning. In this work, incubation conditions were investigated in two biparental Lapwing species (genus Vanellus), the Northern Lapwing (Vanellus vanellus), which faces the risk of egg cooling in temperate areas, and the Red-wattled Lapwing (Vanellus indicus), which faces the risk of egg overheating in the subtropics. A laboratory experiment testing the thermal properties of the Red-wattled Lapwing nest lining showed that it selects lining material that slows down temperature growth during egg heating, thus ensuring suitable thermal conditions during parental absence at high ambient temperatures. Temperature and egg turning during incubation were recorded by an artificial egg with a built-in sensors placed in the nests of both target species; data collected by the sensors were stored by a base-station located nearby. The average egg temperature was 32.5 řC for the Northern Lapwing, and 35.0 řC for the Red-wattled Lapwing. Egg temperature in both species fluctuated significantly, affected by many factors. Egg temperature increased with increasing ambient temperature, it...
Mimicry of hoverflies (Diptera: Syrphidae) in the context of selection pressures from predators, thermoregulation and sexual selection
Daňková, Klára ; Janšta, Petr (advisor) ; Pekár, Stanislav (referee)
Thermoregulation plays an important role in organisms' lives during foraging, escaping from predators, sexual selection or overwintering. Moreover, pressure on efficient thermoregulation could affect species on an evolutionary level and was recently hypothesized to maintain imperfect mimicry in hoverflies (Diptera, Syrphidae). We set these two aims: 1) to study relationships between thermoregulation, mimicry accuracy and resembled model, 2) to closely study effect of developmental temperature in an intermediately accurate honeybee mimic, Eristalis tenax. In the first part of the project, we examined temperature excess of 566 specimens in 47 species of hoverflies in the field. We did not find significant effect of mimicry accuracy on temperature excess in our data. However, we found a strong sexual dimorphism. Females had lower temperature excess, which was very resilient to internal and external factors, whereas males had higher temperature excess, influenced by activity at time of capture (flying > sitting) and resembled model (bumblebee-mimics > honeybee- mimics > wasp-mimics > solitary bee-mimics). We suggest, that males are pushed to higher temperature excess by sexual selection within lekking. In the second part of the project, we reared E. tenax in three different temperatures in laboratory...
An effect of cold showers on the psychological well-being
SCHWACHOVÁ, Nikola
Cold exposure activates the sympathetic nervous system and increases the concentration of beta-endorphin and noradrenaline in the blood, thus contributing to overall well-being. The aim of this thesis is to collect data of a selected sample of the population about their well-being and at the same time-frequency of hardening and find out the possible connection. 39 students from the Pedagogical Faculty of the University of South Bohemia participated in the study of hardening in the age range 19 - 25 years. The probands were divided into experimental and control groups. For about 3 months, 26 probands were hardened by cold showers. Data on the structure of the mental status of probands were obtained using the SUPOS questionnaire before and after the hardening period. Based on this analysis, it was found, that the experimental group showed a higher degree of well-being, with a simultaneous decline in impulsiveness, psychological unrest and anxiety expectations and fears, but statistically inconclusive. The positive influence of hardening of the organism on human well-being cannot be confirmed by the conclusion of this thesis.
Local Control of Seat Ventilation and Its Impact on Human Thermal Comfort
Matuška, Jaroslav ; Toma, Róbert (referee) ; Fišer, Jan (advisor)
Diplomová práce je zaměřena na měření ventilovaného sedadla s ohledem na tepelný komfort člověka. Popisuje a shrnuje tepelný přenos lidského těla s okolím a termoregulaci člověka. Dále zachycuje a zhodnocuje vybrané přístupy hodnocení tepelného komfortu. Zabývá se komplexním přehledem tepelně komfortních jednotek v automobilu. Představuje použitou metodu měření tepelného komfortu u ventilovaného sedadla, načež analyzuje a vyhodnocuje jednotlivá získaná data.
Thermoregulation in ant genus Formica, an individual vs. colony conflict
Kadochová, Štěpánka ; Frouz, Jan (advisor) ; Dauber, Jens (referee) ; Domisch, Timo (referee)
This thesis deals with thermoregulation in red wood ants, in Formica rufa group. Our aim was to better understand the mechanisms by which red wood ants maintain thermal homeostasis in their nests. Red wood ants are known to keep high and stable temperatures in their nests from spring to autumn. Most emphasis is placed on the role of the nest mound as a solar collector or on a heat production by microbial community present in the nest material. However, some researchers believe that wood ants are able of active nest thermoregulation in which they can affect the nest temperature by behavioural reactions, mainly by sun basking, increased metabolic heat production or heat transport. The thesis consists of three research articles. The first one is focused on the timing of thermoregulation in red wood ants, the second one investigates in more detail one specific aspect of red wood ant thermoregulation - a sun basking behaviour. These two papers provide data from long-term field observations and experiments. The last paper is based on laboratory experiments where we tested a hypothesis resulting from field observations. Thanks to the field research we found out that ant activity (traffic on ant trails) significantly correlates with nest temperature; once the activity decreased the thermal homeostasis...
Monitoring body temperature and using thermometers in standard departments
HALAMOVÁ, Veronika
Monitoring physiological functions is one of the basic parts of health care. At the moment there is an infinite number of possibilities how to measure body temperature in an effective, fast and non-invasive way. However, if the tools are not used correctly, there is a high possibility that mistakes will occur during measuring and therefore the patient's general state will be distorted. That is why each department has standards of nursing care which need to be followed. Due to EU regulations thermometers with mercury, which are considered the most accurate concerning the non-invasive way of measuring the body temperature, have been eliminated. For research purposes we used quantitative method based on a non-standard questionnaire for nurses working in surgery departments and on an experiment using three kinds of thermometers for carrying out individual patients measurements. The research showed that the most acceptable thermometer for measuring body temperature for nurses is the infrared contactless thermometer, even though many of them are aware that these thermometers can be inaccurate and the measured data distorted. The experiment clearly shows that there is an obvious difference between individual measurements. The results of this research could be beneficial for hospital managements, in particular as a guide when buying thermometers for individual departments. In this way they could ensure the most accurate measurements of body temperature resulting in discovering an incipient infection.

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