<i>Sorex araneus</i> L., the common shrew, has a basal metabolic rate higher than predicted by allometry. This study investigates how such a small insectivore is able to respond to the extra energy expenditures associated with both reproduction and winter survival. A comparison is also made with the reproductive costs in a tropical insectivore with a low BMR, <i>Echinops telfairi</i> Martin. The daily energy expenditure of <i>S. araneus</i>, estimated using both indirect calorimetry (IC) and doubly-labelled water (DLW), increased during pregnancy and lactation. The energy expenditures estimated using IC were however lower than the estimates made using DLW. During gestation this was explained by the physical confinement and the higher ambient temperatures within the respirometry chambers. During lactation however 30% of the maternal energy expenditure could not be explained by such factors and was probably due to the entry of unlabelled CO₂ into the female. The increase in energy expenditure during reproduction was associated with an increase in food consumption. Both the resting and the daily energy expenditure of <i>S. araneus</i> increased in response to falls in ambient temperature, reflecting the cost of thermoregulation during winter. Homeothermy was always maintained at low temperatures. Prey availability did not decline during the winter months however, so that the increase in thermo-regulatory costs were not compounded by a decrease in the potential intake of energy. In winter, thermoregulatory costs were reduced by a drop in body mass and size, a consequence of which was a decrease in lower critical temperature. Further adaptations included a reduction in activity in cold temperatures, involving long periods spent within the nest. Habitat selection was also important during winter, since shrews remaining within sheltered microclimates would conserve up to 15% of the total daily energy budget. The increase in body mass in <i>Echinops</i> during gestation was attributed to both the growth of the foetuses and the deposition of fat. The lipid stores were carried over into lactation. Both daily and resting energy expenditure increased throughout pregnancy, but there was no further increase in expenditure throughout lactation. Whilst the body temperature (T_b) of adult males and juveniles was dependent upon ambient temperature (T_a), body temperature in pregnant and lactating females was independent of T_a. The females maintained homeothermy during reproduction. Despite the increase in energy expenditure there was no increase in the temperature differential (T_b-T_a) prior to parturition in these females, and this was attributed to an increase in conductance, a consequence of behavioural thermoregulation ('spread-eagling') during late gestation. These behavioural changes included a reduction in activity and hence compensation in the respiratory energy budget, leading to a decrease in food consumption from mid to late gestation. During early to mid gestation and also throughout lactation the increased energy demands were associated with an increase in food consumption.

In this study, digital maps depicting occurrence of invasive species Echinops sphaerocephalus (Asteraceae) in the Blanský les PLA (Protected Landscape Area) and surroundings were created. Localities recorded in last 208 years in the Czech Republic were listed and great globe thistle?s spreading was showed. Germination abilities and growth characteristics of seedlings were also tested. Different management interventions were realized and their effect on great globe thistle regeneration was examined.

Affectant près d'un milliard de personnes dans le monde, l'hypertension artérielle représente un facteur de risque majeur de pathologies cardiovasculaires et d'insuffisance rénale et constitue l'une des principales causes de mortalité. L'identification de traitements anti-hypertenseurs efficaces et tenant compte des particularités des différentes populations du globe présente ainsi un intérêt capital en termes de santé publique. Notre travail a été consacré à l'étude de plantes anti-hypertensives de la Pharmacopée ouïghoure, principale ethnie de la Région autonome du Xinjiang, vaste territoire montagneux et désertique situé au Nord-Ouest de la Chine. L'objectif de la thèse a été d'apporter des arguments scientifiques, phytochimiques et pharmacologiques, permettant de valider et valoriser l'utilisation traditionnelle de ces plantes. La première partie du travail a démontré sur le modèle d'aortes isolées de rat l'effet vasodilatateur de Ziziphora clinopodioides Lam. (Lamiaceae). L'étude des mécanismes impliqués a permis d'identifier une action indépendante de l'endothélium vasculaire et secondaire à une modification des conductances calciques et potassiques. La réalisation d'un fractionnement bioguidé a permis l'identification de 7 métabolites vasoactifs d'origine phénolique. Dans une deuxième partie, les propriétés vasodilatatrices et hypotensives des fruits Nitraria sibirica Pall. (Nitrariaceae) ont été démontrées. L'endothélium vasculaire et la voie du monoxyde d'azote ont été identifiés comme les éléments fondamentaux de cette action vasodilatatrice. Dans une troisième partie, nos travaux ont étudié pour la première fois les effets vasorelaxants et la composition chimique d'Echinops integrifolius Kar. & Kir. (Asteraceae) et ont permis de caractériser 11 métabolites incluant des triterpènes, des flavonoïdes ainsi qu'une coumarine. En conclusion, notre travail de thèse a permis d'apporter, pour la première fois, des arguments expérimentaux soutenant l'usage anti-hypertensif des espèces Ziziphora clinopodioides et Nitraria sibirica. L'étude phytochimique d'Echinops integrifo/ius a également offert des informations chimiotaxonomiques utiles concernant cette espèce et le genre Echinops / Affecting nearly one billion people worldwide, hypertension is the most important risk factor for cardiovascular disease and kidney failure and it is also one of the leading causes of death. The identification of efficient antihypertensive treatments taking into account the specificities of different populations of the world is an important public-health challenge. Our work has been dedicated to the study of anti-hypertensive plants from the Uighur Pharmacopoeia, one of the major ethnie groups in the Xinjiang Autonomous Region, a large desert and mountainous area from the northwestern China. The aim of this work was to provide phytochemical and pharmacological evidences to validate and to enhance the traditional use of these plants. First, the vasodilating properties of Ziziphora clinopodioides Lam. (Lamiaceae) have been shown by using the in vitro model of isolated rat aortic rings. Our data reported an endothelium-independent effect related to changes in calcium and potassium conductances. ln addition, a bioguided fractionation has been carried out and led to the identification of seven vasorelaxant phenolic compounds. Second, the vasodilating and the hypotensive effects of the fruits of Nitraria sibirica Pail. (Nitrariaceae) have been demonstrated and the contribution of vascular endothelium and nitric oxide pathway has been pointed out. Finally, the vasorelaxant properties and the chemical composition of Echinops integrifolius Kar. & Kir. have been investigated for the first time. Eleven secondary metabolites have been isolated including triterpenes, flavonoids and coumarins. ln conclusion, our results provide scientific evidences supporting the traditional use of Ziziphora clinopodioides and Nitraria sibirica as antihypertensive therapy. Additionaly, the phytochemical study of Echinops integrifolius gives chemotaxonomical data about that species and Echinops genus