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361.
Environmental Economics and Policy Studies - This paper examines convergence of per capita carbon dioxide (CO2) emission for a panel of 124 countries taking into account the impact of economic...  相似文献   
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The role of the Siberian musk deer in the diets of the Amur tiger, brown bear, and Asian black bear has been studied in the Sikhote-Alin State Biosphere Reserve in 1992 to 2016. Information has been collected from 763 tiger feeding sites, and the contents of tiger feces have been analyzed. Radiotelemetry has been used to evaluate tiger–musk deer relationships. The musk deer accounted for 0.26% of all animal species found to be eaten by the tiger. Musk deer remains in feces of the tiger, brown bear, and Asian black bear occurred with frequencies of 1.3, 0.2, and 0.3%, respectively. A case of musk deer avoiding the presence of brown bear is described.  相似文献   
365.
Seasonal dynamics of heart rate variability in individuals of late summer and autumn generations have been studied in three rodent species kept in a vivarium: the striped field mouse (Apodemus agrarius), bank vole (Clethrionomys glareolus), and northern red-backed vole (Cl. rutilus). It has been shown that the cardiac function of the rodents in autumn and winter is mainly controlled by autonomic mechanisms: the heart rate is slow, cardiovascular control systems are relaxed. During the winter-spring transition, the role of central cardiovascular circuits increases because of the necessity to activate all body systems by spring.  相似文献   
366.
Glaucium flavum Crantz. is a short-lived perennial herb distributed in coastal zones from the Black Sea to southern, western and north-western Europe. Despite its diminishing area of distribution and potential pharmacological value, little is known about the ecophysiological features of this coastal species. We investigated the photosynthetic performance of G. flavum by measuring gas exchange, chlorophyll fluorescence, photosynthetic pigment concentration and leaf water content over the space of a year in a coastal habitat of SW Spain. We also measured the variation in total concentrations of nitrogen, phosphorus, sulphur, potassium, calcium and magnesium, in the leaves and soil, throughout the study period. G. flavum showed a high resistance to summer drought conditions which appeared to be due to the high degree of stomatal control. The potential photochemical efficiency of photosystem II showed minimum values during the winter, indicating that low temperatures can produce negative effects within the photosynthetic apparatus. However, the marked decline in net photosynthesis during the winter seems to be mainly related to a loss of metabolic activity. Although leaf nutrient concentrations were, in general, within the normal ranges, phosphorus availability seems to be limited by the high calcium concentrations detected in the soil of the study site. Our study points out the efficiency of the different physiological adaptations of this rare and endangered coastal species in coping with the strong seasonal variability of the Mediterranean climate.  相似文献   
367.
While rural transformations are nothing new in human history, current processes of rural change occur under multiple forces at an unprecedented pace, involving profound and unexpected changes in land use and users, and rapid transformations in the metabolic patterns of rural systems. The present special section aims to shed light on current drivers and pathways of rural change by analyzing, under a common conceptual and theoretical framework, examples of new ruralities that are emerging as responses across different world regions. Within this context, this introduction presents: (1) common research questions of the six presented cases of rural change; (2) the general theoretical and methodological framework of integrated assessment of societal metabolism adopted to analyze rural systems and (3) the main contributions and conclusions that could be drawn from six context-specific case studies from Asia, Latin America and Europe.  相似文献   
368.
Experiments have been performed to evaluate the impact of weak permanent horizontal magnetic field of about 400 A/m on seed formation in the main magnetic orientation types of radish, the north-south (NS) and west-east (WE) types. The results show that external magnetic field exposure retards plant progression through all stages of ontogeny but does not alter the ratio of NS and WE types. Under its effect, the numbers of pods and seeds and seed weight decrease in the NS-type but increase in the WS-type plants. Therefore, external magnetic field acts as an ecological factor that differentiates the responses of radish plants depending on the type of their magnetic orientation. Differences in the sensitivity of plants to magnetic field exposure are explained by specific features of their physiological status.  相似文献   
369.
Data are presented on the ecology of Siberian stone pine and Siberian larch in recent Altai mountain glacial basins at elevations above 2100 m a.s.l. The representative example of the Aktru basin is used to demonstrate the ranges of tolerance of these tree species to a series of ecological factors.  相似文献   
370.
Studies in the vicinities of copper smelters and in undisturbed areas of the Middle Urals have been performed to evaluate the effect of industrial pollution with heavy metals on macro- and micromorphological parameters of kidneys (weight, weight index, the spectrum and frequency of histopathologies) in the bank vole (Clethrionomys glareolus Schreber, 1780) and on the accumulation of Cu, Zn, Cd, and Pb in this organ. It has been found that the kidneys of voles from polluted areas accumulate considerable amounts of heavy metals, with their concentrations increasing with age and/or sexual maturation. The kidney weight, index, and the frequency and severity of the majority of observed nephropathies also increase upon change in the reproductive-age status of animals. These parameters show no dependence on the degree of industrial pollution: at individual level, none of the heavy metals accumulated in the kidneys has produced any effect on the frequency and severity of nephropathies. These results contradict the prevailing opinion that toxicants play the determinant role in the development of nephropathies in small mammals inhabiting polluted areas. Therefore, the causes of nephropathies should be sought among other factors, not related to pollution.  相似文献   
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