The composition and contents of secondary metabolites in Flavocetraria lichens from Eastern Siberia were analyzed using herbarium specimens. Based on the composition of identified metabolites, three F. cucullata chemotypes and two F. nivalis chemotypes were distinguished. Distinct geographic differentiation between the F. cucullata chemotypes was revealed, probably reflecting their adaptation to environmental conditions. The content of usnic acid in F. cucullata thalli was found to correlate with the latitude of growing region. This may be regarded as evidence for a protective role of this metabolite in lichens growing at high latitudes and exposed to excess solar irradiation during the polar day. 相似文献
In Iraq, the number of passenger cars, trucks and buses, local generators, and heavy construction equipment rose to a considerable extent since 2003, causing high environmental problems. Many types of pollutants were monitored and recorded for 24 h during March 2016. The study attempts to explore and establish a relationship between the volume of activity and the movement of motor vehicles of various compounds and contaminants resulting from their exhaust pipes, such as sulfur dioxide, particulate matters, oxides of nitrogen, VOCs, and unburned hydrocarbons. The study focused in and around Mohammad Al-Qasim highway adjacent to the University of Technology, Baghdad. The results showed the need for urgent treatments addressed by the environmental authorities in the city. The study results demonstrated that these contaminants are increased during periods of the beginning and end of working hours for government departments. Some types of sulfur compounds (H2S and SO2) concentrations were at serious health-threatening levels, which is a result of the high sulfur content in the Iraqi fuel. The concentrations of NOx and VOC were high, also, which could make the studied area vulnerable to the risk of smog formation. The Iraqi government should make greater efforts to protect the environment and human in this country from the transportation pollution risks. 相似文献
The present study aims to analyse the influences of five meteorological parameters (temperature, wind speed, barometric pressure, rainfall, and solar radiations) on ground-level ozone (GLO) concentrations over the region of Ranchi Municipal Corporation (Jharkhand, India). The diurnal variation of GLO concentration and the meteorological parameters were analysed in each month to understand the associations. The results indicated that the correlation coefficients of GLO concentration with SR, AT, and DPT are found to be positive in each month and also statistically significant. But, the association between WS and GLO concentration was not uniform between the study days. Furthermore, the study also demonstrates an approach for identifying the hot spots that are having the higher level of GLO concentration. The hot spot maps were produced for each month to understand the shifting of the locations of hot spot locations. The results reveal that the hot spot locations are changes frequently in each case. Since the hot spot analysis was conducted with limited data, the presented hot spots are indicative and dependent on the meteorological conditions of the specific period and cannot be considered as a robust epidemiological study. 相似文献
Sustainable groundwater quality is a key global concern and has become a major issue of disquiets in most parts of the world including Bangladesh. Hence, the assessment of groundwater quality is an important study to ensure its sustainability for various uses. In this study, a combination of multivariate statistics, geographical information system (GIS) and geochemical approaches was employed to evaluate the groundwater quality and its sustainability in Joypurhat district of Bangladesh. The results showed that the groundwater samples are mainly Ca–Mg–HCO3 type. Principal component analysis (PCA) results revealed that geogenic sources (rock weathering and cation exchange) followed by anthropogenic activities (domestic sewage and agro-chemicals) were the major factors governing the groundwater quality of the study area. Furthermore, the results of PCA are validated using the cluster analysis and correlation matrix analysis. Based on the groundwater quality index (GWQI), it is found that all the groundwater samples belong to excellent to good water quality domains for human consumption, although iron, fluoride and iodide contaminated to the groundwater, which do not pose any significant health hazard according to World Health Organization’s and Bangladesh’s guideline values. The results of irrigation water quality index including sodium adsorption ratio (SAR), permeability index and sodium percentage (Na %) suggested that most of the groundwater samples are good quality water for agricultural uses. The spatial distribution of the measured values of GWQI, SAR, Fe (iron), EC (electrical conductivity) and TH (total hardness) were spatially mapped using the GIS tool in the study area. 相似文献
Scholars continue to search for solutions to shift climate change skeptics’ views on climate science and policy. However, research has shown that certain audiences are resistant to change regarding environmental issues. To explore this issue further, we examine the presence of reactance among different audiences in response to simple, yet prominently used, climate change messages. Our results show that emphasizing the scientific consensus of climate change produces reactance, but only among people who question the existence of climate change. Moreover, adding political identification to the model as an additional moderating variable shows the increases in reactance occur among Republicans who question the existence of climate change. Finally, our results show that reactance to climate change messaging may lead to backfiring effects on important outcomes tied to climate change such as risk perceptions, climate change beliefs, and support for mitigation policies. 相似文献
Tendencies in the dynamics of harvested northern fur seal (Callorhinus ursinus) population on the Tyulenii Island have been analyzed in detail. The results show that retardation of reproduction (decrease in the numbers of pups) and decline in the survival of young females (up to 3 years of age) by the late 1980s resulted in a reduction of the total number of females and a significant increase in the proportion of older females. This tendency changed during the later observation period (after 1988–1989) due to increase in the survival of young females: the female population has gradually recovered, with the proportion of young females increasing at the expense of old females (aged over 10 years). The age composition of males has also changed: the proportion of young animals has decreased, while that of large mature males (bulls) has increased. Moreover, the number of bulls continues to increase and has already exceeded the level that formerly provided for the well-being of the population. This, a paradoxical situation has arisen: the numbers of females and bulls are increasing, whereas pup production remains at a low level.