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891.
Environmental Science and Pollution Research - Highly time-resolved particle number size distributions (PNSDs) were evaluated during 5 years (2013–2017) at four background stations in the...  相似文献   
892.
Environmental Science and Pollution Research - The present study evaluates the development of visible injury related to phytotoxic ozone dose (PODy) in native tropical species Astronium graveolens...  相似文献   
893.
Environmental Science and Pollution Research - Organochlorine pesticides have generated public concern worldwide because of their toxicity to human health and the environment, even at low...  相似文献   
894.

The contamination of soils and water with copper (Cu) can compromise the crops production and quality. Fungicides containing Cu are widely and intensively used in viticulture contributing to environmental contamination and genotoxicity in Vitis vinifera L. Despite the difficulty in reproducing field conditions in the laboratory, hydroponic solutions enriched with Cu (1, 10, 25 and 50 μM) were used in forced V. vinifera cuttings to evaluate the DNA damage in leaves of four wine-producing varieties (‘Tinta Barroca’, ‘Tinto Cão’, ‘Malvasia Fina’ and ‘Viosinho’). Alkaline comet assay followed by fluorescence in situ hybridisation (Comet-FISH) was performed with the 45S ribosomal DNA (rDNA) and telomeric [(TTTAGGG)n] sequences as probes. This study aimed to evaluate the tolerance of the four varieties to different concentrations of Cu and to determine which genomic regions were more prone to DNA damage. The comet assay revealed comets of categories 0 to 4 in all varieties. The DNA damage increased significantly (p < 0.001) with the Cu concentration. ‘Tinto Cão’ appeared to be the most sensitive variety because it had the highest DNA damage increase in 50 μM Cu relative to the control. Comet-FISH was only performed on slides of the control and 50 μM Cu treatments. Comets of all varieties treated with 50 μM Cu showed rDNA hybridisation on the head, ‘halo’ and tail (category III), and their frequency was significantly higher than that of control. The frequency of category III comets hybridised with the telomeric probe was only significantly different from the control in ‘Malvasia Fina’ and ‘Tinta Barroca’. Comet-FISH revealed partial damage on rDNA and telomeric DNA in response to Cu but also in control, confirming the high sensitivity of these genomic regions to DNA fragmentation.

  相似文献   
895.
Environmental Science and Pollution Research - The study used scattered literature to summarize the effects of excess Cd, As, and Pb from contaminated soils on plant secondary metabolites/bioactive...  相似文献   
896.
Some conservation prioritization methods are based on the assumption that conservation needs overwhelm current resources and not all species can be conserved; therefore, a conservation triage scheme (i.e., when the system is overwhelmed, species should be divided into three groups based on likelihood of survival, and efforts should be focused on those species in the group with the best survival prospects and reduced or denied to those in the group with no survival prospects and to those in the group not needing special efforts for their conservation) is necessary to guide resource allocation. We argue that this decision-making strategy is not appropriate because resources are not as limited as often assumed, and it is not evident that there are species that cannot be conserved. Small population size alone, for example, does not doom a species to extinction; plants, reptiles, birds, and mammals offer examples. Although resources dedicated to conserving all threatened species are insufficient at present, the world's economic resources are vast, and greater resources could be dedicated toward species conservation. The political framework for species conservation has improved, with initiatives such as the UN Sustainable Development Goals and other international agreements, funding mechanisms such as The Global Environment Facility, and the rise of many nongovernmental organizations with nimble, rapid-response small grants programs. For a prioritization system to allow no extinctions, zero extinctions must be an explicit goal of the system. Extinction is not inevitable, and should not be acceptable. A goal of no human-induced extinctions is imperative given the irreversibility of species loss.  相似文献   
897.
The reproductive patterns of four Antarctic gorgonian species have been investigated. Two of them, Dasystenella acanthina and Thouarella sp., present the bottle-brush-shape type; the other two, Fannyella rossii and Fannyella spinosa, are fan-shaped. Two different reproductive patterns have been observed in D. acanthina and Thouarella sp., which point to two size classes in the frequency distribution of oocytes. This feature indicates a reproduction cycle with overlapping generations, being each of them of more than one year, probably with seasonal spawning. F. rossii and F. spinosa show only one size class of oocytes, which could point towards an annual reproductive cycle. The presence of larvae in the gastrovascular cavities in both Fanyella species and Thoaurella sp. is a sign of a possible larvae release during austral summer. The number of oocytes per polyp ranges from 1.1 ± 0.10 SE to 1.5 ± 0.06 SE, and the size ranges from 50 to 1200 μm. The number of spermatic cysts ranges from 2.6 ± 0.19 SE to 5.0 ± 0.21SE, and their sizes range from 50 to 800 μm. These values are comparable to the reproductive trends and features found in gorgonians from other latitudes, which correspond in some cases with similar morphotypes. These coincident strategies could be related to morphological similarities rather than with latitude or water temperature. The results of this study indicate that octocoral morphology may play a crucial role in determining the reproductive output of these organisms.  相似文献   
898.
899.
Spatial heterogeneity of the Rapel reservoir surface waters is analyzed through Landsat images. The image digital counts are used with the aim or developing an aprioristic quantitative sample design.Natural horizontal stratification of the Rapel Reservoir (Central Chile) is produced mainly by suspended solids. The spatial heterogeneity conditions of the reservoir for the Spring 86-Summer 87 period were determined by qualitative analysis and image processing of the MSS Landsat, bands 1 and 3. The space-time variations of the different observed strata obtained with multitemporal image analysis.A random stratified sample design (r.s.s.d) was developed, based on the digital counts statistical analysis. Strata population size as well as the average, variance and sampling size of the digital counts were obtained by the r.s.s.d method.Stratification determined by analysis of satellite images were later correlated with ground data. Though the stratification of the reservoir is constant over time, the shape and size of the strata varys.  相似文献   
900.
The second and third steps of wastewater treatment in the tanning industry generate sludges that are rich in salts, organic matter and suspended solids. Since these are formally catalogued as industrial wastes by environmental legislation, they cannot be disposed of directly but need a final treatment. One of the problems with these wastes is their high water content, which has to be reduced. In the particular case of the concentrated streams from the secondary and tertiary treatment steps, the sludges are first concentrated by evaporation, and the evaporated water is used in other parts of the plant. This study, which preceded evaporator design, analysed the evaporation process (laboratory scale) of a saline residue produced in the reverse osmosis step of the treatment of tanning wastewaters by the company Aquagest Levante, S.A. in Lorca (Murcia, Spain), to ascertain its behaviour in the evaporation process and the evolution of its physical properties. The study served to determine the exact mineralogy and ionic composition as well as the characteristics of the waste in question. This information was used in the last step of the design of the evaporation equipment.  相似文献   
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