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31.
Environmental Science and Pollution Research - The contamination left by abandoned mines demands sustainable mitigation measures. Hence, the aim of this study was to examine the phytoremediator...  相似文献   
32.
We describe a new mantelline frog of the genus Blommersia found in rainforest in North East Madagascar, from the protected areas of Ambatovaky, Betampona, Masoala, and Zahamena. Blommersia angolafa n.sp. is a small frog, with a body size of 17–21 mm, expanded finger and toe tips, and colouration ranging from yellow to dark brown, with pale-bluish spots on the flanks and light tips of fingers and toes. A peculiar aspect characterising this new species is its novel life history and reproductive mode. Both sexes live and breed in a phytotelmic habitat of water accumulated within fallen prophylls and fallen leaf sheaths of at least three species of Dypsis palms. Within these phytotelmata, egg laying and complete larval development occur. Thus, B. angolafa n.sp. represents a new evolutionary lineage of Malagasy frogs in which phytotelmy is known. Up to now, reproduction in phytotelmata in Malagasy frogs has been reported for many cophyline microhylids, most species of Guibemantis, Mantella laevigata, and possibly in a still-undescribed species belonging to the genus Spinomantis. We consider the reproductive mode of B. angolafa as a derived character, having evolved from the more typical reproduction in lentic water bodies. The general scarcity of lentic habitats in Malagasy rainforests may have provided the conditions that favoured the evolution of this phytotelmic breeding strategy. The new species, being specialised to a habitat represented by a few selected Dypsis species, potentially suffers the selective exploitation of these palms.  相似文献   
33.
Theidentification of key biodiversity areas (KBA) was initiated by the International Union for Conservation of Nature in 2004 to overcome taxonomic biases in the selection of important areas for conservation, including freshwater ecosystems. Since then, several KBAs have been identified mainly based on the presence of trigger species (i.e., species that trigger either the vulnerability and or the irreplaceability criterion and thus identify a site as a KBA). However, to our knowledge, many of these KBAs have not been validated. Therefore, classical surveys of the taxa used to identify freshwater KBAs (fishes, molluscs, odonates, and aquatic plants) were conducted in Douro (Iberian Peninsula) and Sebou (Morocco) River basins in the Mediterranean Biodiversity Hotspot. Environmental DNA analyses were undertaken in the Moroccan KBAs. There was a mismatch between the supposed and actual presence of trigger species. None of the trigger species were found in 43% and 50% of all KBAs surveyed in the Douro and Sebou basins, respectively. Shortcomings of freshwater KBA identification relate to flawed or lack of distribution data for trigger species. This situation results from a misleading initial identification of KBAs based on poor (or even inaccurate) ecological information or due to increased human disturbance between initial KBA identification and the present. To improve identification of future freshwater KBAs, we suggest selecting trigger species with a more conservative approach; use of local expert knowledge and digital data (to assess habitat quality, species distribution, and potential threats); consideration of the subcatchment when delineating KBAs boundaries; thoughtful consideration of terrestrial special areas for conservation limits; and periodic field validation.  相似文献   
34.
Food and Environmental Virology - Enteric viruses have been described as important contaminants in fresh and ready-to-eat foods such as sandwiches, deli meat and dairy products. This is a...  相似文献   
35.
Small-scale vertical patterns of larval distribution were studied at a very nearshore larval fish assemblage, during the spring–summer period of several years, at two depth strata (surface and bottom) using sub-surface and bottom trawls. A total of 4,589 larvae (2,016 from surface samples and 2,573 from bottom samples) belonging to 62 taxa included in 22 families were collected. Most larvae belonged to coastal species. Although inter-annual variations in larval density and diversity could be found, total larval abundance was always higher near the bottom whereas diversity was higher at the surface. A marked distinction between the structure of surface and bottom assemblages was found. Sixteen taxa explained 95% of the similarity among surface samples. Larvae which contributed most to this similarity included species like clupeiformes, sparids and serranids, and also blenniids, tripterygiids and some labrids. In the bottom samples, fewer species were present, with only six taxa, almost exclusively from species which lay demersal eggs, contributing to 95% of the similarity between samples. Larvae present at the surface were significantly smaller than at the bottom. For some of the most abundant species found at the bottom, only small larvae occurred at the surface while the whole range of sizes was present at the bottom, indicating that larvae may be completing the entire pelagic phase near the adults’ habitat. These results indicate that larval retention near the reefs probably occurs for these species, although for others dispersal seems to be the prevailing mechanism.  相似文献   
36.
The atmospheric contamination levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were evaluated from the analysis of pine needles in South Korea. Pine needles were collected from 30 sampling points at five main cities in South Korea (Busan, Daegu, Gwangju, Changwon and Jeju island). The highest concentrations of PCDDs/DFs (2.19–26.88 pg I-TEQ/g of dry weight) were measured at Busan, where is the city of the highest population density and traffic volume among five cities. The lowest concentration was detected at Jeju with 0.62 pg I-TEQ/g dry weight, suggesting Jeju could be an environmental background area in Korea. The dominant homologues of PCDDs/DFs in pine needles were the lower chlorine-substituted compounds such as tetra CDDs and CDFs, and the distribution ratios of PCDDs/DFs decreased with increase of the number of chlorine substituents. Homologue profiles of pine needle samples were similar to PCDDs/DFs profiles of the vapor phase in the ambient air, and thus the pine needles absorbed the vapor phase of PCDDs/DFs from air. Results suggested that pine needles could be used as an indicator of the atmospheric contamination for PCDDs/DFs in Korea.  相似文献   
37.
The objective of this work was to evaluate absorption and translocation of the herbicide 2,4-D in plants of Memora peregrina. The herbicide 2,4-D was used alone with the formulation DMA 806 BR and associated with the herbicide picloram in the commercial product Padron. Levels of radioactivity on the treated leaves were determined in sample obtained after washing them with methanol and chloroform at different times after the application of the radiolabelled formulation (1, 2, 4, 8, 24, and 48 h). Translocation was evaluated by cutting plants between stem and root. The parts obtained were: root, stem, leaf treated, leaves above the leaf treated, leaves below the leaf treated, and leaf opposite of the leaf treated. These parts were weighted, dried, ground, burnt, and radioactivity in the samples was determined. The results suggest that the translocation of the radioactive herbicide 2,4-D was insignificant in plants of M. peregrina in the two treatments evaluated. Absorption of 14C 2,4-D in the treatment with DMA 806 BR and the mixture of DMA 806 BR plus Padron had the same behavior. These observations explain the inefficient control obtained with this herbicide in plant species under study.  相似文献   
38.
The Anguillid juvenile glass eel must deal with the osmoregulatory consequences of highly variable environmental salinities on its recruitment migration from coastal to fresh waters. Changes in ionoregulatory parameters and branchial ion transport protein [Na+/K+-ATPase, Na+:K+:2Cl cotransporter (NKCC), cystic fibrosis transmembrane regulator (CFTR) anion channel, V-type proton ATPase] expression (activities, protein and/or mRNA level expression and/or cellular localization) in response to acclimation to a broad range of ionic strengths [distilled water (DW) to hypersaline water (HSW; 150%) sea water (SW 32‰)] was studied. The estuarine glass eels were very euryhaline and successfully acclimated to acute changes in environmental ionic strength from 50% SW, with high mortality only observed in HSW (51%) and sublethal osmoregulatory indicators (whole body water content and sodium levels) disturbed at the extremes (DW and HSW). Central to a high salinity acclimation were elevated branchial Na+/K+-ATPase, NKCC and CFTR expression. At lower salinity, Na+/K+-ATPase expression was maintained and NKCC and CFTR expressions were reduced. Branchial chloride cells increased in size up to SW but decreased in HSW. During hypotonic disturbance (DW), no compensatory elevation in V-ATPase or Na+/K+-ATPase expression was observed.  相似文献   
39.
Rhithropanopeus harrisii (Gould) is an introduced species in the estuary of the Mondego River (Portugal): it was first recorded from the Iberian Peninsula in 1989. The larval development of this population was studied under laboratory conditions at different temperatures and salinities, and showed a larval development pattern very similar to that reported for American estuarine populations of this species. Larval development was negatively correlated with temperature. Time to megalopa varied between 7 and 35 d; the first crab (C1) was reached after a maximum of 11 to 43 d. Larval development was optimum at 25°C and 15S. Larval survival was maximum at 10, 15 and 20S at all three temperatures studied (20, 25 and 30°C). The percentage of abnormal megalopae increased with increasing salinity to a maximum (100%) at 30S; incidence of abnormality was not affected by temperature.  相似文献   
40.
The aim of this study was to investigate hepatitis A virus (HAV), hepatitis E (HEV), and rotavirus (RV) in fresh and processed meat traded on the border of Brazil with Argentina and Uruguay. In total, 159 samples of raw and processed foods of animal origin were collected in Paso de los Libres, Argentina (n?=?53 raw meat, n?=?24 processed meat) and Rivera, Uruguay (n?=?55 raw meat, n?=?18 processed meat), or were seized by the Brazilian International Agricultural Surveillance System—VIGIAGRO (Brazil–Argentina border) (n?=?8 raw meat, n?=?1 bush meat). All samples were tested for the presence of HAV, HEV, and RV genomes. HAV genes were detected in 18.23% of samples and RV genes in 23.89%. No HEV-positive samples were detected. HAV was also detected in two of the VIGIAGRO samples. Processed meats from Argentina and Uruguay had a higher rate of HAV and RV than raw meat (P?>?0.05). The median HAV in the Argentinian and Uruguayan samples was 6.9?×?104 and 3.5?×?103 copies/g, respectively. The presence of RV viral genes in raw meats from Argentina was significant, and this was not observed in processed meats. The presence of HAV and RV genes in a significant portion of products from Argentina and Uruguay is a potential source of human infection. This also indicates precarious conditions of acquisition, processing, and manipulation, which could be improved by improved regulation of food across borders.  相似文献   
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