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121.
Environmental Science and Pollution Research - Toxicity refers to the potential of a substance such as a pesticide to cause damage to the structure or functions of an exposed organism. Pesticides...  相似文献   
122.
This paper explores the nature of tri-sector partnerships applied to community development in the mining sector. The case study approach was used to examine an initiative for environmental improvement and socio-economic development in the diamond province of the Republic of Sakha (Yakutia), in the Russian Federation. The study follows the journey of this initiative from a potential tri-sector partnership model between the diamond mining company ALROSA, the Government of the Republic of Sakha (Yakutia) and the SAPI Foundation, to a bi-lateral partnership between ALROSA and the Government represented by the Target Fund. The study explores the community development in the diamond province in the light of economic and political transition within the mining sector of the Russian Federation.  相似文献   
123.
We explored the potential of using energy-dispersive X-ray analysis (EDX), a non-destructive technique, to assess elemental contents in dolphin bones. Specimens were deposited in museum collections, and prepared by different methodologies. Fifty eight Commerson’s dolphins (Cephalorhynchus c. commersonii) chevron bones and 24 Franciscana dolphins (Pontoporia blainvillei) were analysed. The EDX allowed us to detect the following elements: Ca, P, Na, Mg, Fe, K, Zn, S, Cl and Al; and quantify their proportion (weight percent of element). Principal components analysis differentiates two groups according to the cleaning procedures applied, supporting that cleaning methods could influence the chemical integrity of bone. No significant age-dependent increase was found for elements analysed in species, and no significant differences were found between sex and physical maturity stages. Alternative assessment was made through atomic absorption spectrophotometry, providing quantitative information on the principal elements in bones (Ca, P, Mg, Na, Fe and Zn) and allowing comparisons with other studies. A standard protocol for bone cleaning and conditioning is needed to exclude any effect on the mineral integrity of calcified tissue. This would enable future comparative studies on the bone mineral matrix over time housed in natural history museums or other scientific collections.  相似文献   
124.

Purpose

The aim of this work was to assess the levels of copper and zinc in fish from the main freshwater ecosystems of Moldova, in relation with species, habitat, age, sex, season, and development stage.

Methods

Fish from Cyprinidae and Percidae families (Cyprinus carpio, Carassius auratus gibelio, Rutilus rutilus heckeli, Abramis brama, Aristichthys nobilis, Hypophtalmichthys molitrix, Sander lucioperca) were collected from Prut and Dniester rivers, Cuciurgan, Dubasari, and Costesti-Stanca reservoirs, and ponds of farms in the Dniester delta. The Cu and Zn content of fish tissues (skeletal muscles, liver, gonads, gills, skin, and scales) was determined by flame atomic absorption spectrophotometer AAS-3, of water by graphite furnace HGA 900 of AAnalist 400.

Results

The level of heavy metals accumulation in muscles of immature fish follows their dynamics in water. The highest concentration of zinc was registered in the gonads of mature fish, and of copper??in the liver. The lowest Cu and Zn contents were recorded in the muscles and are in the United Nations Food and Agriculture Organization safety-permissible levels for human consumption. Cu and Zn contents in muscles of fish depend on specimen age. Their level in fish gonads was sharply increasing during pre-spawning period. During the early developmental stages, the metal concentration in fish eggs and larvae varies within wide limits, but the accumulation pattern is similar in the investigated species.

Conclusions

The fish represent one of the most indicative factors for the estimation of trace metals pollution in freshwater systems and this is important not only for monitoring purposes, but also for the fish culture ones.  相似文献   
125.
The influences of spatial scale, local conditions, and small vertebrate preferences on post-dispersal predation of weed seeds were tested in agricultural ecosystems of the Southern Pampas Region of Argentina. Seeds from different weed species were offered through exclusion experiments at different distances from the weedy field borders, inside maize (2005) and wheat (2006) stubbles with contrasting land use in the neighbor fields (annual crop fields vs. seminatural grasslands), and inside seminatural grasslands adjacent to stubbles. Canopy structure was characterized inside the wheat stubbles, and small mammals were sampled in both stubble crops and grasslands. All weed species were predated in both 2005 and 2006 trials, but predation ratios varied among weed species, partly due to their seed size, with larger ones being more preferred. While in the maize stubbles no distance or neighbor field land use effects, or interactions between the different factors were detected, in the wheat stubbles, influence of neighbor field land use on weed species predation varied according to distance from field border and the height of the stubble canopy. In wheat stubbles adjacent to annual crop fields, predation increased with canopy height at every different distance from the field borders (5 m, 30 m and 60 m). The opposite was found in wheat stubbles adjacent to seminatural grasslands, where seed predation sharply decreased with canopy height, except for the farthest distance to the border. Capture results suggest a predominance of Calomys spp. populations in crop areas (stubbles adjacent to annual crops) which contrasted with the more diverse small mammal’s community of the grasslands. Based on these data, we provide an insight into the hierarchical nature of factors affecting the predation of weed seeds and discuss some implications of land use patterns on the regulation of weed populations by small vertebrates.  相似文献   
126.

Phytotoxicity, cytotoxicity and genotoxicity of pesticides with various mechanisms of targeted activity were studied in a hydroponic culture of 2-day-old seedlings of Triticum aestivum. All studied pesticides (with the exception of metribuzin) exhibited dose-dependent phytotoxicity (inhibited the growth of the main root and reduced the yield of root biomass). All studied pesticides did not affect mitotic index in the root apex meristem but did affect the duration of some phases of mitosis. Herbicides increased, while fungicides, on the contrary, decreased the duration of the cytokinesis phase. All pesticides (1 μg/mL) exhibited genotoxic activity: in the root apex meristem the number of cells with mitotic abnormalities was significantly higher than in the control variant (7–14 times). The genotoxic activity of metribuzin and tebuconazole was 2 times lower than for tribenuron-methyl, fenoxaprop-P-ethyl, epoxiconazole and azoxystrobin. The genotoxicity of the studied pesticides was combined: depending on the class of the pesticide, clastogenic or aneugenous effects dominated.

  相似文献   
127.
Hot spots in Brazil include a variety of ecosystems, such as mangroves, forests, and the Brazilian savannah, locally called cerrado. Some of the rural populations in these hot spots are the caiçaras in SE Atlantic Forest coast, and the caboclos in the Amazon. In this study, we are concerned especially with the knowledge of caiçaras and caboclos, associated with practices that might have implications for management. Data were gathered through interviews with adults at the various communities studied, and through systematic observations, including samples of fishing trips and the mapping of fishing spots used in the Atlantic Forest coast. The use of resources from the surrounding vegetation includes collection of plants, cultivated fruit gardens, the swidden system, and a careful and managed extraction of fibres. Among animal resources, food taboos seem to be useful practices that might contribute to the maintenance of local natural resources. Potential management practices should be locally developed, such as the informal division of fishing spots in Atlantic Forest sites, and the maintenance of the diversity of cassava varieties in both the Atlantic Forest and Amazonian areas.  相似文献   
128.
Environmental Science and Pollution Research - The main goal of this research is to evaluate the contributions of Green Chemistry as a potential tool to drive the transition to circularity. For...  相似文献   
129.
We develop a novel statistical approach for classifying generalists and specialists in two distinct habitats. Using a multinomial model based on estimated species relative abundance in two habitats, our method minimizes bias due to differences in sampling intensities between two habitat types as well as bias due to insufficient sampling within each habitat. The method permits a robust statistical classification of habitat specialists and generalists, without excluding rare species a priori. Based on a user-defined specialization threshold, the model classifies species into one of four groups: (1) generalist; (2) habitat A specialist; (3) habitat B specialist; and (4) too rare to classify with confidence. We illustrate our multinomial classification method using two contrasting data sets: (1) bird abundance in woodland and heath habitats in southeastern Australia and (2) tree abundance in second-growth (SG) and old-growth (OG) rain forests in the Caribbean lowlands of northeastern Costa Rica. We evaluate the multinomial model in detail for the tree data set. Our results for birds were highly concordant with a previous nonstatistical classification, but our method classified a higher fraction (57.7%) of bird species with statistical confidence. Based on a conservative specialization threshold and adjustment for multiple comparisons, 64.4% of tree species in the full sample were too rare to classify with confidence. Among the species classified, OG specialists constituted the largest class (40.6%), followed by generalist tree species (36.7%) and SG specialists (22.7%). The multinomial model was more sensitive than indicator value analysis or abundance-based phi coefficient indices in detecting habitat specialists and also detects generalists statistically. Classification of specialists and generalists based on rarefied subsamples was highly consistent with classification based on the full sample, even for sampling percentages as low as 20%. Major advantages of the new method are (1) its ability to distinguish habitat generalists (species with no significant habitat affinity) from species that are simply too rare to classify and (2) applicability to a single representative sample or a single pooled set of representative samples from each of two habitat types. The method as currently developed can be applied to no more than two habitats at a time.  相似文献   
130.
Consideration of gender in the disaster sphere has centred almost exclusively on the vulnerability and capacities of women. This trend stems from a polarised Western understanding of gender as a binary concept of man—woman. Such an approach also mirrors the dominant framing of disasters and disaster risk reduction (DRR), emphasising Western standards and practices to the detriment of local, non‐Western identities and experiences. This paper argues that the man—woman dichotomy is an insufficient construct with which to address the gendered dimensions of a disaster as it fails to capture the realities of diverse gender minorities in non‐Western contexts. The paper presents case studies from the Philippines, Indonesia, and Samoa, where gender minorities display specific patterns of vulnerability associated with their marginal positions in society, yet, importantly, also possess a wide array of endogenous capacities. Recognition of these differences, needs, skills, and unique resources is essential to moving towards inclusive and gender‐sensitive DRR.  相似文献   
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