This study highlights the health status of frogs in coffee plantations of Western Ghats. Coffee is one of the major commercial crops in the Western Ghats of India. In these plantations, farmers extensively use agrochemicals including pesticides and synthetic fertilisers. The practice of agrochemical usage can negatively affect non-target organisms like amphibians. The area has reported many amphibian species living in and around plantations. A total of 334 frogs from reference sites (10 abnormal frogs) and a total of 258 frogs (19 abnormal frogs) were collected from contaminated sites. We considered major biomarkers like hepato-somatic index, gonado-somatic index, morphological abnormalities and acetylcholinestarse activities for evaluating the health status of frogs. In our study, the hepato-somatic index and gonado-somatic index were found to be higher in a grochemical contaminated sites. Whereas, acetycholine esterase activity in brain and liver tissues of frogs in contaminated sites were low compared to reference sites. High rate of incidence of morphological abnormality (7.36%), increased hepato-somatic index (14.86%) and gonado-somatic index (male; 8.88% and female; 17.51%) and low acetylcholine esterase activities in brain (41.5%) and liver (46.9%) indicates the lower health status of frogs living in coffee plantations that are regularly treated with agrochemicals. 相似文献
Semifluorinated n-alkanes (SFAs) with carbon chain lengths of 22 to approximately 36 atoms are present in fluorinated ski waxes to reduce the friction between ski base and snow, resulting in a better glide. Semifluorinated n-alkenes (SFAenes) are byproducts in the production process of SFAs and are also found in ski waxes. Snow and soil samples from a ski area in Sweden were taken after a large skiing competition and after snowmelt, respectively, and analyzed for SFAs and SFAenes. Single analyte concentrations in snow (analyzed as melt water) ranged from a few ng L−1 up to 300 μg L−1. ∑SFA concentrations decreased significantly from the start to the finish of the ski trail. Single analyte concentrations in soil ranged up to 9 ng g−1 dw. ∑SFA concentrations in soil did not show a trend along the ski trail. This may be due to the fact that concentrations in soil, although strongly influenced by the competition, reflect inputs during the whole skiing season. The chemical inventory in snow was greater than the inventory in soil for shorter chain SFAs (C22C28) and for all SFAenes. Additionally, a significant change in SFA patterns between snow and soil samples was found. These observations suggested volatilization of shorter chain SFAs and of SFAenes during snowmelt. Evidence for long-term accumulation of SFAs in surface soil over several skiing seasons was not found. 相似文献
The need to balance agricultural production and environmental protection shifted the focus of Brazilian land-use policy toward sustainable agriculture. In 2010, Brazil established preferential credit lines to finance investments into low-carbon integrated agricultural systems of crop, livestock and forestry. This article presents a simulation-based empirical assessment of integrated system adoption in the state of Mato Grosso, where highly mechanized soybean–cotton and soybean–maize double-crop systems currently prevail. We employ bioeconomic modeling to explicitly capture the heterogeneity of farm-level costs and benefits of adoption. By parameterizing and validating our simulations with both empirical and experimental data, we evaluate the effectiveness of the ABC Integration credit through indicators such as land-use change, adoption rates and budgetary costs of credit provision. Alternative scenarios reveal that specific credit conditions might speed up the diffusion of low-carbon agricultural systems in Mato Grosso.
Raw material supply is essential for all industrial activities. The use of secondary raw material gains more importance since ore grade in primary production is decreasing. Meanwhile urban stock contains considerable amounts of various elements. Photovoltaic (PV) generating systems are part of the urban stock and recycling technologies for PV thin film modules with CdTe as semiconductor are needed because cadmium could cause hazardous environmental impact and tellurium is a scarce element where future supply might be constrained. The paper describes a sequence of mechanical processing techniques for end-of-life PV thin film modules consisting of sandblasting and flotation. Separation of the semiconductor material from the glass surface was possible, however, enrichment and yield of valuables in the flotation step were non-satisfying. Nevertheless, recovery of valuable metals from urban stock is a viable method for the extension of the availability of limited natural resources. 相似文献
In much of the world, the persistence of long‐distance migrations by mammals is threatened by development. Even where human population density is relatively low, there are roads, fencing, and energy development that present barriers to animal movement. If we are to conserve species that rely on long‐distance migration, then it is critical that we identify existing migration impediments. To delineate stopover sites associated with anthropogenic development, we applied Brownian bridge movement models to high‐frequency locations of pronghorn (Antilocapra americana) in the Greater Yellowstone Ecosystem. We then used resource utilization functions to assess the threats to long‐distance migration of pronghorn that were due to fences and highways. Migrating pronghorn avoided dense developments of natural gas fields. Highways with relatively high volumes of traffic and woven‐wire sheep fence acted as complete barriers. At crossings with known migration bottlenecks, use of high?quality forage and shrub habitat by pronghorn as they approached the highway was lower than expected based on availability of those resources. In contrast, pronghorn consistently utilized high?quality forage close to the highway at crossings with no known migration bottlenecks. Our findings demonstrate the importance of minimizing development in migration corridors in the future and of mitigating existing pressure on migratory animals by removing barriers, reducing the development footprint, or installing crossing structures. Identificación de los Impedimentos para las Migraciones de Larga Distancia de Mamíferos 相似文献
To slow the impending loss of wild black ( Diceros bicornis ) and white ( Ceratotherium simum ) rhinos, three African countries have resorted to dehorning, a practice designed to remove the incentive for poachers to kill the hornless animals. The efficacy of this controversial conservation action remains unknown, in part because much uncertainty exists about the functional significance of rhino horns. We assessed the current utility of horns in Namibian black rhinos from phenotypically altered and intact populations in the Namib Desert, and we collated data on mortal fighting among horned females living in Etosha National Park. Infant mortality was 100% when dehorned mothers were sympatric with spotted hyenas ( Crocuta crocuta ). In contrast, infant survival was 100% for both horned mothers living with hyenas and occasional lions ( Panthera leo ) and 100% for dehorned mothers in the absence of dangerous carnivores. These data suggest that female horns can have direct fitness benefits in terms of calf survival. However, because lethal wounding due to fighting may account for up to 33% of the mortality of horned females, dehorning may improve adult survivorship. Our results (1) suggest that, where the aim of conservation programs is to improve population viability through juvenile recruitment, dehorning is unlikely to be a prudent strategy if practiced in areas with dangerous predators, and (2) illustrate the value of experimental approaches to onerous problems in conservation. 相似文献
It is predicted that deep-sea animals adapted to thermally stable conditions should be highly sensitive to temperature change and should not have inducible heat-shock responses. This premise was tested with the cold-seep mussel Bathymodiolus childressi Gustafson, 1998 from 750 m depth in the Gulf of Mexico at a site known as Brine Pool NR-1 (27°43.4157N, 91°16.756W). Mussels were collected during February 2003. Site temperature, measured in different months between 1995 and 2005, ranged between 6.5 and 7.2°C. Although Brine Pool NR-1 is stenothermal, hydrogen sulfide, oxygen, and salinity vary over temporal and spatial scales. In laboratory experiments, B. childressi survived increases up to approximately 20°C above ambient temperature for 6 h before suffering greater than 50% mortality. Although a high thermal tolerance was observed, B. childressi did not express an inducible 70 kDa heat-shock protein. However, high constitutive levels of hsp70 were present in B. childressi suggesting a necessity to remediate protein damage from stressors other than elevated temperature; these constitutive proteins probably confer an indirect thermal tolerance. 相似文献
The numerous tactics used to conserve biodiversity include the designation of protected areas, political change, and research and education, the latter involving paradigms such as insular biogeography and the "umbrella species concept." In Namibia lands removed from national park status in 1970 and currently under the jurisdiction of indigenous people now contain one of the few unfenced populations of black rhinos (Diceros bicornis) remaining in Africa. Theory predicts that the protection of umbrella species will ensure the survival of other biota that require(s) less space. To gauge how well biodiversity might be retained by examining the spatial needs of a small population of black rhinos, I used data gathered under various ecological conditions to estimate mean and minimum population sizes of six large herbivores of the Namib Desert ranging in size from giraffe (Giraffa camelopardalis) to springbok (Antidorcas marsupialis) and ostrich (Struthio camelus). My results indicate that annual differences in rainfall, both within and between seasons, resulted in wide fluctuations in herbivore population sizes for all species except rhino. Although other herbivores switched to areas of higher rainfall, rhinos did not. The data suggest that under conditions of extreme environmental variance the space used by rhinos alone was unlikely to assure the existence of populations of other species in excess of 250 individuals. Fifty percent of the species failed to exceed 150 individuals 50% of the time and one third of the species never attained populations in excess of 50 individuals. However, by employing assumptions about the spatial needs of rhino populations numbering up to 100 individuals, the mean minimum population sizes attained by any of four desert herbivores is 535. A future challenge in using rhinos and other large-bodied species as umbrellas for organisms of either similar or dissimilar trophic levels will be the refinement of estimates of population viability. 相似文献
Air samples were collected from 4 field sites in Europe: 2 sites from the UK, Hazelrigg (semi-rural) and Manchester (urban); 1 site from Ireland: Mace Head (rural); and 1 site from Norway: Kjeller (rural). Additionally, air samples were taken from indoor locations in Troms?, Norway. Air samples were collected using high-volume air samplers employing sampling modules containing glass-fibre filters (GFFs, particle phase), and glass columns with a polyurethane foam (PUF)-XAD-2-PUF sandwich (gaseous phase). Typical outdoor air volumes required for the determination of per- and polyfluorinated alkyl substances (PFAS) ranged from 500-1800 m3. GFFs and PUF-XAD columns were analysed separately to obtain information on phase partitioning. All air samples were analysed for volatile, neutral PFAS, with selected GFF samples halved for analysis of both neutral and airborne particle-bound ionic PFAS. Volatile PFAS were extracted from air samples by cold-column immersion with ethyl acetate, and were analysed by gas chromatography-mass spectrometry in the positive chemical ionisation mode (GC-PCI-MS). Ionic PFAS were extracted from GFFs by sonication in methanol, and were analysed by liquid chromatography-time-of-flight-mass spectrometry (LC-TOF-MS) using electrospray ionisation in the negative ion mode (ESI-). Perfluorooctanoate (PFOA) was often the predominant analyte found in the particulate phase at concentrations ranging from 1-818 pg m(-3), and 8:2 fluorotelomer alcohol (FTOH) and 6:2 FTOH were the prevailing analytes found in the gas phase, at 5-243 pg m(-3) and 5-189 pg m(-3), respectively. These three PFAS were ubiquitous in air samples. Many other PFAS, both neutral and ionic, were also present, and levels of individual analytes were in the 1-125 pg m(-3) range. Levels of some PFAS exceeded those of traditional persistent organic pollutants (POPs). In this study, the presence of 12:2 FTOH and fluorotelomer olefins (FTolefins), and ionic PFAS other than perfluorooctane sulfonate (PFOS) and PFOA, are reported in air samples for the first time. Concentrations of neutral PFAS were several orders of magnitude higher in indoor air than outdoor air, making homes a likely important diffuse source of PFAS to the atmosphere. Our repeated findings of non-volatile ionic PFAS in air samples raises the possibility that they might directly undergo significant atmospheric transport on particles away from source regions, and more atmospheric measurements of ionic PFAS are strongly recommended. 相似文献