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61.
62.
Novel water-soluble polymeric photosensitizers based on a natural polymer, naphthalene-modified hydroxyethylcellulose (HENC), were obtained and used for the photooxidation of cyanide. The reaction leads to the formation of cyanate. The process occurs via photoinduced electron transfer from CN to the naphthalene or naphthoquinone polymeric chromophores. The kinetics of the reaction depend on the degree of substitution of HENC, its concentration, and pH of the solution. The polymers can be easily removed after reaction as prolonged irradiation leads to their photodegradation.  相似文献   
63.
Rice (Oryza sativa L.) agriculture is estimated to cover 161 million ha of land on Earth, with 10% grown in temperate regions. Currently there are strong concerns about surface water nutrient pollution, and the purpose of this study was to determine the impacts of temperate rice cultivation on nutrient dynamics at the small watershed scale. Over the course of the 2008 growing season (May through September), bi-weekly grab samples were collected from outlets of 11 agricultural subwatersheds in California. Samples were analyzed for NO3-N, NH4-N, PO4-P, K, and dissolved organic nitrogen (DON) concentrations, and the average values across all subwatersheds and sampling dates were 0.22, 0.031, 0.047, 1.36, and 0.32 mg L−1, respectively. Linear mixed effects analysis was used to evaluate the magnitude of relationships between nutrient concentration and flux and subwatershed characteristics (i.e. percent soil clay and organic matter, percent rice area, irrigation water reuse, subwatershed discharge, irrigated area, and time, measured as the day in the growing season). For all nutrients, flux decreased over time and increased with discharge. Concentrations of K and DON were highest at the start and end of the growing season. Concentrations of NH4-N were near non-detect levels, with the exception of a peak in mid-July, which corresponds to when many growers top-dress rice fields with N fertilizer. Nitrate-N concentration and flux decreased with percent rice area, whereas PO4-P concentrations increased with percent rice area, indicating that rice area should be considered in future watershed-scale studies of nutrient discharge. In all subwatersheds, the discharge loads of K were smaller than surface water input loads, while NO3-N, NH4-N, PO4-P, and DON discharge loads exceeded input loads when total growing season discharge was greater than 3500-6600 m3 ha−1. This implies that the management of subwatershed discharge can be used to control nutrient export from rice-growing areas.  相似文献   
64.
This article serves as an introduction to this special issue of Marine Biology, but also as a review of the key findings of the AQUASHIFT research program which is the source of the articles published in this issue. AQUASHIFT is an interdisciplinary research program targeted to analyze the response of temperate zone aquatic ecosystems (both marine and freshwater) to global warming. The main conclusions of AQUASHIFT relate to (a) shifts in geographic distribution, (b) shifts in seasonality, (c) temporal mismatch in food chains, (d) biomass responses to warming, (e) responses of body size, (f) harmful bloom intensity, (f), changes of biodiversity, and (g) the dependence of shifts to temperature changes during critical seasonal windows.  相似文献   
65.
State of the art of culturomics and metagenomics to study resistome was presented. The combination of culturomics and metagenomics approaches was proposed. The research directions of antibiotic resistance study has been suggested. Pharmaceutical residues, mainly antibiotics, have been called “emerging contaminants” in the environment because of their increasing frequency of detection in aquatic and terrestrial systems and their sublethal ecological effects. Most of them are undiscovered. Both human and veterinary pharmaceuticals, including antibiotics, are introduced into the environment via many different routes, including discharges from municipal wastewater treatment plants and land application of animal manure and biosolids to fertilize croplands. To gain a comprehensive understanding of the widespread problem of antibiotic resistance, modern and scientific approaches have been developed to gain knowledge of the entire antibiotic-resistant microbiota of various ecosystems, which is called the resistome. In this review, two omics methods, i.e. culturomics, a new approach, and metagenomics, used to study antibiotic resistance in environmental samples, are described. Moreover, we discuss how both omics methods have become core scientific tools to characterize microbiomes or resistomes, study natural communities and discover new microbes and new antibiotic resistance genes from environments. The combination of the method for get better outcome of both culturomics and metagenomics will significantly advance our understanding of the role of microbes and their specific properties in the environment.  相似文献   
66.
The International Union for Conservation of Nature's Red List of Threatened Species (RLS) is the key global tool for objective, repeatable assessment of species’ extinction risk status, and plays an essential role in tracking biodiversity loss and guiding conservation action. Satellite remote sensing (SRS) data sets on global ecosystem distributions and functioning show exciting potential for informing range-based RLS assessment, but their incorporation has been restricted by low temporal resolution and coverage of data sets, lack of incorporation of degradation-driven habitat loss, and noninclusion of assumptions related to identification of changing habitat distributions for taxa with varying habitat dependency and ecologies. For poorly known mangrove-associated Cuban hutias (Mesocapromys spp.), we tested the impact of possible assumptions regarding these issues on range-based RLS assessment outcomes. Specifically, we used annual (1985–2018) Landsat data and land-cover classification and habitat degradation analyses across different internal time series slices to simulate range-based RLS assessments for our case study taxa to explore potential assessment uncertainty arising from temporal SRS data set coverage, incorporating proxies of (change in) habitat quality, and assumptions on spatial scaling of habitat extent for RLS parameter generation. We found extensive variation in simulated species-specific range-based RLS assessments, and this variation was mostly associated with the time series over which parameters were estimated. However, results of some species-specific assessments differed by up to 3 categories (near threatened to critically endangered) within the same time series, due to the effects of incorporating habitat quality and the spatial scaling used in RLS parameter estimation. Our results showed that a one-size-fits-all approach to incorporating SRS information in RLS assessment is inappropriate, and we urge caution in conducting range-based assessments with SRS for species for which habitat dependence on specific ecosystem types is incompletely understood. We propose novel revisions to parameter spatial scaling guidelines to improve integration of existing time series data on ecosystem change into the RLS assessment process.  相似文献   
67.
Species reproduction is an important determinant of population dynamics. As such, this is an important parameter in environmental risk assessment. The closure principle computational approach test (CPCAT) was recently proposed as a method to derive a NOEC/LOEC for reproduction count data such as the number of juvenile Daphnia. The Poisson distribution used by CPCAT can be too restrictive as a model of the data-generating process. In practice, the generalized Poisson distribution could be more appropriate, as it allows for inequality of the population mean \(\mu\) and the population variance \(\sigma ^2\). It is of fundamental interest to explore the statistical power of CPCAT and the probability of determining a regulatory relevant effect correctly. Using a simulation, we varied between Poisson distribution (\(\mu =\sigma ^2\)) and generalized Poisson distribution allowing for over-dispersion (\(\mu <\sigma ^2\)) and under-dispersion (\(\mu >\sigma ^2\)). The results indicated that the probability of detecting the LOEC/NOEC correctly was \(\ge 0.8\) provided the effect was at least 20% above or below the mean level of the control group and mean reproduction of the control was at least 50 individuals while over-dispersion was missing. Specifically, under-dispersion increased, whereas over-dispersion reduced the statistical power of the CPCAT. Using the well-known Hampel identifier, we propose a simple and straight forward method to assess whether the data-generating process of real data could be over- or under-dispersed.  相似文献   
68.
Next-generation herbicides are relatively safe when used properly, but the recommended rates are relatively low, which can lead to overdosing. This study evaluated the responses of soil-dwelling microorganisms and soil enzymes to contamination with the Boreal 58 WG herbicide. The analyzed product contains active ingredients flufenacet and isoxaflutole. All tests were performed under laboratory conditions. The analyzed material was sandy clay. Boreal 58 WG was introduced to soil in four doses. Soil without the addition of the herbicide served as the control. The soil was mixed with the tested herbicide, and its moisture content was maintained at 50% of capillary water capacity. Biochemical and microbiological analyses were performed on experimental days 0, 20, 40, 80 and 160. Accidental contamination of soil with the Boreal 58 WG herbicide led to a relatively minor imbalance in the soil microbiological and biochemical profile. The herbicide dose influenced dehydrogenase activity in only 0.84%, urease activity in 2.04%, β-glucosidase activity in 8.26%, catalase activity in 12.40%, arylsulfatase activity in 12.54%, acid phosphatase activity in 42.11%, numbers of organotrophic bacteria in 18.29%, actinomyces counts in 1.31% and fungi counts in 6.86%.  相似文献   
69.
Environmental Science and Pollution Research - The aim of the study was to (i) investigate the potential of edible mushroom Boletus badius (Fr.) Fr. to accumulate 53 elements from unpolluted acidic...  相似文献   
70.
Australia and Sweden display very different institutional settings and contexts for the production of environmental journalism. This empirical study examined how two major quality newspapers in Sweden and Australia have framed renewable energy as an environmental, political, scientific, economic and civil society issue. A deductive, quantitative methodological approach was used to identify dominant frames and actors in articles in The Australian (Australia) and Dagens Nyheter (Sweden) between October 2010 and June 2011 2010/2011. The findings suggest that the attention given to different types of renewable energy in the two newspapers and how issues were framed was contingent on the domestication of the discussion of renewable energy in the two countries. Reporting on renewable energy in both newspapers was characterized by a focus on “elite” actors and economic frames, the absence of civil society frames and negative (The Australian) or ambiguous (Dagens Nyheter) environmental frames. The study extends our understanding of the contextual conditions that enable and limit journalists when reporting environmental issues.  相似文献   
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