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181.
182.
Bernd Hanisch Bettina Abbas Werner Kratz Gerrit Schüürmann 《Environmental Sciences Europe》2004,16(4):223-238
Goal
In the Brandenburg State Office for the Environment an approach to assess the potential risk of drug residues in aquatic ecosystems has been developed based on an investigation of the consumption amounts in 1999 to identify or to exclude a potential environmental risk of important human drugs and further to define priority substances for monitoring programs in Brandenburg in the future.Method
This assessment approach tested with 60 drug agents is based on an exposure estimation considering the main path for the entry human—waste water—sewage plant—surface water, on a substance specific analysis of effects and on an analysis of the environmental fate as compartment distribution, bioaccumulation and persistence.Results
In Brandenburg surface waters the drug agent concentration for eight of the considered substances is supposed to be greater than 1 μg/l and for at least 13 of the considered substanoes the PNEC in aquatic ecosystems is assumed to be lower than 1 μg/l. A potential risk for the environment can be seen for the antibiotics Ciprofloxacin-HCl and Clarithromycin, the disinfectants Benzalkonium Chloride, Cocospropylendiaminguaniacetat, Glucoprotamine, Laurylpropylenediamine and Polyvidone-iodine, the sexual hormon Ethinylestradiol, the antidiabetic Metformin-HCl, the antiepileptic Carbamazepine and the lipid regulator Clofibrinic acid on the basis of effects because their PEC:PNEC-relation is about 1 or higher. For further 19 drug agents an environmental risk is to be assumed because of their environmental behaviour without support by ecotoxicological data at present.Conclusion
Although there is only a small base of valid ecotoxicological data, this risk assessment shows that adverse effects in the aquatic environment by some drug agents cannot be excluded. However, it should be noted that this first assessment gives only a crude orientation. Appropriate test data are necessary to refine the assessment in future. 相似文献183.
Werner von Bloh Christine Bounama Klaus EisenackBrigitte Knopf Oliver Walkenhorst 《Ecological modelling》2008
To determine the influence of the biosphere on weathering we use a dynamic model of the global carbon cycle. It takes into account the most important processes for the long-term evolution of the Earth. The model is solved under a slowly changing environment of increasing solar luminosity and volcanic activity and continental area. By comparing the model results for the global average temperature with data derived from δ18O values from cherts it is possible to quantify the biogenic enhancement factor of weathering. For this purpose a newly developed inverse viability method is applied, which allows for calculating the range of possible biogenic enhancement factors consistent with the data. We find that in the Precambrian the weathering was 5.4 times lower than in the Phanerozoic era. This supports the hypothesis that the Cambrian explosion was caused by a positive feedback between the spread of biosphere, increased silicate weathering, and a consequent cooling of the climate. 相似文献
184.
Null model analysis of species nestedness patterns 总被引:6,自引:0,他引:6
Nestedness is a common biogeographic pattern in which small communities form proper subsets of large communities. However, the detection of nestedness in binary presence-absence matrices will be affected by both the metric used to quantify nestedness and the reference null distribution. In this study, we assessed the statistical performance of eight nestedness metrics and six null model algorithms. The metrics and algorithms were tested against a benchmark set of 200 random matrices and 200 nested matrices that were created by passive sampling. Many algorithms that have been used in nestedness studies are vulnerable to type I errors (falsely rejecting a true null hypothesis). The best-performing algorithm maintains fixed row and fixed column totals, but it is conservative and may not always detect nestedness when it is present. Among the eight indices, the popular matrix temperature metric did not have good statistical properties. Instead, the Brualdi and Sanderson discrepancy index and Cutler's index of unexpected presences performed best. When used with the fixed-fixed algorithm, these indices provide a conservative test for nestedness. Although previous studies have revealed a high frequency of nestedness, a reanalysis of 288 empirical matrices suggests that the true frequency of nested matrices is between 10% and 40%. 相似文献
185.
Vanessa S. Mascorro Nicholas C. Coops Werner A. Kurz Marcela Olguín 《Regional Environmental Change》2016,16(1):213-228
Detailed observations of natural and anthropogenic disturbance events that impact forest structure and the distribution of carbon are essential to estimate changes in terrestrial carbon pools and the associated emissions and removals of greenhouse gasses. Recent advances in remote sensing approaches have resulted in annual and decadal estimates of land-cover change derived from observations using broad-scale moderate resolution imaging spectroradiometer (MODIS) 250 m–1 km imagery. These land-use change estimates, however, are often not attributed directly to a cause or activity and are not well validated, especially in tropical areas. Knowledge of the type of disturbance that caused the observed land-cover changes is important, however, for the quantification of the associated impacts on ecosystem carbon stocks and fluxes. In this paper, we provide estimates of the amount of forest land-cover change in a Mexican forested region and propose an approach for attributing the cause of the observed changes to the underlying disturbance driver. To do so, we collate geospatial and remote sensing data from a variety of sources to summarize statistics about the major disturbances within the Yucatan Peninsula, an “early action” region for the reduction of emissions from deforestation and degradation, from 2005 to 2010. We combine the datasets to develop rules to estimate the likely disturbances that caused the observed land-cover changes based on their spatially explicit location. Finally, we compare our observed disturbance rates to those detected using classified land-cover data derived from MODIS. 相似文献
186.
Laura Bouriaud Mariella Marzano Manfred Lexer Liviu Nichiforel Christopher Reyer Christian Temperli Heli Peltola Ché Elkin Gabriel Duduman Philip Taylor Stephen Bathgate Jose G. Borges Sandra Clerkx Jordi Garcia-Gonzalo Carlos Gracia Geerten Hengeveld Seppo Kellomäki Georgi Kostov Michael Maroschek Bart Muys Gert-Jan Nabuurs Bruce Nicoll Marc Palahí Werner Rammer Duncan Ray Mart-Jan Schelhaas Louise Sing Margarida Tomé Juergen Zell Marc Hanewinkel 《Regional Environmental Change》2015,15(8):1595-1609
187.
Residential satisfaction is a significant topic in environmental psychology yet there is little research on residential satisfaction among elders. This research aims to identify the cognitive structure of residential satisfaction of elderly persons living in their own dwellings and to identify demographic and psychological variables related to this residential satisfaction. One hundred and three participants, ranging in age from 72 to 86 years old and living at home in the central France, answered (a) a purpose-developed questionnaire to measure their residential satisfaction, (b) an environmental quality questionnaire aimed at evaluating both the physical and social environments, and (c) several psychological variables including: the ESV, a French adaptation of the Satisfaction with Life Scale which examines the general well-being of aging people; and three single well-being items assessing financial well-being, perceived health, and perception of oneself as active. The results indicated that in this sample, residential satisfaction corresponds to a four-dimension structure organized by physical location rather than psychological or behavioral aspects. The four components were the local area, access to services, relations with neighbors, and the home itself. Satisfaction with each component was related to different predictors, supporting the idea that elders hold complex and nuanced views of their homes and neighborhoods. 相似文献
188.
Britta Grote Wilhelm Hagen Marek R. Lipinski Hans M. Verheye Erling K. Stenevik Werner Ekau 《Marine Biology》2011,158(5):1005-1017
Cape hakes, Merluccius paradoxus and M. capensis, are important gadoid fish that are commercially harvested in the Benguela Current system off Namibia and South Africa. The
aim of this study was to elucidate the nutritional condition and feeding preferences of their larvae. Hake eggs and larvae
were sampled in austral spring of two consecutive years, 2007 and 2008, off the west coast of South Africa. They were identified
to species using genetics, and total lipid content and fatty acid (FA) composition were analysed for each individual egg and
larva to compare the condition of different early life stages of both hake species. Higher abundances of M. paradoxus eggs and larvae were consistently found compared to M. capensis. In both species, eggs contained wax esters (WE) and had significantly higher lipid content per dry mass than larvae. Lipid
content as well as FA composition changed with the developmental stage of larvae. Quantities of essential fatty acid (EFA)
increased with feeding of larvae due to dietary lipid incorporation. In 2007, yolk-sac larvae contained significantly lower
total lipids than in 2008. It is argued that this was due to reduced lipid transfer by the spawning females to the eggs. These
findings indicate that maternal effects are important in determining condition of hake larvae and that this may have an effect
on their survival and subsequent recruitment. 相似文献
189.
190.
Frías-Espericueta MG Osuna-López JI Jiménez-Vega MA Castillo-Bueso D Muy-Rangel MD Rubio-Carrasco W López-López G Izaguirre-Fierro G Voltolina D 《Environmental monitoring and assessment》2011,182(1-4):133-139
The increasing order of the mean concentrations of Cd, Cu, and Zn in the tissues of Mugil cephalus of seven coastal lagoons of Sinaloa State (NW Mexico) was liver > gills > muscle, while for Pb it was gills > muscle ≥ liver. There were no differences between the mean concentrations of Cd and Pb of the three tissues determined in the samples of the seven lagoons and, although there were some significant differences, there was no indication of a latitude-related trend in the distribution of Cu and Zn: the Cu content of the muscle tended to be higher in the northern than in the southern lagoons, although in the case of the gills the highest and lowest mean values indicated an opposite trend, with the highest and lowest values in one southern and one northern lagoon. In the case of the liver, there were no differences and no indication of a regional trend. There were no differences in the mean Zn contents of muscle and gills; in the case of the liver, one of the lagoons of the central part of the state had a significantly higher value than one of the southern lagoons and all the rest had similar values. In addition, there was no clear indication of season-related differences in any of the three tissues. According to our results, the metal contents of the muscle of this species are not of concern for human health, since the allowable ingestion would be in the order of 0.9 kg/day. 相似文献