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71.
Pricing of road transport at social marginal cost should make users aware of the cost of damaging the environment (external costs). Such an approach, however, requires a monetary estimate of this damage which can be difficult to derive. On the basis of a study carried out at Neuchâtel (Switzerland), the contingent valuation method was used to estimate the damage caused to buildings of historical and cultural value by traffic‐caused air pollution. In a survey, individuals were asked to contribute to a fund set up to finance the maintenance of pre‐selected historic buildings. A valuation function to predict willingness‐to‐pay responses is estimated.  相似文献   
72.
In Sweden, about 20 per cent of women undergoing prenatal diagnosis (PND) have the test for‘psychological reasons’, which means that they strongly fear giving birth to a disabled child, but have not reached the age limit. Women undergoing amniocentesis or chorionic villus biopsy for these reasons (n = 38) were studied by questionnaires with regard to distress during test procedures. They were compared to women examined because of a known or strongly suspected high risk of giving birth to a congenitally disabled child (n = 27) and to women examined because of an age more than 37 years (n = 144). The most distressed were women who had a high genetic risk. The women who had the test because of their age reported less distress. Women examined for psychological reasons, were moderately distressed, but reported the highest frequency of influence by the distress on their daily living. Women in all groups, however, felt a similar support by the normal test result and reported the whole procedure as rather easy. Different psychological determinants of anxiety of giving birth to a disabled child are discussed. The‘psychological indication’ for PND means that the women' s private interpretation of her risk, and not only the statistical limit, motivates PND.  相似文献   
73.
Until the last decade it was assumed that most marine species have pronounced gene flow over vast areas, largely because of their potential for dispersal during early life stages. However, recent genetic, modeling, and field studies have shown that marine populations may be structured at scales that are inconsistent with extensive dispersal of eggs and larvae. Such findings have stimulated the birth of new studies explaining the mechanisms that promote population structure and isolation in the oceans, in the face of high potential for dispersal. Here we study the vertical and horizontal distribution of cod (Gadus morhua) eggs in relation to small-scale circulation and water column hydrography in a coastal location of southern Norway. Previous studies conducted in this region have shown that cod populations inhabiting fjord locations, which are on average 30 km apart, are genetically differentiated, a remarkable outcome considering that Atlantic cod have pelagic egg stages and long pelagic larval duration. We document that cod eggs are found in greater abundance in shallow water layers, which on average are flowing up the fjord (away from the open ocean), and in the inner portion of the fjord, which is subject to lower current speeds compared to the outer or mouth of the fjord. Eggs were found to be neutrally buoyant at shallow depths, a trait that also favors local retention, given the local circulation. The same patterns held during two environmentally contrasting years. These results strongly suggest that population structure of Atlantic cod is favored and maintained by a balance between water circulation and egg characteristics.  相似文献   
74.
Nonlinear and irregular population dynamics may arise as a result of phase dependence and coexistence of multiple attractors. Here we explore effects of climate and density in the dynamics of a highly fluctuating population of wild reindeer (Rangifer tarandus platyrhynchus) on Svalbard observed over a period of 29 years. Time series analyses revealed that density dependence and the effects of local climate (measured as the degree of ablation [melting] of snow during winter) on numbers were both highly nonlinear: direct negative density dependence was found when the population was growing (Rt > 0) and during phases of the North Atlantic Oscillation (NAO) characterized by winters with generally high (1979-1995) and low (1996-2007) indices, respectively. A growth-phase-dependent model explained the dynamics of the population best and revealed the influence of density-independent processes on numbers that a linear autoregressive model missed altogether. In particular, the abundance of reindeer was enhanced by ablation during phases of growth (Rt > 0), an observation that contrasts with the view that periods of mild weather in winter are normally deleterious for reindeer owing to icing of the snowpack. Analyses of vital rates corroborated the nonlinearity described in the population time series and showed that both starvation mortality in winter and fecundity were nonlinearly related to fluctuations in density and the level of ablation. The erratic pattern of growth of the population of reindeer in Adventdalen seems, therefore, to result from a combination of the effects of nonlinear density dependence, strong density-dependent mortality, and variable density independence related to ablation in winter.  相似文献   
75.
Intraspecific variation in mating behavior is widespread among simultaneous hermaphrodites but its underlying sources remain largely unexplored. In the sea slug Chelidonura sandrana, most matings are reciprocal. However, despite non-conditional sperm exchange and potential polygamy-mediated benefits, 30% of matings end after unilateral insemination. To resolve this apparent inconsistency, we here investigated the effect of body size on the frequency of reciprocal matings by testing the following two hypotheses. First, sex-allocation theory predicts that the likelihood of reciprocity depends on the size difference between mating partners. Second, if both sex functions temporally differ in reaching maturity, reciprocal matings should be more frequent with increasing absolute body size of the smaller partner. The likelihood of reciprocity increased with body size of the smaller partner. Moreover, smaller individuals acted more often as males among unilateral matings. These findings suggest that the ability to donate sperm develops prior to female functionality in C. sandrana.  相似文献   
76.
Infrastructure intended to serve the public good frequently has implications for environmental justice and social sustainability. Drinking water supplies for sub/urban areas in North Carolina, USA, have regularly been secured by constructing dams to impound reservoirs. We used high-resolution, publicly available US Census data to explore whether 66 such reservoirs in North Carolina have induced demographic shifts in the communities that find themselves adjacent to the newly created lakeshores. Our principal findings include: (1) The ratio of white people to non-white people was significantly higher in communities within 0.5 miles of reservoir shorelines than in more distant communities; (2) even as North Carolina overall became less white from 1990 to 2010, the ratio of white people to non-white people within the 0.5 miles of the shoreline increased relative to the overall ratio in the State; and (3) similar, but less distinct, shifts in per capita income occurred during the period. Our results are consistent with the proposition that reservoirs have induced demographic shifts in communities adjacent to newly created lakeshores similar to the shifts associated with environmental gentrification and amenity migration, and may now be associated with perpetuating those shifts. These findings raise concerns about environmental justice and social sustainability that should be considered when planning and building infrastructure that creates environmental amenities. Where reservoirs are being planned, social costs, including the costs of demographic shifts associated with environmental gentrification or amenity migration, and disproportionate regulatory burdens, should be mitigated through innovative policy if possible.  相似文献   
77.
Schebb NH  Ahn KC  Dong H  Gee SJ  Hammock BD 《Chemosphere》2012,87(7):825-827
The antibacterial triclocarban (TCC) concentrates in the cellular fraction of blood. Consequently, plasma levels are at least two-fold lower than the TCC amount present in blood. Utilizing whole blood sampling, a low but significant absorption of TCC from soap during showering is demonstrated for a small group of human subjects.  相似文献   
78.
According to the European legislation, REACH, organic compounds are considered as substances of very high concern (SVHC) if they are persistent, bioaccumulative and toxic (PBT). A substance's long-range transport potential (LRTP) may also pose a risk to remote regions. This is, however, not yet explicitly included. For identification of compounds, which are not PBT according to REACH criteria, but show LRTP, we investigated 22,438 compounds from the Canadian Domestic Substance List (CDSL). The CDSL was searched for organic, neutral compounds. Substance properties were estimated with EPI Suite v4.00. Next, the substance list was edited in two ways: (1) The half-life criterion in air for LRTP as defined in the Stockholm Convention was applied. (2) For all compounds, indicators for persistence and LRTP were calculated with the multimedia model ELPOS v2.2. Applying the half-life criterion, we identified 594 substances, which are prone to LRT but are not PBT (non-PBT-L substances). In contrast, investigations with ELPOS lead to a shorter list of 188 substances, which are non-PBT-L substances. Finally, the list was compared with potential Arctic contaminants identified in previous literature. Our results show that there is a large number of organic chemicals which would not be considered as SVHC since they are not, at the same time, persistent, bioaccumulative and toxic according to REACH criteria. Nevertheless, they show LRTP according to different screening approaches and thus a potential hazard to remote regions.  相似文献   
79.
The abundance of plastics in stomachs of northern fulmars from the North Sea is used in the OSPAR Ecological Quality Objective (EcoQO) for marine litter. The preliminary EcoQO defines acceptable ecological quality as the situation where no more than 10% of fulmars exceed a critical level of 0.1 g of plastic in the stomach. During 2003-2007, 95% of 1295 fulmars sampled in the North Sea had plastic in the stomach (on average 35 pieces weighing 0.31 g) and the critical level of 0.1 g of plastic was exceeded by 58% of birds, with regional variations ranging from 48 to 78%. Long term data for the Netherlands since the 1980s show a decrease of industrial, but an increase of user plastics, with shipping and fisheries as the main sources. The EcoQO is now also used as an indicator for Good Environmental Status in the European Marine Strategy Framework Directive.  相似文献   
80.
Transformation toward a sustainable future requires an earth stewardship approach to shift society from its current goal of increasing material wealth to a vision of sustaining built, natural, human, and social capital—equitably distributed across society, within and among nations. Widespread concern about earth’s current trajectory and support for actions that would foster more sustainable pathways suggests potential social tipping points in public demand for an earth stewardship vision. Here, we draw on empirical studies and theory to show that movement toward a stewardship vision can be facilitated by changes in either policy incentives or social norms. Our novel contribution is to point out that both norms and incentives must change and can do so interactively. This can be facilitated through leverage points and complementarities across policy areas, based on values, system design, and agency. Potential catalysts include novel democratic institutions and engagement of non-governmental actors, such as businesses, civic leaders, and social movements as agents for redistribution of power. Because no single intervention will transform the world, a key challenge is to align actions to be synergistic, persistent, and scalable.  相似文献   
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