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31.
An extremely potent mutagen, 3‐chloro‐4(dichloromethyl)‐5‐hydroxy‐2(5/f)‐furanone (MX) is commonly present in chlorinated drinking water. Due to its high mutagenic activity and according to WHO guidelines its concentration should be controlled in drinking waters. Determination of MX is difficult due to ppt levels at which the compound usually exists in drinking waters. Derivatization with 2‐propanol is presented as a method which significantly lowers GC/MS detection level of MX. Suitability of 2‐propylation for derivatization of other hydroxyfuranones is also shown.  相似文献   
32.
The mechanism of pollutant dispersion in idealized city models is investigated numerically by the introduction of a uniformly distributed pollutant source at street pedestrian level. We first study three short city forms with a single main street or two crossing streets, characterized by street length/street height ratios of L/H = 6 or 7 and a street height/street width ratio of H/W = 1, including a sharp-edged round city model, a smooth-edged round city model, and a sharp-edged square city model. For short city models with a single street and a parallel approaching wind, pollutant dilution mainly depends on the horizontal flow rate which decreases along the street. This decreasing rate is smallest for the smooth-edged round city model, which results in the lowest street concentrations. For city models with two crossing streets and the approaching wind parallel to the main street, the differences in overall city form result in different dispersion processes. For a sharp-edged round city model with two crossing streets, an approaching wind slightly non-parallel to the main street generates a lower pollutant concentration in the entire street volume. We also studied a sharp-edged round city model with one narrow street (L/H = 6; H/W = 6.7), finding that the uniformly distributed pollutants are transported from two street entries to the city centre, and are then removed out across the street roof. In contrast to the short city models we studied a single-street sharp-edged long rectangular city model (L/H = 21.7; H/W = 1) in which the horizontal flow rate remained nearly constant in a region far from the two entries. Within this region the turbulence across the street roof contributed more to the pollutant removal than vertical mean flows.  相似文献   
33.
Leif Hammarström 《Ambio》2012,41(2):103-107
Solar energy has potential to provide a major part of our energy for our future, as heat, electricity, and fuels. Most solar technologies are still at the research and development stage, however. There is therefore a need for bold and enduring efforts in research, development and commercialization, including strategic legislative measures and infrastructure investments. This overview article serves as an introduction to the present Special Report, briefly outlining the potential, principles and possibilities as well as some of the challenges of solar energy conversion.  相似文献   
34.
The current picture of fatal injuries in Sweden is dominated by falls, which account for about 40%. Furthermore, falls are by far the most dominating cause of hospital in-patient care (57%). The aetiologic mechanisms behind falls and fractures are complicated, with a multifactorial causal pattern.The Lidköping Accident Prevention Programme — one of the few comprehensive community intervention programs in the world — provides an opportunity to discuss links between a multifactorial intervention program and related injuries in the elderly. The incidence of femoral fractures in Lidköping shows a significantly declining trend for females (− 6.6% per year) and a − 5.4% decline for males during the study period of 1987–1992. The control area of Skaraborg County showed a minor decrease and Sweden as a whole showed an increasing trend during the same period.In spite of the methodological problems of attributing effects in quasi-experiments, there is some support for the claim that the declining trend in the trial area was largely the result of the intervention program. This conclusion is further strengthened by the recently published report from the USA showing that a multiple-risk-factor intervention strategy resulted in a significant reduction in the risk of falling among elderly persons in the community.  相似文献   
35.
In Sweden there is a strong tradition of using nature areas for outdoor recreation. This paper reports on a study which explored preferences and willingness to pay for outdoor recreation close to home (≤100 km away from home and ≤24 hours stay at a recreation site) using the contingent valuation method. The data originated from a mail survey that involved Swedish residents who were randomly selected from a national register. An ordinary least squares regression model was used to account for factors influencing willingness to pay. The results showed that approximately 50% of the respondents used nature areas close to their home for recreation and their average frequency of visits to these areas was 74 times annually. Areas dominated by forests were the most preferred, followed by water. The respondents were willing to pay approximately 7200 SEK (US$1080) annually. Their willingness to pay was influenced by factors such as type of nature area, distance to and time spent at the recreation site and income. The results provide one input to the land use planning process by considering the demand for nature-based outdoor recreation close to home.  相似文献   
36.
The replacement of fossil fuels by biofuels could be an important means of reducing net carbon dioxide (CO2) emission. An estimation of the CO2 mitigation efficiency of biofuel systems depends on the method and assumptions used. Here, different parameters and methods are discussed for comparing fossil-fuel- and biofuel-based systems. Three parameters are suggested: the monetary cost, the primary energy cost and the biofuel cost of CO2 mitigation. They are defined as the difference in monetary expenditure, primary energy use and biofuel use between the compared systems, divided by the difference in net CO2 emission between the systems. Cogeneration and separate production of electricity and heat is then compared using these parameters and the methods of multi-functional products or subtraction. In both methods, either electricity or heat is regarded as the main product and the other is regarded as a by-product. The multi-functional method is preferable due to its transparency as both the main product and the by-product are part of the functional unit. Using heat as the main product illustrates the typical situation that the heat demand limits the use of cogeneration. When comparing systems the output from them should not differ. If the by-product is not fully, cogenerated part of the by-product has to be produced separately. A logical choice for producing this part of the by-product is to use a similar fuel and technology as used for cogeneration.  相似文献   
37.
Illegal transfer of wildlife has 2 main purposes: trade and scientific research. Trade is the most common, whereas scientific research is much less common and unprofitable, yet still important. Biopiracy in science is often neglected despite that many researchers encounter it during their careers. The use of illegally acquired specimens is detected in different research fields, from scientists bioprospecting for new pharmacological substances, to taxonomists working on natural history collections, to researchers working in zoos, aquariums, and botanical gardens. The practice can be due to a lack of knowledge about the permit requirements in different countries or, probably most often, to the generally high level of bureaucracy associated with rule compliance. Significant regulatory filters to avoid biopiracy can be provided by different stakeholders. Natural history collection hosts should adopt strict codes of conduct; editors of scientific publications should require authors to declare that all studied specimens were acquired legally and to cite museum catalog numbers as guarantee of best practices. Scientific societies should actively encourage publication in peer-reviewed journals of work in which specimens collected from the wild were used. The International Commission on Zoological Nomenclature could require newly designated types based on recently collected specimens to be accompanied by statements of deposition in recognized scientific or educational institutions. We also propose the creation of an online platform that gathers information about environmental regulations and permits required for scientific activities in different countries and respective responsible governmental agencies and the simplification of the bureaucracy related to regulating scientific activities. This would make regulations more agile and easier to comply with. The global biodiversity crisis means data need to be collected ever faster, but biopiracy is not the answer and undermines the credibility of science and researchers. It is critical to find a modus vivendi that promotes compliance with regulations and scientific progress.  相似文献   
38.
Lichens are a bottleneck resource for circumpolar populations of reindeer, and as such, for reindeer husbandry as an indigenous Sami land-use tradition in northern Sweden. This study uses ground lichen data and forest information collected within the Swedish National Forest Inventory since 1953, on the scale of northern Sweden. We found a 71 % decline in the area of lichen-abundant forests over the last 60 years. A decline was observed in all regions and age classes and especially coincided with a decrease of >60 year old, open pine forests, which was the primary explanatory factor in our model. The effects of reindeer numbers were inconclusive in explaining the decrease in lichen-abundant forest. The role that forestry has played in causing this decline can be debated, but forestry can have a significant role in reversing the trend and improving ground lichen conditions.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0759-0) contains supplementary material, which is available to authorized users.  相似文献   
39.
Hammarström L 《Ambio》2012,41(Z2):103-107
Solar energy has potential to provide a major part of our energy for our future, as heat, electricity, and fuels. Most solar technologies are still at the research and development stage, however. There is therefore a need for bold and enduring efforts in research, development and commercialization, including strategic legislative measures and infrastructure investments. This overview article serves as an introduction to the present Special Report, briefly outlining the potential, principles and possibilities as well as some of the challenges of solar energy conversion.  相似文献   
40.
Leif Kullman 《Ambio》2010,39(2):159-169
Alpine plant life is proliferating, biodiversity is on the rise and the mountain world appears more productive and inviting than ever. Upper range margin rise of trees and low-altitude (boreal) plant species, expansion of alpine grasslands and dwarf-shrub heaths are the modal biotic adjustments during the past few decades, after a century of substantial climate warming in the Swedish Scandes. This course of biotic landscape evolution has reached historical dimensions and broken a multi-millennial trend of plant cover retrogression, alpine tundra expansion, floristic and faunal impoverishment, all imposed by progressive and deterministic neoglacial climate cooling. Continued modest warming over the present century will likely be beneficial to alpine biodiversity, geoecological stability, resilience, sustainable reindeer husbandry and aesthetic landscape qualities. These aspects are highlighted by an integrative review of results from long-term monitoring of subalpine/alpine vegetation in the Swedish Scandes. This forms the basis for some tentative projections of landscape transformations in a potentially warmer future. Notably, these results and projections are not necessarily valid in other regions and differ in some respects from model predictions. Continued monitoring is mandatory as a basis for generation of more realistic vegetation and ecosystem models.  相似文献   
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