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71.
社论     
可持续消费与生产第八次国际高级研讨会 全世界面临着贫穷、饥饿、疾病和环境恶化等不断发展的问题.行动指令(最新指令是世界可持续发展峰会的<执行计划>以及联合国千年目标)已经到位.我们政府、企业和民间团体已经承诺改变现实.我们现在的挑战就是我们前进的速度.我们必须更快地开展工作,因为人类的生命和地球的健康正面临险境.在未来两天里我希望你们讨论并确定具体而实际的工作范畴--项目、举措、合作--,以便带来根本性的变化,建立供其他人适应、准备和效仿的模式.中心内容就是执行.  相似文献   
72.
In many animal species, male and female interests often differ when it comes to decisions over mating and fertilization. However, it is intrinsically difficult to determine the degree to which males and females exert control over the various processes that determine the outcome of reproductive interactions, and thus to predict how such conflicts will be resolved. For example, in species where sperm are transferred to females via a spermatophore or other external sperm packaging device, it is unclear which sex determines subsequent sperm transfer dynamics to the female reproductive tract. To address this question, we used a reciprocal cross experimental design in a bushcricket species (Poecilimon veluchianus) comprising two subspecies differing in the dynamics of sperm transfer. The reciprocal crosses show that in these bushcrickets the timing of sperm transfer in inter-subspecies crosses closely resemble those typical of the subspecies of the male partner, indicating that it is the properties of the spermatophore rather than its handling by the female that determine sperm transfer dynamics. There was neither a significant female influence nor any indication of an interaction between males and females with regard to the number of sperm transferred after a set interval. Our study suggests that males rather than females appear to control the timing of the insemination process in this species.  相似文献   
73.
Many regulating ecosystem services exhibit non-excludability and non-rivalry characteristics akin to public goods. This makes it unlikely that such regulating ecosystem services will attract a price in the marketplace. Policymakers, therefore, find difficulties in determining a correct economic valuation for regulating ecosystem services, with potentially severe consequences for aligning policy for ecosystem service provision with public preferences for service delivery. This research used a choice modelling approach to estimate public preferences for delivery of two regulating ecosystem services; reductions in the flood risk to the British city of York (implemented by filling in drainage ditches in peat moorland further up the catchment), and a reduction in CO2 emissions (implemented by planting Poplar trees for biomass either locally in the study area or elsewhere in the UK). The choice experiment presented respondents with options providing different levels of CO2 reduction, implemented locally or nationally, and different levels of flood risk reduction, at a range of different prices, with a tax as the payment vehicle. Subsequent analysis with latent class (LC) models showed considerable heterogeneity of preference among respondents, particularly with regard to the location of tree planting for CO2 reduction. One LC segment showed a significant preference for achieving a high level CO2 reduction through national, as opposed to local tree planting, potentially indicating the existence of NIMBYism. The same LC segment displayed a preference for moderate reductions in the flood risk to York, even though this would deliver no personal benefit for a substantial proportion of the segment. This could, therefore, indicate altruistic behaviour towards geographically proximate beneficiaries.  相似文献   
74.
A new conceptual model for the fate of lignin in decomposing plant litter   总被引:3,自引:0,他引:3  
Lignin is a main component of plant litter. Its degradation is thought to be critical for litter decomposition rates and the build-up of soil organic matter. We studied the relationships between lignin degradation and the production of dissolved organic carbon (DOC) and of CO2 during litter decomposition. Needle or leaf litter of five species (Norway spruce, Scots pine, mountain ash, European beech, sycamore maple) and of different decomposition stage (freshly fallen and up to 27 months of field exposure) was incubated in the laboratory for two years. Lignin degradation was followed with the CuO method. Strong lignin degradation occurred during the first 200 incubation days, as revealed by decreasing yields of lignin-derived phenols. Thereafter lignin degradation leveled off. This pattern was similar for fresh and decomposed litter, and it stands in contrast to the common view of limited lignin degradation in fresh litter. Dissolved organic carbon and CO2 also peaked in the first period of the incubation but were not interrelated. In the later phase of incubation, CO2 production was positively correlated with DOC amounts, suggesting that bioavailable, soluble compounds became a limiting factor for CO2 production. Lignin degradation occurred only when CO2 production was high, and not limited by bioavailable carbon. Thus carbon availability was the most important control on lignin degradation. In turn, lignin degradation could not explain differences in DOC and CO2 production over the study period. Our results challenge the traditional view regarding the fate and role of lignin during litter decomposition. Lignin degradation is controlled by the availability of easily decomposable carbon sources. Consequently, it occurs particularly in the initial phase of litter decomposition and is hampered at later stages if easily decomposable resources decline.  相似文献   
75.
Local mate competition (LMC) occurs when brothers compete with each other for mating opportunities, resulting in selection for a female-biased sex ratio within local groups. If multiple females oviposit in the same patch, their sons compete for mating opportunities with non-brothers. Females, in the presence of other females, should thus produce relatively more sons. Sex ratio theory also predicts a more female-biased sex ratio when ovipositing females are genetically related, and sex-ratio responses to foundress size if it differentially affects fitness gains from sons versus daughters. The mating system of the parasitoid wasp Ooencyrtus kuvanae meets assumptions of LMC. Females insert a single egg into each accessible egg of gypsy moth, Lymantria dispar, host egg masses. Wasps complete development inside host eggs and emerge en masse, as sexually mature adults, resulting in intense competition among brothers. We tested the hypothesis that O. kuvanae exhibits LMC by manipulating the number of wasp foundresses on egg masses with identical numbers of eggs. As predicted by LMC theory, with increasing numbers of wasp foundresses on an egg mass, the proportions of emerging sons increased. In contrast, the presence of a sibling compared to a non-sibling female during oviposition, or the size of a female, did not affect the number or sex ratio of offspring produced. The O. kuvanae system differs from others in that larvae do not compete for local resources and thus do not distort the sex ratio in favor of sons. With no resource competition among O. kuvanae larvae, the sex ratio of emergent son and daughter wasps is due entirely to the sex allocation by ovipositing wasp foundresses on host egg masses.  相似文献   
76.
The 1992 incorporation of an article by referendum in the Swiss Constitution mandating that the federal government issue regulations on the use of genetic material that take into account the dignity of nonhuman organism raises philosophical questions about how we should understand what is meant by “the dignity of nonhuman animals,” and about what sort of moral demands arise from recognizing this dignity with respect to their genetic engineering. The first step in determining what is meant is to clarify the difference between dignity when applied to humans and when applied to nonhumans. Several conceptions of human dignity should be rejected in favor of a fourth conception: the right not to be degraded. This right implies that those who have it have the cognitive capacities that are prerequisite for self-respect. In the case of nonhuman organisms that lack this capacity, respecting their dignity requires the recognition that their inherent value, which is tied to their abilities to pursue their own good, be respected. This value is not absolute, as it is in the case of humans, so it does not prohibit breeding manipulations that make organisms more useful to humans. But it does restrict morally how sentient animals can be used. In regard to genetic engineering, this conception requires that animals be allowed the uninhibited development of species specific functions, a position shared by Holland and Attfield, as opposed to the Original Purpose conception proposed by Fox and the Integrity of the Genetic Make-up position proposed by Rolston. The inherent value conception of dignity, as here defended, is what is meant in the Swiss Constitution article. This paper is a slightly revised version of a paper that had been published in German in 1998 (“Menschenwürde vs. Würde der Kreatur,” Freiburg i.Br.).  相似文献   
77.
To ensure science better informs the decision-making process, researchers and policy/program managers need to understand and respect each other's way of working, culture and operational timelines. However, there is little practical guidance on how this should be done and even less documented experience with specific mechanisms that better link these two groups. The published literature on information transfer has largely emphasized the dissemination of standard packages of information to ill-defined constituencies whose needs for scientific information are not well understood. Environment Canada's National Water Research Institute, on behalf of the Canadian Council of Ministers of the Environment, led a series of “Linking Water Science to Policy Workshops” as one such mechanism by which recent science could be delivered to practitioners, and practitioners could identify their research needs to scientists and research managers. There is a pressing need to explore and share experiences using creative mechanisms for sustained dialogue and networking between scientists and policy and program managers. The lessons learned from the workshop series and the need for science to continually inform the decision-making process has particular relevance for Canada's Ecosystem Initiatives given their integrated, place-based focus on long-term restoration and protection, and the challenge of continually changing ecosystems.The Canadian Crown reserves the right to retain a non-exclusive, royalty free licence in and to any copyright.  相似文献   
78.
We report results of a multigenerational experiment with Chironomus riparius. Two strains with a high and a low level of genetic variability were exposed to a low, environmentally relevant TBT concentration of 80 μg Sn kg−1 sediment dw nominally (time weighted mean, based on measured concentrations: 4.5 μg Sn kg−1 sediment dw), and various life history traits as well as genetic diversity were monitored for eleven consecutive generations. While TBT effects are hardly visible in the outbred and genetically diverse strain, the inbred and genetically impoverished strain shows a clearly reduced population growth rate compared to the control. Moreover, the impoverished strain shows an increase in fitness over time. Analyses of variation at five microsatellite loci revealed that the level of genetic variation is strongly reduced in the inbred compared to the outbred strain. Moreover, genetic diversity increases over time in the inbred strain. This finding explains the observed increase in fitness in both inbred lineages (control and TBT exposed). The results document that inbreeding and the level of genetic diversity might be of crucial importance in populations under pollution stress. Furthermore, ecotoxicological bioassays have to consider genetic diversity if results between laboratories should be comparable. Our data provides evidence that genetic diversity strongly contributes to the survival of a population exposed to chemical pollution.  相似文献   
79.
Mahmoud WM  Kümmerer K 《Chemosphere》2012,88(10):1170-1177
In some countries effluents from hospitals and households are directly emitted into open ditches without any further treatment and with very little dilution. Under such circumstances photo- and biodegradation in the environment can occur. However, these processes do not necessarily end up with the complete mineralization of a chemical. Therefore, the biodegradability of photoproduct(s) by environmental bacteria is of interest. Cardiovascular diseases are the number one cause of death globally. Captopril (CP) is used in this study as it is widely used in Egypt and stated as one of the essential drugs in Egypt for hypertension. Three tests from the OECD series were used for biodegradation testing: Closed Bottle test (CBT; OECD 301 D), Manometric Respirometry test (MRT; OECD 301 F) and the modified Zahn-Wellens test (ZWT; OECD 302 B). Photodegradation (150 W medium-pressure Hg-lamp) of CP was studied. Also CBT was performed for captopril disulfide (CPDS) and samples received after 64 min and 512 min of photolysis. The primary elimination of CP and CPDS was monitored by LC-UV at 210 nm and structures of photoproducts were assessed by LC-UV-MS/MS (ion trap). Analysis of photodegradation samples by LC-MS/MS revealed CP sulfonic acid as the major photodegradation product of CP. No biodegradation was observed for CP, CPDS and of the mixture resulting from photo-treatment after 64 min in CBT. Partial biodegradation in the CBT and MRT was observed in samples taken after 512 min photolysis and for CP itself in MRT. Complete biodegradation and mineralization of CP occurred in the ZWT.  相似文献   
80.
The communication of science to science users is evolving to an approach that translates knowledge to targeted audiences. Under this evolution, knowledge brokers play an increasingly important role and users help ‘pull’ the required science to meet a policy or management imperative. To do this effectively, more insight is required into the knowledge seeking behaviour of science users and practitioners. The findings from a series of interviews that identify the science needs of Ontario’s Conservation Authorities (CAs) are presented. Results indicate that emerging functions, such as source water protection and integrated water resource planning, require more science input than mature functions. Senior CA officials view personal communication with their knowledgeable staff as the most used, accessible, trustworthy, relevant, shared, and preferable source of science information. While the internet and media were considered highly accessible, they were not viewed as trustworthy. We found no relationship between CA size and science use. Further research is needed to identify where junior and intermediate CA staff obtain their science knowledge from and whether this varies as a function of CA size. Our findings will be of interest to both policy/program communities and science providers.  相似文献   
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