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1.
Biodiversity offsets aim to counterbalance the residual impacts of development on species and ecosystems. Guidance documents explicitly recommend that biodiversity offset actions be located close to the location of impact because of higher potential for similar ecological conditions, but allowing greater spatial flexibility has been proposed. We examined the circumstances under which offsets distant from the impact location could be more likely to achieve no net loss or provide better ecological outcomes than offsets close to the impact area. We applied a graphical model for migratory shorebirds in the East Asian–Australasian Flyway as a case study to explore the problems that arise when incorporating spatial flexibility into offset planning. Spatially flexible offsets may alleviate impacts more effectively than local offsets; however, the risks involved can be substantial. For our case study, there were inadequate data to make robust conclusions about the effectiveness and equivalence of distant habitat-based offsets for migratory shorebirds. Decisions around offset placement should be driven by the potential to achieve equivalent ecological outcomes; however, when considering more distant offsets, there is a need to evaluate the likely increased risks alongside the potential benefits. Although spatially flexible offsets have the potential to provide more cost-effective biodiversity outcomes and more cobenefits, our case study showed the difficulty of demonstrating these benefits in practice and the potential risks that need to be considered to ensure effective offset placement.  相似文献   
2.
Mast syndrome is a complicated form of human hereditary spastic paraplegias, caused by a mutation in the gene acid cluster protein 33, which encodes a protein designated as “maspardin.” Maspardin presents similarity to the α/β-hydrolase superfamily, but might lack enzymatic activity and rather be involved in protein–protein interactions. Association with the vesicles of the endosomal network also suggested that maspardin may be involved in the sorting and/or trafficking of molecules in the endosomal pathway, a crucial process for maintenance of neuron health. Despite a high conservation in living organisms, studies of maspardin in other animal species than mammals were lacking. In the cotton armyworm Spodoptera littoralis, an insect pest model, analysis of an expressed sequence tag collection from antenna, the olfactory organ, has allowed identifying a maspardin homolog (SlMasp). We have investigated SlMasp tissue distribution and temporal expression by PCR and in situ hybridization techniques. Noteworthy, we found that maspardin was highly expressed in antennae and associated with the structures specialized in odorant detection. We have, in addition, identified maspardin sequences in numerous “nonmammalian” species and described here their phylogenetic analysis in the context of metazoan diversity. We observed a strong conservation of maspardin in metazoans, with surprisingly two independent losses of this gene in two relatively distant ecdysozoan taxa that include major model organisms, i.e., dipterans and nematodes.  相似文献   
3.
Gaseous emissions from weaned pigs raised on different floor systems   总被引:1,自引:0,他引:1  
Gaseous emissions from agriculture contribute to a number of environmental effects. Carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) are greenhouse gases taking part to the global problem of climate change. Ammonia (NH3) emissions are responsible of soil acidification and eutrophication and contribute also to indirect emissions of N2O. This work evaluated the influence of the type of floor on the emissions of these gases in the raising of weaned pigs. Two trials were carried out. In the first trial, the animals were kept either on fully slatted floor or on straw-based deep litter and, in the second one, either on fully slatted floor or on sawdust-based deep litter. For each trial and on each type of floor, 2 successive batches of weaned pigs were raised without changing the litter or emptying the slurry pit between the 2 batches. The rooms were automatically ventilated to maintain a constant ambient temperature.The performance of the animals was not significantly different according to the floor type. In trial 1, the nitrogen contents of the straw deep litter (including the substrate) and slurry were respectively 276 and 389 g pig−1. In trial 2, the sawdust deep litter and slurry nitrogen contents were respectively 122 and 318 g pig−1.Raising pigs on straw deep litter produced proportionately around 100% more NH3 than raising pigs on slatted floor (0.61 g NH3-N d−1 pig−1 vs. 0.31 g NH3-N d−1 pig−1; P < 0.05). Differences in CO2, H2O and CH4 emissions were not significant between systems. Raising pigs on sawdust deep litter produced also proportionately more NH3 (+52%; 0.55 g NH3-N d−1 pig−1 vs. 0.36 g NH3-N d−1 pig−1; P < 0.01) but also more CO2 (+25%; 427 g d−1 pig−1 vs. 341 g d−1 pig−1; P < 0.001) and H2O (+65%; 981 g d−1 pig−1 vs. 593 g d−1 pig−1; P < 0.001) and less CH4 (−40%; 0.52 g d−1 pig−1 vs. 0.86 g d−1 pig−1; P < 0.001) than raising pigs on slatted floor. Practically no N2O emission was observed from rooms with slatted floor while the N2O emissions were 0.03 and 0.32 g N2O-N d−1 pig−1 for the straw and sawdust deep litter respectively. The warming potential of the greenhouse gases (N2O + CH4), were about 22, 34 and 168 g CO2 equivalents per day and per pig on fully slatted floor, straw or sawdust deep litter respectively.In conclusion, pollutant gas emissions from rearing of weaned pig seem lower with fully slatted plastic floor system than with deep litter systems.  相似文献   
4.
Industrial agriculture is yearly responsible for the loss of 55–100 Pg of historical soil carbon and 9.9 Tg of reactive nitrogen worldwide. Therefore, management practices should be adapted to preserve ecological processes and reduce inputs and environmental impacts. In particular, the management of soil organic matter (SOM) is a key factor influencing C and N cycles. Soil microorganisms play a central role in SOM dynamics. For instance, microbial diversity may explain up to 77 % of carbon mineralisation activities. However, soil microbial diversity is actually rarely taken into account in models of C and N dynamics. Here, we review the influence of microbial diversity on C and N dynamics, and the integration of microbial diversity in soil C and N models. We found that a gain of microbial richness and evenness enhances soil C and N dynamics on the average, though the improvement of C and N dynamics depends on the composition of microbial community. We reviewed 50 models integrating soil microbial diversity. More than 90 % of models integrate microbial diversity with discrete compartments representing conceptual functional groups (64 %) or identified taxonomic groups interacting in a food web (28 %). Half of the models have not been tested against an empirical dataset while the other half mainly consider fixed parameters. This is due to the difficulty to link taxonomic and functional diversity.  相似文献   
5.
Government agencies faced with politically controversial decisions often discount or ignore scientific information, whether from agency staff or nongovernmental scientists. Recent developments in scientific integrity (the ability to perform, use, communicate, and publish science free from censorship or political interference) in Canada, Australia, and the United States demonstrate a similar trajectory. A perceived increase in scientific‐integrity abuses provokes concerted pressure by the scientific community, leading to efforts to improve scientific‐integrity protections under a new administration. However, protections are often inconsistently applied and are at risk of reversal under administrations publicly hostile to evidence‐based policy. We compared recent challenges to scientific integrity to determine what aspects of scientific input into conservation policy are most at risk of political distortion and what can be done to strengthen safeguards against such abuses. To ensure the integrity of outbound communications from government scientists to the public, we suggest governments strengthen scientific integrity policies, include scientists’ right to speak freely in collective‐bargaining agreements, guarantee public access to scientific information, and strengthen agency culture supporting scientific integrity. To ensure the transparency and integrity with which information from nongovernmental scientists (e.g., submitted comments or formal policy reviews) informs the policy process, we suggest governments broaden the scope of independent reviews, ensure greater diversity of expert input and transparency regarding conflicts of interest, require a substantive response to input from agencies, and engage proactively with scientific societies. For their part, scientists and scientific societies have a responsibility to engage with the public to affirm that science is a crucial resource for developing evidence‐based policy and regulations in the public interest.  相似文献   
6.
7.
Dissipation kinetics of mesotrione, a new triketone herbicide, sprayed on soil from Limagne (Puy-de-Dôme, France) showed that the soil microflora were able to biotransform it.Bacteria from this soil were cultured in mineral salt solution supplemented with mesotrione as sole source of carbon for the isolation of mesotrione-degrading bacteria. The bacterial community structure of the enrichment cultures was analyzed by temporal temperature gradient gel electrophoresis (TTGE). The TTGE fingerprints revealed that mesotrione had an impact on bacterial community structure only at its highest concentrations and showed mesotrione-sensitive and mesotrione-adapted strains. Two adapted strains, identified as Bacillus sp. and Arthrobacter sp., were isolated by colony hybridization methods.Biodegradation assays showed that only the Bacillus sp. strain was able to completely and rapidly biotransform mesotrione. Among several metabolites formed, 2-amino-4-methylsulfonylbenzoic acid (AMBA) accumulated in the medium. Although sulcotrione has a chemical structure closely resembling that of mesotrione, the isolates were unable to degrade it.  相似文献   
8.
Information on the exposure of individual persons to radiofrequency (RF) fields is scarce, although such data are crucial in order to develop a suitable exposure assessment method, and frame the hypothesis and design of future epidemiological studies. The main goal of this survey is to assess individual RF exposure on a population basis, while clarifying the relative contribution of different sources to the total exposure. A total of 377 randomly selected people were analyzed. Each participant was supplied with a personal exposure meter for 24-hour measurements (weekday), and kept a time–location–activity diary. Electric field strengths were recorded in 12 different RF bands every 13 s. Summary statistics were calculated with the robust regression on order statistics method. Most of the time, recorded field strengths were not detectable with the exposure meter. Total field, cordless phones, WiFi-microwave, and FM transmitters stood apart with a proportion above the detection threshold of 46.6%, 17.2%, 14.1%, and 11.0%, respectively. The total field mean value was 0.201 V/m, higher in urban areas, during daytime, among adults, and when moving. When focusing on specific channels, the highest mean exposure resulted from FM sources (0.044 V/m), followed by WiFi-microwaves (0.038 V/m), cordless phones (0.037 V/m), and mobile phones (UMTS: 0.036 V/m, UMTS: 0.037 V/m). Various factors, however, contributed to a high variability in RF exposure assessment. These population-based estimates should therefore be confirmed by further surveys to better characterize the exposure situation in different microenvironments.  相似文献   
9.
Since the completion of the Management of Myelomeningocoele Study, maternal-fetal surgery for spina bifida has become a valid option for expecting parents. More recently, multiple groups are exploring a minimally invasive approach and recent outcomes have addressed many of the initial concerns with this approach. Based on a previously published framework, we attempt to delineate the developmental stage of the surgical techniques. Furthermore, we discuss the barriers of performing randomized controlled trials comparing two surgical interventions and suggest that data collection through registries is an alternative method to gather high-grade evidence.  相似文献   
10.
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