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51.
Unique unaffected skeletal muscle fibres, unlike necrotic torso and limb muscles, may pave the way for a more detailed understanding of the molecular pathogenesis of inherited neuromuscular disorders and help to develop new treatment strategies for muscular dystrophies. The sparing of extraocular muscle in Duchenne muscular dystrophy is mostly attributed to the special protective properties of extremely fast-twitching small-diameter fibres, but here we show that distal muscles also represent a particular phenotype that is more resistant to necrosis. Immunoblot analysis of membranes isolated from the well established dystrophic animal model mdx shows that, in contrast to dystrophic limb muscles, the toe musculature exhibits an up-regulation of the autosomal dystrophin homologue utrophin and a concomitant rescue of dystrophin-associated glycoproteins. Thus distal mdx muscle groups provide a cellular system that naturally avoids myofibre degeneration which might be useful in the search for naturally occurring compensatory mechanisms in inherited skeletal muscle diseases.  相似文献   
52.
The degradation rate of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in silica-slurry systems to evaluate the bioavailability of sorbed-phase contaminant. After the silica particles were saturated with 2,4-D, the system was inoculated with the 2,4-D-degrading microorganism Flavorbacterium sp. strain FB4. The disappearance rate of 2,4-D was found to be greater than the rate predicted based upon liquid-phase 2,4-D concentrations. A kinetic formulation, termed the enhanced bioavailability model, was developed to describe the desorption and biodegradation processes in this batch system. The approach assumes that 2,4-D resides in both the liquid and solid phases and degradation occurs via both suspended and attached biomass. All biomass can degrade liquid-phase 2,4-D at one rate, while only attached biomass can degrade sorbed 2,4-D at another rate. An enhanced transformation factor (Ef) was introduced to express the increased biodegradation rate over that expected from the liquid phase only. This approach was able to account for the increased degradation rates observed experimentally. The results provide evidence that desorption to the bulk solution is not prerequisite to degradation, and that sorbed substrate may be available for degradation.  相似文献   
53.
We applied the Theory of Planned Behavior to help understand the relationships between environmental beliefs, support for ecosystem restoration actions, and willingness to pay (WTP) for restoration and protection goals in the Hudson River estuary, New York State, USA. We conducted a mail survey with 3,000 randomly-chosen local residents of the Hudson River estuary in the fall of 1999. As hypothesized, the broad ecosystem restoration goals of the Hudson River Estuary Action Plan were more strongly supported than the corresponding specific implementation actions. We found that beliefs and past behavior were better explanatory variables than sociodemographic characteristics for explaining people's support for ecosystem restoration actions and WTP for restoration and protection goals. Because ecosystem restoration goals appear to be more generally acceptable than specific restoration actions, proponents of restoration programs should not become complacent about the need for active public outreach and involvement even if initial restoration program discussions have been low in controversy. Efforts to assess and foster support for ecosystem restoration should be targeted toward audiences identified on the basis of beliefs and past behaviors rather than on sociodemographic characteristics.  相似文献   
54.
Meeting the demands of today's marketplace has become an increasingly complex challenge for corporations in all industries. The consumer is demanding high-quality products, low cost, and more recently, a new variable: environmental performance. Customers will not accept sacrifices in quality or cost to help businesses meet regulatory requirements or develop environmentally sound products. They want it all. Consequently, companies are faced with the complex task of balancing cost, quality, and environmental performance.  相似文献   
55.
The transfer of radioactive caesium from soils to plants has been well researched. In contrast there is limited knowledge on natural stable 133Cs and its potential role as a predictor for radiocaesium behaviour. In a pot experiment with Agrostis capillaris close correlations were found between plant 137Cs and plant 133Cs concentrations (R2 90-96%). Season and leaf age had significant effects with concentrations increasing 10-30-fold between June and December. Simultaneously the plant concentrations of K, the nutrient analogue of Cs, decreased to around one third. In the soil the exchangeable fractions of K and 137Cs declined. No clear relationships were found between 137+133Cs in the plant and exchangeable K in the soil. However, at the end of the experiment the K content of the above-ground biomass was higher than the exchangeable pool in the soil, suggesting that depletion of soil K could be a key factor in the observed increase of plant 137+133Cs over time.  相似文献   
56.
Larval dispersal is an important component of marine reserve networks. Two conceptually different approaches to incorporate dispersal connectivity into spatial planning of these networks exist, and it is an open question as to when either is most appropriate. Candidate reserve sites can be selected individually based on local properties of connectivity or on a spatial dependency-based approach of selecting clusters of strongly connected habitat patches. The first acts on individual sites, whereas the second acts on linked pairs of sites. We used a combination of larval dispersal simulations representing different seascapes and case studies of biophysical larval dispersal models in the Coral Triangle region and the province of Southeast Sulawesi, Indonesia, to compare the performance of these 2 methods in the spatial planning software Marxan. We explored the reserve design performance implications of different dispersal distances and patterns based on the equilibrium settlement of larvae in protected and unprotected areas. We further assessed different assumptions about metapopulation contributions from unprotected areas, including the case of 100% depletion and more moderate scenarios. The spatial dependency method was suitable when dispersal was limited, a high proportion of the area of interest was substantially degraded, or the target amount of habitat protected was low. Conversely, when subpopulations were well connected, the 100% depletion was relaxed, or more habitat was protected, protecting individual sites with high scores in metrics of connectivity was a better strategy. Spatial dependency methods generally produced more spatially clustered solutions with more benefits inside than outside reserves compared with site-based methods. Therefore, spatial dependency methods potentially provide better results for ecological persistence objectives over enhancing fisheries objectives, and vice versa. Different spatial prioritization methods of using connectivity are appropriate for different contexts, depending on dispersal characteristics, unprotected area contributions, habitat protection targets, and specific management objectives. Comparación entre los métodos de priorización de la conservación espacial con sitio y la conectividad espacial basada en la dependencia  相似文献   
57.
There is a growing international awareness of the health risks associated with water, and particularly in developing countries. For example: (i) a child dies in Africa every 30s due to malaria—a disease related to stagnant water, (ii) every year flooding causes many deaths world-wide, with infant mortality due to diarrhea from contaminated flood waters posing the biggest threat, and (iii) poor sanitation and its relation to hepatitis A continues to be a serious problem. A revealing measure of the extent of such global problems is that more than half of the hospital beds in the world today are occupied by people with water-related diseases. Addressing these issues mandates an interdisciplinary approach by the world’s scientific and engineering community. In this spirit a workshop was held in Phoenix to provide a forum where epidemiologists, hydraulics researchers and other stakeholders of varied backgrounds (e.g., policy makers, environmental groups etc.) could all participate in a debate on a future agenda for hydro-epidemiology. The principal outcome of the workshop was a significant appreciation of the potential for interdisciplinary research and development in hydro-epidemiology and the major contribution that hydraulics professionals could offer, in partnership with the public health community, in addressing such water related disease control and prevention challenges.  相似文献   
58.
The European Water Framework Directive requires the integrated management of point and diffuse pollution to achieve 'good' water quality in 'protected areas'. These include bathing waters, which are regulated using faecal indicator organisms as compliance parameters. Thus, for the first time, European regulators are faced with the control of faecal indicator fluxes from agricultural sources where these impact on bathing water compliance locations. Concurrently, reforms to the European Union (EU) Common Agricultural Policy offer scope for supporting on-farm measures producing environmental benefits through the new 'single farm payments' and the concept of 'cross-compliance'. This paper reports the first UK study involving remedial measures, principally stream bank fencing, designed to reduce faecal indicator fluxes at the catchment scale. Considerable reduction in faecal indicator flux was observed, but this was insufficient to ensure bathing water compliance with either Directive 76/160/EEC standards or new health-evidence-based criteria proposed by WHO and the European Commission.  相似文献   
59.
Under the EU Water Framework Directive (WFD) 20/60/EC and the US Federal Water Pollution Control Act 2002 management of water quality within river drainage basins has shifted from traditional point-source control to a holistic approach whereby the overall contribution of point and diffuse sources of pollutants has to be considered. Consequently, there is a requirement to undertake source-apportionment studies of pollutant fluxes within catchments. The inclusion of the Bathing Water Directive (BWD), under the list of 'protected areas' in the WFD places a requirement to control sources of faecal indicator organisms within catchments in order to achieve the objectives of both the BWD (and its revision - 2006/7/EC) and the WFD. This study was therefore initiated to quantify catchment-derived fluxes of faecal indicator compliance parameters originating from both point and diffuse sources. The Ribble drainage basin is the single UK sentinel WFD research catchment and discharges to the south of the Fylde coast, which includes a number of high profile, historically non-compliant, bathing waters. Faecal indicator concentrations (faecal coliform concentrations are reported herein) were measured at 41 riverine locations, the 15 largest wastewater treatment works (WwTWs) and 15 combined sewer overflows (CSOs) across the Ribble basin over a 44-day period during the 2002 bathing season. The sampling programme included targeting rainfall-induced high flow events and sample results were categorised as either base flow or high flow. At the riverine sites, geometric mean faecal coliform concentrations showed statistically significant elevation at high flow compared to base flow. The resultant faecal coliform flux estimates revealed that over 90% of the total organism load to the Ribble Estuary was discharged by sewage related sources during high flow events. These sewage sources were largely related to the urban areas to the south and east of the Ribble basin, with over half the load associated with the relatively small subcatchment of the River Douglas. The majority of this load was attributed to two WwTWs that discharge through a common outfall close to the tidal limit of this catchment. Budgets adjusted to accommodate the impact of proposed UV disinfection of these effluents showed that the load from these sources would be reduced significantly during base flow conditions. However, during high flow events loads would still remain high due to the operation of storm sewage overflows from stormwater retention tanks. The study identified untreated storm sewage spills from urban infrastructure and WwTW stormwater retention tanks as the dominant component of the high flow flux of faecal indicators to receiving waters of the Fylde coast and the associated bathing waters.  相似文献   
60.
Woodchip corrals are increasingly used as cost effective means of over-wintering livestock in temperate regions but there is little information on their potential environmental impact. Four woodchip corrals of varying characteristics were instrumented to capture and quantify the flows reaching the base, where pollutant fluxes may move either vertically to groundwater, or laterally to a water course. Samples for chemical analysis were collected daily by auto-sampler. Samples for bacterial analysis were aseptically hand-sampled. Sampling frequency was increased during high flow events and sampling was conducted over a 12-month period. Microbiological samples were analysed for total coliform (TC), presumptive Escherichia coli (EC) and intestinal enterococci (IE). Leachate was also analysed for total phosphorus, phosphate, total nitrogen, ammonium, total oxidised nitrogen, nitrite and nitrate. Each corral had a recording rain gauge sited within 10 m of the corral surface. Mean total nitrogen concentration in leachate was 339.5 mg l(-1), of which ammoniacal-N comprised approximately 57%. Mean total phosphorus concentration was 94.7 mg l(-1). Geometric mean concentrations of TC, EC and IE were 95,461, 94,983 and 55,552 cfu100 ml(-1), respectively. Significant flows of leachate occurred at the base of the corrals on most days during the 1-year sampling period and flow rate increased with stocking density. Strong positive linear relationships were found between the concentrations of the nutrient parameters and discharge. Strong positive curvilinear relations were found between faecal indicator concentrations and discharge. Different relationships were observed in the stocked and unstocked corrals. The resulting fluxes are sufficient to give concern and to indicate that corral development is worthy of regulatory attention.  相似文献   
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