The effect of filter material on bioaerosol collection of Bacillus subtilis spores used as a Bacillus anthracis simulant

The objective of this study was to determine filter materials and extraction methods that are appropriate to use for environmental sampling of B. anthracis. Four types of filters were tested: mixed cellulose ester (MCE) with a pore size of 3 microm, polytetrafluoroethylene (PTFE) with pore sizes of 1 and 3 microm, and gelatin with a pore size of 3 microm. Bacillus subtilis var. niger endospores (also known as Bacillus globigii[BG]) were used as a surrogate for B. anthracis. Endospores were collected into Button Inhalable Aerosol Samplers with sampling times of 15 minutes, 1 hour, and 4 hours. Physical collection efficiency was determined by measuring upstream and downstream B. subtilis concentrations with an optical particle counter. Vortexing with ultrasonic agitation and vortexing with shaker agitation extraction methods were evaluated. The MCE, 1 microm PTFE, and gelatin filters provided physical collection efficiencies of 94% or greater. The 3 microm PTFE filter showed inconsistent physical efficiency characteristics between filters. Epifluorescence microscopic analysis of the gelatin filter extraction fluid revealed the presence of contamination by non-culturable bacteria. Mean differences for microbial culturability were not statistically significant for filter materials and extraction methods. However, the vortexing with shaker agitation extraction method resulted in higher total microbial counts in the extraction fluids for MCE and 1 microm PTFE filters when compared to vortexing with ultrasonic agitation. In summary, the MCE and 1 microm PTFE filters in combination with vortexing and shaker extraction demonstrated the best performance for the filter collection and extraction of BG spores.     

通过调节汽油中铅的使用来控制人体血铅浓度

在20世纪60～70年代,铅排放一直保持着最大速率,之后,由于工业国家采取了日益严格的政策来限制铅作为防爆剂在汽油中使用,使得含铅汽油已经变得很少见了.我们利用欧洲铅排放量(PbE)和空气浓度(PbC)的重建及对约1980年以来德国人体血铅浓度(PbB)的重复测定,建立了一个可由铅排放量(PbE)估计人体血铅浓度(PbB)的经验模型.采用这一模型有两种用途[1]估计六七十年代德国的PbB水平,当时铅排放量最大而人体血铅水平监测尚未开始.结果显示,血铅峰值已经达到了卫生官员认为对胎儿和儿童有潜在危害的平均水平.[2]估计PbB水平将如何因有关汽油中铅使用的法规的实施而变化.模型估计,如果没有或延迟法规,PbB水平将远远超过临界水平.因此,自20世纪70年代以来,德国制定的法规已经明显降低了铅对健康的危害.     

Prenatal diagnosis for dystrophia myotonica using the polymerase chain reaction

The polymerase chain reaction has been used to detect an abundant class of short repeat DNA families of the form (dC-dA)n.(dG-dT)n, known as microsatellites. These units are found throughout the human genome and have been characterized for several loci including APOC2 on chromosome 19ql2-ql3.2. The locus APOC2 is linked to the gene for dystrophia myotonica and a microsatellite within this locus was used to derive polymorphisms in a family to predict the inheritance of the disease. Chorionic villus sampling (CVS) was performed at 151/2 weeks' gestation. Following DNA extraction from the CVS material and parental blood samples, microsatellite analysis was carried out by the polymerase chain reaction.     

Reducing car-based journeys to work: What potential is there and whose responsibility is it?

To date the transport solutions seeking to reduce traffic impacts have tended to focus on city/town centres. There has, however, been a substantial increase in traffic levels both in and to suburban areas and the location of large employment sites in such areas has had a significant impact. The typical policy response to traffic in these areas has been the introduction of traffic calming measures and residents' parking but such policies do not address the fundamental issue of travel generation and its consequences (including parking). Major employers should have an important role to play in the consideration of more sensible and sustainable uses of the car including the promotion of alternatives to car use. Using a case study at a large institution in Oxford this paper examines findings from a survey into staff travel behaviour in order to identify how staff currently behave. It explores the potential for transport and non-transport solutions to reduce car-based journeys to work and concludes that there is real potential to encourage a reduction in car-based travel. The paper seeks to widen the debate about who should take responsibility for achieving such a reduction. It argues that whilst travel awareness campaigns primarily push responsibility onto individuals an 'integrated package' is required with employers also assuming responsibility and thereby enabling individuals to adapt.     

Biodiversity laws: State experiences

The Western Governors' Association (WGA) includes both the public lands states with their issues and the plains states, which are 98% privately owned. WGA deals with most legislation affecting biodiversity, whether the effect is direct or tangential. It will probably not be possible, or desirable, for one entity to be in charge of biodiversity conservation. The Endangered Species Act, public lands laws, agricultural laws, water law, environmental laws, and funding legislation all affect biodiversity conservation and the responsibility for it. None of them on their own are enough, and most can cause harmful unintended consequences for biodiversity. The experience of western states in developing consensus principles for reauthorization of the Endangered Species Act provides an example of common-sense ways to improve management of biodiversity, notwithstanding the complexity and large stakes involved. The WGA's proposed changes call for increasing the role of states, streamlining the act, and increasing certainty for landowners and water users. To achieve sustainable conservation for biodiversity, the better question is not “Who is/should be in charge?”, it is “How do we get this done?” To answer this, we need goals, guidance, and bottom lines from federal laws, and management and oversight at the state level, but they all need to support local on-the-ground partnerships. Sustainable conservation requires the active participation of those who live there. WGA's experience in coordinating the Great Plains Partnership as well as its work with watershed efforts shed light on what to expect. Multilevel partnerships are not easy and require a different way of doing business. The ad hoc, sitespecific processes that result do not lend themselves to being legislated, fit into organizational boxes, or scored on a budget sheet. They do require common sense and a longterm perspective.     

THE INFLUENCE OF CLIMATE VARIATION ON THE ESTIMATION OF LOW FLOWS USED TO PROTECT WATER QUALITY: A NATIONWIDE ASSESSMENT1

ABSTRACT: Historical flow records are used to estimate the regulatory low flows that serve a key function in setting discharge permit limits through the National Pollutant Discharge Elimination System, which provides a nationwide mechanism for protecting water quality. Use of historical records creates an implicit connection between water quality protection and climate variability. The longer the record, the more likely the low flow estimate will be based on a broad set of climate conditions, and thus provides adequate water quality protection in the future. Unfortunately, a long record often is not available at a specific location. This analysis examines the connection between climate variability and the variability of biologically based and hydrologically based low flow estimates at 176 sites from the Hydro‐Climatic Data Network, a collection of stream gages identified by the USGS as relatively free of anthropogenic influences. Results show that a record of 10 to 20 years is necessary for satisfactory estimates of regulatory low flows. Although it is possible to estimate a biologically based low flow from a record of less than 10 years, these estimates are highly uncertain and incorporate a bias that undermines water quality protection.     

In situ measurements of nitrate leaching implicate poor nitrogen and irrigation management on sandy soils

Minimizing the risk of nitrate contamination along the waterways of the U.S. Great Plains is essential to continued irrigated corn production and quality water supplies. The objectives of this study were to quantify nitrate (NO(3)) leaching for irrigated sandy soils (Pratt loamy fine sand [sandy, mixed, mesic Lamellic Haplustalfs]) and to evaluate the effects of N fertilizer and irrigation management strategies on NO(3) leaching in irrigated corn. Two irrigation schedules (1.0x and 1.25x optimum) were combined with six N fertilizer treatments broadcast as NH(4)NO(3) (kg N ha(-1)): 300 and 250 applied pre-plant; 250 applied pre-plant and sidedress; 185 applied pre-plant and sidedress; 125 applied pre-plant and sidedress; and 0. Porous-cup tensiometers and solution samplers were installed in each of the four highest N treatments. Soil solution samples were collected during the 2001 and 2002 growing seasons. Maximum corn grain yield was achieved with 125 or 185 kg N ha(-1), regardless of the irrigation schedule (IS). The 1.25x IS exacerbated the amount of NO(3) leached below the 152-cm depth in the preplant N treatments, with a mean of 146 kg N ha(-1) for the 250 and 300 kg N preplant applications compared with 12 kg N ha(-1) for the same N treatments and 1.0x IS. With 185 kg N ha(-1), the 1.25x IS treatment resulted in 74 kg N ha(-1) leached compared with 10 kg N ha(-1) for the 1.0x IS. Appropriate irrigation scheduling and N fertilizer rates are essential to improving N management practices on these sandy soils.     

The temporal stability and developmental differences in the environmental impacts of militarism: the treadmill of destruction and consumption-based carbon emissions

This study examines the relationship between national-level militarism and consumption-based carbon dioxide emissions. We analyze panel data from 1990 to 2010 for 81 nations to determine whether the magnitude of the effects of (1) military expenditures as percent of total gross domestic product and (2) military personnel as percent of total labor force on carbon emissions change over time. Results of two-way fixed effects models highlight the temporal stability of the environmental impacts of both national-level military characteristics. The findings also reveal that the effect of military expenditures on emissions is larger in the more developed OECD nations than in the developing non-OECD nations. Overall, the results support the treadmill of destruction perspective, which suggests that the nations’ militaries are an important social institution to consider in sustainability science research on the human drivers of global environmental change.