The influence of different plant and soil processes on the concentrations of soluble organic forms of carbon, nitrogen, phosphorus and sulphur in soil and drainage waters is reviewed. Current knowledge about soluble organic matter is restricted mainly to dissolved organic carbon. Comparable information about soluble organic nitrogen, phosphorus and sulphur in processes such as eutrophication, plant uptake and decomposition is limited. Data are presented to highlight the potential sources of soluble organic components together with a discussion of their likely fate within the soil profile. the implications of changes in land use and management practices on dissolved organic matter are discussed. 相似文献
To augment mammal conservation in the Eastern Himalayan region, we assessed the resident 255 terrestrial mammal species and identified the 50 most threatened species based on conservation status, endemism, range size, and evolutionary distinctiveness. By using the spatial analysis package letsR and the complementarity core‐area method in the conservation planning software Zonation, we assessed the current efficacy of their protection and identified priority conservation areas by comparing protected areas (PAs), land cover, and global ecoregion 2017 maps at a 100 × 100 m spatial scale. The 50 species that were most threatened, geographically restricted, and evolutionarily distinct faced a greater extinction risk than globally nonthreatened and wide‐ranging species and species with several close relatives. Small, medium‐sized, and data‐deficient species faced extinction from inadequate protection in PAs relative to wide‐ranging charismatic species. There was a mismatch between current PA distribution and priority areas for conservation of the 50 most endangered species. To protect these species, the skewed regional PA distribution would require expansion. Where possible, new PAs and transboundary reserves in the 35 priority areas we identified should be established. There are adequate remaining natural areas in which to expand current Eastern Himalayan PAs. Consolidation and expansion of PAs in the EH requires strengthening national and regional transboundary collaboration, formulating comprehensive regional land‐use plans, diversifying conservation funding, and enhancing information sharing through a consolidated regional database. 相似文献
Despite repeated calls to action, proposals for urban conservation are often met with surprise or scepticism. There remains a pervasive narrative in policy, practice, and the public psyche that urban environments, although useful for engaging people with nature or providing ecosystem services, are of little conservation value. We argue that the tendency to overlook the conservation value of urban environments stems from misconceptions about the ability of native species to persist within cities and towns and that this, in turn, hinders effective conservation action. However, recent scientific evidence shows that these assumptions do not always hold. Although it is generally true that increasing the size, quality, and connectivity of habitat patches will improve the probability that a species can persist, the inverse is not that small, degraded, or fragmented habitats found in urban environments are worthless. In light of these findings we propose updated messages that guide and inspire researchers, practitioners, and decision makers to undertake conservation action in urban environments: consider small spaces, recognize unconventional habitats, test creative solutions, and use science to minimize the impacts of future urban development. 相似文献
Antimicrobial resistance (AMR) represents a major global health threat, as well as a major hazard to sustainable economic development and national security. It remains, therefore, vital that current research aligns to policy development and implementation to alleviate a potential crisis. One must consider, for example, whether drivers of antibiotic resistance can be controlled in the future, or have they already accumulated in the past, whether from antibiotics and/or other pollutants? Unfortunately, industrial heritage and its pollution impact on the prevalence of environmental AMR have largely been ignored. Focussing on industrialised estuaries, we demonstrate that anthropogenic pollution inputs in addition to the natural diurnal environmental conditions can sufficiently create stressful conditions to the microbiome and thus promote selective pressures to shift the resistome (i.e., collection of resistance traits in the microbiological community). Unfortunately, the bacteria’s survival mechanisms, via co-selective pressures, can affect their susceptibility to antibiotics. This review highlights the complexity of estuarine environments, using two key contaminant groups (metals/toxic elements and polyaromatic hydrocarbons), through which a variety of possible chemical and biological pollutant stressors can promote the emergence and dissemination of antimicrobial resistance. We find compelling divers to call on more focused research on historically disrupted ecosystems, in propagating AMR in the real world.
Sixteen and 17 year-olds were surveyed at motor-vehicle offices in Tennessee after qualifying for their first driver's license. When the survey was conducted during October and November 1995, neither a learner's permit nor completion of a driver education course was required to obtain a license at age 16 or 17. The survey was repeated during December and January 1996–97, approximately one year after a requirement to hold a learner's permit for 90 days or complete a driver education course was implemented. Results from the 1991 drivers (ages 16 and 17) surveyed indicated Tennessee's licensing law change was associated with approximately 100 additional miles and 8 additional hours of practice driving prior to licensure for the typical 16 or 17 year-old, most often while supervised by a parent or guardian. Results are discussed in relation to the prelicense practice driving requirements of graduated licensing systems. 相似文献
The Windsor, Ontario Exposure Assessment Study evaluated the contribution of ambient air pollutants to personal and indoor exposures of adults and asthmatic children living in Windsor, Ontario, Canada. In addition, the role of personal, indoor, and outdoor air pollution exposures upon asthmatic children's respiratory health was assessed. Several active and passive sampling methods were applied, or adapted, for personal, indoor, and outdoor residential monitoring of nitrogen dioxide, volatile organic compounds, particulate matter (PM; PM-2.5 pm [PM2.5] and < or =10 microm [PM10] in aerodynamic diameter), elemental carbon, ultrafine particles, ozone, air exchange rates, allergens in settled dust, and particulate-associated metals. Participants completed five consecutive days of monitoring during the winter and summer of 2005 and 2006. During 2006, in addition to undertaking the air pollution measurements, asthmatic children completed respiratory health measurements (including peak flow meter tests and exhaled breath condensate) and tracked respiratory symptoms in a diary. Extensive quality assurance and quality control steps were implemented, including the collocation of instruments at the National Air Pollution Surveillance site operated by Environment Canada and at the Michigan Department of Environmental Quality site in Allen Park, Detroit, MI. During field sampling, duplicate and blank samples were also completed and these data are reported. In total, 50 adults and 51 asthmatic children were recruited to participate, resulting in 922 participant days of data. When comparing the methods used in the study with standard reference methods, field blanks were low and bias was acceptable, with most methods being within 20% of reference methods. Duplicates were typically within less than 10% of each other, indicating that study results can be used with confidence. This paper covers study design, recruitment, methodology, time activity diary, surveys, and quality assurance and control results for the different methods used. 相似文献
Discharge of contaminated ground water may serve as a primary and on-going source of contamination to surface water. A field investigation was conducted at a Superfund site in Massachusetts, USA to define the locus of contaminant flux and support source identification for arsenic contamination in a pond abutting a closed landfill. Subsurface hydrology and ground-water chemistry were evaluated in the aquifer between the landfill and the pond during the period 2005-2009 employing a network of wells to delineate the spatial and temporal variability in subsurface conditions. These observations were compared with concurrent measures of ground-water seepage and surface water chemistry within a shallow cove that had a historical visual record of hydrous ferric oxide precipitation along with elevated arsenic concentrations in shallow sediments. Barium, presumably derived from materials disposed in the landfill, served as an indicator of leachate-impacted ground water discharging into the cove. Evaluation of the spatial distributions of seepage flux and the concentrations of barium, calcium, and ammonium-nitrogen indicated that the identified plume primarily discharged into the central portion of the cove. Comparison of the spatial distribution of chemical signatures at depth within the water column demonstrated that direct discharge of leachate-impacted ground water was the source of highest arsenic concentrations observed within the cove. These observations demonstrate that restoration of the impacted surface water body will necessitate control of leachate-impacted ground water that continues to discharge into the cove. 相似文献
It is widely recognized that our social and moral environments influence our actions and belief formations. We are never fully
immune to the effects of cultural membership. What is not clear, however, is whether these influences excuse average moral
agents who fail to scrutinize conventional norms. In this paper, I argue that the lack of extensive public debate about factory
farming and, its corollary, extreme animal suffering, is probably due, in part, to affected ignorance. Although a complex
phenomenon because of its many manifestations, affected ignorance is morally culpable because it involves a choice not to
investigate whether some practice in which one participates in might be immoral. I contend further that James Montmarquet’s
set of intellectual virtues can provide a positive account of what it means to act as a responsible moral agent while immersed
in a meat eating culture; they also represent the moral and epistemic framework for the kind of public discourse that should
be taking place. 相似文献
Human chemical exposures resulting from transfer of surface deposition on indoor nylon carpets may be estimated by measuring transferable residues (mu g chemical/cm2 carpet). A weighted roller developed at California Department of Food and Agriculture (CDFA) has been extensively used to sample transferable residue for estimates of human exposure in risk characterization. A modified roller has been developed to evaluate the influence of pressure on transferable chemical residue since weight and force (or pressure, kg/m2) may vary person-to-person and activity-to-activity. A 30.5 cm diameter roller was used to apply 60 to 2100 kg/m2 to bracket pressures exerted by humans on a flat nylon-carpeted surface. Measurements of transferable cyfluthrin residues were made after 1, 7, and 21 days. Total Soxhlet extractable cyfluthrin residues were relatively constant during the test period. Residue transferability decreased during the study period. Modest increases in the transferability of surface residues were observed over the broad range of pressures applied by the modified roller. 相似文献
Beaches are now the most popular tourist destination and increased demand in the past 40 years has led not only to beach congestion but also to a differentiation between urban (resorts, overcrowded and under huge pressure), to natural (less crowded beaches). This diversity needs to be further explored not only to characterize individual beaches in a precise way, but also to understand the distinctive characteristics responsible for options made by beach users. Some attempts have been made to create a universal beach typology but sparse research has been undertaken. The topic is of extreme importance for beach management, as most studies only take into consideration beach usage type and few consider the surrounding environment (landscape). This paper presents an exploratory work for Portuguese beaches which creates a new classification, according to usage and surrounding environment, based on several variables, measured and weighted. The results scale between zero and five and assess how a beach can be classified along an urban (0) to natural (5) spectrum. Variables studied include population density, number of hotels urban density, car park distance to the beach, etc. A pilot study applied to 100 beaches in the Lisbon Metropolitan Area, found that a densely populated region, can also contain beaches with natural characteristics. 相似文献