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排序方式: 共有198条查询结果,搜索用时 15 毫秒
161.
Scott C. Burgess Kate Osborne Bianca Sfiligoj Hugh Sweatman 《Environmental monitoring and assessment》2010,168(1-4):345-351
Seasonal variations in the concentrations of groundwater with respect to arsenic, lead, cadmium and aluminium has been studied in Dhemaji district of Assam, India. The water samples were collected from 20 different sites in both dry and wet seasons. The metals were analysed by using atomic absorption spectrometer, Perkin Elmer AAnalyst 200 model. The concentrations of aluminium, lead and cadmium in groundwater were found to be significantly elevated. High concentrations of all the metals were recorded in the dry season than in the wet season. Univariate statistics along with skewness, kurtosis and confidence limit have been calculated for both the seasons to test the distribution normality for each metal. Statistical analyses of the data reveal non-uniform distribution of the metals in the area. The metal contamination of groundwater in the district follows the trend Al > Pb > Cd > As in both the seasons. 相似文献
162.
Peter Chin Christopher DeLuca Cheryl Poth Ingrid Chadwick Nancy Hutchinson Hugh Munby 《Safety Science》2010,48(5):570-579
Work-related injury rates for Canadian youth (ages 15–24) are alarmingly high compared to adult workers even though youth are less likely to be performing hazardous jobs. This paper reports on a document analysis of youth workplace safety education initiatives sponsored by national and provincial/territorial governmental and non-governmental agencies. Web-based documents were analyzed through the theoretical lens of self-advocacy. The self-advocacy framework highlights how youth can be agentic in altering high-risk workplaces by publicly articulating their own interests, needs, and rights (Test et al., 2005); thus, self-advocacy is a critical component in studying educational programs for youth safety. The analysis revealed that instruction on workplace safety identifies safety issues to workers and tells youth to work safely but does little to promote self-advocacy in young workers. 相似文献
163.
Dust monitoring using sticky pads was popularised in the 1980s. The discolouration caused by dust adhering to white adhesive
material was measured with a smoke stain reflectometer. This loss of reflectance was expressed as the percentage effective
area coverage (EAC%) per day. EAC% can be used as a measure of nuisance caused by dust. EAC% may also be measured with a hand-held
Sticky Pad Reader (SPR). Sticky pads can be mounted on flat or cylindrical surfaces to measure dust by deposition or in flux.
An alternative method was developed in the 1990s that measured total dust coverage using computer-based scanning. DustScan
used a transparent adhesive film wrapped around a vertical cylinder with magnetic north marked. The sticky pad was sealed
with another transparent sheet before scanning at 50 dots per inch (dpi). Dust levels were assessed by comparing the grey-scale
values of pixels in the exposed area with an unexposed reference area. Insects and other extraneous material could be ‘masked
out’ from the computer analysis. Dust coverage was expressed as percentage absolute area coverage (AAC%). DustScan has subsequently
been developed commercially. A limited trial indicated that monitoring periods of 7–14 days were preferred to avoid dust saturation
of the sticky pad. A method for calculating EAC% has been developed and shown to have a high degree of correspondence with
an SPR. A trial for the Minerals Industry Research Organisation (MIRO) made comparisons between DustScan and other dust monitoring
methods. Dust nuisance limits based on AAC% and EAC% are proposed.par 相似文献
164.
165.
Controlling range expansion in habitat networks by adaptively targeting source populations 下载免费PDF全文
Karlo Hock Nicholas H. Wolff Roger Beeden Jessica Hoey Scott A. Condie Kenneth R. N. Anthony Hugh P. Possingham Peter J. Mumby 《Conservation biology》2016,30(4):856-866
Controlling the spread of invasive species, pests, and pathogens is often logistically limited to interventions that target specific locations at specific periods. However, in complex, highly connected systems, such as marine environments connected by ocean currents, populations spread dynamically in both space and time via transient connectivity links. This results in nondeterministic future distributions of species in which local populations emerge dynamically and concurrently over a large area. The challenge, therefore, is to choose intervention locations that will maximize the effectiveness of the control efforts. We propose a novel method to manage dynamic species invasions and outbreaks that identifies the intervention locations most likely to curtail population expansion by selectively targeting local populations most likely to expand their future range. Critically, at any point during the development of the invasion or outbreak, the method identifies the local intervention that maximizes the long‐term benefit across the ecosystem by restricting species’ potential to spread. In so doing, the method adaptively selects the intervention targets under dynamically changing circumstances. To illustrate the effectiveness of the method we applied it to controlling the spread of crown‐of‐thorns starfish (Acanthaster sp.) outbreaks across Australia's Great Barrier Reef. Application of our method resulted in an 18‐fold relative improvement in management outcomes compared with a random targeting of reefs in putative starfish control scenarios. Although we focused on applying the method to reducing the spread of an unwanted species, it can also be used to facilitate the spread of desirable species through connectivity networks. For example, the method could be used to select those fragments of habitat most likely to rebuild a population if they were sufficiently well protected. 相似文献
166.
Erik Meijaard Marcel Cardillo Emily M. Meijaard Hugh P. Possingham 《Conservation biology》2015,29(3):920-925
We investigated whether the impact of conservation science is greater for research conducted in countries with more pressing conservation problems. We quantified research impact for 231 countries based on 2 citation metrics (mean cites per paper and h index) and fitted models predicting research impact based on number of threatened bird and mammal species (as a measure of conservation importance of a country) and a range of demographic variables. Citation rates of conservation research increased as a country's conservation need increased and as human population, quality of governance, and wealth increased. Even after accounting for these factors, citation rates among regions and countries within regions varied significantly. The conservation research community needs to consider ways to begin addressing the entrenched disadvantages some countries have when it comes to initiating projects and producing high‐quality research. 相似文献
167.
Graham W. Prescott William J. Sutherland Daniel Aguirre Matthew Baird Vicky Bowman Jake Brunner Grant M. Connette Martin Cosier David Dapice Jose Don T. De Alban Alex Diment Julia Fogerite Jefferson Fox Win Hlaing Saw Htun Jack Hurd Katherine LaJeunesse Connette Felicia Lasmana Cheng Ling Lim Antony Lynam Aye Chan Maung Benjamin McCarron John F. McCarthy William J. McShea Frank Momberg Myat Su Mon Than Myint Robert Oberndorf Thaung Naing Oo Jacob Phelps Madhu Rao Dietrich Schmidt‐Vogt Hugh Speechly Oliver Springate‐Baginski Robert Steinmetz Kirk Talbott Maung Maung Than Tint Lwin Thaung Salai Cung Lian Thawng Kyaw Min Thein Shwe Thein Robert Tizard Tony Whitten Guy Williams Trevor Wilson Kevin Woods Alan D. Ziegler Michal Zrust Edward L. Webb 《Conservation biology》2017,31(6):1257-1270
Political and economic transitions have had substantial impacts on forest conservation. Where transitions are underway or anticipated, historical precedent and methods for systematically assessing future trends should be used to anticipate likely threats to forest conservation and design appropriate and prescient policy measures to counteract them. Myanmar is transitioning from an authoritarian, centralized state with a highly regulated economy to a more decentralized and economically liberal democracy and is working to end a long‐running civil war. With these transitions in mind, we used a horizon‐scanning approach to assess the 40 emerging issues most affecting Myanmar's forests, including internal conflict, land‐tenure insecurity, large‐scale agricultural development, demise of state timber enterprises, shortfalls in government revenue and capacity, and opening of new deforestation frontiers with new roads, mines, and hydroelectric dams. Averting these threats will require, for example, overhauling governance models, building capacity, improving infrastructure‐ and energy‐project planning, and reforming land‐tenure and environmental‐protection laws. Although challenges to conservation in Myanmar are daunting, the political transition offers an opportunity for conservationists and researchers to help shape a future that enhances Myanmar's social, economic, and environmental potential while learning and applying lessons from other countries. Our approach and results are relevant to other countries undergoing similar transitions. 相似文献
168.
Understanding stewardship behaviour: factors facilitating and constraining private water well stewardship 总被引:1,自引:0,他引:1
Kreutzwiser R de Loë R Imgrund K Conboy MJ Simpson H Plummer R 《Journal of environmental management》2011,92(4):1104-1114
Regulatory frameworks to ensure municipal drinking water safety exist in most North American jurisdictions. However, similar protection is rarely provided to people reliant on water provided from private wells. In Canada, approximately 4 million people depend on privately owned, domestic wells for their drinking water. Numerous studies have shown that people who rely on private wells for their water supplies are at risk from nitrate and bacterial contamination. Given the fact that regulations relating to private wells tend to be weak or poorly enforced, actions taken by well owners to protect their own drinking water safety are extremely important. Drawing on one of the largest and most comprehensive surveys of private well owners ever conducted in Canada or elsewhere, this paper explores factors that influence well owner stewardship behaviour. Key behaviours examined included annual testing of well water and inspection of wells, measures to protect water quality, and proper decommissioning of unused wells. A geographically-stratified survey, sent to 4950 well owners in Ontario, Canada, resulted in an effective response rate of 34% (n = 1567). Logistic regression analyses revealed that motivations for well stewardship behaviours included reassurance, the perception of problems, and knowledge of the environment. Knowing how to perform stewardship behaviours was an important antecedent to action. Barriers to stewardship included complacency, inconvenience, ignorance, cost, and privacy concerns. To promote stewardship, local initiatives, better educational materials, and enforcement through real estate laws are all required. Ultimately, drinking water safety for people reliant on private wells is shown to be a responsibility shared by governments and private well owners. 相似文献
169.
Krista J. Patriquin Marty L. Leonard Hugh G. Broders Colin J. Garroway 《Behavioral ecology and sociobiology》2010,64(6):899-913
Social structure, which is a function of the patterns of interactions among individuals, is particularly variable in fission–fusion
societies. The underlying factors that drive this variation are poorly understood. Female northern long-eared bats (Myotis septentrionalis) live in fission–fusion societies where females form preferred associations within groups that vary daily in size and composition
as individuals switch roosts. The goal of our study was to test the predictions that preferred associations and social networks
of female northern long-eared bats vary with reproductive period and age. We also tested the prediction that preferred relationships
persist across years despite movements from summer roosts to winter hibernacula. Network analyses revealed that during gestation,
females roosted in smaller groups where they roosted more regularly with fewer individuals than during lactation. This variation
may reflect different social strategies to mediate higher energetic costs during lactation. Females of all ages roosted more
often with younger individuals, which in turn had more direct and indirect associations than all other age classes. Younger
individuals may play a role in maintaining connections between individuals, perhaps as a result of younger individuals being
more exploratory. Temporal analyses suggested that relationships can persist for years as some pairs roosted together for
multiple summers. We suggest that the dynamic nature of fission–fusion societies is associated with individual strategies
to increase fitness relative to individual characteristics, in this case reproductive condition and age. 相似文献
170.
We consider the street experiences of a group of urban children living in a large East Midlands town in the UK. Our attention focuses upon an issue that has seldom been examined, neighbourhood bullying. We highlight how some children, through their propinquity within neighbourhood spaces, clash and collide to such an extent that their experiences of a locality become severely blighted. For these unfortunate young people local environments are tyrannical spaces, defined in terms of 'no-go areas', danger and threat. These are not remarkable geographies, however, and we suggest that like many school environments, where bullying has increasingly been recognised and disclosed, within many localities there is a 'hidden' geography of fear waiting to be uncovered. The paper is organised into five parts: first, we briefly examine the concept of bullying, particularly in relation to young people in schools; secondly, we extend these ideas into a neighbourhood context drawing upon recent ideas of 'self', 'other' and microgeographies; thirdly, we outline the research project from which this article emerges; fourthly, we look at some empirical evidence from an urban case study that draws attention to the form and consequences of neighbourhood bullying; lastly, we discuss the relevance of these findings to future policy and practice, particularly in relation to the management of neighbourhood spaces. We propose that systematically applied local strategies to tackle bullying within neighbourhoods are needed, particularly those which engage young people and adults together through a whole community approach. 相似文献