排序方式: 共有75条查询结果,搜索用时 546 毫秒
21.
Hamed Haddadi Andrew J. King Alison P. Wills Damien Fay John Lowe A. Jennifer Morton Stephen Hailes Alan M. Wilson 《Behavioral ecology and sociobiology》2011,65(8):1659-1668
Social Network Analysis has become an important methodological tool for advancing our understanding of human and animal group
behaviour. However, researchers tend to rely on arbitrary distance and time measures when defining ‘contacts’ or ‘associations’
between individuals based on preliminary observation. Otherwise, criteria are chosen on the basis of the communication range
of sensor devices (e.g. bluetooth communication ranges) or the sampling frequencies of collection devices (e.g. Global Positioning
System devices). Thus, researchers lack an established protocol for determining both relevant association distances and minimum
sampling rates required to accurately represent the network structure under investigation. In this paper, we demonstrate how
researchers can use experimental and statistical methods to establish spatial and temporal association patterns and thus correctly
characterise social networks in both time and space. To do this, we first perform a mixing experiment with Merino sheep (Ovis aries) and use a community detection algorithm that allows us to identify the spatial and temporal distance at which we can best
identify clusters of previously familiar sheep. This turns out to be within 2–3 m of each other for at least 3 min. We then
calculate the network graph entropy rate—a measure of ease of spreading of information (e.g. a disease) in a network—to determine
the minimum sampling rate required to capture the variability observed in our sheep networks during distinct activity phases.
Our results indicate the need for sampling intervals of less than a minute apart. The tools that we employ are versatile and
could be applied to a wide range of species and social network datasets, thus allowing an increase in both the accuracy and
efficiency of data collection when exploring spatial association patterns in gregarious species. 相似文献
22.
Bolingbroke Damien Ng Kelvin Tsun Wai Vu Hoang Lan Richter Amy 《Journal of Material Cycles and Waste Management》2021,23(3):1015-1025
Journal of Material Cycles and Waste Management - The assessment of solid waste management systems is vital for continued improvement in the efficiency of waste management systems (WMSs). Many... 相似文献
23.
Alain Copinet Estelle Copinet-Legin Florence Fricoteaux Damien Erre 《Journal of Polymers and the Environment》2011,19(1):172-176
The aim of this work was to estimate the biodegradation of a poly(lactic acid) polymeric material by the actinomycetes Kibdelosporangium aridum using a vermiculite based inert solid medium which could simulate compost medium and enable us to achieve complete carbon
balances. The mineralisation rate at the end of the test was compared to those obtained for two basal media. It was shown
that cumulative mineralisation after 45 days of degradation was greater (70%) in vermiculite with a basal medium containing
gelatin than in vermiculite with a basal medium containing glucose (20%). 相似文献
24.
Tran D Massabuau JC Garnier-Laplace J 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):821-826
Multi-stress situations are a major question and low-oxygenated waters (hypoxia) are a growing problem. Importantly, hypoxia stimulates the ventilatory flow rate in aquatic animals and this increases gill exposure to contaminants. Surprisingly, in the freshwater clam Corbicula fluminea, this is associated with increased bioaccumulation of uranium in gills but not in deep tissues. We searched for an explanation by analyzing hemolymph U-transport in Corbicula exposed to 0.36 μM dissolved uranium at various O2-levels for 10 days. In hypoxia, one observed an increased U concentration in the arterial hemolymph flowing from gills to tissues but this was not associated with an increased U concentration in the venous hemolymph nor in the other tissues. We conclude that the cardiac flow rate must have decreased to explain this absence of over-accumulation. In addition to its already known deleterious effects, uranium can thus deeply impair cardiac flow rate in exposed aquatic animals during multi-stress exposures. 相似文献
25.
Damien N. McCarthy Grant C. Edwards 《Journal of the Air & Waste Management Association (1995)》2020,70(7):729-738
ABSTRACT
Toxic gaseous elemental mercury (GEM) is emitted to the atmosphere through a variety of routes at rates estimated at over 5000 tonnes per annum, a large fraction of which is Anthropogenic. It is then widely disbursed atmospherically and eventually deposited, where it is subject to further biogeochemical cycling, including re-emission. Research into capture of point source mercury emissions revolves almost exclusively around the use of activated carbons, various catalytic oxidation substrates, or as a by-product of acidic treatments of flue gas during SOx and NOx reduction methods. GEM is very non-reactive in its native state, but capture rates are greatly enhanced if GEM is first oxidized, or at least where oxidation states play a role at the substrate GEM interface. Little research has been devoted to capture of GEM directly. However, presented here is a novel adaption of coir fibers for use as a substrate in capturing GEM emissions directly. Various coir modifications were investigated, with the most effective being fibers coated with CuI crystals dispersed in a non-crosslinked poly-siloxane matrix. Scanning electron microscopy was used to view surface morphologies, and sorption characteristics were measured using atomic absorption spectroscopy (AAS). These results indicate that coir fibers modified by CuI-[SiO2] n show great promise in their ability to efficiently sorb GEM, and could potentially be utilized in a variety of configurations and settings where GEM emissions need to be captured. 相似文献
26.
Leah Mason Timothy Prior Gavin Mudd Damien Giurco 《Journal of Cleaner Production》2011,19(9-10):958-966
The concept of ‘peaks’ in the production of natural resources has attracted attention in the area of energy production, with concerns about ‘peak oil’ driving recent research and investment in alternative sources of energy. There are fundamental and important differences between a peak in the production of oil and peaks in the production of metalliferous minerals, but in both cases production changes from ‘easier and less expensive’ early in a resource’s life to ‘difficult and expensive’ as time progresses. The impacts of this change in production circumstances require critical consideration in the governance of national and sub-national mineral endowments.This paper develops a framework for evaluating the impacts of changing patterns of mineral production. The framework considers three criteria: availability of a resource (considering its geological characteristics and geographical distribution); society’s addiction to the resource (its centrality and criticality to economic, social and environmental systems); and the possibility of finding alternatives (whether the resource can be substituted or recovered). An initial assessment against these criteria provides an overview of how a production peak might affect the production of minerals in Australia and the impacts that this might have on the Australian economy.Assessing important resources against these three criteria will be imperative in future considerations regarding the roles minerals and metals play as service providers in our economic, social and environmental systems. Additionally, this analysis should prompt a reassessment of the value of minerals beyond economic measures. Indicators derived from these criteria will inform strategies that can address future changes in production characteristics – meeting challenges with strong governance, and realising opportunities with proactive policy. 相似文献
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Yuvin Chinniah Damien Burlet-Vienney 《International journal of occupational safety and ergonomics》2013,19(4):495-511
In Québec, workers intervening in hazardous zones of machines, equipment and processes during maintenance, repairs and unjamming activities have to apply lockout procedures. Lockout procedures involve shutting down the equipment, isolating it, applying individual locks, releasing residual energies and verifying the absence of energies. Lockout has mostly been linked to industrial sectors. However, the municipal sector also faces challenges when it comes to controlling hazardous energies. The objectives of this research are to study serious accidents linked to our subject, study the application of lockout in different municipalities in Québec, identify the specificities for the municipal sector and propose some means to support the application of lockout. We will show that lockout procedures are required in different locations in municipalities and that they are currently being implemented in the municipal sector in Québec. Moreover, we propose a model which aims at facilitating the implementation of lockout procedures in the municipal sector. 相似文献
30.
Devault Damien A. Guillemin Jean-Philippe Millet Maurice Eymery Franck Hulin Marion Merlo Mathilde 《Environmental science and pollution research international》2022,29(1):61-67
Environmental Science and Pollution Research - Prosulfocarb is a thiocarbamate herbicide that is rapidly growing in use due to the progressive bioresistance of weeds to certain pesticides and the... 相似文献