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71.
Jennifer E. Smith Sandra K. Memenis Kay E. Holekamp 《Behavioral ecology and sociobiology》2007,61(5):753-765
When social partners vary in their relative value, individuals should theoretically initiate partnerships with conspecifics
of the highest value. Here, we tested this prediction in a wild population of spotted hyenas (Crocuta crocuta). Crocuta live in complex, fission–fusion societies structured by dominance hierarchies in which individuals vary greatly in their
value as social companions. Because patterns of association among Crocuta reflect social preferences, we calculated association indices (AIs) to examine how social rank influences intrasexual partner
choice among unrelated adults of both sexes. The highest-ranking individuals were generally most gregarious in both sexes.
Females associated most often with dominant and adjacent-ranking females. Females joined subgroups based on the presence of
particular conspecifics such that subordinates joined focal females at higher rates than did dominants. Dominants benefit
from associations with subordinates by enjoying priority of access to resources obtained and defended by multiple group members,
but the benefits of these associations to subordinates are unknown. To investigate this, we tested three hypotheses suggesting
how subordinates might benefit from rank-related partner choice among unrelated females. We found that subordinates who initiated
group formation benefited by gaining social and feeding tolerance from dominants. However, rates at which dominants provided
coalitionary support to subordinates did not vary with AIs. Overall, our data resemble those documenting patterns of association
among cercopithecine primates. We consider our results in light of optimal reproductive skew theory, Seyfarth’s rank attractiveness
model, and biological market theory. Our data are more consistent with the predictions of Seyfarth’s model and of biological
market theory than with those of skew theory. 相似文献
72.
Solitary foragers can balance demands for food and safety by varying their relative use of foraging patches and their level of vigilance. Here, we investigate whether colonies of the ant, Formica perpilosa, can balance these demands by dividing labor among workers. We show that foragers collecting nectar in vegetation near their nest are smaller than are those collecting nectar at sites away from the nest. We then use performance tests to show that smaller workers are more likely to succumb to attack from conspecifics but feed on nectar more efficiently than larger workers, suggesting a size-related trade-off between risk susceptibility and harvesting ability. Because foragers that travel away from the nest are probably more likely to encounter ants from neighboring colonies, this trade-off could explain the benefits of dividing foraging labor among workers. In a laboratory experiment, we show that contact with aggressive workers results in an increase in the mean size of recruits to a foraging site: this increase was not the result of more large recruits, but rather because fewer smaller ants traveled to the site. These results suggest that workers particularly susceptible to risk avoid dangerous sites, and suggest that variation in worker size can allow colonies to exploit profitably both hazardous and resource-poor patches.Communicated by L. Sundström 相似文献
73.
Three agreements addressing environmental and safety performance, zero discharge of wastewater and sustainable development have been signed between Formosa Plastics Corporation, Texas (Formosa Plastics), and its former adversaries. The key element of the agreements is the improvement of the affected community. These agreements go beyond public information and beyond procedures for public participation. They have led to meaningful public participation and partnership and are unique in this respect. The following article explores the setup and results of each agreement. The initial agreement, the Blackburn-Formosa Agreement, signed in 1992, set the stage for subsequent partnerships. The Wilson-Formosa Zero Discharge Agreement followed in 1994. Finally, the Sustainable Development Agreement was signed by Jim Blackburn, Diane Wilson, and Formosa Plastics in late 1997. These agreements have proven very successful in avoiding disputes and helping improve company performance in environmental and safety issues. In many respects, these agreements offer a model for others in working with an affected community. 相似文献
74.
Brain RA Wilson CJ Johnson DJ Sanderson H Bestari KJ Hanson ML Sibley PK Solomon KR 《Environmental pollution (Barking, Essex : 1987)》2005,138(3):425-442
The impact of a mixture of oxytetracycline, chlortetracycline, tetracycline and doxycycline on Myriophyllum sibiricum and Lemna gibba was investigated using fifteen 12,000-L microcosms (k=5, n=3). Significant concentration-response relationships were only found for M. sibiricum, where dry mass was 69, 47, 30, and 7% of controls at respective treatment concentrations of 0.080, 0.218, 0.668, and 2.289 micromol/L. Somatic endpoints were strongly and negatively correlated with percent light transmission, except plant length, which was positively correlated. Treated microcosms experienced a reduction in the percent of surface irradiance penetrating the water column as high as 99.8% at a depth of 70 cm, relative to controls. Position relative to the water column was likely responsible for the differential effects observed between floating (L. gibba) and submerged (M. sibiricum) species of macrophytes. A hazard quotient assessment of the lowest EC10 value indicated significant risk, exceeding the critical HQ value, but not the lowest EC25 value. 相似文献
75.
Rocío Román-Collado Juan Jiménez de Reyna 《Journal of the Air & Waste Management Association (1995)》2019,69(4):438-449
Algeciras Bay is an important industrial and port zone in the south of Spain whose pollution by particulate matter surpasses the threshold levels recommended by the World Health Organization (WHO) in its 2005 Guide on Air Quality. This study analyses the mortality avoided and the economic benefit which would be derived from a reduction of the pollution of PM2.5 and PM10 to the levels recommended by the WHO in Algeciras Bay in the period 2005-2015. The analysis carried out shows that the industrial zones, such as Los Barrios and San Roque, are those which have greater levels of pollution and in which the relative risk is greater. The calculations for Algeciras Bay between 2000 and 2015 show 182 deaths which would be avoided if the particulate matter pollution were reduced to the levels recommended by the WHO. Likewise, the economic valuation which this impact has on health is carried out through two concepts: the cost of illness and the Value of Statistical Life (VSL). The result shows that the economic benefit that would come out with the cost of illness valuation is 5,329,110€ and from the VSL is 414,787,113€.
Implications: PM2.5 has a greater concentration in industrial localities and is linked to the industrial activity. When the particulate matter pollution is reduced to the levels recommended by the WHO in an industrialised area such as Algeciras (Spain), 182 deaths which would be avoided. The result shows that the economic benefit that would come out with the cost of illness valuation is 5,329,110€ and from the value of statistical life is 414,787,113€. 相似文献
76.
A lysimeter experiment to investigate the leaching of veterinary antibiotics through a clay soil and comparison with field data 总被引:8,自引:0,他引:8
Pharmaceuticals used in livestock production may be present in manure and slurry as the parent compound and/or metabolites. The environment may therefore be exposed to these substances due to the application of organic fertilisers to agricultural land or deposition by grazing livestock. For other groups of substances that are applied to land (e.g. pesticides), preferential flow in clay soils has been identified as an extremely important mechanism by which surface water pollution can occur. This lysimeter study was therefore performed to investigate the fate of three antibiotics from the sulphonamide, tetracycline and macrolide groups in a clay soil. Only sulphachloropyridazine was detected in leachate and soil analysis at the end of the experiment showed that almost no antibiotic residues remained. These data were analysed alongside field data for the same compounds to show that soil tillage which breaks the connectivity of macropores formed over the summer months, prior to slurry application, significantly reduces chemical mobility. 相似文献
77.
Heavy metal extractable forms in sludge from wastewater treatment plants 总被引:17,自引:0,他引:17
The analysis of heavy metals is a very important task to assess the potential environmental and health risk associated with the sludge coming from wastewater treatment plants (WWTPs). However, it is widely accepted that the determination of total elements does not give an accurate estimation of the potential environmental impact. So, it is necessary to apply sequential extraction techniques to obtain a suitable information about their bioavailability or toxicity. In this paper, a sequential extraction scheme according to the BCR's guidelines was applied to sludge samples collected from each sludge treatment step of five municipal activated sludge plants. Al. Cd, Co, Cu, Cr, Fe, Mn, Hg, Mo, Ni, Pb, Ti and Zn were determined in the sludge extracts by inductively coupled plasma atomic emission spectrometry. In relation to current international legislation for the use of sludge for agricultural purposes none of metal concentrations exceeded maximum permitted levels. In most of the metal elements under considerations, results showed a clear rise along the sludge treatment in the proportion of two less-available fractions (oxidizable metal and residual metal). 相似文献
78.
Hernández-Huesca R Braos-García P Mérida-Robles J Maireles-Torres P Rodríguez-Castellón E Jiménez-López A 《Chemosphere》2002,48(4):467-474
A series of cobalt containing alumina pillared zirconium phosphate materials have been prepared by ion exchange or by impregnation, and fully characterised. The catalytic behaviour of these materials in the selective catalytic reduction of NO by propane, in excess of oxygen, at temperatures ranging between 350 and 550 degrees C, has been also evaluated. A maximum NO conversion close to 14% is obtained on Co-impregnated catalysts heated at 600 degrees C. The NO reduction seems to be related to the presence of Co3+, thus the calcination temperature of samples influences the resulting activity much more than the cobalt content. 相似文献
79.
Challenges and Opportunities for Creating Intelligent Hazard Alerts: The “FloodHippo” Prototype 下载免费PDF全文
J. Michael Johnson Jim M. Coll Paul J. Ruess Jordan T. Hastings 《Journal of the American Water Resources Association》2018,54(4):872-881
Disasters evolving from hazards are a persistent and deadly occurrence in the United States. Despite this, hazard alerts have remained spatially vague, temporally imprecise, and lack actionable information. These deficiencies indicate a divide between the status quo and what is possible given modern environmental models, geographic information systems (GIS), and smartphone capabilities. This work describes an alternative, prototype system, “FloodHippo,” which integrates operational model outputs, cloud‐based GIS, and expanded communication channels to provide personal and interactive disaster alerts for floods. The precepts and methods underpinning FloodHippo apply equally to other disasters that evolve over space and time, presenting the opportunity for a more intelligent disaster response system. The development of such a system would not only minimize current shortcomings in disaster alerts but also improve resilience through individual action, along with community, academic, and federal cooperation. 相似文献
80.
Paul L. Ringold Barry Mulder Jim Alegria Raymond L. Czaplewski Tim Tolle Kelly Burnett 《Environmental management》1999,23(2):179-192
adaptive monitoring design. Adaptive monitoring design is an iterative process that refines the specifications for monitoring over time as a result of
experience in implementing a monitoring program, assessing results, and interacting with users. An adaptive design therefore
facilitates ecosystem management. We also discuss lessons of temporal and spatial scales raised by the consideration of a
design for ecosystem management. Three additional issues—integration of information from different sources, institutional
infrastructure, and the roles of individuals working in an interagency setting—are also identified, but not developed in detail. 相似文献