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161.
Abstract While US climate change mitigation policy has stalled at the national level, local and regional actors are increasingly taking progressive steps to reduce their greenhouse gas emissions. Universities are poised to play a key role in this grassroots effort by targeting their own emissions and by working with other local actors to develop climate change mitigation programmes. Researchers at the Pennsylvania State University have collaborated with university administrators and personnel to inventory campus emissions and develop mitigation strategies. In addition, they have facilitated a stakeholder-driven climate change mitigation project in one Pennsylvania county and started an ongoing service-learning project aimed at reducing emissions in another county. These campus and community outreach initiatives demonstrate that university-based mitigation action may simultaneously achieve tangible local benefits and develop solutions to broader challenges facing local climate change mitigation efforts. Outcomes include improved tools and protocols for measuring and reducing local emissions, lessons learned about service-learning approaches to climate change mitigation, and methods for creating climate change governance networks involving universities, local governments and community stakeholders. 相似文献
162.
163.
Gilmour JT Cogger CG Jacobs LW Evanylo GK Sullivan DM 《Journal of environmental quality》2003,32(4):1498-1507
This research combines laboratory and field studies with computer simulation to characterize the amount of plant-available nitrogen (PAN) released when municipal biosolids are land-applied to agronomic crops. In the laboratory studies, biosolids were incubated in or on soil from the land application sites. Mean biosolids total C, organic N, and C to N ratio were 292 g kg(-1), 41.7 g kg(-1), and 7.5, respectively. Based on CO2 evolution at 25 degrees C and optimum soil moisture, 27 of the 37 biosolids-soil combinations had two decomposition phases. The mean rapid and slow fraction rate constants were 0.021 and 0.0015 d(-1), respectively, and the rapid fraction contained 23% of the total C assuming sequential decomposition. Where only one decomposition phase existed, the mean first order rate constant was 0.0046 d(-1). The mean rate constant for biosolids stored in lagoons for an extended time was 0.00097 d(-1). The only treatment process that was related to biosolids treatment was stabilization by storage in a lagoon. Biosolids addition rates (dry basis) ranged from 1.3 to 33.8 Mg ha(-1) with a mean value of 10.6 Mg ha(-1). A relationship between fertilizer N rate and crop response was used to estimate observed PAN at each site. Mean observed PAN during the growing season was 18.9 kg N Mg(-1) or 37% of the biosolids total N. Observed PAN was linearly related to biosolids total N. Predicted PAN using the computer model Decomposition, actual growing-season weather, actual analytical data, and laboratory decomposition kinetics compared well with observed PAN. The mean computer model prediction of growing-season PAN was 19.2 kg N Mg(-1) and the slope of the regression between predicted and observed PAN was not significantly different from unity. Predicted PAN obtained using mean decomposition kinetics was related to predicted PAN using actual decomposition kinetics suggesting that mean rate constants, actual weather, and actual analytical data could be used in estimation of PAN. There was a linear relationship between predicted N mineralization for the growing season and for the first year. For this study, the mean values for the growing season and year were 27 and 37% of the organic N, respectively. 相似文献
164.
Miller JJ Beasley BW Yanke LJ Larney FJ McAllister TA Olson BM Selinger LB Chanasyk DS Hasselback P 《Journal of environmental quality》2003,32(5):1887-1894
Nutrients, soluble salts, and pathogenic bacteria in feedlot-pen manure have the potential to cause pollution of the environment. A three-year study (1998-2000) was conducted at a beef cattle (Bos taurus) feedlot in southern Alberta, Canada to determine the effect of bedding material [barley (Hordeum vulgare L.) straw versus wood chips] and season on the chemical and bacterial properties of pen-floor manure. Manure was sampled for chemical content (N, P, soluble salts, electrical conductivity, and pH) and populations of four groups of bacteria (Escherichia coli, total coliforms, and total aerobic heterotrophs at 27 and 39 degrees C). More chemical parameters of manure were significantly (P < or = 0.05) affected by season (SO4, Na, Mg, K, Ca, sodium adsorption ratio [SAR], total C, NO3-N, NH4-N, total P, and available P) than by bedding (K, pH, total C, C to N ratio, NH4-N, and available P). Bedding had no significant (P > 0.05) effect on the four bacterial groups whereas season affected all four groups. Numbers of E. coli and total coliforms (TC) were significantly higher by 1.72 to 2.02 log10 units in the summer than the other three seasons, which was consistent with a strong positive correlation of E. coli and TC with air temperature. The low ratio of bedding to manure in the pens was probably the major cause of the lack of significant bedding effects. Bedding material and seasonal timing of cleaning feedlot pens and land application of manure may be a potential tool to manage nutrients, soluble salts, and pathogens in manure. 相似文献
165.
A Method for Constructing a Social Vulnerability Index: An Application to Hurricane Storm Surges in a Developed Country 总被引:11,自引:1,他引:11
Lisa Rygel David O’sullivan Brent Yarnal 《Mitigation and Adaptation Strategies for Global Change》2006,11(3):741-764
An important goal of vulnerability assessment is to create an index of overall vulnerability from a suite of indicators. Constructing
a vulnerability index raises several problems in the aggregation of these indicators, including the decision of assigning
weights to them. The purpose of this paper is to demonstrate a method of aggregating vulnerability indicators that results
in a composite index of vulnerability, but that avoids the problems associated with assigning weights. The investigators apply
a technique based on Pareto ranking to a complex, developed socioeconomic landscape exposed to storm surges associated with
hurricanes. Indicators of social vulnerability to this hazard are developed and a principal components analysis is performed
on proxies for these indicators. Overall social vulnerability is calculated by applying Pareto ranking to these principal
components. The paper concludes that it is possible to construct an effective index of vulnerability without weighting the
individual vulnerability indicators. 相似文献
166.
167.
No evidence for the work-conflict hypothesis in the eusocial naked mole-rat (Heterocephalus glaber ) 总被引:1,自引:0,他引:1
The work-conflict hypothesis (Reeve 1992) postulates that in eusocial naked mole-rat (Heterocephalus glaber) colonies there is potential conflict between the breeding female and her non-breeding colony mates over how much aid they
provide in support of her reproduction. Non-breeders may withhold aid either because they are hopeful reproductives and/or
because they have less to gain in terms of inclusive fitness. Breeding females should, therefore, preferentially direct aggression
in the form of shoving (prolonged pushes usually involving nose-to-nose contact) towards large (hopeful reproductives) and
less related non-breeders to incite them to provide aid. This study tested the following predictions of the work-conflict
hypotheses. (1) There is kin bias in the shove rate of breeding females and work rates of non-breeders; (2) Shoving activates
work in non-breeders. We found no evidence to suggest that the breeding female shove rate and the amount of colony maintenance
activities performed by non-breeders is influenced by relatedness. Body size was a better predictor of work rate and shove
rate; large animals were shoved more and worked less. Furthermore, shoving did not affect the work rate of non-breeders and
rarely incited activity in inactive mole-rats. Individual mole-rats were also more likely to be shoved when already active
than when resting in the nest. These results suggest that shoving by the breeding female may have functions other than the
incitement of activity, such as the reproductive suppression of non-breeders.
Received: 17 January 1996 / Accepted after revision: 21 September 1996 相似文献
168.
Miguel A. Medina Timothy L. Jacobs Weichao Lin Kuo-Ching Lin 《Journal of the American Water Resources Association》1996,32(1):1-12
ABSTRACT: A groundwater quality modeling advisory system has been developed for the U.S. Air Force for use in investigating remediation alternatives for the cleanup of subsurface contamination. The system is capable of accounting for uncertainty, not only in the prediction of solute transport but also in the optimization of the remediation scheme through chance constraints. The system guides users in the selection of appropriate transport models through an algorithm independently tested with machine learning codes. An application to Hill Air Force Base, Utah, is presented for which different pump-and-treat strategies are considered: the results are evaluated in terms of the cumulative distribution of the contaminant concentration for each case and the tradeoff relationship between the cost of remediation and the probability that the remediation strategy exceeds an established maximum allowable contaminant concentration. 相似文献
169.
The Russian River-Cooper Lake-Resurrection River trail system, on the Kenai Peninsula, Alaska, traverses essential brown bear
habitat. To set management guidelines for this area, the trail system was monitored using questionnaire cards and electronic
trail counters from 1984 through 1987. This helped to determine the extent and type of human use and human-bear encounters
in the area. Management recommendations were intended to reduce the potential displacement of brown bears by hikers and to
inform wilderness users of the proper camping techniques to avoid attracting bears to the campsite. An average of 5800 visitors
hiked or camped along the trail system each year. Encounters between hikers and brown bears averaged 7/yr while encounters
with black bears averaged 35/yr. Minor problems occurred with both the electronic trail counters and the questionnaire. Modilications
to these methods are discussed. A Limits of Acceptable Change format should be considered for the trail system to determine
the character and future direction of recreational activities and monitoring of the trail system should continue in the future. 相似文献
170.
Air pollution control devices (APCDs) are not compulsory for medical waste incinerators (MWIs) in developing countries. In South Africa, combustion gases are usually vented directly to the atmosphere at temperatures greater than the formation temperature of dioxin. The possibility of dioxin formation outside the incinerator stack has been hypothesized. A plume model has been developed and tested in the wind tunnel with a scale model of an incinerator stack. The plume temperature and trajectory predictions of the plume model were verified within a +/- 3% experimental accuracy. Using South African data, the plume model predicts that the residence time of gases in the temperature range of 150-450 degrees C in a plume is 1.3 sec on average for 5% of a year (18 days) at meteorological conditions resulting in wind speeds of less than 1 m/sec. Two published dioxin formation models were used to assess the probability of dioxin formation in the plume. The formation models predict that the average polychlorinated dibenzodioxins/furans (PCDD/Fs) formed in the plume will exceed the stack emission regulations in South Africa of 0.2 ng/Nm3 toxic equivalent quotient (TEQ) by between 2 and 40 times. The calculated concentrations do not include additional gaseous PCDD/F compounds that may be formed at high-temperature post-combustion zones through pyrosynthesis mechanisms. 相似文献