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971.
Urban agriculture has been growing in popularity around the globe. As more land is allocated to urban agriculture, there is a greater need to understand arthropod herbivores and natural enemies in these sites. The area and production type of urban agriculture could influence the risk of pest outbreaks, since larger food production areas are hypothesized to host more abundant herbivore populations. To determine the potential for pest outbreaks, we sampled for pests and above-ground natural enemies at three types of sites with variable amounts of cultivated areas: residential gardens, community gardens, and urban farms. We focused on pests of brassica, a widely cultivated crop family attacked by cabbageworms and aphids. We investigated the relationships of garden characteristics and surrounding land cover on natural enemies and herbivores of brassica. More herbivores and plant damage were expected in larger community gardens and urban farms. However, herbivore populations were low across sites and not explained by garden characteristics or area of production. Herbivory on brassica averaged less than 15% at all sites. Limited plant damage and low herbivore numbers may be attributed to the positive effects of garden flowers on parasitoids and high numbers of parasitoids and generalist predators across sites. Garden area and floral resources had positive relationships with natural enemy abundance, although community composition was similar across sites. Since arthropod natural enemies were abundant across all types of food production, this suggests that urban agriculture is a beneficial habitat that could support regulating ecosystem services such as biological control. 相似文献
972.
Laura Brierton Granruth Peter A. Kindle Michael L. Burford Elena Delavega David H. Johnson Susan Peterson 《Journal of Social Work Education》2018,54(1):110-121
Understanding student political attitudes—feelings about government and perceptions of its role—has long been of interest to social scientists. One factor that may influence political attitudes is belief in a just world, a complex psychological construct well established in the literature. Our study explores changes in social work students’ perception of a supportive role of government and their beliefs in a just world after one policy course using a pretest and posttest design. Student perceptions changed toward a more supportive government role, but there was no significant change for belief in a just world. The study contributes to empirical evaluation of the social work education policy class in terms of the Council on Social Work Education competencies. 相似文献
973.
David E. Clementson 《Public Relations Review》2019,45(1):49-63
Upwards of 200 studies over the past hundred years have reported on the relationship between public relations practitioners and journalists. However, no experiment has compared the group members’ perceptions when seeing their roles in action. Inspired by frameworks of social identity theory, intergroup deception, and the black sheep effect, we test how public relations practitioners and journalists respond to a crisis communication media interview. In our experiment, a company spokesperson either answers questions or engages in stereotypical “spin,” which journalists historically consider one of the most offensive public relations strategies. Results indicate that public relations practitioners align with journalists in their perceptions of a spokesperson’s trustworthiness and the organization’s trustworthiness across treatment conditions. Practitioners also manifest the black sheep effect, disliking their group representative engaging in deception. Furthermore, we explore whether the effects on perceptions of trustworthiness are moderated by psychological identification with their respective industry. Discussion concerns the theoretical and practical ramifications of the groups sharing ingroup affiliation, contrary to prevailing notions of acrimony. 相似文献
974.
Coming out is a significant and sometimes difficult process in the lives of sexual minorities, but disclosure can also affect wellbeing in positive ways, including reduced distress and greater relationship satisfaction. This study investigates the possibility of stress-related growth and depreciation following coming out. To obtain a diverse sample with varying coming-out experiences, data were collected from undergraduate students as well as from online sources, including lesbian, gay, and bisexual support groups and Pride groups. Regression analyses indicated that negative social reactions to coming out predicted both growth and depreciation, although they more strongly predicted depreciation. Positive social reactions were positively related to stress-related growth, while internalized homonegativity was inversely associated with growth. Although the two sample sources (online and campus) differed in some ways, sample source was not a significant predictor in the regressions, nor was it indicated as a moderator in exploratory ANOVA analyses. 相似文献
975.
DEVELOPING FAMILY PSYCHOEDUCATIONAL TREATMENTS FOR PATIENTS WITH BIPOLAR AND OTHER SEVERE PSYCHIATRIC DISORDERS 总被引:1,自引:0,他引:1
Developing family treatments for patients with severe and persistent psychiatric disorder begins at the basic research level, through identifying psychosocial variables that have prognostic significance. Treatment protocols informed by this basic research can then be designed, manualized, and piloted. Next, the efficacy of a new treatment is examined, first in a randomized trial and then, if successful, in a community effectiveness study. We describe this treatment development pathway in a population for whom family attributes have prognostic importance: patients with bipolar affective ddisorder. The methodological complexities of psychosocial treatment studies are many. Moreover, the results of these studies often reflect interactions between treatment, process, and outcome variables. 相似文献
976.
977.
Consumer Sovereignty and Quasi-Market Failure 总被引:2,自引:0,他引:2
978.
Carl A. Latkin Wallace Mandell Amy R. Knowlton David Vlahov Wesley Hawkins 《Journal of Social Distress and the Homeless》1998,7(4):263-278
Injection drug users are at high risk for homelessness and human immunodeficiency virus (HIV) infection. This study sought to examine incidence rates and the social and economic antecedents of homelessness of impoverished inner-city injection drug users. Of the 569 participants, from a nontreatment sample who participated HIV prevention study, interviewed at baseline, 324 (57%) were reinterviewed 5.2 months later. At baseline 48% of the participants reported that they had been homeless in the past 10 years. Of the 324, 18% reported that at both interviews they had been homeless within the prior 6 months, 12% reported homelessness at baseline but not at follow-up, and 8% reported homelessness at follow-up but not at baseline. At baseline personal social support network characteristic of size of material aid and size of sex network was found to be associated with self-reports of homelessness. Baseline reports of presence of mother in personal network, size of material aid network, and network density were found to be associated with reports of homelessness at follow-up. These result suggest the need for alternative approaches to addressing issues of homelessness injection drug users. 相似文献
979.
Gray George M. Allen Jon C. Burmaster David E. Gage Stuart H. Hammitt James K. Kaplan Stanley Keeney Ralph L. Morse Joseph G. North D. Warner Nyrop Jan P. Stahevitch Alina Williams Richard 《Risk analysis》1998,18(6):773-780
The North American Free Trade Agreement (NAFTA) and the General Agreement on Tariffs and Trade (GATT) have focused attention on risk assessment of potential insect, weed, and animal pests and diseases of livestock. These risks have traditionally been addressed through quarantine protocols ranging from limits on the geographical areas from which a product may originate, postharvest disinfestation procedures like fumigation, and inspections at points of export and import, to outright bans. To ensure that plant and animal protection measures are not used as nontariff trade barriers, GATT and NAFTA require pest risk analysis (PRA) to support quarantine decisions. The increased emphasis on PRA has spurred multiple efforts at the national and international level to design frameworks for the conduct of these analyses. As approaches to pest risk analysis proliferate, and the importance of the analyses grows, concerns have arisen about the scientific and technical conduct of pest risk analysis. In January of 1997, the Harvard Center for Risk Analysis (HCRA) held an invitation-only workshop in Washington, D.C. to bring experts in risk analysis and pest characterization together to develop general principles for pest risk analysis. Workshop participants examined current frameworks for PRA, discussed strengths and weaknesses of the approaches, and formulated principles, based on years of experience with risk analysis in other setting and knowledge of the issues specific to analysis of pests. The principles developed highlight the both the similarities of pest risk analysis to other forms of risk analysis, and its unique attributes. 相似文献
980.
The EPA Health Risk Assessment of Methylcyclopentadienyl Manganese Tricarbonyl (MMT) 总被引:1,自引:0,他引:1
This paper describes the U.S. Environmental Protection Agency's assessment of potential health risks associated with the possible widespread use of a manganese (Mn)-based fuel additive, methylcyclopentadienyl manganese tricarbonyl (MMT). This assessment was significant in several respects and may be instructive in identifying certain methodological issues of general relevance to risk assessment. A major feature of the inhalation health risk assessment was the derivation of Mn inhalation reference concentration (RfC) estimates using various statistical approaches, including benchmark dose and Bayesian analyses. The exposure assessment component used data from the Particle Total Exposure Assessment Methodology (PTEAM) study and other sources to estimate personal exposure levels of particulate Mn attributable to the permitted use of MMT in leaded gasoline in Riverside, CA, at the time of the PTEAM study; on this basis it was then possible to predict a distribution of possible future exposure levels associated with the use of MMT in all unleaded gasoline. Qualitative as well as quantitative aspects of the risk characterization are summarized, along with inherent uncertainties due to data limitations. 相似文献