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991.
Pollen specialization by solitary bees in an urban landscape 总被引:1,自引:1,他引:0
Many polylectic bee species are known to specialize locally on one or a few pollen types to increase foraging efficiency. What is relatively unknown is how different landscapes influence foraging decisions, and whether habitat alteration, such as that resulting from urbanization, influences broad-scale foraging activities of bees. This study evaluates the type and diversity of pollen collected by two solitary bees that are common in Toronto, Ontario, Canada, the native Osmia pumila and the exotic O. caerulescens, sampled in trap nests set up in urban parks and gardens. We found that the dominant pollen in every successful brood cell was either of one widespread, cosmopolitan lawn-invasive plant species (Trifolium repens) or one of two wind-pollinated tree genera (Quercus spp. and Betula spp.). In combination, these three represented more than 90 % of all pollen collected by each bee species. Despite considerable overlap in the dominant pollen types collected by each bee species, the exotic O. caerulescens was significantly more specialized than the native O. pumila. Brood cells with Betula as the dominant pollen type were more pollen species-rich than those cells having Trifolium or Quercus as dominant, perhaps a result of the comparatively low protein content in Betula pollen. 相似文献
992.
Deepta Chopra Patience Ekeoba Zahrah Nesbitt-Ahmed Rachel Moussié Mona Sherpa 《Gender and development》2014,22(3):475-494
This article focuses on policy advocacy programmes in Nepal and Nigeria, instigated by ActionAid International with local women's rights organisations and non-government organisations, and supported by the Institute of Development Studies, UK. These programmes aimed to challenge women's unequal responsibility for care work and to influence policymakers to understand the importance of providing services to support them. One of the main components of these programmes was child care, a responsibility which most women experience 24/7 for at least two decades of their lives, and which profoundly shapes their lives and opportunities. We examine the processes through which each of the country teams have engaged with public policies on this issue, focusing on the similarities and differences in each context. Although the programme of activities has been implemented in much the same way in both countries, and each chose to focus on early child-care provision as the main policy demand, the partnerships and policy processes chosen differ greatly. Specifically, we distinguish between ‘critical engagement’ (in the case of Nepal), as compared to ‘constructive engagement’ (in the case of Nigeria). The article ends with some reflections on the challenges facing the teams during their work, and the implications and lessons that can be drawn from these two case studies. 相似文献
993.
Ingrid Phillips Whitaker Mark M. Whitaker Kanata Jackson 《Journal Of Human Behavior In The Social Environment》2014,24(2):230-249
The percentage of female-headed African American families has increased significantly since the 1960s. It is now estimated that over half of all African American children will grow up in a female-headed household. This article examines factors related to the formation of these households as well as the challenges associated with these households. Policies and programs that have been implemented to treat these families are examined. 相似文献
994.
In this study, we examined possible gender differences in reasons for faculty attrition during the last 20 years at a small women's liberal arts college. The attrition rate was calculated from archival data collected through old college directories. As in earlier studies, the attrition rate was higher for women (31%) than for men (18.5%). Reasons for leaving the college were assessed in an online survey completed by 45 out of 66 tenure-track or tenured professors who left (excluding retirees). Work–family conflict was the most frequently cited reason for leaving, with disproportionately more women than men giving this reason. Open-ended responses revealed that work–family conflict typically referred to the difficulty of coordinating two careers. Female faculty who left were also significantly more dissatisfied than males with the support for balancing work and family life at the college. The need for colleges to create spousal policies to help faculty coordinate dual careers was discussed. 相似文献
995.
The objective of this study was to measure the relationships between online sexual compulsivity, three dimensions of dissociation (absorption, depersonalization, and amnesia), and past child abuse among men who have sex with men (MSM). A total of 517 MSM, recruited from Internet chat rooms, completed the survey. Results indicated that past child abuse was significantly related to dissociation but not online sexual compulsivity. It was also found that the amount of time MSM spent online in a one-week period, in general and specifically engaged in sexual activity, was significantly related to online sexual compulsivity and three dimensions of dissociation. Online sexual compulsivity was a significant predictor of absorption, depersonalization, and amnesia. Implications for clinicians and future research are presented. 相似文献
996.
Research has shown that lesbian and gay (LG) individuals are coming out not only to their parents, but also to their siblings. Eighty percent of individuals in the United States are raised with one or more siblings; however, researchers have frequently underestimated the importance of the sibling bond. This study examined potential correlates of heterosexual siblings’ acceptance of their LG sister or brother using an online survey format (N = 189). In addition, psychometric properties for the Acceptance of Sibling Sexual Orientation Scale are provided. Results revealed that greater sibling relationship quality in adulthood, more contact with LG individuals, greater knowledge of LG communities, more support for LG civil rights, and various demographics (being female, having higher educational levels, not having an orthodox/fundamentalist religious orientation, less church attendance, and more liberal political ideology) are related to heterosexual siblings’ acceptance of their LG sister or brother. However, when these variables were examined together in a regression model, only sibling relationship in adulthood, contact with LG individuals, support for LG civil rights, and religious attendance were significant unique predictors of acceptance. 相似文献
997.
The development of one's sexual minority identity is often stunted by a heterosexist society. For individuals with multiple minority oppressions, this process becomes even more complicated. As such, there has been a call among researchers for more empirical research on the experiences of lesbian, gay, bisexual (LGB) individuals from racial/ethnic minority groups. This study uses qualitative methods to fill gaps in the literature related to identity development among same-gender attracted Middle Eastern/Arab individuals living in the United States. From 12 interviews, 13 themes associated with intersectionality, race/ethnicity, sexual identity development, discrimination, stigma, oppression, and invisibility. Themes, subthemes, and their implications are discussed. 相似文献
998.
This investigation sought to elaborate Koerner and Fitzpatrick’s theory of family communication by testing two theoretical models of family communication patterns (FCP), child-to-parent inclusion of the other in the self (IOS), and relational maintenance. Participants included 374 young adults recruited from two universities in different regions of the United States. Results best supported a model positioning maintenance as a mediator of the association between FCP and IOS, as compared to an alternative model with IOS as a mediator of the association between FCP and maintenance. These findings extend Koerner and Fitzpatrick’s theory by highlighting communication as the means by which overarching family schemas influence relationship-specific schemas; additionally, they commend the self-expansion model as a useful theoretical approach to relational maintenance behavior in family contexts. 相似文献
999.
Charlene M. Kalenkoski 《Review of Economics of the Household》2014,12(3):547-563
This paper examines whether receipt of public or private assistance is associated with recipients’ own generosity in the form of formal and informal volunteering. Using matched data from the 2007–2011 American Time Use Survey and the Annual Social and Economic Supplement to the Current Population Survey, this paper finds that receipt of private assistance from friends and relatives is negatively associated with the time women spend caring for non-household adults and the time men spend caring for non-household children. Receipt of public assistance is found to be negatively associated with men’s care of non-household adults. No associations are found between either type of assistance and time spent volunteering for a formal organization. 相似文献
1000.
Grassroots groups often find that they need to manage issues of diversity along racial/ethnic, class, gender, religious, and/or citizenship lines, among several other axes of difference. There are strong reasons to expect that diversity is a benefit to such groups, especially in terms of coalition breadth and the widely held expectation that internal heterogeneity helps organizations to resolve collective action dilemmas. Nonetheless, a long tradition within sociological research sets out the expectation that group heterogeneity thwarts the formation of collective identities and group solidarity, and therefore limits the potential for effective organizing. With a particular emphasis on groups active in local community‐based organizing since the 1970s, we review studies on a variety of features of group diversity and their effects on mobilizing processes. We find that although researchers remain somewhat divided on these critical issues, the preponderance of evidence suggests that managing diversity poses significant challenges for grassroots organizing efforts. While these challenges may not easily be overcome, we point to a variety of cases in which group differences offered a significant asset to social change efforts. 相似文献