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91.
Neeta S. Bijoor Heather R. McCarthy Dachun Zhang Diane E. Pataki 《Urban Ecosystems》2012,15(1):195-214
In semi-arid cities, urban trees are often irrigated, but may also utilize natural water sources such as groundwater. Consequently,
the sources of water for urban tree transpiration may be uncertain, complicating efforts to efficiently manage water resources.
We used a novel approach based on stable isotopes to determine tree water sources in the Los Angeles basin, where we hypothesized
that trees would rely on irrigation water in the soil rather than develop deep roots to tap into groundwater. We evaluated
the oxygen (δ18O) and hydrogen (δD) isotope ratios of xylem water, irrigation water, soil water, and groundwater in a study of temporal patterns
in water sources at two urban sites, and a study of spatial patterns at nine urban sites and one “natural” riparian forest.
Contrary to our hypothesis, we found that despite frequent irrigation, some trees tap into groundwater, although in most species
this was a small water source. Some trees appeared to be using very shallow soil water at <30 cm depth, suggesting that these
mature urban trees were quite shallowly rooted. In the natural site, trees appeared to be using urban runoff in addition to
shallow soil water. We were able to identify tree uptake of precipitation at only 3 sites. The results show that some irrigated
trees utilize groundwater and do not rely solely on irrigation water, which may make them able to withstand drought and/or
water conservation measures. However, some irrigated trees may develop very shallow root systems, which may make them more
susceptible. 相似文献
92.
Childbearing behavior in East Asian countries has changed rapidly during the past half century from an average of five to seven children per family, to replacement-level fertility, and subsequently to unprecedentedly low levels, the lowest in the world. This article analyzes fertility trends in Hong Kong, Japan, singapore, south Korea, and Taiwan using cohort fertility data and methods, then examines social and economic causes of the childbearing trends, and surveys policies pursued to reverse the fertility trends. Postponement of childbearing started in the 1970s with continuously fewer delayed births being "recuperated," which resulted in ultra-low fertility. A rapid expansion of education and employment among women in a patriarchal environment has generated a stark dilemma for women who would like to combine childbearing with a career. Policy responses have been slow, with a more serious attempt to address issues in recent years. Thus far public and private institutions are not devoting sufficient attention to generating broad social change supportive of parenting. 相似文献
93.
Angela Jones 《Sociological focus》2016,49(1):63-83
This article uses a case study of the Niagara Movement, which functioned from 1905–1910, to demonstrate that the use of prosopography (collective biographies) is a propitious methodological tool, particularly for those interested in the social-psychological analysis of movement actors within networks. I present a prosopography of the founders of the Niagara Movement. Learning more about the identity of political actors provides clues to the ways strategic choices are made and how collective action frames are developed. The prosopography of the Niagara Movement also provides theoretical insights into discursive processes that are often lost in studies of long movement trajectories. I analyze potential explanations for the absence of organizations such as the Niagara Movement from the civil rights canon, and, through an analysis of talk as a resource for mobilization, pinpoint directions for future researchers interested in micro theories of mobilization. 相似文献
94.
Patterns of Intimate Partner Violence and Sexual Risk Behavior among Young Heterosexually Active Men
Erin A. Casey Katherine Querna N. Tatiana Masters Blair Beadnell Elizabeth A. Wells Diane M. Morrison 《Journal of sex research》2016,53(2):239-250
Intimate partner violence (IPV) victimization is linked to sexual risk exposure among women. However, less is known about the intersection of IPV perpetration and sexual risk behavior among men. This study used data from a diverse, community sample of 334 heterosexually active young men, aged 18 to 25, across the United States to examine whether and how men with distinct IPV-related behavior patterns differed in sexual risk–related behavior and attitudes. Participants were recruited and surveyed online, and grouped conceptually based on the types of IPV perpetration behavior(s) used in a current or recent romantic relationship. Groups were then compared on relevant sexual risk variables. Men reporting both physical abuse and sexual coercion against intimate partners reported significantly higher numbers of lifetime partners, higher rates of nonmonogamy, greater endorsement of nonmonogamy, and less frequent condom use relative to nonabusive men or those reporting controlling behavior only. This group also had higher sexually transmitted infection (STI) exposure compared to men who used controlling behavior only and men who used sexual coercion only. Findings suggest that interventions with men who use physical and sexual violence need to account for not only the physical and psychological harm of this behavior but also the sexual risk to which men may expose their partners. 相似文献
95.
To Refer or Not to Refer: Exploring Family Therapists' Beliefs and Practices Related to the Referral of Lesbian,Gay, and Bisexual Clients 下载免费PDF全文
Christi R. McGeorge Thomas Stone Carlson Molly Farrell 《Journal of marital and family therapy》2016,42(3):466-480
This study explored how negative beliefs toward lesbian, gay, and bisexual (LGB) individuals and LGB clinical competence influenced family therapists' beliefs and practices regarding referring based on the sexual orientation of the client. The sample consisted of 741 experienced clinicians. The results of this study indicated that the majority of the participants believe it is ethical to refer LGB clients; however, most had never made such a referral. Furthermore, participants who had referred based solely on the client's sexual orientation reported higher levels of negative beliefs toward LGB individuals and lower levels of LGB clinical competence. Finally, negative beliefs toward LGB persons not only predicted the practice of referring, but also the belief that it is ethical to refer an LGB client. 相似文献
96.
Few studies have examined the influence of environmental factors on children's executive functioning (EF) performance. The present study examined the effects of a punitive vs. non‐punitive school environment on West African children's EF skills. Tasks included a ‘cool’ (relatively non‐affective) and ‘hot’ (relatively affective/motivational) version of three EF tasks: delay of gratification; gift delay; and dimensional change card sort. Children had more difficulties with the hot versions of the tasks than the cool versions, and older children outperformed younger children. After controlling for verbal ability (Peabody picture vocabulary test‐third edition), a consistent pattern of interaction between school and grade level emerged. Overall, kindergarten children in the punitive school performed no differently than their counterparts in the non‐punitive school. However, in grade 1, children in the punitive school performed significantly worse than their counterparts in the non‐punitive school. These results point to the need to consider interactions among discipline style, age, and internalization processes of self‐regulation to better understand environmental influences on EF development. 相似文献
97.
98.
The emergence of positive psychology has generated increased interest about the correlates of positive psychological functioning. Researchers have identified and studied various positive psychological constructs (e.g., hope, optimism, self-efficacy, gratitude, and life satisfaction) and found them to covary and to be positively associated with optimal human functioning and negatively associated with mental illness. This study of 528 college students examined the co-occurrence of selected positive psychological traits and explored their relations with a proposed second-order latent construct called covitality and with psychological well-being. Structural equation modeling examined each first-order positive psychology construct related to the second-order concept of covitality. Findings supported the second-order latent factor model of covitality, which was also significantly related to indicators of psychological well-being. Implications for theory development related to understanding positive human resources and applications within the context of college student populations are discussed. 相似文献
99.
100.