There is growing recognition of urban areas as hosts for innovative ways to conserve and promote biodiversity. Parks, as one specific type of urban green space, constitute particularly important biodiversity hotspots in the cityscape. We reviewed empirical findings on the species richness in urban parks across all species groups that have been studied. The aim was to assess and discuss the overall species richness of urban parks, its community attributes and drivers. Search and subsequent selection process resulted in 62 papers from 25 different countries. For all examined species groups, the findings consistently show that parks are among the most species rich types of urban green spaces, but also that exotics constitute large shares, especially of plant species. Key ecological theories like the gradient approach and the island habitat ecological theory, and fundamental ecological relationships such as the species-area relationship are valid despite the manipulated ‘nature’ of parks and the surrounding urban matrix. Most studies surveyed large number of parks and applied ‘multi-scale’ approaches in tests of confounding variables, providing methodological strength. While matrix effects are consistently found to affect species richness negatively, the diversity of habitats and microhabitat heterogeneity contained in urban parks appears as the most decisive factor for the overall species richness. However, a constraint of research to date is the limitation of individual studies to one or a few species groups, rarely bridging between flora and fauna. Adopting ‘multi-species group’ approaches in future research is needed to further advance the understanding of the overall biodiversity of urban parks, and its drivers. 相似文献
To explore questions in history and to construct historical narratives, historians work with evidence from the past. This approach to teaching history (inquiry involving the use of evidence) is an accepted part of the research on history teaching and is promoted widely in standards frameworks and practitioner publications as “good history instruction.” What happens in a standards-based setting where teachers are covering large bodies of content? Do teachers use sources as part of their daily instruction? If so, how? We were afforded the unique opportunity to spend time observing what 35 teachers do by analyzing 352 videos submitted over a 4-year time span. We observed a spectrum of source use within and across teacher practice. In this article we share what we noticed. 相似文献
Conclusions about temporal changes in age and circumstances of first intercourse are generally derived from retrospective reports by people of various ages in cross-sectional studies, with an inherent assumption of no bias stemming from time since the event. We examined this assumption through repeated questions on age and circumstances of first heterosexual intercourse (FHI) at ages 21 and 38 in a birth cohort. Despite considerable movement in individual reports, there was no bias in reported age of FHI. However, a greater proportion of both men and women stated at the later assessment both partners had been equally willing (versus persuading or persuaded). The distribution of current views of the appropriateness of the timing did not differ markedly between assessments, although there were many individual changes. Reports of contraceptive usage were similar at the two assessments for men but differed among women, mainly through more reporting that they could not remember. These findings imply that among cohorts born in the 1970s, there is no bias in reports of age of FHI many years after the event, and views on the appropriateness of timing persist. However, time biases reports in favor of a more mutual willingness. 相似文献
This article links the development of service user involvement championed in the United Kingdom to two examples in Dutch-speaking qualifying social work programmes: one from Belgium and one from the Netherlands. In both projects, a longer lasting cooperation with more marginalised service users was established. The Belgium project highlights social work lecturers and service users living in poverty, working in tandem to deliver a module to social work and socio-educational care work students. The example from the Netherlands involves young people from a homeless shelter as peer-researchers, working together with social work students.
Both projects, one focusing on social work education and on social work research, highlight striking similarities in the positives and challenges of working with service users including how this challenges both groups preconceptions of the other, deepens learning but also creates greater potential for confrontations which need to be managed creatively. The article also identifies the pre-requisites for this to be effective including appropriate resourcing, training, facilitative skills and acknowledges that collaborations can be extremely fragile. However, such projects need further investment, experimentation and implementation on an international scale to share learning and promote creative approaches for the development and learning of social work students. 相似文献
This article contributes to understanding transformational change towards gender equality by examining the transformational change potential of a mentoring programme for women, a type of gender equality intervention both criticized and praised for its ability to bring about change. Drawing upon an empirical case study of a mentoring programme for women academics in a Dutch university, we explore three dimensions of transformational change: organizational members (i) discussing and reflecting upon gendered organizational norms and work practices; (ii) creating new narratives; and (iii) experimenting with new work practices. Our findings indicate five specific conditions that enable transformational change: cross‐mentoring, questioning what is taken for granted, repeating participation and individual stories, facilitating peer support networks and addressing and equipping all participants as change agents. We suggest that these conditions should be taken into account when (re)designing effective organizational gender equality interventions. 相似文献
The aim of this study was to unravel the interrelatedness of friendship and help, and to examine the characteristics of friendship and help networks. The effects of mutual versus one‐sided help relations on friendship initiation and maintenance, and vice versa, were examined. Friendship and help networks were analyzed (N = 953 students; 41 classrooms; Mage = 12.7). The results illustrate that friendship and help networks show some similarities, but only partly overlap and have distinct characteristics. Longitudinal multiplex social network analyses showed that mutual help was important for the maintenance of friendship, but not for the initiation of friendship. Further, particularly mutual friendships provided a context in which help took place. Implications of these findings are discussed. 相似文献
The private nature of psychosexual functioning leads adolescents and their parents to have different perspectives, which highlights studying parent–child informant discrepancies in this domain. We investigated informant discrepancy in psychosexual functioning, using the self‐report and parent report versions of the Teen Transition Inventory (TTI), of adolescents with autism spectrum disorder (ASD; 136 parent–child dyads) compared to adolescents from the general population (GP; 70 parent–child dyads). Significantly larger informant discrepancies exist in ASD dyads than GP dyads in most domains of psychosexual functioning, except for Body image, Sexual behavior, and Confidence in the future. It is important to use and pay attention to both informants, as discrepancies are relevant for both research and clinical practice regarding psychosexual functioning. 相似文献
In many countries, new, broad, and normative “conceptions of society” gained prominence that represent fundamentally different discursive alternatives to the classical welfare state. We present two political projects that contain radical alternative conceptualizations of the classical welfare state, the “Big Society” in Britain and the “Participation Society” in the Netherlands, and contrast these with Norwegian developments, where no such a radical alternative conceptualization of the welfare state can be found. We show that the British and Dutch political projects were attempts to replace the welfare state, whereas there is no comparable big idea about a radical overhaul of the welfare state in Norway. Our analysis contributes to a better understanding of a fundamental shift in welfare state reform, namely a radical reconsidering of the ideational and normative foundation that defines and underpins what the welfare state is or should be. 相似文献
Let G be a graph and
be the complement of G. The complementary prism
of G is the graph formed from the disjoint union of G and
by adding the edges of a perfect matching between the corresponding vertices of G and
. For example, if G is a 5-cycle, then
is the Petersen graph. In this paper we consider domination and total domination numbers of complementary prisms. For any
graph G,
and
, where γ(G) and γt(G) denote the domination and total domination numbers of G, respectively. Among other results, we characterize the graphs G attaining these lower bounds.
Research supported in part by the South African National Research Foundation and the University of KwaZulu-Natal. 相似文献