689 resultados para Deprived communities


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Climatic and land use changes have significant consequences for the distribution of tree species, both through natural dispersal processes and following management prescriptions. Responses to these changes will be expressed most strongly in seedlings near current species range boundaries. In northern temperate forest ecosystems, where changes are already being observed, ectomycorrhizal fungi contribute significantly to successful tree establishment. We hypothesised that communities of fungal symbionts might therefore play a role in facilitating, or limiting, host seedling range expansion. To test this hypothesis, ectomycorrhizal communities of interior Douglas-fir and interior lodgepole pine seedlings were analysed in a common greenhouse environment following growth in five soils collected along an ecosystem gradient. Currently, Douglas-fir’s natural distribution encompasses three of the five soils, whereas lodgepole pine’s extends much further north. Host filtering was evident amongst the 29 fungal species encountered: 7 were shared, 9 exclusive to Douglas-fir and 13 exclusive to lodgepole pine. Seedlings of both host species formed symbioses with each soil fungal community, thus Douglas-fir did so even where those soils came from outside its current distribution. However, these latter communities displayed significant taxonomic and functional differences to those found within the host distribution, indicative of habitat filtering. In contrast, lodgepole pine fungal communities displayed high functional similarity across the soil gradient. Taxonomic and/or functional shifts in Douglas-fir fungal communities may prove ecologically significant during the predicted northward migration of this species; especially in combination with changes in climate and management operations, such as seed transfer across geographical regions for forestry purposes.

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This contribution is about the protection of detained persons in international armed conflict. In particular, it compares how the relationship between IHL and IHRL is understood depending on whether one is speaking of the substantive or the procedural rules of protection for detainees. It will be suggested that, whereas the relationship between IHL and IHRL raises fewer problems when speaking of substantive rules, the situation is very different when speaking of procedural rules.

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This paper argues for the adoption of participatory approaches in historical geography, drawing on the author's experience in working with enthusiast communities in the UK in the context of collaborative research with the Science Museum and ideas of public history and geography.

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Any reader of manuscript catalogues knows how common the unhelpfully vague entry “sermon notes, 17th-century” can be. This essay explores whether we can find in sermon notes the kinds of textual communities that have been found through the reconstruction of other routes of manuscript circulation. It will unpick what those laconic catalogue entries mean, and distinguish the different kinds of sermon notes found in our archival collections (some derived from the original preacher, some from hearers, some from readers of manuscript and printed copies). The physical forms of different sorts of “sermon notes” alerts us to the different types of authors who created these manuscripts, and the different purposes involved in preserving an oration in textual form, purposes which included fostering the creation and maintenance of communal identities among the self-consciously godly or Catholic recusants.

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Purpose This research explored the use of developmental evaluation methods with community of practice programmes experiencing change or transition to better understand how to target support resources. Design / methodology / approach The practical use of a number of developmental evaluation methods was explored in three organisations over a nine month period using an action research design. The research was a collaborative process involving all the company participants and the academic (the author) with the intention of developing the practices of the participants as well as contributing to scholarship. Findings The developmental evaluation activities achieved the objectives of the knowledge managers concerned: they developed a better understanding of the contribution and performance of their communities of practice, allowing support resources to be better targeted. Three methods (fundamental evaluative thinking, actual-ideal comparative method and focus on strengths and assets) were found to be useful. Cross-case analysis led to the proposition that developmental evaluation methods act as a structural mechanism that develops the discourse of the organisation in ways that enhance the climate for learning, potentially helping develop a learning organization. Practical implications Developmental evaluation methods add to the options available to evaluate community of practice programmes. These supplement the commonly used activity indicators and impact story methods. 2 Originality / value Developmental evaluation methods are often used in social change initiatives, informing public policy and funding decisions. The contribution here is to extend their use to organisational community of practice programmes.

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Drought events are projected to increase in frequency and magnitude, which may alter the composition of ecological communities. Using a functional community metric that describes abundance, life history traits and conservation status, based upon Grime’s CSR (Competitive-Stress tolerant-Ruderal)¬ scheme, we investigated how British butterfly communities changed during an extreme drought in 1995. Throughout Britain, the total abundance of these insects had a significant tendency to increase, accompanied by substantial changes in community composition, particularly in more northerly, wetter sites. Communities tended to shift away from specialist, vulnerable species, and towards generalist, widespread species and, in the year following, communities had yet to return to equilibrium. Importantly, heterogeneity in surrounding landscapes mediated community responses to the drought event. Contrary to expectation, however, community shifts were more extreme in areas of greater topographic diversity, whilst land-cover diversity buffered community changes and limited declines in vulnerable specialist butterflies.

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The objective of this study was to investigate the role of environmental factors in sleep duration among adolescents living in rural areas. A total of 1140 students (569 males), aged 10-19 years, and attending two schools in rural regions in southern Brazil, completed a questionnaire about their sleep habits. Demographic data were also obtained. Prevalence ratios (PR) were estimated for the cases of more than 9 h of sleep on weekdays. Sleep duration in adolescents with and without electric lighting at home was analyzed. Average sleep duration at night was 9.63 (1.64) h on school-going days and 10.14 (2.42) h on weekends. The prevalence of adolescents sleeping for more than 9 h at night on school-going days was 58.3%. Older adolescents showed a tendency to delay their sleep onset times, which is associated with a reduction of sleep duration. Adolescents without electric lighting at home slept longer on school-going days (P < 0.001) and on weekends (P = 0.013) when compared to those with electric lighting at home. From multivariate analysis, age (P < 0.001), school schedule (P = 0.007) and work (0.042) were factors affecting sleep duration. In contrast to the data previously reported for urban populations, we found a high prevalence of adolescents sleeping for more than 9 h on school nights. Data on populations living in less industrialized regions reinforce the idea that technological advances are associated with the negative impact of sleep phase delay in adolescents.

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Competition for floral resources is a key force shaping pollinator communities, particularly among social bees. The ability of social bees to recruit nestmates for group foraging is hypothesized to be a major factor in their ability to dominate rich resources such as mass-flowering trees. We tested the role of group foraging in attaining dominance by stingless bees, eusocial tropical pollinators that exhibit high diversity in foraging strategies. We provide the first experimental evidence that meliponine group foraging strategies, large colony sizes and aggressive behavior form a suite of traits that enable colonies to improve dominance of rich resources. Using a diverse assemblage of Brazilian stingless bee species and an array of artificial ""flowers"" that provided a sucrose reward, we compared species` dominance and visitation under unrestricted foraging conditions and with experimental removal of group-foraging species. Dominance does not vary with individual body size, but rather with foraging group size. Species that recruit larger numbers of nestmates (Scaptotrigona aff. depilis, Trigona hyalinata, Trigona spinipes) dominated both numerically (high local abundance) and behaviorally (controlling feeders). Removal of group-foraging species increased feeding opportunities for solitary foragers (Frieseomelitta varia, Melipona quadrifasciata and Nannotrigona testaceicornis). Trigona hyalinata always dominated under unrestricted conditions. When this species was removed, T. spinipes or S. aff. depilis controlled feeders and limited visitation by solitary-foraging species. Because bee foraging patterns determine plant pollination success, understanding the forces that shape these patterns is crucial to ensuring pollination of both crops and natural areas in the face of current pollinator declines.

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Proline-specific dipeptidyl peptidases are emerging as a protease family with important roles in the regulation of signaling by peptide hormones related to energy balance. The treatment of neonatal rats with monosodium glutamate (MSG) is known to produce a selective damage on the arcuate nucleus with development of obesity. This study investigates the relationship among dipeptidyl peptidase IV (DPPIV) hydrolyzing activity, CD26 protein, fasting, and MSG model of obesity in 2 areas of the central nervous system. Dipeptidyl peptidase IV and CD26 were, respectively, evaluated by fluorometry, and enzyme-linked immunosorbent assay and reverse transcriptase polymerase chain reaction in soluble (SF) and membrane-bound (MF) fractions from the hypothalamus and hippocampus of MSG-treated and normal rats, submitted or not to food deprivation (FD). Dipeptidyl peptidase IV in both areas was distinguished kinetically as insensitive (DI) and sensitive (DS) to diprotin A. Compared with the controls, MSG and/or FD decreased the activity of DPPIV-DI in the SF and MF from the hypothalamus, as well as the activity of DPPIV-DS in the SF from the hypothalamus and in the MF from the hippocampus. Monosodium glutamate and/or FD increased the activity of DPPIV-DI in the MF from the hippocampus. The monoclonal protein expression of membrane CD26 by enzyme-linked immunosorbent assay decreased in the hypothalamus and increased in the hippocampus of MSG and/or FD relative to the controls. The existence of DPPIV-like activity with different sensitivities to diprotin A and the identity of insensitive with CD26 were demonstrated for the first time in the central nervous system. Data also demonstrated the involvement of DPPIV-DI/CD26 hydrolyzing activity in the energy balance probably through the regulation of neuropeptide Y and beta-endorphin levels in the hypothalamus and hippocampus. (C) 2011 Elsevier Inc. All rights reserved.

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Biometric parameters, glycemia and activity levels of plasma neutral aminopeptidase (APN) and dipeptidyl peptidase IV (DPPIV) were measured in monosodium glutamate obese and food-deprived rats (MSG-FD), to analyze the involvement of these enzymes in such situations. Plasma APN was distinguished as sensitive (PSA) (K(m) = 7.8 x 10(-5) mol/l) and predominantly insensitive (APM) (K(m) = 21.6 x 10(-5) mol/l) to puromycin, whereas DPPIV was sensitive (DPPIV-DS) (K(m) = 0.24 x 10(-5) mol/l) and predominantly insensitive (DPPIV-DI) (K(m) = 7.04 x 10(-5) mol/l) to diprotin A. Although unchanged in the MSG and food-deprived animals, APM activity levels were closely correlated with body mass, Lee index, and mass of retroperitoneal fat pad in the food deprived, but not in the MSG animals. DPPIV-DI activity levels decreased by 33% and were correlated with body mass, Lee index, and mass of periepididymal fat pad in the food-deprived MSG rats. These data suggest that APM and DPPIV-DI are respectively related to the downregulation of somatostatin in food-deprived rats, and to the recovery of energy balance in MSG obese rats during food deprivation.

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Protein (western blotting) and gene (PCR) expressions, catalytic activity of puromycin-insensitive membrane-bound neutral aminopeptidase (APM/CD13) and in situ regional distribution of CD13 and FOS immunoreactivity (it) were evaluated in the hypothalamus of monosodium glutamate obese (MSG) and/or food deprived (FD) rats in order to investigate their possible interplay with metabolic functions. Variations in protein and gene expressions of CD13 relative to controls coincided in the hypothalamus of MSG and MSG-FD (decreased 2- to 17-fold). Compared with controls, the reduction of hypothalamic CD13 content reflected a negative balance in its regional distribution in the supraoptic, paraventricular, periventricular and arcuate nuclei. CD13-ir increased in the supraoptic nucleus in MSG (2.5-fold) and decreased in the paraventricular nucleus (2-fold) together with FOS-ir (1.5-fold) in FD. In MSG-FD. FOS-ir decreased (7-fold) in the paraventricular nucleus, while CD13-ir decreased in the periventricular (5.6-fold) and the arcuate (3.7-fold) nuclei. It was noteworthy that all these changes of CD13 were not related to catalytic activity of APM. Data suggested that hypothalamic CD13 plays a role in the regulation of energy metabolism not by means of APM enzyme activity. (c) 2010 Elsevier B.V. All rights reserved.