913 resultados para Resilience of communities
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The composition of species communities is changing rapidly through drivers such as habitat loss and climate change, with potentially serious consequences for the resilience of ecosystem functions on which humans depend. To assess such changes in resilience, we analyse trends in the frequency of species in Great Britain that provide key ecosystem functions-specifically decomposition, carbon sequestration, pollination, pest control and cultural values. For 4,424 species over four decades, there have been significant net declines among animal species that provide pollination, pest control and cultural values. Groups providing decomposition and carbon sequestration remain relatively stable, as fewer species are in decline and these are offset by large numbers of new arrivals into Great Britain. While there is general concern about degradation of a wide range of ecosystem functions, our results suggest actions should focus on particular functions for which there is evidence of substantial erosion of their resilience.
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In the past decades, social-ecological systems (SESs) worldwide have undergone dramatic transformations with often detrimental consequences for livelihoods. Although resilience thinking offers promising conceptual frameworks to understand SES transformations, empirical resilience assessments of real-world SESs are still rare because SES complexity requires integrating knowledge, theories, and approaches from different disciplines. Taking up this challenge, we empirically assess the resilience of a South African pastoral SES to drought using various methods from natural and social sciences. In the ecological subsystem, we analyze rangelands’ ability to buffer drought effects on forage provision, using soil and vegetation indicators. In the social subsystem, we assess households’ and communities’ capacities to mitigate drought effects, applying agronomic and institutional indicators and benchmarking against practices and institutions in traditional pastoral SESs. Our results indicate that a decoupling of livelihoods from livestock-generated income was initiated by government interventions in the 1930s. In the post-apartheid phase, minimum-input strategies of herd management were adopted, leading to a recovery of rangeland vegetation due to unintentionally reduced stocking densities. Because current livelihood security is mainly based on external monetary resources (pensions, child grants, and disability grants), household resilience to drought is higher than in historical phases. Our study is one of the first to use a truly multidisciplinary resilience assessment. Conflicting results from partial assessments underline that measuring narrow indicator sets may impede a deeper understanding of SES transformations. The results also imply that the resilience of contemporary, open SESs cannot be explained by an inward-looking approach because essential connections and drivers at other scales have become relevant in the globalized world. Our study thus has helped to identify pitfalls in empirical resilience assessment and to improve the conceptualization of SES dynamics.
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Indigenous communities have actively managed their environments for millennia using a diversity of resource use and conservation strategies. Clam gardens, ancient rock-walled intertidal beach terraces, represent one example of an early mariculture technology that may have been used to improve food security and confer resilience to coupled human-ocean systems. We surveyed a coastal landscape for evidence of past resource use and management to gain insight into ancient resource stewardship practices on the central coast of British Columbia, Canada. We found that clam gardens are embedded within a diverse portfolio of resource use and management strategies and were likely one component of a larger, complex resource management system. We compared clam diversity, density, recruitment, and biomass in three clam gardens and three unmodified nonwalled beaches. Evidence suggests that butter clams (Saxidomus gigantea) had 1.96 times the biomass and 2.44 times the density in clam gardens relative to unmodified beaches. This was due to a reduction in beach slope and thus an increase in the optimal tidal range where clams grow and survive best. The most pronounced differences in butter clam density between nonwalled beaches and clam gardens were found at high tidal elevations at the top of the beach. Finally, clam recruits (0.5-2 mm in length) tended to be greater in clam gardens compared to nonwalled beaches and may be attributed to the addition of shell hash by ancient people, which remains on the landscape today. As part of a broader social-ecological system, clam garden sites were among several modifications made by humans that collectively may have conferred resilience to past communities by providing reliable and diverse access to food resources.
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The Chesapeake Bay is out of balance. As the effects of decades of overharvesting, overdevelopment, and pollution have taken their toll, tidewater communities are confronted with a loss of culture, livelihood, and the environment in which they live. This thesis seeks to reframe the problem of regeneration of community and environment, through the use of resilient design. Resilient design is the process of designing for an uncertain at risk future. Through resilient design, architecture and aquaculture can be combined with food culture to foster stewardship of place. This thesis will explore interconnectedness of tidewater food culture, the waterman culture, aquaculture, and regenerative design in an effort to generate a holistic solution. The final product will consist of a methodology of planning for resilience at a framework scale, and will also propose an architectural solution that combines educational facilities with commercial aquaculture, to foster stewardship and regeneration in the Chesapeake Tidewater.
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In this paper we determine the local and global resilience of random graphs G(n,p) (p >> n(-1)) with respect to the property of containing a cycle of length at least (1 - alpha)n. Roughly speaking, given alpha > 0, we determine the smallest r(g) (G, alpha) with the property that almost surely every subgraph of G = G(n,p) having more than r(g) (G, alpha)vertical bar E(G)vertical bar edges contains a cycle of length at least (1 - alpha)n (global resilience). We also obtain, for alpha < 1/2, the smallest r(l) (G, alpha) such that any H subset of G having deg(H) (v) larger than r(l) (G, alpha) deg(G) (v) for all v is an element of V(G) contains a cycle of length at least (1 - alpha)n (local resilience). The results above are in fact proved in the more general setting of pseudorandom graphs.
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The purpose of this thesis is to study the impact of a port strike on companies that perform as logistic service providers in a supply chain (SC), here denominated 3PL (third-party logistic providers). These companies are highly dependent on ports to perform their activity, since they provide international services. Consequently, a disruption in a port can seriously impair their business. A stevedores’ strike is one of the possible disruptions that can affect ports. This study aims to analyze the negative effects caused by this disruption, and what strategies 3PLs may implement in order to keep their performance levels stable and have a quick recovery time. Within this objective, the first step will be to establish a theoretical context about the maritime port’s sector and 3PLs in a SC context, to then expand the concept of a resilient SC, and finally to develop a theoretical framework in order to better contextualize the case study. Subsequently, the impact of a port strike will be quantified by using a case study comprising three companies, covering the areas of land and sea distribution and port operations. Information from primary sources was assembled in two phases: first via e-mail and, in a second phase, through a personal interview. The information from secondary sources was obtained through television news, internet and conferences, enabling its cross-analysis. Finally, by analyzing the collected data, it will be possible to draw conclusions about the measures carried out by each company to minimize the negative effects of the strike, thus contributing to a more resilient SC. As a conclusion, a stevedores’ strike will create a snow-ball of negative effects in the SC, degrading all relevant KPIs (key performance indicators) of the 3PLs under study. No mitigation and contingency strategies available proved really effective to reduce the negative effects of a port strike disruption.
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Being a part of many radio stations' progra
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Dissertação de mestrado integrado em Engenharia Civil
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This study examines how structural determinants influence intermediary factors of child health inequities and how they operate through the communities where children live. In particular, we explore individual, family and community level characteristics associated with a composite indicator that quantitatively measures intermediary determinants of early childhood health in Colombia. We use data from the 2010 Colombian Demographic and Health Survey (DHS). Adopting the conceptual framework of the Commission on Social Determinants of Health (CSDH), three dimensions related to child health are represented in the index: behavioural factors, psychosocial factors and health system. In order to generate the weight of the variables and take into account the discrete nature of the data, principal component analysis (PCA) using polychoric correlations are employed in the index construction. Weighted multilevel models are used to examine community effects. The results show that the effect of household’s SES is attenuated when community characteristics are included, indicating the importance that the level of community development may have in mediating individual and family characteristics. The findings indicate that there is a significant variance in intermediary determinants of child health between-community, especially for those determinants linked to the health system, even after controlling for individual, family and community characteristics. These results likely reflect that whilst the community context can exert a greater influence on intermediary factors linked directly to health, in the case of psychosocial factors and the parent’s behaviours, the family context can be more important. This underlines the importance of distinguishing between community and family intervention programmes.
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PURPOSE: To investigate the effect of intraocular straylight (IOS) induced by white opacity filters (WOF) on threshold measurements for stimuli employed in three perimeters: standard automated perimetry (SAP), pulsar perimetry (PP) and the Moorfields motion displacement test (MDT).¦METHODS: Four healthy young (24-28 years old) observers were tested six times with each perimeter, each time with one of five different WOFs and once without, inducing various levels of IOS (from 10% to 200%). An increase in IOS was measured with a straylight meter. The change in sensitivity from baseline was normalized, allowing comparison of standardized (z) scores (change divided by the SD of normative values) for each instrument.¦RESULTS: SAP and PP thresholds were significantly affected (P < 0.001) by moderate to large increases in IOS (50%-200%). The drop in motion displacement (MD) from baseline with WOF 5, was approximately 5 dB, in both SAP and PP which represents a clinically significant loss; in contrast the change in MD with MDT was on average 1 minute of arc, which is not likely to indicate a clinically significant loss.¦CONCLUSIONS: The Moorfields MDT is more robust to the effects of additional straylight in comparison with SAP or PP.
A comparative study of the resilience of coal logistics chains in Australia, South Africa and Canada
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Au cours des dernières années l'industrie du charbon a connu un essor important. L'importance du charbon dans l'économie mondiale provient d'une demande mondiale soutenue et de niveaux de production en hausse constante. De ce fait, le nombre élevé d'importateurs et d'exportateurs est à l'origine d'un système d'échange complexe où la compétition est féroce. En effet, un nombre grandissant de pays importateurs se partagent les sources d'approvisionnement tandis qu'un nombre limité de pays exportateurs s'efforcent de répondre à la demande tout en essayant de s'accaparer le plus de parts du marché mondial. L'objectif de cette recherche s'inscrit dans ce contexte en démontrant les bénéfices associés aux chaînes logistiques résilientes pour tout acteur de l'industrie soucieux de devancer la compétition. Une analyse de la logistique de l'industrie du charbon permet entre autres de se pencher sur les questions suivantes: Comment les infrastructures influencent-elles la résilience d'une chaîne logistique? Quels risques est-ce que les catastrophes naturelles présentent pour une chaîne logistique? Comment la gouvernance influence-t-elle la résilience d'une chaîne logistique? Une chaîne logistique représente le trajet effectué par un bien ou produit au cours de son cycle de vie, du point d'origine au point de consommation. Ceci étant dit, le meilleur moyen de régler les problèmes inhérents aux chaînes logistiques est de maintenir de hauts niveaux de résilience. Cette recherche évaluera donc la résilience de chaînes logistiques du charbon des industries australienne, sud-africaine et canadienne. Pour ce faire, trois variables seront étudiées: les infrastructures, les catastrophes naturelles et la gouvernance. La comparaison des trois cas à l'étude se fera par un nombre défini d'indicateurs (12 au total) pour chacune des variables étudiées. Les résultats de cette recherche démontrent que la résilience des trois cas à l'étude se ressemble. Cependant, certaines chaînes logistiques détiennent des avantages comparatifs qui améliorent grandement leur résilience et leur compétitivité. Plusieurs sujets de recherche pourraient être utilisés pour compléter cette recherche. L'analyse comparative pourrait être appliquée à d'autres chaînes logistiques pour vérifier la viabilité des résultats. Une analyse semblable pourrait également être entreprise pour le secteur en aval de la chaîne logistique. Finalement, une méthodologie basée sur des interviews pourrait ajouter un regard différent sur les questions abordées.
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The point of departure for these reflections is life, since its protection is the central purpose encouraging the defense of human rights and of public health. Life in the Andes has an exceptional diversity. Particularly in Ecuador, my country, this diversity constitutes a characteristic sign that is expressed in two main forms: natural megadiversity and multiculturalism. Indeed, Ecuador’s small territory synthesizes practically all types of lifezones that exist on Earth, having received the gift of high average rates of solar energy and abundant nutritional sources, which have facilitated the natural reproduction of countless species that show their beautiful vitality in the variety of ecosystems that compose the Andean mountain range, the tropical plains, the Amazon humid forests, and the Galapagos Islands. But besides being a highly biodiverse country, it is also a plurinational and multi-cultural society, in which the activity of human beings, organized into social conglomerates of different historical and cultural backgrounds, have formed more than a dozen nations and peoples. Regrettably this natural and human wealth has not been able to bear its best fruits due to the violent operation of a deep social inequity – unfortunately also one of the highest in the Americas—which conspires against life and is reproduced in national and international inequitable relations. This structural inequity has changed its form throughout the centuries and currently has reached its highest and most perverse level of development.