836 resultados para carrying capacity, population, limits, sustainability, planning, resilience


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The survival, absolute population size, gonotrophic cycle duration, and temporal and spatial abundance of Nyssomyia neivai (Pinto) were studied in a rural area endemic for American cutaneous leishmaniasis (ACL) in Conchal, Sao Paulo State, southeastern Brazil, using mark-release-recapture techniques and by monitoring population fluctuation. The monthly abundance exhibited a unimodal pattern, with forest and domicile habitats having the highest relative abundances. A total of 1,873 males and 3,557 females were marked and released during the six experiments, of which 4.1-13.0% of males and 4.1-11.8% of females were recaptured. Daily survivorship estimated from the decline in recaptures per day was 0.681 for males and 0.667 for females. Gonotrophic cycle duration was estimated to be 4.0 d. Absolute population size was calculated using the Lincoln Index and ranged from 861 to 4,612 males and from 2,187 to 19,739 females. The low proportion of females that reach the age when they are potentially infective suggests that N. neivai has a low biological capacity to serve as a vector and that factors such as high biting rates and opportunistic feeding behavior would be needed to enable Leishmania (Viannia) braziliensis Vianna transmission. This agreed with the epidemiological pattern of ACL in southeastern Brazil that is characterized by low incidence, with isolated cases acquired principally within domiciliary habitats.

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Most amphibian species have biphasic life histories and undergo an ontogenetic shift from aquatic to terrestrial habitats. In deforested landscapes, streams and forest fragments are frequently disjunct, jeopardizing the life cycle of forest-associated amphibians with aquatic larvae. We tested the impact of habitat split-defined as human-induced disconnection between habitats used by different life-history stages of a species-on four forest-associated amphibian species in a severely fragmented landscape of the Brazilian Atlantic Forest. We surveyed amphibians in forest fragments with and without streams (referred to as wet and dry fragments, respectively), including the adjacent grass-field matrix. Our comparison of capture rates in dry fragments and nearby streams in the matrix allowed us to evaluate the number of individuals that engaged in high-risk migrations through nonforested habitats. Adult amphibians moved from dry fragments to matrix streams at the beginning of the rainy season, reproduced, and returned at the end of the breeding period. Juveniles of the year moved to dry fragments along with adults. These risky reproductive migrations through nonforested habitats that expose individuals to dehydration, predation, and other hazards may cause population declines in dry fragments. Indeed, capture rates were significantly lower in dry fragments compared with wet fragments. Declining amphibians would strongly benefit from investments in the conservation and restoration of riparian vegetation and corridors linking breeding and nonbreeding areas.

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One of the main consequences of habitat loss and fragmentation is the increase in patch isolation and the consequent decrease in landscape connectivity. In this context, species persistence depends on their responses to this new landscape configuration, particularly on their capacity to move through the interhabitat matrix. Here, we aimed first to determine gap-crossing probabilities related to different gap widths for two forest birds (Thamnophilus caerulescens, Thamnophilidae, and Basileuterus culicivorus, Parulidae) from the Brazilian Atlantic rainforest. These values were defined with a playback technique and then used in analyses based on graph theory to determine functional connections among forest patches. Both species were capable of crossing forest gaps between patches, and these movements were related to gap width. The probability of crossing 40 m gaps was 50% for both species. This probability falls to 10% when the gaps are 60 m (for B. culicivorus) or 80 m (for T caerulescens). Actually, birds responded to stimulation about two times more distant inside forest trials (control) than in gap-crossing trials. Models that included gap-crossing capacity improved the explanatory power of species abundance variation in comparison to strictly structural models based merely on patch area and distance measurements. These results highlighted that even very simple functional connectivity measurements related to gap-crossing capacity can improve the understanding of the effect of habitat fragmentation on bird occurrence and abundance.

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J.A. Ferreira Neto, E.C. Santos Junior, U. Fra Paleo, D. Miranda Barros, and M.C.O. Moreira. 2011. Optimal subdivision of land in agrarian reform projects: an analysis using genetic algorithms. Cien. Inv. Agr. 38(2): 169-178. The objective of this manuscript is to develop a new procedure to achieve optimal land subdivision using genetic algorithms (GA). The genetic algorithm was tested in the rural settlement of Veredas, located in Minas Gerais, Brazil. This implementation was based on the land aptitude and its productivity index. The sequence of tests in the study was carried out in two areas with eight different agricultural aptitude classes, including one area of 391.88 ha subdivided into 12 lots and another of 404.1763 ha subdivided into 14 lots. The effectiveness of the method was measured using the shunting line standard value of a parceled area lot`s productivity index. To evaluate each parameter, a sequence of 15 calculations was performed to record the best individual fitness average (MMI) found for each parameter variation. The best parameter combination found in testing and used to generate the new parceling with the GA was the following: 320 as the generation number, a population of 40 individuals, 0.8 mutation tax, and a 0.3 renewal tax. The solution generated rather homogeneous lots in terms of productive capacity.

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Prediction of random effects is an important problem with expanding applications. In the simplest context, the problem corresponds to prediction of the latent value (the mean) of a realized cluster selected via two-stage sampling. Recently, Stanek and Singer [Predicting random effects from finite population clustered samples with response error. J. Amer. Statist. Assoc. 99, 119-130] developed best linear unbiased predictors (BLUP) under a finite population mixed model that outperform BLUPs from mixed models and superpopulation models. Their setup, however, does not allow for unequally sized clusters. To overcome this drawback, we consider an expanded finite population mixed model based on a larger set of random variables that span a higher dimensional space than those typically applied to such problems. We show that BLUPs for linear combinations of the realized cluster means derived under such a model have considerably smaller mean squared error (MSE) than those obtained from mixed models, superpopulation models, and finite population mixed models. We motivate our general approach by an example developed for two-stage cluster sampling and show that it faithfully captures the stochastic aspects of sampling in the problem. We also consider simulation studies to illustrate the increased accuracy of the BLUP obtained under the expanded finite population mixed model. (C) 2007 Elsevier B.V. All rights reserved.

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This thesis focuses on identifying hindrances of achieving a sustainable tourism development on a base of a World Heritage Site. Using a case study of the World Heritage Site Falun Great Copper Mountain, the thesis assesses the situational context by using qualitative methods. Five semi- structured interviews with influential stakeholders were conducted to get an inside view of the current situation and to identify site-specific issues. The thesis identifies a number of factors that determine the successful implementation of measures leading towards sustainable tourism in the long-run; the most important being the lack of clear guidelines for the whole destination and no holistic planning approach within the municipality. The thesis concludes that despite the increased pressures towards establishment of sustainable tourism, the concept remains challenging to operationalize for the World Heritage Site without frameworks and tools from UNESCO.

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Background Pregnancy outcomes in the general population are important public health indicators. Purpose The overall aim of this study was to investigate the outcomes of reported pregnancies within a well-defined population, to identify risk groups for adverse pregnancy outcomes, and to suggest preventive measures. Method A prospective population-based cohort study of pregnant women in Bavi district, Vietnam between 1 January 1999 and 30 June 2004. Results Pregnancy outcome was reported for 5,259 cases; 4,152 (79%) resulted in a live birth, 67 (1.3%) in a stillbirth, 733 (14%) in an induced abortion, and 282 (5.4%) in a spontaneous abortion. There was an increased risk of home delivery for women from ethnic minorities (OR?=?1.85; 95%CI?=?1.06–3.24) or with less than 6 years of schooling (OR?=?7.36; 95%CI?=?3.54–15.30). The risk of stillbirth was increased for ethnic minorities (OR?=?6.34; 95%CI?=?1.33–30.29) and women delivering at home (OR?=?6.81; 95%CI?=?2.40–19.30). The risk of induced abortion increased with maternal age. Conclusion Our findings emphasize the public health significance of access to adequate family planning, counselling, and maternal health care for all women. Policies should specifically target women from high-risk groups.

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A escolha do tema ficou circunscrita ao subsetor de construção habitacional, que é caracterizado pela presença de pequenas e médias empresas. A consolidação de grandes empresas neste ramo de atividades tende a ocorrer sobretudo em conjunturas onde através da intervenção estatal são definidos programas habitacionais de grande escala que requerem das empresas participantes de maior volume de capital e o acesso a tecnologias mais sofisticadas. A importância da pequena empresa neste ramo de atividades pode ser notada atraves da experiência dos países da Comunidade Econômica Europeia, que em 1985 de um total de mais de um milhão de empresas de construção, 90% tinham até 10 empregados. Igual situação se verifica nos Estados Unidos da América onde conforme dados de 1965, também 90 % das 875.000 empresas então existentes no país empregavam menos de 10 pessoas (ONU, 1987). De uma maneira geral a importância do tema fica evidente quando se analisa o peso do setor da construção civil na economia nacional, que se situa em torno de 5% do PIB nos países industrializados, enquanto que nos países de industrialização recente, este percentual pode atingir o índice de 7% (PNU, op.cit.). Tal constatação evidencia que a indústria da construção representa o principal item na composição dos investimentos (formação bruta de capital fixo) das contas nacionais de diversos países, apresentando uma participação relativa quase sempre superior a 55% nos países industrializados e 60% nos países de industrialização recente (ONU, op.cit.). No Brasil tal importância se confirma pelo valor adicionado do setor habitacional correspondente a 2,2% do PIB, e numa visão mais abrangente, dentro dos contornos da indústria da construção civil como um todo, representando cerca de 7,3% do PIB (FIBGE, 1988). Quanto a questão da mão-de-obra, em que pese a ausência de dados no Brasil, e bastante visível sua larga influência na economia atuando como um ramo de atividades multiplicador de alocação de pessoal, principalmente a nível de utilização intensiva de mão-de-obra menos qualificada. Enquanto nos EEUU e CEE 90% das empresas constituíam-se de organizações com menos de 10 empregados, no Brasil onde há ausência de dados oficiais a respeito, na pior das hipóteses pode-se estimar que este percentual pode variar entre 50 a 70% do total de empresas, o que não deixa de ser um dado de extrema magnitude. Foram exatamente a expressão destes números, sem considerar o déficit habitacional em torno de 10 milhões de pessoas, um terço da população, moram em condições inadequadas (Exame, 1991), que influenciaram fortemente a escolha do tema da presente proposta de Tese.

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The rapid growth of urban areas has a significant impact on traffic and transportation systems. New management policies and planning strategies are clearly necessary to cope with the more than ever limited capacity of existing road networks. The concept of Intelligent Transportation System (ITS) arises in this scenario; rather than attempting to increase road capacity by means of physical modifications to the infrastructure, the premise of ITS relies on the use of advanced communication and computer technologies to handle today’s traffic and transportation facilities. Influencing users’ behaviour patterns is a challenge that has stimulated much research in the ITS field, where human factors start gaining great importance to modelling, simulating, and assessing such an innovative approach. This work is aimed at using Multi-agent Systems (MAS) to represent the traffic and transportation systems in the light of the new performance measures brought about by ITS technologies. Agent features have good potentialities to represent those components of a system that are geographically and functionally distributed, such as most components in traffic and transportation. A BDI (beliefs, desires, and intentions) architecture is presented as an alternative to traditional models used to represent the driver behaviour within microscopic simulation allowing for an explicit representation of users’ mental states. Basic concepts of ITS and MAS are presented, as well as some application examples related to the subject. This has motivated the extension of an existing microscopic simulation framework to incorporate MAS features to enhance the representation of drivers. This way demand is generated from a population of agents as the result of their decisions on route and departure time, on a daily basis. The extended simulation model that now supports the interaction of BDI driver agents was effectively implemented, and different experiments were performed to test this approach in commuter scenarios. MAS provides a process-driven approach that fosters the easy construction of modular, robust, and scalable models, characteristics that lack in former result-driven approaches. Its abstraction premises allow for a closer association between the model and its practical implementation. Uncertainty and variability are addressed in a straightforward manner, as an easier representation of humanlike behaviours within the driver structure is provided by cognitive architectures, such as the BDI approach used in this work. This way MAS extends microscopic simulation of traffic to better address the complexity inherent in ITS technologies.

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O cenário geopolítico global de desenvolvimento assimétrico e novas fontes de energia constituem um desafio para a sustentabilidade organizacional, requerendo organizações com capacidade de adaptação a ambientes turbulentos. Os principais aspectos que afetam a sobrevivência das empresas de energia podem ser categorizados em geopolíticos, econômicos, sociais, tecnológicos, legais, ambientais, de segurança, de energia e administrativos. Esta tese doutoral apresenta um modelo de organizações com capacidade de adaptação a ambientes turbulentos que permite à empresa atingir sustentabilidade no tempo, como resposta à pergunta de partida. Essa pergunta procura as características determinantes de um modelo de organização adaptável, considerando o setor energético brasileiro, no cenário geopolítico global de desenvolvimento assimétrico e novas fontes de energia, segundo a percepção de gestores. A metodologia adotada tomou por base a Grounded Theory apoiada pelo software Atlas/ti e aplicada a entrevistas em profundidade. O método utilizado permitiu construir a teoria indutivamente, com base em categorias, propriedades e dimensões. O modelo proposto emergiu da pesquisa configurando a capacidade de adaptação aos cenários turbulentos para atingir sustentabilidade organizacional como fundamentada nas categorias de Planejamento Prospectivo, Sistemas Adaptativos e Integração Estrutural, identificando as propriedades e dimensões requeridas em cada uma dessas categorias.

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Gestão ética, socioambiental e de saúde

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o presente trabalho tem como objetivo a avaliação da capacidade do behaviorismo radical skinneriano'para fundamentar aplicações práticas dotadas de efetiva relevância humana e social, assim definidas em' função do caráter politicamente progressista e democratizante que se lhes possa imprimir. Essa avaliação é desenvolvida através de dois distintos, mas interrelacionados, procedimentos acadêmicos: uma argumentação discursiva baseada em pesquisa bibliográfica pertinente, que se complementapor um estudo empírico de campo a nível exploratório. A apreciação discursiva do behaviorismo radical é inicialmente conduzida sob uma perspectiva histórico-acadêmica, cujo foco contínuo de referência é o próprio agente individual basicamente responsável pelo gradativo processo de constituição desse sistema científico - B. F. Skinner. Em uma da etapa, o behaviorismo radical vem a ser discutido deforma mais impessoalizada, contra os sucessivos panos de fundo da filosofia da ciência, das relações sociais humanas e da ética implicada nas intervenções práticas sobre tais relações. O estudo exploratório, que então-se segue, consiste no julgamento da utilidade potencial de um instrumento de educação política popular, elaborado previamente a partir dos princípios behavioristas radicais básicos e seus desdobramentos psicossociológicos, e destinado a uma clientela sócio-economicamente desprivi1egiada, constituída de indivíduos adultos, de ambos os sexos, com escolaridade 'em torno do 19 grau completo. A avaliação dessa Cartilha de Contracontole Social através de entrevistas semi-estruturadas e um breve questionário objetivo, por quatorze lnformantes - qualificados em termos de sua 1iderança e/ou militância em associações de moradores de bairros e de favelas, sindicatos de trabalhadores, núcleos comunitários re1igiosos, entidades assistenciais autônomas e associações de servidores em organizações de trabalho - vem a apresentar, em linhas gerais, resultados muito positivos. A iniciativa é considerada extremamente séria e responsável; e o conteúdo da Carti1ha, bastante compatível com os objetivos desses movimentos populares, assim como muito útil para dotar as suas atividades de uma maior eficácia social. Evidencia-se, não obstante, uma restrição generalizada quanto à possibilidade de compreensão do texto por parte da população-alvo; o que deve, portanto, ensejar sua reformu1ação para o emprego em futuros projetos de prosseguimento dessa linha de pesquisa. Conclui-se, enfim, que a tese em seu todo parece apta a contribuir, se suficientemente divulgada, para a promoção de um maior interesse pelo behaviorismo de Skinner no âmbito acadêmico do Rio de Janeiro, bem como para a produção de um exercício mais eficaz de contracontro1e sobre as atuais práticas aversivas e/ou exploratórias de controle social.

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The literature has emphasized that absorptive capacity (AC) leads to performance, but in projects its influences still unclear. Additionally, the project success is not well understood by the literature, and AC can be an important mechanism to explain it. Therefore, the purpose of this study is to investigate the effect of absorptive capacity on project performance in the construction industry of São Paulo State. We study this influence through potential and realized absorptive capacity proposed by Zahra and George (2002). For achieving this goal, we use a combination of qualitative and quantitative research. The qualitative research is based on 15 interviews with project managers in different sectors to understand the main constructs and support the next quantitative phase. The content analysis was the technique used to analyze those interviews. In quantitative phase through a survey questionnaire, we collected 157 responses in the construction sector with project managers. The confirmatory factor analysis and hierarchical linear regression were the techniques used to assess the data. Our findings suggest that the realized absorptive capacity has a positive influence on performance, but potential absorptive capacity and the interactions effect have no influence on performance. Moreover, the planning and monitoring have a positive impact on budget and schedule, and customer satisfaction while risk coping capacity has a positive impact on business success. In academics terms, this research enables a better understanding of the importance of absorptive capacity in the construction industry and it confirms that knowledge application in processes and routines enhances performance. For management, the absorptive capacity enables the improvements of internal capabilities reflected in the increased project management efficiency. Indeed, when a company manages project practices efficiently it enhances business and project performance; however, it needs initially to improve its internal abilities to enrich processes and routines through relevant knowledge.

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The control of the spread of dengue fever by introduction of the intracellular parasitic bacterium Wolbachia in populations of the vector Aedes aegypti, is presently one of the most promising tools for eliminating dengue, in the absence of an efficient vaccine. The success of this operation requires locally careful planning to determine the adequate number of mosquitoes carrying the Wolbachia parasite that need to be introduced into the natural population. The latter are expected to eventually replace the Wolbachia-free population and guarantee permanent protection against the transmission of dengue to human. In this paper, we propose and analyze a model describing the fundamental aspects of the competition between mosquitoes carrying Wolbachia and mosquitoes free of the parasite. We then introduce a simple feedback control law to synthesize an introduction protocol, and prove that the population is guaranteed to converge to a stable equilibrium where the totality of mosquitoes carry Wolbachia. The techniques are based on the theory of monotone control systems, as developed after Angeli and Sontag. Due to bistability, the considered input-output system has multivalued static characteristics, but the existing results are unable to prove almost-global stabilization, and ad hoc analysis has to be conducted.

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The IT capability is a organizational ability to perform activities of this role more effectively and an important mechanism in creating value. Its building process (stages of creation and development) occurs through management initiatives for improvement in the performance of their activities, using human resources and IT assets complementary responsible for the evolution of their organizational routines. This research deals with the IT capabilities related to SIG (integrated institutional management systems), built and deployed in UFRN (Universidade Federal do Rio Grande do Norte) to realization and control of administrative, academic and human resources activities. Since 2009, through cooperative agreements with federal and educational institutions of direct administration, UFRN has supported the implementation of these systems, currently involving more than 30 institutions. The present study aims to understand how IT capabilities, relevant in the design, implementation and dissemination of SIG, were built over time. This is a single case study of qualitative and longitudinal nature, performed by capturing, coding and analysis from secondary data and from semi-structured interviews conducted primarily with members of Superintenência de Informática, organizational unit responsible for SIG systems in UFRN. As a result, the technical, of internal relationship and external cooperation capabilities were identified as relevant in the successful trajectory of SIG systems, which have evolved in different ways. The technical capacity, initiated in 2004, toured the stages of creation and development until it reached the stage of stability in 2013, due to technological limits. Regarding the internal relationship capability, begun in 2006, it toured the stages of creation and development, having extended its scope of activities in 2009, being in development since then. Unlike the standard life cycle observed in the literature, the external cooperation capability was initiated by an intensity of initiatives and developments in the routines in 2009, which were decreasing to cease in 2013 in order to stabilize the technological infrastructure already created for cooperative institutions. It was still identified the start of cooperation in 2009 as an important event selection, responsible for changing or creating trajectories of evolution in all three capacities. The most frequent improvements initiatives were of organizational nature and the internal planning activity has been transformed over the routines of the three capabilities. Important resources and complementary assets have been identified as important for the realization of initiatives, such as human resources technical knowledge to the technical capabilities and external cooperation, and business knowledge, for all of them, as well as IT assets: the iproject application for control of development processes, and the document repository wiki. All these resources and complementary assets grew along the capacities, demonstrating its strategic value to SINFO/UFRN