882 resultados para Environment with multiple obstacles


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Objectives: To determine the contribution of the AcrAB efflux system to cyclohexane tolerance in Salmonella enterica. Methods: The expression of the efflux pump gene, acrB, and regulators marA and soxS from 46 isolates of S. enterica of 14 different serovars was determined by comparative RT-PCR and denaturing HPLC analysis. Results: Twenty-one of the 46 isolates were cyclohexane tolerant, a phenotype associated with multiple antibiotic resistance (MAR) and overexpression of efflux pumps. Of the cyclohexane-tolerant isolates 81% were MAR, whereas only 44% of the cyclohexane-susceptible isolates were MAR, confirming the association between cyclohexane tolerance and MAR. However, there was no correlation between cyclohexane tolerance or MAR and overexpression of acrB, soxS or marA. Conclusions: These data suggest that cyclohexane tolerance in S. enterica can be mediated by an acrB-independent mechanism.

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• Objectives The objective of this paper is to propose a framework for mapping the sustainable development and poverty alleviation impacts of social and environmental enterprises in Africa. This framework is then piloted with reference to an East African Ecobusiness. • Prior Work This paper is based on data collected as part of a wider research project examining social and environmental enterprises across the 19 countries of Southern and Eastern Africa. In total, the sustainable development and poverty alleviation impacts of 20 in-depth case studies in 4 countries are being examined. • Approach Data was collected using in-depth interviews with multiple stakeholders associated with the case study business. Secondary materials were also analysed and a quantitative survey of customers undertaken. • Results In addition to their impacts on the environment, African eco businesses can also have substantial social, economic and wider poverty alleviation impacts. This paper maps the impacts of a case study East African ecobusiness, as part of developing a social and environmental enterprise impact framework for Africa and the wider developing world. In our case study, positive and negative impacts are identified, while questions are raised in relation to tradeoffs between social and environmental objectives and temporal dimensions of impact. The usefulness of existing frameworks for understanding the social, environmental and development impacts of these kinds of organisations are also considered. • Implications This paper outlines the necessity of building an African-centric impact map to capture the multi-level poverty alleviation and sustainable development impacts of social and environmental enterprise activity in developing world environments. The framework proposed also offers guidance to businesses operating in Africa about the factors that might be considered as part of their wider social and environmental responsibilities. • Value Assessing the impact of social and environmental enterprises, especially as a route to development within low income countries, is receiving increasing attention in academia and beyond. This paper presents a useful contribution to the scarce literature on social and environmental enterprises in Africa.

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Planning of autonomous vehicles in the absence of speed lanes is a less-researched problem. However, it is an important step toward extending the possibility of autonomous vehicles to countries where speed lanes are not followed. The advantages of having nonlane-oriented traffic include larger traffic bandwidth and more overtaking, which are features that are highlighted when vehicles vary in terms of speed and size. In the most general case, the road would be filled with a complex grid of static obstacles and vehicles of varying speeds. The optimal travel plan consists of a set of maneuvers that enables a vehicle to avoid obstacles and to overtake vehicles in an optimal manner and, in turn, enable other vehicles to overtake. The desired characteristics of this planning scenario include near completeness and near optimality in real time with an unstructured environment, with vehicles essentially displaying a high degree of cooperation and enabling every possible(safe) overtaking procedure to be completed as soon as possible. Challenges addressed in this paper include a (fast) method for initial path generation using an elastic strip, (re-)defining the notion of completeness specific to the problem, and inducing the notion of cooperation in the elastic strip. Using this approach, vehicular behaviors of overtaking, cooperation, vehicle following,obstacle avoidance, etc., are demonstrated.

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Some recent winters in Western Europe have been characterized by the occurrence of multiple extratropical cyclones following a similar path. The occurrence of such cyclone clusters leads to large socio-economic impacts due to damaging winds, storm surges, and floods. Recent studies have statistically characterized the clustering of extratropical cyclones over the North Atlantic and Europe and hypothesized potential physical mechanisms responsible for their formation. Here we analyze 4 months characterized by multiple cyclones over Western Europe (February 1990, January 1993, December 1999, and January 2007). The evolution of the eddy driven jet stream, Rossby wave-breaking, and upstream/downstream cyclone development are investigated to infer the role of the large-scale flow and to determine if clustered cyclones are related to each other. Results suggest that optimal conditions for the occurrence of cyclone clusters are provided by a recurrent extension of an intensified eddy driven jet toward Western Europe lasting at least 1 week. Multiple Rossby wave-breaking occurrences on both the poleward and equatorward flanks of the jet contribute to the development of these anomalous large-scale conditions. The analysis of the daily weather charts reveals that upstream cyclone development (secondary cyclogenesis, where new cyclones are generated on the trailing fronts of mature cyclones) is strongly related to cyclone clustering, with multiple cyclones developing on a single jet streak. The present analysis permits a deeper understanding of the physical reasons leading to the occurrence of cyclone families over the North Atlantic, enabling a better estimation of the associated cumulative risk over Europe.

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This paper aims at two different contributions to the literature on international environmental agreements. First, we model environmental agreements as a generic situation, characterized as a Hawk-Dove game with multiple asymmetric equilibria. Second, the article applies the theory on non-cooperative games with confirmed proposals, based on an alternating proposals bargaining protocol, as a way of overcoming the usual problems of coordination and bargaining failures in environmental agreement games, due to payoff asymmetry and equilibrium multiplicity.

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Purpose. To describe the occurrence of self-reported problems of accessibility to health services used by persons with disabilities in terms of social and health services variables. Methods. We performed a cross-sectional household survey designed to assess problems with accessibility to health services faced by persons with disabilities. We interviewed 333 persons in Sao Paulo city, in 2007. Variables related to the presence of accessibility problems, disabilities, gender, age, family head income, ethnicity, use of health services and others were analysed using frequencies, percentages, chi(2)-test, ANOVA and Poisson regression models. Results. 15.92% of the interviewed persons reported problems with accessibility to health services. Persons having multiple (prevalence ratios; PR = 2.91) or mobility disability (PR = 6.46) had more problems with accessibility than persons with hearing disability. Persons younger than 78 years old had more problems with accessibility; those who needed help to go to the health service (PR = 3.01) also. Conclusions. Persons with multiple or mobility disability, younger than 78 years, and those who needed help of others to go to the health service were more likely to have problems with accessibility to health services. This information could be one of the first steps to the management and/or planning of appropriate health services for persons with disabilities.

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In this study, we describe the first survey in Thailand of Trypanosoma theileri, a widespread and prevalent parasite of cattle that is transmitted by tabanid flies. Investigation of 210 bovine blood samples of Thai cattle from six farms by hematocrit centrifuge technique (HCT) revealed 14 samples with trypanosomes morphologically compatible to T. theileri. Additional animals were positive for T. theileri by PCR based on the Cathepsin L-like sequence (TthCATL-PCR) despite negative by HCT, indicating cryptic infections. Results revealed a prevalence of 26 +/- 15% (95% CI) of T. theileri infection. Additionally, 12 samples positive for T. theileri were detected in cattle from other 11 farms. From a total of 30 blood samples positive by HCT and/or PCR from 17 farms, seven were characterized to evaluate the genetic polymorphism of T. theileri through sequence analysis of PCR-amplified CATL DNA sequences. All CATL sequences of T. theileri from Thai cattle clustered with sequences of the previously described phylogenetic lineages TthI and TthII, supporting only two major lineages of T. theileri in cattle around the world. However, 11 of the 29 CATL sequences analyzed showed to be different, disclosing an unexpectedly large polymorphic genetic repertoire, with multiple genotypes of T. theileri not previously described in other countries circulating in Thai cattle. (C) 2011 Elsevier B.V. All rights reserved.

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The integration of nanostructured films containing biomolecules and silicon-based technologies is a promising direction for reaching miniaturized biosensors that exhibit high sensitivity and selectivity. A challenge, however, is to avoid cross talk among sensing units in an array with multiple sensors located on a small area. In this letter, we describe an array of 16 sensing units, of a light-addressable potentiometric sensor (LAPS), which was made with layer-by-Layer (LbL) films of a poly(amidomine) dendrimer (PAMAM) and single-walled carbon nanotubes (SWNTs), coated with a layer of the enzyme penicillinase. A visual inspection of the data from constant-current measurements with liquid samples containing distinct concentrations of penicillin, glucose, or a buffer indicated a possible cross talk between units that contained penicillinase and those that did not. With the use of multidimensional data projection techniques, normally employed in information Visualization methods, we managed to distinguish the results from the modified LAPS, even in cases where the units were adjacent to each other. Furthermore, the plots generated with the interactive document map (IDMAP) projection technique enabled the distinction of the different concentrations of penicillin, from 5 mmol L(-1) down to 0.5 mmol L(-1). Data visualization also confirmed the enhanced performance of the sensing units containing carbon nanotubes, consistent with the analysis of results for LAPS sensors. The use of visual analytics, as with projection methods, may be essential to handle a large amount of data generated in multiple sensor arrays to achieve high performance in miniaturized systems.

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5-(4-(N-tert-Butyl-N-aminoxylphenyl)) pyrimidine (RL, 4PPN) forms crystallographically isostructural and isomorphic pseudo-octahedral M(RL)(2)(hfac)(2) complexes with M(hfac)(2), M = Zn, Cu, Ni, Co, and Mn. Multiple close contacts occur between sites of significant spin density of the organic radical units. Magnetic behavior of the Zn, Cu, Ni, Co complexes appears to involve multiple exchange pathways, with multiple close crystallographic contacts between sites that EPR (of 4PPN) indicates to have observable spin density. Powder EPR spectra at room temperature and low temperature are reported for each complex. Near room temperature, the magnetic moments of the complexes are roughly equal to those expected by a sum of non-interacting moments (two radicals plus ion). As temperature decreases, AFM exchange interactions become evident in all of the complexes. The closest fits to the magnetic data were found for a 1-D Heisenberg AFM chain model in the Zn(II) complex (J/k = (-)7 K), and for three-spin RL-M-RL exchange in the other complexes (J/k = (-)26 K, (-)3 K, (-) 6 K, for Cu(II), Ni(II), and Co(II) complexes, respectively). (C) 2008 Elsevier B.V. All rights reserved.

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Background Somali-born women constitute one of the largest groups of childbearing refugee women in Sweden after more than two decades of political violence in Somalia. In Sweden, these women encounter antenatal care that includes routine questions about violence being asked. The aim of the study was to explore how Somali-born women understand and relate to violence and wellbeing during their migration transition and their views on being approached with questions about violence in Swedish antenatal care. Method Qualitative interviews (22) with Somali-born women (17) living in Sweden were conducted and analysed using thematic analysis. Findings A balancing actbetween keeping private life private and the new welfare system was identified, where the midwife's questions about violence were met with hesitance. The midwife was, however, considered a resource for access to support services in the new society. A focus on pragmatic strategies to move on in life, rather than dwelling on potential experiences of violence and related traumas, was prominent. Social networks, spiritual faith and motherhood were crucial for regaining coherence in the aftermath of war. Dialogue and mutual adjustments were identified as strategies used to overcome power tensions in intimate relationships undergoing transition. Conclusions If confidentiality and links between violence and health are explained and clarified during the care encounter, screening for violence can be more beneficial in relation to Somali-born women. The focus on “moving on” and rationality indicates strength and access to alternative resources, but needs to be balanced against risks for hidden needs in care encounters. A care environment with continuity of care and trustful relationships enhances possibilities for the midwife to balance these dual perspectives and identify potential needs. Collaborations between Somali communities, maternity care and social service providers can contribute with support to families in transition and bridge gaps to formal social and care services.

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Application of optimization algorithm to PDE modeling groundwater remediation can greatly reduce remediation cost. However, groundwater remediation analysis requires a computational expensive simulation, therefore, effective parallel optimization could potentially greatly reduce computational expense. The optimization algorithm used in this research is Parallel Stochastic radial basis function. This is designed for global optimization of computationally expensive functions with multiple local optima and it does not require derivatives. In each iteration of the algorithm, an RBF is updated based on all the evaluated points in order to approximate expensive function. Then the new RBF surface is used to generate the next set of points, which will be distributed to multiple processors for evaluation. The criteria of selection of next function evaluation points are estimated function value and distance from all the points known. Algorithms created for serial computing are not necessarily efficient in parallel so Parallel Stochastic RBF is different algorithm from its serial ancestor. The application for two Groundwater Superfund Remediation sites, Umatilla Chemical Depot, and Former Blaine Naval Ammunition Depot. In the study, the formulation adopted treats pumping rates as decision variables in order to remove plume of contaminated groundwater. Groundwater flow and contamination transport is simulated with MODFLOW-MT3DMS. For both problems, computation takes a large amount of CPU time, especially for Blaine problem, which requires nearly fifty minutes for a simulation for a single set of decision variables. Thus, efficient algorithm and powerful computing resource are essential in both cases. The results are discussed in terms of parallel computing metrics i.e. speedup and efficiency. We find that with use of up to 24 parallel processors, the results of the parallel Stochastic RBF algorithm are excellent with speed up efficiencies close to or exceeding 100%.

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O estudo descrito neste relato de pesquisa concentra-se na busca por compreender os mecanismos pelos quais o capital intelectual de empresas participantes em redes estratégicas empresariais é afetado pelo capital social desenvolvido no âmbito dessas redes. O autor procura demonstrar, com base em um estudo de caso com múltiplas unidades de análise, realizado na mineradora multinacional Yamana Gold Inc., que, como as redes representam comunidades pautadas por regras de conduta pré-acordadas, mútuo comprometimento entre os seus participantes e compartilhamentos de recursos físicos e conhecimento, não raro, as empresas participantes desenvolvem processos sinérgicos e processos de colaboração interempresarial, trazendo, para o ambiente de interação, elementos que constroem novas competências para os participantes. Esses processos colaborativos favorecem os processos cognitivos, com impacto direto sobre a formação de capital intelectual individual das empresas, em especial as empresas focais, aquelas que lideram os padrões ou concentram a dominância econômica sobre os processos da rede. O estudo resultou na elaboração de um modelo teórico capaz de demonstrar os elementos do capital social das redes que afetam positivamente o capital intelectual da empresas e, por meio de entrevistas e observações de campo, o modelo pode ser testado e operacionalizado para comprovar a tese defendida pelo autor. O estudo traz importantes esclarecimentos sobre como esses elementos propiciam o surgimento de capital intelectual, com implicações práticas e teóricas.

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Access has been one of the main difficulties companies have faced in emerging markets (PRAHALAD, 2005). The capillarity of the market, the existence of small, not professionalized and sometimes informal retailers, the lack of infrastructure and high transportation costs are some of the distribution challenges companies face in poorer regions. The literature concerning the Base of the Pyramid (BoP) is still recent and only after the seminal article by Prahalad and Hart (2002), it evolved into many different management perspectives. However, there is a lack of researches concerning distribution strategies to the BoP. Therefore, the main objective of this research is to identify, in the perception of executives working in the market, the conditions associated to a satisfactory distribution for the BoP market in Brazil and to build a substantive theory that helps to shed light to the understanding of the distribution phenomenon adopted by consumer goods companies to reach the BoP market in Brazil. In order to accomplish the objectives of this thesis, a grounded theory methodology (Glaser; Strauss, 1967; Corbin; Strauss, 2008) was used. This approach helped to identify the channel strategies used by local and global companies in the market. Many techniques for data collection were applied. The most important one was in-depth interviews with 26 executives from 24 different consumer goods companies in Brazil. Among the companies there were small, medium and large enterprises; which were also grouped as manufacturers, distributors and retailers. Furthermore, secondary data were examined to identify business strategies to reach BoP and map global distribution initiatives. A database from a consumer panel was also used to analyze what and where BoP consumers purchase non-durable goods. It was verified that small and traditional retailing is a very strong format in BoP markets and in the Northern/Northeastern regions. Cash & Carry is a format that is growing a lot. On the other hand, hypermarkets are not very used by low income population. The results suggest that three major categories are associated to a satisfactory distribution: (a) willingness, which means the effort, knowledge and enthusiasm a firm has to operate at BoP markets; (b) well-done execution, which is related to designing correctly the marketing channel and operating efficiently in an environment full of obstacles, such as lack of infrastructure, capillarity, lack of safety, regional differences and informality, and (c) relationship, which was perceived to be friendlier and essential at BoP markets, since it is very difficult for manufacturers to reach the entire market alone. It is more likely to have a satisfactory distribution when manufacturers establish strong relationships in the marketing channel. Besides, small retailers have a perception of isolation and expect a higher level of relationship. These major categories explain also the competitive advantage that local companies have in relation to MNCs and large companies. Despite of the limitations of an exploratory study, it is expected that this thesis will contribute to the BoP knowledge as well as to the identification of the peculiarities of distribution in BoP markets.

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A presente dissertação procura identificar a maneira pela qual a problemática da mulher afeta o magistério, majoritariamente feminino, analisando a partir dai, as dificuldades que se apresentam para uma real transformação da escola pública. No movimento das contradições que povoam a Escola em nosso Estado, a questão feminina se faz presente como uma das determinantes, para a super! ção ou não, do conservadorismo que tão bem caracteriza ainda esta Escola Pública proveniente do Brasil Republicano. O histórico da condição feminina através dos séculos denota toda uma· luta pelo seu direito ã esfera pública, principalmente pelo trabalho. Isto demonstra que o "aprisionamento" feminino, na esfera privada,nada tem a ver com caracteres biológicos, mas sim com múltiplas determinações políticas, sociais e econômicas de cada sociedade, em dado momento histórico. E tal "aprisionamento" será uma das dificuldades da mulher-professora em se constituir como profissional consciente, atuando, de forma critica, para a me lnoria de nossa Escola. Nas últimas décadas (de 60 para cá), percebemos todo um movimento de rebeldia que originará lideranças femininas, lutando, não apenas pela libertação das mulheres, mas também por transformações profundas em nossa Escola e na sociedade como um todo. A presença petrificada da MULHER na história oficial brasileira, como mucama, sinhá-moça, escrava ou professorinha, já aponta, hoje, possibilidades de mudança no horizonte de construção de uma NOVA MULHER, sujeito de sua própria história, profissional competente e militante política. Esta NOVA PROFESSORA, não mais será a "tia ou a "professorinha" e sim, finalmente, CIDADÃ ... TORNANDO-SE MULHER (Beauvoir).

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Esta tese busca analisar a atuação de burocracias na implementação de políticas públicas em um ambiente de múltiplios principals, stakeholders e agentes, por meio de um estudo de caso sobre a regulação federal de agrotóxicos, atribuída a três órgãos distintos – MAPA, ANVISA e IBAMA. O referencial teórico foi construído a partir das teorias de controle político da burocracia, teorias de fontes do poder burocrático e da literatura sobre implementação de políticas públicas. O formato da legislação e o nível de complexidade da política dão aos órgãos atribuições exclusivas e inúmeros espaços de autonomia, ao mesmo tempo em que lhes obriga a decidir de forma consensuada. As burocracias adotam diversas estratégias para minimizar a assimetria de informação e o risco moral por parte do setor regulado. Os principals políticos se valem de diversos instrumentos para impor suas preferências, mas o fazem de forma superficial ou esporádica. A baixa efetividade desta influência é explicada mais pelas limitações dos principals do que pela resistência dos agentes. Poder Judiciário e Ministério Público podem ser importantes parceiros ou pontos de veto à ação regulatória dos órgãos. O estilo de liderança dos gestores e a visão sobre qual deve ser o papel da burocracia em uma política regulatória explicam as diferenças observadas nos órgãos no tocante à busca de alianças e à ação estratégica perante os demais atores.