295 resultados para optimistic
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Biological invasions are considered as one of the greatest threats to biodiversity, as they may lead to disruption and homogenization of natural communities, and in the worst case, to native species extinctions. The introduction of gene modified organisms (GMOs) to agricultural, fisheries and forestry practices brings them into contact with natural populations. GMOs may appear as new invasive species if they are able to (1) invade into natural habitats or (2) hybridize with their wild relatives. The benefits of GMOs, such as increased yield or decreased use of insecticides or herbicides in cultivation, may thus be reduced due the potential risks they may cause. A careful ecological risk analysis therefore has to precede any responsible GMO introduction. In this thesis I study ecological invasion in relation to GMOs, and what kind of consequences invasion may have in natural populations. A set of theoretical models that combine life-history evolution, population dynamics, and population genetics were developed for the hazard identification part of ecological risks assessment of GMOs. In addition, the potential benefits of GMOs in management of an invasive pest were analyzed. In the first study I showed that a population that is fluctuating due to scramble-type density dependence (due to, e.g., nutrient competition in plants) may be invaded by a population that is relatively more limited by a resource (e.g., light in plants) that is a cause of contest-type density dependence. This result emphasises the higher risk of invasion in unstable environments. The next two studies focused on escape of a growth hormone (GH) transgenic fish into a natural population. The results showed that previous models may have given too pessimistic a view of the so called Trojan gene -effect, where the invading genotype is harmful for the population as a whole. The previously suggested population extinctions did not occur in my studies, since the changes in mating preferences caused by the GH-fish were be ameliorated by decreased level of competition. The GH-invaders may also have to exceed a threshold density before invasion can be successful. I also showed that the prevalence of mature parr (aka. sneaker) strategy among GH-fish may have clear effect on invasion outcome. The fourth study assessed the risks and developed methods against the invasion of the Colorado Potato Beetle (CPB, Leptinotarsa decemlineata). I showed that the eradication of CPB is most important for the prevention of their establishment, but the cultivation of transgenic Bt-potato could also be effective. In general, my results emphasise that invasion of transgenic species or genotypes to be possible under certain realistic conditions and resulting in competitive exclusion, population decline through outbreeding depression and genotypic displacement of native species. Ecological risk assessment should regard the decline and displacement of the wild genotype by an introduced one as a consequence that is as serious as the population extinction. It will also be crucial to take into account different kinds of behavioural differences among species when assessing the possible hazards that GMOs may cause if escaped. The benefits found of GMO crops effectiveness in pest management may also be too optimistic since CPB may evolve resistance to Bt-toxin. The models in this thesis could be further applied in case specific risk assessment of GMOs by supplementing them with detailed data of the species biology, the effect of the transgene introduced to the species, and also the characteristics of the populations or the environments in the risk of being invaded.
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The book presents a reconstruction, interpretation and critical evaluation of the Schumpeterian theoretical approach to socio-economic change. The analysis focuses on the problem of social evolution, on the interpretation of the innovation process and business cycles and, finally, on Schumpeter s optimistic neglect of ecological-environmental conditions as possible factors influencing social-economic change. The author investigates how the Schumpeterian approach describes the process of social and economic evolution, and how the logic of transformations is described, explained and understood in the Schumpeterian theory. The material of the study includes Schumpeter s works written after 1925, a related part of the commentary literature on these works, and a selected part of the related literature on the innovation process, technological transformations and the problem of long waves. Concerning the period after 1925, the Schumpeterian oeuvre is conceived and analysed as a more or less homogenous corpus of texts. The book is divided into 9 chapters. Chapters 1-2 describe the research problems and methods. Chapter 3 is an effort to provide a systematic reconstruction of Schumpeter's ideas concerning social and economic evolution. Chapters 4 and 5 focus their analysis on the innovation process. In Chapters 6 and 7 Schumpeter's theory of business cycles is examined. Chapter 8 evaluates Schumpeter's views concerning his relative neglect of ecological-environmental conditions as possible factors influencing social-economic change. Finally, chapter 9 draws the main conclusions.
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The goal of this study was to examine the role of organizational causal attribution in understanding the relation of work stressors (work-role overload, excessive role responsibility, and unpleasant physical environment) and personal resources (social support and cognitive coping) to such organizational-attitudinal outcomes as work engagement, turnover intention, and organizational identification. In some analyses, cognitive coping was also treated as an organizational outcome. Causal attribution was conceptualized in terms of four dimensions: internality-externality, attributing the cause of one’s successes and failures to oneself, as opposed to external factors, stability (thinking that the cause of one’s successes and failures is stable over time), globality (perceiving the cause to be operative on many areas of one’s life), and controllability (believing that one can control the causes of one’s successes and failures). Several hypotheses were derived from Karasek’s (1989) Job Demands–Control (JD-C) model and from the Job Demands–Resources (JD-R) model (Demerouti, Bakker, Nachreiner & Schaufeli, 2001). Based on the JD-C model, a number of moderation effects were predicted, stating that the strength of the association of work stressors with the outcome variables (e.g. turnover intentions) varies as a function of the causal attribution; for example, unpleasant work environment is more strongly associated with turnover intention among those with an external locus of causality than among those with an internal locuse of causality. From the JD-R model, a number of hypotheses on the mediation model were derived. They were based on two processes posited by the model: an energy-draining process in which work stressors along with a mediating effect of causal attribution for failures deplete the nurses’ energy, leading to turnover intention, and a motivational process in which personal resources along with a mediating effect of causal attribution for successes foster the nurses’ engagement in their work, leading to higher organizational identification and to decreased intention to leave the nursing job. For instance, it was expected that the relationship between work stressors and turnover intention could be explained (mediated) by a tendency to attribute one’s work failures to stable causes. The data were collected from among Finnish hospital nurses using e-questionnaires. Overall 934 nurses responded the questionnaires. Work stressors and personal resources were measured by five scales derived from the Occupational Stress Inventory-Revised (Osipow, 1998). Causal attribution was measured using the Occupational Attributional Style Questionnaire (Furnham, 2004). Work engagement was assessed through the Utrecht Work Engagement Scale (Schaufeli & al., 2002), turnover intention by the Van Veldhoven & Meijman (1994) scale, and organizational identification by the Mael & Ashforth (1992) measure. The results provided support for the function of causal attribution in the overall work stress process. Findings related to the moderation model can be divided into three main findings. First, external locus of causality along with job level moderated the relationship between work overload and cognitive coping. Hence, this interaction was evidenced only among nurses in non-supervisory positions. Second, external locus of causality and job level together moderated the relationship between physical environment and turnover intention. An opposite pattern of interaction was found for this interaction: among nurses, externality exacerbated the effect of perceived unpleasantness of the physical environment on turnover intention, whereas among supervisors internality produced the same effect. Third, job level also disclosed a moderation effect for controllability attribution over the relationship between physical environment and cognitive coping. Findings related to the mediation model for the energetic process indicated that the partial model in which work stressors have also a direct effect on turnover intention fitted the data better. In the mediation model for the motivational process, an intermediate mediation effect in which the effects of personal resources on turnover intention went through two mediators (e.g., causal dimensions and organizational identification) fitted the data better. All dimensions of causal attribution appeared to follow a somewhat unique pattern of mediation effect not only for energetic but also for motivational processes. Overall findings on mediation models partly supported the two simultaneous underlying processes proposed by the JD-R model. While in the energetic process the dimension of externality mediated the relationship between stressors and turnover partially, all the dimensions of causal attribution appeared to entail significant mediator effects in the motivational process. The general findings supported the moderation effect and the mediation effect of causal attribution in the work stress process. The study contributes to several research traditions, including the interaction approach, the JD-C, and the JD-R models. However, many potential functions of organizational causal attribution are yet to be evaluated by relevant academic and organizational research. Keywords: organizational causal attribution, optimistic / pessimistic attributional style, work stressors, organisational stress process, stressors in nursing profession, hospital nursing, JD-R model, personal resources, turnover intention, work engagement, organizational identification.
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On a journey from marginal to mainstream? The lifestyle and recovery of former drug users This thesis studies the lifestyle and recovery of former users of illicit drugs through their experiences. The study describes the life of people with drug problems both during the time they used drugs regularly and after they stopped the use entirely. The focus is on the development of the lifestyle of 32 persons who no longer use drugs. They may have stopped using drugs independently or with the help of a treatment. In this study, persons who have given up drug use with the help of a psychosocially oriented treatment are called non-medicinally treated former users (n=19) whereas opioid addicts who have stopped using drugs through substitution treatment are referred to as substitution treatment patients (n=13). The research material was gathered from theme interviews. The criteria for the focus group of the study included the following: a) the interviewees had had a serious drug problem in their past; b) they had not used drugs for at least one year prior to the interview; c) they were not in an institutional care at the time of the study. This thesis is basically a lifestyle study in which the aspects of lifestyle are used to describe the everyday life of former drug users. The study reviews the whole spectrum of everyday routines, especially the social interaction and subjective experiences of people. The second concept used in this study is recovery, which is described as a process that starts from the abstinence from substances and adoption of the recovery culture and continues as a comprehensive change of the lifestyle, identity and values of an individual. Disengaging from a drug-oriented lifestyle and connected social network as well as finding an individual frame of reference is a demanding process. Years of drug use have often caused complex health and social disadvantages as well as problems with work, education, livelihood, accommodation and human relationships. The effect of the past on the present arises at all levels. The interviews revealed a recovery culture maintaining the lifestyle as well as an adaptive and optimistic approach to the future among those participating in the study. The study shows that an adequate distance from acute substance use is a precondition for the beginning of the recovery process, yet abstinence in itself tells nothing about the actual recovery. The study describes how some recovering users find a meaning in life easily whereas others have to work actively for their recovery. Detaching oneself from the feeling of adopted abnormality connected with substance addiction forms an important basis for satisfying abstinence. Peer groups support the development of counter-cultures and abstinence or the support is received from the community formed in the substitution treatment clinic.
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This article concentrates on the discursive constmction of success and failure in narratives of post-merger integration. Drawing on extensive interview material from eight Finnish-Swedish mergers and acquisitions, the empirical analysis leads to distinguishing four types of discourse — 'rationalistic', 'cultural', 'role-bound' and 'individualistic' — that narrators employ in recounting their experiences. In particular, the empirical material illustrates how the discursive frameworks enable specific (di.scursive) strategies and moves for (re)framing the success/failure, justification/legitimization of one's own actions, and (re)constniction of responsibility when dealing with socio-psychological pressures associated with success/failtire. The analysis also suggests that, as a result of making use of these discursive strategies and moves, success stories are likely to lead to overly optimistic or, in the case of failure stories, overly pessimistic views on the management's ability to control these change processes. Tliese findings imply that we should take the discursive elements that both constrain our descriptions and explanations seriously, and provide opportunities for more or less intentional (re)interpretations of postmerger integration or other organizational change processes.
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Many real-time database applications arise in electronic financial services, safety-critical installations and military systems where enforcing security is crucial to the success of the enterprise. For real-time database systems supporting applications with firm deadlines, we investigate here the performance implications, in terms of killed transactions, of guaranteeing multilevel secrecy. In particular, we focus on the concurrency control (CC) aspects of this issue. Our main contributions are the following: First, we identify which among the previously proposed real-time CC protocols are capable of providing covert-channel-free security. Second, using a detailed simulation model, we profile the real-time performance of a representative set of these secure CC protocols for a variety of security-classified workloads and system configurations. Our experiments show that a prioritized optimistic CC protocol, OPT-WAIT, provides the best overall performance. Third, we propose and evaluate a novel "dual-CC" approach that allows the real-time database system to simultaneously use different CC mechanisms for guaranteeing security and for improving real-time performance. By appropriately choosing these different mechanisms, concurrency control protocols that provide even better performance than OPT-WAIT are designed. Finally, we propose and evaluate GUARD, an adaptive admission-control policy designed to provide fairness with respect to the distribution of killed transactions across security levels. Our experiments show that GUARD efficiently provides close to ideal fairness for real-time applications that can tolerate covert channel bandwidths of upto one bit per second.
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Previous studies indicate that positive learning experiences are related to academic achievement as well as to well-being. On the other hand, emotional and motivational problems in studying may pose a risk for both academic achievement and well-being. Thus, emotions and motivation have an increasing role in explaining university students learning and studying. The relations between emotions, motivation, study success and well-being have been less frequently studied. The aim of this study was to investigate what kind of academic emotions, motivational factors and problems in studying students experienced five days before an exam of an activating lecture course, and the relations among these factors as well as their relation to self-study time and study success. Furthermore, the effect of all these factors on well-being, flow experience and academic achievement was examined. The term academic emotion was defined as emotion experienced in academic settings and related to studying. In the present study the theoretical background to motivational factors was based on thinking strategies and attributions, flow experience and task value. Problems in studying were measured in terms of exhaustion, anxiety, stress, lack of interest, lack of self-regulation and procrastination. The data were collected in December 2009 in an activating educational psychology lecture course by using a questionnaire. The participants (n=107) were class and kindergarten teacher students from the University of Helsinki. Most of them were first year students. The course grades were also gathered. Correlations and stepwise regression analysis were carried out to find out the factors that were related to or explained study success. The clusters that presented students´ problems in studying as well as thinking strategies and attributions, were found through hierarchical cluster analysis. K-means cluster analysis was used to form the final groups. One-way analysis of variance, Kruskal-Wallis test and crosstabs were conducted to see whether the students in different clusters varied in terms of study success, academic emotions, task value, flow, and background variables. The results indicated that academic emotions measured five days before the exam explained about 30 % of the variance of the course grade; exhaustion and interest positively, and anxiety negatively. In addition, interest as well as the self-study time best explained study success on the course. The participants were classified into three clusters according to their problems in studying as well as their thinking strategies and attributions: 1) ill-being, 2) carefree, and 3) committed and optimistic students. Ill-being students reported most negative emotions, achieved the worst grades, experienced anxiety rather than flow and were also the youngest. Carefree students, on the other hand, expressed the least negative emotions and spent the least time on self-studying, and like committed students, experienced flow. In addition, committed students reported positive emotions the most often and achieved the best grades on the course. In the future, more in-depth understanding how and why especially young first year students experience their studying hard is needed, because early state of the studies is shown to predict later study success.
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The loss and degradation of forest cover is currently a globally recognised problem. The fragmentation of forests is further affecting the biodiversity and well-being of the ecosystems also in Kenya. This study focuses on two indigenous tropical montane forests in the Taita Hills in southeastern Kenya. The study is a part of the TAITA-project within the Department of Geography in the University of Helsinki. The study forests, Ngangao and Chawia, are studied by remote sensing and GIS methods. The main data includes black and white aerial photography from 1955 and true colour digital camera data from 2004. This data is used to produce aerial mosaics from the study areas. The land cover of these study areas is studied by visual interpretation, pixel-based supervised classification and object-oriented supervised classification. The change of the forest cover is studied with GIS methods using the visual interpretations from 1955 and 2004. Furthermore, the present state of the study forests is assessed with leaf area index and canopy closure parameters retrieved from hemispherical photographs as well as with additional, previously collected forest health monitoring data. The canopy parameters are also compared with textural parameters from digital aerial mosaics. This study concludes that the classification of forest areas by using true colour data is not an easy task although the digital aerial mosaics are proved to be very accurate. The best classifications are still achieved with visual interpretation methods as the accuracies of the pixel-based and object-oriented supervised classification methods are not satisfying. According to the change detection of the land cover in the study areas, the area of indigenous woodland in both forests has decreased in 1955 2004. However in Ngangao, the overall woodland area has grown mainly because of plantations of exotic species. In general, the land cover of both study areas is more fragmented in 2004 than in 1955. Although the forest area has decreased, forests seem to have a more optimistic future than before. This is due to the increasing appreciation of the forest areas.
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Javier Alonso Aldama, Cirilo García Román e Idoia Mamolar Sánchez (eds)
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A short review of the actual assessments on the northeast atlantic groundfish stocks of cod, saithe, haddock, redfish and Greenland halibut provided by the ICES „Arctic Fisheries Working Group“is given. All these stocks are presently considered outside safe biological limits. For the first time since 5 years the cod stock is in an endangered situation, because the assessment was to optimistic and the TAC therefore set to high. According to the recent assessments necessary changes in the commercial fishery of the year 1998 off the Nowegian coast and in the Barent-Sea area are discussed. Information on distribution and fishery of cod, haddock, saithe and redfish is given. Biological investigations were carried out onboard the German factory trawler FMS „KIEL“ in January/March and September/ Occtober 1998 in order to collect data of the German fishery in that area. Aspects of length and age distributions, and stomach- and gonad investigation are represented.
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Nessa dissertação procede-se à análise das narrativas do jornal O Globo durante a ocupação da favela da Rocinha pelas forças oficiais, em novembro de 2011. Pretende-se identificar as representações veiculadas pela mídia nesse especial momento da vida da cidade, que convive com a implantação do projeto das Unidades de Polícia Pacificadora UPPs e a expectativa de recepcionar, nos próximos anos, dois megaeventos esportivos internacionais: a Copa do Mundo (2014) e as Olimpíadas (2016). O mote da pesquisa foi, através da análise das representações sobre o processo de ocupação, descobrir pistas que permitissem pensar o impacto dessa medida sobre a cidade e seus habitantes. Foi possível perceber que, diferentemente do que ocorria nas últimas décadas, a violência urbana não se apresentou como questão de grande interesse para o jornal, aparecendo apenas incidentalmente como eventos pontuais em um contexto predominantemente pacífico. Prevaleceu o discurso otimista em relação à cidade e seu futuro. Nesse sentido, diversas matérias registraram o sucesso da operação policial, comemorando a substituição da política policial de confronto pelas ações de inteligência, fator que teria permitido a retomada do morro sem que um tiro sequer fosse disparado. Ênfase especial foi dada às UPPs, sistematicamente representadas de forma positiva pelo jornal, moradores, empresários e especialistas, que apontariam o projeto como fator responsável pela onda de esperança e otimismo que envolve a cidade. As UPPs seriam, ainda, o elemento que permitiria, aos cariocas, ressignificar as favelas da cidade, afastando a aura de violência a elas associadas, fazendo desaparecer o medo que esses espaços da cidade historicamente causam na população em geral, integrando as favelas na cidade formal. O processo de pacificação das favelas do Rio de Janeiro, personificado nas UPPs, seria a ponte que permitiria, à cidade, se redescobrir, se reinventar, recuperando a alegria e a auto-estima, deixando para trás as décadas de pessimismo e desesperança. Observou-se, assim, que durante o período pesquisado, a dinâmica das narrativas rompeu com o padrão anterior de representação de cidade violenta, privilegiando o discurso da cidade pacificada, embora com episódios violentos pontuais.
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Skipjack (Katsuwonus pelamis), yellowfin (Thunnus albacares), and bigeye (Thunnus obesus) tunas are caught by purse-seine vessels in the eastern Pacific Ocean (EPO). Although there is no evidence to indicate that current levels of fishing-induced mortality will affect the sustainability of skipjack or yellowfin tunas, fishing mortality on juvenile (younger than 5 years of age) bigeye tuna has increased, and overall fishing mortality is greater than that necessary to produce the maximum sustainable yield of this species. We investigated whether time-area closures have the potential to reduce purse-seine bigeye catches without significantly reducing skipjack catches. Using catch and effort data for 1995–2002, we identified regions where the ratio of bigeye to skipjack tuna catches was high and applied simple closed-area models to investigate the possible benefits of time-area closures. We estimated that the most optimistic and operationally feasible 3-month closures, covering the equatorial region of the EPO during the third quarter of the year, could reduce bigeye catches by 11.5%, while reducing skipjack tuna catches by 4.3%. Because this level of bigeye tuna catch reduction is insufficient to address sustainability concerns, and larger and longer closures would reduce catches of this species signficantly, we recommend that future research be directed toward gear technology solutions because these have been successful in many other fisheries. In particular, because over 50% of purse-seine catches of bigeye tuna are taken in sets in which bigeye tuna are the dominant species, methods to allow the determination of the species composition of aggregations around floating objects may be important.
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O aumento exponencial dos gastos em saúde demanda estudos econômicos que subsidiem as decisões de agentes públicos ou privados quanto à incorporação de novas tecnologias aos sistemas de saúde. A tomografia de emissão de pósitrons (PET) é uma tecnologia de imagem da área de medicina nuclear, de alto custo e difusão ainda recente no país. O nível de evidência científica acumulada em relação a seu uso no câncer pulmonar de células não pequenas (CPCNP) é significativo, com a tecnologia mostrando acurácia superior às técnicas de imagem convencionais no estadiamento mediastinal e à distância. Avaliação econômica realizada em 2013 aponta para seu custo-efetividade no estadiamento do CPCNP em comparação à estratégia atual de manejo baseada no uso da tomografia computadorizada, na perspectiva do SUS. Sua incorporação ao rol de procedimentos disponibilizados pelo SUS pelo Ministério da Saúde (MS) ocorreu em abril de 2014, mas ainda se desconhecem os impactos econômico-financeiros decorrentes desta decisão. Este estudo buscou estimar o impacto orçamentário (IO) da incorporação da tecnologia PET no estadiamento do CPCNP para os anos de 2014 a 2018, a partir da perspectiva do SUS como financiador da assistência à saúde. As estimativas foram calculadas pelo método epidemiológico e usaram como base modelo de decisão do estudo de custo-efetividade previamente realizado. Foram utilizados dados nacionais de incidência; de distribuição de doença e acurácia das tecnologias procedentes da literatura e de custos, de estudo de microcustos e das bases de dados do SUS. Duas estratégias de uso da nova tecnologia foram analisadas: (a) oferta da PET-TC a todos os pacientes; e (b) oferta restrita àqueles que apresentem resultados de TC prévia negativos. Adicionalmente, foram realizadas análises de sensibilidade univariadas e por cenários extremos, para avaliar a influência nos resultados de possíveis fontes de incertezas nos parâmetros utilizados. A incorporação da PET-TC ao SUS implicaria a necessidade de recursos adicionais de R$ 158,1 (oferta restrita) a 202,7 milhões (oferta abrangente) em cinco anos, e a diferença entre as duas estratégias de oferta é de R$ 44,6 milhões no período. Em termos absolutos, o IO total seria de R$ 555 milhões (PET-TC para TC negativa) e R$ 600 milhões (PET-TC para todos) no período. O custo do procedimento PET-TC foi o parâmetro de maior influência sobre as estimativas de gastos relacionados à nova tecnologia, seguido da proporção de pacientes submetidos à mediastinoscopia. No cenário por extremos mais otimista, os IOs incrementais reduzir-se-iam para R$ 86,9 (PET-TC para TC negativa) e R$ 103,9 milhões (PET-TC para todos), enquanto no mais pessimista os mesmos aumentariam para R$ 194,0 e R$ 242,2 milhões, respectivamente. Resultados sobre IO, aliados às evidências de custo-efetividade da tecnologia, conferem maior racionalidade às decisões finais dos gestores. A incorporação da PET no estadiamento clínico do CPCNP parece ser financeiramente factível frente à magnitude do orçamento do MS, e potencial redução no número de cirurgias desnecessárias pode levar à maior eficiência na alocação dos recursos disponíveis e melhores desfechos para os pacientes com estratégias terapêuticas mais bem indicadas.
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A região Centro-Oeste do Brasil tornou-se nos últimos 40 anos grande produtora de grãos e carne bovina. As condições edafoclimáticas, o sistema de manejo do solo e o descumprimento de leis ambientais trouxeram conseqüências drásticas à região como o agravamento do processo hídrico erosivo, principalmente na Bacia do Alto Taquari (BAT). Cerca de 90% da BAT localiza-se na porção norte do estado de Mato Grosso do Sul (MS), porém os efeitos do transporte de sedimentos e volume de água são refletidos a jusante dos rios, na Bacia do Pantanal. Utilizando-se pressupostos do Painel Intergovernamental de Mudanças Climáticas (IPCC) foram estabelecidos cenários de mudanças climáticas na Bacia do Alto Taquari, visando identificar áreas com maior vulnerabilidade ao processo erosivo em função de pressões de uso da terra. Usando a modelagem dinâmica no TerraME (Environment Modeling) foram gerados cenários topopluviais até 2100, considerando-se para a temperatura do ar média anual um aumento de 1C, em cenário otimista e, em pessimista, elevações térmicas de 3C. Para a precipitação pluvial média anual um cenário foi com aumento de 15% e outro com reduções de 15%. Os dados foram espacializados no ArcGis 9.2 e exportados para o TerraView 3.2, criando-se espaços celulares e integrando-se com as informações do modelo digital do terreno do Shuttle Radar Topography Mission (SRTM) para geração dos mapas topoclimáticos e simulações de cenários no TerraMe. Os resultados apontam que 85% da área da BAT nas condições atuais as temperaturas médias variam entre 23,6 a 25,7C. As simulações térmicas no cenário otimista indicam que em 40 anos as temperaturas tendem a superar o maior limite térmico médio nas áreas ao longo do rio Taquari, no sentido Oeste-Leste. Esses valores evidenciam elevações nas taxas evapotranspiratórias de matas ciliares, indicando reduções na vazão do Taquari. Em cenário pessimista essas temperaturas antecipam sua ocorrência, em um prazo de 20 anos. Os cenários com acréscimo de 15% na precipitação pluvial mostram aumentos no volume de água precipitada na parte norte da Bacia, região mais vulnerável aos problemas de erosão hídrica. Cenários do regime térmico-hídrico apontam áreas mais sensíveis às mudanças climáticas na parte oeste da BAT e impactos ambientais também na Bacia do Pantanal. Conclui-se que o TerraME é indicado para gerar cenários de mudanças climáticas em bacias hidrográficas.
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Adaptive cluster sampling (ACS) has been the subject of many publications about sampling aggregated populations. Choosing the criterion value that invokes ACS remains problematic. We address this problem using data from a June 1999 ACS survey for rockfish, specifically for Pacific ocean perch (Sebastes alutus), and for shortraker (S. borealis) and rougheye (S. aleutianus) rockfish combined. Our hypotheses were that ACS would outperform simple random sampling (SRS) for S. alutus and would be more applicable for S. alutus than for S. borealis and S. aleutianus combined because populations of S. alutus are thought to be more aggregated. Three alternatives for choosing a criterion value were investigated. We chose the strategy that yielded the lowest criterion value and simulated the higher criterion values with the data after the survey. Systematic random sampling was conducted across the whole area to determine the lowest criterion value, and then a new systematic random sample was taken with adaptive sampling around each tow that exceeded the fixed criterion value. ACS yielded gains in precision (SE) over SRS. Bootstrapping showed that the distribution of an ACS estimator is approximately normal, whereas the SRS sampling distribution is skewed and bimodal. Simulation showed that a higher criterion value results in substantially less adaptive sampling with little tradeoff in precision. When time-efficiency was examined, ACS quickly added more samples, but sampling edge units caused this efficiency to be lessened, and the gain in efficiency did not measurably affect our conclusions. ACS for S. alutus should be incorporated with a fixed criterion value equal to the top quartile of previously collected survey data. The second hypothesis was confirmed because ACS did not prove to be more effective for S. borealis-S. aleutianus. Overall, our ACS results were not as optimistic as those previously published in the literature, and indicate the need for further study of this sampling method.