939 resultados para Dispersion Hardening
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INTRODUCTION: An epidemiological study was undertaken to identify determinant factors in the occurrence of American cutaneous leishmaniasis in areas under the influence of hydroelectric plants in Paranapanema river, State of Paraná, Brazil. The ecological aspects of the phlebotomine fauna were investigated. METHODS: Sandflies were sampled with automatic light traps from February 2004 to June 2006 at 25 sites in the urban and rural areas of Itambaracá, and in Porto Almeida and São Joaquim do Pontal. RESULTS: A total of 3,187 sandflies of 15 species were captured. Nyssomyia neivai predominated (34.4%), followed by Pintomyia pessoai (32.6%), Migonemyia migonei (11.6%), Nyssomyia whitmani (8.8%), and Pintomyia fischeri (2.7%), all implicated in the transmission of Leishmania. Males predominated for Ny. neivai, and females for the other vector species, with significant statistical differences (p < 0.001). Nyssomyia neivai, Pi. pessoai, Ny. whitmani, Brumptomyia brumpti, Mg. migonei, and Pi. fischeri presented the highest values for the Standardized Species Abundance Index (SSAI). The highest frequencies and diversities were found in the preserved forest in Porto Almeida, followed by forests with degradation in São Joaquim do Pontal and Vila Rural. CONCLUSIONS: Sandflies were captured in all localities, with the five vectors predominating. Ny. neivai had its highest frequencies in nearby peridomestic environments and Pi. pessoai in areas of preserved forests. The highest SSAI values of Ny. neivai and Pi. pessoai reflect their wider dispersion and higher frequencies compared with other species, which seems to indicate that these two species may be transmitting leishmaniasis in the area.
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RESUMO: INTRODUÇÃO: A OMS (2001) revela que cerca de 450 milhões de pessoas sofrem de perturbações mentais ou comportamentais em todo o mundo, mas apenas uma pequena minoria tem tratamento, ainda que elementar. Transformam-se em vítimas por causa da sua doença e convertem-se em alvos de estigma e discriminação. O suicídio é considerado como um grande problema de saúde pública em todo o mundo, é uma das principais causas de morte de jovens adultos e situa-se entre as três maiores causas de morte na população entre 15-34 anos (OMS, 2001). As perturbações mentais aumentam o risco de suicídio. A depressão, esquizofrenia, e a utilização de substâncias incrementam o risco de suicídio. Estudos (Sartorius, 2002; Magliano et al., 2012) mostram que os profissionais de saúde, tal como o público em geral, podem ter atitudes negativas e estigma em relação às pessoas com perturbações mentais, podendo agir em conformidade, uma vez feito e conhecido o diagnóstico psiquiátrico. Os clínicos gerais são os receptores das perturbações mentais e tentativas de suicídio nas principais portas de entrada no acesso a cuidados de saúde. As crenças, conhecimentos e contacto com a doença mental e o suicídio, podem influenciar a atenção clínica. OBJECTIVOS: Avaliar o estigma e as percepções dos médicos de clínica geral em relação às tentativas de suicídio, o suicídio e perturbações mentais bem como os possíveis factores associados a estes fenómenos. MATERIAIS E MÉTODOS: Estudo do tipo transversal, combinando métodos quantitativos e qualitativos. A amostra é constituída por 125 sujeitos, médicos de clínica geral. Utilizaram-se as versões adaptadas dos seguintes instrumentos: Questionário sobre Percepções e Estigma em Relação à Saúde Mental e ao Suicídio (Liz Macmin e SOQ, Domino, 2005) e a Escala de Atitudes sobre a Doença Mental (Amanha Hahn, 2002). Para o tratamento estatístico dos dados usou-se a estatística 1) descritiva e 2) Análise estatística das hipóteses formuladas (Qui Quadrado - 2) a correlação entre variáveis (Spearman: ρ, rho). Os dados conectados foram limpos de inconsistências com base no pacote informático e estatístico SPSS versão 20. Para a aferição da consistência interna foi usado o teste de Alfa de Cronbach. RESULTADOS: Uma boa parte da amostra (46.4%) refere que não teve formação formal ou informal em saúde mental e (69.35%) rejeitam a ideia de que “grupos profissionais como médicos, dentistas e psicólogos são mais susceptíveis a cometer o suicídio”. Já (28.0%) têm uma perspectiva pessimista quanto a possibilidade de recuperação total dos sujeitos com perturbação mental. Sessenta e oito(54.4%) associa sujeitos com perturbação mental, a comportamentos estranhos e imprevisíveis, 115 (92.0%) a um baixo QI e 35 (26.7%) a poderem ser violentas e e perigosas. Os dados mostram uma associação estatisticamente significativa (p0.001) entre as variáveis: tempo de serviço no SNS, recear estar perto de sujeitos com doença mental e achar que os sujeitos com doença mental são mais perigosos que outros. Em termos estatísticos, existe uma associação estatitisticamente significativa entre as duas variáveis(X2=9,522; p0.05): percepção de que “é vergonhoso ter uma doença mental” e os conhecimentos em relação à doença mental. Existe uma correlação positiva, fraca e estatisticamente significativa entre os conhecimentos dos clínicos gerais(beneficiar-se de formação em saúde mental) e a percepção sobre os factores de risco (0,187; P0,039). DISCUSSÃO E CONCLUSÕES: A falta de conhecimento sobre as causas e factores de risco para os comportamentos suicidários, opções de intervenção e tratamento, particularmente no âmbito da doença mental, podem limitar a procura de ajuda individual ou dos próximos. Percepções negativas como o facto de não merecerem prioridade nos serviços, mitos (frágeis e cobarde, sempre impulsivo, chamadas de atenção, problemas espirituais) podem constituir-se como um indicador de que os clínicos gerais podem sofrer do mesmo sistema de estigma e crenças, de que sofre o público em geral, podendo agir em conformidade (atitudes de afastamento ereceio). As atitudes são influenciadas por factores como a formação, cultura e sistema de crenças. Sujeitos com boa formação na área da saúde mental têm uma percepção positiva e optimista sobre os factores de risco e uma atitude positiva em relação aos sujeitos com doença mental e comportamentos suicidários.-------------ABSTRACT: INTRODUCTION: The WHO (2001) reveals that about 450 million people suffer from mental or behavioral disorders worldwide, but only a small minority have access to treatment, though elementary. They become victims because of their disease and they become the targets of stigma and discrimination. Suicide is seen as a major public health problem worldwide, is a leading cause of death for young adults and is included among the three major causes of death in the population aged 15-34 years (WHO, 2001). Mental disorders increase the risk of suicide. Depression, schizophrenia, and the substances misuse increase the risk of suicide. Studies (Sartorius, 2002; Magliano et al, 2012) show that health professionals, such as the general public, may have negative attitudes and stigma towards people with mental disorders, and can act accordingly after psychiatric diagnosis is known. General practitioners are the main entry points of mental disorders and suicide attempts in the health sistem. Beliefs, knowledge and contact with mental illness and suicide, may influence clinical care. OBJECTIVES: To assess stigma and perceptions of general practitioners in relation to suicide attempts, suicide and mental disorders as well as possible factors associated with these phenomena. MATERIAL AND METHODS: This was a descriptive cross-sectional study, combining quantitative and qualitative methods. The sample consisted of 125 subjects, general practitioners. We used adapted versions of the following instruments: Questionnaire of Perceptions and Stigma in Relation to Mental Health and Suicide (Liz Macmin and SOQ, Domino, 2005) and the Scale of Attitudes on Mental Illness (Tomorrow Hahn, 2002). For the statistical treatment of the data we used: 1) descriptive (Data distribution by absolute and relative frequencies for each of the variables under study (including mean and standard deviation measures of central tendency and deviation), 2) statistical analysis of hypotheses using (Chi Square - 2, a hypothesis test that is intended to find a value of dispersion for two nominal variables, evaluating the association between qualitative variables) and the correlation between variables (Spearman ρ, rho), a measure of non-parametric correlation, which evaluates an arbitrary monotonic function can be the description of the relationship between two variables, without making any assumptions about the frequency distribution of the variables). For statistical analysis of the correlations were eliminated subjects who did not respond to questions. The collected data were cleaned for inconsistencies based on computer and statistical package SPSS version 20. To measure the internal consistency was used the Cronbach's alpha test. RESULTS: A significant part of the sample 64 (46.4%) reported no formal or informal training in mental health and 86 (69.35%) reject the idea that "professional groups such as doctors, dentists and psychologists are more likely to commit suicide." On the other hand, 42 (28.0%) have a pessimistic view of the possibility of full recovery of individuals with mental disorder. Sixty-eight ( 54.4 % ) of them associates subjects with mental disorder to strange and unpredictable behavior, 115 ( 92.0 % ), to low IQ, 35 ( 26.7 % ) and even to violent and dangerous behavior, 78 ( 62.4 % ) The data show a statistically significant (p = 0.001) relationship between the following variables: length of service in the NHS, fear of being close to individuals with mental illness and considering individuals with mental illness more dangerous than others. In statistical terms, there is a dependency between the two variables (X2 = 9.522, p> 0.05): the perception that "it is shameful to have a mental illness" and knowledge regarding mental illness. There is a positive and statistically significant weak correlation between knowledge of general practitioners (benefit from mental health training) and the perception of the risk factors (0,187; P0,039). DISCUSSION AND CONCLUSIONS: The lack of knowledge about the causes and risk factors for suicidal behavior, intervention and treatment, particularly in the context of mental illness options, may decreaseseeking for help by individual and their relatives. Negative perceptions such as considering that they dont deserve priority in services, myths (weak and cowards, always impulsive, seeking for attentions, spirituals problems) may indicate that general practitioners, may suffer the same stigma and beliefs systems as the general public, and can act accordingly (withdrawal and fear attitudes). Attitudes are influenced by factors such as education, culture and belief system. Subjects with good training in mental health have a positive and optimistic perception of the risk factors and a positiveattitude towards individuals with mental illness and suicidal behaviour.
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INTRODUCTION: A retrospective study was conducted to assess the occurrence of blood donations that were ineligible due to Chagas disease infection from 1995 to 2009 at the Uberaba Regional Blood Center (HRU), Brazil, verify the tendency of this ineligibility, and describe the epidemiologic profile of the donors. METHODS: Retrospective studies of serological ineligibility due to Chagas disease, statistical analysis by means of the chi-square test and odds ratio, study of the tendencies using a dispersion graph and the linear correlation coefficient (r) were performed. RESULTS: In the period under study, a 0.2% serum prevalence of ineligibility due to Chagas disease was found, with a significant drop in ineligible donations from 2001 to 2009. Among the serum positive-donors, there was a significant predominance among those aged 30 years or above and non-single individuals. CONCLUSIONS: The results show a rate of occurrence that is lower than that described in literature, as well as a progressive drop during the 15 years under assessment. Such results are a consequence of systematic combat of the vector since the 70s and the progressive and consistent increase of returning donors, resulting in a drop of the contamination risk factor by means of blood transfusion and in the improvement of the quality of hemotherapy practices in the HRU.
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IntroductionYellow fever is a non-contagious infectious disease, highly lethal, transmitted by the Aedes, Haemagogus and Sabethes.MethodsDescriptive retrospective study of the yellow fever cases in Amazonas, between 1996 and 2009.ResultsForty two cases of yellow fever were confirmed, with 30 deaths, 10% of which were foreigners.ConclusionsThe presence of Aedes aegypti and Aedes albopictus in both rural Amazonas and its capital demonstrates the dispersion of these vectors and underscores the need for better and continuous epidemiological and entomological control.
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The work described in this thesis was performed at the Laboratory for Intense Lasers (L2I) of Instituto Superior Técnico, University of Lisbon (IST-UL). Its main contribution consists in the feasibility study of the broadband dispersive stages for an optical parametric chirped pulse amplifier based on the nonlinear crystal yttrium calcium oxi-borate (YCOB). In particular, the main goal of this work consisted in the characterization and implementation of the several optical devices involved in pulse expansion and compression of the amplified pulses to durations of the order of a few optical cycles (20 fs). This type of laser systems find application in fields such as medicine, telecommunications and machining, which require high energy, ultrashort (sub-100 fs) pulses. The main challenges consisted in the preliminary study of the performance of the broadband amplifier, which is essential for successfully handling pulses with bandwidths exceeding 100 nm when amplified from the μJ to 20 mJ per pulse. In general, the control, manipulation and characterization of optical phenomena on the scale of a few tens of fs and powers that can reach the PW level are extremely difficult and challenging due to the complexity of the phenomena of radiation-matter interaction and their nonlinearities, observed at this time scale and power level. For this purpose the main dispersive components were characterized in detail, specifically addressing the demonstration of pulse expansion and compression. The tested bandwidths are narrower than the final ones, in order to confirm the parameters of these elements and predict the performance for the broadband pulses. The work performed led to additional tasks such as a detailed characterization of laser oscillator seeding the laser chain and the detection and cancelling of additional sources of dispersion.
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Economics is a social science which, therefore, focuses on people and on the decisions they make, be it in an individual context, or in group situations. It studies human choices, in face of needs to be fulfilled, and a limited amount of resources to fulfill them. For a long time, there was a convergence between the normative and positive views of human behavior, in that the ideal and predicted decisions of agents in economic models were entangled in one single concept. That is, it was assumed that the best that could be done in each situation was exactly the choice that would prevail. Or, at least, that the facts that economics needed to explain could be understood in the light of models in which individual agents act as if they are able to make ideal decisions. However, in the last decades, the complexity of the environment in which economic decisions are made and the limits on the ability of agents to deal with it have been recognized, and incorporated into models of decision making in what came to be known as the bounded rationality paradigm. This was triggered by the incapacity of the unboundedly rationality paradigm to explain observed phenomena and behavior. This thesis contributes to the literature in three different ways. Chapter 1 is a survey on bounded rationality, which gathers and organizes the contributions to the field since Simon (1955) first recognized the necessity to account for the limits on human rationality. The focus of the survey is on theoretical work rather than the experimental literature which presents evidence of actual behavior that differs from what classic rationality predicts. The general framework is as follows. Given a set of exogenous variables, the economic agent needs to choose an element from the choice set that is avail- able to him, in order to optimize the expected value of an objective function (assuming his preferences are representable by such a function). If this problem is too complex for the agent to deal with, one or more of its elements is simplified. Each bounded rationality theory is categorized according to the most relevant element it simplifes. Chapter 2 proposes a novel theory of bounded rationality. Much in the same fashion as Conlisk (1980) and Gabaix (2014), we assume that thinking is costly in the sense that agents have to pay a cost for performing mental operations. In our model, if they choose not to think, such cost is avoided, but they are left with a single alternative, labeled the default choice. We exemplify the idea with a very simple model of consumer choice and identify the concept of isofin curves, i.e., sets of default choices which generate the same utility net of thinking cost. Then, we apply the idea to a linear symmetric Cournot duopoly, in which the default choice can be interpreted as the most natural quantity to be produced in the market. We find that, as the thinking cost increases, the number of firms thinking in equilibrium decreases. More interestingly, for intermediate levels of thinking cost, an equilibrium in which one of the firms chooses the default quantity and the other best responds to it exists, generating asymmetric choices in a symmetric model. Our model is able to explain well-known regularities identified in the Cournot experimental literature, such as the adoption of different strategies by players (Huck et al. , 1999), the inter temporal rigidity of choices (Bosch-Dom enech & Vriend, 2003) and the dispersion of quantities in the context of di cult decision making (Bosch-Dom enech & Vriend, 2003). Chapter 3 applies a model of bounded rationality in a game-theoretic set- ting to the well-known turnout paradox in large elections, pivotal probabilities vanish very quickly and no one should vote, in sharp contrast with the ob- served high levels of turnout. Inspired by the concept of rhizomatic thinking, introduced by Bravo-Furtado & Côrte-Real (2009a), we assume that each per- son is self-delusional in the sense that, when making a decision, she believes that a fraction of the people who support the same party decides alike, even if no communication is established between them. This kind of belief simplifies the decision of the agent, as it reduces the number of players he believes to be playing against { it is thus a bounded rationality approach. Studying a two-party first-past-the-post election with a continuum of self-delusional agents, we show that the turnout rate is positive in all the possible equilibria, and that it can be as high as 100%. The game displays multiple equilibria, at least one of which entails a victory of the bigger party. The smaller one may also win, provided its relative size is not too small; more self-delusional voters in the minority party decreases this threshold size. Our model is able to explain some empirical facts, such as the possibility that a close election leads to low turnout (Geys, 2006), a lower margin of victory when turnout is higher (Geys, 2006) and high turnout rates favoring the minority (Bernhagen & Marsh, 1997).
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AbstractINTRODUCTION:Despite chemical and physical vector control strategies, persistent infestations of Triatoma sordida have been reported in a large part of Minas Gerais, Brazil, and the cause for this is little investigated. We aimed to characterize the deltamethrin toxicological profile in peridomestic T. sordidapopulations from Triângulo Mineiro area of Minas Gerais.METHODS:Susceptibility to deltamethrin was assessed in seventeen peridomestic T. sordida populations. Serial dilutions of deltamethrin in acetone (0.2µL) were topically applied on the first instar nymphs (F1; five days old; fasting weight, 1.2 ± 0.2mg). Dose response results were analyzed using Probit software, and the lethal doses, slope and resistance ratios were determined. Qualitative tests were also performed.RESULTS:The deltamethrin susceptibility profile of T. sordida populations revealed resistance ratios ranging from 0.84 to 2.8. The percentage mortality in response to a diagnostic dose was 100.0% in all populations.CONCLUSIONS:From our results, the lack of resistance to insecticides but persistent T. sordida infestations in the Triângulo Mineiro area may be because of: 1) environmental degradation facilitating dispersion of T. sordida , allowing colonization in artificial ecotopes; 2) operational failures; and 3) complexity of the peridomicile in the study area.These variables are being investigated.
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ABSTRACTINTRODUCTION: The transmission cycle of Trypanosoma cruzi in the Brazilian Pantanal region has been studied during the last decade. Although considerable knowledge is available regarding the mammalian hosts infected by T. cruzi in this wetland, no studies have investigated its vectors in this region. This study aimed to investigate the presence of sylvatic triatomine species in different habitats of the Brazilian Pantanal region and to correlate their presence with the occurrences of vertebrate hosts and T. cruzi infection.METHODS: The fieldwork involved passive search by using light traps and Noireau traps and active search by visual inspection. The light traps were placed at five selected points along forested areas for seven nights during each of the nine excursions. At each point where a light trap was set, eight Noireau traps were placed in palm trees and bromeliads.RESULTS: In all, 88 triatomine bugs were collected: two and one individuals from light traps and Noireau traps, respectively; three from peridomestic areas; 23 in coati nests; and 59 in thornbird nests. In this study, active search in microhabitats showed higher efficiency than passive search, since 95% of the triatomine bugs were caught in nests. Further, triatomine bugs were only found to be infected by T. cruzi in coati nests.CONCLUSIONS: Coati nests might act as a point of convergence and dispersion for triatomine bugs and mammal hosts infected by T. cruzi, thereby playing an important role in the sylvatic cycle of T. cruziin the Pantanal region.
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Abstract: INTRODUCTION This paper aims to describe the dispersion of Lutzomyia longipalpis and the autochthonous occurrence of visceral leishmaniasis (VL) in the Northwest region of the State of São Paulo between 2007 and 2013 and to analyze their expansion. METHODS Information about the vector and associated cases was described using maps. The incidence, mortality, and lethality of human visceral leishmaniasis (HVL) were calculated. In municipalities in which more than one HVL case occurred, incidences were calculated according to census sector, and spatial and spatiotemporal clusters were identified. RESULTS The first case of HVL was reported in the municipality of Jales in 2007. By 2013, the vector and the disease had expanded from west to east, with the vector being detected in 29 municipalities. A total of 11 municipalities had cases of canine visceral leishmaniasis (CVL), and six had cases of HVL. Vector expansion occurred by vicinity with previously infested municipalities, and the expansion of VL was related to the major highways and the capital municipalities of the micro-regions in the study area. The highest incidence of HVL occurred in children between 0-4 years old, and the highest mortality and lethality occurred among persons aged 60 and older. The occurrence of HLV was more intense in the peripheral areas of municipalities with the disease. CONCLUSIONS The findings of this study may be useful for improving VL surveillance and control activities by slowing VL expansion and/or mitigating VL effects when they occur.