985 resultados para Scientific theory
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La recherche de substances ayant pu jouer un rôle direct ou indirect dans la cause de la mort ou ayant pu modifier le comportement d'un individu constitue la mission première de la toxicologie forensique. L'augmentation de la consommation de substances illégales et de médicaments dans les sociétés modernes a fait connaître à la toxicologie forensique un essor très important ces dernières décennies. D'autre part, les développements technologiques analytiques ont permis d'obtenir des outils très sensibles et spécifiques pour la recherche et le dosage d'une multitude de substances dans une grande variété d'échantillons biologiques, parfois présentes à des concentrations très faibles, conséquence d'une dose équivalente à la prise d'une seule unité galénique. Forensic toxicology has to bring evidence of substances that could have been involved directly or indirectly in the cause of death or that could influence the behaviour of somebody. The increase of the consumption of illegal and legal drugs in modern societies during last decades gave a boost to forensic toxicology. Moreover, improvement with analytical technology gave tools with high degrees of sensitivity and specificity for the screening and quantification of a large amount of substances in various biological specimens, even with very low concentration resulting of a single dose of medication.
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Abstract The object of game theory lies in the analysis of situations where different social actors have conflicting requirements and where their individual decisions will all influence the global outcome. In this framework, several games have been invented to capture the essence of various dilemmas encountered in many common important socio-economic situations. Even though these games often succeed in helping us understand human or animal behavior in interactive settings, some experiments have shown that people tend to cooperate with each other in situations for which classical game theory strongly recommends them to do the exact opposite. Several mechanisms have been invoked to try to explain the emergence of this unexpected cooperative attitude. Among them, repeated interaction, reputation, and belonging to a recognizable group have often been mentioned. However, the work of Nowak and May (1992) showed that the simple fact of arranging the players according to a spatial structure and only allowing them to interact with their immediate neighbors is sufficient to sustain a certain amount of cooperation even when the game is played anonymously and without repetition. Nowak and May's study and much of the following work was based on regular structures such as two-dimensional grids. Axelrod et al. (2002) showed that by randomizing the choice of neighbors, i.e. by actually giving up a strictly local geographical structure, cooperation can still emerge, provided that the interaction patterns remain stable in time. This is a first step towards a social network structure. However, following pioneering work by sociologists in the sixties such as that of Milgram (1967), in the last few years it has become apparent that many social and biological interaction networks, and even some technological networks, have particular, and partly unexpected, properties that set them apart from regular or random graphs. Among other things, they usually display broad degree distributions, and show small-world topological structure. Roughly speaking, a small-world graph is a network where any individual is relatively close, in terms of social ties, to any other individual, a property also found in random graphs but not in regular lattices. However, in contrast with random graphs, small-world networks also have a certain amount of local structure, as measured, for instance, by a quantity called the clustering coefficient. In the same vein, many real conflicting situations in economy and sociology are not well described neither by a fixed geographical position of the individuals in a regular lattice, nor by a random graph. Furthermore, it is a known fact that network structure can highly influence dynamical phenomena such as the way diseases spread across a population and ideas or information get transmitted. Therefore, in the last decade, research attention has naturally shifted from random and regular graphs towards better models of social interaction structures. The primary goal of this work is to discover whether or not the underlying graph structure of real social networks could give explanations as to why one finds higher levels of cooperation in populations of human beings or animals than what is prescribed by classical game theory. To meet this objective, I start by thoroughly studying a real scientific coauthorship network and showing how it differs from biological or technological networks using divers statistical measurements. Furthermore, I extract and describe its community structure taking into account the intensity of a collaboration. Finally, I investigate the temporal evolution of the network, from its inception to its state at the time of the study in 2006, suggesting also an effective view of it as opposed to a historical one. Thereafter, I combine evolutionary game theory with several network models along with the studied coauthorship network in order to highlight which specific network properties foster cooperation and shed some light on the various mechanisms responsible for the maintenance of this same cooperation. I point out the fact that, to resist defection, cooperators take advantage, whenever possible, of the degree-heterogeneity of social networks and their underlying community structure. Finally, I show that cooperation level and stability depend not only on the game played, but also on the evolutionary dynamic rules used and the individual payoff calculations. Synopsis Le but de la théorie des jeux réside dans l'analyse de situations dans lesquelles différents acteurs sociaux, avec des objectifs souvent conflictuels, doivent individuellement prendre des décisions qui influenceront toutes le résultat global. Dans ce cadre, plusieurs jeux ont été inventés afin de saisir l'essence de divers dilemmes rencontrés dans d'importantes situations socio-économiques. Bien que ces jeux nous permettent souvent de comprendre le comportement d'êtres humains ou d'animaux en interactions, des expériences ont montré que les individus ont parfois tendance à coopérer dans des situations pour lesquelles la théorie classique des jeux prescrit de faire le contraire. Plusieurs mécanismes ont été invoqués pour tenter d'expliquer l'émergence de ce comportement coopératif inattendu. Parmi ceux-ci, la répétition des interactions, la réputation ou encore l'appartenance à des groupes reconnaissables ont souvent été mentionnés. Toutefois, les travaux de Nowak et May (1992) ont montré que le simple fait de disposer les joueurs selon une structure spatiale en leur permettant d'interagir uniquement avec leurs voisins directs est suffisant pour maintenir un certain niveau de coopération même si le jeu est joué de manière anonyme et sans répétitions. L'étude de Nowak et May, ainsi qu'un nombre substantiel de travaux qui ont suivi, étaient basés sur des structures régulières telles que des grilles à deux dimensions. Axelrod et al. (2002) ont montré qu'en randomisant le choix des voisins, i.e. en abandonnant une localisation géographique stricte, la coopération peut malgré tout émerger, pour autant que les schémas d'interactions restent stables au cours du temps. Ceci est un premier pas en direction d'une structure de réseau social. Toutefois, suite aux travaux précurseurs de sociologues des années soixante, tels que ceux de Milgram (1967), il est devenu clair ces dernières années qu'une grande partie des réseaux d'interactions sociaux et biologiques, et même quelques réseaux technologiques, possèdent des propriétés particulières, et partiellement inattendues, qui les distinguent de graphes réguliers ou aléatoires. Entre autres, ils affichent en général une distribution du degré relativement large ainsi qu'une structure de "petit-monde". Grossièrement parlant, un graphe "petit-monde" est un réseau où tout individu se trouve relativement près de tout autre individu en termes de distance sociale, une propriété également présente dans les graphes aléatoires mais absente des grilles régulières. Par contre, les réseaux "petit-monde" ont, contrairement aux graphes aléatoires, une certaine structure de localité, mesurée par exemple par une quantité appelée le "coefficient de clustering". Dans le même esprit, plusieurs situations réelles de conflit en économie et sociologie ne sont pas bien décrites ni par des positions géographiquement fixes des individus en grilles régulières, ni par des graphes aléatoires. De plus, il est bien connu que la structure même d'un réseau peut passablement influencer des phénomènes dynamiques tels que la manière qu'a une maladie de se répandre à travers une population, ou encore la façon dont des idées ou une information s'y propagent. Ainsi, durant cette dernière décennie, l'attention de la recherche s'est tout naturellement déplacée des graphes aléatoires et réguliers vers de meilleurs modèles de structure d'interactions sociales. L'objectif principal de ce travail est de découvrir si la structure sous-jacente de graphe de vrais réseaux sociaux peut fournir des explications quant aux raisons pour lesquelles on trouve, chez certains groupes d'êtres humains ou d'animaux, des niveaux de coopération supérieurs à ce qui est prescrit par la théorie classique des jeux. Dans l'optique d'atteindre ce but, je commence par étudier un véritable réseau de collaborations scientifiques et, en utilisant diverses mesures statistiques, je mets en évidence la manière dont il diffère de réseaux biologiques ou technologiques. De plus, j'extrais et je décris sa structure de communautés en tenant compte de l'intensité d'une collaboration. Finalement, j'examine l'évolution temporelle du réseau depuis son origine jusqu'à son état en 2006, date à laquelle l'étude a été effectuée, en suggérant également une vue effective du réseau par opposition à une vue historique. Par la suite, je combine la théorie évolutionnaire des jeux avec des réseaux comprenant plusieurs modèles et le réseau de collaboration susmentionné, afin de déterminer les propriétés structurelles utiles à la promotion de la coopération et les mécanismes responsables du maintien de celle-ci. Je mets en évidence le fait que, pour ne pas succomber à la défection, les coopérateurs exploitent dans la mesure du possible l'hétérogénéité des réseaux sociaux en termes de degré ainsi que la structure de communautés sous-jacente de ces mêmes réseaux. Finalement, je montre que le niveau de coopération et sa stabilité dépendent non seulement du jeu joué, mais aussi des règles de la dynamique évolutionnaire utilisées et du calcul du bénéfice d'un individu.
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Phenytoin is an anticonvulsant that has been used in wound healing. The objectives of this study were to describe how the scientific production presents the use ofphenytoinas a healing agent and to discuss its applicability in wounds. A literature review and hierarchy analysis of evidence-based practices was performed. Eighteen articles were analyzed that tested the intervention in wounds such as leprosy ulcers, leg ulcers, diabetic foot ulcers, pressure ulcers, trophic ulcers, war wounds, burns, preparation of recipient graft area, radiodermatitis and post-extraction of melanocytic nevi. Systemic use ofphenytoinin the treatment of fistulas and the hypothesis of topical use in the treatment of vitiligo were found. In conclusion, topical use ofphenytoinis scientifically evidenced. However robust research is needed that supports a protocol for the use ofphenytoinas another option of a healing agent in clinical practice.
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A critical feature of cooperative animal societies is the reproductive skew, a shorthand term for the degree to which a dominant individual monopolizes overall reproduction in the group. Our theoretical analysis of the evolutionarily stable skew in matrifilial (i.e., mother-daughter) societies, in which relatednesses to offspring are asymmetrical, predicts that reproductive skews in such societies should tend to be greater than those of semisocial societies (i.e., societies composed of individuals of the same generation, such as siblings), in which relatednesses to offspring are symmetrical. Quantitative data on reproductive skews in semisocial and matrifilial associations within the same species for 17 eusocial Hymenoptera support this prediction. Likewise, a survey of reproductive partitioning within 20 vertebrate societies demonstrates that complete reproductive monopoly is more likely to occur in matrifilial than in semisocial societies, also as predicted by the optimal skew model.
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A theoretical study aimed to analyze the existing knowledge in the literature on the perioperative thirst symptom from the perspective of Symptom Management Theory, and supplemented with the experience of the study group and thirst research. Thirst is described as a very intense symptom occurring in the perioperative period, and for this reason it cannot be ignored. The Symptom Management Theory is adequate for understanding the thirst symptom and is a deductive theory, focused on the domains of the Person, Environment and Health / Illness Status, as well as on the dimensions of Experience, Management Strategies and Symptom Outcomes. Using the theory leads us to consider perioperative thirst in its multifactorial aspects, analyzing the interrelation of its domains and dimensions in order to draw attention to this symptom that has been insufficiently valued, recorded and treated in clinical practice.
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This article aims to discuss the concepts of Social Determination of Health and Social Determinants of Health, by establishing a comparison between each of their guiding perspectives and investigating their implications on the development of health policies and health actions. We propose a historical and conceptual reflection, highlighting the Theory on the Social Production of Health, followed by a debate on the concepts, with a comparative approach among them.
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OBJECTIVE To analyze the scientific production about the validity and reliability of the Manchester Triage System (MTS) protocol. METHOD A descriptive study of an integrative literature review. Articles on the validity and reliability of the MTS developed with children and adults published between 1999 and 2013 were included. RESULTS 14 articles were selected from a total of 8438, nine of validity and five of reliability. The reliability of the MTS ranged from moderate to almost perfect, with higher intra-evaluation. Regarding validity, the results seem to point to equivalent and satisfactory sensibility and specificity levels of the MTS. The instrument proved to be a good predictor of the need for hospitalization and of hospital mortality. CONCLUSION The reliability and validity of the MTS obtained in the studies is varied. It is recommended that new studies indicate necessary modifications to the MTS so that it is more safely used by nurses.
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OBJECTIVE To analyze scientific production about workplace bullying and harassment in dissertations and theses in Brazil, with emphasis on the year of publication; educational institution; area of knowledge; professional and academic background of the authors; keywords used; and concept map organization. METHOD Bibliometric study with a quantitative approach with a sample consisting of 57 papers, 5 theses and 52 dissertations, published between 2002 and 2012. RESULTS It was found that 2012 was the year with the highest number of publications in this topic area. The region that stood out was the Southeast. The institution with the highest number of publications was the Federal University of Santa Catarina. There was a predominance of dissertations and most publications were produced by researchers focused on a multidisciplinary perspective. CONCLUSION Expanding the views regarding bullying in order to disseminate scientific production was proposed, promoting further advancement of debates and raising pertinent questions.
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II Resumo Cabo Verde é um país que tem acompanhado as grandes mudanças políticas, sociais, económicas e educativas, atribuindo um papel preponderante aos professores na educação/formação dos indivíduos. Neste sentido a formação inicial não pode constituir um acto “acabado” que não tem em linha de conta as mudanças que decorrem no seu seio. A formação contínua aparece com um processo de construção da mudança, apoiado no desenvolvimento profissional dos professores. A avaliação de necessidade de formação em professores do ensino secundário em Cabo Verde é o tema do trabalho de investigação, realizado nas escolas secundárias da ilha de Santo Antão, em Cabo Verde, no sentido de identificar questões problemáticas na formação inicial e contínua de professores e as suas implicações na qualidade educativa. Neste sentido, ao longo de 5 capítulos apresentamos os pontos desta investigação, estruturados de forma a se poder acompanhar a sua evolução. No 1º capítulo, apresenta-se a Problemática de Investigação, que constitui a parte inicial da dissertação, pela exposição do quadro conceptual do ensino secundário em Cabo Verde através da contextualização e identificação do problema, da formulação dos objectivos e questões de investigação. No 2º capítulo faz-se o percurso histórico/educativo de Cabo Verde, desde a época colonial, passando pela educação após a independência em 1975, à constituição da Lei de Bases do Sistema Educativo e a Reforma Educativa dos anos 90. No 3º capítulo, intitulado “A Formação Inicial e Continua de Professores em Cabo Verde”, é abordado o enquadramento teórico desta investigação, com referência à contextualização geral da formação e modelos de formação de professores, evoluindo para a realidade Cabo-verdiana, tendo em consideração as instituições de formação de professores e o contexto actual do ensino secundário em Cabo Verde. No 4º capítulo faz-se a apresentação da Metodologia de Investigação, adoptada num estudo extensivo, do qual abordamos a natureza da investigação e caracterizamos a amostra e respondentes. Como técnicas de recolha de dados, são utilizados: o inquérito por questionário (n=77), a professores do ensino secundário e o inquérito por entrevista (n=9), aos directores das escolas secundárias da ilha de Santo Antão e a formadores de professores em São Vicente. Como técnica de análise de dados, são utilizados diversos procedimentos estatísticos e a análise de conteúdo. O 5º capítulo corresponde a apresentação e discussão dos resultados da investigação desses três públicos analisados. Para finalizar, apresenta-se uma conclusão que corresponde a síntese dos resultados obtidos, propostas de sugestões de melhoria e limitações do estudo. Cabo Verde is a country willing to follow the great political, social, economic and educational changes. This important role have attributed to teachers to educate and train individuals. In this sense the initial training cannot be considered as a “finished” task without taking into consideration those changes. The in service training appears as a scientific and pedagogic autonomization towards the growing change. The Evaluation of Secondary School teacher training Needs in Cabo Verde constitutes an investigation work, carried out in Santo Antão's island Secondary schools, aiming to identify problems in initial and continuous teachers' training and their implications in the educational quality. In this sense, along five chapters we will present the points of this investigation, structured to facilitate the understanding of its evolution. In the first chapter we present the Problem of Investigation which is an introductory part of the dissertation, the conceptual theory of the Cabo Verde secondary education through the contextualization and identification of the problem, the formulation of the objectives and investigation issues. In the second chapter we present the Cabo Verde historical/educational background, from the colonial time, going through after independence in 1975, to the constitution of the Basic Educational Law of the System and the nineties Educational Reform. In the third chapter entitled “The Initial and in-service Teacher´s Training in Cabo Verde” brings the theoretical framework of this investigation, where we present a general contextualization of teachers' training and models, developed from the reality of Cabo Verde. In this regard we will consider the teachers' training institutions and the current secondary education context in Cabo Verde. In the fourth chapter we present the Research Methodology, adopted in an extensive study, of which we draw the nature of the investigation and we characterized the sample. We carried out questionnaire (n=77) to teachers, interviews (n=9) to headmasters from Santo Antão's island secondary schools and trainers from São Vicente. We used statistical analyses and content analyses as data analyse techniques. The fifth chapter deals with presentation the discussion of results of those three analyzed publics' investigation. Finally, we present a summary of the obtained results, suggestions for improvement and limitations of study.
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AbstractOBJECTIVEPresenting methodology for transferring knowledge to improve maternal outcomes in natural delivery based on scientific evidence.METHOD: An intervention study conducted in the maternity hospital of Itapecerica da Serra, SP, with 50 puerperal women and 102 medical records from July to November 2014. The PACES tool from Joanna Briggs Institute, consisting of pre-clinical audit (phase 1), implementation of best practice (phase 2) and Follow-up Clinical Audit (phase 3) was used. Data were analyzed by comparing results of phases 1 and 3 with Fisher's exact test and a significance level of 5%.RESULTSThe vertical position was adopted by the majority of puerperal women with statistical difference between phases 1 and 3. A significant increase in bathing/showering, walking and massages for pain relief was found from the medical records. No statistical difference was found in other practices and outcomes. Barriers and difficulties in the implementation of evidence-based practices have been identified. Variables were refined, techniques and data collection instruments were verified, and an intervention proposal was made.CONCLUSIONThe study found possibilities for implementing a methodology of practices based on scientific evidence for assistance in natural delivery.
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Abstract OBJECTIVE Analyzing the elements that compose the environment of pregnant women who have experienced intimate partner violence in the light of Levine's Nursing Theory. METHOD A qualitative, descriptive study conducted from September to January 2012, with nine pregnant women in a Municipal Health Center in Rio de Janeiro. The interviews were semi-structured and individual. The theoretical framework was based on Levine's Nursing Theory. RESULTS Thematic analysis evidenced the elements that composed the external environment, such as violence perpetrated by intimate partners before and during pregnancy, violence in childhood and adolescence, alcohol consumption and drug use by the partner, unemployment, low education and economic dependency, which affected health and posed risks to the pregnancy. CONCLUSION Violence perpetrated by an intimate partner was the main external factor that influenced the internal environment with repercussions on health. This theory represents a tool in nursing care which will aid in detecting cases and the fight against violence.