932 resultados para inductive reasoning


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Utilizing the well-known Ultimatum Game, this note presents the following phenomenon. If we start with simple stimulus-response agents,learning through naive reinforcement, and then grant them some introspective capabilities, we get outcomes that are not closer but farther away from the fully introspective game-theoretic approach. The cause of this is the following: there is an asymmetry in the information that agents can deduce from their experience, and this leads to a bias in their learning process.

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"Beauty-contest" is a game in which participants have to choose, typically, a number in [0,100], the winner being the person whose number is closest to a proportion of the average of all chosen numbers. We describe and analyze Beauty-contest experiments run in newspapers in UK, Spain, and Germany and find stable patterns of behavior across them, despite the uncontrollability of these experiments. These results are then compared with lab experiments involving undergraduates and game theorists as subjects, in what must be one of the largest empirical corroborations of interactive behavior ever tried. We claim that all observed behavior, across a wide variety of treatments and subject pools, can be interpretedas iterative reasoning. Level-1 reasoning, Level-2 reasoning and Level-3 reasoning are commonly observed in all the samples, while the equilibrium choice (Level-Maximum reasoning) is only prominently chosen by newspaper readers and theorists. The results show the empirical power of experiments run with large subject-pools, and open the door for more experimental work performed on the rich platform offered by newspapers and magazines.

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Whereas much literature has documented difficulties in making probabilistic inferences, it hasalso emphasized the importance of task characteristics in determining judgmental accuracy.Noting that people exhibit remarkable efficiency in encoding frequency information sequentially,we construct tasks that exploit this ability by requiring people to experience the outcomes ofsequentially simulated data. We report two experiments. The first involved seven well-knownprobabilistic inference tasks. Participants differed in statistical sophistication and answered withand without experience obtained through sequentially simulated outcomes in a design thatpermitted both between- and within-subject analyses. The second experiment involvedinterpreting the outcomes of a regression analysis when making inferences for investmentdecisions. In both experiments, even the statistically naïve make accurate probabilistic inferencesafter experiencing sequentially simulated outcomes and many prefer this presentation format. Weconclude by discussing theoretical and practical implications.

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abstract: Cape Verde is a country of bilingual characteristics, where coexist two languages: the mother tongue – the Creole of Cape Verde (CCV) or the Capeverdian Language (LCV) and the Non Maternal language – the Portuguese that is the official language and, therefore, the language used in the process of education and learning. This situation generates conflicts so much to linguistic level as to cultural level. The two languages presents some lexical resemblances, what drives, many times, to misconceptions and linguistics errors that complicate children in the learning, in particular, of reading that constitute the base for the learning of others knowledge. The learning of reading, in the Non Maternal language, requires a development of the oral language in Portuguese Language, which stimulates the reasoning of the child through playful exercises and cognitivists and construtivists approaches. In this way, the competences of phonological processing in the acquisition of the competences of reading are important for the discrimination of written text and favor the learning and the development of reading. The child, through the discovery, begins to elaborate concepts in the way to obtain a relation with the written language, by functional form. Adopting a methodology of case study and through questionnaires, direct observation and collect of documentary information, this dissertation presents and analyzes connected aspects to the literacy of capeverdian children in the beginning of the schooling and to the learning of reading as basic support for the learning of Non Maternal language. The subsidies collected by the study, presented in this dissertation will contribute for the education progress of reading and, also, for implement successfully the learning of reading of the students, developing to practical of reading and the expectations in uncover the multiplicity of the dimensions of experience in that domain and contribute for a relative comprehension of written and reading modes.

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abstract: Cape Verde is a country of bilingual characteristics, where coexist two languages: the mother tongue – the Creole of Cape Verde (CCV) or the Capeverdian Language (LCV) and the Non Maternal language – the Portuguese that is the official language and, therefore, the language used in the process of education and learning. This situation generates conflicts so much to linguistic level as to cultural level. The two languages presents some lexical resemblances, what drives, many times, to misconceptions and linguistics errors that complicate children in the learning, in particular, of reading that constitute the base for the learning of others knowledge. The learning of reading, in the Non Maternal language, requires a development of the oral language in Portuguese Language, which stimulates the reasoning of the child through playful exercises and cognitivists and construtivists approaches. In this way, the competences of phonological processing in the acquisition of the competences of reading are important for the discrimination of written text and favor the learning and the development of reading. The child, through the discovery, begins to elaborate concepts in the way to obtain a relation with the written language, by functional form. Adopting a methodology of case study and through questionnaires, direct observation and collect of documentary information, this dissertation presents and analyzes connected aspects to the literacy of capeverdian children in the beginning of the schooling and to the learning of reading as basic support for the learning of Non Maternal language. The subsidies collected by the study, presented in this dissertation will contribute for the education progress of reading and, also, for implement successfully the learning of reading of the students, developing to practical of reading and the expectations in uncover the multiplicity of the dimensions of experience in that domain and contribute for a relative comprehension of written and reading modes.

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Nesta dissertação procura-se analisar a problemática da “Centralização versus Descentralização na Governação do Sistema Educativo de Cabo Verde: lógicas em análise” no período compreendido entre (1975 a 2006). Constata-se que Cabo Verde, depois de se tornar um país soberano e independente, assistiu a momentos de grande concentração e de grande centralização na administração do Sistema Educativo. Ao longo deste período assistiuse também a momentos de desconcentração e de ideias de descentralização que culminaram com a abertura do sistema político pluripartidário. Essa abertura abriu a possibilidade de uma nova dinâmica de transformação nos deferentes sectores da administração do sistema educacional. As mudanças políticas verificadas no país, permite-nos conhecer e desocultar as razões, as lógicas e as racionalidades que presidem a manutenção de um sistema centralizado de governação do Sistema Educativo, apesar da presença de forças políticas com diversidades ideológicas. Uma vez conhecido o historial da organização, administração e gestão do Sistema Educativo Cabo-verdiano, a partir de uma retrospectiva histórica, debruçámo-nos sobre as principais teorias que estão na base das perspectivas da centralização e descentralização, e seus conceitos associados enquanto modelo de análise teórica, para tentar perceber este aparente paradoxo. Na parte empírica, a metodologia utilizada apoia-se na abordagem qualitativa de investigação, na qual utilizámos a entrevista, a análise documental e conversas informais, que nos permitiram confirmar ou infirmar a problemática inicialmente formulada. Os dados obtidos dez entrevistados, nomeadamente os responsáveis da política educativa, os administradores do sistema, e os directores dos estabelecimentos de ensino público, levam-nos a tirar várias conclusões sobre um Sistema Educativo centralizado, com uma relativa margem de autonomia. Apesar de encontrarem algumas vantagens no modelo centralizado, a maioria dos entrevistados sublinha a relevância da opção por um modelo descentralizado de governação do Sistema Educativo.

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We perform an experiment on a pure coordination game with uncertaintyabout the payoffs. Our game is closely related to models that have beenused in many macroeconomic and financial applications to solve problemsof equilibrium indeterminacy. In our experiment each subject receives anoisy signal about the true payoffs. This game has a unique strategyprofile that survives the iterative deletion of strictly dominatedstrategies (thus a unique Nash equilibrium). The equilibrium outcomecoincides, on average, with the risk-dominant equilibrium outcome ofthe underlying coordination game. The behavior of the subjects convergesto the theoretical prediction after enough experience has been gained. The data (and the comments) suggest that subjects do not apply through"a priori" reasoning the iterated deletion of dominated strategies.Instead, they adapt to the responses of other players. Thus, the lengthof the learning phase clearly varies for the different signals. We alsotest behavior in a game without uncertainty as a benchmark case. The gamewith uncertainty is inspired by the "global" games of Carlsson and VanDamme (1993).

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In an experiment we study market outcomes under alternative incentive structures for third-party enforcers. Our transactions resemble an anonymous credit market where lenders can give loans and borrowers can repay them. When borrowers default, judges are free to enforce repayment but are themselves paid differently in each of three treatments. First, paying judges according to lenders votes maximizes surplus and the equality of earnings. In contrast, paying judges according to borrowers votes triggers insufficient enforcement, destroying the market and producing the lowest surplus and the most unequal distribution of earnings. Lastly, judges paid the average earnings of borrowers and lenders achieve results close to those based on lender voting. We employ a steps-of-reasoning argument to interpret the performances of different institutions. When voting and enforcement rights are allocated to different classes of actors, the difficulty of their task changes, and arguably as a consequence they focus on high or low surplus equilibria.

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We run experiments on English Auctions where the bidders already own a part (toehold) ofthe good for sale. The theory predicts a very strong effect of even small toeholds, however wefind the effects are not so strong in the lab. We explain this by analyzing the flatness of thepayoff functions, which leads to relatively costless deviations from the equilibrium strategies.We find that a levels of reasoning model explains the results better than the Nash equilibrium.Moreover, we find that although big toeholds can be effective, the cost to acquire them mightbe higher than the strategic benefit they bring. Finally our results show that in general theseller s revenues fall when the playing field is uneven.

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OBJECTIVE: To measure the in vivo variations of CYP3A activity induced by anti-HIV drugs in human immunodeficiency virus (HIV)1-positive patients. METHODS: A low oral dose of midazolam (MID) (0.075 mg) was given to the patients and the 30-min total 1-OH midazolam (1-OHMID)/MID ratio was determined. Patients were phenotyped either before the introduction of antiretroviral treatments (control group, 90 patients) or after a variable period of antiretroviral treatment (56 patients). Twenty-one subjects underwent multiple phenotyping tests (before and during the course of the treatment). RESULTS: The median MID ratio was 3.51 in the control group (range 0.20-14.6). It was 5-fold higher in the group with efavirenz (28 patients; median, range: 16.0, 3.81-367; P < 0.0001), 13-fold lower with nelfinavir (18 patients; 0.27, 0.06-36.3; P < 0.0001), 17-fold lower with efavirenz + ritonavir (three patients; 0.21, 0.05-0.47; P = 0.006), 50-fold lower with ritonavir (four patients; 0.07, 0.06-0.17; P = 0.0007), and 7-fold lower with nevirapine + (ritonavir or nelfinavir or grapefruit juice) (three patients; 0.48, 0.03-1.83; P = 0.03). CYP3A activity was lower in the efavirenz + ritonavir group (P = 0.01) and in the ritonavir group (P = 0.04) than in the nelfinavir group, although already strongly inhibited in the latter. CONCLUSION: The low-dose MID phenotyping test was successfully used to measure the in vivo variations of CYP3A activity induced by antiretroviral drugs. Efavirenz strongly induces CYP3A activity, while ritonavir almost completely inhibits it. Nelfinavir strongly decreases CYP3A activity, but to a lesser extent than ritonavir. The inhibition of CYP3A by ritonavir or nelfinavir offsets the inductive effects of efavirenz or nevirapine administered concomitantly. Finally, no induction of CYP3A activity was noticeable after long-term administration of ritonavir at low dosages (200 mg/day b.i.d.) or of nelfinavir at standard dosages (2,500 mg/day b.i.d.).

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BACKGROUND: There are guidelines on how to develop a food challenge protocol, but at present there is no gold standard guidance on method, and separate units produce differing protocols. METHODS: We performed a retrospective analysis of 200 patients' data from the paediatric allergy units in Lausanne and Geneva, Western Switzerland, and St Thomas' Hospital (STH), UK. RESULTS: St Thomas' Hospital has a younger cohort with a lower overall mean spIgE (2.36 kU/l vs 8.00 kU/l, P = 0.004). The target peanut protein volumes differed: Switzerland 4.4 g vs STH 8.4 g. Despite this, the dose actually achieved in positive challenges was not significantly different (2.33 g vs 1.49 g, P = 0.16). 26% of challenges reacted at 4 g or more of peanut protein. CONCLUSIONS: The differences in results highlight how the variation in reasoning behind food challenge alters the outcome. Standardization of food challenges would allow easy comparison between hospitals and geographical areas for research purposes.

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Repetition of environmental sounds, like their visual counterparts, can facilitate behavior and modulate neural responses, exemplifying plasticity in how auditory objects are represented or accessed. It remains controversial whether such repetition priming/suppression involves solely plasticity based on acoustic features and/or also access to semantic features. To evaluate contributions of physical and semantic features in eliciting repetition-induced plasticity, the present functional magnetic resonance imaging (fMRI) study repeated either identical or different exemplars of the initially presented object; reasoning that identical exemplars share both physical and semantic features, whereas different exemplars share only semantic features. Participants performed a living/man-made categorization task while being scanned at 3T. Repeated stimuli of both types significantly facilitated reaction times versus initial presentations, demonstrating perceptual and semantic repetition priming. There was also repetition suppression of fMRI activity within overlapping temporal, premotor, and prefrontal regions of the auditory "what" pathway. Importantly, the magnitude of suppression effects was equivalent for both physically identical and semantically related exemplars. That the degree of repetition suppression was irrespective of whether or not both perceptual and semantic information was repeated is suggestive of a degree of acoustically independent semantic analysis in how object representations are maintained and retrieved.

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In recent years there has been an explosive growth in the development of adaptive and data driven methods. One of the efficient and data-driven approaches is based on statistical learning theory (Vapnik 1998). The theory is based on Structural Risk Minimisation (SRM) principle and has a solid statistical background. When applying SRM we are trying not only to reduce training error ? to fit the available data with a model, but also to reduce the complexity of the model and to reduce generalisation error. Many nonlinear learning procedures recently developed in neural networks and statistics can be understood and interpreted in terms of the structural risk minimisation inductive principle. A recent methodology based on SRM is called Support Vector Machines (SVM). At present SLT is still under intensive development and SVM find new areas of application (www.kernel-machines.org). SVM develop robust and non linear data models with excellent generalisation abilities that is very important both for monitoring and forecasting. SVM are extremely good when input space is high dimensional and training data set i not big enough to develop corresponding nonlinear model. Moreover, SVM use only support vectors to derive decision boundaries. It opens a way to sampling optimization, estimation of noise in data, quantification of data redundancy etc. Presentation of SVM for spatially distributed data is given in (Kanevski and Maignan 2004).

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Les questions de mal-être au travail et de risques psychosociaux sont centrales dans le monde du travail actuel. L'ergonomie nous enseigne qu'une analyse des formes d'organisation du travail est nécessaire pour comprendre les origines des plaintes des travailleurs. Dans cette recherche, nous avons étudié une population spécifique, les employés du siège d'une organisation non gouvernementale humanitaire en Suisse (150 personnes environ). Partant du constat de l'expression de nombreuses plaintes de fatigue et de mal-être au travail par ces employés, nous avons cherché à objectiver ces plaintes et avons étudié les éléments d'organisation susceptibles d'y être liés.Dans le cadre d'une démarche inductive, nous avons utilisé conjointement des méthodes qualitatives (entretiens semi-directifs, observation non participante) et quantitatives (questionnaires) et avons appliqué le principe de triangulation méthodologique pour l'analyse des données.Trois thématiques relatives au mode de fonctionnement de l'organisation ont émergé des analyses : le fonctionnement dans l'urgence en permanence, la professionnalisation de l'organisation et le fort engagement des employés dans leur activité.L'organisation fonctionne selon une logique d'urgence en permanence. La nature de ses interventions, qui sont considérées de la plus haute importance, et la forte valorisation des activités « de terrain » conduisent à l'enfermement de l'activité dans la gestion des tâches urgentes, ce qui ne laisse pas de place à l'anticipation et à la planification. Ensuite, cette organisation a connu une forte croissance au cours des dernières décennies : d'une petite association, elle est devenue une véritable institution. La logique de fonctionnement institutionnelle n'est cependant pas venue remplacer totalement la logique associative, mais toutes deux cohabitent. L'organisation continue à demander à ses employés un engagement associatif et militant total mais applique parallèlement un management de type entrepreneurial, ce qui génère des messages paradoxaux pour les employés. Finalement, le fonctionnement de l'organisation dans son ensemble repose sur l'engagement de toute la chaîne des acteurs. Ceci est clairement intégré et repris par les employés du siège : ils relèvent que ce qu'ils font représente bien plus qu'un travail et qu'il est nécessaire de « tout donner », car les besoins sont immenses et la charge de travail énorme. Cependant, la limite entre engagement et surengagement conduisant à l'épuisement est très facilement franchie.Ces éléments participent à générer un environnement de travail potentiellement pathogène, où il est peu légitime pour l'employé de se préoccuper de sa propre santé, et où la charge de travail et le rythme ne lui laissent pas le temps de mettre en place des stratégies de préservation de sa santé. Ce mode de fonctionnement spécifique véhicule des messages paradoxaux et soumet les employés à des exigences contradictoires.

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The thymus develops from the third pharyngeal pouch of the anterior gut and provides the necessary environment for thymopoiesis (the process by which thymocytes differentiate into mature T lymphocytes) and the establishment and maintenance of self-tolerance. It contains thymic epithelial cells (TECs) that form a complex three-dimensional network organized in cortical and medullary compartments, the organization of which is notably different from simple or stratified epithelia. TECs have an essential role in the generation of self-tolerant thymocytes through expression of the autoimmune regulator Aire, but the mechanisms involved in the specification and maintenance of TECs remain unclear. Despite the different embryological origins of thymus and skin (endodermal and ectodermal, respectively), some cells of the thymic medulla express stratified-epithelium markers, interpreted as promiscuous gene expression. Here we show that the thymus of the rat contains a population of clonogenic TECs that can be extensively cultured while conserving the capacity to integrate in a thymic epithelial network and to express major histocompatibility complex class II (MHC II) molecules and Aire. These cells can irreversibly adopt the fate of hair follicle multipotent stem cells when exposed to an inductive skin microenvironment; this change in fate is correlated with robust changes in gene expression. Hence, microenvironmental cues are sufficient here to re-direct epithelial cell fate, allowing crossing of primitive germ layer boundaries and an increase in potency.