925 resultados para Four Level Frame Work
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La present Tesi Doctoral, titulada desenvolupament computacional de la semblança molecular quàntica, tracta, fonamentalment, els aspectes de càlcul de mesures de semblança basades en la comparació de funcions de densitat electrònica.El primer capítol, Semblança quàntica, és introductori. S'hi descriuen les funcions de densitat de probabilitat electrònica i llur significança en el marc de la mecànica quàntica. Se n'expliciten els aspectes essencials i les condicions matemàtiques a satisfer, cara a una millor comprensió dels models de densitat electrònica que es proposen. Hom presenta les densitats electròniques, mencionant els teoremes de Hohenberg i Kohn i esquematitzant la teoria de Bader, com magnituds fonamentals en la descripció de les molècules i en la comprensió de llurs propietats.En el capítol Models de densitats electròniques moleculars es presenten procediments computacionals originals per l'ajust de funcions densitat a models expandits en termes de gaussianes 1s centrades en els nuclis. Les restriccions físico-matemàtiques associades a les distribucions de probabilitat s'introdueixen de manera rigorosa, en el procediment anomenat Atomic Shell Approximation (ASA). Aquest procediment, implementat en el programa ASAC, parteix d'un espai funcional quasi complert, d'on se seleccionen variacionalment les funcions o capes de l'expansió, d'acord als requisits de no negativitat. La qualitat d'aquestes densitats i de les mesures de semblança derivades es verifica abastament. Aquest model ASA s'estén a representacions dinàmiques, físicament més acurades, en quant que afectades per les vibracions nuclears, cara a una exploració de l'efecte de l'esmorteïment dels pics nuclears en les mesures de semblança molecular. La comparació de les densitats dinàmiques respecte les estàtiques evidencia un reordenament en les densitats dinàmiques, d'acord al que constituiria una manifestació del Principi quàntic de Le Chatelier. El procediment ASA, explícitament consistent amb les condicions de N-representabilitat, s'aplica també a la determinació directe de densitats electròniques hidrogenoides, en un context de teoria del funcional de la densitat.El capítol Maximització global de la funció de semblança presenta algorismes originals per la determinació de la màxima sobreposició de les densitats electròniques moleculars. Les mesures de semblança molecular quàntica s'identifiquen amb el màxim solapament, de manera es mesuri la distància entre les molècules, independentment dels sistemes de referència on es defineixen les densitats electròniques. Partint de la solució global en el límit de densitats infinitament compactades en els nuclis, es proposen tres nivells de aproximació per l'exploració sistemàtica, no estocàstica, de la funció de semblança, possibilitant la identificació eficient del màxim global, així com també dels diferents màxims locals. Es proposa també una parametrització original de les integrals de recobriment a través d'ajustos a funcions lorentzianes, en quant que tècnica d'acceleració computacional. En la pràctica de les relacions estructura-activitat, aquests avenços possibiliten la implementació eficient de mesures de semblança quantitatives, i, paral·lelament, proporcionen una metodologia totalment automàtica d'alineació molecular. El capítol Semblances d'àtoms en molècules descriu un algorisme de comparació dels àtoms de Bader, o regions tridimensionals delimitades per superfícies de flux zero de la funció de densitat electrònica. El caràcter quantitatiu d'aquestes semblances possibilita la mesura rigorosa de la noció química de transferibilitat d'àtoms i grups funcionals. Les superfícies de flux zero i els algorismes d'integració usats han estat publicats recentment i constitueixen l'aproximació més acurada pel càlcul de les propietats atòmiques. Finalment, en el capítol Semblances en estructures cristal·lines hom proposa una definició original de semblança, específica per la comparació dels conceptes de suavitat o softness en la distribució de fonons associats a l'estructura cristal·lina. Aquests conceptes apareixen en estudis de superconductivitat a causa de la influència de les interaccions electró-fonó en les temperatures de transició a l'estat superconductor. En aplicar-se aquesta metodologia a l'anàlisi de sals de BEDT-TTF, s'evidencien correlacions estructurals entre sals superconductores i no superconductores, en consonància amb les hipòtesis apuntades a la literatura sobre la rellevància de determinades interaccions.Conclouen aquesta tesi un apèndix que conté el programa ASAC, implementació de l'algorisme ASA, i un capítol final amb referències bibliogràfiques.
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“…we have to take into account the fact that museology and museums are two completely different things.” Martin R. Shärer[1] In the 20th century, growing populations produced a growing body of heritage. The transmission of this heritage to succeeding generations coalesced into three major modern institutions: universities, library/archives and museums. Traditional systems of social and cultural memory had become overloaded and therefore evolved conceptually. This evolution took place within the primary context of a naturally occurring museology through the process I call museogenesis. The term museogenesis refers to the origin and development of museological thought in a specific cultural context. By museological thought, I refer to ideas and theories surrounding the parameters of “the natural and cultural heritage, the activities concerned with the preservation and communication of this heritage, the institutional frame-work, and society as a whole” (Mensch 1992). This broadly inclusive definition relates museology to another broadly defined concept: cultural context. By cultural context, I refer to the “webs of significance and systems of meaning which is the collective property of a group” (Geertz 1973). [1] ICOFOM Study Series – ISS 34, 2003, ISS 34_03.pdf, p.7
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None of the current surveillance streams monitoring the presence of scrapie in Great Britain provide a comprehensive and unbiased estimate of the prevalence of the disease at the holding level. Previous work to estimate the under-ascertainment adjusted prevalence of scrapie in Great Britain applied multiple-list capture–recapture methods. The enforcement of new control measures on scrapie-affected holdings in 2004 has stopped the overlapping between surveillance sources and, hence, the application of multiple-list capture–recapture models. Alternative methods, still under the capture–recapture methodology, relying on repeated entries in one single list have been suggested in these situations. In this article, we apply one-list capture–recapture approaches to data held on the Scrapie Notifications Database to estimate the undetected population of scrapie-affected holdings with clinical disease in Great Britain for the years 2002, 2003, and 2004. For doing so, we develop a new diagnostic tool for indication of heterogeneity as well as a new understanding of the Zelterman and Chao’s lower bound estimators to account for potential unobserved heterogeneity. We demonstrate that the Zelterman estimator can be viewed as a maximum likelihood estimator for a special, locally truncated Poisson likelihood equivalent to a binomial likelihood. This understanding allows the extension of the Zelterman approach by means of logistic regression to include observed heterogeneity in the form of covariates—in case studied here, the holding size and country of origin. Our results confirm the presence of substantial unobserved heterogeneity supporting the application of our two estimators. The total scrapie-affected holding population in Great Britain is around 300 holdings per year. None of the covariates appear to inform the model significantly.
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None of the current surveillance streams monitoring the presence of scrapie in Great Britain provide a comprehensive and unbiased estimate of the prevalence of the disease at the holding level. Previous work to estimate the under-ascertainment adjusted prevalence of scrapie in Great Britain applied multiple-list capture-recapture methods. The enforcement of new control measures on scrapie-affected holdings in 2004 has stopped the overlapping between surveillance sources and, hence, the application of multiple-list capture-recapture models. Alternative methods, still under the capture-recapture methodology, relying on repeated entries in one single list have been suggested in these situations. In this article, we apply one-list capture-recapture approaches to data held on the Scrapie Notifications Database to estimate the undetected population of scrapie-affected holdings with clinical disease in Great Britain for the years 2002, 2003, and 2004. For doing so, we develop a new diagnostic tool for indication of heterogeneity as well as a new understanding of the Zelterman and Chao's lower bound estimators to account for potential unobserved heterogeneity. We demonstrate that the Zelterman estimator can be viewed as a maximum likelihood estimator for a special, locally truncated Poisson likelihood equivalent to a binomial likelihood. This understanding allows the extension of the Zelterman approach by means of logistic regression to include observed heterogeneity in the form of covariates-in case studied here, the holding size and country of origin. Our results confirm the presence of substantial unobserved heterogeneity supporting the application of our two estimators. The total scrapie-affected holding population in Great Britain is around 300 holdings per year. None of the covariates appear to inform the model significantly.
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Driven by a range of modern applications that includes telecommunications, e-business and on-line social interaction, recent ideas in complex networks can be extended to the case of time-varying connectivity. Here we propose a general frame- work for modelling and simulating such dynamic networks, and we explain how the long time behaviour may reveal important information about the mechanisms underlying the evolution.
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Objective The relationship between sex/gender differences and autism has attracted a variety of research ranging from clinical, neurobiological to etiological, stimulated by the male bias in autism prevalence. Findings are complex and do not always relate to each other in a straightforward manner. Distinct but interlinked questions on the relationship between sex/gender differences and autism remain under addressed. To better understand the implications from existing research and to help design future studies, we propose a four-level conceptual framework to clarify the embedded themes. Method We searched PubMed for publications before September 2014 using search terms “‘sex OR gender OR females’ AND autism.” 1,906 citations were screened for relevance, along with publications identified via additional literature reviews, resulting in 329 reports that were reviewed. Results Level 1 “Nosological and diagnostic challenges” concerns the question “How should autism be defined and diagnosed in males and females?” Level 2 “Sex/gender-independent and sex/gender-dependent characteristics” addresses the question “What are the similarities and differences between males and females with autism?” Level 3 “General models of etiology: liability and threshold” asks the question “How is the liability for developing autism linked to sex/gender?” Level 4 “Specific etiological-developmental mechanisms” focuses on the question “What etiological-developmental mechanisms of autism are implicated by sex/gender and/or sexual/gender differentiation?” Conclusions Using this conceptual framework, findings can be more clearly summarized, and the implications of the links between findings from different levels can become clearer. Based on this four-level framework, we suggest future research directions, methodology, and specific topics in sex/gender differences and autism.
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This thesis consists of three chapters that have as unifying subject the frame-work of common agency with informed principals. The first two chapters analyze the economic effects of privately informed lobbying applied to tariff protection (Chapter 1) and to customs unions agreements (Chapter 2). The third chapter investigates the choice of retailing strutures when principals (the producers) are privately informed about their production costs. Chapter 1 analyzes how lobbying affects economic policy when the interest groups have private information. I assume that the competitiveness of producers are lobbies private information in a Grossman and Helpman (1994) lobby game. This allows us to analyze the e¤ects of information transmission within their model. I show that the information transmission generates two informational asymmetry problems in the political game. One refers to the cost of signaling the lobby's competitiveness to the policy maker and the other to the cost of screening the rival lobby's competitiveness from the policy maker. As an important consequence information transmission may improve welfare through the reduction of harmful lobbying activity. Chapter 2 uses the framework of chapter 1 to study a customs union agreement when governments are subject to the pressure of special interest groups that have better information about the competitiveness of the industries they represent. I focus on the agreement's effect on the structure of political influence. When join a customs union, the structure of political pressure changes and with privately informed lobbies, a new effect emerges: the governments can use the information they learn from the lobby of one country to extract rents from the lobbies of the other country. I call this the "information transmission effect". This effect enhances the governments'bargaining power in a customs union and makes lobbies demand less protection. Thus, I find that information transmission increases the welfare of the agreement and decreases tari¤s towards non-members. I also investigate the incentives for the creation of a customs union and find that information transmission makes such agreement more likely to be politically sustainable. Chapter 3 investigates the choice of retailing structure when the manufacturers are privately informed about their production costs. Two retailing structures are analyzed, one where each manufacturer chooses her own retailer (exclusive dealing) and another where the manufacturers choose the same retailer (common agency). It is shown that common agency mitigates downstream competition but gives the retailer bargaining power to extract informational rents from the manufacturers, while in exclusive dealing there is no downstream coordination but also there are no incentives problem in the contract between manufacture and retailer. A pre- liminary characterization of the choice of the retailing structure for the case of substitute goods shows that when the uncertainty about the cost increases relatively to the size of the market, exclusive dealing tends to be the chosen retailing structure. On the other hand, when the market is big relatively to the costs, common agency emerges as the retailing structure. This thesis has greatly benefited from the contribution of Professors Humberto Moreira and Thierry Verdier. It also benefited from the stimulating environment of the Toulouse School of Economics, where part of this work was developed during the year of 2007.
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A abordagem do Value at Risk (VAR) neste trabalho será feita a partir da análise da curva de juros por componentes principais (Principal Component Analysis – PCA). Com essa técnica, os movimentos da curva de juros são decompostos em um pequeno número de fatores básicos independentes um do outro. Entre eles, um fator de deslocamento (shift), que faz com que as taxas da curva se movam na mesma direção, todas para cima ou para baixo; de inclinação (twist) que rotaciona a curva fazendo com que as taxas curtas se movam em uma direção e as longas em outra; e finalmente movimento de torção, que afeta vencimentos curtos e longos no mesmo sentido e vencimentos intermediários em sentido oposto. A combinação destes fatores produz cenários hipotéticos de curva de juros que podem ser utilizados para estimar lucros e perdas de portfolios. A maior perda entre os cenários gerados é uma maneira intuitiva e rápida de estimar o VAR. Este, tende a ser, conforme verificaremos, uma estimativa conservadora do respectivo percentual de perda utilizado. Existem artigos sobre aplicações de PCA para a curva de juros brasileira, mas desconhecemos algum que utilize PCA para construção de cenários e cálculo de VAR, como é feito no presente trabalho.Nesse trabalho, verificaremos que a primeira componente principal produz na curva um movimento de inclinação conjugado com uma ligeira inclinação, ao contrário dos resultados obtidos em curvas de juros de outros países, que apresentam deslocamentos praticamente paralelos.
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When, in a dynamic model, choices by an agent : i) are not observed, and; ii) affect preferences conditional on the realization of types, new and unexpected features come up in Mirrlees’ (1971) optimal taxation frame- work. In the simplest possible model where a non-trivial filtration may be incorporated, we show how these two characteristics make it neces- sary for IC constraints to be defined in terms of strategies rather than pure announcements. Tax prescriptions are derived, and we are able to show that uniform taxation prescription of Atkinson and Stiglitz fails to hold, in general. Clean results regarding capital income taxation are not easy to come about because usual assumption on preferences do not allow for determining which constraints bind at the optimum. However, in the most ’natural’ cases, we show that return on capital ought to be taxed.
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This project refers to a study somewhat controversial , as in focusing less recognized and valued hand, although the dynamics of tourism pass to take another view , you can not beforehand consider favorable or unfavorable . Analyzes the phenomenon related to conception or perception of poverty from tourism residents and non residents of the Favela of Rocinha in Rio de Janeiro tourist guides . It is a subject to an object of research somewhat controversial , but about which there is already an academic and scientific concern and deserves an investigator look. Fits as a qualitative study whose methodological procedure based on interviews and participant observation , and the geographic divisions chosen the Rocinha slum , for its expressiveness and for being a pioneer in this type of tourism , had to conducting fieldwork lasting six months, which was accompanied by at least four hours walking work of sixteen tour guides, eight residents and eight non- residents in the community, working for different travel agencies and tourism. End of each tour, all tour guides answered a semi-structured questionnaire, containing nineteen questions. Most respondents tour guides authorized record interview, which has made it possible to analyze the speech through spoken language. In tourism, foreign tourists are the main target, although rarely also count with the participation of domestic tourists. Notes that the relationship between poverty and slums, from the perceptions of tourist guides residents better reflects the reality of favela residents compared with non residents guides, since they fully know all the intricacies and better the difficulties they have endured and still go, when it comes to the issue of stigmatization respect, by which has suffered by Brazilian society, in relation to live in slums, and have your dwelling place as a tourist attraction. While presenting the social reality of Rocinha consistently during his work, the non residents guides worry about being as natural as possible with tourists as much as the locals show slum, in the same way they avoid authorize tourists to take compromising photos and that will expose the intimacy of community residents . Concludes that, while recognizing the importance of elevation to the rank of tourist attraction and its promising prospects, requires attention and priority, given the greater precariousness of the human condition in relation to the prime areas in which it operates tourism should be a vector of development, not a masking of reality
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O estudo foi conduzido com o objetivo de avaliar os efeitos da inclusão de farelo de trigo (FT) na ração sobre o desempenho de frangas semipesadas nas fases de recria 1 (7 a 14 semanas de idade) e recria 2 (15 a 19 semanasde idade) e seu efeito residual durante a fase inicial de produção de ovos. Foram utilizadas 160 frangas Lohmann Brown distribuídas em delineamento inteiramente casualizado, com quatro níveis de FT na ração: 0 (controle), 10, 20 e 30%, que resultaram em quatro tratamentos, com cinco repetições de oito aves na fase de recria 1. Ao completarem 14 semanas, as aves foram transferidas para gaiolas de arame galvanizado, redistribuídas em seis repetições de seis aves. Utilizaram-se 144 aves e descartaram-se, aleatoriamente, quatro aves por tratamento, constituindo a fase de recria 2. A adição de FT diminuiu linearmente o peso vivo final e o ganho de peso, resultando em reduções de 1,15 e 0,03 g, respectivamente, para cada 1% de inclusão de FT na ração. O consumo de água aumentou de forma quadrática e cresceu, em valores absolutos, com o aumento de 0 a 30% de farelo de trigo. A cada aumento de 1% de FT na ração, a idade das aves ao primeiro ovo elevou aproximadamente 0,6 dia e o peso do ovo em 0,22 g. A inclusão de farelo de trigo na ração reduz a taxa de crescimento de frangas, atrasa o início da postura, mas melhora o peso inicial dos ovos em relação a dietas à base de milho e de farelo de soja.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Liposarcus anisitsi is an armoured catfish that presents accessorial air oxygenation through a modified stomach, which allows this species to survive in waters with very low oxygen content. Analysis of its haemolysate has shown the presence of four haemoglobins; this work focuses on the main component, haemoglobin I. It has been crystallized in two different forms and X-ray diffraction data have been collected to 2.77 and 2.86 Angstrom resolution using synchrotron radiation. Crystals were determined to belong to the space groups C2 and P2(1) and preliminary structural analysis revealed the presence of one tetramer in the asymmetric unit in both crystal forms. The structure was determined using a standard molecular-replacement technique.
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The intra- and intermolecular rates of degradation of cephaclor were determined with and without hexadecyltrimethylammonium bromide (CTABr). Micellar-derived spectral shifts were used to measure the association of the ionic forms as well as to determine the effect of CTABr on the apparent acid dissociation constant of the antibiotic. The rate of degradation of cephaclor increased with detergent and was salt sensitive. Micellar effects were analyzed quantitatively within the frame-work of the speudophase ion exchange model. All experimental data were fitted to this model which was used to predict the combined effects of pH and detergent concentration. Micelles increased the rate of OH- attack on cephaclor; most of the effect was due to the concentration of reagents in the micellar pseudophase. The intramolecular degradation was catalyzed 25-fold by micelles, and a working hypothesis to rationalize this effect is proposed. The results demonstrate that quantitative analysis can be utilized to assess and predict effects of detergents on drug stability.
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The purpose of this work is to know the forms of minding to the alcoholics in extra-hospitable services of mental health in Botucatu municipality. This places are: Mental Health Ambulatory and School Health Center both of the Medicine College of the Paulista State University and Mental Health Ambulatory of the NGA-11. For the development of this work was realized a bibliographic raising, presented in the introduction. Four professionals that work in this assistance were interviewed. The data that was collected in the interviews were reported with the literature of the area allowing the knowledge of the main characteristics of the minding to the alcoholist in the three services that were consulted. For example: groupal minding, minding to the family and the kind of therapeutic contract.