Thermodynamics of Ising model with infinite-range interactions by generalized canonical ensemble

In this work we present the idea of how generalized ensembles can be used to simplify the operational study of non-additive physical systems. As alternative of the usual methods of direct integration or mean-field theory, we show how the solution of the Ising model with infinite-range interactions is obtained by using a generalized canonical ensemble. We describe how the thermodynamical properties of this model in the presence of an external magnetic field are founded by simple parametric equations. Without impairing the usual interpretation, we obtain an identical critical behaviour as observed in traditional approaches.

Thermal effective Lagrangian of static gravitational fields

We compute the effective Lagrangian of static gravitational fields interacting with thermal fields. Our approach employs the usual imaginary time formalism as well as the equivalence between the static and space-time independent external gravitational fields. This allows to obtain a closed form expression for the thermal effective Lagrangian in d space-time dimensions.

Statistical Information: A Bayesian Perspective

We explore the meaning of information about quantities of interest. Our approach is divided in two scenarios: the analysis of observations and the planning of an experiment. First, we review the Sufficiency, Conditionality and Likelihood principles and how they relate to trivial experiments. Next, we review Blackwell Sufficiency and show that sampling without replacement is Blackwell Sufficient for sampling with replacement. Finally, we unify the two scenarios presenting an extension of the relationship between Blackwell Equivalence and the Likelihood Principle.

Regularity at infinity of real mappings and a Morse-Sard theorem

We prove a new Morse-Sard-type theorem for the asymptotic critical values of semi-algebraic mappings and a new fibration theorem at infinity for C-2 mappings. We show the equivalence of three different types of regularity conditions which have been used in the literature in order to control the asymptotic behaviour of mappings. The central role of our picture is played by the p-regularity and its bridge toward the rho-regularity which implies topological triviality at infinity.

A comparison of deterministic, reliability-based and risk-based structural optimization under uncertainty

In this paper, the effects of uncertainty and expected costs of failure on optimum structural design are investigated, by comparing three distinct formulations of structural optimization problems. Deterministic Design Optimization (DDO) allows one the find the shape or configuration of a structure that is optimum in terms of mechanics, but the formulation grossly neglects parameter uncertainty and its effects on structural safety. Reliability-based Design Optimization (RBDO) has emerged as an alternative to properly model the safety-under-uncertainty part of the problem. With RBDO, one can ensure that a minimum (and measurable) level of safety is achieved by the optimum structure. However, results are dependent on the failure probabilities used as constraints in the analysis. Risk optimization (RO) increases the scope of the problem by addressing the compromising goals of economy and safety. This is accomplished by quantifying the monetary consequences of failure, as well as the costs associated with construction, operation and maintenance. RO yields the optimum topology and the optimum point of balance between economy and safety. Results are compared for some example problems. The broader RO solution is found first, and optimum results are used as constraints in DDO and RBDO. Results show that even when optimum safety coefficients are used as constraints in DDO, the formulation leads to configurations which respect these design constraints, reduce manufacturing costs but increase total expected costs (including expected costs of failure). When (optimum) system failure probability is used as a constraint in RBDO, this solution also reduces manufacturing costs but by increasing total expected costs. This happens when the costs associated with different failure modes are distinct. Hence, a general equivalence between the formulations cannot be established. Optimum structural design considering expected costs of failure cannot be controlled solely by safety factors nor by failure probability constraints, but will depend on actual structural configuration. (c) 2011 Elsevier Ltd. All rights reserved.

Toward Global Standards for Comparator Pharmaceutical Products: Case Studies of Amoxicillin, Metronidazole, and Zidovudine in the Americas

This study compared in vitro dissolution characteristics and other quality measures of different amoxicillin, metronidazole, and zidovudine products purchased in the Americas to a comparator pharmaceutical product (CPP). These three drugs are classified as Biopharmaceutics Classification System Class I drugs with the possibility that dissolution findings might be used to document bioequivalence. All investigated zidovudine products were found to be in vitro equivalent to the CPP. Only 3 of 12 tested amoxicillin products were found to be in vitro equivalent to the CPP. None of the tested metronidazole products were in vitro equivalent to the CPP. These findings suggest but do not confirm bioinequivalence where in vitro comparisons failed, given that an in vivo blood level study might have confirmed bioequivalence. At times, identifying a CPP in one of the selected markets proved difficult. The study demonstrates that products sold across national markets may not be bioequivalent. When coupled with the challenge of identifying a CPP in different countries, the results of this study suggest the value of an international CPP as well as increased use of BCS approaches as means of either documenting bioequivalence or signaling the need for further in vivo studies. Because of increased movement of medicines across national borders, practitioners and patients would benefit from these approaches.

Acoustic analyses of diadochokinesis in fluent and stuttering children

OBJECTIVES: The purpose of the study was to acoustically compare the performance of children who do and do not stutter on diadochokinesis tasks in terms of syllable duration, syllable periods, and peak intensity. METHODS: In this case-control study, acoustical analyses were performed on 26 children who stutter and 20 aged-matched normally fluent children (both groups stratified into preschoolers and school-aged children) during a diadochokinesis task: the repetition of articulatory segments through a task testing the ability to alternate movements. Speech fluency was assessed using the Fluency Profile and the Stuttering Severity Instrument. RESULTS: The children who stutter and those who do not did not significantly differ in terms of the acoustic patterns they produced in the diadochokinesis tasks. Significant differences were demonstrated between age groups independent of speech fluency. Overall, the preschoolers performed poorer. These results indicate that the observed differences are related to speech-motor age development and not to stuttering itself. CONCLUSIONS: Acoustic studies demonstrate that speech segment durations are most variable, both within and between subjects, during childhood and then gradually decrease to adult levels by the age of eleven to thirteen years. One possible explanation for the results of the present study is that children who stutter presented higher coefficients of variation to exploit the motor equivalence to achieve accurate sound production (i.e., the absence of speech disruptions).

Cross-cultural adaptation and psychometric properties of the Brazilian-Portuguese version of the Duke Anticoagulation Satisfaction Scale

Aim. The aim of this study was to evaluate the internal reliability and validity of the BrazilianPortuguese version of Duke Anticoagulation Satisfaction Scale (DASS) among cardiovascular patients. Background. Oral anticoagulation is widely used to prevent and treat thromboembolic events in several conditions, especially in cardiovascular diseases; however, this therapy can induce dissatisfaction and reduce the quality of life. Design. Methodological and cross-sectional research design. Methods. The cultural adaptation of the DASS included the translation and back-translation, discussions with healthcare professionals and patients to ensure conceptual equivalence, semantic evaluation and instrument pretest. The BrazilianPortuguese version of the DASS was tested among subjects followed in a university hospital anticoagulation outpatient clinic. The psychometric properties were assessed by construct validity (convergent, known groups and dimensionality) and internal consistency/reliability (Cronbachs alpha). Results. A total of 180 subjects under oral anticoagulation formed the baseline validation population. DASS total score and SF-36 domain correlations were moderate for General health (r = -0.47, p < 0.01), Vitality (r = -0.44, p < 0.01) and Mental health (r = -0.42, p < 0.01) (convergent). Age and length on oral anticoagulation therapy (in years) were weakly correlated with total DASS score and most of the subscales, except Limitation (r = -0.375, p < 0.01) (Known groups). The Cronbachs alpha coefficient was 0.79 for the total scale, and it ranged from 0.76 (hassles and burdens)0.46 (psychological impact) among the domains, confirming the internal consistency reliability. Conclusions. The BrazilianPortuguese version of the DASS has shown levels of reliability and validity comparable with the original English version. Relevance to clinical practice. Healthcare practitioners and researchers need internationally validated measurement tools to compare outcomes of interventions in clinical management and research tools in oral anticoagulation therapy.

Personal and Social Performance (PSP) scale for patients with schizophrenia: translation to Portuguese, cross-cultural adaptation and interrater reliability

INTRODUCTION: Schizophrenia is a chronic mental disorder associated with impairment in social functioning. The most widely used scale to measure social functioning is the GAF (Global Assessment of Functioning), but it has the disadvantage of measuring at the same time symptoms and functioning, as described in its anchors. OBJECTIVES:Translation and cultural adaptation of the PSP, proposing a final version in Portuguese for use in Brazil. METHODS: We performed five steps: 1) translation; 2) back translation; 3) formal assessment of semantic equivalence; 4) debriefing; 5) analysis by experts. Interrater reliability (Intraclass correlation, ICC) between two raters was also measured. RESULTS: The final version was applied by two independent investigators in 18 adults with schizophrenia (DSM-IV-TR). The interrater reliability (ICC) was 0.812 (p < 0.001). CONCLUSION: The translation and adaptation of the PSP had an adequate level of semantic equivalence between the Portuguese version and the original English version. There were no difficulties related to understanding the content expressed in the translated texts and terms. Its application was easy and it showed a good interrater reliability. The PSP is a valid instrument for the measurement of personal and social functioning in schizophrenia.

Avaliação da equivalência semântica e consistência interna de uma versão em português do Internet Addiction Test (IAT)

OBJETIVO: Este estudo teve por objetivo a adaptação transcultural do Internet Addiction Test (IAT) para o idioma português. MÉTODOS: O trabalho consistiu em cinco etapas: (1) tradução; (2) retradução; (3) revisão técnica e avaliação da equivalência semântica por profissionais da área; (4) avaliação do instrumento por uma amostra de estudantes, avaliando-se o seu grau de compreensão; e (5) análise da consistência interna por meio do coeficiente alfa de Cronbach. RESULTADOS: O instrumento foi traduzido e adaptado para o idioma português, demonstrando ser facilmente compreendido e apresentando valor de consistência interna de 0,85. CONCLUSÃO: O instrumento encontra-se traduzido e adaptado para o português e apresenta consistência interna satisfatória. São necessárias análises de equivalência de mensuração e reprodutibilidade.

Infinite dimensional Lie algebra associated with conformal transformations of the two-point velocity correlation tensor from isotropic turbulence

We deal with homogeneous isotropic turbulence and use the two-point velocity correlation tensor field (parametrized by the time variable t) of the velocity fluctuations to equip an affine space K3 of the correlation vectors by a family of metrics. It was shown in Grebenev and Oberlack (J Nonlinear Math Phys 18:109–120, 2011) that a special form of this tensor field generates the so-called semi-reducible pseudo-Riemannian metrics ds2(t) in K3. This construction presents the template for embedding the couple (K3, ds2(t)) into the Euclidean space R3 with the standard metric. This allows to introduce into the consideration the function of length between the fluid particles, and the accompanying important problem to address is to find out which transformations leave the statistic of length to be invariant that presents a basic interest of the paper. Also we classify the geometry of the particles configuration at least locally for a positive Gaussian curvature of this configuration and comment the case of a negative Gaussian curvature.

Eficácia e segurança da vacina brasileira contra hepatite B em recém-nascidos

OBJETIVO: Analisar a efi cácia e segurança de vacina recombinante contra hepatite B em recém-nascidos. MÉTODOS: O estudo foi conduzido em hospital geral do município de Guarulhos, SP, entre 2002 e 2005. A vacina recombinante contra hepatite B do Instituto Butantan (VrHB-IB) foi analisada em dois ensaios clínicos. Em ambos os ensaios, os recém-nascidos foram alocados aleatoriamente ao grupo experimental ou controle (vacina de referência). Os recém-nascidos receberam três doses das vacinas, uma em até 24 h após o nascimento e as subseqüentes 30 e 180 dias após. No primeiro ensaio 538 recém-nascidos completaram o protocolo e no segundo ensaio, 486. Considerou-se critério de equivalência a diferença na soroproteção inferior a 5%. RESULTADOS: A soroproteção no primeiro ensaio (anti HBs ≥ 10mUI/ml) foi de 92,5% (247/267) no grupo experimental, comparada a 98,5% (267/271) no grupo controle (p = 0,001). Com este resultado, a VrHB-IB não atingiu o critério de equivalência estabelecido. Após o aumento da concentração de antígeno na vacina para 25μg, a soroproteção no segundo ensaio foi de 100% no grupo experimental e 99,2% no grupo controle. Nenhum evento adverso grave foi registrado. CONCLUSÕES: A vacina VrHB-IB modifi cada foi considerada equivalente à vacina de referência e seu uso recomendado à vacinação de recém-nascidos.

A model and an algebra for semi-structured and full-text queries

The need for a convergence between semi-structured data management and Information Retrieval techniques is manifest to the scientific community. In order to fulfil this growing request, W3C has recently proposed XQuery Full Text, an IR-oriented extension of XQuery. However, the issue of query optimization requires the study of important properties like query equivalence and containment; to this aim, a formal representation of document and queries is needed. The goal of this thesis is to establish such formal background. We define a data model for XML documents and propose an algebra able to represent most of XQuery Full-Text expressions. We show how an XQuery Full-Text expression can be translated into an algebraic expression and how an algebraic expression can be optimized.

Non-Markovian stochastic processes and their applications: from anomalous diffusion to time series analysis

This work provides a forward step in the study and comprehension of the relationships between stochastic processes and a certain class of integral-partial differential equation, which can be used in order to model anomalous diffusion and transport in statistical physics. In the first part, we brought the reader through the fundamental notions of probability and stochastic processes, stochastic integration and stochastic differential equations as well. In particular, within the study of H-sssi processes, we focused on fractional Brownian motion (fBm) and its discrete-time increment process, the fractional Gaussian noise (fGn), which provide examples of non-Markovian Gaussian processes. The fGn, together with stationary FARIMA processes, is widely used in the modeling and estimation of long-memory, or long-range dependence (LRD). Time series manifesting long-range dependence, are often observed in nature especially in physics, meteorology, climatology, but also in hydrology, geophysics, economy and many others. We deepely studied LRD, giving many real data examples, providing statistical analysis and introducing parametric methods of estimation. Then, we introduced the theory of fractional integrals and derivatives, which indeed turns out to be very appropriate for studying and modeling systems with long-memory properties. After having introduced the basics concepts, we provided many examples and applications. For instance, we investigated the relaxation equation with distributed order time-fractional derivatives, which describes models characterized by a strong memory component and can be used to model relaxation in complex systems, which deviates from the classical exponential Debye pattern. Then, we focused in the study of generalizations of the standard diffusion equation, by passing through the preliminary study of the fractional forward drift equation. Such generalizations have been obtained by using fractional integrals and derivatives of distributed orders. In order to find a connection between the anomalous diffusion described by these equations and the long-range dependence, we introduced and studied the generalized grey Brownian motion (ggBm), which is actually a parametric class of H-sssi processes, which have indeed marginal probability density function evolving in time according to a partial integro-differential equation of fractional type. The ggBm is of course Non-Markovian. All around the work, we have remarked many times that, starting from a master equation of a probability density function f(x,t), it is always possible to define an equivalence class of stochastic processes with the same marginal density function f(x,t). All these processes provide suitable stochastic models for the starting equation. Studying the ggBm, we just focused on a subclass made up of processes with stationary increments. The ggBm has been defined canonically in the so called grey noise space. However, we have been able to provide a characterization notwithstanding the underline probability space. We also pointed out that that the generalized grey Brownian motion is a direct generalization of a Gaussian process and in particular it generalizes Brownain motion and fractional Brownain motion as well. Finally, we introduced and analyzed a more general class of diffusion type equations related to certain non-Markovian stochastic processes. We started from the forward drift equation, which have been made non-local in time by the introduction of a suitable chosen memory kernel K(t). The resulting non-Markovian equation has been interpreted in a natural way as the evolution equation of the marginal density function of a random time process l(t). We then consider the subordinated process Y(t)=X(l(t)) where X(t) is a Markovian diffusion. The corresponding time-evolution of the marginal density function of Y(t) is governed by a non-Markovian Fokker-Planck equation which involves the same memory kernel K(t). We developed several applications and derived the exact solutions. Moreover, we considered different stochastic models for the given equations, providing path simulations.