Is the equivalence principle doomed forever to Dante's Inferno on account of quantum mechanics?

It is commonly assumed that the equivalence principle can coexist without conflict with quantum mechanics. We shall argue here that, contrary to popular belief, this principle does not hold in quantum mechanics. We illustrate this point by computing the second-order correction for the scattering of a massive scalar boson by a weak gravitational field, treated as an external field. The resulting cross-section turns out to be mass-dependent. A way out of this dilemma would be, perhaps, to consider gravitation without the equivalence principle. At first sight, this seems to be a too much drastic attitude toward general relativity. Fortunately, the teleparallel version of general relativity - a description of the gravitational interaction by a force similar to the Lorentz force of electromagnetism and that, of course, dispenses with the equivalence principle - is equivalent to general relativity, thus providing a consistent theory for gravitation in the absence of the aforementioned principle. © World Scientific Publishing Company.

Atitudes em relação à Bioestatística de discentes e docentes da Faculdade de Ciências Farmacêuticas de Araraquara-UNESP

In this study, the attitudes of students and teachers at the Faculty of Pharmaceutical Sciences of Araraquara (UNESP University) towards Biostatistics were assessed. The Survey of Attitudes Toward Statistics (SATS) scale was used as the measuring instrument. The reproducibility of the scale was estimated by Cohen's Kappa (κ) coefficient with linear weighting and its internal consistency by Cronbach's alpha coefficient (α). The individuals were first placed in two groups, according to their positive or negative attitude toward Statistics; then, the association of their attitude with the variables of interest was tested by the chi-squared (χ 2) test at a significance level of 5%. The sample consisted of 272 undergraduate students, 83 graduate students and 24 teachers, predominantly female (78.2%). Among the students, 67.5% participated in the scientific research initial training program. Reproducibility and internal consistency of the scale were adequate (κ=0.7093; α=0.9334). Most of the subjects (74.4%) had a positive attitude toward Statistics. Significant association was found between attitude and functional activity (p=0.0204), the course taken (p=0.0316) and effort (p=0.0002). Thus, it was concluded that the great majority of the participants had a positive attitude towards Biostatistics and that undergraduate students and those who reported good performance in Biostatistics showed a significantly higher proportion of positive attitude than the other students.

Relações entre os conhecimentos, as atitudes e a confiança dos alunos do curso de licenciatura em Matemática em resolução de problemas geométricos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Geologia e mineralogia de pegmatito mineralizado em estanho e metais associados (Nb, Ta, Zn, Cu, Pb), Mina Bom Futuro, Rondônia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

As dimensões internacionais das políticas brasileiras de combate ao tráfico de drogas na década de 1990

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of exercise training on the cardiovascular system: Pharmacological approaches

Physical exercise promotes beneficial health effects by preventing or reducing the deleterious effects of pathological conditions, such as arterial hypertension, coronary artery disease, atherosclerosis, diabetes mellitus, osteoporosis, Parkinson's disease, and Alzheimer disease. Human movement studies are becoming an emerging science in the epidemiological area and public health. A great number of studies have shown that exercise training, in general, reduces sympathetic activity and/or increases parasympathetic tonus either in human or laboratory animals. Alterations in autonomic nervous system have been correlated with reduction in heart rate (resting bradycardia) and blood pressure, either in normotensive or hypertensive subjects. However, the underlying mechanisms by which physical exercise produce bradycardia and reduces blood pressure has not been fully understood. Pharmacological studies have particularly contributed to the comprehension of the role of receptor and transduction signaling pathways on the heart and blood vessels in response to exercise training. This review summarizes and examines the data from studies using animal models and human to determine the effect of exercise training on the cardiovascular system. (c) 2007 Elsevier B.V. All rights reserved.

Exercise training as a preventive tool for age-related disorders: a brief review

Aging populations are a worldwide phenomenon affecting both developed and developing countries. This issue raises serious concerns for both governments and the general population. Regular participation in physical activity and/or exercise training programs can minimize the physiological alterations that occur during aging and may contribute to improvements in health and well-being. The present review will discuss the role of regular exercise training in preventing age-related physiological decline and, consequently, associated chronic diseases. Compelling evidence that regular exercise and/or physical activity can improve quality of life, prevent or control the development of chronic disease and increase life expectancy is shown. In summary, regular exercise training and/or physical activity has an important influence on aging and may help to prevent age-related disorders.

Escuta analítica no hospital geral: : implicações com o desejo do analista

Partindo da experiência na enfermaria de um hospital-escola1, do confronto com o status-quo do trabalho dos psicólogos em hospitais e da avaliação da literatura sobre a clínica psicanalítica em hospital, esta pesquisa se propôs a buscar avanços frente a uma questão específica: a escuta psicanalítica no trabalho em enfermarias de hospital geral e as implicações dessa prática com o desejo do psicanalista. Foram entrevistados quinze psicólogos declaradamente de orientação psicanalítica, vinculados a unidades de internação e com experiência mínima de dois anos de trabalho em hospital geral. As entrevistas foram abertas e semi-estruturadas, com o intuito de contemplar de maneira uniforme a coleta de informações de cunho mais objetivo, assim como de facilitar a pertinência ao tema de estudo. A interpretação dos dados foi realizada à luz do referencial clínico psicanalítico (freud-lacaniano), sendo que tal interpretação nos permitiu identificar uma importante interação entre os impasses, presentes na instituição hospitalar, da prática clínica psicanalítica com questões pessoais e de formação do profissional, interação que se vincula à postura de trabalho adotada no hospital. Reafirmamos, através desta pesquisa, a possibilidade de fazer uso de uma escuta analítica no trabalho com pacientes internados, a qual está sempre voltada para as manifestações do inconsciente ao longo da fala, e na qual a direção do tratamento é a emergência do sujeito do inconsciente.

Analytical attitude propagation with non-singular variables and gravity gradient torque for spin stabilized satellite

An analytical approach for the spin stabilized satellite attitude propagation is presented using the non-singular canonical variables to describe the rotational motion. Two sets of variables were introduced for Fukushima in 1994 by a canonical transformation and they are useful when the angle between z-satellite axis of a coordinate system fixed in artificial satellite and the rotational angular momentum vector is zero or when the angle between Z-equatorial axis and rotation angular momentum vector is zero. Analytical solutions for rotational motion equations and torque-free motion are discussed in terms of the elliptic functions and by the application of some simplification to get an approximated solution. These solutions are compared with a numerical solution and the results show a good agreement for many rotation periods. When the mean Hamiltonian associated with the gravity gradient torque is included, an analytical solution is obtained by the application of the successive approximations' method for the satellite in an elliptical orbit. These solutions show that the magnitude of the rotation angular moment is not affected by the gravity gradient torque but this torque causes linear and periodic variations in the angular variables, long and short periodic variations in Z-equatorial component of the rotation angular moment and short periodic variations in x-satellite component of the rotation angular moment. The goal of this analysis is to emphasize the geometrical and physical meaning of the non-singular variables and to validate the approximated analytical solution for the rotational motion without elliptic functions for a non-symmetrical satellite. The analysis can be applied for spin stabilized satellite and in this case the general solution and the approximated solution are coincidence. Then the results can be used in analysis of the space mission of the Brazilian Satellites. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.

TIME-OPTIMAL GEOMAGNETIC ATTITUDE MANEUVERS OF AN AXISYMMETRICAL SPINNING SATELLITE

A formulation used to determine the time-optimal geomagnetic attitude maneuvers subject to dynamic and geometric constraints is proposed in this paper. This was obtained by a direct search procedure based on a control function parametrization method, using linear programming to obtain numerical suboptimal solutions by linear perturbation. Due to its characteristics it can be used in small computers and to generate computer programs of general application. The dynamic modeling, the magnetic torque model and the suboptimal control procedure are presented. Simulation runs have verified the feasibility of the formulation thus derived and have shown a notable improvement in performance.

Extended Hierarchical Censored Production Rules (EHCPRs) system: An approach toward generalized knowledge representation

One common problem in all basic techniques of knowledge representation is the handling of the trade-off between precision of inferences and resource constraints, such as time and memory. Michalski and Winston (1986) suggested the Censored Production Rule (CPR) as an underlying representation and computational mechanism to enable logic based systems to exhibit variable precision in which certainty varies while specificity stays constant. As an extension of CPR, the Hierarchical Censored Production Rules (HCPRs) system of knowledge representation, proposed by Bharadwaj & Jain (1992), exhibits both variable certainty as well as variable specificity and offers mechanisms for handling the trade-off between the two. An HCPR has the form: Decision If(preconditions) Unless(censor) Generality(general_information) Specificity(specific_information). As an attempt towards evolving a generalized knowledge representation, an Extended Hierarchical Censored Production Rules (EHCPRs) system is suggested in this paper. With the inclusion of new operators, an Extended Hierarchical Censored Production Rule (EHCPR) takes the general form: Concept If (Preconditions) Unless (Exceptions) Generality (General-Concept) Specificity (Specific Concepts) Has_part (default: structural-parts) Has_property (default:characteristic-properties) Has_instance (instances). How semantic networks and frames are represented in terms of an EHCPRs is shown. Multiple inheritance, inheritance with and without cancellation, recognition with partial match, and a few default logic problems are shown to be tackled efficiently in the proposed system.

Atitudes distintas de profssionais de diferentes especialidades médicas relacionadas à autonomia e aspectos jurídicos no cuidado de pacientes com demência

The evaluation of competence of Alzheimer's disease (AD) patients to assume personal or collective responsibilities and the resulting legal implications is a relevant issue. Objectives: The aim of this study was to evaluate the attitudes of different medical specialists towards the disability of patients with Alzheimer's disease and practitioners' competence to interfere with decision-making autonomy. Methods: Professionals from different areas (Neurology, Psychiatry, Geriatrics, and General Practice) were interviewed by one of the authors, after being presented a fictitious clinical case which raised several topics, namely: [1] Critical judgment and capacity of the patient to take decisions related to daily activities; [2] The role of family physicians in nominating trustees and caregivers. Results: Answers to the first question did not differ regarding degree of preservation of awareness but at least 25% stressed that the patient must be carefully listened to, independent of caregiver or legal representative opinion. There were significant knowledge gaps in responses to the second question. Half of the physicians interviewed did not have adequate information about the legal aspects of caring for patients with Alzheimer's disease. Conclusions: Legal aspects is a topic that must be incorporated into professional training in order to improve attitudes toward the long-term management of patients with dementia.

Preprocessing data for short-term load forecasting with a general regression neural network and a moving average filter

This paper proposes a filter based on a general regression neural network and a moving average filter, for preprocessing half-hourly load data for short-term multinodal load forecasting, discussed in another paper. Tests made with half-hourly load data from nine New Zealand electrical substations demonstrate that this filter is able to handle noise, missing data and abnormal data. © 2011 IEEE.

The relationship between training status, blood pressure and uric acid in adults and elderly

Background: Hypertension can be generated by a great number of mechanisms including elevated uric acid (UA) that contribute to the anion superoxide production. However, physical exercise is recommended to prevent and/or control high blood pressure (BP). The purpose of this study was to investigate the relationship between BP and UA and whether this relationship may be mediated by the functional fitness index.Methods: All participants (n = 123) performed the following tests: indirect maximal oxygen uptake (VO2max), AAHPERD Functional Fitness Battery Test to determine the general fitness functional index (GFFI), systolic and diastolic blood pressure (SBP and DBP), body mass index (BMI) and blood sample collection to evaluate the total-cholesterol (CHOL), LDL-cholesterol (LDL-c), HDL-cholesterol (HDL-c), triglycerides (TG), uric acid (UA), nitrite (NO2) and thiobarbituric acid reactive substances (T-BARS). After the physical, hemodynamic and metabolic evaluations, all participants were allocated into three groups according to their GFFI: G1 (regular), G2 (good) and G3 (very good).Results: Baseline blood pressure was higher in G1 when compared to G3 (+12% and +11%, for SBP and DBP, respectively, p<0.05) and the subjects who had higher values of BP also presented higher values of UA. Although UA was not different among GFFI groups, it presented a significant correlation with GFFI and VO2max. Also, nitrite concentration was elevated in G3 compared to G1 (140±29 μM vs 111± 29 μM, for G3 and G1, respectively, p<0.0001). As far as the lipid profile, participants in G3 presented better values of CHOL and TG when compared to those in G1.Conclusions: Taking together the findings that subjects with higher BP had elevated values of UA and lower values of nitrite, it can be suggested that the relationship between blood pressure and the oxidative stress produced by acid uric may be mediated by training status. © 2013 Trapé et al.; licensee BioMed Central Ltd.

Da cartolina ao computador: uma proposta para o estudo de Geometria

Pós-graduação em Educação Matemática - IGCE