Desempenho e background familiar: um estudo no acesso a uma instituição de ensino técnico federal no Brasil

This paper comprises an investigation on the influence of the variable family backgrounds (father school level, mother school level and family income) over the pupil s performance in admissions examination (entrance test or PROITEC) at Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte (IFRN). From that point of view, the main goal of this research is to analyze the influence of the family background as a determiner of the pupil´s performance in the access to Technical and Professional education at IFRN. Secondary data were used from two databases (entrance test and PROITEC) adding up to 19.226 observations to the vacancies offered in the year of 2013. Aiming at achieving the proposed goal, a conceptual model composed of three hypothesis was developed. The results were presented in four stages: stage I presentation of the descriptive statistical results of the two databases; stage II separation of the campi in clusters; stage III analysis of multiple regressions; stage IV analysis of the logistics regressions. Two statistical tests were used to validate the hypothesis: T-test and Wald test. Hypothesis 1 and 2 were confirmed and H3 was refused. The results presented favorable causal connections to the family income and the father school level variables (with bigger effect for fathers with a higher education degree). The mother school level variable did not provide statistical significance for this research. Based on this result, after this work, this institution is to develop a strategic plan to assist in the success rate of students preparing diagnoses in order to diminish the effects of the variables that impacted negatively

Exact solution for a fermion in the background of a scalar inversely linear potential

The problem of a fermion subject to a general scalar potential in a two-dimensional world is mapped into a Sturm-Liouville problem for nonzero eigenenergies. The searching for possible bounded solutions is done in the circumstance of power-law potentials. The normalizable zero-eigenmode solutions are also searched. For the specific case of an inversely linear potential, which gives rise to an effective Kratzer potential, exact bounded solutions are found in closed form. The behaviour of the upper and lower components of the Dirac spinor is discussed in detail and some unusual results are revealed. (C) 2004 Elsevier B.V. All rights reserved.

Bounded solutions of fermions in the background of mixed vector-scalar inversely linear potentials

The problem of a fermion subject to a general mixing of vector and scalar potentials in a two-dimensional world is mapped into a Sturm-Liouville problem. Isolated bounded solutions are also searched. For the specific case of an inversely linear potential, which gives rise to an effective Kratzer potential in the Sturm-Liouville problem, exact bounded solutions are found in closed form. The case of a pure scalar potential with their isolated zero-energy solutions, already analyzed in a previous work, is obtained as a particular case. The behavior of the upper and lower components of the Dirac spinor is discussed in detail and some unusual results are revealed. The nonrelativistic limit of our results adds a new support to the conclusion that even-parity solutions to the nonrelativistic one-dimensional hydrogen atom do not exist. (c) 2004 Elsevier B.V. All rights reserved.

Bounded solutions of fermions in the background of mixed vector-scalar Poeschl-Teller-like potentials

The problem of a fermion subject to a convenient mixing of vector and scalar potentials in a two-dimensional space-time is mapped into a Sturm-Liouville problem. For a specific case which gives rise to an exactly solvable effective modified Poschl-Teller potential in the Sturm-Liouville problem, bound-state solutions are found. The behaviour of the upper and lower components of the Dirac spinor is discussed in detail and some unusual results are revealed. The Dirac delta potential as a limit of the modified Poschl-Teller potential is also discussed. The problem is also shown to be mapped into that of massless fermions subject to classical topological scalar and pseudoscalar potentials. Copyright (C) EPLA, 2007.

The peremptory influence of a uniform background for trapping neutral fermions with an inversely linear potential

The problem of neutral fermions subject to an inversely linear potential is revisited. It is shown that an infinite set of bound-state solutions can be found on the condition that the fermion is embedded in an additional uniform background potential. An apparent paradox concerning the uncertainty principle is solved by introducing the concept of effective Compton wavelength.

Temporal stability for unpredictable annual climatic variability for Hevea genotype selection

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA): molecular background, virulence, and relevance for public health

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Socio-climatic hotspots in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Biodiversity conservation in human-modified Amazonian forest landscapes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cosmic microwave background and large-scale structure constraints on a simple quintessential inflation model

We derive constraints on a simple quintessential inflation model, based on a spontaneously broken Phi(4) theory, imposed by the Wilkinson Microwave Anisotropy Probe three-year data (WMAP3) and by galaxy clustering results from the Sloan Digital Sky Survey (SDSS). We find that the scale of symmetry breaking must be larger than about 3 Planck masses in order for inflation to generate acceptable values of the scalar spectral index and of the tensor-to-scalar ratio. We also show that the resulting quintessence equation of state can evolve rapidly at recent times and hence can potentially be distinguished from a simple cosmological constant in this parameter regime.

Superstrings in graviphoton background and N=1/2+3/2 supersymmetry

Motivated by Ooguri and Vafa, we study superstrings in flat R-4 in a constant self-dual graviphoton background. The supergravity equations of motion are satisfied in this background which deforms the N = 2 d = 4 flat space super-Poincare algebra to another algebra with eight supercharges. A D-brane in this space preserves a quarter of the supercharges; i.e. N = 1/2 supersymmetry is realized linearly, and the remaining N = 3/2 supersymmetry is realized nonlinearly. The theory on the brane can be described as a theory in noncommutative superspace in which the chiral fermionic coordinates theta(alpha) of N = 1 d = 4 superspace are not Grassman variables but satisfy a Clifford algebra.

One loop conformal invariance of the superstring in an AdS(5) x S-5 background

It is proven that the pure spinor superstring in an AdS(5) x S-5 background remains conformally invariant at one loop level in the sigma model perturbation theory.

Entanglement and entropy operator for strings in pp-wave time dependent background

In this Letter new aspects of string theory propagating in a pp-wave time dependent background with a null singularity are explored. It is shown the appearance of a 2d entanglement entropy dynamically generated by the background. For asymptotically flat observers, the vacuum close to the singularity is unitarily inequivalent to the vacuum at tau = -infinity and it is shown that the 2d entanglement entropy diverges close to this point. As a consequence. The positive time region is inaccessible for observers in tau = -infinity. For a stationary measure, the vacuum at finite time is seen by those observers as a thermal state and the information loss is encoded as a heat bath of string states. (c) 2006 Elsevier B.V. All rights reserved.

Superstring in a pp-wave background at finite temperature. TFD approach

A thermodynamical analysis for the type IIB superstring in a pp-wave background is considered. The thermal Fock space is built and the temperature SUSY breaking appears naturally by analyzing the thermal vacuum. All the thermodynamical quantities are derived by evaluating matrix elements of operators in the thermal Fock space. This approach seems to be suitable to study thermal effects in the BMN correspondence context. (C) 2004 Elsevier B.V. All rights reserved.

Superstring vertex operators in an AdS(5) x S-5 background

A quantizable action has recently been proposed for the superstring in an AdS(5) x S-5 background with Ramond-Ramond flux. In this paper we construct physical vertex operators corresponding to on-shell fluctuations around the AdS(5) x S-5 background. The structure of these AdS(5) x S-5 vertex operators closely resembles the structure of the massless vertex operators in a flat background. (C) 2001 Elsevier B.V. B.V. All rights reserved.