Stopping a Viscous Fluid by a Feedback Dissipative Field: Thermal Effects without Phase Changing

We show how the action on two simultaneous effects (a suitable coupling about velocity and temperature and a low range of temperature but upper that the phase changing one) may be responsible of stopping a viscous fluid without any changing phase. Our model involves a system, on an unbounded pipe, given by the planar stationary Navier-Stokes equation perturbed with a sublinear term f(x, θ, u) coupled with a stationary (and possibly nonlinear) advection diffusion equation for the temperature θ.After proving some results on the existence and uniqueness of weak solutions we apply an energy method to show that the velocity u vanishes for x large enough

Taxas de letalidade por tuberculose na cidade de Campinas, São Paulo, Brasil, de 2001 a 2009

The mortality rate among tuberculosis patients (TB fatality) has been attributed to irregular chemotherapy, delay in diagnosis, multidrug resistance, and HIV coinfection. To analyze TB fatality rates by sex, clinical presentation and HIV coinfection in Campinas, São Paulo, Brazil. ohorts of residents in the city of Campinas who either died during treatment for tuberculosis or had the disease confirmed after death were divided into three intervals: 2001-2003, 2004-2006, and 2007-2009. Data were obtained from the database of the Tuberculosis Surveillance System of the University of Campinas, and notifications were gathered through TB-WEB Health São Paulo Secretary. Statistical significance was determined using a chi-square test, considering p < 0.05. Between 2001 and 2009, 3,416 TB patients were diagnosed: 2,827 (82.8%) were new TB cases and 589 (17.2%) were retreatments. Between the first and second triennium, the number of new patients decreased by 18%, and 23% among retreatments. Between the second and third intervals, the reduction was 5% and 21%, respectively. General case fatality rate declined from 11.4% to 9.9% across intervals, and was most significant among patients that had previously abandoned treatment (17.3% to 5.1%). Fatality rates among patients coinfected with TB-AIDS were 2-3 times that of patients not infected with TB-AIDS throughout the intervals. Fatality between the first and third triennium among TB-AIDS co-infected patients declined (24.8% to 19.5%), while increasing slightly among non-AIDS TB patients (7.3% to 8%) during this period. Conclusion: Though mortality among TB-AIDS patients declined from 2001-2009, rates among non-AIDS TB remained stagnant. Improved TB diagnosis and treatment is needed to further decrease TB mortality in Campinas22A letalidade por tuberculose tem sido atribuída à quimioterapia irregular, à demora no diagnóstico, à multidrogarresistência, à coinfecção com o vírus da imunodeficiência humana (HIV). Analisar letalidade por tuberculose segundo sexo, apresentação clínica, presença da coinfecção pelo HIV, em Campinas, São Paulo, Brasil. Foram verificadas coortes de residentes em Campinas que morreram durante tratamento para tuberculose e aqueles notificados após óbito, agrupados em três intervalos: 2001-2003, 2004-2006 e 2007-2009. As informações foram obtidas no Banco de Dados para Vigilância da Tuberculose da Universidade Estadual de Campinas (UNICAMP), com captação das notificações no Sistema de Notificação e Acompanhamento de Casos de Tuberculose da Secretaria Estadual de Saúde de São Paulo. A significância estatística foi verificada pelo teste χ2 considerando p < 0,05. Entre 2001 e 2009, foram diagnosticados 3.416 pacientes com tuberculose: 2.827 (82,8%) sem tratamento anterior e 589 (17,2%) com retratamentos. Entre o primeiro e o segundo triênio, o número de pacientes novos diminuiu 18% sem tratamento anterior e 23% entre retratamentos. Entre o segundo e o terceiro intervalo, a redução foi de 5 e 21%, respectivamente. A letalidade geral declinou de 11,4 para 9,9%, diferença mais significante entre os que haviam abandonado tratamento anteriormente (17,3 para 5,1%). A letalidade entre pacientes com coinfecção tuberculose-síndrome da imunodeficiência adquirida (Aids) foi 2-3 vezes maior que entre tuberculose sem aids durante todo o período estudado. A letalidade entre o primeiro e o terceiro triênio declinou no grupo com tuberculose-aids (24,8 para 19,5%), enquanto teve ligeiro aumento entre tuberculose sem aids (7,3 para 8%). Embora a mortalidade entre pacientes com tuberculose-aids tenha diminuído de 2001-2009, as taxas no grupo tuberculose sem aids permaneceram estagnadas. Melhorias no diagnóstico e no tratamento são necessárias para a redução da mortalidade entre pacientes com tuberculose em Campina

Impact of methodological approaches in the agreement between subjective and objective methods for assessing screen time and sedentary behavior in pediatric population: a systematic review

Introduction: sedentary behavior is an important target for health promotion. In this systematic review, we aimed to provide evidence to support decisions about measurement approach choices for subjectively assessing sedentary behavior in pediatric population, adopting objective methods as the reference. Methods: in this systematic review with meta-analysis, published studies were retrieved from electronic databases: Medline (PubMed), Web of Science, Embase, SPORTDiscus, BioMed Central and SCOPUS. We considered studies evaluating sedentary behavior agreement through questionnaire and/or diary in comparison with an objective measure. A total of six inclusion criteria v, rere used. We synthesized the data using correlation coefficients (r) as an indicator of agreement estimates. The review protocol is registered in the PROSPERO database (CRD42014015138). Results: a total of 14 studies met the inclusion criteria with ages ranging from 3 to 17.5 years and provided 17 agreement analyses. Thirteen of these agreement analyses (76.5%) reported correlation coefficients. We found two major groups of sedentary activities: screen time (47.1%) and sedentary behaviors (52.9%). The pooled agreement between questionnaires and accelerometers for assessing self-reported screen time was negative (r =-0.15; Cl 95%:-0.17 to-0.13). Conversely, when the sedentary behavior was assessed by questionnaires and accelerometers, the pooled agreement, vas positive for parent-reporting (r = 0.09; Cl 95%; 0.04 to 0.13) and self-reporting (r = 0.43; CI 95%: 0.40 to 0.47) in children and adolescents, respectively. Conclusion: questionnaires have positive agreement with accelerometers for assessing sedentary behavior, whereas the agreement is negative for assessing screen time. Self-reported questionnaires are recommended methods to measure sedentary behavior in adolescents

Gravitational Collapse in Higher Dimensional Husain Space-Time

We investigate exact solution in higher dimensional Husain model for a null fluid source with pressure $p$ and density $\rho$ are related by the following relations (i) $p=k\rho$, (ii) $p=k\rho-\frac{B(v)}{\rho^{\alpha}}$ (variable modified Chaplygin) and (iii) $p=k\rho^{\alpha}$ (polytropic). We have studied the nature of singularity in gravitational collapse for the above equations of state and also for different choices of the of the parameters $k$ and $B$ namely, (i) $k=0$, $B=$ constant (generalized Chaplygin), (ii) $B=$ constant (modified Chaplygin). It is found that the nature of singularity is independent of these choices of different equation of state except for variable Chaplygin model. Choices of various parameters are shown in tabular form. Finally, matching of Szekeres model with exterior Husain space-time is done.Comment: 12 latex pages, No figure, RevTex styl

D-braneworld cosmology

We discuss D-braneworld cosmology, that is, the brane is described by the Born-Infeld action. Compared with the usual Randall-Sundrum braneworld cosmology where the brane action is the Nambu-Goto one, we can see some drastic changes at the very early universe: (i)universe may experience the rapid accelerating phase (ii)the closed universe may avoid the initial singularity. We also briefly address the dynamics of the cosmology in the open string metric, which might be favorer than the induced metric from the view point of the D-brane.Comment: 6 pages, 3 figures, minor corrections, accepted for publication in Phys. Rev.

De Sitter and Schwarzschild-De Sitter According to Schwarzschild and De Sitter

When de Sitter first introduced his celebrated spacetime, he claimed, following Schwarzschild, that its spatial sections have the topology of the real projective space RP^3 (that is, the topology of the group manifold SO(3)) rather than, as is almost universally assumed today, that of the sphere S^3. (In modern language, Schwarzschild was disturbed by the non-local correlations enforced by S^3 geometry.) Thus, what we today call "de Sitter space" would not have been accepted as such by de Sitter. There is no real basis within classical cosmology for preferring S^3 to RP^3, but the general feeling appears to be that the distinction is in any case of little importance. We wish to argue that, in the light of current concerns about the nature of de Sitter space, this is a mistake. In particular, we argue that the difference between "dS(S^3)" and "dS(RP^3)" may be very important in attacking the problem of understanding horizon entropies. In the approach to de Sitter entropy via Schwarzschild-de Sitter spacetime, we find that the apparently trivial difference between RP^3 and S^3 actually leads to very different perspectives on this major question of quantum cosmology.Comment: 26 pages, 8 figures, typos fixed, references added, equation numbers finally fixed, JHEP versio

Dilatonic current-carrying cosmic strings

We investigate the nature of ordinary cosmic vortices in some scalar-tensor extensions of gravity. We find solutions for which the dilaton field condenses inside the vortex core. These solutions can be interpreted as raising the degeneracy between the eigenvalues of the effective stress-energy tensor, namely the energy per unit length U and the tension T, by picking a privileged spacelike or timelike coordinate direction; in the latter case, a phase frequency threshold occurs that is similar to what is found in ordinary neutral current-carrying cosmic strings. We find that the dilaton contribution for the equation of state, once averaged along the string worldsheet, vanishes, leading to an effective Nambu-Goto behavior of such a string network in cosmology, i.e. on very large scales. It is found also that on small scales, the energy per unit length and tension depend on the string internal coordinates in such a way as to permit the existence of centrifugally supported equilibrium configuration, also known as vortons, whose stability, depending on the very short distance (unknown) physics, can lead to catastrophic consequences on the evolution of the Universe.Comment: 10 pages, ReVTeX, 2 figures, minor typos corrected. This version to appear in Phys. Rev.

Gravitational field around a time-like current-carrying screwed cosmic string in scalar-tensor theories

In this paper we obtain the space-time generated by a time-like current-carrying superconducting screwed cosmic string(TCSCS). This gravitational field is obtained in a modified scalar-tensor theory in the sense that torsion is taken into account. We show that this solution is comptible with a torsion field generated by the scalar field $\phi$. The analysis of gravitational effects of a TCSCS shows up that the torsion effects that appear in the physical frame of Jordan-Fierz can be described in a geometric form given by contorsion term plus a symmetric part which contains the scalar gradient. As an important application of this solution, we consider the linear perturbation method developed by Zel'dovich, investigate the accretion of cold dark matter due to the formation of wakes when a TCSCS moves with speed $v$ and discuss the role played by torsion. Our results are compared with those obtained for cosmic strings in the framework of scalar-tensor theories without taking torsion into account.Comment: 21 pages, no figures, Revised Version, presented at the "XXIV- Encontro Nacional de Fisica de Particulas e Campos ", Caxambu, MG, Brazil, to appear in Phys. Rev.

Measurement of the p-pbar -> Wgamma + X cross section at sqrt(s) = 1.96 TeV and WWgamma anomalous coupling limits

The WWgamma triple gauge boson coupling parameters are studied using p-pbar -> l nu gamma + X (l = e,mu) events at sqrt(s) = 1.96 TeV. The data were collected with the DO detector from an integrated luminosity of 162 pb^{-1} delivered by the Fermilab Tevatron Collider. The cross section times branching fraction for p-pbar -> W(gamma) + X -> l nu gamma + X with E_T^{gamma} > 8 GeV and Delta R_{l gamma} > 0.7 is 14.8 +/- 1.6 (stat) +/- 1.0 (syst) +/- 1.0 (lum) pb. The one-dimensional 95% confidence level limits on anomalous couplings are -0.88 < Delta kappa_{gamma} < 0.96 and -0.20 < lambda_{gamma} < 0.20.Comment: Submitted to Phys. Rev. D Rapid Communication