Confinement of neutral fermions by a pseudoscalar double-step potential in (1+1) dimensions

The problem of confinement of neutral fermions in two-dimensional space-time is approached with a pseudoscalar double-step potential in the Dirac equation. Bound-state solutions are obtained when the coupling is of sufficient intensity. The confinement is made plausible by arguments based on effective mass and anomalous magnetic interaction.Comment: 8 pages, 1 figur

Forced expiratory volume in one second and bronchodilator response in chronic obstructive pulmonary disease: a needless ritual?

Universidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

Modeling non-thermal emission from stellar bow shocks

Runaway O- and early B-type stars passing throughout the interstellar medium at supersonic velocities and characterized by strong stellar winds may produce bow shocks that can serve as particle acceleration sites. Previous theoretical models predict the production of high energy photons by non-thermal radiative processes, but their efficiency is still debated. We aim to test and explain the possibility of emission from the bow shocks formed by runaway stars traveling through the interstellar medium by using previous theoretical models. We apply our model to AE Aurigae, the first reported star with an X-ray detected bow shock, to BD+43 3654, in which the observations failed in detecting high energy emission, and to the transition phase of a supergiant star in the late stages of its life.From our analysis, we confirm that the X-ray emission from the bow shock produced by AE Aurigae can be explained by inverse Compton processes involving the infrared photons of the heated dust. We also predict low high energy flux emission from the bow shock produced by BD+43 3654, and the possibility of high energy emission from the bow shock formed by a supergiant star during the transition phase from blue to red supergiant.Bow shock formed by different type of runaway stars are revealed as a new possible source of high energy photons in our neighbourhood

Relative returns to policy reform - evidence from controlled cross-country regressions

The authors aim at contributing to understand the dispersion of returns from policy reforms using cross-country regressions. The authors compare the"before reform"with"after reform"GDP growth outcome of countries that undertook import-liberalization and fiscal policy reforms. They survey a large sample (about 54) of developing countries over the period 1980-99. The benefits of openness to trade and fiscal prudence have been extensively identified in the growth literature, but the evidence from simple cross-section analysis can sometimes be inconclusive and remains vulnerable to criticism on estimation techniques, such as identification, endogeneity, multi-colinearity, and the quality of the data. The authors use a different analytical framework that establishes additional controls. First, they construct a counterfactual control group. These are countries that-under specific thresholds-did not introduce policy reforms under scrutiny. Second, the authors also try to use the most appropriate variable of policy reform, for example, exogenous changes in import-tariffs instead of the endogenous sum of all trade flows. Third, the authors try to base the before-after reform comparison on the most accurate date for the beginning of a policy reform period (instead of comparing averages over fixed intervals of time). Once these controls are set, they explain the difference between average GDP growth rates during the country-specific post and the pre-reform periods, relative to the average GDP growth of the relevant control group. The explanatory variables in the regressions include the standard growth-regression controls. The results are the following: 1) With a better measurement and timing of the policy reforms, the growth effect (the"returns on reform") is generally smaller than in previous papers. 2) There is evidence of contingent relationships between policy and growth, corresponding to the country's size, its export profile, and its governance. 2) Within the group of policy reformers, some countries have exhibited a relatively weaker growth response. Overall, the findings suggest that more accurate measurement and definition of the timing of reforms does not strengthen the significance of the effects of reforms on GDP growth. In fact, the effects are weaker than indicated in most cross-section studies. This suggests that the policy implications to be derived from these relationships should be treated with even more caution than previously thought.Environmental Economics&Policies,Trade Policy,Public Health Promotion,Economic Theory&Research,Health Monitoring&Evaluation,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT,Economic Theory&Research,Achieving Shared Growth,Environmental Economics&Policies,Trade and Regional Integration

Survival Probability in Patients with Sickle Cell Anemia Using the Competitive Risk Statistical Model.

The clinical picture of patients with sickle cell anemia (SCA) is associated with several complications some of which could be fatal. The objective of this study is to analyze the causes of death and the effect of sex and age on survival of Brazilian patients with SCA. Data of patients with SCA who were seen and followed at HEMORIO for 15 years were retrospectively collected and analyzed. Statistical modeling was performed using survival analysis in the presence of competing risks estimating the covariate effects on a sub-distribution hazard function. Eight models were implemented, one for each cause of death. The cause-specific cumulative incidence function was also estimated. Males were most vulnerable for death from chronic organ damage (p = 0.0005) while females were most vulnerable for infection (p=0.03). Age was significantly associated (p ≤ 0.05) with death due to acute chest syndrome (ACS), infection, and death during crisis. The lower survival was related to death from infection, followed by death due to ACS. The independent variables age and sex were significantly associated with ACS, infection, chronic organ damage and death during crisis. These data could help Brazilian authorities strengthen public policies to protect this vulnerable population

Imagens da religião em um carnaval da Mangueira

A photo essay containing images taken behind the scenes of the Mangueira samba school parade from 2020, whose theme was The Truth Will Set You Free!’ The school proposed a modern carnivalized reading of the life of Christ, depicting him with faces from subalternized groups of contemporary Brazil. More than a documentation, the images in this essay offer a reinterpretation of the parade’s visuality, providing an anthropological reading of an exemplary case of carnivalization of the religious, while also highlighting the ‘staged’ aspects of the festive performance and the social critique that it encompasses.Foto-ensaio dos bastidores do desfile da escola de samba Mangueira em 2020, com o enredo “A verdade vos fará livre!”. A escola propunha uma leitura atualizada e carnavalizada da vida de Cristo, atribuindo-lhe as faces de grupos subalternizados do Brasil atual. Mais do que uma documentação, as imagens do ensaio buscam ser uma reinterpretação da visualidade proposta para o desfile, oferecendo uma leitura antropológica de um caso exemplar de carnavalização do religioso, ao mesmo tempo que apontam para as dimensões da “montagem” da performance festiva e da crítica social que ela engloba