Klein-Gordon Oscillator in Kaluza-Klein Theory

In this contribution we study the Klein-Gordon oscillator on the curved background within the Kaluza-Klein theory. The problem of interaction between particles coupled harmonically with a topological defects in Kaluza-Klein theory is studied. We consider a series of topological defects, that treat the Klein-Gordon oscillator coupled to this background and find the energy levels and corresponding eigenfunctions in these cases. We show that the energy levels depend on the global parameters characterizing these spacetimes. We also investigate a quantum particle described by the Klein-Gordon oscillator interacting with a cosmic dislocation in Som-Raychaudhuri spacetime in the presence of homogeneous magnetic field in a Kaluza-Klein theory. In this case, the spectrum of energy is determined, and we observe that these energy levels are the sum of the term related with Aharonov-Bohm flux and of the parameter associated to the rotation of the spacetime.Comment: 15 pages, no figur

Spatial dynamics of labor markets in Brazil

There was substantial spatial variation in labor market outcomes in Brazil over the 1990s. In 2000, about one-fifth of workers lived in apparently economically stagnant municipios where real wages declined but employment increased faster than the national population growth rate. More than one-third lived in apparently dynamic municipios, experiencing both real wage growth and faster-than-average employment growth. These areas absorbed more than half of net employment growth over the period. To elucidate this spatial variation, the authors estimate spatial labor supply and demand equations describing wage and employment changes of Brazilian municipios. They use Conley's spatial GMM technique to allow for instrumental variable estimation in the presence of spatially autocorrelated errors. The main findings include: (1) a very strong influence of initial workforce educational levels on subsequent wage growth (controlling for possibly confounding variables such as remoteness and climate); (2) evidence of positive spillover effects of own-municipio growth onto neighbors'wage and employment levels; (3) an exodus from farming areas; (4) relatively elastic response of wages to an increase in labor supply; and (5) evidence of a local multiplier effect from government transfers.Labor Markets,Economic Theory&Research,Economic Growth,Municipal Financial Management,Achieving Shared Growth

Síndrome de Austrian: descrição de uma entidade excepcionalmente rara e mortal

Austrian Syndrome is the rare combination of a triad of endocarditis, meningitis, and pneumonia in the context of pneumococcal infection. Due to the involvement of several anatomical sites, the Austrian syndrome has a high mortality. Importantly, endocarditis is usually not considered during pneumococcal infection. We present a case of Austrian syndrome in a previously healthy 67-year-old woman. She featured with mental state alteration, respiratory failure, and shock, and was diagnosed with ceftriaxone-sensitive pneumococcal bacteremia, meningitis, and pneumonia. A transesophageal echocardiogram revealed vegetation of the mitral valve. Despite an improvement in her medical condition, she remained in a coma and died due to neurological complications. Even though the major cause of mortality in Austrian syndrome is cardiac involvement, meningitis is also linked with high morbidity and eventually death. We emphasize the relevance of an early diagnosis of the triad in order to decrease the very high mortality associated with this syndrome.A síndrome de Austrian é uma entidade extremamente rara, pautada por meningite, endocardite e pneumonia secundárias a doença pneumocócica invasiva. Devido à expressão multissistêmica, a mortalidade associada é elevada. Particularmente, a manifestação como endocardite é muitas vezes clinicamente insuspeita, carecendo de elevado índice de suspeita. Apresenta-se um caso de síndrome de Austrian numa doente do sexo feminino, 67 anos, previamente saudável. Clinicamente, apresentava coma, insuficiência respiratória e choque, tendo sido diagnosticada pneumonia e meningite, e com bacteremia a Streptococcus pneumoniae. Ecocardiograma transesofágico evidenciou uma vegetação na válvula mitral. Apesar da regressão do quadro respiratório, persistiu um quadro de coma, acabando a doente por morrer. Apesar da principal causa de morte descrita na síndrome de Austrian estar relacionada com complicações de endocardite, apresenta-se um caso único de apresentação e morte por meningite. Com poucos casos descritos mundialmente, sublinha-se a necessidade de um diagnóstico precoce desta tríade, motivo pelo qual relatamos o caso descrito

Ocorrência de térmitas subterrâneos (Isoptera: Rhinotermitidae e Termitidae) e durabilidade natural da madeira de cinco essências florestais.

This study aimed to evaluating of  the wood natural durability of five arboreal essences: Eucalyptus citriodora Hook, Gliricidia sepium (Jacq.) Steud, Lophantera lactescens Ducke, Piptadenia gonoacantha (Mart.) Macbr. and Samanea saman (Jacq.) Merr. The field experiment was accomplished in the campus of the Universidade Federal Rural do Rio de Janeiro from February, 2001 to November, 2002. Six samples of each essence partially buried in vertical position were disposed at random in five blocks. In laboratory, following a system of notes related to the wood healthy state, the samples were classed accorging to a behavioral index for each species in relation to the wood aspect. The samples bark condition, the hardness of the wood and the presence of longitudinal cracks were also observed in the body of the sample Laphantera lactescens and Piptadenia gonoacantha were the most and less durable woods according to the evaluated parameters, respectively. In 47% of the samples that were attacked three species of termites were identified: Coptotermes havilandi, Nasutitermes jaraguae and Nasutitermes minor.Avaliou-se a durabilidade natural da madeira de cinco essências arbóreas: Eucalyptus citriodora Hook, Gliricidia sepium (Jacq.) Steud, Lophantera lactescens Ducke, Piptadenia gonoacantha (Mart.) Macbr. e Samanea saman (Jacq.) Merr. O ensaio de campo foi realizado no campus da Universidade Federal Rural do Rio de Janeiro, de fevereiro de 2001 a novembro de 2002. Seis amostras de cada essência, parcialmente enterradas em posição vertical, foram dispostas aleatoriamente em cinco blocos. Em laboratório, segundo um sistema de notas relacionado ao estado fitossanitário da madeira, as amostras foram classificadas com um índice de comportamento, para cada essência, conforme seu aspecto fitossanitário. Também foram observados o estado da casca das amostras, a dureza da madeira e a presença de rachaduras longitudinais no corpo da amostra. As madeiras, mais e menos duráveis dentre os parâmetros avaliados, foram Laphantera lactescens e Piptadenia gonoacantha respectivamente. Em 47% das amostras que foram atacadas, três espécies de térmitas foram identificadas: Coptotermes havilandi, Nasutitermes jaraguae e Nasutitermes minor

A preliminary analysis of the wear pathways of sliding contacts on temporomandibular joint total joint replacement prostheses

In the last years, several materials and design have been assessed in an attempt to improve the mechanical performance of temporomandibular joint total joint replacement (TMJ TJR) prostheses. However, the wear of the TMJ TJR condyle to the polymer-based fossa component during loading and sliding movements. That promotes the release of debris and risks of toxicity to the surrounding tissues. The purpose of this study was to perform a narrative literature review on the wear of TMJ TJR sliding contacts and potential toxicity of metallic debris to the patients. Previous studies reported a significant deterioration of the sliding contact surfaces of TMJ TJR prostheses. Material loss as a result of wear can cause a TMJ TJR condyle/fossa mismatch and the modification of the contact pressure and chewing loading. As a further consequence of wear, metal particles are released to the surrounding tissues with a high risk of local tissue and systemic toxicity through the bloodstream. The presence of particles induces the stimulation of inflammatory reactions depending on the concentration and size of debris. Thus, CoCr-based condyle release metallic ions and sub-micron particles that can be engulfed by macrophages or internalized by other tissue cells. The wear and material loss of TMJ TJR could be decreased by design optimization and novel materials with low friction and contact pressure. That consequently decrease the amount of metallic ions and particles to the surrounding tissues, preventing peri-prosthetic inflammatory reactions.This study was supported by FCT-Portugal (UID/EEA/04436/2013, NORTE-01-0145- FEDER-000018—HAMaBICo, POCI-01-0145-FEDER-031035_LaserMULTICER), SFRH/BPD/123769/ 2016 and CNPq-Brazil (CNPq/UNIVERSAL/421229/2018-7)

O PÊNDULO DEFASADO: um exemplo de sistema caótico para estudantes do ciclo inicial do curso de graduação em Física

Neste trabalho é apresentado um estudo realizado por estudantes ingressantes do curso de Física da Universidade Federal do Pará com o objetivo de se analisar os estados de estabilidade de um pêndulo cujo pivô está em movimento circular uniforme (MCU). O modelo teórico foi desenvolvido utilizando-se a descrição de Lagrange da Mecânica Clássica. Após a modelagem, comparou-se as previsões teóricas com um aparato experimental, afim de se observar os casos de estabilidade. O projeto foi desenvolvido em uma disciplina piloto que se utilizou de uma metodologia ativa, baseada na indagação, em particular com o uso de problemas em aberto, para desenvolver nos estudantes habilidades e competências ligadas ao processo investigativo em ciências exatas, contribuindo também indiretamente para o entendimento da natureza da ciências