Two-stream instability in quasi-one-dimensional Bose-Einstein condensates

We apply a kinetic model to predict the existence of an instability mechanism in elongated Bose-Einstein condensates. Our kinetic description, based on the Wigner formalism, is employed to highlight the existence of unstable Bogoliubov waves that may be excited in the counterpropagation configuration. We identify a dimensionless parameter, the Mach number at T=0, that tunes different regimes of stability. We also estimate the magnitude of the main parameters at which two-stream instability is expected to be observed under typical experimental conditions

A new approach to the Sachs-Wolfe effect

We present a new approach to the Sachs-Wolfe effect, which is based on the dynamics of photons in a space and time varying gravitational field. We consider the influence of plasma dispersion effects on photon propagation, and establish the limits of validity of the usual results of the standard cosmological approach, for the large scale temperature anisotropies of the cosmic microwave background. New dynamical contributions to the integrated Sachs-Wolfe effect are also discussed.Comment: 5 page

A new approach to the Sachs-Wolfe effect

We present a new approach to the Sachs-Wolfe effect, which is based on the dynamics of photons in a space and time varying gravitational field. We consider the influence of plasma dispersion effects on photon propagation, and establish the limits of validity of the usual results of the standard cosmological approach, for the large scale temperature anisotropies of the cosmic microwave background. New dynamical contributions to the integrated Sachs-Wolfe effect are also discussed.Comment: 5 page

Molecular and morphological characterization of the predatory mite Amblyseius largoensis (Acari: Phytoseiidae): surprising similarity between an Asian and American populations.

Na publicação: Denise Navia

Resposta genética na população de cebola Alfa Tropical no Vale do São Francisco.

O desenvolvimento de cultivares e/ou populações de cebola no vale do São Francisco tem contribuído largamente para o controle de doenças, como mal-das-sete voltas, para a substituição de importações de sementes e para o aumento da produtividade na região. O objetivo deste trabalho foi estimar parâmetros genéticos, resultantes da seleção e adaptação da população Alfa Tropical nas condições de Petrolina, PE. Os caracteres produtividade total (PROT) e produção comercial (PROC) de bulbos e teor brix foram avaliados para três ciclos de seleção recorrente, no delineamento de blocos ao acaso, com quatro repetições. Ocorreu resposta linear para PROC do ciclo 0 para o ciclo 3. Os valores de herdabilidades para PROC foram bastante superiores aos valores estimados para PROT. Os ganhos de seleção foram mais pronunciados para PROC do que para PROT. Analisando conjuntamente os resultados da seleção e adaptação local da população Alfa Tropical às condições do Petrolina-PE, observa-se resposta à seleção de 10,85 t/ha ou 25,3% nos três ciclos, indicando que o melhoramento genético para as condições locais deve ser realizado.Suplemento. Edição de Resumos expandidos e palestras do 43. Congresso Brasileiro de Olericultura, Recife, jul. 2003

Association of physical activity with physical function and quality of life in people with hip and knee osteoarthritis: longitudinal analysis of a population-based cohort

Hip and knee osteoarthritis (HKOA) is a chronic disease characterized by joint pain that leads to reduced physical function and health-related quality of life (HRQoL). At present, no cure is available. Clinical trials indicate that people with HKOA benefit from physical activity in several health-related outcomes. However, few studies have evaluated the long-term positive effect of regular physical activity. This study analyzed participants with HKOA from a nationwide population-based cohort (EpiDoC Cohort) to assess the impact of physical activity on patients' physical function and HRQoL over a long-term follow-up. The regular weekly frequency of intentional physical activity was self-reported as non-frequent (0 times/week), frequent (1-2 times/week), or very frequent (≥ 3 times/week). This study followed 1086 participants over a mean period of 4.7 ± 3.4 years, during which 6.3% and 14.9% of participants reported frequent and very frequent physical activity, respectively. Using linear mixed models, we found that frequent (β = - 0.101 [- 0.187, - 0.016]; β = 0.039 [- 0.002, 0.080]) and very frequent physical activity (β = - 0.061 [- 0.118, - 0.004]; β = 0.057 [0.029, 0.084]) were associated with improved physical function and HRQoL over time, respectively, when compared with non-frequent exercise, adjusting for years to baseline, sex, age, years of education, body mass index, multimorbidity, hospitalizations, clinical severity, and unmanageable pain levels. These findings raise awareness of the importance of maintaining exercise/physical activity long term to optimize HRQoL and physical function. Further studies must address barriers and facilitators to improve the adoption of regular physical activity among citizens with HKOA.info:eu-repo/semantics/publishedVersio

Caracterização dos solos em duas toposseqüências sobre diferentes litologias em áreas altimontanas na Serra da Mantiqueira.

Estudo de solos em duas toposseqüências em áreas de preservação ambiental na Serra da Mantiqueira, a primeira localizada no Parque Estadual do Ibitipoca, município de Lima Duarte, MG e a segunda localizada na RPPN do Matutú, município de Aiuruoca, MG.bitstream/CNPS/11573/1/doc57_2003_topossequencias.pd

Mediterranean spotted fever and encephalitis: a case report and review of the literature

Mediterranean spotted fever (MSF) is a disease caused by Rickettsia conorii and transmitted by the brown dog tick Rhipicephalus sanguineus. It is widely distributed through southern Europe, Africa, and the Middle East. It is an emerging or a reemerging disease in some regions. Countries of the Mediterranean basin, such as Portugal, have noticed an increased incidence of MSF over the past 10 years. It was believed that MSF was a benign disease associated with a mortality rate of 1-3% before the antimicrobial drug era. It was called benign summer typhus. Severe forms were described in 1981, and the mortality rate reached 32% in Portugal in 1997. However, neurological manifestations associated with brain lesions are a rare event. We describe the case of a man with fever, maculopapular rash, a black spot, and hemisensory loss including the face on the left side of the body with brain lesions in the imaging studies