Life cycle of cosmic-ray electrons in the intracluster medium

We simulate the evolution of relativistic electrons injected into the medium of a small galaxy cluster by a central radio galaxy, studying how the initial jet power affects the dispersal and the emission properties of radio plasma. By coupling passive tracer particles to adaptive-mesh cosmological MHD simulations, we study how cosmic-ray electrons are dispersed as a function of the input jet power. We also investigate how the latter affects the thermal and non-thermal properties of the intracluster medium, with differences discernible up to $\sim$ Gyr after the start of the jet. We evolved the energy spectra of cosmic-ray electrons, subject to energy losses that are dominated by synchrotron and inverse Compton emission as well as energy gains via re-acceleration by shock waves and turbulence. We find that in the absence of major mergers the amount of re-acceleration experienced by cosmic-ray electrons is not enough to produce long-lived detectable radio emissions. However, for all simulations the role of re-acceleration processes is crucial to maintain a significant and volume-filling reservoir of fossil electrons ($\gamma \sim 10^3$) for several Gyrs after the first injection by jets. This is important to possibly explain recent discoveries of cluster-wide emission and other radio phenomena in galaxy clusters.Comment: 25 pages, 24 figures. A & A accepted, in pres

Energetic potential of Sclerobium paniculatum vogel (taxi-branco) and its preferential top climatic condition in Eastern Amazonia, Brasil.

Tropentag 2009

Impact of COVID-19 pandemic on chronic pain management: Looking for the best way to deliver care

Although pain treatment has been described as a fundamental human right, the Coronavirus disease 2019 (COVID-19) pandemic forced healthcare systems worldwide to redistribute healthcare resources toward intensive care units and other COVID-19 dedicated sites. As most chronic pain services were subsequently deemed non-urgent, all outpatient and elective interventional procedures have been reduced or interrupted during the COVID-19 pandemic in order to reduce the risk of viral spread. The shutdown of pain services jointly to the home lockdown imposed by governments has affected chronic pain management worldwide with additional impact on patients' psychological health. Therefore, the aim of this review is to analyze the impact of COVID-19 pandemic on chronic pain treatment and to address what types of strategies can be implemented or supported in order to overcome imposed limitations in delivery of chronic pain patient care

Recuperação de áreas degradadas com base em sistema de produção florestal energético-madeireiro: indicadores de custos, produtividade e renda.

As áreas alteradas na Amazônia brasileira ocupam expressiva proporção do território. A reincorporação dessas áreas ao processo produtivo, a partir de plantações florestais, pode contribuir significativamente para o aumento da oferta de madeira de elevado valor econômico, e diminuir a pressão sobre as florestas nativas. A minimização de danos ambientais decorrentes de aumento na emissão de gases de efeito estufa; perdas de solo, água e nutrientes, além da biodiversidade que deve ser considerada. Para a pesquisa o desafio colocado é oferecer opções de sistemas agrícolas e florestais passíveis de utilização. E, além disso, é preciso que os sistemas de plantios florestais escolhidos, além de economicamente atrativos, sejam adequados à legislação ambiental em termos de manutenção de Áreas de Reserva Legal (ARL). Com a finalidade de contribuir para o fomento de plantios florestais na Amazônia, este trabalho tem por objetivo apresentar um modelo de produção florestal que combina as espécies castanha-do-pará ( Bertholletia excelsa H.B.K.); andiroba ( Carapa guianensis Aubl.), paricá ( Schizolobium amazonicum Huber) e taxi-branco (Sclerolobium paniculatum Vogel)

Land-use in a mulch-based farming system of small holders in the eastern Amazon.

Burning is a commonly used method to clear land for cropping, especially in regions with shifting cultivation. Due to population growth with the resulting intensified land use, it is mostly combined with a shortening of the fallow periods. Both burning and the shortened fallow period are the principal causes of declining soil fertility, and they are symptomatic for Eastern Amazonian agriculture. Based on the assumption that shifting cultivation will be maintained as the basic land-use system, these two adverse factors have to be improved in order to achieve reasonable and increased sustainable productivity. In the framework of a bilateral German-Brazilian research project, mechanized mulching technologies were developed to carry out fire-free land clearing by cutting and chopping the tree-rich fallow vegetation creating a mulch layer. Besides preserving organic matter and mineral nutrients, mulching permits land preparation at any time of the year, as, in contrast to burning, it does not depend on the dry season. Enriching the fallow vegetation with fast growing trees enhances the effect of mulching by increasing biomass: 25 t/ha/year as compared to natural fallow with 10 t/ha/year during the linear growth phase in the first 2 - 3 years. When putting these technologies into practice, the demand on differently behaving nutrient stocks in mulch-based systems has to be met. On the other hand, fire-free land preparation allows for flexible, alternative land utilization practices. Both factors lead to new crop-fallow scenarios where land use is intensified whilst the basic principles of shifting cultivation are maintained. In particular: 1) fallow biomass increase by enrichment reduces the fallow period from 4 - 6 years to 2 years, 2) slow nutrient release from the mulch layer allows highly demanding crops to be planted at the end of the cropping period low mineral fertilizer input is desired, 3) an additional cropping period becomes possible and reduces the land preparation time by half, 4) independent of the dry season crops can be planted taking climate and market demands into consideration, and 5) perennial cash crops can be integrated into the crop rotation