1,327 research outputs found
Pump-and-probe optical transmission phase shift as a quantitative probe of the Bogoliubov dispersion relation in a nonlinear channel waveguide
We theoretically investigate the dispersion relation of small-amplitude
optical waves superimposing upon a beam of polarized monochromatic light
propagating along a single-mode channel waveguide characterized by an
instantaneous and spatially local Kerr nonlinearity. These small luminous
fluctuations propagate along the waveguide as Bogoliubov elementary excitations
on top of a one-dimensional dilute Bose quantum fluid evolve in time. They
consequently display a strongly renormalized dispersion law, of Bogoliubov
type. Analytical and numerical results are found in both the absence and the
presence of one- and two-photon losses. Silicon and silicon-nitride waveguides
are used as examples. We finally propose an experiment to measure this
Bogoliubov dispersion relation, based on a stimulated four-wave mixing and
interference spectroscopy techniques.Comment: 17 pages, 7 figure
Sustainable use of genetic resources: the characterization of an Italian local grapevine variety (‚Grechetto rosso') and its own landscape
Biodiversity and landscape are two tightly liked environmental traits, so that the loss in traditional agricultural landscapes imply the erosion of precious local germplasm. The on-farm conservation of local cultivars assure the preservation of optimized environment-genotype interactions, unique multifunctional agro-ecosystems and landscapes. Therefore, the safeguard of endangered genetic resources has to consider genotyping, phenotyping, but also the characterization of the related landscapes. The objective of this study was to provide the characterization of a local Italian grapevine, i.e. 'Grechetto rosso' through an integrated approach based on conventional ampelographic and molecular determinations and on the characterization of the landscape in the innate environment. 'Grechetto rosso' has affinity with 'Sangiovese', of which keeps the main ampelographic characters. Nonetheless, its diversity is prevalently expressed in berry characters, like the occasional presence of a not uniformly pigmented pulp, week epicuticular waxes and a red-coloured skin. This berry characters appeared to be related to the micro-environmental variables, i.e. the occurrence of cold-temperate nights during the ripening period and a rather temperate climate of the innate area. The 'Grechetto rosso' wine-grape-growing area is characterized by high naturality, and the 47 % of the 'Grechetto rosso' vineyards are still mixed with olive groves (traditional arrangement), while the remaining surface is represented by either specialized (46 %) or neglect (residual/relict) (7 %) vineyards. 'Grechetto Rosso' vineyards are distributed even in steep and extremely steep slope areas. The resulting description represents an example of useful information for promoting a sustainable use of grapevine genetic resources based on the in situ conservation on farm
Comparação de indicadores de desempenho de produtores de leite localizados dentro e fora de assentamentos de reforma agrária no Triângulo Mineiro
Na discussão sobre uma reforma agrária no Brasil, um ponto central é a competitividade dos assentamentos. Por isso, este estudo comparativo entre produtores leiteiros localizados dentro e fora dos assentamentos de reforma agrária busca ampliar a compreensão do potencial econômico e técnico dos assentados. A pesquisa perfaz 81 entrevistas: com 39 produtores de leite do assentamento "Rio das Pedras", no Triângulo Mineiro, com 42 produtores de leite fora do assentamento - nos municípios limítrofes de Uberlândia e Monte Alegre (MG). A pesquisa de campo foi feita entre abril e o início de junho de 2006, mas os dados se referem à produção, aos custos e à renda obtida no mês de março do mesmo ano. Foi recorrido a vários indicadores de desempenho econômico e técnico na produção de leite, como a margem bruta que corresponde à diferença entre receita e custo operacional. Os dados revelaram que a diferença entre as margens brutas médias por litro de leite dos produtores fora e dentro do assentamento é significativa, e a margem bruta média por litro de leite é maior para os produtores de fora do assentamento. A diferença nas margens brutas médias por litro de leite entre os produtores fora e dentro do assentamento resulta do preço por litro leite mais elevado obtido pelos grandes produtores de fora do assentamento. As maiores margens brutas totais foram encontradas entre produtores que produziram de 500 a 999 litros. As maiores margens brutas por litro de leite foram obtidas por médios ou pequenos produtores, inclusive assentados. Em ambos os grupos pesquisados, houve uma grande variação no desempenho. O conjunto dos indicadores de desempenho utilizados não aponta uma superioridade absoluta dos produtores de leite do entorno sobre os assentados. Produtores com desempenho fraco foram encontrados entre grandes e pequenos, independentemente de localização. Com esses resultados, recomenda-se a identificação e a implementação de ações para elevar o preço do litro de leite para os pequenos produtores da região. Este estudo revelou, também, a necessidade de reavaliar a intensidade ótima no uso de insumos adquiridos e de difundir as melhores práticas de produção entre produtores com dotações de recursos similares.In the discussion of agrarian reform in Brazil, a central concern is the competitiveness of farms on land settlements. This comparative study between milk producers on land settlement schemes and outside aims to enhance understanding of the settlers' technical and economical potential. The analysis is based on data collected from 39 milk producers from the Rio das Pedras settlement and 42 milk producers located in the bordering municipalities of Uberlândia and Monte Alegre, State of Minas Gerais. The field research took place on April and June but the farm data refer to production, costs, and income occurred in March 2006. We use various technical and economic measures to assess farm performance, though focused on the gross margin per liter and per hectare. The survey results reveal that the average gross margin per liter of milk obtained by producers from outside the settlement was higher than for the settlers. However, the difference in the two averages can be explained by the higher average price per liter obtained by producers from outside the settlement. The larger total gross margin were found among producers ranging from 600 to 1400 liters. Both outside and on the settlement there was wide variation in farm performance. The highest gross margins per liter were obtained on some of the small and medium-size farms, including a few settler farms. The full range of performance indicators which we used did not demonstrate an absolute superiority of non-settler producers over the settlers: producers with poor performance were found among small and large farms, regardless their location. These results lead us to recommend the identification and implementation of actions designed to raise the price of the liter of milk for small scale producers. The study also revealed a need to reassess the optimum intensity of use of purchased feed-stuffs and for the transfer of best practice between farms with similar resource endowments
Sustained response to infliximab treatment in two cases of early rheumatoid arthritis that has been maintained after drug withdrawal
The authors report two cases of active seropositive rheumatoid arthritis who were treated in an early phase of the disease with infliximab plus methotrexate obtaining a clinical remission. The benefit was maintained after the discontinuation of the anti-TNF alpha inhibitor for adverse events, indicating that the early administration of the drug may be followed by a sustained remission
Comparação de indicadores de desempenho de produtores de leite localizados dentro e fora de assentamentos de reforma agrária no Triângulo Mineiro
In the discussion of agrarian reform in Brazil, a central concern is the competitiveness of farms on land settlements. This comparative study between milk producers on land settlement schemes and outside aims to enhance understanding of the settlers’ technical and economical potential. The analysis is based on data collected from 39 milk producers from the Rio das Pedras settlement and 42 milk producers located in the bordering municipalities of Uberlândia and Monte Alegre, State of Minas Gerais. The field research took place on April and June but the farm data refer to production, costs, and income occurred in March 2006. We use various technical and economic measures to assess farm performance, though focused on the gross margin per liter and per hectare. The survey results reveal that the average gross margin per liter of milk obtained by producers from outside the settlement was higher than for the settlers. However, the difference in the two averages can be explained by the higher average price per liter obtained by producers from outside the settlement. The larger total gross margin were found among producers ranging from 600 to 1400 liters. Both outside and on the settlement there was wide variation in farm performance. The highest gross margins per liter were obtained on some of the small and medium-size farms, including a few settler farms. The full range of performance indicators which we used did not demonstrate an absolute superiority of non-settler producers over the settlers: producers with poor performance were found among small and large farms, regardless their location. These results lead us to recommend the identification and implementation of actions designed to raise the price of the liter of milk for small scale producers. The study also revealed a need to reassess the optimum intensity of use of purchased feed-stuffs and for the transfer of best practice between farms with similar resource endowments.agrarian reform, competitiveness, efficiency, milk production, Triângulo Mineiro., Agribusiness, Q 15,
Oxidative stress in stable cystic fibrosis patients: Do we need higher antioxidant plasma levels?
Efeito da secagem natural e artificial da biomassa foliar de Piper hispidinervum na composição química do óleo essencial.
Pain in systemic sclerosis
Chronic pain is a healthcare problem that significantly affects the mental health, and the professional and private life of patients. It can complicate many disorders and represents a common symptom of rheumatologic diseases, but the data on its prevalence is still limited. Pain is a ubiquitous problem in systemic sclerosis (SSc). SSc-related pain has been studied on the basis of biomedical models and is considered a symptom caused by the disease activity or previous tissue damage. Effective pain management is a primary goal of the treatment strategy, although this symptom in SSc has not yet been investigated in detail. However, these patients do not all respond adequately to pharmacological pain therapies, therefore in these cases a multimodal approach needs to be adopted
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