Measured Quantum Dynamics of a Trapped Ion

The measurement process is taken into account in the dynamics of trapped ions prepared in nonclassical motional states. The induced decoherence is shown to manifest itself both in the inhibition of the internal population dynamics and in a damping of the vibrational motion without classical counterpart. Quantitative comparison with present experimental capabilities is discussed, leading to a proposal for the verification of the predicted effects.Comment: 5 Pages, no figures; Plain REVTeX; to be published in the 1st May issue of Phys. Rev. A, Rap. Commun. (1997

Empirical testing of Tsallis' Thermodynamics as a model for dark matter halos

We study a dark matter halo model from two points of view: the ``stellar polytrope'' (SP) model coming from Tsallis' thermodynamics, and the one coming from the Navarro-Frenk-White (NFW) paradigm. We make an appropriate comparison between both halo models and analyzing the relations between the global physical parameters of observed galactic disks, coming from a sample of actual galaxies, with the ones of the unobserved dark matter halos, we conclude that the SP model is favored over the NFW model in such a comparison.Comment: 5 pages, 1 figure, To appear in the Proceedings of X Mexican Workshop on Particles and Fields, Morelia Michoac\'an, M\'exico, November 7-12, 200

Linfocitose monoclonal de células B: uma breve revisão para clínicos gerais

Monoclonal B-cell lymphocytosis (MBL) is a recently described medical condition that displays biological similarities to the most common subtype of adult leukemia in the Western world, i.e. chronic lymphocytic leukemia (CLL). Diagnostic criteria have been published with the aim of differentiating between these two entities. The overall prevalence of MBL is at least 100 times higher than that of CLL, which indirectly suggests that MBL is not necessarily a pre-leukemic condition, although in some circumstances, CLL cases can really be preceded by MBL. In view of this high prevalence rate, general clinicians and even non-hematological specialists have a high chance of being faced with individuals with MBL in their routine clinical practice. MBL is classified as "clinical MBL", "population-screening MBL" and "atypical MBL" and the clinical management of affected individuals depends greatly on this differentiation. The present review provides a guide to diagnosing and following up MBL patients.A linfocitose monoclonal de células B (LMB) é uma condição médica recentemente descrita que exibe similaridades biológicas com o mais comum subtipo de leucemia em adultos de países ocidentais, qual seja, a leucemia linfocítica crônica (LLC). Critérios diagnósticos foram publicados com o intuito de separar as duas entidades. A prevalência global da LMB é pelo menos 100 vezes maior do que a da LLC, o que, indiretamente, sugere que a LMB não é necessariamente uma condição pré-leucêmica, embora, em algumas circunstâncias, casos de LLC possam realmente ser precedidos pela LMB. Em virtude dessa alta taxa de prevalência, clínicos gerais e mesmo outros especialistas não hematologistas têm grande chance de deparar-se com casos de LMB em suas rotinas clínicas. A LMB é classificada como "LMB clínica", "LMB de screening populacional" e "LMB atípica", sendo que o manuseio clínico dos indivíduos afetados depende substancialmente dessa diferenciação. A presente revisão fornece um guia para o diagnóstico e acompanhamento dos pacientes com LMB.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

The Contribution of the Internet to Reducing Social Isolation in Individuals Aged 50 Years and Older: Quantitative Study of Data From the Survey of Health, Ageing and Retirement in Europe

Background: Social isolation has a negative impact on the quality of life of older people; therefore, studies have focused on identifying its sociodemographic, economic, and health determinants. In view of the growing importance of the internet as a means of communication, it is essential to assess whether internet use interferes with social isolation. Objective: This study specifically aims to clarify the relationship between internet use and social isolation of individuals aged ≥50 years, for which other surveys present contradictory results. Methods: We performed logistic regression analysis with social isolation as the dependent variable, internet use as the interest variable, and several other sociodemographic, economic, and health characteristics of the individuals as control variables. The sample size was 67,173 individuals aged 50 years and older from 17 European countries (Portugal, Greece, Italy, Spain, Denmark, Sweden, Austria, Belgium, France, Germany, Switzerland, Luxemburg, Poland, Czech Republic, Slovenia, Estonia, and Croatia) plus Israel, who were interviewed in the Survey of Health, Ageing and Retirement in Europe (SHARE), wave 6. Results: The results show that countries differ in the level of social isolation and rate of internet use by individuals aged 50 years and older. They also evidence that in most of the countries analyzed, social isolation of internet users was lower compared to that of nonusers after controlling for a set of sociodemographic, economic, and health characteristics of the individuals that have been previously described in the literature as determinants of social isolation. Indeed, on average, although 31.4% of individuals in the nonuser group experienced high social isolation, only 12.9% of individuals who used the internet experienced this condition. Conclusions: Internet users show lower social isolation. This result underlines the importance of promoting e-inclusion in Europe as a way to counter social isolation of individuals aged 50 years and older

The protective role of the Internet in depression for Europeans aged 50+ living alone

Depression is a significant and limiting health problem, and living alone has been identified as an essential determinant of depressive symptoms in middle-aged and older adults. This study looks at this relationship by introducing a new factor into the equation—the Internet—which has become increasingly relevant for communication and interaction. It aims to assess to what extent the use of the Internet can mitigate the association between living alone and depression in middle-aged and older adults. This study focuses on a sample of 64,260 individuals aged 50+ who are resident in Portugal, Greece, Italy, Spain, Denmark, Sweden, Austria, Belgium, France, Germany, Switzerland, Luxemburg, Poland, Czech Republic, Slovenia, Estonia, and Croatia and were surveyed in the context of the SHARE project (Survey of Health, Ageing, and Retirement in Europe), Wave 6. The results showed that living alone relates to greater odds of depression. Nevertheless, of particular relevance is that they also evidenced that the Internet has a moderating role on this relationship, revealing a protective role, since Europeans aged 50+ who live alone and are Internet users are less likely to experience depression than other older adults. The findings reinforce the importance of policies aimed at digital inclusion to benefit the mental health of older adults who live alone in Europe

Can the internet reduce the loneliness of 50+ living alone?

This work was supported by European Commission; Fundação para a Ciência e a Tecnologia; U.S National Institute on Aging; Fundação Calouste Gulbenkian; German Ministry of Education and Research.Living alone has been indicated as a key variable to explain loneliness in older adults. In contemporary society, where technology has become one of the main means of communication and personal interaction, has the internet influenced the relationship between living alone and loneliness? This paper aims to answer this research question by using a sample of 64,297 individuals who were surveyed in SHARE project wave 6 – in European countries with different welfare regimes (Portugal, Greece, Italy and Spain, Denmark, Sweden, Austria, Belgium, France, Germany, Switzerland, Luxemburg, Poland, Czech Republic; Slovenia, Estonia, and Croatia). The results of the regression analysis evidence the moderating role of the internet on the relationship between living alone and feelings of loneliness in individuals aged 50 and over, so that the impact of living alone on loneliness is diminished for internet users as compared to their peers who do not use the internet. The results therefore reinforce the importance of policies aimed at fostering e-inclusion as a way of reducing the loneliness of older adults

E-inclusion: Beyond individual sociodemographic characteristics

The changing demographic structure of the population, resulting in unparalleled growth of the elderly population, means that e-inclusion of this population group is considered to be a social and political priority in the context of the Information Society. Most research studies have only considered individual variables -such as age, gender, education, income and health- in the explanatory models of e-inclusion of senior citizens, while ignoring macro variables, such as the welfare systems and public policies in each country. Simultaneously, most studies focus on small-scale samples, lack international comparisons and do not consider the combined effect of several variables that influence Internet use. This study aims to analyse possible differences between two countries that have different welfare systems and public policies, after controlling for the effects of the individual variables that have been identified in the literature as relevant for Internet use. The study focuses on a sample of 8639 individuals, aged 50 years and over, residing in Portugal and Estonia, who participated in the SHARE project (Survey of Health, Ageing and Retirement in Europe). The results of the logistic regression analysis demonstrate that welfare systems and public policies have an impact on the likelihood of Internet use, thus reinforcing the importance of developing public policies to foster e-inclusion of senior citizens.The Foundation for Science and Technology (FCT

Arquitetura de canais para rádios definidos por software de múltiplas camadas

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-graduação em Engenharia de Automação e Sistemas, Florianópolis, 2010Nos últimos anos, foram criados diversos padrões de redes sem fio para garantir o cumprimento de diferentes requisitos de alcance, vazão de dados, segurança e consumo de energia. Muitas vezes isso obriga a integração de componentes que suportam diversas redes sem fio para criação de equipamentos multipadrões. Essa solução tradicional, apesar de robusta, impõe uma série de limitações relacionadas com o espaço físico, consumo de energia e custo dos sistemas integrados, além da falta de flexibilidade para modificações. Uma alternativa a esse cenário tem sido o uso de Rádios Definidos por Software (SDR), os quais possuem a camada física completamente reconfigurável, permitindo flexibilidade em vários parâmetros de comunicação como faixa de freqüência, tipo de modulação e potência de transmissão. Atualmente, existem várias propostas para implementação de SDRs, destacando-se o GNU Radio em conjunto com a placa USRP como opção de baixo custo, que possibilita a criação de rádios funcionais a partir de modelos de alto nível utilizando computadores pessoais. Entretanto, existe uma lacuna no suporte nativo à implementação de múltiplas camadas físicas compartilhando a mesma interface física, o que causa um overhead maior que o desejado na criação de sistemas multipadrões. Para superar tal desafio, este trabalho apresenta a concepção de uma arquitetura de canais para múltiplas camadas físicas que se destaca por propor uma interface genérica que atende a todos os tipos de camadas físicas e pode ser suportada por diversos hardwares de SDR. Visando a melhor utilização dos recursos a arquitetura proposta permite o deslocamento do estágio de separação de múltiplos canais para o hardware sem a perda de flexibilidade. Para validar a arquitetura proposta foi desenvolvido um protótipo baseado no GNU Radio e USRP2, além das implementações de dois cenários de testes, com múltiplas camadas físicas iguais (IEEE802.15.4) e com múltiplas camadas diferentes (IEEE802.15.4 e IEEE802.11b). Os testes demonstraram uma melhora significativa no desempenho global do sistema e uma simplificação na interface com a camada física, uma vez que não há necessidade de configurar as variáveis relacionadas com os ajustes do próprio hardware