Demonstration of fundamental mode only propagation in highly multimode fibre for high power EDFAs

The use of short lengths of large core phosphate glass fibre, doped with high concentrations of Er or Er:Yb represents an attractive route to achieving high power erbium doped fibre amplifiers (EDFAs) and lasers (EDFLs). With the aim of investigating the potential of achieving diffraction limited output from such large core fibres, we present experimental results of fundamental mode propagation through a 20 cm length of passive 300 micrometer core multimode fibre when the input is a well-aligned Gaussian beam. Through careful control of fibre geometry, input beam parameters and alignment, we measured an output M squared of 1.1 + - 0.05. The fibre had a numerical aperture of 0.389, implying a V number of 236.8. To our knowledge, this is the largest core fibre through which diffraction limited fundamental mode propagation has been demonstrated. Although the results presented here relate to undoped fibre, they do provide the practical basis for a new generation of EDFAs and EDFLs.Comment: 5 figure

O profissional de contabilidade de gestão em Portugal

As transformações e mudanças que ocorrem no mundo empresarial e nos negócios, têm um impacto directo no exercício da profissão de contabilidade. O desenvolvimento das organizações empresariais suscita discussão na sociedade sobre a função do profissional de contabilidade na gestão dos negócios e o seu papel no auxílio à resolução de problemas das empresas. Com estes desenvolvimentos o profissional de contabilidade de gestão passou a ter maior relevância tanto no meio académico, como no mercado, que procura profissionais especializados, com visão de gestão, planeamento fiscal, financeiro e de contabilidade. A classe profissional deve estar atenta às perspectivas e tendências, para que o profissional de contabilidade se torne cada vez mais relevante no apoio à tomada de decisões empresariais. Ele deverá ser visto como um comunicador de informação essencial para a tomada de decisão, com a sua capacidade de avaliar os factos passados, perceber os factos presentes e prever os eventos futuros. Pretende-se, assim, fazer um enquadramento histórico da profissão, alargando o âmbito ao profissional de contabilidade em geral, abordar a situação do profissional de contabilidade de gestão nos dias que correm, bem como enunciar os principais desafios que o profissional de contabilidade de gestão terá que atravessar

Análise e interpretação dos níveis de actividade física de crianças: um tutorial baseado na modelação hierárquica ou multinível

Este tutorial pretende apresentar, de modo didáctico, uma forma alternativa de análise de dados sobre os níveis de actividade física de crianças a partir da modelação hierárquica ou multinível. São mencionadas as diferentes etapas da modelação, os resultados são interpretados com base nos output's do software utilizado – o HLM 6.02. Em cada etapa do percurso são lançadas as hipóteses mais importantes em grau de complexidade crescente. A sua importância é referida a partir dos resultados disponíveis

Hagedorn transition and chronology protection in string theory

We conjecture chronology is protected in string theory due to the condensation of light winding strings near closed null curves. This condensation triggers a Hagedorn phase transition, whose end-point target space geometry should be chronological. Contrary to conventional arguments, chronology is protected by an infrared effect. We support this conjecture by studying strings in the O-plane orbifold, where we show that some winding string states are unstable and condense in the non-causal region of spacetime. The one-loop string partition function has infrared divergences associated to the condensation of these states.Comment: 40 pages, 11 figures. Expanded discussion on evolution of on-shell modes and added appendi

Warm stellar matter with deconfinement: application to compact stars

We investigate the properties of mixed stars formed by hadronic and quark matter in $\beta$-equilibrium described by appropriate equations of state (EOS) in the framework of relativistic mean-field theory. We use the non- linear Walecka model for the hadron matter and the MIT Bag and the Nambu-Jona-Lasinio models for the quark matter. The phase transition to a deconfined quark phase is investigated. In particular, we study the dependence of the onset of a mixed phase and a pure quark phase on the hyperon couplings, quark model and properties of the hadronic model. We calculate the strangeness fraction with baryonic density for the different EOS. With the NJL model the strangeness content in the mixed phase decreases. The calculations were performed for T=0 and for finite temperatures in order to describe neutron and proto-neutron stars. The star properties are discussed. Both the Bag model and the NJL model predict a mixed phase in the interior of the star. Maximum allowed masses for proto-neutron stars are larger for the NJL model ($\sim 1.9$ M$_{\bigodot}$) than for the Bag model ($\sim 1.6$ M$_{\bigodot}$).Comment: RevTeX,14 figures, accepted to publication in Physical Review

Deviation From \Lambda CDM With Cosmic Strings Networks

In this work, we consider a network of cosmic strings to explain possible deviation from \Lambda CDM behaviour. We use different observational data to constrain the model and show that a small but non zero contribution from the string network is allowed by the observational data which can result in a reasonable departure from \Lambda CDM evolution. But by calculating the Bayesian Evidence, we show that the present data still strongly favour the concordance \Lambda CDM model irrespective of the choice of the prior.Comment: 15 Pages, Latex Style, 4 eps figures, Revised Version, Accepted for publication in European Physical Journal

Concurrent and predictive validity of glim criteria to identify undernutrition in hospitalized patients

info:eu-repo/semantics/publishedVersio

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Sarcopenia and associated factors among older adults at high risk of dementia

Abstract Background Sarcopenia and dementia share pathophysiological pathways and risk factors, including advanced age, physical inactivity, unhealthy diet, smoking and diabetes. Older adults at high risk of dementia may face increased susceptibility to sarcopenia, which can also exacerbate cognitive decline. Thus, this study aims to estimate the frequency of sarcopenia and its associated factors within this vulnerable population. Methods This cross-sectional analysis includes data from a subset of older adults (65 years of age) enrolled in the MIND-Matosinhos randomized controlled trial, a community-based cognitive decline prevention program. Per the European Working Group on Sarcopenia in Older People, probable sarcopenia is defined as low muscle strength (handgrip strength &lt;16 kg for women and &lt;27 kg for men). Sociodemographic, lifestyle and health-related data were collected via structured questionnaires. To assess factors associated with sarcopenia, odds ratios (OR) and respective confidence intervals (95% CI) were estimated using logistic regression. Results A total of 157 participants (58.6% female), with a median age of 73 years (range: 65 to 85 years), were included. The overall prevalence of sarcopenia was 21.7% (n=34). After adjusting for sex, age and education, inadequate adherence to Mediterranean Diet (MD) (OR=10.90; 95% CI:1.41-84.52), current smoking status (OR=5.06; 95% CI:1.06-24.18) and poorer self-perceived health (OR=2.74; 95% CI:1.03-7.28) were positively associated with sarcopenia. No other statistically significant associations were found. Conclusions The observed sarcopenia frequency underscores the need for enhanced screening and management of this condition in community settings and among those at dementia risk. Inadequate adherence to MD, smoking and poor self-perceived health, seem to be associated with sarcopenia in older adults at high risk of dementia. Sarcopenia prevention should involve a holistic approach to promoting a healthy lifestyle. Key messages Sarcopenia was observed in 21.7% of older adults at high risk of dementia, indicating a significant burden on this vulnerable population. Inadequate adherence to the Mediterranean diet, smoking and poor self-perceived health were associated with sarcopenia. </jats:sec