On topological spin excitations on a rigid torus

We study Heisenberg model of classical spins lying on the toroidal support, whose internal and external radii are $r$ and $R$, respectively. The isotropic regime is characterized by a fractional soliton solution. Whenever the torus size is very large, $R\to\infty$, its charge equals unity and the soliton effectively lies on an infinite cylinder. However, for R=0 the spherical geometry is recovered and we obtain that configuration and energy of a soliton lying on a sphere. Vortex-like configurations are also supported: in a ring torus ($R>r$) such excitations present no core where energy could blow up. At the limit $R\to\infty$ we are effectively describing it on an infinite cylinder, where the spins appear to be practically parallel to each other, yielding no net energy. On the other hand, in a horn torus ($R=r$) a singular core takes place, while for $R<r$ (spindle torus) two such singularities appear. If $R$ is further diminished until vanish we recover vortex configuration on a sphere.Comment: 11 pages, 9 figure

A Bayesian estimate of the CMB-large-scale structure cross-correlation

Evidences for late-time acceleration of the Universe are provided by multiple probes, such as Type Ia supernovae, the cosmic microwave background (CMB) and large-scale structure (LSS). In this work, we focus on the integrated Sachs--Wolfe (ISW) effect, i.e., secondary CMB fluctuations generated by evolving gravitational potentials due to the transition between, e.g., the matter and dark energy (DE) dominated phases. Therefore, assuming a flat universe, DE properties can be inferred from ISW detections. We present a Bayesian approach to compute the CMB--LSS cross-correlation signal. The method is based on the estimate of the likelihood for measuring a combined set consisting of a CMB temperature and a galaxy contrast maps, provided that we have some information on the statistical properties of the fluctuations affecting these maps. The likelihood is estimated by a sampling algorithm, therefore avoiding the computationally demanding techniques of direct evaluation in either pixel or harmonic space. As local tracers of the matter distribution at large scales, we used the Two Micron All Sky Survey (2MASS) galaxy catalog and, for the CMB temperature fluctuations, the ninth-year data release of the Wilkinson Microwave Anisotropy Probe (WMAP9). The results show a dominance of cosmic variance over the weak recovered signal, due mainly to the shallowness of the catalog used, with systematics associated with the sampling algorithm playing a secondary role as sources of uncertainty. When combined with other complementary probes, the method presented in this paper is expected to be a useful tool to late-time acceleration studies in cosmology.Comment: 21 pages, 15 figures, 4 tables. We extended the previous analyses including WMAP9 Q, V and W channels, besides the ILC map. Updated to match accepted ApJ versio

Decline in duration, satisfaction and sleep quality among informal caregivers of stroke survivors, 18-months post-stroke

Background. Data on stroke caregivers’ sleep is scarce. We aimed to assess changes in duration, satisfaction and sleep quality among informal caregivers of stroke survivors. Methods. Informal caregivers (n = 126) of stroke survivors hospitalized between September 2018 and August 2019 in the 12 Stroke Units of the North of Portugal were invited to participate in the study, 18 months’ post-stroke. Sociodemographic and sleep characteristics (duration, satisfaction and quality) were collected through structured questionnaires. Odds ratios and 95% confidence intervals (95%CI) were estimated through logistic regression, adjusted for age and sex. Answers to open-ended questions were synthetized using content analysis. Results. Due to care provision, informal caregivers reported sleeping, on average (SD), significantly less hours (7.0 (1.7) vs. 6.4 (1.8); p < 0.001). Since its beginning, caregivers’ satisfaction with their sleep decreased approximately 30%. Changes in sleep quality, namely difficulties in falling asleep and constant interruptions during sleep, were reported by almost 70% of caregivers. Only 6.4% described the prescription of medication to sleep after beginning care provision. Participants who returned to work (adjusted OR = 0.34; 95%CI:0.16-0.76) and with a monthly income above 1000€ (adjusted OR = 0.29; 95%CI:0.13-0.66) were less likely to report changes in sleep quality. Conclusions. A decline in duration, satisfaction and sleep quality of informal caregivers of stroke survivors, 18 months’ post-stroke, was observed. Changes in sleep quality revealed socioeconomic inequalities, highlighting the need to prevent adverse health outcomes related to sleep disturbance

Portuguese validation of the Adult Carer Quality of Life Questionnaire (AC-QoL)

Background. Assuring informal carers' quality of life (QoL) must be a priority for public health policies and practices. The Adult Carer Quality of Life Questionnaire (AC-QoL) is a recent and valid instrument, overpassing limitations of previous tools, and being already used among informal stroke carers. This study aimed to assess the feasibility, reliability and validity of the AC-QoL among Portuguese informal carers of stroke survivors. Methods. The linguistic adaptation of the AC-QoL was performed. Informal carers (n = 212) of stroke survivors hospitalized between September 2018 and August 2019 in all Stroke Units of the North of Portugal (n = 12) were invited to participate, 18 to 24 months post-stroke. Data on sociodemographic characteristics, psychological profile, burden and QoL were collected using a structured questionnaire. The psychometric properties of the AC-QoL were investigated through exploratory and confirmatory factor analyses. Cronbach's alpha was used to measure internal consistency. Construct validity was assessed through the association of the overall score of AC-QoL with anxiety and depressive symptoms, burden and sociodemographic characteristics. Results. Exploratory factor analysis supported the original eight-factor structure of the AC-QoL, revealing an adequate goodness of fit to the study sample (X2(674)=1145.926; CFI=0.916; TLI=0.908; RMSEA=0.058). The AC-QoL showed a high degree of reliability, with Cronbach's scores for the subscales ranging from 0.64 to 0.97 and a Cronbach's alpha of 0.91 for the overall score. Anxiety symptoms (p < 0.001), depression symptoms (p < 0.001) and burden (p < 0.001) were inversely associated with the overall score of AC-QoL. Younger (p = 0.032) and employed (p = 0.021) informal carers presented more frequently higher scores of overall QoL, than those older and unemployed. Conclusions. The Portuguese version of the AC-QoL is a comprehensive, simple, reliable and valid instrument to assess informal stroke carers' QoL

Componentes para a integração e extração de padrões em textos para versão 1.0 do Ambiente CRITIC@.

O projeto Compilação e Recuperação de Informações Técnico-científicas e Indução ao Conhecimento de forma Ágil na Rede AgroHidro(CRITIC@) consiste em melhorar a gestão do conhecimento técnico-científico na área de recursos hídricos, por meio de análises cruzadas das informações, bem como subsidiar ações de investigação e disseminação do conhecimento na rede de pesquisa

Delocalization and wave-packet dynamics in one-dimensional diluted Anderson models

We study the nature of one-electron eigen-states in a one-dimensional diluted Anderson model where every Anderson impurity is diluted by a periodic function $f(l)$ . Using renormalization group and transfer matrix techniques, we provide accurate estimates of the extended states which appear in this model, whose number depends on the symmetry of the diluting function $f(l)$. The density of states (DOS) for this model is also numerically obtained and its main features are related to the symmetries of the diluting function $f(l)$. Further, we show that the emergence of extended states promotes a sub-diffusive spread of an initially localized wave-packet.Comment: 6 pages, 6 figures, to appear in EPJ