The mechanical behaviour of compacted Lambeth-group clays with and without fibre reinforcement

This study investigated the effect of fibre reinforcement on the large strain behaviour of compacted clay samples tested using large triaxial test equipment. A novel specimen preparation method was proposed where peds of clay are compacted to closely simulate the in-situ compaction. A large number of 100 × 200 mm triaxial tests and one-dimensional compression tests were performed using reinforced and unreinforced samples. The behaviour of unreinforced samples was observed to be similar to highly fissured clays; ped compaction generated a random fissure pattern due to the contact between peds. The addition of fibres to the compacted samples created fissures with higher mobility at lower friction than those in the unreinforced samples; hence, the state boundary surface of reinforced clay was below that of the unreinforced clay. With the addition of fibres, the failure mechanism changed from the formation of a shear plane to barrelling, demonstrating that the fibres transferred stresses further away from the shear plane, producing a more homogeneous stress distribution. The preparation method proposed here produced a fissure pattern in the clay that introduced transitional behaviour, which was drastically reduced with addition of the fibres, allowing better normalisation and the definition of a unique boundary surface

Aging Effects of Caenorhabditis elegans Ryanodine Receptor Variants Corresponding to Human Myopathic Mutations

Delaying the decline in skeletal muscle function will be critical to better maintenance of an active life-style in old age. The skeletal muscle ryanodine receptor, the major intracellular membrane channel through which calcium ions pass to elicit muscle contraction, is central to calcium ion balance, and is hypothesized to be a significant factor for age-related decline in muscle function. The nematode Caenorhabditis elegans is a key model system for the study of human aging and strains with modified C. elegans ryanodine receptors corresponding to human myopathic variants linked with malignant hyperthermia and related conditions were generated. The altered response of these strains to pharmacological agents reflected results of human diagnostic tests for individuals with these pathogenic variants. Involvement of nerve cells in the C. elegans responses may relate to rare medical symptoms concerning the central nervous system that have been associated with ryanodine receptor variants. These single amino acid modifications in C. elegans also conferred a reduction in lifespan and an accelerated decline in muscle integrity with age, supporting the significance of ryanodine receptor function for human aging

Sense of personal agency in adolescence and young adulthood: A preliminary assessment model

Although there is a growing interest in the concept of sense of personal agency in adolescence and young adulthood, its operationalization and assessment have been inconsistent. We propose and test a preliminary assessment model of sense of agency combining four of the most relevant indicators suggested by the literature for its assessment (setting goals, optimism, decision-making, and self-efficacy). We conducted three independent studies with young adults [study 1 = 692; study 2 = 410] and adolescents [study 3 = 481] to analyze its psychometric properties. The CFA results revealed a good fit to the data in all three studies. The results of studies 1 and 2 indicate that even though the four dimensions share a significant proportion of variance, they do not assess the overlapping aspects of sense of agency. The findings of study 1 clarified that the proposed measurement model is invariant across sex and different levels of psychosocial risk. The results of study 2 suggest that, as expected, the latent construct of sense of agency is linked to different dimensions of psycho-emotional adjustment of young adults. Lastly, the findings of study 3 revealed that our preliminary model is invariant across three assessment points establishing the measurement longitudinal invariance

Stability and Change in Adolescents’ Sense of Agency: Contributions of Sex, Multiple Risk, Pandemic Stress, and Attachment to Parents

Although literature states that individual, relational, and contextual factors contribute to adolescents’ sense of agency, more research is needed to clarify and understand how adolescents develop this belief over time. The current study examined the stability/change trajectories of the sense of agency during adolescence, specifically across high school, analyzing whether attachment to parents over time, adolescents’ sex, cumulative risk in baseline, and pandemic-related stress explained these trajectories. The sample included 467 Portuguese adolescents (40.7% were males; Mage = 15.58 years, SD = 0.80), evaluated three times across 18 months. This work yielded three significant findings. First, adolescents’ sense of agency significantly increased over time, with significant between-subject variance at the initial levels but not at the growth rate. Second, attachment to parents consistently links to adolescents’ sense of agency across time, despite the differential contributions from attachment to mothers and fathers. Third, boys reported greater growth in the sense of agency than girls. Adolescents’ cumulative risk at T1 predicted lower initial levels of sense of agency, whereas higher pandemic-related stress predicted less growth of the sense of agency. These findings emphasize the contributions of individual and family characteristics and the role of the broader social context in shaping the development of adolescents’ sense of agency. The findings underline the need to consider further the differential influences of adolescents’ relationships with mothers and fathers to understand changes in adolescents’ sense of agency

Giant optical anisotropy in a single InAs quantum dot in a very dilute quantum-dot ensemble

We present the experimental evidence of giant optical anisotropy in single InAs quantum dots. Polarization-resolved photoluminescence spectroscopy reveals a linear polarization ratio with huge fluctuations, from one quantum dot to another, in sign and in magnitude with absolute values up to 82%. Systematic measurements on hundreds of quantum dots coming from two different laboratories demonstrate that the giant optical anisotropy is an intrinsic feature of dilute quantum-dot arrays.Comment: submitted to Applied Physics Letter

Relationship of health workers with their organization and work: a cross-cultural study

ABSTRACT We analyzed the differences, by Student’s t-test and ANOVA, between nurses and physicians from Portugal, Poland, Spain, and United Kingdom regarding their relationship with their work and organization. In total, 1,401 professionals answered the HSA-QHPR questionnaire. There are different levels of connection between physicians and nurses. The United Kingdom has the lowest levels of connection with the work while Portugal has the highest levels of relationship with the organization. The results provide guidelines for the development of policies and differential strategies aimed at improving the quality of healthcare service

Thrombolysis in Patients Aged over 80 Years Is Equally Effective and Safe

BACKGROUND: Despite stroke's high prevalence in the elderly, intravenous thrombolysis is licensed in Europe only for patients younger than 80 years old. We aimed to compare the functional outcomes and complication rates in patients older versus younger than 80 years old treated with intravenous thrombolysis. METHODS: A retrospective observational study of patients who received intravenous thrombolysis in a stroke unit between January 1, 2009, and June 30, 2012, was conducted. Variables were compared between 2 subgroups (≤80 and >80 years). RESULTS: Overall, 512 patients underwent intravenous thrombolysis, of which 13.1% were over 80 years. The mean age was 65.4 years in the younger subgroup and 82.9 years in the older subgroup. Prior independence rates did not differ between the subgroups. Prevalence of atrial fibrillation and cardioembolic stroke was higher in the older subgroup (P = .004 and .026). Only 3% of the elderly with atrial fibrillation were taking oral anticoagulants. Symptoms-to-needle time was lower in the older subgroup (P = .048). Stroke severity was higher in patients over 80 years (P = .026). There was significant improvement in the National Institutes of Health Stroke Scale score 7 days after intravenous thrombolysis (P < .001) in both subgroups. The proportion of patients with 3 months' favorable outcome and independence, hemorrhagic transformation, and mortality rates were similar in both subgroups. CONCLUSIONS: Elderly patients' benefits and outcomes from intravenous thrombolysis treatment were identical to the younger subgroup without excess hemorrhagic transformation or mortality. These results favor the use of intravenous thrombolysis in patients over 80 years.info:eu-repo/semantics/publishedVersio

Constraining parameter space in type-II two-Higgs doublet model in light of a 126 GeV Higgs boson

We explore the implications of a 126 GeV Higgs boson indicated by the recent LHC results for two-Higgs doublet model (2HDM). Identifying the 126 GeV Higgs boson as either the lighter or heavier of CP even neutral Higgs bosons in 2HDM, we examine how the masses of Higgs fields and mixing parameters can be constrained by the theoretical conditions and experimental constraints. The theoretical conditions taken into account are the vacuum stability, perturbativity and unitarity required to be satisfied up to a cut-off scale. We also show how bounds on the masses of Higgs bosons and mixing parameters depend on the cut-off scale. In addition, we investigate whether the allowed regions of parameter space can accommodate particularly the enhanced di-photon signals, ZZ* and WW* decay modes of the Higgs boson, and examine the prediction of the signal strength of Z{\gamma} decay mode for the allowed regions of the parameter space.Comment: To be published in JHEP, 20 pages, 11 figures, Figures and results are updated for the recent LHC result

CP properties of symmetry-constrained two-Higgs-doublet models

The two-Higgs-doublet model can be constrained by imposing Higgs-family symmetries and/or generalized CP symmetries. It is known that there are only six independent classes of such symmetry-constrained models. We study the CP properties of all cases in the bilinear formalism. An exact symmetry implies CP conservation. We show that soft breaking of the symmetry can lead to spontaneous CP violation (CPV) in three of the classes.Comment: 14 pages, 2 tables, revised version adapted to the journal publicatio

Arrendamento privado em Portugal: uma leitura a partir da regulação das rendas

Este artigo contribui para o debate do papel do Estado na regulação do sector de arrendamento privado em Portugal num momento em que é implementado um Novo Regime de Arrendamento Urbano. A informação estatística disponível, nomeadamente sobre a duração dos contratos e os valores das rendas, alerta para uma tendência de precarização dos contratos de arrendamento entre 2001 e 2011 e para o declínio da oferta de arrendamento a preços acessíveis. Este artigo enfatiza a importância de medidas de apoio ao mercado de arrendamento privado, focadas simultaneamente no lado da oferta e da procura, que estimulem a oferta de habitação a preços acessíveis