1,006 research outputs found

    Neutron Star Radius-to-mass Ratio from Partial Accretion Disc Occultation as Measured through Fe Kα\alpha Line Profiles

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    We present a new method to measure the radius-to-mass ratio (R/M) of weakly magnetic, disc-accreting neutron stars by exploiting the occultation of parts of the inner disc by the star itself. This occultation imprints characteristic features on the X-ray line profile that are unique and are expected to be present in low mass X-ray binary systems seen under inclinations higher than ~65 degrees. We analyse a NuSTAR observation of a good candidate system, 4U 1636-53, and find that X-ray spectra from current instrumentation are unlikely to single out the occultation features owing to insufficient signal-to-noise. Based on an extensive set of simulations we show that large-area X-ray detectors of the future generation could measure R/M to ~2{\div}3% precision over a range of inclinations. Such is the precision in radius determination required to derive tight constraints on the equation of state of ultradense matter and it represents the goal that other methods too aim to achieve in the future.Comment: 17 pages, 8 figures; this is a pre-print edition of an article that has been accepted for publication in the Astrophysical Journa

    O pós-humano na midiatização da saúde

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    Este artigo apresenta um estudo de publicações científicas recentes que abordaram a midiatização de temas ligados à saúde, mas não apenas a realização da cobertura midiática sobre o assunto, mas também sua relação direta com a abordagem sobre o pós-humano, sobre como os avanços tecnológicos colaboram para aproximar o homem da máquina e se beneficiar desta relação para a melhoria da saúde, o que também gera polêmica

    Toxic Effects on Thyroid Gland of Male Adult Lizards (Podarcis Siculus) in Contact with PolyChlorinated Biphenyls (PCBs)-Contaminated Soil

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    Skin exposure is considered a potentially significant but little-studied pathway for PolyChlorinated Biphenyls uptake in terrestrial reptiles. In this study, a native Italian lizard, Podarcis siculus, was exposed to PCBs-contaminated soil for 120 days. Tissues distribution of PCBs, thyroid hormone levels, and thyroid histo-physiopathology were examined. The accumulation of PCBs in skin, plasma, liver, kidney, and brain were highest at 120 days. The alteration of triiodothyronine (T3) and thyroxine (T4) levels after different concentrations and times to exposure of PCBs was accompanied by the changes in the hormones involved in the hypothalamus-pituitary-thyroid (HPT) axis, namely Thyrotropin Releasing Hormone (TRH) and Thyroid Stimulating Hormone (TSH). Moreover, hepatic levels of deiodinase II (5'ORDII) and content of T3 were positively correlated to exposure to PCBs. These results indicated that in lizards, PCBs exposure through the skin has the potential to disrupt the thyroid endocrine system. Overall, the observed results indicate that PCBs could be associated with changes in thyroid homeostasis in these reptiles, through direct interactions with the metabolism of T4 and T3 through the HPT axis or indirect interactions with peripheral deiodination

    Predictors of mother–child interaction quality and child attachment security in at-risk families

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    Child healthy development is largely influenced by parent-child interaction and a secure parent-child attachment is predictively associated with positive outcomes in numerous domains of child development. However, the parent-child relationship can be affected by several psychosocial and socio-demographic risk factors that undermine its quality and in turn play a negative role in short and long term child psychological health. Prevention and intervention programs that support parenting skills in at-risk families can efficiently reduce the impact of risk factors on mother and child psychological health. This study examines predictors of mother-child interaction quality and child attachment security in a sample of first-time mothers with psychosocial and/or socio-demographic risk factors. Forty primiparous women satisfying specific risk criteria participated in a longitudinal study with their children from pregnancy until 18 month of child age. A multiple psychological and socioeconomic assessment was performed. The Emotional Availability Scales were used to measure the quality of emotional exchanges between mother and child at 12 months and the Attachment Q-Sort served as a measure of child attachment security at 18 months. Results highlight both the effect of specific single factors, considered at a continuous level, and the cumulative risk effect of different co-occurring factors, considered at binary level, on mother-child interaction quality and child attachment security. Implication for the selection of inclusion criteria of intervention programs that support parenting skills in at-risk families are discussed

    Is Smart Working Beneficial for Workers' Wellbeing? A Longitudinal Investigation of Smart Working, Workload, and Hair Cortisol/Dehydroepiandrosterone Sulfate during the COVID-19 Pandemic.

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    Building on the job demands-resources (JD-R) and allostatic load (AL) models, in the present study we examined the role of smart working (SW) in the longitudinal association between workload/job autonomy (JA) and a possible biomarker of work-related stress (WRS) in the hair-namely, the cortisol-dehydroepiandrosterone sulfate (DHEA(S)) ratio-during the COVID-19 pandemic. Overall, 124 workers completed a self-report questionnaire (i.e., psychological data) at Time 1 (T1) and provided a strand of hair (i.e., biological data) three months later (Time 2, T2). Results from moderated multiple regression analysis showed that SW at T1 was negatively associated with the hair cortisol/DHEA(S) ratio at T2. Additionally, the interaction between workload and SW was significant, with workload at T1 being positively associated with the hair cortisol/DHEA(S) ratio at T2 among smart workers. Overall, this study indicates that SW is a double-edged sword, with both positive and negative consequences on employee wellbeing. Furthermore, our findings suggest that the hair cortisol/DHEA(S) ratio is a promising biomarker of WRS. Practical implications that organizations and practitioners can adopt to prevent WRS and promote organizational wellbeing are discussed

    Work addiction among bank employees in Italy: A contribution to validation of the Bergen Work Addiction Scale with a focus on measurement invariance across gender and managerial status

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    This study contributes to the validation of the Bergen Work Addiction Scale (BWAS) in the Italian context, with a focus on measurement invariance across gender and managerial status. The BWAS is a consolidated measure of work addiction (WA) anchored in general addiction theory that comprises seven items representing the core addiction components. Participants were 8419 bank workers (37.7% women, 12.9% managers) who completed a self-report questionnaire including the Italian version of the BWAS (BWAS-I) and the Dutch Work Addiction Scale, as well as measures of work engagement, perfectionism, workload, psycho-physical symptoms, work–family conflict, and job satisfaction. Results confirmed the single-factor structure of the BWAS-I. Partial scalar invariance held across gender and managerial status, meaning that most—but not all—item intercepts were equivalent across different populations. Furthermore, the BWAS-I showed adequate convergent, discriminant, criterion-related, and incremental validity. This study showed that the BWAS-I is a valuable instrument that can be used by researchers and practitioners to assess WA in the Italian context.publishedVersio

    Paris: como a cidade luz é retratada na matéria de capa de revistas de turismo

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    Este trabalho apresenta uma pesquisa sobre a forma como duas revistas de turismo tratam do mesmo assunto em sua matéria de capa, no caso, a cidade de Paris. Para o Estudo de Caso foram selecionadas as revistas Viagem e Turismo, da editora Abril, e Viaje Mais, da editora Europa, ambas do mês de maio de 2013. A partir do estudo do jornalismo de entretenimento (infotenimento) e da base teórica sobre critérios de noticiabilidade e sobre design visual gráfico de ambas revistas, a proposta aponta as semelhanças e diferenças entre os veículos, que utilizam de recursos gráficos para chamar a atenção do leitor para o turismo parisiens

    Pancreatic Progenitor Commitment Is Marked by an Increase in Ink4a/Arf Expression

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    The identification of the molecular mechanisms controlling early cell fate decisions in mammals is of paramount importance as the ability to determine specific lineage differentiation represents a significant opportunity for new therapies. Pancreatic Progenitor Cells (PPCs) constitute a regenerative reserve essential for the maintenance and regeneration of the pancreas. Besides, PPCs represent an excellent model for understanding pathological pancreatic cellular remodeling. Given the lack of valid markers of early endoderm, the identification of new ones is of fundamental importance. Both products of the Ink4a/Arf locus, in addition to being critical cell-cycle regulators, appear to be involved in several disease pathologies. Moreover, the locus’ expression is epigenetically regulated in ES reprogramming processes, thus constituting the ideal candidates to modulate PPCs homeostasis. In this study, starting from mouse embryonic stem cells (mESCs), we analyzed the early stages of pancreatic commitment. By inducing mESCs commitment to the pancreatic lineage, we observed that both products of the Cdkn2a locus, Ink4a and Arf, mark a naïve pancreatic cellular state that resembled PPC-like specification. Treatment with epi-drugs suggests a role for chromatin remodeling in the CDKN2a (Cycline Dependent Kinase Inhibitor 2A) locus regulation in line with previous observations in other cellular systems. Our data considerably improve the comprehension of pancreatic cellular ontogeny, which could be critical for implementing pluripotent stem cells programming and reprogramming toward pancreatic lineage commitment
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