2,369 research outputs found

    Modeling Mortality Based on Pollution and Temperature Using a New Birnbaum–Saunders Autoregressive Moving Average Structure with Regressors and Related-Sensors Data

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    Environmental agencies are interested in relating mortality to pollutants and possible environmental contributors such as temperature. The Gaussianity assumption is often violated when modeling this relationship due to asymmetry and then other regression models should be considered. The class of Birnbaum–Saunders models, especially their regression formulations, has received considerable attention in the statistical literature. These models have been applied successfully in different areas with an emphasis on engineering, environment, and medicine. A common simplification of these models is that statistical dependence is often not considered. In this paper, we propose and derive a time-dependent model based on a reparameterized Birnbaum–Saunders (RBS) asymmetric distribution that allows us to analyze data in terms of a time-varying conditional mean. In particular, it is a dynamic class of autoregressive moving average (ARMA) models with regressors and a conditional RBS distribution (RBSARMAX). By means of a Monte Carlo simulation study, the statistical performance of the new methodology is assessed, showing good results. The asymmetric RBSARMAX structure is applied to the modeling of mortality as a function of pollution and temperature over time with sensor-related data. This modeling provides strong evidence that the new ARMA formulation is a good alternative for dealing with temporal data, particularly related to mortality with regressors of environmental temperature and pollution

    Social determinants of dental treatment needs in Brazilian adults.

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    The chronic cumulative nature of caries makes treatment needs a severe problem in adults. Despite the fact that oral diseases occur in social contexts, there are few studies using multilevel analyses focusing on treatment needs. Thus, considering the importance of context in explaining oral health related inequalities, this study aims to evaluate the social determinants of dental treatment needs in 35-44 year old Brazilian adults, assessing whether inequalities in needs are expressed at individual and contextual levels

    The Vicinity of the Galactic Supergiant B[e] Star CPD-57\deg2874 from Near- and Mid-IR Long Baseline Spectro-Interferometry with the VLTI (AMBER and MIDI)

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    This is the author accepted manuscript. The final version is available from ASP via the link in this record.We present the first spectro-interferometric observations of the circumstellar envelope (CSE) of a B[e] supergiant (CPD−57°2874), performed with the Very Large Telescope Interferometer (VLTI) using the beam-combiner instruments AMBER (near-IR interferometry with three 8.3 m Unit Telescopes or UTs) and MIDI (mid-IR interferometry with two UTs). Our observations of the CSE are well fitted by an elliptical Gaussian model with FWHM diameters varying linearly with wavelength. Typical diameters measured are ≅ 1.8 × 3.4 mas or ≅ 4.5×8.5 AU (adopting a distance of 2.5 kpc) at 2.2 μm, and ≅ 12×15 mas or ≅ 30 × 38 AU at 12 μm. We show that a spherical dust model reproduces the SED but it underestimates the MIDI visibilities, suggesting that a dense equatorial disk is required to account for the compact dust-emitting region observed. Moreover, the derived major-axis position angle in the mid-IR (≅ 144°) agrees well with previous polarimetric data, hinting that the hot-dust emission originates in a disk-like structure. Our results support the non-spherical CSE paradigm for B[e] supergiants

    Phosphate/Silicate Ratio Allows for Fine-Tuning of Bioactive Glass Crystallisation and Glass-Ceramic Microstructure

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    A combination of XRD, solid-state NMR and state-of-the-art imaging techniques were used to investigate how the calcium orthophosphate/calcium silicate ratio affects the crystallisation of bioactive glasses in the system SiO2-P2O5-CaO-CaF2. In the phosphate-free glass, xonotlite, wollastonite and cuspidine crystallised. From 2.4 mol% P2O5, fluorapatite also formed, while the amount of wollastonite decreased. Crystallisation tendency was low for low phosphate contents, while above 3 mol% P2O5 it increased. The phosphate-free glass showed a volume crystallisation mechanism with constant activation energy. By contrast, the glass with the largest phosphate to silicate ratio showed both volume and surface crystallisation, causing a pronounced decrease in activation energy with crystallisation degree. This work shows that by changing the phosphate/silicate ratio we can determine which crystal phases form, obtaining for example fluorapatite-free or wollastonite-free glass-ceramics, depending on the desired application and properties such as mechanical strength or activity in contact with physiological solutions

    Breastfeeding training for health professionals and resultant changes in breastfeeding duration

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    CONTEXT: Promotion of breastfeeding in Brazilian maternity hospitals. OBJECTIVE: To quantify changes in the breastfeeding duration among mothers served by hospitals exposed to the Wellstart-SLC course, comparing them with changes among mothers attended by institutions not exposed to this course. DESIGN: Randomized Institutional Trial. SETTING: The effects of training on breastfeeding duration was assessed in eight Brazilian hospitals assigned at random to either an exposed group (staff attending the Wellstart-SLC course) or a control group. SAMPLE: For each of the eight study hospitals, two cohorts of about 50 children were visited at home at one and six months after birth. The first cohort (n = 494) was composed of babies born in the month prior to exposure to the Wellstart-SLC course, and the second cohort (n = 476) was composed of babies born six months subsequent to this exposure. MAIN MEASUREMENTS: Kaplan-Meier curves were plotted to describe the weaning process and log-rank tests were used to assess statistical differences among survival curves. Hazard ratio (HR) estimates were calculated by fitting Cox proportional hazard regression models to the data. RESULTS: The increases in estimated, adjusted rates for children born in hospitals with trained personnel were 29% (HR = 0.71) and 20% (HR = 0.80) for exclusive and full breastfeeding, respectively. No changes were identified for total breastfeeding. CONCLUSION: This randomized trial supports a growing body of evidence that training hospital health professionals in breastfeeding promotion and protection results in an increase in breastfeeding duration.CONTEXTO: Promoção do aleitamento materno em maternidades brasileiras. OBJETIVO: Quantificar mudanças na duração do aleitamento materno de mães assistidas em maternidades expostas ao curso Wellstart-SLC, comparando-as com mudanças em mães assistidas por maternidades não expostas. TIPO DE ESTUDO: Ensaio institucional randomizado. LOCAL: Os efeitos do treinamento na duração do aleitamento materno foi avaliado em oito maternidades randomicamente alocadas ao grupo exposto (equipe freqüenta o curso Wellstart-SLC) ou controle. AMOSTRA: Em cada uma das oito maternidades, duas coortes de cerca de 50 crianças foram visitadas em suas casas ao completarem um e seis meses de vida. As primeiras coortes (n = 494) foram compostas de bebês nascidos no mês anterior ao treinamento, enquanto que as segundas coortes (n = 476) foram compostas por bebês nascidos seis meses após a exposição ao curso Weelstart-SLC. VARIÁVEIS ESTUDADAS: Para descrever o processo de desmame foram traçadas curvas de Kaplan-Meier. Para avaliar as diferenças estatísticas entre as curvas de sobrevivência foi utilizado o teste log-rank. Foram calculadas estimativas das razões de risco(HR) ajustando modelos de regressão de riscos proporcionais de Cox aos dados. RESULTADOS: O aumento estimado, a partir das razões ajustadas para crianças nascidas em hospitais com pessoal treinado, foi 29% (HR = 0,71) e 20% (HR = 0,80) para aleitamento exclusivo e pleno respectivamente. Não foram identificadas mudanças para o tempo de aleitamento total. CONCLUSÕES: Esse ensaio randomizado confirma evidências crescentes de que treinar profissionais de saúde em hospitais, na promoção e proteção do aleitamento materno, resulta em aumento do tempo de aleitamento materno.Universidade Federal de São Paulo (UNIFESP) Department of PediatricsUniversidade de Santo Amaro Maternal and Child Health Graduate ProgramUniversidade Federal de São Paulo (UNIFESP) School of Public HealthState of São Paulo State Health Secretariat Health InstituteUNIFESP, Department of PediatricsUNIFESP, School of Public HealthSciEL

    Leishmania Parasites Drive PD-L1 Expression in Mice and Human Neutrophils With Suppressor Capacity

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    Neutrophils play an important role in the outcome of leishmaniasis, contributing either to exacerbating or controlling the progression of infection, a dual effect whose underlying mechanisms are not clear. We recently reported that CD4+ and CD8+ T cells, and dendritic cells of Leishmania amazonensis-infected mice present high expression of PD-1 and PD-L1, respectively. Given that the PD-1/PD-L1 interaction may promote cellular dysfunction, and that neutrophils could interact with T cells during infection, we investigated here the levels of PD-L1 in neutrophils exposed to Leishmania parasites. We found that both, promastigotes and amastigotes of L. amazonensis induced the expression of PD-L1 in the human and murine neutrophils that internalized these parasites in vitro. PD-L1-expressing neutrophils were also observed in the ear lesions and the draining lymph nodes of L. amazonensis-infected mice, assessed through cell cytometry and intravital microscopy. Moreover, expression of PD-L1 progressively increased in neutrophils from ear lesions as the disease evolved to the chronic phase. Co-culture of infected neutrophils with in vitro activated CD8+ T cells inhibits IFN-γ production by a mechanism dependent on PD-1 and PD-L1. Importantly, we demonstrated that in vitro infection of human neutrophils by L braziliensis induced PD-L1+ expression and also PD-L1+ neutrophils were detected in the lesions of patients with cutaneous leishmaniasis. Taken together, these findings suggest that the Leishmania parasite increases the expression of PD-L1 in neutrophils with suppressor capacity, which could favor the parasite survival through impairing the immune response

    Coping religioso/espiritual em pessoas com doença renal crônica em tratamento hemodialítico

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    O estudo tem como objetivo investigar o uso do coping religioso/espiritual em pacientes com doença renal crônica em hemodiálise. A investigação ocorreu em uma clínica de hemodiálise, por meio de entrevista utilizando um questionário sociodemográfico e a escala de coping religioso/espiritual. Para análise dos dados, foram empregados a estatística descritiva e o teste coeficiente de correlação de Sperman, a análise de variância e o modelo de regressão linear múltipla. Foram entrevistados 123 indivíduos, dos quais 79,6% apresentaram escore alto para o coping religioso/espiritual e nenhum deles apresentou os escores baixos e irrisórios. As variáveis que influenciaram no comportamento do coping religioso/espiritual foram: sexo, faixa etária, tempo de tratamento, renda familiar e prática religiosa. Conclui-se que os pacientes em estudo utilizam de modo positivo o coping religioso/espiritual como estratégia de enfrentamento da doença, destacando-se as mulheres, com renda familiar maior e que frequentam semanalmente a igreja
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