103 research outputs found

    The benchmark black hole in NGC 4258: dynamical models from high-resolution two-dimensional stellar kinematics

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    NGC 4258 is the galaxy with the most accurate (maser-based) determination for the mass of the supermassive black hole (SMBH) in its nucleus. In this work we present a two-dimensional mapping of the stellar kinematics in the inner 3.0 x 3.0 arcsec = 100 x 100 pc of NGC 4258 using adaptative-optics observations obtained with the Near-Infrared Integral Field Spectrograph of the GEMINI North telescope at a 0.11 arcsec (4 pc) angular resolution. The observations resolve the radius of influence of the SMBH, revealing an abrupt increase in the stellar velocity dispersion within 10 pc from the nucleus, consistent with the presence of a SMBH there. Assuming that the galaxy nucleus is in a steady state and that the velocity dispersion ellipsoid is aligned with a cylindrical coordinate system, we constructed a Jeans anisotropic dynamical model to fit the observed kinematics distribution. Our dynamical model assumes that the galaxy has axial symmetry and is constructed using the multi-gaussian expansion method to parametrize the observed surface brightness distribution. The Jeans dynamical model has three free parameters: the mass of the central SMBH, the mass-luminosity ratio of the galaxy and the anisotropy of the velocity distribution. We test two types of models: one with constant velocity anisotropy, and another with variable anisotropy. The model that best reproduces the observed kinematics was obtained considering that the galaxy has radially varying anisotropy, being the best-fitting parameters with 3σ\sigma significance M=4.80.9+0.8×107MM_\bullet=4.8^{+0.8}_{-0.9}\times 10^7\,{\rm M_\odot} and Γk=4.10.5+0.4\Gamma_k = 4.1^{+0.4}_{-0.5}. This value for the mass of the SMBH is just 25 per cent larger than that of the maser determination and 50 per cent larger that a previous stellar dynamical determination obtained via Schwarzschild models.Comment: Accepted for publication in MNRAS, 19 pages, 19 figure

    Gestational weight gain charts : results from the Brazilian Maternal and Child Nutrition Consortium

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    Background: Monitoring gestational weight gain (GWG) is fundamental to ensure a successful pregnancy for the mother and the offspring. There are several international GWG charts, but just a few for low- and middle-income countries. Objectives: To construct GWG charts according to pre-pregnancy BMI for Brazilian women. Methods: This is an individual patient data analysis using the Brazilian Maternal and Child Nutrition Consortium data, comprising 21 cohort studies. External validation was performed using “Birth in Brazil,” a nationwide study. We selected adult women with singleton pregnancies who were free of infectious and chronic diseases, gestational diabetes, and hypertensive disorders; who delivered a live birth at term; and whose children were adequate for gestational age, and with a birth weight between 2500–4000 g. Maternal self-reported pre-pregnancy weight and weight measured between 10–40 weeks of gestation were used to calculate GWG. Generalized Additive Models for Location, Scale and Shape were fitted to create GWG charts according to gestational age, stratified by pre-pregnancy BMI. Results: The cohort included 7086 women with 29,323 weight gain measurements to construct the charts and 4711 women with 31,052 measurements in the external validation. The predicted medians for GWG at 40 weeks, according to pre-pregnancy BMI, were: underweight, 14.1 kg (IQR, 10.8–17.5 kg); normal weight, 13.8 kg (IQR, 10.7–17.2 kg); overweight, 12.1 kg (IQR, 8.5–15.7 kg); obesity, 8.9 kg (IQR, 4.8–13.2 kg). The 10th, 25th, 50th, 75th, and 90th percentiles were estimated. Results for internal and external validation showed that the percentages below the selected percentiles were close to those expected. Conclusions: The charts proposed provide a description of GWG patterns according to gestational age and pre-pregnancy BMI among healthy Brazilian women with good neonatal outcomes. The external validation indicates that this new tool can be used to monitor GWG in the primary health-care setting and to test potential recommended values

    Brazilian dietary patterns and the dietary approaches to stop hypertension (DASH) diet-relationship with metabolic syndrome and newly diagnosed diabetes in the ELSA-Brasil study

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    Background: Studies evaluating dietary patterns, including the DASH diet, and their relationship with the metabolic syndrome and diabetes may help to understand the role of dairy products (low fat or full fat) in these conditions. Our aim is to identify dietary patterns in Brazilian adults and compare them with the (DASH) diet quality score in terms of their associations with metabolic syndrome and newly diagnosed diabetes in the Brazilian Longitudinal Study of Adult Health-the ELSA-Brasil study. Methods: The ELSA-Brasil is a multicenter cohort study comprising 15,105 civil servants, aged 35–74 years at baseline (2008–2010). Standardized interviews and exams were carried out, including an OGTT. We analyzed baseline data for 10,010 subjects. Dietary patterns were derived by principal component analysis. Multivariable logistic regression investigated associations of dietary patterns with metabolic syndrome and newly diagnosed diabetes and multivariable linear regression with components of metabolic syndrome. Results: After controlling for potential confounders, we observed that greater adherence to the Common Brazilian meal pattern (white rice, beans, beer, processed and fresh meats), was associated with higher frequencies of newly diagnosed diabetes, metabolic syndrome and all of its components, except HDL-C. Participants with greater intake of a Common Brazilian fast foods/full fat dairy/milk based desserts pattern presented less newly diagnosed diabetes. An inverse association was also seen between the DASH Diet pattern and the metabolic syndrome, blood pressure and waist circumference. Diet, light foods and beverages/low fat dairy pattern was associated with more prevalence of both outcomes, and higher fasting glucose, HDL-C, waist circumference (among men) and lower blood pressure. Vegetables/fruit dietary pattern did not protect against metabolic syndrome and newly diagnosed diabetes but was associated with lower waist circumference. Conclusions: The inverse associations found for the dietary pattern characterizing Brazilian fast foods and desserts, typically containing dairy products, with newly diagnosed diabetes, and for the DASH diet with metabolic syndrome, support previously demonstrated beneficial effects of dairy products in metabolism. The positive association with metabolic syndrome and newly diagnosed diabetes found for the pattern characterizing a typical Brazilian meal deserves further investigation, particularly since it is frequently accompanied by processed meat

    Using Barkhausen Noise to Measure Coating Depth of Coated High-Speed Steel

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    Coated high-speed steel tools are widely used in machining processes as they offer an excellent tool life to cost ratio, but they quickly need replacing once the coated layer is worn away. It would be therefore useful to be able to measure the tool life remaining non-destructively and cheaply. To achieve this, the work presented here aims to measure the thickness of the coated layer of high-speed cutting tools by using Barkhausen noise (BHN) techniques. Coated high-speed steel specimens coated with two different materials (chromium nitride (CrN), titanium nitride (TiN)) were tested using a cost-effective measuring system developed for this study. Sensory features were extracted from the signal received from a pick-up coil and the signal features, Root mean square, peak count, and signal energy, were successfully correlated with the thickness of the coating layer on high-speed steel (HSS) specimens. The results suggest that the Barkhausen noise measuring system developed in this study can successfully indicate the different thickness of the coating layer on CrN/TiN coated HSS specimens

    The nurse in the management of materials in teaching hospitals

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    OBJECTIVETo present the nurse's integration within materials management of six teaching hospitals of Paraná - Brazil, and to describe the activities performed by nurses within this process.METHODA study of a qualitative approach and descriptive nature, conducted in teaching hospitals in Paraná, between June and August of 2013. The data collection was conducted through semi-structured interviews with eight nurses who worked in materials management; data were analyzed using content analysis.RESULTSThese showed that nurses perform ten categories of activities, distributed into four of the five steps of the materials management process.CONCLUSIONThe nurse, in performing of these activities, in addition to favoring the development of participative management, contributes to the organization, planning, and the standardization of the hospital supply process, giving greater credibility to the work with professionals who use the materials, and to the suppliers

    Low temperature exposure induces browning of bone marrow stem cell derived adipocytes in vitro

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    Brown and beige adipocytes are characterised as expressing the unique mitochondrial uncoupling protein (UCP)1 for which the primary stimulus in vivo is cold exposure. The extent to which cold-induced UCP1 activation can also be achieved in vitro, and therefore perform a comparable cellular function, is unknown. We report an in vitro model to induce adipocyte browning using bone marrow (BM) derived mesenchymal stem cells (MSC), which relies on differentiation at 32°C instead of 37°C. The low temperature promoted browning in adipogenic cultures, with increased adipocyte differentiation and upregulation of adipogenic and thermogenic factors, especially UCP1. Cells exhibited enhanced uncoupled respiration and metabolic adaptation. Cold-exposed differentiated cells showed a marked translocation of leptin to adipocyte nuclei, suggesting a previously unknown role for leptin in the browning process. These results indicate that BM-MSC can be driven to forming beige-like adipocytes in vitro by exposure to a reduced temperature. This in vitro model will provide a powerful tool to elucidate the precise role of leptin and related hormones in hitherto functions in the browning process
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