9,572 research outputs found

    SPH simulations of the chemical evolution of bulges

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    We have implemented a chemical evolution model on the parallel AP3M+SPH DEVA code which we use to perform high resolution simulations of spiral galaxy formation. It includes feedback by SNII and SNIa using the Qij matrix formalism. We also include a diffusion mechanism that spreads newly introduced metals. The gas cooling rate depends on its specific composition. We study the stellar populations of the resulting bulges finding a potential scenario where they seem to be composed of two populations: an old, metal poor, α\alpha-enriched population, formed in a multiclump scenario at the beginning of the simulation and a younger one, formed by slow accretion of satellites or gas, possibly from the disk due to instabilities.Comment: 2 pages, 3 figures. Proceedings of IAUS 245 "Formation and Evolution of Galaxy Bulges

    Should we recommend reductions in saturated fat intake or in red/processed meat consumption? The SUN prospective cohort study

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    Background & aims: While most studies have shown increased mortality associated with excessive red/processed meat consumption, the association of saturated fatty acids (SFA) intake with mortality is less homogeneous. We aimed to prospectively assess the association of both, meat consumption (red, processed, red + processed, and total) and SFA intake, with the risk of all-cause death. Methods: We assessed 18,540 participants of the SUN (Seguimiento Universidad de Navarra) cohort, followed-up for a mean of 9.5 years. A validated 136-item FFQ was administered at baseline. We used Cox models adjusted for potential confounders. Results: We observed 255 deaths during 176,916 person-years of follow-up. Age modified the association between meat consumption and all-cause mortality (p for interaction = 0.027, 0.075, and 0.013, for red, total, and processed meat, respectively). Among participants aged >45 years the fully-adjusted HRs (95% CIs) for one additional serving/d of red, total, and red + processed meat consumption were 1.47 (1.06, 2.04), 1.23 (1.05, 1.45), and 1.32 (1.05, 1.65), respectively, with significant linear trends (P for trend 0.022, 0.012, and 0.018, respectively). In these participants, SFA intake was non-significantly associated with mortality. However, isocaloric replacement of monounsaturated fat or carbohydrates by SFA resulted in significantly higher mortality risk. Likewise, replacing 100 g of vegetables, fruits & nuts or cereals by 100 g of red meat resulted in higher mortality risk. No association of meat consumption or SFA with all-cause mortality was observed in participants younger than 46 years. Conclusions: Among highly educated persons, aged >45 years, a high consumption of red, total, and red + processed meat was related to increased all-cause mortality, compared with those with low consumption, whereas no significant associations were found for SFA intake. Dietary guidelines should specifically limit meat consumption and not relying only in limiting SFA intake

    Increased adiposity appraised with cun-bae is highly predictive of incident hypertension. The sun project

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    Overweight and obesity are growing worldwide and strongly associated with hypertension. The Clínica Universidad de Navarra-Body Adiposity Estimator (CUN-BAE) index is proposed as an optimal indicator of body fatness. We aimed to investigate the association of body fat as captured by the CUN-BAE index with incident hypertension in a Mediterranean population. We assessed 15,950 participants of the SUN (Seguimiento Universidad de Navarra) prospective cohort (63.7% women) initially free of hypertension. Participants completed follow-up questionnaires biennially. A validated 136-item food-frequency questionnaire was administered at baseline. We used Cox models adjusted for multiple confounders. Among 12.3 years of median follow-up (interquartile range: 8.3, 15.0 years), 2160 participants reported having received a diagnosis of hypertension. We observed a strong direct association between progressively higher the CUN-BAE index at baseline and incident hypertension during follow-up in multivariable-adjusted models for men and women, even after further adjustment for BMI ≥ 30 kg/m2, showing a significant association also in non-obese participants. For each 2-unit increase in the CUN-BAE index, hypertension risk increased by 27% and 29% in men and women, respectively. The results remained significant when considering longitudinal repeated measures of changes in body fat assessed with the CUN-BAE index among the different biennial follow-up questionnaires. Our results emphasize the importance of reducing and maintaining a low body fat to prevent hypertension

    Galaxy groups in the 2dF galaxy redshift survey: A Compactness Analysis of Groups

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    A comprehensive study on compactness has been carried out on the 2dF Galaxy Group Catalogue constructed by Merch\'an & Zandivarez. The compactness indexes defined in this work take into account different geometrical constraints in order to explore a wide range of possibilities. Our results show that there is no clear distinction between groups with high and low level of compactness when considering particular properties as the radial velocity dispersion, the relative fraction of galaxies per spectral type and luminosity functions of their galaxy members. Studying the trend of the fraction of galaxies per spectral type as a function of the dimensionless crossing time some signs of dynamical evolution are observed. From the comparison with previous works on compactness we realize that special care should be taken into account for some compactness criteria definitions in order to avoid possible biases in the identification.Comment: 11 pages, 14 figures, resubmitted to MNRAS after minor revisio

    Galaxy groups in the 2dF redshift survey: Galaxy Spectral Type Segregation in Groups

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    The behaviour of the relative fraction of galaxies with different spectral types in groups is analysed as a function of projected local galaxy density and the group-centric distance. The group sample was taken from the 2dF Group Galaxy Calatogue constructed by Merch\'an & Zandivarez. Our group sample was constrained to have a homogeneous virial mass distribution with redshift. Galaxies belonging to this group sample were selected in order to minimize possible biases such as preferential selection of high luminosity objects. We find a clear distinction between high virial mass groups (M_V\gsim 10^{13.5} M_{\odot}) and the less massive ones. While the massive groups show a significant dependence of the relative fraction of low star formation galaxies on local galaxy density and group-centric radius,groups with lower masses show no significant trends. We also cross-correlate our group subsample with the previously identified clusters finding that this sample shows a very similar behaviour as observed in the high virial mass group subsample.Comment: 3 figures replaced, accepted for publication in MNRA

    Correlational Study of Aminopeptidase Activities between Left or Right Frontal Cortex versus the Hypothalamus, Pituitary, Adrenal Axis of Spontaneously Hypertensive Rats Treated with Hypotensive or Hypertensive Agents.

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    It has been suggested that the neuro-visceral integration works asymmetrically and that this asymmetry is dynamic and modifiable by physio-pathological influences. Aminopeptidases of the renin-angiotensin system (angiotensinases) have been shown to be modifiable under such conditions. This article analyzes the interactions of these angiotensinases between the left or right frontal cortex (FC) and the same enzymes in the hypothalamus (HT), pituitary (PT), adrenal (AD) axis (HPA) in control spontaneously hypertensive rats (SHR), in SHR treated with a hypotensive agent in the form of captopril (an angiotensin-converting enzyme inhibitor), and in SHR treated with a hypertensive agent in the form of the L-Arginine hypertensive analogue L-NG-Nitroarginine Methyl Ester (L-NAME). In the control SHR, there were significant negative correlations between the right FC with HPA and positive correlations between the left FC and HPA. In the captopril group, the predominance of negative correlations between the right FC and HPA and positive correlations between the HPA and left FC was maintained. In the L-NAME group, a radical change in all types of interactions was observed; particularly, there was an inversion in the predominance of negative correlations between the HPA and left FC. These results indicated a better balance of neuro-visceral interactions after captopril treatment and an increase in these interactions in the hypertensive animals, especially in those treated with L-NAME

    Neutrophil to lymphocyte ratio and breast cancer risk: analysis by subtype and potential interactions

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    Multiple studies have found the neutrophil to lymphocyte ratio (NLR) to be associated with adverse breast cancer (BC) prognosis and survival. Very limited data exist on the role of NLR and risk of BC. The BREOGAN study is a population-based case-control study conducted in Galicia, Spain. We examined the WBC- and NLR-BC relationships. The risk of BC increased with increasing levels of neutrophils percentage (NE%) (multivariable OR for the highest category (95% CI) = 2.14 (1.39-3.32), P-trend < 0.001) and of the NLR (multivariable OR for the highest category (95% CI) = 1.93 (1.26-2.97), P-trend < 0.001). Lymphocytes absolute (L#) and percentage (L%) were associated with a decreased risk of BC (multivariable OR for the highest category (95% CI) = 0.54 (0.35-0.83), and 0.51 (0.33-0.79), P-trend = 0.001 and < 0.001, respectively). The NLR-BC association was more pronounced among Luminal A BC (multivariable OR for the highest category (95% CI) = 2.00 (1.17-3.45), P-trend < 0.001), HER2-negative BC (multivariable OR for the highest category (95% CI) = 1.87 (1.16-3.02), P-trend < 0.001), and those with high total cholesterol and low H2O2 levels
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