120 research outputs found
Deep H{\alpha} Observations of NGC 253: a Very Extended and Possibly Declining Rotation Curve?
This study presents a deep H{\alpha} kinematical analysis of the Sculptor
Group galaxy NGC253. The Fabry-Perot data were taken with the 36-cm Marseille
Telescope in La Silla, Chile, using an EMCCD detector. Typical emission
measures of ~0.1 cm^-6 pc are reached. The observations allow the detection of
the Diffuse Ionized Gas component through [N II] emission at very large radii
of 11.5', 12.8' and 19.0', on the receding side of the galaxy. No H{\alpha}
emission is observed at radii larger than the neutral component (11.5'). The
very extended rotation curve confirms previous results and shows signs of a
significant decline, on the order of 30 per cent vmax . Using the rotation
data, mass models are constructed with and without the outer [N II] data
points, and similar results are found. The declining part of the rotation curve
is very well modeled, and seems to be truly declining.Comment: Accepted for publication in MNRAS. 16 pages, 10 figures, 4 table
H-alpha Kinematics of the SINGS Nearby Galaxies Survey. II
This is the second part of an H-alpha kinematics follow-up survey of the
Spitzer Infrared Nearby Galaxies Survey (SINGS) sample. The aim of this program
is to shed new light on the role of baryons and their kinematics and on the
dark/luminous matter relation in the star forming regions of galaxies, in
relation with studies at other wavelengths. The data for 37 galaxies are
presented. The observations were made using Fabry-Perot interferometry with the
photon-counting camera FaNTOmM on 4 different telescopes, namely the
Canada-France-Hawaii 3.6m, the ESO La Silla 3.6m, the William Herschel 4.2m,
and the Observatoire du mont Megantic 1.6m telescopes. The velocity fields are
computed using custom IDL routines designed for an optimal use of the data. The
kinematical parameters and rotation curves are derived using the GIPSY
software. It is shown that non-circular motions associated with galactic bars
affect the kinematical parameters fitting and the velocity gradient of the
rotation curves. This leads to incorrect determinations of the baryonic and
dark matter distributions in the mass models derived from those rotation
curves.Comment: 18 pages, 5 figures, 4 tables. Accepted for publication in MNRAS. All
high-res. figures are available at
http://www.astro.umontreal.ca/fantomm/singsII
An improved method for statistical studies of the internal kinematics of HII regions: the case of M 83
We present the integrated Halpha emission line profile for 157 HII regions in
the central 3.4' x 3.4' of the galaxy M 83 (NGC 5236). Using the Fabry-Perot
interferometer GHaFaS, on the 4.2 m William Herschel on La Palma, we show the
importance of a good characterization of the instrumental response function for
the study of line profile shapes. The luminosity-velocity dispersion relation
is also studied, and in the log(L)-log(sigma) plane we do not find a linear
relation, but an upper envelope with equation log(L)=0.9 *log(sigma)+38.1. For
the adopted distance of 4.5 Mpc, the upper envelope appears at the luminosity
L=10^38.5 ergs, in full agreement with previous studies of other galaxies,
reinforcing the idea of using HII regions as standard candles.Comment: 13 pages, 9 figures, accepted for publication in MNRA
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Protein-coding variants implicate novel genes related to lipid homeostasis contributing to body-fat distribution.
Body-fat distribution is a risk factor for adverse cardiovascular health consequences. We analyzed the association of body-fat distribution, assessed by waist-to-hip ratio adjusted for body mass index, with 228,985 predicted coding and splice site variants available on exome arrays in up to 344,369 individuals from five major ancestries (discovery) and 132,177 European-ancestry individuals (validation). We identified 15 common (minor allele frequency, MAF ≥5%) and nine low-frequency or rare (MAF <5%) coding novel variants. Pathway/gene set enrichment analyses identified lipid particle, adiponectin, abnormal white adipose tissue physiology and bone development and morphology as important contributors to fat distribution, while cross-trait associations highlight cardiometabolic traits. In functional follow-up analyses, specifically in Drosophila RNAi-knockdowns, we observed a significant increase in the total body triglyceride levels for two genes (DNAH10 and PLXND1). We implicate novel genes in fat distribution, stressing the importance of interrogating low-frequency and protein-coding variants
Routine Laboratory Results and Thirty Day and One-Year Mortality Risk Following Hospitalization with Acute Decompensated Heart Failure
INTRODUCTION: Several blood tests are performed uniformly in patients hospitalized with acute decompensated heart failure and are predictive of the outcomes: complete blood count, electrolytes, renal function, glucose, albumin and uric acid. We sought to evaluate the relationship between routine admission laboratory tests results, patient characteristics and 30-day and one-year mortality of patients admitted for decompensated heart failure and to construct a simple mortality prediction tool. METHODS: A retrospective population based study. Data from seven tertiary hospitals on all admissions with a principal diagnosis of heart failure during the years 2002-2005 throughout Israel were captured. RESULTS: 8,246 patients were included in the study cohort. Thirty day mortality rate was 8.5% (701 patients) and one-year mortality rate was 28.7% (2,365 patients). Addition of five routine laboratory tests results (albumin, sodium, blood urea, uric acid and WBC) to a set of clinical and demographic characteristics improved c-statistics from 0.76 to 0.81 for 30-days and from 0.72 to 0.76 for one-year mortality prediction (both p-values <0.0001). Three dichotomized abnormal laboratory results with highest odds ratio for one-year mortality (hypoalbuminaemia, hyponatremia and elevated blood urea) were used to construct a simple prediction score, capable of discriminating from 1.1% to 21.4% in 30-day and from 11.6% to 55.6% in one-year mortality rates between patients with a score of 0 (1,477 patients) vs. score of 3 (544 patients). DISCUSSION: A small set of abnormal routine laboratory results upon admission can risk-stratify and independently predict 30-day and one-year mortality in patients hospitalized with acute decompensated heart failure
Morphological, behavioral and cellular analyses revealed different phenotypes in Wolfram syndrome wfs1a and wfs1b zebrafish mutant lines
Wolfram syndrome (WS) is a rare genetic disease characterized by diabetes, optic atrophy and deafness. Patients die at 35 years of age, mainly from respiratory failure or dysphagia. Unfortunately, there is no treatment to block the progression of symptoms and there is an urgent need for adequate research models. Here, we report on the phenotypical characterization of two loss-of-function zebrafish mutant lines: wfs1aC825X and wfs1bW493X. We observed that wfs1a deficiency altered the size of the ear and the retina of the fish. We also documented a decrease in the expression level of unfolded protein response (UPR) genes in basal condition and in stress condition, i.e. after tunicamycin treatment. Interestingly, both mutants lead to a decrease in their visual function measured behaviorally. These deficits were associated with a decrease in the expression level of UPR genes in basal and stress conditions. Interestingly, basal, ATP-linked and maximal mitochondrial respirations were transiently decreased in the wfs1b mutant. Taken together, these zebrafish lines highlight the critical role of wfs1a and wfs1b in UPR, mitochondrial function and visual physiology. These models will be useful tools to better understand the cellular function of Wfs1 and to develop novel therapeutic approaches for WS
Platelet-Related Variants Identified by Exomechip Meta-analysis in 157,293 Individuals
Platelet production, maintenance, and clearance are tightly controlled processes indicative of platelets important roles in hemostasis and thrombosis. Platelets are common targets for primary and secondary prevention of several conditions. They are monitored clinically by complete blood counts, specifically with measurements of platelet count (PLT) and mean platelet volume (MPV). Identifying genetic effects on PLT and MPV can provide mechanistic insights into platelet biology and their role in disease. Therefore, we formed the Blood Cell Consortium (BCX) to perform a large-scale meta-analysis of Exomechip association results for PLT and MPV in 157,293 and 57,617 individuals, respectively. Using the low-frequency/rare coding variant-enriched Exomechip genotyping array, we sought to identify genetic variants associated with PLT and MPV. In addition to confirming 47 known PLT and 20 known MPV associations, we identified 32 PLT and 18 MPV associations not previously observed in the literature across the allele frequency spectrum, including rare large effect (FCER1A), low-frequency (IQGAP2, MAP1A, LY75), and common (ZMIZ2, SMG6, PEAR1, ARFGAP3/PACSIN2) variants. Several variants associated with PLT/MPV (PEAR1, MRVI1, PTGES3) were also associated with platelet reactivity. In concurrent BCX analyses, there was overlap of platelet-associated variants with red (MAP1A, TMPRSS6, ZMIZ2) and white (PEAR1, ZMIZ2, LY75) blood cell traits, suggesting common regulatory pathways with shared genetic architecture among these hematopoietic lineages. Our large-scale Exomechip analyses identified previously undocumented associations with platelet traits and further indicate that several complex quantitative hematological, lipid, and cardiovascular traits share genetic factors
The genomics of heart failure: design and rationale of the HERMES consortium
AIMS: The HERMES (HEart failure Molecular Epidemiology for Therapeutic targetS) consortium aims to identify the genomic and molecular basis of heart failure. METHODS AND RESULTS: The consortium currently includes 51 studies from 11 countries, including 68 157 heart failure cases and 949 888 controls, with data on heart failure events and prognosis. All studies collected biological samples and performed genome-wide genotyping of common genetic variants. The enrolment of subjects into participating studies ranged from 1948 to the present day, and the median follow-up following heart failure diagnosis ranged from 2 to 116 months. Forty-nine of 51 individual studies enrolled participants of both sexes; in these studies, participants with heart failure were predominantly male (34–90%). The mean age at diagnosis or ascertainment across all studies ranged from 54 to 84 years. Based on the aggregate sample, we estimated 80% power to genetic variant associations with risk of heart failure with an odds ratio of ≥1.10 for common variants (allele frequency ≥ 0.05) and ≥1.20 for low-frequency variants (allele frequency 0.01–0.05) at P < 5 × 10^{-8} under an additive genetic model. CONCLUSIONS: HERMES is a global collaboration aiming to (i) identify the genetic determinants of heart failure; (ii) generate insights into the causal pathways leading to heart failure and enable genetic approaches to target prioritization; and (iii) develop genomic tools for disease stratification and risk prediction
The "Statinth" wonder of the world: a panacea for all illnesses or a bubble about to burst
After the introduction of statins in the market as effective lipid lowering agents, they were shown to have effects other than lipid lowering. These actions were collectively referred to as 'pleiotropic actions of statins.' Pleiotropism of statins formed the basis for evaluating statins for several indications other than lipid lowering. Evidence both in favour and against is available for several of these indications. The current review attempts to critically summarise the available data for each of these indications
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