740 research outputs found
The SAMI Galaxy Survey: gas content and interaction as the drivers of kinematic asymmetry
In order to determine the causes of kinematic asymmetry in the H gas
in the SAMI Galaxy Survey sample, we investigate the comparative influences of
environment and intrinsic properties of galaxies on perturbation. We use
spatially resolved H velocity fields from the SAMI Galaxy Survey to
quantify kinematic asymmetry () in nearby galaxies and
environmental and stellar mass data from the GAMA survey.
{We find that local environment, measured as distance to nearest neighbour,
is inversely correlated with kinematic asymmetry for galaxies with
, but there is no significant correlation for
galaxies with . Moreover, low mass galaxies
() have greater kinematic asymmetry at all
separations, suggesting a different physical source of asymmetry is important
in low mass galaxies.}
We propose that secular effects derived from gas fraction and gas mass may be
the primary causes of asymmetry in low mass galaxies. High gas fraction is
linked to high (where is H velocity
dispersion and the rotation velocity), which is strongly correlated with
, and galaxies with have offset
from the rest of the sample. Further,
asymmetry as a fraction of dispersion decreases for galaxies with
. Gas mass and asymmetry are also inversely correlated
in our sample. We propose that low gas masses in dwarf galaxies may lead to
asymmetric distribution of gas clouds, leading to increased relative
turbulence.Comment: 15 pages, 20 figure
First results on Martian carbon monoxide from Herschel/HIFI observations
We report on the initial analysis of Herschel/HIFI carbon monoxide (CO)
observations of the Martian atmosphere performed between 11 and 16 April 2010.
We selected the (7-6) rotational transitions of the isotopes ^{13}CO at 771 GHz
and C^{18}O at 768 GHz in order to retrieve the mean vertical profile of
temperature and the mean volume mixing ratio of carbon monoxide. The derived
temperature profile agrees within less than 5 K with general circulation model
(GCM) predictions up to an altitude of 45 km, however, show about 12-15 K lower
values at 60 km. The CO mixing ratio was determined as 980 \pm 150 ppm, in
agreement with the 900 ppm derived from Herschel/SPIRE observations in November
2009.Comment: Accepted for publication in Astronomy and Astrophysics (special issue
on HIFI first results); minor changes to match published versio
Methane retrieved from TROPOMI: Improvement of the data product and validation of the first 2 years of measurements
The TROPOspheric Monitoring Instrument (TROPOMI) on board the Sentinel 5 Precursor (S5-P) satellite provides methane (CH4) measurements with high accuracy and exceptional temporal and spatial resolution and sampling. TROPOMI CH measurements are highly valuable to constrain emissions inventories and for trend analysis, with strict requirements on the data quality. This study describes the improvements that we have implemented to retrieve CH from TROPOMI using the RemoTeC full-physics algorithm. The updated retrieval algorithm features a constant regularization scheme of the inversion that stabilizes the retrieval and yields less scatter in the data and includes a higher resolution surface altitude database. We have tested the impact of three state-of-the-art molecular spectroscopic databases (HITRAN 2008, HITRAN 2016 and Scientific Exploitation of Operational Missions – Improved Atmospheric Spectroscopy Databases SEOM-IAS) and found that SEOM-IAS provides the best fitting results. The most relevant update in the TROPOMI XCH data product is the implementation of an a posteriori correction fully independent of any reference data that is more accurate and corrects for the underestimation at low surface albedo scenes and the overestimation at high surface albedo scenes. After applying the correction, the albedo dependence is removed to a large extent in the TROPOMI versus satellite (Greenhouse gases Observing SATellite – GOSAT) and TROPOMI versus ground-based observations (Total Carbon Column Observing Network – TCCON) comparison, which is an independent verification of the correction scheme. We validate 2 years of TROPOMI CH4 data that show the good agreement of the updated TROPOMI CH4 with TCCON (−3.4 ± 5.6 ppb) and GOSAT (−10.3 ± 16.8 ppb) (mean bias and standard deviation). Low- and high-albedo scenes as well as snow-covered scenes are the most challenging for the CH4 retrieval algorithm, and although the a posteriori correction accounts for most of the bias, there is a need to further investigate the underlying cause
Plan de acci?n para la prevenci?n del sobrepeso y la obesidad en Galicia desde una perspectiva de salud p?blica 2022-2030
Na ?ltima d?cada, a obesidade xurdiu como un problema emerxente na nosa poboaci?n e sup?n un desaf?o para a s?a abordaxe desde unha perspectiva de sa?de p?blica que, contemplada como un acto colectivo, debe asegurar un ?ptimo estado de sa?de para a s?a poboaci?n de referencia, produto ? s?a vez de diferentes niveis de influencia. A trav?s deste plan, a Direcci?n Xeral de Sa?de P?blica pretende mellorar o acceso ao co?ecemento sobre h?bitos de vida saudables, a contornas seguras e propicias e a unha oferta alcanzable e de calidade de produtos saudables, como un remedio que permita reducir o sobrepeso e a obesidade e mellorar a sa?de da nosa poboaci?n.En la ?ltima d?cada, la obesidad surgi? como un problema emergente en nuestra poblaci?n y supone un desaf?o para su abordaje desde una perspectiva de salud p?blica que, contemplada como un acto colectivo, debe asegurar un ?ptimo estado de salud para su poblaci?n de referencia, producto a su vez de diferentes niveles de influencia. A trav?s de este plan, la Direcci?n General de Salud P?blica pretende mejorar el acceso al conocimiento sobre h?bitos de vida saludables, a entornos seguros y propicios y a una oferta asequible y de calidad de productos saludables, como un remedio que permita reducir el sobrepeso y la obesidad y mejorar la salud de nuestra poblaci?n
Self-consistent bulge/disk/halo galaxy dynamical modeling using integral field kinematics
We introduce a method for modeling disk galaxies designed to take full advantage of data from integral field spectroscopy (IFS). The method fits equilibrium models to simultaneously reproduce the surface brightness, rotation, and velocity dispersion profiles of a galaxy. The models are fully self-consistent 6D distribution functions for a galaxy with a Sérsic profile stellar bulge, exponential disk, and parametric dark-matter halo, generated by an updated version of GalactICS. By creating realistic flux-weighted maps of the kinematic moments (flux, mean velocity, and dispersion), we simultaneously fit photometric and spectroscopic data using both maximum-likelihood and Bayesian (MCMC) techniques. We apply the method to a GAMA spiral galaxy (G79635) with kinematics from the SAMI Galaxy Survey and deep g- and r-band photometry from the VST-KiDS survey, comparing parameter constraints with those from traditional 2D bulge–disk decomposition. Our method returns broadly consistent results for shared parameters while constraining the mass-to-light ratios of stellar components and reproducing the H i-inferred circular velocity well beyond the limits of the SAMI data. Although the method is tailored for fitting integral field kinematic data, it can use other dynamical constraints like central fiber dispersions and H i circular velocities, and is well-suited for modeling galaxies with a combination of deep imaging and H i and/or optical spectra (resolved or otherwise). Our implementation (MagRite) is computationally efficient and can generate well-resolved models and kinematic maps in under a minute on modern processors.Publisher PDFPeer reviewe
Volume of Bone Metastasis Assessed with Whole-Body Diffusion-weighted Imaging Is Associated with Overall Survival in Metastatic Castration-resistant Prostate Cancer.
Purpose To determine the correlation between the volume of bone metastasis as assessed with diffusion-weighted (DW) imaging and established prognostic factors in metastatic castration-resistant prostate cancer (mCRPC) and the association with overall survival (OS). Materials and Methods This retrospective study was approved by the institutional review board; informed consent was obtained from all patients. The authors analyzed whole-body DW images obtained between June 2010 and February 2013 in 53 patients with mCRPC at the time of starting a new line of anticancer therapy. Bone metastases were identified and delineated on whole-body DW images in 43 eligible patients. Total tumor diffusion volume (tDV) was correlated with the bone scan index (BSI) and other prognostic factors by using the Pearson correlation coefficient (r). Survival analysis was performed with Kaplan-Meier analysis and Cox regression. Results The median tDV was 503.1 mL (range, 5.6-2242 mL), and the median OS was 12.9 months (95% confidence interval [CI]: 8.7, 16.1 months). There was a significant correlation between tDV and established prognostic factors, including hemoglobin level (r = -0.521, P < .001), prostate-specific antigen level (r = 0.556, P < .001), lactate dehydrogenase level (r = 0.534, P < .001), alkaline phosphatase level (r = 0.572, P < .001), circulating tumor cell count (r = 0.613, P = .004), and BSI (r = 0.565, P = .001). A higher tDV also showed a significant association with poorer OS (hazard ratio, 1.74; 95% CI: 1.02, 2.96; P = .035). Conclusion Metastatic bone disease from mCRPC can be evaluated and quantified with whole-body DW imaging. Whole-body DW imaging-generated tDV showed correlation with established prognostic biomarkers and is associated with OS in mCRPC. (©) RSNA, 2016 Online supplemental material is available for this article
Tailored preconceptional dietary and lifestyle counselling in a tertiary outpatient clinic in the Netherlands
Background Adverse reproductive performance has been linked to unhealthy dietary intake and lifestyles. Our objectives were to investigate the prevalence of unhealthy dietary intake and lifestyles before conception and to evaluate whether tailored preconception counselling modifies these behaviours. Methods Between October 2007 and April 2009, 419 couples received tailored preconception dietary and lifestyle counselling at the outpatient clinic of Obstetrics and Gynaecology of the Erasmus University Medical Center Rotterdam, the Netherlands. A subgroup (n = 110 couples) was counselled twice with a fixed time interval of 3 months. Self-administered questionnaires were used for tailored dietary and lifestyle counselling. A cumulative score based on six Dutch dietary guidelines was displayed in the personal Preconception Dietary Risk score (PDR score). In a similar manner, the Rotterdam Reproduction Risk score (R3 score) was calculated from lifestyle factors (women: 13 items, men: 10 items). Univariate and paired tests were used. Results Most couples (93.8) were subfertile. At the second counselling, the percentage consuming the recommended intake of fruit had increased from 65 to 80 in women and from 49 to 68 in men and the percentage of women getting the recommended intake of fish increased from 39 to 52. As a consequence, the median PDR score was decreased [women: 2.6 (95 CI 2.4-2.9) to 2.4 (95 CI 2.1-2.6), men: 2.5 (95 CI 2.3-2.7) to 2.2 (95 CI 1.9-2.4), both P < 0.05]. The median R3 scores were also lower [women: 4.7 (95 CI 4.3-5.0) to 3.1 (95 CI 2.8-3.4), men: 3.0 (95 CI 2.8-3.3) to 2.0 (95 CI 1.7-2.3), both P < 0.01] due to less alcohol use (-14.6), more physical exercise and folic acid use in women, and less alcohol use in men (-19.4) (all P < 0.01). The R3 scores in women and men were decreased in all ethnicity, educational level, neighbourhood and BMI categories. However, low educated women appeared to show a larger reduction than better educated women and men with a normal BMI to show a larger decrease than overweight men. The reduction in the PDR score of women was similar in both ethnic groups. More than 85 women and men found the counselling useful and around 70 would recommend it to others. Conclusions Tailored preconception counselling about unhealthy dietary and lifestyle behaviours of subfertile couples in an outpatient tertiary clinic is feasible and seems to decrease the prevalence of harmful behaviours in the short term. These Results with subfertile couples are promising and illustrate their opportunities to contribute to reproductive performance and pregnancy outcome
Early alterations in the MCH system link aberrant neuronal activity and sleep disturbances in a mouse model of Alzheimer’s disease
Early Alzheimer’s disease (AD) is associated with hippocampal hyperactivity and decreased sleep quality. Here we show that homeostatic mechanisms transiently counteract the increased excitatory drive to CA1 neurons in App NL-G-F mice, but that this mechanism fails in older mice. Spatial transcriptomics analysis identifies Pmch as part of the adaptive response in App NL-G-F mice. Pmch encodes melanin-concentrating hormone (MCH), which is produced in sleep–active lateral hypothalamic neurons that project to CA1 and modulate memory. We show that MCH downregulates synaptic transmission, modulates firing rate homeostasis in hippocampal neurons and reverses the increased excitatory drive to CA1 neurons in App NL-G-F mice. App NL-G-F mice spend less time in rapid eye movement (REM) sleep. App NL-G-F mice and individuals with AD show progressive changes in morphology of CA1-projecting MCH axons. Our findings identify the MCH system as vulnerable in early AD and suggest that impaired MCH-system function contributes to aberrant excitatory drive and sleep defects, which can compromise hippocampus-dependent functions
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