279 research outputs found

    Chemical abundances and ages of the bulge stars in APOGEE high-velocity peaks

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    A cold high-velocity (HV, \sim 200 km/s) peak was first reported in several Galactic bulge fields based on the APOGEE commissioning observations. Both the existence and the nature of the high-velocity peak are still under debate. Here we revisit this feature with the latest APOGEE DR13 data. We find that most of the low latitude bulge fields display a skewed Gaussian distribution with a HV shoulder. However, only 3 out of 53 fields show distinct high-velocity peaks around 200 km/s. The velocity distribution can be well described by Gauss-Hermite polynomials, except the three fields showing clear HV peaks. We find that the correlation between the skewness parameter (h3h_{3}) and the mean velocity (vˉ\bar{v}), instead of a distinctive HV peak, is a strong indicator of the bar. It was recently suggested that the HV peak is composed of preferentially young stars. We choose three fields showing clear HV peaks to test this hypothesis using the metallicity, [α\alpha/M] and [C/N] as age proxies. We find that both young and old stars show HV features. The similarity between the chemical abundances of stars in the HV peaks and the main component indicates that they are not systematically different in terms of chemical abundance or age. In contrast, there are clear differences in chemical space between stars in the Sagittarius dwarf and the bulge stars. The strong HV peaks off-plane are still to be explained properly, and could be different in nature.Comment: 13 pages, 10 figures, published in ApJ. Updated to match the final ApJ published version. Minor revisions to the text and Figure

    The COVID-19 Pandemic and Global Food Security

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    We present scientific perspectives on the impact of the COVID-19 pandemic and global food security. International organizations and current evidence based on other respiratory viruses suggests COVID-19 is not a food safety issue, i.e., there is no evidence associating food or food packaging with the transmission of the virus causing COVID-19 (SARS-CoV-2), yet an abundance of precaution for this exposure route seems appropriate. The pandemic, however, has had a dramatic impact on the food system, with direct and indirect consequences on lives and livelihoods of people, plants, and animals. Given the complexity of the system at risk, it is likely that some of these consequences are still to emerge over time. To date, the direct and indirect consequences of the pandemic have been substantial including restrictions on agricultural workers, planting, current and future harvests; shifts in agricultural livelihoods and food availability; food safety; plant and animal health and animal welfare; human nutrition and health; along with changes in public policies. All aspects are crucial to food security that would require “One Health” approaches as the concept may be able to manage risks in a cost-effective way with cross-sectoral, coordinated investments in human, environmental, and animal health. Like climate change, the effects of the COVID-19 pandemic will be most acutely felt by the poorest and most vulnerable countries and communities. Ultimately, to prepare for future outbreaks or threats to food systems, we must take into account the Sustainable Development Goals of the United Nations and a “Planetary Health” perspective

    Deep-coverage whole genome sequences and blood lipids among 16,324 individuals.

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    Large-scale deep-coverage whole-genome sequencing (WGS) is now feasible and offers potential advantages for locus discovery. We perform WGS in 16,324 participants from four ancestries at mean depth >29X and analyze genotypes with four quantitative traits-plasma total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, and triglycerides. Common variant association yields known loci except for few variants previously poorly imputed. Rare coding variant association yields known Mendelian dyslipidemia genes but rare non-coding variant association detects no signals. A high 2M-SNP LDL-C polygenic score (top 5th percentile) confers similar effect size to a monogenic mutation (~30 mg/dl higher for each); however, among those with severe hypercholesterolemia, 23% have a high polygenic score and only 2% carry a monogenic mutation. At these sample sizes and for these phenotypes, the incremental value of WGS for discovery is limited but WGS permits simultaneous assessment of monogenic and polygenic models to severe hypercholesterolemia

    Maternal corticotropin-releasing hormone is associated with LEP DNA methylation at birth and in childhood: an epigenome-wide study in Project Viva

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    BackgroundCorticotropin-releasing hormone (CRH) plays a central role in regulating the secretion of cortisol which controls a wide range of biological processes. Fetuses overexposed to cortisol have increased risks of disease in later life. DNA methylation may be the underlying association between prenatal cortisol exposure and health effects. We investigated associations between maternal CRH levels and epigenome-wide DNA methylation of cord blood in offsprings and evaluated whether these associations persisted into mid-childhood.MethodsWe investigated mother-child pairs enrolled in the prospective Project Viva pre-birth cohort. We measured DNA methylation in 257 umbilical cord blood samples using the HumanMethylation450 Bead Chip. We tested associations of maternal CRH concentration with cord blood cells DNA methylation, adjusting the model for maternal age at enrollment, education, maternal race/ethnicity, maternal smoking status, pre-pregnancy body mass index, parity, gestational age at delivery, child sex, and cell-type composition in cord blood. We further examined the persistence of associations between maternal CRH levels and DNA methylation in children's blood cells collected at mid-childhood (n = 239, age: 6.7-10.3 years) additionally adjusting for the children's age at blood drawn.ResultsMaternal CRH levels are associated with DNA methylation variability in cord blood cells at 96 individual CpG sites (False Discovery Rate <0.05). Among the 96 CpG sites, we identified 3 CpGs located near the LEP gene. Regional analyses confirmed the association between maternal CRH and DNA methylation near LEP. Moreover, higher maternal CRH levels were associated with higher blood-cell DNA methylation of the promoter region of LEP in mid-childhood (P < 0.05, β = 0.64, SE = 0.30).ConclusionIn our cohort, maternal CRH was associated with DNA methylation levels in newborns at multiple loci, notably in the LEP gene promoter. The association between maternal CRH and LEP DNA methylation levels persisted into mid-childhood

    Trauma Exposure and Posttraumatic Stress Disorder Symptoms Predict Onset of Cardiovascular Events in Women

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    Background—Psychological stress is a proposed risk factor for cardiovascular disease (CVD), and posttraumatic stress disorder (PTSD), the sentinel stress-related mental disorder, occurs twice as frequently in women as men. However, whether PTSD contributes to CVD risk in women is not established. Methods and Results—We examined trauma exposure and PTSD symptoms in relation to incident CVD over a 20-year period in 49 978 women in the Nurses’ Health Study II. Proportional hazards models estimated hazard ratios and 95% confidence intervals for CVD events confirmed by additional information or medical record review (n=548, including myocardial infarction [n=277] and stroke [n=271]). Trauma exposure and PTSD symptoms were assessed by using the Brief Trauma Questionnaire and a PTSD screen. In comparison with no trauma exposure, endorsing ≥4 PTSD symptoms was associated with increased CVD risk after adjusting for age, family history, and childhood factors (hazard ratio,1.60; 95% confidence interval, 1.20–2.13). Being trauma-exposed and endorsing no PTSD symptoms was associated with elevated CVD risk (hazard ratio, 1.45; 95% confidence interval, 1.15–1.83), although being trauma-exposed and endorsing 1 to 3 PTSD symptoms was not. After adjusting for adult health behaviors and medical risk factors, this pattern of findings was maintained. Health behaviors and medical risk factors accounted for 14% of the trauma/no symptoms–CVD association and 47% of the trauma/4+ symptoms–CVD association. Conclusion—Trauma exposure and elevated PTSD symptoms may increase the risk of CVD in this population of women. These findings suggest that screening for CVD risk and reducing health risk behaviors in trauma-exposed women may be promising avenues for prevention and intervention

    Health status in older hospitalized patients with cancer or non-neoplastic chronic diseases

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    BACKGROUND: Whether cancer is more disabling than other highly prevalent chronic diseases in the elderly is not well understood, and represents the objective of the present study. METHODS: We used data from the Gruppo Italiano di Farmacovigilanza nell'Anziano (GIFA) study, a large collaborative observational study based in community and university hospitals located throughout Italy. Our series consisted of three groups of patients with non-neoplastic chronic disease (congestive heart failure, CHF, N = 832; diabetes mellitus, N = 939; chronic obstructive pulmonary disease, COPD, N = 399), and three groups of patients with cancer (solid tumors without metastasis, N = 813; solid tumors with metastasis, N = 259; leukemia/lymphoma, N = 326). Functional capabilities were ascertained using the activities of daily living (ADL) scale, and categorical variables for dependency in at least 1 ADL or dependency in 3 or more ADLs were considered in the analysis. Cognitive status was evaluated by the 10-items Hodgkinson Abbreviated Mental Test (AMT). RESULTS: Cognitive impairment was more prevalent in patients with CHF (28.0%) or COPD (25.8%) than in those with cancer (solid tumors = 22.9%; leukemia/lymphoma = 19.6%; metastatic cancer = 22.8%). Dependency in at least 1 ADL was highly prevalent in patients with metastatic cancer (31.3% vs. 24% for patients with CHF and 22.4% for those with non-metastatic solid tumors, p < 0.001). In people aged 80 years or more, metastatic cancer was not associated with increased prevalence of physical disability. In multivariable analysis, metastatic cancer was associated with a greater prevalence of physical (OR 2.09, 95%CI 1.51–2.90) but not cognitive impairment (OR 1.34, 95%CI 0.94–1.91) with respect to CHF patients. Finally, diabetes was significantly associated with cognitive impairment (OR 1.40, 95%CI 1.11–1.78). CONCLUSION: Cancer should not be considered as an ineluctable cause of severe cognitive and physical impairment, at least not more than other chronic conditions highly prevalent in older people, such as CHF and diabetes mellitus

    Measuring root system traits of wheat in 2D images to parameterize 3D root architecture models

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    Background and aimsThe main difficulty in the use of 3D root architecture models is correct parameterization. We evaluated distributions of the root traits inter-branch distance, branching angle and axial root trajectories from contrasting experimental systems to improve model parameterization.MethodsWe analyzed 2D root images of different wheat varieties (Triticum aestivum) from three different sources using automatic root tracking. Model input parameters and common parameter patterns were identified from extracted root system coordinates. Simulation studies were used to (1) link observed axial root trajectories with model input parameters (2) evaluate errors due to the 2D (versus 3D) nature of image sources and (3) investigate the effect of model parameter distributions on root foraging performance.ResultsDistributions of inter-branch distances were approximated with lognormal functions. Branching angles showed mean values <90°. Gravitropism and tortuosity parameters were quantified in relation to downwards reorientation and segment angles of root axes. Root system projection in 2D increased the variance of branching angles. Root foraging performance was very sensitive to parameter distribution and variance.Conclusions2D image analysis can systematically and efficiently analyze root system architectures and parameterize 3D root architecture models. Effects of root system projection (2D from 3D) and deflection (at rhizotron face) on size and distribution of particular parameters are potentially significant
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