The effect of 12C + 12C rate uncertainties on the evolution and nucleosynthesis of massive stars

[Shortened] The 12C + 12C fusion reaction has been the subject of considerable experimental efforts to constrain uncertainties at temperatures relevant for stellar nucleosynthesis. In order to investigate the effect of an enhanced carbon burning rate on massive star structure and nucleosynthesis, new stellar evolution models and their yields are presented exploring the impact of three different 12C + 12C reaction rates. Non-rotating stellar models were generated using the Geneva Stellar Evolution Code and were later post-processed with the NuGrid Multi-zone Post-Processing Network tool. The enhanced rate causes core carbon burning to be ignited more promptly and at lower temperature. This reduces the neutrino losses, which increases the core carbon burning lifetime. An increased carbon burning rate also increases the upper initial mass limit for which a star exhibits a convective carbon core. Carbon shell burning is also affected, with fewer convective-shell episodes and convection zones that tend to be larger in mass. Consequently, the chance of an overlap between the ashes of carbon core burning and the following carbon shell convection zones is increased, which can cause a portion of the ashes of carbon core burning to be included in the carbon shell. Therefore, during the supernova explosion, the ejecta will be enriched by s-process nuclides synthesized from the carbon core s process. The yields were used to estimate the weak s-process component in order to compare with the solar system abundance distribution. The enhanced rate models were found to produce a significant proportion of Kr, Sr, Y, Zr, Mo, Ru, Pd and Cd in the weak component, which is primarily the signature of the carbon-core s process. Consequently, it is shown that the production of isotopes in the Kr-Sr region can be used to constrain the 12C + 12C rate using the current branching ratio for a- and p-exit channels.Comment: The paper contains 17 figures and 7 tables. Table 7 will be published in full online onl

Stellar Nucleosynthesis in the Hyades Open Cluster

We report a comprehensive light element (Li, C, N, O, Na, Mg, and Al) abundance analysis of three solar-type main sequence (MS) dwarfs and three red giant branch (RGB) clump stars in the Hyades open cluster using high-resolution and high signal-to-noise spectroscopy. For each group (MS or RGB), the CNO abundances are found to be in excellent star-to-star agreement. Our results confirm that the giants have undergone the first dredge-up and that material processed by the CN cycle has been mixed to the surface layers. The observed abundances are compared to predictions of a standard stellar model based on the Clemson-American University of Beirut (CAUB) stellar evolution code. The model reproduces the observed evolution of the N and O abundances, as well as the previously derived 12C/13C ratio, but it fails to predict by a factor of 1.5 the observed level of 12C depletion. Li abundances are derived to determine if non-canonical extra mixing has occurred in the Hyades giants. The Li abundance of the giant gamma Tau is in good accord with the predicted level of surface Li dilution, but a ~0.35 dex spread in the giant Li abundances is found and cannot be explained by the stellar model. Possible sources of the spread are discussed; however, it is apparent that the differential mechanism responsible for the Li dispersion must be unrelated to the uniformly low 12C abundances of the giants. Na, Mg, and Al abundances are derived as an additional test of our stellar model. All three elements are found to be overabundant by 0.2-0.5 dex in the giants relative to the dwarfs. Such large enhancements of these elements are not predicted by the stellar model, and non-LTE effects significantly larger (and, in some cases, of opposite sign) than those implied by extant literature calculations are the most likely cause.Comment: 40 pages, 6 figures, 6 tables; accepted by Ap

Prevalence of comorbidities in rheumatoid arthritis and evaluation of their monitoring: results of an international, cross-sectional study (COMORA)

Background: Patients with rheumatoid arthritis (RA) are at increased risk of developing comorbid conditions.<p></p> Objectives: To evaluate the prevalence of comorbidities and compare their management in RA patients from different countries worldwide.<p></p> Methods Study design: international, cross-sectional. Patients: consecutive RA patients. Data collected: demographics, disease characteristics (activity, severity, treatment), comorbidities (cardiovascular, infections, cancer, gastrointestinal, pulmonary, osteoporosis and psychiatric disorders).<p></p> Results: Of 4586 patients recruited in 17 participating countries, 3920 were analysed (age, 56±13 years; disease duration, 10±9 years (mean±SD); female gender, 82%; DAS28 (Disease Activity Score using 28 joints)–erythrocyte sedimentation rate, 3.7±1.6 (mean±SD); Health Assessment Questionnaire, 1.0±0.7 (mean±SD); past or current methotrexate use, 89%; past or current use of biological agents, 39%. The most frequently associated diseases (past or current) were: depression, 15%; asthma, 6.6%; cardiovascular events (myocardial infarction, stroke), 6%; solid malignancies (excluding basal cell carcinoma), 4.5%; chronic obstructive pulmonary disease, 3.5%. High intercountry variability was observed for both the prevalence of comorbidities and the proportion of subjects complying with recommendations for preventing and managing comorbidities. The systematic evaluation of comorbidities in this study detected abnormalities in vital signs, such as elevated blood pressure in 11.2%, and identified conditions that manifest as laboratory test abnormalities, such as hyperglycaemia in 3.3% and hyperlipidaemia in 8.3%.<p></p> Conclusions: Among RA patients, there is a high prevalence of comorbidities and their risk factors. In this multinational sample, variability among countries was wide, not only in prevalence but also in compliance with recommendations for preventing and managing these comorbidities. Systematic measurement of vital signs and laboratory testing detects otherwise unrecognised comorbid conditions.<p></p&gt

Debris clearance by microglia: an essential link between degeneration and regeneration

Microglia are cells of myeloid origin that populate the CNS during early development and form the brain's innate immune cell type. They perform homoeostatic activity in the normal CNS, a function associated with high motility of their ramified processes and their constant phagocytic clearance of cell debris. This debris clearance role is amplified in CNS injury, where there is frank loss of tissue and recruitment of microglia to the injured area. Recent evidence suggests that this phagocytic clearance following injury is more than simply tidying up, but instead plays a fundamental role in facilitating the reorganization of neuronal circuits and triggering repair. Insufficient clearance by microglia, prevalent in several neurodegenerative diseases and declining with ageing, is associated with an inadequate regenerative response. Thus, understanding the mechanism and functional significance of microglial-mediated clearance of tissue debris following injury may open up exciting new therapeutic avenues

Perception of High Alcohol Use of Peers Is Associated With High Personal Alcohol Use in First-Year University Students in Three Central and Eastern European Countries

Objectives: The objectives of this study were to assess discrepancies between estimated peer and personal drinking behavior and to determine associations between perceptions of peer and personal drinking behavior among university students from Hungary (HU), Lithuania (LT), and the Slovak Republic (SK). Methods: 2,554 freshman university students completed an online questionnaire on the frequency of their personal alcohol use, the number of heavy drinking occasions and on their perception concerning the corresponding drinking behavior of a typical student. Associations between perceived peer and personal use were analyzed by means of logistic regression, adjusting for sex. Results: The majority of students across all countries thought their peers drink more frequently and are more often involved in heavy drinking occasions than themselves. Students who perceived the frequency of peer alcohol use to be higher were more likely to drink alcohol twice a week or more often (SR: OR = 3.81, 95% CI = 2.51–5.79; LT: OR = 3.16, 95% CI = 2.11–4.75; HU: OR = 2.10, 95% CI = 1.53–2.87) compared with students who drink alcohol monthly or less. Those who perceived the number of peer heavy drinking occasions as high were more likely to report heavy drinking weekly or more often (SR: OR = 3.16, 95% CI = 1.92–5.20; LT:OR = 3.56, 95% CI = 2.14–5.94; HU:OR = 1.41, 95% CI = 0.79–2.51) compared with students who report heavy drinking less than monthly. Conclusions/Importance: University students perceived peer alcohol use to be higher than their personal use. Given the association between perceptions and personal alcohol use, future research should investigate if targeting perceptions in the surveyed countries may have an impact on alcohol use

Mitigating the impact of Bats in historic churches: The response of Natterer's Bats Myotis nattereri to artificial roosts and deterrence

© 2016 Zeale et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Bats frequently roost in historic churches, and these colonies are of considerable conservation value. Inside churches, bat droppings and urine can cause damage to the historic fabric of the building and to items of cultural significance. In extreme cases, large quantities of droppings can restrict the use of a church for worship and/or other community functions. In the United Kingdom, bats and their roosts are protected by law, and striking a balance between conserving the natural and cultural heritage can be a significant challenge. We investigated mitigation strategies that could be employed in churches and other historic buildings to alleviate problems caused by bats without adversely affecting their welfare or conservation status. We used a combination of artificial roost provision and deterrence at churches in Norfolk, England, where significant maternity colonies of Natterer's bats Myotis nattereri damage church features. Radio-tracking data and population modelling showed that excluding M. nattereri from churches is likely to have a negative impact on their welfare and conservation status, but that judicious use of deterrents, especially high intensity ultrasound, can mitigate problems caused by bats. We show that deterrence can be used to move bats humanely from specific roosting sites within a church and limit the spread of droppings and urine so that problems to congregations and damage to cultural heritage can be much reduced. In addition, construction of bespoke roost spaces within churches can allow bats to continue to roost within the fabric of the building without flying in the church interior. We highlight that deterrence has the potential to cause serious harm toM. nattereri populations if not used judiciously, and so the effects of deterrents will need careful monitoring, and their use needs strict regulation

The association of anti-CCP antibodies with disease activity in rheumatoid arthritis

Antibodies to citrullinated proteins have been described in patients with rheumatoid arthritis (RA) and these appear to be the most specific markers of the disease. Our objective was to determine the frequency of antibodies to cyclic citrullinated peptides (CCPs) in patients with RA and the association of anti-CCP antibodies with disease activity, radiological erosions and HLA DR genotype. Forty patients with RA and 38 patients with fibromyalgia were included in this study. Serum samples were collected from both patient groups with RA and fibromyalgia. Anti-CCP was measured by the corresponding enzyme-linked immunosorbent assay. Additionally, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), disease activity score (DAS), visual analog scala (VAS), HLA genotype and radiographic information were determined in patients with RA. The rate of sensitivity and specificity of anti-CCP reactivity for the diagnosis RA were measured (sensitivity 50%, specificity100%). There is no significant difference between anti-CCP (+) and anti-CCP (−) RA patients for DAS28, VAS, ESR, CRP, disease duration, HLA genotype, and radiological assessment of hand. However, there was a significant difference between anti-CCP (+) and anti-CCP (−) RA patients for RF and the radiological assessment of left and right wrists (respectively, P < 0.05, P = 0.04, P = 0.01). There was no significant correlation between anti-CCP antibody and ESR, CRP, VAS, DAS 28 or radiological assessment. A small but significant correlation was found between RF and anti-CCP antibody (P = 0.02, r = 0.35)

Suggestion for linkage of chromosome 1p35.2 and 3q28 to plasma adiponectin concentrations in the GOLDN Study

<p>Abstract</p> <p>Background</p> <p>Adiponectin is inversely associated with obesity, insulin resistance, and atherosclerosis, but little is known about the genetic pathways that regulate the plasma level of this protein. To find novel genes that influence circulating levels of adiponectin, a genome-wide linkage scan was performed on plasma adiponectin concentrations before and after 3 weeks of treatment with fenofibrate (160 mg daily) in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) Study. We studied Caucasian individuals (n = 1121) from 190 families in Utah and Minnesota. Of these, 859 individuals from 175 families had both baseline and post-fenofibrate treatment measurements for adiponectin. Plasma adiponectin concentrations were measured with an ELISA assay. All participants were typed for microsatellite markers included in the Marshfield Mammalian Genotyping Service marker set 12, which includes 407 markers spaced at approximately 10 cM regions across the genome. Variance components analysis was used to estimate heritability and to perform genome-wide scans. Adiponectin was adjusted for age, sex, and field center. Additional models also included BMI adjustment.</p> <p>Results</p> <p>Baseline and post-fenofibrate adiponectin measurements were highly correlated (r = 0.95). Suggestive (LOD > 2) peaks were found on chromosomes 1p35.2 and 3q28 (near the location of the adiponectin gene).</p> <p>Conclusion</p> <p>Two candidate genes, <it>IL22RA1 </it>and <it>IL28RA</it>, lie under the chromosome 1 peak; further analyses are needed to identify the specific genetic variants in this region that influence circulating adiponectin concentrations.</p

Genome-wide meta-analysis points to CTC1 and ZNf676 as genes regulating telomere homeostasis in humans

Leukocyte telomere length (LTL) is associated with a number of common age-related diseases and is a heritable trait. Previous genome-wide association studies (GWASs) identified two loci on chromosomes 3q26.2 (TERC) and 10q24.33 (OBFC1) that are associated with the inter-individual LTL variation. We performed a meta-analysis of 9190 individuals from six independent GWAS and validated our findings in 2226 individuals from four additional studies. We confirmed previously reported associations with OBFC1 (rs9419958 P = 9.1 × 10-11) and with the telomerase RNA component TERC (rs1317082, P = 1.1 × 10-8). We also identified two novel genomic regions associated with LTL variation that map near a conserved telomere maintenance complex component 1 (CTC1; rs3027234, P = 3.6 × 10-8) on chromosome17p13.1 and zinc finger protein 676 (ZNF676; rs412658, P = 3.3 × 10-8) on 19p12. The minor allele of rs3027234 was associated with both shorter LTL and lower expression of CTC1. Our findings are consistent with the recent observations that point mutations in CTC1 cause short telomeres in both Arabidopsis and humans affected by a rare Mendelian syndrome. Overall, our results provide novel insights into the genetic architecture of inter-individual LTL variation in the general population.</p

Genome-wide meta-analysis points to CTC1 and ZNf676 as genes regulating telomere homeostasis in humans

Leukocyte telomere length (LTL) is associated with a number of common age-related diseases and is a heritable trait. Previous genome-wide association studies (GWASs) identified two loci on chromosomes 3q26.2 (TERC) and 10q24.33 (OBFC1) that are associated with the inter-individual LTL variation. We performed a meta-analysis of 9190 individuals from six independent GWAS and validated our findings in 2226 individuals from four additional studies. We confirmed previously reported associations with OBFC1 (rs9419958 P = 9.1 × 10-11) and with the telomerase RNA component TERC (rs1317082, P = 1.1 × 10-8). We also identified two novel genomic regions associated with LTL variation that map near a conserved telomere maintenance complex component 1 (CTC1; rs3027234, P = 3.6 × 10-8) on chromosome17p13.1 and zinc finger protein 676 (ZNF676; rs412658, P = 3.3 × 10-8) on 19p12. The minor allele of rs3027234 was associated with both shorter LTL and lower expression of CTC1. Our findings are consistent with the recent observations that point mutations in CTC1 cause short telomeres in both Arabidopsis and humans affected by a rare Mendelian syndrome. Overall, our results provide novel insights into the genetic architecture of inter-individual LTL variation in the general population.</p