Finite-size effects at the hadron-quark transition and heavy hybrid stars

We study the role of finite-size effects at the hadron-quark phase transition in a new hybrid equation of state constructed from an ab-initio Br\"uckner-Hartree-Fock equation of state with the realistic Bonn-B potential for the hadronic phase and a covariant non-local Nambu--Jona-Lasinio model for the quark phase. We construct static hybrid star sequences and find that our model can support stable hybrid stars with an onset of quark matter below $2 M_\odot$ and a maximum mass above $2.17 M_\odot$ in agreement with recent observations. If the finite-size effects are taken into account the core is composed of pure quark matter. Provided that the quark vector channel interaction is small, and the finite size effects are taken into account, quark matter appears at densities 2-3 times the nuclear saturation density. In that case the proton fraction in the hadronic phase remains below the value required by the onset of the direct URCA process, so that the early onset of quark matter shall affect on the rapid cooling of the star.Comment: version to match the one published in PR

Anemia among Adolescent and Young Women in Low-and-Middle-Income Countries

Objective: Anemia is a global public health problem that affects maternal and infant mortality as well as human capital  development.  Yet  there  is  not  much  research  on  anemia  among  young  women  in  low-and-middle-income  countries with nationally representative samples. The aim of the current research is to assess the extent of anemia in a critical age group: adolescents and young adults ages 15 to 24. Methods: The data are from 34 Demographic and Health Surveys and are used to describe the prevalence of anemia among pregnant and non-pregnant women by age, rural/urban residence, and household wealth. Anemia was assessed using the HemoCue® blood hemoglobin testing system.   Findings: The  prevalence  of  anemia  among  young  women  ranges  from  15%  to  over  50%.  This  is  substantially  higher  than 5%, which is the cutoff to identify a population where anemia is a public health problem. African countries show the highest prevalence of anemia; Benin, Ghana and Mali have over 60% anemia prevalence. Moreover, the prevalence of moderate to severe anemia is particularly high in African countries, over 20% in Ghana and Guinea. Our results show that anemia is a public health concern for adolescents and young adult females in all 34 countries we analyzed. Conclusion: The high prevalence of anemia among youth is alarming. Considering the importance of the adolescent and young adult years, when human capital development is consolidated and family formation begins, these findings call for interventions to redress the problem of anemia

An eQTL Landscape of Kidney Tissue in Human Nephrotic Syndrome

© 2018 American Society of Human Genetics Expression quantitative trait loci (eQTL) studies illuminate the genetics of gene expression and, in disease research, can be particularly illuminating when using the tissues directly impacted by the condition. In nephrology, there is a paucity of eQTL studies of human kidney. Here, we used whole-genome sequencing (WGS) and microdissected glomerular (GLOM) and tubulointerstitial (TI) transcriptomes from 187 individuals with nephrotic syndrome (NS) to describe the eQTL landscape in these functionally distinct kidney structures. Using MatrixEQTL, we performed cis-eQTL analysis on GLOM (n = 136) and TI (n = 166). We used the Bayesian “Deterministic Approximation of Posteriors” (DAP) to fine-map these signals, eQTLBMA to discover GLOM- or TI-specific eQTLs, and single-cell RNA-seq data of control kidney tissue to identify the cell type specificity of significant eQTLs. We integrated eQTL data with an IgA Nephropathy (IgAN) GWAS to perform a transcriptome-wide association study (TWAS). We discovered 894 GLOM eQTLs and 1,767 TI eQTLs at FDR \u3c 0.05. 14% and 19% of GLOM and TI eQTLs, respectively, had \u3e1 independent signal associated with its expression. 12% and 26% of eQTLs were GLOM specific and TI specific, respectively. GLOM eQTLs were most significantly enriched in podocyte transcripts and TI eQTLs in proximal tubules. The IgAN TWAS identified significant GLOM and TI genes, primarily at the HLA region. In this study, we discovered GLOM and TI eQTLs, identified those that were tissue specific, deconvoluted them into cell-specific signals, and used them to characterize known GWAS alleles. These data are available for browsing and download via our eQTL browser, “nephQTL.

Effects of QCD phase transition on gravitational radiation from two-dimensional collapse and bounce of massive stars

We perform two-dimensional, magnetohydrodynamical core-collapse simulations of massive stars accompanying the QCD phase transition. We study how the phase transition affects the gravitational waveforms near the epoch of core-bounce. As for initial models, we change the strength of rotation and magnetic fields. Particularly, the degree of differential rotation in the iron core (Fe-core) is changed parametrically. As for the microphysics, we adopt a phenomenological equation of state above the nuclear density, including two parameters to change the hardness before the transition. We assume the first order phase transition, where the conversion of bulk nuclear matter to a chirally symmetric quark-gluon phase is described by the MIT bag model. Based on these computations, we find that the phase transition can make the maximum amplitudes larger up to $\sim$ 10 percents than the ones without the phase transition. On the other hand, the maximum amplitudes become smaller up to $\sim$ 10 percents owing to the phase transition, when the degree of the differential rotation becomes larger. We find that even extremely strong magnetic fields $\sim 10^{17}$ G in the protoneutron star do not affect these results.Comment: 12 pages, 12 figures. Resubmitted to Phys.Rev.

Hadron-Quark Phase Transitions in Hyperon Stars

We compare the Gibbs and Maxwell constructions for the hadron-quark phase transition in neutron and protoneutron stars, including interacting hyperons in the confined phase. We find that the hyperon populations are suppressed, and that neutrino trapping shifts the onset of the phase transition. The effects on the (proto)neutron star maximum mass are explored.Comment: 11 pages, 3 figure

Magnetic Field Decay Due to the Wave-Particle Resonances in the Outer Crust of the Neutron Star

Bearing in mind the application to the outer crust of the neutron stars (NSs), we investigate the magnetic field decay by means of the fully relativistic Particle-In-Cell simulations. Numerical computations are carried out in 2-dimensions, in which the initial magnetic fields are set to be composed both of the uniform magnetic fields that model the global fields penetrating the NS and of the turbulent magnetic fields that would be originated from the Hall cascade of the large-scale turbulence. Our results show that the whistler cascade of the turbulence transports the magnetic energy preferentially in the direction perpendicular to the uniform magnetic fields. It is also found that the distribution function of electrons becomes anisotropic because electrons with lower energies are predominantly heated in the direction parallel to the uniform magnetic fields due to the Landau resonance, while electrons with higher energies are heated mainly by the cyclotron resonance that makes the distribution function isotropic for the high energy tails. Furthermore we point out that the degree of anisotropy takes maximum as a function of the initial turbulent magnetic energy. As an alternative to the conventional ohmic dissipation, we propose that the magnetic fields in the outer crust of NSs, cascading down to the electron inertial scale via the whistler turbulence, would decay predominantly by the dissipation processes through the Landau damping and the cyclotron resonance.Comment: 8pages, 9 figures, accepted for publication in Ap

The importance of the mixed phase in hybrid stars built with the Nambu-Jona-Lasinio model

We investigate the structure of hybrid stars based on two different constructions: one is based on the Gibbs condition for phase coexistence and considers the existence of a mixed phase (MP), and the other is based on the Maxwell construction and no mixed phase is obtained. The hadron phase is described by the non-linear Walecka model (NLW) and the quark phase by the Nambu-Jona-Lasinio model (NJL). We conclude that the masses and radii obtained are model dependent but not significantly different for both constructions.Comment: 8 pages, 7 figures, 3 table

Arabidopsis thaliana encodes a bacterial-type heterodimeric isopropylmalate isomerase involved in both Leu biosynthesis and the Met chain elongation pathway of glucosinolate formation

The last steps of the Leu biosynthetic pathway and the Met chain elongation cycle for glucosinolate formation share identical reaction types suggesting a close evolutionary relationship of these pathways. Both pathways involve the condensation of acetyl-CoA and a 2-oxo acid, isomerization of the resulting 2-malate derivative to form a 3-malate derivative, the oxidation-decarboxylation of the 3-malate derivative to give an elongated 2-oxo acid, and transamination to generate the corresponding amino acid. We have now analyzed the genes encoding the isomerization reaction, the second step of this sequence, in Arabidopsis thaliana. One gene encodes the large subunit and three encode small subunits of this enzyme, referred to as isopropylmalate isomerase (IPMI) with respect to the Leu pathway. Metabolic profiling of large subunit mutants revealed accumulation of intermediates of both Leu biosynthesis and Met chain elongation, and an altered composition of aliphatic glucosinolates demonstrating the function of this gene in both pathways. In contrast, the small subunits appear to be specialized to either Leu biosynthesis or Met chain elongation. Green fluorescent protein tagging experiments confirms the import of one of the IPMI small subunits into the chloroplast, the localization of the Met chain elongation pathway in these organelles. These results suggest the presence of different heterodimeric IPMIs in Arabidopsis chloroplasts with distinct substrate specificities for Leu or glucosinolate metabolism determined by the nature of the different small subunit

Serum brain-derived neurotrophic factor: Determinants and relationship with depressive symptoms in a community population of middle-aged and elderly people

OBJECTIVES: Brain-derived neurotrophic factor (BDNF) is involved in major depressive disorder and neurodegenerative diseases. Clinical studies, showing decreased serum BDNF levels, are difficult to interpret due to limited knowledge of potential confounders and mixed results for age and sex effects. We explored potential determinants of serum BDNF levels in a community sample of 1230 subjects. METHODS: Multiple linear regression analyses with serum BDNF level as the dependent variable were conducted to explore the effect of four categories of potential BDNF determinants (sampling characteristics, sociodemographic variables, lifestyle factors and somatic diseases) and of self-reported depressive symptoms (Beck's Depression Inventory (BDI). RESULTS: Our results show that BDNF levels decline with age in women, whereas in men levels remain stable. Moreover, after controlling for age and gender, the assays still showed lower serum BDNF levels with higher BDI sum scores. Effects remained significant after correction for two main confounders (time of sampling and smoking), suggesting that they serve as molecular trait factors independent of lifestyle factors. CONCLUSIONS: Given the age-sex interaction on serum BDNF levels and the known association between BDNF and gonadal hormones, research is warranted to delineate the effects of the latter interaction on the risk of psychiatric and neurodegenerative diseases