Ionization Corrections For Low-Metallicity H II Regions and the Primordial Helium Abundance

Helium and hydrogen recombination lines observed in low-metallicity, extragalactic H II regions provide the data used to infer the primordial helium mass fraction, Y_P. The ionization corrections for unseen neutral helium (or hydrogen) are usually assumed to be absent; i.e., the ionization correction factor is taken to be unity (icf = 1). In this paper we revisit the question of the icf for H II regions ionized by clusters of young, hot, metal-poor stars. Our key result is that for the H II regions used in the determination of Y_P, there is a ``reverse'' ionization correction: icf < 1. We explore the effect on the icf of more realistic inhomogeneous H II region models and find that for those regions ionized by young stars, with ``hard'' radiation spectra, the icf is reduced further below unity. In Monte Carlos using H II region data from the literature (Izotov and Thuan 1998) we estimate a reduction in the published value of Y_P of order 0.003, which is roughly twice as large as the quoted statistical error in the Y_P determination.Comment: 23 pages, 2 postscript figures; ApJ accepted; minor change

Mitochondrial DNA (mtDNA) haplogroups J and H are differentially associated with the methylation status of articular cartilage: potential role in apoptosis and metabolic and developmental processes

[Abstract] Objective. To analyze the influence of mitochondrial genome variation on the DNA methylome of articular cartilage. Methods. DNA methylation profiling was performed using data deposited in the NCBI Gene Expression Omnibus database (accession no. GSE 43269). Data were obtained for 14 cartilage samples from subjects with haplogroup J and 20 cartilage samples from subjects with haplogroup H. Subsequent validation was performed in an independent subset of 7 subjects with haplogroup J and 9 with haplogroup H by RNA ‐seq. Correlated genes were validated by real‐time polymerase chain reaction in an independent cohort of 12 subjects with haplogroup J and 12 with haplogroup H. Appropriate analyses were performed using R Bioconductor and qB asePlus software, and gene ontology analysis was conducted using DAVID version 6.8. Results. DNA methylation profiling revealed 538 differentially methylated loci, while whole‐transcriptome profiling identified 2,384 differentially expressed genes, between cartilage samples from subjects with haplogroup H and those with haplogroup J. Seventeen genes showed an inverse correlation between methylation and expression. In terms of gene ontology, differences in correlations between methylation and expression were also detected between cartilage from subjects with haplogroup H and those with haplogroup J, highlighting a significantly enhanced apoptotic process in cartilage from subjects with haplogroup H (P = 0.007 for methylation and P = 0.019 for expression) and repressed apoptotic process in cartilage from subjects with haplogroup J (P = 0.021 for methylation), as well as a significant enrichment of genes related to metabolic processes (P = 1.93 × 10−4 for methylation and P = 6.79 x 10−4 for expression) and regulation of gene expression (P = 0.012 for methylation) in cartilage from subjects with haplogroup H, and to developmental processes (P = 0.015 for methylation and P = 8.25 x 10−12 for expression) in cartilage from subjects with haplogroup J. Conclusion. Mitochondrial DNA variation differentially associates with the methylation status of articular cartilage by acting on key mechanisms involved in osteoarthritis, such as apoptosis and metabolic and developmental processes.Instituto de Salud Carlos III; CIBERCB06/01/0040‐SpainInstituto de Salud Carlos III; CPII17/00026Instituto de Salud Carlos III; PI14/01254Instituto de Salud Carlos III; PI16/02124Instituto de Salud Carlos III; PI17/0021

Senior Recital: J. Carlos Diaz H., jazz drumset

This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Performance. Mr. Diaz studies jazz percussion with Prof. Justin Chesarek.https://digitalcommons.kennesaw.edu/musicprograms/2357/thumbnail.jp

Higgs production via gluon fusion from kT-factorisation

Theoretical studies of Higgs production via gluon fusion are frequently carried out in the limit where the top quark mass is much larger than the Higgs mass, an approximation which reduces the top quark loop to an effective vertex. We present a numerical analysis of the error thus introduced by performing a Monte Carlo calculation for gg->h in kT-factorisation, using the parton shower generator CASCADE. We proceed to compare CASCADE to the collinear Monte Carlos PYTHIA, MC@NLO and POWHEG. We study the dependence of parton radiation on the resummation of high-energy corrections taken into account by kT-factorisation, and its influence on predictions for the Higgs pT spectrum.Comment: Contribution to the Workshop Diffraction 2010, Otranto (Italy), September 201

The texture development of ECAP processed AA1050aluminum, before and after a final anneal: effect of the initial texture

Equal Channel Angular Pressing (ECAP) can be used to control deformation and annealing textures. The initial texture has a significant role on texture development and intensity after deformation and anneal. In this work AA 1050 Al samples with different initial textures and initial strain of 0.3 were deformed in a I20° ECAP die. Deformation followed route A, yielding equivalents strains of 1 and 3 above the initial. After ECAP one of the samples was rolled to a thickness reduction of 70%. Texture evaluation was performed by x-ray analysis in the as deformed state and after annealing at 350°C for 1 h, by calculating orientation distribution functions. The microstructure was observed by optical and scanning electron microscopy.Fil: Vega, M. C. V.. Universidade Federal Do Sao Carlos. Departamento de Engenharia de Mteriales; BrasilFil: Piva, B. H.. Universidade Federal Do Sao Carlos. Departamento de Engenharia de Mteriales; BrasilFil: Bolmaro, Raul Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Ferrante, M.. Universidade Federal Do Sao Carlos. Departamento de Engenharia de Mteriales; BrasilFil: Kliauga, A. M.. Universidade Federal Do Sao Carlos. Departamento de Engenharia de Mteriales; Brasi

Pharmacological strategies in lung cancer-induced cachexia: effects on muscle proteolysis, autophagy, structure, and weakness

Muscle wasting and cachexia are important systemic manifestations of highly prevalent conditions including cancer. Inflammation, oxidative stress, autophagy, ubiquitin-proteasome system, nuclear factor (NF)-kB, and mitogen activated protein kinases (MAPK) are involved in the pathophysiology of cancer cachexia. Currently available treatment is limited and data demonstrating effectiveness in in vivo models are lacking. Our objectives were to explore in respiratory and limb muscles of lung cancer (LC) cachectic mice whether proteasome, NF-kB, and MAPK inhibitors improve muscle mass and function loss through several molecular mechanisms. Body and muscle weights, limb muscle force, protein degradation and the ubiquitin-proteasome system, signaling pathways, oxidative stress and inflammation, autophagy, contractile and functional proteins, myostatin and myogenin, and muscle structure were evaluated in the diaphragm and gastrocnemius of LC (LP07 adenocarcinoma) bearing cachectic mice (BALB/c), with and without concomitant treatment with NF-kB (sulfasalazine), MAPK (U0126), and proteasome (bortezomib) inhibitors. Compared to control animals, in both respiratory and limb muscles of LC cachectic mice: muscle proteolysis, ubiquitinated proteins, autophagy, myostatin, protein oxidation, FoxO-1, NF-kB and MAPK signaling pathways, and muscle abnormalities were increased, while myosin, creatine kinase, myogenin, and slow- and fast-twitch muscle fiber size were decreased. Pharmacological inhibition of NF-kB and MAPK, but not the proteasome system, induced in cancer-induced cachectic animals, a substantial restoration of muscle mass and force through a decrease in muscle protein oxidation and catabolism, myostatin, and autophagy, together with a greater content of myogenin, and contractile and functional proteins. These findings may offer new therapeutic strategies in cancer-induced cachexia.Fil: Chacon Cabrera, Alba. Universitat Pompeu Fabra; España. Universidad Carlos III de Madrid. Instituto de Salud; EspañaFil: Fermoselle, Clara. Universitat Pompeu Fabra; España. Universidad Carlos III de Madrid. Instituto de Salud; EspañaFil: Urtreger, Alejandro Jorge. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Mateu Jimenez, Mercè. Universidad Carlos III de Madrid. Instituto de Salud; España. Universitat Pompeu Fabra; EspañaFil: Diament, Miriam. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología; ArgentinaFil: Bal, Elisa Dora. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Sandri, Marco. Università di Padova; ItaliaFil: Barreiro, Eshter. Universitat Pompeu Fabra; España. Universidad Carlos III de Madrid. Instituto de Salud; Españ

Feeding Ecology of the Relict Fish Gymnocharacinus-Bergi, a Characid from Southern South-America

Fil: Escalante, Alicia H.. Universidad Nacional de Mar del Plata. Mar del Plata; ArgentinaFil: Menni, Roberto Carlos. División Zoología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin