Evolution and CNO yields of Z=10^-5 stars and possible effects on CEMP production

Our main goals are to get a deeper insight into the evolution and final fates of intermediate-mass, extremely metal-poor (EMP) stars. We also aim to investigate their C, N, and O yields. Using the Monash University Stellar Evolution code we computed and analysed the evolution of stars of metallicity Z = 10^-5 and masses between 4 and 9 M_sun, from their main sequence until the late thermally pulsing (super) asymptotic giant branch, TP-(S)AGB phase. Our model stars experience a strong C, N, and O envelope enrichment either due to the second dredge-up, the dredge-out phenomenon, or the third dredge-up early during the TP-(S)AGB phase. Their late evolution is therefore similar to that of higher metallicity objects. When using a standard prescription for the mass loss rates during the TP-(S)AGB phase, the computed stars lose most of their envelopes before their cores reach the Chandrasekhar mass, so our standard models do not predict the occurrence of SNI1/2 for Z = 10^-5 stars. However, we find that the reduction of only one order of magnitude in the mass-loss rates, which are particularly uncertain at this metallicity, would prevent the complete ejection of the envelope, allowing the stars to either explode as an SNI1/2 or become an electron-capture SN. Our calculations stop due to an instability near the base of the convective envelope that hampers further convergence and leaves remnant envelope masses between 0.25 M_sun for our 4 M_sun model and 1.5 M_sun for our 9 M_sun model. We present two sets of C, N, and O yields derived from our full calculations and computed under two different assumptions, namely, that the instability causes a practically instant loss of the remnant envelope or that the stars recover and proceed with further thermal pulses. Our results have implications for the early chemical evolution of the Universe.Comment: 12 pages, 13 figures, accepted for publication in A&

On the design of Aircraft Electrical Structure Networks

As part of the technology research engaged in the EU Clean Sky 1 project, we present in this paper an electrical structure network (ESN) designed to prevent the impact on an electronic equipment of unwanted voltage drops appearing when nonmetal composite materials are used for grounding. An iterative process has been followed to reach an optimal tradeoff solution meeting all the aircraft requirements: structural, safety, low weight, electrical, etc. Guidelines on the design of a low-impedance metal ESN, to minimize the inductive behavior of the power distribution network, are outlined in this paper. To this end, we employ the UGRFDTD simulation tool, combining finite-difference time domain to analyze the general EM problem, and a multiconductor transmission-line network to handle internal coupling between cables running along coinciding routes. The capability of this tool to create time-domain snapshots of surface currents is shown to provide a useful way to optimize the ESN, thanks to the insight gained on the physics of the problem.This work was supported from the European Community Seventh Framework Program FP7/2008-2014 under Grant CSJU-GAM-GRA- 2008-01 (Clean Sky 1 project), and from the Projects TEC2013-48414-C3- 01 and TEC2015-68766-REDC (MINECO, Spain), P12-TIC-1442 (Junta de Andalucia, Spain), Alhambra-UGRFDTD (AIRBUS DS), and by the CSIRC alhambra.ugr.es supercomputing cente

Genetska struktura regionalnih prekograničnih populacija istarske ovce u Hrvatskoj i Sloveniji utvrđena mikrosatelitskim markerima

Istrian dairy sheep is a local breed essential for the identity and development of the Northern- Adriatic karstic region through high-quality products, primarily the hard sheep artisanal cheese. Border changes fragmented the initial Istrian dairy sheep population in three genetically isolated sub-populations in Italy (1000 animals), Slovenia (1150 animals) and Croatia (2500 animals). Due to the drastic reduction of their population sizes and fragmentation, the populations in Croatia and Slovenia are included in governmentally supported conservation programs. The initial subpopulation in Italy was restored after near extinction with stock from Slovenia, and is used today in meat production. The aim of this study was to provide an initial understanding of the current genetic structure and distribution of the genetic variability that exists in Istrian sheep by analysing individuals sampled in two regional groups of Istrian sheep from Croatia and Slovenia. Cres island sheep and Lika pramenka sheep were used as out-groups for comparison. Genetic differentiation was analysed using factorial correspondence analysis and structure clustering over 26 microsatellite loci for a total of 104 sheep belonging to three breeds from Croatia and Slovenia. Factorial correspondence analysis and clustering-based structure analysis both showed three distinct populations: Lika pramenka sheep, Cres island sheep and Istrian sheep. We did not find a marked genetic divergence of the regional groups of Istrian sheep. Istrian sheep regional group from Slovenia showed lower genetic variability compared to the one from Croatia. Variability and structure information obtained in this study considered alongside with socio-cultural-contexts and economic goals for the Istrian sheep reared in Croatia and Slovenia indicate that the cross-border exchange of genetic material of animals carrying private alleles among populations would maintain these alleles at low frequencies and minimize the inbreeding rate.Istarska ovca je autohtona pasmina ključna za identitet i razvoj sjevernojadranske regije zbog visokokvalitetnih mliječnih proizvoda. Promjenama granica inicijalna populacija istarske ovce je fragmentirana u tri genetski izolirane sub-populacije u Italiji (1000 životinja), Sloveniji (1150 životinja) i Hrvatskoj (2500 životinja). Zbog fragmentacije i smanjenja veličine populacija, istarske ovce su u Sloveniji i Hrvatskoj uključene u konzervacijske programe državnih potpora. Talijanska populacija je nakon inicijalnog drastičnog smanjenja broja danas obnovljena isključivo iz slovenskih stada. Cilj ovog istraživanja bio je omogućiti razumijevanje današnje genetske strukture i raspodijele genetske raznolikosti istarske ovce istraživanjem slovenske i hrvatske sub-populacije. Creska i lička pramenka korištene su kao grupe za usporedbu. Genetska diferencijacija istražena je faktorijalnom analizom korespondencije i strukturnim klasteriranjem na temelju 26 mikrosatelitskih lokusa genotipiziranih kod 104 ovce. Obje analize pokazale su tri distinktne populacije: lička i creska pramenka, te istarska ovca. Genetička divergencija istarske ovce iz Slovenije i Hrvatske nije izražena. Istarska ovca iz Slovenije pokazala je nižu genetsku varijabilnost od sub-populacije iz Hrvatske. Temeljem informacija o varijabilnosti i strukturi iz ovog istraživanja, kao i društveno-kulturalnog konteksta te ekonomskih ciljeva za slovensku i hrvatsku sub-populaciju istarskih ovaca, može se reći da bi izmjena genetskog materijala životinja s privatnim alelima omogućila održavanje tih alela u niskoj učestalosti, te smanjila genetske posljedice parenja u srodstvu

Influence of Geometric Simplifications on Lightning Strike Simulations

This paper discusses the influence of simplifications in models used in the design of electromagnetic protection against indirect effects of lightning strikes. A real and complex test case such as the power plant of an A400M aircraft, simulated with the FDTD method, is chosen for this. The parameters studied are the inclusion/removal of installations, modification of electrical contacts, material properties, and changes in the cable characteristics. The simulations performed allow us to quantify the impact of different simplification approaches and, in consequence, to draw conclusions on the relative importance of different model features, being the most important ones to maintain the electrical contacts, to include installations and cables carrying high currents, to consider different materials, to respect the accurate cable routes or to take care of isolated equipment.This work has received funding from the Projects TEC2013-48414-C3-01, TEC2013-48414-C3-2-R, TEC2016-79214-C3-1-R, TEC2016-79214-C3-3-R, and TEC2015-68766-REDC (Spanish MINECO, EU FEDER), P12-TIC-1442 (J. de Andalucia, Spain), Alhambra-UGRFDTD (AIRBUS DS), and by the CSIRC alhambra.ugr.es supercomputing center

Genes controlling vaccine responses and disease resistance to respiratory viral pathogens in cattle

AbstractFarm animals remain at risk of endemic, exotic and newly emerging viruses. Vaccination is often promoted as the best possible solution, and yet for many pathogens, either there are no appropriate vaccines or those that are available are far from ideal. A complementary approach to disease control may be to identify genes and chromosomal regions that underlie genetic variation in disease resistance and response to vaccination. However, identification of the causal polymorphisms is not straightforward as it generally requires large numbers of animals with linked phenotypes and genotypes. Investigation of genes underlying complex traits such as resistance or response to viral pathogens requires several genetic approaches including candidate genes deduced from knowledge about the cellular pathways leading to protection or pathology, or unbiased whole genome scans using markers spread across the genome.Evidence for host genetic variation exists for a number of viral diseases in cattle including bovine respiratory disease and anecdotally, foot and mouth disease virus (FMDV). We immunised and vaccinated a cattle cross herd with a 40-mer peptide derived from FMDV and a vaccine against bovine respiratory syncytial virus (BRSV). Genetic variation has been quantified. A candidate gene approach has grouped high and low antibody and T cell responders by common motifs in the peptide binding pockets of the bovine major histocompatibility complex (BoLA) DRB3 gene. This suggests that vaccines with a minimal number of epitopes that are recognised by most cattle could be designed. Whole genome scans using microsatellite and single nucleotide polymorphism (SNP) markers has revealed many novel quantitative trait loci (QTL) and SNP markers controlling both humoral and cell-mediated immunity, some of which are in genes of known immunological relevance including the toll-like receptors (TLRs).The sequencing, assembly and annotation of livestock genomes and is continuing apace. In addition, provision of high-density SNP chips should make it possible to link phenotypes with genotypes in field populations without the need for structured populations or pedigree information. This will hopefully enable fine mapping of QTL and ultimate identification of the causal gene(s). The research could lead to selection of animals that are more resistant to disease and new ways to improve vaccine efficacy

Cutting the cylinder into squares: The square form factor

In this article we present a method for constructing two-point functions in the spirit of the hexagon proposal, which leads us to propose a "square form factor". Since cutting the square gives us two squares, we can write a consistency condition that heavily constrains such form factors. In particular, we are able to use this constraint to reconstruct the Gaudin through the forest expansion of the determinant appearing in its definition. We also use this procedure to compute the norm of off-shell Bethe states for some simple cases.Comment: 34 pages, 10 figure

Relative age effect in European professional football. Analysis by position

The relative age effect (RAE) in sport consists in the lower presence of athletes born in the months furthest from the cut off date established by the competitive system, which normally coincides with the last months of the year. The purpose of this study is to assess if there is an RAE in European professional football, where the current cut off age for training in the different categories is based on the calendar year; and its analysis by position on the playing field. The analysis has included all the footballers playing in the league championships in the United Kingdom, Italy, Germany, France and Spain (N= 2763). The results of our study confirm an RAE in professional football in Italy, France and Spain. When differentiated by playing position there is a different RAE incidence in the five championships analyzed