Structure and shaping processes within the extended atmospheres of AGB stars

We present recent studies using the near-infrared instrument AMBER of the VLT Interferometer (VLTI) to investigate the structure and shaping processes within the extended atmosphere of AGB stars. Spectrally resolved near-infrared AMBER observations of the Mira variable S Ori have revealed wavelength-dependent apparent angular sizes. These data were successfully compared to dynamic model atmospheres, which predict wavelength-dependent radii because of geometrically extended molecular layers. Most recently, AMBER closure phase measurements of several AGB stars have also revealed wavelength-dependent deviations from 0/180 deg., indicating deviations from point symmetry. The variation of closure phase with wavelength indicates a complex non-spherical stratification of the extended atmosphere, and may reveal whether observed asymmetries are located near the photosphere or in the outer molecular layers. Concurrent observations of SiO masers located within the extended molecular layers provide us with additional information on the morphology, conditions, and kinematics of this shell. These observations promise to provide us with new important insights into the shaping processes at work during the AGB phase. With improved imaging capabilities at the VLTI, we expect to extend the successful story of imaging studies of planetary nebulae to the photosphere and extended outer atmosphere of AGB stars.Comment: 6 pages, Proc. of "Asymmetric Planetary Nebulae V", A.A. Zijlstra, F. Lykou, I. McDonald, and E. Lagadec (eds.), Jodrell Bank Centre for Astrophysics, Manchester, UK, 201

The role of impulsivity in dropout from treatment for cigarette smoking

AbstractImpulsivity is a variable that has been associated with drug use. This study analyzes impulsivity from two different paradigms, one considering it as a trait and the other based on its behavioral correlates, such as disinhibition and impulsive decision-making in the treatment prognosis (maintain abstinence, relapse and dropout) of smokers after outpatient treatment. The participants in the study were 113 smokers who requested treatment for nicotine addiction. They were assigned to three groups according to whether or not they remained abstinent one month after beginning treatment; thus, group 1 was abstinent, group 2 had relapsed, and group 3 had dropped out of treatment. The participants filled out the Semi-structured Interview for Smokers, the Fargerström Test for Nicotine Dependence, the Temperament and Character Inventory-Revised (TCI-R) and the Delay Discounting Task (DDT). The Delay Discounting variable presents lower scores in the dropout group than in the relapse and abstinent groups, with the highest scores in the relapse group. Differences were also found on the Harm Avoidance (HA) variable, with lower scores in the dropout group compared to the relapse group. The importance of these results lies in the consideration of the smoker’s personality profile in order to prevent both dropout and relapse

The Spin Glass Phase in the Four-State, Three-Dimensional Potts Model

We perform numerical simulations, including parallel tempering, on the Potts glass model with binary random quenched couplings using the JANUS application-oriented computer. We find and characterize a glassy transition, estimating the location of the transition and the value of the critical exponents. We show that there is no ferromagnetic transition in a large temperature range around the glassy critical temperature. We also compare our results with those obtained recently on the "random permutation" Potts glass.Comment: 7 pages and 3 figures. Corrected minor typo

Inter-calibration trials between the R/V Cornide de Saavedra and the R/V Miguel Oliver in bottom trawl surveys off the Spanish coast

Bottom trawl surveys are conducted by the Spanish Oceanographic Institute (IEO) to provide information independent from the fisheries of commercial stocks: DEMERSALES in the northern Spanish Shelf, ARSA in the Gulf of Cadiz and MEDITS in the Mediterranean Shelf since 1983, 1993 and 1994, respectively. Surveys have been performed annually on board the R/V Cornide de Saavedra until 2013. This vessel (67 m, 1133 GRT) was built in 1972 and nowadays has been replaced by the new R/V Miguel Oliver (70 m, 2495 GRT). To guarantee the continuity between the two vessels of the abundance and biomass indices of the main target species and their length distributions, inter-calibration experiments have been performed for each of the three bottom trawl surveys. The goal of the inter-calibration between both vessels was to establish the most similar fishing conditions to detect and isolate if there was a vessel effect that caused different results in catches. And in if those differences were significant, to estimate calibration coefficients to homogenize abundance and biomass indices of the new vessel R/V Miguel Oliver with respect to the time series built with the old R/V Cornide de Saavedra. The inter-calibration experiment consisted in performing parallel tows with both vessels, using the same gear, and carrying out hauls of the same duration and speed. The parallel surveys in the V/R Cornide de Saavedra and the R/V Miguel Oliver followed the surveys protocols of IBTS for the northern Spain and Gulf of Cadiz and MEDITS for the Mediterranean. A total of 60 paired hauls were completed in the DEMERSALES survey, 43 for the ARSA and 37 hauls in the MEDITS. Comparisons between both vessels were done in each survey addressing: gear performance, total catch, commercial species catches, length distributions of the most representative species and analyzing the faunal fish assemblages detected. Differences between vessels were less significant for the DEMERSALES survey, with the higher catches, number of hauls and less variability; in the Gulf of Cadiz, catches of flatfish and some species of cephalopods were slightly higher in the R/V Miguel Oliver but no significant differences in the length distributions were found; for the MEDITS survey, catches by haul were lower, presenting a great diversity of species, thus complicating to separate the sources of variability due to the change of vessel from the uncertainty associated to the hauls. In general, catches in the R/V Miguel Oliver are similar to catches in the R/V Cornide de Saavedra. To verify the continuity and congruence of the time series special attention must be paid to the new surveys in the R/V Miguel Oliver to test if inter-calibration factors are needed for some species

Ianus: an Adpative FPGA Computer

Dedicated machines designed for specific computational algorithms can outperform conventional computers by several orders of magnitude. In this note we describe {\it Ianus}, a new generation FPGA based machine and its basic features: hardware integration and wide reprogrammability. Our goal is to build a machine that can fully exploit the performance potential of new generation FPGA devices. We also plan a software platform which simplifies its programming, in order to extend its intended range of application to a wide class of interesting and computationally demanding problems. The decision to develop a dedicated processor is a complex one, involving careful assessment of its performance lead, during its expected lifetime, over traditional computers, taking into account their performance increase, as predicted by Moore's law. We discuss this point in detail

The extended atmospheres of Mira variables probed by VLTI, VLBA, and APEX

We present an overview on our project to study the extended atmospheres and dust formation zones of Mira stars using coordinated observations with the Very Large Telescope Interferometer (VLTI), the Very Long Baseline Array (VLBA), and the Atacama Pathfinder Experiment (APEX). The data are interpreted using an approach of combining recent dynamic model atmospheres with a radiative transfer model of the dust shell, and combining the resulting model structure with a maser propagation model.Comment: 5 pages, to appear in Proc. of "Why Galaxies Care About AGB Stars II", ASP Conf. Ser., Franz Kerschbaum, Thomas Lebzelter, and Bob Wing (eds.

Genome-wide association studies for methane production in dairy cattle

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Genomic selection has been proposed for the mitigation of methane (CH4) emissions by cattle because there is considerable variability in CH4 emissions between individuals fed on the same diet. The genome-wide association study (GWAS) represents an important tool for the detection of candidate genes, haplotypes or single nucleotide polymorphisms (SNP) markers related to characteristics of economic interest. The present study included information for 280 cows in three dairy production systems in Mexico: 1) Dual Purpose (n = 100), 2) Specialized Tropical Dairy (n = 76), 3) Familiar Production System (n = 104). Concentrations of CH4 in a breath of individual cows at the time of milking (MEIm) were estimated through a system of infrared sensors. After quality control analyses, 21,958 SNPs were included. Associations of markers were made using a linear regression model, corrected with principal component analyses. In total, 46 SNPs were identified as significant for CH4 production. Several SNPs associated with CH4 production were found at regions previously described for quantitative trait loci of composition characteristics of meat, milk fatty acids and characteristics related to feed intake. It was concluded that the SNPs identified could be used in genomic selection programs in developing countries and combined with other datasets for global selection

Simulating spin systems on IANUS, an FPGA-based computer

We describe the hardwired implementation of algorithms for Monte Carlo simulations of a large class of spin models. We have implemented these algorithms as VHDL codes and we have mapped them onto a dedicated processor based on a large FPGA device. The measured performance on one such processor is comparable to O(100) carefully programmed high-end PCs: it turns out to be even better for some selected spin models. We describe here codes that we are currently executing on the IANUS massively parallel FPGA-based system.Comment: 19 pages, 8 figures; submitted to Computer Physics Communication

Full configuration interaction calculation of BeH adiabatic states

An all-electron full configuration interaction (FCI) calculation of the adiabatic potential energy curves of some of the lower states of BeH molecule is presented. A moderately large ANO basis set of atomic natural orbitals (ANO) augmented with Rydberg functions has been used in order to describe the valence and Rydberg states and their interactions. The Rydberg set of ANOs has been placed on the Be at all bond distances. So, the basis set can be described as 4s3p2d1f/3s2p1d(Be/H)+4s4p2d(Be). The dipole moments of several states and transition dipole strengths from the ground state are also reported as a function of the RBe–H distance. The position and the number of states involved in several avoided crossings present in this system have been discussed. Spectroscopic parameters have been calculated from a number of the vibrational states that result from the adiabatic curves except for some states in which this would be completely nonsense, as it is the case for the very distorted curves of the 3s and 3p math states or the double-well potential of the 4p math state. The so-called “D complex” at 54 050 cm−1 (185.0 nm) is resolved into the three 3d substates (math,math,math). A diexcited valence state is calculated as the lowest state of math symmetry and its spectroscopic parameters are reported, as well as those of the 2 math (4d) state The adiabatic curve of the 4 math state shows a swallow well at large distances (around 4.1 Å) as a result of an avoided crossing with the 3 math state. The probability that some vibrational levels of this well could be populated is discussed within an approached Landau–Zerner model and is found to be high. No evidence is found of the E(4sσ) math state in the region of the “D complex”. Instead, the spectroscopic properties obtained from the (4sσ) 6 math adiabatic curve of the present work seem to agree with those of the experimental F(4pσ) math state. The FCI calculations provide benchmark results for other correlation models for the open-shell BeH system and evidence both the limitations and capabilities of the basis [email protected] [email protected]