Time-sequenced Multi-Radio-Frequency Observations of Cygnus X-3 in Flare

Multifrequency observations from the VLA, VLBA and OVRO Millimeter Array of a major radio outburst of Cygnus X-3 in 2001 September are presented, measuring the evolution of the spectrum of the source over three decades in frequency, over a period of six days. Following the peak of the flare, as the intensity declines the high-frequency spectrum at frequency nu steepens from nu^{-0.4} to nu^{-0.6}, after which the spectral index remains at this latter terminal value; a trend previously observed but hitherto not satisfactorily explained. VLBA observations, for the first time, track over several days the expansion of a sequence of knots whose initial diameters are approximately 8 milliarcseconds. The light-crossing time within these plasmons is of the same order as the time-scale over which the spectrum is observed to evolve. We contend that properly accounting for light-travel time effects in and between plasmons which are initially optically thick, but which after expansion become optically thin, explains the key features of the spectral evolution, for example the observed timescale. Using the VLBA images, we have directly measured for the first time the proper motions of individual knots, analysis of which shows a two-sided jet whose axis is precessing. The best-fit jet speed is roughly beta = 0.63 and the precession period is about 5 days, significantly lower than fitted for a previous flare. Extrapolation of the positions of the knots measured by the VLBA back to zero-separation shows this to occur approximately 2.5 days after the detection of the rise in flux density of Cygnus X-3.Comment: 23 pages, 10 figures, accepted by Ap

Prevalence of Pain on Admission by Level of Cognitive Impairment in Nursing Homes

Purpose: To provide contemporary estimates of pain by level of cognitive impairment among US nursing home residents without cancer. Methods: Newly admitted US nursing home residents without cancer assessed with the Minimum Data Set 3.0 at admission (2010-2016) were eligible (n=8,613,080). The Cognitive Function Scale was used to categorize level of cognitive impairment. Self-report or staff-assessed pain was used based on a 5-day look-back period. Estimates of adjusted prevalence ratios (aPR) were derived from modified Poisson models. Results: Documented prevalence of pain decreased with increased levels of cognitive impairment in those who self-reported pain (68.9% no/mild, 32.9% severe) and those with staff-assessed pain (50.6% no/mild, 37.2% severe staff-assessed pain). Relative to residents with no/mild cognitive impairment, pharmacologic pain management was less prevalent in those with severe cognitive impairment (self-reported: 51.3% severe vs 76.9% in those with no/mild; staff assessed: 52.0% severe vs 67.7% no/mild). Conclusion: Pain was less frequently documented in those with severe cognitive impairment relative to those with no/mild impairments. Failure to identify pain may result in untreated or undertreated pain. Interventions to improve evaluation of pain in nursing home residents with cognitive impairment are needed

Parameter Estimation and Application of Anisotropic Yield Criteria for Cylindrical Aluminum Extrusions: Theoretical Developments and Stereodic Measurements

Theoretical and experimental studies are presented to characterize the anisotropic plastic response under torsion loading of two nominally identical aluminum Al6061-T6 extruded round bars. Theoretical models are developed using isotropic (Von Mises 1913) and anisotropic (Barlat 1991) yield criteria, along with isotropic strain hardening formulae, to model post-yield behavior under simple torsion loading. For the case of simple shear loading, incremental plasticity theory is used to determine the theoretical elastic, plastic, and total shear strains. A set of experiments are performed to calibrate Barlat’s 1991 yield function. Several specimens are extracted at different orientations to the longitudinal direction of each round Al6061-T6 bar and tested under uniaxial tension and simple torsion to optimally determine all anisotropic (Barlat 1991) yield function parameters. During loading, Stereo Digital Image Correlation (DIC) is used to quantify surface deformations for the torsion experiments and a baseline tension specimen to identify and correct measurement anomalies. Results show the isotropic yield model either underestimates or overestimates the experimental shear strains for both extrusions. Conversely, results using the Barlat 1991 anisotropic yield criteria are in excellent agreement with experimental measurements for both extrusions. The presence of significant differences in the anisotropic parameters for nominally similar extrusions confirms that plastic anisotropy is essential for the accurate prediction of mechanical behavior in longitudinally extruded Al6061-T6 bar

A Uniform CO Survey of the Molecular Clouds in Orion and Monoceros

We report the results of a new large scale survey of the Orion-Monoceros complex of molecular clouds made in the J = 1->0 line of CO with the Harvard-Smithsonian 1.2m millimetre-wave telescope. The survey consists of 52,288 uniformly spaced spectra that cover an area of 432 square degrees on the sky and is the most sensitive large-scale survey of the region to date. Distances to the constituent molecular clouds of the complex, estimated from an analysis of foreground and background stars, have provided information on the three dimensional structure of the entire complex.Comment: Accepted for publication in Astronomy and Astrophysics. 19 pages with 17 colour figures - 39 if you count the sub-figures separately. The figures here have been bit-mapped with some loss of quality and beauty. The paper version in A&A will be in greyscale with the on-line version in colour. In the meantime the colour version can be obtained by following links at http://www.star.bris.ac.uk/mrwm . The 9MB PostScript is recommended if you have appropriate bandwidth or otherwise the 2.3MB PDF is usabl

Hyperspectral reflectance as a tool to measure biochemical and physiological traits in wheat

Simultaneous indirect assessment of multiple and diverse plant parameters in an exact and expeditious manner is becoming imperative in irrigated arid regions, with a view toward creating drought-tolerant genotypes or for the management of precision irrigation. This study aimed to evaluate whether spectral reflectance indices (SRIs) in three parts of the electromagnetic spectrum ((visible-infrared (VIS), near-infrared (NIR)), and shortwave-infrared (SWIR)) could be used to track changes in morphophysiological parameters of wheat cultivars exposed to 1.00, 0.75, and 0.50 of the estimated evapotranspiration (ETc). Significant differences were found in the parameters of growth and photosynthetic efficiency, and canopy spectral reflectance among the three cultivars subjected to different irrigation rates. All parameters were highly and significantly correlated with each other particularly under the 0.50 ETc treatment. The VIS/VIS- and NIR/VIS-based indices were sufficient and suitable for assessing the growth and photosynthetic properties of wheat cultivars similar to those indices based on NIR/NIR, SWIR/NIR, or SWIR/SWIR. Almost all tested SRIs proved to assess growth and photosynthetic parameters, including transpiration rate, more efficiently when regressions were analyzed for each water irrigation rate individually. This study, the type of which has rarely been conducted in irrigated arid regions, indicates that spectral reflectance data can be used as a rapid and non-destructive alternative method for assessment of the growth and photosynthetic efficiency of wheat under a range of water irrigation rates.This work was supported by the Sustainable Modernization of Traditional Agriculture (MasAgro) initiative from the Secretariat of Agriculture, Livestock, Rural Development, Fisheries and Food (SAGARPA) and a collaboration between CIMMYT, CSIRO and The Australian National University. We acknowledge financial support for the PhD scholarship of VSP from CONACYT, Mexico number 207607, the financial support of the Australian Research Council Centre of Excellence for Translational Photosynthesis (CE140100015) and access to glasshouse and field experiments supported by Grains Research & Development Corporation funding (CSP00168). SPS was supported by the United States Department of Energy contract No. DE-SC0012704 to Brookhaven National Laborator

Radio source calibration for the VSA and other CMB instruments at around 30 GHz

Accurate calibration of data is essential for the current generation of CMB experiments. Using data from the Very Small Array (VSA), we describe procedures which will lead to an accuracy of 1 percent or better for experiments such as the VSA and CBI. Particular attention is paid to the stability of the receiver systems, the quality of the site and frequent observations of reference sources. At 30 GHz the careful correction for atmospheric emission and absorption is shown to be essential for achieving 1 percent precision. The sources for which a 1 percent relative flux density calibration was achieved included Cas A, Cyg A, Tau A and NGC7027 and the planets Venus, Jupiter and Saturn. A flux density, or brightness temperature in the case of the planets, was derived at 33 GHz relative to Jupiter which was adopted as the fundamental calibrator. A spectral index at ~30 GHz is given for each. Cas A,Tau A, NGC7027 and Venus were examined for variability. Cas A was found to be decreasing at $0.394 \pm 0.019$ percent per year over the period March 2001 to August 2004. In the same period Tau A was decreasing at $0.22\pm 0.07$ percent per year. A survey of the published data showed that the planetary nebula NGC7027 decreased at $0.16\pm 0.04$ percent per year over the period 1967 to 2003. Venus showed an insignificant ($1.5 \pm 1.3$ percent) variation with Venusian illumination. The integrated polarization of Tau A at 33 GHz was found to be $7.8\pm 0.6$ percent at pa $= 148^\circ \pm 3^\circ$.}Comment: 13 pages, 15 figures, submitted to MNRA

¿Legalización de la Marihuana recreativa en Colombia, una propuesta de ley viable?

Ensayo II Congreso Internacional COFACESEn el presente ensayo se hará referencia a la posibilidad de legalizar el comercio, la producción y el consumo del cannabis para uso recreativo en adultos en Colombia. Para lograr esto se debe hacer una modificación a la constitución política, y rebatir todos los argumentos que se tienen sobre el consumo de está, ya que es considerada una sustancia, adictiva, nociva y que representa un problema de salud pública.RESUMEN INTRODUCCIÓN DESARROLLO CONCLUSIONES BIBLIOGRAFÍAEspecializaciónEspecialista en Formulación y Evaluación Social y Económica de Proyecto

Radio continuum observations of Class I protostellar disks in Taurus: constraining the greybody tail at centimetre wavelengths

We present deep 1.8 cm (16 GHz) radio continuum imaging of seven young stellar objects in the Taurus molecular cloud. These objects have previously been extensively studied in the sub-mm to NIR range and their SEDs modelled to provide reliable physical and geometrical parametres.We use this new data to constrain the properties of the long-wavelength tail of the greybody spectrum, which is expected to be dominated by emission from large dust grains in the protostellar disk. We find spectra consistent with the opacity indices expected for such a population, with an average opacity index of beta = 0.26+/-0.22 indicating grain growth within the disks. We use spectra fitted jointly to radio and sub-mm data to separate the contributions from thermal dust and radio emission at 1.8 cm and derive disk masses directly from the cm-wave dust contribution. We find that disk masses derived from these flux densities under assumptions consistent with the literature are systematically higher than those calculated from sub-mm data, and meet the criteria for giant planet formation in a number of cases.Comment: submitted MNRA

Genetic variation for photosynthetic capacity and efficiency in spring wheat

One way to increase yield potential in wheat is screening for natural variation in photosynthesis. This study uses measured and modelled physiological parameters to explore genotypic diversity in photosynthetic capacity (Pc, Rubisco carboxylation capacity per unit leaf area at 25 °C) and efficiency (Peff, Pc per unit of leaf nitrogen) in wheat in relation to fertilizer, plant stage, and environment. Four experiments (Aus1, Aus2, Aus3, and Mex1) were carried out with diverse wheat collections to investigate genetic variation for Rubisco capacity (Vcmax25), electron transport rate (J), CO2 assimilation rate, stomatal conductance, and complementary plant functional traits: leaf nitrogen, leaf dry mass per unit area, and SPAD. Genotypes for Aus1 and Aus2 were grown in the glasshouse with two fertilizer levels. Genotypes for Aus3 and Mex1 experiments were grown in the field in Australia and Mexico, respectively. Results showed that Vcmax25 derived from gas exchange measurements is a robust parameter that does not depend on stomatal conductance and was positively correlated with Rubisco content measured in vitro. There was significant genotypic variation in most of the experiments for Pc and Peff. Heritability of Pc reached 0.7 and 0.9 for SPAD. Genotypic variation and heritability of traits show that there is scope for these traits to be used in pre-breeding programmes to improve photosynthesis with the ultimate objective of raising yield potential