Direct constraint on the distance of y2 Velorum from AMBER/VLTI observations

In this work, we present the first AMBER observations, of the Wolf-Rayet and O (WR+O) star binary system y2 Velorum. The AMBER instrument was used with the telescopes UT2, UT3, and UT4 on baselines ranging from 46m to 85m. It delivered spectrally dispersed visibilities, as well as differential and closure phases, with a resolution R = 1500 in the spectral band 1.95-2.17 micron. We interpret these data in the context of a binary system with unresolved components, neglecting in a first approximation the wind-wind collision zone flux contribution. We show that the AMBER observables result primarily from the contribution of the individual components of the WR+O binary system. We discuss several interpretations of the residuals, and speculate on the detection of an additional continuum component, originating from the free-free emission associated with the wind-wind collision zone (WWCZ), and contributing at most to the observed K-band flux at the 5% level. The expected absolute separation and position angle at the time of observations were 5.1±0.9mas and 66±15° respectively. However, we infer a separation of 3.62+0.11-0.30 mas and a position angle of 73+9-11°. Our analysis thus implies that the binary system lies at a distance of 368+38-13 pc, in agreement with recent spectrophotometric estimates, but significantly larger than the Hipparcos value of 258+41-31 pc

Near-Infrared interferometry of Eta Carinae with high spatial and spectral resolution using the VLTI and the AMBER instrument

We present the first NIR spectro-interferometry of the LBV Eta Carinae. The K band observations were performed with the AMBER instrument of the ESO Very Large Telescope Interferometer using three 8.2m Unit Telescopes with baselines from 42 to 89m. The aim of this work is to study the wavelength dependence of Eta Car's optically thick wind region with a high spatial resolution of 5 mas (11 AU) and high spectral resolution. The medium spectral resolution observations (R=1,500) were performed in the wavelength range around both the HeI 2.059 micron and the Br gamma 2.166 micron emission lines, the high spectral resolution observations (R=12,000) only in the Br gamma line region. In the K-band continuum, a diameter of 4.0 +/-0.2 mas (Gaussian FWHM, fit range 28-89m) was measured for Eta Car's optically thick wind region. If we fit Hillier et al. (2001) model visibilities to the observed AMBER visibilities, we obtain 50 % encircled-energy diameters of 4.2, 6.5 and 9.6mas in the 2.17 micron continuum, the HeI, and the Br gamma emission lines, respectively. In the continuum near the Br gamma line, an elongation along a position angle of 120+/-15 degrees was found, consistent with previous VLTI/VINCI measurements by van Boekel et al. (2003). We compare the measured visibilities with predictions of the radiative transfer model of Hillier et al. (2001), finding good agreement. Furthermore, we discuss the detectability of the hypothetical hot binary companion. For the interpretation of the non-zero differential and closure phases measured within the Br gamma line, we present a simple geometric model of an inclined, latitude-dependent wind zone. Our observations support theoretical models of anisotropic winds from fast-rotating, luminous hot stars with enhanced high-velocity mass loss near the polar regions.Comment: 22 pages, 14 figures, 2 tables; A&A in pres

A Multifactor Perspective on Volatility-Managed Portfolios

Moreira and Muir question the existence of a strong risk-return trade-off by showing that investors can improve performance by reducing exposure to risk factors when their volatility is high. However, Cederburg et al. show that these strategies fail out-of-sample, and Barroso and Detzel show they do not survive transaction costs. We propose a conditional multifactor portfolio that outperforms its unconditional counterpart even out-of-sample and net of costs. Moreover, we show that factor risk prices generally decrease with market volatility. Our results demonstrate that the breakdown of the risk-return trade-off is more puzzling than previously thought

Can competition increase profits in factor investing?

The increasing number of institutions exploiting factor-investing strategies raises concerns that competition may erode profits. We use a game-theoretic model to show that, while competition among investors exploiting a particular factor erodes profits because of the negative externality of their price impact on each other, competition to exploit other factors can increase profits from the first factor because of the positive externality from trading diversification (netting of trades across factors). We calibrate our model using the investment and profitability factors and find that competition to exploit the profitability factor leads to a 68% increase in the capacity and a 143% increase in the profit from the investment factor. Supplemental Material: The online appendix and data files are available at [https://doi.org/10.1287/mnsc.2022.02684](https://doi.org/10.1287/mnsc.2022.02684

Constraining the wind launching region in Herbig Ae stars: AMBER/VLTI spectroscopy of HD 104237

Astronomy and Astrophysics, 464, pp. 55-58, http://dx.doi.org./10.1051/0004-6361:20065719International audienc

Interferometric data reduction with AMBER/VLTI. Principle, estimators, and illustration

This is the author accepted manuscript. The final version is available from EDP Sciences via the DOI in this record.Aims. In this paper, we present an innovative data reduction method for single-mode interferometry. It has been specifically developed for the AMBER instrument, the three-beam combiner of the Very Large Telescope Interferometer, but it can be derived for any single-mode interferometer. Methods. The algorithm is based on a direct modelling of the fringes in the detector plane. As such, it requires a preliminary calibration of the instrument in order to obtain the calibration matrix that builds the linear relationship between the interferogram and the interferometric observable, which is the complex visibility. Once the calibration procedure has been performed, the signal processing appears to be a classical least-square determination of a linear inverse problem. From the estimated complex visibility, we derive the squared visibility, the closure phase, and the spectral differential phase. Results. The data reduction procedures have been gathered into the so-called amdlib software, now available for the community, and are presented in this paper. Furthermore, each step in this original algorithm is illustrated and discussed from various on-sky observations conducted with the VLTI, with a focus on the control of the data quality and the effective execution of the data reduction procedures. We point out the present limited performances of the instrument due to VLTI instrumental vibrations which are difficult to calibrate.The AMBER project4 was founded by the French Centre National de la Recherche Scientifique (CNRS), the Max Planck Institute für Radioastronomie (MPIfR) in Bonn, the Osservatorio Astrofisico di Arcetri (OAA) in Firenze, the French Region “Provence Alpes Côte D’Azur” and the European Southern Observatory (ESO). The CNRS funding has been made through the Institut National des Sciences de l’Univers (INSU) and its Programmes Nationaux (ASHRA, PNPS, PNP). The OAA co-authors acknowledge partial support from MIUR grants to the Arcetri Observatory: A LBT interferometric arm, and analysis of VLTI interferometric data and From Stars to Planets: accretion, disk evolution and planet formation and from INAF grants to the Arcetri Observatory Stellar and Extragalactic Astrophysics with Optical Interferometry. C. Gil work was supported in part by the Fundação para a Ciência e a Tecnologia through project POCTI/CTE-AST/55691/2004 from POCTI, with funds from the European program FEDER

Use of twitter data for waste minimisation in beef supply chain

Approximately one third of the food produced is discarded or lost, which accounts for 1.3 billion tons per annum. The waste is being generated throughout the supply chain viz. farmers, wholesalers/processors, logistics, retailers and consumers. The majority of waste occurs at the interface of retailers and consumers. Many global retailers are making efforts to extract intelligence from customer’s complaints left at retail store to backtrack their supply chain to mitigate the waste. However, majority of the customers don’t leave the complaints in the store because of various reasons like inconvenience, lack of time, distance, ignorance etc. In current digital world, consumers are active on social media and express their sentiments, thoughts, and opinions about a particular product freely. For example, on an average, 45,000 tweets are tweeted daily related to beef products to express their likes and dislikes. These tweets are large in volume, scattered and unstructured in nature. In this study, twitter data is utilised to develop waste minimization strategies by backtracking the supply chain. The execution process of proposed framework is demonstrated for beef supply chain. The proposed model is generic enough and can be applied to other domains as well

Genetic analysis of carcass traits of steers adjusted to age, weight, or fat thickness slaughter endpoints

Carcass measurements from 1,664 steers from the Germ Plasm Utilization project at U.S. Meat Animal Research Center were used to estimate heritabilities (h2) of, and genetic correlations (rg) among, 14 carcass traits adjusted to different endpoints (age, carcass weight, and fat thickness): HCW (kg), dressing percent (DP), adjusted fat thickness (AFT, cm), LM area (LMA, cm2), KPH (%), marbling score (MS), yield grade (YG), predicted percentage of retail product (PRP), retail product weight (RPW, kg), fat weight (FW, kg), bone weight (BNW, kg), actual percentage retail product (RPP), fat percent (FP), and bone percent. Fixed effects in the model included breed group, feed energy level, dam age, birth year, significant (P \u3c 0.05) interactions, covariate for days on feed, and the appropriate covariate for endpoint nested (except age) within breed group. Random effects in the model were additive genetic effect of animal and total maternal effect of dam. Parameters were estimated by REML. For some traits, estimates of h2 and phenotypic variance changed with different endpoints. Estimates of h2 for HCW,DP, RPW, and BNW at constant age, weight, or fat thickness were 0.27, —, and 0.41; 0.19, 0.26, and 0.18; 0.42, 0.32, and 0.50; and 0.43, 0.32, and 0.48, respectively. Magnitude and/or sign of rg also changed across endpoints for 54 of the 91 trait pairs. Estimates for HCW-LMA, AFTRPW, LMA-YG, LMA-PRP, LMA-FW, LMA-RPP, and LMA-FP at constant age, weight, or fat thickness were 0.32, —, and 0.51; −0.26, −0.77, and —; −0.71, −0.89, and −0.66; 0.68, 0.85, and 0.63; −0.16, −0.51, and 0.22; 0.47, 0.57, and 0.27; and −0.44, −0.43, and −0.18, respectively. Fat thickness was highly correlated with YG (0.86 and 0.85 for common age and weight) and PRP (−0.85 and −0.82 for common age and weight), indicating that selection for decreased fat thickness would improve YG and PRP. Carcass quality, however, would be affected negatively because of moderate rg (0.34 and 0.35 for common age and weight) between MS and AFT. Estimates of h2 and phenotypic variance indicate that enough genetic variation exists to change measures of carcass merit by direct selection. For some carcass traits, however, magnitude of change would depend on effect of endpoint on h2 and phenotypic variance. Correlated responses to selection would differ depending on endpoint

Does opening a milk bank in a neonatal unit change infant feeding practices? A before and after study

<p>Abstract</p> <p>Background</p> <p>Donor human milk banks are much more than simple centers for collection, storage, processing, and distribution of donor human milk, as they cover other aspects and represent a real opportunity to promote and support breastfeeding. The aim of our study is to assess the impact that opening a human milk bank has had on the proportion of infants receiving exclusive breast milk at discharge and other aspects related to feeding children with birth weight < or = 1500 g or < 32 weeks gestation admitted to the neonatal unit.</p> <p>Methods</p> <p>The study included babies of < or = 1500 g or < 32 weeks gestation. Fifty infants born from February to July in 2006, before the opening of the human milk bank, and 54 born from February to July in 2008, after its opening, met inclusive criteria. We collected data about days of hospital stay, hours of life when feeding was started, hours of life when full enteral feeding was attained, the type of milk received during admission, and the type of feeding on discharge.</p> <p>Results</p> <p>Children born in 2008 commenced feeding 16 hours earlier than those born in 2006 (p = 0.00). The proportion of infants receiving exclusive breast milk at discharge was 54% in 2006 and 56% in 2008 (p = 0.87). The number of days they received their mother's own milk during the first 28 days of life was 24.2 days in 2006, compared to 23.7 days in 2008 (p = 0.70). In 2006, 60% of infants received infant formula at least once in the first 28 days of life, compared to 37% in 2008 (p = 0.01).</p> <p>Conclusions</p> <p>The opening of a donor human milk bank in a neonatal unit did not reduce the proportion of infants exclusively fed with breast milk at discharge, but did reduce the proportion of infants that received infant formula during the first four weeks of life. Also, having donor human milk available enables commencement of enteral feeding earlier.</p

Unlocking the potential of self-healing and recyclable ionic elastomers for soft robotics applications

The authors acknowledge the State Research Agency of Spain (AEI) for the research contract (PID2019-107501RB-I00/AEI/10.13039/501100011033) and M. Hernandez Santana for the Ramon y Cajal contract (RYC-2017-22837). The authors acknowledge the Spanish National Research Council (CSIC) for the iLink+ contract (LINKA20325) and S. Utrera-Barrios for the predoctoral contract (PIE-202060E183). The authors acknowledge the Fonds Wetenschappelijk Onderzoek (FWO) for the personal grants of S. Terryn (1100416N) and J. Brancart (12E1123N). All authors also acknowledge Arlanxeo for kindly providing XNBR and the PTI+ SusPlast from CSIC for their support