Red-giant stars in eccentric binaries

The unparalleled photometric data obtained by NASA’s Kepler Space Telescope has led to improved understanding of red-giant stars and binary stars. We discuss the characterization of known eccentric system, containing a solar-like oscillating red-giant primary component. We also report several new binary systems that are candidates for hosting an oscillating companion. A powerful approach to study binary stars is to combine asteroseimic techniques with light curve fitting. Seismology allows us to deduce the properties of red giants. In addition, by modeling the ellipsoidal modulations we can constrain the parameters of the binary system. An valuable independent source are ground-bases, high-resolution spectrographs

Core Concepts for Future Cataloguers

The Linked Open Bibliographic Data project at UCL is developing an Open Educational Resource to enable the teaching and learning of BIBFRAME, the new RDF-based framework designed to take over from MARC. A new bibliographic dataset based on BIBFRAME, which will be linked with other online datasets, has been created for that purpose. The learning resource, which will be publicly available under an open licence on completion, will allow learners to access, explore, query and update the dataset through an intuitive interface built on top of the SPARQL query language. This masterclass shares experience in converting MARC records to BIBFRAME using the Library of Congress’s conversion tools [http://bibframe.org/tools/]. More fundamentally, it provides examples of how our model for Cataloguing is changing from linking record:record to field:field. Using publication data from library academics, we’ll look at what’s new in BIBFRAME and why this matters. Finally, we’ll discuss the extent to which those responsible for inputting data may (or may not) need to get to grips with the new data structure and ways that the enthusiastic can keep up

Work in Progress: the Linked Open Bibliographic Data Project

Reports on the first stage of a project to create an Open Educational Resource for the teaching of new cataloguing format BIBFRAME. Collaborative creation of knowledge with students is a key aspect of the project, and this is discussed in the context of UCL's Connected Curriculum

emiT: an apparatus to test time reversal invariance in polarized neutron decay

We describe an apparatus used to measure the triple-correlation term (\D \hat{\sigma}_n\cdot p_e\times p_\nu) in the beta-decay of polarized neutrons. The \D-coefficient is sensitive to possible violations of time reversal invariance. The detector has an octagonal symmetry that optimizes electron-proton coincidence rates and reduces systematic effects. A beam of longitudinally polarized cold neutrons passes through the detector chamber, where a small fraction beta-decay. The final-state protons are accelerated and focused onto arrays of cooled semiconductor diodes, while the coincident electrons are detected using panels of plastic scintillator. Details regarding the design and performance of the proton detectors, beta detectors and the electronics used in the data collection system are presented. The neutron beam characteristics, the spin-transport magnetic fields, and polarization measurements are also described.Comment: 15 pages, 13 figure

A primordial star in the heart of the Lion

Context: The discovery and chemical analysis of extremely metal-poor stars permit a better understanding of the star formation of the first generation of stars and of the Universe emerging from the Big Bang. aims: We report the study of a primordial star situated in the centre of the constellation Leo (SDSS J102915+172027). method: The star, selected from the low resolution-spectrum of the Sloan Digital Sky Survey, was observed at intermediate (with X-Shooter at VLT) and at high spectral resolution (with UVES at VLT). The stellar parameters were derived from the photometry. The standard spectroscopic analysis based on 1D ATLAS models was completed by applying 3D and non-LTE corrections. results: An iron abundance of [Fe/H]=--4.89 makes SDSS J102915+172927 one of the lowest [Fe/H] stars known. However, the absence of measurable C and N enhancements indicates that it has the lowest metallicity, Z<= 7.40x10^{-7} (metal-mass fraction), ever detected. No oxygen measurement was possible. conclusions: The discovery of SDSS J102915+172927 highlights that low-mass star formation occurred at metallicities lower than previously assumed. Even lower metallicity stars may yet be discovered, with a chemical composition closer to the composition of the primordial gas and of the first supernovae.Comment: To be published in A&

Memory consolidation in the cerebellar cortex

Several forms of learning, including classical conditioning of the eyeblink, depend upon the cerebellum. In examining mechanisms of eyeblink conditioning in rabbits, reversible inactivations of the control circuitry have begun to dissociate aspects of cerebellar cortical and nuclear function in memory consolidation. It was previously shown that post-training cerebellar cortical, but not nuclear, inactivations with the GABA(A) agonist muscimol prevented consolidation but these findings left open the question as to how final memory storage was partitioned across cortical and nuclear levels. Memory consolidation might be essentially cortical and directly disturbed by actions of the muscimol, or it might be nuclear, and sensitive to the raised excitability of the nuclear neurons following the loss of cortical inhibition. To resolve this question, we simultaneously inactivated cerebellar cortical lobule HVI and the anterior interpositus nucleus of rabbits during the post-training period, so protecting the nuclei from disinhibitory effects of cortical inactivation. Consolidation was impaired by these simultaneous inactivations. Because direct application of muscimol to the nuclei alone has no impact upon consolidation, we can conclude that post-training, consolidation processes and memory storage for eyeblink conditioning have critical cerebellar cortical components. The findings are consistent with a recent model that suggests the distribution of learning-related plasticity across cortical and nuclear levels is task-dependent. There can be transfer to nuclear or brainstem levels for control of high-frequency responses but learning with lower frequency response components, such as in eyeblink conditioning, remains mainly dependent upon cortical memory storage

The Transit Ingress and the Tilted Orbit of the Extraordinarily Eccentric Exoplanet HD 80606b

We present the results of a transcontinental campaign to observe the 2009 June 5 transit of the exoplanet HD 80606b. We report the first detection of the transit ingress, revealing the transit duration to be 11.64 +/- 0.25 hr and allowing more robust determinations of the system parameters. Keck spectra obtained at midtransit exhibit an anomalous blueshift, giving definitive evidence that the stellar spin axis and planetary orbital axis are misaligned. The Keck data show that the projected spin-orbit angle is between 32-87 deg with 68.3% confidence and between 14-142 deg with 99.73% confidence. Thus the orbit of this planet is not only highly eccentric (e=0.93), but is also tilted away from the equatorial plane of its parent star. A large tilt had been predicted, based on the idea that the planet's eccentric orbit was caused by the Kozai mechanism. Independently of the theory, it is noteworthy that all 3 exoplanetary systems with known spin-orbit misalignments have massive planets on eccentric orbits, suggesting that those systems migrate differently than lower-mass planets on circular orbits.Comment: ApJ, in press [13 pg

Portugal nutritional transition during the last 4 decades: 1974–2011

Objective: To examine trends in food availability for Portugal during the last 4 decades (1974–2011) and analyze such changes in accordance with the nutritional transition theory.Methods: Food balance sheets from Portugal from 1974 to 2011 were analyzed for potential trends by linear regression to study the availability of protein, fat, carbohydrate, ethanol, and total energy and the availability of the following food groups: (i) cereals and tubers; (ii) vegetables; (iii) fruit; (iv) milk; (v) meat, fish, and eggs; (vi) fat; (vii) pulses; (viii) alcoholic beverages; and (ix) sugar and sweeteners. A comparison regarding protein, fat, and carbohydrate availability and WHO recommendation was also performed.Results: The data suggest that in Portugal food availability and consumption have changed throughout the analyzed period. The national availability of most food groups increased considerably, which also resulted in an increase in daily energy. The consumption of cereals and tubers, pulses, and alcohol diminished during this time. Energy availability increased by 406 kcal/person/day, a result from an increase in protein and fat. Protein availability was in accordance with WHO recommendations during the 4 decades analyzed, whereas carbohydrate have always been below the recommended level and fat has been above the recommended level since the second decade (1984).Conclusion: Portugal has crossed into a nutritional transition over the last 4 decades, revealing characteristics of a pattern of degenerative diseases. The country may experience a new nutritional transition that would involve positive changes of behavior, as observed in other developed countries, driven by community multisectorial strategies.info:eu-repo/semantics/publishedVersio

Differences in Enzymatic Properties of the Saccharomyces kudriavzevii and Saccharomyces uvarum Alcohol Acetyltransferases and Their Impact on Aroma-Active Compounds Production

Higher alcohols and acetate esters belong to the most important yeast secondary metabolites that significantly contribute to the overall flavor and aroma profile of fermented products. In Saccharomyces cerevisiae, esterification of higher alcohols is catalyzed mainly by the alcohol acetyltransferases encoded by genes ATF1 and ATF2. Previous investigation has shown other Saccharomyces species, e.g., S. kudriavzevii and S. uvarum, to vary in aroma-active higher alcohols and acetate esters formation when compared to S. cerevisiae. Here, we aimed to analyze the enzymes encoded by the ATF1 and ATF2 genes from S. kudriavzevii (SkATF1, SkATF2) and S. uvarum (SuATF1, SuATF2). The heterologous expression of the individual ATF1 and ATF2 genes in a host S. cerevisiae resulted in the enhanced production of several higher alcohols and acetate esters. Particularly, an increase of 2-phenylethyl acetate production by the strains that harbored ATF1 and ATF2 genes from S. kudriavzevii and S. uvarum was observed. When grown with individual amino acids as the nitrogen source, the strain that harbored SkATF1 showed particularly high 2-phenylethyl acetate production and the strains with introduced SkATF2 or SuATF2 revealed increased production of isobutyl acetate, isoamyl acetate, and 2-phenylethyl acetate compared to the reference strains with endogenous ATF genes. The alcohol acetyltransferase activities of the individual Atf1 and Atf2 enzymes measured in the cell extracts of the S. cerevisiae atf1 atf2 iah1 triple-null strain were detected for all the measured substrates. This indicated that S. kudriavzevii and S. uvarum Atf enzymes had broad range substrate specificity as S. cerevisiae Atf enzymes. Individual Atf1 enzymes exhibited markedly different kinetic properties since SkAtf1p showed c. twofold higher and SuAtf1p c. threefold higher Km for isoamyl alcohol than ScAtf1p. Together these results indicated that the differences found among the three Saccharomyces species during the aroma-active acetate ester formation may be due, to some extent, to the distinct properties of Atf enzymes.This work has been supported by the European Commission FP7: Marie Curie Initial Network CORNUCOPIA no. 264717 and by CICYT grant (ref. AGL2015-67504-C3-1-R) from Ministerio de Economía y Competitividad.Peer reviewedPeer Reviewe

The Ultraviolet Spectral Energy Distributions of Quiescent Black Holes and Neutron Stars

We present HST/ACS ultraviolet photometry of three quiescent black hole X-ray transients: X-ray Nova Muscae 1991 (GU Mus), GRO J0422+32 (V518 Per), and X-ray Nova Vel 1993 (MM Vel), and one neutron star system, Aql X-1. These are the first quiescent UV detections of these objects. All are detected at a much higher level than expected from their companion stars alone and are significant detections of the accretion flow. Three of the four UV excesses can be characterized by a black body of temperature 5000-13,000K, hotter than expected for the quiescent outer disk. A good fit could not be found for MM Vel. The source of the black-body-like emission is most likely a heated region of the inner disk. Contrary to initial indications from spectroscopy there does not appear to be a systematic difference in the UV luminosity or spectral shape between black holes and neutron star systems. However combining our new data with earlier spectroscopy and published X-ray luminosities there is a significant difference in the X-ray to UV flux ratios with the neutron stars exhibiting Lx/Luv about 10x higher than the black hole systems. Since both bandpasses are expected to be dominated by accretion light this suggests the difference in X-ray luminosities cannot simply reflect differences in quiescent accretion rates and so is a more robust discriminator between the black hole and neutron star populations than the comparison of X-ray luminosities alone.Comment: Accepted for publication in the Astrophysical Journa