975 research outputs found
Chemical Evolution of the Galactic Bulge as Derived from High-Resolution Infrared Spectroscopy of K and M Red Giants
We present chemical abundances in K and M red-giant members of the Galactic
bulge derived from high-resolution infrared spectra obtained with the Phoenix
spectrograph on Gemini-South. The elements studied are carbon, nitrogen,
oxygen, sodium, titanium, and iron. The evolution of C and N abundances in the
studied red-giants show that their oxygen abundances represent the original
values with which the stars were born. Oxygen is a superior element for probing
the timescale of bulge chemical enrichment via [O/Fe] versus [Fe/H]. The
[O/Fe]-[Fe/H] relation in the bulge does not follow the disk relation, with
[O/Fe] values falling above those of the disk. Titanium also behaves similarly
to oxygen with respect to iron. Based on these elevated values of [O/Fe] and
[Ti/Fe] extending to large Fe abundances, it is suggested that the bulge
underwent a more rapid chemical enrichment than the halo. In addition, there
are declines in both [O/Fe] and [Ti/Fe] in those bulge targets with the largest
Fe abundances, signifying another source affecting chemical evolution: perhaps
Supernovae of Type Ia. Sodium abundances increase dramatically in the bulge
with increasing metallicity, possibly reflecting the metallicity dependant
yields from supernovae of Type II, although Na contamination from H-burning in
intermediate mass stars cannot be ruled out.Comment: ApJ in pres
NASA's GeneLab Phase II: Federated Search and Data Discovery
GeneLab is currently being developed by NASA to accelerate 'open science' biomedical research in support of the human exploration of space and the improvement of life on earth. Phase I of the four-phase GeneLab Data Systems (GLDS) project emphasized capabilities for submission, curation, search, and retrieval of genomics, transcriptomics and proteomics ('omics') data from biomedical research of space environments. The focus of development of the GLDS for Phase II has been federated data search for and retrieval of these kinds of data across other open-access systems, so that users are able to conduct biological meta-investigations using data from a variety of sources. Such meta-investigations are key to corroborating findings from many kinds of assays and translating them into systems biology knowledge and, eventually, therapeutics
NASA's GeneLab: An Integrated Omics Data Commons and Workbench
GeneLab (http://genelab.nasa.gov) is a NASA initiative designed to accelerate open science biomedical research in support of the human exploration of space and the improvement of life on earth. The GeneLab Data Systems (GLDS) were developed to help investigators corroborate findings from omics (genomics, transcriptomics, proteomics, and metabolomics) assays and translate them into systems biology knowledge and, eventually, therapeutics, including countermeasures to support life in space. Phase I of the project (completed) emphasized developing key capabilities for submission, curation, storage, search, and retrieval of omics data from biomedical research in and of space environments. The development focus for Phase II (completed) was federated data search and retrieval of these kinds of data from other open-access repositories. The last phase of the project (in work) entails developing an omics analysis tool set, and a portal to visualize processed omics data, emphasizing integration with the data repository and search functions developed during the prior phases. The final product will be an open-access system where users can individually or collaboratively publish, search, integrate, analyze, and visualize omics data
NASA's GeneLab: An Integrated Omics Data Commons and Workbench
GeneLab (http://genelab.nasa.gov) is a NASA initiative designed to accelerate "open science" biomedical research in support of the human exploration of space and the improvement of life on earth. The GeneLab Data Systems (GLDS) were developed to help investigators corroborate findings from "omics" (genomics, transcriptomics, proteomics, and metabolomics) assays and translate them into systems biology knowledge and, eventually, therapeutics, including countermeasures to support life in space. Phase I of the project (completed) emphasized developing key capabilities for submission, curation, storage, search, and retrieval of omics data from biomedical research in and of space environments. The development focus for Phase II (completed) was federated data search and retrieval of these kinds of data from other open-access repositories. The last phase of the project (in work) entails developing an omics analysis tool set, and a portal to visualize processed omics data, emphasizing integration with the data repository and search functions developed during the prior phases. The final product will be an open-access system where users can individually or collaboratively publish, search, integrate, analyze, and visualize omics data
GeneLab: Omics Database for Spaceflight Experiments
Motivation - To curate and organize expensive spaceflight experiments conducted aboard space stations and maximize the scientific return of investment, while democratizing access to vast amounts of spaceflight related omics data generated from several model organisms. Results - The GeneLab Data System (GLDS) is an open access database containing fully coordinated and curated "omics" (genomics, transcriptomics, proteomics, metabolomics) data, detailed metadata and radiation dosimetry for a variety of model organisms. GLDS is supported by an integrated data system allowing federated search across several public bioinformatics repositories. Archived datasets can be queried using full-text search (e.g., keywords, Boolean and wildcards) and results can be sorted in multifactorial manner using assistive filters. GLDS also provides a collaborative platform built on GenomeSpace for sharing files and analyses with collaborators. It currently houses 172 datasets and supports standard guidelines for submission of datasets, MIAME (for microarray), ENCODE Consortium Guidelines (for RNA-seq) and MIAPE Guidelines (for proteomics)
High-field magnetization study of the S = 1/2 antiferromagnetic Heisenberg chain [PM Cu(NO)(HO)] with a field-induced gap
We present a high-field magnetization study of the = 1/2
antiferromagnetic Heisenberg chain [PM Cu(NO)(HO)]. For
this material, as result of the Dzyaloshinskii-Moriya interaction and a
staggered tensor, the ground state is characterized by an anisotropic
field-induced spin excitation gap and a staggered magnetization. Our data
reveal the qualitatively different behavior in the directions of maximum and
zero spin excitation gap. The data are analyzed via exact diagonalization of a
linear spin chain with up to 20 sites and on basis of the Bethe ansatz
equations, respectively. For both directions we find very good agreement
between experimental data and theoretical calculations. We extract the magnetic
coupling strength along the chain direction to 36.3(5) K and determine
the field dependence of the staggered magnetization component .Comment: 5 pages, 2 figures (minor changes to manuscript and figures
Abundances in bulge stars from high-resolution, near-IR spectra I. The CNO elements observed during the science verification of CRIRES at VLT
The formation and evolution of the Milky Way bulge is not yet well understood
and its classification is ambiguous. Constraints can, however, be obtained by
studying the abundances of key elements in bulge stars. The aim of this study
is to determine the chemical evolution of CNO, and a few other elements in
stars in the Galactic bulge, and to discuss the sensitivities of the derived
abundances from molecular lines. High-resolution, near-IR spectra in the H band
were recorded using VLT/CRIRES. Due to the high and variable visual extinction
in the line-of-sight towards the bulge, an analysis in the near-IR is
preferred. The CNO abundances can all be determined simultaneously from the
numerous molecular lines in the wavelength range observed. The three giant
stars in Baade's window presented here are the first bulge stars observed with
CRIRES. We have especially determined the CNO abundances, with uncertainties of
less than 0.20 dex, from CO, CN, and OH lines. Since the systematic
uncertainties in the derived CNO abundances due to uncertainties in the stellar
fundamental parameters, notably Teff, are significant, a detailed discussion of
the sensitivities of the derived abundances is included. We find good agreement
between near-IR and optically determined O, Ti, Fe, and Si abundances. Two of
our stars show a solar [C+N/Fe], suggesting that these giants have experienced
the first dredge-up and that the oxygen abundance should reflect the original
abundance of the giants. The two giants fit into the picture, in which there is
no significant difference between the O abundance in bulge and thick-disk
stars. Our determination of the S abundances is the first for bulge stars. The
high [S/Fe] values for all the stars indicate a high star-formation rate in an
early phase of the bulge evolution.Comment: Accepted by A&
Transiting exoplanets from the CoRoT space mission VIII. CoRoT-7b: the first Super-Earth with measured radius
We report the discovery of very shallow (DF/F = 3.4 10-4), periodic dips in
the light curve of an active V = 11.7 G9V star observed by the CoRoT satellite,
which we interpret as due to the presence of a transiting companion. We
describe the 3-colour CoRoT data and complementary ground-based observations
that support the planetary nature of the companion. Methods. We use CoRoT color
information, good angular resolution ground-based photometric observations in-
and out- of transit, adaptive optics imaging, near-infrared spectroscopy and
preliminary results from Radial Velocity measurements, to test the diluted
eclipsing binary scenarios. The parameters of the host star are derived from
optical spectra, which were then combined with the CoRoT light curve to derive
parameters of the companion. We examine carefully all conceivable cases of
false positives, and all tests performed support the planetary hypothesis.
Blends with separation larger than 0.40 arcsec or triple systems are almost
excluded with a 8 10-4 risk left. We conclude that, as far as we have been
exhaustive, we have discovered a planetary companion, named CoRoT-7b, for which
we derive a period of 0.853 59 +/- 3 10-5 day and a radius of Rp = 1.68 +/-
0.09 REarth. Analysis of preliminary radial velocity data yields an upper limit
of 21 MEarth for the companion mass, supporting the finding.
CoRoT-7b is very likely the first Super-Earth with a measured radius.Comment: Accepted in Astronomy and Astrophysics; typos and language
corrections; version sent to the printer w few upgrade
An integrated approach for increasing breeding efficiency in apple and peach in Europe
Despite the availability of whole genome sequences of apple and peach, there has been a considerable gap between genomics and breeding. To bridge the gap, the European Union funded the FruitBreedomics project (March 2011 to August 2015) involving 28 research institutes and private companies. Three complementary approaches were pursued: (i) tool and software development, (ii) deciphering genetic control of main horticultural traits taking into account allelic diversity and (iii) developing plant materials, tools and methodologies for breeders. Decisive breakthroughs were made including the making available of ready-to-go DNA diagnostic tests for Marker Assisted Breeding, development of new, dense SNP arrays in apple and peach, new phenotypic methods for some complex traits, software for gene/QTL discovery on breeding germplasm via Pedigree Based Analysis (PBA). This resulted in the discovery of highly predictive molecular markers for traits of horticultural interest via PBA and via Genome Wide Association Studies (GWAS) on several European genebank collections. FruitBreedomics also developed pre-breeding plant materials in which multiple sources of resistance were pyramided and software that can support breeders in their selection activities. Through FruitBreedomics, significant progresses were made in the field of apple and peach breeding, genetics, genomics and bioinformatics of which advantage will be made by breeders, germplasm curators and scientists. A major part of the data collected during the project has been stored in the FruitBreedomics database and has been made available to the public. This review covers the scientific discoveries made in this major endeavour, and perspective in the apple and peach breeding and genomics in Europe and beyond
Math and language gender stereotypes: Age and gender differences in implicit biases and explicit beliefs
In a cross-sectional study of youth ages 8-15, we examined implicit and explicit gender stereotypes regarding math and language abilities. We investigated how implicit and explicit stereotypes differ across age and gender groups and whether they are consistent with cultural stereotypes. Participants (N = 270) completed the Affect Misattribution Procedure (AMP) and a survey of explicit beliefs. Across all ages, boys showed neither math nor language implicit gender biases, whereas girls implicitly favored girls in both domains. These findings are counter to cultural stereotypes, which favor boys in math. On the explicit measure, both boys' and girls' primary tendency was to favor girls in math and language ability, with the exception of elementary school boys, who rated genders equally. We conclude that objective gender differences in academic success guide differences in children's explicit reports and implicit biases
- …
