888 research outputs found
The SOL Genomics Network Model: Making Community Annotation Work
The concept of community annotation is a growing discipline for achieving participation of the research community in depositing up‐to‐date knowledge in biological databases.
The Solanaceae Genomics Network ("SGN":http://sgn.cornell.edu/) is a clade‐oriented database (COD) focusing on plants of the nightshade family, including tomato, potato, pepper, eggplant, and tobacco, and is one of the bioinformatics nodes of the international tomato genome sequencing project. One of our major efforts is linking Solanaceae phenotype information with the underlying genes, and subsequently the genome. As part of this goal, SGN has introduced a database for locus names and descriptors, and a database for phenotypes of natural and induced variation. These two databases have web interfaces that allow cross references, associations with tomato gene models, and in‐house curated information of sequences, literature, ontologies, gene networks, and the Solanaceae biochemical pathways database ("SolCyc":http://solcyc.sgn.cornell.edu). All of our curator tools are open for online community annotation, through specially assigned “submitter” accounts. 

Currently the community database consists of 5,548 phenotyped accessions, and 5,739 curated loci, out of which more than 300 loci where contributed or annotated by 66 active submitters, creating a database that is truly community driven.
This framework is easily adaptable for other projects working on other taxa (for example see "http://chlamybase.org":http://chlamybase.org), greatly expanding the application of this user‐friendly online annotation system. Community participation is fostered by an active outreach program that includes contacting potential submitters via emails, at meetings and conferences, and by promoting featured user submitted annotations on the SGN homepage. The source code and database schema for all SGN functionalities are freely available. Please contact SGN at "sgn‐feedback[at]sgn.cornell.edu":mailto:[email protected] for more information
It's not easy being green: The evolution of galaxy colour in the EAGLE simulation
We examine the evolution of intrinsic u-r colours of galaxies in the EAGLE cosmological hydrodynamical simulations, which has been shown to reproduce the observed redshift z=0.1 colour-magnitude distribution well. The median u-r of star-forming ('blue cloud') galaxies reddens by 1 mag from z=2 to 0 at fixed stellar mass, as their specific star formation rates decrease with time. A red sequence starts to build-up around z=1, due to the quenching of low-mass satellite galaxies at the faint end, and due to the quenching of more massive central galaxies by their active galactic nuclei (AGN) at the bright end. This leaves a dearth of intermediate-mass red sequence galaxies at z=1, which is mostly filled in by z=0. We quantify the time-scales of colour transition due to satellite and AGN quenching, finding that most galaxies spend less than 2 Gyr in the 'green valley'. On examining the trajectories of galaxies in a colour-stellar mass diagram, we identify three characteristic tracks that galaxies follow (quiescently star-forming, quenching and rejuvenating galaxies) and quantify the fraction of galaxies that follow each track
Miscentring in Galaxy Clusters: Dark Matter to Brightest Cluster Galaxy Offsets in 10,000 SDSS Clusters
We characterise the typical offset between the Dark Matter (DM) projected
centre and the Brightest Cluster Galaxy (BCG) in 10,000 SDSS clusters. To place
constraints on the centre of DM, we use an automated strong-lensing analysis,
mass-modelling technique which is based on the well-tested assumption that
light traces mass. The cluster galaxies are modelled with a steep power-law,
and the DM component is obtained by smoothing the galaxy distribution fitting a
low-order 2D polynomial (via spline interpolation), while probing a whole range
of polynomial degrees and galaxy power laws. We find that the offsets between
the BCG and the peak of the smoothed light map representing the DM, \Delta, are
distributed equally around zero with no preferred direction, and are well
described by a log-normal distribution with <log_{10}(\Delta [h^{-1}
Mpc])>=-1.895^{+0.003}_{-0.004}, and \sigma=0.501\pm0.004 (95% confidence
levels), or =0.564\pm0.005, and
\sigma=0.475\pm0.007. Some of the offsets originate in prior misidentifications
of the BCG or other bright cluster members by the cluster finding algorithm,
whose level we make an additional effort to assess, finding that ~10% of the
clusters in the probed catalogue are likely to be misidentified, contributing
to higher-end offsets in general agreement with previous studies. Our results
constitute the first statistically-significant high-resolution distributions of
DM-to-BCG offsets obtained in an observational analysis, and importantly show
that there exists such a typical non-zero offset in the probed catalogue. The
offsets show a weak positive correlation with redshift, so that higher
separations are generally found for higher-z clusters in agreement with the
hierarchical growth of structure, which in turn could help characterise the
merger, relaxation and evolution history of clusters, in future studies.
[ABRIDGED]Comment: 15 pages, 11 figures; MNRAS in press; V3 includes minor text update
Ensemble Properties of Comets in the Sloan Digital Sky Survey
We present the ensemble properties of 31 comets (27 resolved and 4
unresolved) observed by the Sloan Digital Sky Survey (SDSS). This sample of
comets represents about 1 comet per 10 million SDSS photometric objects.
Five-band (u,g,r,i,z) photometry is used to determine the comets' colors,
sizes, surface brightness profiles, and rates of dust production in terms of
the Af{\rho} formalism. We find that the cumulative luminosity function for the
Jupiter Family Comets in our sample is well fit by a power law of the form N(<
H) \propto 10(0.49\pm0.05)H for H < 18, with evidence of a much shallower fit
N(< H) \propto 10(0.19\pm0.03)H for the faint (14.5 < H < 18) comets. The
resolved comets show an extremely narrow distribution of colors (0.57 \pm 0.05
in g - r for example), which are statistically indistinguishable from that of
the Jupiter Trojans. Further, there is no evidence of correlation between color
and physical, dynamical, or observational parameters for the observed comets.Comment: 19 pages, 8 tables, 11 figures, to appear in Icaru
The Extreme Hosts of Extreme Supernovae
We use GALEX ultraviolet (UV) and optical integrated photometry of the hosts
of seventeen luminous supernovae (LSNe, having peak M_V < -21) and compare them
to a sample of 26,000 galaxies from a cross-match between the SDSS DR4 spectral
catalog and GALEX interim release 1.1. We place the LSNe hosts on the galaxy
NUV-r versus M_r color magnitude diagram (CMD) with the larger sample to
illustrate how extreme they are. The LSN hosts appear to favor low-density
regions of the galaxy CMD falling on the blue edge of the blue cloud toward the
low luminosity end. From the UV-optical photometry, we estimate the star
formation history of the LSN hosts. The hosts have moderately low star
formation rates (SFRs) and low stellar masses (M_*) resulting in high specific
star formation rates (sSFR). Compared with the larger sample, the LSN hosts
occupy low-density regions of a diagram plotting sSFR versus M_* in the area
having higher sSFR and lower M_*. This preference for low M_*, high sSFR hosts
implies the LSNe are produced by an effect having to do with their local
environment. The correlation of mass with metallicity suggests that perhaps
wind-driven mass loss is the factor that prevents LSNe from arising in
higher-mass, higher-metallicity hosts. The massive progenitors of the LSNe
(>100 M_sun), by appearing in low-SFR hosts, are potential tests for theories
of the initial mass function that limit the maximum mass of a star based on the
SFR.Comment: 8 pages, 3 figures, 2 tables, accepted to ApJ, amended references and
updated SN designation
Direct Evidence for Termination of Obscured Star Formation by Radiatively Driven Outflows in Reddened QSOs
We present optical to far-infrared photometry of 31 reddened QSOs that show
evidence for radiatively driven outflows originating from AGN in their
rest-frame UV spectra. We use these data to study the relationships between the
AGN-driven outflows, and the AGN and starburst infrared luminosities. We find
that FeLoBAL QSOs are invariably IR-luminous, with IR luminosities exceeding
10^{12} Solar luminosities in all cases. The AGN supplies 76% of the total IR
emission, on average, but with a range from 20% to 100%. We find no evidence
that the absolute luminosity of obscured star formation is affected by the
AGN-driven outflows. Conversely, we find an anticorrelation between the
strength of AGN-driven outflows, as measured from the range of outflow
velocities over which absorption exceeds a minimal threshold, and the
contribution from star formation to the total IR luminosity, with a much higher
chance of seeing a starburst contribution in excess of 25% in systems with weak
outflows than in systems with strong outflows. Moreover, we find no convincing
evidence that this effect is driven by the IR luminosity of the AGN. We
conclude that radiatively driven outflows from AGN can have a dramatic,
negative impact on luminous star formation in their host galaxies. We find that
such outflows act to curtail star formation such that star formation
contributes less than ~25% of the total IR luminosity. We also propose that the
degree to which termination of star formation takes place is not deducible from
the IR luminosity of the AGN.Comment: Accepted for publication in Ap
The UV-Optical Color Dependence of Galaxy Clustering in the Local Universe
We measure the UV-optical color dependence of galaxy clustering in the local
universe. Using the clean separation of the red and blue sequences made
possible by the NUV - r color-magnitude diagram, we segregate the galaxies into
red, blue and intermediate "green" classes. We explore the clustering as a
function of this segregation by removing the dependence on luminosity and by
excluding edge-on galaxies as a means of a non-model dependent veto of highly
extincted galaxies. We find that \xi (r_p, \pi) for both red and green galaxies
shows strong redshift space distortion on small scales -- the "finger-of-God"
effect, with green galaxies having a lower amplitude than is seen for the red
sequence, and the blue sequence showing almost no distortion. On large scales,
\xi (r_p, \pi) for all three samples show the effect of large-scale streaming
from coherent infall. On scales 1 Mpc/h < r_p < 10 Mpc/h, the projected
auto-correlation function w_p(r_p) for red and green galaxies fits a power-law
with slope \gamma ~ 1.93 and amplitude r_0 ~ 7.5 and 5.3, compared with \gamma
~ 1.75 and r_0 ~ 3.9 Mpc/h for blue sequence galaxies. Compared to the
clustering of a fiducial L* galaxy, the red, green, and blue have a relative
bias of 1.5, 1.1, and 0.9 respectively. The w_p(r_p) for blue galaxies display
an increase in convexity at ~ 1 Mpc/h, with an excess of large scale
clustering. Our results suggest that the majority of blue galaxies are likely
central galaxies in less massive halos, while red and green galaxies have
larger satellite fractions, and preferentially reside in virialized structures.
If blue sequence galaxies migrate to the red sequence via processes like
mergers or quenching that take them through the green valley, such a
transformation may be accompanied by a change in environment in addition to any
change in luminosity and color.Comment: accepted by MNRA
The SDSS Discovery of a Strongly Lensed Post-Starburst Galaxy at z=0.766
We present the first result of a survey for strong galaxy-galaxy lenses in
Sloan Digital Sky Survey (SDSS) images. SDSS J082728.70+223256.4 was selected
as a lensing candidate using selection criteria based on the color and
positions of objects in the SDSS photometric catalog. Follow-up imaging and
spectroscopy showed this object to be a lensing system. The lensing galaxy is
an elliptical at z = 0.349 in a galaxy cluster. The lensed galaxy has the
spectrum of a post-starburst galaxy at z = 0.766. The lensing galaxy has an
estimated mass of and the corresponding
mass to light ratio in the B-band is inside 1.1
effective radii of the lensing galaxy. Our study shows how catalogs drawn from
multi-band surveys can be used to find strong galaxy-galaxy lenses having
multiple lens images. Our strong lensing candidate selection based on
photometry-only catalogs will be useful in future multi-band imaging surveys
such as SNAP and LSST.Comment: Accepted for publication in A
Social science perspectives on drivers of and responses to global
This article provides a review of recent anthropological, archeological, geographical, and sociological research on anthropogenic drivers of climate change, with a particular focus on drivers of carbon emissions, mitigation and adaptation. The four disciplines emphasize cultural, economic, geographic, historical, political, and social‐structural factors to be important drivers of and responses to climate change. Each of these disciplines has unique perspectives and makes noteworthy contributions to our shared understanding of anthropogenic drivers, but they also complement one another and contribute to integrated, multidisciplinary frameworks. The article begins with discussions of research on temporal dimensions of human drivers of carbon emissions, highlighting interactions between long‐term and near‐term drivers. Next, descriptions of the disciplines\u27 contributions to the understanding of mitigation and adaptation are provided. It concludes with a summary of key lessons offered by the four disciplines as well as suggestions for future research
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