62 research outputs found
SNLS3: Constraints on Dark Energy Combining the Supernova Legacy Survey Three Year Data with Other Probes
We present observational constraints on the nature of dark energy using the
Supernova Legacy Survey three year sample (SNLS3) of Guy et al. (2010) and
Conley et al. (2011). We use the 472 SNe Ia in this sample, accounting for
recently discovered correlations between SN Ia luminosity and host galaxy
properties, and include the effects of all identified systematic uncertainties
directly in the cosmological fits. Combining the SNLS3 data with the full WMAP7
power spectrum, the Sloan Digital Sky Survey luminous red galaxy power
spectrum, and a prior on the Hubble constant H0 from SHOES, in a flat universe
we find omega_m=0.269+/-0.015 and w=-1.061+0.069-0.068 -- a 6.5% measure of the
dark energy equation-of-state parameter w. The statistical and systematic
uncertainties are approximately equal, with the systematic uncertainties
dominated by the photometric calibration of the SN Ia fluxes -- without these
calibration effects, systematics contribute only a ~2% error in w. When
relaxing the assumption of flatness, we find omega_m=0.271+/-0.015,
omega_k=-0.002+/-0.006, and w=-1.069+0.091-0.092. Parameterizing the time
evolution of w as w(a)=w_0+w_a(1-a), gives w_0=-0.905+/-0.196,
w_a=-0.984+1.094-1.097 in a flat universe. All of our results are consistent
with a flat, w=-1 universe. The size of the SNLS3 sample allows various tests
to be performed with the SNe segregated according to their light curve and host
galaxy properties. We find that the cosmological constraints derived from these
different sub-samples are consistent. There is evidence that the coefficient,
beta, relating SN Ia luminosity and color, varies with host parameters at
>4sigma significance (in addition to the known SN luminosity--host relation);
however this has only a small effect on the cosmological results and is
currently a sub-dominant systematic.Comment: Accepted for publication in ApJ. Data available from
https://tspace.library.utoronto.ca/snl
The Girgentana Goat Breed: A Zootechnical Overview on Genetics, Nutrition and Dairy Production Aspects
In recent years, there has been a great interest in recovering and preserving
local livestock breeds. An interesting situation is represented by the
Girgentana goat, an ancient local breed reared in Sicily. Over recent years, this
breed has become almost extinct, in part as a consequence of the marked decrease
in fresh goat milk consumption. On the basis of these considerations, several studies
on its genetic structure and management aspects have been conducted in order to
protect the Girgentana goat from the risk of extinction and recover its genetic and
economic value. In this context, information on genetics, nutrition and dairy production
aspects may have a crucial role in the improvement and management of the
breed. Thus, this chapter describes some points of these applications through recent
investigations on this goat breed
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
Co-expression network of neural-differentiation genes shows specific pattern in schizophrenia
Background: Schizophrenia is a neurodevelopmental disorder with genetic and environmental factors contributing to its pathogenesis, although the mechanism is unknown due to the difficulties in accessing diseased tissue during human neurodevelopment. The aim of this study was to find neuronal differentiation genes disrupted in schizophrenia and to evaluate those genes in post-mortem brain tissues from schizophrenia cases and controls.
Methods: We analyzed differentially expressed genes (DEG), copy number variation (CNV) and differential methylation in human induced pluripotent stem cells (hiPSC) derived from fibroblasts from one control and one schizophrenia patient and further differentiated into neuron (NPC). Expression of the DEG were analyzed with microarrays of post-mortem brain tissue (frontal cortex) cohort of 29 schizophrenia cases and 30 controls. A Weighted Gene Co-expression Network Analysis (WGCNA) using the DEG was used to detect clusters of co-expressed genes that werenon-conserved between adult cases and controls brain samples.
Results: We identified methylation alterations potentially involved with neuronal differentiation in schizophrenia, which displayed an over-representation of genes related to chromatin remodeling complex (adjP = 0.04). We found 228 DEG associated with neuronal differentiation. These genes were involved with metabolic processes, signal transduction, nervous system development, regulation of neurogenesis and neuronal differentiation. Between adult brain samples from cases and controls there were 233 DEG, with only four genes overlapping with the 228 DEG, probably because we compared single cell to tissue bulks and more importantly, the cells were at different stages of development. The comparison of the co-expressed network of the 228 genes in adult brain samples between cases and controls revealed a less conserved module enriched for genes associated with oxidative stress and negative regulation of cell differentiation.
Conclusion: This study supports the relevance of using cellular approaches to dissect molecular aspects of neurogenesis with impact in the schizophrenic brain. We showed that, although generated by different approaches, both sets of DEG associated to schizophrenia were involved with neocortical development. The results add to the hypothesis that critical metabolic changes may be occurring during early neurodevelopment influencing faulty development of the brain and potentially contributing to further vulnerability to the illness.We thank the patients, doctors and nurses involved with sample collection and the Stanley Medical Research Institute. This research was supported by either Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq #17/2008) and Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro (FAPERJ). MM (CNPq 304429/2014-7), ACT (FAPESP 2014/00041-1), LL (CAPES 10682/13-9) HV (CAPES) and BP (PPSUS 137270) were supported by their fellowshipsinfo:eu-repo/semantics/publishedVersio
PESSTO: survey description and products from the first data release by the Public ESO Spectroscopic Survey of Transient Objects
Context. The Public European Southern Observatory Spectroscopic Survey of Transient Objects (PESSTO) began as a public spectroscopic survey in April 2012. PESSTO classifies transients from publicly available sources and wide-field surveys, and selects science targets for detailed spectroscopic and photometric follow-up. PESSTO runs for nine months of the year, January – April and August – December inclusive, and typically has allocations of 10 nights per month.
Aims. We describe the data reduction strategy and data products that are publicly available through the ESO archive as the Spectroscopic Survey data release 1 (SSDR1).
Methods. PESSTO uses the New Technology Telescope with the instruments EFOSC2 and SOFI to provide optical and NIR spectroscopy and imaging. We target supernovae and optical transients brighter than 20.5m for classification. Science targets are selected for follow-up based on the PESSTO science goal of extending knowledge of the extremes of the supernova population. We use standard EFOSC2 set-ups providing spectra with resolutions of 13–18 Å between 3345−9995 Å. A subset of the brighter science targets are selected for SOFI spectroscopy with the blue and red grisms (0.935−2.53 μm and resolutions 23−33 Å) and imaging with broadband JHKs filters.
Results. This first data release (SSDR1) contains flux calibrated spectra from the first year (April 2012–2013). A total of 221 confirmed supernovae were classified, and we released calibrated optical spectra and classifications publicly within 24 h of the data being taken (via WISeREP). The data in SSDR1 replace those released spectra. They have more reliable and quantifiable flux calibrations, correction for telluric absorption, and are made available in standard ESO Phase 3 formats. We estimate the absolute accuracy of the flux calibrations for EFOSC2 across the whole survey in SSDR1 to be typically ~15%, although a number of spectra will have less reliable absolute flux calibration because of weather and slit losses. Acquisition images for each spectrum are available which, in principle, can allow the user to refine the absolute flux calibration. The standard NIR reduction process does not produce high accuracy absolute spectrophotometry but synthetic photometry with accompanying JHKs imaging can improve this. Whenever possible, reduced SOFI images are provided to allow this.
Conclusions. Future data releases will focus on improving the automated flux calibration of the data products. The rapid turnaround between discovery and classification and access to reliable pipeline processed data products has allowed early science papers in the first few months of the survey
Insulin gene VNTR genotype associates with frequency and phenotype of the autoimmune response to proinsulin
Immune responses to autoantigens are in part controlled by deletion of autoreactive cells through genetically regulated selection mechanisms. We have directly analyzed peripheral CD4+ proinsulin (PI) 76–90 (SLQPLALEGSLQKRG)-specific T cells using soluble fluorescent major histocompatibility complex class II tetramers. Subjects with type I diabetes and healthy controls with high levels of peripheral proinsulin-specific T cells were characterized by the presence of a disease-susceptible polymorphism in the insulin variable number of tandem repeats (INS-VNTR) gene. Conversely, subjects with a ‘protective' polymorphism in the INS-VNTR gene had nearly undetectable levels of proinsulin tetramer-positive T cells. These results strongly imply a direct relationship between genetic control of autoantigen expression and peripheral autoreactivity, in which proinsulin genotype restricts the quantity and quality of the potential T-cell response. Using a modified tetramer to isolate low-avidity proinsulin-specific T cells from subjects with the susceptible genotype, transcript arrays identified several induced pro-apoptotic genes in the control, but not diabetic subjects, likely representing a second peripheral mechanism for maintenance of tolerance to self antigens
Euclid Preparation. XXXVII. Galaxy colour selections with Euclid and ground photometry for cluster weak-lensing analyses
We derived galaxy colour selections from Euclid and ground-based photometry,
aiming to accurately define background galaxy samples in cluster weak-lensing
analyses. Given any set of photometric bands, we developed a method for the
calibration of optimal galaxy colour selections that maximises the selection
completeness, given a threshold on purity. We calibrated galaxy selections
using simulated ground-based and Euclid
photometry. Both selections produce a purity higher than 97%. The
selection completeness ranges from 30% to 84% in the lens redshift range
. With the full
selection, the completeness improves by up to percentage points, and the
range extends up to . The calibrated colour
selections are stable to changes in the sample limiting magnitudes and
redshift, and the selection based on bands provides excellent results on
real external datasets. The selection is also purer at high redshift and
more complete at low redshift compared to colour selections found in the
literature. We find excellent agreement in terms of purity and completeness
between the analysis of an independent, simulated Euclid galaxy catalogue and
our calibration sample, except for galaxies at high redshifts, for which we
obtain up to 50 percent points higher completeness. The combination of colour
and photo- selections applied to simulated Euclid data yields up to 95%
completeness, while the purity decreases down to 92% at high . We
show that the calibrated colour selections provide robust results even when
observations from a single band are missing from the ground-based data.
Finally, we show that colour selections do not disrupt the shear calibration
for stage III surveys.Comment: 20 pages, 13 figures. Published by A&
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