1,886 research outputs found
Unveiling the nature of the unidentified gamma-ray sources IV: the catalog of potential X-ray counterparts
A significant fraction ( %) of the high-energy gamma-ray sources
listed in the second LAT (2FGL) catalog are still of unknown
origin, being not yet associated with counterparts at lower energies. In order
to investigate the nature of these enigmatic sources, we present here an
extensive search of X-ray sources lying in the positional uncertainty region of
a selected sample of these Unidentified Gamma-ray Sources (UGSs) that makes use
of all available observations performed by the X-ray Telescope
before March 31, 2013, available for 205 UGSs. To detect the fainter sources,
we merged all the observations covering the LAT positional
uncertainty region at 95 % level of confidence of each UGSs. This yields a
catalog of 357 X-ray sources, finding {candidate} X-ray counterparts for % of the selected sample. In particular, 25 % of the UGSs feature a single
X-ray source within their positional uncertainty region while 45 % have
multiple X-ray sources. For each X-ray source we also looked in the
corresponding UVOT merged images for optical and ultraviolet
counterparts, also performing source photometry. We found ultraviolet-optical
correspondences for % of the X-ray sources. We searched several major
radio, infrared, optical and ultraviolet surveys for possible counterparts
within the positional error of the sources in the X-ray catalog to obtain
additional information on their nature. Applying the kernel density estimator
technique to infrared colors of WISE counterparts of our X-ray sources we
select 6 -ray blazar candidates. In addition, comparing our results
with previous analyses, we select 11 additional -ray blazar candidates.Comment: 19 pages, 10 figures, 6 tables. Accepted for publication on Ap
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Distributed analysis with CRAB: The client-server architecture evolution and commissioning
CRAB (CMS Remote Analysis Builder) is the tool used by CMS to enable running physics analysis in a transparent manner over data distributed across many sites. It abstracts out the interaction with the underlying batch farms, grid infrastructure and CMS workload management tools, such that it is easily usable by non-experts. CRAB can be used as a direct interface to the computing system or can delegate the user task to a server. Major efforts have been dedicated to the client-server system development, allowing the user to deal only with a simple and intuitive interface and to delegate all the work to a server. The server takes care of handling the users jobs during the whole lifetime of the users task. In particular, it takes care of the data and resources discovery, process tracking and output handling. It also provides services such as automatic resubmission in case of failures, notification to the user of the task status, and automatic blacklisting of sites showing evident problems beyond what is provided by existing grid infrastructure. The CRAB Server architecture and its deployment will be presented, as well as the current status and future development. In addition the experience in using the system for initial detector commissioning activities and data analysis will be summarized
Detection of MicroRNA processing intermediates through RNA ligation approaches
MicroRNAs (miRNA) are small RNAs of 20–22 nt that regulate diverse biological pathways through the modulation of gene expression. miRNAs recognize target RNAs by base complementarity and guide them to degradation or translational arrest. They are transcribed as longer precursors with extensive secondary structures. In plants, these precursors are processed by a complex harboring DICER-LIKE1 (DCL1), which cuts on the precursor stem region to release the mature miRNA together with the miRNA*. In both plants and animals, the miRNA precursors contain spatial clues that determine the position of the miRNA along their sequences. DCL1 is assisted by several proteins, such as the double-stranded RNA binding protein, HYPONASTIC LEAVES1 (HYL1), and the zinc finger protein SERRATE (SE). The precise biogenesis of miRNAs is of utter importance since it determines the exact nucleotide sequence of the mature small RNAs and therefore the identity of the target genes. miRNA processing itself can be regulated and therefore can determine the final small RNA levels and activity. Here, we describe methods to analyze miRNA processing intermediates in plants. These approaches can be used in wild-type or mutant plants, as well as in plants grown under different conditions, allowing a molecular characterization of the miRNA biogenesis from the RNA precursor perspective.Fil: Moro, Belén. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Rosario. Instituto de BiologÃa Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias BioquÃmicas y Farmacéuticas. Instituto de BiologÃa Molecular y Celular de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias BioquÃmicas y Farmacéuticas; ArgentinaFil: Rojas, Arantxa Maria Larisa. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Rosario. Instituto de BiologÃa Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias BioquÃmicas y Farmacéuticas. Instituto de BiologÃa Molecular y Celular de Rosario; ArgentinaFil: Palatnik, Javier Fernando. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Rosario. Instituto de BiologÃa Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias BioquÃmicas y Farmacéuticas. Instituto de BiologÃa Molecular y Celular de Rosario; Argentina. Universidad Nacional de Rosario. Centro de Estudios Interdisciplinarios; Argentin
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Precision measurement of the top quark mass from dilepton events at CDF II
We report a measurement of the top quark mass, M{sub t}, in the dilepton decay channel of t{bar t} {yields} b{ell}{prime}{sup +} {nu}{sub {ell}}, {bar b}{ell}{sup -}{bar {nu}}{sub {ell}} using an integrated luminosity of 1.0 fb{sup -1} of p{bar p} collisions collected with the CDF II detector. We apply a method that convolutes a leading-order matrix element with detector resolution functions to form event-by-event likelihoods; we have enhanced the leading-order description to describe the effects of initial-state radiation. The joint likelihood is the product of the likelihoods from 78 candidate events in this sample, which yields a measurement of M{sub t} = 164.5 {+-} 3.9(stat.) {+-} 3.9(syst.) GeV/c{sup 2}, the most precise measurement of M{sub t} in the dilepton channel
Inflammatory indexes as predictive factors for platinum sensitivity and as prognostic factors in recurrent epithelial ovarian cancer patients: a MITO24 retrospective study
Neutrophil-to-lymphocyte ratio (NLR) and systemic inflammatory index (SII) are prognostic factors in epithelial ovarian cancer (EOC). Their predictive value for platinum-sensitivity and their role in recurrent EOC are unknown. A total of 375 EOC patients were retrospectively analyzed. The correlation between baseline NLR and SII, and platinum-free interval (PFI) according to first line bevacizumab treatment were analyzed using logistic regression analyses adjusted for baseline patient characteristics. Subsequently NLR and SII calculated before second line treatment initiation were evaluated to identify a potential correlation with progression-free survival (PFS) and overall survival (OS) in platinum-sensitive and in platinum-resistant population. In multivariate analysis, NLR ≥ 3 is an independent predictive factor for PFI at 6 months in the chemotherapy group (OR = 2.77, 95% CI 1.38–5.56, p = 0.004), not in bevacizumab treated patients. After having adjusted for ECOG performance status, histology, ascites, bevacizumab treatment at second line and BRCA status, NLR ≥ 3 and SII ≥ 730 are significantly associated with worse OS in platinum-sensitive (HR = 2.69, 95% CI 1.60–4.53, p = 0.002; HR = 2.11, 95% CI 1.29–3.43, p = 0.003, respectively), not in platinum-resistant EOC patients. Low NLR is an independent predictive factor for platinum-sensitivity in patients treated without bevacizumab. NLR and SII are prognostic factors in recurrent platinum-sensitive EOC patients
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Recurrent Activity in Radio Galaxies
One of the outstanding issues concerning extragalactic radio sources is the total duration of their active phase and the possible existence of duty cycles of their nuclear activity. A duty cycle can be recognized if there is a mechanism which preserves the information of past activity for a sufficiently long time after a new activity has started up. If a new cycle starts before the radio lobes created during a former activity period have faded, we can recognize this by the observations of a young radio source embedded in an old relic structure
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