500 research outputs found

    Swift follow-up observations of 17 INTEGRAL sources of uncertain or unknown nature

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    (abridged) We analysed data from observations of 17 INTEGRAL sources made with the Swift satellite. We refine the position of the hard X-ray sources to an accuracy of a few arcsec. We then browsed the online catalogs (e.g., NED, SIMBAD, 2MASS, 2MASX, USNO) to search for counterparts at other wavelengths. We also made use of the X-ray spectral parameters to try to identify the nature of those sources. We provide the X-ray position with arcsec accuracy, identify possible infrared and optical counterparts (when found), give the magnitudes in those bands and in the optical and UV as seen with the Swift/UVOT telescope when observations are available. We confirm the previously suggested associations and source types for IGR J03532-6829, J05346-5759, J10101-5654, J13000+2529, J13020-6359, J15479-4529, J18214-1318, and J23206+6431. We identify IGR J09025-6814 as an AGN for the first time, and we suggest that it may be a Seyfert 2. We suggest that IGR J05319-6601, J16287-5021, J17353-3539 and J17476-2253 are X-ray binaries, with J05319-6601 being located in the LMC and the other three possibly being HMXBs in our Galaxy. For IGR J15161-3827 and J20286+2544, we find several possible X-ray counterparts in the IBIS error region, and we discuss which, if any, are the likely counterparts. Both are likely AGNs, although the latter could be a blend of two AGNs. For IGR J03184-0014 and J19267+1325, we find X-ray sources slightly outside the IBIS error circle. In the former, we do not favour an association of the Swift and INTEGRAL source, while it is very likely that IGR J19267+1325 and the Swift source are the same.Comment: 12 pages, 3 figures, accepted for publication in A&

    Steady jets from radiatively efficient hard states in GRS 1915+105

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    Recent studies of different X-ray binaries (XRBs) have shown a clear correlation between the radio and X-ray emission. We present evidence of a close relationship found between the radio and X-ray emission at different epochs for GRS1915+105, using observations from the Ryle Telescope and Rossi X-ray Timing Explorer satellite. The strongest correlation was found during the hard state (also known as the `plateau' state), where a steady AU-scale jet is known to exist. Both the radio and X-ray emission were found to decay from the start of most plateau states, with the radio emission decaying faster. An empirical relationship of SradioSXrayξS_{\rm{radio}}\propto S_{\rm{X-ray}}^{\xi} was then fitted to data taken only during the plateau state, resulting in a power-law index of ξ1.7±0.3\xi\sim1.7\pm0.3, which is significantly higher than in other black hole XRBs in a similar state. An advection-flow model was then fitted to this relationship and compared to the universal XRB relationship as described by Gallo et al. (2003). We conclude that either (I) the accretion disk in this source is radiatively efficient, even during the continuous outflow of a compact jet, which could also suggest a universal turn-over from radiatively inefficient to efficient for all stellar-mass black holes at a critical mass accretion rate (m˙c1018.5\dot{m}_{\rm{c}}\approx10^{18.5} g/s); or (II) the X-rays in the plateau state are dominated by emission from the base of the jet and not the accretion disk (e.g. via inverse Compton scattering from the outflow).Comment: 9 pages, 7 figures, accepted in A&

    Detailed Radio to Soft Gamma-ray Studies of the 2005 Outburst of the New X-ray Transient XTE J1818-245

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    XTE J1818-245 is an X-ray nova that experienced an outburst in 2005, first seen by the RXTE satellite. The source was observed simultaneously at various wavelengths up to soft gamma-rays with the INTEGRAL satellite, from 2005 February to September. X-ray novae are extreme systems that often harbor a black hole, and are known to emit throughout the electromagnetic spectrum when in outburst. We analyzed radio, (N)IR, optical, X-ray and soft gamma-ray observations and constructed simultaneous broad-band X-ray spectra. Analyzing both the light curves in various energy ranges and the hardness-intensity diagram enabled us to study the long-term behavior of the source. Spectral parameters were typical of the Soft Intermediate States and the High Soft States of a black hole candidate. The source showed relatively small spectral variations in X-rays with considerable flux variation in radio. Spectral studies showed that the accretion disc cooled down from 0.64 to 0.27 keV in 100 days and that the total flux decreased while the relative flux of the hot medium increased. Radio emission was detected several times, and, interestingly, five days after entering the HSS. Modeling the spectral energy distribution from the radio to the soft gamma-rays reveals that the radio flares arise from several ejection events. XTE J1818-245 is likely a black hole candidate transient source that might be closer than the Galactic Bulge. The results from the data analysis trace the physical changes that took place in the system at a maximum bolometric luminosity of (0.4-0.9)e38 erg/s (assuming a distance between 2.8-4.3 kpc) and they are discussed within the context of disc and jet models.Comment: Accepted for publication in Astronomy and Astrophysics. 11 Figures, 3 Table

    Spectro-timing analysis of Cygnus X-1 during a fast state transition

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    We present the analysis of two long, quasi-uninterrupted RXTE observations of Cygnus X-1 that span several days within a 10 d interval. The spectral characteristics during this observation cover the region where previous observations have shown the source to be most dynamic. Despite that the source behavior on time scales of hours and days is remarkably similar to that on year time scales. This includes a variety of spectral/temporal correlations that previously had only been observed over Cyg X-1's long-term evolution. Furthermore, we observe a full transition from a hard to a soft spectral state that occurs within less than 2.5 hours - shorter than previously reported for any other similar Cyg X-1 transition. We describe the spectra with a phenomenological model dominated by a broken power law, and we fit the X-ray variability power spectra with a combination of a cutoff power law and Lorentzian components. The spectral and timing properties are correlated: the power spectrum Lorentzian components have an energy-dependent amplitude, and their peak frequencies increase with photon spectral index. Averaged over 3.2-10 Hz, the time lag between the variability in the 4.5-5.7 keV and 9.5-15 keV bands increases with decreasing hardness when the variability is dominated by the Lorentzian components during the hard state. The lag is small when there is a large power law noise contribution, shortly after the transition to the soft state. Interestingly, the soft state not only shows the shortest lags, but also the longest lags when the spectrum is at its softest and faintest. We discuss our results in terms of emission models for black hole binaries.Comment: 13 pages, 15 figures, accepted for publication in Astronomy and Astrophysic

    The multidimensional comprehension of Chagas disease. Contributions, approaches, challenges and opportunities from and beyond the information, education and communication field

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    Chagas is a complex, multidimensional phenomenon in which political, economic, environmental, biomedical, epidemiological, psychological, and sociocultural factors intersect. Nonetheless, the hegemonic conceptualisation has long envisioned Chagas as primarily a biomedical question, while ignoring or downplaying the other dimensions, and this limited view has reinforced the disease's long neglect. Integrating the multiple dimensions of the problem into a coherent approach adapted to field realities and needs represents an immense challenge, but the payoff is more effective and sustainable experiences, with higher social awareness, increased case detection and follow-up, improved adherence to care, and integrated participation of various actors from multiple action levels. Information, Education, and Communication (IEC) initiatives have great potential for impact in the implementation of multidimensional programs of prevention and control successfully customised to the diverse and complex contexts where Chagas disease persists

    Transcriptional diversification and functional conservation between DELLA proteins in Arabidopsis

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    [EN] Plasticity and robustness of signaling pathways partly rely on genetic redundancy, although the precise mechanism that provides functional specificity to the different redundant elements in a given process is often unknown. In Arabidopsis, functional redundancy in gibberellin signaling has been largely attributed to the presence of five members of the DELLA family of transcriptional regulators. Here, we demonstrate that two evolutionarily and functionally divergent DELLA proteins, RGL2 and RGA, can perform exchangeable functions when they are expressed under control of the reciprocal promoter. Furthermore, both DELLA proteins display equivalent abilities to interact with PIF4 and with other bHLH transcription factors with a reported role in the control of cell growth and seed germination. Therefore, we propose that functional diversification of Arabidopsis DELLA proteins has largely relied on changes in their gene expression patterns rather than on their ability to interact with different regulatory partners, model also supported by a clustering analysis of DELLA transcript profiles over a range of organs and growth conditions that revealed specific patterns of expression for each of these genes.We deeply appreciate the help of Marta Trenor and Laura Garcia-Carcel in the initial stages of this work. We also thank Tai-ping Sun (Duke University) and the Arabidpsis Biological Resource Center for seeds, Marta Boter for the pGBKT7 and pGADT7 Gateway vectors, Santiago Elena (IBMCP, CSIC-UPV) for useful comments on the manuscript, and Francois Parcy (IRTSV, CNRS-CEA) for fruitful discussions and hosting MAB. Work in the authors' laboratories is funded by grants BIO2007-60923 and BIO2005-07284 from the Spanish Ministry of Science and Innovation. J.G.B. is the recipient of a CSIC I3P Fellowship and J.A.M. is the recipient of a Fellowship from the Fundacion "la Caixa.Gallego-Bartolome, J.; Minguet, E.; Marin, JA.; Prat, S.; Blazquez Rodriguez, MA.; Alabadí Diego, D. (2010). Transcriptional diversification and functional conservation between DELLA proteins in Arabidopsis. Molecular Biology and Evolution. 27(6):1247-1256. https://doi.org/10.1093/molbev/msq0121247125627

    Prognostic ability of EndoPredict compared to research-based versions of the PAM50 risk of recurrence (ROR) scores in node-positive, estrogen receptor-positive, and HER2-negative breast cancer. A GEICAM/9906 sub-study

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    There are several prognostic multigene-based tests for managing breast cancer (BC), but limited data comparing them in the same cohort. We compared the prognostic performance of the EndoPredict (EP) test (standardized for pathology laboratory) with the research-based PAM50 non-standardized qRT-PCR assay in node-positive estrogen receptor-positive (ER+) and HER2-negative (HER2−) BC patients receiving adjuvant chemotherapy followed by endocrine therapy (ET) in the GEICAM/9906 trial. EP and PAM50 risk of recurrence (ROR) scores [based on subtype (ROR-S) and on subtype and proliferation (ROR-P)] were compared in 536 ER+/HER2− patients. Scores combined with clinical information were evaluated: ROR-T (ROR-S, tumor size), ROR-PT (ROR-P, tumor size), and EPclin (EP, tumor size, nodal status). Patients were assigned to risk-categories according to prespecified cutoffs. Distant metastasis-free survival (MFS) was analyzed by Kaplan–Meier. ROR-S, ROR-P, and EP scores identified a low-risk group with a relative better outcome (10-year MFS: ROR-S 87%; ROR-P 89%; EP 93%). There was no significant difference between tests. Predictors including clinical information showed superior prognostic performance compared to molecular scores alone (10-year MFS, low-risk group: ROR-T 88%; ROR-PT 92%; EPclin 100%). The EPclin-based risk stratification achieved a significantly improved prediction of MFS compared to ROR-T, but not ROR-PT. All signatures added prognostic information to common clinical parameters. EPclin provided independent prognostic information beyond ROR-T and ROR-PT. ROR and EP can reliably predict risk of distant metastasis in node-positive ER+/HER2− BC patients treated with chemotherapy and ET. Addition of clinical parameters into risk scores improves their prognostic ability.Electronic supplementary materialThe online version of this article (doi:10.1007/s10549-016-3725-z) contains supplementary material, which is available to authorized users

    Transcriptional Profile Associated with Clinical Outcomes in Metastatic Hormone-Sensitive Prostate Cancer Treated with Androgen Deprivation and Docetaxel

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    (1) Background: Androgen deprivation therapy (ADT) and docetaxel (DX) combination is a standard therapy for metastatic hormone-sensitive prostate cancer (mHSPC) patients. (2) Methods: We investigate if tumor transcriptomic analysis predicts mHSPC evolution in a multicenter retrospective biomarker study. A customized panel of 184 genes was tested in mRNA from tumor samples by the nCounter platform in 125 mHSPC patients treated with ADT+DX. Gene expression was correlated with castration-resistant prostate cancer-free survival (CRPC-FS) and overall survival (OS). (3) Results: High expression of androgen receptor (AR) signature was independently associated with longer CRPC-FS (hazard ratio (HR) 0.6, 95% confidence interval (CI) 0.3-0.9; p = 0.015), high expression of estrogen receptor (ESR) signature with longer CRPC-FS (HR 0.6, 95% CI 0.4-0.9; p = 0.019) and OS (HR 0.5, 95% CI 0.2-0.9, p = 0.024), and lower expression of tumor suppressor genes (TSG) (RB1, PTEN and TP53) with shorter OS (HR 2, 95% CI 1-3.8; p = 0.044). ARV7 expression was independently associated with shorter CRPC-FS (HR 1.5, 95% CI 1.1-2.1, p = 0.008) and OS (HR 1.8, 95% CI 1.2-2.6, p = 0.004), high ESR2 was associated with longer OS (HR 0.5, 95% CI 0.2-1, p = 0.048) and low expression of RB1 was independently associated with shorter OS (HR 1.9, 95% CI 1.1-3.2, p = 0.014). (4) Conclusions: AR, ESR, and TSG expression signatures, as well as ARV7, RB1, and ESR2 expression, have a prognostic value in mHSPC patients treated with ADT+DX

    Promoting Interpersonal Relationships through Elbow Tag, a Traditional Sporting Game. A Multidimensional Approach

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    The aim of this research was to study from a multidimensional point of view (decisional, relational and energetic) the interpersonal relationships established by girls and boys in the traditional sport game of Elbow Tag. Scientific evidence has shown that Traditional Sport Games (TSG) trigger different effects on male and female genders in relation to emotional experiences, decision-making, conflicts and motor relationships. Despite the fact that these dimensions are intertwined, there are hardly any studies that interpret motor behaviors holistically, i.e., taking a multidimensional (360◦ ) view of these dimensions. For this study, a quasi-experimental design was used and a type III design was applied, inspired by the observational methodology N/P/M. A total of 147 university students participated (M = 19.6, SD = 2.3): 47 girls (31.97%) and 100 boys (68.02%). A mixed ‘ad hoc’ registration system was designed with acceptable margins of data quality. Cross-tabulations, classification trees and T-patterns analysis were applied. The results indicated that social interactions between girls and boys in a mixed group were unequal. This difference was mainly due to decisionmaking (sub-role variable), which has much greater predictive power than the energetic variables (MV and steps).This research was funded by the Institut Nacional d’Educació Física de Catalunya (INEFC), Universitat de Lleida (UdL), through the 2016 PINEF 00016 project

    Two Years of INTEGRAL monitoring of GRS 1915+105 Part 2: X-Ray Spectro-Temporal Analysis

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    (abridged) This is the second paper presenting the results of two years of monitoring of GRS 1915+105 with \integral and \rxte and the Ryle Telescope. We present the X-ray spectral and temporal analysis of four observations which showed strong radio to X-ray correlations. During one observation GRS 1915+105 was in a steady state, while during the three others it showed cycles of X-ray dips and spikes (followed by radio flares). We present the time-resolved spectroscopy of these cyclesand show that in all cases the hard X-ray component (the Comptonized emission from a coronal medium) is suppressed in coincidence with a soft X-ray spike that ends the cycle. We interpret these results as evidence that the soft X-ray spike is the trigger of the ejection, and that the ejected medium is the coronal material. In the steady state observation, the X-ray spectrum is indicative of the hard-intermediate state, with the presence of a relatively strong emission at 15 GHz. The X-ray spectra are the sum of a Comptonized component and an extra power law extending to energies >200 keV without any evidence for a cut-off. We observe a possible correlation of the radio flux with that of the power law component, which may indicate that we see direct emission from the jet at hard X-ray energies. We study the energy dependence of a ~4 Hz QPO during the hard-intermediate state observation. The QPO-``spectrum'' is well modeled by a power law with a cut-off at an energy about 11 keV that clearly differs from the relative contribution of the Comptonized component to the overall flux. This may rule out models of global oscillations of the Compton corona.Comment: 13 pages, 8 figures (3 color), accepted for publication in ApJ, scheduled for the March 20, 2008, vol676 issue. Paper 1 is the next astro-ph numbe
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