2,239 research outputs found

    Joint Planck and WMAP Assessment of Low CMB Multipoles

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    The remarkable progress in cosmic microwave background (CMB) studies over past decade has led to the era of precision cosmology in striking agreement with the Λ\LambdaCDM model. However, the lack of power in the CMB temperature anisotropies at large angular scales (low-\ell), as has been confirmed by the recent Planck data also (up to =40\ell=40), although statistically not very strong (less than 3σ3\sigma), is still an open problem. One can avoid to seek an explanation for this problem by attributing the lack of power to cosmic variance orcan look for explanations i.e., different inflationary potentials or initial conditions for infl ation to begin with, non-trivial topology, ISW effect etc. Features in the primordial power spectrum (PPS) motivated by the early universe physics has been the most common solution to address this problem. In the present work we also follow this approach and consider a set of PPS which have features and constrain the parameters of those using WMAP 9 year and Planck data employing Markov-Chain Monte Carlo (MCMC) analysis. The prominent feature of all the models of PPS that we consider is an infra-red cut off which leads to suppression of power at large angular scales. We consider models of PPS with maximum three extra parameters and use Akaike information criterion (AICAIC) and Bayesian information criterion (BICBIC) of model and Bayesian information criterion (BICBIC) of model selection to compare the models. For most models, we find good constraints for the cut off scale kck_c, however, for other parameters our constraints are not that good. We find that sharp cut off model gives best likelihood value for the WMAP 9 year data, but is as good as power law model according to AICAIC. For the joint WMAP 9+Planck data set, Starobinsky model is slightly preferred by AICAIC which is also able to produce CMB power suppression up to 30\ell\leq30 to some extent.Comment: 27 pages, 10 figures, 3 tables, matches with the published version, abstract is shortened to keep it within arXiv's limit (1920 characters

    Mega doses of methotrexate in the treatment of osteosarcoma

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    Little evidence for entropy and energy excess beyond r500r_{500} - An end to ICM preheating?

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    Non-gravitational feedback affects the nature of the intra-cluster medium (ICM). X-ray cooling of the ICM and in situ energy feedback from AGN's and SNe as well as {\it preheating} of the gas at epochs preceding the formation of clusters are proposed mechanisms for such feedback. While cooling and AGN feedbacks are dominant in cluster cores, the signatures of a preheated ICM are expected to be present even at large radii. To estimate the degree of preheating, with minimum confusion from AGN feedback/cooling, we study the excess entropy and non-gravitational energy profiles upto r200r_{200} for a sample of 17 galaxy clusters using joint data sets of {\it Planck} SZ pressure and {\it ROSAT/PSPC} gas density profiles. The canonical value of preheating entropy floor of 300\gtrsim 300 keV cm2^2, needed in order to match cluster scalings, is ruled out at 3σ\approx 3\sigma. We also show that the feedback energy of 1 keV/particle is ruled out at 5.2σ\sigma beyond r500r_{500}. Our analysis takes both non-thermal pressure and clumping into account which can be important in outer regions. Our results based on the direct probe of the ICM in the outermost regions do not support any significant preheating.Comment: 6 pages, 4 figures, 1 table, Accepted in MNRAS Letter

    Excess entropy and energy feedback from within cluster cores up to r200_{200}

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    We estimate the "non-gravitational" entropy-injection profiles, ΔK\Delta K, and the resultant energy feedback profiles, ΔE\Delta E, of the intracluster medium for 17 clusters using their Planck SZ and ROSAT X-Ray observations, spanning a large radial range from 0.2r5000.2r_{500} up to r200r_{200}. The feedback profiles are estimated by comparing the observed entropy, at fixed gas mass shells, with theoretical entropy profiles predicted from non-radiative hydrodynamic simulations. We include non-thermal pressure and gas clumping in our analysis. The inclusion of non-thermal pressure and clumping results in changing the estimates for r500r_{500} and r200r_{200} by 10\%-20\%. When clumpiness is not considered it leads to an under-estimation of ΔK300\Delta K\approx300 keV cm2^2 at r500r_{500} and ΔK1100\Delta K\approx1100 keV cm2^2 at r200r_{200}. On the other hand, neglecting non-thermal pressure results in an over-estimation of ΔK100\Delta K\approx 100 keV cm2^2 at r500r_{500} and under-estimation of ΔK450\Delta K\approx450 keV cm2^2 at r200r_{200}. For the estimated feedback energy, we find that ignoring clumping leads to an under-estimation of energy per particle ΔE1\Delta E\approx1 keV at r500r_{500} and ΔE1.5\Delta E\approx1.5 keV at r200r_{200}. Similarly, neglect of the non-thermal pressure results in an over-estimation of ΔE0.5\Delta E\approx0.5 keV at r500r_{500} and under-estimation of ΔE0.25\Delta E\approx0.25 keV at r200r_{200}. We find entropy floor of ΔK300\Delta K\approx300 keV cm2^2 is ruled out at 3σ\approx3\sigma throughout the entire radial range and ΔE1\Delta E\approx1 keV at more than 3σ\sigma beyond r500r_{500}, strongly constraining ICM pre-heating scenarios. We also demonstrate robustness of results w.r.t sample selection, X-Ray analysis procedures, entropy modeling etc.Comment: 17 pages, 15 figures, 5 tables, Accepted in MNRA

    AGN feedback with the Square Kilometer Array (SKA) and implications for cluster physics and cosmology

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    AGN feedback is regarded as an important non-gravitational process in galaxy clusters, providing useful constraints on large-scale structure formation. It modifies the structure and energetics of the intra-cluster medium (ICM) and hence its understanding is crucially needed in order to use clusters as high precision cosmological probes. In this context, particularly keeping in mind the upcoming high quality radio data expected from radio surveys like SKA with its higher sensitivity, high spatial and spectral resolutions, we review our current understanding of AGN feedback, its cosmological implications and the impact that SKA can have in revolutionizing our understanding of AGN feedback in large-scale structures. Recent developments regarding the AGN outbursts and its possible contribution to excess entropy in the hot atmospheres of groups and clusters, its correlation with the feedback energy in ICM, quenching of cooling flows and the possible connection between cool core clusters and radio mini-halos, are discussed. We describe current major issues regarding modeling of AGN feedback and its impact on the surrounding medium. With regard to the future of AGN feedback studies, we examine the possible breakthroughs that can be expected from SKA observations. In the context of cluster cosmology, for example, we point out the importance of SKA observations for cluster mass calibration by noting that most of z>1z>1 clusters discovered by eROSITA X-ray mission can be expected to be followed up through a 1000 hour SKA-1 mid programme. Moreover, approximately 10001000 radio mini halos and 2500\sim 2500 radio halos at z<0.6z<0.6 can be potentially detected by SKA1 and SKA2 and used as tracers of galaxy clusters and determination of cluster selection function.Comment: 14 pages, 10 figures, Review article accepted in Journal of Astrophysics and Astronomy (JOAA

    Endoscopic Submucosal Tunnel Dissection as a Novel Therapeutic Technique in Patients With Barrett’s Esophagus

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    © 2020 American Federation for Medical Research. With the ameliorated resectability prowess of endoscopic techniques, a myriad of diseases previously treated by major ablative surgeries are now endoscopically curable. Endoscopic submucosal tunnel dissection (ESTD) is a relatively new technique that has diversified endoscopic application. Although ESTD has frequently been used for the resection of esophageal neoplastic lesions, the clinical evidence pertaining to its efficacy in the treatment of circumferential Barrett’s esophagus remains sparse. In this study, we evaluated ESTD as a potential therapeutic technique in patients with Barrett’s esophagus-related high-grade dysplasia. The tunneling strategy helped achieve complete en bloc resection at an increased dissection speed, without any procedural complications. This article illustrates that ESTD can be a feasible, safe, and effective treatment for dysplastic Barrett’s esophagus. Future research should aim to stratify the potential risks and complications associated with this optimization of endoscopic submucosal dissection in patients with superficial esophageal lesions

    Genetic basis of variation for seedling traits in Gossypium hirsutum L.

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    A 6 × 6 complete diallel analysis was performed to study the inheritance of seedling traits in cotton. Significant differences among genotypes showed the genetic variation and formal analysis predicted the presence of both additive and non-additive genetic variation for inheritance of seedling traits. Further, the estimates of genetic components D, H1 and H2 confirmed the presence of both additive and non-additive genetic effects for all the characteristics. Dominant genes were responsible for theincrease of seedling shoot length, root length, shoot weight and root weight. However, recessive genes were accountable for the increase of shoot root ratio by length and by weight. Seedling shoot length, root length and root weight can be improved through heterosis breeding. The magnitude of broad sense heritability was greater than narrow sense for all the six traits under study hence diminished the scope of selection in the early segregating generation therefore pedigree breeding method is suggested for the improvement of these traits.Key words: Additive dominance model, gene action, Gossypium hirsutum L, heritability, seedling traits

    Response of Chickpea Lines to Ascochyta rabiei at Two Growing Stages

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    During winter 2004 and 2005, two field and glasshouse experiments were conducted to evaluate the response of 471 chickpea genotypes to Ascochyta rabiei, as Ascochyta blight (AB) disease in Chickpea (Cicer aurietimum). Frequent rainfall at flowering and pod formation stages made favorite conditions conducive for the infection and symptoms expression. So, the genotypes with high level of tolerance at seedling stage proved response to the pathogen under field condition. Disease at seedling and adult plant stage exhibited high association, although level of infection was higher at adult plant stage. In glasshouse 65 genotypes at seedling stage and in field experiment 14 genotypes at pod formation stage were resistant to the pathogen. Following green house and field screening methods, six genotypes FLIP98-229C, FLIP82-150C,NCS 950204, NCS 950219, NCS 9903 and PaidarxParbat from NARC and six lines (FLIP 00-20C, FLIP 02-18C, FLIP 02-44C, FLIP 97-120C, FLIP 02-39C and FLIP 97-102C) from ICARDA found resistant for multilocational / agronomic evaluation and use as resistant parent trials for high yielding AB resistance breeding varieties
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