Discovery of soft and hard X-ray time lags in low-mass AGNs

The scaling relations between the black hole (BH) mass and soft lag properties for both active galactic nuclei (AGNs) and BH X-ray binaries (BHXRBs) suggest the same underlying physical mechanism at work in accreting BH systems spanning a broad range of mass. However, the low-mass end of AGNs has never been explored in detail. In this work, we extend the existing scaling relations to lower-mass AGNs, which serve as anchors between the normal-mass AGNs and BHXRBs. For this purpose, we construct a sample of low-mass AGNs ($M_{\rm BH}<3\times 10^{6} M_{\rm \odot}$) from the XMM-Newton archive and measure frequency-resolved time delays between the soft (0.3-1 keV) and hard (1-4 keV) X-ray emissions. We report that the soft band lags behind the hard band emission at high frequencies $\sim[1.3-2.6]\times 10^{-3}$ Hz, which is interpreted as a sign of reverberation from the inner accretion disc in response to the direct coronal emission. At low frequencies ($\sim[3-8]\times 10^{-4}$ Hz), the hard band lags behind the soft band variations, which we explain in the context of the inward propagation of luminosity fluctuations through the corona. Assuming a lamppost geometry for the corona, we find that the X-ray source of the sample extends at an average height and radius of $\sim 10r_{\rm g}$ and $\sim 6r_{\rm g}$, respectively. Our results confirm that the scaling relations between the BH mass and soft lag amplitude/frequency derived for higher-mass AGNs can safely extrapolate to lower-mass AGNs, and the accretion process is indeed independent of the BH mass.Comment: 11 pages, 5 figures, 4 tables, Published in MNRA

Video-based simulation among Saudi undergraduate nursing students during COVID-19 : a qualitative study

BACKGROUND: Because of university closures due to COVID-19 confinement, video-based simulation, a training technique based on high-fidelity simulations, was introduced in reaction to the need to adapt high-fidelity clinical simulation experiences to digital platforms. PURPOSE: This study aims to evaluate the perceptions of nursing students in Saudi Arabia regarding the shift from face-to-face simulation experiences to video-based simulation during the COVID-19 pandemic. METHODS: This study employed a phenomenological exploratory qualitative research design among 32 nursing students from various academic levels. RESULTS: The thematic analysis gave rise to five themes namely, “Enhanced Learning and satisfaction”, “Improved communication skills”, “Lack of hands-on experience”, “More comfortable experience”, and “Technical Barriers”. CONCLUSION: The students in this study have indicated that they were satisfied with video-based simulation, where they reported enhanced learning, better communication skills, and more perceived comfort, while concerns regarding technical issues and nursing skills were raised.https://www.cureus.com/Nursing ScienceSDG-04:Quality Educatio

Prospects for Time-Domain and Multi-Messenger Science with AXIS

The Advanced X-ray Imaging Satellite (AXIS) promises revolutionary science in the X-ray and multi-messenger time domain. AXIS will leverage excellent spatial resolution (<1.5 arcsec), sensitivity (80x that of Swift), and a large collecting area (5-10x that of Chandra) across a 24-arcmin diameter field of view to discover and characterize a wide range of X-ray transients from supernova-shock breakouts to tidal disruption events to highly variable supermassive black holes. The observatory's ability to localize and monitor faint X-ray sources opens up new opportunities to hunt for counterparts to distant binary neutron star mergers, fast radio bursts, and exotic phenomena like fast X-ray transients. AXIS will offer a response time of <2 hours to community alerts, enabling studies of gravitational wave sources, high-energy neutrino emitters, X-ray binaries, magnetars, and other targets of opportunity. This white paper highlights some of the discovery science that will be driven by AXIS in this burgeoning field of time domain and multi-messenger astrophysics.Comment: This White Paper is part of a series commissioned for the AXIS Probe Concept Mission; additional AXIS White Papers can be found at http://axis.astro.umd.ed

A review on cancer incidence in India from 25 population-based cancer registries

Background and Objective: An overview of the update of cancer incidence summary findings will be of help to researchers and clinicians for quick reference of facts in cancer control. To present an overview of cancer incidence available from the recent population-based cancer registries (PBCRs) in India from 2009 to 2011. Materials and Methods: Data on age-adjusted incidence rates and cumulative risks of cancer at various sites were collected for both sexes for six major cancer sites from the first report of the National Cancer Registry Programme (NCRP) on 25 PBCRs in India for the years 2009-2011. Site-specific risks in terms of one out of the total number of persons who develop cancer were computed. The summaries, in the form of ranges, are presented in six regions of the country in which the 20 PBCRs are located. The range of age-adjusted rates (AARs) and one out of the number of persons who develop cancer as a lifetime risk in the age of 0-64 years is presented. Results: In different regions, the highest risks for males for developing cancer in the various major sites studied were as follows: One out of 67 for cancer in the lungs in the Northeast, one out of 27 for cancer in the esophagus in the Northeast, one out of 71 for cancer in the mouth in the western region, one out of 100 cancer in the tongue in the rural western region, one out of 333 for cancer in the prostate in the northern region, and one out of 33 for cancer in the stomach in the northeastern region. The highest risks for the various sites studied were as follows: one out of 36 for cancer in the breast in the south, one out of 59 for cancer in the cervix in the western region, one out of 125 for cancer in the ovary in the northern region, one out of 63 for cancer in the esophagus in the northeastern region, one out of 250 for cancer in the mouth in three regions, and one out of 125 for cancer in the gall bladder in the western and central regions. Overall, for all cancers there is a risk of one out of 8-27 persons and one out of 10-25 persons among males and females, respectively, in the Indian population who are likely to develop cancer of any site in their lifetime during the age of 0-64 years. Conclusion: Female breast cancer in the southern region and esophagus and stomach cancers among males in the northeast region were of the highest magnitudes

Food consumption pattern in cervical carcinoma patients and controls

<b>Background:</b> The uterine cervix is the second most common site of cancer among Indian women.Though the human papillomavirus has been demonstrated to be a causative agent for this cancer, a variety of other risk factors are in play, such as sexual and reproductive patterns, socioeconomic, hygienic practices, and diet. The accumulated evidence suggests that cervical cancer is preventable and is highly suitable for primary prevention. The dietary intake of antioxidants and vitamins like vitamin A, carotenoids, vitamin C, folacin and tocopherol is found to have protective effects against cancer of the cervix. Dietary data regarding cervical cancer are still scanty. <b> Objective:</b> The present study was therefore undertaken to study the dietary pattern among uterine cervical cancer patients and normal controls. <b> Materials and Methods:</b> A total of 60 consecutive patients and 60 controls were enrolled from a referral hospital during the year 2004. A schedule inclusive of the food frequency pattern and 24-h dietary recall along with the general information was administered to all the enrolled subjects to describe findings on the food consumption pattern along with other important factors. <b> Results:</b> The mean intake of energy, protein, vitamins, etc., between the cases and controls was not significantly different except for the vitamin C level. Serum vitamin E was found to have lower average in patients as compared to controls. The nutrient intake of cervical cancer patients and controls was grossly deficient in the socioeconomic group studied. With regard to the macronutrient intake, calorie and protein intakes showed a deficit of around 50&#x0025; when compared to RDA. <b> Conclusion:</b> The food consumption profile was not significantly different between cervical cancer patients and normal controls