Accretion rates and radiative efficiencies of Sagittarius A* and nearby supermassive black holes estimated using empirical relations: Implications for accretion models

The Bondi accretion rate of black holes in our and nearby galaxies Messier 87, NGC 3115, NGC 1600, and Cygnus A have been determined or constrained using Chandra or other observations. It, however, remains unknown how much mass from the Bondi radius reaches each black hole and how much is accreted. We determine the accretion rate and radiative efficiency for each black hole using two well-tested empirical relations: one relates a black hole's accretion rate to its mass and redshift, and the other relates the radiative efficiency to the Eddington ratio and redshift. We get an accretion rate of ~0.00002 solar mass per year and radiative efficiency of ~0.9 for Sagittarius A* and an accretion rate of ~0.09 solar masses per year and radiative efficiency of ~0.68 for NGC 1600; and values in between these extremes for the rest. The derived mass inflow rate onto each black hole (not the accretion rate) essentially matches the reported Bondi accretion rate. Thus, the results do not support the ADIOS and CDAF models, but whether the dissipated energy not reflected in a black hole's observed luminosity is advected as in the ADAF model remains uncertain. Furthermore, contrary to current model expectations, the derived radiative efficiencies are orders of magnitude higher and radiative efficiency increases as the accretion rate decreases and a BH ages. A physical basis is found relating the empirical formulation of accretion rate to Bondi accretion.Comment: 11 pages, 1 figure, i tabl

COMPARATIVE EVALUATION OF THE EFFICACY OF THREE ANTI-OXIDANTS VS NAOCL AND EDTA: USED FOR ROOT CANAL IRRIGATION IN SMEAR LAYER REMOVAL–SEM STUDY

Objective: The aim of this study was to compare the efficacy of 3 Anti-Oxidants versus NaOCl and EDTA: used for root canal irrigation in smear layer removal by SEM analysis.Methods: Root canal treatment was performed on 100 single rooted teeth and the smear layer removing abilities of Neem, Triphala, Amla EDTA and Saline were checked by using them as the last irrigant.Results: EDTA and Amla showed the best smear layer removing ability followed by Neem and Triphala. Conclusion: Neem, Triphala and Amla showed the potential to remove the smear layer. EDTA showed the maximum efficacy in removing the smear layer.Â

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

An expert system on diagnosis of mental diseases

Mental disorder is one of the most serious problems in today's time. Mental disorders can be classified into different sub-disorders according to changes in human behavior and mental condition. According to reports one out of seven people suffered from mental disorders. In this research paper, our main emphasis is to build an expert system that diagnoses people based on their symptoms, so people can diagnose themselves early before going to the doctor. Expert Systems are one of the most important applications in artificial intelligence that solves complex problems without human help. We provide different rules, facts, and relationships among different symptoms in our knowledge base, from which users can query their problems and get their results. We used SWI-prolog to build an expert system. There are a few types of disorders, such as mental disorders, neurodevelopmental disorders, eating disorders, etc

Supplementary Information

The spreadsheet containing patient information gathered for the study is among the supplemental information. The consent form and information page included in the patient sheet were used to tell the eligible patients about the study and secure their assent before allowing them to participate voluntarily. To capture the patient's data, a study proforma sheet was created.</p