“Silent Hypoxemia” Leads to Vicious Cycle of Infection,Coagulopathy and Cytokine Storm in COVID-19: Can Prophylactic Oxygen Therapy Prevent It?

Humankind is facing its worst pandemic of the twenty-first century, due to infection of a novel coronavirus named as SARS-CoV2, started from Wuhan in China. Till now, 15 million people are infected, causing more than 600,000 deaths. The disease, commonly known as, COVID-19, was initially thought to be associated with ARDS only, but later on revealed to have many unexplained and atypical clinical features like coagulopathy and cytokinemia, leading to multi-organ involvements. The patients also suffer from ‘Silent Hypoxemia’, where there is no immediate respiratory signs and symptoms even though alarmingly low SpO₂ level. We hypothesize that this covert hypoxemia may lead to molecular changes exacerbating coagulopathy and cytokine storm in COVID19 patients, which again, in turn, causes a vicious cycle of more hypoxemia/hypoxia and progression of the infection to more severe stages through HIF-1α dependent pathway. Although molecular mechanisms are yet to be substantiated by scientific evidence, hypoxemia remains an independent worsening factor in serious COVID 19 patients. Keeping all in mind, we propose that even in the early and asymptomatic cases, prophylactic oxygen therapy to be initiated to break the vicious cycle and to reduce the mortality in COVID 19 to save precious human lives.     

The development, design and delivery of a retail simulation

theRetailGame.com is a web‐based package of e‐learning materials designed to support students on retailing courses. It uses the focal point of a ‘store opening’ to draw attention to key operational variables. The web‐based package allows students to explore the impacts of variable combinations in a risk‐free environment. This paper outlines the rationale for developing this new package; explains the design principles underlying its construction; and describes the delivery and assessment mechanisms in which it has been embedded. The case history of the project is reviewed, and actor‐network theory is used to characterise the alignment of requisite time and expertise as a feat of engineering, facilitated by top‐down support but dependent upon the creative manoeuvrings of the bottom‐up enthusiast.     

Joint routing and rate allocation for multiple video streams in ad-hoc wireless networks

INTRODUCTION Ad-hoc networks are attractive owing to their self-organizing nature and absence of a fixed infra- structure. They are particularly suited for communi- cation in disaster-affected areas, coordinating military operations, and sensing environmental conditions With the growing availability of supporting hardware and decreasing equipment cost, ad-hoc networking based applications are proliferating. Meshes of wire- less nodes are being deployed in cities and housing communities to…     

Public infrastructure,location of private schools and primary school attainment in an emerging economy

The paper argues that access to public infrastructure plays a crucial role on the presence of private schools in a community, as it could not only minimise the cost of production, but also ensure a high return to private investment. Results using community, school and child/household-level PROBE survey data from five north Indian states provide some support to this central hypothesis: even after controlling for all other factors, access to village infrastructural facilities is associated with a higher likelihood of having a private school in the community. This is also corroborated by an analysis of household demand for private schools. The paper concludes by examining the effect of private school presence on year 5 pass rates: while all-school pass rates are significantly higher in villages with a private school, private school presence fails to have significant effect on local state school pass rates.     

Estimation of CKMB from riqas control serum at 37 degree celsius

The quality control sera commonly available in market does not provide the value of CKMB. The CKMB kit of Randox laboratories contains two lyophilized control sera. But the stability of the control serum after reconstitution with 2ml of distilled water is 5 days at 2–8 degree Celsius, 8hrs at 25 degree Celsius and 4 weeks at-20 degree Celsius when frozen once. Hence stability after reconstitution is not sufficient to fulfill the daily need of a laboratory. In quest of a good internal quality assessment (IQA) sample trial run has been performed at 37 degree Celsius using external quality assessment (EQA) samples obtained from Randox international quality assessment sample (RIQAS). The trial run was found to be successful.     

Techniques in X-ray astronomy

X-ray astronomy has benefited enormously with the deployment of imaging X-ray telescopes in space, leading to a veritable revolution. Such telescopes require distortion free focusing of X-rays and the use of position sensitive X-ray detectors. In this article I shall describe the importance of X-ray imaging, the optical principles behind the creation of images and the instruments based on these principles. The various techniques used to fabricate such X-ray telescopes are described briefly. The many types of detectors used in X-ray astronomy will be described in the second part of this article in a subsequent issue ofResonance. Kulinder Pal Singh is in the Department of Astronomy and Astrophysics of the Tata Institute of Fundamental Research, Mumbai. His primary fields of research are X-ray studies of hot plasmas in stars, supernova remnants, galaxies, intergalactic medium in clusters of galaxies, active galactic nuclei, cataclysmic variables and X-ray binaries. He is leading the development of a soft X-ray imaging telescope for the ASTROSAT mission to be launched by India in 2007–2008.     

Discrete time second order sliding mode observer for uncertain linear multi-output system

This paper presents a second order sliding mode observer (SOSMO) design for discrete time uncertain linear multi-output system. The design procedure is effective for both matched and unmatched bounded uncertainties and/or disturbances. A second order sliding function and corresponding sliding manifold for discrete time system are defined similar to the lines of continuous time counterpart. A boundary layer concept is employed to avoid switching across the defined sliding manifold and the sliding trajectory is confined to a boundary layer once it converges to it. The condition for existence of convergent quasi-sliding mode (QSM) is derived. The observer estimation errors satisfying given stability conditions converge to an ultimate finite bound (within the specified boundary layer) with thickness O(T²)$O\left(T^2\right)$ where T is the sampling period. A relation between sliding mode gain and boundary layer is established for the existence of second order discrete sliding motion. The design strategy is very simple to apply and is demonstrated for three examples with different class of disturbances (matched and unmatched) to show the effectiveness of the design. Simulation results to show the robustness with respect to the measurement noise are given for SOSMO and the performance is compared with pseudo-linear Kalman filter (PLKF).     

Alkaline Phosphatase: An Overview

Alkaline phosphatase (ALP; E.C.3.I.3.1.) is an ubiquitous membrane-bound glycoprotein that catalyzes the hydrolysis of phosphate monoesters at basic pH values. Alkaline phosphatase is divided into four isozymes depending upon the site of tissue expression that are Intestinal ALP, Placental ALP, Germ cell ALP and tissue nonspecific alkaline phosphatase or liver/bone/kidney (L/B/K) ALP. The intestinal and placental ALP loci are located near the end of long arm of chromosome 2 and L/B/K ALP is located near the end of the short arm of chromosome 1. Although ALPs are present in many mammalian tissues and have been studied for the last several years still little is known about them. The bone isoenzyme may be involved in mammalian bone calcification and the intestinal isoenzyme is thought to play a role in the transport of phosphate into epithelial cells of the intestine. In this review, we tried to provide an overview about the various forms, structure and functions of alkaline phosphatase with special focus on liver/bone/kidney alkaline phosphatase.     

Introduction of two new programming tools in Bengali and measurement of their reception among high-school students in Purba Bardhaman,India with the prototypic inclusion of a vector-biology module

Education and Information Technologies - We introduce two new software tools, Bongojontro and Bongojontro Baksobandi, aimed at reducing the barriers to programming for native speakers of Bengali,...