Search

The last two decades have witnessed the emergence of three deadly coronaviruses (CoVs) in humans: severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). There are still no reliable and efficient therapeutics to manage the devastating consequences of these CoVs. Of these, SARS-CoV-2, the cause of the currently ongoing coronavirus disease 2019 (COVID-19) pandemic, has posed great global health concerns. The COVID-19 pandemic has resulted in an unprecedented crisis with devastating socio-economic and health impacts worldwide. This highlights the fact that CoVs continue to evolve and have the genetic flexibility to become highly pathogenic in humans and other mammals. SARSCoV-2 carries a high genetic homology to the previously identified CoV (SARS-CoV), and the immunological and pathogenic characteristics of SARS-CoV-2, SARS-CoV, and MERS contain key similarities and differences that can guide therapy and management. This review presents salient and updated information on comparative pathology, molecular pathogenicity, immunological features, and genetic characterization of SARS-CoV, MERS-CoV, and SARS-CoV-2; this can help in the design of more effective vaccines and therapeutics for countering these pathogenic CoVs. [ABSTRACT FROM AUTHOR]

This article focuses on approximating an ellipse with four circular arcs. It explains that elliptic forms are difficult to produce since they have a continuously varying curvature. The article also discusses the basic requirements of the four circular arc approximation of an ellipse as well as the concise outline of the steps needed to derive geometric vision of all four arc constructions. It notes that the arcs need to pass through the external points A and B of the ellipse and that they have tangent continuity at T where they join.

The article discusses a method of visualizing Vandermonde's convolution, also known as the Chu-Vandermonde convolution, on the extended Pascal's triangle. The binomial coefficient represents the number of different combinations of n distinct objects taken k at a time without repetition. The exercise provides a simpler way to visualize a complex identity and can be shown to students whenever the coefficients are introduced. Examples showing the visual method of dealing with Vandermonde's convolution are presented.

The article focuses on a short note whose purpose is to derive several relations for the inradius r of a triangle. In addition the authors use to explore some facts regarding Pythagorean and Heronian triangles. A Pythagorean triangle is a right triangle with all three sides integers, and a Heronian triangle has all three sides and area given by integers. A primitive Pythagorean triangle is one in which all three sides have no common factor. Some of the theorems proved in the article are, that the inradius of a Pythagorean triangle is an integer and the inradius of a Heronian triangle is a rational number.

The article presents the methods in the modification of old QuickBASIC programs so that they will run in Visual BASIC programs. The old QuickBASIC program should be saved in the ASCII code format, drag the mouse onto the form to display the command button. The command button is to be double click to open the window for Visual BASIC code and insert the old Quick BASIC file. The old commands must be changed with the new commands using the tables or replacement of some codes. Methods on how to run and end the program are discussed as well as saving the project.

Illustrates how Pythagorean triangles can be constructed from the geometric parameters of m and n. Construction of primitive Pythagorean triangle from parameters m and n; Calculation of triangle lengths.