Diagnostic Property of COVID-19 by RNA and Antibody Based Tests at any Time of Presentation: a Mathematical Analysis

2021 ◽  
Vol 67 (09/2021) ◽  
Author(s):  
Beuy Joob ◽  
Viroj Wiwanitkit
1967 ◽  
Vol 31 ◽  
pp. 313-317 ◽  
Author(s):  
C. C. Lin ◽  
F. H. Shu

Density waves in the nature of those proposed by B. Lindblad are described by detailed mathematical analysis of collective modes in a disk-like stellar system. The treatment is centered around a hypothesis of quasi-stationary spiral structure. We examine (a) the mechanism for the maintenance of this spiral pattern, and (b) its consequences on the observable features of the galaxy.


Author(s):  
Tim Oliver ◽  
Akira Ishihara ◽  
Ken Jacobsen ◽  
Micah Dembo

In order to better understand the distribution of cell traction forces generated by rapidly locomoting cells, we have applied a mathematical analysis to our modified silicone rubber traction assay, based on the plane stress Green’s function of linear elasticity. To achieve this, we made crosslinked silicone rubber films into which we incorporated many more latex beads than previously possible (Figs. 1 and 6), using a modified airbrush. These films could be deformed by fish keratocytes, were virtually drift-free, and showed better than a 90% elastic recovery to micromanipulation (data not shown). Video images of cells locomoting on these films were recorded. From a pair of images representing the undisturbed and stressed states of the film, we recorded the cell’s outline and the associated displacements of bead centroids using Image-1 (Fig. 1). Next, using our own software, a mesh of quadrilaterals was plotted (Fig. 2) to represent the cell outline and to superimpose on the outline a traction density distribution. The net displacement of each bead in the film was calculated from centroid data and displayed with the mesh outline (Fig. 3).


Author(s):  
Mohammad M. Al-Qattan ◽  
Nada G. AlQadri ◽  
Ghada AlHayaza

Abstract Introduction Herpetic whitlows in infants are rare. Previous authors only reported individual case reports. We present a case series of six infants. Materials and Methods This is a retrospective study of six cases of herpetic whitlows in infants seen by the senior author (MMA) over the past 23 years (1995–2017 inclusive). The following data were collected: age, sex, digit involved in the hand, mode of transmission, time of presentation to the author, clinical appearance, presence of secondary bacterial infection, presence of other lesions outside the hand, method of diagnosis, treatment, and outcome. Results All six infants initially presented with classic multiple vesicles of the digital pulp. In all cases, there was a history of active herpes labialis in the mother. Incision and drainage or deroofing of the vesicles (for diagnostic purposes) resulted in secondary bacterial infection. Conclusion The current report is the first series in the literature on herpetic whitlows in infants. We stress on the mode of transmission (from the mother) and establishing the diagnosis clinically. In these cases, no need for obtaining viral cultures or polymerase chain reaction; and no medications are required. Once the vesicles are disrupted, secondary bacterial infection is frequent and a combination of oral acyclovir and intravenous antibiotics will be required.


2013 ◽  
Vol 41 (2) ◽  
pp. 127-151
Author(s):  
Rudolf F. Bauer

ABSTRACT The benefits of a tire's equilibrium profile have been suggested by several authors in the published literature, and mathematical procedures were developed that represented well the behavior of bias ply tires. However, for modern belted radial ply tires, and particularly those with a lower aspect ratio, the tire constructions are much more complicated and pose new problems for a mathematical analysis. Solutions to these problems are presented in this paper, and for a modern radial touring tire the equilibrium profile was calculated together with the mold profile to produce such tires. Some construction modifications were then applied to these tires to render their profiles “nonequilibrium.” Finite element methods were used to analyze for stress concentrations and deformations within all tires that did or did not conform to equilibrium profiles. Finally, tires were built and tested to verify the predictions of these analyses. From the analysis of internal stresses and deformations on inflation and loading and from the actual tire tests, the superior durability of tires with an equilibrium profile was established, and hence it is concluded that an equilibrium profile is a beneficial property of modern belted radial ply tires.


1986 ◽  
Vol 14 (1) ◽  
pp. 3-32 ◽  
Author(s):  
P. Popper ◽  
C. Miller ◽  
D. L. Filkin ◽  
W. J. Schaffers

Abstract A mathematical analysis of radial tire cornering was performed to predict tire deflections and belt-edge separation strains. The model includes the effects of pure bending, transverse shear bending, lateral restraint of the carcass on the belt, and shear displacements between belt and carcass. It also provides a description of the key mechanisms that act during cornering. The inputs include belt and carcass cord properties, cord angle, pressure, rubber properties, and cornering force. Outputs include cornering deflections and interlaminar shear strains. Key relations found between tire parameters and responses were the optimum angle for minimum cornering deflections and its dependence on cord modulus, and the effect of cord angle and modulus on interlaminar shear strains.


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