Vitamin D [Serum 25(OH) cholecalciferol] Insufficiency is Associated With Childhood Asthma: Recent Case-Control Findings From Bangladesh.

Objectives. To evaluate the interaction between childhood asthma and S. 25(OH) cholecalciferol among Bangladeshi children. Methods. This case control study was conducted in child asthma clinic, Bangladesh Shishu Hospital Institute during March-August 2021. Comparison was made between clinically-diagnosed (following GINA guideline) asthmatic children (2-12 years-old) (cases = 87) and age and sex-matched children having no respiratory illness (controls = 90) using SPSS' (Statistical Package for Social Science, V.23.0 Windows) software. Results. Serum 25(OH) cholecalciferol was found to be significantly lower among the cases than the controls (P < .01). The cases had 3.4 times higher likelihood of having low vitamin D (combined deficient + insufficient) than the controls (P < .01). Conclusions. The results of the study demonstrate an association of Serum 25 (OH) cholecalciferol with asthma which underscores the importance of potential future trial to evaluate the efficacy of Vitamin-D supplementation for understanding the outcomes of asthmatic Bangladeshi children.

Percolation in a simple cubic lattice with distortion.

Site percolation in a distorted simple cubic lattice is characterized numerically employing the Newman-Ziff algorithm. Distortion is administered in the lattice by systematically and randomly dislocating its sites from their regular positions. The amount of distortion is tunable by a parameter called the distortion parameter. In this model, two occupied neighboring sites are considered connected only if the distance between them is less than a predefined value called the connection threshold. It is observed that the percolation threshold always increases with distortion if the connection threshold is equal to or greater than the lattice constant of the regular lattice. On the other hand, if the connection threshold is less than the lattice constant, the percolation threshold first decreases and then increases steadily as distortion is increased. It is shown that the variation of the percolation threshold can be well explained by the change in the fraction of occupied bonds with distortion. The values of the relevant critical exponents of the transition strongly indicate that percolation in regular and distorted simple cubic lattices belong to the same universality class. It is also demonstrated that this model is intrinsically distinct from the site-bond percolation model.

Percolation in a distorted square lattice.

This paper presents a Monte Carlo study of percolation in a distorted square lattice, in which the adjacent sites are not equidistant. Starting with an undistorted lattice, the position of the lattice sites are shifted through a tunable parameter α to create a distorted empty lattice. In this model, two occupied neighboring sites are considered to be connected to each other in order to belong to the same cluster, if the distance between them is less than or equal to a certain value, called connection threshold d. While spanning becomes difficult in distorted lattices as is manifested by the increment of the percolation threshold p_{c} with α, an increased connection threshold d makes it easier for the system to percolate. The scaling behavior of the order parameter studied through relevant critical exponents, and the fractal dimension d_{f} of the percolating cluster at p_{c} suggest that this new type of percolation may belong to the same universality class as ordinary percolation. This model can be very useful in various realistic applications since it is almost impossible to find a natural system that is perfectly ordered.