Excuses, excuses, excuses

In this humor column, a perinatal educator learns that explanations are not always necessary when one is a grownup.     

Mental pause support

In this column, a childbirth educator humorously discusses a strategy for coping with mental lapses during prenatal classes.     

Evaluation of serum zinc level and plasma SOD activity in senile cataract patients under oxidative stress

An imbalance in the systemic redox status leading to oxidative stress has been an important factor in development of senile cataracts, which is reflected by an increase in serum TBARS and a decrease in plasma SOD activity. Zinc has been an important cofactor required for structural stability of SOD. In the present study the role of serum zinc level and plasma SOD activity was analyzed in senile cataract patients showing significant oxidative stress. Serum TBARS, plasma SOD and serum zinc level was measured in thirty randomly selected senile cataract patients against properly matched controls. Although, the analysis of means showed a significant increase in serum TBARS and decrease in plasma SOD and serum zinc level in cases, but plasma SOD was found to be just significantly correlated (p=0.05) with the serum zinc only in the cases. The results of partial correlation studies and multiple regression analysis, also, showed only a significant correlation and predictable dependence between serum TBARS and plasma SOD, excluding any role of serum zinc level. The present study concludes that it is chiefly the plasma SOD activity, but not the serum zinc level, that determines the proneness of the patients for development of senile cataract.     

Microprocessor-based simulation of sampled data systems with/without a hold device using a set of sample-and-hold functions and Dirac delta functions

In the present work, Dirac delta function (DF) set and sample-and-hold functions (SHF) set are used for microprocessor-based simulation of discrete time as well as sample-and-hold systems. Such simulations are useful for identification of control systems with known input and output sequence. The presented method utilizes operational matrices of different orders in the DF and SHF domain to develop different operational transfer functions. A few open-loop as well as closed-loop systems have been studied and the simulation results obtained are compared with exact solutions derived with the help of z-transform analysis. Experiments have also been carried out to establish the validity of the proposal.     

Safety first

In this humor column, a childbirth educator describes an incident involving the installation of what probably was not a safety seat at all.     

A new set of orthogonal functions and its application to the analysis of dynamic systems

The present work proposes a complementary pair of orthogonal triangular function (TF) sets derived from the well-known block pulse function (BPF) set. The operational matrices for integration in TF domain have been computed and their relation with the BPF domain integral operational matrix is shown. It has been established with illustration that the TF domain technique is more accurate than the BPF domain technique as far as integration is concerned, and it provides with a piecewise linear solution.As a further study, the newly proposed sets have been applied to the analysis of dynamic systems to prove the fact that it introduces less mean integral squared error (MISE) than the staircase solution obtained from BPF domain analysis, without any extra computational burden. Finally, a detailed study of the representational error has been made to estimate the upper bound of the MISE for the TF approximation of a function f(t) of Lebesgue measure.     

Electrons in molecules

The electron density distribution in a molecule determines its stability, geometry and reactivity, in short its chemistry.     

What if ... ?

In this column, a childbirth educator wonders how to impress upon parents the importance of accepting their children for who they are, just as they are.