Approximation of a Direction of Nd in Bounded Coordinates

In this paper, we address the following problem: a direction in R ^d is given by a vector with large integral coordinates and we have to find a vector with bounded integral coordinates which realizes a good approximation of this direction. We present a short algorithm that efficiently computes an optimal approximation with respect to the distance to the direction. We then compare experimental results with those of a straightforward rounding algorithm with respect to the distance to the direction and to the angle with it.     

Rice bolus texture changes due to α-amylase

During mastication, starch hydrolysis caused by salivary α-amylase may influence food bolus formation and subsequent breakdown during gastric digestion. The objective of this study was to examine texture changes of rice boluses after simulated mastication. Boluses were prepared with three varieties each of brown and white rice (short, medium, and long grain). After simulated mastication, rice boluses were incubated from 0 to 180 min at 37 °C prior to texture measurement by bulk compression. Saliva was added at concentrations of 0.1 and 0.2 mL saliva/g rice. Boluses were also formed with 0.1 mL/g saliva without α-amylase. The peak force and area under the compression curve were significantly influenced by rice type, saliva level, and incubation time (p < 0.0001). The peak force of the boluses decreased, on average, from 127 to 52 N for brown rice and 111 to 54 N for white rice. Changes in bolus texture were described by a linear-exponential model. For all rice types, bolus texture was significantly lower in the presence of α-amylase. Saliva amount and presence of α-amylase influenced the textural properties of rice boluses during 180 min of incubation. These factors should be carefully considered in future in vitro studies of carbohydrate-based food products.     

Hydrogen peroxide-induced motoneuron apoptosis is prevented by poly ADP ribosyl synthetase inhibitors

The impact of oxidative stress (H2O2) was observed using purified rat motoneuron cultures and H2O2-induced dose-dependent motoneuron death was demonstrated. The apoptotic characteristics of cell death were studied morphologically and using the TUNEL technique. This H2O2-induced motoneuron death was inhibited by the poly ADP ribosyl synthetase (PARS) inhibitors benzamide and nicotinamide. These findings suggest the potential utility of PARS inhibitors in the treatment of neurodegenerative disorders such as amyotrophic lateral sclerosis, in which oxidative stress has been suspected to play an important etiopathogenic role.     

A new approach to the study of plasticizer migration from PVC into methanol

A new approach to the study of the migration rate was attempted for dioctylphthalate as plasticizer from solid PVC into liquid methanol. Two different experiments were carried out: first, a classical one by measuring the increase in the plasticizer concentration in solution; second, a new one by measuring the plasticizer concentration inside the solid PVC itself, for different times and for different depths in that solid. Equations of diffusion in unsteady state were found to correlate well with experiments in both cases. Stirring of the solution measured by Reynold's number was found to be important. Measurements were carried out inside the solid PVC, and the profile of the concentration of dioctylphthalate inside the PVC disc was determined at different times. The diffusion coefficient was calculated inside the PVC disc, and it was found to vary with the DOP concentration.