The transcriptional machinery in individual cells is controlled by a relatively small number of molecules, which may result in stochastic behavior in gene activity. Because of technical limitations in current collection and recording methods, most gene expression measurements are carried out on populations of cells and therefore reflect average mRNA levels. The variability of the transcript lev...

We study in this work the processing of NaNbO3 ceramics prepared in a single thermal treatment of highly reactive precursors obtained by mechanical activation of different reagents, aiming to determine optimum conditions for piezoelectric ceramics production. Pressure-less sintering at 1200oC leads to dense ceramics (<5% porosity) with poor mechanical stability, unsuitable for practical uses. D...

The normal-Laplace (NL) distribution results from convolving independent normally distributed and Laplace distributed components. It is the distribution of the stopped state of a Brownian motion with normally distributed starting value if the stopping hazard rate is constant. Properties of the NL distribution discussed in the article include its shape and tail behaviour (fatter than the normal)...

The quest for evolutionary mechanisms providing separation between the coding (exons) and noncoding (introns) parts of genomic DNA remains an important focus of genetics. This work combines an analysis of the most recent achievements of genomics and fundamental concepts of random processes to provide a novel point of view on genome evolution. Exon sizes in sequenced genomes show a lognormal dis...

Endophytic fungi were isolated from healthy leaves of Manilkara bidentata (Sapotaceae) collected in Puerto Rico. One leaf was collected from each of three trees. Four 5 X 20 mm panels were cut from each leaf, surface sterilized, cut into 50 1 X 2 mm pieces, and plated on malt agar. Petioles were cut into ten 1 mm segments. Fungi were isolated from 90%-95% of the leaf pieces and all of the petio...

In many fields of science there are multivariate observations which are generated by a (physical) linear mixing process of contributions from different sources. If it is assumed that the composition of the sources is constant for different observations, these observations are, up to measurement error, non-negative linear combinations of a fixed set of so-called source profiles which characteriz...

Visual fixation in infants from 6 months to 2 years of age was examined for its fit to the theory of "attentional inertia." A children's movie ("Sesame Street" movie, "Follow that Bird") or an extended audiovisual stimulus (computer-generated patterns) was presented to 40 children for a minimum of 20 min while fixation was videotaped and heart rate (HR) was recorded. Consistent with attentional...

BACKGROUND/OBJECTIVES The prevalence of obesity in South Africa has risen sharply, as has the consumption of sugar-sweetened beverages (SSBs). Research shows that consumption of SSBs leads to weight gain in both adults and children, and reducing SSBs will significantly impact the prevalence of obesity and its related diseases. We estimated the effect of a 20% tax on SSBs on the prevalence of an...

The distribution of magnetic eld magnitudes is derived for the special case of a constant mean eld and uncorrelated components having Gaussian distributions. Of the three cases considered{ isotropic, transverse, and axisymmetric, the latter most closely resembles a lognormal distribution, when the parallel variance is less than the perpendicular variance. Thus, a normally distributed, non-inter...

Turbulent mixing of an inhomogeneous passive scalar field is studied in the context of a nonpremixed reacting flow. Direct numerical simulations of an initial steplike scalar field subjected to homogeneous sheared turbulence have been performed and the results compared with those of the case of decaying isotropic turbulence. For both flow conditions, the gradient of the conserved scalar tends t...