Reducing Contamination in Forensic Science

The sensitivity of modern forensic techniques has drastically increased, with sensitive technology detecting even the smallest traces of DNA evidence left behind. This has made it possible to detect DNA profiles deposited through contamination. When DNA contamination occurs in forensic science, it has the potential to change the outcome of a criminal investigation and may have significant social and financial repercussions. A compilation of global research shows that DNA evidence transfer can occur during forensic product manufacturing, the fingerprinting process, or even autopsy and crime lab examinations. These vital areas of the forensic investigation are vulnerable to contamination, and national standards should address this susceptibility. Understanding the origins of contamination events provides the greatest insight into preventing their occurrence and maintaining the integrity of forensic evidence

A Lagrangian for water waves

A Lagrangian for strongly nonlinear unsteady water waves (including overturning waves) is obtained. It is shown that the system of quadratic equations for the Stokes coefficients, which determine the shape of a steady wave (discovered by Longuet-Higgins 100 years after Stokes derived his system of cubic equations) directly follows from the canonical system of Lagrange equations. Applications to the investigation of the stability of water waves and to the construction of numerical schemes are pointed out

The suppression of short waves by a train of long waves

It is shown that a train of long waves can suppress a short-wave field due to four-wave resonance interactions. These interactions lead to the diffusion (in Fourier space) of the wave action of the short-wave field, so that the wave action is transported to the regions of higher wavenumbers, where it dissipates more effectively. The diffusion equation is derived

Measuring Productivity Change without Neoclassical Assumptions: A Conceptual Analysis

The measurement of productivity change (or difference) is usually based on models that make use of strong assumptions such as competitive behaviour and constant returns to scale. This survey discusses the basics of productivity measurement and shows that one can dispense with most if not all the usual, neoclassical assumptions. By virtue of its structural features, the measurement model is applicable to individual establishments and aggregates such as industries, sectors, or economies.

Turbulent 4-wave Interaction of Two Type of Waves

We consider turbulent 4-wave interaction of two types of waves: acoustic waves (dispersion $\omega = k$) and electromagnetic-type waves (dispersion $\Omega^2 = m^2 + p^2$). For large wave vectors ($k \gg m$), when the dispersion of EM-type waves becomes quasiacoustic, the stationary spectra are obtained following a standard Zakharov approach. In the small wave number region ($k, p \ll m$) we derive nonlinear differential Kompaneets-type kinetic equation for arbitrary distributions of the interacting fields and find when this equation has Kolmogorov-type power law solutions.Comment: 14 pages, 1 figure, accepted for publication in Physics Letters

Life satisfaction questionnaire (Lisat-9): reliability and validity for patients with acquired brain injury

The aim of this study was to determine the reliability and discriminant validity of the Dutch version of the life satisfaction questionnaire (Lisat-9 DV) to assess patients with an acquired brain injury. The reliability study used a test-retest design, and the validity study used a cross-sectional design. The setting was the general rehabilitation centre. There were 159 patients over 18 years of age, with an acquired brain injury, in the chronic phase. The main outcome measures were weighted kappa of test and retest data on the nine questions of the Lisat-9 DV and significance levels of differences between subgroups of patients who are expected to differ in terms of Lisat-9 scores, on the basis of other instruments. The results were as follows: the reliability was moderate, with the weighted kappa ranging from 0.41 to 0.64. In terms of validity, subgroups of patients who were expected to differ in terms of the Lisat-9 domains did indeed differ significantly, except for the difference in the Lisat score for 'contact with friends and acquaintances' between subgroups defined by higher or lower scores on the corresponding domain of the Frenchay Activities Index. As there was a plausible explanation for not finding a significant difference between subgroups defined by one of the Frenchay Activities Index domains and significant differences were found between the subgroups defined by other instruments corresponding to the same domain, we conclude that the discriminant validity is good. The reliability was not clearly affected by cognitive disorder or aphasia. The conclusions were that the reliability of the Lisat-9 DV for patients with an acquired brain injury was moderate; the discriminant validity was good