RNA Profiling for the Identification of the Tissue Origin of Dried Stains in Forensic Biology.

Examination of crime scene items for biological evidence typically begins with a preliminary screening for the presence of biological fluids in order to identify possible sources of DNA. Conventional biochemical and immunological assays employed for this screening require multiple tests to be performed in a serial manner, can consume a significant amount of valuable evidentiary material, and can require a significant amount of time and labor for completion. Moreover, the presence of several biological fluids, such as saliva, vaginal secretions, and menstrual blood, cannot be conclusively identified using current methods. Due to the disadvantages of conventional body fluid testing, some operational crime laboratories have chosen to bypass the body fluid identification process and proceed directly to DNA analysis. However, while reducing the time spent on each case, this "shortcut" could result in a failure to provide important probative information regarding the nature of the crime as well as result in increased cost to crime laboratories if unnecessary DNA testing is performed. In the past several years, a number of forensic researchers have attempted to develop molecular-based approaches to body fluid identification that would provide operational crime laboratories with significantly improved specificity. This has resulted in an increased interest in the use of RNA profiling strategies for the identification of forensically relevant biological fluids. This review provides an overview of studies carried out on the use of both messenger RNA and small (micro) RNA profiling. The results of these studies are encouraging and presage the routine identification the tissue source(s) of forensic evidence using molecular-based approaches.

Vagal cardiac control throughout the day: the relative importance of effort-reward imbalance and within-day measurements of mood, demand and satisfaction.

The effects of variables derived from a work stress theory (the effort-reward imbalance theory) on the power in the high frequency (HF_HRV) band of heart rate (0.14-0.40 Hz) throughout a work day, were determined using multilevel analysis. Explanatory variables were analysed at two levels: at the lowest level (within-day level), the effects of positive mood, negative mood, demand, satisfaction, demand-satisfaction ratio, and time of day were assessed. At the highest level (the subject level), the effects of sleep quality, effort, reward, effort-reward imbalance, need for control, type of work (profession), negative affectivity, gender and smoking on HF_HRV were assessed. Need for control has a negative effect on HF_HRV after controlling for time of day effects, i.e. subjects with a high need for control have a lower vagal control of the heart. In the long run, these subjects may be considered to be at increased health risk, because they have less of the health protective effects of vagal tone. The interaction between effort-reward imbalance and time of day has a positive effect on HF_HRV, i.e. the cardiac vagal control of subjects with a high effort-reward imbalance increases as the day progresses. It is discussed that this probably reflects reduced effort allocation, ensuing from disengagement from the work demands.

The validity and reliability of the Dutch Effort-Reward Imbalance Questionnaire.

The reliability and validity of the Effort-Reward Imbalance Questionnaire were tested in 775 blue- and white-collar workers in the Netherlands. Cronbach's alpha revealed sufficient internal consistency of all subscales except Need for Control. With exploratory probabilistic scaling (Mokken) analysis, the psychometric qualities of the Need for Control scale were improved. With confirmatory factor analysis, the factorial validity of the Extrinsic Effort and Reward subscales was confirmed. A model with 3 separate dimensions for reward (status control, esteem reward, and monetary gratification) proved adequate, emphasizing the importance of distinguishing subscales. The congruent validity of the subscales and a hypothesized relationship with an external construct, health functioning, were confirmed.

Cortisol secretion throughout the day, perceptions of the work environment, and negative affect.

The effects of explanatory variables derived from a work stress model (the effort-reward imbalance model) on salivary cortisol were assessed. A multilevel analysis was used to distinguish the effects of single occasion and multiple occasion measurements of work stress and effect on cortisol. The single (or cross-sectional) factors include Effort-Reward Imbalance (ERI), need for control, negative affect, and other enduring factors (type of occupation, gender, and smoking). The multiple occasion measurements include momentary negative mood, Momentary Demand-Satisfaction Ratio (MD-SR), sleep quality, work load (workday versus day off), at work (versus not being at the workplace), and lunch. The effect of time of day on cortisol was controlled for before the effects of these variables were determined. Momentary negative mood but not trait negative affect was positively associated with ambulatory measured cortisol. The variables from the work stress model--effort, reward, need for control, and the multiple occasion measurements of demand and satisfaction--did not affect cortisol. As could be expected, time of day had an effect on cortisol, but a hypothesised interaction with momentary negative mood was not found. Additionally, the results show that the time course of cortisol differs between individuals and that the effect of sleep quality on cortisol can vary from person to person. This points to the necessity of continued efforts to single out sources of individual variability. The finding that variables derived from the effort-reward imbalance model are not related with cortisol does not support the hypothesis that ERI leads to short-term changes in cortisol, indicating no relation with hypothalamic-pituitary-adrenal (HPA) axis activity. On the other hand, the present results invite further qualification of negative affect as a potential determinant of HPA activity, at least, as far as can be deduced from cortisol measurements.