An evaluation of the underlying mechanisms of bloodstain pattern analysis error

An experiment was designed to explore the underlying mechanisms of blood disintegration and its subsequent effect on area of origin (AO) calculations. Blood spatter patterns were created through the controlled application of pressurized air (20-80 kPa) for 0.1 msec onto suspended blood droplets (2.7-3.2 mm diameter). The resulting disintegration process was captured using high-speed photography. Straight-line triangulation resulted in a 50% height overestimation, whereas using the lowest calculated height for each spatter pattern reduced this error to 8%. Incorporation of projectile motion resulted in a 28% height underestimation. The AO xy-coordinate was found to be very accurate with a maximum offset of only 4 mm, while AO size calculations were found to be two- to fivefold greater than expected. Subsequently, reverse triangulation analysis revealed the rotational offset for 26% of stains could not be attributed to measurement error, suggesting that some portion of error is inherent in the disintegration process.     

Coupling a ladder to the safety net: reinventing MGNREGA for asset creation

India’s rural employment act (MGNREGA), the world’s largest public works programme, is designed to guarantee wage employment as a statutory right. It is viewed by many as a drain on the public exchequer, as wages are paid but durable assets are not created. Can this safety net be restructured to double up as a ladder of opportunity for the poor without altering its entitlement-based framework? This article shows that implementing four sets of interventions – policy for household livelihood assets, convergence approaches, pro-poor participatory planning, and strengthening accountability, can accelerate the creation of livelihood assets in the lands of the poor.     

Police Personnel Affective Profiles: Differences in Perceptions of the Work Climate and Motivation

The affective profile model was used to investigate individual differences in police personnel perceptions about the working climate and its influences on motivation. The Positive Affect, Negative Affect Schedule (PANAS) was used to assign police personnel, sworn and non-sworn (N = 595), to four affective profiles: self-fulfilling, low affective, high affective, and self-destructive. The work climate was assessed using the Learning Climate Questionnaire (Management Relations and Style, Time, Autonomy and Responsibility, Team Style, Opportunities to Develop, Guidelines on How to do the Job, and Contentedness). Motivation was evaluated using a modified version (to refer specifically to the individual’s work situation) of the Situational Motivation Scale (intrinsic motivation, external regulation, identified regulation, and amotivation). Self-fulfilling individuals scored higher on all work climate dimensions compared to the other three groups. Compared to low positive affect profiles, individuals with profiles of high positive affect scored higher in intrinsic motivation and identified regulation. Self-destructive individuals scored higher in amotivation. Different aspects of the work climate were related to each motivation dimension among affective profiles. Police personnel may react to their work environment depending on their affective profile. Moreover, the extent to which the work influences police personnel’s motivation is also related to the affective profile of the individual.     

Charitable giving in the German welfare state: fiscal incentives and crowding out

There are two ways that government activities influence private charitable giving: (1) government spending on the provision of public goods may cause crowding out of private charitable contributions; and (2) tax incentives may boost private charitable giving. From a sample of German income tax returns, we estimate the elasticity of charitable giving relative to tax incentives, income, and government spending. Using censored quantile regression analysis, we derive results for different points of the underlying distribution of charitable giving. Evaluating overall treasury efficiency, the tax deductibility of charitable donations fosters enough private giving to offset foregone tax revenues.