Three-Dimensional Analysis of Cartridge Case Double-Casts

Due to the shot-to-shot variability in tool mark reproduction on fired cartridge cases, a method of replication is needed for the creation of training and testing sets. Double-casting is one method that has been used for this application, but the accuracy and variability of this method needs to be characterized. Three firearms were used to fire 25 cartridges each to create the master cartridge cases. The double-casting method consists of creating a silicone mold of the master cartridge case. A plastic resin mix is then poured into the mold to create the double-cast reproduction. Fifteen double-casts of each of the 75 fired cartridge cases were created across different silicone molds to analyze within- and between-mold variability. The master cartridge cases and double-casts were scanned with a confocal microscope (Sensofar® S neox) to create three-dimensional representations of the surfaces. Two similarity metrics were used for the objective comparison of the double-casts to their master cartridge cases: the areal correlation coefficient (ACCF_MAX) and the number of congruent matching cells (CMC). The ACCF_MAX and CMC data, along with visual examinations, showed that the double-casting method produces accurate reproductions. Within-mold variability was found to be minimal, and between-mold variability was low. These results illustrate that double-casting can be applied for training and testing purposes.     

Concurrent Trajectories of Change in Adolescent and Maternal Depressive Symptoms in the TORDIA Study

Depression has a heightened prevalence in adolescence, with approximately 15 % of adolescents experiencing a major depressive episode by age 18. Depression in adolescence also poses a risk for future distress and impairment. Despite treatment advances, many adolescents relapse after initial remission. Family context may be an important factor in the developmental trajectory of adolescent depression, and thus in enhancing treatment. This study examined concurrent change over time in adolescent and maternal depressive symptoms in the context of the Treatment of Resistant Depression in Adolescents study. Participants were 334 adolescents (mean age: 16; SD: 1.6; 70 % female, 84 % Caucasian), and their mothers (n = 241). All adolescents were clinically depressed when they entered the study and had received previous selective serotonin reuptake inhibitor (SSRI) treatment. Adolescents received acute treatment for 12 weeks and additional treatment for 12 more weeks. Adolescent depression and suicidal ideation were assessed at 0, 6, 12, 24, 48 and 72 weeks, while maternal depressive symptoms were assessed at 0, 12, 24, 48 and 72 weeks. Latent basis growth curve analyses showed a significant correlation over 72 weeks between trajectories of maternal and adolescent depressive symptoms, supporting the hypothesis of concurrent patterns of change in these variables. The trajectories were correlated more strongly in a subsample that included only dyads in which mothers reported at least one depressive symptom at baseline. Results did not show a correlation between trajectories of maternal depressive symptoms and adolescent suicidal ideation. These findings suggest that adolescent and maternal depressive symptoms change in tandem, and that treatment for adolescent depression can benefit the wider family system. Notably, most mothers in this sample had subclinical depressive symptoms. Future research might explore these trajectories in dyads with more severely depressed mothers.     

‘Peasantry’ as an economic category

This paper is concerned to challenge the category ‘peasantry’ as defining a distinct and general type of economy. It is divided into three sections: i. an examination of the work of Lenin and Kautsky on capitalism in agriculture which shows that they investigated economies in which peasant production was important without using such a concept; ii. it is argued that no rigorous concept of a ‘peasant’ mode or ‘peasant’ relations of production can be constructed which has the general applicability of the common‐sense notion of ‘peasantry'; iii. the treatment of ‘peasant’ economy in non‐Marxist literature is considered.     

Understanding commenter influence during agency rule development

We provide the first empirical assessment of commenter influence during the rule development stage of administrative rulemaking. We argue that public com‐menters play a critical agenda‐setting role during rule development. To test this proposition, we analyze data from 36 Department of Transportation rules and almost 500 comments. Each of these rules began with an Advance Notice of Proposed Rulemaking—a procedure that allows us to track the formal participation of interested parties during rule development. Our analyses are supplemented by face‐to‐face interviews with agency officials. We find a strong agenda‐setting role for early commenters—both in terms of affecting the content of future regulations and in thwarting unwanted regulations. We conclude that “early‐bird” com‐menters are well positioned to frame public policy debates as rules move through the regulatory process. © 2009 by the Association for Public Policy Analysis and Management.     

Conscience in public administration: More than just a chirping cricket?

The policy and practice of public administration are caught between two seemingly incommensurate goals. Public servants are expected to be responsible to the oversight and control of democratically elected governments, yet, as the policy space becomes more complex, are forced to exercise more judgment and discretion in their responsibilities. Individual, collective, and professional conscience is motivated across this spectrum of challenges. This article explores the concepts of discretion and conscience in theory and practice in the Canadian context. It offers insights into how conscience can, and perhaps must, be both accommodated and supported more appropriately in the practice of 21^st‐century public administration and service. At root, we argue that an array of strategies and approaches may help to build relational reciprocity to a broader set of norms that are necessary for efficient and effective governance.     

Career De-Separation in Westminster Democracies

In Westminster parliamentary systems there was once a clear separation between the careers of public servants and of elected politicians. Politicians decided what policies they wanted to pursue, while public servants advised, devised and delivered the policies. This separation ensured that policy ideas were developed by a professional elite with experience and knowledge. Politicians came from a variety of backgrounds, entering politics for a variety of reasons. Over time, the source of policy advice for ministers has shifted from the professional public servant to political advisers lacking experience and with different career ambitions than public service. Increasingly, elected politicians are becoming ‘professionalised’—emerging from similar party and adviser backgrounds. The de-separation of what were once distinct career paths has led to poorer policy development, increasing public malfeasance, a lower-quality civil service, and democratic disenchantment. We need to separate the career paths once more.     

The use of error rates to predict and characterize the efficacy of presumptive field tests

From a forensic perspective, a presumptive test, one which indicates the presence or absence of a certain target material such as blood, is an invaluable tool. Among these tests, there are different specificities, sensitivities, and shelf lives. The accuracy of a test is an algebraic combination of the specificity and sensitivity of the test. Each test has limitations as given by its false positive and false negative rates. The aim of this study was to illustrate how the false positive and false negative rates are to be properly determined using a simulation study for the phenolphthalein test. New presumptive tests must be properly evaluated/validated through testing of commonly encountered household items and other potentially probative items usually found at crime scenes, however, the makeup of test sets must appropriately capture all error rates. In order to correctly use these results when the test is applied to an unknown sample recovered at a crime scene, the error rates cannot be applied directly to estimate whether or not the sample is actually the analyte of interest. In a validation study, the forensic scientist calculates the false positive rate as the p(Positive Reaction|Blood), whereas at the scene, the crime scene investigator wishes to determine the p(Blood|Positive Reaction). All crime scene investigators need to ensure that the conditional is not transposed when interpreting such results. Furthermore, this work provides a model for the assessment of a multiple test diagnostic system intended for investigators.     

A Bridge Too Far? Examining Bridging Assumptions in Common-Space Estimations

While most common-space estimations rely upon members who served in both the House and Senate as “bridges” to scale the remaining members, this assumes that these “bridge members” do not change their preferences when they change chambers. Such an assumption conflicts with standard notions of representation, that is, that legislators’ votes reflect (at least to some degree) the wishes of their constituents. We examine the constancy of this common-space voting assumption by focusing on a subset of House members who move to the Senate: those who come from statewide House districts. Using these members as the bridge actors—and thus bridging by constituency explicitly—in a one-dimensional item response theory model, we find that the standard assumption of chamber switchers in common-space estimations is technically, but immaterially, false. While there are statistically distinguishable differences in House and Senate voting records for chamber switchers, they are not sufficiently large to meaningfully undermine bridging.     

Timing and Appearance of Postmortem Root Banding in Nonhuman Mammals,

A study was undertaken using nonhuman mammal specimens to better understand environmental influences on postmortem hair root band (PMRB) formation and to see whether PMRBs would occur in nonhuman mammal hairs in a similar fashion to human hairs. Carcasses from surrounding roadways were the primary source of specimens for this study, augmented by donated deceased domestic pets. Sections of pelt from each specimen were placed in controlled environmental conditions while the remainder of the carcass was left in a secure outdoor setting. Hair samples were collected daily from outdoor and control specimens and examined for evidence of PMRBs. Several environmental factors were also recorded on a daily basis. Results demonstrate PMRBs can occur in nonhuman mammal hairs, and they have microscopic characteristics similar to human PMRBs. Factors found to correlate with PMRB formation include postmortem interval, temperature, pH, and the formation and subsequent volatilization of ammonia from the surrounding tissue.