Automated detection of regions of interest in cartridge case images using deep learning

This paper explores a deep-learning approach to evaluate the position of circular delimiters in cartridge case images. These delimiters define two regions of interest (ROI), corresponding to the breech face and the firing pin impressions, and are placed manually or by an image-processing algorithm. This positioning bears a significant impact on the performance of the image-matching algorithms for firearm identification, and an automated evaluation method would be beneficial to any computerized system. Our contribution consists in optimizing and training U-Net segmentation models from digital images of cartridge cases, intending to locate ROIs automatically. For the experiments, we used high-resolution 2D images from 1195 samples of cartridge cases fired by different 9MM firearms. Our results show that the segmentation models, trained on augmented data sets, exhibit a performance of 95.6% IoU (Intersection over Union) and 99.3% DC (Dice Coefficient) with a loss of 0.014 for the breech face images; and a performance of 95.9% IoU and 99.5% DC with a loss of 0.011 for the firing pin images. We observed that the natural shapes of predicted circles reduce the performance of segmentation models compared with perfect circles on ground truth masks suggesting that our method provide a more accurate segmentation of the real ROI shape. In practice, we believe that these results could be useful for firearms identification. In future work, the predictions may be used to evaluate the quality of delimiters on specimens in a database, or they could determine the region of interest on a cartridge case image.     

Pulp volume quantification methods in cone-beam computed tomography for age estimation: A critical review and meta-analysis

The secondary dentin deposition that occurs after the tooth formation process results in a decrease in pulp cavity volume in adolescents and adults. The purpose of this critical review was to correlate pulpal and/or dental volume on cone-beam computed tomography (CBCT) with chronological age approximation. A subobjective was to investigate which methodology and CBCT technical parameters would be most appropriate to evaluate this correlation. This critical review followed the PRISMA guidelines, and it was conducted by a search through PubMed, Embase, SciELO, Scopus, Web of Science, Cochrane Library databases, as well as gray literature. Primary studies that used pulp volume, or pulp chamber to tooth volume ratio measured using CBCT were included. Seven hundred and eight indexed and 31 non-indexed records were identified. A qualitative analysis was performed including 25 selected studies with a total of 5100 individuals, age ranging from 8 to 87 years without sex predilection. The most used method was pulp volume/tooth volume. CBCT voxel size ranged between 0.09 and 0.5. Manual segmentation associated with threshold algorithms was used in most of the studies. Correlation between the pulp volume/tooth volume ratio was moderate: −0.66 for the upper central incisors, −0.59 for upper canines and −0.56 for lower canines. High heterogeneity was observed among the studies. It is concluded that pulp volume should be used with caution in age estimation. Evidence supports the preferable use of upper incisors with pulp volume/tooth volume ratio for age estimation. There is not enough evidence that voxel size interferes in age estimation by pulp volume.     

Semiotics and performing arts: contemporary issues

ABSTRACT

Contemporary experiences highlight a crisis in representation which reveals itself through profound changes in the processes and instances at work in the postmodern/post-dramatic performance. As well at the level of production as at the one of reception, important transformations have occurred regarding action, feeling, perception of the stage, fragmentation, crisis of the body mediation, and crisis of the invariant supports of the performance. The consequences of those innovative processes are numerous: they influence the theoretical approaches, and among others the semiotic perspectives. Three types of questions about the relationship between semiotics and nowadays theatrical practices should be explored: First, the place of externality. By reconsidering the issue of the origin of meaning, as general semiotics does, the semiotics of performing arts opens the way for externalizing theories (embodiment, the study of bios/life, and theories of corporeity). Second, the issue of the researcher and in particular his or her exteriority regarding the object. This question points the demand of scientific rigor which characterizes recent research on the performing arts. A paradox which is virtually a dual injunction: the more ephemeral the object, the more imperious the need for scholarship. Although particularly relevant with regard to contemporary concerns centred on the subjectivity of the utterance (presence, effect of presence, intermediality, body–machine relations, etc.), does semiotics still have a universalizing vocation? How can one reproduce the experience of subjectivity?     

Is Public Management Neglecting the State?

Public management is a domain of research that is now roughly three decades old. Researchers in this area have made important advances in understanding about the performance of public organizations. But questions have been raised about the scope and methods of public management research (PMR). Does it neglect important questions about the development of major institutions of the modern state? Has it focused unduly on problems of the advanced democracies? Has it made itself irrelevant to public debates about the role and design of government, and the capacity of public institutions to deal with emerging challenges? This set of eight short essays were prepared for a roundtable held at the research conference of the PMR Association at the University of Aarhus in June 2016. Contributors were asked to consider the question: Is PMR neglecting the state?     

The Anti‐Incumbent Effects of Conditional Cash Transfer Programs

Scholars concur that conditional cash transfer (CCT) programs have a strong proincumbent effect among beneficiaries. Although no study has properly focused on the overall effect of cash transfers on incumbents' national vote shares, most scholars have deduced that this effect is positive; i.e., that cash transfers lead to the expansion of incumbents' electoral bases. This article analyzes survey data from nearly all Latin American countries and confirms that beneficiaries of CCT programs are more likely to support incumbents. However, it also shows that CCT programs may induce many voters who were previously incumbent supporters to vote for the opposition. As a consequence, the overall impact of cash transfers on incumbents' vote shares is indeterminate; it depends on the balance between both patterns of behavioral changes among voters. This study is the first to report evidence that cash transfer programs may have significant anti‐incumbent effects.     

An Ever-Shadowed Past? Citizens’ Attitudes towards the Dictatorship in Twenty-First Century Portugal

Abstract

Several years after the transition to democracy, positive attitudes towards the authoritarian past are still observable in Portugal: the belief that the previous regime had more good things than bad things is expressed by about one-fifth of the Portuguese. What explains this nostalgic sentiment? Are factors such as socialisation under the regime, party identification or religiosity more important than satisfaction with democracy and the state of the economy? The empirical analysis suggests that the relevance of these factors varies considerably, but socialisation phases lead to different stances on the past both in routine times and in times of economic crisis.     

The institutionalisation of the Brazilian Chamber of Deputies

ABSTRACT

This article analyses the institutional development of the Brazilian Chamber of Deputies (BCD) from 1826 to the present. Legislature careers, the internal organisation of the BCD, the current system for filling positions within the committees and electoral rules are the objects of this study. The process of development of the BCD should be understood in light of the dynamics of the Brazilian political system, which has undergone significant ruptures of regime, and also in light of the nearly permanent fragility of the democracy, especially of its representative components. It is an institution with legislature career patterns that vary through time, but always point towards opportunities out of the BCD, a stable, hierarchical and complex mode of organisation that currently values parties as distributors of opportunities. It is, above all, an institution that is subject to external influences from other parts of the political system, which diminish its autonomy and self-determination, as shown by the example of the rule for the adjudication of terms. With its 190 years, the BCD has evolved along with Brazilian democracy and today, although boasting a great structure and large resources, it still needs to establish itself as a decisive and permanent actor in driving public policies and communication (parties and government projects) with voters.     

The gendered construction of expert discourse: An analysis of psychiatric evaluations in criminal court

According to critical literature, psychiatrization is a central feature of gendered social control. It operates in a twofold process: by orienting women to medical institutions rather than the penal system, and, for those women who do enter the criminal justice system, by favoring an interpretation of their behavior in terms of mental health problems. However, the production of gendered social control cannot be reduced to institutional decision-making; it also leaves its traces in various discursive forms. One such form is forensic psychiatrists' discourse on the offenders they evaluate. Our study analyzes these forensic reports as units of a computerized database. Our goal is to gain insight into the text by means of systematic quantitative and qualitative procedures. Even though the expert discourse is shaped by specifications requested by the court, the discourse examined here constructs two very distinct identities that do not correspond to stereotyped conceptions about femininity and masculinity.     

The formation of party preferences: Testing the proximity and directional models

Abstract. We review the methodological debate between defenders of the proximity and directional models. We propose what we believe to be a rigorous and fair test of the two models, using the 1997 Canadian Election Study. The analysis is based on responses to questions in which the various issue positions are explicitly spelled out. We rely on individual perceptions of party positions because it is individual perceptions that matter in the formation of party preferences but we control for projection effects through a multivariate model that incorporates, in addition to indicators of distance and direction, socio–demographic characteristics, party identification, and leader ratings. We also take into account whether a party is perceived to be extreme. The empirical evidence vindicates the proximity model.