How Classical Particles Emerge from the Quantum World.

The symmetrization postulates of quantum mechanics (symmetry for bosons, antisymmetry for fermions) are usually taken to entail that quantum particles of the same kind (e.g., electrons) are all in exactly the same state and therefore indistinguishable in the strongest possible sense. These symmetrization postulates possess a general validity that survives the classical limit, and the conclusion seems therefore unavoidable that even classical particles of the same kind must all be in the same state--in clear conflict with what we know about classical particles. In this article we analyze the origin of this paradox. We shall argue that in the classical limit classical particles emerge, as new entities that do not correspond to the "particle indices" defined in quantum mechanics. Put differently, we show that the quantum mechanical symmetrization postulates do not pertain to particles, as we know them from classical physics, but rather to indices that have a merely formal significance. This conclusion raises the question of whether the discussions about the status of identical quantum particles have not been misguided from the very start

Specifying Graph Languages with Type Graphs

We investigate three formalisms to specify graph languages, i.e. sets of graphs, based on type graphs. First, we are interested in (pure) type graphs, where the corresponding language consists of all graphs that can be mapped homomorphically to a given type graph. In this context, we also study languages specified by restriction graphs and their relation to type graphs. Second, we extend this basic approach to a type graph logic and, third, to type graphs with annotations. We present decidability results and closure properties for each of the formalisms.Comment: (v2): -Fixed some typos -Added more reference

Developing an Actuarial Risk Assessment to Inform the Decisions Made by Adult Protective Service Workers

In 2008, the New Hampshire Department of Health and Human Services Bureau of Elderly and Adult Services (BEAS) and the National Council on Crime and Delinquency (NCCD), with funding provided by the National Institute of Justice (NIJ), collaborated to construct an actuarial risk assessment to classify BEAS clients by their likelihood of elder maltreatment and/or self-neglect in the future. Studies in adult and juvenile corrections and child welfare have demonstrated that active service intervention with high risk clients can reduce criminal recidivism and the recurrence of child maltreatment (Wagner, Hull, & Luttrell, 1995; Eisenberg & Markley, 1987; Baird, Heinz, & Bemus, 1981). The purpose of this research was to examine a large set of individual and referral characteristics, determine their relationship to subsequent elder self-neglect and/or maltreatment, and develop an actuarial risk assessment for BEAS workers to complete at the end of an investigation to inform their case decisions.BEAS and NCCD pursued development of an actuarial risk assessment with the goal of reducing subsequent maltreatment of elderly and vulnerable adults who have been involved in an incident of self-neglect or maltreatment by another person (i.e., abuse, exploitation, or neglect). The actuarial risk assessment described in this report provides BEAS workers with a method to more accurately identify high risk clients and therefore more effectively target service interventions in an effort to protect their most vulnerable clients

Remarks

Over the course of one week, the Michigan Journal of Law Reform presented its annual Symposium, this year titled Reimagining Police Surveillance: Protecting Activism and Ending Technologies of Oppression. During this week, the Journal explored complicated questions surrounding the expansion of police surveillance technologies, including how police and federal agencies utilize their extensive resources to identify and surveil public protest, the ways in which technology employed by police is often flawed and disparately impacts people of color, and potential reforms of police surveillance technology. Before delving into these complicated questions, I presented remarks on the history of police surveillance in America to situate subsequent panel conversations on the topic

Rewriting Abstract Structures: Materialization Explained Categorically

The paper develops an abstract (over-approximating) semantics for double-pushout rewriting of graphs and graph-like objects. The focus is on the so-called materialization of left-hand sides from abstract graphs, a central concept in previous work. The first contribution is an accessible, general explanation of how materializations arise from universal properties and categorical constructions, in particular partial map classifiers, in a topos. Second, we introduce an extension by enriching objects with annotations and give a precise characterization of strongest post-conditions, which are effectively computable under certain assumptions

Collateral Damage? Juvenile Snitches in America’s \u27Wars\u27 on Drugs, Crime and Gangs

The government’s use of children as informants in America’s \u27wars\u27 on drugs, crime, and gangs is little recognized and rarely discussed by scholars, policymakers, and the public. As with many governmental practices, only notorious instances make headlines, such as when a child is killed in retaliation for informing. Because public attention rarely is focused on the practice, it has not generated consistent documentation of, regulation of, or accountability for such use of child informants. As a starting point for discussion, this article illuminates the experiences of child informants, describing a facet of the snitching institution that generally operates under the radar. The article then considers the government’s use of child informants in light of its historical child protection function and its contemporary war-like stance regarding the domestic social problems of drugs, crime, and gangs. The article posits that the government’s use of child informants creates discord between the doctrine of parens patriae, which is aimed at protecting children, and the exercise of police power to further public safety. Further, the article observes that the substantial harms posed to child informants are viewed as collateral and bearable consequences in light of the valuable information obtained from child informants. In conclusion, the article asserts that the use of children as informants should be a closely-monitored and limited investigative method and delineates prophylactic measures restricting their use

Criminal Law as Family Law

The criminal justice system has expanded dramatically over the last several decades, extending its reach into family life. This expansion has disproportionately and negatively impacted Black communities and social networks, including Black families. Despite these pervasive shifts, legal scholars have virtually ignored the intersection of criminal, family, and racial justice. This Article explores the gap in literature in two respects. First, the Article weaves together criminal law, family law, and racial justice by cataloging ways in which the modern criminal justice state regulates family life, particularly for Black families. Second, the Article examines the depth of criminal justice interference in family life and autonomy through analysis of the impact of community supervision on families. These explorations reveal that community supervision, and criminal justice more broadly, operate as a de facto family law regime, negatively restructuring Black family autonomy, stability and loyalty, all of which family law seeks to promote. The Article recommends that the practice of community supervision return to its roots in human services and calls on legal scholars to focus critical attention on criminal law’s creation of disparate and unequal family law systems

Decriminalizing Childhood

Even though the number of juveniles arrested, tried and detained has recently declined, there are still a large number of delinquency cases, children under supervision by state officials, and children living in state facilities for youth and adults. Additionally, any positive developments in juvenile justice have not been evenly experienced by all youth. Juveniles living in urban areas are more likely to have their cases formally processed in the juvenile justice system rather than informally resolved. Further, the reach of the justice system has a particularly disparate effect on minority youth who tend to live in heavily-policed urban areas. The original concept of the juvenile justice system consisted of a singular, informal juvenile court focused on rehabilitating youthful offenders engaged in criminal and noncriminal conduct to help them become productive citizens. The original system has been replaced by a network of juvenile, criminal, and specialty courts, any one of which may adjudicate a child’s court case. Once juveniles enter this complex system, many negative legal impacts can occur, including lengthy periods of community supervision or incarceration and substantial fines and fees. Socially, court-involved youth are more likely to reoffend, experience physical or mental health problems, have poor educational outcomes, and have difficulty in the job market in the future. This Article considers legislative decriminalization of juvenile misconduct, an underutilized method for juvenile justice reform. Decriminalization can prevent youth from entering the juvenile justice system and the problems that stem from system contact. This Article endeavors to begin a conversation among youth scholars, advocates, and policymakers about decriminalization as a mechanism for reforming the juvenile justice systems in the United States