Two-Twistor Space, Commuting Composite Minkowski Coordinates and Particle Dynamics

We employ the modification of the basic Penrose formula in twistor theory, which allows to introduce commuting composite space-time coordinates. It appears that in the course of such modification the internal symmetry SU(2) of two-twistor system is broken to U(1). We consider the symplectic form on two-twistor space, permitting to interpret its 16 real components as a phase-space. After a suitable change of variables such a two-twistor phase space is split into three mutually commuting parts, describing respectively the standard relativistic phase space (8 degrees of freedom), the spin sector (6 degrees of freedom) and the canonical pair angle-charge describing the electric charge sector (2 degrees of freedom). We obtain a geometric framework providing a twistor-inspired 18-dimensional extended relativistic phase space $\mathcal{M}^{18}$. In such a space we propose the action only with first class constraints, describing the relativistic particle characterized by mass, spin and electric charge.Comment: LaTeX 2e, 14 pages. To be published in the Proceedings of XIX-th Max Born Symposium "Fundamental Interactions and Twistor-Like Methods", September 2004, American Institute of Physics, Proceedings Serie

Twistors, special relativity, conformal symmetry and minimal coupling - a review

An approach to special relativistic dynamics using the language of spinors and twistors is presented. Exploiting the natural conformally invariant symplectic structure of the twistor space, a model is constructed which describes a relativistic massive, spinning and charged particle, minimally coupled to an external electro-magnetic field. On the two-twistor phase space the relativistic Hamiltonian dynamics is generated by a Poincare scalar function obtained from the classical limit (appropriately defined by us) of the second order, to an external electro-magnetic field minimally coupled, Dirac operator. In the so defined relativistic classical limit there are no Grassman variables. Besides, the arising equation that describes dynamics of the relativistic spin differs significantly from the so called Thomas Bergman Michel Telegdi equation.Comment: 39 pages, no figures, few erronous statements (not affecting anything else in the papper) on page 23 delete

Social work as a career choice (a study of selected variables in the choice of social work as a career)

Thesis (M.S.)--Boston Universit

Public Perceptions of Registry Laws for Juvenile Sex Offenders

Understanding jurors’ perceptions of juvenile defendants has become increasingly important as more and more juvenile cases are being tried in adult criminal court rather than family or juvenile court. Intellectual disability and child maltreatment are overrepresented among juvenile delinquents, and juveniles (particularly disabled juveniles) are at heightened risk for falsely confessing to crimes. In two mock trial experiments, we examined the effects of disability, abuse history, and confession evidence on jurors’ perceptions of a juvenile defendant across several different crime scenarios. Abused juveniles were treated more leniently than nonabused juveniles only when the juvenile’s crime was motivated by self-defense against the abuser. Jurors used disability as a mitigating factor, making more lenient judgments for a disabled than a nondisabled juvenile. Jurors also completely discounted a coerced confession for a disabled juvenile, but not for a nondisabled juvenile. In fact, compared with when it was portrayed as voluntary, jurors generally discounted a juvenile’s coerced confession. Implications for public policy and directions for future research are discussed. Copyright # 2009 John Wiley & Sons, Ltd

A Historical Review and Resource Guide to the Scholarship of Teaching and Training in Psychology and Law and Forensic Psychology

The field of psychology and law, including forensic psychology, is an exciting concentration of research activity and student training and has grown rapidly, but to what extent have teaching and training efforts in the field been systematically catalogued and evaluated? We conducted a historical review and content analysis of the American and Canadian literature on the scholarship of teaching and training in the field. This review catalogs (a) information related to the development of training and teaching, (b) descriptions of programs and courses at various levels, and (c) articles on teaching resources or techniques in this field. We hope it serves as a useful guide to the literature resources for those in the field and a catalyst for future interest in this area of scholarship, especially for future evaluations of teaching and training. (PsycINFO Database Record (c) 2017 APA, all rights reserved

Measuring Radiofrequency and Microwave Radiation from Varying Signal Strengths

This viewgraph presentation discusses the process of measuring radiofrequency and microwave radiation from various signal strengths. The topics include: 1) Limits and Guidelines; 2) Typical Variable Standard (IEEE) Frequency Dependent; 3) FCC Standard 47 CFR 1.1310; 4) Compliance Follows Unity Rule; 5) Multiple Sources Contribute; 6) Types of RF Signals; 7) Interfering Radiations; 8) Different Frequencies Different Powers; 9) Power Summing - Peak Power; 10) Contribution from Various Single Sources; 11) Total Power from Multiple Sources; 12) Are You Out of Compliance?; and 13) In Compliance

Corals Use Similar Immune Cells and Wound-Healing Processes as Those of Higher Organisms

Sessile animals, like corals, frequently suffer physical injury from a variety of sources, thus wound-healing mechanisms that restore tissue integrity and prevent infection are vitally important for defence. Despite the ecological importance of reef-building corals, little is known about the cells and processes involved in wound healing in this group or in phylogenetically basal metazoans in general

Revisiting Clifford algebras and spinors III: conformal structures and twistors in the paravector model of spacetime

This paper is the third of a series of three, and it is the continuation of math-ph/0412074 and math-ph/0412075. After reviewing the conformal spacetime structure, conformal maps are described in Minkowski spacetime as the twisted adjoint representation of the group Spin_+(2,4), acting on paravectors. Twistors are then presented via the paravector model of Clifford algebras and related to conformal maps in the Clifford algebra over the lorentzian R{4,1}$ spacetime. We construct twistors in Minkowski spacetime as algebraic spinors associated with the Dirac-Clifford algebra Cl(1,3)(C) using one lower spacetime dimension than standard Clifford algebra formulations, since for this purpose the Clifford algebra over R{4,1} is also used to describe conformal maps, instead of R{2,4}. Although some papers have already described twistors using the algebra Cl(1,3)(C), isomorphic to Cl(4,1), the present formulation sheds some new light on the use of the paravector model and generalizations.Comment: 17 page

Psychological mechanisms underlying support for juvenile sex offender registry laws: Prototypes, moral outrage, and perceived threat

We investigated whether and how a juvenile’s history of experiencing sexual abuse affects public perceptions of juvenile sex offenders in a series of 5 studies. When asked about juvenile sex offenders in an abstract manner (Studies 1 and 2), the more participants (community members and undergraduates) believed that a history of being sexually abused as a child causes later sexually abusive behavior, the less likely they were to support sex offender registration for juveniles. Yet when participants considered specific sexual offenses, a juvenile’s history of sexual abuse was not considered to be a mitigating factor. This was true when participants considered a severe sexual offense (forced rape; Study 3 and Study 4) and a case involving less severe sexual offenses (i.e., statutory rape), when a juvenile’s history of sexual abuse backfired and was used as an aggravating factor, increasing support for registering the offender (Study 3 and Study 5). Theoretical and practical implications of these results are discussed