Efficacy of property marking: police identification of stolen property

Property marking, as a situational crime prevention technique, has found to be largely ineffectual in the reduction of property theft, although past studies have not considered the role property marking as an aid to the return of stolen or lost property. However, automotive identification and some studies have found that in some cases property marking is effective. Furthermore, many crime prevention groups focus on property marking as a means to reduce crime and the fear of crime. Therefore, the study investigated the processes of lost, stolen and seized goods by law enforcement personnel. The study undertook a qualitative analysis of law enforcement property identification process, including a documentary analysis of procedures and practitioner interviews for content-thematic analysis. The study found that the use of manufacturer serial numbers was the initial line of investigative enquiry. Limiting factors were technical capability to find and use covert property markings. The successful implementation of a code of best practice or standardisation in the recording of serial numbers, and the availability of the community to quickly and easily record their property may have a significant effect in the reduction of property crimes; due to the perceived increase of risk and potential reduction of reward to the offender

Large Scale Baryon Isocurvature Inhomogeneities

Big bang nucleosynthesis constraints on baryon isocurvature perturbations are determined. A simple model ignoring the effects of the scale of the perturbations is first reviewed. This model is then extended to test the claim that large amplitude perturbations will collapse, forming compact objects and preventing their baryons from contributing to the observed baryon density. It is found that baryon isocurvature perturbations are constrained to provide only a slight increase in the density of baryons in the universe over the standard homogeneous model. In particular it is found that models which rely on power laws and the random phase approximation for the power spectrum are incompatible with big bang nucleosynthesis unless an {\em ad hoc}, small scale cutoff is included.Comment: 11pages + 8figures, LaTeX (2.09), postscript figures available via anonymous ftp from oddjob.uchicago.edu:/ftp/ibbn/fig?.ps where ?=1-8 or via email from [email protected], Fermilab-Pub-94/???-A and UMN-TH-1307/9

GW170817 Most Likely Made a Black Hole

There are two outstanding issues regarding the neutron-star merger event GW170817: the nature of the compact remnant and the interstellar shock. The mass of the remnant of GW170817, $\sim$2.7 $M_\odot$, implies the remnant could be either a massive, rotating, neutron star, or a black hole. We report Chandra Director's Discretionary Time observations made in 2017 December and 2018 January, and we reanalyze earlier observations from 2017 August and 2017 September, in order to address these unresolved issues. We estimate the X-ray flux from a neutron star remnant and compare that to the measured X-ray flux. If we assume that the spin-down luminosity of any putative neutron star is converted to pulsar wind nebula X-ray emission in the 0.5-8 keV band with an efficiency of $10^{-3}$, for a dipole magnetic field with $3 \times 10^{11}$ G < $B$ < $10^{14}$ G, a rising X-ray signal would result and would be brighter than that observed by day 107, we therefore conclude that the remnant of GW170817 is most likely a black hole. Independent of any assumptions of X-ray efficiency, however, if the remnant is a rapidly-rotating, magnetized, neutron star, the total energy in the external shock should rise by a factor $\sim$$10^2$ (to $\sim$$10^{52}$ erg) after a few years, therefore, Chandra observations over the next year or two that do not show substantial brightening will rule out such a remnant. The same observations can distinguish between two different models for the relativistic outflow, either an angular or radially varying structure.Comment: 10 pages, 4 figures, accepted to ApJ

Assessing Alternatives for Directional Detection of a WIMP Halo

The future of direct terrestrial WIMP detection lies on two fronts: new, much larger low background detectors sensitive to energy deposition, and detectors with directional sensitivity. The former can large range of WIMP parameter space using well tested technology while the latter may be necessary if one is to disentangle particle physics parameters from astrophysical halo parameters. Because directional detectors will be quite difficult to construct it is worthwhile exploring in advance generally which experimental features will yield the greatest benefits at the lowest costs. We examine the sensitivity of directional detectors with varying angular tracking resolution with and without the ability to distinguish forward versus backward recoils, and compare these to the sensitivity of a detector where the track is projected onto a two-dimensional plane. The latter detector regardless of where it is placed on the Earth, can be oriented to produce a significantly better discrimination signal than a 3D detector without this capability, and with sensitivity within a factor of 2 of a full 3D tracking detector. Required event rates to distinguish signals from backgrounds for a simple isothermal halo range from the low teens in the best case to many thousands in the worst.Comment: 4 pages, including 2 figues and 2 tables, submitted to PR

Understanding Adolescent Intentions to Smoke: An Examination of Relationships Among Social Influence, Prior Trial Behavior, and Antitobacco Campaign Advertising

Telephone interviews were conducted with more than 900 adolescents aged 12 to 18 as part of a multimillion dollar, statewide, antitobacco advertising campaign. The interviews addressed two primary questions: (1) Do counter-advertising campaign attitudes directly affect antismoking beliefs and intent in a manner similar to those of conventional advertisements? and (2) Can advertising campaign attitudes have a stronger effect on beliefs and intent for adolescents with prior smoking behavior and for adolescents exposed to social influence (i.e., friends, siblings, or adult smoker in the home)? The authors\u27 findings show that advertising campaign attitudes, prior trial behavior, and social influence all directly affect antismoking beliefs and that advertising campaign attitudes interact with prior trial behavior to strengthen antismoking beliefs. The results indicate that attitudes related to the campaign, prior trial behavior, and social influence directly influence intent, and advertising campaign attitudes interact with social influence and prior trial behavior to attenuate adolescent intent to smoke. In addition, the effect of advertising campaign attitudes in attenuating social influence and prior trial behavior effects on adolescent intent to smoke persists even when the authors account for strongly held beliefs about smoking. The authors discuss implications for countermarketing communications and the design and understanding of future antismoking campaigns