On Greenberg's Two-Step Model of Criminal Recidivism

With more than two million people currently incarcerated in U.S. prisons and jails, many of them repeat offenders, there is widespread agreement that criminal recidivism is a serious and costly problem in both human and economic terms. In this article, a stochastic model, which is a somewhat simplified version of a model first proposed by Greenberg, is discussed. An argument for the model is made based on recent theoretical and empirical studies that demonstrate the importance of social bonds in both the commission of and the abstinence from crime. This argument provides a stronger theoretical basis for the model, since it suggests that the model's trichotomization of a cohort of released prisoners reflects truly discrete differences and not just a convenient simplification imposed on a continuous variable. The model is shown to fit trial data sets very well, enabling the measurement of asymptotic recidivism—the ultimate percentage of a release cohort who will recidivate.     

Supermolecular liquid crystal dendrimers based on the octasilsesquioxane core

Liquid crystalline dendrimers are proving to be a fascinating class of materials that possess unusual physical properties. The self-assembling process involved in the formation of the mesomorphic state apparently deforms the spherical disposition of the supermolecular dendrimers to give rod-like entities that pack together to yield disordered Smectic A and smectic C mesophases.     

An argumentation-based approach to risk assesment

Reliable quantitative risk assessment requires the use of meaningfulstatistical data and well validated models for their interpretation.In certain domains, neither the data nor the validated modelsare available. Nevertheless, there may still be a requirementto generate a meaningful characterization of risk, presentedin a form which reflects the reliability and accuracy of thedata available. One such domain is the assessment of the potentialcarcinogenic risk in chemical compounds, and there are manyothers. Work is described which is underway to provide a soundframework for the qualitative assessment of risk using a computermodel of 'argumentation'. This work is being applied to thedevelopment of computer-based support for the assessment ofcarcinogenic risk.     

Finite-Element Approximation of Elliptic Equations with a Neumann or Robin Condition on a Curved Boundary

This paper considers a finite-element approximation of a second-orderself adjoint elliptic equation in a region Rⁿ (with n=2 or 3)having a curved boundary on which a Neumann or Robin conditionis prescribed. If the finite-element space defined over , a union of elements, has approximation power h^kin the L² norm, and if the region of integration is approximatedby ^h with dist (, ^h)Ch^k, then it is shown that one retains optimalrates of convergence for the error in the H¹ and L² norms, whetherQ^h is fitted or unfitted , provided that the numerical integration scheme has sufficientaccuracy.     

PHOTO ACTIVATION OF UROCANASE IN PSEUDOMONAS PUTIDA: FACTORS INFLUENCING ACTIVATION

Abstract— –When washed cells of histidine-grown Pseudomonas putida were incubated at 8°C in darkness, urocanase activity diminished after several days; most of this lost activity could be restored by treatment of cell extracts with near-u.v. light. Sunlight and daylight were also effective for activation. Non-irradiated extract, when added to the active preparation, did not inhibit the enzyme activity. Heated and boiled extracts with or without irradiation did not catalyze the urocanase reaction nor did they change the activity of an activated extract when added to it. Photoactivation of cell extracts did not require oxygen, was not dependent on temperature and was not prevented by dialysis. Urocanase purified by gel electrophoresis was capable of light activation. It is suggested that the photoreceptor is closely associated with urocanase since it is not separated from the enzyme by dialysis or electrophoresis.     

Making Chemical Measurements Using the Lab Works Interface and a Handheld Graphing Calculator

The LabWorks learning system is a computer-controlled data acquisition interface that allows students to quickly obtain and analyze chemistry data. This article describes how the LabWorks interface can be controlled with an HP 48G hand-held calculator rather than a personal computer. The calculator provides users with the same automated data acquisition as if a computer were controlling the interface, but it costs less and requires less maintenance and laboratory bench space. The types of measurements made by the system are discussed and a sample experiment described. Student data and comments are also presented.     

KOLMOGOROV BEHAVIOR OF NEAR-WALL TURBULENCE AND ITS APPLICATION IN TURBULENCE MODELING

The near-wall behavior of turbulence is re-examined in a way different from that proposed by Hanjalic and Launder¹ and followers^2,3,4,5. It is shown that at a certain distance from the wall, all energetic large eddies will reduce to Kolmogorov eddies (the smallest eddies in turbulence). All the important wall parameters, such as friction velocity, viscous length scale, and mean strain rate at the wall, are characterised by Kolmogorov microscales. According t o this Kolmogorov behavior of near-wall turbulence, the turbulence quantities, such as turbulent kinetic energy, dissipation rate, etc. at the location where the large eddies become “Kolmogorov” eddies, can be estimated by using both direct numerical simulation (DNS) data and asymptotic analysis of near-wall turbulence. This information will provide useful boundary conditions for the turbulent transport equations. As a n example, the concept is incorporated in the standard κ - εmodel which is then applied t o channel and boundary layer flows. Using appropriate boundary conditions (based on Kolmogorov behaviour of near-wall turbulence), there is no need for any wall-modification to the κ - ε equations (including model constants). Results compare very well with the DNS and experimental data.     

THE EFFECT OF MONOPSONY POWER ON PRORATIONING AND UNITIZATION REGULATION OF THE COMMON POOL

For four decades beginning in the 1930s, the U.S. oil and gas industry was regulated by a quota‐supported price‐floor instrument known as prorationing. Most economists argue that unitization would have been a more efficient form of regulation. This paper studies how monopsony power held by integrated pipeline/refinery firms affects that conclusion. Absent regulation, the underproduction by monopsony dominates the overproduction from common‐property supply. Thus, unitization, which forces producers to internalize costs, causes output to be further restricted. In contrast, prorationing severs the price‐setting ability of the monopsonist, so can increase output to the first‐best. Under prorationing, at the first‐best output level, the marginal monopsony rents equal the Pigouvian output tax that solves the common‐property problem. Also discussed are the distribution of gains under prorationing and unitization as implemented.     

Hydration of neurotransmitters: a computational and spectroscopic study of a noradrenaline analogue, 2-amino-1-phenyl-ethanol

Singly and multiply hydrated clusters of the noradrenaline analogue, 2-amino-I-phenyl-ethanol (APE) have been studied using a combination of resonant two-photon ionization time of flight spectroscopy (R2PI-TOF), infrared ion-dip spectroscopy and ab initio quantum chemical calculation. Singly hydrated clusters populate two distinct structures: the water molecule either hydrogen-bonds to the ethanol group in the extended AG conformer (leaving the intramolecular OH → N hydrogen bond intact) or inserts into the intramolecular hydrogen bond in the (distorted) ethanolamine side chain (promoting a weak NH → O bond). The observed doubly and triply hydrated clusters both display insertion structures only, with the water molecules arrayed as linear chains, hydrogen bonded to the functional groups of the side-chain and again promoting a weak NH → O bond along the distorted ethanolamine side-chain. The infrared spectrum of the 1:4 cluster of APE, which is very similar to that of the corresponding cluster of ephedrine, includes new features in the ‘window region’ (3500–3700 cm^?1), indicating the onset of a three-dimensional assembly. Comparisons with ab initio computed spectra favour a structure that incorporates a cyclic water tetramer linked to the two functional groups on the ethanolamine side-chain.