Showing papers by "Temple University published in 1999"

When interventions harm: Peer groups and problem behavior.

Abstract: This article explored developmental and intervention evidence relevant to iatrogenic effects in peer-group interventions. Longitudinal research revealed that "deviancy training" within adolescent friendships predicts increases in delinquency, substance use, violence, and adult maladjustment. Moreover, findings from 2 experimentally controlled intervention studies suggested that peer-group interventions increase adolescent problem behavior and negative life outcomes in adulthood, compared with control youth. The data from both experimental studies suggested that high-risk youth are particularly vulnerable to peer aggregations, compared with low-risk youth. We proposed that peer aggregation during early adolescence, under some circumstances, inadvertently reinforces problem behavior. Two developmental processes are discussed that might account for the powerful iatrogenic effects.

Moments of social inclusion and exclusion race, class, and cultural capital in family-school relationships

Abstract: This article presents a case study of parents' involvement with their third-grade children. Using interviews and classroom observations, the research revealed how some black parents, deeply concemed about the historical legacy of discrimination against blacks in schooling, approach the school with open criticisms. Since educators seek a positive and deferential role for parents in schooling, race appears to play an independent role in parents' ability to comply with educators' requests (although social class also mediates the ways in which black parents express their concerns). The results highlight the difference between possession and activation of capital and the value accorded displays of capital in particular settings. Taken together, the findings suggest the importance of focusing on moments of inclusion and exclusion in examining how individuals activate social and cultural capital

Contrasts and Effect Sizes in Behavioral Research: A Correlational Approach

Abstract: 1. Basic concepts of focused procedures 2. Basic procedures for two groups 3. One-way contrast analysis 4. Contrasts in factorial designs 5. Contrasts in repeated measures 6. Multiple contrasts.

Accounting Accruals and Auditor Reporting Conservatism

Abstract: Accounting accruals are managers' subjective estimates of future outcomes and cannot, by definition, be objectively verified by auditors prior to occurrence. This causes audits of high-accrual firms to pose more uncertainty than audits of low-accrual firms because of potential estimation error and a greater chance that high-accrual firms have undetected asset realization and/or going concern problems that are related to the high level of accruals. One way that auditors can compensate for this risk exposure is to lower their threshold for issuing modified audit reports, an action that will increase modified reports and, therefore, lessen the likelihood of failing to issue a modified report when appropriate. We call this auditor reporting conservatism and test if high-accrual firms in the United States, are more likely to receive modified audit reports for asset realization uncertainties and going concern problems. Empirical results for a large sample of U.S. publicly listed companies support the hypothesis that auditors are more conservative, that is, more likely to issue both types of modified audit reports for high-accrual firms. Further analyses show that income-increasing accruals are somewhat more likely to result in reporting conservatism than income-decreasing accruals, and that only the Big Six group of auditors show evidence of reporting conservatism. These findings add to our understanding of the audit report formation process and the potentially important role played by accounting accruals in that process.

Unpacking authoritative parenting : Reassessing a multidimensional construct

Abstract: This study examines the independent and joint contributions of three core dimensions of authoritative parenting-acceptance-involvement, strictnesssupervision, and psychological autonomy granting-to adolescent adjustment. A sample of 8, 700 14- to IS-year-olds completed questionnaires that included indices of authoritative parenting and a set of instruments assessing different aspects of adjustment. Behavior problems were related more strongly to behavioral control than to psychological autonomy granting. Psychosocial development and internal distress were more strongly associated with both psychological autonomy granting and acceptance-involvement than with behavioral control Academic competence demonstrated significant relations with all three parenting variables. Curvilinear and interactive relations between parenting practices and adolescent adjustment were observed, but the specific pattern varied as a function of outcome assessed. Over the past four decades, a considerable body of research has accumulated on the relation between psychological well-being in childhood and adolescence and two fundamental aspects of parenting: control and acceptance. This literature has consistently shown that parental acceptance, inductive discipline, nonpunitive punishment practices, and consistency in childrearing are each associated with positive developmental outcomes in children (Maccoby & Martin, 1983). Since the early 1970s, this constellation of practices has come to be known as authoritative parenting, one of several prototypic styles of parenting identified in the seminal studies of Diana Baumrind (1967, 1971). Children who are raised in authoritative homes score higher than their peers raised in authoritarian, indulgent, or neglectful homes on a variety of measures of competence, social development, selfperceptions, and mental health (Maccoby & Martin, 1983). Several recent studies have applied Baumrind's model to explain variations in patterns of adolescent development, including academic achievement, psychosocial development, behavior problems, and psychological symptoms (e.g., Dornbusch, Ritter, Leiderman, Roberts, & Fraleigh, 1987; Lamborn, Mounts, Steinberg, & Dornbusch, 1991; Steinberg, Elmen, & Mounts, 1989; Steinberg, Lamborn, Dornbusch, & Darling, 1992; Steinberg, Mounts, Lamborn, & Dornbusch, 1991), and these reports find that adolescents, like their younger counterparts, benefit from authoritative parenting. Although the strong positive effects of authoritative parenting have been more consistently reported in studies of White, rather than nonWhite, youth (see, for example, Baumrind, 1972; Chao, 1994), no large-scale systematic studies ever have indicated that nonauthoritative parenting has more beneficial effects on adolescent development than authoritative parenting, regardless of the population studied. Despite the breadth and consistency of these findings, most empirical studies of parenting practices and adolescent outcomes continue to focus on single dimensions of the parent-child relationship considered independently. They leave unanswered several questions about the precise nature of this relationship. Three questions, in particular, define the focus of the study presented here. The first concerns the effects of parental control, a construct that continues to evolve amidst debate over its conceptualization (Barber, Olsen, & Shagle, 1994). Although the distinction between psychological control-the relative degree of emotional autonomy that parents allowand behavioral control-the level of monitoring and limit setting that parents use-was articulated more than 30 years ago (Schaefer, 1965; see also Barber et al., 1994, and Steinberg, 1990), little empirical research has focused on the differential effects of these types of control. In light of existing theories about the potential impact of parental intrusiveness (e.g., an excess of psychological control) on the development of internalizing problems and the potential impact of parental leniency (e. …

Psychometric properties of the Liebowitz Social Anxiety Scale.

Abstract: Background. The present study provides data on the reliability, validity and treatment sensitivity of the Liebowitz Social Anxiety Scale (LSAS), one of the most commonly used clinician-administered scales for the assessment of social phobia.Method. Three hundred and eighty-two patients from several studies of the treatment of social phobia were evaluated. An independent assessor administered the LSAS to each patient prior to the initiation of treatment. Patients also completed other measures of social anxiety and avoidance, although the specific measures varied across samples.Results. The LSAS and its subscales were normally distributed and demonstrated excellent internal consistency. The convergent validity of the LSAS was demonstrated via significant correlations with other commonly-used measures of social anxiety and avoidance. These correlations also tended to be larger than correlations with measures of depression, especially after treatment. However, the pattern of correlations of LSAS subscales with one another and with the other measures suggest that the fear subscales and the avoidance subscales may not be sufficiently distinct in clinical samples. The LSAS was also demonstrated to be sensitive to the effects of pharmacological treatments of social phobia over time and in comparison to double-blind pill placebo.Conclusion. The LSAS appears to be a reliable, valid and treatment sensitive measure of social phobia. Further study of the LSAS, both in samples with severe social phobia and in community samples, is needed.

Inorganic–Organic Nanotube Composites from Template Mineralization of Tobacco Mosaic Virus

Abstract: The use of biological molecules, assemblies and systems in the development of inorganic materials synthesis continues to offer new and exciting alternatives to conventional synthetic strategies. Biological templates, such as protein cages, viroid capsules, bacterial rhapidosomes, S-layers, multicellular superstructures, biolipid cylinders, and DNA, have been utilized to direct the deposition, assembly, and patterning of inorganic nanoparticles and microstructures. In this paper, we report a new approach to the template-directed synthesis of inorganic±organic nanotubes using tobacco mosaic virus (TMV). TMV is a remarkably stable virion, remaining intact at temperatures up to 60 C and at pH values between 2 and 10. Each viral particle consists of 2130 identical protein subunits arranged in a helical motif around a single strand of RNA to produce a hollow protein tube, 300 18 nm in size, with a 4 nm-wide central channel. The internal and external surfaces of the protein consist of repeated patterns of charged amino acid residues, such as glutamate, aspartate, arginine, and lysine. In principle, these functionalities should offer a wide variety of nucleation sites for surface-controlled inorganic deposition, which, in association with the high thermal and pH stability, could be exploited in the synthesis of unusual materials such as high-aspect-ratio composites and protein-confined inorganic nanowires. Here we show that TMV is a suitable template for reactions such as co-crystallization (CdS and PbS), oxidative hydrolysis (iron oxides), and sol-gel condensation (SiO2) (Fig. 1).

Loss of Cdk4 expression causes insulin-deficient diabetes and Cdk4 activation results in beta-islet cell hyperplasia.

Abstract: To ascertain the role of cyclin-dependent kinase 4 (Cdk4) in vivo, we have targeted the mouse Cdk4 locus by homologous recombination to generate two strains of mice, one that lacks Cdk4 expression and one that expresses a Cdk4 molecule with an activating mutation. Embryonic fibroblasts proliferate normally in the absence of Cdk4 but have a delayed S phase on re-entry into the cell cycle. Moreover, mice devoid of Cdk4 are viable, but small in size and infertile. These mice also develop insulin-deficient diabetes due to a reduction in beta-islet pancreatic cells. In contrast, mice expressing a mutant Cdk4 that cannot bind the cell-cycle inhibitor P16INK4a display pancreatic hyperplasia due to abnormal proliferation of beta-islet cells. These results establish Cdk4 as an essential regulator of specific cell types.

The Researcher's Own Therapy Allegiances: A "Wild Card" in Comparisons of Treatment Efficacy

Abstract: This report examines a possible distortion in the results of comparative treatment studies due to the association of the researcher's treatment allegiances with outcomes of those treatments. In eight past reviews a trend appeared for significant associations between the researcher's allegiance and outcomes of treatments compared. In a new review of 29 studies of treatment comparisons, a similar trend appeared. Allegiance ratings were based not only on the usual reprint method, but also on two new methods: ratings by colleagues who knew the researcher well, and self-ratings by the researchers themselves. The two new allegiance methods Interco related only moderately, but each allegiance measure correlated significantly with outcomes of the treatments compared, and when combined, the three measures explained 69% of the variance in outcomes Such an association can distort comparative treatment results. Our report concludes with how the researcher's allegiance may become associated with treatment outcomes and how studies should deal with these associations.

Dimensions of information systems success

Abstract: The value added by an organization’s IT assets is a critical concern to both research and practice. Not surprisingly, a large number of IS effectiveness measures can be found in the IS literature. What is not clear in the literature is what measures are appropriate in a particular context. In this paper we propose a two-dimensional matrix for classifying IS Effectiveness measures. The first dimension is the type of system studied. The second dimension is the stakeholder in whose interests the system is being evaluated. The matrix was tested by using it to classify IS effectiveness measures from 186 empirical papers in three major IS journals for the last nine years. The results indicate that the classifications are meaningful. Hence, the IS Effectiveness Matrix provides a useful guide for conceptualizing effectiveness measurement in IS research, and for choosing appropriate measures, both for research and practice.

The myb gene family in cell growth, differentiation and apoptosis.

Abstract: The myb gene family consists of three members, named A, B and c-myb which encode nuclear proteins that function as transcriptional transactivators. Proteins encoded by these three genes exhibit a tripartate structure with an N-terminal DNA-binding domain, a central transactivation domain and a C-terminal regulatory domain. These proteins exhibit highest homology in their DNA binding domains and appear to bind DNA with overlapping sequence specificities. Transactivation by myb gene family varies considerably depending on cell type and promoter context suggesting a dependence on interaction with other cell type specific co-factors. While the C-terminal domains of A-Myb and c-Myb proteins exert a negative regulatory effect on their transcriptional transactivation function, the C-terminal domain of B-Myb appears to function as a positive regulator of this activity. One or more of these proteins interact with other transcription factors such as Ets-2, CEBP and NF-M. In addition, expression of these genes is cell cycle-regulated and inhibition of their expression with anti-sense oligonucleotides has been found to affect cell cycle-progression, cell division and/or differentiation. Members of the myb gene family exhibit different temporal and spatial expression patterns suggesting a distinctive function for each of these genes. Gene knockout experiments show that these genes play an essential role in development. Loss of c-myb function results in embryonic lethality due to failure of fetal hepatic hematopoiesis. A-myb null mutant mice, on the other hand are viable but exhibit growth abnormalities, and defects in spermatogenesis and female breast development. While the role of c-myb in oncogenesis is well established, future experiments are likely to provide further clues regarding the role of A-myb and B-myb in tumorigenesis.

The roles of modified input and output in the incidental acquisition of word meanings

Abstract: This article reports an experimental study of the differential effects of premodified input, interactionally modified input, and modified output on the comprehension of directions in a listen-and-do task and the acquisition of new words embedded in the directions. The modified output group achieved higher comprehension and vocabulary acquisition scores than either of the input groups. There was no difference between the premodified and interactionally modified input groups. The advantage of the modified output group is explained in terms of the qualitatively superior dialogic interaction that occurred in this condition rather than in terms of actual language production.

Normative comparisons for the evaluation of clinical significance.

Abstract: Normative comparisons are a procedure for evaluating the clinical significance of therapeutic interventions. This procedure, consisting of comparing data on treated individuals with that of normative individuals, is described, and a step-by-step statistical methodology for conducting normative comparisons in the context of treatment-outcome research is presented. Four examples of the methodology are outlined in detail. Attention is paid to potential theoretical, statistical, and methodological challenges to the implementation of normative comparisons, as well as to the advantages of normative comparisons in providing evidence for the beneficial gains of treatment.

Consolidation and efficiency in the US life insurance industry

Abstract: This paper examines the relationship between mergers and acquisitions, efficiency, and scale economies in the US life insurance industry. We estimate cost and revenue efficiency over the period 1988–1995 using data envelopment analysis (DEA). The Malmquist methodology is used to measure changes in efficiency over time. We find that acquired firms achieve greater efficiency gains than firms that have not been involved in mergers or acquisitions. Firms operating with non-decreasing returns to scale (NDRS) and financially vulnerable firms are more likely to be acquisition targets. Overall, mergers and acquisitions in the life insurance industry have had a beneficial effect on efficiency.

Books Make a Difference: A Study of Access to Literacy.

Abstract: This study examines the impact of an intervention targeting economically disadvantaged children in child care centers. The program was designed to flood over 330 child care centers with high-quality children's books, at a ratio of 5 books per child, and provide 10 hours of training to child-care staff. Conceptualized as a formative experiment, this study examined the project's impact, systematically sampling 400 3- and 4-year-old children randomly selected from 50 centers across 10 regions and 100 control children from comparable child care centers not involved in the project. Children's early literacy skills (receptive language, concepts of print, environmental print, letter name knowledge, concepts of writing, and narrative competence) were assessed prior to and following the study. In addition, a posttest-only sample and a kindergarten sample were included, focusing on the project's longerterm impact. Changes in child care practices were assessed throughout the project, using photographic accounts of the physical environments of classrooms, literacy-related interactions between teachers and children in sample classrooms, and storybook reading activity in both treatment and control classrooms. Process measures indicated enhanced physical access to books, greater verbal interaction around literacy, and more time spent reading and relating to books as a result of the intervention. With greater access, children in the intervention group scored statistically significantly higher than the control group on four of six assessment measures, with gains still very much evident 6 months later in kindergarten. Findings provide powerful support for the physical proximity of books and the psychological support to child care staff on children's early literacy development. ESTE ESTUDIO examina el impacto de una intervencion disenada para ninos de sectores economicamente en desventaja que asistian a centros de atencion para ninos. El programa fue elaborado para colmar de libros infantiles de buena calidad 330 centros, a un promedio de 5 libros por nino, asi como proveer 10 horas de entrenamiento al personal de los centros. Conceptualizado como un experimento de formacion, este estudio examino el impacto del proyecto mediante el muestreo sistematico de 400 ninos de 3 y 4 anos seleccionados al azar en 50 centros de 10 regiones y, 100 ninos control de centros comparables que no estuvieran involucrados en el proyecto. Antes de comenzar el estudio y al final del proyecto se evaluaron las habilidades tempranas de los ninos en comprension del lenguaje, conceptos sobre la escritura, lectura de logos, nombre de las letras, conceptos sobre el lenguaje escrito y competencia narrativa. Ademas se incluyeron una muestra post-test y una muestra de preescolar, poniendo el foco en el impacto del proyecto a largo plazo. Durante el transcurso del proyecto se evaluaron los cambios en las practicas de atencion a los ninos usando fotografias del contexto fisico de las aulas, asi como las interacciones docente-nino relacionadas con la lectoescritura en las aulas de la muestra y las actividades de lectura de cuentos en los grupos de tratamiento y en el grupo de control. Las medidas tomadas durante el proceso indicaron, como resultado de la intervencion, un mayor acceso a los libros, mayor interaccion verbal acerca de la lectoescritura y mas tiempo dedicado a la lectura y a la relacion con los libros. Con mayor acceso al lenguaje escrito, los ninos del grupo de intervencion se desempenaron estadisticamente mejor que los del grupo control en 4 de las 6 medidas de evaluacion; la ventaja de los ninos del grupo de intervencion fue evidente aun seis meses mas tarde, en preescolar. Los hallazgos constituyen evidencia poderosa acerca de los efectos del contacto con los libros y el soporte psicologico al personal de los centros de atencion sobre el desarrollo temprano de la lectoescritura. DIESE STUDIE untersucht die Auswirkungen mit einer gezielten Intervention von wirtschaftlich benachteiligten Kindern in zentralen Kindertagesstatten. Das Progamm wurde darauf ausgerichtet, uber 330 Zentren von Kindertagesstatten mit hochwertigen Buchern zu beliefern, im Verhaltnis von 5 Buchern pro Kind, und die Kinderbetreuer mit jeweils 10 Stunden Training zu versorgen. Als formatives Experiment konzipiert, untersuchte diese Studie die Auswirkungen des Projektes, indem sie systematisch 400 3- und 4-jahrige Kinder wahllos aus 50 Zentren quer uber 10 Regionen aussuchte und zur Kontrolle 100 Kinder aus vergleichbaren zentralen Kindertagesstatten auswahlte, die nicht in das Projekt einbezogen waren. Fruhe Leseund Schreibfertigkeiten der Kinder (rezeptive Sprachanwendung, Konzepte des Ausdrucks, Umweltausdruck und-schrift, Buchstabenkenntnis, Konzepte beim Schreiben, und die Befahigung zum Nacherzahlen) wurden vor und nach erfolgter Studie bewertet. Zusatzlich wurde ein Anschlustest-Alleinbeispiel und ein Kindergarten-Beispiel eingefugt, welche auf die Langzeitauswirkungen des Projekts ausgerichtet waren. Veranderungen in der praktischen Handhabung der Kinderbetreuung wurden uber die ganze Laufzeit des Projektes erfast, durch die Anwendung fotografischer Mittel in gegen standlich Bereichen des Klassenraums, durch lese- und schreibbezogene Wechselbeziehungen zwischen Lehrern und Kindern in ausgewahlten Klassenraumen, und durch das aktive Lesen von Erzahlungen und Geschichte—sowohl in beiden Klassenraumtypen—den betreuten und den kontrollierten. Als Ergebnis dieser Eingriffe zeigten die undersuchten Masnahmen einen verbesserten physischen Zugang zu Buchern, grosere mundliche wechselseitige Beteiligung beim Lesen und Schreiben und mehr mit dem Lesen und dem Zugang zu Buchern verbrachter Zeit. Mit ihrem groseren Zugang erzielten die Kinder in der Interventionsgruppe wesentlich hohere statistische Werte als die Kontrollgruppe bei 4 von 6 Bewertungsmasstaben; mit Verbesserungen, die auch nach sechs Monaten immer noch recht deutlich im Kindergarten erkennbar waren. Die Erkenntnisse unterstutzen ganz erheblich die Bedeutung der physischen Nahe von Buchern und des psychologischen Ruckhalts des Kinderbetreuungspersonals bei der Fruhentwicklung von Lese- und Schreibfertigkeiten. CETTE ETUDE examine l'impact d'une intervention ayant pour cible des enfants de milieu defavorise frequentant des centres de jour pour enfants. Le programme a ete planifie de facon a plonger plus de 330 centres de jour pour enfants dans des livres de haute qualite, a raison de 5 livres par enfant, et de fournir 10 heures d'entrainement aux equipes chargees des enfants. Concue comme une experience de formation, cette etude a examine l'impact du projet en echantillonnant 400 enfants de 3 et 4 ans choisis au hasard dans 50 centres de 10 regions differentes et 100 enfants temoins provenant de centres de jour pour enfants comparables qui n'etaient pas impliques dans le projet. Les competences relatives a l'entree dans l'ecrit (comprehension orale, representations de l'ecrit, ecrits de l'environnement, connaissance du nom des lettres, representations de l'ecriture, et capacites discursives) ont ete evaluees avant et apres l'intervention. On a inclus egalement un echantillon ne passant que le post-test, et un echantillon de jardin d'enfant, en se centrant sur l'impact a plus long terme du projet. On a evalue les changements des pratiques relatives aux enfants tout au long du projet, au moyen de comptes rendus photographiques de l'environnement physique des classes, des interactions maitre-enfants concernant la litteracie dans les classes de l'echantillon, et l'activite de lecture de livres dans les classes de l'intervention et les classes temoins. Les mesures de processus ont montre, suite a l'intervention, un developpement de l'acces physique aux livres, plus d'interactions verbales autour de la litteracie, et plus de temps consacre a la lecture et aux livres. L'acces etant plus important, les enfants du groupe concerne par l'intervention ont obtenu des resultats statistiquement plus eleves que les enfants du groupe controle dans 4 des 6 evaluations effectuees, ces benefices etant encore plus grands six mois apres l'intervention quand ils etaient au jardin d'enfants. Ces resultats fournissent un soutien puissant en faveur d'une proximite physique des livres et un soutien psychologique aux equipes s'occupant des enfants en ce qui concerne le developpement de l'entree des enfants dans l'ecrit.

The Origins of Grammar: Evidence from Early Language Comprehension

Abstract: Theories of language acquisition the intermodel preferential looking paradigm infants' perception of constituent structure single-word speakers' comprehension of word order young children's use of syntactic frames to derive meaning a coalition model of language comprehension.

Depression, hopelessness, suicidality, and related factors in sexual minority and heterosexual adolescents.

Abstract: In the present study, the researchers examined factors related to depression, hopelessness, and suicidality in gay, lesbian, and bisexual adolescents, compared with demographically similar heterosexual adolescents. Sexual minority adolescents reported greater depression, hopelessness, and past and present suicidality than did heterosexual adolescents. However, when controlling for other psychosocial predictors of present distress, significant differences between the 2 samples disappeared. For past suicidality scores, the effects of sexual orientation were reduced, but still significant, when accounting for the other predictor variables. These results suggest that environmental factors associated with sexual orientation, which can be targeted and changed through prevention and intervention efforts, play a major role in predicting distress in this population.

Social Contracts and Marketing Ethics

Abstract: In this article, the authors describe the need and the search to date for a normative moral foundation for marketing. Social contract theory appears promising because of its clear correspondence to...

TESOL and Culture

Abstract: Culture is a central yet underexamined concept in TESOL. In comparison to other fields such as anthropology and cultural studies, there has been little serious discussion and critique of the concept in TESOL over the last two decades. This article offers a reassessment of the notion of culture in TESOL, taking recent work in critical anthropology and cultural studies, and to a lesser degree TESOL itself, as a starting point. It proposes a revised view of culture that is intended to serve TESOL practitioners into the 21st century, or that can at least provide a takeoff point from which such a view may be developed.

Sourcing strategies of U.S. service companies : A modified transaction-cost analysis

Abstract: Global procurement of services has been receiving an increasing amount of managerial attention in recent years. Service firms seem to have begun sourcing part of their service activities from abroad in much the same way as manufacturing firms have sourced components and finished goods in the past 30 years. However, little is known about the nature of service sourcing strategy. In this study, we employ a modified transaction–cost analysis to examine empirically the locational (domestic vs. global sourcing) and the ownership (internal vs. external sourcing) aspects of service sourcing strategy. In addition, performance implications on both the locational and ownership aspects of service sourcing are investigated. The results show that, similar to components and finished goods procurement, supplementary services are sourced globally, either internally or externally. Furthermore, the relationship between asset specificity and internal sourcing of supplementary services is moderated by the level of inseparability and transaction frequency. Finally, internal sourcing and foreign sourcing of supplementary services are negatively related to a service’s market performance. Copyright © 1999 John Wiley & Sons, Ltd.

Retention of heroin and morphine-6 beta-glucuronide analgesia in a new line of mice lacking exon 1 of MOR-1.

Abstract: Morphine produces analgesia by activating mu opioid receptors encoded by the MOR-1 gene. Although morphine-6 beta-glucuronide (M6G), heroin and 6-acetylmorphine also are considered mu opioids, recent evidence suggests that they act through a distinct receptor mechanism. We examined this question in knockout mice containing disruptions of either the first or second coding exon of MOR-1. Mice homozygous for either MOR-1 mutation were insensitive to morphine. Heroin, 6-acetylmorphine and M6G still elicited analgesia in the exon-1 MOR-1 mutant, which also showed specific M6G binding, whereas M6G and 6-acetylmorphine were inactive in the exon-2 MOR-1 mutant. These results provide genetic evidence for a unique receptor site for M6G and heroin analgesia.

Organizational Form and Efficiency: The Coexistence of Stock and Mutual Property-Liability Insurers

Abstract: This article introduces a new approach, cross-frontier analysis, for estimating the relative efficiency of alternative organizational forms in an industry. The technique is illustrated by analyzing a sample of stock and mutual property-liability insurers using nonparametric frontier efficiency methods. Cross-frontier analysis measures the relative efficiency of each organizational form by computing the efficiency of each stock (mutual) firm relative to a reference set consisting of all mutual (stock) firms. We test agency-theoretic hypotheses about organizational form, including the managerial discretion and expense preference hypotheses. The results indicate that stocks and mutuals are operating on separate production and cost frontiers and thus represent distinct technologies. Consistent with the managerial discretion hypothesis, the stock technology dominates the mutual technology for producing stock outputs and the mutual technology dominates the stock technology for producing mutual outputs. However, consistent with the expense preference hypothesis, the stock cost frontier dominates the mutual cost frontier. Our findings thus suggest a richer interpretation of organizational form than provided by previous researchers.

The effects of free fatty acids on gluconeogenesis and glycogenolysis in normal subjects

Abstract: We have quantitatively determined gluconeogenesis (GNG) from all precursors, using a novel method employing 2H20 to address the question of whether changes in plasma free fatty acids (FFA) affect GNG in healthy, nonobese subjects. In the first study (n = 6), plasma FFA were lowered at 16 to 20 hours with nicotinic acid (NA) and were then allowed to rise at 20 to 24 hours (FFA rebound after administration of NA). FFA decreased from 387 μM at 16 hours to 43 μM at 20 hours, and then rebounded to 1,823 μM at 24 hours. GNG decreased from 58.1% at 16 hours to 38.6% of endogenous glucose production at 20 hours (P < 0.005) and then rebounded to 78.9% at 24 hours (P < 0.05). Conversely, glycogenolysis (GL) increased from 41.9% at 16 hours to 61.4% at 20 hours (P < 0.05), and then decreased to 21.1% at 24 hours (P < 0.05). In the second study (controls; n = 6), volunteers were analyzed between 16 and 24 hours after the last meal. FFA rose from 423 to 681 μM (P < 0.05), and GNG from 50.3% to 61.7% (P < 0.02), whereas GL decreased from 49.7% to 38.3% (P < 0.05). Endogenous glucose production decreased at the same rate in both studies, from 10.7 to 8.6 μmol/kg/min (P < 0.05). In study 3 (n = 6), in which the NA-mediated decrease of plasma FFA was prevented by infusion of lipid and heparin, neither FFA nor GNG changed significantly. In summary, our data suggest that (a) acute changes in plasma FFA produce acute changes in GNG and reciprocal changes in GL; (b) the decrease in EGP between 16 and 24 hours of fasting is due to a fall in GL; and (c) NA has no direct effect on GNG.

Social and personal determinants of workplace aggression: Evidence for the impact of perceived injustice and the Type A Behavior Pattern

Abstract: Four hundred fifty-two employed persons rated the frequency with which they had been the victims of a wide range of aggressive actions at work. In addition, they also rated the frequency with which they themselves had aggressed against others in their workplaces. Three hypotheses were investigated: (1) covert forms of aggression, in which aggressors seek to conceal their identity from target persons, are significantly more frequent in workplaces than overt forms of aggression; (2) the greater the perceived injustice reported by employees, the greater their tendency to engage in workplace aggression; and (3) the higher individuals' scores on a measure of the Type A Behavior Pattern, the greater their reported frequency of engaging in various forms of workplace aggression, Results offered support for all three hypotheses. In addition, several demographic variables (participants' age and gender; the physical location of their workplaces) were also found to play a role in the occurrence of workplace aggression. Together, these findings were interpreted as underscoring the importance of establishing close conceptual links between research on workplace aggression andbasic research on human aggression.