Showing papers by "Temple University published in 2001"

Peripheral Arterial Disease Detection, Awareness, and Treatment in Primary Care

Abstract: ContextPeripheral arterial disease (PAD) is a manifestation of systemic atherosclerosis that is common and is associated with an increased risk of death and ischemic events, yet may be underdiagnosed in primary care practice.ObjectiveTo assess the feasibility of detecting PAD in primary care clinics, patient and physician awareness of PAD, and intensity of risk factor treatment and use of antiplatelet therapies in primary care clinics.Design and SettingThe PAD Awareness, Risk, and Treatment: New Resources for Survival (PARTNERS) program, a multicenter, cross-sectional study conducted at 27 sites in 25 cities and 350 primary care practices throughout the United States in June-October 1999.PatientsA total of 6979 patients aged 70 years or older or aged 50 through 69 years with history of cigarette smoking or diabetes were evaluated by history and by measurement of the ankle-brachial index (ABI). PAD was considered present if the ABI was 0.90 or less, if it was documented in the medical record, or if there was a history of limb revascularization. Cardiovascular disease (CVD) was defined as a history of atherosclerotic coronary, cerebral, or abdominal aortic aneurysmal disease.Main Outcome MeasuresFrequency of detection of PAD; physician and patient awareness of PAD diagnosis; treatment intensity in PAD patients compared with treatment of other forms of CVD and with patients without clinical evidence of atherosclerosis.ResultsPAD was detected in 1865 patients (29%); 825 of these (44%) had PAD only, without evidence of CVD. Overall, 13% had PAD only, 16% had PAD and CVD, 24% had CVD only, and 47% had neither PAD nor CVD (the reference group). There were 457 patients (55%) with newly diagnosed PAD only and 366 (35%) with PAD and CVD who were newly diagnosed during the survey. Eighty-three percent of patients with prior PAD were aware of their diagnosis, but only 49% of physicians were aware of this diagnosis. Among patients with PAD, classic claudication was distinctly uncommon (11%). Patients with PAD had similar atherosclerosis risk factor profiles compared with those who had CVD. Smoking behavior was more frequently treated in patients with new (53%) and prior PAD (51%) only than in those with CVD only (35%; P <.001). Hypertension was treated less frequently in new (84%) and prior PAD (88%) only vs CVD only (95%; P <.001) and hyperlipidemia was treated less frequently in new (44%) and prior PAD (56%) only vs CVD only (73%, P<.001). Antiplatelet medications were prescribed less often in patients with new (33%) and prior PAD (54%) only vs CVD only (71%, P<.001). Treatment intensity for diabetes and use of hormone replacement therapy in women were similar across all groups.ConclusionsPrevalence of PAD in primary care practices is high, yet physician awareness of the PAD diagnosis is relatively low. A simple ABI measurement identified a large number of patients with previously unrecognized PAD. Atherosclerosis risk factors were very prevalent in PAD patients, but these patients received less intensive treatment for lipid disorders and hypertension and were prescribed antiplatelet therapy less frequently than were patients with CVD. These results demonstrate that underdiagnosis of PAD in primary care practice may be a barrier to effective secondary prevention of the high ischemic cardiovascular risk associated with PAD.

We Know Some Things: Parent-Adolescent Relationships in Retrospect and Prospect.

Abstract: This article examines the most important ideas to have emerged from the last 25 years of research on adolescent development in the family context and suggests some directions for the future. Two major sets of questions organize the review. First, how can we best characterize normative family relationships during adolescence, and, more specifically, is adolescence a time of parent A child conflict? Second, how do variations in parent – child relationships affect the developing adolescent? The answer to the first question depends on what is meant by conflict and, more importantly, from whom one gathers data. There is a need for a new perspective on the family, one that emphasizes the different viewpoints and stakes that parents and adolescents bring to their relationship with each other. Special attention should be paid to studies of the mental health of parents of adolescents. With regard to the second question, it is argued that there is enough evidence to conclude that adolescents benefit from having parents who are authoritative: warm, firm, and accepting of their needs for psychological autonomy. Therefore, it would seem most beneficial to institute a systematic, large-scale, multifaceted, and ongoing public health campaign to educate parents about adolescence, one that draws on the collective resources and expertise of health-care professionals, scientists, governmental agencies, community organizations, schools, religious institutions, and the mass media.

Keys with Upward Wildcards for XML

Abstract: The paper proposes a key constraint language for XML and investigates its associated decision problems. The language is defined in terms of regular path expressions extended with downward and upward wildcards, which can not only move down XML document trees, but also upwards. In a uniform syntax it is capable of expressing both absolute keys and relative keys, which are important to hierarchically structured data. In addition, keys defined in the language can be reasoned about efficiently. The paper provides a sound and complete set of inference rules and a cubic time algorithm for determining implication of the keys.

Stock Return Characteristics, Skew Laws, and the Differential Pricing of Individual Equity Options

Abstract: This article provides several new insights into the economic sources of skewness. First, we document the differential pricing of individual equity options versus the market index, and relate it to variations in return skewness. Second, we show how risk aversion introduces skewness in the risk-neutral density. Third, we derive laws that decompose individual return skewness into a systematic component and an idiosyncratic component. Empirical analysis of OEX options and 30 stocks demonstrates that individual risk-neutral distributions differ from that of the market index by being far less negatively skewed. This paper explains the presence and evolution of risk-neutral skewness over time and in the cross-section of individual stocks.

Magnetodendrimers allow endosomal magnetic labeling and in vivo tracking of stem cells

Abstract: Magnetic resonance (MR) tracking of magnetically labeled stem and progenitor cells is an emerging technology, leading to an urgent need for magnetic probes that can make cells highly magnetic during their normal expansion in culture. We have developed magnetodendrimers as a versatile class of magnetic tags that can efficiently label mammalian cells, including human neural stem cells (NSCs) and mesenchymal stem cells (MSCs), through a nonspecific membrane adsorption process with subsequent intracellular (non-nuclear) localization in endosomes. The superparamagnetic iron oxide nanocomposites have been optimized to exhibit superior magnetic properties and to induce sufficient MR cell contrast at incubated doses as low as 1 microg iron/ml culture medium. When containing between 9 and 14 pg iron/cell, labeled cells exhibit an ex vivo nuclear magnetic resonance (NMR) relaxation rate (1/T2) as high as 24-39 s-1/mM iron. Labeled cells are unaffected in their viability and proliferating capacity, and labeled human NSCs differentiate normally into neurons. Furthermore, we show here that NSC-derived (and LacZ-transfected), magnetically labeled oligodendroglial progenitors can be readily detected in vivo at least as long as six weeks after transplantation, with an excellent correlation between the obtained MR contrast and staining for beta-galactosidase expression. The availability of magnetodendrimers opens up the possibility of MR tracking of a wide variety of (stem) cell transplants.

Negotiation of identities in multilingual contexts

Abstract: New theoretical approaches to the study of negotiation of identities in multilingual contexts "The making of an American" - negotiation of identities at the turn of the 20th century, Aneta Pavlenko constructions of identity in political discourse in multilingual Britain, Adrian Blackledge negotiating between bourge and racaille - Verlan as youth identity practice in suburban Paris, Meredith Doran (Pennsylvania State University) Black Deaf or Deaf Black? being Black and Deaf in Britain, Melissa James and Bencie Woll (City University, London) mothers and mother tongue - perspectives on self-construction by mothers of Pakistani heritage, Jean Mills (University of Birmingham) the politics of identity, representation, and the discourses of self-identification, Frances Giampapa (University of Toronto) Alice doesn't live here anymore - foreign language learning and identity reconstruction, Celeste Kinginger (Pennsylvania State University) intersections of literacy and construction of social identities, Benedicta Egbo (University of Windsor) multilingual writers and the struggle for voice in academic discourse, Suresh Canagarajah (City University of New York) identity and language use - the politics of speaking ESL in schools, Jennifer Miller (University of Queensland) sending mixed messages - language minority education at a Japanese public elementary school, Yasuko Kanno (University of Washington)

The Liebowitz Social Anxiety Scale: a comparison of the psychometric properties of self-report and clinician-administered formats

Abstract: Background. The clinician-administered version of the Liebowitz Social Anxiety Scale (LSAS-CA) is a commonly used assessment device for the evaluation of social anxiety disorder and has been shown to have strong psychometric characteristics. Because of its apparently straightforward rating format and potential savings in time and effort, interest in the use of the LSAS as a self-report (LSAS-SR) measure has increased, and the LSAS-SR has been used in a number of studies. However, the psychometric properties of the LSAS-SR have not been well established.Methods. This study examined the psychometric properties of the LSAS-SR in comparison to the LSAS-CA in a sample of 99 individuals with a primary diagnosis of social anxiety disorder and 53 individuals with no current psychiatric disorder.Results. There was little difference between the two versions of the LSAS on any scale or subscale score. Both forms were internally consistent and the subscale intercorrelations for the two forms were essentially identical. Correlations of each LSAS-SR index with its LSAS-CA counterpart were all highly significant. Finally, the convergent and discriminant validity of the two forms of the LSAS was shown to be strong.Conclusion. Results of this study suggest that the self-report version of the LSAS compares well to the clinician-administered version and may be validly employed in the assessment of social anxiety disorder.

Delta-Hedged Gains and the Negative Market Volatility Risk Premium

Abstract: We investigate whether the volatility risk premium is negative by examining the statistical properties of delta-hedged option portfolios (buy the option and hedge with stock). Within a stochastic volatility framework, we demonstrate a correspondence between the sign and magnitude of the volatility risk premium and the mean delta-hedged portfolio returns. Using a sample of S&P 500 index options, we provide empirical tests that have the following general results. First, the delta-hedged strategy underperforms zero. Second, the documented underperformance is less for options away from the money. Third, the underperformance is greater at times of higher volatility. Fourth, the volatility risk premium significantly affects delta-hedged gains even after accounting for jump-fears. Our evidence is supportive of a negative market volatility risk premium.

Drug Synergism: Its Detection and Applications

Abstract: Two drugs that produce overtly similar effects will sometimes produce exaggerated or diminished effects when used concurrently. A quantitative assessment is necessary to distinguish these cases from simply additive action. This distinction is based on the classic pharmacologic definition of additivity that, briefly stated, means that each constituent contributes to the effect in accord with its own potency. Accordingly, the relative potency of the agents, not necessarily constant at all effect levels, allows a calculation using dose pairs to determine the equivalent of either agent and the effect by using the equivalent in the dose-response relation of the reference compound. The calculation is aided by a popular graph (isobologram) that provides a visual assessment of the interaction but also requires independent statistical analysis. The latter can be accomplished from calculations that use the total dose in a fixed-ratio combination along with the calculated additive total dose for the same effect. Different methods may be used, and each is applicable to experiments in which a single drug is given at two different sites. When departures from additivity are found, whether in "two-drug" or "two-site" experiments, the information is useful in designing new experiments for illuminating mechanisms. Several examples, mainly from analgesic drug studies, illustrate this application. Even when a single drug (or site) is used, its introduction places it in potential contact with a myriad of chemicals already in the system, a fact that underscores the importance of this topic in other areas of biological investigation.

The influence of complementarity, compatibility, and relationship capital on alliance performance

Abstract: Value creation through alliances requires the simultaneous pursuit of partners with similar characteristics on certain dimensions and different characteristics on other dimensions. Partnering firms need to have different resource and capability profiles yet share similarities in their social institutions. In this article, the authors empirically examine the impact of partner characteristics on the performance of alliances. In particular, they test hypotheses related to both direct impact of partner characteristics on alliance performance and indirect effects through relational capital aspects of the alliance. Empirical results based on a sample of alliances in the global construction contracting industry suggest that complementarity in partner resources and compatibility in cultural and operational norms have different direct and indirect effects on alliance performance. Accordingly, organizational routines aimed at partner selection need to be complemented by relationship management routines to maximize the potential benefits from an alliance.

Correlation between sagittal plane changes and adjacent segment degeneration following lumbar spine fusion.

Abstract: Adjacent segment degeneration following lumbar spine fusion remains a widely acknowledged problem, but there is insufficient knowledge regarding the factors that contribute to its occurrence. The aim of this study is to analyse the relationship between abnormal sagittal plane configuration of the lumbar spine and the development of adjacent segment degeneration. Eighty-three consecutive patients who underwent lumbar fusion for degenerative disc disease were reviewed retrospectively. Patients with spondylolytic spondylolisthesis and degenerative scoliosis were not included in this study. Mean follow-up period was 5 years. Results were analysed to determine the association between abnormal sagittal configuration and post operative adjacent segment degeneration. Thirty-one out of 83 patients (36.1%) showed radiographic evidence of adjacent segment degeneration. Patients with normal C7 plumb line and normal sacral inclination in the immediate post operative radiographs had the lowest incidence of adjacent level change compared with patients who had abnormality in one or both of these parameters. The difference was statistically significant (P<0.02). There was no statistically significant difference in the incidence of adjacent level degeneration between male and female patients; between posterior fusion alone and combined posterolateral and posterior interbody fusions; and between fusions extending down to the sacrum and fusions stopping short of the sacrum. It was concluded was that normality of sacral inclination is an important parameter for minimizing the incidence of adjacent level degeneration. Retrolisthesis was the most common type of adjacent segment change. Patients with post operative sagittal plane abnormalities should preferably be followed-up for at least 5 years to detect adjacent level changes.

A Temporal Analysis of Earnings Surprises: Profits Versus Losses

Abstract: I show that the median earnings surprise has shifted rightward from small negative (miss analyst estimates by a small amount) to zero (meet analyst estimates exactly) to small positive (beat analyst estimates by a small amount) during the 16 years, 1984 to 1999. I show that a rightward temporal shift in median surprise from negative to positive describes earnings, but neither profits nor losses. Median profit surprise shifts within the positive quadrant, from zero to one cent per share. Median loss surprise shifts within the negative quadrant from extreme negative (about -33 cents per share) to zero. I show that the median surprise for profits exceeds that for losses in every year. I document significant positive temporal trends in both meet and beat analyst estimates for both profits and losses, but I find a greater frequency of profits that either meet or beat analyst estimates in every year. I find a significant positive temporal trend in positive profits that are 'a little bit of good news,' and a significant negative temporal trend in managers who report losses that are an 'extreme amount of bad news.' My results are robust to the four internal validity threats I consider - namely temporal changes in: (1) analyst forecast accuracy, (2) the mix of earnings of one sign preceded by earnings of another sign four quarters ago, (3) the timeliness of the most recent analyst forecast, and (4) the I/B/E/S definition of actual earnings. I find that managers of growth firms are relatively more likely than managers of value firms to report good news profits. I show that when they do report positive profit surprises, managers of growth firms are more likely to report 'a little bit of good news' in every year.

The protein trinity--linking function and disorder.

Abstract: http://biotech.nature.com • SEPTEMBER 2001 • VOLUME 19 • nature biotechnology Interpreting function in terms of specific three-dimensional structure has dominated thinking about proteins for more than 100 years, starting with the lock-and-key proposal of Fischer1 and continuing with the equating of denaturation with loss of specific structure by Wu2 and independently at a slightly later date by Mirsky and Pauling3. This dependence of function on structure is even embedded in our language: unfolded protein and denatured protein are used interchangeably. Furthermore, the avalanche of protein three-dimensional structures determined by X-ray diffraction and by nuclear magnetic resonance (NMR)4 has diverted attention away from alternative views. Numerous counterexample proteins have surfaced over the years—proteins for which lack of three-dimensional structure is required for function. One clear example is calcineurin, a serine/threonine phosphatase that becomes activated by the binding of the Ca2+–calmodulin complex to a region that exists as a disordered ensemble5,6. The disorder spans the calmodulin binding site and is essential for calcineurin function. That is, when calmodulin binds to its target helix, the helix becomes completely surrounded7. Thus, the open, flexible disordered region of calcineurin provides the space needed by calmodulin so it can completely surround its target helix. Even though hundreds of other examples of proteins with intrinsic disorder have surfaced over the past 50 years, review articles on this topic are only just now beginning to appear8–10. Wright and Dyson8 suggested that the existence of proteins with intrinsic protein disorder calls for a reassessment of the protein–structure– function paradigm. Since amino acid sequence determines three-dimensional structure, amino acid sequence should also determine lack of three-dimensional structure. Furthermore, if intrinsic disorder provides the basis for some biological functions, then the operation of natural selection should conserve the lack of folding and thereby preserve those functions that depend on this property. If disorder is indeed encoded by the amino acid sequence, then predictors of disorder should exceed the accuracies expected by chance. Work in our group has used literature and database searches to collect a set of proteins structurally characterized to have regions of disorder, some of which were indicated by NMR to be wholly disordered under physiological conditions. Using this set of proteins with intrinsic disorder, we have set out to construct the predictors needed to test the hypothesis.

Effects of Acute Changes of Plasma Free Fatty Acids on Intramyocellular Fat Content and Insulin Resistance in Healthy Subjects

Abstract: The reason for the 3- to 4-h delay between a rise in plasma free fatty acid (FFA) levels and the development of insulin resistance remains unknown. In the current study, we have tested the hypothesis that the delay may be caused by the need for plasma FFAs to first enter muscle cells and to be re-esterified there before causing insulin resistance. To this end, we have determined intramyocellular triglyceride (IMCL-TG) content with proton nuclear magnetic resonance ((1)H-NMR) spectroscopy in healthy volunteers before and 4 h after lowering of plasma FFAs (with euglycemic-hyperinsulinemic clamping) or after increasing plasma FFAs (with lipid plus heparin infusions). Increasing plasma FFAs (from 516 to 1,207 micromol/l or from 464 to 1,857 micromol/l, respectively) was associated with acute increases in IMCL-TG from 100 to 109 +/- 5% (P < 0.05) or to 133 +/- 11% (P < 0.01), respectively, and with a significant increase in insulin resistance (P < 0.05 after 3.5 h). Lowering of plasma FFAs from 560 to 41 micromol/l was associated with a tendency for IMCL-TG to decrease (from 100 to 95 +/- 3%). Changes in plasma FFAs correlated linearly with IMCL-TG (r = 0.74, P < 0.003). The demonstration that acute changes in plasma FFAs were accompanied by corresponding changes in IMCL-TG and with the development of insulin resistance, taken together with previous reports of a close correlation between IMCL-TG and insulin resistance, supported the notion that accumulation of IMCL-TG is a step in the development of FFA-induced insulin resistance.

Access to Print in Low‐Income and Middle‐Income Communities: An Ecological Study of Four Neighborhoods

Abstract: Building on a growing body of ecological research, this study examines access to print in two low-income and two middle-income neighborhood communities in a large industrial city. It documents the availability of print in these communities, focusing on resources considered to be influential in a child's beginning development as a writer and reader. It describes the likelihood that children will find books and other resources, see signs, labels, and logos, public places (spaces) conducive to reading, books in local preschools, school libraries, and public library branches. Results of the year-long analysis indicated striking differences between neighborhoods of differing income in access to print at all levels of analyses, with middle-income children having a large variety of resources to choose from, while low-income children having to rely on public institutions which provide unequal resources across communities. Such differences in access to print resources may have important implications for children's early literacy development. Fundamentado en un creciente numero de investigaciones ecologicas, este estudio examina el acceso a la escritura en dos comunidades vecinales de bajos ingresos y dos de ingresos medios de una gran ciudad industrial. El estudio documenta la accesibilidad a la escritura en estas comunidades, centrandose en los recursos que se consideran influencias importantes en el desarrollo inicial de los ninos como escritores y lectores. Se describe la posibilidad de que los ninos encuentren libros y otros recursos, ver signos, etiquetas y logos, espacios publicos que conducen a la lectura, libros en los jardines de infantes locales, bibliotecas escolares y bibliotecas publicas. Los resultados del analisis llevado a cabo durante un ano indicaron impactantes diferencias entre los vecindarios de diferente nivel de ingresos en cuanto al acceso a la escritura en todos los niveles de analisis. Los ninos de nivel medio disponen de una amplia variedad de recursos para elegir, en tanto que los ninos de bajos ingresos dependen de las instituciones publicas que proporcionan recursos desiguales en las distintas comunidades. Estas diferencias en el acceso a los recursos escritos podria tener importantes implicancias para la alfabetizacion inicial de los ninos. Aufbauend auf einen anwachsenden Grundstock an okologischer Forschung untersucht diese Studie den Zugang zum Gedruckten in zwei Nachbarschaftsgemeinden mit niedrigen Einkommen und zwei mittleren Einkommens in einer grosen Industriestadt. Sie dokumentiert die Verfugbarkeit von Gedrucktem in diesen Gemeinden mit Hinblick auf jene Mittel, die als beeinflussend auf die beginnende Entwicklung eines Kindes hin zum Schreiber und Leser gelten konnen. Sie beschreibt die Wahrscheinlichkeit, das Kinder Bucher und andere Hilfsmittel finden werden, Schilder, Etiketten und Logos wahrnehmen, sowie offentlich vermittelnde Stellen (Ausstellflachen), die dem Lesen dienen, Buchern in ortlichen Vorschulen, Schul buchereien und offentlichen Buchereien. Die Ergebnisse der einjahrigen Untersuchung liesen auf erstaunliche Unterschiede zwischen den Nachbarschaften mit unterschiedlichen Einkommensstrukturen im Zugang zum Gedruckten auf allen Ebenen der Analyse schliesen, wobei Kinder aus mittleren Einkommen uber eine grose Auswahl an Mitteln verfugen konnen, wahrend Kinder aus niedrigen Einkommen sich auf offentliche Einrichtungen verlassen mussen, die nicht vergleichbare Mittel quer durch die Gemeinden anbieten. Solche Differenzen im Zugang zu Druckerzeugnissen konnen bei Kindern wesentliche Einflusse auf die fruhe Schreib- und Leseentwicklung haben. Partant d'un corps croissant de recherches, cette etude examine l'accessiblite de l'ecrit pour deux groupes sociaux a bas et a moyens revenus d'une grande ville industrielle. Elle apporte des donnees sur les ecrits accessibles a ces deux groupes, en mettant l'accent sur des ressources dont on peut penser qu'elles ont une influence sur le debut du developpement de l'enfant en tant que lecteur et scripteur. Elle decrit quelles possibilites ont les enfants de trouver des livres ou d'autres resssources, signes, panneaux, logos, lieux publics (espaces) incitant a la lecture, livres dans les maternelles, bibliotheques d'ecole, et sections de bibliotheques publiques. Les resultats d'une analyse portant sur une annee montrent des differences frappantes d'accessibilite de l'ecrit a tous les niveaux de l'analyse entre les environnements aux revenus differents, les enfants de milieu aux revenus moyens ayant la possibilite de faire des choix parmi des ressources nombreuses et variees, tandis que les enfants des milieux a bas revenus doivent s'en remettre a des services publics qui procurent des ressources inegales d'un groupe a l'autre. Ces differences d'acces aux ressources ecrites peuvent avoir des consequences importantes sur l'entree dans l'ecrit des jeunes enfants.

Rumination as a common mechanism relating depressive risk factors to depression.

Abstract: Rumination was examined as a potential common mechanism linking risk factors with depression. Initially nondepressed individuals (N = 137) were assessed for presence of a ruminative response style and 4 other hypothesized risk factors for depression. They were followed for 2.5 years. Negative cognitive styles, self-criticism, dependency, neediness, and history of past depression were all significantly associated with rumination. Rumination mediated the predictive relationships of all risk factors except dependency with the number of prospective Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.; American Psychiatric Association, 1987) major depressive episodes (MDEs; definite and subthreshold) during the follow-up period. In contrast, private self-consciousness did not mediate any relationships between risk factors and subsequent MDEs. Thus, rumination, as a special kind of self-focus, may act as a general proximal mechanism through which other vulnerability factors affect depression.

The Role of IL-10 in Promoting Disease Progression in Leishmaniasis

Abstract: To determine the role of IL-10 in cutaneous leishmaniasis, we examined lesion development following Leishmania major infection of genetically susceptible BALB/c mice lacking IL-10. Whereas normal BALB/c mice developed progressive nonhealing lesions with numerous parasites within them, IL-10(-/-) BALB/c mice controlled disease progression, and had relatively small lesions with 1000-fold fewer parasites within them by the fifth week of infection. We also examined a mechanism whereby Leishmania induced the production of IL-10 from macrophages. We show that surface IgG on Leishmania amastigotes allows them to ligate Fc gamma receptors on inflammatory macrophages to preferentially induce the production of high amounts of IL-10. The IL-10 produced by infected macrophages prevented macrophage activation and diminished their production of IL-12 and TNF-alpha. In vitro survival assays confirmed the importance of IL-10 in preventing parasite killing by activated macrophages. Pretreatment of monolayers with either rIL-10 or supernatants from amastigote-infected macrophages resulted in a dramatic enhancement in parasite intracellular survival. These studies indicate that amastigotes of Leishmania use an unusual and unexpected virulence factor, host IgG. This IgG allows amastigotes to exploit the antiinflammatory effects of Fc gamma R ligation to induce the production of IL-10, which renders macrophages refractory to the activating effects of IFN-gamma.

When Workers Flout Convention: A Study of Workplace Incivility

Abstract: Many organizations are concerned about the potential for workplace aggression and violence, yet pay little heed to lesser forms of interpersonal and organizational mistreatment. Drawing from knowledge and experiences of managers, attorneys, law enforcement officers and emergency medical professionals, we report a multi-method, multidisciplinary inductive study addressing two questions: (1) what is the nature of workplace incivility and how does incivility differ from and fit among other types of workplace mistreatment; and (2) what are some implications of incivility for employees and organizations?

Research Report: A Reexamination of IT Investment and the Market Value of the Firm--An Event Study Methodology

Abstract: Evaluating the effectiveness of Information Technology (IT) investments has always been an elusive but important goal of IS researchers. This study builds on a prior study that examined changes in the market value of the firm as reflected by the stock price in response to IT investment announcements. Data on stock prices were analyzed for 238 publicly traded companies. In addition to the stock price analysis, reaction of trading volume to the announcements was also examined to identify whether IT investment announcements affect investors' beliefs about IT value. Potentially confounding factors such as industry, size, and time lag effects were also analyzed. Size and time lag effects were found for all IT investment announcements. Reactions of price and volume were negatively related to firm size and became more positive over time. The positive excess return for smaller firms shows that smaller firms can leverage the lower price/performance ratio of new IT and reap greater rewards from IT investments than larger firms. Also, the result of time lag effect demonstrates that the stock market has recently begun to identify both tangible and intangible benefits of IT investments. For recent IT investment announcements, industry classification and firm size also affected the reactions of stock price to the announcements. This study provides optimism on the stock market reaction to IT investment announcements as well as further insight into the study of IT impacts on organizational performance.

Keys for XML

Abstract: We discuss the definition of keys for XML documents, payingparticular attention to the concept of a relative key, which is commonly used in hierarchically structured documents and scientific databases. � 2002 Published by Elsevier Science B.V.

Immunopathology of secondary‐progressive multiple sclerosis

Abstract: Twenty-three plaques obtained at early autopsy from 2 patients with secondary-progressive multiple sclerosis were examined immunohistochemically for microglia/macrophages, and for immunoglobulins and components of activated complement. Most of the lesions examined in both cases exhibited evidence of low-grade active demyelination of an unusual type (frustrated phagocytosis) in periplaque white matter. This included linear groups of microglia engaging short segments of disrupted myelin that were associated with deposits of C3d, an opsonin formed during complement activation. Similar microglia/C3d/myelin profiles were not observed in newly forming lesions in cases of acute multiple sclerosis or other central white matter diseases. As C3d coupling is known to increase the immunogenicity of potential antigens enormously, present findings point to disrupted myelin close to plaques as a possible source of the putative multiple sclerosis antigen. Ongoing myelin destruction found in a high proportion of old, established plaques was surprising. It suggests that slowly expanding lesions (progressive plaques), in which ongoing myelin breakdown occurs in the absence of florid perivascular cell cuffing or other histological signs of acute inflammation, contribute to disease progression in cases of secondary-progressive multiple sclerosis.

CNS invasion by CD14+/CD16+ peripheral blood-derived monocytes in HIV dementia: perivascular accumulation and reservoir of HIV infection

Abstract: Increases in circulating CD14+/CD16+ monocytes have been associated with HIV dementia; trafficking of these cells into the CNS has been proposed to play an important role in the pathogenesis of HIV-induced neurological disorders. This model suggests that events outside the CNS leading to monocyte activation initiate the process leading to HIV dementia. To investigate the role of this activated monocyte subset in the pathogenesis of HIV dementia, we examined brain specimens from patients with HIV encephalopathy (HIVE), HIV without encephalopathy, and seronegative controls. An accumulation of perivascular macrophages was observed in HIVE. The majority of these cells identified in microglial nodules and in the perivascular infiltrate were CD14+/CD16+. P24 antigen colocalized with both CD14 and CD16 suggesting that the CD14+/CD16+ macrophage is a major reservoir of HIV-1 infection in CNS. Using CD45/LCA staining, the perivascular macrophage was distinguished from resident microglia. In addition to perivascular and nodular localizations, CD16 also stained ramified cells throughout the white matter. These cells were more ramified and abundant than cells positive for CD14 in white matter. Double staining for p24 and CD16 suggests that these cells were often infected with HIV-1. The prominent distribution of CD14+ cells in HIVE prompted our analysis of soluble CD14 levels in cerebrospinal fluid. Higher levels of soluble CD14 (sCD14) were observed in patients with moderate-to-severe HIV dementia, suggesting the utility of sCD14 as a surrogate marker. CD14+/CD16+ monocytes may play a role in other neurological disorders and sCD14 may be useful for evaluating these conditions.

Comparison of Pharmacological Activities of Buprenorphine and Norbuprenorphine: Norbuprenorphine Is a Potent Opioid Agonist

Abstract: Buprenorphine (BUP) is an oripavine analgesic that is beneficial in the maintenance treatment of opiate-dependent individuals. Although BUP has been studied extensively, relatively little is known about norbuprenorphine (norBUP), a major dealkylated metabolite of BUP. We now describe the binding of norBUP to opioid and nociceptin/orphanin FQ (ORL1) receptors, and its effects on [35S]guanosine-5′-O-(γ-thio)triphosphate ([35S]GTPγS) binding mediated by opioid or ORL1 receptors and in the mouse acetic acid writhing test. Chinese hamster ovary cells stably transfected with each receptor were used for receptor binding and [35S]GTPγS binding. NorBUP exhibited high affinities for μ-, δ-, and κ-opioid receptors withKi values in the nanomolar or subnanomolar range, comparable to those of BUP. NorBUP and BUP had low affinities for the ORL1 receptor with Ki values in the micromolar range. In the [35S]GTPγS binding assay, norBUP displayed characteristics distinct from BUP. At the δ-receptor, norBUP was a potent full agonist, yet BUP had no agonist activity and antagonized actions of norBUP and DPDPE. At μ- and κ-receptors, both norBUP and BUP were potent partial agonists, with norBUP having moderate efficacy and BUP having low efficacy. At the ORL1 receptor, norBUP was a full agonist with low potency, while BUP was a potent partial agonist. In the writhing test, BUP and norBUP both suppressed writhing in an efficacious and dose-dependent manner, giving A50 values of 0.067 and 0.21 mg/kg, s.c., respectively. These results highlight the similarities and differences between BUP and norBUP, each of which may influence the unique pharmacological profile of BUP.

Customer value analysis in a heterogeneous market

Abstract: In recent years, customer value has become a major focus among strategy researchers and practitioners as an essential element of a firm's competitive strategy Many firms have been interested in Customer Value Analysis (CVA) which involves a structural analysis of the antecedent factors of perceived value (ie, perceived quality and perceived price) to assess their relative importance in the perceptions of their buyers We develop a statistical approach for performing CVA utilizing a recursive simultaneous equation model that is formulated to accommodate buyer heterogeneity In particular, the proposed finite-mixture methodology allows one to estimate the relative effects and integration rules of perceived value drivers at the market segment level, as well as to simultaneously determine the (unknown) segments themselves We demonstrate the utility of the proposed methodology via an actual commercial application involving a large electric utility company Finally, we discuss the contributions of our research from the perspective of firm strategy and how it may be extended in the future Copyright © 2001 John Wiley & Sons, Ltd

The effect of export assistance program usage on export performance: A contingency explanation

Abstract: On the basis of a synthesis of prior research, the authors develop a model, which integrates export marketing involvement and the use of government export promotion assistance programs as critical variables affecting export performance, and subject it to empirical evaluation. In this context, the authors also investigate organizational and managerial differences among the firms involved in export marketing to ascertain the robustness of and replicate the observed differences in firms’ export marketing involvement behavior. The results indicate that export marketing involvement of firms and firms’ usage of government export assistance programs are important export success factors. However, the relevance of export assistance programs and the role they play vary depending on the dimension of export performance being considered.