Showing papers by "University at Buffalo published in 1996"

The Impact of Human Resource Management on Organizational Performance: Progress and Prospects

Abstract: We describe why human resource management (HRM) decisions are likely to have an important and unique influence on organizational performance. Our hope is that this research forum will help advance ...

Intramuscular interferon beta-1a for disease progression in relapsing multiple sclerosis

Abstract: The accepted standard treatment of relapsing multiple sclerosis consists of medications for disease symptoms, including treatment for acute exacerbations. However, currently there is no therapy that alters the progression of physical disability associated with this disease. The purpose of this study was to determine whether interferon beta-1a could slow the progressive, irreversible, neurological disability of relapsing multiple sclerosis. Three hundred one patients with relapsing multiple sclerosis were randomized into a double-blinded, placebo-controlled, multicenter phase I11 trial of interferon beta-la. Interferon beta-la, 6.0 million units (30 μg), was administered by intramuscular injection weekly. The primary outcome variable was time to sustained disability progression of at least 1.0 point on the Kurtzke Expanded Disability Status Scale (EDSS). Interferon beta-la treatment produced a significant delay in time to sustained EDSS progression (p equals; 0.02). The Kaplan-Meier estimate of the proportion of patients progressing by the end of 104 weeks was 34.9% in the placebo group and 21.9% in the interferon beta-la-treated group. Patients treated with interferon beta-la also had significantly fewer exacerbations (p = 0.03) and a significantly lower number and volume of gadolinium-enhanced brain lesions on magnetic resonance images (pvalues ranging between 0.02 and 0.05). Over 2 years, the annual exacerbation rate was 0.90 in placebo-treated patients versus 0.61 in interferon beta-la-treated patients. There were no major adverse events related to treatment. Interferon beta- la had a significant beneficial impact in relapsing multiple sclerosis patients by reducing the accumulation of permanent physical disability, exacerbation frequency, and disease activity measured by gadolinium-enhanced lesions on brain magnetic resonance images. This treatment may alter the hndamen- tal course of relapsing multiple sclerosis.

Crime, Punishment, and the Market for Offenses

Abstract: Crime is a subject of intense emotions, conflicting ideologies. However, economists have generally explained it as a reflection of individual choice and equilibrating market forces. Two major themes of the literature are outlined: the evolution of a 'market model' to explain the diversity of crime across time and space, and the debate about the usefulness of 'positive' versus 'negative' incentives. Systematic analyses generally indicate that crime is affected on the margin by both positive and negative incentives; there are serious limitations to the effectiveness of incapacitation and rehabilitation; and optimal enforcement strategies involve trade-offs between narrow efficiency and equity considerations.

Cohort studies of fat intake and the risk of breast cancer--a pooled analysis.

Abstract: Background. Experiments in animals, international correlation comparisons, and case-control studies support an association between dietary fat intake and the incidence of breast cancer. Most cohort studies do not corroborate the association, but they have been criticized for involving small numbers of cases, homogeneous fat intake, and measurement errors in estimates of fat intake. Methods. We identified seven prospective studies in four countries that met specific criteria and analyzed the primary data in a standardized manner. Pooled estimates of the relation of fat intake to the risk of breast cancer were calculated, and data from study-specific validation studies were used to adjust the results for measurement error. Results. Information about 4980 cases from studies including 337,819 women was available. When women in the highest quintile of energy-adjusted total fat intake were compared with women in the lowest quintile, the multivariate pooled relative risk of breast cancer was 1.05 (95 percent confidence interval, 0.94 to 1.16). Relative risks for saturated, monounsaturated, and polyunsaturated fat and for cholesterol, considered individually, were also close to unity. There was little overall association between the percentage of energy intake from fat and the risk of breast cancer, even among women whose energy intake from fat was less than 20 percent. Correcting for error in the measurement of nutrient intake did not materially alter these findings. Conclusions. We found no evidence of a positive association between total dietary fat intake and the risk of breast cancer. There was no reduction in risk even among women whose energy intake from tat was less than 20 percent of total energy intake. In the context of the Western lifestyle, lowering the total intake of fat in midlife is unlikely to reduce the risk of breast cancer substantially. Chemicals/CAS: Dietary Fats

Revision of the Brief Visuospatial Memory Test: Studies of normal performance, reliability, and validity.

Abstract: There is an increasing demand for alternate-form neuropsychological tests that can be used in clinical trials with little risk of direct practice effect. Although the Brief Visuospatial Memory Test (BVMT) includes six equivalent alternate forms, its administration is limited to an immediate and 25-min delayed free-recall trial. We now present a revised version of the BVMT called the Brief Visuospatial Memory Test-Revised (BVMT-R) that includes three learning trials, a 25-min delayed recall trial, and a delayed yes/no recognition task. A new scoring system, which accounts for the location of test stimuli as well as the accuracy of recall, is also introduced. Using these new administration and scoring procedures, we administered the BVMT-R to 261 neuropsychiatric patients and 456 normal healthy adults. The results indicated that the test has excellent interform reliability, and the construct and criterion-related validity of the test were supported in studies using clinical samples. Although the BVMT-R is not without its limitations, the test's brevity and alternate-form capacity make it a valuable instrument for serial neuropsychological assessments.

Crime, Punishment, and the Market for Offenses

Abstract: Crime is a subject of intense emotions, conflicting ideologies. However, economists have generally explained it as a reflection of individual choice and equilibrating market forces. Two major themes of the literature are outlined: the evolution of a 'market model' to explain the diversity of crime across time and space, and the debate about the usefulness of 'positive' versus 'negative' incentives. Systematic analyses generally indicate that crime is affected on the margin by both positive and negative incentives; there are serious limitations to the effectiveness of incapacitation and rehabilitation; and optimal enforcement strategies involve trade-offs between narrow efficiency and equity considerations.

Ultrafast Computed Tomography as a Diagnostic Modality in the Detection of Coronary Artery Disease A Multicenter Study

Abstract: Background Ultrafast computed tomography (CT), by acquiring images of the proximal coronary arteries, detects coronary calcifications and has been demonstrated to be highly sensitive for the detection of coronary artery disease in many small studies. The aim of this study was to determine the relationship between ultrafast CT scanning and coronary angiography in a large number of symptomatic patients. Methods and Results The study population consisted of 710 patients from six participating centers. A multivariate logistic regression model was used to evaluate the individual contributions of age, number of calcified vessels, and the calcium score for the probability of angiographically significant disease. Of the 710 patients enrolled, 427 patients had significant angiographic disease, and coronary calcification was detected in 404, yielding a sensitivity of 95%. Of the 23 patients without calcifications, 19 (83%) had single-vessel disease at angiography. Of the 283 patients without angiographically signif...

Identifying factors of comfort and discomfort in sitting.

Abstract: We conducted a classification analysis to identify factors associated with sitting comfort and discomfort. The objective was to investigate the possible multidimensional nature of comfort and discomfort. Descriptors of feelings of comfort and discomfort were solicited from office workers and validated in a questionnaire study. From this study, 43 descriptors emerged. The 42 participants rated the similarity of all 903 pairs of descriptors, and we subjected the resulting similarity matrix to multidimensional scaling, factor analysis, and cluster analysis. Two main factors emerged, which were interpreted as comfort and discomfort. Based on these findings, we postulate a hypothetical model for perception of comfort and discomfort. Comfort and discomfort need to be treated as different and complementary entities in ergonomic investigations.

Partial Liquid Ventilation with Perflubron in Premature Infants with Severe Respiratory Distress Syndrome

Abstract: Background The intratracheal administration of a perfluorocarbon liquid during continuous positive-pressure ventilation (partial liquid ventilation) improves lung function in animals with surfactant deficiency. Whether partial liquid ventilation is effective in the treatment of infants with severe respiratory distress syndrome is not known. Methods We studied the efficacy of partial liquid ventilation with perflubron in 13 premature infants with severe respiratory distress syndrome in whom conventional treatment, including surfactant therapy, had failed. Partial liquid ventilation was initiated by instilling perflubron during conventional mechanical ventilation to a volume approximating the functional residual capacity. Infants were considered to have completed the study if they received partial liquid ventilation for at least 24 hours. Results Ten infants received partial liquid ventilation for 24 to 76 hours. In the other three infants, partial liquid ventilation was discontinued within four hours in fa...

Asymmetric Cyclopropanations by Rhodium(II) N-(Arylsulfonyl)prolinate Catalyzed Decomposition of Vinyldiazomethanes in the Presence of Alkenes. Practical Enantioselective Synthesis of the Four Stereoisomers of 2-Phenylcyclopropan-1-amino Acid

Abstract: The rhodium N-(arylsulfonyl)prolinate catalyzed decomposition of vinyldiazomethanes in the presence of alkenes leads to a very general method for the synthesis of functionalized cyclopropanes in a highly diastereoselective and enantioselective mode. A detailed study was undertaken to determine the key factors that control the enantioselectivity of this process. The highest levels of enantioselectivity were obtained using cyclic N-(arylsulfonyl)amino acids as ligands for the dirhodium catalyst, and the optimized catalyst was tetrakis[N-[(4-dodecylphenyl)sulfonyl]-(L)-prolinato]dirhodium. The carbenoid structure has a critical effect on the degree of asymmetric induction, and the combination of a small electron-withdrawing group such as a methyl ester and an electron-donating group such as vinyl or phenyl resulted in the highest levels of enantioselectivity. The use of electron neutral alkenes and pentane as solvent also enhanced the enantioselectivity of the process. The synthetic utility of this chemistry...

Retinoic acid biosynthesis and metabolism.

Abstract: Metabolic activation of retinol into the hormone retinoic acid and metabolism of retinoic acid entail essential aspects of retinoid biology that seem interdependent with functions of retinoid binding-proteins. Cellular retinol binding protein and cellular retinoic acid binding protein enjoy widespread expression and, where expressed, their liganded forms represent the major physiological forms of retinol and retinoic acid, respectively. These retinoid binding proteins may protect cells from the amphipathic properties of retinoids and protect the structurally sensitive retinoids from the cellular milieu. Starting from the perspective that the enzymes most likely to metabolize retinoids in vivo might recognize the major forms of retinoids that occur in vivo, several laboratories have produced results that support a model of retinoid metabolism with prominent roles for the cellular retinoid binding proteins. In this model, liganded cellular retinoid binding proteins serve as substrates for the metabolism of some retinoids (retinol, retinoic acid), restricting access to those enzymes that recognize both the binding protein and the retinoid. Other retinoids (3,4-didehydroretinol, 4-oxo-retinoic acid) liganded to binding-proteins have their metabolism arrested. In its unliganded form, at least one retinoid binding protein (cellular retinol binding protein) serves as a retinoid concentration-sensitive modulator of enzymes that catalyze retinol metabolism. This review will describe the model and the intrinsic relationships among retinoid-specific enzymes and retinoid binding proteins.

The Impact of Security Analysts' Monitoring and Marketing Functions on the Market Value of Firms

Abstract: In this study, we examine the impact of security analysts' monitoring and marketing functions on firms' market value. We postulate that security analysts' monitoring of corporate performance helps motivate managers, thus reducing the agency costs associated with the separation of ownership and control. We also argue that the information intermediary function provided by security analysts helps expand the breadth of investor cognizance. Consistent with these conjectures, this study finds that analyst following exerts a significant and positive impact on firms' market value. We also find evidence that security analysts have a stronger incentive to follow stocks of high-quality companies, since such stocks are easier to market. Hence, the security analysis activities appear to be determined, in part, by the marketing considerations of brokerage companies.

A hyperphosphorylated form of the large subunit of RNA polymerase II is associated with splicing complexes and the nuclear matrix

Abstract: A hyperphosphorylated form of the largest subunit of RNA polymerase II (pol IIo) is associated with the pre-mRNA splicing process Pol IIo was detected in association with a subset of small nuclear ribonucleoprotein particle and Ser-Arg protein splicing factors and also with pre-mRNA splicing complexes assembled in vitro A subpopulation of pol IIo was localized to nuclear "speckle" domains enriched in splicing factors, indicating that it may also be associated with RNA processing in vivo Moreover, pol IIo was retained in a similar pattern following in situ extraction of cells and was quantitatively recovered in the nuclear matrix fraction The results implicate nuclear matrix-associated hyperphosphorylated pol IIo as a possible link in the coordination of transcription and splicing processes

Movement disorders associated with the serotonin selective reuptake inhibitors

Abstract: Background : To review the case reports and case series of movement disorders ascribed to the use of serotonin selective reuptake inhibitors (SSRIs). Method : Reports of SSRI-induced extrapyramidal symptoms (EPS) in the literature were located using a MEDLINE search and review of bibliographies. Results : Among the 71 cases of SSRI-induced EPS reported in the literature, the most common side effect was akathisia (45.1%), followed by dystonia (28.2%), parkinsonism (14.1%), and tardive dyskinesia-like states (11.3%). Among patients with Parkinson's disease treated with SSRIs, there were 16 cases of worsening parkinsonism. Patients who developed dystonia, parkinsonism, or tardive dyskinesia were older on average than patients with akathisia ; 67.6% of affected patients were females. Fluoxetine, the most commonly prescribed SSRI to date, was implicated in 53 (74.6%) of cases of SSRI-induced EPS. Several reports (57.7%) were confounded by the concomitant use of other medications that can contribute to the development of EPS. Conclusion : SSRI-induced EPS are probably related to agonism of serotonergic input to dopaminergic pathways within the CNS. Several patient-dependent and pharmacokinetic variables may determine the likelihood that EPS will emerge. Although these side effects are infrequent, clinicians should be alert to the possibility of their occurrence.

Relationships Between Periodontal Disease and Bacterial Pneumonia.

Abstract: Bacterial pneumonia is a prevalent and costly infection that is a significant cause of morbidity and mortality in patients of all ages. The continuing emergence of antibiotic-resistant bacteria (e.g., penicillin-resistant pneumococci) suggests that bacterial pneumonia will assume increasing importance in the coming years. Thus, knowledge of the pathogenesis of, and risk factors for, bacterial pneumonia is critical to the development of strategies for prevention and treatment of these infections. Bacterial pneumonia in adults is the result of aspiration of oropharyngeal flora into the lower respiratory tract and failure of host defense mechanisms to eliminate the contaminating bacteria, which multiply in the lung and cause infection. It is recognized that community-acquired pneumonia and lung abscesses can be the result of infection by anaerobic bacteria; dental plaque would seem to be a logical source of these bacteria, especially in patients with periodontal disease. It is also possible that patients with high risk for pneumonia, such as hospitalized patients and nursing home residents, are likely to pay less attention to personal hygiene than healthy patients. One important dimension of this personal neglect may be diminished attention to oral hygiene. Poor oral hygiene and periodontal disease may promote oropharyngeal colonization by potential respiratory pathogens (PRPs) including Enterobacteriaceae (Klebsiella pneumoniae, Escherichia coli, Enterobacter species, etc.), Pseudomonas aeruginosa, and Staphylococcus aureus. This paper provides the rationale for the development of this hypothesis especially as it pertains to mechanically ventilated intensive care unit patients and nursing home residents, two patient groups with a high risk for bacterial pneumonia. J Periodontol 1996;67:1114-1122.

Recursive valuation of defaultable securities and the timing of resolution of uncertainty

Abstract: We derive the implications of default risk for valuation of securities in an abstract setting in which the fractional default recovery rate and the hazard rate for default may depend on the market value of the instrument itself, or on the market values of other instruments issued by the same entity (which are determined simultaneously). A key technique is the use of backward recursive stochastic integral equations. We characterize the dependence of the market value on the manner of resolution of uncertainty, and in particular give conditions for monotonicity of value with respect to the information filtration.