Uniqueness logic

A uniqueness type system is used to distinguish values which are referenced at most once from values which may be referenced an arbitrary number of times in a program. Uniqueness type systems are used in the Clean and Mercury programming languages to provide efficiently updatable data-structures and I/O without compromising referential transparency.     

Creativity of undergraduates with and without family history of alcohol and other drug problems

BACKGROUND: Colonoscopic surveillance is a standard procedure in many patients with long standing, extensive ulcerative colitis (UC), in order to avoid death from colorectal cancer. No conclusive proof of its benefits has been presented however. AIMS: To evaluate the association between colonoscopic surveillance and colorectal cancer mortality in patients with UC. PATIENTS: A population based, nested case control study comprising 142 patients with a definite UC diagnosis, derived from a study population of 4664 patients with UC, was conducted. METHODS: Colonoscopic surveillance in all patients with UC who had died from colorectal cancer after 1975 was compared with that in controls matched for age, sex, extent, and duration of the disease. Information on colonoscopic surveillance was obtained from the medical records. RESULTS: Two of 40 patients with UC and 18 of 102 controls had undergone at least one surveillance colonoscopy (relative risk (RR) 0.29, 95% confidence interval 0.06 to 1.31). Twelve controls but only one patient with UC had undergone two or more surveillance colonoscopies (RR 0.22, 95% confidence interval 0.03 to 1.74), indicating a protective dose response relation. CONCLUSION: Colonoscopic surveillance may be associated with a decreased risk of death from colorectal cancer in patients with long standing UC.     

Age differences in trust and reliance of a medication management system

The present study examined age differences in trust and reliance of an automated decision aid. In Experiment 1, older and younger participants performed a simple mathematical task concurrent with a simulated medication management task. The decision aid was designed to facilitate medication management, but with varying reliability. Trust, self-confidence and usage of the aid were measured. The results indicated that older adults had greater trust in the aid and were less confident in their performance, but they did not calibrate trust differently than younger adults. In Experiment 2, a variant of the same task was used to investigate whether older adults are subject to over-reliance on the automation. Differences in omission and commission errors were examined. The results indicated that older adults were more reliant on the decision aid and committed more automation-related errors. A signal detection analyses indicated that older adults were less sensitive to automation failures. Results are discussed with respect to the perceptual and cognitive factors that influence age differences in the use of fallible automation.     

Status and cockpit dynamics: A review and empirical study.

One of the most troublesome dynamics evident in the airplane cockpit is related to patterns of authority relations between the captain and the first officer. Too often, captains fail to listen and first officers fail to speak. The authors propose that many instances of superordinate and subordinate behavior in the cockpit—the captain's tendency to reject input from other team members and the first officer's hesitancy to question the captain—represent cases of status generalization. First, the authors describe the theory of status generalization and show support for the operation of the theory by presenting examples of flightcrew behavior that the theory predicts. Second, an initial empirical test was conducted to instantiate the claim that captain–first officer differences can be seen as status differences. Finally, the significance and implications of this perspective are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of alkane sulfonic acid catalysts and derivatives for curing activity in a melamine/acrylic polyol coating formulation using fourier transform infrared spectroscopy

FTIR measurements may be able to replace more laborious physical property determinations and thus serve as an efficient screening methodology in catalysis driven processes. This possibility was considered in evaluating alkane sulfonic acids catalyst performance to promote the cure of a melamine resin with acrylic polyols. The example chosen here is an evaluation of alkane sulfonic acid derivatives to measure catalytic efficiency of the cure reaction between hexamethoxymethylmelamine (HMMM) and an acrylicpolyol. The IR measurements provided information on the extent of reaction, via monitoring the disappearance of the OH stretching mode at 3472 cm⁻¹ associated with the acrylic polyol. This method may also be used to provide detailed information on reaction kinetics and insight into the cure mechanism. As the reaction proceeds, the coating’s properties change and IR measurements can serve as a probe for these changes. 900 First Ave., King of Prussia, PA 19406.     

Enhanced discriminated bar-press avoidance in the rat through appetitive preconditioning.

In 2 experiments with 57 male albino rats, an appetitive preconditioning procedure produced superior performance on a discriminated bar-press avoidance task. The technique was designed to minimize the number of shocks received early in training and consisted primarily of rewarding Ss with food pellets for an avoidance response in addition to terminating the warning stimulus. Ss so preconditioned were found to achieve sustained, high levels of avoidance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hybrid photovoltaic devices of polymer and ZnO nanofiber composites

Organic semiconductor-based photovoltaic devices offer the promise of a low-cost photovoltaic technology that could be manufactured via large-scale, roll-to-roll printing techniques. Existing organic photovoltaic devices have currently achieved solar power conversion efficiencies greater than 3%. Although encouraging, the reasons higher efficiencies have not been achieved are poor overlap between the absorption spectrum of the organic chromophores and the solar spectrum, non-ideal band alignment between the donor and acceptor species, and low charge carrier mobilities resulting from the disordered nature of organic semiconductors. To address the latter issues, we are investigating the development of nanostructured oxide/conjugated polymer composite photovoltaic (PV) devices. These composites can take advantage of the high electron mobilities attainable in oxide semiconductors and can be fabricated using low-temperature solution-based growth techniques. Additionally, the morphology of the composite can be controlled in a systematic way through control of the nanostructured oxide growth. ZnO nanostructures that are vertically aligned with respect to the substrate have been grown. Here we discuss the fabrication of such nanostructures and present results from ZnO nanofiber/poly(3-hexylthiophene) (P3HT) composite PV devices. The best performance with this cell structure produced an open circuit voltage (V_oc) of 440 mV, a short circuit current density (J_sc) of 2.2 mA/cm², a fill factor (FF) of 0.56, and a conversion efficiency (η) of 0.53%. Incorporation of a blend of P3HT and (6,6)-phenyl C₆₁ butyric acid methyl ester (PCBM) into the ZnO nanofibers produced enhanced performance with a V_oc of 475 mV, J_sc of 10.0 mA/cm², FF of 0.43, and η of 2.03%. The power efficiency is limited in these devices by the large fiber spacing and the reduced V_oc.     

Anticipatory anxiety in women receiving chemotherapy for breast cancer.

Examined (1) the prevalence and course of anxiety before the 1st 6 infusions of cancer chemotherapy and (2) the contribution of trait anxiety, side effect expectations, and prior occurrence of posttreatment side effects to anxiety before infusions. 53 women receiving adjuvant chemotherapy for breast cancer participated. Anxiety was most prevalent and intense before the 1st infusion. Trait anxiety predicted anxiety before the 1st and subsequent infusions. Prior occurrence of posttreatment nervousness also predicted anxiety before subsequent infusions, even after accounting for trait anxiety and other posttreatment side effects. Results are discussed in terms of the role that anxiety proneness, response expectancy, and classical conditioning may play in the development of anxiety before repeated chemotherapy infusions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is industrial psychology none of Marxism's business?

Responds to criticisms by H. Toch, R. Stagner, H. M. Parsons, J. Feldman, and E. A. Locke (see PA, Vol 69:6878, 6877, 6874, 6864, and 6870, respectively) regarding the authors' reexamination, within a Marxist framework, of the Hawthorne studies of industrial workers. The authors stand by their claim that abundant evidence of worker resistance at Hawthorne was suppressed in influential accounts of the research. The controversy aroused by the Marxist viewpoint is considered in terms of class bias in psychology. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)