Cocaethylene formation following ethanol and cocaine administration by different routes.

Ethanol alters the hepatic biotransformation of cocaine, resulting in transesterification to a novel active metabolite, cocaethylene. Because of first pass metabolism, oral drug administration might be expected to produce relatively larger concentrations of cocaethylene than would intravenous or smoked administration. We, therefore, compared the effects of route of cocaine administration on the formation and elimination of cocaethylene. Six experienced cocaine users were tested in 6 sessions, approximately 1 week apart. Deuterium-labeled cocaine (d?) was administered in all conditions. Oral cocaine-d? 2.0 mg/kg, intravenous cocaine-d? 1.0 mg/kg, and smoked cocaine-d? (200 mg) were administered after oral ethanol 1.0g/kg or placebo. A small, intravenous dose of deuterated cocaethylene (d?) also was administered with all conditions for determination of cocaethylene formation. Physiologic and subjective effects were recorded and plasma cocaine-d?, cocaethylene-d?, cocaethylene-d?, and benzoylecgonine-d? were measured by gas chromatography-mass spectrometry. About 24% (± 11) of intravenous cocaine was converted to cocaethylene. The oral route (34% ± 20) was significantly greater than from the smoked route (18% ± 11) and showed a trend toward significance for greater formation of cocaethylene compared to the intravenous route. Within each route, the cocaine-ethanol combination produced greater increases in heart rate and rate-pressure product than cocaine alone. Global intoxication effects across time after smoking or intravenous administration were significantly greater when cocaine and ethanol were both given. Administration of cocaine by different routes alters the amount of cocaethylene formed through hepatic first-pass effects. Increased cardiovascular and subjective effects might explain the toxicity and popularity of the combined drugs. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Technological coupling, job characteristics and operators' well-being as moderated by desirability of control

This study proposes that the nature of Automated Manufacturing Technology (AMT)-as reflected in the degree of 'technological coupling' and as perceived by shop floor operators in terms of new job control characteristics (timing and method control, monitoring and problem solving demand, production responsibility)-affects operators' psychological well-being (satisfaction and mental health). The study sample consisted of 216 operators of AMT equipment. Findings indicate that technological coupling is negatively related to the job characteristics of timing and method control, and to psychological well-being variables. Operators' satisfaction is positively related to problem solving, production responsibility and timing and method control. Mental health is negatively related to production responsibility. Implications for job redesign and employees selection to AMT work units are discussed. Yet, results indicate that operators' response to technological coupling is contingent upon their desirability of control (DC). For operators with low DC (as opposed to high DC) coupling conditions did not make any difference in psychological well-being.     

Variations in optical absorption spectra of adult and fetalhaemoglobins and its effect on pulse oximetry

One of the concerns clinicians have relates to the interpretation of noninvasive pulse oximeters in newborns since at birth high levels of fetal hemoglobin (HbF) is present in the blood. Accurate in vivo studies of pulse oximeters in infants with predominantly HbF cannot be easily performed. Therefore, the objective of this in vitro study was to determine whether the presence of high levels of HbF in the blood can significantly affect the accuracy of noninvasive pulse oximeters. It is evident from our results that there is no perceptible difference in the 650-1000 nm wavelength region, which is commonly used in pulse oximetry, between the optical absorption spectra of hemolyzed whole adult and fetal blood. Our observations are in good agreement with in vivo studies published by other investigators showing considerable correlations between SpO2 measured by a pulse oximeter and SaO2 values analyzed in vitro by an IL 282 CO-Oximeter.     

Affective and cardiovascular effects of experimentally-induced social status.

Objective: Observational research suggests subordinate social status is associated with negative mental and physical health outcomes. However, observational studies have limitations, including confounding of social status with other factors, limited ability to infer causality, and difficulty of obtaining detailed affective and physiologic data. This study used experimental methods to test the hypothesis that subordinate social status per se causes psychological distress and cardiovascular arousal. Design: Forty-four women were randomly assigned to an induced subordinate or dominant status condition. Social status was manipulated using a procedure derived from status construction theory. Main Outcome Measures: Affective responses were assessed via self-report. Cardiovascular responses were assessed by measures of systolic and diastolic blood pressures obtained with an automated blood pressure machine. Results: Participants in the subordinate condition perceived themselves as lower in status; the reverse was true for dominant condition participants. Compared with induced dominant status, induced subordinate status produced increased negative affect and systolic blood pressure over the course of the study. Conclusion: Findings suggest social status can be experimentally manipulated and short-term induction of subordinate status can have adverse effects on affect and stress-related physiological systems. Results have implications for understanding how socioeconomic status "gets under the skin" to influence health. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of molecular structure on polyethylene melt rheology. III. Effects of long-chain branching and of temperature on melt elasticity in shear

The effects of long-chain branching and of temperature on the melt elasticity in shear of polyethylene were investigated using die swell measurements and relating them to recoverable shear strain, normal stress, and shear modulus. Die swell measurements, as a function of shear rate, were obtained for high- and low-density polyethylenes at temperatures ranging from 130° to 225°C. The samples were characterized by GPC and intrinsic viscosity for molecular weight distributions and degrees of long-chain branching. The importance of annealing the extrudates at temperatures above the polymer melting temperature to achieve equilibrium, or strain-free, values of die swell was demonstrated. The effect of long-chain branch was to decrease elastic deformation. At constant shear stress, the melt elasticity of both high- and low-density polyethylene was found to be essentially independent of temperature. Thus, at constant shear rate, elastic deformation decreased with increasing temperature, and it was demonstrated that this decrease could be quantitatively defined in terms of previously determined shear rate–temperature viscosity superposition shift factors.     

Impact of maternal alcoholism on separation of children from their mothers: findings from a sample of incarcerated women

Research on achievement goal orientation in sport has relied primarily on traditional statistical methodology to examine group mean differences. Unfortunately, examination of the measurement model is generally ignored prior to means testing. This study reports an application of structural equation modeling (SEM) in testing measurement invariance and latent mean structure of the Task and Ego Orientation in Sport Questionnaire (TEOSQ; Duda & Nicholls, 1989) using male and female college students. A confirmatory factor analysis for testing invariance revealed invariant measurement properties and factor structures across gender, indicating that task and ego orientation are similarly conceptualized by male and female students. Subsequent testing of latent mean structures, however, showed significant gender differences with respect to ego orientation, but no difference in task orientation. The SEM procedures used in the present study demonstrate additional construct validity and internal consistency reliability for the TEOSQ and, by confirming its factor structure, provide a sound psychometric basis for its continued use in substantive studies focusing on the comparison of achievement goal orientation across gender.     

The shapes of the motor domains of two oppositely directed microtubule motors, ncd and kinesin: a neutron scattering study

The shapes of the motor domains of kinesin and ncd, which move in opposite directions along microtubules, have been investigated. Using proteins expressed in Escherichia coli, it was found that at high salt (> 200 mM) Drosophila ncd motor domain (R335-K700) and human kinesin motor domain (M1-E349) were both sufficiently monomeric to allow an accurate determination of their radii of gyration (Rg) and their molecular weights. The measured Rg values of the ncd and kinesin motor domains in D2O were 2.06 +/- 0.06 and 2.05 +/- 0.04 nm, respectively, and the molecular weights were consistent with those computed from the amino acid compositions. Fitting of the scattering curves to approximately 3.5 nm resolution showed that the ncd and kinesin motor domains can be described adequately by triaxial ellipsoids having half-axes of 1.42 +/- 0.38, 2.24 +/- 0.44, and 3.65 +/- 0.22 nm, and half-axes of 1.52 +/- 0.23, 2.00 +/- 0.25, and 3.73 +/- 0.10 nm, respectively. Both motor domains are described adequately as somewhat flattened prolate ellipsoids with a maximum dimension of approximately 7.5 nm. Thus, it appears that the overall shapes of these motor domains are not the major determinants of the directionality of their movement along microtubules.     

A performance analysis of Pentium processor systems

Using a CPI metric, we analyze the performance of Pentium-based systems and examine their use of the processor's architectural features under different software environments. We break down the CPI into its basic constituents and examine the effects of various operating systems and applications on the CPI. This analysis indicates where the application spends its time during execution, giving designers a better understanding of design tradeoffs and potential causes of performance bottlenecks