Sex differences in validity for academic and employment criteria, and different types of predictors.

Sex differences in validity coefficients were examined for a total of 6,219 pairs of validities. Differences were also examined for subsets of predictors and criteria and a random sample of pairs of validities from independent data sets. Data were taken from studies in Educational and Psychological Measurement, the Journal of Applied Psychology, and Personnel Psychology from 1955 to the present and from the manuals of the Differential Aptitude Test Battery and the College Qualification Tests. Female validities were slightly but significantly higher than male validities for academic criteria and for all predictor subsets, with the exception of high school background and personality predictors. Female validities were also greater than male validities (.037 in correlation units) in the random sample of independent validity pairs. Male validities were slightly higher for high school background and personality predictors and for employment criteria. The generalizability of the finding concerning employment criteria and the latter 2 predictor subsets is questionable because of the small number of pairs of validities available and the nonindependence of the pairs that were available. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of Elaboration on Socially Desirable Responding and the Validity of Biodata Measures.

The current study investigated the impact of requiring respondents to elaborate on their answers to a biodata measure on mean scores, the validity of the biodata item composites, subgroup mean differences, and correlations with social desirability. Results of this study indicate that elaborated responses result in scores that are much lower than nonelaborated responses to the same items by an independent sample. Despite the lower mean score on elaborated items, it does not appear that elaboration affects the size of the correlation between social desirability and responses to biodata items or that it affects criterion-related validity or subgroup mean differences in a practically significant way. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Nearly Linear-Time PTAS for Explicit Fractional Packing and Covering Linear Programs

We give an approximation algorithm for fractional packing and covering linear programs (linear programs with non-negative coefficients). Given a constraint matrix with n non-zeros, r rows, and c columns, the algorithm (with high probability) computes feasible primal and dual solutions whose costs are within a factor of 1+ε of opt (the optimal cost) in time O((r+c)log(n)/ε ²+n).     

Exploring age differences in the stress-buffering function of social support.

The purpose of this study is to see if there are age differences in the relationship between chronic financial strain, emotional support, and life satisfaction among people aged 65 and older. Data from a nationwide survey of older people (N = 1,518) indicate that emotional support tends to reduce the noxious effects of economic problems on life satisfaction for the sample as a whole. However, the findings further reveal that the potential benefits of emotional support arise primarily among the oldest-old. In contrast, emotional support does not offset the negative effects of financial strain on life satisfaction among the young-old. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transcutaneous electrical nerve stimulation and temporary S3 neuromodulation in idiopathic detrusor instability

PURPOSE: We studied the effects of electrical stimulation on idiopathic detrusor instability. MATERIALS AND METHODS: Between January 1993 and December 1994, 30 men and 41 women (mean age plus or minus standard deviation 48 +/- 16 years) underwent transcutaneous electrical nerve stimulation (TENS) of the S2-S3 dermatomes, and 13 men and 22 women (mean age 48 +/- 12 years) underwent S3 neuromodulation. Subjective assessment was performed using a diary and symptom score of 0 to 14. Objective outcome was analyzed with urodynamic studies. RESULTS: Mean duration of TENS was 3 +/- 1 weeks (range 2 to 4). Although there were no major complications 31% of the patients reported local skin irritation. The overall urinary symptom scores improved from 10 +/- 2 (range 5 to 14) before the study to 7 +/- 3 (range 1 to 14) during stimulation. Urodynamic analysis revealed significant (p < 0.05) improvements in total bladder capacity and voided volume, and decreases in the number and frequency of unstable contractions. Mean duration of S3 neuromodulation was 6 +/- 1 days (range 4 to 8 days). Four procedures failed due to electrode displacement in 3 cases and procedure intolerance in 1. Hemorrhage from the puncture site occurred in 1 patient. Overall urinary symptom scores were 10 +/- 3 (range 5 to 14) before the study and 5 +/- 2 (range 2 to 10) during stimulation. Although symptomatic relief was more pronounced with S3 neuromodulation, no statistically significant differences were found regarding urinary symptoms compared to TENS. CONCLUSIONS: In patients with severe detrusor instability refractory to conservative treatments the use of TENS and S3 neuromodulation produced significant changes in urodynamic parameters and presenting symptoms. Our results appear to justify evaluation with neuromodulatory techniques before definitive surgical intervention in these patients.     

Nicotine, cotinine, withdrawal, and craving patterns during smoking and nicotine nasal spray use: results from a pilot study with African American men.

Nicotine intake via smoking is highly variable. Individualized dosing of nicotine replacement therapy (NRT) may improve product efficacy, but a better understanding of the within-day and within-subject relationships between smoking, NRT use, nicotine and cotinine concentrations in blood, and cravings and withdrawal symptoms is needed to inform dosing algorithms. A pilot study was undertaken to collect data on these relationships and to assess the feasibility of the methods needed for this type of research, including a sophisticated statistical modeling technique (a two-part mixed-effects model with correlated random effects that accounts for clumping at zero). Because nicotine metabolism varies by gender and race, the sample was homogeneous with respect to these characteristics. In a within-subjects study, 27 African American adult male smokers carried a computerized cigarette dispenser for 1 week, capturing the time each cigarette was smoked. Subjects then entered an inpatient setting for 1 day of scheduled smoking (matched to data from the cigarette dispenser to create an ecologically valid schedule) and 4 days of ad libitum nicotine nasal spray use, while tobacco abstinent. Eight times per day, at 2-hour intervals, blood was drawn and ratings of cigarette cravings and withdrawal symptoms were obtained. On average, subjects used less than half of the manufacturer's recommended minimum daily dose of nicotine nasal spray. Large differences in nicotine and cotinine levels were observed between individuals. When predicting nicotine, cotinine, withdrawal, and cravings, we observed significant interactions between route of nicotine intake and a variety of independent variables.     

Public policy and biofuels: The way forward?

The use of biofuels has been given much attention by governments around the world, especially in increasingly energy-hungry OECD nations. Proponents have argued that they offer various advantages over hydrocarbon-based fuels, especially with respect to reducing dependence on OPEC-controlled oil, minimizing greenhouse gas (GHG) emissions, and ensuring financial and lifestyle continuity to farmers and agriculturally dependent communities. This paper adds to the continuing technical debate by addressing the issue from a holistic public policy perspective. In particular, it looks at the proposed benefits of biofuels, yet also addresses the implications of increased demand on the global and regional environment, in addition to the economic welfare of developing nations. Furthermore, it posits that short-term reliance on biofuels vis-à-vis other alternative energy sources may potentially inhibit the development and maturation of longer-term technologies that have greater potential to correct the harmful effects of fossil-fuel dependence. In light of this, the manifold policy instruments currently employed or proposed by governments in developed nations to promote biofuels emerge as questionable.     

Pro-oxidant effects of delta-aminolevulinic acid (delta-ALA) on Chinese hamster ovary (CHO) cells

delta-Aminolevulinic Acid (delta-ALA) is a heme precursor accumulated in lead poisoning and acute intermittent porphyria. Although no single mechanism for lead toxicity has yet been defined, recent studies suggest at least some of the lead-induced damage may originate from delta-ALA-induced oxidative stress. The present study was designed to test the hypothesis that delta-ALA accumulation in Chinese hamster ovary (CHO) cells contributes to the cumulative oxidative challenge of lead poisoning as indicated by the oxidative stress parameters glutathione (GSH), glutathione disulfide (GSSG), malondialdehyde equivalents (MDA), and catalase (CAT). It will also examine the possibility that this oxidative challenge can be reversed by treatment with an antioxidant such as N-acetylcysteine (NAC). First in vitro administration of delta-ALA to CHO cells was found to have a concentration-dependent inhibitory effect on colony formation and cell survival. NAC administration was shown to alleviate this inhibition in CHO survival. The oxidative status of CHO cell cultures exposed to increasing concentrations of delta-ALA was then examined. Decreases in GSH levels (P < 0.05) were observed in the delta-ALA-treated cultures as compared to the controls, while GSSG and MDA levels were significantly increased in delta-ALA-treated cells (P < 0.05). CAT activity was not significantly affected. NAC administration concurrent with delta-ALA exposure resulted in GSH and GSSG levels similar to the control levels, while no significant improvement in MDA was observed. These results indicate a state of oxidative stress and suggest that the delta-ALA- induced inhibitory effect on CHO colony formation may be due to its pro-oxidant effect. To assess whether this oxidative challenge would induce antioxidant increases during extended exposure to delta-ALA, CHO cells were exposed to 5 mM delta-ALA for increasing time periods. The GSH and GSSG levels were measured and a rebound effect was observed after 12 h of delta-ALA exposure.     

Schedule induction conditions not only exaggerate intake but also enhance drug solution choice

In previous research, rats exposed to daily, 3 h sessions of schedule-induced polydipsia (SIP) self-administered high doses of cocaine orally. However, a strong and durable preference for cocaine solution to water requires training in addition to mere oral self-administration exposure. If cocaine is dissolved in a preferred vehicle solution, and the vehicle is subsequently faded to water, then a strong preference for cocaine remains. A similar preference can be instituted for lidocaine solution. Such preferences may develop because the gustatory property of a drug becomes associated with the preferred vehicle and remains to function as a durable conditioned reinforcer after vehicle fading. To determine if drug preference is solely a function of this posited conditioning mechanism, or whether it also depends upon the SIP condition, rats were exposed to daily, 3 h sessions of single-ration feeding, rather than the SIP condition. A preferred vehicle (glucose/saccharin solution) was slowly faded from a 0.19 mg/ml lidocaine solution, which was presented concurrently with a choice for water. Although a preference for lidocaine solution to water could be generated, it occurred for only 5 out of 9 rats, and the preference was relatively unstable. By contrast, in two previous studies using SIP, 26 out of 27 rats maintained a preference for lidocaine solution. Thus, SIP not only exaggerates the amount of drug solution ingested but also contributes to the fixation of the associative drug solution choice.