A Randomized Trial of Long-Term Reinforcement of Cocaine Abstinence in Methadone-Maintained Patients Who Inject Drugs.

This study determined whether long-term abstinence reinforcement could maintain cocaine abstinence throughout a yearlong period. Patients who injected drugs and used cocaine during methadone treatment (n = 78) were randomly assigned to 1 of 2 abstinence-reinforcement groups or to a usual care control group. Participants in the 2 abstinence-reinforcement groups could earn take-home methadone doses for providing opiate- and cocaine-free urine samples; participants in 1 of those groups also could earn $5,800 in vouchers for providing cocaine-free urine samples over 52 weeks. Both abstinence-reinforcement interventions increased cocaine abstinence, but the addition of the voucher intervention resulted in the largest and most sustained abstinence. Therefore, voucher-based reinforcement of cocaine abstinence in methadone patients can be a highly effective maintenance intervention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Iron chelating polypropylene films: Manipulating photoinitiated graft polymerization to tailor chelating activity

Transition metals, especially iron, enhance the oxidative degradation of lipids. Nonmigratory metal chelating active packaging can inhibit lipid oxidation and meet consumer demand for ‘cleaner' labels. Recently, the development of iron chelating films prepared by photoinitiated graft polymerization of acrylic acid on polypropylene (PP‐g‐PAA) was reported. The objective of this study was to tailor the chelating activity of PP‐g‐PAA by manipulating graft conditions. Carboxylic acids graft density and PAA graft thickness increased with graft time and acrylic acid concentration, with carboxylic acids density of up to 143 ± 32 nmol cm^?2, PAA graft thickness of ～6–18 μm, and ligand (carboxylic acid) to metal (Fe²⁺) binding ratio of ～4–5. Reducing photoinitiator graft density decreased this ratio to ～2–2.5, suggesting that graft chain density influences chelating activity. This work demonstrates the ability to tailor chelating activity of PP‐g‐PAA with potential applications in active packaging, chelation therapy, and water purification. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39948.     

Factors associated with serum polybrominated diphenyl ether (PBDE) levels among school-age children in the CHAMACOS cohort

Polybrominated diphenyl ethers (PBDEs) are a class of flame retardants historically used in textiles, furniture, and electronic products. Recent studies have documented widespread PBDE exposure to humans, with higher levels measured in children than adults. We analyzed 10 tri- to hepta-BDE congener levels in blood collected from 7-year old Mexican-American children living in an agriculture community in California (n = 272). The most frequently detected PBDE congeners in child serum were BDE-47, -99, -100, and -153, all of which were measured in >99% of the children. We used multiple linear regression models to examine associations between child total PBDE levels (ng/g lipid) and determinants of exposure. Factors positively associated with higher PBDE levels in the children were total PBDE levels in maternal serum during pregnancy, duration of exclusive breastfeeding, and having no safe places to play in their neighborhood. Child BMI was inversely associated with serum PBDE levels (regression p-values <0.05). Our findings confirm that exposure to the penta-BDE mixture is ongoing, and that Mexican-American children living in California may be experiencing higher PBDE exposure from their environment compared to children sampled from the general U.S. population. Additional research is needed to assess the health impacts of these exposures.     

Abstinence-contingent reinforcement and engagement in non-drug-related activities among illicit drug abusers.

Methadone-maintained cocaine abusers (N = 78) were randomly assigned to 1 of the following 52-week interventions: (a) usual care only (UC), (b) take-home methadone doses contingent on cocaine- and opiate-negative results (THM), or (c) take-home methadone doses for cocaine- and opiate-negative results and monetary-based vouchers contingent on cocaine-negative urinalysis results (THM + V). Cocaine use was assessed by urinalysis on a thrice-weekly schedule. Frequency and enjoyability of non-drug-related activities were assessed with the Pleasant Events Schedule (PES) at baseline, midtreatment, and end of treatment. The THM + V condition achieved the greatest abstinence from cocaine and opiate use, followed by the THM and UC conditions. The THM + V condition had the highest PES frequency ratings at midtreatment and at the end of treatment, followed by the THM and UC conditions. There were significant differences between the THM + V and UC conditions on 10 of 12 PES-derived subscales. Analyses revealed that abstinence mediated the effects of treatment condition on frequency ratings. There were no significant differences in enjoyability ratings. These results suggest that when contingency-management interventions increase abstinence from drug abuse, they also increase engagement in non-drug-related activities in naturalistic settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predictors of persistence to graduation: Extending a model and data on the transition to university model.

Persistence to graduation was investigated with 944 (272 males, 672 females) undergraduate students at a large, commuter Canadian university. Within six years, 57.9% of the students had graduated, 9% remained enrolled, and 33.1% were not enrolled or graduated. Results indicate that gender, parental support, stress, depression, and first-year GPA were direct predictors of persistence. When Baker and Siryk's (1985) adaptation scales were added to the model, social adaptation and goal and school commitment became direct predictors in addition to parental support and first-year GPA, whereas high school average and academic adaptation were indirect predictors of graduation. Results indicate that the predictors of persistence to graduation are not the same as the predictors of the transition to university. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimization of human plasma 1H NMR spectroscopic data processing for high-throughput metabolic phenotyping studies and detection of insulin resistance related to type 2 diabetes

Optimizing NMR experimental parameters for high-throughput metabolic phenotyping requires careful examination of the total biochemical information obtainable from (1)H NMR data, which includes concentration and molecular dynamics information. Here we have applied two different types of mathematical transformation (calculation of the first derivative of the NMR spectrum and Gaussian shaping of the free-induction decay) to attenuate broad spectral features from macromolecules and enhance the signals of small molecules. By application of chemometric methods such as principal component analysis (PCA), orthogonal projections to latent structures discriminant analysis (O-PLS-DA) and statistical spectroscopic tools such as statistical total correlation spectroscopy (STOCSY), we show that these methods successfully identify the same potential biomarkers as spin-echo (1)H NMR spectra in which broad lines are suppressed via T2 relaxation editing. Finally, we applied these methods for identification of the metabolic phenotype of patients with type 2 diabetes. This "virtual" relaxation-edited spectroscopy (RESY) approach can be particularly useful for high-throughput screening of complex mixtures such as human plasma and may be useful for extraction of latent biochemical information from legacy or archived NMR data sets for which only standard 1D data sets exist.     

Explanatory style change during cognitive therapy for unipolar depression.

We administered the Attributional Style Questionnaire to 39 unipolar depressed patients at the beginning and end of cognitive therapy and at one-year follow-up, and we administered it to 12 bipolar patients during a depressed episode. A pessimistic explanatory style for bad events correlated with severity of depression for unipolars at cognitive therapy intake (r?=?.56, p?     

ASR-based exercises for listening comprehension practice in European Portuguese

Spoken European Portuguese (EP) is known to be difficult to understand for L2 learners, due to phenomena such as strong vowel reduction. In this paper, we present a method to automatically generate exercises aimed at improving listening comprehension skills in EP. Learners identify the words pronounced in real speech utterances. The exercises introduce two innovative aspects: using broadcast news videos for curriculum and automatically generating exercises with material updated on a daily basis. The videos are automatically transcribed by a speech recognition engine. A filtering chain, used to select appropriate sentences, was validated by a first survey comprised of both manually and automatically selected sentences. Both sets were assigned good to very good subjective quality scores. A second survey concerned the features of the exercise interface. Subjects with varying self-reported exposure to Portuguese as a second language tested several interfaces and functionalities and highlighted their preferred features. The results confirmed that the largest difficulty was the fast speech rate. All participants valued slowed-down audio and video documents, though this feature was more often used by the lowest proficiency subjects. The exercises were integrated into a Web platform where they are automatically updated daily. Though further evaluation is needed to find whether the platform affords skill acquisition, it is expected to be particularly valuable for distance learners who need opportunities to access authentic audio documents in EP.