Size Effects in Internal Friction of Nanocrystalline Aluminum Films

Al thin film is extensively used in micro-electromechanical systems (MEMS) and electronic interconnections; however, most previous research has concentrated on their quasi-static properties and applied their designs on larger scales. The present study designed a paddle-like cantilever specimen with metal films deposited on the upper surface to investigate the quasi-static properties of Al thin film at room temperature under high vacuum conditions at microscopic scales. Energy loss was determined using a decay technique in the oscillation amplitude of a vibrating structure following resonant excitation. Grain size and film thickness size were strictly controlled considering the quasi-static properties of the films. This study found that the internal friction of ultra-thin and thin Al films was more dependent on the grain boundaries than film thickness.     

A randomized trial comparing levo-alpha acetylmethadol with methadone maintenance for patients in primary care settings in Australia

Aims The present study aimed to compare the efficacy of levo‐alpha‐acetylmethadol (LAAM) and methadone, as measured by retention in treatment and heroin use, in a randomized trial conducted under naturalistic conditions. Setting This study is the first randomized trial comparing LAAM with methadone in the primary care setting. Participants were recruited through 29 medical practitioners working in specialist and generalist settings in Australia. Participants Existing methadone maintenance patients, aged 18 years and over and able to give informed consent, were randomized to receive either LAAM or methadone. A total of 93 patients participated. Intervention After being trained in the use of LAAM, existing methadone prescribers were then able to determine an individually tailored treatment regimen for each patient. The trial was an open‐label study. Methadone and LAAM dosing was supervised through local community pharmacies. Participation in ancillary services (e.g. counselling) was optional for all patients. The treatment period for the trial was 12 months. Measurements Baseline, 3‐, 6‐ and 12‐month interviews were conducted. Outcome measures were retention in treatment, self‐reported heroin use and serious adverse events. Findings There were no significant differences between LAAM and methadone on retention in treatment, nor heroin use. There was a trend for LAAM patients to have lower heroin use than methadone patients. Of the seven serious adverse events in the LAAM group, three were not drug‐related. There were two dosing errors. Conclusions This study demonstrates (a) the efficacy of LAAM as a treatment for heroin dependence, and (b) the capacity for LAAM to be effectively delivered in primary care settings by trained general practitioners and pharmacists. The next challenge is to resolve outstanding safety concerns with LAAM.     

Residential Trajectories of Street Youth—the Montréal Cohort Study

Little is known about the course of homelessness among youth between the ages of 18 and 25 despite the many characteristics distinguishing them from adolescents and from older street-involved populations. We examined the residential trajectories of homeless young adults in Montréal over a 21-month period and identified determinants of various trajectory profiles. The 365 study participants (79 % men, mean age 21.9 years) were followed for an average of 515 days (range 81–630 days). We assessed housing status with a questionnaire based on the residential follow-back calendar designed by the New Hampshire Dartmouth Research Center. Using latent growth analysis to examine achievement of residential stability over time, we observed three different trajectories: group 1 presented a low probability of housing throughout the entire study period; group 2 showed a high probability of early and stable housing; group 3 displayed a fluctuating pattern. Protective correlates of residential stability included high school education, birth in Canada, and presence of mental health problems. Drug abuse or dependence was associated with a decreased probability of housing.     

Songwriting to Target State Shame,Guilt, and Pride in Adults with Substance Use Disorder on a Detoxification Unit: A Cluster-Randomized Study

Background: Resultant of engaging in behaviors outside of their value systems to maintain addiction, many people with substance use disorder (SUD) feel shame and guilt. Although shame, guilt, and pride do not represent traditional dependent measures in SUD research, experimental studies targeting these constructs are warranted. Objective: The purpose of this study was to determine the effects of a single songwriting intervention on state shame, guilt, and pride with adults with SUD on a detoxification unit. Method: Participants (N?=?118) were cluster-randomized to songwriting or control conditions. To avoid testing fatigue in this single-session study, experimental participants received a group-based blues songwriting protocol targeting state shame, guilt, and pride and then completed the questionnaire. Control participants completed the questionnaire before receiving an intervention. Results: While there was no significant between-group difference in state shame or guilt, there tended to be slightly lower mean scores in the experimental condition. There was a significant between-group difference in state pride (p = .012), with experimental participants having higher mean scores than control participants. Conclusion: Although only the state pride measure reached significance, shame, guilt, and pride represent consequential constructs for people with SUD. As addressing shame and guilt can be perceived as confrontational, group-based blues songwriting may represent a positive, engaging, and creative intervention to target these challenging but important topics. Implications for clinical practice, limitations, and suggestions for future research are provided.     

Stochastic dynamic causal modeling of working memory connections in cocaine dependence

Although reduced working memory brain activation has been reported in several brain regions of cocaine‐dependent subjects compared with controls, very little is known about whether there is altered connectivity of working memory pathways in cocaine dependence. This study addresses this issue by using functional magnetic resonance imaging‐based stochastic dynamic causal modeling (DCM) analysis to study the effective connectivity of 19 cocaine‐dependent subjects and 14 healthy controls while performing a working memory task. Stochastic DCM is an advanced method that has recently been implemented in SPM8 that can obtain improved estimates, relative to deterministic DCM, of hidden neuronal causes before convolution with the hemodynamic response. Thus, stochastic DCM may be less influenced by the confounding effects of variations in blood oxygen level‐dependent response caused by disease or drugs. Based on the significant regional activation common to both groups and consistent with previous working memory activation studies, seven regions of interest were chosen as nodes for DCM analyses. Bayesian family level inference, Bayesian model selection analyses, and Bayesian model averaging (BMA) were conducted. BMA showed that the cocaine‐dependent subjects had large differences compared with the control subjects in the strengths of prefrontal–striatal modulatory (B matrix) DCM parameters. These findings are consistent with altered cortical–striatal networks that may be related to reduced dopamine function in cocaine dependence. As far as we are aware, this is the first between‐group DCM study using stochastic methodology. Hum Brain Mapp 35:760–778, 2014. © 2012 Wiley Periodicals, Inc.