Modal spectra extracted from nonequilibrium fluid patterns in laboratory experiments on Rayleigh-Bénard convection.

We describe a method to extract from experimental data the important dynamical modes in spatiotemporal patterns in a system driven out of thermodynamic equilibrium. Using a novel optical technique for controlling fluid flow, we create an experimental ensemble of Rayleigh-Bénard convection patterns with nearby initial conditions close to the onset of secondary instability. An analysis of the ensemble evolution reveals the spatial structure of the dominant modes of the system as well as the corresponding growth rates. The extracted modes are related to localized versions of instabilities found in the ideal unbounded system. The approach may prove useful in describing instability in experimental systems as a step toward prediction and control.

Buprenorphine and medication management in a community corrections population: a pilot study.

AIMS: This project sought to demonstrate the feasibility and acceptability of providing on-site buprenorphine treatment to individuals under community corrections supervision. METHODS: Seventeen women and 13 men were enrolled on-site over a 2-week period at a community corrections location. Study participants received open-label study medication dispensed weekly over 12 weeks, weekly medication management therapy, and returned for a 1-month follow-up. RESULTS: Participants were predominantly female (56%) and white (90%) with an average age of 31.7 ± 7.4 years. More than half (53%) had hepatitis C virus infection and 75.9% reported intravenous use of opioids in the 30 days before treatment. Rates of illicit substance use was high, as 37.9% of urines were positive for benzodiazepines, 31.7% were positive for cocaine, and 13.7% were positive for alcohol across the time in the study. Although rates of positive urines for opiate use and sex with multiple partners did not change during treatment, rates of injection drug use significantly decreased during treatment. Overall, 86.7% of participants were retained through the 1-month follow-up with low rates of adverse events. CONCLUSIONS: Acceptability and feasibility of this approach were demonstrated by the ability to enroll and randomize the target sample of participants over 2 weeks with high retention and low rates of adverse events through 1-month follow-up. This pilot study demonstrated that this population could be successfully engaged in treatment and show reductions in risky behaviors. However, more intensive interventions may be needed to reduce opiate use to reach this vulnerable population at their point of contact with the criminal justice system.

Relationship between psychiatric status and frontal-subcortical systems in HIV-infected individuals.

Human immunodeficiency virus (HIV)-infected adults frequently evidence both neurocognitive and psychiatric dysfunction. It was hypothesized that apathy and irritability, but not anxiety and depression, are related to HIV effects on frontal-subcortical systems. This hypothesis was evaluated by determining the degree to which these psychiatric features are associated with neurocognitive functioning that is dependent upon frontal-subcortical circuitry and, therefore, thought to be sensitive to the central nervous system effects of HIV. Rating scales assessing irritability, apathy, depression, and anxiety and a dual-task paradigm were administered to 189 HIV-seropositive (HIV+) and 53 HIV-seronegative participants. Deficits in dual-task performance and greater anxiety, depression, apathy, and irritability were observed in HIV+ participants. Simultaneous multivariate regression and communality analyses revealed that only apathy and irritability were associated with dual-task performance in HIV+ participants. Thus, these findings suggest that apathy and irritability, but not depression and anxiety, are likely associated with the effects of HIV on frontal-subcortical circuitry.