Youth-Nominated Support Team for suicidal adolescents (Version 1): A randomized controlled trial.

In this study, the authors investigated the efficacy of the Youth-Nominated Support Team-Version 1 (YST-1), a psychoeducational social network intervention, with 289 suicidal, psychiatrically hospitalized adolescents (197 girls, 92 boys). Adolescents were randomly assigned to treatment-as-usual plus YST-1 or treatment-as-usual only. Assessments were completed pre- and postintervention (6 months). There were no main effects for YST-1 on suicide ideation or attempts, internalizing symptoms, or related functional impairment. Relative to other girls, however, those who received YST-1 reported greater decreases in self-reported suicidal ideation (actually treated analytic strategy) and significantly greater decreases in mood-related functional impairment reported by their parents (intent to treat and actually treated analytic strategies). This is the first randomized controlled clinical trial to investigate the efficacy of a social network intervention with suicidal youths. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A planning system based on Markov decision processes to guide people with dementia through activities of daily living.

Older adults with dementia often cannot remember how to complete activities of daily living and require a caregiver to aid them through the steps involved. The use of a computerized guidance system could potentially reduce the reliance on a caregiver. This paper examines the design and preliminary evaluation of a planning system that uses Markov decision processes (MDPs) to determine when and how to provide prompts to a user with dementia for guidance through the activity of handwashing. Results from the study suggest that MDPs can be applied effectively to this type of guidance problem. Considerations for the development of future guidance systems are presented.     

Analytical and experimental determination of the multipole cusp magnetic field in the VISIONI plasmatron

The VISIONI plasmatron is a plasma simulator dedicated to thermonuclear fusion material studies. The plasma is confined by means of a strong multipole cusp magnetic field produced by rectangular permanent samarium–cobalt magnets positioned just outside of the plasma chamber. The magnitude of this field as a function of the location in the plasma chamber is an important input for the ongoing plasma and material migration computer simulations for VISIONI. In this work the magnetic field in the VISIONI plasma chamber was calculated analytically. The calculated results were benchmarked and verified experimentally by Hall probe measurements. The analytical formulas are very convenient for use in different simulation codes.     

Concealable stigmas and positive self-perceptions: feeling better around similar others

In an 11-day experience-sampling study, 86 Harvard undergraduates rated their momentary self-esteem and affect and then described the who, what, and where of their daily lives. Those with concealable stigmas (students who indicated that they were gay, that they were bulimic, or that their family earned less than $20,000 each year) reported lower self-esteem and more negative affect than both those whose stigmas were visible and those without stigmatizing characteristics. Only the presence of similar others lifted the self-esteem and mood of students with concealable stigmas, and these particular students were the least likely to experience such occasions. Thus, contact with similar others protects the psychological self from negative cultural messages.     

Automated detection of unusual events on stairs

This paper presents a method for automatically detecting unusual human events on stairs from video data. The motivation is to provide a tool for biomedical researchers to rapidly find the events of interest within large quantities of video data. Our system identifies potential sequences containing anomalies, and reduces the amount of data that needs to be searched by a human. We compute two sets of features from a video of a person descending a stairwell. The first set of features are the foot positions and velocities. We track both feet using a mixed state particle filter with an appearance model based on histograms of oriented gradients. We compute expected (most likely) foot positions given the state of the filter at each frame. The second set of features are the parameters of the mean optical flow over a foreground region. Our final classification system inputs these two sets of features into a hidden Markov model (HMM) to analyse the spatio-temporal progression of the stair descent. A single HMM is trained on sequences of normal stair use, and a threshold on sequence likelihoods is used to detect unusual events in new data. We demonstrate our system on a data set with five people descending a set of stairs in a laboratory environment. We show how our system can successfully detect nearly all anomalous events, with a low false positive rate. We discuss limitations and suggest improvements to the system.     

Aerosol flow through a long micro-capillary: collimated aerosol beam

A micro-capillary system capable of generating a focused collimated aerosol beam (CAB) is demonstrated both theoretically and experimentally. The approach is based on a manifestation of the Saffman force where high velocity (∼100 m/s) aerosol particles, flowing through a micro-capillary (d ∼ 100 μm and l ∼ 1 cm), migrate perpendicular to the centerline of the capillary. Upon exiting the micro-capillary system, the particles maintain momentum, and when the aerosol is comprised of solid-in-liquid dispersions such as Ag nanoparticle ink, the CAB approach enables printing of advanced materials features with linewidth ≤ 10 μm.     

Comparison of the action potential prolonging and positive inotropic activity of DPI 201-106 and BDF 9148 in human ventricular myocardium

The aim of our study was to compare the effects on contractile function and action potential duration of the new Na+ channel modulator BDF 9148 with the parent compound DPI 201-106 in human ventricular myocardium. Right ventricular papillary muscles were obtained from explanted hearts of heart transplant recipients or from non-failing hearts not suitable for transplantation. BDF 9148 induced an increase in force of contraction that was accompanied by prolongation of action potential duration. The action potential duration prolonging effect of BDF 9148 was not significantly different to that of DPI 201-106. The effects of BDF 9148 were similar in muscles obtained from non-failing and failing hearts. Using Na(+)-sensitive electrodes, we have demonstrated that the positive inotropic effect of BDF 9148 is accompanied by an increase in intracellular Na+ activity. Our results indicate: (i) that BDF 9148 is as effective as DPI 201-106 in increasing force of contraction and prolonging action potential duration in human ventricular myocardium: (ii) that BDF 9148 is effective in enhancing force of contraction, in spite of heart failure; (iii) that the positive inotropic effect is related to an increased Na+ load; and (iv) due to action potential duration prolongation, changes in Q-T interval of the electrocardiogram could be possible during in vivo use of BDF 9148.     

High cycle fatigue of welded joints: The TCD experience

This paper reports on the use of two methods for the prediction of high cycle fatigue failure in welded joints. The development of these methods – known as the crack modelling method and the theory of critical distances – is described, summarising previously published work on test specimens using steels and aluminium alloys. It is concluded that the methods work well, predicting fatigue strength with errors of less than 20% in the great majority of cases. Certain types of joint were found to give rise to large, conservative errors, but similar errors also occurred when using other, well established, methods of prediction. Some restrictions also arise with the use of the TCD for bodies having very small section thicknesses. Finally, two case studies, described here for the first time, illustrate the issues that arise when making predictions during investigations into the failure of welded joints in real engineering components in service.