Electronic Transport and Possible Superconductivity at Van Hove Singularities in Carbon Nanotubes.

Van Hove singularities (VHSs) are a hallmark of reduced dimensionality, leading to a divergent density of states in one and two dimensions and predictions of new electronic properties when the Fermi energy is close to these divergences. In carbon nanotubes, VHSs mark the onset of new subbands. They are elusive in standard electronic transport characterization measurements because they do not typically appear as notable features and therefore their effect on the nanotube conductance is largely unexplored. Here we report conductance measurements of carbon nanotubes where VHSs are clearly revealed by interference patterns of the electronic wave functions, showing both a sharp increase of quantum capacitance, and a sharp reduction of energy level spacing, consistent with an upsurge of density of states. At VHSs, we also measure an anomalous increase of conductance below a temperature of about 30 K. We argue that this transport feature is consistent with the formation of Cooper pairs in the nanotube.

Disclosure of diagnosis of multiple sclerosis in the workplace positively affects employment status and job tenure.

BACKGROUND: For many employees with multiple sclerosis (MS), disclosure of their diagnosis at work is seen as a high-risk strategy that might lead to diminished perceptions of their capabilities by supervisors and colleagues, if not outright discrimination. The consequence of this mistrust surrounding the disclosure process is that employees with MS may leave it until too late to effectively manage symptoms at work. OBJECTIVE: The objective of this paper is to statistically evaluate the relationship between disclosure of diagnosis at work and maintenance of employment. METHODS: Three annual, large-sample self-report surveys of MS patients prospectively examined the relationship between disclosure of diagnosis at work and employment status. A total of 1438 people responded to all three surveys. Of employed persons in 2010 (n = 946), 673 also responded to the 2012 survey. Of these 673 respondents 564 were still employed. RESULTS: People who had disclosed their MS status to an employer were more likely to remain in employment in Year 3. The effect of disclosure in predicting employment status remained after controlling for age, gender, hours worked and level of disability. CONCLUSION: This study provides the first empirical support for the positive role of disclosure in maintaining employment status, measured both as job retention and tenure in current employment.

The Situational Confidence Questionnaire (Heroin).

This paper describes the derivation of a 22-item Situational Confidence Questionnaire for heroin users [SCQ (Heroin)]. Results revealed the SCQ (Heroin) to be an internally consistent scale with an acceptable level of test-retest reliability. Construct and discriminant validation were demonstrated through moderately significant correlations of all subscales with the short form of the Beck Depression Inventory. Factor analysis revealed a three-factor structure which could be labeled: coping with or enhancing arousal states, casual or occasional usage, and coping with negative emotions.