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We performed density functional theory calculations using niobium (Nb) as a model system of a conventional superconductor, to correlate the distortion of twin defects with the electron-phonon coupling properties. Calculations using different settings of the Nb elementary cell (relaxed, distorted, super cell with zig-zag twin defect) showed that only by including real structure elements into the setting, the Eliashberg spectral function representing the electron-phonon coupling properties was derived convincingly. Based on these density functional theory calculations of the electron-phonon cou- pling properties of Nb, we suggest a model for a combined superconducting/charge density wave ground state which uses a lattice distortion induced into the crystal by two-dimensional defects as modulated background potential of the charge density wave phase. The coexistence of both phases is hereby necessary for a fine-tuning of the Fermi surface within the small local domain of the defect to match the wavelength of the lattice distortion and the Fermi wavelength by pairing fermions to bosons. (© 2015 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

This study investigated the impact of the 9/11 attacks on substance use in Chicago, Illinois. The study design was a cross-sectional, audio-computer-assisted self-interview survey conducted in 2001 and 2002. Biological samples were also collected for toxicological analyses. Using a multistage area probability design, residents between the ages of 18 and 40 years were randomly selected. Compared to pre-9/11 interviewees, post-9/11 interviewees showed significantly less self-reported marijuana use, marijuana use per test results, and cocaine use per test results. Law enforcement and social-structural explanations for the findings are discussed. [ABSTRACT FROM AUTHOR]

AIMS: To examine whether neighborhood racial characteristics are associated with the under reporting of life time cocaine/crack use. DESIGN: A household survey of high-risk communities with above-average admissions to state-supported drug and alcohol treatment programs. SETTING: Chicago, Illinois, USA. PARTICIPANTS: A total of 303 adults. MEASURES: Self-reported use of cocaine/crack during a respondent's life time, hair test assays for cocaine use and level of neighborhood diversity measured using the Simpson Index. FINDINGS: Respondents from more segregated neighborhoods were more likely than those from diverse neighborhoods to under report life time cocaine/crack use. CONCLUSIONS: Neighborhood racial characteristics should be considered as an important factor in household surveys on illicit substance use. [ABSTRACT FROM AUTHOR]

AIMS: To better understand the prevalence, correlates, risk factors and context of club drug use among US adults in the City of Chicago. DESIGN: An Audio Computer-Assisted Self Interview was administered to a household probability sample of adults, aged 18-40 years, from June 2001 to January 2002. SETTING: Subjects were drawn from randomly selected households using a multi-stage area probability design. PARTICIPANTS: The data represent 627 randomly selected adult participants. MEASUREMENT: Weighted prevalence estimates with design-effect adjusted confidence intervals of life-time, past 12 month and past 30 day use of any club drug and of specific club drugs; prevalence of rave attendance, other drug use, motivation for use among club drug users; chi2 tests of significance, logistic regression and adjusted odds ratios. FINDINGS: Overall club drug prevalence rates were nearly twice those obtained for MDMA alone. Club drug users were more likely to use multiple illicit substances and to report having been in treatment for substance use. A majority of life-time club drug users never attended a rave although rave attendees were more likely to report frequent use of MDMA. Use was associated with gender, race and sexual orientation. CONCLUSIONS: Prevention research should be informed by further population-based research on club drug use. Research should not focus exclusively on rave attendees, as they are only a subset of club drug users. Research is needed on neurological and behavioral sequelae across different types of club drugs, gender differences in the impact of sexual orientation on club drug risk and on the effects of personality characteristics such as sensation seeking on club drug use behavior. [ABSTRACT FROM AUTHOR]

We analyzed recanting of substance use reports for lifetime use of alcohol, alcohol to get drunk, cigarettes, marijuana and cocaine in an 8-wave panel study designed to evaluate the Drug Abuse Resistance Education program in the State of Illinois. Although this phenomenon has been identified elsewhere, the current analysis of recanting is a unique attempt to track this behavior over the entire course of adolescence. Overall, rates of recanting for specific drugs were extremely high, ranging from 45% for lifetime reports of alcohol use to 81% for lifetime reports of cocaine. Most recanting occurred in the wave immediately following the wave of first disclosure. Paralleling results from other studies, race/ethnicity was an important correlate of recanting in both bivariate and multivariate analyses. African American respondents had higher rates of recanting than White subjects. Even after controlling for the number of follow-up waves, the later the wave of first disclosed lifetime drug use, the lower the probability that drug use would be recanted ever (for all substances) or in the wave immediately following first disclosure (for reports of ever having been drunk or for lifetime marijuana or cocaine use). Alternative causes for this phenomenon are discussed. Implications for the design and interpretation of multiwave school-based panel surveys targeted toward adolescents are also addressed. [ABSTRACT FROM AUTHOR]

The growth of N,N′-dimethylperylene-3,4,9,10-bis(dicarboximide) (DiMe-PTCDI) on KBr(001) has been studied by frequency modulation atomic force microscopy. At low coverages, DiMe-PTCDI forms molecular wires with a length of up to 600 nm; at higher coverages, wire networks were found. The height of the wires is two or more molecular layers; if the sample is cooled to 250 K during evaporation, also wires of one layer are found. All wires grow along the [110] and [110] directions of the KBr(001) substrate. There is no wetting layer of molecules. Atomic resolution of the substrate could be achieved between the wires. Due to their size and shape, the molecular nanowires might act as a model system for organic electronics research on insulating substrates. [ABSTRACT FROM AUTHOR]

Grandparents and other relatives increasingly assume the role of primary caregiver to minor children. This study interviewed family members caring for children whose parents were not available due to parental incarceration, other involvement in the criminal justice system, and substance abuse-related issues. Interviews with 25 African American women examined the impact of caregiving including stress and depression. Stress included caregiver issues related to finances, time allocation, care responsibilities, and concerns about the absent parent, as well as issues specific to the children related to school concerns, child behavior, and emotional problems. These stresses were examined along with caregiver depression scores using the Center for Epidemiological Studies Depression Scale, which indicated more depression related to caregiver illnesses, older caregivers, and care for older and a larger number of children. This study suggests that caring for these children is both challenging and stressful, and caregivers are at risk for depression and other mental health concerns. Health and service providers should carefully assess the needs of caregivers when determining the needs of families where children are under care of nonparental relatives. Family-based services are needed that include caregiver supports as well as support for children. [ABSTRACT FROM AUTHOR]

We present a new method to measure lateral dissipation in frequency-modulation atomic force microscopy (FM-AFM). Conventional FM-AFM has been used to measure the topography. Additionally the cantilever has been excited in the first torsional mode, leading to a tip motion parallel to the surface. The dissipation of this motion is measured and reveals information that is different from the information provided by the dissipation of the tip motion normal to the surface. [ABSTRACT FROM AUTHOR]

Data were analyzed from two years (1993 and 1995) of a statewide survey of high school students on drug use. Changes in the rates of inhalant use, and associations between inhalant use and sociodemographic variables, were examined across the two survey years. Measures of inhalant use included lifetime use, past year use, and past month use. Analyses showed no significant difference in the rates of inhalant use across years. Associations with sex, ethnicity, and age were partly consistent with previous research findings. Both lifetime and recent inhalant use were more prevalent among males than females. Blacks were less likely to use inhalants (lifetime and recent) than other racial/ethnic groups in both survey years. Native Americans showed elevated rates of recent inhalant use in 1993, but not in 1995. While age trends in the 1993 survey were consistent with expectations, age trends in the 1995 survey were not. Recent inhalant use was constant across age groups in the 1995 sample. Also contrary to expectations, inhalant use was not more prevalent in low-income or high-poverty areas. The associations of inhalant use with family intactness and academic performance varied by race/ethnicity. Family intactness was a significant protective factor only for whites and Hispanics. Poor grades were not a significant predictor of lifetime inhalant use for blacks, and the protective effect of high grades was found only for whites. Poor grades were highly predictive of lifetime inhalant use for Asians. [ABSTRACT FROM AUTHOR]

To better understand and control the spread of sexually transmitted diseases among high-risk youth, we must first acquire reliable reports of sexual risk behavior. This study evaluates one potential method for validating such reports. We examined the association between marijuana and cocaine use reporting patterns and the number of reported recent sexual partners in a sample of juvenile arrestees/detainees. Using urinalysis to validate self-reported drug use, we categorized drug use reporting patterns into four groups: overreporters, underreporters, honest users, and honest nonusers. Analyses showed, in general, that overreporters reported more sexual partners than either underreporters or accurate reporters, suggesting that overreporters of drug use may also exaggerate sex partner reports. Findings suggest a new method for validating self-reported sexual behavior and provide a challenge to theories of juvenile delinquency. [ABSTRACT FROM AUTHOR]