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Despite the increase in media attention on "meth cooking" in rural areas of the United States, little is known about rural stimulant use--particularly, the criminality associated with stimulant use. Data were collected from community stimulant users in rural Ohio, Arkansas, and Kentucky (N = 709). Findings from three logistic regression models indicate that younger stimulant users (M = 32.55, SD = 10.35), those with more convictions, and those who used crack frequently were significantly more likely to have been arrested for committing a substance-related crime, a property crime, or another crime in the 6 months before entering the study. Implications include the need for longitudinal studies to further understand rural stimulant use, as well as increased community and corrections-based drug abuse prevention and treatment interventions for stimulant users who live in rural areas. (Contains 4 tables.)

Context: There is growing concern about illicit rural stimulant use, especially regarding methamphetamine use and its health consequences. Purpose: The present study describes associations between aspects of stimulant use and illness experience in rural areas, with additional focus on the role of demographic characteristics in these associations. Methods: The research participants were 710 stimulant drug users who were recruited from rural areas of Arkansas, Kentucky, and Ohio using Heckathorn's respondent-driven sampling method. Health was measured by self-reports of perceived health and extent of current, recent, and lifelong health problems. Drug use was measured with self-reports of type and frequency of use. Findings: Several associations were found between drug use and illness, controlling for demographics. Stimulant use pattern related significantly with the sum of health problems in the previous 6 months and the sum of lifetime illness diagnoses, after adjustment for demographic factors. Extent of illicit drug use in the past month and self-perceived drug and alcohol problems were associated with several measures of health. Conclusions: In this sample of stimulant users, methamphetamine use was associated with fewer recent medical problems than crack cocaine, combined crack and powder cocaine use, and use of all 3 of these stimulants. These results, across the 3 sites, suggest that prevalent assumptions about the methamphetamine "plague" and its negative health consequences must be viewed cautiously and examined with additional research.

Context: Although the nonmedical use of stimulant drugs such as cocaine and methamphetamine is increasingly common in many rural areas of the United States, little is known about the health beliefs of people who use these drugs. Purpose: This research describes illicit stimulant drug users' views on health and health-related concepts that may affect their utilization of health care services. Methods: A respondent-driven sampling plan was used to recruit 249 not-in-treatment, nonmedical stimulant drug users who were residing in 3 rural counties in west central Ohio. A structured questionnaire administered by trained interviewers was used to collect information on a range of topics, including current drug use, self-reported health status, perceived need for substance abuse treatment, and beliefs about health and health services. Findings: Participants reported using a wide variety of drugs nonmedically, some by injection. Alcohol and marijuana were the most commonly used drugs in the 30 days prior to the interview. Powder cocaine was used by 72.3% of the sample, crack by 68.3%, and methamphetamine by 29.7%. Fair or poor health status was reported by 41.3% of the participants. Only 20.9% of the sample felt they needed drug abuse treatment. Less than one third of the sample reported that they would feel comfortable talking to a physician about their drug use, and 65.1% said they preferred taking care of their problems without getting professional help. Conclusions: Stimulant drug users in rural Ohio are involved with a range of substances and hold health beliefs that may impede health services utilization.

The weak signals of artificial seismic records contain the subsurface medium information that is required in the inversion. But in the full waveform inversion (FWI), the weak signals contribute less to the objective functions. Therefore, how to improve the contribution of the weak signals in the objective functions of FWI is the problem that needs to be solved urgently. The research shows (Ren, D. 1980. Preliminary research on seismic record and instantaneous frequency. Oil Geophysical Prospecting 15 no. 1: 7–21) that instantaneous frequency attributes, which are very sensitive to the changes in subsurface velocity, have the potential to extract the weak signals from the seismic records. However, this frequency can only be estimated from the complex seismic signals. Empirical mode decomposition (EMD) method has been widely used in signal analysis so as to estimate the instantaneous frequency, but it is difficult to be applied in FWI due to the huge computation. In order to solve this problem, the instantaneous frequency is replaced with the first-order approximation of the exponential frequency in FWI. In this paper, the objective functions of the first-order approximate exponential frequency FWI (FRE-EFWI) in elastic waves and the source terms of its back propagation formula were derived. Besides, the FRE-EFWI method was proved to improve the contribution of the weak signals in the objective functions of FWI. In addition, the correctness and effectiveness of the method were demonstrated by the examples of FWI. [ABSTRACT FROM AUTHOR]

In addition to assessing the rate of change in outcome measures, it may be useful to test the significance of outcome changes during specific time periods within an entire observation period under study. While discussing the delta method and bootstrapping, this study demonstrates how to use these 2 methods to estimate the standard errors of the predicted mean changes in the outcome of interest. Different latent growth models were run, and the results of the delta method and bootstrapping were compared. The findings of the study suggest that the 2 methods, bootstrapping in particular, may be very useful to those who are interested in scrutiny of outcome changes in longitudinal studies.

Used nine different confirmatory factor analysis models to test the factorial structure of Rosenberg's (M. Rosenberg, 1965) self-esteem scale with a sample of 430 crack-cocaine users. Results partly support earlier research to show a single global self-esteem factor underlying responses to the Rosenberg scale, method effects associated with item wording, and method effects associated with positively worded items. (SLD)

Demonstrates how the latent growth model can be applied to the evaluation of programs targeting HIV risk behavior among drug users. Multigroup piecewise latent growth models were fit to longitudinal data with three repeated response measures. Participants were 430 drug users and their sex partners. (SLD)