Determination of the smoke-plume heights and their dynamics with ground-based scanning lidar.

Lidar-data processing techniques are analyzed, which allow determining smoke-plume heights and their dynamics and can be helpful for the improvement of smoke dispersion and air quality models. The data processing algorithms considered in the paper are based on the analysis of two alternative characteristics related to the smoke dispersion process: the regularized intercept function, extracted directly from the recorded lidar signal, and the square-range corrected backscatter signal, obtained after determining and subtracting the constant offset in the recorded signal. The analysis is performed using experimental data of the scanning lidar obtained in the area of prescribed fires.

Identification of macrolide-resistant Mycoplasma genitalium using real-time PCR.

OBJECTIVES: Mycoplasma genitalium is a common cause of non-gonococcal urethritis (NGU) in Western Europe, but is not routinely tested for in all clinics. A high prevalence of macrolide-resistant M. genitalium has been reported. An easy to use test that can predict likely macrolide treatment failure is potentially very valuable. We report the development of a rapid and reliable real-time PCR-assay which detects all relevant resistance loci in the M. genitalium 23S rRNA gene. METHODS: Mycoplasma genitalium-positive clinical samples were collected between December 2012 and May 2013, from samples sent routinely to the laboratory for diagnostic testing for M. genitalium. The real-time PCR assay was designed using forward amplification primers complementary to all relevant commonly identified 23s rRNA gene mutations, a common reverse amplification primer and a common TaqMan Probe. RESULT: We report a Taqman assay for detection of common 23S rRNA genotypes at position 2058 and 2059 (Escherichia coli numbering) associated with macrolide resistance, directly from clinical samples. We validated the assay by comparison with DNA sequence determination. CONCLUSION: Our TaqMan assay detects common genotypes associated with macrolide-resistant M. genitalium, namely, A2058G, A2059G and A2058C. We show association between the presence of resistant M. genitalium and treatment failure, thereby confirming the validity of testing for these mutants to prevent further spread of antimicrobial resistance and to allow informed choice of antibiotics for treatment.

Selective chromatographic separation of polycarbonate according to hydroxyl end-groups using a porous graphitic carbon column.

Porous graphitic carbon (PGC) has shown unique separation efficiency in liquid chromatography for a wide range of substance classes. In the characterization of polymers PGC has particularly been used for analysis of polyolefins. Its retention mechanisms differ dramatically from those of silica-based stationary phases and therefore allow interesting applications. Due to its unprecedented retention mechanisms PGC does not only promise good separation performance for polyolefins but also for more polar polymers such as Polycarbonate (PC). In this study, we determined the critical conditions of PC on PGC using CHCl3/dichlorobenzene (DCB) and CHCl3/trichlorobenzene (TCB) as eluents achieving separations according to hydroxyl end-groups, which was confirmed by MALDI-TOF-MS analysis. As the content of TCB at the critical point was lower compared to that of DCB, it was concluded that TCB is a stronger desorption promoting eluent than DCB for the present system. The temperature influence on the critical point was then investigated revealing that with increasing temperature the content of desorption promoting eluent has to be raised in order to achieve critical conditions. Furthermore, a peak shifting over time was observed using TCB as desorption promoting eluent, which was attributed to irreversibly adsorbed PC on the column material. However, when a flow cell-IR detector was applied monitoring the eluted samples, a recovery rate close to 100% was found.

Comparison of on-line flow-cell and off-line solvent-elimination interfaces for size-exclusion chromatography and Fourier-transform infrared spectroscopy in polymer analysis.

Two commercial liquid chromatography-Fourier-transform infrared spectroscopy interfaces (LC-FTIR), viz. a flow cell and a solvent-elimination interface have been assessed for use in size-exclusion chromatography (SEC) with respect to their chromatographic integrity (i.e. peak asymmetry, chromatographic resolution), quantitative and qualitative aspects. A polycarbonate/aliphatic polyester (PC/APE) blend and a polycarbonate-co-polydimethylsiloxane (PC-co-PDMS) copolymer were selected for the assessment. Both samples were successfully and selectively analyzed. The relatively large volume of the flow cell and the inherent deposition characteristics of the solvent-elimination interface led to a comparable decrease in the chromatographic resolution. The separation of oligomers was diminished in comparison with SEC-ultra-violet (UV). However, the peak asymmetry was not significantly affected by either interface. For both interfaces, a linear relationship was obtained for the FTIR response versus the injected concentration. The sensitivity was found to be higher for the solvent-elimination interface. For the current model compounds, the flow-cell interface detection limits are worse. However, the repeatability of flow-cell SEC-FTIR, evaluated by means of four SEC-FTIR analyses of polycarbonate, was considerably better than for solvent-elimination SEC-FTIR. This is probably due to the well-defined optical path length of the sample in the flow cell. By spectral subtraction, it was very well possible to obtain qualitative (functional group) information for compound identification also with flow-cell SEC-FTIR.

HIV and hepatitis B infection and risk behavior in young gay and bisexual men.

OBJECTIVES: To estimate the prevalence of and identify risk factors for human immunodeficiency virus type 1 (HIV-1) and hepatitis B virus (HBV) infections and unprotected anal intercourse among young homosexual and bisexual men. METHODS: The authors performed a cross-sectional analysis of data from a prospective cohort of 508 young gay and bisexual men ages 18-29. RESULTS: HIV-1 seroprevalence was 2.4%, with five (1.3%) of 390 college students and seven (6.0%) of 117 non-students infected. After adjusting for confounders, HIV-1 infection was associated with having a history of a sexually transmitted disease other than HIV-1 or hepatitis B. The prevalence of hepatitis B markers in unvaccinated men was 12.9%. The presence of hepatitis B markers in unvaccinated men was significantly associated with Asian ethnicity, off-campus residence, and history of a sexually transmitted disease other than HIV-1 or hepatitis B and inversely associated with recent non-intravenous drug use. Eighteen percent of the participants reported having had sex with women during the previous 12 months, and 26.4% reported a history of unprotected anal intercourse during the previous six months. Men who reported unprotected anal intercourse were more likely to have at least one steady partner, to have met their partners in anonymous settings, and to be identified as probably alcohol dependent. CONCLUSIONS: Although the prevalence of HIV-1 infection among young homosexual and bisexual men in Boston was relatively low, the high rates of unprotected anal intercourse suggest a potential for future HIV-1 and hepatitis B transmission. Interventions should focus on young men with histories of sexually transmitted diseases, alcohol abuse, and depression.

A work-sampling tool to measure the effect of electronic medical record implementation on health care workers.

This article presents baseline work sampling data from an outpatient oncology clinic prior to an electronic medical record implementation. The physicians and medical office assistants spent 29% and 39% of their time, respectively, entering and retrieving information from medical records. The physicians and medical office assistants spent 43% and 17% of their time, respectively, on direct patient contact. Using scheduled outpatient counts to measure the productivity of the physicians and medical office assistants failed to capture 19% and 29% of their workload.

Relationship of staff development activity to opinions about mental illness.

When 1971 and 1974 student psychiatric aides, staff psychiatric aides, and professionals at Topeka State Hospital in Kansas were given the five-factor Opinions about Mental Illness Scale as pre- and posttests, no significant differences were found in scores of the student aide groups. Significant differences, however, were found among 1974 student aides, staff aides, and professionals, with students scoring higher than professionals (p less than .05) on factors A-authoritarianism, D-social restrictiveness, and E-interpersonal etiology. Staff aides scored higher than professionals on factor B-benevolence, factor A-authoritarianism (p=.005), and factor D-social restrictiveness (p=.05). Implications for nursing are discussed.

Health behaviors, health status, and access to and use of health care: a population-based study of lesbian, bisexual, and heterosexual women.

BACKGROUND: There is a dearth of validated information about lesbian and bisexual women's health. To better understand some of these issues, we used population-based data to assess variations in health behaviors, health status, and access to and use of health care based on sexual orientation. METHODS: Our study population was drawn from a population-based sample of women, the 1997 Los Angeles County Health Survey. Participants reported their sexual orientation and these analyses included 4697 women: 4610 heterosexual women, 51 lesbians, and 36 bisexual women. We calculated adjusted relative risks to assess the effect of sexual orientation on important health issues. RESULTS: Lesbians and bisexual women were more likely than heterosexual women to use tobacco products and to report any alcohol consumption, but only lesbians were significantly more likely than heterosexual women to drink heavily. Lesbians and bisexual women were less likely than heterosexual women to have health insurance, more likely to have been uninsured for health care during the preceding year, and more likely to have had difficulty obtaining needed medical care. During the preceding 2 years, lesbians, but not bisexual women, were less likely than heterosexual women to have had a Papanicolaou test and a clinical breast examination. CONCLUSIONS: In this first population-based study of lesbian and bisexual women's health, we found that lesbians and bisexual women were more likely than heterosexual women to have poor health behaviors and worse access to health care. These findings support our hypothesis that sexual orientation has an independent effect on health behaviors and receipt of care, and indicate the need for the increased systematic study of the relationship between sexual orientation and various aspects of health and health care. Arch Fam Med. 2000;9:1043-1051

Meeting the data needs of a local health department: the Los Angeles County Health Survey.

Monitoring the health status of populations is a core function of all public health agencies but is particularly important at the municipal and community levels, where population health data increasingly are used to drive public health decision making and community health improvement efforts. Unfortunately, most local health jurisdictions lack important data for developing population health profiles, such as data on chronic disease prevalence, quality-of-life measures, functional status, and self-perceptions of health status. In addition, data on important determinants of health, including health behaviors and access to health care services, are rarely available locally. These data frequently are collected in national and state surveys (e.g., the National Health Interview Survey and the Behavioral Risk Factor Surveillance System) and provide critical information to assess progress toward achieving state and national health objectives. The surveys rarely serve local data needs, however, because of insufficient sample size and lack of flexibility to address local health issues. To address gaps in local health data, in 1997 the Los Angeles County Department of Health Services inaugurated the Los Angeles County Health Survey.

Childhood sexual abuse among homosexual men. Prevalence and association with unsafe sex.

Of 327 homosexual and bisexual men participating in an ongoing cohort study pertaining to risk factors for HIV infection who completed a survey regarding history of sexual abuse, 116 (35.5%) reported being sexually abused as children. Those abused were more likely to have more lifetime male partners, to report more childhood stress, to have lied in the past in order to have sex, and to have had unprotected receptive anal intercourse in the past 6 months (odds ratio 2.13; 95% confidence interval 1.15-3.95). Sexual abuse remained a significant predictor of unprotected receptive anal intercourse in a logistic model adjusting for potential confounding variables.

Interest among gay/bisexual men in greater Boston in participating in clinical trials of preventive HIV vaccines.

To estimate interest in HIV preventive vaccine trials, we administered questionnaires to two otherwise demographically similar cohorts of older (mean 40 years) and younger (mean 23 years) gay men in Boston. Questionnaire responses were linked to concurrent behavioral and demographic data. Univariate analyses, performed separately for older and younger cohorts, identified factors that distinguished participants who were "very interested" from those who were "not at all interested". Multivariate logistic regression analyses were used to adjust for confounding. Among all 630 participants, 215 (34%) were "not at all" interested in participating, 306 (49%) were "somewhat" interested, and 102 (16%) were "very" interested. Older men were significantly more likely than younger men to be "very" interested and less likely to be "not at all interested." Among both older and younger men, perceived peer willingness to enroll in vaccine trials predicted interest after adjusting for confounding. Among older men, optimism about success in vaccine development also predicted interest. In the younger cohort, men recruited in community settings (e.g., bars, nightclubs) were more interested in vaccine trial participation than were those recruited by outreach workers and word of mouth on college campuses. Vaccine-induced seroconversion evoked significant concern.

Unsafe sex in men who have sex with both men and women.

The sexual behaviors of bisexually active men, defined as men having sex with a man and a woman in previous 6 months, were compared with men who had sex with men only. Differential sexual practices associated with HIV risk between the two groups of men, as well as in the bisexual men with their male and female partners, were evaluated. Cross-sectional analyses were performed on baseline data from a prospective cohort of 508 young gay men recruited from bars, college campuses, and a health center in Boston from 1993 to 1994. Odds ratios (OR) and 95% confidence intervals (CI) were calculated on categorical variables, and McNemar's chi2 was used to compare the behaviors of bisexual men with their male versus female sex partners. Six months before the interview, 47 (10%) men had male and female sex partners, and 383 men had only male sex partners during the past year or ever. Fifty-eight percent of the men in the study had a female sexual partner in their lifetime, and 18% during the past year. Bisexual men were more likely to have drinking problems as identified by the Michigan Alcoholism Screening Test (MAST; OR = 3.96, 95% CI = 1.54-10.20), and fewer male partners over their lifetime (mean +/- standard deviation [SD], 24+/-42; median, 7; versus mean +/- SD, 69+/-516; median, 12), although this difference was not statistically significant. The two groups had similar levels of unprotected anal intercourse (25.5% versus 29.5%); however, bisexual men were half as likely to have anal sex as homosexual men (OR = 0.50; 95% CI = 0.27-0.93). Bisexual men were three times as likely to have unprotected sex with their female partner as their male partner (OR = 3.0; 95% CI = 1.02-8.8). Stratified analysis revealed similar discordant behavior while sober (OR = 4.0), drinking (OR = 7.0), and while drinking with concurrent drug use (OR = 8.0). Among this cohort of men who have sex with men (MSM), a sizable proportion also had vaginal sex with female partners in the previous 6 months. Bisexually active men were more likely to have unprotected sex with their female partners compared with their male partners, potentially increasing the risk for HIV and other sexually transmitted diseases. Behavioral interventions directed toward MSM need to address bisexual behaviors.

PIP: Data were collected from 508 gay men recruited from bars, 17 Boston area college campuses, and a health center in Boston during 1993-94 for use in a study comparing the sex behaviors of men who had sex with a man and a woman during the previous 6 months against men who had sex with only men. Study participants were aged 18 to over 27 years, although 85.1% were aged 18-26. 6 months before the interview, 10% of the men had both male and female sex partners, while 383 men had only male sex partners during the past year or ever. 58% of the men in the study had ever had a female sex partner, and 18% during the past year. Bisexual men were more likely to have drinking problems as identified by the Michigan Alcoholism Screening Test and fewer male partners over their lifetime. 25.5% of the bisexual men and 29.5% of the homosexuals reported having unprotected anal intercourse, but bisexual men were less likely than homosexual men to have anal sex. Bisexual men were 3 times more likely to have unprotected sex with a female partner as with their male partner. Stratified analysis revealed this same discordant behavior while sober, drinking, and drinking together with other drug use.

The social context of drinking, drug use, and unsafe sex in the Boston Young Men Study.

The objective of this study was to evaluate the relation between drinking, drug use, and unprotected anal intercourse in young men who have sex with men. A cross-sectional analysis of first-visit data from a prospective cohort of 508 young gay men recruited from 1993 through 1994 from bars, college campuses, and the Fenway Community Health Center in Boston was performed. The major outcome measures were any unprotected anal intercourse, after drinking and when sober, stratified by type of sexual partner (steady or nonsteady) during the previous 6 months and during the most recent sexual encounter. The average age of the cohort was 23.3 years; 77.6% were white, and 76.4% were in college. These young men had a median of 10.5 male sexual partners in their lifetimes, and 3 sexual partners in the previous 6 months before enrollment. One hundred and thirty-four (26%) reported unprotected anal intercourse during the previous 6 months. Individuals who had unprotected anal intercourse were more likely to have a drinking problem (odds ratio [OR] = 1.95; 95% confidence interval [CI] = 1.26-3.01) and drank more (20.4 ml/day versus 13.9 ml/day; p < or = 0.01), compared with individuals who did not engage in unprotected anal intercourse. Overall, men were significantly less likely to have unprotected anal intercourse after alcohol or drug use, based on a series of paired analysis (OR = 0.27; 95% CI = 0.15-0.48). However, when we stratified by type of sexual partner, men were significantly more likely to have unprotected anal intercourse with their nonsteady sexual partners after drinking than when sober (OR = 4.33; 95% CI = 1.37-13.7), but were significantly less likely to have unprotected anal intercourse with steady partners (OR = 0.27; 95% CI = 0.15-0.48). The patterns observed as already mentioned for drinking were also found for substance use in general. Men who were more likely to have unprotected anal intercourse after substance use were significantly more likely to have a drinking problem (OR = 7.65; 95% CI = 2.34-24.59). These results suggest that the role of alcohol and unsafe sex in young gay men is complex, with the role of situational factors of paramount importance. Alcohol and substance use interventions designed to reduce HIV risk need to specify the role of substance use in the sexual context to be successful.