results from a cross-sectional internet survey

Background Recent evidence suggests that the majority of HIV transmissions among men who have sex with men (MSM) occur between steady partners. We sought to determine factors associated with HIV transmission risks in steady partnerships. Methods Data is from the German cross-sectional 2013 Gay Men and AIDS survey. The study population was HIV-negative or untested men reporting a steady partnership and at least one non-steady anal sex partner in the previous year. Bivariate and multivariate logistic regression was used to determine which of several independent variables best predicted both unprotected anal intercourse (UAI) with a non-steady partner and lack of HIV testing in the past year (high-risk outcome group). Results The study population consisted of 1731 men. Among individuals in the outcome group (n = 271), 67 % reported UAI with a non-steady partner of unknown status and 9 % reported UAI with a non-steady HIV-positive partner in the past 12 months; 55 % considered themselves to be at low risk for HIV acquisition. In multivariate analyses (n = 1304), participants were statistically more likely to belong to the outcome group if they reported UAI with their steady partner in the past year (OR = 2.21), did not know their steady partner’s HIV status (OR = 1.98), or agreed that condoms were disruptive during sex (OR = 3.82 (strongly agree), OR = 2.19 (agree)). Participants were less likely to belong to the outcome group if they were out to their primary doctor (OR = 0.54), were well-educated about post-exposure prophylaxis (OR = 0.46), had sought information on HIV in the past year and kept condoms in an accessible place (OR = 0.20), or believed that insisting on condoms would lead partners to assume they were HIV-negative (OR = 0.20). Participants in the outcome group were more likely to say they would use HIV home tests (OR = 1.58) or pre-exposure prophylaxis (OR = 2.11). Conclusions Based on our results, we reflect on HIV prevention measures that should be improved in order to better target behaviors that may lead to HIV transmission between MSM in steady relationships. In particular, we highlight the need for multifaceted interventions focusing not only on members of the at-risk community themselves, but on communities as a whole

Nuclear Magnetic Resonance Logging While Drilling (NMR-LWD): from an experiment to a day-to-day Service for the oil industry

NMR T2 distribution measurement is our chosen everyday method for NMR logging while drilling oil and gas wells. This method yields straightforward preparation and execution of the job as well as a normally easy interpretation of the measured data. For instance, gas and light oil discrimination against water is feasible by direct observation of the T2 distribution. A condition for this measurement method is a NMR logging tool that hardly moves while drilling and in addition uses a small static magnetic field gradient and short inter-echo time TE to be motion tolerant. Using data compression techniques, we can transmit by mud pulse telemetry the T2 distribution in real time from the borehole to the surface. This enables the drilling operator to use the NMR data for real-time decisions such as geosteering

Geo-Information Harvesting from Social Media Data

As unconventional sources of geo-information, massive imagery and text messages from open platforms and social media form a temporally quasi-seamless, spatially multi-perspective stream, but with unknown and diverse quality. Due to its complementarity to remote sensing data, geo-information from these sources offers promising perspectives, but harvesting is not trivial due to its data characteristics. In this article, we address key aspects in the field, including data availability, analysis-ready data preparation and data management, geo-information extraction from social media text messages and images, and the fusion of social media and remote sensing data. We then showcase some exemplary geographic applications. In addition, we present the first extensive discussion of ethical considerations of social media data in the context of geo-information harvesting and geographic applications. With this effort, we wish to stimulate curiosity and lay the groundwork for researchers who intend to explore social media data for geo-applications. We encourage the community to join forces by sharing their code and data.Comment: Accepted for publication IEEE Geoscience and Remote Sensing Magazin

Geo-Information Harvesting from Social Media Data

As unconventional sources of geo-information, massive imagery and text messages from open platforms and social media form a temporally quasi-seamless, spatially multiperspective stream, but with unknown and diverse quality. Due to its complementarity to remote sensing data, geo-information from these sources offers promising perspectives, but harvesting is not trivial due to its data characteristics. In this article, we address key aspects in the field, including data availability, analysisready data preparation and data management, geo-information extraction from social media text messages and images, and the fusion of social media and remote sensing data. We then showcase some exemplary geographic applications. In addition, we present the first extensive discussion of ethical considerations of social media data in the context of geo-information harvesting and geographic applications. With this effort, we wish to stimulate curiosity and lay the groundwork for researchers who intend to explore social media data for geo-applications. We encourage the community to join forces by sharing their code and data

Recency and frequency of HIV testing among men who have sex with men in Germany and socio-demographic factors associated with testing behaviour

Background: Testing for presence of HIV infection is a pre-requisite to qualify for antiretroviral treatment. A considerable proportion of German men who have sex with men (MSM) infected with HIV have a CD4 cell count below 350 cells/μl at time of diagnosis and are thus defined as “late presenters”. Late presentation increases the risk of adverse disease outcomes. In addition, knowledge and assessment of HIV status is often used for decisions about condom use and anal intercourse with steady and non-steady partners. Incorrect assumptions may result in high risk for HIV transmission. Methods: Between 11/2013 and 01/2014 MSM were recruited to an online survey predominantly by personalized invitation messages from MSM social networking and dating websites. Respondents were asked about demographic characteristics, HIV testing history, reasons for testing decisions, and sexual behaviours. We describe reasons for not testing and analyse factors associated with not or infrequent testing using univariable and multivariable multinomial regression. Results: Questions on HIV testing history were answered by 15,297 respondents. An HIV test within the last 12 months was reported by 38 %, a test more than 12 months ago by 27 % and 35 % had never been tested for HIV. Compared to recently tested, respondents who had never tested were more likely to be younger than 25 years (adjusted relative risk ratio (aRRR) 2.90, 95 % CI 2.11-3.99), living in a settlement with less than 100,000 inhabitants (aRRR 1.47, 95 % CI 1.18-1.83), being less open about their sexual orientation to their co-workers/classmates, and particularly to their primary care provider (aRRR 4.54, 95 % CI 4.02-5.11). Untested and less frequently tested respondents reported less sex partners and a lower proportion reported unprotected anal intercourse (UAI) with a non-steady partner (24 % compared to 38 % among those recently tested). Conclusions: MSM who were younger, who did not live in large cities, and who were not out about their sexual orientation tested less frequently for HIV. Apart from strengthening protection from sexual orientation-related discrimination and empowering MSM who conceal their orientation, more opportunities to test anonymously and without revealing one’s sexual orientation should be provided

The impact of meeting locations for men having sex with men on the risk for bacterial sexually transmitted infections: analyses from a cross-sectional online survey

Objectives: Opportunities for men having sex with men (MSM) to meet each other have very much improved by new communication technologies. Meeting venue-based characteristics can impact how many partners are met and how much sexual risk is taken. We analysed the association between physical and virtual venues and the risk for bacterial sexually transmitted infections (bSTIs) among participants in an MSM online survey. Methods: Data were collected during 2013/2014 with a survey targeting MSM living in Germany. The impact of the meeting place with the last non-steady anal sex partner on diagnosis with a bSTI in the previous year was analysed using bivariate and multivariate regression analysis, taking into account self-reported HIV status, serostatus communication, condom use, partner number, age and city size. Results: The study sample consisted of 8878 respondents (7799 not diagnosed with HIV; 1079 diagnosed with HIV). Meeting partners online was most common (62% HIV−/51% HIV+), followed by sex venues (11% HIV−/25% HIV+); other venues were each reported by 2–6% of the respondents. Venue-dependent proportions reporting bSTIs in the recent year were 2–4 folds higher among men diagnosed with HIV. In multivariate analysis, HIV status was the strongest predictor for bSTIs (OR=5.0; 95% CI 2.8 to 8.7). Compared with meeting partners online, sex (OR 1.6; 95% CI 1.0 to 2.5) and social venues (OR 1.9; 95% CI 1.4 to 2.6) were associated with increased bSTI risk for men not diagnosed with HIV, but the risk when meeting partners by smartphone apps was only of borderline significance (OR 1.5; 95% CI 0.9 to 2.3). For men diagnosed with HIV, bSTI risk increased for sex venues (OR 1.5; 95% CI 1.1 to 2.1), and was lower for non-gay/other venues (OR 0.2; 95% CI 0.1 to 0.5). Conclusions: Venues are connected to social-behavioural facets of corresponding sexual encounters, and may be important arenas for differential HIV and STI education, treatment and prevention

Factors associated with sexual risk behaviors with non-steady partners and lack of recent HIV testing among German men who have sex with men in steady relationships: results from a cross-sectional internet survey

Background: Recent evidence suggests that the majority of HIV transmissions among men who have sex with men (MSM) occur between steady partners. We sought to determine factors associated with HIV transmission risks in steady partnerships. Methods: Data is from the German cross-sectional 2013 Gay Men and AIDS survey. The study population was HIV-negative or untested men reporting a steady partnership and at least one non-steady anal sex partner in the previous year. Bivariate and multivariate logistic regression was used to determine which of several independent variables best predicted both unprotected anal intercourse (UAI) with a non-steady partner and lack of HIV testing in the past year (high-risk outcome group). Results: The study population consisted of 1731 men. Among individuals in the outcome group (n = 271), 67 % reported UAI with a non-steady partner of unknown status and 9 % reported UAI with a non-steady HIV-positive partner in the past 12 months; 55 % considered themselves to be at low risk for HIV acquisition. In multivariate analyses (n = 1304), participants were statistically more likely to belong to the outcome group if they reported UAI with their steady partner in the past year (OR = 2.21), did not know their steady partner’s HIV status (OR = 1.98), or agreed that condoms were disruptive during sex (OR = 3.82 (strongly agree), OR = 2.19 (agree)). Participants were less likely to belong to the outcome group if they were out to their primary doctor (OR = 0.54), were well-educated about post-exposure prophylaxis (OR = 0.46), had sought information on HIV in the past year and kept condoms in an accessible place (OR = 0.20), or believed that insisting on condoms would lead partners to assume they were HIV-negative (OR = 0.20). Participants in the outcome group were more likely to say they would use HIV home tests (OR = 1.58) or pre-exposure prophylaxis (OR = 2.11). Conclusions: Based on our results, we reflect on HIV prevention measures that should be improved in order to better target behaviors that may lead to HIV transmission between MSM in steady relationships. In particular, we highlight the need for multifaceted interventions focusing not only on members of the at-risk community themselves, but on communities as a whole

Nuclear Magnetic Resonance Logging While Drilling (NMR-LWD): from an experiment to a day-to-day Service for the oil industry

NMR T2 distribution measurement is our chosen everyday method for NMR logging while drilling oil and gas wells. This method yields straightforward preparation and execution of the job as well as a normally easy interpretation of the measured data. For instance, gas and light oil discrimination against water is feasible by direct observation of the T2 distribution. A condition for this measurement method is a NMR logging tool that hardly moves while drilling and in addition uses a small static magnetic field gradient and short inter-echo time TE to be motion tolerant. Using data compression techniques, we can transmit by mud pulse telemetry the T2 distribution in real time from the borehole to the surface. This enables the drilling operator to use the NMR data for real-time decisions such as geosteering

Nuclear Magnetic Resonance Logging While Drilling (NMR-LWD): from an experiment to a day-to-day Service for the oil industry

NMR T2 distribution measurement is our chosen everyday method for NMR logging while drilling oil and gas wells. This method yields straightforward preparation and execution of the job as well as a normally easy interpretation of the measured data. For instance, gas and light oil discrimination against water is feasible by direct observation of the T2 distribution. A condition for this measurement method is a NMR logging tool that hardly moves while drilling and in addition uses a small static magnetic field gradient and short inter-echo time TE to be motion tolerant. Using data compression techniques, we can transmit by mud pulse telemetry the T2 distribution in real time from the borehole to the surface. This enables the drilling operator to use the NMR data for real-time decisions such as geosteering