25 research outputs found
Use of Multiple Sex Venues and Prevalence of HIV Risk Behavior: Identifying High-Risk Men Who Have Sex with Men
The National HIV/AIDS Strategy emphasizes the importance of bringing prevention to the most at-risk populations. Interventions targeting all men who have sex with men (MSM) fail in that respect because only a minority engages in behavior that is likely to lead to HIV infection. Previous studies have shown that MSM who seek male sexual partners in more than one venue type (e.g., bathhouse, cruising area, online) are most likely to engage in unprotected anal intercourse (UAI), compared to men who only meet partners in any one of these setting types or who do not use venues. The present study reports differences in prevalence of UAI among MSM by their use of venue sites to meet sexual partners. A probability sample of 459 bathhouse patrons completed exit surveys. In the three months before the current bathhouse visit, 63.5% visited a bathhouse (not including the visit at which they were recruited), 46.7% visited a cruising area, 46.5% used online cruise sites to find sex partners, and 30.9% reported UAI. While UAI was associated with online cruise site use, prevalence of UAI with men met online was relatively low. The odds of UAI among men who used all three venues was significantly higher compared to men using zero [Odds Ratio (OR)=4.4; 95% Confidence Interval (CI): 1.6, 12.1)] one (OR=5.3; 95% CI: 2.2, 12.8) or two venues (OR=4.3; 95% CI: 1.9, 9.6). The findings suggest that prevention would benefit from screening for venue use to help identify men with the greatest behavioral risk
Germination responses of four native terrestrial orchids from south-west Western Australia to temperature and light treatments
We report an investigation into the impact of temperature and illumination on in vitro symbiotic and asymbiotic germination of the threatened taxon Caladenia huegelii, and three other orchid spp. namely—Caladenia latifolia, Microtis media and Pterostylis sanguinea, all species from south-west Western Australia, a recognized biodiversity hotspot. High symbiotic germination on oatmeal agar (OMA + fungal symbionts specific to each species) was recorded in three species in continuous dark incubation i.e. C. huegelii seeds (98 % germination at 25 °C), and M. media and P. sanguinea (93 and 98 % respectively at 20 °C). Highest symbiotic germination for C. latifolia (100 %) was observed at 15 and 20 °C under light treatment (12/12 h light/dark). Low temperature incubation (10 °C) significantly suppressed symbiotic germination/development of seedlings across all species. Asymbiotic media treatments assessed (OMA minus fungal symbionts, Pa5 and ½ MS), failed to stimulate any germination with C. latifolia seeds at 20 °C in either light or dark treatments after an 8 week incubation period. Seeds of M. media sown onto ½ MS medium resulted in higher germination in all developmental stages (3–5) in dark treatment than OMA and Pa5. Seeds of P. sanguinea sown onto ½ MS medium resulted in higher overall germination in all developmental stages (3–5) in light and dark incubation compared to OMA and Pa5. OMA supported the highest asymbiotic germination (100 %) in both light and dark incubation with M. media (only to stage 3) but did not support germination and development with other spp. tested.Caladenia huegelii seeds reached developmental Stage 3 (i.e. germinated), but only on Pa5 medium and only at a relatively low rate in either light (2.6 %) or dark (2.1 %). Germination was higher and development of seedlings faster overall in all test species in symbiotic compared with asymbiotic media treatments. P. sanguinea seeds demonstrated the best response (among species tested) to asymbiotic germination on ½ MS with 40–53 % of germinated seeds spread over developmental stages 3–5 in light or dark incubation (at 20 °C) respectively. Illumination had no effect on fungal symbiont growth across all species, however incubation temperature treatments (10, 15, 20 and 25 °C) affected fungal growth rate. Growth of the fungal symbionts of C. huegelii, M. media and C. latifolia demonstrated significantly lower activity at 10 °C, but the cumulative radial growth rate of the P. sanguinea fungal symbiont reached 64 cm2 after only 2 weeks at all temperatures tested, including 10 °C. The study highlights differences in symbiotic and aysmbiotic germination and early protocorm development in vitro between co-occurring herbaceous terrestrial Australian orchid taxa in response to variations in basal media, temperature and light