100 research outputs found

    Nematode associates and susceptibility of a protected slug (Geomalacus maculosus) to four biocontrol nematodes

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    The impact of selected entomopathogenic nematodes and Phasmarhabditis hermaphrodita on the European-Union-protected slug Geomalacus maculosus and the sympatric Lehmannia marginata was investigated. There was no significant difference in mortality between slugs treated with nematodes and their controls. The presence of P. hermaphrodita in two G. maculosus cadavers may be the result of necromenic behaviour. This study constitutes the first record of P. californica in Europe

    Assessment of the Biological Control Potential of Common Carabid Beetle Species for Autumn- and Winter-Active Pests (Gastropoda, Lepidoptera, Diptera: Tipulidae) in Annual Ryegrass in Western Oregon.

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    While carabid beetles have been shown to feed on a variety of crop pests, little is known about their species assemblages in US annual ryegrass crops, where invertebrate pests, particularly slugs, lepidopteran larvae and craneflies, incur major financial costs. This study assesses the biological control potential of carabid beetles for autumn- and winter-active pests in annual ryegrass grown for seed by: (a) investigating the spatial and temporal overlap of carabids with key pests; and (b) molecular gut content analysis using qPCR. Introduced Nebria brevicollis was the only common carabid that was active during pest emergence in autumn, with 18.6% and 8.3% of N. brevicollis collected between September and October testing positive for lepidopteran and cranefly DNA, respectively, but only 1.7% testing positive for slug DNA. While pest DNA was also detected in the guts of the other common carabid species-Agonum muelleri, Calosoma cancellatum and Poecilus laetulus-these were active only during spring and summer, when crop damage by pests is less critical. None of the four carabid species was affected by disk tilling and only N. brevicollis was significantly associated with a vegetated field margin. However, as its impact on native ecosystems is unknown, we do not recommend managing for this species

    Predicted effectiveness of daily and non-daily PrEP for MSM based on sex and pill-taking patterns from HPTN 067/ADAPT

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    Background: HPTN 067/ADAPT evaluated the feasibility of daily and non-daily HIV pre-exposure prophylaxis (PrEP) regimens among high-risk populations, including men who have sex with men (MSM) and transgender women, in Bangkok, Thailand and Harlem, New York, U.S. We used a mathematical model to predict the efficacy and effectiveness of different dosing regimens. Methods: An individual-based mathematical model was used to simulate annual HIV incidence among MSM cohorts. PrEP efficacy for covered sex acts, as defined in the HPTN 067/ADAPT protocol, was estimated using subgroup efficacy estimates from the iPrEx trial. Effectiveness was estimated by comparison of the HIV incidence with and without PrEP use. Results: We estimated that PrEP was highly protective (85%–96% efficacy across regimens and sites) for fully covered acts. PrEP was more protective for partially covered acts in Bangkok (71%–88% efficacy) than in Harlem (62%–81% efficacy). Our model projects 80%, 62%, and 68% effectiveness of daily, time-driven, and event-driven PrEP for MSM in Harlem compared with 90%, 85% and 79% for MSM in Bangkok. Halving the efficacy for partially covered acts decreases effectiveness by 8–9 percentage points in Harlem and by 5–9 percentage points in Bangkok across regimens. Conclusions: Our analysis suggests that PrEP was more effective among MSM in Thailand than in the U.S. as a result of more fully covered sex acts and more pills taken around partially covered acts. Overall, non-daily PrEP was less effective than daily PrEP, especially in the U.S. where the sex act coverage associated with daily use was substantially higher

    Monitoring the EU protected Geomalacus maculosus (Kerry Slug): what are the factors affecting catch returns in open and forested habitats?

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    Geomalacus maculosus is a slug species protected under EU law with a distribution limited to the west of Ireland and north-west Iberia. The species, originally thought to be limited within Ireland to deciduous woodland and peatland, has been found in a number of commercial conifer plantations since 2010. While forest managers are now required to incorporate the protection of the species where it is present, no clear species monitoring protocols are currently available. This study examines the efficacy of De Sangosse refuge traps across three habitats frequently associated with commercial forest plantations in Ireland and compares them with hand searching, a commonly used method for slug monitoring. Catch data during different seasons and under different weather conditions are also presented. Results indicate that autumn is the optimal time for sampling G. maculosus but avoiding extremes of hot or cold weather. While refuge traps placed at 1.5 m on trees in mature conifer plantations and directly on exposed rock in blanket peatlands result in significantly greater catches, hand searching is the most successful approach for clear-fell areas. Hand searches in clear-fell preceded by rain are likely to result in greater numbers caught. The results of this study form, for the first time, the basis for G. maculosus monitoring guidelines for forestry managers. © 2016, The Ecological Society of Japa

    HIV Treatment as Prevention: Debate and Commentary-Will Early Infection Compromise Treatment-as-Prevention Strategies?

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    Universal HIV testing and immediate antiretroviral therapy for infected individuals has been proposed as a way of reducing the transmission of HIV and thereby bringing the HIV epidemic under control. It is unclear whether transmission during early HIV infection—before individuals are likely to have been diagnosed with HIV and started on antiretroviral therapy—will compromise the effectiveness of treatment as prevention. This article presents two opposing viewpoints by Powers, Miller, and Cohen, and Williams and Dye, followed by a commentary by Fraser

    Antiretroviral Drugs Protect Against HIV-1 Infection in Heterosexuals

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    BackgroundAntiretroviral preexposure prophylaxis is a promising approach for preventing human immunodeficiency virus type 1 (HIV-1) infection in heterosexual populations.MethodsWe conducted a randomized trial of oral antiretroviral therapy for use as preexposure prophylaxis among HIV-1-serodiscordant heterosexual couples from Kenya and Uganda. The HIV-1-seronegative partner in each couple was randomly assigned to one of three study regimens--once-daily tenofovir (TDF), combination tenofovir-emtricitabine (TDF-FTC), or matching placebo--and followed monthly for up to 36 months. At enrollment, the HIV-1-seropositive partners were not eligible for antiretroviral therapy, according to national guidelines. All couples received standard HIV-1 treatment and prevention services.ResultsWe enrolled 4758 couples, of whom 4747 were followed: 1584 randomly assigned to TDF, 1579 to TDF-FTC, and 1584 to placebo. For 62% of the couples followed, the HIV-1-seronegative partner was male. Among HIV-1-seropositive participants, the median CD4 count was 495 cells per cubic millimeter (interquartile range, 375 to 662). A total of 82 HIV-1 infections occurred in seronegative participants during the study, 17 in the TDF group (incidence, 0.65 per 100 person-years), 13 in the TDF-FTC group (incidence, 0.50 per 100 person-years), and 52 in the placebo group (incidence, 1.99 per 100 person-years), indicating a relative reduction of 67% in the incidence of HIV-1 with TDF (95% confidence interval [CI], 44 to 81; P<0.001) and of 75% with TDF-FTC (95% CI, 55 to 87; P<0.001). Protective effects of TDF-FTC and TDF alone against HIV-1 were not significantly different (P=0.23), and both study medications significantly reduced the HIV-1 incidence among both men and women. The rate of serious adverse events was similar across the study groups. Eight participants receiving active treatment were found to have been infected with HIV-1 at baseline, and among these eight, antiretroviral resistance developed in two during the study.ConclusionsOral TDF and TDF-FTC both protect against HIV-1 infection in heterosexual men and women. (Funded by the Bill and Melinda Gates Foundation; Partners PrEP ClinicalTrials.gov number, NCT00557245.)
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