102 research outputs found

    Development of Fungal Applications on Netting Substrates for Malaria Vector Control

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    Mosquito resistance to chemical insecticides is considered a serious threat for the sustainable use of contemporary malaria vector control methods. Fungal entomopathogens show potential as alternative biological control agents against (insecticide-resistant) anophelines. This study was designed to test whether the fungus, Beauveria bassiana, could be delivered to mosquitoes on netting materials that might be used in house screens, such as eave curtains. Tests were conducted to determine effects of formulation, application method, netting material, and nature of mosquito contact. Beauveria had a twice as high impact on Anopheles gambiae s.s. longevity when suspended in Shellsol solvent compared with Ondina oil (HR = 2.12, 95% confidence interval = 1.83–2.60, P 90% of mosquitoes within 10 d. Results indicate that the use of fungal spores dissolved in Shellsol and sprayed on small-meshed cotton eave curtain nets would be the most promising option for field implementation. Biological control with fungus-impregnated eave curtains could provide a means to target host-seeking mosquitoes upon house entry, and has potential for use in integrated vector management strategies, in combination with chemical vector control measures, to supplement malaria control in areas with high levels of insecticide resistance

    Field-aged phosphate impacts on glyphosate and phosphorus sorption patterns in two prairie soils

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    Non-Peer ReviewedThis research measured field-aged phosphate concentrations in sandy clay-loam, clay-loam soils and utilized samples in batch equilibrium studies to quantify adsorption maximum of phosphate and glyphosate retention. Soil samples were collected in 2013 from two research sites that had received annual applications of mono ammonium phosphate at different rates from 2002 to 2009. The effect of fresh phosphate addition on glyphosate sorption in soil was also determined. Measured parameters were the glyphosate sorption distribution constant, Kd, as well as the Langmuir adsorption constants, b (phosphorus adsorption maximum), and k (affinity constant). Glyphosate Kd values significantly decreased with increasing phosphate level in soils, regardless of the background liquid (CaCl2 and KCl) used in the batch equilibrium experiment. Applications of potassium dihydrogen phosphate in the laboratory with glyphosate reduced the available sorption sites to retain glyphosate in soil. Field-aged phosphate did not significantly influence the adsorption maximum (b), but b was significantly higher with CaCl2 than KCl as background liquid. The affinity constant was significantly greater in soils with lower field-aged phosphate concentrations, suggesting that these soils had more readily-available sorption sites for phosphate than soils with higher phosphate concentrations

    Development and evaluation of a novel contamination device that targets multiple life-stages of Aedes aegypti.

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    BACKGROUND: The increasing global threat of Dengue demands new and easily applicable vector control methods. Ovitraps provide a low-tech and inexpensive means to combat Dengue vectors. Here we describe the development and optimization process of a novel contamination device that targets multiple life-stages of the Aedes aegypti mosquito. Special focus is directed to the diverse array of control agents deployed in this trap, covering adulticidal, larvicidal and autodissemination impacts. METHODS: Different trap prototypes and their parts are described, including a floater to contaminate alighting gravid mosquitoes. The attractiveness of the trap, different odor lures and floater design were studied using fluorescent powder adhering to mosquito legs and via choice tests. We demonstrate the mosquitocidal impacts of the control agents: a combination of the larvicide pyriproxyfen and the adulticidal fungus Beauveria bassiana. The impact of pyriproxyfen was determined in free-flight dissemination experiments. The effect on larval development inside the trap and in surrounding breeding sites was measured, as well as survival impacts on recaptured adults. RESULTS: The developmental process resulted in a design that consists of a black 3 Liter water-filled container with a ring-shaped floater supporting vertically placed gauze dusted with the control agents. On average, 90% of the mosquitoes in the fluorescence experiments made contact with the gauze on the floater. Studies on attractants indicated that a yeast-containing tablet was the most attractive odor lure. Furthermore, the fungus Beauveria bassiana was able to significantly increase mortality of the free-flying adults compared to controls. Dissemination of pyriproxyfen led to >90% larval mortality in alternative breeding sites and 100% larval mortality in the trap itself, against a control mortality of around 5%. CONCLUSION: This ovitrap is a promising new tool in the battle against Dengue. It has proven to be attractive to Aedes aegypti mosquitoes and effective in contaminating these with Beauveria bassiana. Furthermore, we show that the larvicide pyriproxyfen is successfully disseminated to breeding sites close to the trap. Its low production and operating costs enable large scale deployment in Dengue-affected locations

    Clinical determinants of vaginal dryness in patients with primary Sjögren's syndrome

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    Objective. The majority of women with primary Sjogren's syndrome (pSS) suffer from vaginal dryness, which negatively impacts daily and sexual activities. As little is known about the aetiology and clinical context of this complaint, this study investigated the relationship between vaginal dryness and other clinical parameters associated with pSS. Methods. Female participants of the REgistry of Sjogren syndrome at UMCG - LongiTudinal (RESULT) cohort who fulfilled ACR-EULAR and/or AECG classification criteria for pSS were included, using baseline data for analyses. Patient-reported vaginal dryness (range 0-10) was correlated with demographic characteristics, systemic disease activity (i.e. ESSDAI), Sjogren's Syndrome Disease Damage Index, salivary and lacrimal gland function, patient-reported outcomes (ESSPRI, MFI), serology and quality of life (SF-36, EQ-5D). Significantly associated parameters (p Results. This cross-sectional study included 199 women with pSS; mean age was 52 +/- 14 years, 53% were postmenopausal, and median vaginal dryness score was 5 (IQR 2-7). Vaginal dryness was significantly associated with older age, postmenopausal status, peripheral neuropathy, oral and ocular dryness, ESSPRI and SF-36 mental and general health. After correction for age, menopausal status and medication use, peripheral neuropathy (B=1.632), oral dryness (B=0.302), and ocular dryness (B=0.230) were independently associated with vaginal dryness. Conclusion. The independent association of vaginal dryness with oral and ocular dryness might imply that the aetiology of these symptoms is partly shared. Of all extraglandular features, only peripheral neuropathy was independently associated with vaginal dryness, suggesting that peripheral neuropathy plays a significant role in the pathology of vaginal dryness in pSS
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