2,227 research outputs found

    Attractants for Synanthropic Flies. 2. Response Patterns of House Flies to Attractive Baits on Poultry Ranches

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    A proteinaceous attractant, prepared by freeze-drying fermented whole egg solids, was found to attract Musca domestica L. and other synanthropic Diptera. In field experiments, a mixture of 2 g of the attractant and 2 g of dichlorvos sugar-bait increased fly collection two-fold on manure substrate in trays set on the ground and three-fold in suspended bait units over the sugar-toxicant bait alone. This increase was due primarily to the increased response of nulliparous and parous females in which vitellogenesis was about to occur. Attractancy of the bait declined sharply after 48 hours of field exposure. The location of bait stations significantly affected the number, sex ratio, and female age structure of the flies collected. Stations collecting the greatest number of flies were generally situated at the ends of the cage rows in sunlight-shade border areas. Fly collections from areas of greatest fly activity were characterized by a high proportion of hoth nulliparous and parous protein-searching females, and the sex ratio in these high-activity zones approached 1. East-west and north-south preferences of certain female age groups were manifested in the collection

    Bait Units for Collection of House Flies

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    Lurtox™4 is a proteinaceous attractant for Musca domestica L. and other synanthropic Diptera (Mulla et al. 1973: Willson and Mulla 1973a) and is easily mixed with commercial poison sugar baits. The mixture of Lurtox and dichlorvos sugar bait (50:50 by wt) can be administered in measurable quantities into compact bait units where dead flies can be easily recovered for counting and for other studies. While developing Lurtox for control of Hippelates eye gnats, Mulla et al. (1973) found that moisture was essential for the emanation of the volatile attractants contained in the bait. Therefore, if the prevalent humidity level is not sufficient to activate the attractant, the bait unit designed for use with the bait mixture should include a moisture sourc

    Determination of Urinary Neopterin/Creatinine Ratio to Distinguish Active Tuberculosis from Latent Mycobacterium tuberculosis Infection.

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    BACKGROUND: Biomarkers to distinguish latent from active Mycobacterium (M.) tuberculosis infection in clinical practice are lacking. The urinary neopterin/creatinine ratio can quantify the systemic interferon-gamma effect in patients with M. tuberculosis infection. METHODS: In a prospective observational study, urinary neopterin levels were measured by enzyme linked immunosorbent assay in patients with active tuberculosis, in people with latent M. tuberculosis infection, and in healthy controls and the urinary neopterin/creatinine ratio was calculated. RESULTS: We included a total of 44 patients with M. tuberculosis infection and nine controls. 12 patients had active tuberculosis (8 of them culture-confirmed). The median age was 15 years (range 4.5 to 49). Median urinary neopterin/creatinine ratio in patients with active tuberculosis was 374.1 micromol/mol (129.0 to 1072.3), in patients with latent M. tuberculosis infection it was 142.1 (28.0 to 384.1), and in controls it was 146.0 (40.3 to 200.0), with significantly higher levels in patients with active tuberculosis (p < 0.01). The receiver operating characteristics curve had an area under the curve of 0.84 (95% CI 0.70 to 0.97) (p < 0.01). CONCLUSIONS: Urinary neopterin/creatinine ratios are significantly higher in patients with active tuberculosis compared to patients with latent infection and may be a significant predictor of active tuberculosis in patients with M. tuberculosis infection

    Determinants of drug absorption in different ECMO circuits

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    Purpose: The aim of this in vitro study was to evaluate potential determinants of drug loss in different ECMO circuits. Methods: Midazolam, morphine, fentanyl, paracetamol, cefazolin, meropenem and vancomycin were injected into three neonatal roller pump, two paediatric roller pump and two clinically used neonatal roller pump circuits, all with a silicone membrane, and two neonatal centrifugal pump circuits with polypropylene hollow-fibre membranes. Serial blood samples were taken from a post-oxygenator site. Drug recovery was calculated as the ratio between the determined and the theoretical maximum concentration. The latter was obtained by dividing dose by theoretical circuit volume. Results: Average drug recoveries at 180 min in three neonatal silicone membrane roller pump circuits were midazolam 0.62%, morphine 23.9%, fentanyl 0.35%, paracetamol 34.0%, cefazolin 84.3%, meropenem 82.9% and vancomycin 67.8%. There was a significant correlation between the lipophilicity of the drug expressed as log P and the extent of drug absorption, p < 0.001. The recovery of midazolam and fentanyl in centrifugal pump circuits with hollow-fibre membrane oxygenator was significantly higher compared to neonatal roller pump circuits with silicone membranes: midazolam 63.4 versus 0.62%, fentanyl 33.8 versus 0.35%, p < 0.001. Oxygenator size and used circuits do not significantly affect drug losses. Conclusions: Significant absorption of drugs occurs in the ECMO circuit, correlating with increased lipophilicity of the drug. Centrifugal pump circuits with hollow-fibre membrane oxygenators show less absorption for all drugs, most pronounced for lipophilic drugs. These results suggest that pharmacokinetics and hence optimal doses of these drugs may be altered during ECMO

    Views on allocation concealment methods in randomized clinical trials: a survey of clinical trialists

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    Allocation concealment is the process of implementing the randomization sequence in a manner that prevents foreknowledge of upcoming group assignments. It protects against preferential enrolment of study participants, which could disrupt the prognostic balance that randomization aims to create in the first place. Envelopes are one method perceived by clinical trial authorities to adequately conceal allocation, despite evidence suggesting otherwise. We do not believe that envelopes are adequate, and we wanted to know the extent to which our sentiment resonated within the clinical trials community. We administered an internet-based survey to a random sample (n=1,926) of corresponding authors of recently published randomized clinical trials (RCTs). We sent non-responders up to two e-mail reminders starting from two weeks after the original invitation. We received 490 complete surveys (25.4% response rate) after collecting data for seven weeks. Most participants (61%) preferred central randomization to conceal allocation, yet a majority (64%) also accepted that envelopes are adequate. After they were shown examples that suggested envelopes’ vulnerability, 11% of participants shifted their preference away from envelopes and 38% of participants became less accepting of envelopes. Compared to their initial ratings and after they were shown the examples, significantly more participants (69%) preferred central randomization (pMaster of Science (MSc
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