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Anthelmintic resistance in the United States has recently gained the attention of the veterinary and livestock communities. The rapid rise in resistance to 2 new drug classes shortly after approval outside the United States calls for new strategies and recommendations for maintaining an effective anthelmintic program even as new drugs become available. The development of resistance is product-dependent, with observable differences between classes. Methods used to test anthelmintic efficacy allow the veterinary practitioner to make informed treatment decisions; however, the results should be interpreted carefully due to the limitations for the fecal egg count procedure., American Association of Bovine Practitioners Proceedings of the Annual Conference, 2019

Bagana, arguably the most active volcano in Papua New Guinea, has been in a state of near-continuous eruption for over 150 years, with activity dominated by sluggish extrusion of thick blocky lava flows. If current extrusion rates are representative, the entire edifice may have been constructed in only 300–500 years. Bagana exhibits a remarkably high gas flux to the atmosphere, with persistent sulfur dioxide (SO2) emissions of several thousand tons per day. This combination of apparent youth and high outgassing fluxes is considered unusual among persistently active volcanoes worldwide. We have used satellite observations of SO2 emissions and thermal infrared radiant flux to explore the coupling of lava extrusion and gas emission at Bagana. The highest gas emissions (up to 10 kt/day) occur during co-extrusive intervals, suggesting a degree of coupling between lava and gas, but gas emissions remain relatively high (~2,500 t/d) during inter-eruptive pauses. These passive emissions, which clearly persist for decades if not centuries, require a large volume of degassing but non-erupting magma beneath the volcano with a substantial exsolved volatile phase to feed the remarkable SO2 outgassing: an additional ~1.7–2 km3 basaltic andesite would be required to supply the excess SO2 emissions we observe in our study interval (2005 to present). That this volatile phase can ascend freely to the surface under most conditions is likely to be key to Bagana's largely effusive style of activity, in contrast with other persistently active silicic volcanoes where explosive and effusive eruptive styles alternate.

The 2014–2015 Holuhraun eruption in Iceland, emitted ∼11 Tg of SO2 into the troposphere over 6 months, and caused one of the most intense and widespread volcanogenic air pollution events in centuries. This study provides a number of source terms for characterisation of plumes in large fissure eruptions, in Iceland and elsewhere. We characterised the chemistry of aerosol particle matter (PM) and gas in the Holuhraun plume, and its evolution as the plume dispersed, both via measurements and modelling. The plume was sampled at the eruptive vent, and in two populated areas in Iceland. The plume caused repeated air pollution events, exceeding hourly air quality standards (350 μg/m3) for SO2 on 88 occasions in Reykjahlíð town (100 km distance), and 34 occasions in Reykjavík capital area (250 km distance). Average daily concentration of volcanogenic PM sulphate exceeded 5 μg/m3 on 30 days in Reykjavík capital area, which is the maximum concentration measured during non-eruptive background interval. There are currently no established air quality standards for sulphate. Combining the results from direct sampling and dispersion modelling, we identified two types of plume impacting the downwind populated areas. The first type was characterised by high concentrations of both SO2 and S-bearing PM, with a high Sgas/SPM mass ratio (SO2(g)/SO4 2− (PM) > 10). The second type had a low Sgas/SPM ratio (1 and PM2.5), sulphate (on average ∼90% of the PM mass) and various trace species, including heavy metals. The fine size of the volcanic PM mass (75–80% in PM2.5), and the high environmental lability of its chemical components have potential adverse implications for environmental and health impacts. However, only the dispersion of volcanic SO2 was forecast in public warnings and operationally monitored during the eruption. We make a recommendation that sulphur gas-to-aerosol conversion processes, and a sufficiently large model domain to contain the transport of a tropospheric plume on the timescale of days be utilized for public health and environmental impact forecasting in future eruptions in Iceland and elsewhere in the world.

IF 6.023; International audience

Gamma irradiation is a technique for inactivation of biological warfare agents (BWAs). Detection of these irradiated agents by sensor technologies may be affected,; altering sensitivity compared to that of non-irradiated organisms. Here for the first time, we aim to determine if spore morphology, or other physical or chemical properties beyond viability and PCR, is altered by the gamma irradiation process. This study analyzed common detection methods to determine the effects the irradiation process has on Bacillus thuringiensis subspecies kurstaki (Btk) spores compared to nonirradiated spores. Liquid concentrations of 108, 106, and 104 CFU ml-1 of Btk spores and one dry powder sample of 109 CFU g-1 were exposed to varying levels of gamma irradiation. Cell viability studies showed complete inactivation for all concentrations at doses of 5.43 kGy and higher. PCR analysis indicated no loss in sensitivity with increasing doses for both wet and dry spore samples. Visual inspection of the spores through scanning electron microscopy showed a change in morphology as the dosage of irradiation increased. With The inability to distinguish whole spores from cell debris occurred in at the 10.86 kGy samples level. Similarly, fluorescence readings remained stable among all but one dose with only the 10.86 kGy sample showing an increase in fluorescence. For PCR based detection methods, no bias towards irradiated versus non-irradiated spore samples exist while optical detection technologies are likely affected by the physical changes to spore morphology and rupturing. Results from this study demonstrate that gamma irradiation of Bacillus spores causes damage to the organism which may make them unrecognizable alter how they to are perceived by detection technologies. When using irradiated analyte to evaluate performance of detection technologies, the results may be impacted by the irradiation process.