Infrasound detection of approaching lahars.

Infrasound may be used to detect the approach of hazardous volcanic mudflows, known as lahars, tens of minutes before their flow fronts arrive. We have analyzed signals from more than 20 secondary lahars caused by precipitation events at Fuego Volcano during Guatemala's rainy season in May through October of 2022. We are able to quantify the capabilities of infrasound monitoring through comparison with seismic data, time lapse camera imagery, and high-resolution video of a well-recorded event on August 17. We determine that infrasound sensors, deployed adjacent to the lahar path and in small-aperture (10 s of meters) arrays, are particularly sensitive to remote detection of lahars, including small-sized events, at distances of at least 5 km. At Fuego Volcano these detections could be used to provide timely alerts of up to 30 min before lahars arrive at a downstream monitoring site, such as in the frequently impacted Ceniza drainage. We propose that continuous infrasound monitoring, from locations adjacent to a drainage, may complement seismic monitoring and serve as a valuable tool to help identify approaching hazards. On the other hand, infrasound arrays located a kilometer or more from the lahar path can be effectively used to track a lahar's progression.

The 2018 rift eruption and summit collapse of Kilauea Volcano.

In 2018, Kilauea Volcano experienced its largest lower East Rift Zone (LERZ) eruption and caldera collapse in at least 200 years. After collapse of the Pu'u 'O'o vent on 30 April, magma propagated downrift. Eruptive fissures opened in the LERZ on 3 May, eventually extending ~6.8 kilometers. A 4 May earthquake [moment magnitude (M w) 6.9] produced ~5 meters of fault slip. Lava erupted at rates exceeding 100 cubic meters per second, eventually covering 35.5 square kilometers. The summit magma system partially drained, producing minor explosions and near-daily collapses releasing energy equivalent to M w 4.7 to 5.4 earthquakes. Activity declined rapidly on 4 August. Summit collapse and lava flow volume estimates are roughly equivalent-about 0.8 cubic kilometers. Careful historical observation and monitoring of Kilauea enabled successful forecasting of hazardous events.

Development of a clinically relevant liquid chromatography tandem mass spectrometry assay for 13 drugs of abuse in urine, designed to meet the needs of the service users.

BACKGROUND: The clinical requirements of the users of assay results must be at the centre of assay development. We aimed to develop a single liquid chromatography tandem mass spectrometry (LC-MS/MS) assay for drugs of abuse in urine that would meet the needs of our service users and replace the multiple screening and confirmatory techniques previously in use. METHODS: After discussion with our users, it was decided that 13 drugs and metabolites should be measured in our panel: morphine, codeine, norcodeine, dihydrocodeine, 6-monoacetylmorphine, acetyl codeine, methadone and its metabolite, buprenorphine and its metabolite, amphetamine, benzoylecgonine and cotinine. Urine samples were prepared by the addition of internal standard, enzymatic hydrolysis and solid-phase extraction. Chromatography conditions were optimized so that the analytes were separated within a run time of 6 min. Optimal parent to daughter m/z ion transitions were chosen for all drugs and daughter ion ratios were used. RESULTS: The LC-MS/MS assay was successfully validated with acceptable precision and lower limits of quantification for all drugs. No matrix effects were seen. The results produced by the LC-MS/MS assay compared well with the previous combination of techniques in use. CONCLUSIONS: We have developed and validated a fit-for-purpose LC-MS/MS assay for 13 drugs of abuse in urine that obviates the need for multiple screening and confirmatory analytical techniques.

The GOX/CAT system: a novel enzymatic method to independently control hydrogen peroxide and hypoxia in cell culture.

The increasing demand in studying cellular functions in cultured cells under various levels of oxygen and hydrogen peroxide (H2O2) is only partly fulfilled by conventional approaches such as hypoxia chambers, bolus additions of H2O2 or redox-cycling drugs. This article describes the recently developed enzymatic GOX/CAT system consisting of glucose oxidase (GOX) and catalase (CAT) that allows the independent control and maintenance of both H2O2 and hypoxia in cell culture. In contrast to hypoxia chambers, the GOX/CAT system more rapidly induces hypoxia within minutes at a defined rate. The degree of hypoxia is dependent on the GOX activity and the diffusion distance of oxygen from the medium surface to the adherent cells. In contrast, H2O2 levels are solely controlled by the ratio of GOX and CAT activities. They can be adjusted at non-toxic or toxic dosages over 24 hours. Thus, the GOX/CAT system mimics a non-phosphorylating respiratory chain and allows to adjust H2O2 levels under hypoxic conditions truly simulating H2O2 release e.g. by inflammatory cells or intracellular sources. GOX/CAT can be employed to address many questions ranging from redox signaling to ischemia/reperfusion studies in transplantation medicine. Factors such as HIF1 alpha that respond both to hypoxia and H2O2 are an especially attractive target for the novel methodology. Several applications are discussed in detail to demonstrate the technical requirements and potentials. In addition, simplified protocols are presented for cell or molecular biology labs without dedicated biophysical equipment.

Identification of presumed pheromone blend from australasian predaceous bug,Oechalia schellenbergii (Heteroptera: Pentatomidae).

Oechalia schellenbergii is one of the most common predatory insects in Australia and the islands of the South Pacific. Adult males of this predaceous "true bug" collected during March near Gatton, Queensland, Australia, had a pair of enlarged exocrine glands opening underneath their wings that presumably produce an attractant pheromone. The two major components of the secretion are 3-methylenehexyl acetate and 9-hydroxygeranyl diacetate [2,6-dimethyl-2(E),6(E)-octadien-1,8-diol diacetate].

Male-specific volatiles from nearctic and Australasian true bugs (Heteroptera: Coreidae and Alydidae).

Aeration and exocrine gland extracts were analyzed for three Coreidae and two Alydidae. Males of all the species studied emit volatile blends that are probably pheromones, but sexual communication in these insects evolved differently. In the alydids,Riptortus serripes andMirperus scutellaris, the metathoracic scent glands are sexually dimorphic, and the dimorphisms are expressed chemically. Secretions from the male alydids contain high concentrations of esters or alcohols [e.g., (E)-2-hexenyl (Z)-3-hexenoate, (E)-2-hexenyl butyrate, and (E)-2-octenol], while females produce mainly acids and aldehydes [e.g., butyric and hexanoic acids, and (E)-2-hexenal]. In the coreids,Amblypelta lutescens lutescens, Amblypelta nitida, andLeptoglossus phyllopus, the metathoracic scent glands are not sexually dimorphic, but male- and species-specific volatiles are released, apparently from cells in the cuticular epidermis. The coreid male-specific volatiles are primarily monoterpenes and sesquiterpenes, including (-)-(3R)-(E)-nerolidol as the major component fromA. lutescens lutescens (an Australasian species) andL. phyllopus (a Nearctic species). Only (+)-(3S)-(E)-nerolidol is commonly found in plants so (E)-nerolidol from these coreids is environmentally unique because of its chirality.

Public health in pre-colonial east-central Africa.

This study is the first of its kind to suggest that a rich public health tradition existed in east-central Africa before the twentieth century, and that the tradition can be reconstructed historically. It breaks with earlier studies of public health history for the region in that it does not define public health on the basis of western institutions and activities. The definition of public health that is used in this study makes a simple equation between politics and medicine. It includes all activities that ruling authorities undertake to promote the well-being of the societies over which they have charge. Thus rainmaking and sorcery control, the principal services in traditional African societies, are the focus of this study. Evidence is presented here of the control exercised by kings, chiefs, priests over these services in various societies located in southeastern Zaire, southern Tanzania, Zambia, Malawi, northern Mozambique, and Zimbabwe. The cases are all set in the pre-colonial period, before the twentieth century and the beginning of most written records. The evidence is derived primarily, though not exclusively, from non-written sources, such as archaeology, linguistic, and ethnographic records. The best data are those that come from cultural exchanges between people, for historical records are created in this way. Therefore, the cases discussed here all involve contacts between immigrant and autochthonous groups. The political histories of these contacts are already known. What this study does is link up those traditions with independently-acquired evidence of change in medical traditions. Political change often, but not always, led to change in public health institutions. The control of ruling elites over health services is thus made apparent by the manner in which new medical institutions were implanted when new political authorities arose.

Physical training and fasting serum insulin levels in sedentary men.

The present study examined fasting serum insulin levels in relation to body composition and dietary intake during the initial 4 weeks of a 12-week physical training programme in 26 previously sedentary men. Fasting serum insulin concentrations decreased markedly during the first 4 weeks of training and remained at these reduced levels for the rest of the study. The early fall in serum insulin concentration was significantly correlated with the concomitant decrease in body fat, the increase in lean body weight and the age of the subjects. Body weight and reported dietary intake on the other hand, did not change significantly over this period. These results indicate that the decrease in fasting serum insulin in previously sedentary men with physical training is associated with the concomitant changes in body composition. Increased muscle tissue in particular may contribute to this training-induced decrease in serum insulin.