Physiological responses during ascent to high altitude and the incidence of acute mountain sickness.

Acute mountain sickness (AMS) occurs when there is failure of acclimatisation to high altitude. The aim of this study was to describe the relationship between physiological variables and the incidence of AMS during ascent to 5300 m. A total of 332 lowland-dwelling volunteers followed an identical ascent profile on staggered treks. Self-reported symptoms of AMS were recorded daily using the Lake Louise score (mild 3-4; moderate-severe ≥5), alongside measurements of physiological variables (heart rate, respiratory rate (RR), peripheral oxygen saturation (SpO2 ) and blood pressure) before and after a standardised Xtreme Everest Step-Test (XEST). The overall occurrence of AMS among participants was 73.5% (23.2% mild, 50.3% moderate-severe). There was no difference in gender, age, previous AMS, weight or body mass index between participants who developed AMS and those who did not. Participants who had not previously ascended >5000 m were more likely to get moderate-to-severe AMS. Participants who suffered moderate-to-severe AMS had a lower resting SpO2 at 3500 m (88.5 vs. 89.6%, p = 0.02), while participants who suffered mild or moderate-to-severe AMS had a lower end-exercise SpO2 at 3500 m (82.2 vs. 83.8%, p = 0.027; 81.5 vs. 83.8%, p 5000 m (OR 2.740, p-value 0.003) predicted the development of moderate-to-severe AMS. The Xtreme Everest Step-Test offers a simple, reproducible field test to help predict AMS, albeit with relatively limited predictive precision

Physiological responses during ascent to high altitude and the incidence of acute mountain sickness.

Acute mountain sickness (AMS) occurs when there is failure of acclimatisation to high altitude. The aim of this study was to describe the relationship between physiological variables and the incidence of AMS during ascent to 5300 m. A total of 332 lowland-dwelling volunteers followed an identical ascent profile on staggered treks. Self-reported symptoms of AMS were recorded daily using the Lake Louise score (mild 3-4; moderate-severe ≥5), alongside measurements of physiological variables (heart rate, respiratory rate (RR), peripheral oxygen saturation (SpO2 ) and blood pressure) before and after a standardised Xtreme Everest Step-Test (XEST). The overall occurrence of AMS among participants was 73.5% (23.2% mild, 50.3% moderate-severe). There was no difference in gender, age, previous AMS, weight or body mass index between participants who developed AMS and those who did not. Participants who had not previously ascended >5000 m were more likely to get moderate-to-severe AMS. Participants who suffered moderate-to-severe AMS had a lower resting SpO2 at 3500 m (88.5 vs. 89.6%, p = 0.02), while participants who suffered mild or moderate-to-severe AMS had a lower end-exercise SpO2 at 3500 m (82.2 vs. 83.8%, p = 0.027; 81.5 vs. 83.8%, p 5000 m (OR 2.740, p-value 0.003) predicted the development of moderate-to-severe AMS. The Xtreme Everest Step-Test offers a simple, reproducible field test to help predict AMS, albeit with relatively limited predictive precision

METHODS FOR THE DIAGNOSIS OF ACUTE 3-CHLORO-\u3ci\u3ep\u3c/i\u3e-TOLUIDINE HYDROCHLORIDE POISONING IN BIRDS AND THE ESTIMATION OF SECONDARY HAZARDS TO WILDLIFE

Female boat-tailed grackles poisoned with 3-chloro-p-toluidine hydrochloride (CPTH) were analyzed by necropsy and gas chromatography–mass spectrometry (GC-MS). The necropsies identified the presence of a white precipitate in the pericardium, which had been previously reported as a characteristic of CPTH-exposed birds. The GC-MS method, which utilized deuterated CPTH as a surrogate, quantified CPTH residues in the breast tissue and gastrointestinal tract of CPTH-exposed birds. Comparison of these techniques indicated that the GC-MS method was more accurate for assessing CPTH poisoning in birds. Regression analyses of consumption versus residue data indicated that the sum of breast and gastrointestinal residues can be used as an estimator of CPTH exposure. Comparison of CPTH residues in grackles with toxicity data for a variety of scavenger and predator species provided risk quotients of less than 0.1. Analysis of these data suggests that secondary hazards associated with the use of CPTH as an avicide for the control of pest birds are minimal

Rain Gauges to Range Conditions: Collaborative Development of a Drought Information System to Support Local Decision-Making

Drought monitoring and drought planning are complex endeavors. Measures of precipitation or streamflow provide little context for understanding how social and environmental systems impacted by drought are responding. Here the authors report on collaborative work with the Hopi Tribe-a Native American community in the U.S. Southwest-to develop a drought information system that is responsive to local needs. A strategy is presented for developing a system that is based on an assessment of how drought is experienced by Hopi citizens and resource managers, that can incorporate local observations of drought impacts as well as conventional indicators, and that brings together local expertise with conventional science-based observations. The system described here is meant to harness as much available information as possible to inform tribal resource managers, political leaders, and citizens about drought conditions and to also engage these local drought stakeholders in observing, thinking about, and helping to guide planning for drought.National Oceanic and Atmospheric Administration's Climate Program Office from the Regional Integrated Science and Assessment program [NA13OAR4310166]; Sectoral Applications Research Program [NA10OAR4310183]Published Online: 18 August 2016; 6 month embargoThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Japanese encephalitis virus tropism in experimentally infected pigs.

Pigs are considered to be the main amplifying host for Japanese encephalitis virus (JEV), and their infection can correlate with human cases of disease. Despite their importance in the ecology of the virus as it relates to human cases of encephalitis, the pathogenesis of JEV in pigs remains obscure. In the present study, the localization and kinetics of virus replication were investigated in various tissues after experimental intravenous infection of pigs. The data demonstrate a rapid and broad spreading of the virus to the central nervous system (CNS) and various other organs. A particular tropism of JEV in pigs not only to the CNS but also for secondary lymphoid tissue, in particular the tonsils with the overall highest viral loads, was observed. In this organ, even 11 days post infection, the latest time point of the experiment, no apparent decrease in viral RNA loads and live virus was found despite the presence of a neutralizing antibody response. This was also well beyond the clinical and viremic phase. These results are of significance for the pathogenesis of JEV, and call for further experimental studies focusing on the cellular source and duration of virus replication in pigs