Into Thick(er) Air? Oxygen Availability at Humans’ Physiological Frontier on Mount Everest

Global audiences are captivated by climbers pushing themselves to the limits in the hypoxic environment of Mount Everest. However, air pressure sets oxygen abundance, meaning it varies with the weather and climate warming. This presents safety issues for mountaineers, but also an opportunity for public engagement around climate change. Here we blend new observations from Everest with ERA5 reanalysis (1979- 2019) and climate model results to address both perspectives. We find that plausible warming could generate subtle but physiologically relevant changes in summit oxygen availability, including an almost 5% increase in annual minimum VO 2 max for 2°C warming since pre-industrial. In the current climate we find evidence of swings in pressure sufficient to change Everest’s apparent elevation by almost 750 m. Winter pressures can also plunge lower than previously reported, highlighting the importance of air pressure forecasts for the safety of those trying to push the physiological frontier on Mt. Everest

Improving household surveys and use of data to address health inequities in three Asian cities: protocol for the Surveys for Urban Equity (SUE) mixed methods and feasibility study

Introduction: As rapid urbanisation transforms the sociodemographic structures within cities, standard survey methods, which have remained unchanged for many years, under-represent the urban poorest. This leads to an overly positive picture of urban health, distorting appropriate allocation of resources between rural and urban and within urban areas. Here, we present a protocol for our study which (i) tests novel methods to improve representation of urban populations in household surveys and measure mental health and injuries, (ii) explores urban poverty and compares measures of poverty and ‘slumness’ and (iii) works with city authorities to understand, and potentially improve, utilisation of data on urban health for planning more equitable services. Methods and analysis: We will conduct household surveys in Kathmandu, Hanoi and Dhaka to test novel methods: (i) gridded population sampling; (ii) enumeration using open-access online maps and (iii) one-stage versus two-stage cluster sampling. We will test reliability of an observational tool to categorise neighbourhoods as slum areas. Within the survey, we will assess the appropriateness of a short set of questions to measure depression and injuries. Questionnaire data will also be used to compare asset-based, consumption-based and income-based measures of poverty. Participatory methods will identify perceptions of wealth in two communities in each city. The analysis will combine quantitative and qualitative findings to recommend appropriate measures of poverty in urban areas. We will conduct qualitative interviews and establish communities of practice with government staff in each city on use of data for planning. Framework approach will be used to analyse qualitative data allowing comparison across city settings. Ethics and dissemination: Ethical approvals have been granted by ethics committees from the UK, Nepal, Bangladesh and Vietnam. Findings will be disseminated through conference papers, peer-reviewed open access articles and workshops with policy-makers and survey experts in Kathmandu, Hanoi and Dhaka

Frontal and piggy-back seismic ruptures in the external thrust belt of western Nepal.

International audiencehis paper gives structural and morphological evidence for meter-scale episodic displacement pulses along the MFT and MDT during a complex sequence of thrusting in the sub-Himalayan fold and thrust belt. The studied cross-section is located in Western Nepal at a latitude of E 82° 20′. Along this section, the Main Dun Thrust (MDT) is in a piggy-back setting and comprises three splays that are spaced by less than 200 m. The splays display the following sequence of motion: (1) the medium splay was active; (2) the internal splay was active and had a dip-slip displacement of not, vert, similar3 m that could be the surface rupture of an earthquake; (3) a period of quiescence occurred for all the splays of the MDT; (4) the external splay is active. The motion along the medium and internal thrust predates not, vert, similar70 kyr whereas motion along the external splay postdates 5468–5214 yr before J.C. The Main Frontal Thrust (MFT) is the most external Himalayan thrust. Ten encased strath terraces are found at its hangingwall. Sudden not, vert, similar1.5 m uplift events could have induced their abandonment and could have been linked to not, vert, similar2 m slip events along the MFT, a value close to the lower bound inferred for co-seismic slip along the basal detachment (MHT) during Mnot, vert, similar8 earthquakes. From the offset of a terrace level, a displacement of not, vert, similar8 m is inferred between 1224–1280 yr after J.C. and 1828–1883 yr after J.C.; it could be linked to a succession of several seisms along the MFT. This study suggests that: (a) several thrusts, that branch off the basal décollement, are active faults; (b) great earthquakes, that occur along the outer part of the basal décollement of the Himalayan thrust belt, reach the surface at different location; (c) only one thrust moves during one earthquake; (d) the sequence of thrusting is successively out-of-sequence and in sequence and changes at an intermediate time-scale between earthquake cycle and finite geometry of the thrust system

A novel ciprofloxacin-resistant subclade of H58 Salmonella Typhi is associated with fluoroquinolone treatment failure

The interplay between bacterial antimicrobial susceptibility, phylogenetics and patient outcome is poorly understood. During a typhoid clinical treatment trial in Nepal, we observed several treatment failures and isolated highly fluoroquinolone-resistant Salmonella Typhi (S. Typhi). Seventy-eight S. Typhi isolates were genome sequenced and clinical observations, treatment failures and fever clearance times (FCTs) were stratified by lineage. Most fluoroquinolone-resistant S. Typhi belonged to a specific H58 subclade. Treatment failure with S. Typhi-H58 was significantly less frequent with ceftriaxone (3/31; 9.7%) than gatifloxacin (15/34; 44.1%)(Hazard Ratio 0.19, p=0.002). Further, for gatifloxacin-treated patients, those infected with fluoroquinolone-resistant organisms had significantly higher median FCTs (8.2 days) than those infected with susceptible (2.96) or intermediately resistant organisms (4.01)(pS. Typhi clade internationally, but there are no data regarding disease outcome with this organism. We report an emergent new subclade of S. Typhi-H58 that is associated with fluoroquinolone treatment failure

Feasibility of Innovative Tools and Methods to Improve Household Surveys in Complex Urban Settings: Multiple Methods Analysis of the Surveys for Urban Equity (SUE) Study in Kathmandu, Dhaka and Hanoi

Background: The methods used in low- and middle-income countries (LMICs) household surveys have not changed in four decades; however, LMIC societies have changed substantially. This mismatch may result in unintentional exclusion of vulnerable and mobile urban populations. We compare three survey method innovations with standard survey methods in Kathmandu, Dhaka, and Hanoi, and summarize feasibility of our innovative methods in terms of time, cost, skill requirements, and experiences. Methods: We used descriptive statistics and regression techniques to compare respondent characteristics in samples drawn with innovative versus standard survey designs and household definitions, adjusting for sample probability weights and clustering. Feasibility of innovative methods was evaluated using a thematic framework analysis of focus group discussions with survey field staff, and via survey planner budgets. Results: We found that a common household definition excluded single adult (46.9%) and migrant headed households (6.7%), as well as non-married (8.5%), unemployed (10.5%), disabled (9.3%), and studying (14.3%) adults. Further, standard two-stage sampling resulted in fewer single adult and non-family households than an innovative one-stage design; however, two-stage sampling resulted in more tent and shack dwellers. Our survey innovations provided good value for money and field staff experiences were neutral or positive. Staff recommended streamlining field tools and pairing technical and survey content experts during fieldwork. Conclusions: This evidence of unintentional exclusion of vulnerable and mobile urban populations in LMIC household surveys is deeply concerning, and underscores the need to modernize survey methods and practices