Application and Evaluation of a Snowmelt Runoff Model in the Tamor River Basin, Eastern Himalaya Using a Markov Chain Monte Carlo (MCMC) Data Assimilation Approach

Previous studies have drawn attention to substantial hydrological changes taking place in mountainous watersheds where hydrology is dominated by cryospheric processes. Modelling is an important tool for understanding these changes but is particularly challenging in mountainous terrain owing to scarcity of ground observations and uncertainty of model parameters across space and time. This study utilizes a Markov Chain Monte Carlo data assimilation approach to examine and evaluate the performance of a conceptual, degree-day snowmelt runoff model applied in the Tamor River basin in the eastern Nepalese Himalaya. The snowmelt runoff model is calibrated using daily streamflow from 2002 to 2006 with fairly high accuracy (average Nash-Sutcliffe metric approx. 0.84, annual volume bias <3%). The Markov Chain Monte Carlo approach constrains the parameters to which the model is most sensitive (e.g. lapse rate and recession coefficient) and maximizes model fit and performance. Model simulated streamflow using an interpolated precipitation data set decreases the fractional contribution from rainfall compared with simulations using observed station precipitation. The average snowmelt contribution to total runoff in the Tamor River basin for the 2002-2006 period is estimated to be 29.7+/-2.9% (which includes 4.2+/-0.9% from snowfall that promptly melts), whereas 70.3+/-2.6% is attributed to contributions from rainfall. On average, the elevation zone in the 4000-5500m range contributes the most to basin runoff, averaging 56.9+/-3.6% of all snowmelt input and 28.9+/-1.1% of all rainfall input to runoff. Model simulated streamflow using an interpolated precipitation data set decreases the fractional contribution from rainfall versus snowmelt compared with simulations using observed station precipitation. Model experiments indicate that the hydrograph itself does not constrain estimates of snowmelt versus rainfall contributions to total outflow but that this derives from the degree-day melting model. Lastly, we demonstrate that the data assimilation approach is useful for quantifying and reducing uncertainty related to model parameters and thus provides uncertainty bounds on snowmelt and rainfall contributions in such mountainous watersheds

Systemic tuberculosis presenting with acute transient myopia: a case report

<p>Abstract</p> <p>Introduction</p> <p>Transient myopia has been reported to occur in a number of conditions, either ocular in origin or associated with an underlying systemic cause. We present a rare case of this abnormality occurring in the setting of systemic tuberculosis.</p> <p>Case presentation</p> <p>A 29-year-old Indian woman presented with sudden onset blurred distance vision and fever. Examination revealed visual acuity of counting fingers in both eyes improving to 6/9 with pinhole with N5 reading acuity. Anterior segment examination revealed narrow angles on gonioscopy. Posterior segments were normal. Systemic examination revealed a fluctuant mass in her left loin, aspiration of which yielded pus which was culture-positive for <it>Mycobacterium tuberculosis</it>. The Mantoux test elicited a strongly positive reaction. Chest X-ray and magnetic resonance imaging of the brain were unremarkable. Computed tomography scan and magnetic resonance imaging of the spine and abdomen revealed a large psoas abscess communicating with the loin mass. Two vertebrae were involved but not the spinal cord or canal.</p> <p>Conclusion</p> <p>Transient myopia is a rare presenting feature of systemic tuberculosis. A postulated mechanism in this patient is that development of a uveal effusion related to systemic tuberculosis caused anterior rotation of the iris-lens diaphragm, thereby inducing narrowing of the angle and acute myopia.</p

Polar opposites? NGOs, left parties and the fight for social change in Nepal

In the early 1990s, when NGOs were rising to prominence as an ostensible force for social change in Nepal, the Maoists were also beginning to organise, and denounced NGOs as agents of imperialism. The Maoists came to prominence by fighting a People’s War launched in 1996, with the intention of improving life for the poor peasant and working-class majority. But after a decade-long struggle, the Maoists became incorporated into the parliamentary system. While Nepal’s first democratic revolution in 1990 met formal, popular political demands, which were consolidated in a subsequent revolution in 2006 overthrowing the monarchy and bringing the People’s War to an end, there was little socio-economic progress for the vast majority. The argument advanced in this article is that this lack of progress relied on the interplay of two phenomena: an anti-Maoist alliance consisting of the international community, the domestic ruling elite and NGOs, and a fundamental ambiguity at the heart of the Maoists’ political theory

Predicting late aortic complications after acute type A dissection surgery with volumetric measurements in a Singapore cohort

Introduction: This study was conducted to evaluate the efficacy of postoperative computed tomography (CT) measurements of aortic lumen volumes in predicting aortic-related complications following acute type A aortic dissection (ATAAD) repair. Methods: We conducted a single-institution retrospective aortic volumetric analysis of patients after ascending aorta replacement performed during 2001-2015. The volumetric measurements of total lumen (total-L), true lumen (TL), false lumen (FL), as well as the TL:FL ratio from the first and second postoperative computer angiograms were obtained. A generalised structural equation model was created to analyse the predictive utility of TL:FL ratio. Results: One hundred and twenty-five patients underwent surgical intervention, of whom 97 patients were eventually discharged and analysed for postoperative complications. A total of 19 patients were included in the final analysis. Patients with late postoperative aortic complications had a significantly higher FL volume and total-L volume on the first (FL volume P = 0.041, total-L volume P = 0.05) and second (FL volume P = 0.01, total-L volume P = 0.007) postoperative scans. The odds of having aortic complications were raised by 1% with a 1 cm3 increase in total-L volume and by 2% with a 1 cm3 increase in FL volume. The TL:FL ratio was significantly lower in patients who developed complications. Conclusion: Postoperative CT volumetric measurements in patients who developed complications are characterised by a significant increase in the FL volume and total-L volume from the first postoperative scans. Patients with disproportionately expanded FL presenting with TL:FL ratios less than 1 were associated with aortic complications. Hence, the TL:FL ratio may be a reliable and useful parameter to monitor postoperative disease progression and to evaluate the risk of late complications in ATAAD patients

Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): Emissions of particulate matter and sulfur dioxide from vehicles and brick kilns and their impacts on air quality in the Kathmandu Valley, Nepal

Air pollution is one of the most pressing environmental issues in the Kathmandu Valley, where the capital city of Nepal is located. We estimated emissions from two of the major source types in the valley (vehicles and brick kilns) and analyzed the corresponding impacts on regional air quality. First, we estimated the on-road vehicle emissions in the valley using the International Vehicle Emissions (IVE) model with local emissions factors and the latest available data for vehicle registration. We also identified the locations of the brick kilns in the Kathmandu Valley and developed an emissions inventory for these kilns using emissions factors measured during the Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE) field campaign in April 2015. Our results indicate that the commonly used global emissions inventory, the Hemispheric Transport of Air Pollution (HTAP_v2.2), underestimates particulate matter emissions from vehicles in the Kathmandu Valley by a factor greater than 100. HTAP_v2.2 does not include the brick sector and we found that our sulfur dioxide (SO2) emissions estimates from brick kilns are comparable to 70 % of the total SO2 emissions considered in HTAP_v2.2. Next, we simulated air quality using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) for April 2015 based on three different emissions scenarios: HTAP only, HTAP with updated vehicle emissions, and HTAP with both updated vehicle and brick kilns emissions. Comparisons between simulated results and observations indicate that the model underestimates observed surface elemental carbon (EC) and SO2 concentrations under all emissions scenarios. However, our updated estimates of vehicle emissions significantly reduced model bias for EC, while updated emissions from brick kilns improved model performance in simulating SO2. These results highlight the importance of improving local emissions estimates for air quality modeling. We further find that model overestimation of surface wind leads to underestimated air pollutant concentrations in the Kathmandu Valley. Future work should focus on improving local emissions estimates for other major and underrepresented sources (e.g., crop residue burning and garbage burning) with a high spatial resolution, as well as the model\u27s boundary layer representation, to capture strong spatial gradients of air pollutant concentrations

Long-term changes in dysnatremia incidence in the ICU: a shift from hyponatremia to hypernatremia

Background: Dysnatremia is associated with adverse outcome in critically ill patients. Changes in patients or treatment strategies may have affected the incidence of dysnatremia over time. We investigated long-term changes in the incidence of dysnatremia and analyzed its association with mortality. Methods: Over a 21-year period (1992–2012), all serum sodium measurements were analyzed retrospectively in two university hospital ICUs, up to day 28 of ICU admission for the presence of dysnatremia. The study period was divided into five periods. All serum sodium measurements were collected from the electronic databases of both ICUs. Serum sodium was measured at the clinical chemistry departments using standard methods. All sodium measurements were categorized in the following categories: 160 mmol/L. Mortality was determined at 90 days after ICU admission. Results: In 80,571 ICU patients, 913,272 serum sodium measurements were analyzed. A striking shift in the pattern of ICU-acquired dysnatremias was observed: The incidence of hyponatremia almost halved (47–25 %, p  155 mmol/L) increased dramatically over the years. On ICU day 10 this incidence was 0.7 % in the 1992–1996 period, compared to 6.3 % in the 2009–2012 period (p < 0.001). More severe dysnatremia was associated with significantly higher mortality throughout the 21-year study period (p < 0.001). Conclusions: In two large Dutch cohorts, we observed a marked shift in the incidence of dysnatremia from hyponatremia to hypernatremia over two decades. As hypernatremia was mostly ICU acquired, this strongly suggests changes in treatment as underlying causes. This shift may be related to the increased use of sodium-containing infusions, diuretics, and hydrocortisone. As ICU-acquired hypernatremia is largely iatrogenic, it should be—to an important extent—preventable, and its incidence may be considered as an indicator of quality of care. Strategies to prevent hypernatremia deserve more emphasis; therefore, we recommend that further study should be focused on interventions to prevent the occurrence of dysnatremias during ICU stay

Observation and analysis of spatiotemporal characteristics of surface ozone and carbon monoxide at multiple sites in the Kathmandu Valley, Nepal

Residents of the Kathmandu Valley experience severe particulate and gaseous air pollution throughout most of the year, even during much of the rainy season. The knowledge base for understanding the air pollution in the Kathmandu Valley was previously very limited but is improving rapidly due to several field measurement studies conducted in the last few years. Thus far, most analyses of observations in the Kathmandu Valley have been limited to short periods of time at single locations. This study extends the past studies by examining the spatial and temporal characteristics of two important gaseous air pollutants (CO and O3) based on simultaneous observations over a longer period at five locations within the valley and on its rim, including a supersite (at Bode in the valley center, 1345&thinsp;m above sea level) and four satellite sites: Paknajol (1380&thinsp;m&thinsp;a.s.l.) in the Kathmandu city center; Bhimdhunga (1522&thinsp;m&thinsp;a.s.l.), a mountain pass on the valley's western rim; Nagarkot (1901&thinsp;m&thinsp;a.s.l.), another mountain pass on the eastern rim; and Naikhandi (1233&thinsp;m&thinsp;a.s.l.), near the valley's only river outlet. CO and O3 mixing ratios were monitored from January to July 2013, along with other gases and aerosol particles by instruments deployed at the Bode supersite during the international air pollution measurement campaign SusKat-ABC (Sustainable Atmosphere for the Kathmandu Valley – endorsed by the Atmospheric Brown Clouds program of UNEP). The monitoring of O3 at Bode, Paknajol and Nagarkot as well as the CO monitoring at Bode were extended until March 2014 to investigate their variability over a complete annual cycle. Higher CO mixing ratios were found at Bode than at the outskirt sites (Bhimdhunga, Naikhandi and Nagarkot), and all sites except Nagarkot showed distinct diurnal cycles of CO mixing ratio, with morning peaks and daytime lows. Seasonally, CO was higher during premonsoon (March–May) season and winter (December–February) season than during monsoon season (June–September) and postmonsoon (October–November) season. This is primarily due to the emissions from brick industries, which are only operational during this period (January–April), as well as increased domestic heating during winter, and regional forest fires and agro-residue burning during the premonsoon season. It was lower during the monsoon due to rainfall, which reduces open burning activities within the valley and in the surrounding regions and thus reduces sources of CO. The meteorology of the valley also played a key role in determining the CO mixing ratios. The wind is calm and easterly in the shallow mixing layer, with a mixing layer height (MLH) of about 250&thinsp;m, during the night and early morning. The MLH slowly increases after sunrise and decreases in the afternoon. As a result, the westerly wind becomes active and reduces the mixing ratio during the daytime. Furthermore, there was evidence of an increase in the O3 mixing ratios in the Kathmandu Valley as a result of emissions in the Indo-Gangetic Plain (IGP) region, particularly from biomass burning including agro-residue burning. A top-down estimate of the CO emission flux was made by using the CO mixing ratio and mixing layer height measured at Bode. The estimated annual CO flux at Bode was 4.9&thinsp;µg&thinsp;m−2&thinsp;s−1, which is 2–14 times higher than that in widely used emission inventory databases (EDGAR HTAP, REAS and INTEX-B). This difference in CO flux between Bode and other emission databases likely arises from large uncertainties in both the top-down and bottom-up approaches to estimating the emission flux. The O3 mixing ratio was found to be highest during the premonsoon season at all sites, while the timing of the seasonal minimum varied across the sites. The daily maximum 8&thinsp;h average O3 exceeded the WHO recommended guideline of 50&thinsp;ppb on more days at the hilltop station of Nagarkot (159 out of 357 days) than at the urban valley bottom sites of Paknajol (132 out of 354 days) and Bode (102 out of 353 days), presumably due to the influence of free-tropospheric air at the high-altitude site (as also indicated by Putero et al., 2015, for the Paknajol site in the Kathmandu Valley) as well as to titration of O3 by fresh NOx emissions near the urban sites. More than 78&thinsp;% of the exceedance days were during the premonsoon period at all sites. The high O3 mixing ratio observed during the premonsoon period  is of a concern for human health and ecosystems, including agroecosystems in the Kathmandu Valley and surrounding regions.</p

Publishing, identifiers & metrics: Playing the numbers game

The number of scientific articles published each year is rapidly growing and so is the number of academic journals. This makes it impossible for an individual practitioner or researcher to keep track of all research published in their own field or sub-discipline. With the growing amount of publications, it is also becoming more difficult to distinguish between similar papers published on the same topic, in the same journal, or by the same researchers (or research team). This perspective paper could support students and novice researchers, outlines the difference between the unique identifier for: (1) you as the researcher, (2) a specific paper; and (3) a specific journal. This paper further outlines the various numerical identifiers associated with academic publishing to help demystify academic publishing

Participatory policy analysis in health policy and systems research: reflections from a study in Nepal.

Background Participatory policy analysis (PPA) as a method in health policy and system research remains underexplored. Using our experiences of conducting PPA workshops in Nepal to explore the impact of the country’s move to federalism on its health system, we reflect on the method’s strengths and challenges. We provide an account of the study context, the design and implementation of the workshops, and our reflections on the approach’s strengths and challenges. Findings on the impact of federalism on the health system are beyond the scope of this manuscript. Main body We conducted PPA workshops with a wide range of health system stakeholders (political, administrative and service-level workforce) at the local and provincial levels in Nepal. The workshops consisted of three activities: river of life, brainstorming and prioritization, and problem-tree analysis. Our experiences show that PPA workshops can be a valuable approach to explore health policy and system issues – especially in a context of widespread systemic change which impacts all stakeholders within the health system. Effective engagement of stakeholders and activities that encourage both individual- and system-level reflections and discussions not only help in generating rich qualitative data, but can also address gaps in participants’ understanding of practical, technical and political aspects of the health system, aid policy dissemination of research findings, and assist in identifying short- and long-term practice and policy issues that need to be addressed for better health system performance and outcomes. Conducting PPA workshops is, however, challenging for a number of reasons, including the influence of gatekeepers and power dynamics between stakeholders/participants. The role and skills of researchers/facilitators in navigating such challenges are vital for success. Although the long-term impact of such workshops needs further research, our study shows the usefulness of PPA workshops for researchers, for participants and for the wider health system. Conclusions PPA workshops can effectively generate and synthesize health policy and system evidence through collaborative engagement of health system stakeholders with varied roles. When designed with careful consideration for context and stakeholders’ needs, it has great potential as a method in health policy and systems research

Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): Emissions of particulate matter from wood-and dung-fueled cooking fires, garbage and crop residue burning, brick kilns, and other sources

The Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE) characterized widespread and under-sampled combustion sources common to South Asia, including brick kilns, garbage burning, diesel and gasoline generators, diesel groundwater pumps, idling motorcycles, traditional and modern cooking stoves and fires, crop residue burning, and heating fire. Fuel-based emission factors (EFs; with units of pollutant mass emitted per kilogram of fuel combusted) were determined for fine particulate matter (PM2.5), organic carbon (OC), elemental carbon (EC), inorganic ions, trace metals, and organic species. For the forced-draft zigzag brick kiln, EFPM2.5 ranged from 12 to 19gkg-1 with major contributions from OC (7%), sulfate expected to be in the form of sulfuric acid (31.9%), and other chemicals not measured (e.g., particle-bound water). For the clamp kiln, EFPM2.5 ranged from 8 to 13gkg-1, with major contributions from OC (63.2%), sulfate (23.4%), and ammonium (16%). Our brick kiln EFPM2.5 values may exceed those previously reported, partly because we sampled emissions at ambient temperature after emission from the stack or kiln allowing some particle-phase OC and sulfate to form from gaseous precursors. The combustion of mixed household garbage under dry conditions had an EFPM2.5 of 7.4±1.2gkg-1, whereas damp conditions generated the highest EFPM2.5 of all combustion sources in this study, reaching up to 125±23gkg-1. Garbage burning emissions contained triphenylbenzene and relatively high concentrations of heavy metals (Cu, Pb, Sb), making these useful markers of this source. A variety of cooking stoves and fires fueled with dung, hardwood, twigs, and/or other biofuels were studied. The use of dung for cooking and heating produced higher EFPM2.5 than other biofuel sources and consistently emitted more PM2.5 and OC than burning hardwood and/or twigs; this trend was consistent across traditional mud stoves, chimney stoves, and three-stone cooking fires. The comparisons of different cooking stoves and cooking fires revealed the highest PM emissions from three-stone cooking fires (7.6-73gkg-1), followed by traditional mud stoves (5.3-19.7gkg-1), mud stoves with a chimney for exhaust (3.0-6.8gkg-1), rocket stoves (1.5-7.2gkg-1), induced-draft stoves (1.2-5.7gkg-1), and the bhuse chulo stove (3.2gkg-1), while biogas had no detectable PM emissions. Idling motorcycle emissions were evaluated before and after routine servicing at a local shop, which decreased EFPM2.5 from 8.8±1.3 to 0.71±0.45gkg-1 when averaged across five motorcycles. Organic species analysis indicated that this reduction in PM2.5 was largely due to a decrease in emission of motor oil, probably from the crankcase. The EF and chemical emissions profiles developed in this study may be used for source apportionment and to update regional emission inventories