Electropolishing Valve Metals with a Sulfuric Acid-Methanol Electrolyte at Low Temperature

This study reports the electropolishing Ti and Nb metals using a fluoride-free electrolyte of sulfuric acid and methanol at low temperature (-70°C) without prior treatment. A fluoride-free electrolyte provides a less hazardous and more environmentally friendly option for electropolishing procedure. Experimental studies are presented on electropolishing with sulfuric acid electrolyte, which provides high quality macro- and micro-smoothing of the metal surfaces. Optimal conditions yielded leveling and brightening of the surface of Ti and Nb metals beyond that of the currently utilized electropolishing procedures with fluoride-containing electrolytes. The root mean squared roughness (Rq) from atomic force microscopy (AFM) analysis was 1.64 and 0.49 nm for Ti and Nb, respectively. Lower temperature experiments led to noticeable kinetic effects, indicated by a dramatic drop in current densities and the expansion of the steady-state current density plateau in anodic polarization curves. In addition, the voltage range of the current plateau expanded with increasing acid concentration. Surface characterization of Ti and Nb metals after polishing provided evidence of salt film formation. In addition, these metals were used as substrates in the formation of nanostructured metal oxides. The overall quality of the polishing led to a dramatic improvement in the uniformity of the nanostructures

MS-nowcasting: Operational Precipitation Nowcasting with Convolutional LSTMs at Microsoft Weather

We present the encoder-forecaster convolutional long short-term memory (LSTM) deep-learning model that powers Microsoft Weather's operational precipitation nowcasting product. This model takes as input a sequence of weather radar mosaics and deterministically predicts future radar reflectivity at lead times up to 6 hours. By stacking a large input receptive field along the feature dimension and conditioning the model's forecaster with predictions from the physics-based High Resolution Rapid Refresh (HRRR) model, we are able to outperform optical flow and HRRR baselines by 20-25% on multiple metrics averaged over all lead times.Comment: Minor updates to reflect final submission to NeurIPS worksho

138 Levetiracetam add-on for drug-resistant focal epilepsy: an updated Cochrane systematic review and meta-analysis

ObjectiveTo evaluate the effectiveness of adjuvant levetiracetam in drug-resistant focal epilepsy. This is an update to the 2001 and 2012 reviews.MethodsThe search included the Cochrane Register of Studies and MEDLINE to 09/2018 for randomised, placebo-controlled trials of add-on levetiracetam in drug-resistant focal epilepsy. Two authors indepen- dently performed study selection, data extraction, and risk of bias assessments. Outcomes included≥50% reduction in seizure frequency (response) and adverse effects. We performed Mantel-Haenszel meta-analyses for risk ratios (RR), with 95% CI (99% for adverse effects). We assessed heterogeneity using I².ResultsThis update includes 14 trials (three more than the previous update), assessing 2,452 participants (296 children). Risks of bias were predominantly low. There were important levels of heterogeneity across multiple comparisons. There were two new findings: 1) Levetiracetam at either 500 mg/day or 4000 mg/day did not perform better than placebo for response (500 mg: RR 1.60, CI 0.71–3.62; 4000 mg: RR 1.64, CI 0.59–4.57). Levetiracetam was significantly better than placebo at all other individual doses (1000–3000 mg). 2) Odds of achieving response were increased by nearly 40% (odds ratio 1.39, CI 1.23–1.58) for each 1000 mg increase in dose of levetiracetam. Somnolence remained the most common adverse effect, and changes in behaviour were negligible overall.ConclusionsIt seems reasonable to continue using levetiracetam in drug-resistant focal epilepsy,10a2lthough a 500-mg dose may be no more effective than [email protected]</jats:sec

Levetiracetam add-on for drug-resistant focal epilepsy.

BackgroundDrug resistance is common in focal epilepsy. In this update, we summarised the current evidence regarding add-on levetiracetam in treating drug-resistant focal epilepsy. The original review was published in 2001 and last updated in 2012.ObjectivesTo evaluate the effectiveness of levetiracetam when used as an add-on treatment for people with drug-resistant focal epilepsy.Search methodsWe searched the Cochrane Register of Studies (CRS Web, which includes the Cochrane Epilepsy Group Specialized Register and CENTRAL), MEDLINE Ovid, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform (ICTRP) to November 2018. We contacted the manufacturers of levetiracetam and researchers in the field to seek any ongoing or unpublished trials.Selection criteriaRandomised, placebo-controlled trials of add-on levetiracetam treatment in people with drug-resistant focal epilepsy.Data collection and analysisTwo review authors independently selected trials for inclusion, assessed trials for bias, extracted data, and evaluated the overall certainty of the evidence. Outcomes investigated included 50% or greater reduction in focal seizure frequency (response), treatment withdrawal, adverse effects (including a specific analysis of changes in behaviour), cognitive effects, and quality of life (QoL). Primary analysis was intention-to-treat. We performed meta-analysis for all outcomes using a Mantel-Haenszel approach and calculated risk ratios (RR), with 95% confidence intervals (CI) for all estimates apart from adverse effects (99% CIs). We assessed heterogeneity using a Chi² test and the I² statistic.Main resultsThis update included 14 trials (2455 participants), predominantly possessing low risks of bias. Participants were adults in 12 trials (2159 participants) and children in the remaining two (296 participants). The doses of levetiracetam tested were 500 mg/day to 4000 mg/day in adults, and 60 mg/kg/day in children. Treatment ranged from 12 to 24 weeks. When individual doses were examined, levetiracetam at either 500 mg/day or 4000 mg/day did not perform better than placebo for the 50% or greater reduction in seizure frequency outcome (500 mg: RR 1.60, 95% CI 0.71 to 3.62; P = 0.26; 4000 mg: RR 1.64, 95% CI 0.59 to 4.57; P = 0.34). Levetiracetam was significantly better than placebo at all other individual doses (1000 mg to 3000 mg). RR was significantly in favour of levetiracetam compared to placebo when results were pooled across all doses (RR 2.37, 95% CI 2.02 to 2.78; 14 studies, 2455 participants; moderate-certainty evidence). Dose-response analysis demonstrated that the odds of achieving response (50% or greater reduction in seizure frequency) were increased by nearly 40% (odds ratio (OR) 1.39, 95% CI 1.23 to 1.58) for each 1000 mg increase in dose of levetiracetam. There were important levels of heterogeneity across multiple comparisons. Participants were not significantly more likely to experience treatment withdrawal with levetiracetam than with placebo (pooled RR 1.11, 95% CI 0.89 to 1.40; 13 studies, 2428 participants; high-certainty evidence). Somnolence was the most common adverse effect, affecting 13% of participants, and it was significantly associated with levetiracetam compared to placebo (pooled RR 1.62, 99% CI 1.19 to 2.20; 13 studies, 2423 participants; moderate-certainty evidence). Changes in behaviour were negligible in adults (1% affected; RR 1.79, 99% CI 0.59 to 5.41), but significant in children (23% affected; RR 1.90, 99% CI 1.16 to 3.11). Levetiracetam had a positive effect on some aspects of cognition and QoL in adults and worsened certain aspects of child behaviour.Authors' conclusionsOverall, this review update finds that in both adults and children with drug-resistant focal epilepsy, levetiracetam added on to usual care is more effective than placebo at reducing seizure frequency, it is unlikely to be stopped by patients, and it has minimal adverse effects outside of potential worsening behaviour in children. These findings are unchanged from the previous review update in 2012. This review update contributes two key additional findings: 1. a 500 mg daily dose of levetiracetam is no more effective than placebo at reducing seizures; and 2. the odds of response (50% reduction in seizure frequency) are increased by nearly 40% for each 1000 mg increase in dose of levetiracetam. It seems reasonable to continue the use of levetiracetam in both adults and children with drug-resistant focal epilepsy

Electrochemically Induced Amorphous-to-Rock-Salt Phase Transformation in Niobium Oxide Electrode for Li-Ion Batteries

Intercalation-type metal oxides are promising negative electrode materials for safe rechargeable lithium-ion batteries due to the reduced risk of Li plating at low voltages. Nevertheless, their lower energy and power density along with cycling instability remain bottlenecks for their implementation, especially for fast-charging applications. Here, we report a nanostructured rock-salt Nb2O5 electrode formed through an amorphous-to-crystalline transformation during repeated electrochemical cycling with Li+. This electrode can reversibly cycle three lithiums per Nb2O5, corresponding to a capacity of 269 mAh g−1 at 20 mA g−1, and retains a capacity of 191 mAh g−1 at a high rate of 1 A g−1. It exhibits superb cycling stability with a capacity of 225 mAh g−1 at 200 mA g−1 for 400 cycles, and a Coulombic efficiency of 99.93%. We attribute the enhanced performance to the cubic rock-salt framework, which promotes low-energy migration paths. Our work suggests that inducing crystallization of amorphous nanomaterials through electrochemical cycling is a promising avenue for creating unconventional high-performance metal oxide electrode materials

Achieving mitigation and adaptation to climate change through sustainable agroforestry practices in Africa

Peer reviewedPublisher PD

The Top 100 questions for the sustainable intensification of agriculture in India’s rainfed drylands

India has the largest area of rainfed dryland agriculture globally, with a variety of distinct types of farming systems producing most of its coarse cereals, food legumes, minor millets, and large amounts of livestock. All these are vital for national and regional food and nutritional security. Yet, the rainfed drylands have been relatively neglected in mainstream agricultural and rural development policy. As a result, significant social-ecological challenges overlap in these landscapes: endemic poverty, malnutrition and land degradation. Sustainable intensification of dryland agriculture is essential for helping to address these challenges, particularly in the context of accelerating climate change. In this paper, we present 100 questions that point to the most important knowledge gaps and research priorities. If addressed, these would facilitate and inform sustainable intensification in Indian rainfed drylands, leading to improved agricultural production and enhanced ecosystem services. The horizon scanning method used to produce these questions brought together experts and practitioners involved in a broad range of disciplines and sectors. This exercise resulted in a consolidated set of questions covering the agricultural drylands, organized into 13 themes. Together, these represent a collective programme for new cross- and multi-disciplinary research on sustainable intensification in the Indian rainfed drylands

Sustainable Diets: another hurdle or a better food future?,

The notion of sustainable diets has emerged forcibly onto the food policy agenda in recent years, but has also met resistance. The article reviews the case for sustainable diets. It counterbalances the current dominant policy emphasis on raising food output as the best route to a sustainable food future. The article suggests that a process of democratic experimentation is underway. Some official guidelines have emerged alongside a mix of civil society and academic formulations. More coherence of data, principles and purpose is needed at the global and regional policy-making levels for these to become effective in the common task of reducing the food system’s negative impact on health, environment and economies