Rivers of the Asian Highlands

Rivers of the Asian Highlands introduces readers to the intersecting headwaters of Asia’s eight largest rivers, focusing on the upper reaches of two river systems: the Brahmaputra’s highland tributaries in the eastern Himalayan Mountains and the Dri Chu (upper Yangzi), which descends from the Tibetan Plateau’s east through the Hengduan Mountains. This book guides its readers through these two rivers’ physical, environmental, cultural, social, and political histories before providing a multifaceted assessment of their present. It uses general and detailed insights from multiple disciplines, including anthropology, conservation, geography, geomorphology, climate science, ecology, history, hydrology, and religious studies. The rivers’ stories explain how the catchments’ hazards—earthquakes, landslides, floods, droughts, and erosion—interact with their energetic, hydrological, ecological, cultural, and social abundance. This book’s multiple cultural and disciplinary perspectives on the rivers will interest anyone who wants to understand the rivers of this critically important region as the environment faces climate change and other ecological crises

Conformational Transition Pathway in the Inhibitor Binding Process of Human Monoacylglycerol Lipase

Human monoacylglycerol lipase (MGL) catalyzes the hydrolysis of 2-arachidonoylglycerol to arachidonic and glycerol, which plays a pivotal role in the normal biological processes of brain. Co-crystal structure of the MGL in complex with its inhibitor, compound 1, shows that the helix α4 undergoes large-scale conformational changes in response to the compound 1 binding compared to the apo MGL. However, the detailed conformational transition pathway of the helix α4 in the inhibitor binding process of MGL has remained unclear. Here, conventional molecular dynamics (MD) and nudged elastic band (NEB) simulations were performed to explore the conformational transition pathway of the helix α4. Conventional MD simulations unveiled that the compound 1 induced the closed conformation of the active site of MGL, reduced the conformational flexibility of the helix α4, and elicited the large-scale conformational rearrangement of the helix α4, leading to the complete folding of the helix α4. Moreover, NEB simulations revealed that the conformational transition pathway of helix α4 underwent an almost 180° counter-clockwise rotation of the helix α4. Our computational results advance the structural and mechanistic understanding of the inhibitory mechanism

A novel hybrid organosolv: steam explosion method for the efficient fractionation and pretreatment of birch biomass

Background: The main role of pretreatment is to reduce the natural biomass recalcitrance and thus enhance sac- charification yield. A further prerequisite for efficient utilization of all biomass components is their efficient fractiona- tion into well-defined process streams. Currently available pretreatment methods only partially fulfill these criteria. Steam explosion, for example, excels as a pretreatment method but has limited potential for fractionation, whereas organosolv is excellent for delignification but offers poor biomass deconstruction. Results: In this article, a hybrid method combining the cooking and fractionation of conventional organosolv pre - treatment with the implementation of an explosive discharge of the cooking mixture at the end of pretreatment was developed. The effects of various pretreatment parameters (ethanol content, duration, and addition of sulfuric acid) were evaluated. Pretreatment of birch at 200 °C with 60% v/v ethanol and 1% w/w biomass H 2 SO 4 was proven to be the most efficient pretreatment condition yielding pretreated solids with 77.9% w/w cellulose, 8.9% w/w hemicellulose, and 7.0 w/w lignin content. Under these conditions, high delignification of 86.2% was demonstrated. The recovered lignin was of high purity, with cellulose and hemicellulose contents not exceeding 0.31 and 3.25% w/w, respectively, and ash to be < 0.17% w/w in all cases, making it suitable for various applications. The pretreated solids presented high saccharification yields, reaching 68% at low enzyme load (6 FPU/g) and complete saccharification at high enzyme load (22.5 FPU/g). Finally, simultaneous saccharification and fermentation (SSF) at 20% w/w solids yielded an ethanol titer of 80 g/L after 192 h, corresponding to 90% of the theoretical maximum. Conclusions: The novel hybrid method developed in this study allowed for the efficient fractionation of birch biomass and production of pretreated solids with high cellulose and low lignin contents. Moreover, the explosive dis- charge at the end of pretreatment had a positive effect on enzymatic saccharification, resulting in high hydrolyzability of the pretreated solids and elevated ethanol titers in the following high-gravity SSF. To the best of our knowledge, the ethanol concentration obtained with this method is the highest so far for birch biomass

Rivers of the Asian Highlands: From Deep Time to the Climate Crisis

Rivers of the Asian Highlands introduces readers to the intersecting headwaters of Asia’s eight largest rivers, focusing on the upper reaches of two river systems: the Brahmaputra’s highland tributaries in the eastern Himalayan Mountains and the Dri Chu (upper Yangzi), which descends from the Tibetan Plateau’s east through the Hengduan Mountains.This book guides its readers through these two rivers’ physical, environmental, cultural, social, and political histories before providing a multifaceted assessment of their present. It uses general and detailed insights from multiple disciplines, including anthropology, conservation, geography, geomorphology, climate science, ecology, history, hydrology, and religious studies. The rivers’ stories explain how the catchments’ hazards—earthquakes, landslides, floods, droughts, and erosion—interact with their energetic, hydrological, ecological, cultural, and social abundance.This book’s multiple cultural and disciplinary perspectives on the rivers will interest anyone who wants to understand the rivers of this critically important region as the environment faces climate change and other ecological crises.</p

Performance Analysis of GYRO: A Tool Evaluation

The performance of the Eulerian gyrokinetic-Maxwell solver code GYRO is analyzed on five high performance computing systems. First, a manual approach is taken, using custom scripts to analyze the output of embedded wall clock timers, floating point operation counts collected using hardware performance counters, and traces of user and communication events collected using the profiling interface to Message Passing Interface (MPI) libraries. Parts of the analysis are then repeated or extended using a number of sophisticated performance analysis tools: IPM, KOJAK, SvPablo, TAU, and the PMaC modeling tool suite. The paper briefly discusses what has been discovered via this manual analysis process, what performance analyses are inconvenient or infeasible to attempt manually, and to what extent the tools show promise in accelerating or significantly extending the manual performance analyses