Waseda University

About: Waseda University is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Catalysis & Large Hadron Collider. The organization has 24220 authors who have published 46859 publications receiving 837855 citations. The organization is also known as: Waseda daigaku & Sōdai.

Identifying elephant flows through periodically sampled packets

Abstract: Identifying elephant flows is very important in developing effective and efficient traffic engineering schemes. In addition, obtaining the statistics of these flows is also very useful for network operation and management. On the other hand, with the rapid growth of link speed in recent years, packet sampling has become a very attractive and scalable means to measure flow statistics; however, it also makes identifying elephant flows become much more difficult. Based on Bayes' theorem, this paper develops techniques and schemes to identify elephant flows in periodically sampled packets. We show that our basic framework is very flexible in making appropriate trade-offs between false positives (misidentified flows) and false negatives (missed elephant flows) with regard to a given sampling frequency. We further validate and evaluate our approach by using some publicly available traces. Our schemes are generic and require no per-packet processing; hence, they allow a very cost-effective implementation for being deployed in large-scale high-speed networks.

The Anticoagulant Nafamostat Potently Inhibits SARS-CoV-2 S Protein-Mediated Fusion in a Cell Fusion Assay System and Viral Infection In Vitro in a Cell-Type-Dependent Manner.

Abstract: Although infection by SARS-CoV-2, the causative agent of coronavirus pneumonia disease (COVID-19), is spreading rapidly worldwide, no drug has been shown to be sufficiently effective for treating COVID-19. We previously found that nafamostat mesylate, an existing drug used for disseminated intravascular coagulation (DIC), effectively blocked Middle East respiratory syndrome coronavirus (MERS-CoV) S protein-mediated cell fusion by targeting transmembrane serine protease 2 (TMPRSS2), and inhibited MERS-CoV infection of human lung epithelium-derived Calu-3 cells. Here we established a quantitative fusion assay dependent on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) S protein, angiotensin I converting enzyme 2 (ACE2) and TMPRSS2, and found that nafamostat mesylate potently inhibited the fusion while camostat mesylate was about 10-fold less active. Furthermore, nafamostat mesylate blocked SARS-CoV-2 infection of Calu-3 cells with an effective concentration (EC)50 around 10 nM, which is below its average blood concentration after intravenous administration through continuous infusion. On the other hand, a significantly higher dose (EC50 around 30 mM) was required for VeroE6/TMPRSS2 cells, where the TMPRSS2-independent but cathepsin-dependent endosomal infection pathway likely predominates. Together, our study shows that nafamostat mesylate potently inhibits SARS-CoV-2 S protein-mediated fusion in a cell fusion assay system and also inhibits SARS-CoV-2 infection in vitro in a cell-type-dependent manner. These findings, together with accumulated clinical data regarding nafamostat's safety, make it a likely candidate drug to treat COVID-19.

Readiness of the ATLAS Tile Calorimeter for LHC collisions.

Abstract: The Tile hadronic calorimeter of the ATLAS detector has undergone extensive testing in the experimental hall since its installation in late 2005. The readout, control and calibration systems have been fully operational since 2007 and the detector has successfully collected data from the LHC single beams in 2008 and first collisions in 2009. This paper gives an overview of the Tile Calorimeter performance as measured using random triggers, calibration data, data from cosmic ray muons and single beam data. The detector operation status, noise characteristics and performance of the calibration systems are presented, as well as the validation of the timing and energy calibration carried out with minimum ionising cosmic ray muons data. The calibration systems’ precision is well below the design value of 1%. The determination of the global energy scale was performed with an uncertainty of 4%.

Mesoporous metallic rhodium nanoparticles

Abstract: Mesoporous noble metals are an emerging class of cutting-edge nanostructured catalysts due to their abundant exposed active sites and highly accessible surfaces Although various noble metal (eg Pt, Pd and Au) structures have been synthesized by hard- and soft-templating methods, mesoporous rhodium (Rh) nanoparticles have never been generated via chemical reduction, in part due to the relatively high surface energy of rhodium (Rh) metal Here we describe a simple, scalable route to generate mesoporous Rh by chemical reduction on polymeric micelle templates [poly(ethylene oxide)-b-poly(methyl methacrylate) (PEO-b-PMMA)] The mesoporous Rh nanoparticles exhibited a ∼26 times enhancement for the electrocatalytic oxidation of methanol compared to commercially available Rh catalyst Surprisingly, the high surface area mesoporous structure of the Rh catalyst was thermally stable up to 400 °C The combination of high surface area and thermal stability also enables superior catalytic activity for the remediation of nitric oxide (NO) in lean-burn exhaust containing high concentrations of O2 Mesoporous noble metal nanostructures offer great promise in catalytic applications Here, Yamauchi and co-workers synthesize mesoporous rhodium nanoparticles using polymeric micelle templates, and report appreciable activities for methanol oxidation and NO remediation