ViCE: Visual Concept Embedding Discovery and Superpixelization

Recent self-supervised computer vision methods have demonstrated equal or better performance to supervised methods, opening for AI systems to learn visual representations from practically unlimited data. However, these methods are classification-based and thus ineffective for learning dense feature maps required for unsupervised semantic segmentation. This work presents a method to effectively learn dense semantically rich visual concept embeddings applicable to high-resolution images. We introduce superpixelization as a means to decompose images into a small set of visually coherent regions, allowing efficient learning of dense semantics by swapped prediction. The expressiveness of our dense embeddings is demonstrated by significantly improving the SOTA representation quality benchmarks on COCO (+16.27 mIoU) and Cityscapes (+19.24 mIoU) for both low- and high-resolution images

Characterization of the human herpesvirus 6A U23 gene

AbstractHuman herpesvirus 6 (HHV-6), which replicates abundantly in T cells, belongs to the Roseolovirus genus within the betaherpesvirus subfamily. Members of the Roseolovirus genus encode seven unique genes, U20, U21, U23, U24, U24A, U26, and U100. The present study focused on one of these, U23, by analyzing the characteristics of its gene product in HHV-6A-infected cells. The results indicated that the U23 protein was expressed at the late phase of infection as a glycoprotein, but was not incorporated into virions, and mostly stayed within the trans Golgi network (TGN) in HHV-6A-infected cells. Furthermore, analysis using a U23-defective mutant virus showed that the gene is nonessential for viral replication in vitro

A nationwide, multi-center, retrospective study of symptomatic small bowel stricture in patients with Crohn\u27s disease.

BACKGROUND:Small bowel stricture is one of the most common complications in patients with Crohn\u27s disease (CD). Endoscopic balloon dilatation (EBD) is a minimally invasive treatment intended to avoid surgery; however, whether EBD prevents subsequent surgery remains unclear. We aimed to reveal the factors contributing to surgery in patients with small bowel stricture and the factors associated with subsequent surgery after initial EBD.METHODS:Data were retrospectively collected from surgically untreated CD patients who developed symptomatic small bowel stricture after 2008 when the use of balloon-assisted enteroscopy and maintenance therapy with anti-tumor necrosis factor (TNF) became available.RESULTS:A total of 305 cases from 32 tertiary referral centers were enrolled. Cumulative surgery-free survival was 74.0% at 1 year, 54.4% at 5 years, and 44.3% at 10 years. The factors associated with avoiding surgery were non-stricturing, non-penetrating disease at onset, mild severity of symptoms, successful EBD, stricture length < 2 cm, and immunomodulator or anti-TNF added after onset of obstructive symptoms. In 95 cases with successful initial EBD, longer EBD interval was associated with lower risk of surgery. Receiver operating characteristic analysis revealed that an EBD interval of ≤ 446 days predicted subsequent surgery, and the proportion of smokers was significantly high in patients who required frequent dilatation.CONCLUSIONS:In CD patients with symptomatic small bowel stricture, addition of immunomodulator or anti-TNF and smoking cessation may improve the outcome of symptomatic small bowel stricture, by avoiding frequent EBD and subsequent surgery after initial EBD

Methanol production by reversed methylotrophy constructed in Escherichia coli

We constructed a reversed methylotrophic pathway that produces methanol, a promising feedstock for production of useful compounds, from fructose 6-phosphate (F6P), which can be supplied by catabolism of biomass-derived sugars including glucose, by a synthetic biology approach. Using Escherichia coli as an expression host, we heterologously expressed genes encoding methanol utilization enzymes from methylotrophic bacteria, i.e. the NAD⁺-dependent methanol dehydrogenase (MDH) from Bacillus methanolicus S1 and an artificial fusion enzyme of 3-hexulose-6-phosphate synthase and 6-phospho-3-hexuloisomerase from Mycobacterium gastri MB19 (HPS-PHI). We confirmed that these enzymes can catalyze reverse reactions of methanol oxidation and formaldehyde fixation. The engineered E. coli strain co-expressing MDH and HPS-PHI genes produced methanol in resting cell reactions not only from F6P but also from glucose. We successfully conferred reversed methylotrophy to E. coli and our results provide a proof-of-concept for biological methanol production from biomass-derived sugar compounds

High-temperature operation of gallium oxide memristors up to 600 K

Abstract Memristors have attracted much attention for application in neuromorphic devices and brain-inspired computing hardware. Their performance at high temperatures is required to be sufficiently reliable in neuromorphic computing, potential application to power electronics, and the aerospace industry. This work focuses on reduced gallium oxide (GaO x ) as a wide bandgap memristive material that is reported to exhibit highly reliable resistive switching operation. We prepared amorphous GaO x films to fabricate Pt/GaO x /indium tin oxide memristors using pulsed laser deposition. Stable resistive switching phenomena were observed in current–voltage properties measured between 300 and 600 K. The conduction mechanism analysis revealed that the resistive switching is caused by the transition between ohmic and space charge limiting current conductions. We elucidated the importance of appropriate control of the density of oxygen vacancies to obtain a high on/off resistance ratio and distinct resistive switching at high temperatures. These results indicate that GaO x is a promising memristor material that can be stably operated even at the record-high temperature of 600 K

Sulfonate Ionic Liquid as a Stable and Active Catalyst for Levoglucosenone Production from Saccharides via Catalytic Pyrolysis

In this study, various types of ionic liquids (ILs) were examined for catalytic activity in the pyrolysis of cellulose for the production of levoglucosenone, which is a valuable and versatile compound for the synthesis of a variety of novel compounds. Cellulose was simply mixed with the ILs and subjected for the pyrolysis, typically at 300 °C, to produce volatile products, including levoglucosenone, separated from the ILs phase. The type of IL anion significantly affected the catalysis, and the use of ILs bearing sulfonate anion resulted in distinguished yields of levoglucosenone and IL recoveries for the reutilization. Detailed thermogravimetric analysis and discussion on properties of ILs revealed the active and thermally stable nature of the sulfonate ILs. Catalytic pyrolysis with those ILs was applied to the conversion of other saccharides composed of glucose molecules, resulting in a preferential formation of levoglucosenone but at low yields as compared to that from cellulose

Synthesis of Chiral TFA-Protected α-Amino Aryl-Ketone Derivatives with Friedel–Crafts Acylation of α-Amino Acid N-Hydroxysuccinimide Ester

Chiral N-protected alpha-amino aryl-ketones are one of the useful precursors used in the synthesis of various biologically active compounds and can be constructed via Friedel-Crafts acylation of N-protected alpha-amino acids. One of the drawbacks of this reaction is the utilization of toxic, corrosive and moisture-sensitive acylating reagents. In peptide construction via amide bond formation, N-hydroxysuccinimide ester (OSu), which has high storage stability, can react rapidly with amino components and produces fewer side reactions, including racemization. This study reports the first synthesis and utilization of N-trifluoroacetyl (TFA)-protected alpha-amino acid-OSu as a potential acyl donor for Friedel-Crafts acylation into various arenes. The TFA-protected isoleucine derivative and its diastereomer TFA-protected allo-isoleucine derivative were investigated to check the retention of alpha-proton chirality in the Friedel-Crafts reaction. Further utilization of OSu in other branched-chain and unbranched-chain amino acids results in an adequate yield of TFA-protected alpha-amino aryl-ketone without loss of optical purity