Effective data reduction algorithm for topological data analysis

One of the most interesting tools that have recently entered the data science toolbox is topological data analysis (TDA). With the explosion of available data sizes and dimensions, identifying and extracting the underlying structure of a given dataset is a fundamental challenge in data science, and TDA provides a methodology for analyzing the shape of a dataset using tools and prospects from algebraic topology. However, the computational complexity makes it quickly infeasible to process large datasets, especially those with high dimensions. Here, we introduce a preprocessing strategy called the Characteristic Lattice Algorithm (CLA), which allows users to reduce the size of a given dataset as desired while maintaining geometric and topological features in order to make the computation of TDA feasible or to shorten its computation time. In addition, we derive a stability theorem and an upper bound of the barcode errors for CLA based on the bottleneck distance.Comment: 13 pages, 10 figures, 2 table

A CRY-BIC negative-feedback circuitry regulating blue light sensitivity of Arabidopsis.

Cryptochromes are blue light receptors that regulate various light responses in plants. Arabidopsis cryptochrome 1 (CRY1) and cryptochrome 2 (CRY2) mediate blue light inhibition of hypocotyl elongation and long-day (LD) promotion of floral initiation. It has been reported recently that two negative regulators of Arabidopsis cryptochromes, Blue light Inhibitors of Cryptochromes 1 and 2 (BIC1 and BIC2), inhibit cryptochrome function by blocking blue light-dependent cryptochrome dimerization. However, it remained unclear how cryptochromes regulate the BIC gene activity. Here we show that cryptochromes mediate light activation of transcription of the BIC genes, by suppressing the activity of CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), resulting in activation of the transcription activator ELONGATED HYPOCOTYL 5 (HY5) that is associated with chromatins of the BIC promoters. These results demonstrate a CRY-BIC negative-feedback circuitry that regulates the activity of each other. Surprisingly, phytochromes also mediate light activation of BIC transcription, suggesting a novel photoreceptor co-action mechanism to sustain blue light sensitivity of plants under the broad spectra of solar radiation in nature

Fatty liver disease and the risk of erosive oesophagitis in the Korean population: a cross-sectional study

Objectives To investigate an association between fatty liver disease (FLD) and erosive oesophagitis. Design and setting This was a cross-sectional study of subjects selected from examinees who underwent health check-up, including oesophagogastroduodenoscopy in one hospital between 2004 and 2011. Erosive oesophagitis was classified according to the Los Angeles classification and FLD was diagnosed with ultrasonography. The anthropometric and laboratory data of the subjects were analysed using X-2 test and multivariate logistic regression. Additionally, we have analysed our data with two-stage least square estimation using the Baltagi-Chang one-way model to clarify unobserved confounding variable. Primary outcome measure The effect of FLD on erosive oesophagitis. Results Among the 14 723 eligible subjects, 4232 (28.7%) subjects diagnosed with FLD were classified into the fatty liver group and 10 491 (71.3%) subjects without FLD were classified into the non-fatty liver group. The incidence rate of erosive oesophagitis was significantly higher in the fatty liver group than in the non-fatty liver group (10.4% vs6.1%, p< 0.0001). The multivariate analysis revealed that the fatty liver group was significantly associated with erosive oesophagitis (OR 1.19, 95% CI 1.03 to 1.37, p= 0.016). Conclusion FLD diagnosed by ultrasonography is an independent risk factor of erosive oesophagitis. It suggests that FLD-related metabolic abnormality may be associated with erosive oesophagitis

Ultra-Narrow Metallic Nano-Trenches Realized by Wet Etching and Critical Point Drying

A metallic nano-trench is a unique optical structure capable of ultrasensitive detection of molecules, active modulation as well as potential electrochemical applications. Recently, wet-etching the dielectrics of metal-insulator-metal structures has emerged as a reliable method of creating optically active metallic nano-trenches with a gap width of 10 nm or less, opening a new venue for studying the dynamics of nanoconfined molecules. Yet, the high surface tension of water in the process of drying leaves the nano-trenches vulnerable to collapsing, limiting the achievable width to no less than 5 nm. In this work, we overcome the technical limit and realize metallic nano-trenches with widths as small as 1.5 nm. The critical point drying technique significantly alleviates the stress applied to the gap in the drying process, keeping the ultra-narrow gap from collapsing. Terahertz spectroscopy of the trenches clearly reveals the signature of successful wet etching of the dielectrics without apparent damage to the gap. We expect that our work will enable various optical and electrochemical studies at a few-molecules-thick level

Klebsiella pneumoniae Orbital Cellulitis with Extensive Vascular Occlusions in a Patient with Type 2 Diabetes

A 39-year-old woman visited the emergency room complaining of right eye pain and swelling over the preceding three days. The ophthalmologist's examination revealed orbital cellulitis and diabetic retinopathy in the right eye, although the patient had no prior diagnosis of diabetes. It was therefore suspected that she had diabetes and orbital cellulitis, and she was started on multiple antibiotic therapies initially. She then underwent computed tomography scans of the orbit and neck and magnetic resonance imaging of the brain. These studies showed an aggravated orbital cellulitis with abscess formation, associated with venous thrombophlebitis, thrombosis of the internal carotid artery, and mucosal thickening of maxillary sinus with multiple paranasal abscesses. Three days later, initial blood culture grew Klebsiella pneumoniae. She recovered after incision and drainage and antibiotic therapy for 37 days

Ultrathin titania coating for high-temperature stable SiO2/Pt nanocatalysts

The facile synthesis of silica supported platinum nanoparticles with ultrathin titania coating to enhance metal-support interactions suitable for high temperature reactions is reported, as thermal and structure stability of metal nanoparticles is important for catalytic reactions.close8

Prognostic significance of respiratory quotient in patients undergoing extracorporeal cardiopulmonary resuscitation in Korea

Background Respiratory quotient (RQ) may be used as a tissue hypoxia marker in various clinical settings but its prognostic significance in patients undergoing extracorporeal cardiopulmonary resuscitation (ECPR) is not known. Methods Medical records of adult patients admitted to the intensive care units after ECPR in whom RQ could be calculated from May 2004 to April 2020 were retrospectively reviewed. Patients were divided into good neurologic outcome and poor neurologic outcome groups. Prognostic significance of RQ was compared to other clinical characteristics and markers of tissue hypoxia. Results During the study period, 155 patients were eligible for analysis. Of them, 90 (58.1%) had a poor neurologic outcome. The group with poor neurologic outcome had a higher incidence of out-of-hospital cardiac arrest (25.6% vs. 9.2%, P=0.010) and longer cardiopulmonary resuscitation to pump-on time (33.0 vs. 25.2 minutes, P=0.001) than the group with good neurologic outcome. For tissue hypoxia markers, the group with poor neurologic outcome had higher RQ (2.2 vs. 1.7, P=0.021) and lactate levels (8.2 vs. 5.4 mmol/L, P=0.004) than the group with good neurologic outcome. On multivariable analysis, age, cardiopulmonary resuscitation to pump-on time, and lactate levels above 7.1 mmol/L were significant predictors for a poor neurologic outcome but not RQ. Conclusions In patients who received ECPR, RQ was not independently associated with poor neurologic outcome

Myotonic Dystrophy Type 1 Presenting as Male Infertility

Myotonic dystrophy 1 (DM1) is a multi-system disorder characterized by endocrine defects that include testicular and tubular atrophy, oligospermia and azoospermia, and increased follicle-stimulating hormone levels. We describe a rare case of DM1 presenting as infertility in a 29-year-old man