Evolutes of curves in the Lorentz-Minkowski plane

We can use a moving frame, as in the case of regular plane curves in the Euclidean plane, in order to define the arc-length parameter and the Frenet formula for non-lightlike regular curves in the Lorentz-Minkowski plane. This leads naturally to a well defined evolute associated to non-lightlike regular curves without inflection points in the Lorentz-Minkowski plane. However, at a lightlike point the curve shifts between a spacelike and a timelike region and the evolute cannot be defined by using this moving frame. In this paper, we introduce an alternative frame, the lightcone frame, that will allow us to associate an evolute to regular curves without inflection points in the Lorentz-Minkowski plane. Moreover, under appropriate conditions, we shall also be able to obtain globally defined evolutes of regular curves with inflection points. We investigate here the geometric properties of the evolute at lightlike points and inflection points

The horospherical geomoetry of submanifolds in hyperbolic space

We study some geometrical properties associated to the contact of submanifolds with hyperhorospheres in hyperbolic $n$-space as an application of the theory of Legendrian singularities

Label-free imaging by stimulated parametric emission microscopy reveals a difference in hemoglobin distribution between live and fixed erythrocytes

Hieu M. Dang, Gen Omura, Toshiyuki Omano, Masatomo Yamagiwa, Shin'ichiro Kajiyama, Yasuyuki Ozeki, Kazuyoshi Itoh, and Kiichi Fukui "Label-free imaging by stimulated parametric emission microscopy reveals a difference in hemoglobin distribution between live and fixed erythrocytes," Journal of Biomedical Optics 14(4), 040506 (1 July 2009). https://doi.org/10.1117/1.320715

Strain-induced creation and switching of anion vacancy layers in perovskite oxynitrides

Using strain to control oxynitride properties. 京都大学プレスリリース. 2020-12-01.原子空孔の配列を制御する新手法の発見. 京都大学プレスリリース. 2020-12-02.Perovskite oxides can host various anion-vacancy orders, which greatly change their properties, but the order pattern is still difficult to manipulate. Separately, lattice strain between thin film oxides and a substrate induces improved functions and novel states of matter, while little attention has been paid to changes in chemical composition. Here we combine these two aspects to achieve strain-induced creation and switching of anion-vacancy patterns in perovskite films. Epitaxial SrVO3 films are topochemically converted to anion-deficient oxynitrides by ammonia treatment, where the direction or periodicity of defect planes is altered depending on the substrate employed, unlike the known change in crystal orientation. First-principles calculations verified its biaxial strain effect. Like oxide heterostructures, the oxynitride has a superlattice of insulating and metallic blocks. Given the abundance of perovskite families, this study provides new opportunities to design superlattices by chemically modifying simple perovskite oxides with tunable anion-vacancy patterns through epitaxial lattice strain

Prevalence of asthma symptoms based on the European Community Respiratory Health Survey questionnaire and FENO in university students: gender differences in symptoms and FENO

<p>Abstract</p> <p>Background</p> <p>The fractional concentration of nitric oxide in exhaled air (F<smcaps>E</smcaps>NO) is used as a biomarker of eosinophilic airway inflammation. F<smcaps>E</smcaps>NO is increased in patients with asthma. The relationship between subjective asthma symptoms and airway inflammation is an important issue. We expected that the subjective asthma symptoms in women might be different from those in men. Therefore, we investigated the gender differences of asthma symptoms and F<smcaps>E</smcaps>NO in a survey of asthma prevalence in university students.</p> <p>Methods</p> <p>The information about asthma symptoms was obtained from answers to the European Community Respiratory Health Survey (ECRHS) questionnaire, and F<smcaps>E</smcaps>NO was measured by an offline method in 640 students who were informed of this study and consented to participate.</p> <p>Results</p> <p>The prevalence of asthma symptoms on the basis of data obtained from 584 students (266 men and 318 women), ranging in age from 18 to 24 years, was analyzed. Wheeze, chest tightness, an attack of shortness of breath, or an attack of cough within the last year was observed in 13.2% of 584 students. When 38.0 ppb was used as the cut-off value of F<smcaps>E</smcaps>NO to make the diagnosis of asthma, the sensitivity was 86.8% and the specificity was 74.0%. F<smcaps>E</smcaps>NO was ≥ 38.0 ppb in 32.7% of students. F<smcaps>E</smcaps>NO was higher in men than in women. The prevalence of asthma symptoms estimated by considering F<smcaps>E</smcaps>NO was 7.2%; the prevalence was greater in men (9.4%) than women (5.3%). A F<smcaps>E</smcaps>NO ≥ 38.0 ppb was common in students who reported wheeze, but not in students, especially women, who reported cough attacks.</p> <p>Conclusions</p> <p>The prevalence of asthma symptoms in university students age 18 to 24 years in Japan was estimated to be 7.2% on the basis of F<smcaps>E</smcaps>NO levels as well as subjective symptoms. Gender differences were observed in both F<smcaps>E</smcaps>NO levels and asthma symptoms reflecting the presence of eosinophilic airway inflammation.</p> <p>Trial registration number</p> <p>UMIN000003244</p

Serum markers in interstitial pneumonia with and without Pneumocystis jirovecii colonization: a prospective study

<p>Abstract</p> <p>Background</p> <p>In patients with chronic respiratory disease, <it>Pneumocystis jirovecii (P. jirovecii) </it>colonization is observed, and may influence disease progression and systemic inflammation. <it>Pneumocystis </it>pneumonia causes interstitial changes, so making a diagnosis of PCP in patients who have interstitial pneumonia (IP) with <it>P. jirovecii </it>colonization is sometimes difficult based on radiography.</p> <p>Methods</p> <p>This study investigated the prevalence of <it>P. jirovecii </it>colonization in IP patients and assessed pulmonary injury due to <it>P. jirovecii </it>colonization by measurement of serum markers (KL-6, SP-A, SP-D, and (1→3) β-D-glucan (β-D-glucan)) and the peripheral lymphocyte counts, prospectively. A total of 75 patients with idiopathic pulmonary fibrosis (n = 29), collagen vascular-related interstitial pneumonia (n = 19), chronic bronchitis or pneumonia (n = 20), and <it>Pneumocystis </it>pneumonia (n = 7) were enrolled in this prospective study. <it>P. jirovecii </it>DNA was detected in sputum samples, while serum markers and the lymphocyte count were measured in the peripheral blood.</p> <p>Results</p> <p>IP patients (idiopathic pulmonary fibrosis and collagen vascular-related IP) who received oral corticosteroids had a high prevalence of <it>P. jirovecii </it>colonization (23.3%). In IP patients, oral corticosteroid therapy was a significant risk factor for <it>P. jirovecii </it>colonization (<it>P </it>< 0.05). Serum markers did not show differences between IP patients with and without <it>P. jirovecii </it>colonization. The β-D-glucan level and lymphocyte count differed between patients with <it>Pneumocystis </it>pneumonia or <it>P. jirovecii </it>colonization.</p> <p>Conclusion</p> <p>Serum levels of KL-6, SP-A, SP-D, and β-D-glucan were not useful for detecting <it>P. jirovecii </it>colonization in IP patients. However, the serum β-D-glucan level and lymphocyte count were useful for distinguishing <it>P. jirovecii </it>colonization from <it>pneumocystis </it>pneumonia in IP patients.</p

Infection of XC Cells by MLVs and Ebola Virus Is Endosome-Dependent but Acidification-Independent

Inhibitors of endosome acidification or cathepsin proteases attenuated infections mediated by envelope proteins of xenotropic murine leukemia virus-related virus (XMRV) and Ebola virus, as well as ecotropic, amphotropic, polytropic, and xenotropic murine leukemia viruses (MLVs), indicating that infections by these viruses occur through acidic endosomes and require cathepsin proteases in the susceptible cells such as TE671 cells. However, as previously shown, the endosome acidification inhibitors did not inhibit these viral infections in XC cells. It is generally accepted that the ecotropic MLV infection in XC cells occurs at the plasma membrane. Because cathepsin proteases are activated by low pH in acidic endosomes, the acidification inhibitors may inhibit the viral infections by suppressing cathepsin protease activation. The acidification inhibitors attenuated the activities of cathepsin proteases B and L in TE671 cells, but not in XC cells. Processing of cathepsin protease L was suppressed by the acidification inhibitor in NIH3T3 cells, but again not in XC cells. These results indicate that cathepsin proteases are activated without endosome acidification in XC cells. Treatment with an endocytosis inhibitor or knockdown of dynamin 2 expression by siRNAs suppressed MLV infections in all examined cells including XC cells. Furthermore, endosomal cathepsin proteases were required for these viral infections in XC cells as other susceptible cells. These results suggest that infections of XC cells by the MLVs and Ebola virus occur through endosomes and pH-independent cathepsin activation induces pH-independent infection in XC cells

Introduction to the SPARC Reanalysis Intercomparison Project (S-RIP) and overview of the reanalysis systems

The climate research community uses atmospheric reanalysis data sets to understand a wide range of processes and variability in the atmosphere, yet different reanalyses may give very different results for the same diagnostics. The Stratosphere–troposphere Processes And their Role in Climate (SPARC) Reanalysis Intercomparison Project (S-RIP) is a coordinated activity to compare reanalysis data sets using a variety of key diagnostics. The objectives of this project are to identify differences among reanalyses and understand their underlying causes, to provide guidance on appropriate usage of various reanalysis products in scientific studies, particularly those of relevance to SPARC, and to contribute to future improvements in the reanalysis products by establishing collaborative links between reanalysis centres and data users. The project focuses predominantly on differences among reanalyses, although studies that include operational analyses and studies comparing reanalyses with observations are also included when appropriate. The emphasis is on diagnostics of the upper troposphere, stratosphere, and lower mesosphere. This paper summarizes the motivation and goals of the S-RIP activity and extensively reviews key technical aspects of the reanalysis data sets that are the focus of this activity. The special issue The SPARC Reanalysis Intercomparison Project (S-RIP) in this journal serves to collect research with relevance to the S-RIP in preparation for the publication of the planned two (interim and full) S-RIP reports

Concordant inter-laboratory derived concentrations of ceramides in human plasma reference materials via authentic standards

In this community effort, we compare measurements between 34 laboratories from 19 countries, utilizing mixtures of labelled authentic synthetic standards, to quantify by mass spectrometry four clinically used ceramide species in the NIST (National Institute of Standards and Technology) human blood plasma Standard Reference Material (SRM) 1950, as well as a set of candidate plasma reference materials (RM 8231). Participants either utilized a provided validated method and/or their method of choice. Mean concentration values, and intra- and inter-laboratory coefficients of variation (CV) were calculated using single-point and multi-point calibrations, respectively. These results are the most precise (intra-laboratory CVs ≤ 4.2%) and concordant (inter-laboratory CVs < 14%) community-derived absolute concentration values reported to date for four clinically used ceramides in the commonly analyzed SRM 1950. We demonstrate that calibration using authentic labelled standards dramatically reduces data variability. Furthermore, we show how the use of shared RM can correct systematic quantitative biases and help in harmonizing lipidomics. Collectively, the results from the present study provide a significant knowledge base for translation of lipidomic technologies to future clinical applications that might require the determination of reference intervals (RIs) in various human populations or might need to estimate reference change values (RCV), when analytical variability is a key factor for recall during multiple testing of individuals