Outdoor Localization Using BLE RSSI and Accessible Pedestrian Signals for the Visually Impaired at Intersections

One of the major challenges for blind and visually impaired (BVI) people is traveling safely to cross intersections on foot. Many countries are now generating audible signals at crossings for visually impaired people to help with this problem. However, these accessible pedestrian signals can result in confusion for visually impaired people as they do not know which signal must be interpreted for traveling multiple crosses in complex road architecture. To solve this problem, we propose an assistive system called CAS (Crossing Assistance System) which extends the principle of the BLE (Bluetooth Low Energy) RSSI (Received Signal Strength Indicator) signal for outdoor and indoor location tracking and overcomes the intrinsic limitation of outdoor noise to enable us to locate the user effectively. We installed the system on a real-world intersection and collected a set of data for demonstrating the feasibility of outdoor RSSI tracking in a series of two studies. In the first study, our goal was to show the feasibility of using outdoor RSSI on the localization of four zones. We used a k-nearest neighbors (kNN) method and showed it led to 99.8% accuracy. In the second study, we extended our work to a more complex setup with nine zones, evaluated both the kNN and an additional method, a Support Vector Machine (SVM) with various RSSI features for classification. We found that the SVM performed best using the RSSI average, standard deviation, median, interquartile range (IQR) of the RSSI over a 5 s window. The best method can localize people with 97.7% accuracy. We conclude this paper by discussing how our system can impact navigation for BVI users in outdoor and indoor setups and what are the implications of these findings on the design of both wearable and traffic assistive technology for blind pedestrian navigation

Enhanced ceramides production by Lactobacillus rhamnosus IDCC 3201 and its proposed mechanism

The use of probiotics has been applied for a variety of fields (e.g., immune system, mental health, and heart). In this study, the feasibility of lysates from L. rhamnosus IDCC 3201 for cosmetic ingredients was evaluated. More specifically, enhanced ceramides production in human epidermal keratinocytes by the lysates and its proposed machanism were investigated through in vitro and genome analysis. In results, enhanced spingomyelinase activity and thereby increased ceramides production by the lysates from L. rhamnosus IDCC 3201 was observed. Furthermore, it was found that the existence of glucosylceramdase in L. rhamonsus IDCC 3201 was attributed to enhanced ceramides production. Finally, it was verified that the lysates from L. rhamonsus IDCC 3201 was regarded as safe for its use as cosmetic materials. Thus, these findings have significant implications that might lead to the development of functional and safe cosmetic products from probiotics.Ceramides Glucosylceramidase Probiotics Skin health Sphingomyelinas

Characterization of the role of the mitochondrial one-carbon metabolism during embryonic development

Neural tube defects (NTDs) are one of serious structural birth defects resulting from failure of neural tube closure. Folic acid supplementation is the essential factor for prevention of NTDs. Folate-dependent one-carbon metabolism is a central metabolic pathway participating in a diverse range of metabolic reactions. Mitochondrial one-carbon metabolism is crucial for production of formate as a major 1C donor to the cytoplasm and regeneration of redox cofactors. Mitochondrial MTHFD family enzymes, MTHFD2, MTHFD2L, and MTHFD1L, are major contributors for formate production in mammalian mitochondria. The MTHFD2 and MTHFD2L isozymes possess both CH₂-THF dehydrogenase and CH⁺-THF cyclohydrolase activities, catalyzing the reaction of 10-CHO-THF production in mitochondria. The dehydrogenase activity of these bifunctional enzymes can use either NAD⁺ or NADP⁺ with dual redox cofactor specificity, but requires both phosphate and Mg²⁺ when using NAD⁺. The NADP⁺-dependent dehydrogenase activity is inhibited by inorganic phosphate. With polyglutamylated THF substrate, both of MTHFD2 and MTHFD2L show higher NADP⁺-dependent activity than the monoglutamylated substrate. Phylogenetic analysis indicates that MTHFD2L may be evolved from invertebrate MTHFD2 which is homologous to a primitive fungal MTHFD1. MTHFD1L is expressed ubiquitously throughout the embryogenesis during neural tube closure, and significantly detected at the basal surface of the dorsal neuroepithelium. Lacking Mthfd1l causes retardation in growth and developmental progression. Mthfd1l knockout mouse embryos show defects in proliferation during late neural tube closure and head mesenchyme development during early neural tube closure. However, proliferation during early neural tube closure, apoptosis, and neural crest cell migration were not affected by the loss of Mthfd1l. Finally, we show that maternal formate supplementation significantly improves the dysregulated cellular processes in Mthfd1l [superscript z/z] embryos. This study elucidates the specific metabolic mechanisms underlying folate-associated birth defects, including NTDs.Biochemistr

Human mitochondrial MTHFD2 is a dual redox cofactor-specific methylenetetrahydrofolate dehydrogenase/methenyltetrahydrofolate cyclohydrolase

Abstract Background Folate-dependent one-carbon metabolism provides one-carbon units for several biological processes. This pathway is highly compartmentalized in eukaryotes, with the mitochondrial pathway producing formate for use in cytoplasmic processes. The mitochondrial enzyme MTHFD2 has been reported to use NAD+ as a cofactor while the isozyme MTHFD2L utilizes NAD+ or NADP+ at physiologically relevant conditions. Because MTHFD2 is highly expressed in many cancer types, we sought to determine the cofactor preference of this enzyme. Results Kinetic analysis shows that purified human MTHFD2 exhibits dual redox cofactor specificity, utilizing either NADP+ or NAD+ with the more physiologically relevant pentaglutamate folate substrate. Conclusion These results show that the mitochondrial folate pathway isozymes MTHFD2 and MTHFD2L both exhibit dual redox cofactor specificity. Our kinetic analysis clearly supports a role for MTHFD2 in mitochondrial NADPH production, indicating that this enzyme is likely responsible for mitochondrial production of both NADH and NADPH in rapidly proliferating cells

An Examination of Longitudinal Changes in Korean Middle School Students’ Psychological Health According to Their Body Mass Index and Weekly Exercise Hours

Background: It is necessary for adolescents to maintain proper body mass index (BMI) and regular exercise for proper growth, development, and psychological health. Existing studies have demonstrated the significant positive effect of regular physical activity or exercise on preventing socio-psychological problems and cognitive body image issues in adolescents. This study aimed to investigate the longitudinal changes in psychological health factors of mental health, self-concept, self-esteem, and self-efficacy according to BMI and weekly exercise hours among Korean middle school students. Methods: Cohort data were obtained from the Gyeonggi Institute of Education for three years (2015–2017), and a total of 16,027 data points were analyzed. We performed a repeated-measures analysis of variance (3 grades × 4 body mass index groups × 5 weekly exercise hours groups) using SPSS software (version 21.0, IBM Corp., Armonk, NY, USA) for data analysis. Results: The results obtained through the analysis are as follows. As school grades rose among Korean middle school students, psychological health factors such as mental health, self-concept, self-esteem, and self-efficacy decreased. And the deterioration of psychological health factors showed lower positive results for normal and underweight students than for overweight and obese students. Students with a lot of exercise time every week showed a lower decrease in psychological health factors. Conclusions: The results suggest that education for health promotion, considering body mass index and daytime exercise, is necessary to prevent the deterioration of psychological health factors in Korean middle school students

Optimization of Operating Conditions for CO2 Methanation Process Using Design of Experiments

In this study, the Taguchi experimental design method using an L16 orthogonal array was attempted in order to investigate the optimal operating conditions for the CO2 methanation process in Ni-based catalysts. The relative influence of the main factors affecting CO2 conversion and CH4 yield was ranked as follows: reactor pressure > space velocity > reaction temperature. The optimal combination of operating conditions was a reactor temperature of 315 °C, a pressure of 19 bar, and a space velocity of 6000 h−1. The effect of the H2/CO2 ratio on CO2 conversion and CH4 yield was further considered under these optimal operating conditions. Moreover, the catalyst was characterized in order to investigate the production of coke through Brunauer–Emmett–Teller analysis, thermogravimetric analysis, and scanning electron microscopy. The amount of coke produced after the reaction for approximately 24 h was ~2 wt.%. Therefore, the desired CH4 yield and long-term operational stability were successfully obtained using the Taguchi design method and catalyst characterization