28 research outputs found
Development of Formation Flying CubeSats and Operation Systems for the CANYVAL-C Mission: Launch and Lessons Learned
The CubeSat Astronomy NASA and Yonsei using Virtual telescope ALignment for Coronagraph (CANYVAL-C) is a technology demonstration mission that shows the concept of a virtual space telescope using two CubeSats in formation flying. The final goal of the mission is to obtain several images of the solar corona during an artificial solar eclipse created by the two CubeSats, Timon (1U CubeSat) and Pumbaa (2U CubeSat). To implement this mission, two CubeSats in formation flying and a ground segment have been developed. The CubeSats were constructed mainly with commercial off the shelf components, sharing the bus architecture. The payload of each CubeSat is a visible camera and an occulter to block the light from the photosphere of the Sun. The occulter is composed of tape measures and a black-colored polyimide film; the system size is smaller than 0.5U (10 × 10 × 5 cm3) while it stowed and enlarged to 0.75 × 0.75 m2 after spreading the film. The 3D-printed propulsion system is smaller than 0.5U and facilitates accurate positioning maneuvers of Pumbaa. The on-board computer has multi-task processing capabilities and a space-saving configuration which is integrated with the GNSS receiver and the UHF transceiver. The core technology for the mission implementation is the precise formation flying guidance, navigation, and control system with a cold-gas propulsion system and an inter-satellite link system. The specification of each CubeSat system was evaluated using numerical simulations and ground testing. To operate CubeSats, the ground segment was constructed with some components, including the UHF ground station (UGS), flight dynamics system (FDS), mission analysis and planning system (MAPS), and spacecraft operation system (SOS). Each component works under the environment of an integrated graphic user interface. In particular, the UGS handles the RF communication, data storage, and instrument control for tracking CubeSats. The FDS processes the navigation data to precisely estimate absolute position and velocity. Then, the MAPS determines the allowable mission schedule and parameter set for implementing maneuvers of each CubeSat. Using the MAPS, feasibility of the mission operation canbe ensured through numerical simulations based on the solutions from the FDS. Finally, the SOS is the interface system between each component, processing telemetry and generating telecommand. The CubeSats were launched on March 22, 2021, by Soyuz-2.1a with a Fregat stage
Procalcitonin as a Predictive Factor for the Clinical Outcome of Patients with Coronavirus Disease 2019
Purpose The coronavirus disease 2019 (COVID-19) pandemic continues. It has been reported that patients with bacterial coinfection have a higher mortality rate than patients without coinfection. However, there are no clear standard guidelines for the use of antibacterial drugs. Therefore, the purpose of this study was to determine the usefulness of procalcitonin, a specific indicator of bacterial infection, as a biomarker for predicting death in COVID-19 patients. Methods This was a retrospective study of confirmed COVID-19 patients (N = 283) between December 2020 and February 2021 who survived or died. Logistic regression analysis was performed to determine whether there was an association between the level of procalcitonin and death. In addition, receiver operating characteristic curve analysis was performed to determine the usefulness of procalcitonin as a predictor of death. Results In the non-survivor group, age, the number of patients transferred from a health care center, segment neutrophil ratio, C reactive protein, ferritin, and procalcitonin were significantly higher in the survivor group. In multivariate analysis, procalcitonin was identified as an independent factor associated with death (hazard ratio 6.162, confidential interval 2.285–26.322, p = 0.014). In addition, the predictive power of procalcitonin level and mortality was statistically significant using receiver operating characteristic curve analysis which gave an area under the curve value of 0.823, a cut-off value of 0.05, a sensitivity of 72.2%, a specificity of 87.5% (p < 0.001). Conclusion Measurement of procalcitonin and other biomarkers may be useful to determine whether to use or discontinue use of antibacterial drugs in patients with COVID-19
Multicolor plate reader fluorescence calibration
This is a pre-copyedited, author-produced version of an article accepted for publication in Synthetic Biology following peer review. The version of record Jacob Beal, Cheryl A Telmer, Alejandro Vignoni, Yadira Boada, Geoff S Baldwin, Liam Hallett, Taeyang Lee, Vinoo Selvarajah, Sonja Billerbeck, Bradley Brown, Guo-nan Cai, Liang Cai, Edward Eisenstein, Daisuke Kiga, David Ross, Nina Alperovich, Noah Sprent, Jaclyn Thompson, Eric M Young, Drew Endy, Traci Haddock-Angelli, Multicolor plate reader fluorescence calibration, Synthetic Biology, Volume 7, Issue 1, 2022, ysac010, https://doi.org/10.1093/synbio/ysac010, is available online at: https://doi.org/10.1093/synbio/ysac010.[EN] Plate readers are commonly used to measure cell growth and fluorescence, yet the utility and reproducibility of plate reader data is limited by the fact that it is typically reported in arbitrary or relative units. We have previously established a robust serial dilution protocol for calibration of plate reader measurements of absorbance to estimated bacterial cell count and for green fluorescence from proteins expressed in bacterial cells to molecules of equivalent fluorescein. We now extend these protocols to calibration of red fluorescence to the sulforhodamine-101 fluorescent dye and blue fluorescence to Cascade Blue. Evaluating calibration efficacy via an interlaboratory study, we find that these calibrants do indeed provide comparable precision to the prior calibrants and that they enable effective cross-laboratory comparison of measurements of red and blue fluorescence from proteins expressed in bacterial cells.This work was supported in part by the following funding sources: J.B. was supported by Air Force Research Laboratory (AFRL) and DARPA contract FA8750-17-C-0184. N.S. was supported by funding from the BBSRC under award BB/M011178/1. G.B., L.H., and T.L. were supported by the EPSRC under award EP/R034915/1 and EP/S022856/1. G.C. and L.C. were supported by funds from YF Capital and the National Top Talent Undergraduate Training Program, China. A.V. and Y.B. were funded by Grant MINECO/AEI, EU DPI2017-82896-C2-1-R and MCIN/AEI/10.13039/501100011033 grant number PID2020117271RB-C21. Y.B. was supported by Secretaria de Educaci ' on Superior, Ciencia, Tecnologia e Innovacion-Ecuador (Scholarship Convocatoria Abierta 2011). D.K. was supported by JST, CREST Grant Number JPMJCR21N4, Japan. E.Y. was supported by the National Science Foundation under Grant No. 1939860. J.T. was supported by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA) under Finding Engineering Linked Indicators (FELIX) program contract N66001-18-C-4507. This document does not contain technology or technical data controlled under either the U.S. International Traffic in Arms Regulations or the U.S. Export Administration Regulations. Views, opinions, and/or findings expressed are those of the author(s) and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government.Beal, J.; Telmer, CA.; Vignoni, A.; Boada-Acosta, YF.; Baldwin, GS.; Hallett, L.; Lee, T.... (2022). Multicolor plate reader fluorescence calibration. Synthetic Biology. 7(1):1-9. https://doi.org/10.1093/synbio/ysac010197
Characteristics of Human Brain Activity during the Evaluation of Service-to-Service Brand Extension
Brand extension is a marketing strategy to apply the previously established brand name into new goods or service. A number of studies have reported the characteristics of human event-related potentials (ERPs) in response to the evaluation of goods-to-goods brand extension. In contrast, human brain responses to the evaluation of service extension are relatively unexplored. The aim of this study was investigating cognitive processes underlying the evaluation of service-to-service brand extension with electroencephalography (EEG). A total of 56 text stimuli composed of service brand name (S1) followed by extended service name (S2) were presented to participants. The EEG of participants was recorded while participants were asked to evaluate whether a given brand extension was acceptable or not. The behavioral results revealed that participants could evaluate brand extension though they had little knowledge about the extended services, indicating the role of brand in the evaluation of the services. Additionally, we developed a method of grouping brand extension stimuli according to the fit levels obtained from behavioral responses, instead of grouping of stimuli a priori. The ERP analysis identified three components during the evaluation of brand extension: N2, P300, and N400. No difference in the N2 amplitude was found among the different levels of a fit between S1 and S2. The P300 amplitude for the low level of fit was greater than those for higher levels (p < 0.05). The N400 amplitude was more negative for the mid- and high-level fits than the low level. The ERP results of P300 and N400 indicate that the early stage of brain extension evaluation might first detect low-fit brand extension as an improbable target followed by the late stage of the integration of S2 into S1. Along with previous findings, our results demonstrate different cognitive evaluation of service-to-service brand extension from goods-to-goods
Multicolor plate reader fluorescence calibration
Plate readers are commonly used to measure cell growth and fluorescence, yet the utility and reproducibility of plate reader data is limited by the fact that it is typically reported in arbitrary or relative units. We have previously established a robust serial dilution protocol for calibration of plate reader measurements of absorbance to estimated bacterial cell count and for green fluorescence from proteins expressed in bacterial cells to molecules of equivalent fluorescein. We now extend these protocols to calibration of red fluorescence to the sulforhodamine-101 fluorescent dye and blue fluorescence to Cascade Blue. Evaluating calibration efficacy via an interlaboratory study, we find that these calibrants do indeed provide comparable precision to the prior calibrants and that they enable effective cross-laboratory comparison of measurements of red and blue fluorescence from proteins expressed in bacterial cells
Evaluation of TV commercials using neurophysiological responses
Background: In recent years, neuroscientific knowledge has been applied to marketing as a novel and efficient means to comprehend the cognitive and behavioral aspects of consumers. A number of studies have attempted to evaluate media contents, especially TV commercials using various neuroimaging techniques such as electroencephalography (EEG). Yet neurophysiological examination of detailed cognitive and affective responses in viewers is still required to provide practical information to marketers. Here, this study develops a method to analyze temporal patterns of EEG data and extract affective and cognitive indices such as happiness, surprise, and attention for TV commercial evaluation. Methods: Twenty participants participated in the study. We developed the neurophysiological indices for TV commercial evaluation using classification model. Specifically, these model-based indices were customized using individual EEG features. We used a video game for developing the index of attention and four video clips for developing indices of happiness and surprise. Statistical processes including one-way analyses of variance (ANOVA) and the cross validation scheme were used to select EEG features for each index. The EEG features were composed of the combinations of spectral power at selected channels from the cross validation for each individual. The Fisher's linear discriminant classifier (FLDA) was used to estimate each neurophysiological index during viewing four different TV commercials. Post hoc behavioral responses of preference, short-term memory, and recall were measured. Results: Behavioral results showed significant differences for all preference, short-term memory rates, and recall rates between commercials, leading to a 'high-ranked' commercial group and a 'low-ranked' group (P < 0.05). Neural estimation of happiness results revealed a significant difference between the high-ranked and the low-ranked commercials in happiness index (P < 0.01). The order of rankings based on happiness and attention matched well with the order of behavioral response rankings. In the elapsed-time analysis of the highest-ranked commercial, we could point to visual and auditory semantic structures of the commercial that induced increases in the happiness index. Conclusions: Our results demonstrated that the neurophysiological indices developed in this study may provide a useful tool for evaluating TV commercialsclose0
Secure and Lightweight Authentication Protocol for Mobile RFID Privacy
A mobile RFID system is a radio frequency identification technology that allows users to read the information on its tags. When this free reading function is combined with a mobile RFID system featuring radio frequency identification, it may violate an individuals privacy. This is because others may obtain personal information by reading the tags. In addition, user tracking can be a problem, because the fixed ID values of tags can be traced in network segments. Although various solutions have previously been proposed to resolve this RFID privacy problem, most of these solutions involve numerous calculations within the tags. Therefore, these techniques can only be applied to expensive active tags with high-capacity embedded processors. In addition, it is not practical to apply these techniques to a mobile RFID system based on passive tags attached to devices because of the increase in the price and volume of the tags themselves. In this paper, we propose an efficient protocol that can be used to implement authentication functions in order to transfer the high-performance calculation functions to mobile devices, thus storing only the resulting values on the tags. This study mainly focuses on improving the limitations of the existing RFID authentication functions, which usually assume active tags. It shows that the same security level and performance can be obtained through passive tags. The proposed protocol meets various security requirements such as tag protection, location- and traffic-tracking prevention; the proposed protocol also meets other requirements such as lightweightness and the desired level of performance
The Nonglycemic Actions of Dipeptidyl Peptidase-4 Inhibitors
A cell surface serine protease, dipeptidyl peptidase 4 (DPP-4), cleaves dipeptide from peptides containing proline or alanine in the N-terminal penultimate position. Two important incretin hormones, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), enhance meal-stimulated insulin secretion from pancreatic β-cells, but are inactivated by DPP-4. Diabetes and hyperglycemia increase the DPP-4 protein level and enzymatic activity in blood and tissues. In addition, multiple other functions of DPP-4 suggest that DPP-4 inhibitor, a new class of antidiabetic agents, may have pleiotropic effects. Studies have shown that DPP-4 itself is involved in the inflammatory signaling pathway, the stimulation of vascular smooth cell proliferation, and the stimulation of oxidative stress in various cells. DPP-4 inhibitor ameliorates these pathophysiologic processes and has been shown to have cardiovascular protective effects in both in vitro and in vivo experiments. However, in recent randomized clinical trials, DPP-4 inhibitor therapy in high risk patients with type 2 diabetes did not show cardiovascular protective effects. Some concerns on the actions of DPP-4 inhibitor include sympathetic activation and neuropeptide Y-mediated vascular responses. Further studies are required to fully characterize the cardiovascular effects of DPP-4 inhibitor