Development of a Compact Wide-Field Telescope to be Mounted on VERTECS

In recent years, CubeSat projects have initiated plans to conduct astronomical observations by deploying mission payloads. CubeSats present a promising solution for swiftly addressing critical challenges in astrophysics with flexibility. Within Cubeats, where both the bus system and mission payload occupy about half of the volume, there is a necessity to miniaturize mission equipment. The critical factor in astronomical observations, light-gathering ability, is determined not only by the aperture size but, more importantly for diffuse emission, by the optical throughput, i.e., the product of the aperture area and the observing solid angle. Consequently, even with a compact optical system, specializing in wide-field observations enables achieving light-gathering ability equivalent to that of a large-diameter telescope. Therefore, we propose equipping CubeSats with small, wide-field telescopes specialized for observing essential quantities in understanding the cosmic history of star formation, such as extragalactic background Light (EBL), and foreground components like zodiacal light and diffuse galactic light. Radiation from first-generation celestial bodies, which is challenging to detect due to their darkness in the distant universe, is included in the EBL in the visible to near-infrared wavelengths. Hence, wide-field survey observations in the visible and near-infrared play a crucial role in unraveling when, where, and how the first-generation stars were born in the early universe. However, current technology has not enabled the development of CubeSats with mechanisms capable of cooling infrared detectors to temperatures below a few tens of Kelvin. Therefore, we have designed an optical system focusing on the visible EBL. In the astronomical W6U CubeSat mission VERTECS (Visible Extragalactic background RadiaTion Exploration by CubeSat), we are developing a 3U mission payload, comprised of 1U-sized lens optics, camera modules, and baffles each. The lens optical system achieves a high throughput ( \u3e 10-6 m2 sr) by covering the entire field of view with 6 degrees by 6 degrees and each pixel with a field of view of 11 arcseconds by 11 arcseconds. The camera module uses a CMOS sensor with high quantum efficiency in visible light, featuring sufficiently low dark current noise (approximately 0.01 electrons per second at 269 K) and readout noise (approximately 2.6 electrons at 24 dB analog gain), compared to the photocurrent generated by the EBL and foreground photon noise. The baffle is designed to attenuate stray light from the Sun and Earth to negligible levels compared to the EBL signal. Additionally, a set of color filters divides the wavelength range of 400 to 800 nm into four bands. In our observation strategy, we capture 60-second exposure images by shifting the field of view by 3 degrees and perform photometry on the stacked images in the four bands. VERTECS project was selected in JAXA-Small Satellite Rush Program in 2022 and is currently advancing in satellite development, with a scheduled launch in FY2025. Thus far, a significant portion of the mission payload design meets the required specifications, and progress is underway towards the fabrication of the engineering model. In this presentation, we will report on the progress of our optical telescope development, our strategy for visible EBL observations, and our future plans

Facile synthesis of C-terminal peptide thioacids under mild conditions from N-sulfanylethylanilide peptides

A facile procedure has been developed for the synthesis of C-terminal peptide thioacids under mild conditions. A series of N-sulfanylethylanilide peptides prepared using Fmoc-based solid-phase peptide synthesis were successfully converted to the corresponding thioacids via a hydrothiolysis reaction in a phosphate buffer with only trace epimerization of the C-terminal amino acid

〈Original Papers〉Diurnal and seasonal variation of air temperature profile in the mountain forest at Sugadaira, central Japan

Air temperature profiles were observed for a year with micro-climate observation in and around the mixed mountain forest. The shading effects of tree crown, depending on the solar elevation angle and abscission of broad leaf species, controlled the diurnal and seasonal variation of radiation budget and temperature gradients in the forest. Vertical mixing of air in the forest was infrequent even the wind speed over the forest was high. Sasa albo-marginata served as another important daytime heat source at the forest floor in snow-free season. In the forest, weak but clear diurnal wind variation was observed on fair summer days indicating prevailing of daytime up-slope winds and nocturnal gravity currents. After leaf abscission, the nocturnal temperature inversion prevailed in and out of the forest. The importance of the local winds blowing through the forest and their effect on the data from the station in an open space are discussed with regard to the long-term assessment of mountain meteorological and forest phonological data

VERTECS: 6U CubeSat Mission to Study Star-Formation History by Observation of Visible Extragalactic Background Light

We describe an astronomical 6U CubeSat mission VERTECS (Visible Extragalactic background RadiaTion Exploration by CubeSat). The scientific purpose of VERTECS is to reveal star-formation history of the universe by observation of the extragalactic background light (EBL) in visible wavelengths. Earlier observations by sounding rockets and infrared astronomical satellites have shown that the near-infrared EBL is several times brighter than the integrated light of known galaxies. As candidates for the excess light, first-generation stars in the early universe or low-redshift intra-halo light have been proposed, but it has not been concluded. Since these objects are expected to show different emission spectra in visible wavelengths, precise visible observation is important to reveal the origin of excess light. Since detection sensitivity of the EBL is determined by the product of telescope aperture and field of view, a small wide-field telescope system enables the EBL observation with high sensitivity. In VERTECS mission, we develop a 6U CubeSat equipped with a 3U size telescope optimized for observation of visible EBL. The telescope is composed of lens optics and a CMOS sensor of 3k times 3k array format, which is designed to observe the sky in four photometric bands in 400-800nm. The satellite bus is composed of on-board computer (OBC), electric power system (EPS), communication (COM), attitude determination and control system (ACDS), and thermal structure. Design of OBC and EPS is based on heritage of CubeSats developed at Kyushu Institute of Technology, but deployable solar array wings is added to EPS to supply sufficient power to the VERTECS subsystems. In COM system, S-band is used for command uplink and X-band is used for high-speed downlink of large-size images captured by the telescope. Since the EBL measurement need discrimination of the background light from discrete foreground stars, VERTECS requires 10 arcseconds pointing stability (1 sigma) over 1 minute exposure. In 2022, VERTECS was selected for JAXA-Small Satellite Rush Program (JAXA-SMASH Program), a new program that encourages universities, private companies and JAXA to collaborate to realize small satellite missions utilizing commercial small launch opportunities, and to diversify transportation services in Japan. We have been working on functionality and interface teast using Bread Board Model (BBM), and enviroonmental tests by using the satellite structure thermal model. Launch of the satellite is planned in FY2025. We aim at developing the satellite and obtaining scientific results much more quickly than recent large astronomical-satellite missions

Protein model accuracy estimation based on local structure quality assessment using 3D convolutional neural network.

In protein tertiary structure prediction, model quality assessment programs (MQAPs) are often used to select the final structural models from a pool of candidate models generated by multiple templates and prediction methods. The 3-dimensional convolutional neural network (3DCNN) is an expansion of the 2DCNN and has been applied in several fields, including object recognition. The 3DCNN is also used for MQA tasks, but the performance is low due to several technical limitations related to protein tertiary structures, such as orientation alignment. We proposed a novel single-model MQA method based on local structure quality evaluation using a deep neural network containing 3DCNN layers. The proposed method first assesses the quality of local structures for each residue and then evaluates the quality of whole structures by integrating estimated local qualities. We analyzed the model using the CASP11, CASP12, and 3D-Robot datasets and compared the performance of the model with that of the previous 3DCNN method based on whole protein structures. The proposed method showed a significant improvement compared to the previous 3DCNN method for multiple evaluation measures. We also compared the proposed method to other state-of-the-art methods. Our method showed better performance than the previous 3DCNN-based method and comparable accuracy as the current best single-model methods; particularly, in CASP11 stage2, our method showed a Pearson coefficient of 0.486, which was better than those of the best single-model methods (0.366-0.405). A standalone version of the proposed method and data files are available at https://github.com/ishidalab-titech/3DCNN_MQA

The Influence of a Nanopatterned Scaffold that Mimics Abnormal Renal Mesangial Matrix on Mesangial Cell Behavior

The alteration of mesangial matrix (MM) components in mesangium, such as type IV collagen (COL4) and type I collagen (COL1), is commonly found in progressive glomerular disease. Mesangial cells (MCs) responding to altered MM, show critical changes in cell function. This suggests that the diseased MM structure could play an important role in MC behavior. To investigate how MC behavior is influenced by the diseased MM 3D nanostructure, we fabricated the titanium dioxide (TiO2)-based nanopatterns that mimic diseased MM nanostructures. Immortalized mouse MCs were used to assess the influence of disease-mimic nanopatterns on cell functions, and were compared with a normal-mimic nanopattern. The results showed that the disease-mimic nanopattern induced disease-like behavior, including increased proliferation, excessive production of abnormal MM components (COL1 and fibronectin) and decreased normal MM components (COL4 and laminin α1). In contrast, the normal-mimic nanopattern actually resulted in cells displaying normal proliferation and the production of normal MM components. In addition, increased expressions of α-smooth muscle actin (α-SMA), transforming growth factor β1 (TGF-β1) and integrin α5β1 were detected in cells grown on the disease-mimic nanopattern. These results indicated that the disease-mimic nanopattern induced disease-like cell behavior. These findings will help further establish a disease model that mimics abnormal MM nanostructures and also to elucidate the molecular mechanisms underlying glomerular disease

Excited state properties of 5‐fluoro‐4‐thiouridine derivative^†

The excited state properties of thionated 5- fluorouridine (2′,3′,5′- tri- O- acetyl- 5- fluoro- 4- thiouridine; ta5F4TUrd), synthesized with Lawesson's reagent, have been intensively investigated with nanosecond transient absorption spectroscopy, time- resolved thermal lensing, near- infrared emission, and quantum chemical calculation. The intrinsic triplet lifetime of ta5F4TUrd was determined to be 4.2±0.7μs in acetonitrile, and the formation quantum yield of the excited tri-plet state was as large as 0.79±0.01. The quenching rate constants of the triplet ta5F4TUrd by the dissolved oxygen molecule and by the self- quenching process were found to be nearly equal to the diffusion- controlled rate of acetonitrile. The quantum yield of the singlet molecular oxygen produced through energy transfer between the triplet ta5F4TUrd and the dissolved oxygen, ΦΔ, was successfully de-termined to be 0.61±0.02 under the oxygen- saturated condition. From the oxy-gen concentration dependence of the ΦΔ value, the fraction of triplet ta5F4TUrd quenched by dissolved oxygen which gives rise to the 1O2* formation, SΔ, was successfully obtained to be 0.78±0.01, which was the largest among the thionu-cleobases and the thionucleosides reported so far. This could be due to the lower energy and/or the ππ* character of the triplet state

Development and Feasibility of a Mobile Asthma App for Children and Their Caregivers: Mixed Methods Study

BackgroundMobile health apps can support the self-management of pediatric asthma. Previous studies on mobile apps for children aged >7 years with asthma are limited, and most reports on asthma apps do not consider interactions between the children and their caregivers. Therefore, we developed an asthma app for children aged 0-12 years and their caregivers based on the results of our previous study regarding user needs. ObjectiveThe aim of this study was to evaluate the feasibility of a developed mobile app for children with asthma and their caregivers and to modify and complete the app according to the feasibility results. MethodsWe recruited children diagnosed with persistent asthma by an allergy specialist at 2 children’s hospitals, 1 university hospital, 2 general hospitals, and 1 pediatric clinic. Thereafter, the app usage was assessed, and questionnaires were administered. This study used convergent mixed methods, including providing user feedback about the pediatric asthma app, completing questionnaire surveys regarding preferences, and obtaining quantitative data about app usage. Quantitative data were analyzed based on the ratings provided for the app features used by the participants, and the usage of the app features was analyzed using descriptive statistics. Qualitative data were analyzed via a descriptive qualitative research analysis and were used to identify codes from the content-characteristic words. ResultsIn total, 30 pairs of children aged 2-12 years and their caregivers responded to the 3-month survey, and 20 pairs of children aged 4-12 years and their caregivers responded to the 6-month survey. In the 3- and 6-month surveys, “record” was the most commonly used feature by both caregivers and children. The average access logs per month among the 20 pairs ranged from 50 to 79 in the 6-month survey. The number of access logs decreased over time. In the qualitative results, app utilization difficulties were identified for 6 categories: record, preparing, alert settings, change settings, mobile phone owner, and display and motivation. Regarding app feasibility, 60% (12/20) of the caregivers strongly agreed or agreed for all evaluation items, while 63% (7/11) of the children strongly agreed or agreed for 6 items, excluding satisfaction. In the qualitative results, feasibility evaluation of the app was classified into 3 categories: high feasibility of the app, improvement points for the app, and personal factors preventing app utilization. Based on the results of the feasibility analysis, the final version of the app was modified and completed. ConclusionsThe app feasibility among children with asthma and their caregivers was generally good. Children aged 7-12 years used elements such as record, quiz, and manga. This app can support the continuous self-management of pediatric asthma. However, efforts must be taken to maintain and improve the app quality. Trial RegistrationUMIN Clinical Trials Registry UMIN000039058; https://tinyurl.com/3na9zyf