Development of Attitude Sensor using Deep Learning

A new method for attitude determination utilizing color earth images taken with COTS visible light camera is presented. The traditional earth camera has been used for coarse attitude determination by detecting the edge of the earth, and therefore it can only provide coarse and 2-axis information. In contrast, our method recognizes the ground pattern with an accuracy of sub-degrees and can provide 3-axis attitude information by comparing the detected ground pattern and the global map. Moreover, this method has advantages in the size, mass and cost of the detector system which consists of a cheap optical color camera and a single board computer. To demonstrate the method in space, we have developed a sensor system named “Deep Learning Attitude Sensor (DLAS)”. DLAS uses COTS camera modules and single board computers to reduce the cost. The obtained images are promptly analyzed with a newly developed real-time image recognition algorithms

Variable Shape Attitude Control Demonstration with Microsat Hibari

This paper presents the ongoing feasibility study and bus system for microsatellite “Hibari”. The main technical missions for Hibari is called “Variable Shape Attitude Control (VSAC)”. This VSAC is based on an idea to utilize a reaction torque when a part of the satellite structure, for example, solar array paddles is appropriately rotated by actuators. The previous research concluded that VSAC successfully achieved the rapid maneuvering while maintain the high attitude stability against disturbances [1], and thus, it can be applied to a variety of advanced attitude control missions. Hibari project also aims at its application to astronomical mission requiring high pointing stability and agile maneuvering. This paper is mainly comprised of 3 parts: detail mission statement, ongoing feasibility studies and bus system configuration. First, we mention the mission requirement and detail mission sequence for both technical and science missions. Second, we show the ongoing feasibility studies to confirm that all mission requirement is satisfied by VSAC. Third, this paper describes each subsystem configuration to meet the system requirement stated in the mission’s section. And then, we wrap up in the conclusion section and stated the future study for advanced VSAC use in the end

The pros and cons of virtual networking events: online exploratory survey of psychiatrists’ opinions

We conducted an online questionnaire-based cross-sectional study to clarify psychiatrists’ perspectives on virtual networking events. We compared two groups of respondents: those who had participated in virtual networking events (experienced group, n = 85) and those who had not (inexperienced group, n = 13). The experienced group had a greater level of agreement than the inexperienced group that virtual events were generally useful and helped with forming professional relationships and improving professional skills. Respondents in the experienced group considered the ease of participation and low financial burden to be advantages of virtual networking meetings and difficulties in building friendships and socialising to be disadvantages

Development and Initial On-orbit Performance of Multi-Functional Attitude Sensor using Image Recognition

This paper describes a multi-functional attitude sensor mounted on the “Innovative Satellite 1st” led by Japan Aerospace Exploration Agency which was launched in January 2019. In order to achieve the high accuracy determination in low cost, we developed a novel attitude sensor utilizing real-time image recognition technology, named “Deep Learning Attitude Sensor (DLAS)”. DLAS has two type of attitude sensors: Star Tracker(STT) and Earth Camera (ECAM). For the low-cost development, we adopted commercial off-the-shelf cameras. DLAS uses real-time image recognition technology and a new attitude determination algorithm. In this paper, we present the missions, methods and system configuration of DLAS and initial results of on-orbit experiment that was conducted after the middle of February 2019, and it is confirmed that attitude determinations using ECAM and STT are performed correctly

Treatment algorithm of ACTH deficiency

Objective : To examine diagnostic performance of corticotropin-releasing hormone (CRH) test combined with baseline dehydroepiandrosterone sulfate (DHEA-S) in patients with a suspect of central adrenal insufficiency. Methods : Patients (n=215) requiring daily or intermittent hydrocortisone replacement, or no replacement were retrospectively checked with their peak cortisol after CRH test and baseline DHEA-S. Results : None of 106 patients with the peak cortisol ≥ 17.5 μg / dL after CRH test required replacement, and all 64 patients with the peak cortisol < 10.0 μg / dL required daily replacement. Among 8 patients with 10.0 μg / dL ≤ the peak cortisol < 17.5 μg / dL and baseline DHEA-S below the reference range, 6 patients required daily replacement and 1 patient was under intermittent replacement. Among 37 patients with 10.0 μg / dL ≤ the peak cortisol < 17.5 μg / dL and baseline DHEA-S within the reference range, 10 and 6 patients were under intermittent and daily replacement, respectively. Conclusions : No patients with the peak cortisol ≥ 17.5 μg / dL required hydrocortisone replacement, and all patients with the peak cortisol below 10.0 μg / dL required daily replacement. Careful clinical evaluation was required to determine requirement for replacement in patients with 10.0 μg / dL ≤ the peak cortisol < 17.5 μg / dL even in combination with baseline DHEA-S

The <i>Saccharomyces cerevisiae</i> AMPK, Snf1, Negatively Regulates the Hog1 MAPK Pathway in ER Stress Response

<div><p>Accumulation of unfolded proteins in the lumen of the endoplasmic reticulum (ER) causes ER stress. Snf1, the <i>Saccharomyces cerevisiae</i> ortholog of AMP–activated protein kinase (AMPK), plays a crucial role in the response to various environmental stresses. However, the role of Snf1 in ER stress response remains poorly understood. In this study, we characterize Snf1 as a negative regulator of Hog1 MAPK in ER stress response. The <i>snf1</i> mutant cells showed the ER stress resistant phenotype. In contrast, Snf1-hyperactivated cells were sensitive to ER stress. Activated Hog1 levels were increased by <i>snf1</i> mutation, although Snf1 hyperactivation interfered with Hog1 activation. Ssk1, a specific activator of MAPKKK functioning upstream of Hog1, was induced by ER stress, and its induction was inhibited in a manner dependent on Snf1 activity. Furthermore, we show that the <i>SSK1</i> promoter is important not only for Snf1-modulated regulation of Ssk1 expression, but also for Ssk1 function in conferring ER stress tolerance. Our data suggest that Snf1 downregulates ER stress response signal mediated by Hog1 through negatively regulating expression of its specific activator Ssk1 at the transcriptional level. We also find that <i>snf1</i> mutation upregulates the unfolded protein response (UPR) pathway, whereas Snf1 hyperactivation downregulates the UPR activity. Thus, Snf1 plays pleiotropic roles in ER stress response by negatively regulating the Hog1 MAPK pathway and the UPR pathway.</p></div

Proposed model for Snf1-mediated Hog1 regulation in ER stress response.

<p>Left panel. In the absence of ER stress, Ssk1 is inactivated through phosphorylation mediated by the upstream phosphorelay system. Right panel. In the presence of ER stress, increased expression of Ssk1 leads to accumulation of dephosphorylated Ssk1 and consequent activation of the Hog1 MAPK cascade. ER stress also induces the activation of Snf1. Activated Snf1 downregulates the signaling from Ssk1 by inhibiting Ssk1 expression.</p

Snf1 phosphorylation is important for its role in ER stress response.

<p>(A) Effect of tunicamycin on Snf1 activity. Wild-type (WT) cells were grown at 25°C until exponential phase and treated with 2 μg/ml tunicamycin (TM) for the indicated time. Extracts prepared from each cell were immunoblotted with anti-phospho-AMPK (P-Snf1) and anti-Snf1 antibodies. (B) Effect of DTT on Snf1 activity. Wild-type (WT) cells were grown at 25°C until exponential phase and treated with 4 mM dithiothreitol (DTT) for the indicated time. Immunoblot was performed as described in (A). The intensities of phosphorylated Snf1 were measured and normalized to total Snf1 level. The values are plotted as the fold change from cells at the time of DTT addition. The data show mean ± SEM (n = 4). *<i>P</i> < 0.05 as determined by Student’s <i>t</i>-test. (C) Effects of the <i>sak1</i>Δ <i>tos3</i>Δ <i>elm1</i>Δ mutations on ER stress-induced Snf1 activation. Wild-type (WT) and <i>sak1</i>Δ <i>tos3</i>Δ <i>elm1</i>Δ mutant strains were grown at 25°C until exponential phase and treated with 2 μg/ml tunicamycin (TM) for the indicated time. Immunoblot was performed as described in (A). (D) Effects of the <i>reg1</i>Δ mutation on ER stress-induced Snf1 activation. Wild-type (WT) and <i>reg1</i>Δ mutant strains were analyzed as described in (C). (E) ER stress sensitivity in the <i>snf1</i>Δ mutants expressing a phospho-defective form of Snf1. Wild-type (WT) and <i>snf1</i>Δ mutant strains harboring the indicated multicopy plasmids were spotted onto SD medium lacking or containing 1.5 μg/ml tunicamycin (TM) and incubated at 25°C. Wild-type Snf1 and Snf1(T210A) proteins were expressed in comparable amounts as shown in <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005491#pgen.1005491.s005" target="_blank">S3E Fig</a>. (F) ER stress resistance caused by deletion of the genes encoding the upstream kinases of the Snf1 complex. Wild-type (WT) and <i>sak1</i>Δ <i>tos3</i>Δ <i>elm1</i>Δ mutant strains were spotted onto YPD medium lacking or containing 1.5 μg/ml tunicamycin (TM) and incubated at 25°C. (G) ER stress sensitivity caused by deletion of the <i>reg1</i> gene. Wild-type (WT) and <i>reg1</i>Δ, <i>snf1</i>Δ, and <i>reg1</i>Δ <i>snf1</i>Δ mutant strains were spotted as described in (F). (H) DTT sensitivity of the <i>snf1</i>Δ and <i>reg1</i>Δ mutants. The mean of the DTT sensitivity index was shown with standard errors (n = 4). **<i>P</i> < 0.01 as determined by Student’s <i>t</i>-test.</p

Snf1 negatively regulates the expression level of <i>SSK1</i> mRNA.

<p>(A) Effects of the <i>snf1</i>Δ and <i>reg1</i>Δ mutations on ER stress-induced upregulation of <i>SSK1</i> mRNA. Wild-type (WT) and <i>snf1</i>Δ, <i>reg1</i>Δ, and <i>reg1</i>Δ <i>snf1</i>Δ mutant strains were grown at 25°C until exponential phase and treated with 4 mM dithiothreitol (DTT) for the indicated time. The mRNA levels were quantified by qRT-PCR analysis, and relative mRNA levels were calculated using <i>ACT1</i> mRNA. The data show mean ± SEM (n = 3). *<i>P</i> < 0.05 as determined by Student’s <i>t</i>-test. (B) Schematic representation of the structure of <i>P</i>_<i>SSK1</i><i>-GFP</i> and <i>P</i>_<i>MCM2</i><i>-GFP</i>. (C) Effects of ER stress on expression of <i>P</i>_<i>SSK1</i><i>-GFP</i> and <i>P</i>_<i>MCM2</i><i>-GFP</i> reporters. Wild-type (WT) cells harboring the indicated plasmids were grown at 25°C until exponential phase and treated with 4 mM dithiothreitol (DTT) for the indicated time. Extracts prepared from each cell were immunoblotted with anti-GFP and anti-Mcm2 antibodies. (D) Effects of the <i>snf1</i>Δ and <i>reg1</i>Δ mutation on <i>SSK1</i> promoter activity. Wild-type (WT) and <i>reg1</i>Δ and <i>reg1</i>Δ <i>snf1</i>Δ mutant strains harboring the integration which expresses GFP under the control of <i>SSK1</i> promoter were grown at 25°C until exponential phase and treated with 4 mM dithiothreitol (DTT) for the indicated time. Extracts prepared from each cell were immunoblotted with anti-GFP and anti-Mcm2 antibodies. The intensities of GFP were measured and normalized to Mcm2 level. The values are plotted as the fold change from wild-type cells at the time of DTT addition. The data show mean ± SEM (n = 4). *<i>P</i> < 0.05 and **<i>P</i> < 0.01 as determined by Student’s <i>t</i>-test. (E) ER stress sensitivity in the <i>ssk1</i>Δ mutants. Wild-type (WT) and <i>ssk1</i>Δ mutant strains carrying the empty, <i>P</i>_<i>SSK1</i><i>-SSK1</i>, or <i>P</i>_<i>MCM2</i><i>-SSK1</i> plasmids were spotted onto YPD medium lacking or containing 1 μg/ml tunicamycin (TM) and incubated at 25°C. (F) Osmotic stress sensitivity in the <i>ssk1</i>Δ mutants. Wild-type (WT) and <i>ssk1</i>Δ <i>sho1</i>Δ mutant strains carrying the empty, <i>P</i>_<i>SSK1</i><i>-SSK1</i>, or <i>P</i>_<i>MCM2</i><i>-SSK1</i> plasmids were spotted onto YPD medium lacking or containing 1 M sodium chloride (NaCl) and incubated at 25°C.</p

Snf1 downregulates the protein level of Ssk1.

<p>(A, B) Genetic interaction between the <i>ypd1</i>Δ, <i>sln1</i>Δ and <i>reg1</i>Δ mutations. Diploid <i>ypd1</i>Δ/<i>YPD1 reg1</i>Δ/<i>REG1</i> and <i>sln1</i>Δ/<i>SLN1 reg1</i>Δ/<i>REG1</i> yeast cells were sporulated, dissected on YPD plates and the meiotic products were incubated for 4 days at 25°C. Each genotype was shown in the right panel. Wild-type cells were labeled with W. The <i>ypd1</i>Δ, <i>sln1</i>Δ, and <i>reg1</i>Δ mutations were labeled with y, s, and r, respectively. (C) Effects of hyperosmotic stress on Ssk1 expression. Wild-type (WT) cells harboring Myc-tagged <i>SSK1</i> were grown at 25°C until exponential phase and treated with 0.4 M sodium chloride (NaCl) for the indicated time. Extracts prepared from each cell were immunoblotted with anti-Myc (Ssk1-Myc) and anti-Mcm2 antibodies. The intensities of Ssk1-Myc were measured and normalized to Mcm2 level. The values are plotted as the fold change from cells at the time of NaCl addition. The data show mean ± SEM (n = 4). The statistical difference was determined by Student’s <i>t</i>-test. ns, not significant. (D) Effects of the <i>snf1</i>Δ mutation on ER stress-induced upregulation of Ssk1. Wild-type (WT) and <i>snf1</i>Δ mutant strains harboring Myc-tagged <i>SSK1</i> were grown at 25°C until exponential phase and treated with 4 mM dithiothreitol (DTT) for the indicated time. Immunoblot was performed as described in (C). The intensities of Ssk1-Myc were measured and normalized to the Mcm2 level. The values are plotted as the fold change from wild-type cells at the time of DTT addition. The data show mean ± SEM (n = 4). *<i>P</i> < 0.05 as determined by Student’s <i>t</i>-test. (E) Effects of the <i>reg1</i>Δ and <i>snf1</i>Δ mutations on DTT-induced upregulation of Ssk1. Wild-type (WT) and <i>reg1</i>Δ and <i>reg1</i>Δ <i>snf1</i>Δ mutant strains harboring Myc-tagged <i>SSK1</i> were analyzed as described in (D). The data show mean ± SEM (n = 4). *<i>P</i> < 0.05 and **<i>P</i> < 0.01 as determined by Student’s <i>t</i>-test. (F) Effects of the <i>snf1</i>Δ and <i>reg1</i>Δ mutations on tunicamycin-induced upregulation of Ssk1. Wild-type (WT) and <i>reg1</i>Δ and <i>reg1</i>Δ <i>snf1</i>Δ mutant strains harboring Myc-tagged <i>SSK1</i> were grown at 25°C until exponential phase and treated with 2 μg/ml tunicamycin (TM) for the indicated time. Immunoblot was performed as described in (C). (G) Effects of the <i>ssk1</i>Δ and <i>snf1</i>Δ mutations on ER stress-induced Hog1 activation. Wild-type (WT) and <i>ssk1</i>Δ, and <i>snf1</i>Δ <i>ssk1</i>Δ mutant strains were grown at 25°C until exponential phase and treated with 4 mM dithiothreitol (DTT) for the indicated time. Extracts prepared from each cell were immunoblotted with anti-phospho-p38 (P-Hog1) and anti-Hog1 antibodies. (H) ER stress sensitivity in the <i>snf1</i>Δ <i>ssk1</i>Δ mutants. Wild-type (WT) and <i>ssk1</i>Δ, <i>snf1</i>Δ, and <i>snf1</i>Δ <i>ssk1</i>Δ mutant strains were spotted onto YPD medium lacking or containing 1 or 1.5 μg/ml tunicamycin (TM) and incubated at 25°C.</p