CAMELOT: Design and performance verification of the detector concept and localization capability

A fleet of nanosatellites using precise timing synchronization provided by the Global Positioning System is a new concept for monitoring the gamma-ray sky that can achieve both all-sky coverage and good localization accuracy. We are proposing this new concept for the mission CubeSats Applied for MEasuring and LOcalising Transients (CAMELOT). The differences in photon arrival times at each satellite are to be used for source localization. Detectors with good photon statistics and the development of a localization algorithm capable of handling a large number of satellites are both essential for this mission. Large, thin CsI scintillator plates are the current candidates for the detectors because of their high light yields. It is challenging to maximize the light-collection efficiency and to understand the position dependence of such thin plates. We have found a multi-channel readout that uses the coincidence technique to be very effective in increasing the light output while keeping a similar noise level to that of a single channel readout. Based on such a detector design, we have developed a localization algorithm for this mission and have found that we can achieve a localization accuracy better than 20 arc minutes and a rate of about 10 short gamma-ray bursts per year

CAMELOT: Cubesats Applied for MEasuring and LOcalising Transients mission overview

We propose a fleet of nanosatellites to perform an all-sky monitoring and timing based localisation of gamma-ray transients. The fleet of at least nine 3U cubesats shall be equipped with large and thin CsI(Tl) scintillator based soft gamma-ray detectors read out by multi-pixel photon counters. For bright short gamma-ray bursts (GRBs), by cross-correlating their light curves, the fleet shall be able to determine the time difference of the arriving GRB signal between the satellites and thus determine the source position with an accuracy of similar to 10'. This requirement demands precise time synchronization and accurate time stamping of the detected gamma-ray photons, which will be achieved by using on-board GPS receivers. Rapid follow up observations at other wavelengths require the capability for fast, nearly simultaneous downlink of data using a global inter-satellite communication network. In terms of all-sky coverage, the proposed fleet will outperform all GRB monitoring missions

Optimality of mutation and selection in germinal centers

The population dynamics theory of B cells in a typical germinal center could play an important role in revealing how affinity maturation is achieved. However, the existing models encountered some conflicts with experiments. To resolve these conflicts, we present a coarse-grained model to calculate the B cell population development in affinity maturation, which allows a comprehensive analysis of its parameter space to look for optimal values of mutation rate, selection strength, and initial antibody-antigen binding level that maximize the affinity improvement. With these optimized parameters, the model is compatible with the experimental observations such as the ~100-fold affinity improvements, the number of mutations, the hypermutation rate, and the "all or none" phenomenon. Moreover, we study the reasons behind the optimal parameters. The optimal mutation rate, in agreement with the hypermutation rate in vivo, results from a tradeoff between accumulating enough beneficial mutations and avoiding too many deleterious or lethal mutations. The optimal selection strength evolves as a balance between the need for affinity improvement and the requirement to pass the population bottleneck. These findings point to the conclusion that germinal centers have been optimized by evolution to generate strong affinity antibodies effectively and rapidly. In addition, we study the enhancement of affinity improvement due to B cell migration between germinal centers. These results could enhance our understandings to the functions of germinal centers.Comment: 5 figures in main text, and 4 figures in Supplementary Informatio

Effect of tempering treatment upon the residual stress of bimetallic roll

2018 International Conference on Material Strength and Applied Mechanics (MSAM 2018), 10–13 April, 2018, Kitakyushu City, Japa

CubeSats in Support of Astrophysics, GRBAlpha and Beyond

Space science, including the field of astrophysics, is continuously finding innovative use cases for small satellites and CubeSat platforms. These missions support efforts in the democratisation and improved accessibility of space technologies. GRBAlpha, as one of such missions, is a 1U CubeSat carrying an experimental payload for the detection of gamma-ray bursts (GRB)

Identification of a novel human memory T cell population with the characteristics of stem-like chemo-resistance

我々は新しいヒトCD8+免疫記憶T幹細胞であるYoung memory T（TYM）細胞を同定した。TYM細胞は高い増殖能，多分化能，抗がん剤耐性を持ちウイルス免疫および癌免疫に関わっている。TYM細胞の制御が今後の免疫療法の効果の増強に重要と考える

Immunohistological analysis of pancreatic carcinoma after vaccination with survivin 2B peptide: Analysis of an autopsy series.

当教室では本学消化器・総合，乳腺・内分泌外科および東京大学医科学研究所，神奈川県立がんセンターと共同で有効な治療法のない進行膵臓がん患者にサバイビン2Bペプチドワクチンを用いた無作為化二重盲検群間比較試験を行った．本研究では上記の臨床試験参加者に対して施行された病理解剖組織検体を用いて腫瘍微小環境における免疫学的効果の判定を目的として，対照群を含む13例（うち7例がワクチン投与群）の病理解剖検体組織を用いて腫瘍組織局所における各種の免疫細胞浸潤の評価した

Lack of association between polymorphisms of the IL18R1 and IL18RAP genes and cardiovascular risk: the MORGAM Project

<p>Abstract</p> <p>Background</p> <p>Interleukin-18 is a pro-inflammatory cytokine suspected to be associated with atherosclerosis and its complications. We had previously shown that one single nucleotide polymorphism (SNP) of the <it>IL18 </it>gene was associated with cardiovascular disease (CVD) through an interaction with smoking. As a further step for elucidating the contribution of the IL-18 pathway to the etiology of CVD, we here investigated the association between the genetic variability of two IL-18 receptor genes, <it>IL18R1 </it>and <it>IL18RAP</it>, with the risk of developing CVD.</p> <p>Methods</p> <p>Eleven tagging SNPs, 5 in <it>IL18R1 </it>and 6 in <it>IL18RAP</it>, characterizing the haplotypic variability of the corresponding genes; were genotyped in 5 European prospective CVD cohorts including 1416 cases and 1772 non-cases, as part of the MORGAM project. Both single-locus and haplotypes analyses were carried out to investigate the association of these SNPs with CVD.</p> <p>Results</p> <p>We did not find any significant differences in allele, genotype and haplotype frequencies between cases and non-cases for either of the two genes. Moreover, the search for interactions between SNPs located in different genes, including 5 <it>IL18 </it>SNPs previously studied in the MORGAM project, and between SNPs and environmental factors remained unfruitful.</p> <p>Conclusion</p> <p>Our analysis suggests that the variability of <it>IL18R1 </it>and <it>IL18RAP </it>genes are unlikely to contribute to modulate the risk of CVD.</p