Heliocentric Distance Dependence of Zodiacal Light Observed by Hayabusa2#

Zodiacal light (ZL) is sunlight scattered by interplanetary dust particles (IDPs) at optical wavelengths. The spatial distribution of IDPs in the Solar System may hold an important key to understanding the evolution of the Solar System and material transportation within it. The number density of IDPs can be expressed as $n(r) \sim r^{-\alpha}$, and the exponent $\alpha \sim 1.3$ was obtained by previous observations from interplanetary space by Helios 1/2 and Pioneer 10/11 in the 1970s and 1980s. However, no direct measurements of $\alpha$ based on ZL observations from interplanetary space outside Earth's orbit have been performed since then. Here, we introduce initial results for the radial profile of the ZL at optical wavelengths observed over the range 0.76-1.06 au by ONC-T aboard the Hayabusa2# mission in 2021-2022. The ZL brightness we obtained is well reproduced by a model brightness, although there is a small excess of the observed ZL brightness over the model brightness at around 0.9 au. The radial power-law index we obtained is $\alpha = 1.30 \pm 0.08$, which is consistent with previous results based on ZL observations. The dominant source of uncertainty arises from the uncertainty in estimating the diffuse Galactic light (DGL).Comment: 22 pages, 19 figures, 4 tables, accepted for publication by Earth, Planets and Spac

Вклад А.А.Вагина в развитие советской методики преподавания истории

В работе рассматривается вклад ученого-методиста Алексея Алексеевича Вагина в развитие советской методики преподавания истории в общеобразовательных школах

Recommendation Systems and Their Preference Prediction Algorithms in a Large-Scale Database

As the market of electronic commerce grows explosively, it becomes more and more important to provide the recommendation system which suggests the preferred items for consumers using the large-scale customers database. In this paper, we discuss the algorithms and their performances of the recommendation systems using the collaborative filtering in the case of the Netflix database: they are, 1) memory-based system (k-nearest neighbor using the correlation coefficients), 2) model-based system (matrix decomposition), and 3) the combination method. When the customer-item matrix is a sparse matrix like the Netflix database, the matrix decomposition method shows better performance than the k-nearrest neighbor; in addition, it is found that the combination method of the two methods provide a much better performance

Effects of in utero radiation exposure on lymphomagenesis in Mlh1-deficient mice

The Oxford Survey of Childhood Cancers after in utero exposure has demonstrated an increase in childhood lymphoma/leukemia. However, the potential role of fetal exposure in the increase of childhood cancers is still a matter of debate. Environmental and genetic factors, or combined effects of radiation with these factors need to be considered. Moreover, data are insufficient for estimation the cancer risk later in life after in utero exposure. We studied the effect of in utero exposure on lymphoma development using Mlh1-deficient mice, which are genetically prone to lymphoma. A germline mutation in MLH1, one of the DNA mismatch repair (MMR) genes associated with hereditary nonpolyposis colorectal cancer, causes childhood T- and B-cell leukemia, when homozygously defective. The tumors obtained from non-irradiated and in utero irradiated groups were diagnosed either thymic lymphoma or splenic lymphoma based on lymphoma-appearing anatomical site. Microsatellite instability in thymic lymphoma was higher than that in splenic lymphoma. According the cell-surface marker status, splenic lymphomas were further divided into two groups, T-cell origin (TCR+, CD4+ and CD8+) and B-cell origin (IgH+). Mutation analysis of Ikaros, Pax5 and Trp53 revealed that these genes were frequently mutated by one base insertion or deletion at mononucleotide repeat sequences, resulting in a frameshift mutation. Ikaros frameshift mutations were only found in thymic lymphomas, which were characterized TCR+, CD4+ and CD8+, indicating an immature T-cell. Trp53 frameshift mutation was found both T-cell and B-cell splenic lymphomas, the mutations were occurred about 50 % in each lymphoma with a heterozygous status. Pax5 frameshift mutations were found in a part of splenic lymphomas. Radiation exposure increased point mutations in these genes in both thymic and splenic lymphomas. Interestingly, in utero exposure significantly shortened the latency of B-cell origin splenic lymphomas only, but did not affect those of thymic lymphomas and T-cell origin splenic lymphoma. Our data demonstrated that B-cell lymphoma development is accelerated by in utero exposure in Mlh1-deficient mice. Hence, in utero exposure should be paid more attention especially to persons with MMR gene-deficient background.International scientific conference on early exposure and childhood cance

Temario Provisional. Foro sobre Educación para la reproducción y la paternidad responsable en Nicaragua.

The list of distinct transcripts identified in the priests. (XLSX 22 kb