194 research outputs found

    Subaru Observations for the K-band Luminosity Distribution of Galaxies in Clusters near to 3C 324 at z\sim1.2

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    We investigate the KK-band luminosity distribution of galaxies in the region of clusters at z1.2z\sim1.2 near to the radio galaxy 3C 324. The imaging data were obtained during the commissioning period of the Subaru telescope. There is a significant excess of the surface number density of the galaxies with K=K = 17--20 mag in the region within \sim 40'' from 3C 324. At this bright end, the measured luminosity distribution shows a drop, which can be represented by the exponential cut off of the Schechter-function formula; the best-fitted value of the characteristic magnitude, KK^{*}, is 18.4±0.8\sim 18.4\pm0.8. This measurement follows the evolutionary trend of the KK^* of the rich clusters observed at an intermediate redshift, which is consistent with passive evolution models with a formation redshift z_f \gtsim 2. At K \gtsim 20 mag, however, the excess of the galaxy surface density in the region of the clusters decreases abruptly, which may imply that the luminosity function of the cluster galaxies has a negative slope at the faint end. This may imply strong luminosity segregation between the inner and outer parts of the clusters, or some deficit of faint galaxies in the cluster central region of the cluster.Comment: 12 pages, 9 figures, accepted for publication in PAS

    High-Resolution Near-Infrared Imaging of the Powerful Radio Galaxy 3C 324 at z = 1.21 with the Subaru Telescope

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    We have obtained high-resolution K'-band images of the powerful z=1.206 radio galaxy 3C 324 with the Subaru telescope under seeing conditions of 0.3--0.4 arcsec. We clearly resolved the galaxy and directly compared it to the optical images obtained with the Hubble Space Telescope. The host galaxy of 3C 324 is revealed to be a moderately luminous elliptical galaxy with a smooth light profile. The effective radius of the galaxy, as determined by profile fitting, is 1.3+-0.1 arcsec (1.2 kpc), which is significantly smaller than the value of 2.2 arcsec, published in Best et al. (1998, MNRAS, 292, 758). The peak of the K'-band light coincides with the position of the radio core, which implies that the powerful AGN lies at the nucleus of the host galaxy. The peak also coincides with the gap in the optical knotty structures which may be a dust lane hiding the UV-optical emission of the AGN from our line of sight; it is very likely that we are seeing the obscuring structure almost edge-on. We clearly detected the `aligned component' in the K'-band image by subtracting a model elliptical galaxy from the observed image. The red R_F702W-K color of the outer region of the galaxy avoiding the aligned component indicates that the near infrared light of the host galaxy is dominated by an old stellar population.Comment: 21 pages (10 figures), accepted for publication in PAS

    Elevated levels of plasma lactate dehydrogenase is an unfavorable prognostic factor in patients with epidermal growth factor receptor mutation-positive non-small cell lung cancer, receiving treatment with gefitinib or erlotinib.

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    Treatment with epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) has been shown to prolong survival in patients with EGFR mutation-positive non-small cell lung cancer (NSCLC). The present study performed a retrospective analysis to investigate the association between the plasma lactate dehydrogenase (LDH) levels and survival in patients with EGFR mutation-positive NSCLC receiving treatment with EGFR-TKIs. The medical charts of patients with EGFR mutation-positive NSCLC who were receiving treatment with EGFR-TKIs at Toyama University Hospital between 2007 and 2014 were assessed. The data from 65 patients were included in the analysis. Patients with higher plasma LDH levels exhibited shorter progression-free survival (6.2 vs. 13.2 months; P<0.01) and overall survival (10.5 vs. 36.1 months; P<0.01) periods compared with patients with lower plasma LDH levels. A Cox proportional hazards model identified that the plasma LDH level was associated with the progression-free survival (P=0.05) and overall survival (P<0.01). An association was demonstrated between the pretreatment plasma LDH level and the survival in patients with EGFR mutation-positive NSCLC receiving treatment with EGFR-TKIs. Close observation is required in EGFR mutation-positive NSCLC patients exhibiting high plasma LDH levels following the initiation of treatment with EGFR-TKIs.出版社サイトへのリンク:https://doi.org/10.3892/mco.2016.77

    Plasma neuron-specific enolase level as a prognostic marker in patients with non-small cell lung cancer receiving gefitinib.

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    Determination of the presence of epidermal growth factor receptor (EGFR) gene mutation is useful for predicting the efficacy of gefitinib. However, the survival rate following the initiation of treatment with gefitinib varies among individuals. A retrospective study was conducted to investigate the associations of the pretreatment serum pro-gastrin-releasing peptide (pro-GRP) and plasma neuron-specific enolase (NSE) levels to the patient survival rate following initiation of treatment with gefitinib in non-small cell lung cancer (NSCLC) patients receiving gefitinib treatment. Patients with NSCLC harboring EGFR gene mutations who received gefitinib therapy between 2004 and 2012 were included in the study. Data from a total of 41 patients were analyzed. The serum pro-GRP level was measured in 31 patients and the plasma NSE in 22 patients. The progression-free survival (PFS) (P=0.013) and overall survival (OS) (P=0.014, log-rank test) rates decreased as the plasma NSE level increased. Statistical analysis using a Cox proportional hazards regression model adjusted for age, gender, performance status (PS) and disease stage showed that higher NSE levels were associated with shorter PFS (P=0.021) and OS (P=0.0024). By contrast, no association was detected between the serum level of pro-GRP and survival rate. The results suggest that pretreatment NSE measurement could be clinically useful in patients with NSCLC scheduled to receive gefitinib treatment.出版社サイトへのリンク: https://doi.org/10.3892/mco.2015.56

    Functional Sperm of the Yellowtail (Seriola quinqueradiata) Were Produced in the Small-Bodied Surrogate, Jack Mackerel (Trachurus japonicus).

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    Production of xenogeneic gametes from large-bodied, commercially important marine species in closely related smaller surrogates with short generation times may enable rapid domestication of the targeted species. In this study we aimed to produce gametes of Japanese yellowtail (Seriola quinqueradiata) using jack mackerel (Trachurus japonicus) as a surrogate with a smaller body size and shorter maturation period. Donor spermatogonia were collected from the testes of yellowtail males and transferred into the peritoneal cavity of 10- and 12-day-old jack mackerel larvae. Twenty days later, 59.5% of the recipients survived of which 88.2% had donor-derived germ cells in their gonads. One year later, genomic DNA templates were prepared from the semen of 96 male recipients and subjected to PCR analyses using primers specific for the yellowtail vasa sequence, resulting in the detection of positive signals in semen from two recipients. The milt collected from the recipients was used for fertilization with yellowtail eggs. Of eight hatchlings obtained from the crosses, two were confirmed to be derived from donor yellowtail by DNA markers, although the others were gynogenetic diploids. These findings indicate that it is possible to produce donor-derived sperm in xenogeneic recipients with smaller body size and shorter generation time by transplanting spermatogonia. Thus, the xenogeneic transplantation of spermatogonia might be a potential tool to produce gametes of large-bodied, commercially important fish although the efficiency of the method requires further improvement. This is the first report demonstrating that donor-derived sperm could be produced in xenogeneic recipient via spermatogonial transplantation in carangid fishes

    Citizen science "Thundercloud Project" -- multi-point radiation measurements of gamma-ray glows from accelerated electrons in thunderstorms

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    38th International Cosmic Ray Conference (ICRC2023), 26 July - 3 August, 2023, Nagoya, JapanIt has been a long-standing question whether cosmic rays promote the triggering of lightning and how cosmic-ray air showers interact with the electric field of thunderclouds. The strong electric field in the thunderclouds accelerates electrons to the relativistic regime, of which seed electrons are thought to be supplied from cosmic-ray air shower. Such relativistic electrons emit bremsstrahlung photons in gamma rays, which have been detected by on-ground measurements called gamma-ray glows. Low-altitude winter thunderstorm in Japan provides an ideal environment for observations of gamma-ray glows. We newly launched the citizen science ``Thundercloud Project" to construct a multi-point radiation mapping campaign for glows from winter thunderstorms around Kanazawa, Japan. We developed a new handy radiation monitor and shipped about 60 detectors to citizen supporters. The radiation data are stored in the microSD cards in the detectors, and a part of them is remotely sent to the web server so that researchers and supporters can watch the real-time data. In addition, an automatic alert is sent to public Twitter from the server when a glow is detected. The purpose of this project is (1) to characterize the methodological condition of electron acceleration, (2) to investigate whether accelerated relativistic electrons can enhance the chance of the initiation of lightning discharges, and (3) to find a new way of the citizen science to join in the cutting edge science in the physics field. Here we report this growing citizen science project and examples of successful gamma-ray glow observations. Our first scientific result from this citizen science project was published in Tsurumi et al., GRL 2023, where we reported lightning discharges started in or near the electron acceleration site of a gamma-ray glow

    Search for Outer Massive Bodies around Transiting Planetary Systems: Candidates of Faint Stellar Companions around HAT-P-7

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    We present results of direct imaging observations for HAT-P-7 taken with the Subaru HiCIAO and the Calar Alto AstraLux. Since the close-in transiting planet HAT-P-7b was reported to have a highly tilted orbit, massive bodies such as giant planets, brown dwarfs, or a binary star are expected to exist in the outer region of this system. We show that there are indeed two candidates for distant faint stellar companions around HAT-P-7. We discuss possible roles played by such companions on the orbital evolution of HAT-P-7b. We conclude that as there is a third body in the system as reported by Winn et al. (2009, ApJL, 763, L99), the Kozai migration is less likely while planet-planet scattering is possible.Comment: 8 pages, 3 figures, 2 tables, PASJ in pres
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