234 research outputs found

    Higgsinoless Supersymmetry and Hidden Gravity

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    We present a simple formulation of non-linear supersymmetry where superfields and partnerless fields can coexist. Using this formalism, we propose a supersymmetric Standard Model without the Higgsino as an effective model for the TeV-scale supersymmetry breaking scenario. We also consider an application of the Hidden Local Symmetry in non-linear supersymmetry, where we can naturally incorporate a spin-two resonance into the theory in a manifestly supersymmetric way. Possible signatures at the LHC experiments are discussed.Comment: 30 pages, 3 figures, references added, version to appear in JHE

    The Halpha Luminosity Function of the Galaxy Cluster Abell 521 at z = 0.25

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    We present an optical multicolor-imaging study of the galaxy cluster Abell 521 at z=0.25z = 0.25, using Suprime-Cam on the Subaru Telescope, covering an area of 32×2032 \times 20 arcmin2^2 (9.4×5.8h5029.4 \times 5.8 h_{50}^{-2} Mpc2^2 at z=0.25z = 0.25). Our imaging data taken with both a narrow-band filter, NB816NB816 (λ0=8150\lambda_0 = 8150\AA and Δλ=120\Delta \lambda = 120\AA), and broad-band filters, B,V,RC,iB,V,R_{\rm C}, i^\prime, and zz^\prime allow us to find 165 Hα\alpha emitters. We obtain the Hα\alpha luminosity function (LF) for the cluster galaxies within 2 Mpc; the Schechter parameters are α=0.75±0.23\alpha = -0.75 \pm 0.23, ϕ=100.25±0.20\phi^\star = 10^{-0.25 \pm 0.20} Mpc3^{-3}, and L=1042.03±0.17L^\star = 10^{42.03 \pm 0.17} erg s1^{-1}. Although the faint end slope, α\alpha, is consistent with that of the local cluster Hα\alpha LFs, the characteristic luminosity, LL^\star, is about 6 times (or 2\approx 2 mag) brighter. This strong evolution implies that Abell 521 contains more active star-forming galaxies than the local clusters, being consistent with the observed Butcher-Oemler effect. However, the bright LL^\star of Abell 521 may be, at least in part, due to the dynamical condition of this cluster.Comment: 21 pages, 7 figures, ApJ, Part 1, in pres

    The HI content of star-forming galaxies at z = 0.24

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    We use observations from the Giant Metrewave Radio Telescope (GMRT) to measure the atomic hydrogen gas content of star-forming galaxies at z = 0.24 (i.e. a look-backtime of ~3 Gyr). The sample of galaxies studied were selected from Halpha-emitting field galaxies detected in a narrow-band imaging survey with the Subaru Telescope. The Anglo-Australian Telescope was used to obtain precise optical redshifts for these galaxies. We then coadded the HI 21 cm emission signal for all the galaxies within the GMRT spectral line data cube. From the coadded signal of 121 galaxies, we measure an average atomic hydrogen gas mass of (2.26 +- 0.90)*10^9 solar masses. We translate this HI signal into a cosmic density of neutral gas at z = 0.24 of Omega_gas = (0.91 +- 0.42)*10^-3. This is the current highest redshift at which Omega_gas has been constrained from 21 cm emission and our value is consistent with that estimated from damped Lyman-alpha systems around this redshift. We also find that the correlations between the Halpha luminosity and the radio continuum luminosity and between the star formation rate and the HI gas content in star-forming galaxies at z = 0.24 are consistent with the correlations found at z = 0. These two results suggest that the star formation mechanisms in field galaxies ~3 Gyr ago were not substantially different from the present, even though the star formation rate is 3 times higher.Comment: 11 pages, contains 9 figures and 1 table. Accepted for publishing in MNRAS 2007 January 22. Received 2007 January 22; in original form 2006 November 3

    Expression of human mutant cyclin dependent kinase 4, Cyclin D and telomerase extends the life span but does not immortalize fibroblasts derived from loggerhead sea turtle (Caretta caretta)

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    Conservation of the genetic resources of endangered animals is crucial for future generations. The loggerhead sea turtle (Caretta caretta) is a critically endangered species, because of human hunting, hybridisation with other sea turtle species, and infectious diseases. In the present study, we established primary fibroblast cell lines from the loggerhead sea turtle, and showed its species specific chromosome number is 2n = 56, which is identical to that of the hawksbill and olive ridley sea turtles. We first showed that intensive hybridization among multiple sea turtle species caused due to the identical chromosome number, which allows existence of stable hybridization among the multiple sea turtle species. Expressions of human-derived mutant Cyclin-dependent kinase 4 (CDK4) and Cyclin D dramatically extended the cell culture period, when it was compared with the cell culture period of wild type cells. The recombinant fibroblast cell lines maintained the normal chromosome condition and morphology, indicating that, at the G1/S phase, the machinery to control the cellular proliferation is evolutionally conserved among various vertebrates. To our knowledge, this study is the first to demonstrate the functional conservation to overcome the negative feedback system to limit the turn over of the cell cycle between mammalian and reptiles. Our cell culture method will enable the sharing of cells from critically endangered animals as research materials

    Multicentre multiobserver study of diffusion-weighted and fluid-attenuated inversion recovery MRI for the diagnosis of sporadic Creutzfeldt–Jakob disease: a reliability and agreement study

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    Objectives: To assess the utility of the display standardisation of diffusion-weighted MRI (DWI) and to compare the effectiveness of DWI and fluid-attenuated inversion recovery (FLAIR) MRI for the diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD). Design: A reliability and agreement study. Setting: Thirteen MRI observers comprising eight neurologists and five radiologists at two universities in Japan. Participants: Data of 1.5-Tesla DWI and FLAIR were obtained from 29 patients with sCJD and 13 controls. Outcome measures: Standardisation of DWI display was performed utilising b0 imaging. The observers participated in standardised DWI, variable DWI (the display adjustment was observer dependent) and FLAIR sessions. The observers independently assessed each MRI for CJD-related lesions, that is, hyperintensity in the cerebral cortex or striatum, using a continuous rating scale. Performance was evaluated by the area under the receiver operating characteristics curve (AUC). Results: The mean AUC values were 0.84 (95% CI 0.81 to 0.87) for standardised DWI, 0.85 (95% CI 0.82 to 0.88) for variable DWI and 0.68 (95% CI 0.63 to 0.72) for FLAIR, demonstrating the superiority of DWI (p<0.05). There was a trend for higher intraclass correlations of standardised DWI (0.74, 95% CI 0.66 to 0.83) and variable DWI (0.72, 95% CI 0.62 to 0.81) than that of FLAIR (0.63, 95% CI 0.53 to 0.74), although the differences were not statistically significant. Conclusions: Standardised DWI is as reliable as variable DWI, and the two DWI displays are superior to FLAIR for the diagnosis of sCJD. The authors propose that hyperintensity in the cerebral cortex or striatum on 1.5-Tesla DWI but not FLAIR can be a reliable diagnostic marker for sCJD

    Reliability of DWI and FLAIR for diagnosis of sporadic CJD

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    Objectives: To assess the utility of the display standardisation of diffusion-weighted MRI (DWI) and to compare the effectiveness of DWI and fluid-attenuated inversion recovery (FLAIR) MRI for the diagnosis of sporadic Creutzfeldte–Jakob disease (sCJD). Design: A reliability and agreement study. Setting: Thirteen MRI observers comprising eight neurologists and five radiologists at two universities in Japan. Participants: Data of 1.5-Tesla DWI and FLAIR were obtained from 29 patients with sCJD and 13 controls. Outcome measures: Standardisation of DWI display was performed utilising b0 imaging. The observers participated in standardised DWI, variable DWI (the display adjustment was observer dependent) and FLAIR sessions. The observers independently assessed each MRI for CJD-related lesions, that is, hyperintensity in the cerebral cortex or striatum, using a continuous rating scale. Performance was evaluated by the area under the receiver operating characteristics curve (AUC). Results: The mean AUC values were 0.84 (95% CI 0.81 to 0.87) for standardised DWI, 0.85 (95% CI 0.82 to 0.88) for variable DWI and 0.68 (95% CI 0.63 to 0.72) for FLAIR, demonstrating the superiority of DWI (p<0.05). There was a trend for higher intraclass correlations of standardised DWI (0.74, 95% CI 0.66 to 0.83) and variable DWI (0.72, 95% CI 0.62 to 0.81) than that of FLAIR (0.63, 95% CI 0.53 to 0.74), although the differences were not statistically significant. Conclusions: Standardised DWI is as reliable as variable DWI, and the two DWI displays are superior to FLAIR for the diagnosis of sCJD. The authors propose that hyperintensity in the cerebral cortex or striatum on 1.5-Tesla DWI but not FLAIR can be a reliable diagnostic marker for sCJD

    Innovative TEM-coupled approaches to study foraminiferal cells

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    © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Marine Micropaleontology 138 (2018): 90-104, doi:10.1016/j.marmicro.2017.10.002.Transmission electron microscope (TEM) observation has revealed much about the basic cell biology of foraminifera. Yet, there remains much we do not know about foraminiferal cytology and physiology, especially for smaller benthic foraminifera, which inhabit a wide range of habitats. Recently, some TEM-coupled approaches have been developed to study correlative foraminiferal ecology and physiology in detail: Fluorescently Labeled Embedded Core (FLEC)-TEM for observing foraminiferal life-position together with their cytoplasmic ultrastructure, micro-X-ray computed tomography (CT)-TEM for observing and reconstructing foraminiferal cytoplasm in three dimensions (3D), and TEM-Nanometer-scale secondary ion mass spectrometry (NanoSIMS) for mapping of elemental and isotopic compositions at sub-micrometer resolutions with known ultrastructure. In this contribution, we review and illustrate these recent advances of TEM-coupled methods.This work was financially supported by the Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology, Japan (Scientific Research (C) grant number 17K05697 to HN) and the Swiss National Science Foundation (grant no. 200021_149333). JMB’s contributions were funded by US NSF grants OCE-0551001 and OCE-1634469, the WHOI Robert W. Morse Chair for Excellence in Oceanography, and The Investment in Science Fund at WHOI. The micro-X-ray CT imaging was performed under the cooperative research program of Center for Advanced Marine Core Research (CMCR), Kochi University (accept No. 17A021)

    Decadal–centennial-scale solar-linked climate variations and millennial-scale internal oscillations during the Early Cretaceous

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    Understanding climate variability and stability under extremely warm ‘greenhouse’ conditions in the past is essential for future climate predictions. However, information on millennial-scale (and shorter) climate variability during such periods is scarce, owing to a lack of suitable high-resolution, deep-time archives. Here we present a continuous record of decadal- to orbital-scale continental climate variability from annually laminated lacustrine deposits formed during the late Early Cretaceous (123–120 Ma: late Barremian–early Aptian) in southeastern Mongolia. Inter-annual changes in lake algal productivity for a 1091-year interval reveal a pronounced solar influence on decadal- to centennial-scale climatic variations (including the ~ 11-year Schwabe cycle). Decadally-resolved Ca/Ti ratios (proxy for evaporation/precipitation changes) for a ~ 355-kyr long interval further indicate millennial-scale (~ 1000–2000-yr) extreme drought events in inner-continental areas of mid-latitude palaeo-Asia during the Cretaceous. Millennial-scale oscillations in Ca/Ti ratio show distinct amplitude modulation (AM) induced by the precession, obliquity and short eccentricity cycles. Similar millennial-scale AM by Milankovitch cycle band was also previously observed in the abrupt climatic oscillations (known as Dansgaard–Oeschger events) in the ‘intermediate glacial’ state of the late Pleistocene, and in their potential analogues in the Jurassic ‘greenhouse’. Our findings indicate that external solar activity forcing was effective on decadal–centennial timescales, whilst the millennial-scale variations were likely amplified by internal process such as changes in deep-water formation strength, even during the Cretaceous ‘greenhouse’ period

    コウコウセイ ニヨル スウガク ノ ゼンコウ イッセイ セイト ジュギョウ ノ イギ ト ガッコウ ケイエイ ニ モタラス イミ

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    本研究は,数学の学習に自信がない生徒が約7割いる置籍校の高等学校で,二次曲線の学習をした生徒が先生役となって実施した,全校一斉生徒授業について,その意義と学校経営にもたらす意義を示す。当初,先生役生徒は,全校一斉生徒授業を行うことを不安に思っていたが,置籍校の教職員の支援を受けながら,主体的に教材を検討し,授業計画を作成して,全校一斉生徒授業に積極的に取り組んだ。生徒アンケートから,先生役生徒はこの取り組みを通して,それぞれが自信を持ち,主体的に活動する意義を自ら見いだし,全校一斉生徒授業後には,意欲的に活動する様子が多く見られるようになった。本研究では,全校一斉生徒授業の意義をとらえるために,学校・学年・学級経営にもたらす意味についても考察した。The students’ classes of school were held in our high school where the students of seventy percent who had not have confidence in mathematics. The learning content of students’ classes of school was quadric curve. In this study, we show the actual influence of these classes. The teacher students tried to understand the content of teaching and to make teaching materials by themselves. Through these activities, the teacher students had confidence of their work. The teacher students’ activities motivate whole students of our high school. We also emphasize the significance these classes and clarify the importance of these classes in our school managements, grade management and classroom administration
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