Conditional knockout mice for Atg9a, specifically in brain tissue, were generated to understand t... more Conditional knockout mice for Atg9a, specifically in brain tissue, were generated to understand the roles of ATG9A in the neural tissue cells. The mice were born normally, but half of them died within one wk, and none lived beyond 4 wk of age. SQSTM1/p62 and NBR1, receptor proteins for selective autophagy, together with ubiquitin, accumulated in Atg9a-deficient neurosoma at postnatal d 15 (P15), indicating an inhibition of autophagy, whereas these proteins were significantly decreased at P28, as evidenced by immunohistochemistry, electron microscopy and western blot. Conversely, degenerative changes such as spongiosis of nerve fiber tracts proceeded in axons and their terminals that were occupied with aberrant membrane structures and amorphous materials at P28, although no clear-cut degenerative change was detected in neuronal cell bodies. Different from autophagy, diffusion tensor magnetic resonance imaging and histological observations revealed Atg9a-deficiency-induced dysgenesis of the corpus callosum and anterior commissure. As for the neurite extensions of primary cultured neurons, the neurite outgrowth after 3 d culturing was significantly impaired in primary neurons from atg9a-KO mouse brains, but not in those from atg7-KO and atg16l1-KO brains. Moreover, this tendency was also confirmed in Atg9a-knockdown neurons under an atg7-KO background, indicating the role of ATG9A in the regulation of neurite outgrowth that is independent of autophagy. These results suggest that Atg9a deficiency causes progressive degeneration in the axons and their terminals, but not in neuronal cell bodies, where the degradations of SQSTM1/p62 and NBR1 were insufficiently suppressed. Moreover, the deletion of Atg9a impaired nerve fiber tract formation.
The OPERA neutrino experiment is designed to perform the first observation of neutrino oscillatio... more The OPERA neutrino experiment is designed to perform the first observation of neutrino oscillations in direct appearance mode in the ν μ → ν τ channel, via the detection of the τ-leptons created in charged current ν τ interactions. The detector, located in the underground Gran Sasso Laboratory, consists of an emulsion/lead target with an average mass of about 1.2 kt, complemented by electronic detectors. It is exposed to the CERN Neutrinos to Gran Sasso beam, with a baseline of 730 km and a mean energy of 17 GeV. The observation of the first ν τ candidate event and the analysis of the 2008-2009 neutrino sample have been reported in previous publications. This work describes substantial improvements in the analysis and in the evaluation of the detection efficiencies and backgrounds using new simulation tools. The analysis is extended to a sub-sample of 2010 and 2011 data, resulting from an electronic detector-based pre-selection, in which an additional ν τ candidate has been observed...
The OPERA neutrino experiment at the underground Gran Sasso Laboratory has measured the velocity ... more The OPERA neutrino experiment at the underground Gran Sasso Laboratory has measured the velocity of neutrinos from the CERN CNGS beam over a baseline of about 730 km. The measurement is based on data taken by OPERA in the years 2009, 2010 and 2011. Dedicated upgrades of the CNGS timing system and of the OPERA detector, as well as a high precision geodesy campaign for the measurement of the neutrino baseline, allowed reaching comparable systematic and statistical accuracies. An arrival time of CNGS muon neutrinos with respect to the one computed assuming the speed of light in vacuum of $ \left( {6.5\pm 7.4\left( {\mathrm{stat}.} \right)_{-8.0}^{+8.3}\left( {\mathrm{sys}.} \right)} \right)\mathrm{ns} $ was measured corresponding to a relative difference of the muon neutrino velocity with respect to the speed of light $ {{{\left( {\upsilon -c} \right)}} \left/ {c} \right.}=\left( {2.7\pm 3.1\left( {\mathrm{stat}.} \right)_{-3.3}^{+3.4}\left( {\mathrm{sys}.} \right)} \right)\times {10^{...
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
... Full-size table (<1K). View Within Article. 3. Tracking and vertex reconstructionNET-scan... more ... Full-size table (<1K). View Within Article. 3. Tracking and vertex reconstructionNET-scan method. ... Submicron accuracy of alignment can be achieved by a sufficient number of penetrating tracks. An example of the NET-scan method in the DONUT experiment is shown in Fig. ...
A study of 1.66 GeVc K− beam induced (K−,K+) reactions in the nuclear emulsion target is presente... more A study of 1.66 GeVc K− beam induced (K−,K+) reactions in the nuclear emulsion target is presented and 796 (K−, K+) reaction vertices (pK+ ⩾ 1 GeV/c) containing 18 single hyperfragments are identified. There is no clear(spatially separated) double hyperfragment nor twin single hyperfragment in the identified 796 (K−,K+) reactions. These events are classified and their characteristics are described in
Corresponding author 0168-9002/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved SSDI 01... more Corresponding author 0168-9002/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved SSDI 0168-9002(94)01720-4 E
We report upper limits on the cross sections for the Xi-p elastic and conversion processes based ... more We report upper limits on the cross sections for the Xi-p elastic and conversion processes based on the observation of one Xi-p elastic scattering events with an invisible Lambda decay. The cross section for the Xi-p elastic scattering is, for simplicity, assumming an isotropic angular distribution, found to be 40 mb at 90% confidence level, whereas that for the Xi-p --> LambdaLambda reaction is 11 mb at 90% confidence level. While the results on the elastic cross section give no stringent constraint on theoretical estimates, the upper limit on the conversion process suggests that the estimate of the RGM-F model prediction could be ruled out. We also report some preliminary results on the obervation of the stopped-Xi- hyperon-nucleus interaction with respect to hypernuclear production and existence of doubly-strange H-dibaryon.
Enhanced production of ΛΛ pairs, above the prediction of a two-step process model, is observed ne... more Enhanced production of ΛΛ pairs, above the prediction of a two-step process model, is observed near threshold (around the masses of 2.23 – 2.26 GeV/c2) in the12C(K−,K+) reaction at PK− = 1.66GeV/c using a scintillating fiber target. The differential cross section for the ΛΛ production averaged over 2.3° ≤ $$K + ≤ 14.7° in the momentum region 0.95 ≤ pK
A hybrid emulsion experiment was carried out to study double-strangeness nuclei produced via Ξ− h... more A hybrid emulsion experiment was carried out to study double-strangeness nuclei produced via Ξ− hyperon capture at rest with the expectation of ten times larger statistics than previous experiments. We have analyzed 5% of the total emulsion and found one “twin-hypernuclei” event involving the emission of two single-Λ hypernuclei and a nuclear fragment from a Ξ− hyperon stopping point. The
The OPERA experiment was designed to search for νµ → ντ oscillations in appearance mode, i.e. by ... more The OPERA experiment was designed to search for νµ → ντ oscillations in appearance mode, i.e. by detecting the τ -leptons produced in charged current ντ interactions. The experiment took data from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam. The observation of νµ → ντ appearance, achieved with four candidate events in a sub-sample of the data, was previously reported. In this paper, a fifth ντ candidate event, found in an enlarged data sample, is described. Together with a further reduction of the expected background, the candidate events detected so far allow assessing the discovery of νµ → ντ oscillations in appearance mode with a significance larger than 5 σ.
We report on the first direct observation of a neutrino induced charged-current interaction with ... more We report on the first direct observation of a neutrino induced charged-current interaction with two subsequent decays of short-lived particles close to the interaction vertex. This rare double-kink signature in the CHORUS emulsion target is interpreted as a D + s production followed by the decay chain D + s ! D + s ;D + s ! + ; + ! + . The event is characterised by small Q 2 and small four-momentum transfer squared t to the target nucleon, which indicates a diffractive production mechanism. A complete analysis of the event is presented.
Detecting the first electron pairs with nuclear emulsion allows a precise measurement of the dire... more Detecting the first electron pairs with nuclear emulsion allows a precise measurement of the direction of incident gamma-rays as well as their polarization. With recent innovations in emulsion scanning, emulsion analyzing capability is becoming increasingly powerful. Presently, we are developing a balloonborne gamma-ray telescope using nuclear emulsion. An overview and a status of our telescope is given.
Conditional knockout mice for Atg9a, specifically in brain tissue, were generated to understand t... more Conditional knockout mice for Atg9a, specifically in brain tissue, were generated to understand the roles of ATG9A in the neural tissue cells. The mice were born normally, but half of them died within one wk, and none lived beyond 4 wk of age. SQSTM1/p62 and NBR1, receptor proteins for selective autophagy, together with ubiquitin, accumulated in Atg9a-deficient neurosoma at postnatal d 15 (P15), indicating an inhibition of autophagy, whereas these proteins were significantly decreased at P28, as evidenced by immunohistochemistry, electron microscopy and western blot. Conversely, degenerative changes such as spongiosis of nerve fiber tracts proceeded in axons and their terminals that were occupied with aberrant membrane structures and amorphous materials at P28, although no clear-cut degenerative change was detected in neuronal cell bodies. Different from autophagy, diffusion tensor magnetic resonance imaging and histological observations revealed Atg9a-deficiency-induced dysgenesis of the corpus callosum and anterior commissure. As for the neurite extensions of primary cultured neurons, the neurite outgrowth after 3 d culturing was significantly impaired in primary neurons from atg9a-KO mouse brains, but not in those from atg7-KO and atg16l1-KO brains. Moreover, this tendency was also confirmed in Atg9a-knockdown neurons under an atg7-KO background, indicating the role of ATG9A in the regulation of neurite outgrowth that is independent of autophagy. These results suggest that Atg9a deficiency causes progressive degeneration in the axons and their terminals, but not in neuronal cell bodies, where the degradations of SQSTM1/p62 and NBR1 were insufficiently suppressed. Moreover, the deletion of Atg9a impaired nerve fiber tract formation.
The OPERA neutrino experiment is designed to perform the first observation of neutrino oscillatio... more The OPERA neutrino experiment is designed to perform the first observation of neutrino oscillations in direct appearance mode in the ν μ → ν τ channel, via the detection of the τ-leptons created in charged current ν τ interactions. The detector, located in the underground Gran Sasso Laboratory, consists of an emulsion/lead target with an average mass of about 1.2 kt, complemented by electronic detectors. It is exposed to the CERN Neutrinos to Gran Sasso beam, with a baseline of 730 km and a mean energy of 17 GeV. The observation of the first ν τ candidate event and the analysis of the 2008-2009 neutrino sample have been reported in previous publications. This work describes substantial improvements in the analysis and in the evaluation of the detection efficiencies and backgrounds using new simulation tools. The analysis is extended to a sub-sample of 2010 and 2011 data, resulting from an electronic detector-based pre-selection, in which an additional ν τ candidate has been observed...
The OPERA neutrino experiment at the underground Gran Sasso Laboratory has measured the velocity ... more The OPERA neutrino experiment at the underground Gran Sasso Laboratory has measured the velocity of neutrinos from the CERN CNGS beam over a baseline of about 730 km. The measurement is based on data taken by OPERA in the years 2009, 2010 and 2011. Dedicated upgrades of the CNGS timing system and of the OPERA detector, as well as a high precision geodesy campaign for the measurement of the neutrino baseline, allowed reaching comparable systematic and statistical accuracies. An arrival time of CNGS muon neutrinos with respect to the one computed assuming the speed of light in vacuum of $ \left( {6.5\pm 7.4\left( {\mathrm{stat}.} \right)_{-8.0}^{+8.3}\left( {\mathrm{sys}.} \right)} \right)\mathrm{ns} $ was measured corresponding to a relative difference of the muon neutrino velocity with respect to the speed of light $ {{{\left( {\upsilon -c} \right)}} \left/ {c} \right.}=\left( {2.7\pm 3.1\left( {\mathrm{stat}.} \right)_{-3.3}^{+3.4}\left( {\mathrm{sys}.} \right)} \right)\times {10^{...
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
... Full-size table (<1K). View Within Article. 3. Tracking and vertex reconstructionNET-scan... more ... Full-size table (<1K). View Within Article. 3. Tracking and vertex reconstructionNET-scan method. ... Submicron accuracy of alignment can be achieved by a sufficient number of penetrating tracks. An example of the NET-scan method in the DONUT experiment is shown in Fig. ...
A study of 1.66 GeVc K− beam induced (K−,K+) reactions in the nuclear emulsion target is presente... more A study of 1.66 GeVc K− beam induced (K−,K+) reactions in the nuclear emulsion target is presented and 796 (K−, K+) reaction vertices (pK+ ⩾ 1 GeV/c) containing 18 single hyperfragments are identified. There is no clear(spatially separated) double hyperfragment nor twin single hyperfragment in the identified 796 (K−,K+) reactions. These events are classified and their characteristics are described in
Corresponding author 0168-9002/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved SSDI 01... more Corresponding author 0168-9002/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved SSDI 0168-9002(94)01720-4 E
We report upper limits on the cross sections for the Xi-p elastic and conversion processes based ... more We report upper limits on the cross sections for the Xi-p elastic and conversion processes based on the observation of one Xi-p elastic scattering events with an invisible Lambda decay. The cross section for the Xi-p elastic scattering is, for simplicity, assumming an isotropic angular distribution, found to be 40 mb at 90% confidence level, whereas that for the Xi-p --> LambdaLambda reaction is 11 mb at 90% confidence level. While the results on the elastic cross section give no stringent constraint on theoretical estimates, the upper limit on the conversion process suggests that the estimate of the RGM-F model prediction could be ruled out. We also report some preliminary results on the obervation of the stopped-Xi- hyperon-nucleus interaction with respect to hypernuclear production and existence of doubly-strange H-dibaryon.
Enhanced production of ΛΛ pairs, above the prediction of a two-step process model, is observed ne... more Enhanced production of ΛΛ pairs, above the prediction of a two-step process model, is observed near threshold (around the masses of 2.23 – 2.26 GeV/c2) in the12C(K−,K+) reaction at PK− = 1.66GeV/c using a scintillating fiber target. The differential cross section for the ΛΛ production averaged over 2.3° ≤ $$K + ≤ 14.7° in the momentum region 0.95 ≤ pK
A hybrid emulsion experiment was carried out to study double-strangeness nuclei produced via Ξ− h... more A hybrid emulsion experiment was carried out to study double-strangeness nuclei produced via Ξ− hyperon capture at rest with the expectation of ten times larger statistics than previous experiments. We have analyzed 5% of the total emulsion and found one “twin-hypernuclei” event involving the emission of two single-Λ hypernuclei and a nuclear fragment from a Ξ− hyperon stopping point. The
The OPERA experiment was designed to search for νµ → ντ oscillations in appearance mode, i.e. by ... more The OPERA experiment was designed to search for νµ → ντ oscillations in appearance mode, i.e. by detecting the τ -leptons produced in charged current ντ interactions. The experiment took data from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam. The observation of νµ → ντ appearance, achieved with four candidate events in a sub-sample of the data, was previously reported. In this paper, a fifth ντ candidate event, found in an enlarged data sample, is described. Together with a further reduction of the expected background, the candidate events detected so far allow assessing the discovery of νµ → ντ oscillations in appearance mode with a significance larger than 5 σ.
We report on the first direct observation of a neutrino induced charged-current interaction with ... more We report on the first direct observation of a neutrino induced charged-current interaction with two subsequent decays of short-lived particles close to the interaction vertex. This rare double-kink signature in the CHORUS emulsion target is interpreted as a D + s production followed by the decay chain D + s ! D + s ;D + s ! + ; + ! + . The event is characterised by small Q 2 and small four-momentum transfer squared t to the target nucleon, which indicates a diffractive production mechanism. A complete analysis of the event is presented.
Detecting the first electron pairs with nuclear emulsion allows a precise measurement of the dire... more Detecting the first electron pairs with nuclear emulsion allows a precise measurement of the direction of incident gamma-rays as well as their polarization. With recent innovations in emulsion scanning, emulsion analyzing capability is becoming increasingly powerful. Presently, we are developing a balloonborne gamma-ray telescope using nuclear emulsion. An overview and a status of our telescope is given.
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Papers by Shigeki Aoki