bluuebunny/crossref_metadata_2025 huggingface dataset:
THE BAIKAL NEUTRINO TELESCOPE — RESULTS AND PLANS
Authors:   for the BAIKAL COLLABORATION., WISCHNEWSKI RALF , AYNUTDINOV V. , BALKANOV V. , BELOLAPTIKOV I. , BUDNEV N. , BEZRUKOV L. , CHENSKY A. , CHERNOV D. , DANILCHENKO I. , DZHILKIBAEV ZH.-A. , DOMOGATSKY G. , DYACHOK A. N. , FIALKOVSKY S. , GAPONENKO O. , GRESS O. , GRESS T. , KAZAKOV K. , KLABUKOV A. , KLIMOV A. , KLIMUSHIN S. , KONISCHEV K. , KOSHECHKIN A. , KUZMICHEV L. , KULEPOV V. , KUZNETZOV VY. , LUBSANDORZHIEV B. , MIKHEYEV S. , MILENIN M. , MIRGAZOV R. , OSIPOVA E. , PAVLOV A. , PAN'KOV G. , PAN'KOV L. , PANFILOV A. , PARFENOV YU. , PLISKOVSKY E. , POKHIL P. , POLECSHUK V. , POPOVA E. , PROSIN V. , ROSANOV M. , RUBTZOV V. , SEMENEY Y. , SHAIBONOV B. , SPIERING CH. , STREICHER O. , TARASHANSKY B. , VASILIEV R. , VYATCHIN E. , YASHIN I. , ZHUKOV V.
Published: December 2005

New results from the Baikal neutrino telescope NT200, based on the first 5 years of operation (1998–2003), are presented. We derive an all-flavor limit on the diffuse flux of astrophysical neutrinos between 20 TeV and 50 PeV, extract an enlarged sample of high energy muon neutrino events, and obtain limits on the flux of high energy atmospheric muons. In 2005, the upgraded telescope NT200+ will be commissioned: 3 additional distant strings with only 12 photo-multipliers each will rise the effective volume to 20 Mton at 10 PeV for this largest running neutrino telescope in the Northern hemisphere.
OBSERVATION OF UHECRs IN HORIZONTAL FLUX
Authors: YASHIN I. I. , AMELCHAKOV M. B. , BARBASHINA N. S. , BOGDANOV A. G. , CHERNOV D. V. , KINDIN V. V. , KOKOULIN R. P. , KOMPANIETS K. G. , KONOREVA E. O. , PETRUKHIN A. A. , SHUTENKO V. V. , TIMASHKOV D. A. , YANSON E. E. , ZOLINA O. S. , MANNOCCHI G. , TRINCHERO G. , SAAVEDRA O.
Published: December 2005

Preliminary results of muon bundle studies in of zenith angle range θ ≥ 60° and multiplicities by means of coordinate detector DECOR are discussed. Estimates of muon bundle characteristics at large zenith angles obtained with CORSIKA code demonstrate the ability of such not large detector as NEVOD-DECOR complex to perform cosmic ray studies in a very wide energy range from 1011 eV to more than 1017 eV.
SEARCH FOR ENHANCEMENTS OF MUONS AT SEA LEVEL FROM TRANSIENT EVENTS
Authors: AUGUSTO C. R. A. , NAVIA C. E. , ROBBA M. B.
Published: December 2005

The main target of this study is a search for the origin of two ground level enhancements (GLEs), observed on December of 2003 at sea level by using the TUPI muon telescope. The results show that one of them has a strong correlation with solar flare, while the other has an unknown origin, because there is not satellite report of solar flare, nor the prompt X-ray emission and neither the excess of nuclei during the raster scan where the GLE was observed. Even so, two possibilities are analyzed: the solar flare hypothesis and the gamma ray burst (GRB) hypothesis.
WAVELET ANALYSIS OF ATMOSPHERIC MUON DATA
Authors: BARBASHINA N. S. , KOKOULIN R. P. , KOMPANIETS K. G. , PETRUKHIN A. A. , TIMASHKOV D. A. , YASHIN I. I. , MANNOCCHI G. , TRINCHERO G. , SAAVEDRA O.
Published: December 2005

Experimental data on atmospheric muons obtained with Russian-Italian coordinate detector DECOR have been processed by means of method of wavelet transformation. Results of analysis exhibit time perturbations caused by effects like Forbush decreases and allow to determine not only their periods but also moments of their appearance.
THE NEMO PROJECT
Authors:   on behalf of the NEMO COLLABORATION., CHIARUSI TOMMASO
Published: December 2005

Since 1998 the NEMO Collaboration started a long term activity to select and characterize an optimal deep-sea site for the installation of a km3 neutrino telescope. In more than 20 sea campaigns, the water and oceanographic properties have been studied. Moreover, an intense program has been performed to study the technical feasibility of a km3 detector and many computer simulations have been made to define a suitable detector architecture. Recently the project NEMO Phase-1 has been funded by INFN and MIUR. It foresees the realization of an underwater laboratory with 3 junction boxes and a couple of instrumented towers according to the design proposed by the NEMO collaboration. The project should be completed by 2006.
SIMULATION OF THE ATMOSPHERIC MUON FLUX WITH CORSIKA
Authors: DJEMIL T. , ATTALLAH R. , CAPDEVIELLE J. N.
Published: December 2005

We present in this paper the results of 3D-calculation of the atmospheric muon flux at different altitudes. We have used for this purpose the extensive air shower simulation package CORSIKA (v. 6.031) in combination with the hadronic interaction models VENUS (v. 4.12) at high energy (beyond 80 GeV) and GHEISHA (v. 2002) and UrQMD (v. 1.1) at lower energy. Our results are compared to data from different experiments (CAPRICE, BESS and HEAT). The correlation of the atmospheric muon flux to the primary zenith angle and primary energy is also investigated.
COMPARATIVE STUDY OF POWER SPECTRA OF GROUND AND SHALLOW UNDERGROUND MUON DATA
Authors: DRAGIĆ A. , BANJANAC R. , UDOVIČIĆ V. , JOKOVIĆ D. , ANIČIN I. , PUZOVIĆ J.
Published: December 2005

Cosmic muon flux is recorded by two plastic scintillator detectors: one located at ground level and the other located in the Belgrade underground laboratory (25 m w.e.). Power spectral analysis of the raw detector data for the period from January 1st 2002 to December 31st 2002 is performed. Similar periodicities are found in both data sets (ground and underground), but with different amplitudes. Main periodicity in the underground detector data has a 26.5 days period, while the highest amplitude signal in the ground detector data has a 243 ± 45 days period. Other signals present in the time series correspond to higher harmonics of the solar rotation period. There is also a wave with a 34.4 days period, whose significance is confirmed by different methods of spectral analysis. The same periodicity is recently found in some processes on the Sun.
CHARGED LEPTON-NUCLEUS INELASTIC SCATTERING AT HIGH ENERGIES
Authors: KUZMIN K. S. , LOKHTIN K. S. , SINEGOVSKY S. I.
Published: December 2005

The composite model is made to describe inelastic high-energy scattering of muons and taus in standard rock. It involves photonuclear interactions at low Q2 as well as moderate Q2 processes and the deep inelastic scattering (DIS). In the DIS region the neutral current contribution is taken into consideration. Approximation formulas both for the muons and tau energy loss in standard rock are presented for wide energy range.
ON THE DEFICIT OF CALCULATED MUON FLUX AT SEA LEVEL FOR ENERGIES > 100 GEV
Authors: LAGUTIN A. A. , TYUMENTSEV A. G. , YUSHKOV A. V.
Published: December 2005

In this paper we discuss the problem why the use of the direct data on primary nuclei spectra together with the modern hadronic interaction models leads to a significant deficit of computed vertical muon flux at sea level for energies above 100 GeV. We suggest that to find out the source of this inconsistency it is necessary to perform an analysis of sensitivity of emulsion chamber data to variations of hadron-nucleus interaction characteristics. Such analysis will give more ground for discussion of adequacy of the up-to-date interaction models and of mutual compatibility of primary nuclei spectra, obtained in direct and EAS experiments.
SEARCH FOR BURST SIGNALS FROM POINT SOURCES
Authors:   on behalf of the L3+C COLLABORATION., LE COULTRE P.
Published: December 2005

A sky survey for flaring point sources emitting high energy gamma rays has been performed with the L 3+ C underground muon spectrometer at LEP, CERN. Data were collected from mid July to October 1999 and from April to November 2000. No signal excesses in any direction have been found with muons above 20, 30, 50 and 100 GeV within one day and longer time windows. The steady muon flux sensitivity is of the order of a few times 10-9 cm-2 s-1 for muon energies above 20 GeV, and between 2 × 10-11 and 5 × 10-10 cm -2 s -1 for muon energies above 20 GeV depending on the source position.
THE ANTARES DETECTOR
Authors:   on behalf of the ANTARES COLLABORATION: See Ref. 1 for a list of the ANTARES Collaborators., MARGIOTTA ANNARITA
Published: December 2005

ANTARES is a neutrino telescope under construction in the Mediterranean Sea at the depth of 2500 m, about 40 km off the French coast. A short review of its design and expected performances is presented as well as the status of the project.
UNDERGROUND MUON ENERGY SPECTRA WITH THE MACRO TRD
Authors: MAZZIOTTA M. N. , BRIGIDA M. , FAVUZZI C. , FUSCO P. , GARGANO F. , GIGLIETTO N. , GIORDANO F. , LOPARCO F. , RAINÒ S. , SPINELLI P.
Published: December 2005

The MACRO detector was located in the Hall B of the Gran Sasso underground Laboratories under an average rock overburden of 3700 hg/cm2. A TRD composed by three identical modules, covering an horizontal area of 36 m2, was added to the MACRO detector in order to measure the residual energy of muons entering MACRO. This kind of measurement provides a useful tool to study the primary cosmic ray energy spectra and composition, their interactions with the Earth's atmosphere and the propagation of muons inside the rock. The results of the measurement of the energy of single and double muons crossing MACRO will be presented. Our data show that double muons are more energetic than single ones in the rock depth range from 3000 to 6500 hg/cm2. Single muon data confirm the reliability of the models adopted to describe the cosmic ray interactions with the atmosphere and the muon propagation inside the rock.
POSSIBLE CHARM PRODUCTION AND DIRECT MUON CONTRIBUTION TO EAS AT VERY HIGH ENERGIES
Authors: RYAZHSKAYA O. G. , VOLKOVA L. V. , ZATSEPIN G. T.
Published: December 2005

The paper considers the possibility of EAS production by charmed particles and direct muons (muons produced in decays of particles with a very short life-time comparing to that of charmed particles, as, for example, in decays of resonances). At large angles (≳ 70°) charmed particles and direct muons could be completely responsible for EAS measured at the sea level. The estimations are made for the primary nucleon energy 1019 eV and the angles 45–72°.
EUNO: A NEUTRINO SPACE OBSERVATORY
Authors: SPILLANTINI P. , BOTTAI S. , PACE E. , BRATINA V. , MAZZINGHI P.
Published: December 2005

The physics of Cosmic Rays of Extreme Energy will be deeply investigated by the next generation of fluorescence space detectors. For the Extreme Energy Neutrino Astronomy such detectors will probably exhibit a lack of statistics and a further increase of sensitivity will be necessary for this goal. The critical items in designing a future Neutrino Space Observatory suited for Neutrino Astronomy are discussed.
ALBEDO MUONS: NEW DATA AND CALCULATIONS
Authors: TIMASHKOV D. A. , AMELCHAKOV M. B. , CHERNOV D. V. , KINDIN V. V. , KOKOULIN R. P. , KOMPANIETS K. G. , KONOPATOV R. V. , PETRUKHIN A. A. , ROOM D. A. , YASHIN I. I. , MANNOCCHI G. , TRINCHERO G. , SAAVEDRA O.
Published: December 2005

Data on near-horizontal muons obtained with experimental complex NEVOD-DECOR are analyzed. More than 1.5 × 103 atmospheric muons scattered into upper hemisphere with energy above 7 GeV were registered. Calculations show that the main process forming albedo muon flux near horizon is multiple Coulomb scattering.
GROUND-BASED GAMMA-RAY ASTRONOMY
Authors: BILAND ADRIAN
Published: December 2005

Very High Energy Gamma-Ray Astronomy (the measurement of γ above 10 GeV) is a rather young but fast evolving field. In the past 16 years some 20 sources have been discovered, about half of them are firmly established and seen with high significance by more than one experiment. This rather short list already contains very different objects like plerions, supernova remnants and active galactic nuclei. A new generation of instruments (CANGAROO III, HESS, MAGIC, VERITAS) is just starting to take data, and first preliminary results show that the sensitivity is improved by at least a factor of 100. Already during commissioning, some new sources have been discovered.

This overview will summarize the techniques used in VHE gamma-ray observations as well discuss briefly some physics topics that can be investigated in this energy range.
EXTRAGALACTIC GAMMA-RAYS: GAMMA RAY BURSTS AND BLAZARS
Authors: GHISELLINI GABRIELE
Published: December 2005

The extragalactic gamma-ray sky is dominated by two classes of sources: Gamma-Ray Bursts (GRBs) and radio loud active galactic nuclei whose jets are pointing at us (blazars). We believe that the radiation we receive from them originates from the transformation of bulk relativistic energy into random energy. Although the mechanisms to produce, collimate and accelerate the jets in these sources are uncertain, it is fruitful to compare the characteristics of both classes of sources in search of enlightening similarities. I will review some general characteristics of radio loud AGNs and GRBs and I will discuss the possibility that both classes of sources can work in the same way. Finally, I will discuss some recent exciting prospects to use blazars to put constraints on the cosmic IR-Optical-UV backgrounds, and to use GRBs as standard candles to measure the Universe.
RESULTS FROM H.E.S.S.
Authors:   for the H.E.S.S. COLLABORATION., HEINZELMANN GÖTZ
Published: December 2005

H.E.S.S. is an experiment for ground based GeV/TeV gamma ray astronomy of the new generation. It consists of four large Cherenkov telescopes operating in stereoscopic observation mode. Its construction in Namibia was completed at the end of 2003. Already during the installation phase, exciting results have been achieved, and after completion several discoveries have been made. Some of the results and discoveries are reported, such as the first image of a shell-type supernova remnant resolved at arc minute scale (RXJ 1713 – 3946), the discovery of the unique binary pulsar system PSR B1259 – 63 and of a yet-unidentified source in the same field of view (HESS J1303 – 631), and the observation of the galactic centre region. Amongst the extragalactic sources, the blazers Mkn 421 and PKS 2155 – 304 have also been detected.
LOW ENERGY γ-RAY DETECTION (E ≤ 30 GEV): EFFECT OF EARTH'S MAGNETIC FIELD AND A NOVEL TRIGGER TECHNIQUE
Authors:   for the MAGIC COLLABORATION., DE LOS REYES R. , OÑA-WILHELMI E. , CONTRERAS J. L. , DE JAGER O. C. , FONSECA M. V.
Published: December 2005

Here we discuss two related aspects of the detection of low energy gammas by IACT's (Imaging Atmospheric Cherenkov Telescope): the effect of the Earth's magnetic field and a possible novel trigger technique. The Earth's magnetic field affects the development of extensive air showers (EAS), spreading the collected photons and, therefore, decreasing the sensitivity of the Cherenkov telescope. The new effects that appear in low energy showers can be partially offset modifying the trigger criteria. The result is a large collection area (> 1000 m2) below 10 GeV for a typical 17 m class telescope, increasing its sensitivity at these energies.
STATUS AND PERSPECTIVES OF GLAST GAMMA RAY EXPERIMENT
Authors:   for the GLAST COLLABORATION., GIGLIETTO N.
Published: December 2005

GLAST, the Gamma-ray Large Area Telescope, is a satellite-based experiment able to measure the cosmic gamma-ray flux in the energy range between 20 MeV and 300 GeV or above. The sensitivity is more than 30 times respect to EGRET and the good spatial and time resolution over a large field of view let us to cover a large variety of high energy phenomena. In particular GLAST will be able to study both diffuse emission and point-like gamma ray sources, including active galactic nuclei, gamma ray bursts, pulsars and supernova remnants. In addition, the potentialities of GLAST to explore rare or exotic phenomena like supersymmetric dark matter annihilations will be shown. The present knowledge of the science opportunities that the GLAST experiment can explore will be completed with the detector description and the current status of the experiment.
THE TIMING SYSTEM OF THE MAGIC TELESCOPE
Authors:   for the MAGIC COLLABORATION., LUCARELLI F. , LÓPEZ M. , OÑA-WILHELMI E. , FONSECA M. V. , BÖRST H. G.
Published: December 2005

The Major Atmospheric Gamma-ray Imaging Čerenkov Telescope (MAGIC) will be the first ground-based Čerenkov telescope able to detect photons with E > 30 GeV . This region of the electromagnetic spectrum, yet unexplored, is fundamental for pulsar physics since theoretical models foreseen a cut-off in the pulsed emission at tens of GeV. In order to perform timing analysis of pulsars, accuracy below milliseconds in the time stamp of the detected event is needed. In this work, we present the timing system of the MAGIC telescope and the first timing analysis performed on real data.
GAMMA RAYS STUDIES BASED ON ATMOSPHERIC CHERENKOV TECHNIQUE AT HIGH MOUNTAIN ALTITUDE
Authors: MISHEV A. , MAVRODIEV S. , STAMENOV J.
Published: December 2005

We present a new method for ground based gamma ray astronomy based only on atmospheric Cherenkov light flux analysis. The Cherenkov light flux densities in extensive air showers initiated by different primaries are simulated in the energy range 100 GeV – 100 PeV for different primaries using the CORSIKA 6.003 code at (536 g/cm2). An approximation of lateral distribution of Cherenkov light flux densities in EAS is obtained using a nonlinear fit such as Breit-Wigner. The simulated and reconstructed events are compared and the accuracy in energy and primary mass reconstruction are obtained.
ULTRA HIGH ENERGY GAMMA RAY OBSERVATION BY SPACE-BASED EXPERIMENTS
Authors: SAKAKI NAOTO
Published: December 2005

If Ultra-high energy cosmic rays (UHECRs) with E > 1020 eV are produced by a top down model, most of them are expected to be γ-rays. When a UHE gamma ray comes almost parallel to the geomagnetic field, it does not suffer geomagnetic cascade and its air shower development is suppressed by the Landau-Pomeranchuk-Migdal (LPM) effect. In order to investigate UHECRs of the top down origin, the correlation of "LPM hole" and the geomagnetic field observed by a space-based experiment may be a unique method to detect UHE γ-rays.
ENERGY SPECTRUM OF VERY HIGH ENERGY GAMMA-QUANTA FROM CYGNUS X-3 IN YEAR 2003
Authors: SINITSYNA V. G. , ARSOV T. P. , ALAVERDIAN A. Y. , BORISOV S. S. , MIRZAFATIKOV R. M. , NIKOLSKY S. I. , SINITSYNA V. Y. , PLATONOV G. F. , CAPDEVIELLE J. N.
Published: December 2005

The observational data for the Galactic source Cygnus X-3 collected with the SHALON mirror Cherenkov telescope are presented. The Cygnus X-3 binary have been regularly observed since 1995 with the average γ-ray flux F (E > 0.8 TeV ) = (6.8 ± 0.7) × 10-13 cm -2 s -1. The flux in year 2003 was (1.79 ± 0.33) × 10-12 cm -2 s -1. Earlier, in 1997, an increase of the flux was also observed.
OBSERVED AND EXPECTED 1–30 TEV GAMMA-RAY EMISSION FROM GEMINGA AND TYCHO'S SUPERNOVA REMNANTS
Authors: SINITSYNA V. G. , ARSOV T. P. , ALAVERDIAN A. Y. , BORISOV S. S. , MUSIN F. I. , NIKOLSKY S. I. , SINITSYNA V. Y. , PLATONOV G. F.
Published: December 2005

The gamma-quantum emitting objects in our Galaxy are the supernova remnants and binaries. Preliminary analysis of the data for γ-ray sources Tycho Brage and Geminga obtained with the SHALON γ-ray telescope is briefly discussed. The energy spectra of γ's from the Geminga and Tycho's sources, F (E > 0.8 TeV ) ∝ Ek are found to be harder than the spectrum from Crab Nebula. The expected π0-decay γ-ray flux [Formula: see text] extends up to ~ 30 TeV, whereas the inverse Compton γ-ray flux has a cutoff above a few TeV. Hence, the detection of γ rays at energies ~ 10 – 30 TeV provides a hint of their hadronic origin.
OBSERVATION OF DISTANT QUASAR 1739+522 AND COMPARISON WITH OTHER METAGALACTIC SOURCES
Authors: SINITSYNA V. G. , ARSOV T. P. , BORISOV S. S. , MUSIN F. I. , NIKOLSKY S. I. , MALYSHKO A. A. , SINITSYNA V. Y. , PLATONOV G. F.
Published: December 2005

The new distant metagalactic γ-sources 1739+522 ( z = 1.375) and 3c454.3 ( z = 0.857) are detected at energies E > 0.8 TeV with the fluxes (0.53 ± 0.10) × 10-12 cm -2 s -1 and (0.43 ± 0.13) × 10-12 cm -2 s -1, respectively. The γ-ray spectra and fluxes of known blazars Mkn 421, Mkn 501 and distant flat-spectrum radio quasars 1739+522 and 3c454.3 are presented.
ALIGNMENT PHENOMENON IN GAMMA FAMILIES WITH ENERGIES 100–1000 TEV
Authors: YULDASHBAEV T. S. , NURITDINOV KH.
Published: December 2005

According to Pamir X-ray Emulsion Chamber (XEC) experimental data at the energies E est > 2 × 1016 eV the fraction of events with four "aligned" most energetic particles increases sharply for families without leading secondary particles. That energy dependence is not described by Quark Gluon String Models.
THE DOUBLE PULSAR SYSTEM J0737–3039
Authors: LORIMER D. R.
Published: December 2005

The double pulsar system J0737 – 3039 – a 22.7 ms pulsar in a compact 2.4 hr orbit about a 2.7 s pulsar was one of the long-awaited "holy grails" of pulsar astronomy. After only two years of timing, the system is close to surpassing the original Hulse-Taylor binary as a test of general relativity. On-going timing should soon reveal second-order effects in the post-Newtonian parameters. In addition, the observed interactions of the radio beams of the two pulsars provide a unique laboratory for probing neutron star magnetospheres and relativistic winds. Finally, a revised estimate of the cosmic rate of double neutron star mergers including J0737 – 3039 boosts previous estimates by an order of magnitude and suggests a high detection rate for the advanced LIGO gravitational wave detector.
ADVANCED GRAVITATIONAL WAVE DETECTORS AND THE GLOBAL NETWORK
Authors: VICERÉ ANDREA
Published: December 2005

A wide range of gravitational wave detectors is currently operating, and in a few years will reach a sensitivity enabling them to potentially detect sources tens of megaparsec away. In the next years, the instruments will be upgraded, giving birth to a new generation of improved, more sensitive detectors. Alternative techniques are also being explored which have the potential in a longer term of even better sensitivities. Such improvements are needed to turn a still elusive hunt for a first detection into a real gravitational-wave astronomy; it is the purpose of this talk to outline the path toward the design and realization of advanced detectors, and to discuss how they will be integrated into a global network.
RAP — ACOUSTIC DETECTION OF PARTICLES: FIRST RESULTS AT 4.2 K
Authors: LIGI C. , BASSAN M. , BERTOLUCCI S. , BUONOMO B. , COCCIA E. , DELLE MONACHE G. , D'ANTONIO S. , DI GIOACCHINO D. , FAFONE V. , MARINI A. , MAZZITELLI G. , MODESTINO G. , QUINTIERI L. , PIZZELLA G. , ROCCELLA S. , RONGA F. , SPERANDIO L. , TRIPODI P. , VALENTE P.
Published: December 2005

RAP (Rivelazione Acustica di Particelle) is a small cylindrical aluminum bar (l = 500 mm , d = 181.7 mm ) placed at the DAΦNE Beam Test Facility, where it is hit by a 510 MeV electron beam, coming from the DAΦNE Linac. Aim of the experiment is to measure the mechanical vibrations of the bar caused by the interaction with the beam. On June, 2004 RAP successfully collected data for the first time at cryogenic temperature. Several runs at different temperatures (4.5, 70 and 273 K) have been performed and a number of shots in normal-conducting state of the bar were detected. The preliminary results are in good agreement with the Thermo-Acoustic Model. In the next months the mounting of a dilution refrigerator and the data taking of the bar in the superconducting state (T = 100 mK ) have been planned.
MAKING A DATA ANALYSIS PROCESSOR WITH FPGA FOR GRAVITATIONAL-WAVE EVENT SEARCH
Authors: SATO NOBUAKI , HARUYAMA TOMIYOSHI , SHINTOMI TAKAKAZU , SUZUKI TOSHIKAZU , TOMARU TAKAYUKI , YAMAMOTO AKIRA , KURODA KAZUAKI , MIYOKI SHINJI , OHASHI MASATAKE , UCHIYAMA TAKASHI , YAMAMOTO KAZUHIRO , TATSUMI DAISUKE
Published: December 2005

We are trying to make a hardware logic-circuit for pipelines of fast Fourier transformation (FFT) with a field programmable gate array (FPGA) for data analyses of an interferometric gravitational-wave detector. That FFT processor is connected to a personal computer (PC) through PCI bus and will increase the calculation speed of FFT which is the most time-consuming step for typical gravitational-wave analyses.
APPLICATION OF SAPPHIRE BONDING FOR INTERFEROMETRIC GRAVITATIONAL WAVE DETECTOR WITH CRYOGENIC MIRRORS
Authors: SUZUKI TOSHIKAZU , TOMARU TAKAYUKI , SATO NOBUAKI , HARUYAMA TOMIYOSHI , SHINTOMI TAKAKAZU , YAMAMOTO AKIRA , TAYLOR COLIN T. , CONTI LIVIA , UCHIYAMA TAKASHI , MIYOKI SHINJI , OHASHI MASATAKE , KURODA KAZUAKI
Published: December 2005

Thermal conductance and light scattering were measured for two bonded sapphire samples. A sample with adhesion free bonding (AFB) showed the same thermal conductivity as that of the bulk at cryogenic temperatures. In contrast, a finite thermal resistance was observed in the sample with hydroxide-catalysis bonding (HCB). Light scattering at λ = 488 nm from bonded region was about 10% larger than the bulk part and was about 800 ppm of an incident laser power for AFB sample.
SMALL VIBRATION CRYOCOOLER SYSTEM FOR CRYOGENIC GRAVITATIONAL WAVE INTERFEROMETER
Authors: TOMARU TAKAYUKI , SUZUKI TOSHIKAZU , HARUYAMA TOMIYOSHI , SHINTOMI TAKAKAZU , SATO NOBUAKI , YAMAMOTO AKIRA , IKUSHIMA YUKI , LI RUI , UCHIYAMA TAKASHI , AKUTSU TOMOMI , MIYOKI SHINJI
Published: December 2005

An ultra-small vibration cryocooler system for a cryogenic interferometric gravitational wave detector has been developed. The system consists of a pulse tube cryocooler and a vibration-reduction system. Its vibration level was about 50 nm for the vertical direction at 1 Hz, which was three orders of magnitude smaller than that of an original pulse tube cryocooler.
PRESENT STATUS OF CLIO IN 2004
Authors:   for the CLIO COLLABORATION: ICRR, the University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8582 Japan; National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588 Japan; National Institute for Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki, 305-8563 Japan; Department of Physics, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8654 Japan; High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki, 305-0801 Japan; Earth, UCHIYAMA TAKASHI
Published: December 2005

The CLIO project in Japan consists of two kinds of interferometric detectors in a tunnel of Kamioka mine. One is a geophysical strain meter and the other one is a gravitational wave (GW) detector. The GW detector is called Cryogenic Laser Interferometer Observatory (CLIO). The characteristics of CLIO are the use of cryogenic to reduce the thermal noises and an underground site for low seismic vibration. CLIO is under construction, and installation of the first cryogenic system was completed in the autumn of 2004.
Lymphatic chylomicron size is inversely related to biliary phospholipid secretion in mice
Authors: Werner Anniek , Havinga Rick , Perton Frank , Kuipers Folkert , Verkade Henkjan J.
Published: December 2005

Biliary phospholipids (PL) stimulate dietary fat absorption by facilitating intraluminal lipid solubilization and by providing surface components for chylomicron (CM) assembly. Impaired hepatic PL availability induces secretion of large very-low-density lipoproteins, but it is unclear whether CM size depends on biliary PL availability. Biliary PL secretion is absent in multidrug resistance protein 2-deficient ( Mdr2−/−) mice, whereas it is strongly increased in essential fatty acid (EFA)-deficient mice. We investigated lymphatic CM size and composition in mice with absent ( Mdr2−/−) or enhanced (EFA deficient) biliary PL secretion and in their respective controls under basal conditions and during enteral lipid administration. EFA deficiency was induced by feeding mice a high-fat, EFA-deficient diet for 8 wk. Lymph was collected by mesenteric lymph duct cannulation with or without intraduodenal lipid administration. Lymph was collected in 30-min fractions for up to 4 h, and lymphatic lipoprotein size was determined by dynamic light-scattering techniques. Lymph lipoprotein subfractions were isolated by ultracentrifugation, and lipid composition was measured. Lymphatic CMs were significantly larger in Mdr2−/−mice than in Mdr2+/+controls either without (+50%) or with (+25%) enteral lipid administration, and molar core-surface ratios were increased [triglyceride (TG)-to-PL ratio: 4.4 ± 1.4 in Mdr2−/−mice vs. 2.7 ± 0.8 in Mdr2+/+mice, P < 0.001]. In contrast, EFA-deficient mice secreted lipoproteins into lymph that were significantly smaller than in EFA-sufficient controls (173 ± 32 vs. 236 ± 47 nm), with correspondingly decreased core-surface ratios (TG-to-PL ratio: 3.0 ± 1.0 in EFA-deficient mice vs. 6.0 ± 1.9 in EFA-sufficient mice, P < 0.001). CM size increased during fat absorption in both EFA-deficient and EFA-sufficient mice, but the difference between the groups persisted. In conclusion, the present results strongly suggest that the availability of biliary PL is a major determinant of the size of intestinally produced lipoproteins both under basal conditions and during lipid absorption. Altered CM size may have physiological consequences for postprandial CM processing.
CRF-induced calcium signaling in guinea pig small intestine myenteric neurons involves CRF-1 receptors and activation of voltage-sensitive calcium channels
Authors: Bisschops R. , Vanden Berghe P. , Sarnelli G. , Janssens J. , Tack J.
Published: December 2005

Corticotropin-releasing factor (CRF) is a 41-amino acid peptide with distinct effects on gastrointestinal motility involving both CRF-1 and CRF-2 receptor-mediated mechanisms that are generally claimed to be centrally mediated. Evidence for a direct peripheral effect is rather limited. Electrophysiological studies showed a cAMP-dependent prolonged depolarization of guinea pig myenteric neurons on application of CRF. The current study aimed to test the direct effect of CRF on myenteric neurons and to identify the receptor subtype and the possible mechanisms involved. Longitudinal muscle myenteric plexus preparations and myenteric neuron cultures of guinea pig small intestine were incubated with the calcium indicator Fluo-4. Confocal Ca2+ imaging was used to visualize activation of neurons on application of CRF. All in situ experiments were performed in the presence of nicardipine 10−6 M to reduce tissue movement. Images were analyzed using Scion image and a specifically developed macro to correct for residual minimal movements. A 75 mM K+-Krebs solution identified 1,076 neurons in 46 myenteric ganglia (16 animals). Administration of CRF 10−6 M and CRF 10−7 M during 30 s induced a Ca2+ response in 22.4% of the myenteric neurons ( n = 303). Responses were completely abolished in the presence of the nonselective CRF antagonist astressin ( n = 55). The selective CRF-1 receptor antagonist CP 154,526 ( n = 187) reduced the response significantly to 2.1%. Stresscopin, a CRF-2 receptor agonist, could not activate neurons at 10−7 M, and its effect at 10−6 M (15.3%, n = 59) was completely blocked by CP 154,526. TTX 10−6 M ( n = 70) could not block the CRF-induced Ca2+ transients but reduced the amplitude of the signals significantly. Removal of extracellular Ca2+ blocked all responses to CRF ( n = 47). L-type channels did not contribute to the CRF-induced Ca2+ transients. Blocking N- or P/Q-type Ca2+ channels did not reduce the responses significantly. Combined L- and R-type Ca2+ channel blocking (SNX-482 10−8 M, n = 64) abolished nearly all responses in situ. Combined L-, N-, and P/Q-type channel blocking also significantly reduced the response to 8.6%. Immunohistochemical staining for CRF-1 receptors clearly labeled individual cell bodies in the ganglia, whereas the CRF-2 receptor staining was barely above background. CRF induces Ca2+ transients in myenteric neurons via a CRF-1 receptor-dependent mechanism. These Ca2+ transients highly depend on somatic calcium influx through voltage-operated Ca2+ channels, in particular R-type channels. Action potential firing through voltage-sensitive sodium channels increases the amplitude of the Ca2+ signals. Besides centrally mediated effects, CRF is likely to modulate gastrointestinal motility on the myenteric neuronal level.
Intestinal alkaline phosphatase gene expression is activated by ZBP-89
Authors: Malo Madhu S. , Mozumder Moushumi , Zhang Xiao Bo , Biswas Shaluk , Chen Alexander , Bai Long-Chuan , Merchant Juanita L. , Hodin Richard A.
Published: December 2005

Intestinal alkaline phosphatase (IAP) is an enterocyte differentiation marker that functions to limit fat absorption. Zinc finger binding protein-89 (ZBP-89) is a Kruppel-type transcription factor that appears to promote a differentiated phenotype in the intestinal epithelium. The purpose of this study was to investigate the regulation of IAP gene expression by ZBP-89. RT-PCR, quantitative real-time RT-PCR, Western blot analyses, and reporter assays were used to determine the regulation of IAP by ZBP-89 in HT-29 and Caco-2 colon cancer cells. ZBP-89 knockdown was achieved by specific short interfering (si)RNA. EMSA and chromatin immunoprecipitation (ChIP) were performed to examine the binding of ZBP-89 to the IAP promoter. The results of RT-PCR, quantitative real-time PCR, and Western blot analyses showed that ZBP-89 was expressed at low levels in Caco-2 and HT-29 cells, whereas IAP was minimally expressed and absent in these cells, respectively. Transfection with ZBP-89 expression plamid increased IAP mRNA and protein levels in both cell lines, whereas knockdown of endogenous ZBP-89 by siRNA reduced basal levels of IAP gene expression in Caco-2 cells. IAP-luciferase reporter assays, EMSA, and ChIP established that ZBP-89 activated the IAP gene through a response element (ZBP-89 response element: 5′-CCTCCTCCC-3′) located between −1018 and −1010 bp upstream of the AUG start codon. We conclude that ZBP-89 is a direct transcriptional activator of the enterocyte differentiation marker IAP. These findings are consistent with the role that this transcription factor is thought to play as a tumor suppressor and suggests its possible function in the physiology of fat absorption.
Endothelin-1, an ulcer inducer, promotes gastric ulcer healing via mobilizing gastric myofibroblasts and stimulates production of stroma-derived factors
Authors: Nishida Tsutomu , Tsuji Shingo , Kimura Arata , Tsujii Masahiko , Ishii Syuji , Yoshio Toshiyuki , Shinzaki Shinichiro , Egawa Satoshi , Irie Takanobu , Yasumaru Masakazu , Iijima Hideki , Murata Hiroaki , Kawano Sunao , Hayashi Norio
Published: December 2005

Endothelin (ET)-1 is a potent inducer of peptic ulcers. The roles of ET-1 in ulcer healing, however, have remained unclear, and these were investigated in mice. Gastric ulcers were induced in mice by serosal application of acetic acid. Three days later, mice were given a neutralizing ET-1 antibody or nonimmunized serum. The ulcer size, amount of fibrosis and myofibroblasts, and localization of ET-1 and ETA/Breceptors were analyzed. To elucidate the mechanisms underlying the effects of ET-1, we examined the proliferation, migration, and release of growth and angiogenic factors in gastric myofibroblasts with or without ET-1. The expression of prepro-ET-1 (an ET-1 precursor) and ET-converting enzyme-1 was examined in gastric myofibroblasts using RT-PCR. Immunoneutralization of ET-1 delayed gastric ulcer healing. The areas of fibrosis and myofibroblasts were smaller in the anti-ET-1 antibody group than in the control. ET-1 was expressed in the gastric epithelium, myofibroblasts, and other cell types. ETAreceptors, but not ETBreceptors, were present in myofibroblasts. ET-1 increased proliferation and migration of gastric myofibroblasts. ET-1 stimulated the release of hepatocyte growth factor, VEGF, PGE2, and IL-6 from gastric myofibroblasts. mRNA for prepro-ET-1 and ET-converting enzyme-1 was also expressed. ET-1 promotes the accumulation of gastric myofibroblasts and collagen fibrils at gastric ulcers. ET-1 also stimulates migration and proliferation of gastric myofibroblasts and enhances the release of growth factors, angiogenic factors, and PGE2. Thus ET-1 has important roles not only in ulcer formation but also in ulcer healing via mobilizing myofibroblasts and inducing production of stroma-derived factors.
Intracoronary infusion of Gd3+ into ischemic region does not suppress phase Ib ventricular arrhythmias after coronary occlusion in swine
Authors: Barrabés José A. , Garcia-Dorado David , Agulló Luis , Rodríguez-Sinovas Antonio , Padilla Ferran , Trobo Lourdes , Soler-Soler Jordi
Published: December 2005

Increased mechanical tension in the ischemic region during acute coronary occlusion might favor the occurrence of phase Ib ventricular arrhythmias. We aimed to investigate whether intracoronary administration of Gd3+, a stretch-activated channel blocker, into the ischemic zone reduces the incidence of these arrhythmias. In thiopental-anesthetized, open-chest pigs, the left anterior descending coronary artery (LAD) was ligated for 45 or 48 min. Phosphate-free, HEPES-buffered saline bubbled with 100% N2 was infused into the ischemic region for 4 min, starting 5 min ( series A; n = 16) or 20 min ( series B; n = 16) after coronary occlusion, at a rate doubling the baseline blood flow. Animals were blindly allocated to receive 40 μM Gd3+ or only the buffer during the final 2 min of the infusion. There were no differences between groups with respect to hemodynamic variables, plasma K+ levels, or size of the ischemic region. In neither series was the number of phase Ib premature ventricular beats reduced by Gd3+ (46 ± 20 in untreated vs. 91 ± 37 in Gd3+-treated animals in series A and 19 ± 7 vs. 22 ± 13, respectively, in series B; both P = not significant). The occurrence of ventricular tachycardia or fibrillation was significantly associated with the magnitude of early ischemic expansion of the LAD region, as measured by ultrasonic crystals, but was also not prevented by Gd3+. These results argue against a major role of stretch-activated channels inside the area at risk in the genesis of phase Ib ischemic ventricular arrhythmias.
Priming of polymorphonuclear leukocytes: a culprit in the initiation of endothelial cell injury
Authors: Jacobi Jeanna , Sela Shifra , Cohen Hector I. , Chezar Judith , Kristal Batya
Published: December 2005

Peripheral polymorphonuclear leukocytes (PMNL) in hemodialysis (HD) patients are primed, continually releasing and exposing the vascular endothelium to soluble factors such as reactive oxygen species and inflammatory mediators. To mimic the close proximity between PMNL and the endothelial monolayer and to monitor and characterize the influence of soluble mediators released from PMNL, we developed a novel cocultivation system using primary human umbilical vein endothelial cell (HUVEC) cultures and PMNL, with a sieve separating the two cell types to prevent direct adhesive effects. PMNL (106) from HD patients or from healthy normal controls were cocultivated with HUVEC (105) for 15 min, and endothelial cell injury was assessed by HUVEC morphology, cell detachment, and apoptosis. Proinflammatory changes were estimated by expression of HUVEC adhesion molecule P-selectin and by endothelial IL-8 and endothelial nitric oxide synthase mRNA. The levels of intracellular tissue factor reflected the procoagulant state, whereas NADPH oxidase activity served as an indicator for prooxidative changes in HUVEC. Mediators released from the primed PMNL triggered activation/dysfunction of endothelial cells, causing 1) an increase in endothelial cell detachment and apoptosis, 2) a proinflammatory state manifested by increased IL-8 mRNA expression and P-selectin on the endothelial surface, 3) activation of endothelial NADPH oxidase, 4) an increase in endothelial cell tissue factor that directly correlated with PMNL priming index, and 5) a decrease in endothelial nitric oxide synthase mRNA. Our data support a pathogenic link between PMNL priming and endothelial dysfunction, suggesting that PMNL priming is a potential new nontraditional risk factor for the development of atherosclerosis.
Interaction of electrophilic lipid oxidation products with mitochondria in endothelial cells and formation of reactive oxygen species
Authors: Landar Aimee , Zmijewski Jaroslaw W. , Dickinson Dale A. , Le Goffe Claire , Johnson Michelle S. , Milne Ginger L. , Zanoni Giuseppe , Vidari Giovanni , Morrow Jason D. , Darley-Usmar Victor M.
Published: December 2005

Electrophilic lipids, such as 4-hydroxynonenal (HNE), and the cyclopentenones 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) and 15-J2-isoprostane induce both reactive oxygen species (ROS) formation and cellular antioxidant defenses, such as heme oxygenase-1 (HO-1) and glutathione (GSH). When we compared the ability of these distinct electrophiles to stimulate GSH and HO-1 production, the cyclopentenone electrophiles were somewhat more potent than HNE. Over the concentration range required to observe equivalent induction of GSH, dichlorofluorescein fluorescence was used to determine both the location and amounts of electrophilic lipid-dependent ROS formation in endothelial cells. The origin of the ROS on exposure to these compounds was largely mitochondrial. To investigate the possibility that the increased ROS formation was due to mitochondrial localization of the lipids, we prepared a novel fluorescently labeled form of the electrophilic lipid 15d-PGJ2. The lipid demonstrated strong colocalization with the mitochondria, an effect which was not observed by using a fluorescently labeled nonelectrophilic lipid. The role of mitochondria was confirmed by using cells deficient in functional mitochondria. On the basis of these data, we propose that ROS formation in endothelial cells is due to the direct interaction of these lipids with the organelle.
Surfactant protein D is proatherogenic in mice
Authors: Sorensen Grith L. , Madsen Jens , Kejling Karin , Tornoe Ida , Nielsen Ole , Townsend Paul , Poulain Francis , Nielsen Claus H. , Reid Kenneth B. M. , Hawgood Samuel , Falk Erling , Holmskov Uffe
Published: December 2005

Surfactant protein D (SP-D) is an important innate immune defense molecule that mediates clearance of pathogens and modulates the inflammatory response. Moreover, SP-D is involved in lipid homeostasis, and pulmonary accumulation of phospholipids has previously been observed in SP-D-deficient ( Spd−/−) mice. Atherogenesis involves both inflammation and lipid deposition, and we investigated the role of SP-D in the development of atherosclerosis. SP-D synthesis was localized to vascular endothelial cells. Atherosclerotic lesion areas were 5.6-fold smaller in the aortic roots in Spd−/− mice compared with wild-type C57BL/6N mice on an atherogenic diet. HDL cholesterol (HDL-C) was significantly elevated in Spd−/− mice. Treatment of Spd−/− mice with a recombinant fragment of human SP-D resulted in decreases of HDL-C (21%) as well as total cholesterol (26%), and LDL cholesterol (28%). Plasma TNF-α was reduced in Spd−/− mice (45% difference). SP-D was proatherogenic in the mouse model used. The effect is likely to be due to the observed disturbances of plasma lipid metabolism and alteration of the inflammatory process, which underlie the reduced susceptibility to atherosclerosis in Spd−/− mice.
Endurance exercise training attenuates cardiac β2-adrenoceptor responsiveness and prevents ventricular fibrillation in animals susceptible to sudden death
Authors: Billman George E. , Kukielka Monica , Kelley Robert , Moustafa-Bayoumi Moustafa , Altschuld Ruth A.
Published: December 2005

Enhanced cardiac β2-adrenoceptor (β2-AR) responsiveness can increase susceptibility to ventricular fibrillation (VF). Exercise training can decrease cardiac sympathetic activity and could, thereby, reduce β2-AR responsiveness and decrease the risk for VF. Therefore, dogs with healed myocardial infarctions were subjected to 2 min of coronary occlusion during the last minute of a submaximal exercise test; VF was observed in 20 susceptible, but not in 13 resistant, dogs. The dogs were then subjected to a 10-wk exercise-training program ( n = 9 susceptible and 8 resistant) or an equivalent sedentary period ( n = 11 susceptible and 5 resistant). Before training, the β2-AR antagonist ICI-118551 (0.2 mg/kg) significantly reduced the peak contractile (by echocardiography) response to isoproterenol more in the susceptible than in the resistant dogs: −45.5 ± 6.5 vs. −19.2 ± 6.3% . After training, the susceptible and resistant dogs exhibited similar responses to the β2-AR antagonist: −12.1 ± 5.7 and −16.2 ± 6.4%, respectively. In contrast, ICI-118551 provoked even greater reductions in the isoproterenol response in the sedentary susceptible dogs: −62.3 ± 4.6%. The β2-AR agonist zinterol (1 μM) elicited significantly smaller increases in isotonic shortening in ventricular myocytes from susceptible dogs after training ( n = 8, +7.2 ± 4.8%) than in those from sedentary dogs ( n = 7, +42.8 ± 5.8%), a response similar to that of the resistant dogs: +3.0 ± 1.4% ( n = 6) and +3.2 ± 1.8% ( n = 5) for trained and sedentary, respectively. After training, VF could no longer be induced in the susceptible dogs, whereas four sedentary susceptible dogs died during the 10-wk control period and VF could still be induced in the remaining seven animals. Thus exercise training can restore cardiac β-AR balance (by reducing β2-AR responsiveness) and could, thereby, prevent VF.
Airway remodeling in allergen-challenged Brown Norway rats: distribution of proteoglycans
Authors: Pini Laura , Torregiani Chiara , Martin James G. , Hamid Qutayba , Ludwig Mara S.
Published: December 2005

Proteoglycans (PG) have important effects on the mechanical properties of tissues and the phenotype of various structural cells. Little is known about changes in PG deposition in the airways in animal models of asthma. We studied changes in PG in the airway wall of Brown Norway rats sensitized to ovalbumin (OA) and exposed to repeated OA challenge. Control (Sal) animals were sensitized and challenged with saline. After the 3rd challenge, animals were killed and lungs fixed in formalin. Tissue sections were incubated with antibodies to the small, leucine-rich PG, decorin, and biglycan and collagen type I. Airways were classified according to basement membrane perimeter length (≤0.99, 1–2.99, and ≥3 mm). Decorin, biglycan, and collagen type I were increased in the airways of OA vs. Sal rats. Remodeling was most prominent in central airways. The distribution of PG differed with respect to the subepithelial vs. airway smooth muscle (ASM) vs. adventitial layer. Whereas biglycan was readily detected within the ASM, decorin and collagen were detected outside the ASM and especially in the adventitial layer. Differences in the distribution of these molecules within the layers of the airway wall may reflect their specific functional roles.