Time-Evolution of Collective Meson Fields and Amplification of Quantum Meson Modes in Chiral Phase Transition

The time evolution of quantum meson fields in the O(4) linear sigma model is investigated in a context of the dynamical chiral phase transition. It is shown that amplitudes of quantum pion modes are amplified due to both mechanisms of a parametric resonance and a resonance by the forced oscillation according to the small oscillation of the chiral condensate in the late time of chiral phase transition.Comment: 4 pages; Talk presented at the XVIth International Conference on Particles and Nuclei (PANIC02), Sep. 30 - Oct. 4, 2002, Osaka, Japan, to appear in Nuclear Physics

Simultaneous Measurements of Proton Ratio and Beam Divergence of Positive-ion-based Neutral Beam in the Large Helical Device

A spectroscopy system was installed on the diagnostic neutral beam injector in LHD. The Hα lines spectrum emitted by full, half and one-third energy component are clearly observed, and the proton ratio and the beam divergence were estimated by the line intensity and the line width, respectively. The proton ratio of 85?90 % is achieved in high arc power discharge. The beam divergence of them shows their minimum with the same perveance. It was experimentally confirmed that the spectroscopy system is useful for the monitor of the proton ratio and the divergence of the beam

A Systems Genetics Approach Provides a Bridge from Discovered Genetic Variants to Biological Pathways in Rheumatoid Arthritis

Genome-wide association studies (GWAS) have yielded novel genetic loci underlying common diseases. We propose a systems genetics approach to utilize these discoveries for better understanding of the genetic architecture of rheumatoid arthritis (RA). Current evidence of genetic associations with RA was sought through PubMed and the NHGRI GWAS catalog. The associations of 15 single nucleotide polymorphisms and HLA-DRB1 alleles were confirmed in 1,287 cases and 1,500 controls of Japanese subjects. Among these, HLA-DRB1 alleles and eight SNPs showed significant associations and all but one of the variants had the same direction of effect as identified in the previous studies, indicating that the genetic risk factors underlying RA are shared across populations. By receiver operating characteristic curve analysis, the area under the curve (AUC) for the genetic risk score based on the selected variants was 68.4%. For seropositive RA patients only, the AUC improved to 70.9%, indicating good but suboptimal predictive ability. A simulation study shows that more than 200 additional loci with similar effect size as recent GWAS findings or 20 rare variants with intermediate effects are needed to achieve AUC = 80.0%. We performed the random walk with restart (RWR) algorithm to prioritize genes for future mapping studies. The performance of the algorithm was confirmed by leave-one-out cross-validation. The RWR algorithm pointed to ZAP70 in the first rank, in which mutation causes RA-like autoimmune arthritis in mice. By applying the hierarchical clustering method to a subnetwork comprising RA-associated genes and top-ranked genes by the RWR, we found three functional modules relevant to RA etiology: “leukocyte activation and differentiation”, “pattern-recognition receptor signaling pathway”, and “chemokines and their receptors”

Dynamics of rheumatoid joint

In the present communication the recent works done by the Rheumatism Research Group of Department of Orthopedic Surgery, Okayama University, are described. The principal findings may briefly be summarized as follows. 1. Pathohistological pictures of the synovial membrane are classified into six types. Among them, Fibrinoid type and Follicular-Fibrosis type are the representative ones of chronic rheumatoid arthritis. 2. For the evaluation of the systemic as well as the local activities in rheumatoid arthritis and for judging the therapeutic effect, some indices have been established. 3. Injection of steroid hormones into the local joints fails to give satisfactory results in advanced, chronic rheumatoid arthritis. In such instances the flushing of the joint with physiological saline solution is effective. 4. In the case of chronic rheumatoid arthritis where the inflammation of hand and phalangeal joints is marked, RA-test gives rapid and more intense reaction, and most of such cases are of Follicular-Fibrosis type. 5. When lymph follicles appearing in the synovial membrane are stained when methyl green pyronine, the arrangement of lymphoid cells and plasma cells becomes distinctly clear. By micro-autoradiographic observations it can be seen that ³H-thymindine injected into the joint cavity is mostly ingested by the lymphoid cells in lymph follicles. 6. In the observation by the fluorescent antibody method multinuclear leucocytes found in the joint fluid and in the peripheral blood react with 19S and 7S-gamma-globulins. 7. When the serum and the joint fluid of the patient with rheumatoid arthritis are fractionated, they separate into three peaks at 19S, 7S, and 4S. Both S. S. C. A.-test and L. F. T. tests reveal the peak at 19S. The serum of chronic hepatitis positive to RA-test and the serum of rheumatoid arthritis are found to react immunologically the same to anti-&#946;2 M globulin sheep serum. 8. When the reticulo-endothelial system of rat is blocked by 900,000 molecules of poly-vinyl-pyrroridon, the ability of antibody production is diminished. 9. Chemical synovectomy of injecting osmic acid is effective to FibrinoidCoating type. Its action mechanism lies in the complete cleaning of the surface of synovial membrane. 10. By radiating synovectomy with 193Au a fairly good result can be expected. 198Au is ingested by those cells in the surface layer of the synovial membrane and also by histiocytes in the synovial membrane. When 5 mc of 198Au are injected into the knee joint, a marked necrosis of the synovial membrane occurs. When 198Au is added to the ascites cells of rabbit during the tissue culture, in the concentration of over 14 &#956;C degeneration of these cells can be recognized. 11. From the examination results of prognosis on those 25 cases with 41 rheumatoid knee joints after surgical synovectomy, it is considered that this method is indicated for Follicular-Fibrosis type. Ones with rheumatoid knee joint of Fibrinoid-Coating type gold sol treatment should be resorted to. In the cases of hand joints, surgical synovectemy is to be recommended at a relatively early stage.</p

FGF2 Has Distinct Molecular Functions from GDNF in the Mouse Germline Niche

Both glial cell line-derived neurotrophic factor (GDNF) and fibroblast growth factor 2 (FGF2) are bona fide self-renewal factors for spermatogonial stem cells, whereas retinoic acid (RA) induces spermatogonial differentiation. In this study, we investigated the functional differences between FGF2 and GDNF in the germline niche by providing these factors using a drug delivery system in vivo. Although both factors expanded the GFRA1+ subset of undifferentiated spermatogonia, the FGF2-expanded subset expressed RARG, which is indispensable for proper differentiation, 1.9-fold more frequently than the GDNF-expanded subset, demonstrating that FGF2 expands a differentiation-prone subset in the testis. Moreover, FGF2 acted on the germline niche to suppress RA metabolism and GDNF production, suggesting that FGF2 modifies germline niche functions to be more appropriate for spermatogonial differentiation. These results suggest that FGF2 contributes to induction of differentiation rather than maintenance of undifferentiated spermatogonia, indicating reconsideration of the role of FGF2 in the germline niche

Spatial resolved high-energy particle diagnostic system using time-of-flight neutral particle analyzer in Large Helical Device

The time-of-flight-type neutral particle analyzer has an ability of horizontal scanning from 40 to 100° of the pitch angle. The information from the spatially resolved energy spectrum gives not only the ion temperature but also the information of the particle confinement and the electric field in plasmas. We have been studying the energy distributions at various magnetic configurations in the neutral beam injection (NBI) plasma. The spatially resolved energy spectra can be observed during long discharges of the NBI plasma by continuous scanning of the neutral particle analyzer. The shape of spectra is almost similar from 44° to 53°. However, the spectra from 55° are strongly varied. They reflect the injection pitch angle of the beam. The pitch angle scanning experiment during the long discharge of NBI plasma has also been made under the reversal of the magnetic field direction. NBI2 becomes counter injected with the reversal. We can easily observe the difference between co- and counter injections of NBI. During the electron cyclotron heating in the low-density plasma for the formation of the internal thermal barrier, large neutral particle increase or decease can be observed. The degree of the increase/decrease depends on the energy and the density. The reason for the variation of the particle flux is that the orbit of the trapped particle changes due to the electric field formed by the strong electron cyclotron heating

High Energy Particle Measurements during Long Discharge in LHD

The spatial resolved energy spectra can be observed during a long discharge of NBI plasma bycontinuously scanning the neutral particle analyzer. In these discharges, the plasmas are initiated by the ECH heating, after that NBI#2 (Co-injection) sustains the plasma during 40-60 seconds. The scanned pitch angle is from 44 degrees to 74 degrees. The injected neutral beam (hydrogen) energy of NBI#2 is only 130 keV because the original ion source polarity is negative. The shape of spectra is almost similar from 44 degrees to 53 degrees. However the spectra from 55 degrees are strongly varied. It reflects the injection pitch angle of the beam according to the simulation (53 degrees ot R* = 3.75 m in simulation). The beam keeps the pitch angle at incidence until the beam energy becomes to the energy, which the pitch angle scattering is occurred by the energy loss due to the electron collision. The low flux region can be observed around 10-15 keV, which is 15 times of the electron temperature. The energy region may be equal to the energy at which the pitch angle scattering is occurred. At the energy, the particle is scattered by the collision with the plasma ions and some of particles may run away from the plasma because they have a possibility to enter the loss cone. According to the simulation, the loss cone can be expected at the 10 keV with the small angular dependence. The depth of the loss cone is deep at the small pitch angle. The hollow in the spectrum may be concluded to be the loss cone as the tendency is almost agreed with the experimental result

Improvement of Ion Confinement in Core Electron-Root Confinement (CERC) Plasmas in Large Helical Device

An increase in ion temperature has been observed with superposition of centrally focused electron cyclotron resonance heating (ECRH) to plasmas heated by high-energy neutral beam injection (NBI) in Large Helical Device. The ion-temperature (Ti) rise is accompanied by the formation of electron internal transport barrier (ITB). A transport analysis shows that ion transport as well as electron transport is improved with the reduction of anomalous transport. A neoclassical ambipolar flux calculation shows a positive radial-electric field (Er) in the region of the Ti rise, and Er should suppress the enhancement of ripple transport due to the Ti-rise. These analyses indicate the ion transport improvement in the core electron-root confinement plasmas. Toroidal rotation is driven in the co-direction by applying ECRH, and the toroidal rotation velocity is increased with the Ti rise. A correlation between the Ti rise and toroidal rotation is suggested

Impurity emission characteristics of long pulse discharges in Large Helical Device

Line spectra from intrinsic impurity ions have been monitored during the three kinds of long-pulse discharges (ICH, ECH, NBI). Constant emission from the iron impurity shows no preferential accumulation of iron ion during the long-pulse operations. Stable Doppler ion temperature has been also measured from Fe XX, C V and C III spectra

Recent Results from LHD Experiment with Emphasis on Relation to Theory from Experimentalist’s View

he Large Helical Device (LHD) has been extending an operational regime of net-current free plasmas towardsthe fusion relevant condition with taking advantage of a net current-free heliotron concept and employing a superconducting coil system. Heating capability has exceeded 10 MW and the central ion and electron temperatureshave reached 7 and 10 keV, respectively. The maximum value of β and pulse length have been extended to 3.2% and 150 s, respectively. Many encouraging physical findings have been obtained. Topics from recent experiments, which should be emphasized from the aspect of theoretical approaches, are reviewed. Those are (1) Prominent features in the inward shifted configuration, i.e., mitigation of an ideal interchange mode in the configuration with magnetic hill, and confinement improvement due to suppression of both anomalous and neoclassical transport, (2) Demonstration ofbifurcation of radial electric field and associated formation of an internal transport barrier, and (3) Dynamics of magnetic islands and clarification of the role of separatrix