Fractionalization and Fermi surface volume in heavy fermion compounds: the case of YbRh2_2 Si2_2

We establish an effective theory for heavy fermion compounds close to a zero temperature Anti-Ferromagnetic (AF) transition. Coming from the heavy Fermi liquid phase across to the AF phase, the heavy electron fractionalizes into a light electron, a bosonic spinon and a {\it new} excitation: a spinless fermionic field. Assuming this field acquires dynamics and dispersion when one integrates out the high energy degrees of freedom, we give a scenario for the volume of its Fermi surface through the phase diagram. We apply our theory to the special case of YbRh$_2$(Si$_{1-x}$ Ge$_x$)$_2$ where we recover, within experimental resolution, several low temperature exponents for transport and thermodynamics.Comment: 4 pages, 5 figure

An Unbiased Survey for Molecular Clouds in the Southern Galactic Warp

We have made an unbiased survey for molecular clouds in the Galactic Warp. This survey, covering an area of 56 square degrees at l = 252 deg to 266 deg and b = -5 deg to -1 deg, has revealed 70 molecular clouds, while only 6 clouds were previously known in the region. The number of molecular clouds is, then, an order of magnitude greater than previously known in this sector at R > 14.5 kpc. The mass of the clouds is in a range from 7.8x10(2) Mo to 8.4x10(4) Mo, significantly less than the most massive giant molecular clouds in the inner disk, ~10(6) Mo, while the cloud mass spectrum characterized by a power law is basically similar to other parts of the Galaxy. The X factor, N(H2)/Wco(12CO), derived from the molecular clouds in the Warp is estimated to be 3.5(+/-1.8) times larger than that in the inner disk. The total molecular mass in the Warp is estimated as 7.3x10(5) Mo, and total mass in the far-outer Galaxy (R > 14.5 kpc) can be estimated as 2x10(7) Mo. The spatial correlation between the CO and HI distribution appears fairly good, and the mass of the molecular gas is about 1% of that of the atomic gas in the far-outer Galaxy. This ratio is similar to that in the interarm but is ten times smaller than those of the spiral arms. Only 6 of the 70 Warp clouds show signs of star formation at the IRAS sensitivity and star formation efficiency for high-mass stars in the Warp is found to be smaller than those in other molecular clouds in the Galaxy.Comment: 29 pages, including 12 (pages of) figures, accepted for PASJ, and will be published in PASJ Vol.57, No.6. Tables and color-figures are available on-line: http://www.a.phys.nagoya-u.ac.jp/~masa/study/nakagawa_etal2005_warp.pd

The relationship between the COPD Assessment Test score and airflow limitation in Japan in patients aged over 40 years with a smoking history.

BACKGROUND: A large number of chronic obstructive pulmonary disease (COPD) patients in Japan remain undiagnosed, primarily due to the underuse of spirometry. Two studies were conducted to see whether the COPD Assessment Test (CAT) in primary care has the potential to identify those patients who need spirometry for a diagnosis of COPD and to determine whether patients with cardiovascular disease had airflow limitation, which could be detected by CAT. MATERIALS AND METHODS: Two multicenter, noninterventional, prospective studies (studies 1 and 2) were conducted across Japan. Patients in both studies were ≥40 years old with a smoking history. Those in study 1 were seen in primary care and had experienced repeated respiratory tract infections, but had no diagnosis of COPD. Patients in study 2 were identified in cardiovascular disease clinics when routinely visiting for their cardiovascular disease. All patients completed the CAT prior to lung-function testing by hand-held spirometry. The presence of airflow limitation was defined as a forced expiratory volume in 1 second (FEV1)/FEV6 ratio<0.73. RESULTS: A total of 3,062 subjects completed the CAT (2,067 in study 1, 995 in study 2); 88.8% were male, and the mean age (±standard deviation) was 61.5±11.6 years. Airflow limitation was found in 400 (19.4%) patients in study 1, and 269 (27.0%) in study 2. The CAT score in patients with airflow limitation was significantly higher than in patients without airflow limitation in both studies: 8.6 (95% confidence interval [CI] 7.9-9.2) versus 7.4 (95% CI 7.1-7.6) in study 1, and 8.3 (95% CI 7.5-9.2) versus 6.4 (95% CI 6.0-6.8) in study 2 (both P<0.001). CONCLUSION: These findings suggest that the CAT has the potential to identify patients with cardiovascular disease or a history of frequent chest infections who need spirometry to diagnose COPD

Catalogue of 12CO(J=1-0) and 13CO(J=1-0) Molecular Clouds in the Carina Flare Supershell

We present a catalogue of 12CO(J=1-0) and 13CO(J=1-0) molecular clouds in the spatio-velocity range of the Carina Flare supershell, GSH 287+04-17. The data cover a region of ~66 square degrees and were taken with the NANTEN 4m telescope, at spatial and velocity resolutions of 2.6' and 0.1 km/s. Decomposition of the emission results in the identification of 156 12CO clouds and 60 13CO clouds, for which we provide observational and physical parameters. Previous work suggests the majority of the detected mass forms part of a comoving molecular cloud complex that is physically associated with the expanding shell. The cloud internal velocity dispersions, degree of virialization and size-linewidth relations are found to be consistent with those of other Galactic samples. However, the vertical distribution is heavily skewed towards high-altitudes. The robust association of high-z molecular clouds with a known supershell provides some observational backing for the theory that expanding shells contribute to the support of a high-altitude molecular layer.Comment: To be published in PASJ Vol. 60, No. 6. (Issued on December 25th 2008). 35 pages (including 13 pages of tables), 7 figures. Please note that formatting problems with the journal macro result in loss of rightmost data columns in some long tables. These will be fixed in the final published issue. In the meantime, please contact the authors for missing dat

Multipole correlations of t2gt_{\rm 2g}-orbital Hubbard model with spin-orbit coupling

We investigate the ground-state properties of a one-dimensional $t_{\rm 2g}$-orbital Hubbard model including an atomic spin-orbit coupling by using numerical methods, such as Lanczos diagonalization and density-matrix renormalization group. As the spin-orbit coupling increases, we find a ground-state transition from a paramegnetic state to a ferromagnetic state. In the ferromagnetic state, since the spin-orbit coupling mixes spin and orbital states with complex number coefficients, an antiferro-orbital state with complex orbitals appears. According to the appearance of the complex orbital state, we observe an enhancement of $\Gamma_{4u}$ octupole correlations.Comment: 3 pages, 3 figures, To appear in J. Phys. Soc. Jpn. Suppl., Proceedings of ICHE2010 (September 17-20, 2010, Hachioji, Japan

Changes in plasma levels of B-type natriuretic peptide with acute exacerbations of chronic obstructive pulmonary disease.

Background: Elevated plasma B-type natriuretic peptide (BNP) levels and their association with heart failure have been reported in subjects with acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Purpose: To examine and compare plasma BNP levels and diastolic and systolic dysfunction in subjects with AECOPD and s table chronic obstructive pulmonary disease (COPD). Methods: In all,87 unselected consecutive hospitalizations due to AECOPD in 61 subjects and a total of 190 consecutive subjects with stable COPD were recruited. Plasma BNP levels were compared cross-sectionally and longitudinally. Transthoracic echocardiographic examinations were also performed in the hospitalized subjects. Results: In the hospitalized subjects, the median plasma BNP level (interquartile range) was 55.4 (26.9–129.3) pg/mL and was higher than that of patients with stable COPD: 18.3 (10.0–45.3)for Global Initiative for Chronic Obstructive Lung Disease grade I; 25.8 (11.0–53.7) for grade II; 22.1 (9.1–52.6) for grade III; and 17.2 (9.6–22.9) pg/mL for grade IV, all P,0.001. In 15 subjects studied prospectively, the median plasma BNP level was 19.4 (9.8–32.2) pg/mL before AECOPD, 72.7 (27.7–146.3) pg/mL during AECOPD, and 14.6 (12.9–39.0) pg/mL after AECOPD (P,0.0033 and P,0.0013, respectively). Median plasma BNP levels during AECOPD were significantly higher in ten unsuccessfully discharged subjects 260.5 (59.4–555.0) than in 48 successfully discharged subjects 48.5(24.2–104.0) pg/mL (P=0.0066). Only 5.6% of AECOPD subjects were associated with systolic dysfunction defined as a left ventricular ejection fraction (LVEF),50%; a further 7.4% were considered to have impaired relaxation defined as an E/A wave velocity ratio,0.8 and a deceleration time of E.240 ms. BNP levels were weakly correlated with the E/peak early diastolic velocity of the mitral annulus (Ea) ratio (Spearman’s rank correlation coefficient =0.353,P =0.018), but they were not correlated with the LVEF (Spearman’s rank correlation coefficient =−0.221,P = 0.108). Conclusion: A modest elevation of plasma BNP is observed during AECOPD. It appears that AECOPD may have an impact on plasma BNP levels that is not attributable to heart failure

Spin, charge, and orbital correlations in the one-dimensional t2g-orbital Hubbard model

We present the zero-temperature phase diagram of the one-dimensional t2g-orbital Hubbard model, obtained using the density-matrix renormalization group and Lanczos techniques. Emphasis is given to the case for the electron density n=5 corresponding to five electrons per site, of relevance for some Co-based compounds. However, several other cases for electron densities between n=3 and 6 are also studied. At n=5, our results indicate a first-order transition between a paramagnetic (PM) insulator phase and a fully-polarized ferromagnetic (FM) state by tuning the Hund's coupling. The results also suggest a transition from the n=5 PM insulator phase to a metallic regime by changing the electron density, either via hole or electron doping. The behavior of the spin, charge, and orbital correlation functions in the FM and PM states are also described in the text and discussed. The robustness of these two states varying parameters suggests that they may be of relevance in more realistic higher dimensional systems as well.Comment: 9 pages, 8 figure

Cranked Hartree-Fock-Bogoliubov Calculation for Rotating Bose-Einstein Condensates

A rotating bosonic many-body system in a harmonic trap is studied with the 3D-Cranked Hartree-Fock-Bogoliubov method at zero temperature, which has been applied to nuclear many-body systems at high spin. This method is a variational method extended from the Hartree-Fock theory, which can treat the pairing correlations in a self-consistent manner. An advantage of this method is that a finite-range interaction between constituent particles can be used in the calculation, unlike the original Gross-Pitaevskii approach. To demonstrate the validity of our method, we present a calculation for a toy model, that is, a rotating system of ten bosonic particles interacting through the repulsive quadrupole-quadrupole interaction in a harmonic trap. It is found that the yrast states, the lowest-energy states for the given total angular momentum, does not correspond to the Bose-Einstein condensate, except a few special cases. One of such cases is a vortex state, which appears when the total angular momentum $L$ is twice the particle number $N$ (i.e., $L=2N$).Comment: accepted to Phys. Rev.