424 research outputs found
Examining the Functional Specification of Two-Parameter Model under Location and Scale Parameter Condition
The functional specification of mean-standard deviation approach is examined under location and scale parameter condition. Firstly, the full set of restrictions imposed on the mean-standard deviation function under the location and scale parameter condition are made clear. Secondly, the examination based on the restrictions mentioned in the previous sentence derives the new properties of the mean-standard deviation function on the applicability of additive separability and the curvature of expansion path which links the points that give the same slope of indifference curve. It reveals that attention has not been sufficiently paid to the restrictions in interpreting the linear mean-standard deviation model and the nonlinear mean-standard deviation model that have been used in previous research. Thirdly, the interpretation of the nonlinear mean-standard deviation model is reconsidered in detail and then an alternative nonlinear mean-standard deviation model is proposed. The implication of the two nonlinear mean-standard deviation models to the empirical approach called "joint analysis of risk preference structure and technology" is discussed.mean-standard deviation approach, location and scale parameter condition, functional specification, risk aversion, uncertainty, Research Methods/ Statistical Methods,
Observations of SiO Maser Sources within a Few Parsec from the Galactic Center
Mapping and monitoring observations of SiO maser sources near the Galactic
center were made with the Nobeyama 45-m telescope at 43 GHz. Rectangular
mapping an area of approximately 200'' x 100''$ in a 30'' grid, and triangular
mapping in a 20'' grid toward the Galactic center, resulted in 15 detections of
SiO sources; the positions of the sources were obtained with errors of 5--10'',
except for a few weak sources. Three-year monitoring observations found that
the component at V_lsr=-27 km/s of IRS 10 EE flared to about 1.5 Jy during 2000
March--May, which was a factor of more than 5 brighter than its normal
intensity. Using the radial velocities and positions of the SiO sources, we
identified 5 which are counterparts of previously observed OH 1612 MHz sources.
The other 10 SiO sources have no OH counterparts, but two were previously
detected with VLA, and four are located close to the positions of
large-amplitude variables observed at near-infrared wavelengths. A
least-squares fit to a plot of velocities versus Galactic longitudes gives a
rather high speed for the rotation of the star cluster around the Galactic
center. The observed radial-velocity dispersion is roughly consistent with a
value obtained before. It was found that all of the SiO sources with OH 1612
MHz counterparts have periods of light variation longer than 450 days, while
SiO sources without OH masers often have periods shorter than 450 days. This
fact suggests that lower-mass AGB stars are more often detected in SiO masers
than in the OH 1612 MHz line.Comment: 9 pages, 7 figures. PASJ 54, No. 1 (2002) in pres
Diagnostic value of ventilation/perfusion single-photon emission computed tomography/computed tomography for bronchiolitis obliterans syndrome in patients after lung transplantation
OBJECTIVE:
To evaluate the diagnostic value of function volume/morphological volume ratio calculated from ventilation/perfusion single-photon emission computed tomography/computed tomography in distinguishing the lungs with bronchiolitis obliterans syndrome (BOS) from the lungs without this syndrome after lung transplantation and to assess its relationship with spirometry parameters.
MATERIALS AND METHODS:
We retrospectively identified 84 consecutive lung transplant recipients and 13 donors who underwent ventilation/perfusion single-photon emission computed tomography/computed tomography. Differences in the function volume/morphological volume ratio of unilateral lungs were tested for significance between the lungs with and without BOS. Receiver operating characteristics and correlations between function volume/morphological volume ratios of bilateral lungs and forced expiratory volume in 1 s, forced vital capacity, and total lung capacity were analyzed.
RESULTS:
The function volume/morphological volume ratios of ventilation and perfusion images of unilateral lungs were significantly lower in lungs with BOS (each P
CONCLUSION:
The function volume/morphological volume ratio enables a semiquantitative assessment of ventilation and perfusion lung functions and is useful for diagnosing BOS after lung transplantation
Rapid Contamination During Storage of Carbonaceous Chondrites Prepared for Micro FTIR Measurements
The carbonaceous chondrites Tagish Lake and Murchison, which contain abundant hydrous minerals, when pressed on aluminum plates and analyzed by micro FTIR, were found to have been contaminated during brief (24 hours) storage. This contamination occurred when the samples were stored within containers which included silicone rubber, silicone grease or adhesive tape. Long-path gas cell FTIR measurements for silicone rubber revealed the presence of contaminant volatile molecules having 2970 cm(sup -1) (CH3) and 1265 cm(sup -1) (Si-CH3) peaks. These organic contaminants are found to be desorbed by in-situ heating infrared measurements from room temperature to 200-300 C. Careful preparation and storage are therefore needed for precious astronomical samples such as meteorites, IDPs and mission returned samples from comets, asteroids and Mars, if useful for FTIR measurements are to be made
Regulation of gonadotropin secretion and puberty onset by neuromedin U
AbstractNeuromedin U (NMU), an anorexigenic peptide, was originally isolated from porcine spinal cord in 1985. As NMU is abundant in the anterior pituitary gland, we investigated the effects of NMU on gonadotropin secretion. Both NMU and its receptors, NMUR1 and NMUR2, were expressed in the pituitary gland. NMU suppressed LH and FSH releases from rat anterior pituitary cells. Moreover, NMU-deficient mice exhibit an early onset of vaginal opening. The LHβ/FSHβ ratio, which is an index of puberty onset, is high in young NMU-deficient mice. These results indicate that NMU suppresses gonadotropin secretion and regulates the onset of puberty
Assessing the Geomechanical Responses of Storage System in CO2 Geological Storage: an Introduction of Research Program in the National Institute for Advanced Industrial Science and Technology (AIST)
AbstractThis paper overviews studies being conducted in the National Institute for Advanced Industrial Science and Technology (AIST) on the fluid-rock mechanical interaction associated with CO2 geological storage (CGS). Our studies include the extension of TOUGH-FLAC simulator developed in LBNL to CGS under the geologic conditions of Japan where the young sedimentary basins underlain by so-called “soft rocks” are postulated to be the place of CO2 storage. Experimental studies and basic studies on the petrophysical properties of “soft rocks” are also the important parts of the whole research program to elucidate their mechanical behaviors under the conditions in and around a CO2 reservoir and its caprock
Association of Oxidized Low-Density Lipoprotein in Nonalcoholic Fatty Liver Disease with High-Risk Plaque on Coronary Computed Tomography Angiography: A Matched Case-Control Study
Nonalcoholic fatty liver disease (NAFLD) is a risk factor for the development of atherosclerotic cardiovascular diseases (CVDs), and oxidative stress has been proposed as a shared pathophysiological condition. This study examined whether oxidized low-density lipoprotein (LDL) is involved in the underlying mechanism that links coronary atherosclerosis and NAFLD. This study included 631 patients who underwent coronary computed tomography angiography (CTA) for suspected coronary artery disease. NAFLD was defined on CT images as a liver-to-spleen attenuation ratio of <1.0. Serum-malondialdehyde-modified LDL (MDA-LDL) and coronary CTA findings were analyzed in a propensity-score-matched cohort of patients with NAFLD (n = 150) and those without NAFLD (n = 150). This study analyzed 300 patients (median age, 65 years; 64% men). Patients with NAFLD had higher MDA-LDL levels and a greater presence of CTA-verified high-risk plaques than those without NAFLD. In the multivariate linear regression analysis, MDA-LDL was independently associated with NAFLD (beta = 11.337, p = 0.005) and high-risk plaques (beta = 12.487, p = 0.007). Increased MDA-LDL may be a mediator between NAFLD and high-risk coronary plaque on coronary CTA. Increased oxidative stress in NAFLD, as assessed using MDA-LDL, may be involved in the development of CVDs
Flexible inverted polymer solar cells on polyethylene terephthalate substrate containing zinc oxide electron-collection-layer prepared by novel sol-gel method and low-temperature treatments
Flexible and air-stable polymer solar cells were fabricated on a polyethylene terephthalate (PET) substrate. The cell structure was indium tin oxide (ITO) on PET/zinc oxide (ZnO)/[6,6]-phenyl C 61butyric acid methyl ester (PCBM):regioregular poly(3-hexylthiophene) (P3HT)/poly (3,4-ethylenedioxylenethiophene):poly(4-styrene sulfonic acid) (PEDOT:PSS)/Au, this being called the ZnO cell. Reproducible cell performances were obtained despite the ZnO cells being fabricated in air and at low temperature, using a novel ZnO precursor solution containing zinc(II) acetylacetonate as a metal source and acetylacetone as a Zn 2+ complexing agent. The power conversion efficiency (PCE) of the flexible ZnO cells without sealing was 2.15% under irradiating AM1.5G simulated sunlight at 100 mW cm -2. In addition, the performance of the non-sealed ZnO cells was almost constant in ambient atmosphere under continuous light irradiation for 100 h. © 2012 Elsevier B.V. All rights reserved
Association of perivascular fat attenuation on computed tomography and heart failure with preserved ejection fraction
Aims Heart failure with a preserved ejection fraction (HFpEF) is associated with chronic inflammation. We aimed to investigate the association between pericoronary adipose tissue attenuation (PCATA) on coronary computed tomography angiography as a novel noninvasive marker of pericoronary inflammation and the presence of HFpEF.
Methods and results This retrospective study included 607 outpatients (median age, 65 years; 50% male) who underwent both echocardiography and coronary computed tomography angiography. Patients with obstructive coronary artery disease were excluded from this study. PCATA was compared between patients with and without HFpEF, which was diagnosed according to the Heart Failure Association (HFA)-PEFF score. PCATA was assessed at the proximal 40-mm segments of all three major coronary arteries on coronary computed tomography angiography. Patients with HFpEF had higher PCATA in all coronary arteries compared to the control participants: left anterior descending artery (LAD), -65.2 +/- 6.9 Hounsfield units (HU) vs. -68.1 +/- 6.7 HU; left circumflex artery (LCX), -62.7 +/- 6.8 HU vs. -65.4 +/- 6.6 HU; and right coronary artery (RCA), -63.6 +/- 8.5 HU vs. -65.5 +/- 7.7 HU (P
Conclusions High PCATA score was significantly associated with the presence of HFpEF. Our results suggest that inflammation in the pericoronary artery adipose tissue is one of the underlying mechanisms of HFpEF
The Association of Triglyceride to High-Density Lipoprotein Cholesterol Ratio with High-Risk Coronary Plaque Characteristics Determined by CT Angiography and Its Risk of Coronary Heart Disease
The triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio is an independent risk index for cardiovascular events. This study aimed to evaluate the association between TG/HDL-C ratio and coronary plaque characteristics as seen on coronary computed tomography angiography (CCTA) and the corresponding increase in the likelihood of cardiovascular events. A total of 935 patients who underwent CCTA for suspected coronary artery disease (CAD) were included. High-risk plaques (HRP) were defined based on three characteristics: positive remodeling, low-density plaques, and spotty calcification. Significant stenosis was defined as luminal narrowing of >70%. Patients with a higher TG/HDL-C ratio showed significantly greater prevalence of HRP and significant stenosis than patients with low TG/HDL-C ratios (p < 0.01). Multivariate logistic analysis demonstrated that the TG/HDL-C ratio was significantly associated with the presence of HRP (p < 0.01) but not with significant coronary stenosis (p = 0.24). During the median follow-up period of 4.1 years, 26 cardiovascular events including cardiovascular death and acute coronary syndrome occurred. The highest TG/HDL-C tertile was associated with cardiovascular events, with the lowest TG/HDL-C tertile as the reference (hazard ratio, 3.75; 95% confidence interval, 1.04-13.50). A high TG/HDL-C ratio is associated with the presence of CCTA-verified HRP, which can lead to cardiovascular events in patients with suspected CAD
- …