12 research outputs found
Angular Trispectrum of CMB Temperature Anisotropy from Primordial Non-Gaussianity with the Full Radiation Transfer Function
We calculate the cosmic microwave background (CMB) angular trispectrum,
spherical harmonic transform of the four-point correlation function, from
primordial non-Gaussianity in primordial curvature perturbations characterized
by a constant non-linear coupling parameter, . We fully take into
account the effect of the radiation transfer function, and thus provide the
most accurate estimate of the signal-to-noise ratio of the angular trispectrum
of CMB temperature anisotropy. We find that the predicted signal-to-noise ratio
of the trispectrum summed up to a given is approximately a power-law,
, up to the maximum multipole
that we have reached in our numerical calculation, , assuming that the
error is dominated by cosmic variance. Our results indicate that the
signal-to-noise ratio of the temperature trispectrum exceeds that of the
bispectrum at the critical multipole, .
Therefore, the trispectrum of the Planck data is more sensitive to primordial
non-Gaussianity than the bispectrum for . We also
report the predicted constraints on the amplitude of trispectrum, which may be
useful for other non-Gaussian models such as curvaton models.Comment: 6 pages, 2 figures, version to be published in PR
Constraining Cosmological Parameters by the Cosmic Inversion Method
We investigate the question of how tightly we can constrain the cosmological
parameters by using the ``cosmic inversion'' method in which we directly
reconstruct the power spectrum of primordial curvature perturbations, ,
from the temperature and polarization spectra of the cosmic microwave
background (CMB). In a previous paper, we suggested that it may be possible to
constrain the cosmological parameters using the fact that the reconstructed
does not depend on how many polarization data we incorporate in our
inversion procedure if and only if the correct values of the cosmological
parameters are used. The advantage of this approach is that we need no
assumption regarding the functional form of . In this paper, we estimate
typical errors in the determination of the cosmological parameters when our
method is applied to the PLANCK observation. We investigate constraints on ,
, , and through Monte Carlo simulations.Comment: 18 pages, 15 figures, version to be published in Prog. Theor. Phy
Reconstructing the Primordial Spectrum with CMB Temperature and Polarization
We develop a new method to reconstruct the power spectrum of primordial
curvature perturbations, , by using both the temperature and polarization
spectra of the cosmic microwave background (CMB). We test this method using
several mock primordial spectra having non-trivial features including the one
with an oscillatory component, and find that the spectrum can be reconstructed
with a few percent accuracy by an iterative procedure in an ideal situation in
which there is no observational error in the CMB data. In particular, although
the previous ``cosmic inversion'' method, which used only the temperature
fluctuations, suffered from large numerical errors around some specific values
of that correspond to nodes in a transfer function, these errors are found
to disappear almost completely in the new method.Comment: 18 pages, 17 figures, submitted to PR
Development of airflow limitation, dyspnoea, and both in the general population: the Nagahama study
Subjects with subclinical respiratory dysfunction who do not meet the chronic obstructive pulmonary disease (COPD) criteria have attracted attention with regard to early COPD intervention. Our aim was to longitudinally investigate the risks for the development of airflow limitation (AFL) and dyspnoea, the main characteristics of COPD, in a large-scale community-based general population study. The Nagahama study included 9789 inhabitants, and a follow-up evaluation was conducted after 5 years. AFL was diagnosed using a fixed ratio (forced expiratory volume in one second (FEV₁)/forced vital capacity (FVC) < 0.7). We enrolled normal subjects aged 40-75 years with no AFL, dyspnoea or prior diagnosis of asthma or COPD at baseline. In total, 5865 subjects were analysed, 310 subjects had subclinical respiratory dysfunction (FEV₁/FVC < the lower limit of normal; n = 57, and FEV₁ < 80% of the predicted value (preserved ratio impaired spirometry); n = 256). A total of 5086 subjects attended the follow-up assessment, and 449 and 1021 subjects developed AFL and dyspnoea, respectively. Of these, 100 subjects developed AFL with dyspnoea. Baseline subclinical respiratory dysfunction was independently and significantly associated with AFL with dyspnoea development within 5 years. Subjects with subclinical respiratory dysfunction are at risk of developing COPD-like features and require careful monitoring
A Japanese Male Patient with `Fibular Aplasia, Tibial Campomelia and Oligodactyly': An Additional Case Report
Rigid External Distraction Osteogenesis for a Patient with Maxillary Hypoplasia and Oligodontia
Association of lower plasma citric acid with prolonged cough: the Nagahama study
Abstract Little is known about the association of prolonged cough, a common and troublesome symptom, with metabolic pathways. We aimed to clarify this association using data from the Nagahama cohort, a prospective study of participants from the general population. Self-report questionnaires on prolonged cough were collected at baseline and 5-year follow-up assessments. Blood tests at follow-up were used for gas chromatography-mass spectrometry-based metabolomics. The association between metabolites and prolonged cough was examined using the partial least squares discriminant analysis and multiple regression analysis. Among the 7432 participants, 632 had newly developed prolonged cough at follow-up, which was defined as “new-onset prolonged cough”. Low plasma citric acid was significantly associated with new-onset prolonged cough, even after the adjustment of confounding factors including the presence of asthma, upper airway cough syndrome (UACS), and gastroesophageal reflux disease (GERD). A similar association was observed for isocitric acid, 3-hydroxybutyric acid, and 3-hydroxyisobutyric acid. The analysis of these four metabolites revealed that citric acid had the strongest association with new-onset prolonged cough. This significant association remained even when the analysis was confined to participants with UACS or GERD at baseline or follow-up, and these associations were also observed in participants (n = 976) who had prolonged cough at follow-up regardless of baseline status. In conclusion, low blood citric acid may be associated with prolonged cough