241 research outputs found
Simulating the Anisotropic Clustering of Luminous Red Galaxies with Subhalos: A Direct Confrontation with Observation and Cosmological Implications
We model the apparent clustering anisotropy of Luminous Red Galaxies (LRGs)
in the Sloan Digital Sky Survey using subhalos identified in cosmological
-body simulations. We first conduct a Markov-chain Monte Carlo analysis on
the parameters characterizing subhalos hosting LRGs assuming a specific
CDM cosmology on which we run the simulations. We show that simple
models with central and satellite subhalos can explain the observed multipole
moments of the power spectrum up to hexadecapole on large scales
(). A satellite fraction of to per
cent is favored weakly depending on the detail of the model. The fraction is
shown to be robust when we adopt a more refined model based on the halo
occupation number from the literature. We then vary cosmological parameters
controlling the anisotropy in redshift-space effectively by deforming the
simulation box (the Alcock-Paczynski effect) and changing the amplitude of the
velocities (the redshift-space distortions). We demonstrate that we can
constrain the geometry of the universe, the structure growth rate, and the
parameters characterizing LRGs simultaneously. This is a step toward
cosmological analysis with realistic bias description beyond empirical bias
functions with nuisance parameters.Comment: 18 pages, 21 figures. HOD analysis added. Accepted for publication in
MNRA
Simultaneous constraints on the growth of structure and cosmic expansion from the multipole power spectra of the SDSS DR7 LRG sample
The anisotropic galaxy clustering on large scales provides us with a unique
opportunity to probe into the gravity theory through the redshift-space
distortions (RSDs) and the Alcock-Paczynski effect. Using the multipole power
spectra up to hexadecapole (ell=4), of the Luminous Red Galaxy (LRG) sample in
the data release 7 (DR7) of the Sloan Digital Sky Survey II (SDSS-II), we
obtain simultaneous constraints on the linear growth rate f, angular diameter
distance D_A, and Hubble parameter H at redshift z = 0.3. For this purpose, we
first extensively examine the validity of a theoretical model for the
non-linear RSDs using mock subhalo catalogues from N-body simulations, which
are constructed to match with the observed multipole power spectra. We show
that the input cosmological parameters of the simulations can be recovered well
within the error bars by comparing the multipole power spectra of our
theoretical model and those of the mock subhalo catalogues. We also carefully
examine systematic uncertainties in our analysis by testing the dependence on
prior assumption of the theoretical model and the range of wavenumbers to be
used in the fitting. These investigations validate that the theoretical model
can be safely applied to the real data. Thus, our results from the SDSS DR7 LRG
sample are robust including systematics of theoretical modeling; f(z = 0.3)
sigma_8(z = 0.3) =0.49+-0.08(stat.)+-0.04(sys.), D_A (z = 0.3)
=968+-42(stat.)+-17(sys.)[Mpc], H (z = 0.3)
=81.7+-5.0(stat.)+-3.7(sys.)[km/s/Mpc]. We believe that our method to constrain
the cosmological parameters using subhaloes catalogues will be useful for more
refined samples like CMASS and LOWZ catalogues in the Baryon Oscillation
Spectroscopic Survey in SDSS-III.Comment: accepted for publication in MNRA
The First Synthesis of an Optically Active Molecular Bevel Gear with Only Two Cogs on Each Wheel (SYNTHETIC ORGANIC CHEMISTRY-Fine Organic Synthesis)
Both enantiomers of the molecular bevel gear 1 having only two cogs on each wheel consisting of 8,8'-disubstituted 1,1'-binaphthyl ether were synthesized for the first time
A Chain of Dark Clouds in Projection Against the Galactic Center
In the J, H, and Ks bands survey of the the Galactic Center region over an
area of 2deg x 5deg, we have found many dark clouds, among which a
distinguished chain of dark clouds can be identified with a quiescent CO cloud.
The distances of the clouds is estimated to be 3.2-4.2 kpc, corresponding to
the Norma arm by our new method to determine distance to dark clouds using the
cumulative number of stars against J-Ks colors. Adopting these estimated
distances, the size is about 70 pc in length and the total mass of the cloud is
6x10^4 M_solar. Three compact HII regions harbor in the cloud, indicating that
star forming activities are going on at the cores of the quiescent CO cloud on
the spiral arm.Comment: 13 pages, 7 figures, accepted for publication in PAS
Cancer activity and bleeding events post-PCI
Purpose : Limited data exist about clinically relevant bleeding events related to antiplatelet therapy after percutaneous coronary intervention (PCI) in cancer patients. We investigated the risk factors for clinically relevant bleeding events in patients with cancer after PCI with stent implantation. Patients and Methods : Patients with solid cancer subjected to first PCI were divided into active (n = 45) and non-active cancer groups (n = 44). The active group included non-operable patients on treatment or with metastasis ; the non-active included those already subjected to or for whom radical surgery was planned within 3 months after the index PCI. Results : During a median follow-up of 2.2 years, 11 bleeding events occurred, with only one occurring in the non-active cancer group. Half of them occurred during the dual-antiplatelet therapy (DAPT) period, and the rest occurred during single-antiplatelet therapy (SAPT) period. Kaplan-Meier analysis showed significantly more bleeding events in the active cancer group (p = 0.010). Multivariate Cox regression hazard analysis revealed cancer activity as a significant independent risk factor for bleeding (p = 0.023) ; but not for three-point major adverse cardiovascular events. Conclusion : Clinically relevant bleeding risk after PCI was significantly lower in non-active cancer. Active cancer group had clinically relevant bleeding during both DAPT and SAPT periods
Increased Expression of Proliferating Cell Nuclear Antigen in Rejecting Rat Lung Allografts
The aim of this study was to investigate the expression of proliferating cell nuclear antigen (PCNA) as an index of cell proliferation in the Brown Norway (BN) to Lewis (LEW) rat lung allograft model.Following transplantation of BN left lungs into LEW recipients, counts of PCNA-positive cells in the perivascular cellular infiltrate and bronchus-associated lymphoid tissue (BALT) were compared with the histological grade of rejection. Lungs were excised on postoperative days 3 and 5. LEW-to-LEW donor-recipient transplantation was performed as a control. Routinely processed, paraffinembedded sections were selected and stained with PCNA. The PCNA index (% of nuclei positive for PCNA) in the BALT was significantly higher in allograft (19.1%, p < 0.05) compared with isograft (4.2%) at 3 days following transplantation. Similarly, the PCNA index was also greater in the perivascular cellular infiltrates of rejecting lungs (23.9% at 3 days, 31.6% at 5 days). These findings indicate that the cells stimulated by the rejection reaction could be increase the expression of PCNA, and the increasing severity of rejection was paralleled by an increase in the number of PCNA-positive cells. In conclusion, PCNA may be a useful marker of acute cellular rejection in lung allografts
Measurement of fatigue in knee flexor and extensor muscles.
In order to examine fatigue of the knee flexor and extensor muscles and to investigate the characteristics of muscular fatigue in different sports, a Cybex machine was used to measure muscle fatigue and recovery during isokinetic knee flexion and extension. Eighteen baseball players, 12 soccer players and 13 marathon runners were studied. Each subject was tested in the sitting position and made to perform 50 consecutive right knee bends and stretches at maximum strength. This was done 3 times with an interval of 10 min between each series. The peak torque to body weight ratio and the fatigue rate were determined in each case. In all subjects, the peak torque to body weight ratio was higher for extensors than flexors. Over the 3 trials, the fatigue rate of extensors showed little change, while that of flexors had a tendency to increase. In each subject, knee extensors showed a high fatigue rate but a quick recovery, while knee flexors showed a low fatigue rate but a slow recovery. As the marathon runners had the smallest fatigue rates for both flexors and extensors, we concluded that marathon runners had more stamina than baseball players and soccer players.</p
Detection of Disease-specific Fusion Genes of Soft Tissue Tumors Using Formalin-fixed Paraffin-embedded Tissues; Its Diagnostic Usefulness and Factors Affecting the Detection Rates
[Background] Recent rapid advances in molecular biology have led the discovery of disease-specific novel fusion genes in a variety of soft tissue tumors. In this study, we attempted to detect these fusion genes using formalin-fixed paraffin-embedded (FFPE) tumor tissues and investigated their clinical utility and factors that affect the results of examination. [Methods] Reverse transcription polymerase chain reaction for the detection of tumor-specific fusion genes was performed using 41 FFPE tumor samples obtained from 37 patients representing nine histological types of soft tissue tumors that were diagnosed from 2006 to 2017 in our laboratory. [Results] Fusion genes in 19 (51.3%) out of 37 cases were detected successfully. Relatively high detection rates were observed in synovial sarcomas (100%, 4/4) and alveolar rhabdomyosarcomas (75%, 3/4). The detection rates of fusion genes were inversely correlated with the storage period of FFPE blocks. Decalcification by Plank-Rychlo solution significantly affected detection rates of the internal control gene (P = 0.0038). In contrast, there was no significant difference in detection rates between primary and metastatic lesion, or biopsy and resection material, or presence and absence of treatment history. [Conclusion] In certain histological types, detection of disease-specific fusion genes of soft tissue tumors using FFPE tissues showed high sensitivity and thus had diagnostic utility. However, due to the diversity of fusion patterns and the low-quality of nucleic acid, the detection rate as a whole was sluggish and required further improvement. For factors affecting the detection results, our results suggested that it was impossible to detect fusion genes by decalcified FFPE tissues, but it may be not necessary to consider factors such as the type of specimen (biopsy or resection) and treatment history of the patients when selecting the FFPE tissues
Cell jamming, stratification and p63 expression in cultivated human corneal epithelial cell sheets
Corneal limbal epithelial stem cell transplantation using cultivated human corneal epithelial cell sheets has been used successfully to treat limbal stem cell deficiencies. Here we report an investigation into the quality of cultivated human corneal epithelial cell sheets using time-lapse imaging of the cell culture process every 20 minutes over 14 days to ascertain the level of cell jamming, a phenomenon in which cells become smaller, more rounded and less actively expansive. In parallel, we also assessed the expression of p63, an important corneal epithelial stem cell marker. The occurrence of cell jamming was variable and transient, but was invariably associated with a thickening and stratification of the cell sheet. p63 was present in all expanding cell sheets in the first 9 days of culture, but it’s presence did not always correlate with stratification of the cell sheet. Nor did p63 expression necessarily persist in stratified cell sheets. An assessment of cell jamming, therefore, can shed significant light on the quality and regenerative potential of cultivated human corneal epithelial cell sheets
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