328 research outputs found
Maximum Score Estimation of Preference Parameters for a Binary Choice Model under Uncertainty
This paper develops maximum score estimation of preference parameters in the
binary choice model under uncertainty in which the decision rule is affected by
conditional expectations. The preference parameters are estimated in two
stages: we estimate conditional expectations nonparametrically in the first
stage and then the preference parameters in the second stage based on Manski
(1975, 1985)'s maximum score estimator using the choice data and first stage
estimates. The paper establishes consistency and derives rate of convergence of
the two-stage maximum score estimator. Moreover, the paper also provides
sufficient conditions under which the two-stage estimator is asymptotically
equivalent in distribution to the corresponding single-stage estimator that
assumes the first stage input is known. These results are of independent
interest for maximum score estimation with nonparametrically generated
regressors. The paper also presents some Monte Carlo simulation results for
finite-sample behavior of the two-stage estimator
Competition between structural distortion and magnetic moment formation in fullerene C
We investigated the effect of on-site Coulomb interactions on the structural
and magnetic ground state of the fullerene C based on
density-functional-theory calculations within the local density approximation
plus on-site Coulomb corrections (LDA+). The total energies of the high
symmetry () and distorted () structures of C were
calculated for different spin configurations. The ground state configurations
were found to depend on the forms of exchange-correlation potentials and the
on-site Coulomb interaction parameter , reflecting the subtle nature of the
competition between Jahn-Teller distortion and magnetic instability in
fullerene C. While the non-magnetic state of the distorted
structure is robust for small , a magnetic ground state of the undistorted
structure emerges for larger than 4 eV when the LDA
exchange-correlation potential is employed.Comment: 4 figures, 1 tabl
Structural and optical properties of ZnO nanorods by electrochemical growth using multi-walled carbon nanotube-composed seed layers
We reported the enhancement of the structural and optical properties of electrochemically synthesized zinc oxide [ZnO] nanorod arrays [NRAs] using the multi-walled carbon nanotube [MWCNT]-composed seed layers, which were formed by spin-coating the aqueous seed solution containing MWCNTs on the indium tin oxide-coated glass substrate. The MWCNT-composed seed layer served as the efficient nucleation surface as well as the film with better electrical conductivity, thus leading to a more uniform high-density ZnO NRAs with an improved crystal quality during the electrochemical deposition process. For ZnO NRAs grown on the seed layer containing MWCNTs (2 wt.%), the photoluminescence peak intensity of the near-band-edge emission at a wavelength of approximately 375 nm was enhanced by 2.8 times compared with that of the ZnO nanorods grown without the seed layer due to the high crystallinity of ZnO NRAs and the surface plasmon-meditated emission enhancement by MWCNTs. The effect of the MWCNT-composed seed layer on the surface wettability was also investigated
Cell-free synthesis of functional phospholipase A1 from Serratia sp.
Additional file 1: Figure S1 Gas chromatography analysis of sesame oil incubated with cell-free synthesized PLA1
Stress-induced Cardiomyopathy during Pulmonary Resection (Takotsubo Syndrome) - A case report -
Stress-induced cardiomyopathy is caused by emotional or physical stressors and mimics acute myocardial infarction, though Stress-induced cardiomyopathy is characterized by reversible left ventricular (LV) apical ballooning in the absence of significant coronary artery disease. We describe a 51-year-old male who underwent left upper lobectomy for non-small cell lung cancer, and during which cardiogenic arrest occurred due to stress-induced cardiomyopathy, successfully managed by intra-aortic balloon pumping and extracorporeal membrane oxygenation
An Isolated True Aneurysm of the Superficial Femoral Artery in a Young Woman - A case report -
A 39-year-old woman was admitted to the hospital due to a pulsatile mass on her right inner thigh that was evident for two months. She did not exhibit any risk factors of atherosclerosis, no evidence of vasculitis, or any signs of previous trauma history. Ultrasound and computed tomography revealed an adult fist-sized aneurysm on the distal superficial femoral artery. The aneurysm was resected and peripheral circulation was restored with the interposition of a saphenous vein graft. The resected aneurysm had three layers that showed atherosclerosis on histological examination
Unveiling the Role of Ruthenium in Layered Sodium Cobaltite Toward High-Performance Electrode Enabled by Anionic and Cationic Redox
The effect of Ru substitution on the structure and electrochemical properties of P2-type Na0.67CoO2 is investigated. The first-discharge capacities of Na0.67CoO2 and Na0.6 [Co0.78Ru0.22]O2 materials are 128 and 163 mAh g−1 (23.5 mA g−1), respectively. Furthermore, the rate capability is improved due to the electro-conducting nature of Ru doping. Operando X-ray diffraction analysis reveals that the Na0.67CoO2 does not undergo a phase transition; however, multiple Na+/vacancy ordered superstructures within the P2 phase appear during Na+ extraction/insertion. In contrast, the Na0.6[Co0.78Ru0.22]O2 material undergoes a P2–OP4 phase transition during desodiation, with no formation of Na+/vacancy ordering within the P2 phase. The increased discharge capacity of Na0.6[Co0.78Ru0.22]O2 is most likely associated with additional cationic Ru4+/Ru5+ redox and increased anionic O2−/(O2n−) redox participation. Combined experimental (galvanostatic cycling, X-ray absorption spectroscopy, differential electrochemical mass spectrometry) and theoretical (density functional theory calculations) studies confirm that Ru substitution provokes the oxygen-redox reaction and that partial O2 release from the oxide lattice is the origin of the reaction. The findings provide new insight for improving the electrode performance of cathode materials via 4d Ru substitution and motivate the development of a new strategy for the design of high-capacity cathode materials for sodium-ion batteries.</p
Estrogen receptor-α gene haplotype is associated with primary knee osteoarthritis in Korean population
Estrogen and estrogen receptors (ERs) are known to play important roles in the pathophysiology of osteoarthritis (OA). To investigate ER-α gene polymorphisms for its associations with primary knee OA, we conducted a case–control association study in patients with primary knee OA (n = 151) and healthy individuals (n = 397) in the Korean population. Haplotyping analysis was used to determine the relationship between three polymorphisms in the ER-α gene (intron 1 T/C, intron 1 A/G and exon 8 G/A) and primary knee OA. Genotypes of the ER-α gene polymorphism were determined by PCR followed by restriction enzyme digestion (PvuII for intron 1 T/C, XbaI for intron 1 A/G, and BtgI for exon 8 G/A polymorphism). There was no significant difference between primary knee OA patients and healthy control individuals in the distribution of any of the genotypes evaluated. However, we found that the allele frequency for the exon 8 G/A BtgI polymorphism (codon 594) was significantly different between primary knee OA patients and control individuals (odds ratio = 1.38, 95% confidence interval = 1.01–1.88; P = 0.044). In haplotype frequency estimation analysis, there was a significant difference between primary knee OA patients and control individuals (degrees of freedom = 7, χ(2 )= 21.48; P = 0.003). Although the number OA patients studied is small, the present study shows that ER-α gene haplotype may be associated with primary knee OA, and genetic variations in the ER-α gene may be involved in OA
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