Reducing the Size Distortion of the KPSS Test

This paper proposes a new stationarity test based on the KPSS test with less size distortion. We extend the boundary rule proposed by Sul, Phillips and Choi (2005) to the autoregressive spectral density estimator and parametrically estimate the long-run variance. We also derive the finite sample bias of the numerator of the test statistic up to the 1/T order and propose a correction to the bias term in the numerator. Finite sample simulations show that the correction term effectively reduces the bias in the numerator and that the finite sample size of our test is close to the nominal one as long as the long-run parameter in the model satisfies the boundary condition.Stationary test, size distortion, boundary rule, bias correction

Investigating Finite Sample Properties of Estimators for Approximate Factor Models When N Is Small

This paper examines the finite sample properties of estimators for approximate factor models when N is small via simulation study. Although the "rule-of-thumb" for factor models does not support using approximate factor models when N is small, we find that the principal component analysis estimator and quasi-maximum likelihood estimator proposed by Doz et al. (2008) perform very well even in this case. Our findings provide an opportunity for applying approximate factor models to low-dimensional data, which was thought to have been inappropriate for a long time.Approximate factor model, Principal components, Quasi-maximum likelihood

Fabrication of submicron La2−x_{2-x}Srx_{x}CuO4_{4} intrinsic Josephson junction stacks

Intrinsic Josephson junction (IJJ) stacks of cuprate superconductors have potential to be implemented as intrinsic phase qubits working at relatively high temperatures. We report success in fabricating submicron La$_{2-x}$Sr$_{x}$CuO$_{4}$ (LSCO) IJJ stacks carved out of single crystals. We also show a new fabrication method in which argon ion etching is performed after focused ion beam etching. As a result, we obtained an LSCO IJJ stack in which resistive multi-branches appeared. It may be possible to control the number of stacked IJJs with an accuracy of a single IJJ by developing this method.Comment: 5 pages, 6 figure

Isolation of a transcriptionally active element of high copy number retrotransposons in sweetpotato genome

Many plant retrotransposons have been characterized, but only three families (Tnt1, Tto1 and Tos17) have been demonstrated to be transpositionally competent. We followed a novel approach that enabled us to identify an active element of the Ty1-copia retrotransposon family with estimated 400 copies in the sweetpotato genome. DNA sequences of Ty1 -copia reverse transcriptase (RTase) from the sweetpotato genome were analyzed, and a group of retrotransposon copies probably formed by recent transposition events was further analyzed. 3’RACE on callus cDNA amplified transcripts containing long terminal repeats (LTR) of this group. The sequence -specific amplification polymorphism (S-SAP) patterns of the LTR sequence in the genomic DNA were compared between a normal plant and callus lines derived from it. A callus -specific S-SAP product was found into which the retrotransposon detected by the 3’RACE had been transposed apparently during cell culture. We conclude that our approach provides an effective way to identify active elements of retrotransposons with high copy numbers.</p

Acute myocardial infarction complicated by cardiogenic shock: an algorithm based ECMO program can improve clinical outcomes.

Objective: Extracorporeal membrane oxygenation (ECMO) in our institution resulted in near total mortality prior to the establishment of an algorithm-based program in July 2010. We hypothesized that an algorithm based ECMO program improves the outcome of patients with acute myocardial infarction complicated with cardiogenic shock. Methods: Between March 2003 and July 2013, 29 patients underwent emergent catheterization for acute myocardial infarction due to left main or proximal left anterior descending artery occlusion complicated with cardiogenic shock (defined as systolic blood pressure \u3c 90mmHg despite multiple inotropes, +- balloon pump, lactic acidosis). Of 29 patients, 15 patients were before July 2010 (Group 1, old program), 14 patients were after July 2010 (Group 2, new program). Results: There were no significant differences in the baseline characteristics, including age, sex, coronary risk factors and left ventricular ejection fraction, between the two groups. Cardiopulmonary resuscitation prior to ECMO was performed in 2 cases (13%) in Group 1 and 4 cases (29%) in Group 2. ECMO support was performed in 1 case (6.7%) in Group 1 and 6 cases (43%) in Group 2. The 30-day survival of Group 1 vs. Group 2 was 40% vs. 79% (p = 0.03), and one-year survival rate was 20% vs. 56% (p=0.01). The survival rate for patients who underwent ECMO was 0% in Group 1 vs. 83% in Group 2 (p = 0.09). In Group 2, the mean duration on ECMO was 9.8 ± 5.9 days. Of the 6 patients who required ECMO in Group 2, 100% were successfully weaned off ECMO or were bridged to ventricular assist device implantation. Conclusions: Initiation of an algorithm based ECMO program improved the outcomes in patients with acute myocardial infarction complicated by cardiogenic shock

A Rare Course of Scoliosis Associated with Chiari Malformation and Syringomyelia

Spinal deformity is an important clinical manifestation of Chiari I malformation (CM-I) and syringomyelia. Here we report the result of an 8-year follow-up of a 13-year-old girl with severe scoliosis associated with Chiari malformation and a large syringomyelia. The patient presented at our hospital at the age of 13 with a 68° scoliosis. Magnetic resonance imaging showed Chiari malformation and a large syringomyelia. Neurosurgical treatment involved foramen magnum decompression and partial C1 laminectomy, but the scoliosis still progressed. We present the first case report of a rare course of scoliosis in a patient with CM-I and a large syringomyelia