Ordering of the Heisenberg spin glass in two dimensions

The spin and the chirality orderings of the Heisenberg spin glass in two dimensions with the nearest-neighbor Gaussian coupling are investigated by equilibrium Monte Carlo simulations. Particular attention is paid to the behavior of the spin and the chirality correlation lengths. In order to observe the true asymptotic behavior, fairly large system size L\gsim 20 (L the linear dimension of the system) appears to be necessary. It is found that both the spin and the chirality order only at zero temperature. At high temperatures, the chiral correlation length stays shorter than spin correlation length, whereas at lower temperatures below the crossover temperature T_\times, the chiral correlation length exceeds the spin correlation length. The spin and the chirality correlation-length exponents are estimated above T_\times to be \nu_SG=0.9+-0.2 and \nu_CG=2.1+-0.3, respectively. These values are close to the previous estimates on the basis of the domain-wall-energy calculation. Discussion is given about the asymptotic critical behavior realized below T_\times.Comment: to appear in a special issue of J. Phys.

The Hyper Suprime-Cam SSP survey: Overview and survey design

Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of the 8.2-m Subaru telescope on the summit of Mauna Kea in Hawaii. A team of scientists from Japan, Taiwan, and Princeton University is using HSC to carry out a 300-night multi-band imaging survey of the high-latitude sky. The survey includes three layers: the Wide layer will cover 1400 deg2 in five broad bands (grizy), with a 5 σ point-source depth of r ≈ 26. The Deep layer covers a total of 26 deg2 in four fields, going roughly a magnitude fainter, while the UltraDeep layer goes almost a magnitude fainter still in two pointings of HSC (a total of 3.5 deg2). Here we describe the instrument, the science goals of the survey, and the survey strategy and data processing. This paper serves as an introduction to a special issue of the Publications of the Astronomical Society of Japan, which includes a large number of technical and scientific papers describing results from the early phases of this survey

Sciatic Hernia with an Early-stage Adenocarcinoma of the Appendix : Report of a case

Sciatic hernia and early-stage appendiceal adenocarcinoma are rare disorders. We report herein a case of an early stage of appendiceal adenocarcinoma found incidentally during an operation for sciatic hernia. An 80-year-old woman was admitted to our hospital with abdominal distension. Abdominal computed tomography showed a small bowel obstruction and a small bowel loop through the right sciatic foramen outside the pelvic cavity. During an operation for the repair of the sciatic hernia, a deformed appendix was found incidentally and a simple appendectomy was also performed. Histological examination of the excised appendix showed well-differentiated adenocarcinoma confined to the mucosal layer in a tubulo-villous adenoma. At 13-month follow-up, the patient is doing well without evidence of recurrence or metastasis

A Gastric Fibrolipoma Presenting as Acute Gastrointestinal Hemorrhage

A 56-year-old woman was admitted to our hospital with upper gastrointestinal hemorrhage from a gastric submucosal tumor that was treated by a laparoscopic technique. Endoscopy and endoscopic ultrasonography (EUS) revealed a 2-cm submucosal tumor located in the posterior wall of the upper gastric body, showing a heterogeneous hyperechoic tumor. A laparoscopic wedge resection of the stomach was performed. Pathological examinations revealed that the tumor was composed of spindle cells like fibroblasts and mature adipocytes. Immunohistochemical examinations revealed that the tumor was negative for desmin and α-smooth muscle actin. Based on these findings, a diagnosis of fibrolipoma was made. EUS is useful for differentiating a fibrolipoma from a gastrointestinal stromal tumor or lipoma by the findings of characteristic echogenesity and detection of the tumor origin

Lack of activation induced cell death in human T blasts despite CD95L up‐regulation: protection from apoptosis by MEK signalling

The generation of effective immunity requires that antigen‐specific T cells are activated, clonally expanded and ultimately eliminated by apoptosis. The involvement of CD95‐mediated apoptosis in T‐cell elimination is well established, but the conditions which regulate the death pathway under normal circumstances are still emerging. Using superantigen‐activated human T cells, we found that whilst T‐cell receptor (TCR) signalling triggered up‐regulation of CD95 ligand (CD95L), the majority of T cells were resistant to apoptosis induction, despite co‐expressing high levels of CD95. Resistance was maintained following direct antibody‐mediated cross‐linking of CD95 and was not confined to early time periods following activation. Our data implicate TCR‐derived signals in protection from apoptosis and reveal a role for the mitogen‐activated protein (MAP) kinase pathway by use of a MAP kinase kinase (MEK) inhibitor. Collectively these data demonstrate that resistance to activation‐induced cell death in human T cells is prolonged rather than transient, is not attributable to a lack of CD95L up‐regulation and is due, at least in part, to signalling via the MEK pathway