71 research outputs found
Direct derivation of the Veneziano-Yankielowicz superpotential from matrix model
We derive the Veneziano-Yankielowicz superpotential directly from the matrix
model by fixing the measure precisely. The essential requirement here is that
the effective superpotential of the matrix model corresponding to the supersymmetric Yang-Mills theory vanishes except for the tree gauge
kinetic term. Thus we clarify the reason why the matrix model reproduces the
Veneziano-Yankielowicz superpotential correctly in the Dijkgraaf-Vafa theory.Comment: 13 pages, to appear in Phys. Lett.
Theoretical and Numerical Analysis of an Optimal Execution Problem with Uncertain Market Impact
This paper is a continuation of Ishitani and Kato (2015), in which we derived
a continuous-time value function corresponding to an optimal execution problem
with uncertain market impact as the limit of a discrete-time value function.
Here, we investigate some properties of the derived value function. In
particular, we show that the function is continuous and has the semigroup
property, which is strongly related to the Hamilton-Jacobi-Bellman
quasi-variational inequality. Moreover, we show that noise in market impact
causes risk-neutral assessment to underestimate the impact cost. We also study
typical examples under a log-linear/quadratic market impact function with
Gamma-distributed noise.Comment: 24 pages, 14 figures. Continuation of the paper arXiv:1301.648
Cognitive dysfunction and amyloid β accumulation are ameliorated by the ingestion of green soybean extract in aged mice
AbstractThe effects of soybean extracts were investigated in senescence-accelerated (SAMP10) mice, a mouse model of brain senescence with cognitive dysfunction. Mature soybeans are usually yellow. However, the green soybean retains green color after being ripened. Cognitive functions were significantly better-preserved in aged mice fed green soybean than age-matched control mice with or without yellow soybean feeding. Molecular mechanisms of the beneficial effect of green soybean on brain functions were examined through transcriptome analysis of SAMP10 hippocampus. The high expression of Ptgds was significantly associated with green soybean diet, which encodes lipocalin-type prostaglandin D2 synthase, a putative endogenous amyloid β(Αβ)-chaperone. In consonance, Aplp1 expression was significantly reduced, a member of amyloid precursor proteins. Furthermore, the amount of Aβ 40 and 42 was reduced in the insoluble fraction of cerebral cortex. These results suggest that the intake of green soybean ameliorates cognitive dysfunction of aged mice through the reduction of Aβ accumulation
N=1* model and glueball superpotential from Renormalization-Group-improved perturbation theory
A method for computing the low-energy non-perturbative properties of SUSY
GFT, starting from the microscopic lagrangian model, is presented. The method
relies on covariant SUSY Feynman graph techniques, adapted to low energy, and
Renormalization-Group-improved perturbation theory. We apply the method to
calculate the glueball superpotential in N=1 SU(2) SYM and obtain a potential
of the Veneziano-Yankielowicz type.Comment: 19 pages, no figures; added references; note added at the end of the
paper; version to appear in JHE
Development and validation of a new scoring system for prognostic prediction of community-acquired pneumonia in older adults
The discriminative power of CURB-65 for mortality in community-acquired pneumonia (CAP) is suspected to decrease with age. However, a useful prognostic prediction model for older patients with CAP has not been established. This study aimed to develop and validate a new scoring system for predicting mortality in older patients with CAP. We recruited two prospective cohorts including patients aged ≥ 65 years and hospitalized with CAP. In the derivation (n = 872) and validation cohorts (n = 1, 158), the average age was 82.0 and 80.6 years and the 30-day mortality rate was 7.6% (n = 66) and 7.4% (n = 86), respectively. A new scoring system was developed based on factors associated with 30-day mortality, identified by multivariate analysis in the derivation cohort. This scoring system named CHUBA comprised five variables: confusion, hypoxemia (SpO2 ≤ 90% or PaO2 ≤ 60 mmHg), blood urea nitrogen ≥ 30 mg/dL, bedridden state, and serum albumin level ≤ 3.0 g/dL. With regard to 30-day mortality, the area under the receiver operating characteristic curve for CURB-65 and CHUBA was 0.672 (95% confidence interval, 0.607–0.732) and 0.809 (95% confidence interval, 0.751–0.856; P < 0.001), respectively. The effectiveness of CHUBA was statistically confirmed in the external validation cohort. In conclusion, a simpler novel scoring system, CHUBA, was established for predicting mortality in older patients with CAP
CpG Island Methylator Phenotype in Primary Gastric Carcinoma
Gastric cancers (GC) with methylation of multiple CpG islands have a CpG island methylator phenotype (CIMP) and they can have different biological features. The aim of this study was to investigate the DNA methylation status of GCs and its association with their clinicopathological features. We evaluated the methylation status of four genes (MINT1, MINT2, MINT25 and MINT31) in 105 primary GCs using bisulfite-pyrosequencing analysis. We classified tumors as CIMP-high (CIMP-H), CIMP-low (CIMP-L) or CIMP-negative (CIMP-N) based on the methylation of MINT1, MINT2, MINT25, and MINT31. Overall, the prevalence of CIMP-H, CIMP-L and CIMP-N was 22% (23/105), 52% (55/105) and 26% (27/105), respectively. We observed a significant difference in tumor stage (stages I-II vs. stages III-IV) between CIMP-H and CIMP-N tumors (P = 0.0435). No significant differences were observed in clinicopathological characteristics (gender, age, location and tumor differentiation) among the CIMP phenotypes. The prognoses of patients with a CIMP-H tumor is likely to be better than those with CIMP-L or CIMP-N tumors, but these differences are not statistically significant (P = 0.074 and P = 0.200). Our results suggest that CIMP may define a subgroup of GCs with distinct biological features
- …