An improved analysis of SRPT scheduling algorithm on the basis of functional optimization

The competitive performance of the SRPT scheduling algorithm has been open for a long time except for being 2-competitive, where the objective is to minimize the total completion time. Chung et al. proved that the SRPT algorithm is 1.857-competitive. In this paper we improve their analysis and show a 1.792-competitiveness. We clearly mention that our result is not the best so far, since Sitters recently proved the algorithm is 1.250-competitive. Nevertheless, it is still well worth reporting our analytical method; our analysis is based on the modern functional optimization, which can scarcely be found in the literature on the analysis of algorithms. Our aim is to illustrate the potentiality of functional optimization with a concrete application. (C) 2012 Elsevier B.V. All rights reserved.ArticleINFORMATION PROCESSING LETTERS. 112(23): 911-915 (2012)journal articl

Gallbladder Cancer with Biliary Intraepithelial Neoplasia Complicated by Pancreaticobiliary Maljunction: A Case Report

We report herein a case of gallbladder cancer with biliary intraepithelial neoplasia (BilIN) complicated by pancreaticobiliary maljunction (PBM). A 60-year-old woman was referred to our hospital for thickening of the gallbladder wall diagnosed via ultrasonography at the referring clinic. The Radiographic images showed thickening of the gallbladder wall and a high confluence of pancreaticobiliary ducts outside the duodenal wall without dilatation of the bile duct. The amylase level in the bile duct was highly elevated. The patient was initially diagnosed with PBM without biliary dilatation, and laparoscopic cholecystectomy was performed. Histopathology of the resected specimen revealed gallbladder cancer localized in the mucosa propria with widespread BilIN. Immunohistochemical analyses showed positive results for S100P,IMP3 and p16ink4a in tumor cells, but a positive result for only IMP3 in adenocarcinoma. Expression of p53 was negative. Oncogenic KRAS mutations were not detected in tumor cells. The patient was diagnosed with gallbladder cancer with BilIN complicated by PBM. This case report may be useful in clarifying the carcinogenic process and genetic mutations for gallbladder cancer associated with PBM

Financial markets forecasts revisited: are they rational, herding or bold?

We test whether professional forecasters forecast rationally or behaviorally using a unique database, QSS Database, which is the monthly panel of forecasts on Japanese stock prices and bond yields. The estimation results show that (i) professional forecasts are behavioral, namely, significantly influenced by past forecasts, (ii) there exists a stock-bond dissonance: while forecasting behavior in the stock market seems to be herding, that in the bond market seems to be bold in the sense that their current forecasts tend to be negatively related to past forecasts, and (iii) the dissonance is due, at least partially, to the individual forecasters' behavior that is influenced by their own past forecasts rather than others. Even in the same country, forecasting behavior is quite different by market.

Average-case competitive analyses for one-way trading

Consider a trader who exchanges one dollar into yen and assume that the exchange rate fluctuates within the interval [m, M]. The game ends without advance notice, then the trader is forced to exchange all the remaining dollars at the minimum rate m. El-Yaniv et al. presented the optimal worst-case threat-based strategy for this game (El-Yaniv et al. 2001). In this paper, under the assumption that the distribution of the maximum exchange rate is known, we provide average-case analyses using all the reasonable optimization measures and derive different optimal strategies for each of them. Remarkable differences in behavior are as follows: Unlike other strategies, the average-case threat-based strategy that minimizes E[OPT/ALG] exchanges little by little. The maximization of E[ALG/OPT] and the minimization of E[OPT]/E[ALG] lead to similar strategies in that both exchange all at once. However, their timing is different. We also prove minimax theorems with respect to each objective function.ArticleJOURNAL OF COMBINATORIAL OPTIMIZATION. 21(1): 83-107 (2011)journal articl

An Improved Analysis of SRPT Scheduling Algorithm on the Basis of Functional Optimization *

Abstract The competitive performance of the SRPT scheduling algorithm has been open for a long time except for being 2-competitive, where the objective is to minimize the total completion time. Chung et al. proved that the SRPT algorithm is 1.857-competitive. In this paper we improve their analysis and show a 1.792-competitiveness. We clearly mention that our result is not the best so far, since Sitters recently proved the algorithm is 1.250-competitive. Nevertheless, it is still well worth reporting our analytical method; our analysis is based on the modern functional optimization, which can scarcely be found in the literature on the analysis of algorithms. Our aim is to illustrate the potentiality of functional optimization with a concrete application

Evaluation of Blood Supply with Indocyanine Green Fluorescence in Resection for Concurrent Gastric and Pancreatic Cancer: A Case Report

We present a rare case of concurrent resection of pancreatic and gastric cancer in which indocyanine green (ICG) fluorescence was used to evaluate the remnant stomach. An 80-year-old man was referred with a tumor in the distal pancreas. Computed tomography showed a 25-mm mass in the pancreatic tail; endoscopic ultrasound-guided fine-needle aspiration revealed adenocarcinoma. Upper gastrointestinal endoscopy and subsequent upper gastrointestinal series revealed advanced gastric cancer in the mid-stomach. Concurrent resection of the pancreatic and gastric tumors was performed. After distal pancreatectomy and distal gastrectomy, ICG evaluation of the stomach showed fluorescence extending only 3 cm distal from the cardia. To avoid ischemic change at the remnant stomach, total gastrectomy was performed. Since remnant gastric necrosis and anastomotic leak following ischemia can lead to fatal outcomes, the use of ICG to evaluate blood supply at anastomotic sites can help determine the extent of safe resection in such cases

HBx and c-MYC Cooperate to Induce URI1 Expression in HBV-Related Hepatocellular Carcinoma

Unconventional prefoldin RNA polymerase II subunit 5 interactor (URI1) has emerged as an oncogenic driver in hepatocellular carcinoma (HCC). Although the hepatitis B virus (HBV) represents the most common etiology of HCC worldwide, it is unknown whether URI1 plays a role in HBV-related HCC (HCC-B). In the present study, we investigated URI1 expression and its underlying mechanism in HCC-B tissues and cell lines. URI1 gene-promoter activity was determined by a luciferase assay. Human HCC-B samples were used for a chromatin immunoprecipitation assay. We found that c-MYC induced URI1 expression and activated the URI1 promoter through the E-box in the promoter region while the HBx protein significantly enhanced it. The positivity of URI1 expression was significantly higher in HCC-B tumor tissues than in non-HBV-related HCC tumor tissues, suggesting that a specific mechanism underlies URI1 expression in HCC-B. In tumor tissues from HCC-B patients, a significantly higher level of c-MYC was recruited to the E-box than in non-tumor tissues. These results suggest that HBx and c-MYC are involved in URI1 expression in HCC-B. URI1 expression may play important roles in the development and progression of HCC-B because HBx and c-MYC are well-known oncogenic factors in the virus and host, respectively

Gain-of-function oncogenic mutations in TP53 enhance defined factor-mediated cellular reprogramming

Cancer is a disorder with various genetic and epigenetic alterations. Genetic alterations such as mutations, i.e., substitutions, amplifications, and deletions of nucleotide sequences, are largely irreversible, whereas epigenetic alterations can be modified by pharmacological agents that target components of the epigenetic machinery. Recent studies have showed that introduction of defined factors such as those encoded by c-MYC, SOX2, OCT3/4, and KLF4 in normal somatic cells results in their dedifferentiation into induced pluripotent stem (iPS) cells. In addition, we have reported that these iPS factors induce the development of induced multipotent cancer (iPC) cells from gastrointestinal cancer cells by reducing tumor aggressiveness. The efficiency of iPS reprogramming increased when p53 was inhibited. The study of cancer cells suggests that the p53 pathways might be involved in the aggressive phenotypes of iPC cells in a long-term culture. However, the roles of gain-of-function oncogenic mutations in TP53, which is a key tumor suppressor gene, remain to be elucidated. We investigated reprogramming efficiency of iPS generation in human diploid fibroblasts that were co-transfected with TP53 mutants and defined factors. The results suggest that mutations in those TP53 regions that are involved in DNA contact might play a critical role in the efficiency of iPS generation. Taken together, our studies suggest 2 roles of TP53 mutations in reprogramming: (1) the structural mutations might contribute to, or collaborate with, other mutations to regulate the maintenance of genomic stability; (2) the DNA-contact mutations could affect the downstream target genes, which may be distinct from those involved in wild-type p53 function. These molecular manipulations of tumorigenicity and enhancement of cellular reprogramming efficiency by the p53 pathway will open an attractive and useful avenue for future medicine

NEAT1 is Required for the Expression of the Liver Cancer Stem Cell Marker CD44

CD44, a cancer stem cell (CSC) marker, is required for maintaining CSC properties in hepatocellular carcinoma (HCC). Nuclear enriched abundant transcript 1 (NEAT1), a long noncoding RNA (lncRNA), is an oncogenic driver in HCC. In the present study, we investigated the significance of the NEAT1 gene in association with CD44 expression in liver CSCs of human HCC cell lines. The CSC properties were evaluated by spheroid culture, CSC marker expression, and sensitivity to anti-cancer drugs. The expression of both NEAT1 variant 1 (NEAT1v1) and variant 2 (NEAT1v2) as well as CD44 was significantly increased in the spheroid culture, compared with that in monolayer culture. Overexpression of Neat1v1, but not Neat1v2, enhanced the CSC properties, while knockout of the NEAT1 gene suppressed them. CD44 expression was increased by the overexpression of Neat1v1 and abrogated by NEAT1 knockout. The overexpression of NEAT1v1 restored the CSC properties and CD44 expression in NEAT1-knockout cells. NEAT1v1 expression in HCC tissues was correlated with poor prognosis and CD44 expression. These results suggest that NEAT1v1 is required for CD44 expression. To our surprise, NEAT1v1 also restored the CSC properties even in CD44-deficient cells, suggesting that NEAT1v1 maintains the properties of CSCs in a CD44-independent manner

Duration of Postoperative Fever as a Simple and Useful Prognostic Indicator in Gastric Cancer Patients

[Background] Postoperative inflammation is associated with cancer progression in several cancers. However, the prognostic significance of postoperative fever remains unclear in gastric cancer patients. [Methods] We enrolled 442 patients with a histopathological diagnosis of gastric adenocarcinoma who underwent curative surgery. [Results] The mean duration of postoperative fever ≥ 37°C was 8.7 days (range: 0–186 days) and significantly longer in patients with advanced gastric cancer, venous invasion, and open or total gastrectomy vs. patients with early gastric cancer (P = 0.0072), no venous invasion (P = 0.025), laparoscopic gastrectomy (P = 0.027), and either proximal or distal partial gastrectomy (P = 0.0015). Five-year overall survival rates were 69.5% vs. 83.6% in the prolonged postoperative fever group (≥ 6 days of ≥ 37°C) vs. the nonprolonged group (< 6 days of ≥ 37°C), respectively (P = 0.0008). In patients without Clavien-Dindo classification postoperative infectious complications grade ≥ 2, 5-year overall survival was 69.7% vs. 84.0% in patients with prolonged postoperative fever vs. those without, respectively (P = 0.0067). Five-year disease-specific survival was 85.9% vs. 93.1% in patients with prolonged fever vs. those without, respectively (P = 0.041). Multivariate analysis indicated that postoperative fever was an independent prognostic indicator. [Conclusion] Postoperative fever ≥ 37°C duration may be useful in predicting prognosis in gastric cancer patients