Approximate Analysis of Optimal Operating Policies for a GI/G/1 Queueing System

In this paper, applying a method of diffusion approximation, we consider optimal operating policies for a GI/G/1 queueing system with a removable server. The following costs are incurred in the system : a cost per unit time of keeping the server running, fixed costs for turning the server on or off, and a holding cost per customer in the system per unit time. The average cost rate is used as a criterion for optimality. By using a couple of diffusion processes that approximate the number of customers in the system, an explicit form of the average cost rate is derived. Furthermore, some sufficient conditions under which the optimal operating policy falls into specific forms are obtained. It is examined numerically how the boundary condition at the origin of the diffusion process effects the optimal operating policy and its cost

Ventricular androgenic-anabolic steroid-related remodeling: an immunohistochemical study

Background: Several fatal cases of bodybuilders, following a myocardial infarction after long exposure to androgenicanabolic steroids (AAS), are reported. In recent years, evidence has emerged of cases of heart failure related to AAS consumption, with no signs of coronary or aorta atherosclerosis. This study aims to further investigate the pathogenesis of the ventricular AAS-related remodeling performing immunohistochemistry (IHC). Method: In order to examine innate immunity activity and myocytes and endothelial cell apoptosis, IHC analyses were performed on heart tissue of two cases of bodybuilders who died after years of supratherapeutic use of metelonone and nandrolone and where no atherosclerosis or thrombosis were found, using the following antibodies: anti-CD68, anti-iNOS, anti-CD163, anti-CD 15, anti-CD8, anti-CD4, anti-HIF1 α, and in situ TUNEL staining. Results: Results confirm the experimental findings of recent research that, in the absence of other pathological factors, if intensive training is combined with AAS abuse, myocytes and endothelial cells undergo apoptotic alterations. The absence of inflammatory reactions and the presence of an increased number of M2 macrophages in the areas of fibrotic remodeling confirm that the fibrotic changes in the heart are apoptosisrelated and not necrosis-related. Conclusions In conclusion, the study indicates that, in very young subjects with chronic hypoxia-related alterations of the heart, signs of a heart failure in the other organs and a history of AAS abuse, death can be ascribed to progressive heart failure due to the direct apoptotic cardiac and endothelial changes produced by AAS

未破裂脳動脈瘤の出血率に関する単施設後方視的研究

学位の種別: 論文博士審査委員会委員 : （主査）東京大学教授 康永 秀生, 東京大学教授 辻 省次, 東京大学教授 小山 博史, 東京大学准教授 國松 聡, 東京大学准教授 中冨 浩文University of Tokyo(東京大学

Evaluation of heat extraction through sapphire fibers for the GW observatory KAGRA

Currently, the Japanese gravitational wave laser interferometer KAGRA is under construction in the Kamioka mine. As one main feature, it will employ sapphire mirrors operated at a temperature of 20K to reduce the impact from thermal noise. To reduce seismic noise, the mirrors will also be suspended from multi-stage pendulums. Thus the heat load deposited in the mirrors by absorption of the circulating laser light as well as heat load from thermal radiation will need to be extracted through the last suspension stage. This stage will consist of four thin sapphire fibers with larger heads necessary to connect the fibers to both the mirror and the upper stage. In this paper, we discuss heat conductivity measurements on different fiber candidates. While all fibers had a diameter of 1.6mm, different surface treatments and approaches to attach the heads were analyzed. Our measurements show that fibers fulfilling the basic KAGRA heat conductivity requirement of $\kappa\geq$5000W/m/K at 20K are technologically feasible.Comment: 11 pages, 4 figure

737–1 Heart Fatty Acid-binding Protein and Myoglobin can Accurately Detect Successful Reperfusion as Early as 15 Minutes After Reperfuslon

Human heart fatty acid-binding protein (FABP) is an abundant low molecular weight protein in cytoplasm of myocardial cell similar to myoglobin (Mb). To evaluate whether FABP can also detect successful reperfusion very early like Mb, we examined serum FABP and Mb levels in 45 patients (pts) undergoing PTCR or PTCA within 6 hours after the onset of acute myocardial infarction. Coronary angiography was performed every 5minutes (min) during reperfusion therapy to determine the exact time of reperfusion. In 30 pts with reperfusion (reperfused group: TIMI grade 3 [23 pts] and grade 2 [7 pts]), serum samples were taken just before and at 15, 30 and 60min after initial angiographic confirmation of reperfusion. In 15 pts without reperfusion (nonreperfused group), serum samples were taken just before and at 15, 30 and 60min after the initiation of therapy. FABP was measured by competitive enzyme immunoassay and Mb by latex agglutination turbidimetry. The FABP ratio (FABP after/FABP before) and Mb ratio (Mb after/Mb before) were calculated. FABP and Mb levels increased rapidly, peaked within 60min after reperfusion. The FABP and Mb ratios in the reperfused group significantly (p<0.01) exceeded those in the nonreperfused group at 15, 30 and 60 min. The sensitivity (Sen) and specificity (Spe) of these markers for reperfusion were as follows:Criteria15 min30 min60 minSenSpeSenSpeSenSpeFABP ratio>1.6*93%100%97%100%100%100%Mb ratio>2.4**90%100%93%100%100%100%*mean +2SD at 60 min in the nonreperfused group**published criteriaConclusionFABP, like Mb could accurately detect successful reperfusion as early as 15min after reperfusion and could provide a high level of accuracy within 60min after reperfusion