128 research outputs found

    Productivity of Service Providers: Microeconometric measurement in the case of hair salons

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    In this paper we measure the productivity of service industries using micro dataset. The "service industry" is a very broad category including many sectors, such as education, finance, insurance, transportation, logistics, food service, and many more. These sectors exhibit, in our understanding, very different structures from one another, and it is not easy to construct one model that can be applied to all service sectors. It is common in the literature to measure the productivity of manufacturing industries, typically by the Solow residual or its modification from production function estimations. We may possibly follow the same track in studying productivity in service industries. However, they may be different in their structures. In the case of hair salon services, it is impossible for service providers to hold inventories. They can serve only when customers arrive at the hair salon.1In this paper, we study the case of hairdressers using micro data collected by hair salons. We believe that our approach is applicable to the food industry, beauty industry and health clinic industry.

    An Econometric Analysis of Firm Specific Productivities: Evidence from Japanese plant level data

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    In estimating the production function of firms, problems of endogeneity and self selection exist as a result of firm-specific productivity shocks and entry/exit decisions. Several methods have been proposed to handle these problems, such as those by Olley and Pakes (1996) and Levinsohn and Petrin (1999, 2003). However, the endogeneity of labor input does not seem to be completely solved by these methods. We therefore propose an alternative semiparametric IV estimator. We suppose that firm-specific productivity influences labor input as well as capital input. We adopt the lagged variables of inputs as their instruments instead of investment inputs, unlike Olley and Pakes. Moreover, our econometric model should automatically adapt to the effect of the exit decision of each firm. We applied the model to Japanese plant-level panel data from 1982 to 2004 on the Census of Manufactures provided by the Ministry of Economy, Trade and Industry. We found that our estimator works well in an empirical study in terms of sign and magnitude of the technological parameters. Using the estimation residuals, we decomposed the TFP into firm-specific productivity and other exogenous shocks. We also aggregated the productivity shocks to industry-level productivities to determine the transition. We examined whether negative technological shocks were the main cause of poor economic performance in Japan during the "lost decade", and found that productivity did not decline in most Japanese industries since the 1980s. This implies that the recession might have been caused by demand-side factors rather than supply-side issues.

    イヌ蛔虫幼虫の電子顕微鏡学的研究: 横断面の超微形態について

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    取得学位 : 博士(医学), 学位授与番号 : 医博乙第1223号,学位授与年月日:平成5年4月21日,学位授与年:199

    Study of LEO-SAT microwave link for broad-band mobile satellite communication system

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    In the field of mobile satellite communications, a system based on low-earth-orbit satellites (LEO-SAT's) such as the Iridium system has been proposed. The LEO-SAT system is able to offer mobile telecommunication services in high-latitude areas. Rain degradation, fading and shadowing are also expected to be decreased when the system is operated at a high elevation angle. Furthermore, the propagation delay generated in the LEO-SAT system is less pronounced than that in the geostationary orbit satellite (GEO-SAT) system and, in voice services, the effect of the delay is almost negligible. We proposed a concept of a broad-band mobile satellite communication system with LEO-SAT's and Optical ISL. In that system, a fixed L-band (1.6/1.5 GHz) multibeam is used to offer narrow band service to the mobile terminals in the entire area covered by a LEO-SAT and steerable Ka-band (30/20 GHz) spot beams are used for the wide band service. In this paper, we present results of a study of LEO-SAT microwave link between a satellite and a mobile terminal for a broad-band mobile satellite communication system. First, the results of link budget calculations are presented and the antennas mounted on satellites are shown. For a future mobile antenna technology, we also show digital beamforming (DBF) techniques. DBF, together with modulation and/or demodulation, is becoming a key technique for mobile antennas with advanced functions such as antenna pattern calibration, correction, and radio interference suppression. In this paper, efficient DBF techniques for transmitting and receiving are presented. Furthermore, an adaptive array antenna system suitable for this LEO-SAT is presented

    Numerical Calculation and Experimental Validation of RCS Analysis for Radome-Enclosed Scatterer by Using PMCHWT-formulation

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    Abstract This paper investigates the accuracy of RCS analysis for radome-enclosed scatterer by using the PMCHWTformulation. The analysis method based on a surface integral equation known as the PMCHWT-formulation is outlined shortly. We show that calculated scattering cross section patterns of a dielectric coated conducting sphere agree with exact solutions. Then a RCS pattern of an acrylic hemisphere covered conducting disk is compared with measurement result. Calculated RCS patterns of ellipsoidal radome-enclosed scatterer are also presented. We verify the method of moments using the PMCHWT-formulation is sufficiently accurate for RCS analysis of radomeenclosed scatterer

    MALIGNANT ONCOCYTOMA OF THE PARANASAL SINUS

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    A case of malignant oncocytoma developing in the paranasal sinus of a 37-year-old Japanese man with a habit of heavy smoking is described. The primary tumor was found in the right maxillary sinus with local invasion to the nose and right ethmoidal sinus ; it was composed of nests of large oncocytic cells, with finely granular and eosinophilic cytoplasm, nuclear pleomorphism and prominent nucleoli, surrounded by proliferation of spindle-shaped cells in some areas. Electron microscopically, the cytoplasm of oncocytic tumor cells was characterized by abundant mitochondria, and immunohistochemical investigation revealed positive binding for antibodies to S-100 protein and α₁-antitrypsin, but a negative reaction for both cytokeratin and vimentin. At autopsy, metastatic nodules of tumor in the lungs, liver and pancreas independently exhibited both oncocytic cell- and sarcomatous cell compartments. This phenomenon is rare, and to the authors' knowledge, this would be histologically an ususual report of malignant oncocytoma with sarcomatous metastatic nodules arising from the paranasal sinus to be described in the literature

    Structure Effect on Antioxidant Activity of Catecholamines toward Singlet Oxygen and Other Reactive Oxygen Species in vitro

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    The reactivity of catecholamine neurotransmitters and the related metabolites were precisely investigated toward 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and reactive oxygen species. Catecholamines reacted immediately with DPPH radicals, their reactivity being stronger than that of ascorbic acid as a reference. Superoxide scavenging activities of catecholamines determined by WST-1 and electron spin resonance (ESR) spin trapping methods were also high. Whereas tyrosine, the dopamine precursor showed no reactivity toward superoxide. The reactivity toward singlet oxygen was evaluated by observing specific photon emission from singlet oxygen. The results revealed that reactivity of catecholamines was markedly higher than that of sodium azide, and catechin as catechol reference. The reaction of catecholamines and singlet oxygen was further studied by ESR using 55-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trapping reagent and rose bengal as photosensitizer. DMPO-OH signal of epinephrine was significantly small compared to other catecholamines, catechin, and 4-methylcatechol as a reference compound and was as small as that of tyrosine. The signal formation was totally dependent on singlet oxygen, and the presence of catechol compounds. These results indicated that epinephrine is the most potent singlet oxygen quencher than other catecholamines, and the secondary amino group in its alkyl side chain could play a role in unique singlet oxygen quenching property of epinephrine

    Calculated Tumor Volume Is an Independent Predictor of Biochemical Recurrence in Patients Who Underwent Retropubic Radical Prostatectomy

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    Purpose. The purpose of this study is to investigate whether the clinicopathological biopsy findings can predict the oncological outcome in patients who undergo radical prostatectomy. Materials and Methods. Between January 1997 and March 2006, 255 patients with clinically localized adenocarcinoma of the prostate (clinical T1-3N0M0) who had undergone retropubic radical prostatectomy were enrolled in this study. None of the patients received neoadjuvant or adjuvant therapy. Clinicopathological parameters were assessed to determine a predictive parameter of biochemical recurrence. Results. Of the total 255 patients, 77 showed biochemical recurrence during the follow-up period. The estimated 5-year overall survival, 5-year cause-specific survival, and 5-year biochemical recurrence-free survival rates were 97.7%, 99.5%, and 67.3%, respectively. Multivariate analysis using the Cox proportional hazards model showed that calculated cancer volume was an independent predictor among the preoperative clinicopathological parameters (P < 0.05). SVI and PSM were independent predictors among the postoperative parameters (SVI; P < 0.001, PSM; P = 0.049). Among the significant preoperative and postoperative parameters, calculated cancer volume remained an independent predictive parameter in multivariate analysis (P < 0.01). Conclusions. Tumor volume, as calculated by preoperative parameters, is an independent predictor of biochemical recurrence in patients who had undergone radical prostatectomy

    卵巣明細胞腺癌における転写因子HNF-1βはDNA損傷チェックポイント機構の一つであるCHK1タンパクを制御し、抗癌剤耐性を獲得する

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    Objective Appropriate cell cycle checkpoints are essential for the maintenance of normal cells and chemosensitivity of cancer cells. Clear cell adenocarcinoma (CCA) of the ovary is highly resistant to chemotherapy. Hepatocyte nuclear factor-1β (HNF-1β) is known to be overexpressed in CCA, but its role and clinical significance is unclear. We investigated the role of HNF-1β in regulation of the cell cycle in CCA. Methods To clarify the effects of HNF-1β on cell cycle checkpoints, we compared the cell cycle distribution and the expression of key proteins involved in CCA cells in which HNF-1β had been stably knocked down and in vector-control cell lines after treatment with bleomycin. HNF-1β (+) cells were arrested in G2 phase because of DNA damage. Results HNF-1β (−) cells died because of a checkpoint mechanism. G2 arrest of HNF-1β (+) cells resulted from sustained CHK1 activation, a protein that plays a major role in the checkpoint mechanism. HNF-1β (+) cells were treated with a CHK1 inhibitor after bleomycin treatment. Flow cytometric analysis of the cell cycle demonstrated that DNA damage–induced G2-arrested cells were released from the checkpoint and killed by a CHK1 inhibitor. Conclusions The chemoresistance of CCA may be due to aberrant retention of the G2 checkpoint through overexpression of HNF-1β. This is the first study demonstrating cell cycle regulation and chemosensitization by a CHK1 inhibitor in CCA.博士(医学)・乙第1345号・平成26年12月3日© 2014 by the International Gynecologic Cancer Society and the European Society of Gynaecological Oncology
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