335 research outputs found

    Lost in Transaction: Individual-Level Welfare Loss in Quickly-Circulating Durable Goods Markets with Planned Temporary Ownership

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    A new style of durable goods consumption through a large scale online redistribution marketplace (e.g. eBay and Yahoo! Auction), characterized by a relatively small degree of usage and a short-term ownership, is becoming increasingly popular these days. Yet, the welfare structures of such emerging markets have not been investigated. By using a unique dataset of quickly-circulating multi-use train ticket resale markets, and by investigating perfectly-substitutable goods, this short article models, estimates, and analyzes individual-level welfare loss in such rapidly-growing market sectors. Our analysis shows that individual-level welfare losses caused by search and resale costs are non-negligibly large, ranging from 3% to 15% of the new good price. We also find that such individual-level welfare losses, which could be considered as hidden charges, are largely heterogeneous across buyers with differing degrees of intended use. These losses are described as disadvantageous to users who demand light degrees of usage

    Search and resale frictions in a two-sided online platform: A case of multi-use assets

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    How large are two-sided transaction costs in online platform trades, and who are the major beneficiaries of friction cost reductions? Using a dataset of a multi-use train ticket resale market, we analyze the welfare structure with buyer-seller matching frictions on an online platform. Our model shows that competitive online resale market prices work as a conductor of transaction cost externalities, clarifying what types of buyers bear what friction costs. The estimation results show that individual-level welfare losses, which could be considered an online resale market dead-weight loss, are non-negligibly large and heterogeneous across buyers, ranging from 3% to 21% of the new good price. Welfare losses are particularly disadvantageous to users who demand small degrees of usage, as they are more likely to be excluded from trading opportunities. Our model also suggests that, when competitive resale markets experience friction cost reductions, welfare gains are larger among small degree users of resalable goods, providing an explanation for the recent expansion of high-turnover online trades

    Cytological alteration of cultured rat liver cells by 3'-methyl-4-dimethylaminoazobenzene with special reference to chromosome changes, changes of growth patterns at a colony level and alpha-fetoprotein production.

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    A near diploid clone derived from a rat liver cell line was continuously treated with various concentrations of 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) in culture. By treatment with 2.8 micrograms/ml, cells with 41 chromosomes formed a mode and which then shifted to 39. The chromosome numbers of cells treated with 5.4 micrograms/ml were widely distributed at early stages, but later the mode shifted to hypotetraploid region. Untreated control cells were confirmed as near diploid. Increased plating efficiency by 3'-Me-DAB as well as the appearance of large sized colonies was obtained. The production of alpha-fetoprotein (AFP) by the cells was slightly enhanced by treatment with 3'-Me-DAB. The cells treated with and without 3'-Me-DAB did not produce any tumor in rats 6 months after their intraperitoneal injection.</p

    Development of high-pressure low-temperature plane strain testing apparatus for methane hydrate-bearing sand

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    AbstractA high-pressure low-temperature plane strain testing apparatus was developed for visualizing the deformation of methane hydrate-bearing sand due to methane hydrate production. Using this testing apparatus, plane strain compression tests were performed on pure Toyoura sand and methane hydrate-bearing sand with localized deformation measurements. From the results, it was observed that the methane hydrate-free specimens, despite their relatively high density, showed changes in compressive volume. Marked increases in the initial stiffness and strength of the methane hydrate-bearing sand were observed (methane hydrate saturation of SMH=60%). Moreover, the volumetric strain changed from compressive to dilative. For the specimens with methane hydrate, a dilative behavior above SMH=0% was observed. An image analysis showed that the shear bands of the methane hydrate-bearing sand were thinner and steeper than those of the host sand. In addition, the dilative volumetric strain in the shear band increased markedly when methane hydrate existed in the pore spaces

    Pre-operative weight loss program

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    Background : The aim of this study was to investigate the influence of obesity and the usefulness of a pre-operative weight loss program (PWLP) for obese patients undergoing laparoscopic gastrectomy (LG) for gastric cancer (GC). Materials and Methods : Study1 : 219 patients who underwent laparoscopic distal gastrectomy (LDG) for GC were divided into 2 groups : body mass index (BMI) ≧ 28 and BMI < 28kg / m2. The influence of BMI in LG surgery was investigated. Study2 : The BMI ≧ 28 kg / m2 patients with a planned LG (n = 8) undertook a PWLP including calorie restriction and exercise. The effects of this program were evaluated. Results : Study1 : The BMI ≧ 28kg / m2 group showed significantly longer operation times, more blood loss and a higher frequency of post-operative complications than that of the BMI < 28kg / m2 group. Study 2 : The patients achieved a weight loss of 4.2%. The visceral fat area (VFA) was significantly decreased by 10.6%, whereas skeletal muscle mass was unaffected. The PWLP group showed shorter operation times, less blood loss and a lower frequency of post-operative complications compared with that of the BMI ≧ 28kg / m2 group. Conclusion : Obesity is an important risk factor and a pre-operative weight loss program is useful for obese patients undergoing a LG

    The influence and countermeasure of obesity in laparoscopic colorectal resection

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    Background: The aim of this study was to investigate the influence of obesity and the usefulness of a preoperative weight loss program (PWLP) for obese patients undergoing laparoscopic colorectal resection (LCR). Methods: Study 1: 392 patients who underwent LCR for colorectal cancer were divided into two groups: those with a body mass index (BMI) ≥25 kg/m2 (n = 113) and those with a BMI <25 kg/m2 (n = 279). The influence of BMI on LCR was investigated. Study 2: Patients with a BMI ≥28 kg/m2 who were scheduled to undergo LCR (n = 7, mean body weight 87.0 kg, mean BMI 33.9 kg/m2) undertook a PWLP including caloric restriction and exercise for 29.6 (15–70) days. The effects of this program were evaluated. Results: Study 1: The BMI ≥25 kg/m2 group had a prolongation of operation time and hospital stay than the BMI <25 kg/m2 group. Study 2: The patients achieved a mean weight loss of 6.9% (−6.0 kg). The mean visceral fat area was significantly decreased by 18.0%, whereas the skeletal muscle mass was unaffected. The PWLP group had a significantly lower prevalence of postoperative complications compared with the BMI ≥25 kg/m2 group. Conclusion: Obesity affected the surgical outcomes in LCR. A PWLP may be useful for obese patients undergoing LCR

    CMTM6 is a Prognostic Factor in GC

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    Background : CKLF-like MARVEL transmembrane domain containing 6 (CMTM6) is the master regulator of programmed cell death-ligand 1 (PD-L1). We aimed to clarify the significance of CMTM6 expression in gastric cancer (GC). Methods : A total of 105 patients who had undergone curative surgical resection for stage II / III GC at Tokushima University Hospital were included in this study. The expression of CMTM6 was examined by immunohistochemistry. Additionally, the relationship of each expression level to several prognostic factors was examined using univariate and multivariate analyses. Results : CMTM6 was not positively correlated with any of the factors examined. The overall survival (OS) rates were significantly poorer in the CMTM6 high-expression group than in the CMTM low-expression group (5-year OS : 57.2% vs. 79.2%, respectively ; p < 0.05). Disease-free survival (DFS) was significantly poorer in the CMTM high-expression group than in the CMTM6 low-expression group (5-year DFS : 52.8% vs. 72.4%, respectively ; p < 0.05). Multivariate analysis confirmed CMTM6 expression as an independent prognostic factor in DFS (p < 0.05). CMTM6 expression tended to be correlated with PD-L1 expression (p = 0.07). Conclusions : CMTM6 is associated with a poor prognosis and immunotolerance through PD-L1 in GC

    Molecular Cloning and Expression Analysis of a Putative Nuclear Protein, SR-25

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    We cloned a full-length mouse cDNA and its human homologue encoding a novel protein designated as “SR-25.” In Northern blot analysis, SR-25 mRNA was expressed in all organs tested, and relatively abundant in testis and thymus. Deduced amino acid sequences of mouse SR-25 and human SR-25 showed 77.7% identity. SR-25 has a serine-arginine repeat (SR repeat) and two types of amino acid clusters: a serine cluster and a highly basic cluster. Based on the presence of many nuclear localizing signals and a similarity to RNA splicing proteins, SR-25 is strongly suggested to be a nuclear protein and may contribute to RNA splicing

    SDF-1 expression in rectal cancer

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    Stromal cell-derived factor-1 (SDF-1) expression is associated with cancer progression, as a biomarker of prognosis. We clarified the significance of SDF-1 expression on chemoradiotherapy (CRT) resistance and prognosis in advanced lower rectal cancer patients. We evaluated 98 patients with advanced lower rectal cancer who underwent preoperative CRT. All patients received 40 Gy of radiation therapy, with concurrent chemotherapy containing fluorinated pyrimidines, followed by surgical resection. SDF-1 expression in surgical specimens was examined by immunohistochemistry. We divided the patients into SDF-1-positive- (n = 52) and SDF-1-negative groups (n = 46) and compared the clinicopathological factors and survival rates. The SDF-1-positive group was more resistant to CRT than the SDF-1-negative group (non-responder rate, 63.5% vs. 47.8%, respectively ; p = 0.12). Overall survival (OS) in the SDF-1 positive group was significantly poorer vs. the SDF-1-negative group (5-year OS, 73.4% vs. 88.0%, respectively ; p = 0.02), and disease-free survival (DFS) was worse (5-year DFS, 61.0% vs. 74.1%, respectively ; p = 0.07). Multivariate analysis confirmed that SDF-1 expression was a significant independent prognostic predictor of OS (p = 0.04). SDF-1 expression after preoperative CRT is significantly associated with a poor prognosis in advanced lower rectal cancer patients and is a promising biomarker
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