1,354 research outputs found

    Asset Bubbles and Endogenous Growth

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    We study the interaction between productive and nonproductive savings in an economy that grows in the long run due to endogenous improvements in labor productivity. As in the neoclassical growth setting with overlapping generations studied by Tirole (1985), asset bubbles can exist in an economy with endogenous growth provided they are not too large and that the growth rate in the equilibrium without bubbles exceeds the interest rate. Since the growth rate in the bubble-less equilibrium is endogenous, the existence condition reflects parameters of tastes and technology. We find that bubbles, when they exist, retard the growth of the economy, perhaps even in the long run, and reduce the welfare of all generations born after the bubble appears.

    A perception based approach for acoustic events modeling in interactive sound field network

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    Presented at the 8th International Conference on Auditory Display (ICAD), Kyoto, Japan, July 2-5, 2002.This paper describes the relation between physical / acoustic parameters and psychological scale for the sound fields in order to create an artificial impulse response of the room based on the perception. First, 19 specific words were chosen that expressing subjective impressions of the sound field from a Japanese language dictionary with 42,000 vocabularies. To classify the 19 words, speech sounds are compared in the way of dichotic listening. The speech sounds are convolution of an anechoic speech and impulse responses of rooms measured by using a dummy head microphone. The words are clustered into 4 categories, 1) high tone timbre, 2) low tone timbre, 3) spaciousness and 4) naturalness or clearness. Then, the 'spatial impression' was selected among 19words and a scale of it was obtained by way of Thurstone's case V since it is one of the important factors in the sound field design. Second, to create an impulse response corresponding to the 'spatial impression', we investigate the relation between the 'spatial impression' and physical/acoustic parameters. As a result, we found that the initial part of impulse response is an important part for controlling 'spatial impression'. The result is confirmed by listening test using artificial impulse responses. Finally, we propose a psychological approach for AEML(Acoustic Modeling Language) for Interactive Sound Field Network

    A patient-derived orthotopic xenograft (PDOX) mouse model of a cisplatinum-resistant osteosarcoma lung metastasis that was sensitive to temozolomide and trabectedin: implications for precision oncology.

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    In the present study, we evaluated the efficacy of trabectedin (TRAB) and temozolomide (TEM) compared to cisplatinum (CDDP) on a patient-derived orthotopic xenogrraft (PDOX) of a lung-metastasis from an osteosarcoma of a patient who failed CDDP therapy. Osteosarcoma resected from the patient was implanted orthotopically in the distal femur of mice to establish PDOX models which were randomized into the following groups when tumor volume reached approximately 100 mm3: G1, control without treatment; G2, CDDP (6 mg/kg, intraperitoneal injection, weekly, for 2 weeks); G3, TRAB (0.15 mg/kg, intravenous injection, weekly, for 2 weeks); G4, TEM (25 mg/kg, oral, daily, for 14 days). Tumor sizes and body weight were measured with calipers and a digital balance twice a week. On day 14 after initiation of treatment, TEM and TRAB, but not CDDP, significantly inhibited tumor volume compared to untreated control: control (G1): 814.5±258.8 mm3; CDDP (G2): 608.6±126.9 mm3, TRAB (G3): 286.6±133.0 mm3; TEM (G4): 182.9±69.1 mm3. CDDP vs. control, p=0.07; TRAB vs. control, p=0.0004; TEM vs. control p =0.0002; TRAB vs. CDDP, p =0.0002; TEM vs. CDDP, p =0.00003. The results of the present study show that a PDOX model of an osteosarcoma lung-metastasis that recurred after adjuvant CDDP-treatment has identified potentially, highly-effective drugs for this recalcitrant disease, while precisely maintaining the CDDP resistance of the tumor in the patient, thereby demonstrating the potential of the osteosarcoma PDOX model for precision oncology

    Production of interleukin-10 by alveolar macrophages from lung cancer patients

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    AbstractInterleukin (IL)-10 is known to be an autoregulatory factor of functions of monocyte macrophages. The purpose of this study was to determine whether IL-10 production by alveolar macrophages (AMs) is altered in patients with lung cancer. AMs were obtained by bronchoalveolar lavage from 25 patients with lung cancer and 14 control patients. The production of IL-10 by AMs was quantitated by enzyme immunoassay with or without stimulation with lipopolysaccharide (LPS). No significant difference in spontaneous and LPS-stimulated IL-10 production by AMs was observed between lung cancer patients and control patients (mean ± sem; 288·0 ± 56·7 vs. 249·6 ± 58·4 pg ml−1). IL-10 production of LPS-stimulated AMs was not impaired even in lung cancer patients with systemic metastasis. IL-4 failed to suppress LPS-induced production of IL-10 by AMs both in control patients and in lung cancer patients. In eight patients with lung cancer, IL-10 production by AMs was estimated before and after systemic chemotherapy and IL-10 production by LPS-stimulated AMs tended to increase after systemic chemotherapy from 152·3 ± 51·9 to 278·0 ± 112·8 pg ml−1. As IL-10 is a potent inhibitor of tumour angiogenesis, an important process of tumour progression, these results suggest that, even in advanced cancer patients, macrophages can produce potent angiogenesis inhibitor and systemic chemotherapy may augment this inhibitory activity in the lung

    Tumor-targeting Salmonella typhimurium A1-R regresses an osteosarcoma in a patient-derived xenograft model resistant to a molecular-targeting drug.

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    Osteosarcoma occurs mostly in children and young adults, who are treated with multiple agents in combination with limb-salvage surgery. However, the overall 5-year survival rate for patients with recurrent or metastatic osteosarcoma is 20-30% which has not improved significantly over 30 years. Refractory patients would benefit from precise individualized therapy. We report here that a patient-derived osteosarcoma growing in a subcutaneous nude-mouse model was regressed by tumor-targeting Salmonella typhimurium A1-R (S. typhimurium A1-R, p<0.001 compared to untreated control). The osteosarcoma was only partially sensitive to the molecular-targeting drug sorafenib, which did not arrest its growth. S. typhimurium A1-R was significantly more effective than sorafenib (P <0.001). S. typhimurium grew in the treated tumors and caused extensive necrosis of the tumor tissue. These data show that S. typhimurium A1-R is powerful therapy for an osteosarcoma patient-derived xenograft model
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