1,694 research outputs found

    Price Competition in a Mixed Duopoly

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    We analyze sequential and simultaneous price setting under a mixed duopoly with homogeneous products and symmetric quadratic cost functions. When public firm is the follower, there exists the case that the equilibrium price is highest of all timings.

    Current State of Educational Reform and Approaches to Active Learning in NIT, Gifu College

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    AbstractStudents’ generic skills cannot be developed only by classroom lectures unilaterally performed by teachers, but they can be developed by a highly practical form of learning such as active learning (AL). Our college is promoting educational reform by practicing AL in all classes. This paper describes current approaches of our college based on the directions of National Institute of Technology (NIT), Japan. Also, regarding the AL classes of respective teachers, the content of an AL class and the actual plan of his/her style of an AL class are stated. Moreover, the content of a practical report on an AL class and the approaches of utilization are reported

    Brain tumors induced in rats by human adenovirus type 12

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    Oncogenesis of human adenovirus type 12 in the brain of rats was examined. Newborn rats of Sprague-Dawley and Donryu&#12288;strains were injected intracranially with human adenovirus type 12.&#12288;The incidence of intracranial tumors was 91% (30/33) in SpragueDawley&#12288;and 56% (14/25) in Donryu rats. Except for one tumor nodule&#12288;located in the parietal cortex of a Sprague.Dawley rat, all tumors&#12288;developed in the paraventricular areas or in the meninges. Tumors were quite similar histologically to those induced in hamsters and&#12288;mice resembling the undifferentiated human brain tumors such as medulloblastoma,&#12288;ependymoblastoma and embryonic gliomas. From&#12288;the histological features and primary sites of tumor development, it is&#12288;suggested that the tumors in the brain of rats induced by adenovirus type 12 originate from the embryonic cells in the&#12288;paraventricular area&#12288;and also from the undifferentiated supporting cells of the peripheral&#12288;nerves in the&#12288;leptomeninges.</p

    Hormone Signaling and Phenotypic Plasticity in Nematode Development and Evolution

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    Phenotypic plasticity refers to the ability of an organism to adopt different phenotypes depending on environmental conditions. In animals and plants, the progression of juvenile development and the formation of dormant stages are often associated with phenotypic plasticity, indicating the importance of phenotypic plasticity for life-history theory. Phenotypic plasticity has long been emphasized as a crucial principle in ecology and as facilitator of phenotypic evolution. In nematodes, several examples of phenotypic plasticity have been studied at the genetic and developmental level. In addition, the influence of different environmental factors has been investigated under laboratory conditions. These studies have provided detailed insight into the molecular basis of phenotypic plasticity and its ecological and evolutionary implications. Here, we review recent studies on the formation of dauer larvae in Caenorhabditis elegans, the evolution of nematode parasitism and the generation of a novel feeding trait in Pristionchus pacificus. These examples reveal a conserved and co-opted role of an endocrine signaling module involving the steroid hormone dafachronic acid. We will discuss how hormone signaling might facilitate life-history and morphological evolution

    Cryptococcus, Pathological observations of five autopsy cases and one biopsy case

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    Pathologic, anatomical, and histological findings of 5 autopsy cases and one biopsy case of cryptococcosis have been described. Macroscopically the foci of the lung are grayish white or yellowish white in color and range in size from the small acinous-nodular ones to the larger lobular-nodular ones. In the brain the meninx appears gelatinous and edematous showing many small spots with indistinct boundary and with grayish white color. Lymph nodes infected with fungi are swollen in various degrees. Histologically the foci are mainly consisted of granulomatous inflammation containing giant cells. Besides, there are small degenerative foci having no inflammatory response and the lesions of marked fibrosis; the former will be newly formed foci and the latter the old ones. The size of C. neoformans found in tissue ranges from 3 to 30 &#956;, and the majority of fungi possess thick gelatinous capsule, but some of them in granulative lesions often possess no capsule. From the staining properties the capsule of C. neoformans is believed to be a kind of acid mucopolysaccharide. As for the staining method including general fungi, GOMORI's methenamine silver method is best, especially for the detailed examination of fungus structures, and for the differential diagnosis mucicarmine stain is the most suitable one. In tracing the distribution of the foci in the various organs, it seems that the first attack of this fungus occurs in the lung. The authors have called general attention, through their own experiences, to the fact that the small granulomatous foci caused by Cryptococcus infection, especially in the lung, may often escape the detection at autopsy.</p

    A case of histoplasmosis Report 1. Cinical, mycological and pathological observations

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    In our country it has been believed that there is no histoplasmosis here in Japan. However, from the above clinical signs, radiological characteristics, laboratory tests, pathological and mycological examinations, and experimental findings, we believe this is the first case of histoplasmosis in Japan.</p

    Aminolevulinate synthase 2 mediates erythrocyte differentiation by regulating larval globin expression during Xenopus primary hematopoiesis

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    AbstractHemoglobin synthesis by erythrocytes continues throughout a vertebrate’s lifetime. The mechanism of mammalian heme synthesis has been studied for many years; aminolevulinate synthase 2 (ALAS2), a heme synthetase, is associated with X-linked dominant protoporphyria in humans. Amphibian and mammalian blood cells differ, but little is known about amphibian embryonic hemoglobin synthesis. We investigated the function of the Xenopus alas2 gene (Xalas2) in primitive amphibian erythrocytes and found that it is first expressed in primitive erythroid cells before hemoglobin alpha 3 subunit (hba3) during primary hematopoiesis and in the posterior ventral blood islands at the tailbud stage. Xalas2 is not expressed during secondary hematopoiesis in the dorsal lateral plate. Hemoglobin was barely detectable by o-dianisidine staining and hba3 transcript levels decreased in Xalas2-knockdown embryos. These results suggest that Xalas2 might be able to synthesize hemoglobin during hematopoiesis and mediate erythrocyte differentiation by regulating hba3 expression in Xenopus laevis
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