358 research outputs found

    Rb-Sr, Sm-Nd ages of the Phalaborwa Carbonatite Complex, South Africa

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    We analyzed Rb-Sr and Sm-Nd isotopic compositions of whole-rock and minerals from syenite, biotite gneiss xenolith, dolerite dyke, phoscorite, and carbonatite from the Phalaborwa Carbonatite Complex located in northeastern Transvaal, South Africa. Syenite does not give significant Rb-Sr and Sm-Nd whole-rock and mineral isochron ages. Dolerite gives an Rb-Sr whole-rock and mineral isochron age of 2062±74Ma. This age overlaps with the timing of the magmatism of the Phalaborwa Carbonatite Complex. Biotite gneiss and phoscorite do not also give significant Rb-Sr and Sm-Nd isochrons. The Rb-Sr whole-rock and mineral isochron of phoscorite, however, gives an age of 2013±93Ma. The age is clearly the cooling age of this complex. Carbonatites are divided into two groups, having low and high initial Sr isotopic ratios. This coordinates with the result of S.C. Eriksson (Carbonatites, ed. by K. Bell, 1989). In addition, these groups indicate different initial Nd isotopic ratios. These suggest that carbonatite and related rocks were formed by mixing of two source magmas having different Sr and Nd isotopic compositions

    Reforestation following harvesting of conifer plantations in Japan: Current issues from silvicultural and ecological perspectives

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    Following the Second World War, the number of Cupressaceae plantations in Japan increased, in accordance with government policy for the restoration of timber resources and conservation of soil and water. Currently, these even-aged plantations occupy approximately 44% of the forested area and 24% of the national land area of Japan. Although many of these plantations have become available as timber resources, there are several silviculture-related problems associated with reforestation following clear-cutting of these plantations. The abundant annual precipitation in Japan allows for dominance by competitive vegetation, which makes natural regeneration difficult and increases the cost of silvicultural operations during and after the planting of seedlings. Because the number of seedling producers has decreased, there has been little incentive to keep seedling production techniques up to date. Additionally, damage to planted seedlings by the overabundant sika deer (Cervus nippon) population has increased dramatically in the last dozen years or so. To determine how to overcome these difficulties, various studies are underway in Japan. For example, seedling studies have examined the relationship between seedling size and competitive ability with other species in reforested areas, and have led to the development of lower-cost systems to produce customized Cupressaceae seedlings, as well as measures to minimize transplanting damage to seedlings. Previous studies have shown that no-weeding operations might lower the risk of sika deer browsing seedlings, although this silvicultural countermeasure may potentially reduce seedling growth. Studies have also examined the types of physical protection against sika deer browsing that are most efficient. We must combine these findings into a unified silvicultural system for successful restoration via lower-cost plantations

    A new meridian imaging spectrogarph for the auroral spectroscopy

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    Spectroscopic and monochromatic imaging observations of emissions in the upper atmosphere are mutually complementary. A meridian imaging auroral spectrograph (ASG) that can measure a spectrum in the visible region along a meridian has been developed for research on the auroral physics and the polar upper-atmosphere dynamics. Combination of a fast optical system inherited from a monochromatic all-sky imager, a grism as a dispersive element, and a cooled CCD camera has enabled a wide field-of-view of 180° along a meridian, spectral coverage of 420-730 nm, spectral resolution of 1.5-2.0 nm, and high sensitivity to be obtained. The absolute sensitivity over a full-image field was calibrated using a National Institute of Standards and Technology (NIST) traceable integrating sphere and determined to be 0.06 cts/s/R at a wavelength of 560 nm at the zenith. The ASG was installed at Longyearbyen in March 2000, and routine operation was started in the 2000/2001 winter season. An example of an auroral spectral image is presented in this report to demonstrate the performance of the ASG

    Localisation of the hyaluronan receptor CD44 in porcine cumulus cells during in vivo and in vitro maturation

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    Polyspermy is fairly common during porcine in vitro fertilisation (IVF), perhaps due to incomplete in vitro oocyte maturation (IVM). Porcine cumulus cells (CCs) layered around the oocyte produce large amounts of extracellular hyaluronan (HA) when forming an expanding cell cloud during the last phase of oocyte maturation. The specific actions of HA are mediated via HA-binding proteins (HABPs), such as CD44, which act as receptors. In this study using immunocytochemistry and western blotting we investigated the localisation of CD44 in CCs obtained from in vivo-matured pig cumulus–oocyte complexes (COCs) and compared it with that in CCs from immature COCs and of COCs subjected to IVM and IVF procedures. Immunolabelling of CD44 was absent or very weak in CCs from immature COCs but strongly present on the surface of the CCs obtained from in vivo, displaying a similar localisation in the in vitromatured COCs. In the latter, the labelling decreased but did not disappear in CCs 4 h after sperm co-incubation during IVF. Immunoblotting detected bands of between 73 and 88 kDa, corresponding to CD44, in the protein extract from in vivo CCs collected immediately prior to, or following spontaneous ovulation. The in vitro-matured CCs, however, presented bands ranging from 81 kDa to 88 kDa. Also, the bands found in the in vivo-matured CCs showed a larger variation of intensity and migration among animals than did the batches of in vitro-matured CCs. No CD44 band was detected on aliquots of the frozenthawed boar spermatozoa used for IVF. The results clearly demonstrate that the specific HA receptor CD44 is present in expanding CCs of in vivo-matured pig COCs, in relation to increasing amounts of inter-CC HA. The subtle differences in molecular weight and migration ability observed between in vivo and in vitro samples may relate to differences in glycosylation and thus explain differences in HA-binding ability, of consequence for optimising in vitro culture conditions.</p

    \u3ci\u3eIn vitro\u3c/i\u3e assembly of apophytochrome and apophytochrome deletion mutants expressed in yeast with phycocyanobilin

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    Recombinant pea type I phytochrome apoprotein expressed in yeast is shown to assemble in vitro with phycocyanobilin to produce a photoreversible phytochromelike adduct. As an initial investigation of the amino acid sequence requirements for chromophore incorporation, three phyA gene product deletion mutants were produced in yeast. Truncation of the N-terminal tail to residue 46 demonstrates that this region is not critical to bilin attachment, but a deletion mutant lacking 222 amino acids from the N terminus failed to yield holophytochrome in vitro, under the same conditions. A mutant comprising a deletion of the C terminus to residue 548 showed bilin incorporation and red/far-red photoreversibility, indicating that bilin-apophytochrome assembly still occurred even when the entire C-terminal domain was truncated

    エジプト紅海沿岸のマングローブ林の林分構造

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    Established mangrove forests along the coastal area of the Arabian Peninsula and African side of the Red Sea are uniquely different from mangrove forests in other parts of the world because of their low biodiversity and harsh habitat of arid and highly saline conditions. Therefore mangrove forests in this area appear in patchy and scattered patterns at mouths of wadi or in sheltered lagoons with rare and irregular flooding. Most of them are pure forests of Avicennia marina, occasionally mixed with Rhizophora mucronata in the southern part of the Red Sea. In this study, we analyze the forest structure of A. marina and discuss the regeneration strategy and the forest dynamics of this unique mangrove species. Three experimental plots of 1000 to 2000 trees/ha were selected from north to south along the Red Sea coast. The highest tree size (6.8m) suggested severe effects of the high salinity of the Red Sea (3.2 to 4.9%) on tree growth. Dense mantle vegetation had developed at the forest edge facing the open sea to protect the forest interior against strong waves and wind. Tree growth was also prevented by severe drought on the landside edge of the forest. All the forests had a dense seedling bank throughout the forest floor, with a very high rate of turnover and regeneration, which seldom occurred in other forests

    Mycoflora of plant litter collecting in winter in Ny-Ålesund, Svalbard

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    第2回極域科学シンポジウム/第33回極域生物シンポジウム 11月18日(金) 統計数理研究所 3階リフレッシュフロ

    Mohawk promotes the maintenance and regeneration of the outer annulus fibrosus of intervertebral discs.

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    The main pathogenesis of intervertebral disc (IVD) herniation involves disruption of the annulus fibrosus (AF) caused by ageing or excessive mechanical stress and the resulting prolapse of the nucleus pulposus. Owing to the avascular nature of the IVD and lack of understanding the mechanisms that maintain the IVD, current therapies do not lead to tissue regeneration. Here we show that homeobox protein Mohawk (Mkx) is a key transcription factor that regulates AF development, maintenance and regeneration. Mkx is mainly expressed in the outer AF (OAF) of humans and mice. In Mkx(-/-) mice, the OAF displays a deficiency of multiple tendon/ligament-related genes, a smaller OAF collagen fibril diameter and a more rapid progression of IVD degeneration compared with the wild type. Mesenchymal stem cells overexpressing Mkx promote functional AF regeneration in a mouse AF defect model, with abundant collagen fibril formation. Our results indicate a therapeutic strategy for AF regeneration

    Evaluation of pharmaceutical lifesaving skills training oriented pharmaceutical intervention

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    Background: Many pharmacists are participating in team-based medical care in emergency hospitals. Therefore, there is a desperate need to improve the education system. In the present study, we provided a “pharmaceutical lifesaving skills training” to the students in their fifth and sixth year of the pharmaceutical school and evaluated the program’s impact on the students’ learning and confidence in their ability to perform pharmaceutical interventions for emergency patients. Methods: We conducted a pharmaceutical lifesaving skills training program with 12 participants who were in their fifth and six year of pharmaceutical school. We prepared a fictional scenario in which a patient with cardiac arrest has been rushed into a hospital. We measured the participants’ level of knowledge of pharmaceutical lifesaving procedures and participants’ confidence to perform pharmaceutical interventions before and after the training session. Using the data obtained from type II quantification method, we examined what elements in the content of the pharmaceutical lifesaving skill training attended by pharmacy students will affect the students’ confidence to perform pharmaceutical interventions. In addition, using the correspondence structural analysis, we examined which sections of the content of the pharmaceutical lifesaving skill training should be improved in the future. Results: When we evaluated the level of knowledge acquired in pharmaceutical lifesaving skills training, the post-training overall correct answer rate was significantly higher than the pre-training overall correct answer rate. And also, level of participants' confidence to perform pharmaceutical interventions similarly increased after pharmaceutical lifesaving skill training. The influence degree graph indicates that the items likely to have a major impact on the participants’ confidence to perform pharmaceutical interventions was “Selecting medicine”. According to the correspondence structural analysis graph based on the questionnaire survey, one item identified as an improvement required was “Selecting medicine”. Conclusions: Our high-performance patient simulator-based lifesaving skills training program not only increased the participants’ understanding of the training content but also increased their confidence in their ability to perform pharmaceutical interventions. Therefore, the pharmaceutical lifesaving skills training program we developed will contribute to the education of emergency care pharmacists who can perform pharmaceutical interventions for emergency patients

    重度大動脈弁狭窄症患者の大動脈弁置換術後における血小板機能および高分子量 von Willebrand 因子多量体の急速な回復

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    AIM: Patients with severe aortic stenosis (AS) may have bleeding episodes due to the loss of high-molecular-weight (HMW) von Willebrand factor multimers (VWFMs). The absence of HMW-VWFMs and bleeding tendency are usually corrected after aortic valve replacement (AVR). To investigate the process of VWFM recovery and symptoms in patients with severe AS, we analyzed changes in VWF antigen (VWF:Ag), ADAMTS13 activity (ADAMTS13:AC), and platelet thrombus formation under high shear stress conditions. METHODS: Nine patients with severe AS undergoing AVR were analyzed. RESULTS: Evident deficiency of HMW-VWFMs was observed in six patients before surgery, which was rapidly restored within 8 days after AVR. Median levels of VWF:Ag before surgery, on postoperative days (PODs) 1, 8, 15, and 22, and one year after AVR were 78.1%, 130%, 224%, 155%, 134%, and 142%, respectively. In contrast, ADAMTS13:AC was 50.5%, 35.5%, 25.5%, 25.1%, 30.3%, and 84.6%, respectively. Preoperative thrombus formation but not surface coverage was significantly lower than that on POD 22, which was considered as normal level in each patient. Compared with preoperative levels, thrombus volume was significantly lower on POD 1, but rapidly increased by POD 8. CONCLUSION: Bleeding tendency and loss of HMW-VWFMs observed in patients with severe AS before surgery was rapidly corrected after AVR. Instead, patients were in a VWF-predominant state between POD 8 and 22.博士(医学)・乙第1395号・平成29年3月15日Copyright © 2016 Japan Atherosclerosis Society本論文の著作権は日本動脈硬化学会が保持しています。This article is distributed under the terms of the latest version of CC BY-NC-SA defined by the Creative Commons Attribution License
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