517 research outputs found
Shock melting origin of a troilite-rich clast in the Moorabiechondrite (L3)
A troilite-rich clast enclosing chondrules was found in the Moorabie chondrite (L3). This chondrite is characterized by elongate morphology of chondrules produced by shock deformation. Average composition of the metal and troilite grains in the clast is close to the eutectic composition of the Fe-S system, indicating the melting origin of the clast. The eutectic composition provides the heating temperature to be around 1000℃. Size and distribution of troilite and metal grains in the clast suggest the slow cooling after the melting. Pentlandite as an exsolved phase of troilite in the clast, found first in ordinary chondrites, also supports the melting and slow cooling. Thermal history of the clast indicates that the melting of the opaque minerals and the elongate morphology of chondrules were caused inside the parent body by the shock event which occurred at an early hot stage (around 400℃) of the cooling after the accretion of the chondrite
Evaluation of Environments by the Species Composition of Carabid Beetles in Different Husbandry Fields
To clarify whether the species composition of carabid beetles can be used to evaluate the field environments of 3 different husbandry practices(fertilizer(F), tillage(T) and green manure(Gr)), pitfall trappings were taken between June and October 2003 in Nagano Prefecture, Japan. The surveyed field was divided into 8 plots(7.5m X 14m) growing the same kinds of vegetables, and combinations of the 3 husbandry practices were decided using an experimental design based on 3 factors and 2 levels. ANOVA based on a table of orthogonal arrays of the L⁸(2⁷) type was used for the numbers of carabid beetles, species richness and species diversity. A total of 821 carabid beetles of 6 subfamilies representing 31 species were captured during the survey period. The three dominant species were Dolichus halensis, Pterostichus microcephalus and Harpalus tridens. Through cluster analysis using an a index, the 8 plots were classified into a green manure group and a non-green manure group, except for 1 plot. The numbers of captured beetles of Pterostichinae, especially D. halensis, were significantly more abundant in chemical fertilizer plots and non-green manure plots. For Zabrinae and Harpalinae, more individuals were captured in tillage plots and green manure plots. In the tillage plots and green manure plots, the values of the species diversity index(1/λ and H') were significantly higher. These results suggest that carabid assemblages may be used as a bio-indicator for evaluating the field environments of different husbandry practices.ゴミムシ群集を指標種として栽培されている植物は全く同じであるが, 異なった耕作法が実施された圃場環境の評価の可能性を検討するため, 有機肥料と化学肥料, 耕起と不耕起, 緑肥ありと緑肥なしという3要因2水準の実験計画法に沿った8区画を長野県波田町に設け, ゴミムシ群集の調査を2003年の6月から10月まで行った. 結果の解析は, L₈(2⁷)型直交配列表に従った分散分析を用いた. ゴミムシは合計で31種821個体捕獲され, 優占種は多い順にセアカヒラタゴミムシ, コガシラナガゴミムシ, コゴモクムシであった. 類似度指数αをもとにしたクラスター分析では, 8区画は緑肥ありグループとなしグループに分かれた. 分散分析の結果, ナガゴミムシ亜科, 特にセアカヒラタゴミムシでは化学肥料区と緑肥なし区で個体数が多く, 反対にマルガタゴミムシ亜科とゴモクムシ亜科では耕起区と緑肥あり区で個体数が多かった. また耕起区と緑肥あり区では多様度指数(1/λとH')が有意に高くなった. 以上の結果から, ゴミムシ群集を指標種として耕作法が異なった圃場環境を評価できる可能性が示唆された.Article環動昆 16(1): 39-47 (2005)journal articl
Refractory precursor components in an Allende ferromagnesian chondrule
Chemical and petrological studies of chondrules revealed that they were formed through melting of pre-existing solid precursor materials, and that one of the refractory lithophile precursors was a high temperature condensate from the nebular gas and related to Ca, Al-rich inclusions (CAIs). Sheng et al. found relict spinel grains with isotopically fractionated Mg in plagioclase-olivine inclusions from CV chondrites and suggested that the major fractionation processes were common to CAIs and chondrules. We have determined the Mg isotopic compositon of five barred olivine chondrules and one coarse-grained rim from the Allende (CV3) meteorite. A reproducibility of instrumental isotope fractionation is plus or minus 2 per thousand per amu. The precision of the Mg-26/Mg-24 data after normalization for mass fractionation can be as good as 0.5 per thousand (2 sigma(mean)). The Mg analytical results are given and indicate that delta Mg-25/Mg-24 and sigma Mg-26 of the chondrules are normal within errors
MicroRNA, hsa-miR-200c, is an independent prognostic factor in pancreatic cancer and its upregulation inhibits pancreatic cancer invasion but increases cell proliferation
<p>Abstract</p> <p>Background</p> <p>Recently, the microRNA-200 family was reported to affect cancer biology by regulating epithelial to mesenchymal transition (EMT). Especially, the expression of <it>miR-200c </it>has been shown to be associated with upregulating the expression of <it>E-cadherin</it>, a gene known to be involved in pancreatic cancer behavior. However, the significance of <it>miR-200c </it>in pancreatic cancer is unknown.</p> <p>Methods</p> <p>In the present study, we investigated the relationship between <it>E-cadherin </it>and <it>miR-200c </it>expression in a panel of 14 pancreatic cancer cell lines and in macro-dissected formalin-fixed paraffin-embedded (FFPE) tissue samples obtained from 99 patients who underwent pancreatectomy for pancreatic cancer. We also investigated the effects of <it>miR-200c </it>on the proliferation and invasion of pancreatic cancer cells.</p> <p>Results</p> <p>We found that patients with high levels of <it>miR-200c </it>expression had significantly better survival rates than those with low levels of <it>miR-200c </it>expression. We also found a remarkably strong correlation between the levels of <it>miR-200c </it>and <it>E-cadherin </it>expression.</p> <p>Conclusions</p> <p>These data indicate that <it>miR-200c </it>may play a role in the pancreatic cancer biology and may be a novel marker for the prognosis of pancreatic cancer.</p
<Abstract of annual report>Diazidation of Allylsilanes with a Combination of Iodosylbenzene and Trimethylsilyl Azide, and Synthesis of Ally Azides.
Proposal of PPS Multivariate Public Key Cryptosystems
In this paper we propose a new MPKC, called PPS, based on (i) the 2-layer nonlinear piece in hand method, (ii) PMI, and (iii) STS. The PPS is a specific MPKC obtained by applying the 2-layer nonlinear piece in hand method to STS, in the manner that the rank and randomness of the lower rank steps in the original secret polynomial
vector of STS are enhanced by adding a perturbation polynomial vector and moreover PMI is used in the auxiliary part. The PPS overcomes the drawbacks of the three schemes by the advantage of the three schemes themself. Thus, PPS can be thought to be immune simultaneously from the algebraic attacks, such as the Groebner bases
attacks, from the rank attacks, and from the differential attacks
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