98 resultados para Calabi-Yau
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Vascular endothelial growth factor (VEGF) promotes growth of blood or lymphatic vessels. The aim of the current study is to identify relationships between VEGF-A and VEGF-C, and their impact in angiogenesis and metastases in thyroid cancers. VEGF-A and VEGF-C mRNA and protein expression was investigated in 136 thyroid cancers (123 papillary thyroid carcinomas and 13 undifferentiated thyroid carcinomas) and 40 matched lymph node metastases with papillary thyroid carcinoma using reverse transcription polymerase chain reaction and immunohistochemistry. VEGF-A and VEGF-C mRNA expression was significantly different between conventional papillary thyroid carcinoma, follicular variant of papillary thyroid carcinoma, and undifferentiated thyroid carcinomas (P = 1 x 10(-6) and 1 x 10(-5), respectively). In undifferentiated carcinoma, VEGF-A and VEGF-C protein overexpression was noted in all cases. VEGF-A and VEGF-C mRNA overexpression was noted in 51% (n = 62) and 27% (n = 33) of the papillary thyroid carcinomas, whereas VEGF-A and VEGF-C protein overexpression was also identified in 70% (n = 86) and 62% (n = 76) of the carcinomas. VEGF-A mRNA was significantly higher in cancers with lymph node metastases compared with nonmetastatic cancers (P = .001), whereas most metastatic cancers underexpressed VEGF-C (P = .0002), with a similar trend for protein. The expression of VEGF-A and VEGF-C correlated with each other at both mRNA and protein levels (P = .00004 and .003, respectively). In summary, VEGF-A and -C expressions correlate with the pathological parameters and metastatic status of thyroid carcinomas. The significant correlations between the expressions of these genes add weight to hypotheses concerning VEGF-A and -C interaction in cancer progression.
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Fiber Bragg Grating (FBG) accelerometers using transverse forces with an inertial object placed at the middle of the FBG have a high sensitivity but low resonant frequency. The resonant frequency 26 Hz and sensitivity at 6 Hz 1.29 nm/g were reported based on a 50mm-long FBG accelerometer. We demonstrate that the first FBG accelerometer based on a transversely rotating stick, which can, at the same or even larger size, keep the high sensitivity and significantly increase the low resonant frequency. In our experiments, a 77.5mm-long FBG accelerometer has achieved a similar sensitivity but 65% higher resonant frequency. This novel structure not only significantly widens the potential applications of FBG accelerometers by increasing their resonant frequencies but also provides a new route to design other accelerometers, e.g. micro accelerometers.
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Copy number variants (CNVs) account for a major proportion of human genetic polymorphism and have been predicted to have an important role in genetic susceptibility to common disease. To address this we undertook a large, direct genome-wide study of association between CNVs and eight common human diseases. Using a purpose-designed array we typed 19,000 individuals into distinct copy-number classes at 3,432 polymorphic CNVs, including an estimated 50% of all common CNVs larger than 500 base pairs. We identified several biological artefacts that lead to false-positive associations, including systematic CNV differences between DNAs derived from blood and cell lines. Association testing and follow-up replication analyses confirmed three loci where CNVs were associated with diseaseIRGM for Crohns disease, HLA for Crohns disease, rheumatoid arthritis and type 1 diabetes, and TSPAN8 for type 2 diabetesalthough in each case the locus had previously been identified in single nucleotide polymorphism (SNP)-based studies, reflecting our observation that most common CNVs that are well-typed on our array are well tagged by SNPs and so have been indirectly explored through SNP studies. We conclude that common CNVs that can be typed on existing platforms are unlikely to contribute greatly to the genetic basis of common human diseases. © 2010 Macmillan Publishers Limited. All rights reserved.
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Corepresentations of a coalgebra over a quadratic operad are defined, and various characterizations of them are given. Cohomology of such an operadic coalgebra with coefficients in a corepresentation is then studied.
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O Presidente da Confederação Nacional dos Trabalhadores da Agricultura, José Francisco da Silva, presente na Subcomissão da Política Fundiária e da Reforma Agrária, defende a distribuição de terras rurais para propriedades produtivas. Esta Subcomissão recebe também Arquimedes Pedreira Franco, Presidente da Confederação dos Servidores Públicos do Brasil que explica sobre o direito dos servidores públicos à sindicalização da categoria. A Subcomissão de Orçamento e Fiscalização Financeira recebe Andréa Calabi, Secretário do Tesouro Nacional, que afirma a necessidade de estabelecer limites de endividamento da União, Estados e Municípios e expõe a importância da independência do Banco Central em relação ao Ministério da Fazenda. O Deputado José Serra (PMDB-SP) explica que a nova Constituição impõe limites para o endividamento desordenado. Joaquim Francisco Cavalcanti, Ministro do Interior, fala na Subcomissão dos Estados da Assembleia Nacional Constituinte (ANC) e defende a descentralização da administração do País. O Deputado Siqueira Campos (PDC-GO), relator da Subcomissão, também defende a redivisão da administração do País.
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During the 18th Annual 2008 SAIL meeting at the Smithsonian Tropical Research Institute in Panama, Vielka Chang-Yau, librarian, mentioned the need to digitize and make available through the Aquatic Commons some of the early documents related to the U.S. biological survey of Panama from 1910 to 1912. With the assistance of SAIL, a regional marine librarian’s group, a digital project developed and this select bibliography represents the sources used for the project. It will assist researchers and librarians in finding online open access documents written during the construction of the Panama Canal, specifically between 1910-1912. As the project progressed, other items covering the region and its biological diversity were discovered and included. The project team expects that the coverage will continue to expand over time. (PDF contains 9 pages)
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Between March 2000 and April 2001 two commercial fishing vessels fished for toothfish (Dissostichus eleginoides) off South Georgia using pots. A significant number of lithodid crabs (three species of Paralomis spp.) were caught as bycatch. Paralomis spinosissima occurred in shallow water, generally shallower than 700 m. Paralomis anamerae, not previously reported from this area and therefore representing a considerable southerly extension in the reported geographic range of this species, had an intermediate depth distribution from 400 to 800 m. Paralomis formosa was present in shallow waters but reached much higher catch levels (and, presumably, densities) between 800 and 1400 m. Differences were also noted in depth distribution of the sexes and size of crabs. Depth, soak time, and area were found to significantly influence crab catch rates. Few crabs (3% of P. spinosissima and 7% of P. formosa) were males above the legal size limit and could therefore be retained. All other crabs were discarded. Most crabs (>99% of P. formosa, >97% of P. spinosissima, and >90% of P. anamerae) were lively on arrival on deck and at subsequent discard. Mortality rates estimated from re-immersion experiments indicated that on the vessel where pots were emptied directly onto the factory conveyor belt 78–89% of crabs would survive discarding, whereas on the vessel where crabs were emptied down a vertical chute prior to being sorted, survivorship was 38–58%. Of the three, P. anamerae was the most vulnerable to handling onboard and sub-sequent discarding. Paralomis spinosissima seemed more vulnerable than P. formosa.
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In the first part of the paper steady two-phase flow predictions have been performed for the last stage of a model steam turbine to examine the influence of drag between condensed fog droplets and the continuous vapour phase. In general, droplets due to homogeneous condensation are small and thus kinematic relaxation provides only a minor contribution to the wetness losses. Different droplet size distributions have been investigated to estimate at which size inter-phase friction becomes more important. The second part of the paper deals with the deposition of fog droplets on stator blades. Results from several references are repeated to introduce the two main deposition mechanisms which are inertia and turbulent diffusion. Extensive postprocessing routines have been programmed to calculate droplet deposition due to these effects for a last stage stator blade in three-dimensions. In principle the method to determine droplet deposition by turbulent diffusion equates to that of Yau and Young [1] and the advantages and disadvantages of this relatively simple method are discussed. The investigation includes the influence of different droplet sizes on droplet deposition rates and shows that for small fog droplets turbulent diffusion is the main deposition mechanism. If the droplets size is increased inertial effects become more and more important and for droplets around 1 μm inertial deposition dominates. Assuming realistic droplet sizes the overall deposition equates to about 1% to 3% of the incoming wetness for the investigated guide vane at normal operating conditions. Copyright © 2013 by Solar Turbines Incorporated.
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本文从两个侧面研究了高聚物辐射交联与裂解反应。辐照高聚物分子量分布(MWD)的表征与研究。辐照高聚物MWD的研究对于辐射交联的理论与应用均有一定的意义。但由于长链支化的存在,实验准确测定MWD很困难。本文旨在运用SEC-LALLS技术来解决这一问题。为此,我们首先分析了长链支化存在下,SEC柱扩展效应对测定数据的影响,导出了一基本议程组。{c(t) = ∫g(t,τ) Co(τ)dτ (1) s(t) = ∫g(t,τ) So(τ) dτ τ = f(j)式中,t和τ均为流出时间,J为聚合物分子流体力学体积。g(t,τ)为柱扩展函数,f为标准校正函数,c(t)、s(t)分别为浓度和光散射响应函数,为可测量。Co(τ)、So(τ)分别为样品流体力学体积为f~(-1)(τ)的那部分分子的浓度及浓度与重均分子量的积。当样品为线型聚合物时,它就转化为相应的Tung和Yau方程。围绕(1)的解,我们分别利用最小二乘法拟合σ~2-T关系和Wiener滤波法解扩展方程,并用计算机模拟,检验了这些数值运算的可靠性。同时,还讨论了扩展效应、改正参数实验误差对测定结果的影响,为实际测定提供了依据。在此基础上,建议了以SEC-LALLS联用技术为核心的表征辐 照高聚物MWD的系统化方法。最后我们运用此方法初步研究了聚苯乙烯(PS)辐照后凝胶点前后溶胶性质的变化。从MWD的变化,证实反应初期参与交联反应的主要是较高分子量部分分子。低分子量分布的浓度在凝胶点前变化不大,而在凝胶点附近及以后变化较大,支化分布的变化证明这是由于小分子量部分被支化分子掩盖了的缘故。由平均分子量测点。我们观察到了凝胶点附近重均分子量变化急剧而数均分子量缓和这一现象,并求出反应G值。数学期望法在多分体系非线性交联反应中的应用。鉴于共混高聚物辐射交联技术的发展,本文运用数学期望法,系统地考虑了一类内涵很广的多组分体系的非线性交联反应。对于重均分子量及凝胶化条件,我们把它们归结为简单的矩阵运算各矩阵元的物理意义清晰、明确、可直接写出,这为不熟悉高分子反统计理论的工作者提供了方便。对于溶胶分数,我们给出了-非线性方程组,并就r元共混体系中,当初始分布皆为Flory分布时,给出了裂解和交联同时发生时的近似结果。特别地我们针对二元共混体系在实际应用中的广泛性,我们讨论了相结构,共混比的影响。最后,结合PDMS/EVA共混体系辐射交联的研究,提出了较为一般的共混体系溶胶分数分析方法。为了考察我们的方法的可靠性,文中我们还讨论了几个小分子参与的非线性交联反应体系,并与其它理论结果,作了对照,表明该方法的可靠性和直观性皆优于某些经典理论方法。
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This article documents the addition of 512 microsatellite marker loci and nine pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Alcippe morrisonia morrisonia, Bashania fangiana, Bashania fargesii, Chaetodon vagabundus, Colletes floralis, Coluber constrictor flaviventris, Coptotermes gestroi, Crotophaga major, Cyprinella lutrensis, Danaus plexippus, Fagus grandifolia, Falco tinnunculus, Fletcherimyia fletcheri, Hydrilla verticillata, Laterallus jamaicensis coturniculus, Leavenworthia alabamica, Marmosops incanus, Miichthys miiuy, Nasua nasua, Noturus exilis, Odontesthes bonariensis, Quadrula fragosa, Pinctada maxima, Pseudaletia separata, Pseudoperonospora cubensis, Podocarpus elatus, Portunus trituberculatus, Rhagoletis cerasi, Rhinella schneideri, Sarracenia alata, Skeletonema marinoi, Sminthurus viridis, Syngnathus abaster, Uroteuthis (Photololigo) chinensis, Verticillium dahliae, Wasmannia auropunctata, and Zygochlamys patagonica. These loci were cross-tested on the following species: Chaetodon baronessa, Falco columbarius, Falco eleonorae, Falco naumanni, Falco peregrinus, Falco subbuteo, Didelphis aurita, Gracilinanus microtarsus, Marmosops paulensis, Monodelphis Americana, Odontesthes hatcheri, Podocarpus grayi, Podocarpus lawrencei, Podocarpus smithii, Portunus pelagicus, Syngnathus acus, Syngnathus typhle,Uroteuthis (Photololigo) edulis, Uroteuthis (Photololigo) duvauceli and Verticillium albo-atrum. This article also documents the addition of nine sequencing primer pairs and sixteen allele specific primers or probes for Oncorhynchus mykiss and Oncorhynchus tshawytscha; these primers and assays were cross-tested in both species.