1,230 research outputs found

    Structure, Stratigraphy, and Metamorphism of a Part of the Columbus Promontory, Western Inner Piedmont, North Carolina

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    The geology of the Inner Piedmont in a part of southwestern North Carolina, called the Columbus Promontory, is characterized by a complex history involving high grade metamorphism and penetrative ductile deformation. This study involved detailed (1:24,000) geologic mapping, petrography, whole rock geochemical analysis, and structural analysis to study the stratigraphy, structural geology, and metamorphism of a part of the Columbus Promontory. Rocks in the study area can be divided into three major lithotectonic units, each separated by a ductile thrust fault, and strike NE and dip gently to the SE. Unit 1, theStructurally lowermost and northwesternmost unit in the study area is composed entirely of Henderson Gneiss, a 509 Ma granitic augen gneiss. It also contains a 438 Ma intrusion of granitic gneiss. Unit 2 contains rocks of the upper Mill Spring complex with biotite gneiss and pelitic schist and the Poor Mountain Formation, dominated by amphibolite and quartzite. Unit 3, the structurally highest and southeasternmost unit, contains a lower unit of biotite gneiss associated with the upper Mill Spring complex and an upper unit of undifferentiated biotite gneiss, amphibolite, granitic gneiss, and pelitic schist. Based on the ordering of lithologies, the Poor Mountain and Mill Spring complex are interpreted to be correlative with rocks in other parts of the Inner Piedmont and eastern Blue Ridge of Virginia, North Carolina, South Carolina, Georgia, and Alabama. The structure of the Columbus Promontory is dominated by a series of SE-dipping, penetratively deformed, ductile, thrust sheets. Five episodes of deformation (D1 to D5) have been recognized but the two most significant were D2 and D3. Of these two episodes, D2 accounts for virtually all the shear strain observed in the Inner Piedmont and is synchronous with peak M2 metamorphism. D2 deformation is associated with a regionally penetrative mylonitic C-fabric (S2), mineral lineation, folds, and S-C fabrics. The penetrative nature of these structures, the parallel orientations of the foliation, thrust faults, fold girdles, and great circle defined by mineral lineations, the parallel orientation of fold axes and mineral lineations, and the presence of sheath folds indicate that D2 involved very high shear strains ([see original document] \u3e10) and that the Inner Piedmont represented a crustal-scale ductile shear zone. D3 occurred during the cooling stages of M2 metamorphism and forms a continuum with D2 deformation. Shear sense during D2, as indicated by mineral lineations, winged porphyroclasts, S-C fabrics, and snowball garnets, varied gradually from W-directed in areas to the SE to SW-directed in areas to the NW. Hansen analysis of F2 and F3 folds suggest that shear sense did not change significantly between D2 and D3 deformation. This change in the orientation of shearing from W to SW-directed transport is probably related to a dextral component of shearing along the primordial Brevard fault zone. M2 metamorphism reached the lower sillimanite zone in pelitic schist and upper amphibolite facies in amphibolite. Textural relationships and optical zoning in garnet indicate that sillimanite grew by a series of continuous reactions involving garnet growth and garnet consumption. The observations are consistent with relationships observed in other parts of the Columbus Promontory suggesting that sillimanite growth occurred along the retrograde portion of the P-T path. Whole rock geochemical analysis was conducted on Poor Mountain Amphibolite using X-ray fluorescence. Covariation diagrams and Niggli trends indicate that the amphibolite was metamorphosed from a tholeiitic basalt. Tectonic discrimination diagrams and spider diagrams suggest they evolved from a mid-ocean ridge basalt

    Interpolation and harmonic majorants in big Hardy-Orlicz spaces

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    Free interpolation in Hardy spaces is caracterized by the well-known Carleson condition. The result extends to Hardy-Orlicz spaces contained in the scale of classical Hardy spaces HpH^p, p>0p>0. For the Smirnov and the Nevanlinna classes, interpolating sequences have been characterized in a recent paper in terms of the existence of harmonic majorants (quasi-bounded in the case of the Smirnov class). Since the Smirnov class can be regarded as the union over all Hardy-Orlicz spaces associated with a so-called strongly convex function, it is natural to ask how the condition changes from the Carleson condition in classical Hardy spaces to harmonic majorants in the Smirnov class. The aim of this paper is to narrow down this gap from the Smirnov class to ``big'' Hardy-Orlicz spaces. More precisely, we characterize interpolating sequences for a class of Hardy-Orlicz spaces that carry an algebraic structure and that are strictly bigger than p>0Hp\bigcup_{p>0} H^p. It turns out that the interpolating sequences are again characterized by the existence of quasi-bounded majorants, but now the weights of the majorants have to be in suitable Orlicz spaces. The existence of harmonic majorants in such Orlicz spaces will also be discussed in the general situation. We finish the paper with an example of a separated Blaschke sequence that is interpolating for certain Hardy-Orlicz spaces without being interpolating for slightly smaller ones.Comment: 19 pages, 2 figure

    Apoptosis and p53 status predict the efficacy of postoperative administration of UFT in non-small cell lung cancer

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    To examine whether efficacy of postoperative oral administration of UFT, a 5-fluorouracil derivative chemotherapeutic agent, may be influenced by incidence of apoptosis (apoptosis index) or apoptosis-related gene status (p53 and bcl-2) of the tumour, a total of 162 patients with pathologic stage I non-small cell lung cancer were retrospectively reviewed. UFT was administrated postoperatively to 44 patients (UFT group), and not to the other 118 patients (Control group). For all patients, 5-year survival rate of the UFT group (79.9%) seemed higher than that of the Control group (69.8%), although without significant difference (P = 0.054). For patients with higher apoptotic index, 5-year survival rate of the UFT group (83.3%) was significantly higher than that of the Control group (67.6%, P = 0.039); for patients with lower apoptotic index, however, there was no difference in the prognosis between these two groups. Similarly, UFT was effective for patients without p53 aberrant expression (5-year survival rates: 95.2% for the UFT group and 74.3% for the Control group, P = 0.022), whereas not effective for patients with p53 aberrant expression. Bcl-2 status did not influence the efficacy of UFT. In conclusion, apoptotic index and p53 status are useful factors to predict the efficacy of postoperative adjuvant therapy using UFT. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Concepts of GPCR-controlled navigation in the immune system

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    G-protein-coupled receptor (GPCR) signaling is essential for the spatiotemporal control of leukocyte dynamics during immune responses. For efficient navigation through mammalian tissues, most leukocyte types express more than one GPCR on their surface and sense a wide range of chemokines and chemoattractants, leading to basic forms of leukocyte movement (chemokinesis, haptokinesis, chemotaxis, haptotaxis, and chemorepulsion). How leukocytes integrate multiple GPCR signals and make directional decisions in lymphoid and inflamed tissues is still subject of intense research. Many of our concepts on GPCR-controlled leukocyte navigation in the presence of multiple GPCR signals derive from in vitro chemotaxis studies and lower vertebrates. In this review, we refer to these concepts and critically contemplate their relevance for the directional movement of several leukocyte subsets (neutrophils, T cells, and dendritic cells) in the complexity of mouse tissues. We discuss how leukocyte navigation can be regulated at the level of only a single GPCR (surface expression, competitive antagonism, oligomerization, homologous desensitization, and receptor internalization) or multiple GPCRs (synergy, hierarchical and non-hierarchical competition, sequential signaling, heterologous desensitization, and agonist scavenging). In particular, we will highlight recent advances in understanding GPCR-controlled leukocyte navigation by intravital microscopy of immune cells in mice

    Electronic structure of MgB2_2: X-ray emission and absorption studies

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    Measurements of x-ray emission and absorption spectra of the constituents of MgB2_2 are presented. The results obtained are in good agreement with calculated x-ray spectra, with dipole matrix elements taken into account. The comparison of x-ray emission spectra of graphite, AlB2_2, and MgB2_2 in the binding energy scale supports the idea of charge transfer from σ\sigma to π\pi bands, which creates holes at the top of the bonding σ\sigma bands and drives the high-Tc_cComment: final version as published in PR

    Phytoestrogens

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    Collectively, plants contain several different families of natural products among which are compounds with weak estrogenic or antiestrogenic activity toward mammals. These compounds, termed phytoestrogens, include certain isoflavonoids, flavonoids, stilbenes, and lignans. The best-studied dietary phytoestrogens are the soy isoflavones and the flaxseed lignans. Their perceived health beneficial properties extend beyond hormone-dependent breast and prostate cancers and osteoporosis to include cognitive function, cardiovascular disease, immunity and inflammation, and reproduction and fertility. In the future, metabolic engineering of plants could generate novel and exquisitely controlled dietary sources with which to better assess the potential health beneficial effects of phytoestrogens

    DNA methylation and histone deacetylation associated with silencing DAP kinase gene expression in colorectal and gastric cancers

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    Death-associated protein kinase is a positive regulator of programmed cell death induced by interferon γ. To investigate the role of epigenetic inactivation of death-associated protein kinase in gastrointestinal cancer, we examined the methylation status of the 5′ CpG island of the death-associated protein kinase gene. Methylation of the 5′ CpG island was detected in 3 of 9 colorectal and 3 of 17 gastric cancer cell lines, while among primary tumours, it was detected in 4 of 28 (14%) colorectal and 4 of 27 (15%) gastric cancers. By contrast, methylation of the edge of the CpG island was detected in virtually every sample examined. Death-associated protein kinase expression was diminished in four cell lines that showed dense methylation of the 5′ CpG island, and treatment with 5-aza-2′-deoxycitidine, a methyltransferase inhibitor, restored gene expression. Acetylation of histones H3 and H4 in the 5′ region of the gene was assessed by chromatin immunoprecipitation and was found to correlate directly with gene expression and inversely with DNA methylation. Thus, aberrant DNA methylation and histone deacetylation of the 5′ CpG island, but not the edge of the CpG island, appears to play a key role in silencing death-associated protein kinase expression in gastrointestinal malignancies
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