30 research outputs found

    Phylogenetic support values are not necessarily informative: the case of the Serialia hypothesis (a mollusk phylogeny)

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    Background: Molecular phylogenies are being published increasingly and many biologists rely on the most recent topologies. However, different phylogenetic trees often contain conflicting results and contradict significant background data. Not knowing how reliable traditional knowledge is, a crucial question concerns the quality of newly produced molecular data. The information content of DNA alignments is rarely discussed, as quality statements are mostly restricted to the statistical support of clades. Here we present a case study of a recently published mollusk phylogeny that contains surprising groupings, based on five genes and 108 species, and we apply new or rarely used tools for the analysis of the information content of alignments and for the filtering of noise (masking of random-like alignment regions, split decomposition, phylogenetic networks, quartet mapping). Results: The data are very fragmentary and contain contaminations. We show that that signal-like patterns in the data set are conflicting and partly not distinct and that the reported strong support for a "rather surprising result" (monoplacophorans and chitons form a monophylum Serialia) does not exist at the level of primary homologies. Split-decomposition, quartet mapping and neighbornet analyses reveal conflicting nucleotide patterns and lack of distinct phylogenetic signal for the deeper phylogeny of mollusks. Conclusion: Even though currently a majority of molecular phylogenies are being justified with reference to the 'statistical' support of clades in tree topologies, this confidence seems to be unfounded. Contradictions between phylogenies based on different analyses are already a strong indication of unnoticed pitfalls. The use of tree-independent tools for exploratory analyses of data quality are highly recommended. Concerning the new mollusk phylogeny more convincing evidence is needed

    T cell responses against tumor associated antigens and prognosis in colorectal cancer patients

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    INTRODUCTION: Spontaneous T cell responses against specific tumor-associated antigens (TAA) are frequently detected in peripheral blood of tumor patients of various histiotypes. However, little is known about whether these circulating, spontaneously occurring, TAA-reactive T cells influence the clinical course of disease. METHODS: Fifty-four HLA-A2 positive colorectal cancer patients had been analyzed for the presence of T cell responses against epitopes derived from the TAA Ep-CAM, her-2/neu, and CEA either by ELISPOT assay or by intracellular cytokine staining. Then, Kaplan-Meier survival analysis was performed comparing T-cell-responders and T-cell-non-responders. For comparison, a group of T-cell-non-responders was compiled stringently matched to T-cell-responders based on clinical criteria and also analyzed for survival. RESULTS: Sixteen out of 54 patients had a detectable T cell response against at least one of the three tested TAA. Two out of 21 patients (9.5%) with limited stage of disease (UICC I and II) and 14 out of 33 patients (42.4%) with advanced disease (UICC III and IV) were T cell response positive. Comparing all T-cell-responders (n = 16) and all T-cell-non-responders (n = 38), no survival difference was found. In an attempt to reduce the influence of confounding clinical factors, we then compared 16 responders and 16 non-responders in a matched group survival analysis; and again no survival difference was found (p = 0.7). CONCLUSION: In summary, we found no evidence that spontaneous peripheral T cell responses against HLA-A2-binding epitopes of CEA, her-2/neu and Ep-CAM are a strong prognostic factor for survival

    Exercitationem Philologicam De Cunabulis Christi, In Illustri ad Albim Athenaeo A. D. 23. Feb. A. S. M. DC. LXI. ... in Auditorio Minori publicae ventilationi subiiciunt Praeses M. Johannes Christoph. Letschius, Et Respondens Balthasar Gerhardus, Briga Silesius

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    EXERCITATIONEM PHILOLOGICAM DE CUNABULIS CHRISTI, IN ILLUSTRI AD ALBIM ATHENAEO A. D. 23. FEB. A. S. M. DC. LXI. ... IN AUDITORIO MINORI PUBLICAE VENTILATIONI SUBIICIUNT PRAESES M. JOHANNES CHRISTOPH. LETSCHIUS, ET RESPONDENS BALTHASAR GERHARDUS, BRIGA SILESIUS Exercitationem Philologicam De Cunabulis Christi, In Illustri ad Albim Athenaeo A. D. 23. Feb. A. S. M. DC. LXI. ... in Auditorio Minori publicae ventilationi subiiciunt Praeses M. Johannes Christoph. Letschius, Et Respondens Balthasar Gerhardus, Briga Silesius ([1]) Titelblatt ([1]) Text ([2]

    Efficient and Innovative Polishing Processes for Smoothing Complex Surface Geometries and Internal Contours on Brittle-Hard Components

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    The material fused silica, as well as other brittle-hard materials such as glass ceramics, have great potential for use in a wide range of applications due to their special material properties. The technical advantages of these materials require sophisticated processing technologies, including polishing steps, in order to be able to use these interesting materials advantageously. In addition, a current trend in modern optical manufacturing is the use of free-form surfaces and monolithic components that combine several optical and mechanical functions in one part. Novel or improved processes are needed in order to meet future requirements for resource-saving and effective production methods at the same time

    Efficient and Innovative Polishing Processes for Smoothing Complex Surface Geometries and Internal Contours on Brittle-Hard Components

    No full text
    The material fused silica, as well as other brittle-hard materials such as glass ceramics, have great potential for use in a wide range of applications due to their special material properties. The technical advantages of these materials require sophisticated processing technologies, including polishing steps, in order to be able to use these interesting materials advantageously. In addition, a current trend in modern optical manufacturing is the use of free-form surfaces and monolithic components that combine several optical and mechanical functions in one part. Novel or improved processes are needed in order to meet future requirements for resource-saving and effective production methods at the same time
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