14,325 research outputs found

    Alinement fixture for precision cutting of printed-wiring boards

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    Six alinement templates are used to trim-cut majority of boards fabricated. Their use has reduced time required for cutting operation and has also reduced high rejection rate of cut boards to near zero

    Regulation of Cancer Stem Cells: Lysine Methylation of p53

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    The highly studied p53 protein regulates multiple transitions through the cell cycle effectively halting the growth of tumorlike masses.[1] This gene was primitively identified an oncogene; however, it was later derived that p53 functions as a tumor suppressor.[1] Named due to its mass in kDa, p53 is a phosphoprotein comprised of 393 amino acids.[1] Normal cells contain controlled, small quantities of p53 in order to facilitate the regulation of normal cell activities such as growth arrest, senescence,DNArepair, and apoptosis.[1,2] These features are pivotal the continuation of healthy cell production. Constructively, the functions of p53 work together to pause the cell growth cycles in order to address and repair certain sequences of DNA if needed before cell division commences. If repair cannot be completed, then p53 signals for the cell to become senescent and/or later to destroy itself via apoptosis.[1] Upon DNA damage and other cellular stressors, the quantity of p53 is upregulated in order to instigate either the repair or apoptotic cellular pathways; however, continued high levels of p53 are detrimental as its increased ability to activate the apoptotic pathway is likened to an accelerated aging process.[1] The C-terminus domain (CTD) of p53 contains several modifiable lysine residues that may be augmented in different patterns resulting in an array of dissimilar protein-protein interactions thus greatly adding to the multiplicity of functions for the protein itself. This study aims to show that the control of these modifications may not only reduce the causation of multiple forms of cancers but may also be used as a preventative mechanism by never allowing malignant masses to have formed in the firstplace

    Split Cycle: A New Condorcet Consistent Voting Method Independent of Clones and Immune to Spoilers

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    We propose a Condorcet consistent voting method that we call Split Cycle. Split Cycle belongs to the small family of known voting methods that significantly narrow the choice of winners in the presence of majority cycles while also satisfying independence of clones. In this family, only Split Cycle satisfies a new criterion we call immunity to spoilers, which concerns adding candidates to elections, as well as the known criteria of positive involvement and negative involvement, which concern adding voters to elections. Thus, in contrast to other clone-independent methods, Split Cycle mitigates both "spoiler effects" and "strong no show paradoxes."Comment: 71 pages, 15 figures. Added a new explanation of Split Cycle in Section 1, updated the caption to Figure 2, the discussion in Section 3.3, and Remark 4.11, and strengthened Proposition 6.20 to Theorem 6.20 to cover single-voter resolvability in addition to asymptotic resolvability. Thanks to Nicolaus Tideman for helpful discussio

    Complete Additivity and Modal Incompleteness

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    In this paper, we tell a story about incompleteness in modal logic. The story weaves together a paper of van Benthem, `Syntactic aspects of modal incompleteness theorems,' and a longstanding open question: whether every normal modal logic can be characterized by a class of completely additive modal algebras, or as we call them, V-BAOs. Using a first-order reformulation of the property of complete additivity, we prove that the modal logic that starred in van Benthem's paper resolves the open question in the negative. In addition, for the case of bimodal logic, we show that there is a naturally occurring logic that is incomplete with respect to V-BAOs, namely the provability logic GLB. We also show that even logics that are unsound with respect to such algebras do not have to be more complex than the classical propositional calculus. On the other hand, we observe that it is undecidable whether a syntactically defined logic is V-complete. After these results, we generalize the Blok Dichotomy to degrees of V-incompleteness. In the end, we return to van Benthem's theme of syntactic aspects of modal incompleteness

    Split Cycle: A New Condorcet Consistent Voting Method Independent of Clones and Immune to Spoilers

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    We introduce a new Condorcet consistent voting method, called Split Cycle. Split Cycle belongs to the small family of known voting methods satisfying independence of clones and the Pareto principle. Unlike other methods in this family, Split Cycle satisfies a new criterion we call immunity to spoilers, which concerns adding candidates to elections, as well as the known criteria of positive involvement and negative involvement, which concern adding voters to elections. Thus, relative to other clone-independent Paretian methods, Split Cycle mitigates “spoiler effects” and “strong no show paradoxes.

    Effectiveness of retrieval in similarity searches of chemical databases: A review of performance measures

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    This article reviews measures for evaluating the effectiveness of similarity searches in chemical databases, drawing principally upon the many measures that have been described previously for evaluating the performance of text search engines. The use of the various measures is exemplified by fragment-based 2D similarity searches on several databases for which both structural and bioactivity data are available. It is concluded that the cumulative recall and G-H score measures are the most useful of those tested

    Grouping of coefficients for the calculation of inter-molecular similarity and dissimilarity using 2D fragment bit-strings

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    This paper compares 22 different similarity coefficients when they are used for searching databases of 2D fragment bit-strings. Experiments with the National Cancer Institute's AIDS and IDAlert databases show that the coefficients fall into several well-marked clusters, in which the members of a cluster will produce comparable rankings of a set of molecules. These clusters provide a basis for selecting combinations of coefficients for use in data fusion experiments. The results of these experiments provide a simple way of increasing the effectiveness of fragment-based similarity searching systems
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