1,579 research outputs found

    Inclusive One Jet Production With Multiple Interactions in the Regge Limit of pQCD

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    DIS on a two nucleon system in the regge limit is considered. In this framework a review is given of a pQCD approach for the computation of the corrections to the inclusive one jet production cross section at finite number of colors and discuss the general results.Comment: 4 pages, latex, aicproc format, Contribution to the proceedings of "Diffraction 2008", 9-14 Sep. 2008, La Londe-les-Maures, Franc

    Better Synchronizability Predicted by Crossed Double Cycle

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    In this brief report, we propose a network model named crossed double cycles, which are completely symmetrical and can be considered as the extensions of nearest-neighboring lattices. The synchronizability, measured by eigenratio RR, can be sharply enhanced by adjusting the only parameter, crossed length mm. The eigenratio RR is shown very sensitive to the average distance LL, and the smaller average distance will lead to better synchronizability. Furthermore, we find that, in a wide interval, the eigenratio RR approximately obeys a power-law form as R∼L1.5R\sim L^{1.5}.Comment: 4 pages, 5 figure

    Fundamental Cycles and Graph Embeddings

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    In this paper we present a new Good Characterization of maximum genus of a graph which makes a common generalization of the works of Xuong, Liu, and Fu et al. Based on this, we find a new polynomially bounded algorithm to find the maximum genus of a graph

    Characterizing extremal digraphs for identifying codes and extremal cases of Bondy's theorem on induced subsets

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    An identifying code of a (di)graph GG is a dominating subset CC of the vertices of GG such that all distinct vertices of GG have distinct (in)neighbourhoods within CC. In this paper, we classify all finite digraphs which only admit their whole vertex set in any identifying code. We also classify all such infinite oriented graphs. Furthermore, by relating this concept to a well known theorem of A. Bondy on set systems we classify the extremal cases for this theorem

    Counting flags in triangle-free digraphs

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    Motivated by the Caccetta-Haggkvist Conjecture, we prove that every digraph on n vertices with minimum outdegree 0.3465n contains an oriented triangle. This improves the bound of 0.3532n of Hamburger, Haxell and Kostochka. The main new tool we use in our proof is the theory of flag algebras developed recently by Razborov.Comment: 19 pages, 7 figures; this is the final version to appear in Combinatoric

    Bipartite partial duals and circuits in medial graphs

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    It is well known that a plane graph is Eulerian if and only if its geometric dual is bipartite. We extend this result to partial duals of plane graphs. We then characterize all bipartite partial duals of a plane graph in terms of oriented circuits in its medial graph.Comment: v2: minor changes. To appear in Combinatoric

    Anti-CRISPR-mediated control of gene editing and synthetic circuits in eukaryotic cells.

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    Repurposed CRISPR-Cas molecules provide a useful tool set for broad applications of genomic editing and regulation of gene expression in prokaryotes and eukaryotes. Recent discovery of phage-derived proteins, anti-CRISPRs, which serve to abrogate natural CRISPR anti-phage activity, potentially expands the ability to build synthetic CRISPR-mediated circuits. Here, we characterize a panel of anti-CRISPR molecules for expanded applications to counteract CRISPR-mediated gene activation and repression of reporter and endogenous genes in various cell types. We demonstrate that cells pre-engineered with anti-CRISPR molecules become resistant to gene editing, thus providing a means to generate "write-protected" cells that prevent future gene editing. We further show that anti-CRISPRs can be used to control CRISPR-based gene regulation circuits, including implementation of a pulse generator circuit in mammalian cells. Our work suggests that anti-CRISPR proteins should serve as widely applicable tools for synthetic systems regulating the behavior of eukaryotic cells

    Multi-sideband interference structures by high-order photon-induced continuum-continuum transitions in helium

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    Following up on a previous paper on two-color photoionization of Ar(3p) [Bharti et al., Phys. Rev. A 103 (2021) 022834], we present measurements and calculations for a modified three-sideband (3-SB) version of the "reconstruction of attosecond beating by interference of two-photon transitions" (RABBITT) configuration applied to He(1s). The 3-SB RABBITT approach allows us to explore interference effects between pathways involving different orders of transitions within the continuum. The relative differences in the retrieved oscillation phases of the three sidebands provide insights into the continuum-continuum transitions. The ground state of helium has zero orbital angular momentum, which simplifies the analysis of oscillation phases and their angle-dependence within the three sidebands. We find qualitative agreement between our experimental results and the theoretical predictions for many cases but also observe some significant quantitative discrepancies.Comment: 9 pages, 6 figure

    Tur\'an numbers for Ks,tK_{s,t}-free graphs: topological obstructions and algebraic constructions

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    We show that every hypersurface in Rs×Rs\R^s\times \R^s contains a large grid, i.e., the set of the form S×TS\times T, with S,T⊂RsS,T\subset \R^s. We use this to deduce that the known constructions of extremal K2,2K_{2,2}-free and K3,3K_{3,3}-free graphs cannot be generalized to a similar construction of Ks,sK_{s,s}-free graphs for any s≥4s\geq 4. We also give new constructions of extremal Ks,tK_{s,t}-free graphs for large tt.Comment: Fixed a small mistake in the application of Proposition
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