1,331 research outputs found

    Impact of Gene-Gender Effects of Adrenergic Polymorphisms on Hypothalamic-Pituitary-Adrenal Axis Activity in Depressed Patients

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    Objective: There is overwhelming evidence that activation of the hypothalamic-pituitary-adrenal (HPA) system plays a major role in depression and cardiovascular disease in genetically susceptible individuals. We hypothesized that due to the multiple interactions between the sympathetic and the HPA systems via adrenoceptors, polymorphisms in these genes could have an impact on HPA axis activity in major depression. Methods: Using the dexamethasone/corticotrophin-releasing hormone (DEX/CRH) test, we investigated the association of alpha 2-adrenoceptor (ADRA2A -1291C -> G) and the beta 2-adrenoceptor gene (ADRB2 Arg16Gly) in 189 patients with major depression during the acute state of the disease and after remission. Results: Male ADRA2A -1291G allele homozygotes showed significant pretreatment HPA axis hyperactivity, with increased adrenocorticotropin (ACTH; F = 4.9, d.f. = 2, p = 0.009) and cortisol responses (F = 6.4, d.f. = 2, p = 0.003). In contrast, female ADRB2 Arg/Arg homozygotes had increased pretreatment ACTH (F = 7.17, d.f. = 2, p = 0.001) and cortisol (F = 8.95, d.f. = 2, p = 0.000) levels. Interestingly, in the respective genotypes, the stress hormones remained elevated in the second DEX/CRH test, despite a reduction in depressive symptoms. Conclusions: This study provides evidence that, depending on gender and polymorphisms, there is continuous HPA axis overdrive in a proportion of patients irrespective of the status of depression. Considering the importance of stress hormones for cardiovascular disorders, our data might suggest that these patients are at high risk of comorbidity between depression and cardiovascular disorders. Copyright (c) 2008 S. Karger AG, Base

    Size reconstructibility of graphs

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    The deck of a graph GG is given by the multiset of (unlabelled) subgraphs {Gv:vV(G)}\{G-v:v\in V(G)\}. The subgraphs GvG-v are referred to as the cards of GG. Brown and Fenner recently showed that, for n29n\geq29, the number of edges of a graph GG can be computed from any deck missing 2 cards. We show that, for sufficiently large nn, the number of edges can be computed from any deck missing at most 120n\frac1{20}\sqrt{n} cards.Comment: 15 page

    The ‘Ombuds Watchers’: Collective Dissent and Legal Protest Among Users of Public Services Ombuds

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    This article examines the phenomenon of the ‘ombuds watchers’. These are groups of dissatisfied users of public service ombuds schemes who engage in legal protest against the current system of redress for citizen-state complaints. Through the lens of legal consciousness scholarship we propose a framework that conceptualizes the collectivized protest of the ombuds watchers. Based on an empirical dataset, our analysis has shown that the ombuds watchers meet each of the defining characteristics of dissenting collectivism and demonstrates the existence of forms of legal consciousness which present ‘opportunities to build alternative imaginaries and institutions’ (Morgan and Kutch 2015, p. 567). Our case study provides an insight into the potential for dissenting collectives to challenge the hegemonic structures of state law, while at the same time emphasising the continuing power of legal ideology in shaping popular understandings of justice. The article also suggests a pathway for future empirical research into ombuds

    The generalized 3-edge-connectivity of lexicographic product graphs

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    The generalized kk-edge-connectivity λk(G)\lambda_k(G) of a graph GG is a generalization of the concept of edge-connectivity. The lexicographic product of two graphs GG and HH, denoted by GHG\circ H, is an important graph product. In this paper, we mainly study the generalized 3-edge-connectivity of GHG \circ H, and get upper and lower bounds of λ3(GH)\lambda_3(G \circ H). Moreover, all bounds are sharp.Comment: 14 page

    Inductive Construction of 2-Connected Graphs for Calculating the Virial Coefficients

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    In this paper we give a method for constructing systematically all simple 2-connected graphs with n vertices from the set of simple 2-connected graphs with n-1 vertices, by means of two operations: subdivision of an edge and addition of a vertex. The motivation of our study comes from the theory of non-ideal gases and, more specifically, from the virial equation of state. It is a known result of Statistical Mechanics that the coefficients in the virial equation of state are sums over labelled 2-connected graphs. These graphs correspond to clusters of particles. Thus, theoretically, the virial coefficients of any order can be calculated by means of 2-connected graphs used in the virial coefficient of the previous order. Our main result gives a method for constructing inductively all simple 2-connected graphs, by induction on the number of vertices. Moreover, the two operations we are using maintain the correspondence between graphs and clusters of particles.Comment: 23 pages, 5 figures, 3 table

    A Hybrid Artificial Bee Colony Algorithm for Graph 3-Coloring

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    The Artificial Bee Colony (ABC) is the name of an optimization algorithm that was inspired by the intelligent behavior of a honey bee swarm. It is widely recognized as a quick, reliable, and efficient methods for solving optimization problems. This paper proposes a hybrid ABC (HABC) algorithm for graph 3-coloring, which is a well-known discrete optimization problem. The results of HABC are compared with results of the well-known graph coloring algorithms of today, i.e. the Tabucol and Hybrid Evolutionary algorithm (HEA) and results of the traditional evolutionary algorithm with SAW method (EA-SAW). Extensive experimentations has shown that the HABC matched the competitive results of the best graph coloring algorithms, and did better than the traditional heuristics EA-SAW when solving equi-partite, flat, and random generated medium-sized graphs

    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,TRsS,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 s4s\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

    Characterising the Performance of XOR Games and the Shannon Capacity of Graphs

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    In this paper we give a set of necessary and sufficient conditions such that quantum players of a two-party {\sc xor} game cannot perform any better than classical players. With any such game, we associate a graph and examine its zero-error communication capacity. This allows us to specify a broad new class of graphs for which the Shannon capacity can be calculated. The conditions also enable the parametrisation of new families of games which have no quantum advantage, for arbitrary input probability distributions up to certain symmetries. In the future, these might be used in information-theoretic studies on reproducing the set of quantum non-local correlations.Comment: 5 pages. Clarified proof of theorem 1, typos correcte
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