Betweenness Centrality as a Driver of Preferential Attachment in the Evolution of Research Collaboration Networks

We analyze whether preferential attachment in scientific coauthorship networks is different for authors with different forms of centrality. Using a complete database for the scientific specialty of research about "steel structures," we show that betweenness centrality of an existing node is a significantly better predictor of preferential attachment by new entrants than degree or closeness centrality. During the growth of a network, preferential attachment shifts from (local) degree centrality to betweenness centrality as a global measure. An interpretation is that supervisors of PhD projects and postdocs broker between new entrants and the already existing network, and thus become focal to preferential attachment. Because of this mediation, scholarly networks can be expected to develop differently from networks which are predicated on preferential attachment to nodes with high degree centrality.Comment: Journal of Informetrics (in press

Evolutionary Dynamics of Scientific Collaboration Networks: Multi-Levels and Cross-time Analysis

Several studies exist which use scientific literature for comparing scientific activities (e.g., productivity, and collaboration). In this study, using co-authorship data over the last 40 years, we present the evolutionary dynamics of multi level (i.e., individual, institutional and national) collaboration networks for exploring the emergence of collaborations in the research field of "steel structures". The collaboration network of scientists in the field has been analyzed using author affiliations extracted from Scopus between 1970 and 2009. We have studied collaboration distribution networks at the micro-, meso- and macro-levels for the 40 years. We compared and analyzed a number of properties of these networks (i.e., density, centrality measures, the giant component and clustering coefficient) for presenting a longitudinal analysis and statistical validation of the evolutionary dynamics of "steel structures" collaboration networks. At all levels, the scientific collaborations network structures were central considering the closeness centralization while betweenness and degree centralization were much lower. In general networks density, connectedness, centralization and clustering coefficient were highest in marco-level and decreasing as the network size grow to the lowest in micro-level. We also find that the average distance between countries about two and institutes five and for authors eight meaning that only about eight steps are necessary to get from one randomly chosen author to another.Comment: Accepted for publication in Scientometric

Hybrid Centrality Measures for Binary and Weighted Networks

Existing centrality measures for social network analysis suggest the im-portance of an actor and give consideration to actor's given structural position in a network. These existing measures suggest specific attribute of an actor (i.e., popularity, accessibility, and brokerage behavior). In this study, we propose new hybrid centrality measures (i.e., Degree-Degree, Degree-Closeness and Degree-Betweenness), by combining existing measures (i.e., degree, closeness and betweenness) with a proposition to better understand the importance of actors in a given network. Generalized set of measures are also proposed for weighted networks. Our analysis of co-authorship networks dataset suggests significant correlation of our proposed new centrality measures (especially weighted networks) than traditional centrality measures with performance of the scholars. Thus, they are useful measures which can be used instead of traditional measures to show prominence of the actors in a network.Comment: a short version accepted in the 3rd workshop on Complex Network [Full Paper submitted to JASIST in April 2011

"More than kin and less than kind": Hamlet and his (linguistic) problems

T.S. Eliot's "Hamlet and His Problems" (1921) seems to be a pretext to add another erudite concept to the lexis of literary criticism. He charged both Hamlet and Hamlet of lacking "objective correlative." Eliot's own problem with the play, however, seems to arise from his particular epistemological perspective, his formalism, and even his implicit structuralism, and moreover, from his traditional, classic Cartesian modernity that suffers him to hold the notion of subject-object dichotomy in his literary speculations. Hamlet's problem, however, surpasses T. S. Eliot's structuralist view and anticipates the poststructuralist linguistic enigma. Hamlet and Hamlet's problems are, together with the other characters that are caught in the maze of language, linguistic. Hamlet's epistemological/ontological quest for the meaning or the truth are checked, patterned, done and ultimately undone by the language. He cannot find any "objective correlative" for his "particular emotion," for, in the signifying system of the language, all he can think or feel is restrained by "words". He cannot escape from the symbolic order of the language until his death, and "the rest is silence"

SOME REMARKS ON THE CLASSICAL PRIME SPECTRUM OF MODULES

Let R be a commutative ring with identity and let M be an R-module. A proper submodule P of M is called a classical prime submodule if abm ∈ P, for a,b ∈ R, and m ∈ M, implies that am ∈ P or bm ∈ P. The classical prime spectrum of M, Cl.Spec(M), is defined to be the set of all classical prime submodules of M. We say M is classical primefule if M = 0, or the map ψ from Cl.Spec(M) to Spec(R/Ann(M)), defined by ψ(P) = (P : M)/Ann(M) for all P ∈ Cl.Spec(M), is surjective. In this paper, we study classical primeful modules as a generalisation of primeful modules. Also we investigate some properties of a topology that is defined on Cl.Spec(M), named the Zariski topology

5,6-Dioxo-1,10-phenanthrolin-1-ium nitrate

In the title salt, C12H7N2O2 +·NO3 −, the monoprotonated cation is connected to the nitrate anion by a hydrogen bond. Weak C—H⋯O hydrogen bonds hold the planar cations together in a layer structure

Entanglement Of The Rights Of The Child, Well-Being And Justice: A Conceptual Framework For Child Protection And Well-Being

Background: Human Rights (HRs) framework supports improving human health status and the reduction of health inequalities through action on Social Determinants of Health (SDH). Given the shortcoming of HRs to protect the children, the question is, how can we ensure child protection and well-being rather than just child health?Methods: In this conceptual analysis study, first, we explain the fundamental rights of the child and the steering role of them in moving towards health equity through action on SDH; second, meanwhile argue the shortcoming of rights-based protection, provide a list of the core capabilities and corresponding rights of the child; and third, we represent a conceptual framework for child protection and well-being using both HRs norms and moral entitlements based on recent ethical theories of justice, with a preventive approach.Results: According to the framework, HRs instruments should lead to the protection of the child and the development of core capabilities through addressing social determinants and providing equal opportunities, of which the ability to live a healthy life is just one. In addition, actualizing these capabilities depends on the context. Since achieving well-being rather than just the health, in addition to acquiring the core capabilities as states of beings, implies their function as doings, that requires considering the socioecological context to provide means necessary to meet the essential dimensions of well-being at the level of adequacy.Conclusion: Implementing the suggested framework requires that each country create a national action framework and determine the role and duties of the responsible organizations

(E)-2-(5,5-Dimethyl­hexa­hydro­pyrimidin-2-yl)-4-(phenyl­diazen­yl)phenol

In the title Schiff base, C18H22N4O, the hexa­hydro­pyrimidinyl ring adopts a chair conformation. The dihedral angle between the aromatic rings of the 4-(2-phenyl­diazen­yl)phenol unit is 15.7 (1)°. There is an intra­molecular O—H⋯N hydrogen bond between the hydroxyl group and an N atom of the hexa­hydro­pyimidinyl unit. Inter­molecular N—H⋯O and N—H⋯N hydrogen bonds give rise to a layer structure