The Enhancon and N=2 Gauge Theory/Gravity RG Flows

We study the family of ten dimensional type IIB supergravity solutions corresponding to renormalisation group flows from N=4 to N=2 supersymmetric Yang-Mills theory. Part of the solution set corresponds to a submanifold of the Coulomb branch of the gauge theory, and we use a D3-brane probe to uncover details of this physics. At generic places where supergravity is singular, the smooth physics of the probe yields the correct one-loop form of the effective low energy gauge coupling. The probe becomes tensionless on a ring at finite radius. Supergravity flows which end on this ``enhancon'' ring correspond to the vacua where extra massless degrees of freedom appear in the gauge theory, and the gauge coupling diverges there. We identify an SL(2,Z) duality action on the enhancon ring which relates the special vacua, and comment on the massless dyons within them. We propose that the supergravity solution inside the enhancon ring should be excised, since the probe's tension is unphysical there.Comment: 25 pages, 3 composite figures, LaTex (v2: reference added. clarifying footnote added. typos corrected, with addition to discussion of BPS dyons in section 7.

Concert recording 2016-04-09c

[Track 01]. Into the air / Ivan Trevino -- [Track 02]. Preludes. II ; [Track 03]. III ; [Track 04]. I / Michael Burritt -- [Track 05]. Arabesque no. 2 / Claude Debussy ; arranged by Caleb Evans -- [Track 06]. Somewhere over the rainbow / Harold Arlen ; arranged by Max Seide Leth -- [Track 07]. Pure imagination / Leslie Bricusse and Anthony Newly ; arranged by Alex Stopa -- [Track 08]. Claire de lune / Claude Debussy ; arranged by Nick Baron -- [Track 09]. Trio per uno. II ; [Track 10]. I / Nebosja Zivkovic

Automorphism groups of countable algebraically closed graphs and endomorphisms of the random graph

We establish links between countable algebraically closed graphs and the endomorphisms of the countable universal graph $R$. As a consequence we show that, for any countable graph $\Gamma$, there are uncountably many maximal subgroups of the endomorphism monoid of $R$ isomorphic to the automorphism group of $\Gamma$. Further structural information about End $R$ is established including that Aut $\Gamma$ arises in uncountably many ways as a Sch\"{u}tzenberger group. Similar results are proved for the countable universal directed graph and the countable universal bipartite graph.Comment: Minor revision following referee's comments. 27 pages, 3 figure

“Speak up!” An Examination of the Language Capacities of Children Displaying Various Forms of Social Withdrawal and Aggression

Language serves as a mechanism through which children are able to interact and communicate with others. Thus, when children do not develop language at a typical pace, there may be cause for concern. The purpose of the current study was to examine the language production of children displaying various forms of social withdrawal (reticent, solitary-passive, and solitary-active behavior) and children engaging in subtypes of aggression (relational, physical, and comorbid). Participants came from preschools operated by a large private university located in the intermountain region of the western United States (N = 220, Mage = 4.58, 53% female). We observed the participating children, and teachers and parents completed reports on the children’s behaviors. Results revealed that reticent, solitary-passive, and solitary-active children produced less language compared to their nonwithdrawn peers. Further analyses revealed language differences between subtypes of social withdrawal. Physically aggressive children produced less language compared to nonaggressive children, and comorbid aggressive children produced more language compared to their nonaggressive, physically aggressive, and relationally aggressive peers. The discussion focuses on contextual and conceptual factors that may play a role in understanding the relation between language production, social withdrawal, and aggression

Trends and gender differences in age at sex debut among adolescents and young adults in urban Cape Area, South Africa

Background: Adolescents and young adults in South Africa are at increased risk of experiencing negative outcomes from early sex initiation due to the context they develop in. This study aimed at investigating trends and gender differences in early age at sexual debut. Methods: Data from the Cape Area Panel Study (CAPS) of young adults\u2019 conducted between 2002 and 2009 in urban Cape Town were used. Correlates of early sex using ecological risk factors were analysed. Results: Overall mean age at sexual debut at follow-up was 17.5 years (standard deviation (SD) =2.5), with males at 16.8 years (SD=2.5) and 18.1 years (SD=2.4) for females. Males consistently reported an earlier age at sex debut across the five waves of the survey. Significant risk factors for early sex appeared at all levels of the ecology to include individual, household, and community factors. Conclusions: Integrated interventions for delaying early sex debut should consider factors within the ecology of the young adults\u2019 development context