Focal ventromedial prefrontal cortex damage impairs convergence in discourse

Conversational partners tend to converge (become more similar) on various speech and discourse characteristics, enhancing social affiliation. We examined convergence in the discourse of eight participants with bilateral ventromedial prefrontal cortex (VMPC) damage and eight healthy comparison participants (NC) each interacting with a clinician. Changes in total words, words/turn, and backchannels were assessed across the interaction by comparing the first ¼ and last ¼ of the session. Preliminary results suggest that convergence was displayed in NC interactions as conversational partners become more similar to one another across variables. In striking contrast, VMPC interactions did not display convergence across any variables

Membranes and Three-form Supergravity

We discuss membranes in four-dimensional N=1 superspace. The kappa-invariance of the Green-Schwarz action implies that there is a dual version of N=1 supergravity with a three-form potential. We formulate this new supergravity in terms of a three-form superfield in curved superspace, giving the relevant constraints on the field strength. We find the corresponding membrane soliton in the new supergravity and discuss how the extended supersymmetry algebra emerges from the symmetries of the flat superspace background.Comment: 34 pages, Latex2

Soft Functions for Generic Jet Algorithms and Observables at Hadron Colliders

We introduce a method to compute one-loop soft functions for exclusive $N$-jet processes at hadron colliders, allowing for different definitions of the algorithm that determines the jet regions and of the measurements in those regions. In particular, we generalize the $N$-jettiness hemisphere decomposition of [Jouttenus 2011] in a manner that separates the dependence on the jet boundary from the observables measured inside the jet and beam regions. Results are given for several factorizable jet definitions, including anti-$k_T$, XCone, and other geometric partitionings. We calculate explicitly the soft functions for angularity measurements, including jet mass and jet broadening, in $pp \to L + 1$ jet and explore the differences for various jet vetoes and algorithms. This includes a consistent treatment of rapidity divergences when applicable. We also compute analytic results for these soft functions in an expansion for a small jet radius $R$. We find that the small-$R$ results, including corrections up to $\mathcal{O}(R^2)$, accurately capture the full behavior over a large range of $R$.Comment: 33 pages + appendices, 17 figures, v2: journal version, v3: fixed typo in eq.(4.37

Cosmological Solutions of Type II String Theory

We study cosmological solutions of type II string theory with a metric of the Kaluza--Klein type and nontrivial Ramond--Ramond forms. It is shown that models with only one form excited can be integrated in general. Moreover, some interesting cases with two nontrivial forms can be solved completely since they correspond to Toda models. We find two types of solutions corresponding to a negative time superinflating phase and a positive time subluminal expanding phase. The two branches are separated by a curvature singularity. Within each branch the effect of the forms is to interpolate between different solutions of pure Kaluza--Klein theory.Comment: 13 pages, LATEX, 2 eps figure

Superspace approach to the renormalization of the O'Raifeartaigh model up to the second order in the LDE parameter

We adopt a superspace/supergraph formalism to pursue the investigation of the structure of one- and two-loop divergences in the frame of the minimal O'Raifeartaigh model that realizes the F-term spontaneous supersymmetry breaking. The linear delta expansion(LDE) procedure is introduced and renormalization is carried out up to the second order in the LDE expansion parameter. In agreement with the nonrenormalization theorem for the (chiral/antichiral) matter potential of ${\mathcal N}=1, \ D=4$ supersymmetry, our explicit supergraph calculations confirm that only the K\"{a}hler potential is actually renomalized.Comment: 23 pages, 4 figures, revtex4. arXiv admin note: text overlap with arXiv:0904.467

Distributed impact of cognitive-communication impairment: Disruptions in the use of definite references when speaking to individuals with amnesia

Definite references signal the belief that listeners can uniquely identify referents. Our previous research found participants with amnesia used fewer definite references, as directors in a barrier task, than comparison participants. If this is an interactional consequence of managing memory impairments (as opposed to a language deficit), we should expect a decrease in definite referencing by their communication partners. This paper presents a follow-up study in which the communication partners became directors. In addition to documenting the communicative and linguistic consequences of amnesia in interaction, this analysis may have implications for basic models of common ground

Purdue Conference on Active Nonproliferation

Conference for the discussion of nuclear nonproliferatio

String and M-Theory Cosmological Solutions with Ramond Forms

A general framework for studying a large class of cosmological solutions of the low-energy limit of type II string theory and of M-theory, with non-trivial Ramond form fields excited, is presented. The framework is applicable to spacetimes decomposable into a set of flat or, more generally, maximally symmetric spatial subspaces, with multiple non-trivial form fields spanning one or more of the subspaces. It is shown that the corresponding low-energy equations of motion are equivalent to those describing a particle moving in a moduli space consisting of the scale factors of the subspaces together with the dilaton. The choice of which form fields are excited controls the potential term in the particle equations. Two classes of exact solutions are given, those corresponding to exciting only a single form and those with multiple forms excited which correspond to Toda theories. Although typically these solutions begin or end in a curvature singularity, there is a subclass with positive spatial curvature which appears to be singularity free. Elements of this class are directly related to certain black p-brane solutions.Comment: 34 pages, Latex, 3 figures using eps

Partitioning Strategies for the Block Cimmino algorithm (Precond 2011)

Session 9International audienc

Medial Temporal Lobe Damage Impairs Representation of Simple Stimuli

Medial temporal lobe (MTL) damage in humans is typically thought to produce a circumscribed impairment in the acquisition of new enduring memories, but recent reports have documented deficits even in short-term maintenance. We examined possible maintenance deficits in a population of MTL amnesics, with the goal of characterizing their impairments as either representational drift or outright loss of representation over time. Patients and healthy comparisons performed a visual search task in which the similarity of various lures to a target was varied parametrically. Stimuli were simple shapes varying along one of several visual dimensions. The task was performed in two conditions, one presenting a sample target simultaneously with the search array and the other imposing a delay between sample and array. Eye-movement data collected during search revealed that the duration of fixations to items varied with lure-target similarity for all participants, i.e., fixations were longer for items more similar to the target. In the simultaneous condition, patients and comparisons exhibited an equivalent effect of similarity on fixation durations. However, imposing a delay modulated the effect differently for the two groups: in comparisons, fixation duration to similar items was exaggerated; in patients, the original effect was diminished. These findings indicate that MTL lesions subtly impair short-term maintenance of even simple stimuli, with performance reflecting not the complete loss of the maintained representation but rather a degradation or progressive drift of the representation over time