A Homogeneous Model of Spinfoam Cosmology

We examine spinfoam cosmology by use of a simple graph adapted to homogeneous cosmological models. We calculate dynamics in the isotropic limit, and provide the framework for the aniostropic case. The dynamical behaviour is calculating transition amplitudes between holomorphic coherent states on a single node graph. The resultant dynamics is peaked on solutions which have no support on the zero volume state, indicating that big bang type singularities are avoided within such models.Comment: 22 pages, 4 figure

Investigating dynamic stiffening and softening of a system of colloids cross-linked via polymers

With the goal of ultimately deciphering the design principles for biomimetic materials that can autonomously stiffen and soften, we investigate colloids as a model system that can dynamically transition from fluid-like (sol) to gel-like (gel) when crosslinked with polymers. The model was first developed with colloids only, interacting via a Lennard-Jones potential and undergoing Brownian dynamics, with experimentally relevant parameters, to test and refine the simulation. We then added polymer crosslinkers that connect the colloids via an attractive spring force, and investigate resulting collective properties, such as the time needed for the formation of system spanning networks and the elastic moduli, for various colloid densities, interaction strengths, and cross-linker rest lengths and densities. Using experimental parameters for polystyrene spheres and Bovine Serum Albumin (BSA) crosslinkers, we predicted the behavior of real systems. Finally, we replaced the passive, one-shot crosslinkers in our system by active cross-linkers that can dynamically and attach and detach, and characterized how the degree of order and the mechanical response of the system change with time. Our results provide insights into the design of self-sustaining soft materials that can dynamically stiffen and soften, and how the properties of such materials can be tuned

Visual Input in Simultaneous Interpreting

This article looks at the interaction of the visual and the verbal in simultaneous interpreting, describing the significance of different elements of visual nonverbal communication with focus on those that facilitate understanding or need to be rendered in some way in the interpretation. While studies show that this visual information is often redundant, it can nevertheless aid the processing of verbal information. Visual contact can certainly be of importance when the verbal message refers to something visible to the audience or when the nonverbal adds information not present in the verbal message. A small experiment was conducted at the University of Vienna in order to determine whether there were any appreciable differences in interpreting with and without visual contact. The descriptive analysis sought to identify types of visual nonverbal communication that were particularly important for understanding the message.Le présent article traite de l’interaction entre le visuel et le verbal lors de l’interprétation simultanée. La signification des différentes composantes de la communication non verbale visuelle est étudiée, avec un accent particulier sur les éléments qui facilitent la bonne compréhension ou qui doivent être pris en compte dans l’interprétation. Ces informations d’ordre visuel, dont certaines études semblent prouver le caractère redondant, peuvent pourtant aider à bien assimiler l’information verbalisée. Le contact visuel est sans doute important lorsque le message verbal porte sur quelque chose qui est visible pour l’audience ou lorsque la composante non verbale apporte une information supplémentaire non explicitée dans l’énoncé. Une expérience à petite échelle a été conduite à l’Université de Vienne pour faire apparaître les éventuelles différences entre l’interprétation effectuée avec ou sans contact visuel. L’analyse descriptive qui en est donnée se propose d’identifier les modes de communication non verbale visuelle qui importent tout particulièrement pour la bonne compréhension du message

The impact of fluency on the subjective assessment of interpreting quality

Prosodic features such as fluency are key components of natural speech and, thus, also of simultaneous interpreting. Disfluencies, such as hesitations, vowel lengthening and repairs, are particularly significant in the output of simultaneous interpreters, which presents a pattern of pausing and disfluencies that differs from other forms of spontaneous speech. This paper provides an overview of aspects of fluency and a brief introduction to previous research in the area of fluency and user perceptions, and describes a study conducted by the author at the University of Vienna. The results of this experiment indicate that there may be a link between perceived fluency of an interpretation and users’ assessment of the interpreter’s accuracy. There also appears to be a link between self-assessed comprehension and assessment of the interpreter’s performance

Statistical Methods For Truncated Survival Data

{Truncation is a well-known phenomenon that may be present in observational studies of time-to-event data. For example, autopsy-confirmed survival studies of neurodegenerative diseases are subject to selection bias due to the simultaneous presence of left and right truncation, also known as double truncation. While many methods exist to adjust for either left or right truncation, there are very few methods that adjust for double truncation. When time-to-event data is doubly truncated, the regression coefficient estimators from the standard Cox regression model will be biased. In this dissertation, we develop two novel methods to adjust for double truncation when fitting the Cox regression model. The first method uses a weighted estimating equation approach. This method assumes the survival and truncation times are independent. The second method relaxes this independence assumption to an assumption of conditional independence between the survival and truncation times. As opposed to methods that ignore truncation, we show that both proposed methods result in consistent and asymptotically normal regression coefficient estimators and have little bias in small samples. We use these proposed methods to assess the effect of cognitive reserve on survival in individuals with autopsy-confirmed Alzheimer’s disease. We also conduct an extensive simulation study to compare survival distribution function estimators in the presence of double truncation and conduct a case study to compare the survival times of individuals with autopsy-confirmed Alzheimer’s disease and frontotemporal lobar degeneration. Furthermore, we introduce an R-package for the above methods to adjust for double truncation when fitting the Cox model and estimating the survival distribution function

Perceptions of surveillance: exploring feelings held by Black community leaders in Boston toward camera enforcement of roadway infractions

Roadway camera enforcement programs have been found to effectively reduce vehicle travel speeds, as well as decrease the number and severity of collisions. Despite a wealth of evaluative research confirming this enforcement approach's aptitude at promoting safer roadway behavior, fewer than 50 % of US states currently host camera-based programs. Public opposition is frequently cited as the cause for the slow proliferation of this enforcement strategy. However, with public demand for police reform having an increasing presence on the national political stage, how might feelings toward camera technology currently stand among groups most marginalized by existing enforcement systems, and how might those feelings vary by type of enforcement application? Through a series of focus groups, this work centers Black voices on matters of surveillance and roadway enforcement by discussing sentiment toward camera programs with Black community leaders. This discussion is contextually situated in Boston, Massachusetts, where legislation that would allow for camera enforcement of roadway infractions is actively being deliberated in the State Senate. Findings culminate in a list of right-sizing and procedural recommendations for policy makers hoping to gain support for camera enforcement, improve roadway safety, and advance racial equity in our systems of policing and governance

A theoretical model for the authentic assessment of teaching

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Decomposing data sets into skewness modes

We derive the nonlinear equations satisfied by the coefficients of linear combinations that maximize their skewness when their variance is constrained to take a specific value. In order to numerically solve these nonlinear equations we develop a gradient-type flow that preserves the constraint. In combination with the Karhunen-Lo\`eve decomposition this leads to a set of orthogonal modes with maximal skewness. For illustration purposes we apply these techniques to atmospheric data; in this case the maximal-skewness modes correspond to strongly localized atmospheric flows. We show how these ideas can be extended, for example to maximal-flatness modes.Comment: Submitted for publication, 12 pages, 4 figure