The Identity of Activism: How Gender and Racial Identity Relate to Activism Among African Americans

In response to the murders of several unarmed African American citizens by police officers and the emergence of movements such as #BlackLivesMatter in the past 10 years, there has been a resurgence of activism in the African American community. Research shows that racial identity influences an individual’s motivation for engagement in activism while gender predicts the type of activism that one might engage. The current study examined gender differences in activism and the associations between gender, racial identity, racial discrimination, and activism. The study included 326 college students (142 men and 183 women) who completed a survey that assessed perceived discrimination, racial identity, and black activism. Correlation and regression analyses were used to examine the associative questions, and an independent t-test was used to examine gender differences in activism. The results indicated that private regard and perceived discrimination are positively associated with activism, however, racial centrality and gender did not predict activism. The findings suggest that racial identity and experiences of discrimination are important determinants of activism. Therefore, this research is relevant as awareness of the interrelatedness of social identities is becoming more prevalent to contemporary activist motivation

de Branges-Rovnyak spaces: basics and theory

For $S$ a contractive analytic operator-valued function on the unit disk ${\mathbb D}$, de Branges and Rovnyak associate a Hilbert space of analytic functions ${\mathcal H}(S)$ and related extension space ${\mathcal D(S)}$ consisting of pairs of analytic functions on the unit disk ${\mathbb D}$. This survey describes three equivalent formulations (the original geometric de Branges-Rovnyak definition, the Toeplitz operator characterization, and the characterization as a reproducing kernel Hilbert space) of the de Branges-Rovnyak space ${\mathcal H}(S)$, as well as its role as the underlying Hilbert space for the modeling of completely non-isometric Hilbert-space contraction operators. Also examined is the extension of these ideas to handle the modeling of the more general class of completely nonunitary contraction operators, where the more general two-component de Branges-Rovnyak model space ${\mathcal D}(S)$ and associated overlapping spaces play key roles. Connections with other function theory problems and applications are also discussed. More recent applications to a variety of subsequent applications are given in a companion survey article

Static and dynamic fluid-driven fracturing of adhered elastica

The transient spreading of a viscous fluid beneath an elastic sheet adhered to the substrate is controlled by the dynamics at the tip where the divergence of viscous stresses necessitates the formation of a vapour tip separating the fluid front and fracture front. The model for elastic-plated currents is extended for an axisymmetric geometry with analysis showing that adhesion gives rise to the possibility of static, elastic droplets and to two dynamical regimes of spreading; viscosity dominant spreading controlled by flow of viscous fluid into the vapour tip, and adhesion dominant spreading. Constant flux experiments using clear, PDMS elastic sheets enable new, direct measurements of the vapour tip, and confirm the existence of spreading regimes controlled by viscosity and adhesion. The theory and experiments thereby provide an important test coupling the dynamics of flow with elastic deformation and have implications in fluid-driven fracturing of elastic media more generally.J. A. N. is supported by a Royal Society University Research Fellowship

Finite element modelling of pellet-clad interaction during operational transients

A finite element model of pellet-clad interaction in advanced gas cooled reactor fuel experiencing extended reduced power operations is presented. The model considers a 1/8th segment of fuel and overlaying cladding bonded to it. A radial crack is introduced to the pellet, this is able to open and close, straining a section of cladding above the crack. In addition, circumferential cracks in the fuel pellet result in a sliver of fuel being bonded to the cladding; this sliver of fuel contains hairline radial cracks, known as ladder cracks, the opening and closing of which are modelled. Finally, the model predicts the creep strain at the tip of an incipient crack in the cladding, ahead of the radial crack in the fuel pellet. Results show that the crack tip creep strain is strongly dependent on the model of ladder cracking chosen

The Engagement Pathway: A Conceptual Framework of Engagement-Related Terms in Weight Management

Engagement denotes the extent to which, and how, individuals participate in weight management (WM) services. Effective WM services should generate meaningful outcomes and promote high participant engagement; however, research is predominantly focused on the former. Given that engagement is a poorly understood phenomenon, and that engagement-related concepts are often used synonymously (e.g., dropout and attrition), the engagement pathway is hereby introduced. This pathway defines key concepts (e.g., recruitment, adherence, attrition) and their relationships in the enrolment, intervention, and maintenance stages of treatment. The pathway will help researchers and practitioners better understand engagement-related concepts whilst encouraging greater conceptual consistency between studies

Operator theory and function theory in Drury-Arveson space and its quotients

The Drury-Arveson space $H^2_d$, also known as symmetric Fock space or the $d$-shift space, is a Hilbert function space that has a natural $d$-tuple of operators acting on it, which gives it the structure of a Hilbert module. This survey aims to introduce the Drury-Arveson space, to give a panoramic view of the main operator theoretic and function theoretic aspects of this space, and to describe the universal role that it plays in multivariable operator theory and in Pick interpolation theory.Comment: Final version (to appear in Handbook of Operator Theory); 42 page

Computing Linear Matrix Representations of Helton-Vinnikov Curves

Helton and Vinnikov showed that every rigidly convex curve in the real plane bounds a spectrahedron. This leads to the computational problem of explicitly producing a symmetric (positive definite) linear determinantal representation for a given curve. We study three approaches to this problem: an algebraic approach via solving polynomial equations, a geometric approach via contact curves, and an analytic approach via theta functions. These are explained, compared, and tested experimentally for low degree instances.Comment: 19 pages, 3 figures, minor revisions; Mathematical Methods in Systems, Optimization and Control, Birkhauser, Base

Two-loop Corrections to the B to pi Form Factor from QCD Sum Rules on the Light-Cone and |V(ub)|

We calculate the leading-twist O(alphas^2 beta0) corrections to the B to pi transition form factor f+(0) in light-cone sum rules. We find that, as expected, there is a cancellation between the O(alphas^2 beta0) corrections to fB f+(0) and the large corresponding corrections to fB, calculated in QCD sum rules. This suggests the insensitivity of the form factors calculated in the light-cone sum rules approach to this source of radiative corrections. We further obtain an improved determination of the CKM matrix element |V(ub)|, using latest results from BaBar and Belle for f+(0)|V(ub)|.Comment: 18 pages, 3 figure

Can oral infection be a risk factor for Alzheimer’s disease?

Alzheimer’s disease (AD) is a scourge of longevity that will drain enormous resources from public health budgets in the future. Currently, there is no diagnostic biomarker and/or treatment for this most common form of dementia in humans. AD can be of early familial-onset or sporadic with a late-onset. Apart from the two main hallmarks, amyloid-beta and neurofibrillary tangles, inflammation is a characteristic feature of AD neuropathology. Inflammation may be caused by a local central nervous system insult and/or by peripheral infections. Numerous microorganisms are suspected in AD brains ranging from bacteria (mainly oral and non-oral Treponema species), viruses (Herpes simplex type I) and yeasts (Candida species). A causal relationship between periodontal pathogens/non-oral Treponema species of bacteria has been proposed via the amyloid-beta and inflammatory links. Periodontitis constitutes a peripheral oral infection that can provide the brain with intact bacteria and virulence factors and inflammatory mediators due to daily, transient bacteraemias. If and when genetic risk factors meet environmental risk factors in the brain, disease is expressed, in which neurocognition may be impacted, leading to the development of dementia. To achieve the goal of finding a diagnostic biomarker and possible prophylactic treatment for AD, there is an initial need to solve the etiological puzzle contributing to its pathogenesis. This review therefore addresses oral infection as the plausible aetiology of late onset AD (LOAD)