Development of rapid, automated diagnostics for infectious disease: advances and challenges

The last 2 years has seen an exponential rise in the amount of research funding made available for the development of rapid diagnostic devices for infectious agents of medical importance. This review reports on several such projects. These highlight the development of fully automated devices for rapid diagnostics, ranging from fully automated real-time PCR-based detection methods to fully automated PCR- and array-based machines for the detection and typing of influenza. This review will also highlight the importance of refocusing work on classical immunoassay techniques, showing how biosensor-based immunoassays can greatly enhance existing assays and at a much reduced cost to molecular-based methods

Analysis of slow (theta) oscillations as a potential temporal reference frame for information coding in sensory cortices

While sensory neurons carry behaviorally relevant information in responses that often extend over hundreds of milliseconds, the key units of neural information likely consist of much shorter and temporally precise spike patterns. The mechanisms and temporal reference frames by which sensory networks partition responses into these shorter units of information remain unknown. One hypothesis holds that slow oscillations provide a network-intrinsic reference to temporally partitioned spike trains without exploiting the millisecond-precise alignment of spikes to sensory stimuli. We tested this hypothesis on neural responses recorded in visual and auditory cortices of macaque monkeys in response to natural stimuli. Comparing different schemes for response partitioning revealed that theta band oscillations provide a temporal reference that permits extracting significantly more information than can be obtained from spike counts, and sometimes almost as much information as obtained by partitioning spike trains using precisely stimulus-locked time bins. We further tested the robustness of these partitioning schemes to temporal uncertainty in the decoding process and to noise in the sensory input. This revealed that partitioning using an oscillatory reference provides greater robustness than partitioning using precisely stimulus-locked time bins. Overall, these results provide a computational proof of concept for the hypothesis that slow rhythmic network activity may serve as internal reference frame for information coding in sensory cortices and they foster the notion that slow oscillations serve as key elements for the computations underlying perception

Irregular speech rate dissociates auditory cortical entrainment, evoked responses, and frontal alpha

The entrainment of slow rhythmic auditory cortical activity to the temporal regularities in speech is considered to be a central mechanism underlying auditory perception. Previous work has shown that entrainment is reduced when the quality of the acoustic input is degraded, but has also linked rhythmic activity at similar time scales to the encoding of temporal expectations. To understand these bottom-up and top-down contributions to rhythmic entrainment, we manipulated the temporal predictive structure of speech by parametrically altering the distribution of pauses between syllables or words, thereby rendering the local speech rate irregular while preserving intelligibility and the envelope fluctuations of the acoustic signal. Recording EEG activity in human participants, we found that this manipulation did not alter neural processes reflecting the encoding of individual sound transients, such as evoked potentials. However, the manipulation significantly reduced the fidelity of auditory delta (but not theta) band entrainment to the speech envelope. It also reduced left frontal alpha power and this alpha reduction was predictive of the reduced delta entrainment across participants. Our results show that rhythmic auditory entrainment in delta and theta bands reflect functionally distinct processes. Furthermore, they reveal that delta entrainment is under top-down control and likely reflects prefrontal processes that are sensitive to acoustical regularities rather than the bottom-up encoding of acoustic features

Predicting Sense Of Community in a Historic Latino/Latina Neighborhood Undergoing Gentrification

Neighborhoods with generational Mexican American populations may have high levels of block Social Cohesion and neighborhood Sense of Community. Streetcar-focused development via federal and local investment often spurs gentrification in neighborhoods with ethnic concentrations, which shifts neighborhood demographics towards more White and higher income households. The new residential and business investment in the neighborhood often has an impact on existing neighborhood social dynamics. This study includes mixed methods resident survey data of long term and newer residents. The qualitative data analysis informs quantitative data analysis in order to better understand resident descriptions of the impact of neighborhood streetcar focused gentrification on social factors in a generational Latino/Latina neighborhood at one point in time just before the streetcar opening. Specifically the study seeks to: (a) provide a description of generational and new resident experiences with block Social Cohesion and neighborhood Sense of Community; (b) determine differences (between Latino/Latina households and those with children present and other study participants) in block Social Cohesion, neighborhood Sense of Community, and Involvement in Neighborhood and Voluntary Associations; and (c) determine what factors predict neighborhood Sense of Community. The study highlights the Latino/Latina residents’ maintenance of a strong ethnic identity, generational neighborhood based social ties, and ongoing involvement in neighborhood schools and religious traditions that contribute to a strong neighborhood Sense of Community. Newer residents report being drawn to and supporting the maintenance of the neighborhood Sense of Community

Just Mathematics: Getting Started Teaching Postsecondary Math for Social Justice

Following the summer 2020 civil rights movement and increasing attention to the intersections of mathematics with politics and power, many math educators have reported a desire to implement an antiracist pedagogy and to examine the intersections of their subject with issues of equity, inclusion, and social justice. Many resources exist for K-12 math educators interested in incorporating social justice into their curricula, but resources are comparatively scarce for college and university instructors (though this is changing quickly!). We discuss why one may want to teach mathematics for social justice, how to begin to implement issues of social justice into postsecondary math courses, and publicly available social justice materials for postsecondary math courses

Penrose Limit and String Theories on Various Brane Backgrounds

We investigate the Penrose limit of various brane solutions including Dp-branes, NS5-branes, fundamental strings, (p,q) fivebranes and (p,q) strings. We obtain special null geodesics with the fixed radial coordinate (critical radius), along which the Penrose limit gives string theories with constant mass. We also study string theories with time-dependent mass, which arise from the Penrose limit of the brane backgrounds. We examine equations of motion of the strings in the asymptotic flat region and around the critical radius. In particular, for (p,q) fivebranes, we find that the string equations of motion in the directions with the B field are explicitly solved by the spheroidal wave functions.Comment: 41 pages, Latex, minor correction

Root asymptotics of spectral polynomials for the Lame operator

The study of polynomial solutions to the classical Lam\'e equation in its algebraic form, or equivalently, of double-periodic solutions of its Weierstrass form has a long history. Such solutions appear at integer values of the spectral parameter and their respective eigenvalues serve as the ends of bands in the boundary value problem for the corresponding Schr\"odinger equation with finite gap potential given by the Weierstrass $\wp$-function on the real line. In this paper we establish several natural (and equivalent) formulas in terms of hypergeometric and elliptic type integrals for the density of the appropriately scaled asymptotic distribution of these eigenvalues when the integer-valued spectral parameter tends to infinity. We also show that this density satisfies a Heun differential equation with four singularities.Comment: final version, to appear in Commun. Math. Phys.; 13 pages, 3 figures, LaTeX2