Efficient optimisation of structures using tabu search

This paper presents a novel approach to the optimisation of structures using a Tabu search (TS) method. TS is a metaheuristic which is used to guide local search methods towards a globally optimal solution by using flexible memory cycles of differing time spans. Results are presented for the well established ten bar truss problem and compared to results published in the literature. In the first example a truss is optimised to minimise mass and the results compared to results obtained using an alternative TS implementation. In the second example, the problem has multiple objectives that are compounded into a single objective function value using game theory. In general the results demonstrate that the TS method is capable of solving structural optimisation problems at least as efficiently as other numerical optimisation approaches

Accelerating Metric Filtering by Improving Bounds on Estimated Distances

Filtering is a fundamental strategy of metric similarity indexes to minimise the number of computed distances. Given a triple of objects for which distances of two pairs are known, the lower and upper bounds on the third distance can be set as the difference and the sum of these two already known distances, due to the triangle inequality rule of the metric space. For efficiency reasons, the tightness of bounds is crucial, but as angles within triangles of distances can be arbitrary, the worst case with zero and straight angles must also be considered for correctness. However, in data of real-life applications, the distribution of possible angles is skewed and extremes are very unlikely to occur. In this paper, we enhance the existing definition of bounds on the unknown distance with information about possible angles within triangles. We show that two lower bounds and one upper bound on each distance exist in case of limited angles. We analyse their filtering power and confirm high improvements of efficiency by experiments on several real-life datasets

The First World War Centenary in the UK: ‘A Truly National Commemoration’?

Prime Minister David Cameron has called for ‘a truly national commemoration of the First World War’. This article shows this to be problematic, politicised and contested. This is in part due to the elision of English and British histories. Scottish, Welsh and Irish responses are noted, and the role and commemorations of ‘our friends in the Commonwealth’. There are tensions around interpretations of empire and race. There has been a failure to appreciate that the debates about the legacies of the First World War are deeply entangled with those of colonialism

Enhancing Student Engagement in Wayne State University School of Medicine (WSUSOM) Curriculum Design, Development, Evaluation, and Implementation

Purpose: There are a variety of ways in which the 1200 medical students at Wayne State University School of Medicine (WSUSOM) can formally participate in curricular efforts. To date, a formal inventory and evaluation of these programs has not been reported. Methods: We compiled a list of students involved in courses, committees, and formal activities related to the medical school curriculum. We then developed and delivered a survey to measure student perceptions utilizing the following constructs: 1) Guidance/Support for Student Role, 2) Project Successes and Challenges, 3) Curricular Project Measurement and Monitoring, 4) Curriculum Management Committee Engagement and Accessibility, 5) Frequency of Engagement with other Students in these Roles, and 6) Strengths and Opportunities for Improvement: Curriculum Management Infrastructure. Results: With a response rate of 57.7% from 123 students, participants reported that they receive sufficient support/guidance for their roles (74%), but more than half were unaware of a process to monitor progress. Students remained siloed, communicating with other groups less than monthly, and 72% reported lacking sufficient knowledge of other groups’ curricular projects. Thematic qualitative analysis of suggestions for improving the curriculum management infrastructure yielded the following priorities: communication/feedback; transparency; and organizational efficiency. Similar analysis of suggestions for improving medical student roles showed: defining roles; increasing support, training, and guidance; and communication. Discussion: Our study represents the first inventory of student engagement in curriculum design, development, evaluation and implementation at the nation’s largest single-campus medical school. There is a clear need for greater collaboration and communication, systems to track curricular projects, and improved training/definition of roles. As primary stakeholders in their own educational environment, students involved in curricular projects are uniquely placed to make such observations and pleas for improvement. Development of a comprehensive roster specifying roles and responsibilities, an accompanying work-flow model for interacting roles, and a central hub to track projects would each greatly improve the efficacy of curricular planning

Plans for the next GRAPE balloon flight

The Gamma RAy Polarimeter Experiment (GRAPE) was first flown on a 26-hour balloon flight in the fall of 2011. GRAPE consists of an array of Compton polarimeter modules (based on traditional scintillation technologies) designed to operate in the energy range from 50 keV up to 500 keV. The ultimate goal is to operate GRAPE in a wide FoV configuration for the study of gamma-ray bursts. For the first (demonstration) balloon flight, GRAPE was configured in a collimated mode to facilitate observations of known point sources. The Crab nebula/pulsar, the active Sun, and Cygnus X-1 were the primary targets for the first flight. Although the Crab was detected, the polarization sensitivity was worse than expected. This paper will review the plans for the next GRAPE balloon flight, which is scheduled to take place in the fall of 2014 from Ft. Sumner, NM. These plans involve several modifications designed to improve the polarization sensitivity, including an expansion of the array of polarimeter modules from 16 to 24 and improvements to the instrument shielding. Sensitivity estimates of the resulting instrument, based on GEANT4 simulations, will be presented

The HSV-1 Latency-Associated Transcript Functions to Repress Latent Phase Lytic Gene Expression and Suppress Virus Reactivation from Latently Infected Neurons

open access articleHerpes simplex virus 1 (HSV-1) establishes life-long latent infection within sensory neurons, during which viral lytic gene expression is silenced. The only highly expressed viral gene product during latent infection is the latency-associated transcript (LAT), a non-protein coding RNA that has been strongly implicated in the epigenetic regulation of HSV-1 gene expression. We have investigated LAT-mediated control of latent gene expression using chromatin immunoprecipitation analyses and LAT-negative viruses engineered to express firefly luciferase or β-galactosidase from a heterologous lytic promoter. Whilst we were unable to determine a significant effect of LAT expression upon heterochromatin enrichment on latent HSV-1 genomes, we show that reporter gene expression from latent HSV-1 genomes occurs at a greater frequency in the absence of LAT. Furthermore, using luciferase reporter viruses we have observed that HSV-1 gene expression decreases during long-term latent infection, with a most marked effect during LAT-negative virus infection. Finally, using a fluorescent mouse model of infection to isolate and culture single latently infected neurons, we also show that reactivation occurs at a greater frequency from cultures harbouring LAT-negative HSV-1. Together, our data suggest that the HSV-1 LAT RNA represses HSV-1 gene expression in small populations of neurons within the mouse TG, a phenomenon that directly impacts upon the frequency of reactivation and the maintenance of the transcriptionally active latent reservoir

Statistical Mechanics for Unstable States in Gel'fand Triplets and Investigations of Parabolic Potential Barriers

Free energies and other thermodynamical quantities are investigated in canonical and grand canonical ensembles of statistical mechanics involving unstable states which are described by the generalized eigenstates with complex energy eigenvalues in the conjugate space of Gel'fand triplet. The theory is applied to the systems containing parabolic potential barriers (PPB's). The entropy and energy productions from PPB systems are studied. An equilibrium for a chemical process described by reactions $A+CB\rightleftarrows AC+B$ is also discussed.Comment: 14 pages, AmS-LaTeX, no figur

The role of concussion history and biological sex on pupillary light reflex metrics in adolescent rugby players: a cross-sectional study.

Abstract: Background: Concussion examination is based primarily on clinical evaluation and symptomatic reporting. Pupillary light reflex (PLR) metrics may provide an objective physiological marker to inform concussion diagnosis and recovery, but few studies have assessed PLR, and normative data are lacking, particularly for adolescents. Aim: To capture PLR data in adolescent rugby players and examine the effects of concussion history and biological sex. Design: Cross‐sectional. Methods: Male and female adolescent rugby union players aged 16 to 18 years were recruited at the start of the 2022–2023 playing season. PLR was recorded using a handheld pupillometer which provided seven different metrics relating to pupil diameter, constriction/dilation latency, and velocity. Data were analysed using a series of 2 × 2 ANOVAs to examine the main effects of independent variables: biological sex, concussion history, and their interactions, using adjusted p‐values (p < 0.05). Results: 149 participants (75% male) were included. A total of 42% reported at least one previous concussion. Most metrics were unaffected by the independent variables. There were however significant main effects for concussion history (F = 4.11 (1); p = 0.05) and sex (F = 5.42(1); p = 0.02) in end pupil diameters, and a main effect for sex in initial pupil diameters (F = 4.45 (1); p = 0.04). Although no significant interaction effects were found, on average, females with a concussion history presented with greater pupillary diameters and velocity metrics, with many pairwise comparisons showing large effects (SMD > 0.8). Conclusions: Pupillary diameters in adolescent athletes were significantly affected by concussion history and sex. The most extreme PLRmetrics were recorded in females with a history of concussion (higher pupillary diameters and velocities). This highlights the importance of establishing baseline PLR metrics prior to interpretation of the PLR post‐concussion. Long‐standing PLR abnormalities post‐concussion may reflect ongoing autonomic nervous system dysfunction. This warrants further investigation in longitudinal studies

Semiclassical quantization of the hydrogen atom in crossed electric and magnetic fields

The S-matrix theory formulation of closed-orbit theory recently proposed by Granger and Greene is extended to atoms in crossed electric and magnetic fields. We then present a semiclassical quantization of the hydrogen atom in crossed fields, which succeeds in resolving individual lines in the spectrum, but is restricted to the strongest lines of each n-manifold. By means of a detailed semiclassical analysis of the quantum spectrum, we demonstrate that it is the abundance of bifurcations of closed orbits that precludes the resolution of finer details. They necessitate the inclusion of uniform semiclassical approximations into the quantization process. Uniform approximations for the generic types of closed-orbit bifurcation are derived, and a general method for including them in a high-resolution semiclassical quantization is devised