Contact and self-segregation in ethnically diverse schools: a multi-methodological approach

This thesis investigates 'self-segregation,' the voluntary separation and clustering of ethnic groups within a diverse environment that ostensibly provides opportunities for intergroup contact. While previous research has demonstrated self-segregation within such settings, using either self-reports, observations of behaviour, or social network analysis (SNA), such studies tend to be mono-methodological and cross-sectional. I review this literature in Chapter 1. I then present three empirical chapters which provide both longitudinal data and comparisons between observations, surveys, and SNA: Chapter 2, with two observational studies of seating patterns in a diverse sixth form cafeteria (Studies 1 and 2), and a third observational study in a diverse secondary school (Study 3); Chapter 3, where I report an SNA study collected from the first-year students at the same secondary school (Study 4); and Chapter 4, where I report the results from a self-report survey in the sixth form college, where students indicate their cafeteria seating preferences (Study 5). In Chapter 5, I discuss these findings, summarising 1) the strong self-segregation, and inclination towards self-segregation, found in all studies; 2) the comparisons between the two educational settings, where younger students were both more likely to be gender segregated, and to increase in ethnic integration over time; 3) the greater inclination of Asian British students than White British students to ethnically integrate; and 4) the need for further research triangulating multiple methods. From these conclusions, I suggest implications for targeted interventions, and argue the continued (and indeed, heightened) need for the contributions of social psychologists in public and policy discourse on ethnic integration

Infection control, genetic assessment of drug resistance and drug susceptibility testing in the current management of multidrug/extensively-resistant tuberculosis (M/XDR-TB) in Europe: A tuberculosis network European Trialsgroup (TBNET) study

Aim Europe has the highest documented caseload and greatest increase in multidrug and extensively drug-resistant tuberculosis (M/XDR-TB) of all World Health Organization (WHO) regions. This survey examines how recommendations for M/XDR-TB management are being implemented. Methods TBNET is a pan-European clinical research collaboration for tuberculosis. An email survey of TBNET members collected data in relation to infection control, access to molecular tests and basic microbiology with drug sensitivity testing. Results 68/105 responses gave valid information and were from countries within the WHO European Region. Inpatient beds matched demand, but single rooms with negative pressure were only available in low incidence countries; ultraviolet decontamination was used in 5 sites, all with >10 patients with M/XDR-TB per year. Molecular tests for mutations associated with rifampicin resistance were widely available (88%), even in lower income and especially in high incidence countries. Molecular tests for other first line and second line drugs were less accessible (76 and 52% respectively). A third of physicians considered that drug susceptibility results were delayed by > 2 months. Conclusion Infection control for inpatients with M/XDR-TB remains a problem in high incidence countries. Rifampicin resistance is readily detected, but tests to plan regimens tailored to the drug susceptibilities of the strain of Mycobacterium tuberculosis are significantly delayed, allowing for further drug resistance to develop

Communication through Reordering of Resources: Capacity Results and Trellis Code Design

We define protocol coding as a way to encode information in the actions taken by a communication protocol. In this work we investigate strategies for protocol coding via combinatorial ordering of the labelled user resources (packets, channels) in an existing, primary system. This introduces a new, secondary communication channel in the existing system, which has been considered in the prior work exclusively in a steganographic context. Instead, we focus on the use of secondary channel for reliable communication with newly introduced secondary devices, that are low-complexity versions of the primary devices, capable only to decode the robustly encoded header information in the primary signals. We introduce a suitable communication model, capable to capture the constraints that the primary system puts on protocol coding. We derive the capacity of the secondary channel under arbitrary error models. The insights from the information–theoretic analysis are used to design practical error–correcting schemes for secondary channels based on trellis codes

If not a fake, what’s in the lake?

AbstractAn animal dubbed ‘Champ’ has been sighted by hundreds of eyewitnesses in a large, near-oligotrophic lake in North America. A widely-publicised photograph taken by Mansi purportedly depicting the animal was published to much fanfare. In the present study, sightings were coded and analysed using interrupted time-series models, Pearson correlation coefficients, and descriptive statistics. The number of sightings per year was statistically significantly higher after publication of the Mansi photograph compared to before, which may be evidence of expectant attention, or publicity leading to more lake-goers and therefore more animal sightings. Sightings were consistent in condition (mostly Summer, from Noon to Evening, &gt; 1 witness, and a calm lake surface) which may be interpreted as consistency of when lake-goers visit Champlain, or as evidence of consistent behavioural characteristics of Champ animals. Sightings were highly inconsistent in reported Champ characteristics with widely varying morphology, and most sightings were missing morphological data entirely. More than a quarter of sightings were likened to logs, land mammals, birds, fish, and boats, which are all found in the lake. There were no associations between distance to sighting, estimated length, and estimated height of objects witnessed, which may suggest that eyewitnesses provide inaccurate estimates of these measurements in lake settings. If not a fake, what’s in the lake may be ordinary phenomena mistaken for Champ. Alternatively, Lake Champlain is inhabited by as-yet undiscovered multi-humped, dark-coloured serpents approximately seven meters in length, which locomote in a fast and sinuous fashion, and which enjoy pleasant Summer evenings and crowds. Deciding which explanation best accounts for the data is left as an exercise for the reader.</jats:p

Supplemental materials for paper: Fast or slow, how long can snakes grow?

Model code and data corresponding to article 'Fast or slow, how long can snakes grow?

Supplemental materials for paper: A Treatise on the Rilke Cryptogram

An updated full-text transcription of the 'Rilke Cryptogram

Iron Abundance in the Solar Photosphere: The Role of Ions, Non-LTE, Model Atmospheres, Oscillator Strengths, and Free Parameters

Abstract The photospheric iron abundance is important to understanding solar system formation and evolution, but methodological designs in the literature have produced significantly different abundance estimates. 315 original photospheric iron abundances were extracted from 70 primary publications identified through SAO/NASA Astrophysics Data System and Google Scholar. Methodological characteristics corresponding to each abundance estimate were categorised, including the ion studied, local thermodynamic equilibrium (LTE) assumption, the atmospheric model and its dimensions, the source of oscillator strengths, and microturbulence velocity. A linear mixed-effects regression model was implemented to quantify the role these variables play in abundance estimates. The mean photospheric iron abundance across all sources was 7.44 ± 0.02 dex on the astronomical log scale. On the average, abundance estimates from Fe II lines were 0.106 dex higher than those from Fe I lines (main effect), after controlling for other factors. Compared to LTE estimates, NLTE estimates were higher by 0.098 dex (main effect). The role of LTE was different for neutral and ionised iron analyses. LTE abundance predictions were lower than NLTE predictions for Fe I, but higher than NLTE predictions for Fe II. Other differences are described for various model atmospheres and oscillator strengths. A subgroup analysis of 257 1D and &lt;3D&gt; model abundances suggests every 0.1 km s−1 increase in the microturbulence velocity parameter results in a 0.04 dex decrease in estimated abundance. These findings explain much of the differences in photospheric iron abundance estimates over time.</jats:p