Empirical Agent-Based Modelling for exploring Intergroup Contact in a Segregated Society

Agent-based modelling has a long history of application in the study of segregation, but is rarely deployed beyond the examination of residential segregation. This study leverages multiple datasets: including census, survey, PGIS and GPS traces; in order to create an empirical agent-based model for the exploration of mobility practices between segregated communities in Belfast (Northern Ireland). In doing so, we are able to conduct novel examinations into the impact of day-to-day mobility choices upon intergroup attitudes and activity-space segregation; with policy implications for understanding and combatting segregation in cities around the world

Negotiating the Ground: ‘Mobilizing’ a Divided Field Site in the ‘Post-Conflict’ City

While an exploration of mobility patterns in ‘post-conflict’ societies has much to tell us about how division is produced through ordinary activities, less work has considered the practical application of a mobilities ‘lens’ during fieldwork in such contexts. Negotiating the ground in highly polarized contexts presents a unique array of challenges, but also offers opportunities to make use of mobile methodologies. This paper discusses the advantages of GPS-based technologies and walking interviews to a recent activity-space segregation study in Belfast, Northern Ireland, and reflects on methodological issues posed by the ‘post-conflict’ field site

Parallel lives: Intergroup contact, threat and the segregation of everyday activity spaces

Although intergroup contact can reduce prejudice, opportunities to experience such contact are often constrained by systems of segregation. Work on this problem has focused on divisions entrenched within institutions of residence, education and employment. Our research employed a complementary approach, which treated segregation as the outcome of individuals’ movements over time within everyday life spaces. Taking as a case study Catholics’ and Protestants’ use of public environments in north Belfast, we used GPS tracking technology, combined with GIS analytics, to explore the time geography of residents’ activity space use over a two-week period (Study 1). We also conducted a field survey to explore how psychological factors shaped their willingness to use activity spaces beyond their own communities (Study 2). Analysis based on around 1000 hours of raw movement data revealed that north Belfast is marked by high levels of segregation, expressed via residents’ limited use of public spaces, facilities and pathways located in outgroup areas. However, use of shared spaces is also common, with Catholics spending more time in such spaces than Protestants. Structural equation modelling suggested that residents’ self-reported willingness to use activity spaces outside their own communities was associated with both negative and positive intergroup contact - relationships partially mediated by realistic threat, symbolic threat, and anxiety over interaction across sectarian lines. Both kinds of contact and realistic threat were also associated with the time residents actually spent in spaces beyond their own communities. Opportunities for integrating psychological and geographic research on contact and segregation are highlighted

Networks of (Dis)connection: Mobility Practices, Tertiary Streets and Sectarian Divisions in North Belfast

Long-standing tensions between Protestant and Catholic communities in Northern Ireland have led to high levels of segregation. This article explores the spaces within which residents of north Belfast move within everyday life and the extent to which these are influenced by segregation. We focus in particular on the role that interconnecting tertiary streets have on patterns of mobility. We adapt Grannis’s (1998) concept to define T-communities from sets of interconnecting tertiary streets within north Belfast. These are combined with more than 6,000 Global Positioning System (GPS) tracks collected from local residents to assess the amount of time spent within different spaces. Spaces are divided into areas of residents’ own community affiliations (in-group), areas not clearly associated with either community (mixed), or areas of opposing community affiliation (out-group). We further differentiate space as being either within a T-community or along a section of main road. Our work extends research on T-communities by expanding their role beyond exploring residential preference, to explore, instead, networks of (dis)connection through which social divisions are expressed via everyday mobility practices. We conclude that residents are significantly less likely to move within mixed and out-group areas and that this is especially true within T-communities. It is also evident that residents are more likely to travel along out-group sections of a main road if they are in a vehicle and that women show no greater likelihood than men to move within out-group space. Evidence from GPS tracks also provides insights into some areas where mixing appears to occur

Fuzzy Bayesian inference for mapping vague and place-based regions:a case study of sectarian territory

The problem of mapping regions with socially-derived boundaries has been a topic of discussion in the GIS literature for many years. Fuzzy approaches have frequently been suggested as solutions, but none have been adopted. This is likely due to difficulties associated with determining suitable membership functions, which are often as arbitrary as the crisp boundaries that they seek to replace. This paper presents a novel approach to fuzzy geographical modelling that replaces the membership function with a possibility distribution that is estimated using Bayesian inference. In this method, data from multiple sources are combined to estimate the degree to which a given location is a member of a given set and the level of uncertainty associated with that estimate. The Fuzzy Bayesian Inference approach is demonstrated through a case study in which census data are combined with perceptual and behavioural evidence to model the territory of two segregated groups (Catholics and Protestants) in Belfast, Northern Ireland, UK. This novel method provides a robust empirical basis for the use of fuzzy models in GIS, and therefore has applications for mapping a range of socially-derived and otherwise vague boundaries

Ab Initio Screening Approach for the Discovery of Lignin Polymer Breaking Pathways

The directed depolymerization of lignin biopolymers is of utmost relevance for the valorization or commercialization of biomass fuels. We present a computational and theoretical screening approach to identify potential cleavage pathways and resulting fragments that are formed during depolymerization of lignin oligomers containing two to six monomers. We have developed a chemical discovery technique to identify the chemically relevant putative fragments in eight known polymeric linkage types of lignin. Obtaining these structures is a crucial precursor to the development of any further kinetic modeling. We have developed this approach by adapting steered molecular dynamics calculations under constant force and varying the points of applied force in the molecule to diversify the screening approach. Key observations include relationships between abundance and breaking frequency, the relative diversity of potential pathways for a given linkage, and the observation that readily cleaved bonds can destabilize adjacent bonds, causing subsequent automatic cleavage.Massachusetts Institute of Technology (Research Support Corporation, Reed Grant)United States. Dept. of Energy. Computational Science Graduate Fellowship Program (DOE-CSGF)Burroughs Wellcome Fund (Career Award at the Scientific Interface

Preclinical evaluation of a TEX101 protein ELISA test for the differential diagnosis of male infertility

BACKGROUND: TEX101 is a cell membrane protein exclusively expressed by testicular germ cells and shed into seminal plasma. We previously verified human TEX101 as a biomarker for the differential diagnosis of azoospermia, and developed a first-of-its-kind TEX101 ELISA. To demonstrate the clinical utility of TEX101, in this work we aimed at evaluating ELISA performance in a large population of fertile, subfertile, and infertile men. METHODS: Mass spectrometry, size-exclusion chromatography, ultracentrifugation, and immunohistochemistry were used to characterize TEX101 protein as an analyte in seminal plasma. Using the optimized protocol for seminal plasma pretreatment, TEX101 was measured by ELISA in 805 seminal plasma samples. RESULTS: We demonstrated that TEX101 was present in seminal plasma mostly in a free soluble form and that its small fraction was associated with seminal microvesicles. TEX101 median values were estimated in healthy, fertile pre-vasectomy men (5436 ng/mL, N = 64) and in patients with unexplained infertility (4967 ng/mL, N = 277), oligospermia (450 ng/mL, N = 270), and azoospermia (0.5 ng/mL, N = 137). Fertile post-vasectomy men (N = 57) and patients with Sertoli cell-only syndrome (N = 13) and obstructive azoospermia (N = 36) had undetectable levels of TEX101 (≤0.5 ng/mL). A cut-off value of 0.9 ng/mL provided 100% sensitivity at 100% specificity for distinguishing pre- and post-vasectomy men. The combination of a concentration of TEX101 > 0.9 ng/mL and epididymis-specific protein ECM1 > 2.3 μg/mL provided 81% sensitivity at 100% specificity for differentiating between non-obstructive and obstructive azoospermia, thus eliminating the majority of diagnostic testicular biopsies. In addition, a cut-off value of ≥0.6 ng/mL provided 73% sensitivity at 64% specificity for predicting sperm or spermatid retrieval in patients with non-obstructive azoospermia. CONCLUSIONS: We demonstrated the clinical utility of TEX101 ELISA as a test to evaluate vasectomy success, to stratify azoospermia forms, and to better select patients for sperm retrieval. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12916-017-0817-5) contains supplementary material, which is available to authorized users