A Bayesian spatial random effects model characterisation of tumour heterogeneity implemented using Markov chain Monte Carlo (MCMC) simulation

The focus of this study is the development of a statistical modelling procedure for characterising intra-tumour heterogeneity, motivated by recent clinical literature indicating that a variety of tumours exhibit a considerable degree of genetic spatial variability. A formal spatial statistical model has been developed and used to characterise the structural heterogeneity of a number of supratentorial primitive neuroecto-dermal tumours (PNETs), based on diffusionweighted magnetic resonance imaging. Particular attention is paid to the spatial dependence of diffusion close to the tumour boundary, in order to determine whether the data provide statistical evidence to support the proposition that water diffusivity in the boundary region of some tumours exhibits a deterministic dependence on distance from the boundary, in excess of an underlying random 2D spatial heterogeneity in diffusion. Tumour spatial heterogeneity measures were derived from the diffusion parameter estimates obtained using a Bayesian spatial random effects model. The analyses were implemented using Markov chain Monte Carlo (MCMC) simulation. Posterior predictive simulation was used to assess the adequacy of the statistical model. The main observations are that the previously reported relationship between diffusion and boundary proximity remains observable and achieves statistical significance after adjusting for an underlying random 2D spatial heterogeneity in the diffusion model parameters. A comparison of the magnitude of the boundary-distance effect with the underlying random 2D boundary heterogeneity suggests that both are important sources of variation in the vicinity of the boundary. No consistent pattern emerges from a comparison of the boundary and core spatial heterogeneity, with no indication of a consistently greater level of heterogeneity in one region compared with the other. The results raise the possibility that DWI might provide a surrogate marker of intra-tumour genetic regional heterogeneity, which would provide a powerful tool with applications in both patient management and in cancer research

From adolescent to adult gambling: an analysis of longitudinal gambling patterns in South Australia [forthcoming]

Although there are many cross-sectional studies of adolescent gambling, very few longitudinal investigations have been undertaken. As a result, little is known about the individual stability of gambling behaviour and the extent to which behaviour measured during adolescence is related to adult behaviour. In this paper, we report the results of a 4-wave longitudinal investigation of gambling behaviour in a probability sample of 256 young people (50% male, 50% female) who were interviewed in 2005 at the age of 16-18 years and then followed through to the age of 20-21 years. The results indicated that young people showed little stability in their gambling. Relatively few reported gambling on the same individual activities consistently over time. Gambling participation rates increased rapidly as young people made the transition from adolescence to adulthood and then were generally more stable. Gambling at 15-16 years was generally not associated with gambling at age 20-21 years. These results highlight the importance of individual-level analyses when examining gambling patterns over time

The role of structural characteristics in problem video game playing: a review

The structural characteristics of video games may play an important role in explaining why some people play video games to excess. This paper provides a review of the literature on structural features of video games and the psychological experience of playing video games. The dominant view of the appeal of video games is based on operant conditioning theory and the notion that video games satisfy various needs for social interaction and belonging. However, there is a lack of experimental and longitudinal data that assesses the importance of specific features in video games in excessive video game playing. Various challenges in studying the structural features of video games are discussed. Potential directions for future research are outlined, notably the need to identify what problem (as opposed to casual) players seek from the video games they play

Prevalence of Asthma Severities in Children and Adolescents in a Wilmington, DE Hospital

Asthma affects over 24 million individuals in the US and the prevalence of the condition is increasing in the US and worldwide. The prevalence of severe persistent asthma, which incurs a significant health and economic burden, is still poorly understood in children and adolescents. We aimed to define the prevalence of asthma severities in children and adolescents in an urban hospital setting as a function of age, sex, race, and ethnicity by assessing prescribed medications as a proxy for asthma severity according to NIH guidelines for care. We found that a plurality of patients across all age groups, sexes, races, and ethnicities were severe persistent asthmatics. We also found that younger individuals as well as those who are African American have higher odds of being moderate to severe asthmatics. This information can be used to generate hypotheses for future studies and can be used to better address patient needs. In addition, these results suggest that a health disparity among African Americans exists that is consistent with other aspects of the condition. To reduce the prevalence of asthma in all populations, future research should place a greater emphasis on identifying more indicative risk factors for prevention, finding strategies to identify asthma at an earlier age, and developing more effective and personalized therapeutics

Memoryscapes of the homeland by two generations of British Bangladeshis

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When migrants become hosts and nonmigrants become mobile: Bangladeshis visiting their friends and relatives in London

Most studies of migrants visiting their friends and relatives (VFR) are on homeland visits. In this article, we reverse the transnational optic and study nonmigrants from the country of origin visiting their migrated friends and relatives abroad. We draw on participant observation and 57 interviews with migrant hosts and nonmigrant visitors carried out in London and in the Sylhet region of Bangladesh. Visits from the homeland to the diaspora are found to be deeply meaningful for the maintenance of transnational familyhood, especially at critical moments such as weddings, childbirth, and end of life. They are performative acts of belonging with unwritten rules of mutual obligations and choreographed itineraries to the houses of relatives and friends and to tourist sites. They also represent inequalities in economic status and social mobility between the migrants and their left‐behind relatives and friends in Bangladesh. Most visits are enjoyable for all concerned, but subtle tensions can arise, for instance, in the hosts' difficulty in managing their ongoing working lives with duties of hospitality and acting as guides and in visitors' intense schedule of duty visits to many relatives and lack of agency in stepping out of the Bangladeshi community in London. Furthermore, in an increasingly hostile environment for getting visas to visit the United Kingdom, an unequal and inhumane situation arises of blocked mobility

Multiangle observations of Arctic clouds from FIRE ACE: June 3, 1998, case study

In May and June 1998 the Airborne Multiangle Imaging Spectroradiometer (AirMISR) participated in the FIRE Arctic Cloud Experiment (ACE). AirMISR is an airborne instrument for obtaining multiangle imagery similar to that of the satellite-borne MISR instrument. This paper presents a detailed analysis of the data collected on June 3, 1998. In particular, AirMISR radiance measurements are compared with measurements made by two other instruments, the Cloud Absorption Radiometer (CAR) and the MODIS airborne simulator (MAS), as well as to plane-parallel radiative transfer simulations. It is found that the AirMISR radiance measurements and albedo estimates compare favorably both with the other instruments and with the radiative transfer simulations. In addition to radiance and albedo, the multiangle AirMISR data can be used to obtain estimates of cloud top height using stereoimaging techniques. Comparison of AirMISR retrieved cloud top height (using the complete MISR-based stereoimaging approach) shows excellent agreement with the measurements from the airborne Cloud Lidar System (CLS) and ground-based millimeterwave cloud radar

The conceptualisation and measurement of DSM-5 Internet Gaming Disorder: the development of the IGD-20 Test

Background: Over the last decade, there has been growing concern about ‘gaming addiction’ and its widely documented detrimental impacts on a minority of individuals that play excessively. The latest (fifth) edition of the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-5) included nine criteria for the potential diagnosis of Internet Gaming Disorder (IGD) and noted that it was a condition that warranted further empirical study. Aim: The main aim of this study was to develop a valid and reliable standardised psychometrically robust tool in addition to providing empirically supported cut-off points. Methods: A sample of 1003 gamers (85.2% males; mean age 26 years) from 57 different countries were recruited via online gaming forums. Validity was assessed by confirmatory factor analysis (CFA), criterion-related validity, and concurrent validity. Latent profile analysis was also carried to distinguish disordered gamers from non-disordered gamers. Sensitivity and specificity analyses were performed to determine an empirical cut-off for the test. Results: The CFA confirmed the viability of IGD-20 Test with a six-factor structure (salience, mood modification, tolerance, withdrawal, conflict and relapse) for the assessment of IGD according to the nine criteria from DSM-5. The IGD-20 Test proved to be valid and reliable. According to the latent profile analysis, 5.3% of the total participants were classed as disordered gamers. Additionally, an optimal empirical cut-off of 71 points (out of 100) seemed to be adequate according to the sensitivity and specificity analyses carried

Internet pornography viewing preference as a risk factor for adolescent Internet addiction: the moderating role of classroom personality factors

Background and aims: Adolescent Internet pornography viewing has been significantly increased in the last decade with research highlighting its association with Internet addiction (IA). However, there is little longitudinal data on this topic, particularly in relation to peer context effects. This study aimed to examine age- and context-related variations in the Internet pornography–IA association. Methods: A total of 648 adolescents, from 34 classrooms, were assessed at 16 years and then at 18 years to examine the effect of Internet pornography preference on IA in relation to the classroom context. IA was assessed using the Internet Addiction Test (Young, 1998), Internet pornography preference (over other Internet applications) was assessed with a binary (yes/no) question, and classroom introversion and openness to experience (OTE) with the synonymous subscales within the Five Factor Questionnaire (Asendorpf & Van Aken, 2003). Results: Three-level hierarchical linear models were calculated. Findings showed that viewing Internet pornography exacerbates the risk of IA over time, while classroom factors, such as the average level of OTE and introversion, differentially moderate this relationship. Discussion and conclusion: The study demonstrated that the contribution of Internet pornography preference (as an IA risk factor) might be increased in more extroverted classrooms and decreased in OTE classrooms