Immersive virtual reality as a novel approach to investigate the association between adverse events and adolescent paranoid ideation.

PURPOSE: Paranoid ideation is common among adolescents, yet little is known about the precursors. Using a novel immersive virtual reality (VR) paradigm, we tested whether experiences of bullying, and other interpersonal/threatening events, are associated with paranoid ideation to a greater degree than other types of (i) non-interpersonal events or (ii) adverse childhood experiences. METHODS: Self-reported exposure to adverse life events and bullying was collected on 481 adolescents, aged 11-15. We used mixed effects (multilevel) linear regression to estimate the magnitude of associations between risk factors and paranoid ideation, assessed by means of adolescents' reactions to ambiguously behaving avatars in a VR school canteen, adjusting for putative confounders (gender, year group, ethnicity, free school meal status, place of birth, family mental health problems). RESULTS: Lifetime exposure to interpersonal/threatening events, but not non-interpersonal events or adverse circumstances, was associated with higher levels of state paranoid ideation, with further evidence that the effect was cumulative (1 type: ϐadj 0.07, 95% CI -0.01-0.14; 2 types: ϐadj 0.14, 95% CI 0.05-0.24; 3 + types: ϐadj 0.24, 95% CI 0.12-0.36). More tentatively, for girls, but not boys, recent bullying was associated with heightened paranoid ideation with effect estimates ranging from ϐadj 0.06 (95% CI -0.02-0.15) for physical bullying to ϐadj 0.21 (95% CI 0.10-0.32) for cyber bullying. CONCLUSIONS: Our data suggest a degree of specificity for adversities involving interpersonal threat or hostility, i.e. those that involve unwanted interference and/or attempted control of an individual's personal boundaries being associated with heightened levels of state paranoid ideation among adolescents.

Measuring coefficient of thermal expansion of materials of micrometre size using SEM/FIB microscope with in situ MEMS heating stage.

A new method is proposed to measure the linear coefficient of thermal expansion (CTE) of solid metals and ceramics of micron-sized dimensions. This approach uses a focused ion beam (FIB) to extract and transfer a slab of the sample, typically (15-20) ×10 × (3-5) µm onto a Micro-Electro-Mechanical Systems (MEMS) in situ heating holder inside a scanning electron microscope (SEM). CTE is thereafter calculated by image correlating the change of length (ΔL) between the fiducial marks on the slab as a function of temperature, taking advantage of the temperature calibration of the MEMS heating holder and nanometre resolution of the scanning electron microscope. The CTE results are validated to be consistent with standard copper and silicon. We further demonstrate the method on a graphene platelet reinforced copper composite and a graphite filler phase isolated from a bulk sample, these represent materials that cannot be practically synthesised or isolated at the macro-scale. Errors associated with the measurement are discussed.

Breakdown and Modification of Microplastic Beads by Aeolian Abrasion.

Saltation is an important wind erosion process that can cause the modification and breakdown of particles by aeolian abrasion. It is recognized that microplastic particles can be transported by wind, but the effect of saltation on microplastic properties is unknown. This study examined the impact of simulated saltation alongside quartz grains on the size, shape, and surface properties of spherical microplastic beads. The diameter of the microplastics was reduced by 30-50% over 240-300 h of abrasion with a mass loss of c. 80%. For abrasion periods up to 200 h, the microplastic beads remained spherical with minimal change to overall shape. Over 95% of the fragments of plastic removed from the surface of the microbeads during the abrasion process had a diameter of ≤10 µm. In addition, during the abrasion process, fine particles derived from breakdown of the quartz grains became attached to the surfaces of the microbeads resulting in a reduction in carbon and an increase in silicon detected on the particle surface. The results suggest that microplastics may be mechanically broken down during aeolian saltation and small fragments produced have the potential for long distance transport as well as being within the size range for human respiration.

Prevalence of conduct problems and social risk factors in ethnically diverse inner-city schools.

BACKGROUND: In the UK, around 5% of 11-16-year olds experience conduct problems of clinical importance. However, there are limited data on prevalence of conduct problems by ethnic group, and how putative social risk factors may explain any variations in prevalence. This study has two main aims: (1) to estimate the prevalence and nature of conduct problems overall, and by ethnic group and gender, among adolescents in diverse inner-city London schools; (2) to assess the extent to which putative risk factors - racial discrimination, socioeconomic status, parental control, and troublesome friends - explain any observed differences in prevalence of conduct problems between ethnic groups. METHODS: This study uses baseline data from REACH, an accelerated cohort study of adolescent mental health in inner-city London. Self-report questionnaire data were collected on conduct problems and a range of distinct putative social risk factors (including racial discrimination, free school meals, troublesome friends, and parental care and control). A total of 4353 pupils, 51% girls, aged 11-14 participated. We estimated prevalence of conduct problems and used multilevel logistic regression to examine differences by ethnicity and gender and associations with putative risk factors. RESULTS: Prevalence of conduct problems in inner-city schools was around three times higher than reported in national studies (i.e., 16% [95%CI: 15·2-17·5] vs. 5% [95%CI 4·6-5·9]). Compared with overall prevalence, conduct problems were lower among Indian/Pakistani/Bangladeshi (RR: 0.53 [95% CI:0.31-0.87]) and white British (RR: 0.65 [0.51-0.82]) groups, and higher among black Caribbean (RR: 1.39 [95%CI:1.19-1.62]) and mixed white and black (RR: 1.29 [95% CI: 1.02-1.60]) groups. Risk of conduct problems was higher among those who were exposed to racial discrimination compared with those who were not (RR: 1.95 [95% CI: 1.59-2.31]). CONCLUSIONS: Conduct problems are markedly more common in inner-city schools, and variations in the prevalence of conduct problems are, to some extent, rooted in modifiable social contexts and experiences, such as experiences of racial discrimination.

Development of a cost model for the production of carbon fibres.

Carbon fibre composites offer considerable potential for mass reduction in automotive applications. However, raw material cost is one of the major factors that constraints its extensive use in this mass market. Here we report a systematic study that presents the cost contributors by considering the entire process chain of the carbon fibre manufacturing. The sensitivity analysis revealed that the final cost of Polyacrylonitrile (PAN) precursor and carbon fibres were strongly influenced by tow size. It was observed that a prompt decrease in the precursor and carbon fibre cost per kg for tow sizes from 3k to 12k, later this decrement was gradual and almost became stable above 50k. Moreover, with an increase in tow size from 3k to 50k, the contribution of the precursor on the final carbon fibre cost decreased from 76.6% to 49.6%. On the other hand, the contribution of the other factors increased with increase in the tow size, for instance, labour (9.86%-17.78%), Energy (2.49%-6.48%) and Depreciation (6.11%-11.01%). Nevertheless, precursor holds the major share in determining the final price of the carbon fibres.

Testing the ability of the nonalcoholic fatty liver disease fibrosis score to predict 1-year all-cause hospital admission.

The nonalcoholic fatty liver disease fibrosis score (NFS) has been shown to be a cost-effective screening strategy in the primary care setting to determine when gastroenterology referral is needed, but NFS as a predictor of hospitalization within 1 year is uncertain. This retrospective observational cohort study involved 1803 patients with a diagnosis of nonalcoholic fatty liver disease or nonalcoholic steatohepatitis. The NFS was categorized into the following: low (less than -1.455), moderate (between -1.455 and 0.676), and high (>0.676). The average NFS score by hospital admission was -0.760, the average number of admissions was 1.81, and the median number of days to hospital admission was 135.8 days (45.5-363, 25th to 75th percentile). A univariate logistic regression model showed that NFS significantly predicted hospital admission (P = 0.007); however, a multivariate logistic regression model, after adjusting for hypertension and tobacco use, indicated that NFS was not significantly associated with hospital admission. Using the logistic regression model, hypertension predicted admission at low (P < 0.0001) and moderate (P = 0.0005) NFS. Using this same model, tobacco use also predicted admission at low (P < 0.0001) and moderate (P = 0.0002) NFS. The NFS should not be used to determine which patients are at increased risk of hospitalization.

Influence of rurality on diagnosing dementia in Australian general practice.

This article reviews the literature concerning barriers in making a diagnosis of dementia in general practice and examines these from a rural perspective. It is proposed that the increasing prevalence of dementia in coming years in Australia will be felt most keenly in rural communities where there are already shortages of GPs and dementia-specific services to manage growing demand. Evidence suggests that dementia is often not specifically diagnosed by GPs and that this is a global issue. There are many barriers to the diagnosis of dementia in general practice, including time constraints, diagnostic uncertainty, denial of symptoms by patients and families, and stigma. This review examines these barriers and their impact on making a dementia diagnosis from a rural general practice perspective. Identification of these practice issues and their influence on service delivery is essential to inform relevant policy decisions and to improve dementia management in rural general practice.

VEGF-Trap: a VEGF blocker with potent antitumor effects.

Vascular endothelial growth factor (VEGF) plays a critical role during normal embryonic angiogenesis and also in the pathological angiogenesis that occurs in a number of diseases, including cancer. Initial attempts to block VEGF by using a humanized monoclonal antibody are beginning to show promise in human cancer patients, underscoring the importance of optimizing VEGF blockade. Previous studies have found that one of the most effective ways to block the VEGF-signaling pathway is to prevent VEGF from binding to its normal receptors by administering decoy-soluble receptors. The highest-affinity VEGF blocker described to date is a soluble decoy receptor created by fusing the first three Ig domains of VEGF receptor 1 to an Ig constant region; however, this fusion protein has very poor in vivo pharmacokinetic properties. By determining the requirements to maintain high affinity while extending in vivo half life, we were able to engineer a very potent high-affinity VEGF blocker that has markedly enhanced pharmacokinetic properties. This VEGF-Trap effectively suppresses tumor growth and vascularization in vivo, resulting in stunted and almost completely avascular tumors. VEGF-Trap-mediated blockade may be superior to that achieved by other agents, such as monoclonal antibodies targeted against the VEGF receptor.