Panel on future challenges in modeling methodology

This panel paper presents the views of six researchers and practitioners of simulation modeling. Collectively we attempt to address a range of key future challenges to modeling methodology. It is hoped that the views of this paper, and the presentations made by the panelists at the 2004 Winter Simulation Conference will raise awareness and stimulate further discussion on the future of modeling methodology in areas such as modeling problems in business applications, human factors and geographically dispersed networks; rapid model development and maintenance; legacy modeling approaches; markup languages; virtual interactive process design and simulation; standards; and Grid computing

Allergic gastroenteritis hospital admission time trends in Australia and New Zealand

AIM: Recent epidemiological studies indicate increases in hospital food allergy-related anaphylaxis admission rates in Australian and New Zealand. The aim of the study was to examine whether non-IgE-mediated food allergy might have increased in parallel. METHODS: We analysed childhood hospital admissions rates by ICD 10 codes for allergic gastroenteritis (AG) and infective gastroenteritis in Australia and New Zealand between June 1998 and July 2014. RESULTS: In Australia, most AG-related admissions (73%) occurred in those aged <1 year and increased by 7.3%/year (95% confidence interval (CI) 5.5-9.3, P < 0.0001) from 6.8 to 26.5/10(5) population. Similar trends were observed for New Zealand; 81% of admissions occurred in those aged <1 year and increased by 9.4%/year (95% CI 5.5-9.3, P < 0.0001) from 7.2 to 30.7/10(5) population. By contrast there were no significant changes in AG-related admission rates in the older patients and infective gastroenteritis admissions fell in both countries in those aged <1 year; Australia by 4.4%/year (95% CI 4.3-4.6, P < 0.0001) and in New Zealand by 5.8%/year (95% CI 5.4-6.2, P < 0.0001). CONCLUSION: We observed a fourfold increase in AG-related admission rates in two countries with known high rates of IgE-mediated food allergy/anaphylaxis. If confirmed by other studies, it will be of interest to determine if factors thought to contribute to the increase in IgE-mediated food allergy might also play a role in non-IgE-mediated gastroenterological food allergy syndromes

Biomolecular composition of capping layer and stability of biogenic selenium nanoparticles synthesized by five bacterial species

Biogenic metal/metalloid nanoparticles of microbial origin retain a functional biomolecular capping layer that confers structural stability. Little is known about the composition of such capping material. In this study, selenium nanoparticles (SeNPs) synthesized by five different bacterial strains underwent comparative analysis with newly proposed protocols for quantifying the concentration of carbohydrates, proteins and lipids present in capping layers. SeNPs were therefore treated with two different detergents to remove portions of the surrounding caps in order to assess the resulting effects. Capping material quantification was carried out along with the measure of parameters such as hydrodynamic diameter, polydispersity and surface charge. SeNPs from the five strains showed differences in their distinct biomolecule ratios. On the other hand, structural changes in the nanoparticles induced by detergents did not correlate with the amounts of capping matrix removed. Thus, the present investigation suggests a hypothesis to describe capping layer composition of the bacterial SeNPs: some biomolecules are bound more strongly than others to the core metalloid matrix, so that the diverse capping layer components differentially contribute to the overall structural characteristics of the nanoparticles. Furthermore, the application of the approach here in combining quantification of cap-associated biomolecules with the measurement of structural integrity-related parameters can give the biogenic nanomaterial field useful information to construct a data bank on biogenically synthesized nanostructures

Next Generation Sequencing Assay for Detection of Circulating HPV DNA (cHPV-DNA) in Patients Undergoing Radical (Chemo)Radiotherapy in Anal Squamous Cell Carcinoma (ASCC).

Background: Following chemo-radiotherapy (CRT) for human papilloma virus positive (HPV+) anal squamous cell carcinoma (ASCC), detection of residual/recurrent disease is challenging. Patients frequently undergo unnecessary repeated biopsies for abnormal MRI/clinical findings. In a pilot study we assessed the role of circulating HPV-DNA in identifying "true" residual disease. Methods: We prospectively collected plasma samples at baseline (n = 21) and 12 weeks post-CRT (n = 17). Circulating HPV-DNA (cHPV DNA) was measured using a novel next generation sequencing (NGS) assay, panHPV-detect, comprising of two primer pools covering distinct regions of eight high-risk HPV genomes (16, 18, 31, 33, 35, 45, 52, and 58) to detect circulating HPV-DNA (cHPV DNA). cHPV-DNA levels post-CRT were correlated to disease response. Results: In pre-CRT samples, panHPV-detect demonstrated 100% sensitivity and specificity for HPV associated ASCC. PanHPV-detect was able to demonstrate cHPV-DNA in 100% (9/9) patients with T1/T2N0 cancers. cHPV-DNA was detectable 12 weeks post CRT in just 2/17 patients, both of whom relapsed. 1/16 patients who had a clinical complete response (CR) at 3 months post-CRT but relapsed at 9 months and 1/1 patient with a partial response (PR). PanHPV-detect demonstrated 100% sensitivity and specificity in predicting response to CRT. Conclusion: We demonstrate that panHPV-detect, an NSG assay is a highly sensitive and specific test for the identification of cHPV-DNA in plasma at diagnosis. cHPV-DNA post-treatment may predict clinical response to CRT

Interpreting radiative efficiency in radio-loud AGNs

Author submitted version of unrefereed Nature Astronomy comment. Version in journal format available at https://rdcu.be/KH6WRadiative efficiency in radio-loud active galactic nuclei is governed by the accretion rate onto the central black hole rather than directly by the type of accreted matter; while it correlates with real differences in host galaxies and environments, it does not provide unambiguous information about particular objects.Non peer reviewedFinal Accepted Versio

Microplastic transport and deposition in a beach-dune system (Saunton Sands-Braunton Burrows, southwest England)

Although microplastics (MPs) are ubiquitous contaminants that have been extensively studied in the marine setting, there remain gaps in our understanding of their transport and fate in the coastal zone. In this study, MPs isolated from surface sediments sampled from a large beach-dune complex in southwest England have been quantified and characterised. Concentrations above a detectable size limit of 30 to 50 μm ranged from about 40 to 560 MP kg-1 dry weight but, despite local sources of plastics such as an estuary and seasonal tourism, there were no significant differences in median concentrations between different orthogonal foreshore transects and the dunes or according to zonal location on the beach. The majority of MPs were black and blue fibres of  1 g cm-3 (e.g., rayon, polyester, acrylic). A significant correlation was found between MP concentration and the proportion of very fine sand (100 to 250 μm) but relationships with other granulometric or compositional markers of sediment (e.g., volume-weighted mean diameter, circularity, calcium content) were not evident. An association of MP concentration with very fine sand was attributed to similar particle depositional characteristics and the entrapment of fibres within small interstitial spaces. Overall, the observations reflect the wavelaid and windlaid deposition of MPs from a diffuse, offshore source, and, despite their role as accumulators of particles from the foreshore, dunes do not appear to act as a landward barrier of MPs