Mathematical Modelling of Chemical Diffusion through Skin using Grid-based PSEs

A Problem Solving Environment (PSE) with connections to remote distributed Grid processes is developed. The Grid simulation is itself a parallel process and allows steering of individual or multiple runs of the core computation of chemical diffusion through the stratum corneum, the outer layer of the skin. The effectiveness of this Grid-based approach in improving the quality of the simulation is assessed

Using EcoYieldSAFE to compare soil carbon dynamics under future climate in two contrasting agroforestry systems

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The impacts of feral boar on woodland flora and fauna in Great Britain

Mayle, B., Harmer, R., Kewitt, A., Peace, A., Straw, N., Williams, D., Upson, M

Where does prepotency come from on developmental tests of inhibitory control?

Understanding the processes that make responses prepotent is central to understanding the role of inhibitory control in cognitive development. The question of what makes responses prepotent was investigated using the two most widely studied measures of preschoolers' inhibitory control. Across two experiments, 80 children were tested either on a series of stimulus-response compatibility (SRC) tasks or on a series of Go/No-go tasks. Results indicated that high levels of prepotency on SRC tasks (such as the Day/Night task) occur only under specific conditions; making a verbal response can be highly prepotent if the stimulus and response are associated with each other (e.g., saying "cup" to a cup) but is less prepotent when they are unassociated (e.g., saying "cup" to a doorstop). Action responses (e.g., lifting a cup to your mouth) show little prepotency irrespective of whether the stimulus and response are associated. In contrast, with Go/No-go tasks, a much wider variety of behaviors are highly prepotent regardless of whether the stimulus and response are associated. These data suggest that prepotency arises in very different ways, depending on the type of task used. Although both Go/No-go tasks and SRC tasks can make inhibitory demands, they do so for fundamentally different reasons

Deficient calcium, zinc, and iron intake on absorption of cadmium from diet

Background/Aim: In vitro and in vivo studies have demonstrated that deficient calcium, zinc, and iron dietary intake upregulates metal ion transporters to increase intestinal absorption. However, these gut transporters are not specific and bind to other metals, including cadmium. Few human studies have investigated whether deficient calcium, zinc, and iron intake increases intestinal absorption of dietary cadmium. Methods: We used enrollment data (2010-2012) from the Study of Environment, Lifestyle & Fibroids, a cohort of 1693 African American women ages 23-35 who reside in the Detroit, Michigan area. Whole blood cadmium concentrations (proxy for cadmium absorption) were measured in 1548 participants. Dietary and supplemental calcium, zinc, and iron intake was estimated using Block 2005 Food Frequency Questionnaire data; deficient intake was defined as <80% of the recommended daily allowance. Daily dietary intake of total grains was used as the proxy for dietary cadmium intake as grains are a major source of cadmium exposure in U.S. diet. We estimated the percent difference in blood cadmium concentrations per median daily intake of total grains (4.55 ounce equivalents) using multivariable linear regression, stratified by deficient and sufficient calcium, zinc, and/or iron intake. We restricted the analyses to never smokers with plausible values for total energy intake (>400 and <5000 kcal/day) (n=1087). We adjusted for age at enrollment, total energy intake, body mass index, height, education, and natural log-transformed blood lead concentrations. Results: The observed percent difference in blood cadmium concentrations in relation to intake of total grains was stronger among those with deficient intake of calcium, zinc, and/or iron (28%, 95% CI; 6, 53%) than among those with sufficient intake of all 3 essential nutrients (5%, 95% CI: -7, 19%). Conclusions: Our preliminary findings suggest that women with deficient calcium, zinc, and/or iron intake have increased absorption of cadmium from the diet

Integrating belowground carbon dynamics into Yield-SAFE, a parameter sparse agroforestry model

Agroforestry combines perennial woody elements (e.g. trees) with an agricultural understory (e.g. wheat, pasture) which can also potentially be used by a livestock component. In recent decades, modern agroforestry systems have been proposed at European level as land use alternatives for conventional agricultural systems. The potential range of benefits that modern agroforestry systems can provide includes farm product diversification (food and timber), soil and biodiversity conservation and carbon sequestration, both in woody biomass and the soil. Whilst typically these include benefits such as food and timber provision, potentially, there are benefits in the form of carbon sequestration, both in woody biomass and in the soil. Quantifying the effect of agroforestry systems on soil carbon is important because it is one means by which atmospheric carbon can be sequestered in order to reduce global warming. However, experimental systems that can combine the different alternative features of agroforestry systems are difficult to implement and long-term. For this reason, models are needed to explore these alternatives, in order to determine what benefits different combinations of trees and understory might provide in agroforestry systems. This paper describes the integration of the widely used soil carbon model RothC, a model simulating soil organic carbon turnover, into Yield-SAFE, a parameter sparse model to estimate aboveground biomass in agroforestry systems. The improvement of the Yield-SAFE model focused on the estimation of input plant material into soil (i.e. leaf fall and root mortality) while maintaining the original aspiration for a simple conceptualization of agroforestry modeling, but allowing to feed inputs to a soil carbon module based on RothC. Validation simulations show that the combined model gives predictions consistent with observed data for both SOC dynamics and tree leaf fall. Two case study systems are examined: a cork oak system in South Portugal and a poplar system in the UK, in current and future climate. (c) 2017, Springer Science+Business Media B.V.European Commission through the AGFORWARD FP7 research Project (contract 613520), Forest Research Center strategic Project (PEst OE/AGR/UI0239/2014), the Portuguese Foundation for Science and Technology (FCT) fellowships SFRH/BD/52691/2014 and SFRH/BPD/96475/2013, XUNTA DE GALICIA, Consellería de Cultura, Educación e Ordenación Universitaria (“Programa de axudas á etapa posdoutoral”) (contract ED481B 2016/071-0

Biomimetic Properties of Force-spun PHBV Membranes Functionalised with Collagen as Substrates for Biomedical Application

The force-spinning process parameters (i.e., spin speed, spinneret-collector distance, and polymer concentration), optimised and characterised in previous work by this group, allowed the rapid fabrication of large quantities of high surface area poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHBV) polymeric fibre membranes. This paper examined the potential application for force-spun PHBV fibres functionalised with type I collagen for tissue regeneration applications. PHBV fibre scaffolds provide a biologically suitable substrate to guide the regeneration of dermal tissues, however, have poor cellular adhesion properties. The grafting of collagen type-I to PHBV fibres demonstrated improved cell adhesion and growth in Neo-NHDF (neonatal human dermal fibroblasts) fibroblasts. The examination of fibre morphology, thermal properties, collagen content, and degradability was used to contrast the physicochemical properties of the PHBV and PHBV-Collagen fibres. Biodegradation models using phosphate buffered saline determined there was no appreciable change in mass over the course of 6 weeks; a Sirius Red assay was performed on degraded samples, showing no change in the quantity of collagen. Cell metabolism studies showed an increase in cell metabolism on conjugated samples after three and 7 days. In addition, in vitro cytocompatibility studies demonstrated superior cell activity and adhesion on conjugated samples over 7 days

Routine activities and proactive police activity: a macro-scale analysis of police searches in London and New York City

This paper explored how city-level changes in routine activities were associated with changes in frequencies of police searches using six years of police records from the London Metropolitan Police Service and the New York City Police Department. Routine activities were operationalised through selecting events that potentially impacted on (a) the street population, (b) the frequency of crime or (c) the level of police activity. OLS regression results indicated that routine activity variables (e.g. day of the week, periods of high demand for police service) can explain a large proportion of the variance in search frequency throughout the year. A complex set of results emerged, revealing cross-national dissimilarities and the differential impact of certain activities (e.g. public holidays). Importantly, temporal frequencies in searches are not reducible to associations between searches and recorded street crime, nor changes in on-street population. Based on the routine activity approach, a theoretical police-action model is proposed