224 research outputs found
Quantifying gross vs. net agricultural land use change in Great Britain using the Integrated Administration and Control System
Land use change has impacts upon many natural processes, and is one of the key measures of anthropogenic disturbance on ecosystems. Agricultural land covers 70% of Great Britain's (GB) land surface and annually undergoes disturbance and change through farming practices such as crop rotation, ploughing and the planting and subsequent logging of forestry. It is important to quantify how much of GB's agricultural land undergoes such changes and what those changes are at an annual temporal resolution. Integrated Administration and Control System (IACS) data give annual snapshots of agricultural land use at the field level, allowing for high resolution spatiotemporal land use change studies at the national scale. Crucially, not only do the data allow for simple net change studies (total area change of a land use, in a specific areal unit) but also for gross change calculations (summation of all changes to and from a land use), meaning that both gains and losses to and from each land use category can be defined. In this study we analysed IACS data for GB from 2005 to 2013, and quantified gross change for over 90% of the agricultural area in GB for the first time. It was found that gross change totalled 63,500 km2 in GB compared to 20,600 km2 of net change, i.e. the real year-on-year change is, on average, three times larger than net change. This detailed information on nature of land use change allows for increased accuracy in modelling the impact of land use change on ecosystem processes and is directly applicable across EU member states, where collection of such survey data is a requirement. The modelled carbon flux associated with gross land use change was at times >100 Gg C y−1 larger than that based on net land use change for some land use transitions
Nitrogen deposition in the UK at 1 km resolution from 1990 to 2017
An atmospheric chemistry transport model (FRAME) is used here to calculate annual UK N deposition for the years 1990–2017, at a 1 km × 1 km resolution. Reactive nitrogen (N) deposition is a threat that can lead to adverse effects on the environment and human health. In Europe, substantial reductions in N deposition from nitrogen oxide emissions have been achieved in recent decades. This paper quantifies reductions in UK N deposition following the N emissions peak in 1990. In the UK, estimates of N deposition are typically available at a coarse spatial resolution (typically 5 km × 5 km grid resolution), and it is often difficult to compare estimates between years due to methodological changes in emission estimates. Through efforts to reduce emissions of N from industry, traffic, and agriculture, this study predicts that UK N deposition has reduced from 465 kt N in 1990 to 278 kt N in 2017. However, as part of this overall reduction, there are non-uniform changes for wet and dry deposition of reduced N (NHx) and oxidised N (NOy). In 2017, it is estimated 59 % of all N deposition is in the form of reduced N, a change from 35 % in 1990. This dataset uses 28 years of emissions data from 1990 to 2017 to produce the first long-term dataset of 28 years of N deposition at 1 km × 1 km resolution in the UK. Full data are available at https://doi.org/10.5285/9b203324-6b37-4e91-b028-e073b197fb9f (Tomlinson et al., 2020)
A model for slip and drag in turbulent flows over superhydrophobic surfaces with surfactant
International audienceSuperhydrophobic surfaces (SHSs) can reduce the friction drag in turbulent flows. In the laminar regime, it has been shown that trace amounts of surfactant can negate this drag reduction, at times rendering these surfaces no better than solid walls (Peaudecerf et al., Proc. Natl. Acad. Sci. USA 114(28), 7254-9, 2017). However, surfactant effects on the drag-reducing properties of SHSs have not yet been studied under turbulent flow conditions, where predicting the effects of surfactant in direct numerical simulations remains expensive by today’s standards. We present a model for turbulent flow inclusive of surfactant, in either a channel or boundary-layer configuration, over long but finite-length streamwise ridges that are periodic in the spanwise direction, with period and gas fraction . We adopt a technique based on a shifted log law to acquire an expression for the drag reduction. The average streamwise and spanwise slip lengths are derived by introducing a local laminar model within the viscous sublayer, whereby the effect of surfactant is modelled by modifying the average streamwise and spanwise slip lengths. Our model agrees with available laboratory experimental data from the literature when conditions are clean (surfactant-free), or when there are low surfactant levels. However, we find an appreciable drag increase for larger background surfactant concentrations that are characteristic of turbulent flows over SHSs for marine applications
Virtual Exploration of Safe Entry Zones in the Brainstem: Comprehensive Definition and Analysis of the Operative Approach
Background
Detailed and accurate understanding of intrinsic brainstem anatomy and the inter-relationship between its internal tracts and nuclei and external landmarks is of paramount importance for safe and effective brainstem surgery. Using anatomical models can be an important step in sharpening such understanding.
Objective
To show the applicability of our developed virtual 3D model in depicting the safe entry zones (SEZs) to the brainstem.
Methods
Accurate 3D virtual models of brainstem elements were created using high-resolution magnetic resonance imaging and computed tomography to depict brainstem SEZs.
Results
All the described SEZs to different aspects of the brainstem were successfully depicted using our 3D virtual models.
Conclusions
The virtual models provide an immersive experience of brainstem anatomy, allowing users to understand the intricacies of the microdissection that is necessary to appropriately traverse the brainstem nuclei and tracts toward a particular target. The models provide an unparalleled learning environment for illustrating SEZs into the brainstem that can be used for training and research
Modelling public health improvements as a result of air pollution control policies in the UK over four decades – 1970 to 2010
In much of the industrialised world, policy interventions to address the challenges of wide-spread air pollution as resulting from development and economic progress in the 2nd half of the 20th century have overall led to reductions in air pollution levels and related health effects since the 1970s. While overall improvements towards reducing health effects from ambient air pollution are recorded, comprehensive and consistent assessments of the long-term impact of policy interventions are still scarce. In this paper, we conduct a model assessment over a 40 year period of air pollution in the UK. In order to correct for the short and longer term variability of meteorological factors contributing to trends in ambient concentrations of priority air pollutants (nitrogen dioxide, sulphur dioxide, fine particulate matter and ozone), we use a fixed meteorological year for all model simulations. Hence, the modelled changes in air pollutant concentrations and related health effects are solely a function of the changes in emissions since 1970. These changes in emissions are primarily driven by policy interventions, ranging from phasing out of specific fuels or substances, to regulating the use of chemicals and driving the development of cleaner, more efficient technologies. Over the 40 year period, UK attributable mortality due to exposure to PM2.5 and NO2 have declined by 56% and 44% respectively, while ozone attributable respiratory mortality increased by 17% over the same period (however, with a slight decrease by 14% between 2000 and 2010)
Integrated guidance on the care of familial hypercholesterolaemia from the International FH Foundation.
Familial hypercholesterolaemia (FH) is a dominantly inherited disorder present from birth that markedly elevates plasma low-density lipoprotein (LDL) cholesterol and causes premature coronary heart disease. There are at least 20million people with FH worldwide, but the majority remain undetected and current treatment is often suboptimal. To address this major gap in coronary prevention we present, from an international perspective, consensus-based guidance on the care of FH. The guidance was generated from seminars and workshops held at an international symposium. The recommendations focus on the detection, diagnosis, assessment and management of FH in adults and children, and set guidelines for clinical purposes. They also refer to best practice for cascade screening and risk notifying and testing families for FH, including use of genetic testing. Guidance on treatment is based on risk stratification, management of non-cholesterol risk factors, and safe and effective use of LDL lowering therapies. Recommendations are given on lipoprotein apheresis. The use of emerging therapies for FH is also foreshadowed. This international guidance acknowledges evidence gaps, but aims to make the best use of contemporary practice and technology to achieve the best outcomes for the care of FH. It should accordingly be employed to inform clinical judgement and be adjusted for country-specific and local health care needs and resources
Integrated Guidance on the Care of Familial Hypercholesterolaemia from the International FH Foundation: Executive Summary
Familial hypercholesterolaemia (FH) is a dominantly inherited disorder present from birth that markedly elevates plasma low-density lipoprotein (LDL) cholesterol and causes premature coronary heart disease. There are at least 20 million people with FH worldwide, but the majority remains undetected and current treatment is often suboptimal. To address this major gap in coronary prevention we present, from an international perspective, consensus-based guidance on the care of FH. The guidance was generated from seminars and workshops held at an international symposium. The recommendations focus on the detection, diagnosis, assessment and management of FH in adults and children, and set guidelines for clinical purposes. They also refer to best practice for cascade screening and risk notifying and testing families for FH, including use of genetic testing. Guidance on treatment is based on risk stratification, management of non-cholesterol risk factors and safe and effective use of LDL lowering therapies. Recommendations are given on lipoprotein apheresis. The use of emerging therapies for FH is also foreshadowed. This international guidance acknowledges evidence gaps, but aims to make the best use of contemporary practice and technology to achieve the best outcomes for the care of FH. It should accordingly be employed to inform clinical judgment and be adjusted for country-specific and local healthcare needs and resources
The individual and combined effects of obesity- and ageing-induced systemic inflammation on human skeletal muscle properties.
BACKGROUND/OBJECTIVES: The purpose of this study was to determine whether circulating pro-inflammatory cytokines, elevated with increased fat mass and ageing, were associated with muscle properties in young and older people with variable adiposity. SUBJECTS/METHODS: Seventy-five young (18-49 yrs) and 67 older (50-80 yrs) healthy, untrained men and women (BMI: 17-49 kg/m(2)) performed isometric and isokinetic plantar flexor maximum voluntary contractions (MVCs). Volume (Vm), fascicle pennation angle (FPA), and physiological cross-sectional area (PCSA) of the gastrocnemius medialis (GM) muscle were measured using ultrasonography. Voluntary muscle activation (VA) was assessed using electrical stimulation. GM specific force was calculated as GM fascicle force/PCSA. Percentage body fat (BF%), body fat mass (BFM), and lean mass (BLM) were assessed using dual-energy X-ray absorptiometry. Serum concentration of 12 cytokines was measured using multiplex luminometry. RESULTS: Despite greater Vm, FPA, and PCSA (P0.05), while IL-8 correlated with VA in older but not young adults (r⩾0.378, P⩽0.027). TNF-alpha correlated with MVC, lean mass, GM FPA and maximum force in older adults (r⩾0.458; P⩽0.048). CONCLUSIONS: The age- and adiposity-dependent relationships found here provide evidence that circulating pro-inflammatory cytokines may play different roles in muscle remodelling according to the age and adiposity of the individual.International Journal of Obesity accepted article preview online, 29 August 2016. doi:10.1038/ijo.2016.151
Vascular endothelial growth factor-A165b prevents diabetic neuropathic pain and sensory neuronal degeneration
Diabetic peripheral neuropathy affects up to half of diabetic patients. This neuronal damage leads to sensory disturbances, including allodynia and hyperalgesia. Many growth factors have been suggested as useful treatments for prevention of neurodegeneration, including the vascular endothelial growth factor (VEGF) family. VEGF-A is generated as two alternative splice variant families. The most widely studied isoform, VEGF-A165a is both pro-angiogenic and neuroprotective, but pro-nociceptive and increases vascular permeability in animal models. Streptozotocin (STZ)-induced diabetic rats develop both hyperglycaemia and many of the resulting diabetic complications seen in patients, including peripheral neuropathy. In the present study, we show that the anti-angiogenic VEGF-A splice variant, VEGF-A165b, is also a potential therapeutic for diabetic neuropathy. Seven weeks of VEGF-A165b treatment in diabetic rats reversed enhanced pain behaviour in multiple behavioural paradigms and was neuroprotective, reducing hyperglycaemia-induced activated caspase 3 (AC3) levels in sensory neuronal subsets, epidermal sensory nerve fibre loss and aberrant sciatic nerve morphology. Furthermore, VEGF-A165b inhibited a STZ-induced increase in Evans Blue extravasation in dorsal root ganglia (DRG), saphenous nerve and plantar skin of the hind paw. Increased transient receptor potential ankyrin 1 (TRPA1) channel activity is associated with the onset of diabetic neuropathy. VEGF-A165b also prevented hyperglycaemia-enhanced TRPA1 activity in an in vitro sensory neuronal cell line indicating a novel direct neuronal mechanism that could underlie the anti-nociceptive effect observed in vivo. These results demonstrate that in a model of Type I diabetes VEGF-A165b attenuates altered pain behaviour and prevents neuronal stress, possibly through an effect on TRPA1 activity
Image-based consensus molecular subtype (imCMS) classification of colorectal cancer using deep learning
OBJECTIVE
Complex phenotypes captured on histological slides represent the biological processes at play in individual cancers, but the link to underlying molecular classification has not been clarified or systematised. In colorectal cancer (CRC), histological grading is a poor predictor of disease progression, and consensus molecular subtypes (CMSs) cannot be distinguished without gene expression profiling. We hypothesise that image analysis is a cost-effective tool to associate complex features of tissue organisation with molecular and outcome data and to resolve unclassifiable or heterogeneous cases. In this study, we present an image-based approach to predict CRC CMS from standard H&E sections using deep learning.
DESIGN
Training and evaluation of a neural network were performed using a total of n=1206 tissue sections with comprehensive multi-omic data from three independent datasets (training on FOCUS trial, n=278 patients; test on rectal cancer biopsies, GRAMPIAN cohort, n=144 patients; and The Cancer Genome Atlas (TCGA), n=430 patients). Ground truth CMS calls were ascertained by matching random forest and single sample predictions from CMS classifier.
RESULTS
Image-based CMS (imCMS) accurately classified slides in unseen datasets from TCGA (n=431 slides, AUC)=0.84) and rectal cancer biopsies (n=265 slides, AUC=0.85). imCMS spatially resolved intratumoural heterogeneity and provided secondary calls correlating with bioinformatic prediction from molecular data. imCMS classified samples previously unclassifiable by RNA expression profiling, reproduced the expected correlations with genomic and epigenetic alterations and showed similar prognostic associations as transcriptomic CMS.
CONCLUSION
This study shows that a prediction of RNA expression classifiers can be made from H&E images, opening the door to simple, cheap and reliable biological stratification within routine workflows
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