Understanding the controls on deposited fine sediment in the streams of agricultural catchments

Excessive sediment pressure on aquatic habitats is of global concern. A unique dataset, comprising instantaneous measurements of deposited fine sediment in 230 agricultural streams across England and Wales, was analysed in relation to 20 potential explanatory catchment and channel variables. The most effective explanatory variable for the amount of deposited sediment was found to be stream power, calculated for bankfull flow and used to index the capacity of the stream to transport sediment. Both stream power and velocity category were highly significant (p<<0.001), explaining some 57% variation in total fine sediment mass. Modelled sediment pressure, predominantly from agriculture, was marginally significant (p<0.05) and explained a further 1% variation. The relationship was slightly stronger for erosional zones, providing 62% explanation overall. In the case of the deposited surface drape, stream power was again found to be the most effective explanatory variable (p<0.001) but velocity category, baseflow index and modelled sediment pressure were all significant (p<0.01); each provided an additional 2% explanation to an overall 50%. It is suggested that, in general, the study sites were transport-limited and the majority of stream beds were saturated by fine sediment. For sites below saturation, the upper envelope of measured fine sediment mass increased with modelled sediment pressure. The practical implications of these findings are that (i) targets for fine sediment loads need to take into account the ability of streams to transport/retain fine sediment, and (ii) where agricultural mitigation measures are implemented to reduce delivery of sediment, river management to mobilise/remove fines may also be needed in order to effect an improvement in ecological status in cases where streams are already saturated with fines and unlikely to self-cleanse

Cold War : a Transnational Approach to a Global Heritage

Although within living memory, many countries now consider their surviving Cold War architecture as part of their heritage. It can even be a priority for heritage managers given that significant buildings are often suitable for reuse while extensive ‘brownfield’ sites such as airfields can be used for large-scale redevelopment. In a number of countries whose work we refer to here (notably the United Kingdom and elsewhere in Europe), agencies responsible for managing their country’s heritage have approached this priority by creating national inventories of sites and buildings with a view to taking informed decisions on their future. This paper presents the argument that the wider international context of the Cold War provides a more appropriate (or additional, higher-level) framework for such decision making. Such a ‘transnational’ approach would allow the comparison of similar (e.g. European) sites not merely within national borders but across the full extent of their western NATO1 deployment in Europe and North America. Taking this approach would also allow comparison with related sites in countries that formed part of the eastern-bloc Warsaw Pact.2 After outlining some examples of how national agencies have approached their Cold War heritage, this paper presents the four stages of this transnational approach making provision for an improved understanding and management of Cold War heritage sites wherever they occur. With a specific focus on the direct comparison between England and Russia, and also referring to sites surviving elsewhere within the former NATO and Warsaw Pact regions, as well as the United States, we argue that this four-stage approach: provides new understandings of a complex archaeological and architectural record; gives fresh perspectives on significance; and (importantly in a time of geopolitical instability) does so in a spirit of cooperation and friendship

Hyperglycaemic preterm babies have sex differences in insulin secretion

Background: Hyperglycaemia is a common complication of prematurity and is associated with neonatal mortality and morbidity, yet the aetiology is incompletely understood. C-peptide has been used in adults to estimate endogenous insulin secretion due to its simple clearance kinetics. Objective: To determine insulin secretion calculated from plasma C-peptide concentrations in hyperglycaemic preterm babies. Methods: A retrospective analysis of a cohort of 41 very preterm babies (median gestational age, weeks: 27.2 (26.2-28.7)) enrolled in a randomised controlled trial of tight glycaemic control when they developed hyperglycaemia (2 consecutive blood glucose concentrations (BGC) > 8.5 mmol.L-1). Insulin secretion was determined using a steady state analysis of a 2 compartment C-peptide kinetic model. Results: BGC, plasma insulin concentration, plasma C-peptide concentrations and insulin secretion were higher at randomisation than 1-2 weeks following randomisation (p≤0.02). Insulin secretion was higher in girls (11.7 (5.3-18.7) vs. 4.7 (2.1-8.3) mU.L-1.kg-1.min-1, p0.25). Insulin secretion was lower in samples taken during exogenous insulin delivery (3.7 (1.8 - 6.9) vs. 9.8 (4.7 - 17.8) mU.L-1.kg-1.min-1, p=0.02). Conclusions: Insulin secretion was higher when babies had higher BGC, indicating endogenous insulin secretion is sensitive to BGC. Girls had higher insulin secretion, at similar blood glucose and plasma insulin concentrations, than boys

A C-Peptide-Based Model of Pancreatic Insulin Secretion in Extremely Preterm Neonates in Intensive Care

Background: Model-based glycaemic control relies on sufficiency of underlying models to describe underlying patient physiology. In particular, very preterm infant glucose-insulin metabolism can differ significantly from adults, and is relatively unstudied. In this study, C-peptide concentrations are used to develop insulin-secretion models for the purposes of glycaemic control in neonatal intensive care. Methods: Plasma C-peptide, Insulin, and blood glucose concentrations (BGC) were retrospectively analyzed from a cohort of 41 hyperglycemic very preterm (median age 27.2 [26.2 - 28.7] weeks) and very low birth-weight infants (median birth weight 839 [735 – 1000] g). A 2-compartment model of C-peptide kinetics was used to estimate insulin secretion. Insulin secretion was examined with respect to nutritional intake, exogenous and plasma insulin concentration, and BGC. Results: Insulin secretion was found to be highly variable between patients and over time, and could not be modeled with respect to age, weight, or protein or dextrose intake. In 13 of 54 samples exogenous insulin was being administered, and insulin secretion was lower. However, low data numbers make this result inconclusive. Insulin secretion was found to increase with BG, with a stronger association in female infants than males (R2=0.51 vs. R2=0.13, and R2=0.26 for the combined cohort). Conclusions: A sex-based insulin secretion model was created and incorporated into a model-based glycemic control framework. Nutritional intake did not predict insulin secretion, indicating that insulin secretion is a complex function of a number of metabolic factors

Contrasting physical activity patterns in children and adolescents living in differing environments in the UK

Aims: There is evidence for lower physical activity (PA) in rural adults; it is important to evaluate how the environment influences the PA of children and adolescents. Methods: We compared the PA of 6485 English 10—15.9 year olds according to two systems for classifying the immediate environment. System one compared urban and rural areas. System two compared urban, town and fringe, and rural areas. Analyses were carried out separately for children (&lt;13 years) and adolescents (&gt;13 years). Results: Rural children were more active than those from urban areas (OR 1.38, 95% CI 1.15—1.66) as were adolescents (OR 1.30, 95% CI 1.11—1.51). Using trilateral division, children were more active if they lived in town and fringe (OR 1.32, 95% CI 1.03—1.67) or rural (OR 1.45, 95% CI 1.14—1.84) areas compared with urban areas. Adolescents from town and fringe areas were more active than urban dwellers (OR 1.50, 95% CI 1.24—1.81). Rural adolescents’ PA did not differ from urban dwellers’. Conclusions: Rural environments support PA in children but not that of adolescents. Town and fringe areas with mixed elements of rural and urban land use appear to facilitate and sustain PA in both children and adolescents. </jats:p

mAGiC DRAGONS: A Protocol for Accurate Glycaemic Control in General Wards

Accurate glycaemic control (AGC) has been shown to be beneficial to the outcomes of critically ill patients. These benefits may also extend to patients in less acute wards, particularly those with existing diabetes. However, the clinical demands of an intensive care glycaemic control protocol are not appropriate for the general wards where the nurse-to-patient ratio is much lower and patients do not typically have an intravenous line available for insulin delivery. Thus, there is a need for a safe, effective glycemic control protocol tailored to the needs of general wards to enable appropriate care for diabetic patients and further testing of the benefits of glycaemic control for this cohort. This paper presents the development and testing of such a protocol for glycaemic control in the general wards. The DRAGONS protocol (Dynamic Regulation for Accurate Glycaemic-control Optimising iNsulin Subcutaneously) was designed to use subcutaneous insulin and only require blood glucose (BG) measurements every four hours, while maintaining BG concentrations within the range 4.4-8.0 mmol/L. Virtual trial simulation indicated an expected time in the target band of 73.0%, with < 2% risk of BG < 4.0 mmol/L. In the first patient recruited to the pilot trial, the DRAGONS protocol achieved 46% time in band and no severe hypoglycaemic episodes. This trial has also highlighted the need for careful selection of the insulin injection site to prevent excessively rapid transport to plasma

Evolution of insulin sensitivity and its variability in out-of-hospital cardiac arrest (OHCA) patients treated with hypothermia.

INTRODUCTION: Therapeutic hypothermia (TH) is often used to treat out-of-hospital cardiac arrest (OHCA) patients who also often simultaneously receive insulin for stress-induced hyperglycaemia. However, the impact of TH on systemic metabolism and insulin resistance in critical illness is unknown. This study analyses the impact of TH on metabolism, including the evolution of insulin sensitivity (SI) and its variability, in patients with coma after OHCA. METHODS: This study uses a clinically validated, model-based measure of SI. Insulin sensitivity was identified hourly using retrospective data from 200 post-cardiac arrest patients (8,522 hours) treated with TH, shortly after admission to the intensive care unit (ICU). Blood glucose and body temperature readings were taken every one to two hours. Data were divided into three periods: 1) cool (T &lt;35°C); 2) an idle period of two hours as normothermia was re-established; and 3) warm (T &gt;37°C). A maximum of 24 hours each for the cool and warm periods was considered. The impact of each condition on SI is analysed per cohort and per patient for both level and hour-to-hour variability, between periods and in six-hour blocks. RESULTS: Cohort and per-patient median SI levels increase consistently by 35% to 70% and 26% to 59% (P &lt;0.001) respectively from cool to warm. Conversely, cohort and per-patient SI variability decreased by 11.1% to 33.6% (P &lt;0.001) for the first 12 hours of treatment. However, SI variability increases between the 18th and 30th hours over the cool to warm transition, before continuing to decrease afterward. CONCLUSIONS: OCHA patients treated with TH have significantly lower and more variable SI during the cool period, compared to the later warm period. As treatment continues, SI level rises, and variability decreases consistently except for a large, significant increase during the cool to warm transition. These results demonstrate increased resistance to insulin during mild induced hypothermia. Our study might have important implications for glycaemic control during targeted temperature management

Protocol for the collection of datasets used in the production of 'Insect Time Series (IN-TIME)' - a database of global insect trends.

&lt;h2&gt;The goal of this protocol is to outline the process for the collection of datasets from across the globe describing high taxonomic resolution trends in insect populations. Here we consider population trends to exclude simple presence/absence data, although we do include a diverse range of metrics of population size including abundance, density, biomass, and a variety of corrected population indices. This data is collected with the goal of creating an open access database curated with a standardised taxonomy to facilitate accessibility and access across datasets. Data collected under this work was undertaken as part of the Global Insect Threat-Response Synthesis (GLiTRS) project (https://glitrs.ceh.ac.uk/).&nbsp;&lt;/h2&gt