Explaining the imbalance in δ13C between soil and biomass in fire-prone tropical savannas

Currently, models of terrestrial 13C discrimination indicate that about one quarter of the gross primary productivity (GPP - total carbon fixed as biomass by plants) by the terrestrial biosphere is attributable to tropical savanna/grassland plants that use the C, photosynthetic pathway. However, the fraction of C,-derived biomass in soil organic carbon in savanna systems is much lower than these GPP estimates imply. Determining this imbalance has significant implications for correctly interpreting soil and palaeosol carbon isotope data, and for modelling studies that use variations in the atmospheric δ13CO, record to apportion sources and sinks of carbon. Here, we present preliminary results using hydrogen pyrolysis (HyPy) for quantifying the abundance and identifying the source of pyrogenic carbon (PC) in tropical savannas of North Queensland (Australia). We collected sediment from a series of micro-catchments covering the broadest possible range of C, and C, environments, and compared the abundances and stable isotope compositions of the total organic carbon (TOC) and pyrogenic carbon (PC) fractions. Hydrogen pyrolysis (HyPy) can be used to quantify the production, fate and stable isotope composition of PC produced by vegetation burning. HyPy is pyrolysis (up to ~600°C) under high hydrogen pressures (>10 MPa) in the presence of a catalyst, and when applied to sediments, soils, or organic samples results in the reductive removal of labile organic matter. Therefore, this technique offers great potential to effectively isolate and quantify pyrogenic carbon in a rapid and cost effective manner. Moreover, comparison of the stable carbon isotope composition of PC with bulk carbon has the potential to discern if there is a dominant vegetation source contributing to burning. The results indicate that the δ13C value of PC in the sediments is up 6‰ higher than the 613C value of TOC. There is a larger difference when TOC abundances in the sediments are lowest. This suggests a significant component of C,-derived PC is present in the sediments, even when the proportion of C, biomass in the catchment is relatively low. This in turn, provides evidence for the preferential combustion and transport of C4-derived PC in tropical savannas. Savanna fires preferentially burn the grass understorey rather than large trees, leading to a bias toward the finer C,-derived PC being exported from a fire and accumulated in the sedimentary record while large particles of Crderived PC are more likely to remain at the site of burning. Our preliminary data suggest that application of HyPy in environmental studies enables accurate quantification of an essential component of the terrestrial C cycle. Moreover, the use of HyPy also enables the reliable determination of the stable carbon isotope composition of PC, which will enable deeper understanding of the dynamic role of biomass burning in the global carbon cycle

Screening for obstructive sleep apnea on the internet: randomized trial.

BACKGROUND: Obstructive sleep apnea is underdiagnosed. We conducted a pilot randomized controlled trial of an online intervention to promote obstructive sleep apnea screening among members of an Internet weight-loss community. METHODS: Members of an Internet weight-loss community who have never been diagnosed with obstructive sleep apnea or discussed the condition with their healthcare provider were randomized to intervention (online risk assessment+feedback) or control. The primary outcome was discussing obstructive sleep apnea with a healthcare provider at 12 weeks. RESULTS: Of 4700 members who were sent e-mail study announcements, 168 (97% were female, age 39.5 years [standard deviation 11.7], body mass index 30.3 [standard deviation 7.8]) were randomized to intervention (n=84) or control (n=84). Of 82 intervention subjects who completed the risk assessment, 50 (61%) were low risk and 32 (39%) were high risk for obstructive sleep apnea. Intervention subjects were more likely than control subjects to discuss obstructive sleep apnea with their healthcare provider within 12 weeks (11% [9/84] vs 2% [2/84]; P=.02; relative risk=4.50; 95% confidence interval, 1.002-20.21). The number needed to treat was 12. High-risk intervention subjects were more likely than control subjects to discuss obstructive sleep apnea with their healthcare provider (19% [6/32] vs 2% [2/84]; P=.004; relative risk=7.88; 95% confidence interval, 1.68-37.02). One high-risk intervention subject started treatment for obstructive sleep apnea. CONCLUSION: An online screening intervention is feasible and likely effective in encouraging members of an Internet weight-loss community to discuss obstructive sleep apnea with their healthcare provider

Where the wild things are! Do urban green spaces with greater avian biodiversity promote more positive emotions in humans?

Urban green space can help mitigate the negative impacts of urban living and provide positive effects on citizens’ mood, health and well-being. Questions remain, however, as to whether all types of green space are equally beneficial, and if not, what landscape forms or key features optimise the desired benefits. For example, it has been cited that urban landscapes rich in wildlife (high biodiversity) may promote more positive emotions and enhance well-being. This research utilised a mobile phone App, employed to assess people’s emotions when they entered any one of 945 green spaces within the city of Sheffield, UK. Emotional responses were correlated to key traits of the individual green spaces, including levels of biodiversity the participant perceived around them. For a subsample of these green spaces, actual levels of biodiversity were assessed through avian and habitat surveys. Results demonstrated strong correlations between levels of avian biodiversity within a green space and human emotional response to that space. Respondents reported being happier in sites with greater avian biodiversity (p < 0.01, r = 0.78) and a greater variety of habitats (p < 0.02, r = 0.72). Relationships were strengthened when emotions were linked to perceptions of overall biodiversity (p < 0.001, r = 0.89). So, when participants thought the site was wildlife rich, they reported more positive emotions, even when actual avian biodiversity levels were not necessarily enhanced. The data strengthens the arguments that nature enhances well-being through positive affect, and that increased ‘engagement with nature’ may help support human health within urban environments. The results have strong implications for city planning with respect to the design, management and use of city green spaces

JRA3 Electromagnetic Calorimeter Technical Design Report

This report describes the design of the prototype for an Silicon Tungsten electromagnetic calorimeter with unprecedented high granularity to be operated in a detector at the International Linear Collider (ILC). The R&D for the prototype is co-funded by the European Union in the FP6 framework within the so called EUDET project in the years 2006-2010. The dimensions of the prototype are similar to those envisaged for the final detector. Already at this stage the prototype features a highly compact design. The sensitive layers, the Very Front End Electronics serving 64 channels per ASIC and copper plates for heat draining are integrated within 2000 μm

Development of a modular and scalable data acquisition system for calorimeters at a linear collider

A data acquisition (DAQ) system has been developed which will read out and control calorimeters serving as prototype systems for a future detector at an electron-positron linear collider. This is a modular, flexible and scalable DAQ system in which the hardware and signals are standards-based, using FPGAs and serial links. The idea of a backplaneless system was also pursued with a commercial development board housed in a PC and a chain of concentrator cards between it and the detector forming the basis of the system. As well as describing the concept and performance of the system, its merits and disadvantages are discussed.Comment: 12 pages, 6 figures, accepted by JINST. Version updated accounting for comments from journal referee

Infrastructure for Detector Research and Development towards the International Linear Collider

The EUDET-project was launched to create an infrastructure for developing and testing new and advanced detector technologies to be used at a future linear collider. The aim was to make possible experimentation and analysis of data for institutes, which otherwise could not be realized due to lack of resources. The infrastructure comprised an analysis and software network, and instrumentation infrastructures for tracking detectors as well as for calorimetry.Comment: 54 pages, 48 picture

Health, not weight loss, focused programmes versus conventional weight loss programmes for cardiovascular risk factors:A systematic review and meta-analysis

© 2019 The Authors. Published by BMC. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website:Background: Obesity is a cardiovascular disease risk factor. Conventional weight loss (CWL) programmes focus on weight loss, however 'health, not weight loss, focused' (HNWL) programmes concentrate on improved health and well-being, irrespective of weight loss. What are the differences in CVD risk outcomes between these programmes? Aim: To conduct a systematic review and meta-analysis to compare the effects of HNWL with CWL programmes on cardiovascular disease risk factors. Methods: We searched CENTRAL, MEDLINE, EMBASE, PsycINFO, CINAHL, ASSIA, clinical trial registers, commercial websites and reference lists for randomised controlled trials comparing the two programmes (initially searched up to August 2015 and searched updated to 5 April 2019). We used the Mantel-Haneszel fixed-effect model to pool results. Sub-group and sensitivity analyses that accounted for variations in length of follow-up, enhanced programmes and risk of bias dealt with heterogeneity. Results: Eight randomised controlled trials of 20,242 potential studies were included. Improvements in total cholesterol-HDL ratio (mean difference-0.21 mmol/L, 95% confidence interval [-3.91, 3.50]) and weight loss (-0.28 kg [-2.00, 1.44]) favoured HNWL compared to CWL programmes in the long term (53-104 week follow-up), whereas improvements in systolic (-1.14 mmHg, [-5.84, 3.56]) and diastolic (-0.15 mmHg, [-3.64, 3.34]) blood pressure favoured CWL programmes. These differences did not reach statistical significance. Statistically significant improvements in body satisfaction (-4.30 [-8.32,-0.28]) and restrained eating behaviour (-4.30 [-6.77,-1.83]) favoured HNWL over CWL programmes. Conclusions: We found no long-term significant differences in improved CVD risk factors; however, body satisfaction and restrained eating behaviour improved more with HNWL compared to CWL programmes. Yet firm conclusions cannot be drawn from small studies with high losses to follow-up and data sometimes arising from a single small study.Published versio

The Data Acquisition and Calibration System for the ATLAS Semiconductor Tracker

The SemiConductor Tracker (SCT) data acquisition (DAQ) system will calibrate, configure, and control the approximately six million front-end channels of the ATLAS silicon strip detector. It will provide a synchronized bunch-crossing clock to the front-end modules, communicate first-level triggers to the front-end chips, and transfer information about hit strips to the ATLAS high-level trigger system. The system has been used extensively for calibration and quality assurance during SCT barrel and endcap assembly and for performance confirmation tests after transport of the barrels and endcaps to CERN. Operating in data-taking mode, the DAQ has recorded nearly twenty million synchronously-triggered events during commissioning tests including almost a million cosmic ray triggered events. In this paper we describe the components of the data acquisition system, discuss its operation in calibration and data-taking modes and present some detector performance results from these tests

The ATLAS SCT Optoelectronics and the Associated Electrical Services

The requirements for the optical links of the ATLAS SCT are described. From the individual detector modules to the first patch panel, the electrical services are integrated with the optical links to aid in mechanical design, construction and integration. The system architecture and critical elements of the system are described. The optical links for the ATLAS SCT have been assembled and mounted onto the carbon fibre support structures. The performance of the system as measured during QA is summarised and compared to the final performance obtained after mounting modules onto the support structures