440 research outputs found
Childhood Obesity
Childhood obesity is a serious global health problem. It begins early in life during the preschool years, and, for many, the obesity is carried forward into later childhood and adult life. Once established, obesity is difficult to reverse and is associated with poorer health outcomes in the short and long term. Tackling obesity in childhood is important to reduce life-long risk and protect health. However, service provision is lacking in the UK and other countries. Interventions that are successful in the prevention and management of childhood obesity are urgently needed. These should ideally be evidence-based and target the youngest children and their families. Multicomponent lifestyle programmes and strategies can be effective in reducing childhood obesity. For greatest success, these should be tailored to individual family needs
Improving and disaggregating N2O emission factors for ruminant excreta on temperate pasture soils
pre-printCattle excreta deposited on grazed grasslands are a major source of the greenhouse gas (GHG) nitrous oxide (N2O). Currently, many countries use the IPCC default emission factor (EF) of 2% to estimate excreta-derived N2O emissions. However, emissions can vary greatly depending on the type of excreta (dung or urine), soil type and timing of application. Therefore three experiments were conducted to quantify excreta-derived N2O emissions and their associated EFs, and to assess the effect of soil type, season of application and type of excreta on the magnitude of losses. Cattle dung, urine and artificial urine treatments were applied in spring, summer and autumn to three temperate grassland sites with varying soil and weather conditions. Nitrous oxide emissions were measured from the three experiments over 12 months to generate annual N2O emission factors. The EFs from urine treated soil was greater (0.30–4.81% for real urine and 0.13–3.82% for synthetic urine) when compared with dung (− 0.02–1.48%) treatments. Nitrous oxide emissions were driven by environmental conditions and could be predicted by rainfall and temperature before, and soil moisture deficit after application; highlighting the potential for a decision support tool to reduce N2O emissions by modifying grazing management based on these parameters. Emission factors varied seasonally with the highest EFs in autumn and were also dependent on soil type, with the lowest EFs observed from well-drained and the highest from imperfectly drained soil. The EFs averaged 0.31 and 1.18% for cattle dung and urine, respectively, both of which were considerably lower than the IPCC default value of 2%. These results support both lowering and disaggregating EFs by excreta type.This research was financially supported under the National Development Plan, through the Research Stimulus Fund, administered by the Department of Agriculture, Food and the Marine (Grant numbers RSF10/RD/SC/716 and 11S138)
A lactate-derived chiral aldehyde for determining the enantiopurity of enantioenriched primary amines
In this paper we describe the use of a chiral aldehyde derived from lactate esters for determining the enantiopurity of primary amines, via the formation of diastereomeric imines. The method was shown to be suitable for reproducibly determining the enantiopurity of a diverse set of chiral amines. Both enantiomers of the aldehyde can be prepared in two steps from commercially available materials
Field trials of a methodology for locomotive brake testing to assess friction enhancement in the wheel/rail interface using a representative leaf layer
There are two options for testing the performance of rail vehicles and the application of material to the wheel/rail interface to influence friction, and therefore braking performance, in a low adhesion environment: laboratory work which is not representative of conditions in the field, and expensive track tests using fully instrumented modern vehicles largely using low adhesion simulants that are not representative of those that occur in the real world and usually applied over great lengths of track. This paper presents a third option: low-cost track tests. We determined the minimum of equipment and resources needed to produce low adhesion using a method more representative on Autumn conditions on rail and monitor the performance of rail vehicles when braking on it. This was mainly targeted at use for testing products applied to the wheel/rail interface to enhance traction, hence the need for real low adhesion causes. We present the methodology that we have developed, and some initial results showing that using it we can generate a low adhesion scenario when braking from 10 mph. This can be used to develop mitigation solutions for low adhesion in a more cost effective manner
Confirmation of co-denitrification in grazed grassland
peer-reviewedPasture-based livestock systems are often associated with losses of reactive forms of nitrogen (N) to the environment. Research has focused on losses to air and water due to the health, economic and environmental impacts of reactive N. Di-nitrogen (N2) emissions are still poorly characterized, both in terms of the processes involved and their magnitude, due to financial and methodological constraints. Relatively few studies have focused on quantifying N2 losses in vivo and fewer still have examined the relative contribution of the different N2 emission processes, particularly in grazed pastures. We used a combination of a high 15N isotopic enrichment of applied N with a high precision of determination of 15N isotopic enrichment by isotope-ratio mass spectrometry to measure N2 emissions in the field. We report that 55.8 g N m−2 (95%, CI 38 to 77 g m−2) was emitted as N2 by the process of co-denitrification in pastoral soils over 123 days following urine deposition (100 g N m−2), compared to only 1.1 g N m−2 (0.4 to 2.8 g m−2) from denitrification. This study provides strong evidence for co-denitrification as a major N2 production pathway, which has significant implications for understanding the N budgets of pastoral ecosystems.The authors are grateful for the funding that was provided through the Research Stimulus Fund Program administered by the Department of Agriculture & Food under the National Development Plan 2007–2013 RSF 07536. The first author is grateful for the funding provided by Teagasc through the Walsh Fellowship Scheme
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Impact of fertiliser nitrogen formulation, and N stabilisers on nitrous oxide emissions in spring barley
The application of nitrogen (N) fertilisers to agricultural soils is a major source of nitrous oxide (N2O) emissions. The Intergovernmental Panel on Climate Change (IPCC) has set a default emission factor of 1% (EF1) for N fertiliser applied to managed agricultural soils. This value does not differentiate between different N fertiliser formulations or rates of N application. The objective of this field study under spring barley was to determine N2O EF’s for different N fertiliser formulations including urea and urea stabilised with the nitrification inhibitor dicyandiamide (DCD) and/or the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) and to evaluate their N2O loss abatement potential relative to calcium ammonium nitrate (CAN). The highest EF1 measured was 0.49% for CAN which was less than half the IPCC default value of 1%. While the urease inhibitor did not reduce emissions relative to CAN; the nitrification inhibitor significantly reduced emissions compared to CAN with EF1 as low as 0.00% for a typical spring barley site. There was no significant impact of CAN or urea application rate on EF1 but there was a significant negative relationship observed for urea in 2013. The study highlights the importance of generating higher Tier emission factors in terms of fertiliser type for use in national inventories
Direct amidation of unprotected amino acids using B(OCH2CF3)3
A commercially available borate ester, B(OCH2CF3)3, can be used to achieve protecting-group free direct amidation of α-amino acids with a range of amines in cyclopentyl methyl ether. The method can be applied to the synthesis of medicinally relevant compounds, and can be scaled up to obtain gram quantities of products
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