Effect of water table management and elevated CO2 on radish productivity and on CH4 and CO2 fluxes from peatlands converted to agriculture.

Anthropogenic activity is affecting the global climate through the release of greenhouse gases (GHGs) e.g. CO2 and CH4. About a third of anthropogenic GHGs are produced from agriculture, including livestock farming and horticulture. A large proportion of the UK's horticultural farming takes place on drained lowland peatlands, which are a source of significant amounts of CO2 into the atmosphere. This study set out to establish whether raising the water table from the currently used -50cm to -30cm could reduce GHGs emissions from agricultural peatlands, while simultaneously maintaining the current levels of horticultural productivity. A factorial design experiment used agricultural peat soil collected from the Norfolk Fens (among the largest of the UK's lowland peatlands under intensive cultivation) to assess the effects of water table levels, elevated CO2, and agricultural production on GHG fluxes and crop productivity of radish, one of the most economically important fenland crops. The results of this study show that a water table of -30cm can increase the productivity of the radish crop while also reducing soil CO2 emissions but without a resultant loss of CH4 to the atmosphere, under both ambient and elevated CO2 concentrations. Elevated CO2 increased dry shoot biomass, but not bulb biomass nor root biomass, suggesting no immediate advantage of future CO2 levels to horticultural farming on peat soils. Overall, increasing the water table could make an important contribution to global warming mitigation while not having a detrimental impact on crop yield.

Exhaled nitric oxide in the diagnosis of asthma in adults: a systematic review.

OBJECTIVES: To identify and synthesize evidence on the diagnostic accuracy of FE NO for asthma in adults. MATERIALS AND METHODS: Systematic searches (nine key biomedical databases and trial registers) were carried out on November 2014. Records were included if they recruited patients with the symptoms of asthma; used a single set of inclusion criteria; measured FE NO50 in accordance with American Thoracic Society guidelines, 2005 (off-line excluded); reported/allowed calculation of true-positive, true-negative, false-positive and false-negative patients as classified against any reference standard. Study quality was assessed using QUADAS II. Meta-analysis was planned where clinical study heterogeneity allowed. Rule-in and rule-out uses of FE NO were considered. RESULTS: A total of 4861 records were identified originally and 1312 in an update. Twenty-seven studies were included. Heterogeneity precluded meta-analysis. Results varied even within subgroups of studies. Cut-off values for the best sum of sensitivity and specificity varied from 12 to 55 p.p.b., but did not produce high accuracy. 100% sensitivity or 100% specificity was reported by some studies indicating potential use as a rule-in or rule-out strategy. CONCLUSIONS AND CLINICAL RELEVANCE: FE NO50 had variable diagnostic accuracy even within subgroups of studies with similar characteristics. Diagnostic accuracy, optimal cut-off values and best position for FE NO50 within a pathway remain poorly evidenced.

The effect of dietary intervention on the metabolic and behavioural impairments generated by short term high fat feeding in the rat.

Previous studies have shown that rats fed a high calorie diet rich in saturated fat for 12weeks exhibit peripheral insulin resistance and impairments of behavioural flexibility when switched from an operant delayed matching to place (DMTP) schedule to a delayed non-matching to place (DNMTP) schedule. However, the metabolic changes evoked by feeding a high fat (HF) diet can be observed within two weeks of commencing the diet. The current study has confirmed that 4weeks exposure to an HF diet resulted in increased body weight, peripheral insulin resistance and plasma leptin. Studies performed during weeks 3 and 4 on the HF diet revealed suppressed lever pressing rates and impaired behavioural flexibility in the operant DMTP/DNMTP task. When animals fed the HF diet were then returned to a standard chow (SC) diet for 5weeks their weight and blood biochemistry no longer differed from those measured in animals that had never been exposed to the HF diet. The animals restored to the SC diet exhibited a clear ability to acquire the DNMTP schedule of reinforcement although these animals continued to lever press at a lower rate when compared with animals that received the SC diet throughout. The data suggest that exposure to an HF diet diminishes the motivation to respond for a reward and, thus, the capacity to adapt behavioural performance. This deficit was ameliorated, but not totally reversed, by the dietary intervention. If also true for humans, the results suggest that deficits in behavioural flexibility develop after only a short period on a high calorie diet but may be largely reversible through simple dietary intervention, at least in the early stages of deficit development. However, the putative effects of short-term exposure to an HF diet on behavioural motivation may persist for some time after switching to a healthier low fat diet and remain a problem for those seeking to adopt a healthier diet.

Home telemonitoring or structured telephone support programmes after recent discharge in patients with heart failure: systematic review and economic evaluation.

BACKGROUND: Remote monitoring (RM) strategies have the potential to deliver specialised care and management to patients with heart failure (HF). OBJECTIVE: To determine the clinical effectiveness and cost-effectiveness of home telemonitoring (TM) or structured telephone support (STS) strategies compared with usual care for adult patients who have been recently discharged (within 28 days) from acute care after a recent exacerbation of HF. DATA SOURCES: Fourteen electronic databases (including MEDLINE, EMBASE, PsycINFO and The Cochrane Library) and research registers were searched to January 2012, supplemented by hand-searching relevant articles and contact with experts. The review included randomised controlled trials (RCTs) or observational cohort studies with a contemporaneous control group that included the following RM interventions: (1) TM (including cardiovascular implanted monitoring devices) with medical support provided during office hours or 24/7; (2) STS programmes delivered by human-to-human contact (HH) or human-to-machine interface (HM). REVIEW METHODS: A systematic review and network meta-analysis (where appropriate) of the clinical evidence was carried out using standard methods. A Markov model was developed to evaluate the cost-effectiveness of different RM packages compared with usual care for recently discharged HF patients. TM 24/7 or using cardiovascular monitoring devices was not considered in the economic model because of the lack of data and/or unsuitability for the UK setting. Given the heterogeneity in the components of usual care and RM interventions, the cost-effectiveness analysis was performed using a set of costing scenarios designed to reflect the different configurations of usual care and RM in the UK. RESULTS: The literature searches identified 3060 citations. Six RCTs met the inclusion criteria and were added to the 15 trials identified from the previous systematic reviews giving a total of 21 RCTs included in the systematic review. No trials of cardiovascular implanted monitoring devices or observational studies met the inclusion criteria. The methodological quality of the studies varied widely and reporting was generally poor. Compared with usual care, RM was beneficial in reducing all-cause mortality for STS HH [hazard ratio (HR) 0.77, 95% credible interval (CrI) 0.55 to 1.08], TM during office hours (HR 0.76, 95% CrI 0.49 to 1.18) and TM 24/7 (HR 0.49, 95% CrI 0.20 to 1.18); however, these results were statistically inconclusive. The results for TM 24/7 should be treated with caution because of the poor methodological quality of the only included study in this network. No favourable effect on mortality was observed with STS HM. Similar reductions were observed in all-cause hospitalisations for TM interventions, whereas STS interventions had no major effect. A sensitivity analysis, in which a study was excluded because it provided better-than-usual support to the control group, showed larger beneficial effects for most outcomes, particularly for TM during office hours. In the cost-effectiveness analyses, TM during office hours was the most cost-effective strategy with an estimated incremental cost-effectiveness ratio (ICER) of £11,873 per quality-adjusted life-year (QALY) compared with usual care, whereas STS HH had an ICER of £228,035 per QALY compared with TM during office hours. STS HM was dominated by usual care. Similar results were observed in scenario analyses performed using higher costs of usual care, higher costs of STS HH and lower costs of TM during office hours. LIMITATIONS: The RM interventions included in the review were heterogeneous in terms of monitored parameters and HF selection criteria and lacked detail in the components of the RM care packages and usual care (e.g. communication protocols, routine staff visits and resources used). As a result, the economic model developed scenarios for different RM classifications and their costs were estimated using bottom-up costing methods. Although the users can decide which of these scenarios is most representative of their setting, uncertainties still remain about the assumptions made in the estimation of these costs. In addition, the model assumed that the effectiveness of the interventions was constant over time, irrespective of the duration of deployment, and that the intervention was equally effective in different age/severity groups. CONCLUSION: Despite wide variation in usual care and RM strategies, cost-effectiveness analyses suggest that TM during office hours was an optimal strategy (in most costing scenarios). However, clarity was lacking among descriptions of the components of RM packages and usual care and there was a lack of robust estimation of costs. Further research is needed in these areas. STUDY REGISTRATION: PROSPERO registration no. CRD42011001368. FUNDING: The National Institute for Health Research Health Technology Assessment programme.