Spatial and temporal melt variability at Helheim Glacier, East Greenland, and its effect on ice dynamics

This is the publisher's version, also available electronically from "http://onlinelibrary.wiley.com".[1] Understanding the behavior of large outlet glaciers draining the Greenland Ice Sheet is critical for assessing the impact of climate change on sea level rise. The flow of marine-terminating outlet glaciers is partly governed by calving-related processes taking place at the terminus but is also influenced by the drainage of surface runoff to the bed through moulins, cracks, and other pathways. To investigate the extent of the latter effect, we develop a distributed surface-energy-balance model for Helheim Glacier, East Greenland, to calculate surface melt and thereby estimate runoff. The model is driven by data from an automatic weather station operated on the glacier during the summers of 2007 and 2008, and calibrated with independent measurements of ablation. Modeled melt varies over the deployment period by as much as 68% relative to the mean, with melt rates approximately 77% higher on the lower reaches of the glacier trunk than on the upper glacier. We compare melt variations during the summer season to estimates of surface velocity derived from global positioning system surveys. Near the front of the glacier, there is a significant correlation (on >95% levels) between variations in runoff (estimated from surface melt) and variations in velocity, with a 1 day delay in velocity relative to melt. Although the velocity changes are small compared to accelerations previously observed following some calving events, our findings suggest that the flow speed of Helheim Glacier is sensitive to changes in runoff. The response is most significant in the heavily crevassed, fast-moving region near the calving front. The delay in the peak of the cross-correlation function implies a transit time of 12–36 h for surface runoff to reach the bed

A real-life cost-effectiveness evaluation of budesonide/formoterol maintenance and reliever therapy in asthma

Objective: To evaluate direct asthma-related costs in Swedish primary care in a real-life setting. Design: 12-month open-label study. Setting: Swedish primary care in a real-life setting. Participants: 1776 patients with persistent asthma. Interventions: Patients with persistent asthma were randomised to one of three treatments: a free adjustable combination of budesonide (100-400 mu g/inhalation) and formoterol (4.5 or 9 mu g/inhalation) via separate inhalers plus terbutaline as needed; budesonide/formoterol (160/4.5 mu g or 80/4.5 mu g, two inhalations twice daily) plus terbutaline as needed; budesonide/formoterol, (160/4.5 mu g or 80/4.5 mu g, one inhalation twice daily or two inhalations once daily), for maintenance plus additional inhalations as needed. Doses depended on previous inhaled corticosteroid dose. Patients attended the clinic at 0, 1.5, and 12 months. Telephone interviews were conducted at 4, 6, 8, and 10 months. Main outcome measures: The primary endpoint was direct asthma-related healthcare costs. Results: Statistically significant reductions in annual direct costs per patient were observed with budesonide/formoterol maintenance and reliever therapy compared with the free adjustable combination of budesonide and formoterol (-13%, P<0.001) and fixed-dose budesonide/formoterol plus terbutaline (-20%, P<0.001). Time to first severe exacerbation did not differ significantly across treatment groups, with a mean reduction of 28% versus the free adjustable combination of budesonide and formoterol (P=0.076). Patients receiving budesonide/formoterol maintenance and reliever therapy used a significantly lower daily dose of budesonide compared with the conventional (P<0.001). Conclusions: This study reports direct cost savings with budesonide/formoterol maintenance and reliever therapy compared with conventional treatment regimens with at least equivalent efficacy. (C) 2008 Elsevier Ltd. All rights reserved

Comparison of formoterol and terbutaline for as-needed treatment of asthma: a randomised trial

BACKGROUND: Asthma guidelines recommend that long-acting inhaled beta-agonists should be used as maintenance therapy for patients with asthma inadequately controlled on an inhaled corticosteroid. We studied the safety and efficacy of the long-acting beta-agonist formoterol compared with terbutaline, each taken as needed, in patients with moderate to severe asthma. METHODS: Patients were taking an inhaled corticosteroid (mean dose 870 microg daily) and had a forced expiratory volume in 1 s (FEV1) of at least 50% predicted (mean 74%). Those requiring an inhaled beta-agonist three to eight times a day during the study run-in period (362 of 621 who started) were randomly assigned formoterol 4.5 microg or terbutaline 0.5 mg as needed by Turbuhaler in daily doses up to 54 microg and 6 mg, respectively, for 12 weeks in a double-blind, parallel-group study. Analyses were by intention to treat. FINDINGS: The 362 randomised patients (157 men, 205 women) had a mean age of 47 years. Patients taking formoterol had a longer time to their first severe asthma exacerbation (relative-risk ratio 0.55 [95% CI 0.34-0.89]), took fewer inhalations of study drug, and had larger increases in FEV1 (5%) and morning and evening peak expiratory flow (mean difference in increase 11 L/min and 8 L/min) than those taking terbutaline. No safety issues were identified. INTERPRETATION: When taken as needed, formoterol 4.5 microg provided better asthma control than terbutaline 0.5 mg in patients requiring moderate doses of relief medication despite inhaled corticosteroid treatment. Safety studies should be extended to a wider population of patients with asthma

Maternal BMI at the start of pregnancy and offspring epigenome-wide DNA methylation: findings from the pregnancy and childhood epigenetics (PACE) consortium

Pre-pregnancy maternal obesity is associated with adverse offspring outcomes at birth and later in life. Individual studies have shown that epigenetic modifications such as DNA methylation could contribute. Within the Pregnancy and Childhood Epigenetics (PACE) Consortium, we meta-analysed the association between pre-pregnancy maternal BMI and methylation at over 450,000 sites in newborn blood DNA, across 19 cohorts (9,340 mother-newborn pairs). We attempted to infer causality by comparing the effects of maternal versus paternal BMI and incorporating genetic variation. In four additional cohorts (1,817 mother-child pairs), we meta-analysed the association between maternal BMI at the start of pregnancy and blood methylation in adolescents. In newborns, maternal BMI was associated with small (<0.2% per BMI unit (1 kg/m2), P < 1.06 x 10-7) methylation variation at 9,044 sites throughout the genome. Adjustment for estimated cell proportions greatly attenuated the number of significant CpGs to 104, including 86 sites common to the unadjusted model. At 72/86 sites, the direction of the association was the same in newborns and adolescents, suggesting persistence of signals. However, we found evidence for acausal intrauterine effect of maternal BMI on newborn methylation at just 8/86 sites. In conclusion, this well-powered analysis identified robust associations between maternal adiposity and variations in newborn blood DNA methylation, but these small effects may be better explained by genetic or lifestyle factors than a causal intrauterine mechanism. This highlights the need for large-scale collaborative approaches and the application of causal inference techniques in epigenetic epidemiology