Species-environment relationship in marine soft-bottom communities: regression modeling and the implications of scale

A literature study was performed aiming to explore the relation between the spatial scale of marine benthic surveys and the observed goodness-of-fit of regression models relating animal abundance to the environment. A further objective was to tabulate the abiotic factors and processes that predominantly explain the variation in abundance and to examine whether or not the type of important factors differ in relation to the scale of the study. Single studies in which benthos-environment regression models were applied at different spatial scales and which would have allowed a within-study comparison of the goodness-of-fit in relation to scale, were not found. The paucity of studies that reported quantitative information and, if they did so, the use of a variety of incomparable statistical models resulted in very few observations and a lack of statistical power of the (between-study) relation between scale and goodness-of-fit. Most studies confirmed the importance of sediment characteristics and elevation (in case of intertidal areas) or water depth (in case of subtidal areas) in determining the benthos. Further studies on the importance of the spatial scale of marine benthos-environment surveys should be based on a unified analytical approach, which can only be realized if original data are available

MyAirCoach: The use of home-monitoring and mHealth systems to predict deterioration in asthma control and the occurrence of asthma exacerbations; Study protocol of an observational study

© Published by the BMJ Publishing Group Limited. Introduction Asthma is a variable lung condition whereby patients experience periods of controlled and uncontrolled asthma symptoms. Patients who experience prolonged periods of uncontrolled asthma have a higher incidence of exacerbations and increased morbidity and mortality rates. The ability to determine and to predict levels of asthma control and the occurrence of exacerbations is crucial in asthma management. Therefore, we aimed to determine to what extent physiological, behavioural and environmental data, obtained by mobile healthcare (mHealth) and home-monitoring sensors, as well as patient characteristics, can be used to predict episodes of uncontrolled asthma and the onset of asthma exacerbations. Methods and analysis In an 1-year observational study, patients will be provided with mHealth and home-monitoring systems to record daily measurements for the first-month (phase I) and weekly measurements during a follow-up period of 11 months (phase II). Our study population consists of 150 patients, aged ≥18 years, with a clinician's diagnosis of asthma, currently on controller medication, with uncontrolled asthma and/or minimally one exacerbation in the past 12 months. They will be enrolled over three participating centres, including Leiden, London and Manchester. Our main outcomes are the association between physiological, behavioural and environmental data and (1) the loss of asthma control and (2) the occurrence of asthma exacerbations. Ethics This study was approved by the Medical Ethics Committee of the Leiden University Medical Center in the Netherlands and by the NHS ethics service in the UK. Trial registration number NCT02774772

Domiciliary fractional exhaled nitric oxide and spirometry in monitoring asthma control and exacerbations

Background: Domiciliary measurements of airflow obstruction and inflammation may assist healthcare teams and patients in determining asthma control and facilitate self-management. Objective: To evaluate parameters derived from domiciliary spirometry and fractional exhaled nitric oxide (FENO) in monitoring asthma exacerbations and control. Methods: Patients with asthma were provided with hand-held spirometry and FENO devices in addition to their usual asthma care. Patients were instructed to perform twice-daily measurements for 1 month. Daily symptoms and medication change were reported through a mobile health system. The Asthma Control Questionnaire was completed at the end of the monitoring period. Results: One hundred patients had spirometry, of which 60 were given additional FENO devices. Compliance rates for twice-daily measurements were poor (median [interquartile range], 43% [25%-62%] for spirometry; 30% [3%-48%] for FENO); at least 15% of patients took little or no spirometry measurements and 40% rarely measured FENO. The coefficient of variation (CV) values in FEV1 and FENO were higher, and the mean % personal best FEV1 lower in those who had major exacerbations compared with those without (P < .05). FENO CV and FEV1 CV were associated with asthma exacerbation during the monitoring period (area under the receiver-operating characteristic curve, 0.79 and 0.74, respectively). Higher FENO CV also predicted poorer asthma control (area under the receiver-operating characteristic curve, 0.71) at the end of the monitoring period. Conclusions: Compliance with domiciliary spirometry and FENO varied widely among patients even in the setting of a research study. However, despite significant missing data, FENO and FEV1 were associated with asthma exacerbations and control, making these measurements potentially clinically valuable if used

Femorodistal venous bypass evaluated with intravascular ultrasound

Objective:To evaluate the feasibility of intravascular ultrasound imaging during femorodistal venous bypass procedures to assess qualitative and quantitative parameters of the greater saphenous vein and to detect potential causes for (re)stenosis and/or occlusion.Methods:Intravascular ultrasound data obtained from 15 patients were reviewed and compared with angiographic data.Results:Intravascular ultrasound enabled differentiation between normal and thickened vein wall. Venous side-branches could be located. Intact valves could be differentiated from valves disrupted by valve cutting. Patent anastomoses could be distinguished from anastomoses with some degree of obstruction. Intravascular ultrasound imaging of the inflow and outflow tracts revealed obstructive lesions, not evidenced angiographically. Quantitative analysis revealed that the median normal vein wall thickness (tunica intima and tunica media) was 0.25 mm (range 0.17–0.40 mm). The distinct vein wall thickening encountered in three patients measured 0.82, 0.95 and 1.06 mm, respectively, and was associated with narrowing in two patients. In five of 15 patients intravascular ultrasound findings altered surgical management.Conclusion:Intravascular ultrasound is able to assess qualitative and quantitative parameters of the venous bypass and has the potential to influence surgical management based on morphologic and quantitative data

Intravascular ultrasound evidence for coarctation causing symptomatic renal artery stenosis

BACKGROUND: A recent study of human cadaveric renal arteries revealed that renal artery narrowing could be due not only to atherosclerotic plaque compensated for by adaptive remodeling, but also to hitherto undescribed focal narrowing of an otherwise normal renal arterial wall (ie, coarctation). The present study investigated whether vessel coarctation could be identified in patients with symptomatic renal artery stenosis (RAS). METHODS AND RESULTS: Consecutive symptomatic patients with angiographically proven atherosclerotic RAS who were referred for stent placement were studied by 30-MHz intravascular ultrasound before intervention (n=18) or after predilatation (n=18). Analysis included assessment of the media-bounded area and plaque area (PLA) at the most stenotic site and at a distal reference site (most distal cross-section in the main renal artery with normal appearance). Coarctation was considered present whenever the target/reference media-bounded area was </=85%. Before intervention, coarctation was observed in 9 of 18 patients and adaptive remodeling in 9 of 18 patients. Coarctation lesions had a significantly smaller PLA than adaptive remodeled lesions (P=0.001). Similarly, despite predilatation, coarctation was seen in 8 of 18 patients who had significantly smaller PLAs (P=0. 008) when compared with those patients who had adaptive remodeled lesions. No differences in severity of RAS or angiographic or clinical parameters were observed. CONCLUSIONS: Low-plaque coarctation may cause a considerable proportion of symptomatic RAS, which is angiographically and clinically indistinguishable from plaque-rich RAS