67 research outputs found
Investigation of the link between fluid shift and airway collapsibility as a mechanism for obstructive sleep apnea in congestive heart failure
The increased prevalence of obstructive sleep apnea (OSA) in congestive heart failure (CHF) may be associated with rostral fluid shift. We investigated the effect of overnight rostral fluid shift on pharyngeal collapsibility (Pcrit), pharyngeal caliber (APmean), and apneaâhypopnea index (AHI) in CHF patients. Twentyâthree optimally treated systolic CHF patients were studied. Neck circumference was measured immediately prior to sleep in the evening and immediately after waking in the morning as a marker of rostral fluid shift. Pcrit was measured during sleep, early and late in the night. APmean was measured using acoustic reflection at the same times as neck circumference measurements. 15/23 CHF patients experienced an overnight increase in neck circumference; overall neck circumference significantly increased overnight (mean±SD, evening: 41.7 ± 3.2 cm; morning: 42.3 ± 3.1 cm; P = 0.03). Pcrit increased significantly overnight (earlyânight: â3.8 ± 3.3 cmH2O; lateânight: â2.6 ± 3.0 cmH2O; P = 0.03) and APmean decreased (evening: 4.2 ± 1.3 cm2; morning: 3.7 ± 1.3 cm2; P = 0.006). The total AHI correlated with neck circumference (r = 0.4; P = 0.04) and Pcrit (r = 0.5; P = 0.01). APmean correlated with neck circumference (r = â0.47; P = 0.02). There was no significant change in AHI between the first and second half of the night (firstâhalf: 12.9 ± 12.4/h; secondâhalf: 13.7 ± 13.3/h; P = 0.6). Overnight rostral fluid shift was associated with increased pharyngeal collapsibility and decreased pharyngeal caliber during sleep in CHF patients. Rostral fluid shift may be an important mechanism of OSA in this patient group
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Blanket bog CO2 flux driven by plant functional type during summer drought
Recent climate predictions for the United Kingdom expect a nationwide shift towards drier and warmer summers, increasing the risk of more frequent and severe drought events. Such shifts in weather patterns impede functioning of global peatlands, especially rare intact blanket bogs abundant in Scotland and representing nearly a quarter of the UK's soil carbon. In this in situ study, carbon dioxide (CO2) fluxes from dominant peatland plant functional types (PFTs) such as Sphagnum spp., graminoids, ericoids and other key cover types (i.e., pools and bare peat) were measured and compared across upland and low-lying blanket bog margins and centres, immediately before and during a summer drought in 2018, and over the subsequent year. During that period, most sites acted as net sources of CO2 to the atmosphere. Our results showed that net ecosystem exchange (NEE) was limited by water availability during the drought, with ericoid shrubs showing the highest drought resilience, followed by graminoids (which were still limited in GPP in 2019) and Sphagnum mosses. Diverging NEE estimates were observed across centre and margin areas of the blanket bogs, with highest variability across the upland site where signs of active erosion were visible. Overall, our study suggests that estimating growing season carbon fluxes from in situ peatland PFT and cover types can help us better understand global climate change impacts on the dynamics and trajectories of peatland C cycles
Using remote sensing to assess peatland resilience by estimating oil surface moisture and drought recovery
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordPeatland areas provide a range of ecosystem services, including biodiversity, carbon
storage, clean water, and flood mitigation, but many areas of peatland in the UK have been
degraded through human land use including drainage. Here, we explore whether remote
sensing can be used to monitor peatland resilience to drought. We take resilience to mean
the rate at which a system recovers from perturbation; here measured literally as a recovery
timescale of a soil surface moisture proxy from drought lowering. Our objectives were (1) to
assess the reliability of Sentinel-1 Synthetic Aperture Radar (SAR) backscatter as a proxy
for water table depth (WTD); (2) to develop a method using SAR to estimate below-ground
(hydrological) resilience of peatlands; (3) to apply the developed method to different sites
and consider the links between resilience and land management. Our inferences of WTD
from Sentinel-1 SAR data gave results with an average Pearsonâs correlation of 0.77 when
compared to measured WTD values. The 2018 summer drought was used to assess
resilience across three different UK peatland areas (Dartmoor, the Peak District, and the
Flow Country) by considering the timescale of the soil moisture proxy recovery. Results
show clear areas of lower resilience within all three study sites, which often correspond to
areas of high drainage and may be particularly vulnerable to increasing drought
severity/events under climate change. This method is applicable to monitoring peatland
resilience elsewhere over larger scales, and could be used to target restoration work
towards the most vulnerable areas.Leverhulme Trus
A cluster randomized controlled trial of a clinical pathway for hospital treatment of heart failure: study design and population
<p>Abstract</p> <p>Background</p> <p>The hospital treatment of heart failure frequently does not follow published guidelines, potentially contributing to the high morbidity, mortality and economic cost of this disorder. Consequently the development of clinical pathways has the potential to reduce the current variability in care, enhance guideline adherence, and improve outcomes for patients. Despite enthusiasm and diffusion, the widespread acceptance of clinical pathways remain questionable because very little prospective controlled data demonstrated their effectiveness. The Experimental Prospective Study on the Effectiveness and Efficiency of the Implementation of Clinical Pathways was designed in order to conduct a rigorous evaluation of clinical pathways in hospital treatment of acute heart failure. The primary objective of the trial was to evaluate the effectiveness of the implementation of clinical pathways for hospital treatment of heart failure in Italian hospitals.</p> <p>Methods/design</p> <p>Two-arm, cluster-randomized trial. 14 community hospitals were randomized either to arm 1 (clinical pathway: appropriate use of practice guidelines and supplies of drugs and ancillary services, new organization and procedures, patient education, etc.) or to arm 2 (no intervention, usual care). 424 patients sample (212 in each group), 80% of power at the 5% significance level (two-sided). The primary outcome measure is in-hospital mortality. We will also analyze the impact of the clinical pathways comparing the length and the appropriateness of the stay, the rate of unscheduled readmissions, the customers' satisfaction and the costs treating the patients with the pathways and with the current practice along all the observation period. The quality of the care will be assessed by monitoring the use of diagnostic and therapeutic procedures during hospital stay and by measuring key quality indicators at discharge.</p> <p>Discussion</p> <p>This paper examines the design of the evaluation of a complex intervention. Since clinical pathways are made up of various interconnecting parts we have chosen the cluster-randomized controlled trial because is widely accepted as the most reliable method of determining effectiveness when measuring cost-effectiveness in real practice.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov ID [NCT00519038]</p
The influence of a virtual companion on amusement when watching funny films
We investigated the role of a virtual companion and trait cheerfulness on the elicitation of amusement. Ninety participants watched funny films in four conditions: either alone, with a virtual companion laughing or verbally expressing amusement at fixed time points (pre-scripted), or additionally joining the participantâs laughter (responsive companion). Amusement was assessed facially and vocally by coding Duchenne Displays and laughter vocalizations. Participantsâ cheerful mood pre and post the film watching and positive experience were assessed. Results showed that high trait cheerful individuals generally experienced and expressed more amusement than low trait cheerful individuals. The presence of a virtual companion (compared to being alone) led to more laughter for individuals low in trait cheerfulness. Unexpectedly, the responsive companion did not elicit more amusement than the pre-scripted companion. The general disliking of virtual companions and gelotophobia related negatively to amusement. Amusement expressing virtual companions may be used in interventions aiming at eliciting positive responses, especially for individuals with higher thresholds for amusement.European Union Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. 27078
Differential impact of impaired fasting glucose versus impaired glucose tolerance on cardiometabolic risk factors in multi-ethnic overweight/obese children
We aimed to investigate the prevalence of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), and their associations with cardiometabolic risk factors, according to ethnicity in a large obese paediatric cohort. A 75-g oral glucose tolerance test was performed in 1,007 overweight/obese Dutch children of multi-ethnic origin, referred to the obesity outpatient clinics of two Dutch hospitals in Amsterdam (mean age, 11.4â±â3.2 years; 50.7% boys). Anthropometric parameters and blood samples were collected, and cardiometabolic risk factors were assessed. The cohort consisted of Dutch native (26.0%), Turkish (23.7%), Moroccan (18.8%) and children of âotherâ (31.5%) ethnicity. The prevalence of IFG was significantly higher in Moroccan and Turkish children as compared to Dutch native children (25.4% and 19.7% vs. 11.8%, respectively, Pâ<â0.05). IGT was most frequently present in Turkish and Dutch native children, relative to Moroccan children (6.3% and 5.3% vs. 1.6%, Pâ<â0.05). Besides pubertal status and ethnicity, components of âmetabolic syndromeâ (MetS) which were associated with IGT, independent of hyperinsulinaemia, were hypertension [odds ratio (OR), 2.3; 95% CI, 1.1â4.9] while a trend was seen for high triglycerides (OR, 2.0; 95% CI, 0.9â4.3). When analyzing components of MetS which were associated with IFG, only low high-density lipoprotein cholesterol was significantly associated (OR, 1.7; 95% CI, 1.2â2.5) independent of hyperinsulinaemia. In conclusion, in a Dutch multi-ethnic cohort of overweight/obese children, a high prevalence of IFG was found against a low prevalence of IGT, which differed in their associations with cardiometabolic risk factors
Sleep-disordered breathing-do we have to change gears in heart failure?
The majority of patients with heart failure have sleep-disordered breathing (SDB)-with central (rather than obstructive) sleep apnoea becoming the predominant form in those with more severe disease. Cyclical apnoeas and hypopnoeas are associated with sleep disturbance, hypoxaemia, haemodynamic changes, and sympathetic activation. Such patients have a worse prognosis than those without SDB. Mask-based therapies of positive airway pressure targeted at SDB can improve measures of sleep quality and partially normalise the sleep and respiratory physiology, but recent randomised trials of cardiovascular outcomes in central sleep apnoea have been neutral or suggested the possibility of harm, likely from increased sudden death. Further randomised outcome studies (with cardiovascular mortality and hospitalisation endpoints) are required to determine whether mask-based treatment for SDB is appropriate for patients with chronic systolic heart failure and obstructive sleep apnoea, for those with heart failure with preserved ejection fraction, and for those with decompensated heart failure. New therapies for sleep apnoea-such as implantable phrenic nerve stimulators-also require robust assessment. No longer can the surrogate endpoints of improvement in respiratory and sleep metrics be taken as adequate therapeutic outcome measures in patients with heart failure and sleep apnoea
The Role of Tourism and Recreation in the Spread of Non-Native Species: A Systematic Review and Meta-Analysis
Managing the pathways by which non-native species are introduced and spread is considered the most effective way of preventing species invasions. Tourism and outdoor recreation involve the frequent congregation of people, vehicles and vessels from geographically diverse areas. They are therefore perceived to be major pathways for the movement of non-native species, and ones that will become increasingly important with the continued growth of these sectors. However, a global assessment of the relationship between tourism activities and the introduction of non-native speciesâparticularly in freshwater and marine environmentsâis lacking. We conducted a systematic review and meta-analysis to determine the impact of tourism and outdoor recreation on non-native species in terrestrial, marine and freshwater environments. Our results provide quantitative evidence that the abundance and richness of non-native species are significantly higher in sites where tourist activities take place than in control sites. The pattern was consistent across terrestrial, freshwater and marine environments; across a variety of vectors (e.g. horses, hikers, yachts); and across a range of taxonomic groups. These results highlight the need for widespread biosecurity interventions to prevent the inadvertent introduction of invasive non-native species (INNS) as the tourism and outdoor recreation sectors grow
Observations of Ly Emitters at High Redshift
In this series of lectures, I review our observational understanding of
high- Ly emitters (LAEs) and relevant scientific topics. Since the
discovery of LAEs in the late 1990s, more than ten (one) thousand(s) of LAEs
have been identified photometrically (spectroscopically) at to . These large samples of LAEs are useful to address two major astrophysical
issues, galaxy formation and cosmic reionization. Statistical studies have
revealed the general picture of LAEs' physical properties: young stellar
populations, remarkable luminosity function evolutions, compact morphologies,
highly ionized inter-stellar media (ISM) with low metal/dust contents, low
masses of dark-matter halos. Typical LAEs represent low-mass high- galaxies,
high- analogs of dwarf galaxies, some of which are thought to be candidates
of population III galaxies. These observational studies have also pinpointed
rare bright Ly sources extended over kpc, dubbed
Ly blobs, whose physical origins are under debate. LAEs are used as
probes of cosmic reionization history through the Ly damping wing
absorption given by the neutral hydrogen of the inter-galactic medium (IGM),
which complement the cosmic microwave background radiation and 21cm
observations. The low-mass and highly-ionized population of LAEs can be major
sources of cosmic reionization. The budget of ionizing photons for cosmic
reionization has been constrained, although there remain large observational
uncertainties in the parameters. Beyond galaxy formation and cosmic
reionization, several new usages of LAEs for science frontiers have been
suggested such as the distribution of {\sc Hi} gas in the circum-galactic
medium and filaments of large-scale structures. On-going programs and future
telescope projects, such as JWST, ELTs, and SKA, will push the horizons of the
science frontiers.Comment: Lecture notes for `Lyman-alpha as an Astrophysical and Cosmological
Tool', Saas-Fee Advanced Course 46. Verhamme, A., North, P., Cantalupo, S., &
Atek, H. (eds.) --- 147 pages, 103 figures. Abstract abridged. Link to the
lecture program including the video recording and ppt files :
https://obswww.unige.ch/Courses/saas-fee-2016/program.cg
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