Controls on the spatio-temporal patterns of induced seismicity in Groningen constrained by physics-based modelling with Ensemble-Smoother data assimilation

The induced seismicity in the Groningen gas field, The Netherlands, presents contrasted spatio-temporal patterns between the central area and the south west area. Understanding the origin of this contrast requires a thorough assessment of two factors: (1) the stress development on the Groningen faults and (2) the frictional response of the faults to induced stresses. Both factors have large uncertainties that must be honoured and then reduced with the observational constraints. Ensembles of induced stress realizations are built by varying the Poisson's ratio in a poro-elastic model incorporating the 3-D complexities of the geometries of the Groningen gas reservoir and its faults, and the historical pore pressure distribution. The a priori uncertainties in the frictional response are mapped by varying the parameters of a seismicity model based on rate-and-state friction. The uncertainties of each component of this complex physics-based model are honoured through an efficient data assimilation algorithm. By assimilating the seismicity data with an Ensemble-Smoother, the prior uncertainties of each model parameter are effectively reduced, and the posterior seismicity rate predictions are consistent with the observations. Our integrated workflow allows us to disentangle the contributions of the main two factors controlling the induced seismicity at Groningen, induced stress development and fault frictional response. Posterior distributions of the model parameters of each modelling component are contrasted between the central and south west area at Groningen. We find that, even after honouring the spatial heterogeneity in stress development across the Groningen gas field, the spatial variability of the observed induced seismicity rate still requires spatial heterogeneity in the fault frictional response. This work is enabled by the unprecedented deployment of an Ensemble-Smoother combined with physics-based modelling over a complex case of reservoir induced seismicity

Mobile app-based symptom-rhythm correlation assessment in patients with persistent atrial fibrillation

Background: The assessment of symptom-rhythm correlation (SRC) in patients with persistent atrial fibrillation (AF) is challenging. Therefore, we performed a novel mobile app-based approach to assess SRC in persistent AF.Methods: Consecutive persistent AF patients planned for electrical cardioversion (ECV) used a mobile app to record a 60-s photoplethysmogram (PPG) and report symptoms once daily and in case of symptoms for four weeks prior and three weeks after ECV. Within each patient, SRC was quantified by the SRC-index defined as the sum of symptomatic AF recordings and asymptomatic non-AF recordings divided by the sum of all recordings.Results: Of 88 patients (33% women, age 68 +/- 9 years) included, 78% reported any symptoms during recordings. The overall SRC-index was 0.61 (0.44-0.79). The study population was divided into SRC-index tertiles: low (= 0.73). Patients within the low (vs high) SRC-index tertile had more often heart failure and diabetes mellitus (both 24.1% vs 6.9%). Extrasystoles occurred in 19% of all symptomatic non-AF PPG recordings. Within each patient, PPG recordings with the highest (vs lowest) tertile of pulse rates conferred an increased risk for symptomatic AF recordings (odds ratio [OR] 1.26, 95% coincidence interval [CI] 1.04-1.52) and symptomatic non-AF recordings (OR 2.93, 95% CI 2.16-3.97). Pulse variability was not associated with reported symptoms.Conclusions: In patients with persistent AF, SRC is relatively low. Pulse rate is the main determinant of reported symptoms. Further studies are required to verify whether integrating mobile app-based SRC assessment in current workflows can improve AF management

Variability in the articulation and perception of a word

The words making up a speaker’s mental lexicon may be stored as abstract phonological representations or else they may be stored as detailed acoustic-phonetic representations. The speaker’s articulatory gestures intended to represent a word show relatively high variability in spontaneous speech. The aim of this paper is to explore the acoustic-phonetic patterns of the Hungarian word akkor ‘then, at that time’. Ten speakers’ recorded spontaneous speech with a total duration of 255 minutes and containing 286 occurrences of akkor were submitted to analysis. Durational and frequency patterns were measured by means of the Praat software. The results obtained show higher variability both within and across speakers than it had been expected. Both the durations of the words and those of the speech sounds, as well as the vowel formants, turned out to significantly differ across speakers. In addition, the results showed considerable within-speaker variation as well. The correspondence between variability in the objective acoustic-phonetic data and the flexibility and adaptive nature of the mental representation of a word will be discussed.For the perception experiments, two speakers of the previous experiment were selected whose 48 words were then used as speech material. The listeners had to judge the quality of the words they heard using a five-point scale. The results confirmed that the listeners used diverse strategies and representations depending on the acoustic-phonetic parameters of the series of occurrences of akkor

Mobile health solutions for atrial fibrillation detection and management: a systematic review

AimWe aimed to systematically review the available literature on mobile Health (mHealth) solutions, including handheld and wearable devices, implantable loop recorders (ILRs), as well as mobile platforms and support systems in atrial fibrillation (AF) detection and management.MethodsThis systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The electronic databases PubMed (NCBI), Embase (Ovid), and Cochrane were searched for articles published until 10 February 2021, inclusive. Given that the included studies varied widely in their design, interventions, comparators, and outcomes, no synthesis was undertaken, and we undertook a narrative review.ResultsWe found 208 studies, which were deemed potentially relevant. Of these studies included, 82, 46, and 49 studies aimed at validating handheld devices, wearables, and ILRs for AF detection and/or management, respectively, while 34 studies assessed mobile platforms/support systems. The diagnostic accuracy of mHealth solutions differs with respect to the type (handheld devices vs wearables vs ILRs) and technology used (electrocardiography vs photoplethysmography), as well as application setting (intermittent vs continuous, spot vs longitudinal assessment), and study population.ConclusionWhile the use of mHealth solutions in the detection and management of AF is becoming increasingly popular, its clinical implications merit further investigation and several barriers to widespread mHealth adaption in healthcare systems need to be overcome

Articulatory planning is continuous and sensitive to informational redundancy

Contains fulltext : 41028.pdf (author's version ) (Open Access)14 p

Management of idiopathic recurrent pericarditis during pregnancy

Background: Data concerning idiopathic recurrent pericarditis in pregnancy are scarce. Objectives: To evaluate the management and outcome of idiopathic recurrent pericarditis during pregnancy. Methods and results: Twenty-one pregnancies were evaluated in fourteen women with a history of recurrent idiopathic pericarditis (mean maternal age 31.5 years, mean gestational age 39.0 weeks), and subdivided in 2 cohorts: eight pregnancies were analyzed retrospectively (2002 122010), thirteen (2011\u20132017) prospectively and followed according a predefined management protocol. Ten pregnancies were uneventful, three ended in spontaneous early abortion, one fetal death occurred at 19 weeks. Recurrences of pericarditis occurred in eight and were treated by adding NSAIDs in two cases; in five cases the dose of corticosteroids was increased and in two cases aspirin was started/increased; paracetamol was always allowed. Colchicine was used in two cases in the prospective cohort. HELLP syndrome occurred in one patient, which resolved after delivery, and one patient experienced arterial hypertension and elevated transaminase. All infants had a good outcome (mean birth weight 3114 g, 10 males). Birth weight was significantly lower in the retrospective cohort (respectively 2806 g vs. 3320 g, p-value 0.017) in which higher doses of corticosteroids were used (median dose respectively 10.0 mg vs. 2.5 mg, p-value 0.048). Five recurrences of pericarditis occurred after delivery, easily treated with standard therapy. Conclusion: General outcomes of pregnancy in patients with idiopathic recurrent pericarditis is good, especially when patients are carefully followed by multidisciplinary teams according to standardized protocols