Stretching Method-Based Operational Modal Analysis of An Old Masonry Lighthouse.

We present in this paper a structural health monitoring study of the Egyptian lighthouse of Rethymnon in Crete, Greece. Using structural vibration data collected on a limited number of sensors during a 3-month period, we illustrate the potential of the stretching method for monitoring variations in the natural frequencies of the structure. The stretching method compares two signals, the current that refers to the actual state of the structure, with the reference one that characterizes the structure at a reference healthy condition. For the structure under study, an 8-day time interval is used for the reference quantity while the current quantity is computed using a time window of 24 h. Our results indicate that frequency shifts of 1% can be detected with high accuracy allowing for early damage assessment. We also provide a simple numerical model that is calibrated to match the natural frequencies estimated using the stretching method. The model is used to produce possible damage scenarios that correspond to 1% shift in the first natural frequencies. Although simple in nature, this model seems to deliver a realistic response of the structure. This is shown by comparing the response at the top of the structure to the actual measurement during a small earthquake. This is a preliminary study indicating the potential of the stretching method for structural health monitoring of historical monuments. The results are very promising. Further analysis is necessary requiring the deployment of the instrumentation (possibly with additional instruments) for a longer period of time

Genome-wide Analyses Identify KIF5A as a Novel ALS Gene

To identify novel genes associated with ALS, we undertook two lines of investigation. We carried out a genome-wide association study comparing 20,806 ALS cases and 59,804 controls. Independently, we performed a rare variant burden analysis comparing 1,138 index familial ALS cases and 19,494 controls. Through both approaches, we identified kinesin family member 5A (KIF5A) as a novel gene associated with ALS. Interestingly, mutations predominantly in the N-terminal motor domain of KIF5A are causative for two neurodegenerative diseases: hereditary spastic paraplegia (SPG10) and Charcot-Marie-Tooth type 2 (CMT2). In contrast, ALS-associated mutations are primarily located at the C-terminal cargo-binding tail domain and patients harboring loss-of-function mutations displayed an extended survival relative to typical ALS cases. Taken together, these results broaden the phenotype spectrum resulting from mutations in KIF5A and strengthen the role of cytoskeletal defects in the pathogenesis of ALS.Peer reviewe

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Early diagnosis and better rhythm management to improve outcomes in patients with atrial fibrillation: the 8th AFNET/EHRA consensus conference

Aims Despite marked progress in the management of atrial fibrillation (AF), detecting AF remains difficult and AF-related complications cause unacceptable morbidity and mortality even on optimal current therapy.Methods and results This document summarizes the key outcomes of the 8th AFNET/EHRA Consensus Conference of the Atrial Fibrillation NETwork (AFNET) and the European Heart Rhythm Association (EHRA). Eighty-three international experts met in Hamburg for 2 days in October 2021. Results of the interdisciplinary, hybrid discussions in breakout groups and the plenary based on recently published and unpublished observations are summarized in this consensus paper to support improved care for patients with AF by guiding prevention, individualized management, and research strategies. The main outcomes are (i) new evidence supports a simple, scalable, and pragmatic population-based AF screening pathway; (ii) rhythm management is evolving from therapy aimed at improving symptoms to an integrated domain in the prevention of AF-related outcomes, especially in patients with recently diagnosed AF; (iii) improved characterization of atrial cardiomyopathy may help to identify patients in need for therapy; (iv) standardized assessment of cognitive function in patients with AF could lead to improvement in patient outcomes; and (v) artificial intelligence (AI) can support all of the above aims, but requires advanced interdisciplinary knowledge and collaboration as well as a better medico-legal framework.Conclusions Implementation of new evidence-based approaches to AF screening and rhythm management can improve outcomes in patients with AF. Additional benefits are possible with further efforts to identify and target atrial cardiomyopathy and cognitive impairment, which can be facilitated by AI.</p

Educational Seismology through an Immersive Virtual Reality Game: Design, Development and Pilot Evaluation of User Experience

Virtual Reality (VR), especially in its immersive form, is a promising technology employed to support education and training in various fields. VR offers unique opportunities to experience situations and environments that are otherwise inaccessible or risky. Educational Seismology aims to inform and educate the public on earthquakes; to this end, the use of VR is investigated as an attractive solution. VRQuake is an immersive VR application designed and developed for Educational Seismology purposes. VRQuake is structured in five consecutive scenes and is organized as a game. It allows users to interact with virtual objects in real time and apply learned rules and good practices in reaction to an earthquake, thus providing a dynamic learning environment. A pilot evaluation of VRQuake is performed by volunteer university students who play the game and then answer a questionnaire with closed- and open-type questions referring mostly to the user experience. Analysis of the answers has shown positive results regarding usability, clarity and acceptance of the application. Answers are also encouraging as to the educational potential of VRQuake. Furthermore, qualitative analysis of open-type questions has contributed user suggestions and demands that point to interesting new directions for further improvement of user experience and learning outcomes

High-frequency ground motion scaling in the Gulf of Corinth (Greece)

The evaluation of the expected peak ground motion caused by an earthquake is of great importance in seismicity and earthquake engineering studies. In the present study, weak-motion data related to small earthquakes are used, in order to extrapolate peak ground motion parameters beyond the magnitude range of the weak-motion dataset, on which they are calculated. A complete description of the seismic ground-motion characteristics in the Gulf of Corinth region in Greece is provided, with parameterization of the attenuation of seismic ground motions with distance and their variability in excitation with earthquake magnitude. We use over 1000 earthquakes recorded at the Hellenic Unified Seismic Network (HUSN) with magnitudes larger than 2.5 ML. Following a regression analysis of this large number of weak-motion data, we determine a frequency-dependent crustal quality factor, a geometrical spreading function and the absolute source scaling. In order to calibrate sufficiently the source scaling, it is necessary to use the available moment magnitude values of events from the selected dataset. The National Observatory of Athens Moment Tensor Database (NOA-MTs) is used, which includes 52 events in the range 3.3 to 5.4 MW for the time period in analysis. Complementary, we calculate moment tensor solutions with high-quality for small events not included in the NOA-MTs catalogue, using the 'Cut And Paste' technique. Results on region-specific crustal attenuation and source scaling, together with the effective duration of seismic ground motion in the region, are used to estimate the peak ground motion parameters, such as PGA, PGV, and SA at different frequencies. Using stochastic ground motion simulations, we predict the absolute level of ground shaking and compare them with strong motion data in the region. The attenuation of simulated ground motion is compared with recent global and regional ground motion prediction equations (GMPEs). The performance of the stochastic model is also tested against moderate sized earthquakes (~5-6 MW) recorded by HUSN in the area under study.peer-reviewe

The Chios, Greece Earthquake of 23 July 1949: Seismological Reassessment and Tsunami Investigations

We present a modern seismological reassessment of the Chios earthquake of 23 July 1949, one of the largest in the Central Aegean Sea. We relocate the event to the basin separating Chios and Lesvos, and confirm a normal faulting mechanism generally comparable to that of the recent Lesvos earthquake located at the Northern end of that basin. The seismic moment obtained from mantle surface waves, M-0=7x10(26) dyn cm, makes it second only to the 1956 Amorgos earthquake. We compile all available macroseismic data, and infer a preference for a rupture along the NNW-dipping plane. A field survey carried out in 2015 collected memories of the 1949 earthquake and of its small tsunami from surviving witnesses, both on Chios Island and nearby Oinousses, and on the Turkish mainland. While our results cannot help discriminate between the two possible fault planes of the 1949 earthquake, an important result is that both models provide an acceptable fit to the reported amplitudes, without the need to invoke ancillary sources such as underwater landslides, in contrast to the case of other historical tsunamis in the Aegean Sea, such as the 1956 Amorgos and 1948 Rhodos events

Linking distributed and integrated fiber-optic sensing

Distributed Acoustic Sensing (DAS) has become a popular method of observing seismic wavefields: backscattered pulses of light reveal strains or strain-rates at any location along a fiber-optic cable. In contrast, a few newer systems transmit light through a cable and collect integrated phase delays over the entire cable, such as the Microwave Frequency Fiber Interferometer (MFFI). These integrated systems can be deployed over significantly longer distances, may be used in conjunction with live telecommunications, and can be significantly cheaper. However, they provide only a single time series representing strain over the entire length of fiber. This work discusses theoretically how a distributed and integrated system can be quantitatively compared, and we note that the sensitivity depends strongly on points of curvature. Importantly, this work presents the first results of a quantitative, head-to-head comparison of a DAS and the integrated MFFI system using pre-existing telecommunications fibers in Athens, Greece.Comment: Submitted to Geophysical Research Letters. 12 pages, 5 figure