bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in sleep EEG with aging in humans and rodents
Authors: Campos-Beltrán Diana , Marshall Lisa 
Published: April 2021

AbstractSleep is one of the most ubiquitous but also complex animal behaviors. It is regulated at the global, systems level scale by circadian and homeostatic processes. Across the 24-h day, distribution of sleep/wake activity differs between species, with global sleep states characterized by defined patterns of brain electric activity and electromyography. Sleep patterns have been most intensely investigated in mammalian species. The present review begins with a brief overview on current understandings on the regulation of sleep, and its interaction with aging. An overview on age-related variations in the sleep states and associated electrophysiology and oscillatory events in humans as well as in the most common laboratory rodents follows. We present findings observed in different studies and meta-analyses, indicating links to putative physiological changes in the aged brain. Concepts requiring a more integrative view on the role of circadian and homeostatic sleep regulatory mechanisms to explain aging in sleep are emerging.
The effect of pain on reference memory for duration
Authors: Piovesan Andrea , Mirams Laura , Poole Helen , Ogden Ruth 
Published: April 2021

AbstractPrevious research has consistently reported that pain related stimuli are perceived as lasting longer than non-pain related ones, suggesting that pain lengthens subjective time. However, to date, the investigation has been limited to the immediate effects of pain on time perception. The current study aims to investigate whether pain affects how a duration is recalled after a period of delay. In two experiments, participants were asked to complete four temporal generalisation tasks, where they were required first to remember the duration of a standard tone (learning phase) and then to compare the standard duration to a series of comparison durations (testing phase). Using a 2 × 2 design, the four tasks differed in terms of whether participants were exposed to a painful or non-painful stimulus during the learning phase, and whether the testing phase started immediately or 15 min after the learning phase. Participants were exposed to low pain in Experiment 1 and high pain in Experiment 2. Two possible results were expected: pain could decrease temporal accuracy, because pain disrupts cognitive processes required for accurate timing, or pain could increase temporal accuracy, because pain facilitates memory consolidation. Contrary to expectations, results from both Experiments indicated that participants’ temporal performances were similar in the pain and no-pain conditions when testing occurred 15 min after the learning phase. Findings, therefore, suggest that pain neither disrupts nor enhances long-term memory representations of duration.
The risks associated with tourniquet use in lower limb trauma surgery: a systematic review and meta-analysis
Authors: Farhan-Alanie Muhamed M. , Dhaif Fatema , Trompeter Alex , Underwood Martin , Yeung Joyce , Parsons Nick , Metcalfe Andy , Wall Peter D. H. 
Published: April 2021

Abstract
Purpose
Tourniquet use in lower limb fracture surgery may reduce intra-operative bleeding, improve surgical field of view and reduce length of procedure. However, tourniquets may result in pain and the production of harmful metabolites cause complications or affect functional outcomes. This systematic review aimed to compare outcomes following lower limb fracture surgery performed with or without tourniquet.

Methods
We searched databases for RCTs comparing lower limb fracture surgery performed with versus without tourniquet reporting on outcomes pain, physical function, health-related quality of life, complications, cognitive function, blood loss, length of stay, length of procedure, swelling, time to union, surgical field of view, volume of anaesthetic agent, biochemical markers of inflammation and injury, and electrolyte and acid–base balance. Random-effects meta-analysis was performed. PROSPERO ID CRD42020209310.

Results
Six RCTs enabled inclusion of 552 procedures. Pooled analysis demonstrated that tourniquet use reduced length of procedure by 6 minutes (95% CI −10.12 to −1.87; p < 0.010). We were unable to exclude increased harms from tourniquet use. Pooled analysis showed post-operative pain score was higher in tourniquet group by 12.88 on 100-point scale (95% CI −1.25–27.02; p = 0.070). Risk differences for wound infection, deep venous thrombosis and re-operation were 0.06 (95% CI −0.00–0.12; p = 0.070), 0.05 (95% CI −0.02–0.11; p = 0.150) and 0.03 (95% CI -0.03–0.09; p = 0.340).

Conclusion
Tourniquet use was associated with a reduced length of procedure. It is possible that tourniquets also increase incidence of important complications, but the data are too sparse to draw firm conclusions. Methodological weaknesses of the included RCTs prevent any solid conclusions being drawn for outcomes investigated. Further studies are required to address these limitations.
Weight-scheduling for linear time-variant model predictive wind turbine control toward field testing
Authors: Wintermeyer-Kallen Thorben , Dickler Sebastian , Zierath János , Konrad Thomas , Abel Dirk 
Published: April 2021

AbstractModern multi-megawatt wind turbines require powerful control algorithms which consider several control objectives at the same time and respect process constraints. Model predictive control (MPC) is a promising control method and has been a research topic for years. So far, very few studies evaluated MPC algorithms in field tests. This work aims to prepare a real-time MPC system for a full-scale field test in a 3 MW wind turbine. To this end, we introduce a weight-scheduling scheme for a linear time-variant MPC in order to ensure control operation over the entire operating range from the partial to the full load range. We use a rapid control prototyping process, in particular with comprehensive software-in-the-loop (SiL) tests, in order to design and validate the MPC system for the field test.In this contribution, we present the implementation of the linear time-variant MPC with weight-scheduling to be tested in the field test. With the weight-scheduling for the optimization problem inside the MPC, we achieved good performance over the entire operating range of the wind turbine. In the SiL tests, the proposed MPC algorithm achieved loads, comparable to the baseline controller of the wind turbine and improved the reference tracking of the power output and the rotational speed. The proposed linear time-variant MPC with weight-scheduling is fully validated in the presented software-in-the-loop tests and is ready for full-scale field test in the 3 MW wind turbine. We present the experimental field test results of the introduced MPC system in a separated contribution.
First comparison of the electrical properties of two grid emulators for UVRT test against field measurement
Authors: Frehn Anica , Azarian Soroush , Quistorf Gesa , Adloff Stephan , Santjer Fritz , Monti Antonello 
Published: April 2021

AbstractThe technical rules for connecting turbines to the medium, high or extra-high voltage grid in Germany require the certification of the UVRT characteristics of wind turbines. The state-of-art voltage divider-based test equipment, also named UVRT-Container, is well equipped for executing UVRT tests in field. To conduct the UVRT in field the full wind turbine should be already installed. A second option to perform UVRT tests are system level test benches. They enable the testing of the nacelle. The components that are not actually present, such as the turbine tower or the blades, are emulated via a mechanical hardware in the loop (HiL) system. In this work, for the first time, the performance of two different grid simulators installed at the DyNaLab at Fraunhofer IWES and at the CWD at RWTH Aachen University is compared with a field measurement of the same type of wind turbine. Thus, not only a system test bench measurement is compared to a field measurement. Rather, two system test benches with individual technical approaches are additionally compared with each other. The focus of this work is to investigate the characteristics of the grid simulators within the steady-state range of the UVRT tests to replicate identical fault shapes on the test benches and in the field.
The spherical primitive and perlin noise method to recreate realistic aggregate shapes
Authors: Michot-Roberto S. , Garcia-Hernández A. , Dopazo-Hilario S. , Dawson A. 
Published: April 2021

Abstract
An algorithm to re-create virtual aggregates with realistic shapes is presented in this paper. The algorithm has been implemented in the Unity 3D platform. The idea is to re-create realistically the virtual coarse and crushed aggregates that are normally used as a material for the construction of roads. This method consists of two major procedures: (i) to combine a spherical density function with a noise matrix based on the Perlin noise to obtain shapes of appropriate angularity and, (ii) deform the shapes until their minor ferret, aspect ratio and, thickness are equivalent to those wanted. The efficiency of the algorithm has been tested by reproducing nine types of aggregates from different sources. The results obtained indicate that the method proposed can be used to realistically re-create in 3D coarse aggregates.

Graphic abstract
T2-weighted, apparent diffusion coefficient and 18F-FDG PET histogram analysis of rectal cancer after preoperative chemoradiotherapy
Authors: Crimì F. , Stramare R. , Spolverato G. , Aldegheri V. , Barison A. , D’Alimonte L. , Bao Q. R. , Spimpolo A. , Albertoni L. , Cecchin D. , Campi C. , Quaia E. , Pucciarelli S. , Zucchetta P. 
Published: April 2021

Abstract
Background
The aim of our study was to investigate the correlation among T2-weighted (T2w) images, apparent diffusion coefficient (ADC) maps, 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) images, histogram analysis and the pathological response in locally advanced rectal cancer (LARC) after preoperative chemoradiotherapy (pCRT).

Methods
Patients with LARC were prospectively enrolled between February 2015 and August 2018 and underwent PET/magnetic resonance imaging (MRI). MRI included T2w and diffusion-weighted imaging (DWI)-sequences. ADC maps and PET images were matched to the T2w images. Voxel-based standardized uptake values (SUVs,) ADC and T2w-signal-intensity values were collected from the volumes of interest (VOIs) and mean, skewness and kurtosis were calculated. Spearman’s correlation coefficient was applied to evaluate the correlation among the variables and tumor regression grade (TRG), T stage, N stage and fibrosis.

Results
Twenty-two patients with biopsy-proven LARC in the low or mid rectum were enrolled [17 males, mean age was 69 years (range 49–85 years)]. Seven patients experienced complete regression (TRG1). A significant positive correlation was found between SUV mean values (ρ = 0.480; p = 0.037) and TRG. No other significant correlations were found.

Conclusions
Histogram analysis of SUV values is a predictor of TRG in LARC.
All-case Japanese post-marketing surveillance of the real-world safety and efficacy of rituximab treatment in patients with refractory nephrotic syndrome
Authors: Kobayashi Mana , Kageyama Yutaro , Ando Takashi , Sakamoto Junko , Kimura Shohji 
Published: April 2021

Abstract
Background
Rituximab is conditionally approved in Japan for use in patients with refractory nephrotic syndrome. To meet the conditions of approval, an all-case post-marketing surveillance study was conducted to confirm the real-world safety and efficacy of rituximab in patients of all ages with refractory nephrotic syndrome.

Methods
All patients scheduled to receive rituximab treatment for refractory nephrotic syndrome were eligible to register (registration: August 29, 2014 through April 15, 2016); the planned observation period was 2 years from the initiation of rituximab treatment (intravenous infusion, 375 mg/m2 once weekly for four doses). The study was conducted at 227 hospitals throughout Japan. Adverse drug reactions (ADRs) were collected for safety outcomes. The efficacy outcomes were relapse-free period and the degree of growth in pediatric (< 15 years) patients.

Results
In total, 997 (447 pediatric) patients were registered; 981 (445) were included in the safety analysis set; 852 (402) completed the 2-year observation period; and 810 (429) were included in the efficacy analysis set. Refractory nephrotic syndrome had developed in childhood for 85.0% of patients, and 54.6% were aged ≥15 years. ADRs were observed in 527 (53.7%) patients, treatment-related infection/infestation in 235 (24.0%) patients, and infusion reactions in 313 (31.9%) patients. The relapse-free period was 580 days (95% confidence interval, 511–664). There was a significant change in height standard deviation score (pediatric patients; mean change, 0.093; standard deviation, 0.637; P = 0.009).

Conclusion
The safety and efficacy of rituximab treatment in patients with refractory nephrotic syndrome were confirmed in the real-world setting.

Clinical trial registration
UMIN000014997.
Subject-specific multiscale modeling of aortic valve biomechanics
Authors: Rossini G. , Caimi A. , Redaelli A. , Votta E. 
Published: April 2021

AbstractA Finite Element workflow for the multiscale analysis of the aortic valve biomechanics was developed and applied to three physiological anatomies with the aim of describing the aortic valve interstitial cells biomechanical milieu in physiological conditions, capturing the effect of subject-specific and leaflet-specific anatomical features from the organ down to the cell scale. A mixed approach was used to transfer organ-scale information down to the cell-scale. Displacement data from the organ model were used to impose kinematic boundary conditions to the tissue model, while stress data from the latter were used to impose loading boundary conditions to the cell level. Peak of radial leaflet strains was correlated with leaflet extent variability at the organ scale, while circumferential leaflet strains varied over a narrow range of values regardless of leaflet extent. The dependency of leaflet biomechanics on the leaflet-specific anatomy observed at the organ length-scale is reflected, and to some extent emphasized, into the results obtained at the lower length-scales. At the tissue length-scale, the peak diastolic circumferential and radial stresses computed in the fibrosa correlated with the leaflet surface area. At the cell length-scale, the difference between the strains in two main directions, and between the respective relationships with the specific leaflet anatomy, was even more evident; cell strains in the radial direction varied over a relatively wide range ($$0.36-0.87$$

0.36
-
0.87

) with a strong correlation with the organ length-scale radial strain ($$R^{2}= 0.95$$

R
2

=
0.95

); conversely, circumferential cell strains spanned a very narrow range ($$0.75-0.88$$

0.75
-
0.88

) showing no correlation with the circumferential strain at the organ level ($$R^{2}= 0.02$$

R
2

=
0.02

). Within the proposed simulation framework, being able to account for the actual anatomical features of the aortic valve leaflets allowed to gain insight into their effect on the structural mechanics of the leaflets at all length-scales, down to the cell scale.
Enhancing finite difference approximations for double barrier options: mesh optimization and repeated Richardson extrapolation
Authors: Ballestra Luca Vincenzo 
Published: April 2021

AbstractWe show that the performances of the finite difference method for double barrier option pricing can be strongly enhanced by applying both a repeated Richardson extrapolation technique and a mesh optimization procedure. In particular, first we construct a space mesh that is uniform and aligned with the discontinuity points of the solution being sought. This is accomplished by means of a suitable transformation of coordinates, which involves some parameters that are implicitly defined and whose existence and uniqueness is theoretically established. Then, a finite difference scheme employing repeated Richardson extrapolation in both space and time is developed. The overall approach exhibits high efficacy: barrier option prices can be computed with accuracy close to the machine precision in less than one second. The numerical simulations also reveal that the improvement over existing methods is due to the combination of the mesh optimization and the repeated Richardson extrapolation.
Agent-based simulation of pedestrian dynamics for exposure time estimation in epidemic risk assessment
Authors: Harweg Thomas , Bachmann Daniel , Weichert Frank 
Published: April 2021

Abstract
Purpose
With the coronavirus disease 2019 (COVID-19) pandemic spreading across the world, protective measures for containing the virus are essential, especially as long as no vaccine or effective treatment is available. One important measure is the so-called physical distancing or social distancing.

Methods
In this paper, we propose an agent-based numerical simulation of pedestrian dynamics in order to assess the behavior of pedestrians in public places in the context of contact transmission of infectious diseases like COVID-19, and to gather insights about exposure times and the overall effectiveness of distancing measures.

Results
To abide by the minimum distance of 1.5 m stipulated by the German government at an infection rate of 2%, our simulation results suggest that a density of one person per 16m2 or below is sufficient.

Conclusions
The results of this study give insight into how physical distancing as a protective measure can be carried out more efficiently to help reduce the spread of COVID-19.
Social acceptance of serious games for physical and cognitive training in older adults residing in ambient assisted living environments
Authors: Brauner Philipp , Ziefle Martina 
Published: April 2021

AbstractAimsAlthough ambient assisted living (AAL) environments and serious games for healthcare have been proposed as solutions to meet the changing demographics, the two approaches are rarely combined. We present the development and empirical evaluation of two serious games for healthcare in AAL. The first uses a cooking scenario for training of cognitive functioning. The latter uses a gardening scenario and motion capture for training agility and endurance. As the frequent lack of social acceptance is a major challenge in consumer health technology, we integrated methods of technology acceptance research by means of the UTAUT2-model and intention to use into the evaluation.Subject and methodsWe developed both games utilizing user-centered and participatory design methods ranging from low-fidelity paper prototypes to usability and acceptance evaluations of functional prototypes. In the final evaluation, each game prototype was evaluated by 64 participants form different age groups.ResultsThe results show that although performance decreases with age, the performance attained in the games is not decisive for social acceptance measured as intention to use. However, user diversity factors shape the evaluation of the games, and older people and people with low technical competence are in danger of being excluded from using serious games for healthcare.ConclusionExercise games, if designed right, can mitigate the negative effects of demographic change. Nevertheless, user diversity needs must be considered to ensure that the games are usable and used by a broad audience. The article concludes with guidelines and open research questions for the design of serious games in AAL environments.
Large Eddy Simulation of an Ethanol Spray Flame with Secondary Droplet Breakup
Authors: Gallot-Lavallée S. , Jones W. P. , Marquis A. J. 
Published: April 2021

AbstractA computational investigation of three configurations of the Delft Spray in Hot-diluted Co-flow (DSHC) is presented. The selected burner comprises a hollow cone pressure swirl atomiser, injecting an ethanol spray, located in the centre of a hot co-flow generator, with the conditions studied corresponding to Moderate or Intense Low-oxygen Dilution (MILD) combustion. The simulations are performed in the context of Large Eddy Simulation (LES) in combination with a transport equation for the joint probability density function (pdf) of the scalars, solved using the Eulerian stochastic field method. The liquid phase is simulated by the use of a Lagrangian point particle approach, where the sub-grid-scale interactions are modelled with a stochastic approach. Droplet breakup is represented by a simple primary breakup model in combination with a stochastic secondary breakup formulation. The approach requires only a minimal knowledge of the fuel injector and avoids the need to specify droplet size and velocity distributions at the injection point. The method produces satisfactory agreement with the experimental data and the velocity fields of the gas and liquid phase both averaged and ‘size-class by size-class’ are well depicted. Two widely accepted evaporation models, utilising a phase equilibrium assumption, are used to investigate the influence of evaporation on the evolution of the liquid phase and the effects on the flame. An analysis on the dynamics of stabilisation sheds light on the importance of droplet size in the three spray flames; different size droplets play different roles in the stabilisation of the flames.
Is free-energy minimisation the mark of the cognitive?
Authors: Kiverstein Julian , Sims Matt 
Published: April 2021

AbstractA mark of the cognitive should allow us to specify theoretical principles for demarcating cognitive from non-cognitive causes of behaviour in organisms. Specific criteria are required to settle the question of when in the evolution of life cognition first emerged. An answer to this question should however avoid two pitfalls. It should avoid overintellectualising the minds of other organisms, ascribing to them cognitive capacities for which they have no need given the lives they lead within the niches they inhabit. But equally it should do justice to the remarkable flexibility and adaptiveness that can be observed in the behaviour of microorganisms that do not have a nervous system. We should resist seeking non-cognitive explanations of behaviour simply because an organism fails to exhibit human-like feats of thinking, reasoning and problem-solving. We will show how Karl Friston’s Free-Energy Principle (FEP) can serve as the basis for a mark of the cognitive that avoids the twin pitfalls of overintellectualising or underestimating the cognitive achievements of evolutionarily primitive organisms. The FEP purports to describe principles of organisation that any organism must instantiate if it is to remain well-adapted to its environment. Living systems from plants and microorganisms all the way up to humans act in ways that tend in the long run to minimise free energy. If the FEP provides a mark of the cognitive, as we will argue it does, it mandates that cognition should indeed be ascribed to plants, microorganisms and other organisms that lack a nervous system.