bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of a Probabilistic Health Monitoring System Using Embedded Piezoelectric Patch Sensors
Authors: Eshghi Amin Toghi , Lee Soobum , Jung HyunJun , Wang Pingfeng
Published: December 2019

This paper proposes a probabilistic model for the placement of sensors that considers uncertain factors in the sensing system to find the best arrangement of sensor locations. Traditional procedures for structural health monitoring (SHM) usually rely on simplified behavior and deterministic factors from structure’s response. Incorporating the sources of uncertainty (e.g., loading condition, material properties, and geometrical parameters) in the design of sensor network will enhance the safety and extend the useful life of the complex mechanical systems. The proposed method is defined in a reliability-based design optimization framework to search for the sufficient number of sensors for failure detection using Genetic Algorithm. The optimal arrangement is found as the one that minimizes the number and size of sensor patches and maximizes the expected probability for failure detection. This design concept involves a new failure diagnosis indicator, named detectability, formulated based on the Mahalanobis Distance (MD). MD distribution is used as a measure of the quality of the obtained sensor configuration suitable for many sensing/actuation SHM processes, while considering the uncertainties such as those from structure properties and operation condition. The MD classifier categorizes large sets of testing data by comparing the distances of the mean with the distribution of available training data sets. Statistical evaluation of failure detectability can be obtained by comparing the distribution of MD for different failure modes. Kriging modeling, used for metamodel-based design optimization, is applied for surrogate modeling of the stochastic performance of system to reduce computational cost. The surrogate model is constructed by correlating the sensor output to the vibration pattern of the structure and sensor variable inputs (e.g., size and location). Direct finite element analysis (FEA) evaluates the sensor output with respect to the input variables. Consequently, the constructed kriging model enables the estimation of sensor output for any arbitrary sensor arrays. As a case study, a rectangular panel with a size of 40 cm × 30 cm is considered that is fastened using eight screw joints. The harmonic vibration force is applied to the center of the plate and its varied vibration pattern is used to detect the joint failure. Eight different combinations of join failure are defined as health statuses (failure modes), and different size and layouts of the piezoelectric sensors are considered to detect the health status. The results verify the capabilities of the new method for failure diagnosis of screw joints in a panel with high sensitivity of fault detection.
Design and Realization of Temperature-Driven Smart Structure Based on Shape Memory Polymer in 4D Printing
Authors: Feng Yixiong , Zeng Siyuan , Gao Yicong , Zheng Hao , Qiu Hao , Tan Jianrong
Published: December 2019

In the traditional 4D printing method using Shape Memory Polymer (SMP), the design process and preparation of 4d printing are complex. In this research, we proposed a design method of a temperature-driven SMP smart structure and made Realization. This smart structure also a bilayer structure use an SMP material in one printing process to realize the deformation in 4D printing. The design of the smart structure is mainly realized by parameter allocation in the printing process, such as print line width, print line height, print temperature, simulation temperature, and fill the form in Fused Deposition Modelling (FDM). Through experimental determination and analysis of statics and thermodynamics, our method fitting out the model relationship between process parameters and the curvature and strain of smart structure. This bilayer smart structure widely applied to the self-folding. In the example stage, this paper mainly uses PLA as an SMP material for the preparation of structure. Observing that the motion behaviors of the smart structure conformed to the model measured in this paper, the average accuracy of the strategy reaches 95%.
Geometrically Nonlinear Vibration Attenuation of Functionally Graded Magneto-Electro-Elastic Shells
Authors: Kattimani Subhaschandra , Joladarashi Sharnappa , Mahesh Vinyas
Published: December 2019

In this paper, Geometrically Nonlinear Vibrations (GNV) of Functionally Graded Magneto-Electro-Elastic (FGMEE) shells integrated with a patch of Active Constrained Layer Damping (ACLD) treatment is studied. In case of FG material, properties vary along the z-coordinates using power-law index. Finite element model is developed for FGMEE doubly curved shell using a shear deformation theory by considering non linearity to analyze the FGMEE shell. The structure consists of magnetostrictive material (CoFe2O4) and piezoelectric material (BaTiO3) FGMEE doubly curved shell with piezoelectric composite (1-3 PZC) is used as a constraining layer for viscoelastic layer, which is modelled using Golla-Hughes-McTavish (GHM) method. The analysis is carried out in time domain by considering the effects of coupling coefficients, curvature ratio and patch location on the behaviour of the nonlinear frequency of the shell. The amplitude of vibrations reduces considerably by considering the active ACLD patches (1-3 PZC) of the FGMEE shell with nominal control voltage.
Analytical Modeling and Simulation of the Blocked Force and Large Deformation of Multifunctional Segmented Lithium Ion Battery Unimorph Actuator
Authors: Gonzalez Cody , Ma Jun , Frecker Mary , Rahn Christopher
Published: December 2019

A self-powered, and self-actuating lithium ion battery (LIB) has the potential to achieve large deformation while still maintaining actuation force. The energy storage capability allows for continual actuation without an external power source once charged. Reshaping the actuator requires a nonuniform distribution of charge and/or bending stiffness. Spatially varying the state of charge and bending stiffness along the length of a segmented unimorph configuration have the effect of improving the tailorability of the deformed actuator. In this paper, an analytical model is developed to predict the actuation properties of the segmented unimorph beam to determine its usefulness as an actuator. The model predicts the free deflection, blocked deflection, and blocked force at the tip as a function of spatially varying state of charge and bending stiffness. The main contribution of the paper is the development of blocked deflection over the length of the segmented unimorph, which has not yet been considered in the literature. The model is verified using experimental data and commercial finite element analysis.
Versatile Layering Approach to Pneumatic Soft Actuator Manufacturing
Authors: Allen Emily A. , Swensen John P.
Published: December 2019

This paper presents a layering approach for the manufacturing of pneumatic soft actuators as a coalesced solution to the diverse array of existing fabrication methods. While most research groups have developed their own (often tedious) fabrication strategies for soft actuators, these methods are usually based on available equipment and project-specific design requirements, making them impractical for use in other laboratories. In contrast, the layered substrate approach enables repeatable production of highly-capable pneumatic actuators that can be easily customized to suit a variety of applications. Here we propose layering fiber-reinforced silicone on both sides of a thin pneumatic chamber to directionally constrain expansion. Similar in concept to the Venus flytrap, pressurization of the chamber causes the module to deform and expand where unrestrained. Strategic orientation and patterning of the fiber reinforcement layers results in multiple unique shear and bending capabilities upon pressurization. Combinations of multiple reinforced pneumatic units in series or parallel could match the capabilities of most soft pneumatic actuators, while requiring only simple, universal fabrication methods that may be replicated by other research groups.
Shape Memory Alloys in Continuum and Soft Robotic Applications
Authors: Goergen Yannik , Chadda Romol , Britz Rouven , Scholtes Dominik , Koev Nataliya , Motzki Paul , Werthschützky Roland , Kupnik Mario , Seelecke Stefan
Published: December 2019

Continuum robots are inspired by biological trunks, snakes and tentacles. Unlike conventional robot manipulators, there are no rigid structures or joints. Advantageous is the ease of miniaturization combined with high dexterity, since limiting components such as bearings or gears can be omitted. Most currently used actuation elements in continuum robots require a large drive unit with electric motors or similar mechanisms. Contrarily, shape memory alloys (SMAs) can be integrated into the actual robot. The actuation is realized by applying current to the wires, which eliminates the need of an additional outside drive unit. In the presented study, SMA actuator wires are used in variously scaled continuum robots. Diameters vary from 1 to 60 mm and the lengths of the SMA driven tentacles range from 75 to 220 mm. The SMAs are arranged on an annulus in a defined distance to the neutral fiber, whereby the used cores vary from superelastic NiTi rods to complex structures and also function as restoring unit. After outlining the theoretical basics for the design of an SMA actuated continuum robot, the design process is demonstrated exemplarily using a guidewire for cardiac catheterizations. Results regarding dynamics and bending angle are shown for the presented guidewire.
Full-Field Deformation and Thermal Characterization of GNP/Epoxy and GNP/SMA Fiber/Epoxy Composites
Authors: Kilic Ugur , Sherif Muhammad M. , Daghash Sherif M. , Ozbulut Osman E.
Published: December 2019

Shape memory alloys (SMAs) are a class of metallic alloys that possess remarkable characteristics such as superelasticity and shape memory effect. Superelastic SMAs have been considered as fiber in polymer composites due to their ability to recover their deformation upon removal of load, good energy dissipation capacity and impact resistance. Graphene nanoplatelets (GNPs) consists of small stacks of graphene sheets that are two-dimensional. Both sides of atomic lattice of GNPs contact matrix of a composite system and can generate more sites for potential chemical and physical bonding with the host material. Most importantly, graphene sheets and their derivatives can be produced at large-scale for industrial demand at low-cost.

This study explores the fabrication of multi-scale reinforced epoxy matrix composites in which GNPs and SMA strands are employed as nano- and micro-scale reinforcements, respectively. First, GNPs are dispersed into a ductile and brittle epoxy matrix to produce GNP/epoxy nanocomposites. To study the effect of GNP content on the behavior of the developed nanocomposite, GNPs are added to the epoxy-hardener mixture at different weight percentages (neat, 0.1%, 0.25%, 0.5%, 1%, and 2%). Uniaxial tensile tests of the developed nanocomposites are conducted under monotonic load up to failure. The optimum GNP content for GNP-reinforced epoxy matrix is determined and used in the fabrication of SMA fiber/epoxy composite. The developed multiscale reinforced epoxy composites are tested under tensile loading and their full-field strain and temperature behavior are monitored and evaluated using a digital image correlation system and an infrared thermal camera.
Developing a Smart Façade System Controller for Wind-Induced Vibration Mitigation in Tall Buildings
Authors: Abdelaziz Khalid M. , Hobeck Jared D.
Published: December 2019

Tall and slender buildings often endure disturbances resulting from winds composed of various mean and fluctuating velocities. These disturbances result in discomfort for the occupants as well as accelerated fatigue life cycles and premature fatigue failures in the building. This work presents the development of a smart morphing façade (Smorphaçade) system that dynamically alters a buildings’ external shape or texture to minimize the effect of wind-induced vibrations on the building. The Smorphacade system is represented in this work by a series of plates that vary their orientation by means of a central controller module. To validate the simulation, a simple NACA0012 airfoil is simulated in a stream of air at a Reynolds number (RE) of 2 million. The pressure and viscous force profiles are captured to plot the variation of the lift force for different angles of attack that are then validated using published experimental airfoil data. After validation, the airfoil is attached to a linear spring-damper combination and is allowed to translate vertically without rotation according to the force profile captured from the surrounding air stream. A PID controller is developed to equilibrate the vertical position of the airfoil by altering its angle of attack. The model and its utility functions are implemented as an OpenFOAM® module (MSLSolid). Thereafter, the model is expanded to handle a planar case of a building floor carrying 4 controllable plates. The forces on the building profile are summed at the centroid of the building and the windward rigid body motion of the floor is estimated by reflecting the horizontal force component on a Finite Element (FE) model of the building. The time series information of the force acting on the building and the resulting oscillations are captured for exhaustive combinations of the plate angles. This data is used to build a lookup table that gives the best plate configuration for a given wind condition. A controller operates in real-time by searching the lookup table using readings of the wind condition. Preliminary results show a 94% reduction in the amplitudes of wind-induced vibrations.
Modeling and Prototyping of Self-Folding Origami Structure
Authors: Jovanova Jovana , Domazetovska Simona , Changoski Vasko
Published: December 2019

Inspired by the spring blossoms of tulips and origami engineering, we have designed a monolithic self-deployable structure with the ability to fold (close) and unfold (open). The focus of this paper is the 3D design and prototyping of a self-folding origami structure actuated by shape memory alloys (SMAs). SMA actuators, spring and wires, provide controllable actuation based on the simplicity of their design and the shape memory effect. In mechanical engineering, the art of origami provides a novel approach for compliant mechanisms devices enabling relative movement between the components with reduction of the number of parts. The self-folding origami structures can be used in many applications for volume reduction in packaging and space engineering.

Additive manufacturing technologies enable easy and fast prototyping of the monolithic structure. The geometry of the structure and the integration of smart active materials within the structure enable the design to achieve complete self-folding.
Towards Highly Reconfigurable Carbon Fiber Composite
Authors: Casalotti Arnaldo , Lanzara Giulia , Snyder Matthew P.
Published: December 2019

This article discusses an approach to develop innovative carbon fiber composites that have the capability to change shape according to a prescribed input. The approach is based on the study of specific stacking sequences of unidirectional fiber plies cured on a curved mold.

The effects of the above-mentioned aspects are investigated on the manufactured specimen. The combined thermo-mechanical response is investigated by performing mechanical tests at various prescribed temperatures and the intensity of the shape change is evaluated together with the corresponding stiffness variation.

The experimental campaign is mostly devoted to characterize the response of the manufactured sample and demonstrate the great capability of the proposed approach to develop a smart material with enhanced shape and stiffness variation according the prescribed input.
Ultra-Long Nanocomposite Wire Ropes
Authors: Marini Marco , Talò Michela , Lanzara Giulia , Lacarbonara Walter
Published: December 2019

Carbon nanotubes (CNT) represent an effective filler to be incorporated into polymer matrices. Their physical properties allow them to exert a remarkable strengthening effect, while their nano-scale leaves the polymer weight unaltered. Exploiting their high strength-to-weight ratio, CNT/polymer nanocomposites appear to be the ideal materials to be shaped as wires and fibers. In this work, an ad-hoc innovative extrusion process is proposed to fabricate though and ultralong CNT/polymer nanocomposite wires. The process parameters are finely tuned to produce nanocomposite filaments exhibiting optimized mechanical properties. Optical analyses validate the morphological features of the fabricated filaments having an averaged diameter of 350 μm. Monotonic tensile tests are carried out to investigate the mechanical response of wires with CNTs content ranging from 1 wt% to 3 wt%. Young’s modulus and tensile strength registered increments of 47% and 43%, respectively, when comparing the 3 wt% CNT nanocomposite wires with the neat polymer wires. Finally, cyclic tensile tests are employed to investigate the change in damping capacity that accompanies the integration of CNTs into the polymer matrix. Such optimized CNTs nanocomposite wires can be easily integrated into several devices or assembled into ropes and yarns with multifunctional, improved properties.
Morphing Airfoil Design via L-System Generated Topology Optimization
Authors: Mikkelsen Madalyn , Mathew Michayal , Walgren Patrick , Bielefeldt Brent , Leal Pedro B. C. , Hartl Darren , Arrieta Andres
Published: December 2019

Morphing airfoils present an effective approach to managing the different requirements in each segment of a mission profile (e.g., takeoff/landing, cruise, and active maneuvering). In this work, an approach to morphing airfoil design that couples aerodynamic performance and internal structural configuration is detailed. The internal structural topology is formulated using a Lindenmayer System (L-System) coupled with a graph-based interpreter known as Spatial Interpretation for Development of Reconfigurable Structures (SPIDRS). The L-System encodes design variables that are interpreted via SPIDRS graphical operations and governs the development of the internal configuration (composed of elastic structural members and actuators). The global optimization uses a weakly coupled fluid-structure interaction (FSI) scheme for a first-order estimation of the aeroelastic loads that are critical for airfoil aerodynamic performance and structural integrity. Each airfoil is evaluated in two states: a standard non-actuated state to determine performance in standard operating conditions (e.g., cruise) and a high lift state, where internal shape memory alloy actuators are deformed to create a high lift configuration for the airfoil (e.g., takeoff/landing). Evaluating the aerodynamic performance of airfoils in these two states results in a series of potential solutions that best manage the tradeoff between aerodynamic metrics for both evaluated cases.
Annoyance penalty of periodically amplitude-modulated wide-band sound
Authors: Virjonen Petra , Hongisto Valtteri , Radun Jenni
Published: December 2019

Amplitude modulation exists in many environmental noise types. A penalty has been suggested for legal noise assessment to such sounds, but the scientific evidence is limited. The purpose of this research was to determine the annoyance penalty of amplitude modulated (AM) sound as a function of the modulation frequency fm and depth Dm. A psychoacoustic laboratory experiment was conducted with 40 participants to explore how subjective loudness and annoyance of AM sound depends on fm (from 0.25 to 16 Hz), Dm (from 1 to 14 dB), and overall spectrum (two alternatives). The sounds consisted of both AM sounds and reference sounds without amplitude modulation. The AM sounds were played at 35 dB LAeq, which is typical for environmental noise both indoors and in residential yards. The annoyance penalty increased with increasing fm and Dm. The penalties varied from 4 to 12 dB, when Dm ranged from 4 to 14 dB and fm ranged from 1 to 16 Hz. For the lowest fm= 0.25 Hz, and Dm = 1 dB, no penalty could be suggested. The results suggest a potential need for a penalty for low-level AM sounds for certain ranges of fm and Dm, applied for the periods with AM sound.
Durational properties of Polish geminate consonants
Authors: Rojczyk Arkadiusz , Porzuczek Andrzej
Published: December 2019

Polish is a geminating language with true lexical geminates that form minimal pairs with their singleton counterparts. What is more, Polish, unlike many other geminating languages, allows both single-articulated and rearticulated geminate realisations. In this study, durational properties of Polish geminates together with preceding and following vowels were analysed to compare Polish to other geminating languages. Fifty-four native speakers of Polish were recorded producing geminates and singletons in controlled carrier sentences during a reading task. The results revealed that the main durational cue to the geminate/singleton contrast was consonant duration with a geminate-to-singleton ratio (G/S) of 2.48. Vowels preceding or following geminates and singletons did not differ significantly in duration. Rearticulated geminates occurred 22% of the time and were not significantly longer or shorter than single-articulated geminates. The current results locate Polish among the languages with a medium-to-high G/S ratio and without vowel duration as a cue to a geminate/singleton contrast. Finally, the results allow for the discussion of the behaviour of Polish geminates relative to other languages as well as to indicate directions for further research into the phenomenon of geminate rearticulation.
General properties of auditory spectro-temporal receptive fields
Authors: Mahajan Nagaraj R. , Mesgarani Nima , Hermansky Hynek
Published: December 2019

The analyses of more than 2000 spectro-temporal receptive fields (STRFs) obtained from the ferret primary auditory cortex revealed their dominant encoding properties along time and frequency domains. Results showed that the peak responses of the STRFs were roughly aligned along the time axis, and enhanced low modulation components of the signal around 3 Hz. On the contrary, the peaks of the STRF population along the frequency axis varied and were distributed widely. Further analyses revealed that there were some general properties along the frequency axis around the best frequency of each STRF. The STRFs enhanced modulation frequencies around 0.25 cycles/octave. These findings are consistent with techniques that have been reported in the literature to result in improvements in speech recognition performance, highlighting the significant potential of biological insights into the design of better machines.
Unintended Changes in Contralateral Limb as a Result of Acute Gait Modification
Authors: Eddo Oladipo O. , Lindsey Bryndan W. , Caswell Shane V. , Prebble Matt , Cortes Nelson
Published: December 2019

Gait modification using real-time biofeedback is a conservative intervention associated with positive outcomes. Results from systematic reviews corroborate the effectiveness of various strategies employing real-time biofeedback for reducing estimated knee joint load. The effects on the nonmodified limb, however, remain unclear. Biomechanical changes to the nonmodified limb were investigated during unilaterally implemented medial knee thrust, lateral trunk lean, and toe-in foot progression. Nineteen healthy participants were recruited. Ten trials were completed for each gait condition including baseline. Assigned magnitude for each gait modification strategy was individualized based on the mean and SD of the gait parameter during baseline. Visual real-time biofeedback was provided. During medial knee thrust, participants’ nonmodified limb presented with increased: first peak medial knee contact force, internal first peak knee extensor moment, as well as knee- and hip-flexion angles at internal first peak knee extensor moment. Observed biomechanical changes are elucidative of the body’s attempt to attenuate increased external loads. These findings may carry significant implications for pathological populations. Load redistribution to the nonmodified side may result in unfavorable long-term outcomes particularly in patients with bilateral diagnosis. Future studies should explore acute and chronic changes in the nonmodified limb of individuals with knee osteoarthritis.
Acute Effects of Water-Based Concurrent Training Intrasession Exercise Sequences on Energy Expenditure in Young Women
Authors: Silva Mariana R. , Alberton Cristine L. , Braga Caroline O. , Pinto Stephanie S.
Published: December 2019

Background: To compare the acute effects of water-based aerobic–resistance and resistance–aerobic concurrent training (CT) sessions on energy expenditure (EE) during and postexercise in young women.Methods: Nine active women (24 [3] y; 60 [5] kg) completed 4 sessions: (1) familiarization, (2) aquatic maximal test to determine the heart rate corresponding to the anaerobic threshold, (3) CT protocol with aerobic–resistance sequence, and (4) CT protocol with resistance–aerobic sequence. Both protocols started and ended with the participants in the supine position for 30 minutes to perform resting and postexercise oxygen consumption measurements. The water-based resistance protocol comprised 4 sets of 15 seconds at maximal velocity, and the water-based aerobic protocol was performed at a continuous intensity (heart rate corresponding to the anaerobic threshold). EE measurements were calculated based on oxygen consumption and the corresponding caloric equivalent. Pairedttest was used to compare the EE values between the water-based CT intrasession exercise sequences (α = .05).Results: There was no difference between the water-based aerobic–resistance and resistance–aerobic in total EE (330.78 vs 329.56 kcal;P = .96), EE per minute (7.35 vs 7.32 kcal·min−1;P = .96), and postexercise EE (63.65 vs 59.92 kcal;P = .50).Conclusions: The intrasession exercise sequence during water-based CT had no influence on the EE in young women.
Approaches to Improve Causal Inference in Physical Activity Epidemiology
Authors: Lynch Brigid M. , Dixon-Suen Suzanne C. , Ramirez Varela Andrea , Yang Yi , English Dallas R. , Ding Ding , Gardiner Paul A. , Boyle Terry
Published: December 2019

Background: It is not always clear whether physical activity is causally related to health outcomes, or whether the associations are induced through confounding or other biases. Randomized controlled trials of physical activity are not feasible when outcomes of interest are rare or develop over many years. Thus, we need methods to improve causal inference in observational physical activity studies. Methods: We outline a range of approaches that can improve causal inference in observational physical activity research, and also discuss the impact of measurement error on results and methods to minimize this. Results: Key concepts and methods described include directed acyclic graphs, quantitative bias analysis, Mendelian randomization, and potential outcomes approaches which include propensity scores, g methods, and causal mediation. Conclusions: We provide a brief overview of some contemporary epidemiological methods that are beginning to be used in physical activity research. Adoption of these methods will help build a stronger body of evidence for the health benefits of physical activity.
Epigenetic stabilization of DC and DC precursor classical activation by TNFα contributes to protective T cell polarization
Authors: Eastman Alison J. , Xu Jintao , Bermik Jennifer , Potchen Nicole , den Dekker Aaron , Neal Lori M. , Zhao Guolei , Malachowski Antoni , Schaller Matt , Kunkel Steven , Osterholzer John J. , Kryczek Ilona , Olszewski Michal A.
Published: December 2019

TNFα is critical for epigenetic DC maturation, DC phenotype stabilization, and driving protective T
H
1 immunity to fungal infection.
Amino acid exchangeabilities vary across the tree of life
Authors: Zou Zhengting , Zhang Jianzhi
Published: December 2019

Long thought to be invariant, proteome-wide amino acid exchangeabilities in evolution actually vary widely among species.
Probiotics leap from gut to blood
Authors: Kulkarni Rajan P.
Published: December 2019

In critically ill patients, probiotics are associated with probiotic strain bacteremia and can evolve in response to antibiotic administration.
Computationally Aided Discovery of LysEFm5 Variants with Improved Catalytic Activity and Stability
Authors: Baryakova Tsvetelina H. , Ritter Seth C. , Tresnak Daniel T. , Hackel Benjamin J.
Published: December 2019

Broad-spectrum antibiotics can indiscriminately kill most bacteria, including commensal species that are a part of the normal human flora. This can potentially lead to the proliferation of drug-resistant bacteria upon elimination of competing species and to unwanted autoimmune effects in patients. Bacteriophage-derived lysin proteins are an alternative to conventional antibiotics that have coevolved alongside specific bacterial hosts. Lysins are capable of targeting conserved substrates in the bacterial cell wall essential for its viability. To engineer these proteins to exhibit improved therapeutically relevant properties, homology-guided statistical approaches can be used to identify compelling sites for mutation and to quantify the functional constraints acting on these sites to direct mutagenic library creation. The platform described herein couples this informed approach with a visual plate assay that can be used to simultaneously screen hundreds of mutants for catalytic activity, allowing for the streamlined identification of improved lysin variants.
Grenvillean evolution of the Beishan Orogen, NW China: Implications for development of an active Rodinian margin
Authors: Soldner Jérémie , Yuan Chao , Schulmann Karel , Štípská Pavla , Jiang Yingde , Zhang Yunying , Wang Xinyu
Published: December 2019

New geochemical and geochronological data are used to characterize the geodynamic setting of metasediments, felsic orthogneisses, and eclogite and amphibolite lenses forming the Beishan complex, NW China, at the southern part of the Central Asian Orogenic Belt. The metasediments correspond compositionally to immature greywackes receiving detritus from a heterogeneous source involving a magmatic arc and a Precambrian continental crust. Metagranitoids, represented by felsic orthogneisses, show both composition of greywacke-derived granitic melt with incompatible trace element patterns similar to the host metasediments. The eclogite lenses are characterized by high Nb contents (5.34–27.3 ppm), high (Nb/La)N (>1), and low Zr/Nb ratios (<4.5), which together with variable and negative whole-rock εNd(t) (–4.3 to –10.3) and zircon εHf(t) (–5.0 to + 2.3) values indicate an origin of enriched mantle source as commonly manifested by back-arc basalts at stretched continental margins. Combined with monazite rare earth element analysis, the in situ monazite U-Pb dating of metagraywacke (880.7 ± 7.9) suggests garnet growth during a high-temperature (HT) metamorphic event. Together with U-Pb dating of zircon metamorphic rims in amphibolite (910.9 ± 3.0 Ma), this indicates that the whole crustal edifice underwent a Grenvillian-age metamorphic event. The protolith ages of the eclogite (889.3 ± 4.8 Ma) and orthogneiss (867.5 ± 1.9 Ma) suggest that basalt underplating and sediment melting were nearly coeval with this HT metamorphism. Altogether, the new data allow placing the Beishan Orogen into a Grenvillean geodynamic scenario where: (1) The late Mesoproterozoic to early Neoproterozoic was marked by deposition of the greywacke sequence coeval with formation of an early arc. (2) Subsequently, an asthenospheric upwelling generated basaltic magma underneath the thinned subcontinental mantle lithosphere that was responsible for HT metamorphism, melting of the back-arc basin greywackes and intrusion of granitic magmas. These events correspond to a Peri-Rodinian supra-subduction system that differs substantially from the Neoproterozoic ophiolite sequences described in the Mongolian part of the Central Asian Orogenic Belt, thus indicating important lateral variability of supra-subduction processes along the Rodinian margin.
Tumour-induced osteomalacia due to an intra-abdominal mesenchymal tumour
Authors: Krishnappa Brijesh , Jadhav Swati Ramteke , Lila Anurag R , Bandgar Tushar R
Published: December 2019

A 50-year-man presented with debilitating lower-limb proximal muscle weakness and hip pain since 3 years. Investigations (serum calcium (8.9 mg/dL), serum phosphorus (1.5 mg/dL), serum albumin (40 g/L), parathyroid hormone (116 pg/mL (12.30 pmol/L)), 25(OH)D3 (25.2 ng/mL (63 nmol/L)) 1,25(OH)2D3 (19 pg/mL (45.60 pmol/L)), tubular reabsorption of phosphate of 0.22 and elevated serum fibroblast growth factor 23 (FGF23) (387.7 RU/mL)) were consistent with tumour-induced osteomalacia (TIO). Localisation studies (68Ga DOTATATE positron emission tomography (PET)/CT and18FDG-PET/CT) did not reveal any lesion. Re-evaluation after 2 and 5 years with68Ga-DOTANOC PET/CT showed 2×1.4 cm progressively increasing rounded soft tissue enhancing mass close to splenic hilum (SUV max: 26.4). Tumour was resected by laparotomy. Both FGF23 (120 RU/mL on day 3) and serum phosphorus (2.5 mg/dL on day 10) normalised with significant clinical improvement after surgery. Histopathology revealed phosphaturic mesenchymal tumour. Here, we report the first case of intra-abdominal mesenchymal tumour causing TIO diagnosed by serial functional imaging.
Pelvic injury is not just pelvic fracture
Authors: Morgan Owen , Davenport Dominic , Enright Kevin
Published: December 2019

Pelvic trauma is complex, most of current work centres around pelvic haemorrhage and fractures. It is important to remember that there is more anatomy in the pelvis than bones and vessels. A 29-year-old male patient was admitted after an Road Traffic Collision (RTC) where his motorbike T-boned a car. He was noted to have a traumatic dislocation of his right testicle, which spontaneously reduced in the emergency department and he was admitted for scrotal exploration and observation. Due to difficulty in mobilising postoperatively, he underwent an MRI, which showed diastasis of his pubis symphysis as well as left-sided adductor tendon rupture, not evident on his initial CT scan, and underwent pelvic fixation. Why should an emergency physician be aware of this? This case emphasises the alternate differentials with pelvic trauma in a haemodynamically stable patient, and the requirement for continuous reassessment in patients failing to improve.
Effectiveness and reporting standards of psychological interventions for improving short-term and long-term pain outcomes after total knee replacement: a systematic review
Authors: Whale Katie , Wylde Vikki , Beswick Andrew , Rathbone James , Vedhara Kavita , Gooberman-Hill Rachael
Published: December 2019

Objectives

To assess the effectiveness and reporting standards of psychological interventions for improving outcomes after total knee replacement (TKR).

Design

Medline, Embase, and PsycINFO were searched from inception to up to 9 May 2019 with no language restrictions applied. Randomised controlled trials (RCTs) assessing the effectiveness of psychological interventions for short-term and long-term postoperative pain after TKR were included. Screening, data extraction, and assessment of methodological quality were performed in duplicate by two reviewers. The primary effectiveness outcome was postoperative pain severity and the primary harm outcome was serious adverse events. Secondary outcomes included function, quality of life, and psychological well-being. Reporting standards were assessed using the Template for Intervention Description and Replication (TIDieR) checklist for intervention reporting.

Results

12 RCTs were included, with a total of 1299 participants. Psychological interventions comprised music therapy (five studies), guided imagery and music (one study), hypnosis (one study), progressive muscle relaxation with biofeedback (one study), pain coping skills programme (one study), cognitive–behavioural therapy (two studies), and a postoperative management programme (one study). Due to the high heterogeneity of interventions and poor reporting of harms data, it was not possible to make any definitive statements about the overall effectiveness or safety of psychology interventions for pain outcomes after TKR.

Conclusion

Further evidence about the effectiveness of psychological interventions for improving pain outcomes after TKR is needed. The reporting of harm outcomes and intervention fidelity is currently poor and could be improved. Future work exploring the impact of intervention timing on effectiveness and whether different psychological approaches are needed to address acute postoperative pain and chronic postoperative pain would be of benefit.

PROSPERO registration number

CRD42018095100.
Peripheral blood helper T cell profiles and their clinical relevance in MOG-IgG-associated and AQP4-IgG-associated disorders and MS
Authors: Liu Jia , Mori Masahiro , Sugimoto Kazuo , Uzawa Akiyuki , Masuda Hiroki , Uchida Tomohiko , Ohtani Ryohei , Kuwabara Satoshi
Published: December 2019

Objective

To investigate the immunological characteristics and their clinical relevance in anti-myelin oligodendrocyte glycoprotein (MOG)-IgG-associated and anti-aquaporin-4 (AQP4)-IgG-associated disorders (MOGAD and AQPAD) and multiple sclerosis (MS).

Methods

We measured peripheral blood helper T cell subsets (Th1, Th2, Th17 and regulatory T cell (Treg)) in patients with MOGAD (n=26), AQPAD (n=32) and MS (n=28) in the attack and remission phases by flow cytometry with intracellular cytokine staining. We also studied their correlation with clinical parameters. Ten normal subjects served as healthy controls.

Results

In all the three disorders, Th17 significantly increased at attack, and downregulated in the remission phases, although still elevated compare with healthy controls. MOGAD and AQPAD patients shared the common T cell profiles, while the extent of Th17 shift was more prominent in AQPAD. Patients with MS showed decreased Th2 than ones with MOGAD and AQPAD at attack. In terms of clinical correlation, MS patients showed that higher Th1 and Th17 proportion was associated with more frequent relapse and more severe clinical disability, whereas in MOGAD, higher Treg was associated with milder clinical severity. In AQPAD, no obvious correlation of Th profiles with clinical manifestation was found.

Conclusions

The present study first investigated intracellular cytokine levels among MOGAD, AQPAD and MS. The different patterns and extent of helper T cell profiles could reflect the pathogenesis of each disorders, and may affect disease severity and activity.
Investigation of early signs of systolic and diastolic dysfunction among persons with type 1 diabetes
Authors: Vestberg Daniel , Johansson Magnus Carl , Letho Anette , Pivodic Aldina , Hallström Sara , Ólafsdóttir Arndís Finna , Rosengren Annika , Lind Marcus
Published: December 2019

Background

Persons with type 1 diabetes have a higher risk to develop heart failure than the general population, and the mechanism behind the increased risk is unclear. In epidemiological studies with hospitalisation for heart failure as endpoint HbA1c, body mass index and decreased kidney function are significant risk factors, but it is unclear how these risk factors influence the development of heart failure.

Methods

In this study, we investigated early signs of systolic and diastolic dysfunction with transthoracic echocardiography. Statistical analysis on correlation of risk factors and early signs of diastolic and systolic dysfunction was made.

Results

In this study population of 287 persons with type 1 diabetes, 160 were men and 127 were women with a mean age of 53.8 (SD 11.6) years and a mean diabetes duration of 36.2 (SD 13.5) years. There were 23 (8.2%) persons who fulfilled the definition of systolic dysfunction (ejection fraction <50% or regional wall motion abnormalities) and 24 persons (9%) the definition for diastolic dysfunction. When comparing the groups with either systolic or diastolic dysfunction to the rest of the population, the only significant risk factor was age in both groups and previous myocardial infarction in the systolic group.

Conclusion

In our study population with type 1 diabetes, we found signs of diastolic dysfunction in 9% and systolic dysfunction in 8.2%. Compared with published data from the general population, this rate is somewhat higher in a younger population. Only age was a significant risk factor in the study.
Hamish Christopher Wilson
Authors: Beynon Peter , Paull Nicky , Beynon Paddy
Published: December 2019

An all‐round ‘GP’ vet with a special interest in the work he did as an official veterinarian. A passion for fast cars, motorcycles and skiing meant he lived life to the full.
Randomized Memoryless Algorithms for the Weighted and the Generalized
k
-server Problems
Authors: Chiplunkar Ashish , Vishwanathan Sundar
Published: December 2019

The weighted
k
-server problem is a generalization of the
k
-server problem wherein the cost of moving a server of weight β

i

through a distance
d
is β

i

⋅
d
. On uniform metric spaces, this models caching with caches having different page replacement costs. A memoryless algorithm is an online algorithm whose behavior is independent of the history given the positions of its
k
servers. In this article, we develop a framework to analyze the competitiveness of randomized memoryless algorithms. The key technical contribution is a method for working with potential functions defined implicitly as the solution of a linear system. Using this, we establish tight bounds on the competitive ratio achievable by randomized memoryless algorithms for the weighted
k
-server problem on uniform metrics. We first prove that there is an α

k

-competitive memoryless algorithm for this problem, where α

k

=α

k
− 1

2
+ 3α

k
− 1

+1; α
1
= 1. We complement this result by proving that no randomized memoryless algorithm can have a competitive ratio less than α

k

.

Finally, we prove that the above bounds also hold for the generalized
k
-server problem on weighted uniform metrics.
Technical Report Column
Authors: Kelley Dean
Published: December 2019

Welcome to the Technical Reports Column. If your institution publishes technical reports that you'd like to have included here, please contact me at the email address above.
Distributed Computing Column 76
Authors: Alistarh Dan
Published: December 2019

As this is the first column I am editing, I would like to sincerely thank Jennifer Welch for inviting me as editor, and for being extremely helpful with the transition. I will do my best to maintain the very high standard set for the column by her, and by the previous editors. Following custom, the December issue is devoted to a review of some notable events related to distributed
computing which occurred during the year.

First, congratulations to Alessandro Panconesi and Aravind Srinivasan for being awarded the 2019 Edsger W. Dijkstra Prize in Distributed Computing for their paper “Randomized Distributed
Edge Coloring via an Extension of the Chernoff-Hoeffding Bounds," which appeared in the SIAM Journal on Computing in 1997. The prize is jointly sponsored by ACM and EATCS, and is given alternately at PODC and DISC; this year it was awarded at DISC.
PODC 2019 Review
Authors: Ben-David Naama , Chang Yi-Jun , Dory Michal , Leitersdorf Dean
Published: December 2019

The 38th ACM SIGACT-SIGOPS Symposium on Principles of Distributed Computing (PODC 2019) was held on July 29-August 2, 2019 at the Double Tree Hilton hotel in Toronto, Canada. With three keynotes, over 40 accepted papers, over 20 accepted brief announcements, two workshops, and roughly 150 attendants, PODC 2019 constituted a composition of fascinating improvements in many areas of distributed and parallel computing.

On the evening of the 31st of July, the conference banquet was held on a cruise over beautiful Lake Ontario and included the best papers award ceremony. The best paper award went to Yi-Jun Chang, and Thatchaphol Saranurak for their work titled, \Improved Distributed Expander Decomposition and Nearly Optimal Triangle Enumeration" [19]; two best student paper awards were given to Yi-Jun Chang, Manuela Fischer, and Yufan Zheng for their work titled, \The Complexity of (Δ + 1) Coloring in Congested Clique, Massively Parallel Computation, and Centralized Local Computation" [17] which was co-authored with Mohsen Gha ari, and Jara Uitto, and to Michal Dory and Dean Leitersdorf for the work on \Fast Approximate Shortest Paths in the Congested Clique" [16] which was co-authored with Keren Censor-Hillel, and Janne H. Korhonen. Congratulations to all the awardees and a special congratulations to Yi-Jun Chang for having received both awards!

This review would be incomplete without mentioning perhaps one of the most notable results in the eld in recent years which was uploaded to the online archive just days before the conference gathered, and which was not presented at PODC 2019 but a ected many works presented at the conference: the work titled, ¶olylogarithmic-Time Deterministic Network Decomposition and Distributed Derandomization" [48] by Vaclav Rozhon, and Mohsen Gha ari. Throughout the entire conference there was talk regarding the implications of this work, culminating with perhaps one of the more memorable moments of PODC 2019, where Mohsen described this result during his talk on a di erent paper which he co-authored with Fabian Kuhn - Mohsen quoted from his and Kuhn's paper [31]: \we provide results that are in some sense the strongest that one can achieve, barring a major breakthrough", and on the next slide was that major breakthrough - a picture of Vaclav Rozhon along with the rst page of [48]. Congratulations to the authors on this work!

We hope that this review will give readers the opportunity to experience some of PODC 2019 and potentially attend the conference in future years. Thank you to the organizers and authors for a captivating and though-provoking conference!
Review of the Second Sankt Petersburg Summer School on Practice and Theory of Distributed Computing (SPTDC 2019)
Authors: Kuznetsov Petr
Published: December 2019

The second Summer School on Practice and Theory of Distributed Computing (SPTDC 2019) took place on July 8-12, 2019, in Saint-Petersburg, Russia. In addition to graduate and undergraduate students from all around the world, the audience featured a considerable presence of industrial researchers and software engineers. The program offered a wide range of classes on practical and theoretical aspects of distributed systems, given by renowned experts: Leslie Lamport, Michael Scott, Maurice Herlihy, Eli Gafni, Danny Hendler, Achour Mostefaoui, Ittai Abraham, and Trevor Brown.
SETH vs Approximation
Authors: Rubinstein Aviad , Williams Virginia Vassilevska
Published: December 2019

Our story is about hardness of problems in P, but its roots begin with two algorithmic approaches that have been developed to cope with NP-hard problems: approximation algorithms and fasterthan- brute-force algorithms.

Approximation algorithms were proposed as a response for NP-hardness almost immediately (in historical perspective of almost half a century), and have been one of the most celebrated success stories of our eld. An outstanding complexity result in this area, which has since turned into a sub- eld of its own, is the Probabilistically Checkable Proof (PCP) Theorem. For many problems like Max-3-SAT we now have nearly tight hardness-of-approximation results.