bluuebunny/crossref_metadata_2025 huggingface dataset:
Control and application of accuracy positioning estimation based real-time location system
Authors: Aktaş Ahmet
Published: February 2019

Nowadays, with the development of ultra-wide band antennas and internet of thing technologies, tracing systems are being developed in many fields such as security, health, mining and transportation. The accuracy location estimation issue is becoming very important in areas of application where occupational health and safety are high. In these applications, the transfer of information between the target and the manager, whose location must be accuracy known, has become indispensable. Especially when the target person is human, the movement parameters such as speed, acceleration, position and altitude compose the calculation parameters of the central management system. The information to be sent by the worker in emergency situations and warnings explain the need for real-time location systems to avoid a possible occupational accident. This paper includes real-time location system structure and improved accuracy location control algorithm, which are being used in occupational health and safety, hospital, storage, mine and tracing areas. The real-time location system was designed using a DWM1000 location sensor module with an ultra-wide band integrated antenna. Product usage time has been extended in designed real-time location cards with low power consuming processors. An accuracy positioning control algorithm has been improved to quickly and exactly locate the target to be tracked. With this algorithm, a new approach to real-time location systems has been introduced and worker tracing, information and warning systems are made with fast response time. The control cards developed in a sample workspace were tested and the application results on the developed computer virtual map interface were given.
La construcción de la identidad en contextos hegemónicos
Authors: Rascón-Gómez María Teresa
Published: February 2019

El presente ensayo nace de una serie de deliberaciones fruto de la trayectoria investigadora de la autora en el ámbito de la interculturalidad. El interés por profundizar en el proceso de construcción identitario de las minorías étnico culturales, nos descubre la presencia de múltiples contextos de desigualdad generados por las propias sociedades receptoras. Desde una perspectiva crítica, reflexionaremos sobre la necesidad de que estas personas, como sujetos subalternos, se apropien de su discurso, y se liberen de la interpretación hegemónica que a menudo los estudiosos de la identidad cultural realizan de las concepciones cognitivas, afectivas y morales de estas minorías.
El prácticum en la formación de maestros: percepciones de los protagonistas
Authors: Tejada-Fernández José , Carvalho-Dias Maria Lurdes , Ruiz-Bueno Carmen
Published: February 2019

El objetivo es analizar las percepciones sobre el Prácticum en los procesos de adquisición de competencias y de construcción de la identidad profesional en la formación inicial de maestros de educación infantil y primaria de la Universidad Autónoma de Barcelona, UAB.
Se presentan los resultados de un estudio de caso, obtenidos por medio de entrevistas a tutores, trianguladas con un cuestionario a los estudiantes. Se concluye sobre el frágil trabajo colaborativo y la débil coordinación entre tutores, la poca observación y orientación in situ del ejercicio profesional, y se valora la reflexión individual y colectiva, mediada por el tutor universitario.
Percepciones sobre la tutoría entre pares en escritura académica
Authors: López-Higuera Amparo , Prado-Mosquera Diana Marcela , Cajas-paz Edwin Yamir , Chois-lenis Pilar Mirely , Casas-Bustillo Adriana Carolina
Published: February 2019

Esta investigación cualitativa retomó elementos de la etnografía educativa y de la fenomenología, para comprender las percepciones de los participantes en tutorías de escritura académica entre pares. Los hallazgos permitieron advertir que tutor y tutorado perciben beneficios tanto en el campo académico como en el social; cada uno valora positivamente en el otro algunos rasgos de personalidad, y también otros atribuibles específicamente a sus roles de aprendiz y tutor.
Reconocimiento de los jóvenes desmovilizados de los grupos armados en Colombia: transiciones y desafíos para las prácticas de orientación escolar
Authors: Bejarano-Sanabria Henry Camilo , Delgado-Salazar Ricardo Mauricio
Published: February 2019

Este artículo examina cómo los modelos de reconocimiento social contribuyen a las prácticas de orientación escolar de jóvenes desmovilizados de las organizaciones implicadas en el conflicto armado en Colombia, que deciden insertarse al sistema educativo. Los resultados de esta reflexión derivada de investigación se presentan en cuatro apartados.
Rethinking the Uses of Assessment in the Second Language Classroom
Authors: Muñoz-Restrepo Ana
Published: February 2019

El objetivo principal de este artículo es discutir los usos de la evaluación como herramienta para el aprendizaje de una segunda lengua. El artículo explica el concepto de la evaluación para el aprendizaje y describe cuatro estrategias que han demostrado ser eficaces para aumentar el aprendizaje de los estudiantes. Como conclusión, el artículo enfatiza la necesidad de cambiar las creencias respecto a la naturaleza y el papel de la evaluación en el proceso de aprendizaje.
Lateral Forces in Rolling-Cut Shearing and Their Consequences on Common Edge Defects
Authors: Zeiler Alexander , Steinboeck Andreas , Kugi Andreas , Jochum Martin
Published: February 2019

This paper deals with the detailed analysis of the lateral process forces in rolling-cut shearing of heavy steel plates and their impact on edge defects. Rolling-cut shearing is still the most common method of heavy-plate side trimming. However, this method can entail edge defects like uneven longitudinal shape as well as burr and fractures in the area of the cut-changeover (beginning and end of the periodical cuts). In the existing literature, neither the root cause of these edge defects nor their nexus with the upper blade trajectory (blade drive-kinematics) has been analyzed in detail. In this work, these issues will be explored based on the finite element method (FEM) simulations and measurements from an industrial plant. The complex interrelation between drive-kinematics, varying lateral force, unintended lateral motion of the upper blade, unintended variation of the blade clearance, and quality defects is analyzed. The variation of the lateral force is identified as the root cause of such quality defects and a physical explanation for variations of the lateral force is given. The detailed understanding of the shearing process serves as a solid basis for an optimization and re-design of the drive-kinematics in a future work. Measurements from an industrial plant and simulation results show good agreement and thus confirm the theory. The results are transferable to other rolling-cut trimming shears.
Cryogenic Machining of Titanium Ti-5553 Alloy
Authors: Kaynak Yusuf , Gharibi Armin
Published: February 2019

Titanium alloy Ti-5Al-5V-3Cr-0.5Fe (Ti-5553) is a new generation of near-beta titanium alloy that is commonly used in the aerospace industry. Machining is one of the manufacturing methods to produce parts that are made of this near-beta alloy. This study presents the machining performance of new generation near-beta alloys, namely, Ti-5553, by focusing on a high-speed cutting process under cryogenic cooling conditions and dry machining. The machining experiments were conducted under a wide range of cutting speeds, including high speeds that used liquid nitrogen (LN2) and carbon dioxide (CO2) as cryogenic coolants. The experimental data on the cutting temperature, tool wear, force components, chip breakability, dimensional accuracy, and surface integrity characteristics are presented and were analyzed to evaluate the machining process of this alloy and resulting surface characteristics. This study shows that cryogenic machining improved the machining performance of the Ti-5553 alloy by substantially reducing the tool wear, cutting temperature, and dimensional deviation of the machined parts. The cryogenic machining also produced shorter chips as compared to dry machining.
A Hybrid Computational and Analytical Model of Inline Drip Emitters
Authors: Narain Jaya , Winter V Amos G.
Published: February 2019

This paper details a hybrid computational and analytical model to predict the performance of inline pressure compensating drip irrigation emitters. Pressure compensating emitters deliver a constant flow rate over a range of applied pressures to accurately meter water to crops. Flow rate is controlled within the emitter via a fixed resistance tortuous path, and a variable flow resistance composed of a flexible membrane that deflects under changes in pressure, restricting the flow path. A pressure resistance parameter was derived using an experimentally validated computational fluid dynamics (CFD) model to describe the flow behavior in tortuous paths. The bending mechanics of the membrane were modeled analytically and refined by deriving a correction factor using finite element analysis (FEA). A matrix formulation that calculates the force applied by a line or a patch load of any shape on a rectangular membrane, along which there is a prescribed deflection, was derived and was found to be accurate to be 1%. The combined hybrid computational–analytical model reduces the computational time of modeling emitters from hours to less than 30 min, dramatically lowering the time required to iterate and select optimal designs. The model was validated experimentally using three commercially available drip emitters and was accurate to within 12% of the experimental results.
Design and Optimization of Graded Cellular Structures With Triply Periodic Level Surface-Based Topological Shapes
Authors: Li Dawei , Dai Ning , Tang Yunlong , Dong Guoying , Zhao Yaoyao Fiona
Published: February 2019

Periodic cellular structures with excellent mechanical properties widely exist in nature. A generative design and optimization method for triply periodic level surface (TPLS)-based functionally graded cellular structures is developed in this work. In the proposed method, by controlling the density distribution, the designed TPLS-based cellular structures can achieve better structural or thermal performances without increasing its weight. The proposed technique can be divided into four steps. First, the modified 3D implicit functions of the triply periodic minimal surfaces are developed to design different types of cellular structures parametrically and generate spatially graded cellular structures. Second, the numerical homogenization method is employed to calculate the elastic tensor and the thermal conductivity tensor of the cellular structures with different densities. Third, the optimal relative density distribution of the object is computed by the scaling laws of the TPLS-based cellular structures added optimization algorithm. Finally, the relative density of the numerical results of structure optimization is mapped into the modified parametric 3D implicit functions, which generates an optimum lightweight cellular structure. The optimized results are validated subjected to different design specifications. The effectiveness and robustness of the obtained structures is analyzed through finite element analysis and experiments. The results show that the functional gradient cellular structure is much stiffer and has better heat conductivity than the uniform cellular structure.
Structural and Biomechanical Adaptations of Right Ventricular Remodeling—In Pulmonary Arterial Hypertension—Reduces Left Ventricular Rotation During Contraction: A Computational Study
Authors: Kheyfets Vitaly O. , Truong Uyen , Ivy Dunbar , Shandas Robin
Published: February 2019

Pulmonary hypertension (PH) is a degenerative disease characterized by progressively increased right ventricular (RV) afterload that leads to ultimate functional decline. Recent observational studies have documented a decrease in left ventricular (LV) torsion during ejection, with preserved LV ejection fraction (EF) in pediatric and adult PH patients. The objective of this study was to develop a computational model of the biventricular heart and use it to evaluate changes in LV torsion mechanics in response to mechanical, structural, and hemodynamic changes in the RV free wall. The heart model revealed that LV torsion and apical rotation were decreased when increasing RV mechanical rigidity and during re-orientation of RV myocardial fibers, both of which have been demonstrated in PH. Furthermore, structural changes to the RV appear to have a notable impact on RV EF, but little influence on LV EF. Finally, RV pressure overload exponentially increased LV myocardial stress. The computational results found in this study are consistent with clinical observations in adult and pediatric PH patients, which reveal a decrease in LV torsion with preserved LV EF. Furthermore, discovered causes of decreased LV torsion are consistent with RV structural adaptations seen in PH rodent studies, which might also explain suspected stress-induced changes in LV myocardial gene and protein expression.
Estimation of the Balance-Keeping Control Law Applied by a Human Being Upon a Sudden Sagittal Tilt Perturbation
Authors: Bilgin Nurdan , Kemal Özgören M.
Published: February 2019

This study aims to estimate the control law employed by the central nervous system (CNS) to keep a person in balance after a sudden disturbance. For this aim, several experiments were carried out, in which the subjects were perturbed sagittally by using a single-axis tilt-platform and their motions were recorded with appropriate sensors. The analysis of the experimental results leads to the contribution of this paper as a conjecture that the CNS commands the muscular actuators of the joints according to an adaptive proportional-derivative (PD) control law such that its gains and set points are updated continuously. This conjecture is accompanied with an assumption that the CNS is able to acquire perfect and almost instantaneous position and velocity feedback by means of a fusion of the signals coming from the proprioceptive, somatosensory, and vestibular systems. In order to verify the conjectured control law, an approximate biomechanical model was developed and several simulations were carried out to imitate the experimentally observed motions. The time variations of the set points and the control gains were estimated out of the experimental data. The simulated motions were observed to be considerably close to the experimental motions. Thus, the conjectured control law is validated. However, the experiments also indicate that the mentioned adaptation scheme is quite variable even for the same subject tested repeatedly with the same perturbation. In other words, this experimental study also leads to the implication that the way the CNS updates the control parameters is not quite predictable.
Model-Based Analysis of the Stiffness of the Wrist Joint in Active and Passive Conditions
Authors: Zonnino Andrea , Sergi Fabrizio
Published: February 2019

The control of joint stiffness is a fundamental mechanism used to control human movements. While many studies have observed how stiffness is modulated for tasks involving shoulder and elbow motion, a limited amount of knowledge is available for wrist movements, though the wrist plays a crucial role in manipulation. We have developed a computational framework based on a realistic musculoskeletal model, which allows one to calculate the passive and active components of the wrist joint stiffness. We first used the framework to validate the musculoskeletal model against experimental measurements of the wrist joint stiffness, and then to study the contribution of different muscle groups to the passive joint stiffness. We finally used the framework to study the effect of muscle cocontraction on the active joint stiffness. The results show that thumb and finger muscles play a crucial role in determining the passive wrist joint stiffness: in the neutral posture, the direction of maximum stiffness aligns with the experimental measurements, and the magnitude increases by 113% when they are included. Moreover, the analysis of the controllability of joint stiffness showed that muscle cocontraction positively correlates with the stiffness magnitude and negatively correlates with the variability of the stiffness orientation (p < 0.01 in both cases). Finally, an exhaustive search showed that with appropriate selection of a muscle activation strategy, the joint stiffness orientation can be arbitrarily modulated. This observation suggests the absence of biomechanical constraints on the controllability of the orientation of the wrist joint stiffness.
Semi-Adaptive Closed-Loop Control for Infusion of Medications With Transport Delay in Clinical Effects
Authors: Jin Xin , Kim Chang-Sei , Shipley Steven T. , Dumont Guy A. , Hahn Jin-Oh
Published: February 2019

This paper presents a semi-adaptive closed-loop control approach to autonomous infusion of medications exhibiting significant transport delay in clinical effects. The basic idea of the approach is to enable stable adaptive control of medication infusion by (1) incorporating transport delay explicitly into control design by way of a Padé approximation while (2) facilitating linear parameterization of control design model by desensitization of nonlinearly parameterized cooperativity constant associated with pharmacodynamics (PD). A novel dynamic dose–response model for control design is presented, in which the cooperativity constant exerts zero influence on the model output in the steady-state. Then, an adaptive pole placement control (APPC) technique was employed to fulfill adaptive control design in the presence of nonminimum phase dynamics associated with the Padé approximation of transport delay. The controller was evaluated in silico using a case study of regulating a cardiovascular variable with a sedative under a wide range of transport delay and pharmacological profiles. The results suggest that adaptation of transport delay and pharmacological characteristics may be beneficial in achieving consistent and robust regulation of medication-elicited clinical effects.
Experimental Demonstration of the Effect of Magnetic Polaritons on the Radiative Properties of Deep Aluminum Gratings
Authors: Yang Peiyan , Ye Hong , Zhang Zhuomin M.
Published: February 2019

Despite the abundant theoretical studies of magnetic polaritons (MPs) in tailoring the radiative properties of nanostructures, experimental investigation of MPs in deep metal gratings is still lacking. This work experimentally demonstrates the excitation of MP from several microfabricated aluminum gratings in the mid-infrared region by measuring the specular reflectance (zeroth-order diffraction) of the specimen using a Fourier-transform infrared (FTIR) spectrometer. The rigorous coupled-wave analysis (RCWA) and an LC-circuit model are employed to elucidate the mechanism of various resonant modes and their coupling effect. The influence of incidence angle, plane of incidence, polarization, and the trench depth on the spectral reflectance is also discussed. Moreover, the MP dispersion for off-plane layout has been investigated and demonstrated for the first time. The insight gained from this work may facilitate future design and applications of subwavelength periodic structures with desired radiative properties.
Dynamic Modeling of the Heat Pipe-Assisted Annealing Line
Authors: Celik Metin , Patki Mrunal , Paulussen Geert , de Jong Wiebren , Jan Boersma Bendiks
Published: February 2019

In a conventional continuous annealing line, the energy supplied to steel strip during heating is not recovered while cooling it. Therefore, an alternative heat transfer technology for energy efficient continuous annealing of steel was developed. This technology enables reusing the heat extracted during cooling of the strip in the heating part of the process. This is achieved by thermally linking the cooling strip to the heating strip via multiple rotating heat pipes. In this context, the dynamic simulation of a full heat pipe assisted annealing line is performed. The dynamic simulation consists of the interaction of computational building blocks, each comprising of a rotating heat pipe and strip parts wrapped around the heat pipe. The simulations are run for different installation configurations and operational settings, with the heat pipe number varying between 50 and 100 and with varying strip line speed and dimensions. The heat pipes are sized to be 0.5 m in diameter and 3 m in length. The simulation results show that the equipment is capable of satisfying the thermal cycle requirements of annealing both at steady-state and during transition between steady-states following changes in boundary conditions. With this concept, energy savings of up to 70% are feasible.
Simulation of Nuclear Fuel Behavior in Accident Conditions With the DIONISIO Code
Authors: Lemes Martín , Denis Alicia , Soba Alejandro
Published: February 2019

DIONISIO is a computer code designed to simulate the behavior of one nuclear fuel rod during its permanence within the reactor. Starting from the power history and the external conditions to which the rod is subjected, the code predicts all the meaningful variables of the system. Its application range has been recently extended to include accidental conditions, in particular the so-called loss of coolant accidents (LOCA). In order to make realistic predictions, the conditions in the rod environment have been taken into account since they represent the boundary conditions with which the differential equations describing the fuel phenomena are solved. Without going into the details of the thermal-hydraulic modeling, which is the task of the specific codes, a simplified description of the conditions in the cooling channel during a LOCA event has been developed and incorporated as a subroutine of DIONISIO. This has led to an improvement of the fuel behavior simulation, which is evidenced by the considerable number of comparisons with experiments carried out, many of them reported in this paper. Moreover, this work describes a model of high temperature capture and release of hydrogen in the nuclear fuel cladding, in scenarios typical of LOCA events. The corresponding computational model is being separately tested and will be next included in the DIONISIO thermal-hydraulic module.
Characterization of the Nonroad Modified Diesel Engine Using a Novel Entropy-VIKOR Approach: Experimental Investigation and Numerical Simulation
Authors: Kumar Sharma Pushpendra , Sharma Dilip , Lal Soni Shyam , Jhalani Amit
Published: February 2019

Excessive use of diesel engines and continuous increase in environmental pollution has drawn the attention of researchers in the area of the compression ignition engine. In this research article, an innovative investigation of the nonroad modified diesel engine is reported with the effective use of the hybrid Entropy-VIKOR approach. Hence, it becomes necessary to prioritize and optimize the performance defining criteria, which provides higher BTE along with lower emission simultaneously. The engine load, injection timing (Inj Tim), injection pressure (Inj Pre), and compression ratio (Com R) were selected as engine operating parameters for experimentation at the constant speed of 1500 rpm engine. The effect on engine performance parameters (BTE and BSEC) and emission (carbon monoxide (CO), total oxide of carbon (TOC), oxides of nitrogen (NOx), hydrocarbon (HC), and smoke) was studied experimentally. The optimum results were observed at load 10.32 kg, Inj Tim 20 deg btdc, Inj Pre 210 bar, and Com R 21:1 at which highest BTE of 22.24% and lowest BSEC of 16,188.5 kJ/kWh were obtained. Hybrid entropy-VIKOR approach was applied to establish the optimum ranking of the nonroad modified diesel engine. The experimental results and numerical simulation show that optimizing the engine operating parameters using the entropy-VIKOR multicriteria decision-making (MCDM) technique is applicable.
Deep convolutional network for animal sound classification and source attribution using dual audio recordings
Authors: Oikarinen Tuomas , Srinivasan Karthik , Meisner Olivia , Hyman Julia B. , Parmar Shivangi , Fanucci-Kiss Adrian , Desimone Robert , Landman Rogier , Feng Guoping
Published: February 2019

This paper introduces an end-to-end feedforward convolutional neural network that is able to reliably classify the source and type of animal calls in a noisy environment using two streams of audio data after being trained on a dataset of modest size and imperfect labels. The data consists of audio recordings from captive marmoset monkeys housed in pairs, with several other cages nearby. The network in this paper can classify both the call type and which animal made it with a single pass through a single network using raw spectrogram images as input. The network vastly increases data analysis capacity for researchers interested in studying marmoset vocalizations, and allows data collection in the home cage, in group housed animals.
Spatial analysis of modal time evolution in room acoustics
Authors: Saarelma Jukka , Savioja Lauri
Published: January 2019

Time-domain simulation methods allow the observation of the state of the simulation domain at each discrete time step. In this work an approach to analyze the progress of the sound field in the simulation domain using time-windowing and spectrum analysis is presented. The method makes it possible to analyze the effect of geometric structures into the spatiotemporal distribution of energy in the domain at a frequency range of interest. Several examples are presented.
Covariation of stop voice onset time across languages: Evidence for a universal constraint on phonetic realization
Authors: Chodroff Eleanor , Golden Alessandra , Wilson Colin
Published: January 2019

Stop consonant voice onset time (VOT) was examined in a typological survey of over 100 languages. Within broadly defined laryngeal categories (long-lag, short-lag, and lead voicing), VOT means were found to vary extensively. Importantly, the means for members of the same laryngeal series did not vary independently but instead were highly correlated across languages. The strong linear relations identified here cannot be reduced to previously reported ordinal relations, and provide evidence for a uniformity constraint on phonetic realization: within a language, each laryngeal specification must be realized in approximately the same way across stops of different places of articulation.
Swimming Fast When It Counts: A 7-Year Analysis of Olympic and World Championships Performance
Authors: Mujika Iñigo , Villanueva Luis , Welvaert Marijke , Pyne David B.
Published: January 2019

Context/Background: International-level swimmers periodize their training to qualify for major championships, then improve further at these events. However, the effects of various factors that could affect performance progressions have not been described systematically. Purpose: To quantify the pattern of change in performance between season best qualifying time and the major championships of the year and to assess the influence of time between performance peaks, ranking at the major events, stroke, event distance, sex, age, and country. Methods: A total of 7832 official competition times recorded at 4 FINA World Championships and 2 Olympic Games between 2011 and 2017 were compared with each swimmer’s season best time prior to the major event of the year. Percentage change in performance was related with the time elapsed between season best and major competition, race event, sex, age, and country using linear mixed modeling. Results: Faster performance (−0.79% [0.67%]; mean [SD]) at the major competition of the year occurred in 38% of all observations vs 62% no change or regression (1.10% [0.88%]). The timing between performance peaks (<34 to >130 d) had little effect on performance progressions (P = .83). Only medal winners (−0.87% [0.91%]), finalists (−0.16% [0.97%]), and US swimmers (−0.44% [1.08%]) progressed between competitions. Stroke, event distance, sex, and age had trivial impact on performance progression. Conclusions: Performance progressions at Olympic Games and World Championships were not determined by timing between performance peaks. Performance progression at a major competition appears necessary to win a medal or make the final, independent of race event, sex, and age.
The comparative genomics and complex population history ofPapiobaboons
Authors: Rogers Jeffrey , Raveendran Muthuswamy , Harris R. Alan , Mailund Thomas , Leppälä Kalle , Athanasiadis Georgios , Schierup Mikkel Heide , Cheng Jade , Munch Kasper , Walker Jerilyn A. , Konkel Miriam K. , Jordan Vallmer , Steely Cody J. , Beckstrom Thomas O. , Bergey Christina , Burrell Andrew , Schrempf Dominik , Noll Angela , Kothe Maximillian , Kopp Gisela H. , Liu Yue , Murali Shwetha , Billis Konstantinos , Martin Fergal J. , Muffato Matthieu , Cox Laura , Else James , Disotell Todd , Muzny Donna M. , Phillips-Conroy Jane , Aken Bronwen , Eichler Evan E. , Marques-Bonet Tomas , Kosiol Carolin , Batzer Mark A. , Hahn Matthew W. , Tung Jenny , Zinner Dietmar , Roos Christian , Jolly Clifford J. , Gibbs Richard A. , Worley Kim C. ,   Baboon Genome Analysis Consortium
Published: January 2019

We analyzed genome sequences from 6 baboon species and found evidence of ancient and recent hybridization among divergent species.
Metastable asymmetrical structure of a shaftless V
1
motor
Authors: Maruyama Shintaro , Suzuki Kano , Imamura Motonori , Sasaki Hikaru , Matsunami Hideyuki , Mizutani Kenji , Saito Yasuko , Imai Fabiana L. , Ishizuka-Katsura Yoshiko , Kimura-Someya Tomomi , Shirouzu Mikako , Uchihashi Takayuki , Ando Toshio , Yamato Ichiro , Murata Takeshi
Published: January 2019

The V
1
-ATPase motor forms metastable asymmetrical structures that suggest the basis for the cooperative transition mechanism.
Robot learning in science fiction
Authors: Murphy Robin R.
Published: January 2019

We should discard expectations that a robot will become a virtuoso at a new task overnight and that learning leads to sentience.
Squeezing inspiration from embryonic hearts
Authors: Au Sam H.
Published: January 2019

Bioinspired valveless impedance pumps are driven by contracting rings of tissue engineered muscle cells.
Targeting pacemaker channels in depression
Authors: Liston Conor
Published: January 2019

Hyperpolarization-activated cyclic nucleotide–gated channel dysfunction drives stress susceptibility and depression-like behavior.
Axenic Biofilm Formation and Aggregation by
Synechocystis
sp. Strain PCC 6803 Are Induced by Changes in Nutrient Concentration and Require Cell Surface Structures
Authors: Allen Rey , Rittmann Bruce E. , Curtiss Roy
Published: February 2019

Microbes can exist as suspensions of individual cells in liquids and also commonly form multicellular communities attached to surfaces. Surface-attached communities, called biofilms, can confer antibiotic resistance to pathogenic bacteria during infections and establish food webs for global nutrient cycling in the environment. Phototrophic biofilm formation is one of the earliest phenotypes visible in the fossil record, dating back over 3 billion years. Despite the importance and ubiquity of phototrophic biofilms, most of what we know about the molecular mechanisms, genetic regulation, and environmental signals of biofilm formation comes from studies of heterotrophic bacteria. We aim to help bridge this knowledge gap by developing new assays for
Synechocystis
, a phototrophic cyanobacterium used to study oxygenic photosynthesis and biofuel production. With the aid of these new assays, we contribute to the development of
Synechocystis
as a model organism for the study of axenic phototrophic biofilm formation.
Longitudinal Study of Shiga Toxin-Producing
Escherichia coli
and
Campylobacter jejuni
on Finnish Dairy Farms and in Raw Milk
Authors: Jaakkonen Anniina , Castro Hanna , Hallanvuo Saija , Ranta Jukka , Rossi Mirko , Isidro Joana , Lindström Miia , Hakkinen Marjaana
Published: February 2019

The increased popularity of raw milk consumption has created demand for relaxing legislation, despite the risk of contamination by pathogenic bacteria, notably STEC and
C. jejuni
. However, the epidemiology of these milk-borne pathogens on the herd level is still poorly understood, and data are lacking on the frequency of milk contamination on farms with cattle shedding these bacteria in their feces. This study suggests (i) that STEC contamination in milk can be reduced, but not prevented, by on-farm hygienic measures while fecal shedding is observable, (ii) that milk filters are more suitable sampling targets for monitoring than milk although pathogen detection from both sample matrices may be challenging, and (iii) that STEC and
C. jejuni
genotypes may persist in cattle herds for several months. The results can be utilized in developing and targeting pathogen monitoring and risk management on the farm level and contributed to the revision of Finnish legislation in 2017.
Use of a Fluorescent Analog of Glucose (2-NBDG) To Identify Uncultured Rumen Bacteria That Take Up Glucose
Authors: Tao Junyi , McCourt Courtney , Sultana Halima , Nelson Corwin , Driver John , Hackmann Timothy J.
Published: February 2019

We introduce a method for identifying what substrates are consumed by bacteria in natural communities. Our method offers significant improvement over existing methods for studying this characteristic. Our method uses a fluorescently labeled substrate which clearly labels target bacteria (glucose consumers in our case). Previous methods use isotope-labeled substrates, which are notorious for off-target labeling (due to cross-feeding of labeled metabolites). Our method can be deployed with a variety of substrates and microbial communities. It represents a major advance in connecting bacteria to the substrates they take up.
Polyomavirus T Antigen InducesAPOBEC3BExpression Using an LXCXE-Dependent and TP53-Independent Mechanism
Authors: Starrett Gabriel J. , Serebrenik Artur A. , Roelofs Pieter A. , McCann Jennifer L. , Verhalen Brandy , Jarvis Matthew C. , Stewart Teneale A. , Law Emily K. , Krupp Annabel , Jiang Mengxi , Martens John W. M. , Cahir-McFarland Ellen , Span Paul N. , Harris Reuben S.
Published: February 2019

The APOBEC3B DNA cytosine deaminase is overexpressed in many different cancers and correlates with elevated frequencies of C-to-T and C-to-G mutations in 5′-TC motifs, oncogene activation, acquired drug resistance, and poor clinical outcomes. The mechanisms responsible for APOBEC3B overexpression are not fully understood. Here, we show that the polyomavirus truncated T antigen (truncT) triggers APOBEC3B overexpression through its RB-interacting motif, LXCXE, which in turn likely modulates the binding of E2F family transcription factors to promoteAPOBEC3Bexpression. This work strengthens the mechanistic linkage between active cell cycling, APOBEC3B overexpression, and cancer mutagenesis. Although this mutational mechanism damages cellular genomes, viruses may leverage it to promote evolution, immune escape, and pathogenesis. The cellular portion of the mechanism may also be relevant to nonviral cancers, where genetic mechanisms often activate the RB/E2F axis and APOBEC3B mutagenesis contributes to tumor evolution.
Peptidoglycan Remodeling Enables Escherichia coli To Survive Severe Outer Membrane Assembly Defect
Authors: Morè Niccolò , Martorana Alessandra M. , Biboy Jacob , Otten Christian , Winkle Matthias , Serrano Carlos K. Gurnani , Montón Silva Alejandro , Atkinson Lisa , Yau Hamish , Breukink Eefjan , den Blaauwen Tanneke , Vollmer Waldemar , Polissi Alessandra
Published: February 2019

In Gram-negative bacteria, the outer membrane protects the cell against many toxic molecules, and the peptidoglycan layer provides protection against osmotic challenges, allowing bacterial cells to survive in changing environments. Maintaining cell envelope integrity is therefore a question of life or death for a bacterial cell. Here we show that
Escherichia coli
cells activate the LD-transpeptidase LdtD to introduce 3-3 cross-links in the peptidoglycan layer when the integrity of the outer membrane is compromised, and this response is required to avoid cell lysis. This peptidoglycan remodeling program is a strategy to increase the overall robustness of the bacterial cell envelope in response to defects in the outer membrane.
A Disintegrin and Metalloproteinase 9 Domain (ADAM9) Is a Major Susceptibility Factor in the Early Stages of Encephalomyocarditis Virus Infection
Authors: Bazzone Lindsey E. , King Michael , MacKay Christopher R. , Kyawe Pyae P. , Meraner Paul , Lindstrom Daniel , Rojas-Quintero Joselyn , Owen Caroline A. , Wang Jennifer P. , Brass Abraham L. , Kurt-Jones Evelyn A. , Finberg Robert W.
Published: February 2019

Viral myocarditis is a leading cause of death in the United States, contributing to numerous unexplained deaths in people ≤35 years old. Enteroviruses contribute to many cases of human myocarditis. Encephalomyocarditis virus (EMCV) infection causes viral myocarditis in rodent models, but its receptor requirements have not been fully identified. CRISPR-Cas9 screens can identify host dependency factors essential for EMCV infection and enhance our understanding of key events that follow viral infection, potentially leading to new strategies for preventing viral myocarditis. Using a CRISPR-Cas9 screen, we identified
a
d
isintegrin
a
nd
m
etalloproteinase 9 domain (ADAM9) as a major factor required for the early stages of EMCV infection in both human and murine infection.
Metabolic Responses to Polymyxin Treatment in
Acinetobacter baumannii
ATCC 19606: Integrating Transcriptomics and Metabolomics with Genome-Scale Metabolic Modeling
Authors: Zhu Yan , Zhao Jinxin , Maifiah Mohd Hafidz Mahamad , Velkov Tony , Schreiber Falk , Li Jian
Published: February 2019

Combating antimicrobial resistance has been highlighted as a critical global health priority. Due to the drying drug discovery pipeline, polymyxins have been employed as the last-line therapy against Gram-negative “superbugs”; however, the detailed mechanisms of antibacterial killing remain largely unclear, hampering the improvement of polymyxin therapy. Our integrative modeling using the constructed genome-scale metabolic model
i
ATCC19606 and the correlative multiomics data provide the fundamental understanding of the complex metabolic responses to polymyxin treatment in
A. baumannii
at the systems level. The model
i
ATCC19606 may have a significant potential in antimicrobial systems pharmacology research in
A. baumannii
.
Parallel planning and the paediatric critical care patient
Authors: Sidgwick Peter , Fraser James , Fortune Peter-Marc , McCulloch Renee
Published: January 2019

A growing number of children with life-limiting conditions (LLCs) are being cared for in paediatric critical care (PCC) settings. Children with LLCs admitted to PCC are at a high risk of developing complications and many die after prolonged admissions. Relatively few of these patients and their parents or carers have had documented discussions about their wishes for care in the event of a serious clinical deterioration before admission to PCC. There is a need for improved understanding of (1) how parents arrive at decisions regarding what is best for their child at times of critical illness and (2) the role of parallel planning and advance care plans in that process. This review examines the complexities of decision-making in children with LLCs who are admitted to PCC settings.
Takotsubo cardiomyopathy triggered by status epilepticus: case report and literature review
Authors: Nandal Savvy , Castles Anastasia , Asrar ul Haq Muhammad , van Gaal William
Published: January 2019

Takotsubo cardiomyopathy (TC) is acute stress-induced cardiomyopathy with characteristic transient wall motion abnormalities. TC has a clinical presentation similar to an acute coronary syndrome, including chest pain or dyspnoea, ECG changes and elevated cardiac enzymes. TC often occurs after emotional stress. There are approximately 50 TC cases reported related to seizure activity, and our review revealed 15 articles which were associated with status epilepticus. This condition can be a serious complication of seizures. We report a case of TC after status epilepticus in a patient who had been seizure-free for 20 years.
Placental chorioangioma associated with polyhydramnios and hydrops fetalis
Authors: Willis Charlotte , Ferguson Siobhan , Soydemir Fatimah
Published: January 2019

A 27-year-old multigravida woman was noted on routine growth scan at 27 weeks gestation to have a central placental hypoechoic area measuring 6.7×6.0×4.4 cm. A subsequent magnetic resonance scan confirmed a solid mass in the placenta lying anteriorly; therefore, a preliminary diagnosis of giant placental chorioangioma was made. A repeat ultrasound scan at 30 weeks gestation indicated that the mass had increased, with the presence of polyhydramnios. The patient experienced reduced fetal movements at 31 weeks gestation. There was persistent fetal tachycardia at 33 weeks gestation, and consequently the neonate was delivered by emergency caesarean section. The placenta revealed a large chorioangioma. The neonate’s birth weight was 2.85 kg and non-immune hydrops fetalis was diagnosed. The neonate improved significantly in the neonatal intensive care unit and is currently well with no medical problems.
Do changes in weight status affect cognitive function in children and adolescents with obesity? A secondary analysis of a clinical trial
Authors: Anderson Yvonne C , Kirkpatrick Kaye , Dolan Gerard M S , Wouldes Trecia A , Grant Cameron C , Cave Tami L , Wild Cervantée E K , Derraik José G B , Cutfield Wayne S , Hofman Paul L
Published: February 2019

Objectives

It is unclear whether an association exists between obesity in children/adolescents and cognitive function, and whether the latter can be altered by body mass index (BMI) standard deviation score (SDS) reductions. We aimed to determine whether an association exists between BMI SDS and cognitive function in children/adolescents with obesity engaged in an obesity intervention. Second, we sought to determine if BMI SDS reduction at 12 months was associated with improved cognitive function.

Design

Secondary analysis of a clinical trial.

Participants

Participants (n=69) were recruited from an obesity intervention. Eligible participants (recruited June 2013 to June 2015) were aged 6–16 years, with a BMI ≥98th centile or BMI >91st centile with weight-related comorbidities.

Outcome measures

Primary outcome measure was change in BMI SDS from baseline at 12 months. Dependent variables of cognitive functioning and school achievement were assessed at baseline and 12 months, using dependent variables of cognitive functioning (elements of Ravens Standard Progressive Matrices, Wide Range Achievement Test-fourth edition and Wechsler Intelligence Scale for Children-fourth edition).

Results

At baseline, BMI SDS was not associated with all aspects of cognitive function tested (n=69). Reductions in BMI SDS over time did not alter cognitive function overall. However, there was a greater reduction in comprehension standard scores in participants who increased their BMI SDS (adjusted estimated difference −6.1, 95% CI −11.6 to −0.6; p=0.03).

Conclusions

There were no observed associations between BMI SDS and cognitive function in participants, apart from comprehension in the exploratory analyses, which may have been a random finding. Further studies need to include larger longitudinal cohorts incorporating a wider BMI range at entry to determine whether our findings persist.

Trial registration number

ANZCTR12611000862943; Pre-results.
Can pulse check by the photoplethysmography sensor on a smart watch replace carotid artery palpation during cardiopulmonary resuscitation in cardiac arrest patients? a prospective observational diagnostic accuracy study
Authors: Lee Yoonje , Shin Hyungoo , Choi Hyuk Joong , Kim Changsun
Published: February 2019

Objective

The purpose of this study was to assess whether a photoplethysmography (PPG) sensor in a smart watch can accurately recognise the return of spontaneous circulation (ROSC) in cardiac arrest patients compared with carotid artery palpation.

Methods

This prospective observational study was conducted on 50 out-of-hospital cardiac arrest patients who visited the emergency department (ED) of one tertiary hospital. As soon as the patient arrived at the ED, advanced cardiac life support was carried out immediately. At this time, three smart watches were attached to the carotid artery, forehead and wrist and were checked for pulse measurements every 2 min. In the case of ROSC, blood pressure, heart rate and heart rate regularity were confirmed, and pulse was simultaneously measured at three sites with smart watches. In the case of no ROSC, only the pulse was measured at three sites with the smart watches.

Results

There were 33 males (66%) and the mean age was 68±11.57 years. In 14 patients (28%), spontaneous circulation was recovered through cardiopulmonary resuscitation, and all survived. The sensitivity and specificity of manual palpation were 78.6% and 90.4%, respectively. False-positive and false-negative rates were 9.6% and 21.4%, respectively. Smart watches at all three sites had the same or higher sensitivity than manual palpation. The sensitivity of the smart watch was the highest, at 100%, in the carotid region and the lowest, at 78.6%, in the wrist region. The specificity of the smart watch was the highest, at 100%, in the wrist region and the lowest, at 78.7%, in the carotid region.

Conclusion

Compared with manual pulse check, the PPG sensor embedded in the smart watch showed the same sensitivity and a higher specificity for recognising ROSC when measured at the wrist.
Temporal trends in severe morbidity and mortality associated with ectopic pregnancy requiring hospitalisation in Washington State, USA: a population-based study
Authors: Lisonkova Sarka , Tan Justin , Wen Qi , Abdellatif Lobna , Richter Lindsay L , Alfaraj Sukainah , Yong Paul J , Bedaiwy Mohamed A
Published: February 2019

Objective

To examine temporal trend in maternal mortality/severe morbidity associated with hospitalisation due to ectopic pregnancy.

Design

A population-based observational study.

Setting and participants

All women hospitalised for ectopic pregnancy in Washington State, USA, 1987–2014 (n=20 418). The main composite outcome of severe morbidity/mortality included death, sepsis, need for transfusion, hysterectomy and systemic or organ failure, identified by diagnostic and procedure codes from hospitalisation files. Severe morbidity/mortality due to ectopic pregnancy were expressed as incidence ratios among women of reproductive age (15–64 years) and among women hospitalised for ectopic pregnancy. Comparisons were made between 1987–1991 (reference) and 2010–2014 using ratios of incidence ratios (RR) and ratio differences (RD). The Cochran-Armitage test for trend assessed statistical significance; logistic regression was used to obtain adjusted OR (AOR) and 95% CI, adjusted for demographic factors and comorbidity.

Results

Hospitalisation for ectopic pregnancy declined from 0.89 to 0.16 per 1000 reproductive age women between 1987–1991 and 2010–2014 (p<0.001). Among reproductive age women, ectopic pregnancy mortality remained stable (0.03 per 100 000); and mortality/severe morbidity increased among women aged 25–34 years (p=0.022). Among women hospitalised for ectopic pregnancy, mortality increased from 0.29 to 1.65 per 1000 between 1987–1991 and 2010–2015 (p=0.06); severe morbidity/mortality increased from 3.85% to 19.63% (RR=5.10, 95% CI 4.36 to 5.98; RD=15.78 per 100 women, 95% CI 13.90 to 17.66; AOR for 1-year change was 1.08, 95% CI 1.07 to 1.08).

Conclusions

Hospitalisation for ectopic pregnancy declined in Washington State, USA, between 1987 and 2014; however, mortality/severe morbidity associated with ectopic pregnancy increased in female population aged 25–34 years.