bluuebunny/crossref_metadata_2025_split huggingface dataset:
Symmetry breaking and structural polymorphism in a bacterial microcompartment shell protein for choline utilization
Authors: Ochoa Jessica M. , Nguyen Vy N. , Nie Mengxiao , Sawaya Michael R. , Bobik Thomas A. , Yeates Todd O. 
Published: September 2020

AbstractBacterial microcompartments are protein‐based organelles that carry out specialized metabolic functions in diverse bacteria. Their outer shells are built from several thousand protein subunits. Some of the architectural principles of bacterial microcompartments have been articulated, with lateral packing of flat hexameric BMC proteins providing the basic foundation for assembly. Nonetheless, a complete understanding has been elusive, partly owing to polymorphic mechanisms of assembly exhibited by most microcompartment types. An earlier study of one homologous BMC shell protein subfamily, EutS/PduU, revealed a profoundly bent, rather than flat, hexameric structure. The possibility of a specialized architectural role was hypothesized, but artifactual effects of crystallization could not be ruled out. Here we report a series of crystal structures of an orthologous protein, CutR, from a glycyl‐radical type choline‐utilizing microcompartment from the bacterium Streptococcus intermedius. Depending on crystal form, expression construct, and minor mutations, a range of novel quaternary architectures was observed, including two spiral hexagonal assemblies. A new graphical approach helps illuminate the variations in BMC hexameric structure, with results substantiating the idea that the EutS/PduU/CutR subfamily of BMC proteins may endow microcompartment shells with flexible modes of assembly.
Incorporation of thermal explosion scenarios into the multilevel risk analysis procedure
Authors: Masin Jindrich , Ferjencik Milos 
Published: September 2020

AbstractThe work's starting point is the multilevel risk analysis procedure (MLRAP), the difficulty of which sits comfortably between the easiest qualitative risk studies and the most complicated quantitative analysis. MLRAP was originally developed for use in explosive‐handling plants. During the application of MLRAP, a gap in the procedure was found. The approach was not easily applicable to functional nodes with possible exothermic reactions. This article aims to the identification of a reasonable number of layer of protection analysis thermal explosion scenarios for such functional nodes. Two tools are utilized for this purpose: the Stoessel's concept of criticality classes and the use of adiabatic calorimetry results to classify functional nodes with the possibility of an exothermic reaction. The article modifies the original MLRAP so that for functional nodes where an exothermic reaction is possible, it identifies initiating events and scenarios depending on the criticality class and the type of reactor. A detailed flow chart complements the modification of MLRAP. The application of the modified MLRAP for the identification of thermal runaway scenarios not only in the explosive‐handling processes is illustrated by two examples.
Protein stable isotope probing with H218O differentiated cold stress response at permissive temperatures from general growth at optimal conditions in Escherichia coli K12
Authors: Starke Robert , Schäpe Stephanie Serena , Jehmlich Nico , von Bergen Martin 
Published: September 2020

RationaleTracing isotopically labeled water into proteins allows for the detection of species‐specific metabolic activity in complex communities. However, a stress response may alter the newly synthesized proteins.MethodsWe traced 18‐oxygen from heavy water into proteins of Escherichia coli K12 grown from permissive to retardant temperatures. All samples were analyzed using UPLC/Orbitrap Q‐Exactive‐MS/MS operating in positive electrospray ionization mode.ResultsWe found that warmer temperatures resulted in significantly (P‐value < 0.05) higher incorporation of 18‐oxygen as seen by both substrate utilization as relative isotope abundance (RIA) and growth as labeling ratio (LR). However, the absolute number of peptides with incorporation of 18‐oxygen showed no significant correlation to temperature, potentially caused by the synthesis of different proteins at low temperatures, namely, proteins related to cold stress response.ConclusionsOur results unveil the species‐specific cold stress response of E. coli K12 that could be misinterpreted as general growth; this is why the quantity as RIA and LR but also the quality as absolute number of peptides with incorporation (relative abundance, RA) and their function must be considered to fully understand the activity of microbial communities.
Adaptive practical leader‐following formation control of multiple nonholonomic wheeled mobile robots
Authors: Yan Lixia , Ma Baoli 
Published: September 2020

SummaryThis article investigates the leader‐following formation control of multiple uncertain nonholonomic wheeled mobile robots. The leader trajectory can be any sufficiently smooth signal, either feasible or nonfeasible. This includes but not limited to a fixed point, a trimming trajectory, and the one that does not satisfy the nonholonomic constraint as robots in question do. To compensate for the effects that only a subset of follower robots has connected to the leader, we develop a distributed observer to estimate the leader's position and velocities. Using leader's estimated states, we convert formation errors into an augmented system with external oscillator states, which introduce an additional control variable and overcome the difficulties caused by underactuation. Subsequently, an adaptive tracking control law dealing with model uncertainties and stabilizing the augmented system is proposed, ensuring that formation errors are globally uniformly ultimately convergent to arbitrarily small balls near the origin. Simulation results are performed to validate the proposed control design.
A Confluence of Complexity: Intersections Among Reading Theory, Neuroscience, and Observations of Young Readers
Authors: Compton‐Lilly Catherine F. , Mitra Ayan , Guay Mary , Spence Lucy K. 
Published: September 2020

ABSTRACTIn this position article, the authors explore a confluence of evidence that supports the understanding that multiple factors, various processes, and multiple sources of information inform reading. The authors open by briefly describing concerns related to how some scholars and media reporters have characterized the simple view of reading and narrowly applied that model to teaching young readers. The authors then explore a confluence of complexity across (a) theoretical models of reading based on empirical research, (b) emerging information related to the brain and reading, and (c) research findings based on close observations of young learners. Finally, the authors argue that reductive and singular models of reading fail to not only honor the individuality of young readers but also to recognize the systemic changes needed in schools and communities to equitably serve all students.
Mode interaction in cold‐formed steel members: state‐of‐art report
Authors: Camotim Dinar , Martins André Dias , Dinis Pedro Borges , Young Ben , Chen Man‐Tai , Landesmann Alexandre 
Published: September 2020

AbstractExtended keynote paper of Eurosteel 2021This is Part 2 of a two‐part paper providing a state‐of‐art report of the most recent findings concerning the behaviour, strength and Direct Strength Method (DSM) design of cold‐formed steel (CFS) columns and beams affected by mode coupling phenomena not adequately covered by the current specifications for CFS members. This second paper covers interactions involving global buckling modes, namely local‐distortional‐global (L‐D‐G), distortional‐global (D‐G) and global‐global (flexural‐torsional/flexural – FT‐F) interaction – note that local‐global (L‐G) interaction, already well mastered by the technical/scientific community, is not dealt with. Like Part 1 [1], this paper also addresses experimental tests, numerical simulations and DSM‐based design approaches, intended to i) acquire in‐depth knowledge on the non‐linear behaviour (elastic and elastic‐plastic), load‐carrying capacity and failure mode nature of the members under consideration, and ii) make use of the above knowledge to develop, propose and assess the merits of efficient DSM‐based design approaches to estimate their failure loads/moments. Taking into account the fundamental concepts and DSM design curves presented in Part 1 [1], the paper addresses separately each mode coupling phenomenon dealt with, for columns, and only D‐G interaction for beams – recall that L‐D interaction (columns and beams) was covered in Part 1 [1]. For columns undergoing L‐D‐G interaction and angle columns susceptible to FT‐F interaction, the work reported includes experimental studies, numerical simulations and DSM‐based design considerations and/or guidelines. For columns and beams experiencing D‐G interaction and channel columns prone to FT‐F coupling, only numerical results are reported – they reveal surprising behavioural features that will be very useful in planning future test campaigns and achieving efficient design approaches. Finally, the two‐part paper closes with a few concluding remarks and a perspective about future developments in this field.
Investigations on mechanical and thermal properties of concrete with different proportions of insulation aggregates
Authors: Ch Naga Satish Kumar , A Parvathidevi 
Published: September 2020

AbstractInvestigation of mechanical properties and thermal behavior of expanded polystyrene concrete (EPS) and exfoliated vermiculite (EV) concrete has been accomplished in this research. It includes how EPS concrete is prepared by substituting the coarse aggregate with 0, 10, 15, and 20% with EPS aggregates. Similarly, EV concrete is prepared by replacing the fine aggregates with 0, 15, 45, and 60% with EV aggregates. The influence of EPS and EV proportion on mechanical and thermal properties was detected. Thermal properties were studied with an adiabatic box technique. Clear improvement in thermal behavior was observed in comparison with normal concrete and reduction in compressive strength was observed for an appreciable increase in the amount of EPS and EV. Also, the properties like split tensile strength, load–deflection curves, and durability properties of the EPS and EV concretes were experimented.
Resolving the relationships of the enigmatic Sapotaceae genera Beauvisagea and Boerlagella, and the position of Planchonella suboppositifolia
Authors: Swenson Ulf , Lowry Porter P. , Cronholm Bodil , Nylinder Stephan 
Published: September 2020

AbstractThe pantropical plant family Sapotaceae currently includes 65–70 genera. Two genera, Beauvisagea and Boerlagella, were described in 1890s using incomplete material from West New Guinea (Bird's Head Peninsula) and Sumatra, neither of which has been collected since. Their systematic position has long been regarded doubtful and Boerlagella was once placed in its own family, Boerlagellaceae. We show here how useful and important it can be to obtain small leaf fragments from type specimens that are up to 150 years old for molecular analysis aiming to determine their phylogenetic position and clarify their taxonomic status. We used nuclear ribosomal DNA (ETS, ITS) and the nuclear gene RPB2 from 170 terminals to estimate phylogenetic relationships in a Bayesian framework using BEAST. The old type material yielded full length sequences of ETS and ITS from both genera (less successful with RPB2), revealing that both are firmly placed in Planchonella. Boerlagella is placed in synonymy with Planchonella and its type is accepted as Planchonella spectabilis, a species from Sumatra that possibly has gone extinct due to deforestation. Beauvisagea from the Bird's Head Peninsula of western New Guinea is likewise regarded as a synonym of Planchonella and its type, accepted as P. pomifera, is conspecific with Pouteria doonsaf (currently circumscribed to include material of at least two different species), not Planchonella maclayana as earlier believed. Our study also included Planchonella suboppositifolia, an odd species with a character combination in conflict with the current definition of the genus. Our results show that it is sister to a lineage comprising several genera, including Planchonella, and that it represents a distinct lineage constituting a monotypic genus that will be described in a subsequent paper. The most recent classification of subfamily Chrysophylloideae and the character combinations used to distinguish its constituent genera are supported, and our results confirm that taxa can reliably be assigned to a genus based on morphology alone.
Context Matters: The Effect of Textual Tone on the Evaluation of Mediated Social Touch
Authors: Askari Sima Ipakchian , Haans Antal , Bos Pieter , Eggink Maureen , Lu Emily Mengfei , Kwong Fenella , IJsselsteijn Wijnand 
Published: September 2020

AbstractMediated Social Touch (MST) promises interpersonal touch over a distance through haptic or tactile displays. Tests of the efficacy of MST often involve attempts to demonstrate that effects of social touch (e.g., on affective responses or helping behavior) can be replicated with MST. Results, however, have been mixed. One possible explanation is that contextual factors have not sufficiently been taken into account in these experiments. A touch act is accompanied by other verbal and non-verbal expressions, and whom we touch, when, and in what manner is regulated through social and personal norms. Previous research demonstrated, amongst others, effects of gender and the facial expression of the toucher on the recipients’ touch experience. People can use expressions of the toucher’s emotions as a cue to anticipate the meaning of the ensuing social touch. This current study examines whether emotions expressed in text (i.e., textual tone) affects the meaning and experience of MST. As expected we found textual tone to affect both the comfortableness of the touch as well as its perceived meaning. Limitations and implications are discussed.
Visuo-Haptic Display by Embedding Imperceptible Spatial Haptic Information into Projected Images
Authors: Miyatake Yamato , Hiraki Takefumi , Maeda Tomosuke , Iwai Daisuke , Sato Kosuke 
Published: September 2020

AbstractVisuo-haptic augmented reality (AR) systems that represent visual and haptic sensations in a spatially and temporally consistent manner are used to improve the reality in AR applications. However, existing visual displays either cover the user’s field-of-view or are limited to flat panels. In the present paper, we propose a novel projection-based AR system that can present consistent visuo-haptic sensations on a non-planar physical surface without inserting any visual display devices between a user and the surface. The core technical contribution is controlling wearable haptic displays using a pixel-level visible light communication projector. The projection system can embed spatial haptic information into each pixel, and the haptic displays vibrate according to the detected pixel information. We confirm that the proposed system can display visuo-haptic information with pixel-precise alignment with a delay of 85 ms. We can also employ the proposed system as a novel experimental platform to clarify the spatio-temporal perceptual characteristics of visual and haptic sensations. As a result of the conducted user studies, we revealed that the noticeable thresholds of visual-haptic asynchrony were about 100 ms (temporal) and 10 mm (spatial), respectively.
Manipulating the Perceived Directions of Wind by Visuo-Audio-Haptic Cross-Modal Effects
Authors: Ito Kenichi , Ban Yuki , Warisawa Shin’ichi 
Published: September 2020

AbstractWind displays, which simulate the sensation of wind, have been known to enhance the immersion of virtual reality content. However, certain wind displays require an excessive number of wind sources to simulate wind from various directions. To realize wind displays with fewer wind sources, a method to manipulate the perceived directions of wind by audio-haptic cross-modal effects was proposed in our previous study. As the visuo-haptic cross-modal effect on perceived wind directions has not yet been quantitatively investigated, this study focuses on the effect of visual stimuli on the perception of wind direction. We present virtual images of flowing particles and three-dimensional sounds of wind as information to indicate wind directions and induce cross-modal effects in users. The user study has demonstrated that adding visual stimuli effectively improved the result corresponding to certain virtual wind directions. Our results suggest that perceived wind directions can be manipulated by both visuo-haptic and audio-haptic cross-modal effects.
KATIB: Haptic-Visual Guidance for Handwriting
Authors: Korres Georgios , Eid Mohamad 
Published: September 2020

AbstractHaptic-visual guidance is shown to improve handwriting. This work presents a platform named KATIB (writer in Arabic) to support multi-stroke handwriting using haptic-visual guidance. A rotating neodymium magnet mounted onto a 2 DoF parallel robot underneath the writing surface is proposed to improve the fidelity of haptic guidance and mechanically decouple the stylus. The stylus utilizes stackable magnets to intensify magnetic forces. Full and partial haptic guidance methods are developed and evaluated. The current implementation demonstrates sufficient workspace of 80 mm $$\times $$
×
60 mm and a perceivable (tangential) guidance force of 0.4 N. Magnetostatic analysis is conducted to study the effects of friction and tilting on the rendered force.
Midair Haptic Presentation Using Concave Reflector
Authors: Ariga Kentaro , Fujiwara Masahiro , Makino Yasutoshi , Shinoda Hiroyuki 
Published: September 2020

AbstractAn airborne ultrasound tactile display (AUTD) can focus on an arbitrary position by controlling the phase shift and amplitude of each transducer, and provide a tactile stimulus on the human body without direct contact. However, beyond a distance from the phased array, it cannot secure a focal size comparable to the wavelength and the displayed pressure pattern blurs. In this study, we propose a method with a concave reflector to focus at a farther position and present a tactile sensation without enlarging the array. By appropriately designing the focal length of the concave reflector, the focal point can be formed at a distant position using a mirror formula while keeping the focus size non-extended. We conducted two experiments, the results of which show that the proposed method is valid and that a workspace of several square centimeters can be achieved.
Confinement of Vibrotactile Stimuli in Periodically Supported Plates
Authors: Ben Dhiab Ayoub , Hudin Charles 
Published: September 2020

AbstractFor multitouch and multiuser interactions on a touch surface, providing a local vibrotactile feedback is essential. Usually, vibration propagation impedes this localization. Previous work showed that narrow strip-shaped plates could allow the confinement of vibrotactile stimuli to the actuated area. Adding to this principle, periodically supported plates also provide a non-propagative effect at low frequencies. Using both geometrical properties, we provide a device allowing a multitouch interaction through an array of piezoelectric actuator. Experimental validation show that vibrations are well confined on top of actuated areas with vibration amplitude over 2 $$\upmu $$
μ
m.
A Proposal and Investigation of Displaying Method by Passive Touch with Electrostatic Tactile Display
Authors: Tomita Hirobumi , Saga Satoshi , Takahashi Shin , Kajimoto Hiroyuki 
Published: September 2020

AbstractIn the field of tactile displays, electrostatic force displays have been developed for presenting tactile stimulation on a screen. However, with the conventional electrostatic force displays, the user cannot feel the stimulation without rubbing on the display. In this paper, to solve this problem, we propose a new method to present a tactile sensation without moving a finger by creating a small space between an electrode and an insulating surface. Moreover, we evaluate the perceived threshold of the proposed display through the experiment.
Surface Roughness Judgment During Finger Exploration Is Changeable by Visual Oscillations
Authors: Ota Yusuke , Ujitoko Yusuke , Ban Yuki , Sakurai Sho , Hirota Koichi 
Published: September 2020

AbstractPreviously, we proposed a pseudo-haptic method of changing the perceived roughness of virtual textured surfaces represented by vibrational feedback during pen-surface interaction. This study extends the method to finger-surface interactions in order to change the roughness judgment of real surface. Users watched computer-generated visual oscillations of the contact point while exploring the texture using bare fingers. The user study showed that our method could modify roughness judgment of real textured surfaces.
Sensing Ultrasonic Mid-Air Haptics with a Biomimetic Tactile Fingertip
Authors: Alakhawand Noor , Frier William , Freud Kipp McAdam , Georgiou Orestis , Lepora Nathan F. 
Published: September 2020

AbstractUltrasonic phased arrays are used to generate mid-air haptic feedback, allowing users to feel sensations in mid-air. In this work, we present a method for testing mid-air haptics with a biomimetic tactile sensor that is inspired by the human fingertip. Our experiments with point, line, and circular test stimuli provide insights on how the acoustic radiation pressure produced by the ultrasonic array deforms the skin-like material of the sensor. This allows us to produce detailed visualizations of the sensations in two-dimensional and three-dimensional space. This approach provides a detailed quantification of mid-air haptic stimuli of use as an investigative tool for improving the performance of haptic displays and for understanding the transduction of mid-air haptics by the human sense of touch.
Wearable Vibrotactile Interface Using Phantom Tactile Sensation for Human-Robot Interaction
Authors: Seiler Julian , Schäfer Niklas , Latsch Bastian , Chadda Romol , Hessinger Markus , Beckerle Philipp , Kupnik Mario 
Published: September 2020

AbstractWe present a wearable vibrotactile feedback device consisting of four linear resonant actuators (LRAs) that are able to generate virtual stimuli, known as phantom tactile sensation, for human-robot interaction. Using an energy model, we can control the location and intensity of the virtual stimuli independently. The device consists of mostly 3D-printed rigid and flexible components and uses commercially available haptic drivers for actuation. The actuators have a rated frequency of 175 Hz which is close to the highest skin sensitivity regarding vibrations (150 to 300 Hz). Our experiment was conducted with a prototype consisting of two bracelets applied to the forearm and upper arm of six participants. Eight possible circumferential angles were stimulated, of which four originated from real actuators and four were generated by virtual stimuli. The responses given by the participants showed a nearly linear relationship within $$\pm {10}{^\circ }$$

±
10

∘

for the responded angle against the presented stimulus angle. These results show that phantom tactile sensation allows for an increase of spatial resolution to design vibrotactile interfaces for human-robot interaction with fewer actuators.