bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of the coronavirus disease 2019 pandemic on periodontal practice: A questionnaire survey
Authors: Rocha‐Gomes Gabriela , Flecha Olga D. , Miranda Tamires S. , Duarte Poliana M. , Shaddox Luciana M. , Galvão Endi L. , Gonçalves Patricia F.
Published: January 2021

Aim

This cross‐sectional study sought to investigate the factors possibly related to the impact caused by the coronavirus disease 2019 pandemic in the practice of periodontists, in two countries.

Materials and methods

A total of 254 periodontists with active periodontics licensing in Brazil and the United States participated in the survey. Data were collected through an online questionnaire and the dependent variable was the perceived impact of the pandemic on periodontists' practice routines. Odds ratios were assessed by logistic regression analysis.

Results

Periodontists in private practice were 83% less likely to report a significant impact of the pandemic on their clinical routine as compared with professionals who work in the public sector or in academic institutions (CI 95%: 0.05–0.47). The financial impact of the pandemic was significantly associated with a perceived severe impact of the pandemic on their routines (OR: 1.36; CI 95%: 1.16–1.61). Professionals who have enhanced their hand‐washing routine were more likely to report a significant impact of the pandemic by 3.41 times (CI 95%: 1.28–9.04) relative to those who have not altered their hand‐washing protocols.

Conclusion

The pandemic is associated with a negative impact on the practice of periodontists, especially those working in public sectors and academic institutions.
A patient presentation: Planning and executing a difficult case in a full digital workflow
Authors: Poggio Carlo E. , Bonfiglioli Roberto , Dosoli Riccardo
Published: January 2021

Objective

In patients requiring extensive tooth replacement, including a change of VDO and/or a new orientation of the occlusal plane, a fully digital workflow still tends to be considered too much complex to be planned and performed. This clinical report describes a full mouth rehabilitation performed with a full digital approach.

Clinical considerations

In a 50‐year‐old man with several missing teeth in the upper and lower arch, extensive decay on multiple teeth, severe attrition of the anterior teeth, treatment of the upper and lower arches was performed with dental implants, crowns and veneers. All prosthodontic therapy was realized with full monolithic ceramic materials (zirconia and lithium disilicate). The combination of digital information and monolithic materials enabled the clinician, the dental laboratory technician and the patient, to communicate effectively during treatment planning and to use the combination of digital workflow and monolithic materials to simplify the steps of treatment of a difficult case.

Conclusions

The combination of full digital workflow with full monolithic restorations in a full mouth rehabilitation allows a simplification of every clinical and lab step in a typically complex treatment.
Implementing a Rapid, Two‐Step Delirium Screening Protocol in Acute Care: Barriers and Facilitators
Authors: Husser Erica K. , Fick Donna M. , Boltz Marie , Shrestha Priyanka , Siuta Jonathan , Malloy Shannon , Overstreet Abigail , Leslie Douglas L. , Ngo Long , Jung Yoojin , Inouye Sharon K. , Marcantonio Edward R.
Published: January 2021

BACKGROUND/OBJECTIVES

An effective and efficient protocol for delirium identification is needed to improve health outcomes for older adults and reduce healthcare costs. This study describes the barriers and facilitators related to the implementation of the ultra‐brief confusion assessment method (UB‐CAM), a rapid two‐step delirium identification protocol (ultra‐brief screen, followed by CAM in positives), field tested with hospitalized older adults (70+).

DESIGN

A qualitative descriptive design using observational data collection and brief semi‐structured interviews.

SETTINGS

An urban academic medical center and a community teaching hospital.

PARTICIPANTS

Participants included 50 physician hospitalists, 189 registered nurses, and 83 nursing assistants (NAs).

MEASUREMENTS

Field researchers guided by a modified multi‐level implementation framework, collected observational data as participants administered the UB‐CAM (n = 767). Thematic analysis was conducted on five observational categories: structural, organizational, patient, clinician, and innovation. Field notes and brief semi‐structured interviews (n = 231) with clinicians, explored the utility, acceptability, and feasibility of the protocol, and supplemented the observations.

RESULTS

The UB‐CAM was generally positively received by all three clinician types. Six themes describe barriers and/or facilitators to implementing the UB‐CAM: (1) physical setting and milieu; (2) practice environment; (3) integrating into role; (4) adaptive techniques; (5) patient responses; and (6) systematic assessment. The composition and interaction of the six themes determined if the theme was expressed as a barrier or facilitator, affirming the importance of context when implementing system‐level delirium screening.

CONCLUSION

This is one of the first studies to test a two‐step process for delirium identification, and to involve NAs in screening, and the findings demonstrate overall support from clinicians for delirium identification, and describe the need for a multifaceted, contextualized, and systemic approach to implementation and evaluation of delirium screening.
Matrilineal evidence for genetic structure and Late Pleistocene demographic expansion of the Ornate goby Istigobiusornatus (Teleostei: Gobiidae) in the Persian Gulf and Oman Sea
Authors: Sadeghi Reza , Esmaeili Hamid Reza , Zarei Fatah , Reichenbacher Bettina
Published: January 2021

The Persian Gulf and Oman Sea are characterized by an interesting paleoclimatic history and different ecological settings, and offer a unique study area to investigate the genetic structure of marine organisms including fishes. The Ornate goby Istigobius ornatus is widely distributed throughout the tropical Indo‐West Pacific including the Persian Gulf and Oman Sea. Here, we present the population structure, genetic diversity, and demographic history of four populations of I. ornatus from the latter two regions using the D‐loop marker of mitochondrial DNA. The results reveal a shallow genealogy, a star‐like haplotype network, significance of neutrality tests, and unimodal mismatch distribution. This is concordant with a recent demographic expansion of I. ornatus in the Persian Gulf and Oman Sea at about 63,000–14,000 years ago, which appears to be related to Late Pleistocene sea level fall and rise. The results of the pairwise Fst estimates imply high gene flow along the coast of the Persian Gulf, which is probably due to larval dispersion, whereas the Oman Sea population clearly differs from all Persian Gulf populations. The AMOVA result indicates that 7.74% of the variation is related to differences among ecoregions, while inter‐ and intra‐population differences explained −3.20% and 95.47% of the variation, respectively. The haplotype network depicts two groups of haplotypes, most of them were specific to the Persian Gulf. No further evidence for geographic lineage substructuring was evident. The Mantel test result indicates that isolation by distance is not the main mechanism that promoted the genetic differentiation among the studied populations of I. ornatus. We suggest that cumulative effects of ecological and geographic barriers such as salinity, oceanographic conditions, and the presence of the Strait of Hormuz have shaped the genetic structure of I. ornatus in the Persian Gulf and Oman Sea.
Case report of anorexia nervosa showing periventricular gliosis at autopsy
Authors: Umeda Kentaro , Kawakami Ito , Ikeda Kenji , Tanei Zen‐ichi , Matsubara Tomoyasu , Murayama Shigeo , Murahashi Yuki , Niizato Kazuhiro , Oshima Kenichi , Iritani Shuji
Published: January 2021

Anorexia nervosa (AN) is a serious eating disorder characterized by self‐starvation and extreme weight loss. It has the highest mortality rate among all psychiatric disorders. Recent research indicates that malnutrition in AN patients induces various kinds of functional brain damage, but the pathophysiology of AN remains unclear. We report here the neuropathological findings of a 31‐year‐old Japanese woman. At age 24, she had a fear of gaining weight and reduced her dietary intake; she had extremely low body weight associated with overeating then self‐induced vomiting. She was clinically diagnosed as having AN and was admitted to a psychiatric hospital with severe depression and suicidal thoughts. At age 31, she died despite intensive physical care and psychotherapy. Neuropathological examination revealed increased capillary blood vessels and slight fibrillary gliosis in the mammillary bodies, with similarities to Wernicke encephalopathy. The brainstem exhibited the characteristic features of central pontine myelinolysis, characterized by a sharply demarcated region of myelin pallor and relative sparing of axons. Senile changes, including neurofibrillary tangles/senile plaques, were not significant. Severe fibrillary gliosis was prominent around periventricular regions, including the caudate nucleus and nucleus accumbens, which are associated with cognition, emotion, and emotional behaviors via the dopaminergic pathways. These findings indicate that prolonged malnutrition in AN patients may induce brain damage, leading to dysfunction of the reward‐related dopaminergic pathways. Furthermore, they represent the first pathological evidence that dysfunction of the cortico–limbic–striatal circuitry is involved in the pathophysiology of psychiatric symptoms in AN patients.
Desmethyl butenolides are optimal ligands for karrikin receptor proteins
Authors: Yao Jiaren , Scaffidi Adrian , Meng Yongjie , Melville Kim T. , Komatsu Aino , Khosla Aashima , Nelson David C. , Kyozuka Junko , Flematti Gavin R. , Waters Mark T.
Published: January 2021

Strigolactones and karrikins are butenolide molecules that regulate plant growth. They are perceived by the α/β‐hydrolase DWARF14 (D14) and its homologue KARRIKIN INSENSITIVE2 (KAI2), respectively. Plant‐derived strigolactones have a butenolide ring with a methyl group that is essential for bioactivity. By contrast, karrikins are abiotic in origin, and the butenolide methyl group is nonessential. KAI2 is probably a receptor for an endogenous butenolide, but the identity of this compound remains unknown.

Here we characterise the specificity of KAI2 towards differing butenolide ligands using genetic and biochemical approaches.

We find that KAI2 proteins from multiple species are most sensitive to desmethyl butenolides that lack a methyl group. Desmethyl‐GR24 and desmethyl‐CN‐debranone are active by KAI2 but not D14. They are more potent KAI2 agonists compared with their methyl‐substituted reference compounds both in vitro and in plants. The preference of KAI2 for desmethyl butenolides is conserved in Selaginella moellendorffii and Marchantia polymorpha, suggesting that it is an ancient trait in land plant evolution.

Our findings provide insight into the mechanistic basis for differential ligand perception by KAI2 and D14, and support the view that the endogenous substrates for KAI2 and D14 have distinct chemical structures and biosynthetic origins.
Aphid feeding induces the relaxation of epigenetic control and the associated regulation of the defense response in Arabidopsis
Authors: Annacondia Maria Luz , Markovic Dimitrije , Reig‐Valiente Juan Luis , Scaltsoyiannes Vassilis , Pieterse Corné M. J. , Ninkovic Velemir , Slotkin R. Keith , Martinez German
Published: January 2021

Environmentally induced changes in the epigenome help individuals to quickly adapt to fluctuations in the conditions of their habitats.

We explored those changes in Arabidopsis thaliana plants subjected to multiple biotic and abiotic stresses, and identified transposable element (TE) activation in plants infested with the green peach aphid, Myzus persicae. We performed a genome‐wide analysis mRNA expression, small RNA accumulation and DNA methylation

Our results demonstrate that aphid feeding induces loss of methylation of hundreds of loci, mainly TEs. This loss of methylation has the potential to regulate gene expression and we found evidence that it is involved in the control of plant immunity genes. Accordingly, mutant plants deficient in DNA and H3K9 methylation (kyp) showed increased resistance to M. persicae infestation.

Collectively, our results show that changes in DNA methylation play a significant role in the regulation of the plant transcriptional response and induction of defense response against aphid feeding.
Aerobic bacteria and archaea tend to have larger and more versatile genomes
Authors: Nielsen Daniel A. , Fierer Noah , Geoghegan Jemma L. , Gillings Michael R. , Gumerov Vadim , Madin Joshua S. , Moore Lisa , Paulsen Ian T. , Reddy T. B. K. , Tetu Sasha G. , Westoby Mark
Published: January 2021

A recent compilation of traits across culturable species of bacteria and archaea allows relationships to be quantified between genome size and other traits and habitat. Cell morphology, size, motility, sporulation and doubling time were not strongly correlated with genome size. Aerobic species averaged ca 35% larger genomes than anaerobic, adjusted for growth temperature. Aerobes had a similar mix of gene functions compared to anaerobes of the same genome size. Shifting proportions of aerobes to anaerobes accounted for about half of previously‐known differences in mean genome size between habitats. One possible factor in these results could be if effective population sizes are larger for aerobes, reducing the potential for gene loss via genetic drift. Larger genomes also confer versatility. They can transport and metabolise a wider range of substrates. More of their genome is engaged in signal detection and response, indicating they benefit from different resources at different times or under different condition. Aerobic habitats might well present opportunities and challenges that vary through time more than anaerobic habitats. The genome size trait‐dimension contributes a useful quantitative descriptor for ecological strategies.
Methodology for Maritime Risk Assessment in Ports due to Meteo‐oceanographic Factors: The Case of the port of Suape, Brazil
Authors: Azevêdo Lucas , Duarte Heitor , Galvão Daniel , Michima Paula , Veleda Doris , Kreuger Alexander
Published: January 2021

Exploring the effects of meteo‐oceanographic (MO) events on ships’ maneuverability and safety has great potential, since most maritime accidents occur in confined waters, where the speed of ships is low, and the forces of wind and current on ships have particular importance. Therefore, we put forward a methodology that will be used to qualify and classify the risks caused by MO factors to how ships maneuver, dock or undock in a port. The objective is to generate important information for managing risk. The methodology is validated and illustrated step‐by‐step by applying it in Suape, one of the most important ports in Brazil, where the docking of larger tankers (e.g., Suezmax) was not allowed until recently when dredging was done to fit the specifications of such ships, thereby expanding the port's operations. MO data on Suape were collected and recorded from September 2016 to November 2017 and used for the application. Based on expert opinion and discussion with a Suape pilot, 36 accidental scenarios (ASs) were identified and categorized using preliminary hazard analysis. From these, the seven most severe ASs were selected so as to assess in more detail the frequency and consequences of accidents on human health, the environment, and property, for which the MO statistics for the likelihood of an accident and/or dispersal of an oil spill were used. The results show that the methodology is viable to assess risks caused by bad weather and to communicate these to pilots and competent authorities, thus improving the safety of operations.
A novel HLA class I allele: HLA‐A*24:241
Authors: Zheng Jie Wei , Xie Jun Hua , Sun Ying , Xiang Dong
Published: January 2021

The HLA‐A*24:241 allele differs from A*24:02:01:01 by one nucleotide substitution at position 319.
A cost‐effective maize ear phenotyping platform enables rapid categorization and quantification of kernels
Authors: Warman Cedar , Sullivan Christopher M. , Preece Justin , Buchanan Michaela E. , Vejlupkova Zuzana , Jaiswal Pankaj , Fowler John E.
Published: January 2021

High‐throughput phenotyping systems are powerful, dramatically changing our ability to document, measure, and detect biological phenomena. Here, we describe a cost‐effective combination of a custom‐built imaging platform and deep‐learning‐based computer vision pipeline. A minimal version of the maize (Zea mays) ear scanner was built with low‐cost and readily available parts. The scanner rotates a maize ear while a digital camera captures a video of the surface of the ear, which is then digitally flattened into a two‐dimensional projection. Segregating GFP and anthocyanin kernel phenotypes are clearly distinguishable in ear projections and can be manually annotated and analyzed using image analysis software. Increased throughput was attained by designing and implementing an automated kernel counting system using transfer learning and a deep learning object detection model. The computer vision model was able to rapidly assess over 390 000 kernels, identifying male‐specific transmission defects across a wide range of GFP‐marked mutant alleles. This includes a previously undescribed defect putatively associated with mutation of Zm00001d002824, a gene predicted to encode a vacuolar processing enzyme. Thus, by using this system, the quantification of transmission data and other ear and kernel phenotypes can be accelerated and scaled to generate large datasets for robust analyses.
A Comprehensive Experiment-Based Approach to Generate Stress Field and Slip Lines in Cutting Process
Authors: Yang Zheng-Yan , Zhang Xiao-Ming , Nie Guang-Chao , Zhang Dong , Ding Han
Published: January 2021

This study proposes a comprehensive experiment-based method to determine stress field and slip lines in metal cutting process. The chip geometry and workpiece's strain and strain rate fields are determined using an in situ imaging technique. The two-dimensional (2D) heat transfer problem for the steady-state cutting process is solved to derive the cutting temperature, and the flow stresses of work material in the main deformation zone are calculated based on the plasticity theory. Furthermore, the stress field is comprehensively determined to satisfy the stress equilibrium, friction law along the tool-chip interface, and traction-free boundary condition along the uncut chip surface. In addition, slip lines in the main deformation zone are derived according to the direction of maximum shear stress without the assumption of perfect rigid-plastic material. The proposed method is validated by comparing the cutting forces calculated based on the obtained stress field with the experimental results.
Effects of Endwall Film Coolant Flowrate on Secondary Flows and Coolant Mixing in a First Stage Nozzle Guide Vane
Authors: Alqefl Mahmood H. , Nawathe Kedar P. , Chen Pingting , Zhu Rui , Kim Yong W. , Simon Terrence W.
Published: January 2021

Modern gas turbines are subjected to very high thermal loading. This leads to a need for aggressive cooling to protect components from damage. Endwalls are particularly challenging to cool due to a complex system of secondary flows near them that wash and disrupt the protective coolant films. This highly three-dimensional flow not only affects but is also affected by the momentum of film cooling flows, whether injected just upstream of the passage to intentionally cool the endwall or as combustor cooling flows injected further upstream in the engine. This complex interaction between the different cooling flows and passage aerodynamics has been recently studied in a first stage nozzle guide vane. The present paper presents a detailed study on the sensitivity of aero-thermal interactions to endwall film cooling mass flow to mainstream flow ratio. The test section represents a first stage nozzle guide vane with a contoured endwall and endwall film cooling injected just upstream of it. The test section also includes an engine-representative combustor–turbine interface geometry with combustor cooling flows injected at a constant rate. The approach flow conditions represent flow exiting a low-NOx combustor. Adiabatic surface thermal measurements and in-passage velocity and thermal field measurements are presented and discussed. The results show the dynamics of passage vortex suppression and the increase of impingement vortex strength as MFR changes. The effects of these changes of secondary flows on coolant distribution are presented.
Bridging Between Topology Optimization and Additive Manufacturing via Laplacian Smoothing
Authors: Barroqueiro B. , Andrade-Campos A. , Dias-de-Oliveira J. , Valente R. A. F.
Published: January 2021

The potential of additive layer manufacturing (ALM) is high, with a whole new set of manufacturable parts with unseen complexity being offered. Moreover, the combination of topology optimization (TO) with ALM has brought mutual advantages. However, the transition between TO and ALM is a nontrivial step that requires a robust methodology. Thus, the purpose of this work is to evaluate the capabilities of adopting the commonly used Laplacian smoothing methodology as the bridging tool between TO and ALM. Several algorithms are presented and compared in terms of efficiency and performance. Most importantly, a different concept of Laplacian smoothing is presented as well as a set of metrics to evaluate the performance of the algorithms, with the advantages and disadvantages of each algorithm being discussed. In the end, the proposed mutable diffusion Laplacian algorithm is presented and exhibits less volume shrinkage and shows better preservation of some geometrical features such as thin members and edges. Moreover, a new volume constraint is presented, decreasing the resulting structural changes in the presented geometry and improving the final mesh quality.
Thermal Model of an Omnimagnet for Performance Assessment and Temperature Control
Authors: Esmailie Fateme , Cavilla Matthew S. , Abbott Jake J. , Ameel Tim A.
Published: January 2021

An Omnimagnet is an electromagnetic device that enables remote magnetic manipulation of devices such as medical implants and microrobots. It is composed of three orthogonal nested solenoids with a ferromagnetic core at the center. Electrical current within the solenoids leads to undesired temperature increase within the Omnimagnet. If the temperature exceeds the melting point of the wire insulation, device failure may occur. Thus, a study of heat transfer within an Omnimagnet is a necessity, particularly to maximize the performance of the device. A transient heat transfer model that incorporates all three heat transfer modes is proposed and experimentally validated with an average normalized root-mean-square error of less than 4% (data normalized by temperature in degree celsius). The transient model is not computationally expensive and is applicable to Omnimagnets with different structures. The code is applied to calculate the maximum safe operational time at a fixed input current or the maximum safe input current for a fixed time interval. The maximum safe operational time and maximum safe input current depend on size and structure of the Omnimagnet and the lowest critical temperature of all the Omnimagnet materials. A parametric study shows that increasing convective heat transfer during cooling, and during heating with low input currents, is an effective method to increase the maximum operational time of the Omnimagnet. The thermal model is also presented in a state-space equation format that can be used in a real-time Kalman filter current controller to avoid device failure due to excessive heating.
Coupled Computation Fluid Dynamics Models for Air Flow and Thermal Analysis of Marine Engine Room
Authors: George Jithin A. , Saha Sandip K.
Published: January 2021

Thermal management of machinery spaces of marine vessels using a heating ventilation and air conditioning (HVAC) system is needed to maintain the temperature within the tolerable limit for efficient combustion in internal combustion engines and proper functioning of on-board electronic devices by removing high heat generations from in-house auxiliary systems. This study presents a numerical methodology using coupled simple and detailed computational fluid dynamics (CFD) models of air passages and engine components. The developed method is found to have a good agreement with the experimental results. Further, different layouts of vents and heat-generating components in the engine room are analyzed to obtain air flow and temperature distributions. It is found that the locations of vents and heat generating components have a significant effect on the maximum temperature distribution in the engine room.
Modeling and Prediction of Rigid Body Motion With Planar Non-Convex Contact
Authors: Xie Jiayin , Chakraborty Nilanjan
Published: January 2021

We present a principled method for motion prediction via dynamic simulation for rigid bodies in intermittent contact with each other where the contact region is a planar non-convex contact patch. Such methods are useful in planning and controlling for robotic manipulation. The planar non-convex contact patch can either be a topologically connected set or a disconnected set. Most works in rigid body dynamic simulation assume that the contact between objects is a point contact, which may not be valid in many applications. In this paper, using the convex hull of the contact patch, we build on our recent work on simulating rigid bodies with convex contact patches for simulating motion of objects with planar non-convex contact patches. We formulate a discrete-time mixed complementarity problem to solve the contact detection and integration of the equations of motion simultaneously. We solve for the equivalent contact point (ECP) and contact impulse of each contact patch simultaneously along with the state, i.e., configuration and velocity of the objects. We prove that although we are representing a patch contact by an equivalent point, our model for enforcing non-penetration constraints ensures that there is no artificial penetration between the contacting rigid bodies. We provide empirical evidence to show that our method can seamlessly capture transition among different contact modes like patch contact, multiple or single point contact.
Embedded Actuation for Shape-Adaptive Origami
Authors: Grey Steven W. , Scarpa Fabrizio , Schenk Mark
Published: January 2021

Origami-inspired approaches to deployable or morphing structures have received significant interest. For such applications, the shape of the origami structure must be actively controlled. We propose a distributed network of embedded actuators which open/close individual folds and present a methodology for selecting the positions of these actuators. The deformed shape of the origami structure is tracked throughout its actuation using local curvatures derived from discrete differential geometry. A Genetic Algorithm (GA) is used to select an actuation configuration, which minimizes the number of actuators or input energy required to achieve a target shape. The methodology is applied to both a deployed and twisted Miura-ori sheet. The results show that designing a rigidly foldable pattern to achieve shape-adaptivity does not always minimize the number of actuators or input energy required to reach the target geometry.
Confidence-Based Design Optimization for a More Conservative Optimum Under Surrogate Model Uncertainty Caused by Gaussian Process
Authors: Jung Yongsu , Kang Kyeonghwan , Cho Hyunkyoo , Lee Ikjin
Published: January 2021

Even though many efforts have been devoted to effective strategies to build accurate surrogate models, surrogate model uncertainty is inevitable due to a limited number of available simulation samples. Therefore, the surrogate model uncertainty, one of the epistemic uncertainties in reliability-based design optimization (RBDO), has to be considered during the design process to prevent unexpected failure of a system that stems from an inaccurate surrogate model. However, there have been limited attempts to obtain a reliable optimum taking into account the surrogate model uncertainty due to its complexity and computational burden. Thus, this paper proposes a confidence-based design optimization (CBDO) under surrogate model uncertainty to find a conservative optimum despite an insufficient number of simulation samples. To compensate the surrogate model uncertainty in reliability analysis, the confidence of reliability is brought to describe the uncertainty of reliability. The proposed method employs the Gaussian process modeling to explicitly quantify the uncertainty of a surrogate model. Thus, metamodel-based importance sampling and expansion optimal linear estimation are exploited to reduce the computational burden on confidence estimation. In addition, stochastic sensitivity analysis of the confidence is developed for CBDO, which is formulated to find a conservative optimum than an RBDO optimum at a specific confidence level. Numerical examples using mathematical functions and finite element analysis show that the proposed confidence analysis and CBDO can prevent overestimation of reliability caused by an inaccurate surrogate model.
A Digital Twin-Driven Method for Product Performance Evaluation Based on Intelligent Psycho-Physiological Analysis
Authors: Feng Yixiong , Li Mingdong , Lou Shanhe , Zheng Hao , Gao Yicong , Tan Jianrong
Published: January 2021

Digital twin, a new emerging and fast-growing technology which is one of the most promising technologies for smart design and manufacturing, has attracted much attention worldwide recently. With the application of digital twin, product performance evaluation has entered the data-driven era. However, traditional methods for evaluation mainly place emphasis on structure analysis in the stage of manufacturing and service in digital twin. They cannot synthesize multi-source information and take the high-level emotional response into consideration in the design stage. To overcome these disadvantages, a digital twin-driven method is proposed evaluating product design schemes in this study. It enables the acquisition of electroencephalogram (EEG) data, physical data, and emotional feedback. Human factors are systematically considered in the evaluation process to establish the information association between EEG and performance levels. Moreover, intelligent psycho-physiological analysis that incorporates EEG into the fuzzy comprehensive evaluation (FCE) and machine learning methods is adopted within the proposed method. It synthesizes human factors such as psychological requirements, subjective and objective assessment indicators to realize a novel machine learning-based EEG analysis. Taking advantage of the binary particle swarm optimization (BPSO) improved Riemannian manifold mapping, Riemann geometry (RG) features are extracted and selected from EEG signals. Differences of implicit psychological states while using the product produced by different design schemes can be more easily detected and classified. A case study of high-speed elevator is conducted to verify the feasibility and effectiveness of the proposed method. The accuracy of EEG classification for performance evaluation reaches 92%.
Co3O4 nanoparticles characterized by XPS and UPS
Authors: Cole Kevin M. , Kirk Donald W. , Thorpe Steven J.
Published: January 2021

X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy (UPS) were performed on as-received analytical grade Co3O4 nanoparticles (<50 nm). Co3O4 has proven to be an extremely useful material for a wide variety of applications. This report provides a detailed photoelectron spectroscopy investigation of Co3O4 to aid with identification from other cobalt oxides, hydroxides, and oxyhydroxides. In addition to the survey scan, detailed charge-corrected scans for Co 2s, Co 2p, Co 3s, Co 3p, O 1s, O 2s, and C 1s surface photoelectron signals are reported. The valence states were analyzed using UPS.
On levitation by blowing
Authors: Newton Paul K. , Ma Y.
Published: January 2021

Anyone who has visited a science museum has seen the demonstration where a beach (or ping-pong) ball is suspended in mid-air at a fixed position by constant blowing from below. After a while, the ball inevitably tumbles to the ground but can easily be rebalanced, by hand, again at the suspension point. Here, we ask a different more delicate question. Can we blow the ball from rest, starting at the nozzle opening (x = 0), moving it up to the suspension point x=x* above the nozzle? We show that it is not possible to do this using constant blowing because the point at which the downward gravitational force balances the upward blowing force is an elliptic fixed point of the governing equations, so there is no transfer trajectory that connects the origin to x*. To overcome this problem, we design time-dependent blowing schedules that achieve the transfer, making use of orbit transfer ideas developed in the orbital mechanics literature. Then, we ask which of these time-dependent schedules are optimal? We show that, generally, it is bang–bang (on–off) blowing schedules that achieve the transfer in minimal time, using minimal energy (action) and minimal air volume. For certain parameter values, however, there are more complicated blowing schedules that are optimal (with respect to energy), which can be designed using the Pontryagin Maximum Principle (PMP) and singular control. We use elementary concepts from mechanics, nonlinear dynamics, and control theory and challenge the inclined experimentalist to try to implement some of these nonconstant blowing schedules in the lab.
d'Alembert digitized: A wave pulse method for visualizing electromagnetic waves in matter and for deriving the finite difference time domain method for numerically solving Maxwell's equations
Authors: Hyman Ross , Stern Nathaniel P. , Taflove Allen
Published: January 2021

An alternative way of visualizing electromagnetic waves in matter and of deriving the Finite Difference Time Domain (FDTD) method for simulating Maxwell's equations for one-dimensional systems is presented. The method uses d'Alembert's splitting of waves into forward and backward pulses of arbitrary shape and allows for grid spacing and material properties that vary with the position. Constant velocity of waves in dispersionless dielectric materials, partial reflection and transmission at boundaries between materials with different indices of refraction, and partial reflection, transmission, and attenuation through conducting materials are derived without recourse to exponential functions, trigonometric functions, or complex numbers. Placing d'Alembert's method on a grid is shown to be equivalent to the FDTD method and allows for simple and visual proof that the FDTD method is exact for dielectrics when the ratio of the spatial and temporal grid spacing is the wave speed, a straightforward way to incorporate reflectionless boundary conditions and a derivation that the FDTD method retains second-order accuracy when the grid spacing varies with the position and the material parameters make sudden jumps across layer boundaries.
Basics of sound in air: Correspondence with electromagnetic waves
Authors: Zürcher Ulrich
Published: January 2021

The wave equation of sound is developed starting from the equations of fluid mechanics for the velocity and pressure variation in air. The equations for sound are analogous to Maxwell's equations for linear polarized electromagnetic plane waves: the pressure variation and the velocity correspond to the electric and magnetic fields, respectively. The order of magnitude of sound properties is explained in terms of the amplitude and energy density of the corresponding wave.
Spatial structuring of light for undergraduate laboratories
Authors: Panarin Sergei , Müller Jonas , Prabhakar Shashi , Fickler Robert
Published: January 2021

In recent times, spatial light modulators have become a common tool in optics laboratories as well as industrial environments for shaping the spatial structure of a light beam. Although these devices are often easy to use, their high cost has limited their use in many undergraduate laboratories. However, in recent years the progress in developing more cost-effective projectors has led to affordable spatial light modulators in the form of so-called Digital Micromirror Devices (DMD). This reduction in price, as well as their simple employment, make such devices increasingly suitable for use in undergraduate instructional laboratories to demonstrate optical effects and the shaping of light fields. Here, we show one of the most cost-effective ways to make a DMD available, namely, turning a projector evaluation module into a computer-controlled spatial light modulator. We explain the underlying functioning and how this low-cost spatial light modulator can be used in undergraduate laboratories. We further characterize the efficiency of the device for the most commonly used laser wavelengths and demonstrate various exemplary optics experiments suitable for undergraduate laboratories ranging from single and multi-slit diffraction to optical Fourier transformations. Finally, we show that by using amplitude holography, the device can generate transverse spatial modes, e.g., Laguerre-Gaussian beam, which are one of the most commonly used spatially structured beams.
Index matching computerized tomography
Authors: Daley Vincent , Paetkau Owen , Paetkau Mark
Published: January 2021

Computerized tomography (CT) has been used for decades by medical professionals to detect and diagnose injuries and ailments. CT scanners are based on interesting physics, but due to their bulk, cost, and safety, hands on experience with a medical CT scanner are unrealistic for undergraduate students. Therefore, operationally similar, yet small, safe, and inexpensive CT scanners are desirable teaching tools. This project details the development of a novel model CT scanning apparatus. The experimental setup presented utilizes visible light, has short data acquisition time, and operates on the same physics as its X-ray counterpart. The apparatus employs a laser and photodiode to image a transparent material, while avoiding loss of transmitted intensity through index of refraction matching. A simple back-projection algorithm results in a 2D cross section of the scan object. We found we could collect data and reliably image samples in 15 min.
Reliability and critical differences for an implementation of the coordinate response measure in speech-shaped noise
Authors: Mertes Ian B.
Published: January 2021

This study established test-retest reliability and critical differences for an implementation of the coordinate response measure (CRM) for the purpose of detecting significant changes in task performance. In normal-hearing adults, speech stimuli were presented monaurally at 50 dB sound pressure level in speech-shaped noise at signal-to-noise ratios (SNRs) of –12, –9, and –6 dB. Two runs were obtained. Intrasubject and intersubject variability were examined. Performance increased significantly with increasing SNR and in the second run. High variability was observed at each SNR. Critical differences indicated that only large changes in performance would be significant for the CRM as implemented in this study.
Improved multimodal formulation of the wave propagation in a 3D waveguide with varying cross-section and curvature
Authors: Guennoc Thomas , Doc Jean-Baptiste , Félix Simon
Published: January 2021

An efficient method is proposed to solve the multimodal wave propagation within a three-dimensional waveguide bounded by a hard wall with varying cross section and curvature. This is achieved by first turning the original problem, in a complex-shaped waveguide, into a cylindrical waveguide with unit radius, by means of an adapted and flexible geometrical transformation. Then supplementary modes are defined to enrich the standard modal basis that is usually considered in such methods and to help restore the right boundary condition. It is shown through various numerical applications that the introduction of these supplementary modes, whatever the complexity of the waveguide geometry, significantly enhances the multimodal method, notably by increasing its convergence rate, whether one's aim is to solve the wavefield or the scattering problem.
Exercise-Induced Salivary Hormone Responses to High-Intensity, Self-Paced Running
Authors: Leal Diogo V. , Taylor Lee , Hough John
Published: January 2021

Purpose:Physical overexertion can lead to detrimental overreaching states without sufficient recovery, which may be identifiable by blunted exercise-induced cortisol and testosterone responses. A running test (RPETP) elicits reproducible plasma cortisol and testosterone elevations (in a healthy state) and may detect blunted hormonal responses in overreached athletes. This current study determined the salivary cortisol and testosterone responses reproducibility to the RPETP, to provide greater practical validity using saliva compared with the previously utilized blood sampling. Second, the relationship between the salivary and plasma responses was assessed.Methods:A total of 23 active, healthy males completed the RPETPon 3 occasions. Saliva (N = 23) and plasma (N = 13) were collected preexercise, postexercise, and 30 minutes postexercise.Results:Salivary cortisol did not elevate in any RPETPtrial, and reduced concentrations occurred 30 minutes postexercise (P = .029,η2 = .287); trial differences were observed (P < .001,η2 = .463). The RPETPelevated (P < .001,η2 = .593) salivary testosterone with no effect of trial (P = .789,η2 = .022). Intraindividual variability was 25% in cortisol and 17% in testosterone. “Fair” intraclass coefficients of .46 (cortisol) and .40 (testosterone) were found. Salivary and plasma cortisol positively correlated (R = .581,P = .037) yet did not for testosterone (R = .345,P = .248).Conclusions:The reproducibility of salivary testosterone response to the RPETPis evident and supports its use as a potential tool, subject to further confirmatory work, to detect hormonal dysfunction during overreaching. Salivary cortisol responds inconsistently in a somewhat individualized manner to the RPETP.
Disgraced COVID-19 studies are still routinely cited
Authors: Piller Charles
Published: January 2021

Journal mentions of studies based on disputed data from Surgisphere often fail to clearly flag retractions.
What causes IBS pain? Maybe immune flare-ups
Authors: Couzin-Frankel Jennifer
Published: January 2021

New study suggests certain foods trigger a localized reaction in the gut.
Noncanonical scaffolding of G
αi
and β-arrestin by G protein–coupled receptors
Authors: Smith Jeffrey S. , Pack Thomas F. , Inoue Asuka , Lee Claudia , Zheng Kevin , Choi Issac , Eiger Dylan S. , Warman Anmol , Xiong Xinyu , Ma Zhiyuan , Viswanathan Gayathri , Levitan Ian M. , Rochelle Lauren K. , Staus Dean P. , Snyder Joshua C. , Kahsai Alem W. , Caron Marc G. , Rajagopal Sudarshan
Published: January 2021

Another way for GPCRs to signal

G protein–coupled receptors (GPCRs) normally transmit signals by coupling to heterotrimeric guanine nucleotide–binding proteins (G proteins) or by binding β-arrestin proteins. Smith
et al.
provide evidence for another mechanism, an approximate combination of the two. They monitored the interaction of vasopressin type 2 receptors (V2Rs) and G
α
proteins in cultured cells using bioluminescent resonance energy transfer. Even though V2Rs do not signal canonically through G

α
i

proteins, they promoted the formation of complexes containing β-arrestin and G

α
i

, and this led to downstream signaling to extracellular signal-regulated kinase protein kinases.

Science
, this issue p.
eaay1833
Host succinate is an activation signal for
Salmonella
virulence during intracellular infection
Authors: Rosenberg Gili , Yehezkel Dror , Hoffman Dotan , Mattioli Camilla Ciolli , Fremder Moran , Ben-Arosh Hadar , Vainman Leia , Nissani Noa , Hen-Avivi Shelly , Brenner Shirley , Itkin Maxim , Malitsky Sergey , Ohana Ehud , Ben-Moshe Noa Bossel , Avraham Roi
Published: January 2021

Salmonella
profits from immunometabolism

Extensive metabolic rewiring occurs in various immune cells during the course of infection. Whether these changes can be exploited by intracellular pathogens remains an open question. Rosenberg
et al.
report that infection with
Salmonella enterica
serovar Typhimurium (
S.
Tm) induces the accumulation of the metabolite succinate in macrophages (see the Perspective by Lynch and Lesser). This key intermediate in the citric acid cycle activates virulence genes in
S.
Tm, leading to microbial resistance. Moreover, the active transport of succinate through the C4-dicarboxylate transporter DcuB is required for
S.
Tm virulence and survival within macrophages. Sensing of citric acid cycle intermediates may more generally serve as a cue to initiate the resistance programs of intracellular pathogens.

Science
, this issue p.
400
; see also p.
344
Convergent evolution of pain-inducing defensive venom components in spitting cobras
Authors: Kazandjian T. D. , Petras D. , Robinson S. D. , van Thiel J. , Greene H. W. , Arbuckle K. , Barlow A. , Carter D. A. , Wouters R. M. , Whiteley G. , Wagstaff S. C. , Arias A. S. , Albulescu L.-O. , Plettenberg Laing A. , Hall C. , Heap A. , Penrhyn-Lowe S. , McCabe C. V. , Ainsworth S. , da Silva R. R. , Dorrestein P. C. , Richardson M. K. , Gutiérrez J. M. , Calvete J. J. , Harrison R. A. , Vetter I. , Undheim E. A. B. , Wüster W. , Casewell N. R.
Published: January 2021

From offense to defense

Venom in snakes is largely used to subdue and/or kill prey, and most venoms have clear actions that facilitate death or paralysis. In one group of snakes, however, venom has evolved and shifted from predation to protection. Specifically, in three different lineages of “spitting” snakes, venom is used to deter predators. Kazandjian
et al.
show that similar adaptions have occurred within these lineages that transform cytotoxic components into a mixture that acts on mammalian sensory neurons and causes pain. The authors argue that increased predation on these lineages led to similar shifts in venom function.

Science
, this issue p.
386
Iridium-catalyzed
Z
-retentive asymmetric allylic substitution reactions
Authors: Jiang Ru , Ding Lu , Zheng Chao , You Shu-Li
Published: January 2021

Keeping
Z
-olefins intact with iridium

Transition metal catalysis offers a versatile means of modifying carbon centers adjacent to carbon-carbon double bonds. However, in the course of these reactions, the double bond tends to get weakened, allowing its substituents to swivel back and forth. Thus, if two large groups start out on the same side of the bond axis (a geometry known as a
Z
-olefin), they end up on opposite sides in the product. Jiang
et al.
report a chiral iridium catalyst that prevents this swiveling just long enough to substitute the adjacent carbon enantioselectively (see the Perspective by Malcolmson).

Science
, this issue p.
380
; see also p.
345
Snapshots of a light-triggered transition
Authors: Kogar Anshul
Published: January 2021

A new method captures real-space movies of ordered states on ultrafast time scales
A barrier breaker's complicated legacy
The Doctors Blackwell: How Two Pioneering Sisters Brought Medicine to Women—and Women to Medicine
Janice P. Nimura
Norton, 2021. 336 pp.
Authors: Stark Laura
Published: January 2021

Certain of her own exceptional nature, Elizabeth Blackwell dismissed those who aided her
Drivers of mosquito mating
Authors: Manoukis Nicholas C.
Published: January 2021

Light cycle genes and environmental and chemical cues modulate male mosquito swarming
Racing against unwanted isomerization
Authors: Malcolmson Steven J.
Published: January 2021

Control of relative reaction rates paves the way for (
Z
)-alkene stereochemical retention