bluuebunny/crossref_metadata_2025 huggingface dataset:
Boundary Layers on a Rotating Rough Disk
Authors: Heydari Ali , Miryan Ramin , Sharifi Saeid
Published: March 2021

In this paper the turbulent fluid flow over a rotating disk with roughness is considered. The disk is assumed to be at uniform wall temperature. The surface roughness is assumed to influence the turbulent boundary layer by adding a roughness parameter height k. Boundary-layer approximation reduces the elliptic Navier-Stockes equations to parabolic equations, where the Keller-Cebeci method of finite-difference solution is used to solve the resulting system of partial-differential equations. The resulting curve-fit equations to the numerically calculated results for three regions of laminar, transition and turbulent flow is shown to be consistent to those obtained for flow over a flat plate or inside a circular cylinder. Calculations for various surface roughness parameters are made and results are presented.
Detailed Transportation Simulation for Improved Logistics Quality
Authors: Petersen Harry C. , Rummel Amy
Published: March 2021

This paper demonstrates the advantages of logistics studies which include detailed transportation simulations based on mechanical engineering principles. Complex transportation system parameters are often averaged, aggregated, or assumed, resulting in models with questionable validity. Detailed simulations of route-specific real-world vehicle performance for analysis systems (such as Transport Probability Analysis) can often provide more accurate predictors of logistics system performance, resulting in valid projections of system transport times, costs, inventory levels, energy usage, standards, and quality control measures. A discussion of logistics is followed by examples of progressively complex logistics transportation simulations and models. Results of a moderately detailed performance-based simulation of high speed trains for the Texas Triangle are used to demonstrate the fallacy of assuming “average” performance measures. Future logistics studies will require detailed vehicle performance simulations using sound mechanical engineering practice, requiring interdisciplinary teams which include mechanical engineers.
On Development of Engineering Animation Software
Authors: Pao Y. C.
Published: March 2021

A collection of demonstration programs for animation of engineering problems, ranging from the simple stretching of a rubber band to the cam rotary motion of a wankel engine, are discussed. Fundamental concept of animation using a microcomputer and a display monitor is explained through application of the extended ASCII codes and the BASIC commands ASC, BLOAD, BSAVE, CHR$, DEF FN, DEF SEG, GET, INKEY$, LEN, LINE, PAINT, PSET, PUT, RIGHT$, and SCREEN, and the QuickBASIC commands VARPTR and VARSEG. Menu arrangement of 14 animation programs for interactive selection is also illustrated as another example of employing these codes and commands.
A Study of Creative Design Based on the Axiomatic Design Theory
Authors: Sekimoto Shinya , Ukai Makoto
Published: March 2021

This paper deals with creative processes in engineering design. The study is based on the axiomatic design theory (Suh, 1988, 1990). The creative processes involved in engineering design are not yet fully understood. However, it is an exciting theme to study how human designers can generate designs or design concepts that are superior to those currently possible in terms of performance, manufacturability, reliability, cost, etc. This paper first reviews the axiomatic design theory. Then, the creative processes in three different design steps are discussed based on the axiomatic design theory. The creative processes are illustrated using the design of paper handling mechanisms of an ATM (Automatic teller machine).
Complexity Analysis of Computational Engineering Design Processes
Authors: Ahn Jeong-Soo , Crawford Richard H.
Published: March 2021

An Important part of engineering design is development of the design process itself. In general, design processes are not unique; many solution processes can be created to solve the same problem. Choosing one from a number of competing design processes requires assessment and comparison of the processes according to well-defined criteria. This paper presents an initial study of complexity analysis as one such criterion. A graphical representation is proposed to provide a model of computational design processes that can be analyzed for complexity. Several software metrics are adapted for analyzing such design processes, and demonstrated with a simple design example. The results illustrate that complexity analysis can be used for differentiating among computational design processes.
Computational Synthesis and Simulation of Dynamic Systems
Authors: Malmqvist Johan
Published: March 2021

This paper presents an approach to computational synthesis of dynamic systems. The foundation of the approach is a function vocabulary for energy-transforming systems that is based on the modelling concepts of bond graphs. The function vocabulary extends those described in the literature by including functions prevalent in dynamic systems.

A computational synthesis procedure for dynamic systems, which is based on the developed function vocabulary and “classical” design methodology, and its implementation in a computer program is outlined. The program can also simulate the dynamic behaviour of a proposed design concept. The application of the procedure is demonstrated on an accelerometer design problem.
An Improved Shape Annealing Method for Truss Topology Generation
Authors: Reddy Giridhar , Cagan Jonathan
Published: March 2021

A method for the design of truss structures which encourages lateral exploration, pushes away from violated spaces, models design intentions, and produces solutions with a wide variety of characteristics is introduced. An improved shape annealing algorithm for truss topology generation and optimization, based on the techniques of shape grammars and simulated annealing, implements the method. The algorithm features a shape grammar to model design intentions, an ability to incorporate geometric constraints to avoid obstacles, and a shape optimization method using only simulated annealing with more consistent convergence characteristics; no traditional gradient-based techniques are employed. The improved algorithm is illustrated on various structural examples generating a variety of solutions based on a simple grammar.
Extending C and FORTRAN for Design Automation
Authors: Cheng Harry H.
Published: March 2021

The CH programming language, a high-performance C, is designed to be a superset of ANSI C. CH bridges the gap between ANSI C and FORTRAN; it encompasses almost all the programming capabilities of FORTRAN 77 in the current implementation and consists of features of many other programming languages and software packages. Unlike other general-purpose programming languages, CH is designed to be especially suitable for applications in mechanical systems engineering. Because of our research interests, many programming features in CH have been implemented for design automation, although they are useful in other applications as well. In this paper we will describe these new programming features for design automation, as they are currently implemented in CH in comparison with ANSI C and FORTRAN 77.
Heuristics Based Feature Recognition: A Graph Approach
Authors: Narayan Shyam V. , Ling Zhi-Kui
Published: March 2021

Feature based modeling has been used as a means to bridge the gap between engineering design and manufacturing. Features can represent an artifact with higher level entities which relate directly to its design functionalities and manufacturing characteristics, such as surface finish, manufacturability, fits, tolerance etc. In this study, a heuristic based feature recognition approach is proposed by using the graph representation of a design. The process consists of two steps: subgraph construction, and subgraph to feature identification. In this study, the subgraph construction is accomplished by using a set of heuristic rules. The process of subgraph to feature identification is carried out with a set of integers and characters which represent the geometric, topological, and semantic characteristics of the corresponding feature. This feature recognition scheme is used for the identification of machine features in a design.
Position Registration of Scanning Lasers for Experimental Spatial Dynamics Modeling
Authors: Montgomery David E. , West Robert L.
Published: March 2021

Experimental spatial dynamics modeling involves using scanning lasers to sample surface shape and dynamic response of structures in order to verify structural dynamics design intent. Formation of accurate spatial models from laser-based measurements requires that laser position and orientation be registered relative to a fixed coordinate system. A three point direct registration procedure is defined for shape modeling using laser range and mirror deflection angles. Surface velocity measurements with a portable laser Doppler vibrometer (LDV) also require registration, but range information is unavailable. A multiple point indirect registration algorithm for the LDV is described that involves minimizing three nonlinear equations.

A simulated laser rangefinder (LRF) was developed for demonstrating three point direct registration. The 3-D geometry of a compressor housing was modeled by combining range data from multiple laser positions. The multiple point indirect registration was applied to 3-D velocity response field reconstruction of a composite plate from velocity measurements scanned at three separate positions.
Approximate Re-Analysis of Dynamic Systems
Authors: Cao Qiushi , Krishnaswami Prakash
Published: March 2021

Dynamic analysis of a mechanical system is extremely time consuming. It may be desirable for a designer to approximate the state variables at a new design if state and sensitivity information at previous designs are already available. In this paper, several approximate re-analysis schemes have been explored. These include Taylor’s series of first and second order, weighted sum of state variables and weighted sum of Taylor’s series. The results show that Taylor’s series of second order can predict state variables quite well if the perturbation in design is relatively small. Weighted sum approximation based on state variables can generally give acceptable results, while weighted Taylor’s series is generally unsatisfactory if the perturbation is large.
Solution of Load Distribution on the Contact Line of Helical Gears With EHL Theory
Authors: Tonghui Yu , Chenwen Chen , Liqin Wang
Published: March 2021

On the base of analysis of the effects of each term in Renolds equaiton on the lubrication state of helical gears, the three dimensional elastohydrodynamic lubrication (EHL) problem is discomposed into two dimensional problems to deal with. A special boundary condition for helical gear EHL problem is led in and applying multigrid method (MGM), numerical solutions for the helical gear EHL problem are accomplished along the contact line. Film shapes and pressure ditributions with typical EHL features are obtained at discreted points on the contact line. The procedure presented here to calculate the load distribution on the contact line can also be used to calculate the load shares among different contact lines.
Bilevel Models for Optimum Designs Which Are Insensitive to Perturbations in Variables and Parameters
Authors: Badhrinath Krishnakumar , Rao J. R. Jagannatha
Published: March 2021

Design models may be subject to a variety of perturbations or uncertainties, such as in variables, parameters and the constraint right-hand sides. In this paper, we study the specific cases of deterministic variations in the variables and the parameters. The goal is to obtain designs that not only reduce cost but which are also insensitive to such perturbations. We formulate bilevel models for this purpose and illustrate with examples the nature of insensitive designs, as well as the singularities that occur in such bilevel models.
Artificial Neural Network and the Taguchi Method Application for Robust Wheatstone Bridge Design
Authors: Hong Jung-eui , Dagli Cihan H. , Ragsdell Kenneth M.
Published: March 2021

The primary function of the Wheatstone bridge is to measure an unknown resistance. The elements of this well-known measurement circuit will take on different values depending upon the range and accuracy required for a particular application. The Taguchi approach to parameter design is used to select values for the measurement circuit elements so as to reduce measurement error. Next we introduce the use of an artificial neural network to extrapolate limited experimental results to predict system response over a wide range of applications. This approach can be employed for on-line quality control of the manufacture of such device.
Multicriterion Optimization: A Tool in Advanced Materials Technology
Authors: Wang Jianxiang , Thomsen Niels B. , Karihaloo Bhushan L.
Published: March 2021

This paper will demonstrate on two advanced materials — a fibre-reinforced composite laminate (FRC) and a transformation toughened ceramic (TTC) — the importance of multicriterion optimization in the production of useful advanced materials with enhanced mechanical properties. In a previous paper (Thomsen et al., 1994a), the authors have demonstrated the application of single-criterion optimization to these materials which are based on a brittle matrix and thus prone to cracking at very low applied stresses. The optimization process aims at altering their microstructure so that all their desirable mechanical properties are enhanced. Currently, the advanced materials technologists must take a heuristic approach to meeting the often competing requirements. The present paper will show how multicriterion optimization can come to the aid of the technologists and reduce their reliance on empirical approaches.
Power Converter Design With Coupled Thermal Analysis Using Multidisciplinary Design Optimization
Authors: Kott Gregory , Gabriele Gary A. , Korngold Jacob
Published: March 2021

This paper describes the application of multidisciplinary design optimization to the power stage design of a power converter. Multidisciplinary design is used to integrate the electrical, loss, and thermal analyses into one system problem. The Sequential Global Approximation method, a non-hierarchic algorithm, is used to optimize the power stage design problem. The code used for the thermal analysis, COSMOS/M, runs externally to the Sequential Global Approximation algorithm. A comparison of the results of the non-hierarchic formulation and the non-decomposed formulation shows a 67 percent decrease in total system iterations and a 12 percent decrease in total finite element analyses required.
Design System for Blow Moulded Products
Authors: Geilen Johannes , Fuchs Willi J.
Published: March 2021

In recent years the spectrum of applications for thermoplastics has experienced constant growth. They do not only exhibit good specific materials properties and lend themselves to costeffective processing, but it is also possible to manufacture products of great complexity. Numerous possibilities for structural configuration are thus presented, enabling product material and form to be adapted to specific requirements. Computer-aided simulation techniques are among the tools utilized in developing optimal components or products. This led to a design system which can accelerate the entire development process of a product or component. It starts from the idea and results in the production stage making use of multidisciplinary combination of C-technologies, structural analysis procedures, material data bases, production, inspection and testing.

The propagated concept is significantly furthered by the rapid development in the areas of hardware and software. A comparison of a traditional development process with the development process utilizing the design system illustrates the possibilities which exist to exploit simulation thechniques in every stage of product development in order to enhance quality and reduce costs.
Modeling of a Leg System to Illustrate the Feasibility of Energy Recovery in Walking Machines
Authors: Dhandapani Sivakumar , Ogot Madara M.
Published: March 2021

A key consideration in the design of walking machines is the minimization of energy consumption. Two main avenues of research have been pursued in the past (a) finding an optimal gait which reduces energy consumption or (b) the employment of energy storage devices to recover energy from one step to the next. This study follows the latter approach, which has hitherto concentrated on hopping machines. Several practical design considerations for energy recovery in multi-legged walking machines, where a stance phase prevents the immediate recovery of energy from one step to the next, are investigated. Two schemes, passive and active locking, are introduced. The simplified models presented serve to illustrate the feasibility of these schemes.
Isotropic Design of Spherical Parallel Manipulators
Authors: Mohammadi Daniali Hamid R. , Zsombor-Murray Paul J. , Angeles Jorge
Published: March 2021

Manipulator designs with isotropic architectures have a number of advantages, including good servo accuracy and low sensitivity to measuring and manufacturing errors. The isotropic design continua of two classes of spherical 3-dof parallel manipulators are found. These continua describe the complete set of isotropic design possibilities for the respective manipulator types.
Structural Analysis and Optimization of Pneumatic Components
Authors: Post Peter U.
Published: March 2021

Within the last few years engineering analysis and optimization methods became more and more reasonable in the development stage not only of specialised high-tech products but also of industrial standard components and systems. This trend is forced by establishing simultaneous engineering concepts in R&D-departments. Acceptance of these methods in industrial practice goes along with increasing power of solution procedures as well as reliability and ease-of-use of software implementations.

This paper shows practical applications on the development of pneumatic actuators and control-components. Optimal design of cylinder housings and profile shapes as well as structural analysis and optimization of rubber elements with their non-linear structural behaviour due to hyperelastic material law, contacting surfaces and friction are discussed.
Topological Characteristics and Automatic Generation of Structural Synthesis of Planar Mechanisms Based on the Ordered Single-Opened-Chains
Authors: Yang Ting-Li , Yao Fang-Hua
Published: March 2021

This paper presents a new viewpoint about structural composition of planar kinematic chains: single-opened-chains, which is composed of binary links, are regarded as basic structural units of mechanisms. The constraint characteristics (the constraint factors, Δj) of single opened chains and the constraint characteristics (the coupled degree κ and the κ-algorithm) of mechanical networks are presented. Thus a kinematic chain with v independent loops is regarded to be composed of one basic link and v single-opened-chains in regular sequence.

Based on the ordered single-opened-chains and the topological constraints characteristics of mechanisms, a powerful new method for structural synthesis of planar kinematic chains with plane and nonplane linear graphs has been developed. This permits the development of a highly efficient and completely automatic program for the computer-generated enumeration of structural types of mechanisms. The method is illustrated by applying to the case of kinematic chains with up to six independent loops on a personal computer.

The ordered single-opened-chains and the topological characteristics are used for setting up a new unified model for structics, kinematics and dynamics of planar mechanisms.
Kinematic Analysis of Skew Cardanic Motion and the Skew Swinging-Block Linkage
Authors: Freudenstein F. , Primrose E. J. F. , Chen Hong-Jen
Published: March 2021

The classical cardanic motion and the swinging-block linkage are basic planar mechanisms. In the following investigation, the objective is the analysis of their three-dimensional (and, hence, more versatile) counterparts: the skew slider-crank mechanism and the skew swinging-block linkage. These linkages as far as we are aware, have not yet been analyzed analytically. An analysis utilizing their algebraic geometry will be instructive in determining their displacements and derivatives in closed form. This, in turn, should be useful in facilitating three-dimensional applications.

With the ever-increasing sophistication in the area of mechanisms design and analysis, we believe that the time has come for the analysis of these linkages, including their algebraic geometry. This is the objective of this investigation.
On the Analysis and Synthesis of Type I Spatial 6R Overconstrained Mechanism
Authors: Lee Chung-Ching
Published: March 2021

Based on matrix algebra and its differentiation, we derive the general analytical kinematic solutions and simple stationary configurations of Type I spatial 6R overconstrained mechanism. This mechanism is a general form of Sarrus 6R mechanism. Its coupler point of a certain link has straight-line motion and this is used for the synthesis of straight-line mechanism by the optimization method. Moreover, a graphical synthesis technique with descriptive geometry is presented to design the linkage type of double-toggle mechanism for spatial clamping device. Two numerical examples are given for illustration and their results are verified by computer animation of motion.
Synthesis of Defect Free Six Bar Linkages for Body Guidance Through up to Six Finitely Separated Positions
Authors: Tylaska Timothy , Kazerounian Kazem
Published: March 2021

In the synthesis of watt I six bar linkage, for finitely separated design positions, or in higher order design, constraint equations become highly nonlinear and transcendental. This paper presents a method to decouple the synthesis problem to the synthesis of two path generator 4-bar linkages. Based on this decoupled system, an explicit design methodology is developed, enabling a three, four, five or six body guidance position Watt I linkage to be designed while the designer has choice of some body pivots and ground pivots. Numerical procedures for higher number of positions are also discussed. The methodology allows the designer to obtain an entire set of solutions to a particular design problem. As a spin off from this work, a methodology is also presented to obtain complete solution sets of four bar path generators capable of passing through up to seven precision points, with a procedure that can be eventually extended to eight and nine path points. Design considerations such as branching and transmission angles are also considered.
A Force Transmission Index for Planar Linkage Mechanisms
Authors: Holte Jennifer E. , Chase Thomas R.
Published: March 2021

A new transmission index based on a static force analysis, the joint-force index, is presented. The joint-force index is an improved transmission index for mechanisms which support external loads. No other transmission index in the literature predicts the effect of specific external loads on the force transmission, even though mechanisms that are subjected to external loads are very common. The joint-force index provides a meaningful transmission guideline regardless of the complexity of the mechanism. Planar four-bar linkages as well as complex planar linkages of six or more links may be evaluated using the joint-force index.
Velocity and Acceleration Analysis of Contact Between Three-Dimensional Rigid Bodies
Authors: Sarkar Nilanjan , Kumar Vijay , Yun Xiaoping
Published: March 2021

During manipulation and locomotion tasks encountered in robotics, it is often necessary to control the relative motion between two contacting rigid bodies. In this paper we obtain the equations relating the motion of the contact points on the pair of contacting bodies to the rigid body motions of the two bodies. The equations are developed up to the second order. The velocity and acceleration constraints for contact, for rolling, and for pure rolling are derived. These equations depend on the local surface properties of each contacting body. Several examples are presented to illustrate the nature of the equations.
A More Direct Method for Structural Synthesis of Simple-Jointed Planar Kinematic Chains
Authors: Dharanipragada Varada Raju , Yenugadhati Nagaraja Kumar , Rao A. C.
Published: March 2021

Structural synthesis of kinematic chains leans heavily on indirect methods, most of them based on Graph Theory, mainly because reliable isomorphism tests are not available. Recently however, the first and third authors have established the Secondary Hamming String of a kinematic chain as an excellent indicator of its isomorphism. In the present paper this Hamming String method was applied with slight modifications for synthesizing on a PC-386, distinct kinematic chains with given number of links and family description. The computer program, written in Pascal, generated both the six-bar and all 16 eight-bar chains as well as one sample family (2008) of ten-bar chains, verifying previously established results. Hence this paper presents a direct, quick and reliable method to synthesize planar simple-jointed chains, open or closed, with single- or multi-degree of freedom, containing any number of links. A spin-off of this paper is a simple, concise and unambiguous notation for representing a chain.
Dynamic Model of a Spur Gear System With Backlash and Friction Consideration
Authors: Shing T. K. , Tsai Lung-Wen , Krishnaprasad P. S.
Published: March 2021

A new model which accounts for both backlash and friction effects is proposed for the dynamics of a spur gear system. The model estimates average friction torque and uses it to replace the instantaneous friction torque to simplify the dynamical equations of motion. Two simulations, free oscillation and constant load operation, are performed to illustrate the effects of backlash and friction on gear dynamics. The results are compared with that of a previously established model which does not account for the friction. Finally, the effect of adding a damper on the driving shaft is also studied. This model is judged to be more realistic for real time control of electronmechanical systems to reduce gear noise and to achieve high precision.
Gerotor Configurations With Non-Uniform Cross Sections
Authors: Adams Glynn P. , Beard John E.
Published: March 2021

This study investigates the displacement, compression ratio and surface area to volume ratio of epitrochoidal gerotor mechanisms created with non-uniform cross sectional areas perpendicular to the rotor axis of rotation, skew gerotors. An algorithm is presented for modelling the gerotor mechanisms using a quadratic surface as the generating pin. The method used to model the skew gerotors consists of rotating the axis of the generating pin such that it is skewed relative to the rotor axis of rotation. The resulting effects on the displacement, compression ratio and surface area to volume ratio are presented for various configurations.
Design and Evaluation of Flexible Gas Fired Forging System
Authors: Clark R. K. , Avasarala Pantulu V. , Soni Athamaram H.
Published: March 2021

The advances in the furnace and high speed press technologies for forging applications necessitate the installation of automated material handling systems. In order to study the effect of integrating all these three new technologies, a simulation model of a flexible forging system (FFS) concept is developed. In this work a design procedure of the FFS is developed. A FFS is designed and evaluated. A simulation model of the FFS is developed on a computer using AutoMod simulation software. The developed model is simulated for various scenarios and the results are presented in this paper.
Identification of Dynamics Bodies From Part Mating Conditions
Authors: Fung-Ho Victor , Wu J. K.
Published: March 2021

A method to automatically identify bodies for Dynamics Analysis based on a given set of arbitrary parts and their mating conditions has been developed. The use of this method is considered within the context of Concurrent Engineering design of mechanical systems, where an entity translator from a shared global database to a Dynamics database is intended to automatically identify the bodies for rapid Dynamics model setup and simulation. A simplified formulation of the mating conditions that reduces the number of equations needed with respect to previous research is presented. The importance of detecting the equations associated with redundant constraints, in order to obtain the set of bodies, is presented. The method has been demonstrated by using some examples.
An Authorization Mechanism for a Document Database
Authors: Peltonen Hannu , Alho Kari , Männistö Tomi , Sulonen Reijo
Published: March 2021

A programmable authorization mechanism for an engineering document database is described. The database stores documents and their versions in a commercial relational database. Documents and other objects contain user-defined attributes. Release and approval procedures of the documents are described by means of state graphs that specify the possible states of a document and the transitions between them. The system consists of centralized server and client programs, which communicate with the server using a specific protocol.

The database administrator must be able to formulate rules that tell who is allowed to do particular database operations; rules that tell which operations are allowed in particular document states; and rules that describe consistency invariants between attributes.

These rules are expressed by means of authorization procedures written in a special language. Whenever the server receives an operation request, it executes the corresponding authorization procedure. The system can thus be easily adapted to an organization without actually modifying the client or server programs.
Using Critical Incident Technique to Investigate Anxiety in Physical Activity Settings
Authors: Dasinger Timothy M. , Solmon Melinda A.
Published: March 2021

Physical activity participation is linked with many benefits including a reduction in anxiety; it is, however, also important to explore aspects of activity that incite anxiety. One way to investigate sources of anxiety in physical activity is to use the critical incident technique (CIT). The purpose of this study was to explore anxiety-inducing events in physical activity settings and to evaluate the impact on future behavior. A total of 122 participants (M = 21.23 ± 1.77 years) completed an online survey asking when a physical activity setting incited anxiety using the CIT. Four common sources of anxiety were evident in the responses: fragile self-beliefs, social interaction and the threat of negative social evaluation, competition, and a lack of knowledge or unfamiliarity with surroundings. Tenets from achievement goal theory can help to explain the incitement of anxiety and can help shape physical activity settings to be more inclusive and welcoming for all.
Anatomy of digital contact tracing: Role of age, transmission setting, adoption, and case detection
Authors: Moreno López Jesús A. , Arregui García Beatriz , Bentkowski Piotr , Bioglio Livio , Pinotti Francesco , Boëlle Pierre-Yves , Barrat Alain , Colizza Vittoria , Poletto Chiara
Published: March 2021

Digital contact tracing apps could slow down COVID-19 transmission at moderate adoption: A model-based study.
Atoh7-independent specification of retinal ganglion cell identity
Authors: Brodie-Kommit Justin , Clark Brian S. , Shi Qing , Shiau Fion , Kim Dong Won , Langel Jennifer , Sheely Catherine , Ruzycki Philip A , Fries Michel , Javed Awais , Cayouette Michel , Schmidt Tiffany , Badea Tudor , Glaser Tom , Zhao Haiqing , Singer Joshua , Blackshaw Seth , Hattar Samer
Published: March 2021

Atoh7 promotes retinal ganglion survival and is not required for specification of most retinal ganglion cells.
Interplay between Pds5 and Rec8 in regulating chromosome axis length and crossover frequency
Authors: Song Meihui , Zhai Binyuan , Yang Xiao , Tan Taicong , Wang Ying , Yang Xuan , Tan Yingjin , Chu Tingting , Cao Yanding , Song Yulong , Wang Shunxin , Zhang Liangran
Published: March 2021

Pds5 works with Rec8 to regulate chromosome axis length and crossover frequency in a dosage-dependent manner.
Surface-directed engineering of tissue anisotropy in microphysiological models of musculoskeletal tissue
Authors: Mondrinos Mark J. , Alisafaei Farid , Yi Alex Y. , Ahmadzadeh Hossein , Lee Insu , Blundell Cassidy , Seo Jeongyun , Osborn Matthew , Jeon Tae-Joon , Kim Sun Min , Shenoy Vivek B. , Huh Dongeun
Published: March 2021

A developmentally inspired tissue engineering method enables the construction of microphysiological musculoskeletal tissue models.
People use both heterogeneity and minority representation to evaluate diversity
Authors: Abascal Maria , Xu Janet , Baldassarri Delia
Published: March 2021

Americans think of racial diversity in terms of heterogeneity; Blacks, Latinos, and Asians also weigh minority presence.
Optimization of (S)-3-Hydroxybutyric Acid Biosynthesis from Glucose through the Reversed Fatty Acid β-Oxidation Pathway by Recombinant Escherichia coli Strains
Authors: Gulevich A. Yu. , Skorokhodova A. Yu. , Debabov V. G.
Published: March 2021

The microaerobic synthesis of 3-hydroxybutyric acid by the Escherichia coli strain BOX3.1 ∆4 PL-atoB PL-tesB (MG1655 lacIQ, ∆ackA-pta, ∆poxB, ∆ldhA, ∆adhE, ∆fadE, PL-SDphi10-atoB, Ptrc-ideal-4-SDphi10-fadB, PL-SDphi10-tesB), which was previously directly engineered for the biosynthesis of the target compound from glucose through the reversed fatty acid β-oxidation pathway, was studied. A target product yield of 0.12 mol/mol was achieved. Inactivation of the nonspecific YciA thioesterase gene in the strain led to an increase in the yield of 3-hydroxybutyric acid to 0.15 mol/mol. For the optimization of biosynthesis of target product the strain MG∆4 PL-tesB (MG1655 ∆ackA-pta, ∆poxB, ∆ldhA, ∆adhE, PL-SDphi10-tesB) was engineered, and the genes encoding key enzymes of fatty acid β-oxidation were overexpressed in the strain from the plasmid pMW118m-atoB-fadB. The level of microaerobic synthesis of 3-hydroxybutyric acid by the strain MG∆4 PL-tesB (pMW118m-atoB-fadB) achieved in primary evaluation conditions reached 0.35 mol/mol. Inactivation in the strain of the gene of nonspecific thioesterase YciA led to only minor decrease in acetate byproduction. Further inactivation in the strain of gene encoding nonspecific thioesterase YdiI had virtually no effect on the level of synthesis of side products. Cultivation of the constructed strain MG∆4 PL-tesB ∆yciA (pMW118m-atoB-fadB) in bioreactor under the controlled conditions ensured achievement of a yield of 3‑hydroxybutyric acid amounting to 0.75 mol/mol.
Effects of implementing Pressure Ulcer Prevention Practice Guidelines (PUPPG) in the prevention of pressure ulcers among hospitalised elderly patients: a systematic review protocol
Authors: Wung Buh Amos , Mahmoud Hassan , Chen Wenjun , McInnes Matthew D F , Fergusson Dean A
Published: March 2021

Introduction

Pressure ulcers are serious and potentially life-threatening problems across all age groups and across all medical specialties and care settings. The hospitalised elderly population is the most common group to develop pressure ulcers. This study aims to systematically review studies implementing pressure ulcer prevention strategies recommended in the Pressure Ulcer Prevention Practice Guidelines for the prevention of pressure ulcers among hospitalised elderly patients globally.

Methods and analysis

A systematic review of all studies that have assessed the use of pressure ulcer prevention strategies in hospital settings among hospitalised elderly patients shall be conducted. A comprehensive search of all published articles in Medline Ovid, Cumulative Index to Nursing and Allied Health Literature, PubMed, Embase, Cochrane library, Scopus and Web of Science will be done using terms such as pressure ulcers, prevention strategies, elderly patients and hospital. Studies will be screened for eligibility through title, abstract and full text by two independent reviewers. Study quality and risk of bias will be assessed using the Joanna Briggs Institute for Meta-Analysis of Statistics Assessment and Review Instrument. If sufficient data are available, a meta-analysis will be conducted to synthesise the effect size reported as OR with 95% CIs using both fixed and random effect models. I2statistics and visual inspection of the forest plots will be used to assess heterogeneity and identify the potential sources of heterogeneity. Publication bias will be assessed by visual inspections of funnel plots and Egger’s test.

Ethics and dissemination

No formal ethical approval or consent is required as no primary data will be collected. We aim to publish the research findings in a peer-reviewed scientific journal to promote knowledge transfer, as well as in conferences, seminars, congresses or symposia in a traditional manner.

PROSPERO registration number

CRD42019129088.
Norepinephrine, plasma renin activity and cardiovascular mortality in systolic heart failure
Authors: Aimo Alberto , Prontera Concetta , Passino Claudio , Emdin Michele , Vergaro Giuseppe
Published: March 2021

Objective

We analysed the circulating levels and prognostic value of N-terminal pro-B-type natriuretic peptide (NT-proBNP), norepinephrine (NE), epinephrine (E), plasma renin activity (PRA) and aldosterone in patients with systolic heart failure (HF) receiving therapies that target the sympathetic system and the renin-angiotensin-aldosterone axis.

Methods

We retrieved data from consecutive HF outpatients with left ventricular ejection fraction (LVEF) <50% and available neurohormones, evaluated at a tertiary referral centre for HF from 1999 to 2016.

Results

Patients (n=1477) were aged 66±13 years, 75% were men, median LVEF was 32% (IQR 25–38), 77% had LVEF <40% and 44% ischaemic HF. At the time of sampling, 69% were on beta-blockers, 75% on ACE inhibitors/angiotensin receptor blockers and 48% on mineralocorticoid receptor antagonists vs 88%, 87% and 66%, respectively, after therapy optimisation. Median NT-proBNP, NE, E, PRA and aldosterone were 1441 ng/L, 494 ng/L, 30 ng/L, 1.2 ng/mL/hour and 130 ng/dL, respectively. Over a 4.8-year follow-up (2.4–8.2), 376 patients died from cardiovascular causes (26%). NT-proBNP and PRA predicted cardiovascular mortality after adjusting for all other univariable predictors. The risk of cardiovascular death increased by 8% or 7% per each doubling of PRA in 2 models considering therapies at the time of sampling or after therapy optimisation. PRA improved metrics of reclassification and discrimination, and independently predicted outcome even in the LVEF <40% subgroup.

Conclusions

In patients with HF with LVEF <50% or <40%, PRA shows independent prognostic significance from a model that includes NT-proBNP, and might represent an additive tool for risk stratification.
Extracellular HMGB1 blockade inhibits tumor growth through profoundly remodeling immune microenvironment and enhances checkpoint inhibitor-based immunotherapy
Authors: Hubert Pascale , Roncarati Patrick , Demoulin Stephanie , Pilard Charlotte , Ancion Marie , Reynders Celia , Lerho Thomas , Bruyere Diane , Lebeau Alizee , Radermecker Coraline , Meunier Margot , Nokin Marie-Julie , Hendrick Elodie , Peulen Olivier , Delvenne Philippe , Herfs Michael
Published: March 2021

Background

High-mobility group box 1 (HMGB1) is a multifunctional redox-sensitive protein involved in various intracellular (eg, chromatin remodeling, transcription, autophagy) and extracellular (inflammation, autoimmunity) processes. Regarding its role in cancer development/progression, paradoxical results exist in the literature and it is still unclear whether HMGB1 mainly acts as an oncogene or a tumor suppressor.

Methods

HMGB1 expression was first assessed in tissue specimens (n=359) of invasive breast, lung and cervical cancer and the two distinct staining patterns detected (nuclear vs cytoplasmic) were correlated to the secretion profile of malignant cells, patient outcomes and the presence of infiltrating immune cells within tumor microenvironment. Using several orthotopic, syngeneic mouse models of basal-like breast (4T1, 67NR and EpRas) or non-small cell lung (TC-1) cancer, the efficacy of several HMGB1 inhibitors alone and in combination with immune checkpoint blockade antibodies (anti-PD-1/PD-L1) was then investigated. Isolated from retrieved tumors, 14 immune cell (sub)populations as well as the activation status of antigen-presenting cells were extensively analyzed in each condition. Finally, the redox state of HMGB1 in tumor-extruded fluids and the influence of different forms (oxidized, reduced or disulfide) on both dendritic cell (DC) and plasmacytoid DC (pDC) activation were determined.

Results

Associated with an unfavorable prognosis in human patients, we clearly demonstrated that targeting extracellular HMGB1 elicits a profound remodeling of tumor immune microenvironment for efficient cancer therapy. Indeed, without affecting the global number of (CD45+) immune cells, drastic reductions of monocytic/granulocytic myeloid-derived suppressor cells (MDSC) and regulatory T lymphocytes, a higher M1/M2 ratio of macrophages as well as an increased activation of both DC and pDC were continually observed following HMGB1 inhibition. Moreover, blocking HMGB1 improved the efficacy of anti-PD-1 cancer monoimmunotherapy. We also reported that a significant fraction of HMGB1 encountered within cancer microenvironment (interstitial fluids) is oxidized and, in opposite to its reduced isoform, oxidized HMGB1 acts as a tolerogenic signal in a receptor for advanced glycation endproducts-dependent manner.

Conclusion

Collectively, we present evidence that extracellular HMGB1 blockade may complement first-generation cancer immunotherapies by remobilizing antitumor immune response.
Survey of feeding practices on dairy farms in Ontario and western Canada
Authors: Gee S.W. , Kelton D.F. , Carpenter A.J.
Published: March 2021

To establish a baseline understanding of feeding practices on Canadian dairies, a survey was distributed online to dairy producers. Responses were split into three categories as follows: western provinces (WP; Alberta, British Columbia, Manitoba, and Saskatchewan; n = 84), Ontario freestall farms (n = 75), and Ontario tiestall (OT) farms (n = 71). Regional differences were observed for many feed ingredients; for example, corn and soybean meal were more commonly used in Ontario, whereas barley, wheat products, and grass hays were more commonly used in the WP (P ≤ 0.01), consistent with local production of those crops. Producers ranked the most important factors in balancing rations in the following order: production (lactating cattle or heifers) or health (dry cows), cost, simplicity, and nutrient management; however, nutrient management was more important in the west for all types of diets (P < 0.01). Most farms frequently tested for ration dry matter and nutrient composition, although OT farms tested less often than other groups (P = 0.09). Overall, feeds aligned with common crops grown within region. Canadian farmers have a stated interest for improving production and health and place less emphasis on other factors such as cost, simplicity, and nutrient management.
Effects of group size and homeopathic product supplement consisting of botanicals and mineral mixture on the performance and production traits of finishing pigs
Authors: Upadhaya Santi Devi , Park Hyun Ju , Kim In Ho
Published: March 2021

A total of 144 mixed sex pigs [(Landrace × Yorkshire) × Duroc] with an initial average body weight (BW) of 52 kg were used in a 11 wk trial in a 2 × 2 factorial design with the following factors: group size (three pigs per pen vs. five pigs per pen) and 0% or 0.2% homeopathic product supplementation to evaluate growth performance, nutrient digestibility, meat quality, and stress-related hormones. The homeopathic product supplementation resulted in increased (P < 0.05) BW at week 11, average daily gain (ADG) during days 42–63 and 64–77. In addition, an increase (P < 0.05) in ADG and average daily feed intake during overall experiment period and an increase (P < 0.05) in apparent total tract digestibility of dry matter at day 77 were observed in pigs receiving homeopathic product. A trend in increase (P = 0.088) in serum cortisol concentration during day 42 and increase (P > 0.05) during day 77 was observed in pigs with group size of five pigs per pen, and this was reduced when homeopathic product was supplemented to the diet. In conclusion, the variation in number of animals per pen had no effects on performance and production traits, but the animals in bigger group size had higher serum cortisol concentrations which were reduced by the homeopathic product supplementation.
Probing mechanotransduction in living cells by optical tweezers and FRET-based molecular force microscopy
Authors: Sergides M. , Perego L. , Galgani T. , Arbore C. , Pavone F. S. , Capitanio M.
Published: March 2021

Cells sense mechanical signals and forces to probe the external environment and adapt to tissue morphogenesis, external mechanical stresses and a wide range of diverse mechanical cues. Here, we propose a combination of optical tools to manipulate single cells and measure the propagation of mechanical and biochemical signals inside them. Optical tweezers are used to trap microbeads that are used as handles to manipulate the cell plasma membrane; genetically encoded FRET-based force sensors inserted in F-actin and alpha-actinin are used to measure the propagation of mechanical signals to the cell cytoskeleton, while fluorescence microscopy with single-molecule sensitivity can be used with a huge array of biochemical and genetic sensors. We describe the details of the setup implementation, the calibration of the basic components and preliminary characterization of actin and alpha-actinin FRET-based force sensors.
On Lie bialgebroid crossed modules
Authors: Lang Honglei , Qiao Yu , Yin Yanbin
Published: March 2021

We study Lie bialgebroid crossed modules which are pairs of Lie algebroid crossed modules in duality that canonically give rise to Lie bialgebroids. A one-one correspondence between such Lie bialgebroid crossed modules and co-quadratic Manin triples [Formula: see text] is established, where [Formula: see text] is a co-quadratic Lie algebroid and [Formula: see text] is a pair of transverse Dirac structures in [Formula: see text].
Theoretical research on the effects of third-order dispersion on multi-pulse signal propagation based on Runge–Kutta algorithm
Authors: Yin Shenwei , Rong Haichen , Dong Jiayuan , Li Xin , Yan Yichen , Liu Linbo , Zhang Yiming
Published: March 2021

In recent years, integrated signal processing system has been attracting increasing attention for its significant potential in future data transmission and information interaction. There is a key technical requirement for multi-pulse signal propagation that keeps the waveform shape, which contributes to the practical value of the system. Here, we investigate the effects of third-order dispersion on pulses in mid-infrared multi-pulse signal propagation via numerical simulation based on Runge–Kutta algorithm. The phenomenon of waveform distortion and reduction of conversion efficiency induced by third-order dispersion is explored and discussed in detail. To reduce the impact of nonlinear factors, we propose an on-chip signal processing system based on a lithium niobate waveguide, which achieves high-efficiency signal transmission. It opens a new way to establish a novel transmission system to process multi-pulse signal.