bluuebunny/crossref_metadata_2025 huggingface dataset:
A Sensitivity Analysis Based Method for Robot Calibration
Authors: Kaizerman S. , Benhabib B. , Fenton R. G. , Zak G.
Published: March 2021

A new robot kinematic calibration procedure is presented. The parameters of the kinematic model are estimated through a relationship established between the deviations in the joint variables and the deviations in the model parameters. Thus, the new method can be classified as an inverse calibration procedure. Using suitable sensitivity analysis methods, the matrix of the partial derivatives of joint variables with respect to robot parameters is calculated without having explicit expressions of joint variables as a function of task space coordinates (closed inverse kinematic solution). This matrix provides the relationship between the changes in the joint variables and the changes in the parameter values required for the calibration. Two deterministic sensitivity analysis methods are applied, namely the Direct Sensitivity Approach and the Adjoint Sensitivity Method. The new calibration procedure was successfully tested by the simulated calibrations of a two degree of freedom revolute-joint planar manipulator.
Force and Stiffness Transmission in Redundantly Actuated Mechanisms: The Case for a Spherical Shoulder Mechanism
Authors: Yi Byung-Ju , Freeman Robert A. , Tesar Delbert
Published: March 2021

This work deals with the analysis of three degree of freedom spherical shoulder mechanisms which have force redundancies in their parallel structure. First, a comparative study between a fully parallel shoulder mechanism (three legs with three inputs) and a redundantly actuated parallel shoulder mechanism (four legs with four inputs) is performed in terms of force transmission capability. The mode in which all joints of the shoulder (three- and four-legged) are actuated is studied next, in terms of active stiffness transmission capability. It is shown that the four-legged shoulder is superior to the three-legged shoulder in both force and active stiffness transmission, and that force and active stiffness transmission capability are operational trade-offs. Design issues associated with general redundantly actuated systems are mentioned.
Studies on a New Snake-Like Manipulator
Authors: Sen Dibakar , Mruthyunjaya T. S.
Published: March 2021

In this paper the capabilities of a proposed serial, multi-link, snake-like, planar manipulator with highly restricted joint motion (only three states per joint) have been studied. Two different types of problem namely reach-the-point and follow-the-path problems, have been solved for such a manipulator when the number of links is assumed unlimited. The reach-the-point problem has been solved also for the case of fixed number of links. By adopting a coded representation of the configuration a set of transformation rules has been developed to decide whether two different configurations lead to the same point in the work-space. This avoids the time-consuming evaluation of trigonometric functions involved in actually computing the tip location.
A General Procedure for Dimensional Synthesis of Mechanisms
Authors: Hansen Michael Rygaard
Published: March 2021

A method for dimensional synthesis of arbitrary planar mechanisms is presented. The method is based on identification of the mutually independent vector loops of the mechanism, and the design equations that fulfil the desired kinematic behaviour are formulated on the basis of these loops. The identification of the branches is done on the basis of a separation of the mechanism into a number of modules (input bodies and Assur groups). As the design equations are strongly nonlinear (involving both dimensions and rotations of bodies), a continuation method is employed for their solution. The method, with the definition and analysis of the initial mechanism, the subdivision of the mechanism into modules, the definition of the desired kinematic behaviour, and the generation and solution of the vector loop equations, has been implemented in a menu-controlled CAD-system called CADME (Computer Aided Design of MEchanisms).
A Unified Analysis and Implementation of Four Multiply Separated Position Synthesis of Four-Bar Linkages
Authors: Srikrishna P. , Waldron Kenneth J.
Published: March 2021

The objective of this paper is to derive analytically the circle-point and center-point curve equations for the synthesis of four-bar linkages for rigid body guidance through four multiply separated design positions. A unified approach is evolved to deal with the different combinations of four finitely and infinitesimally separated design position, namely the PP-P-P, PP-PP and PPP-P cases. The design procedure incorporates the rectification procedures developed by Waldron (1977) to eliminate the branch and order problems and is implemented in the interactive synthesis package RECSYN.
On the Design of Planar and Spherical Pure-Rolling Indexing Cam Mechanisms
Authors: González-Palacios Max Antonio , Angeles Jorge
Published: March 2021

A new design of indexing cam mechanisms for parallel and intersecting shafts is presented here in a unified framework, so that both pure rolling and positive motion are achieved. Power losses due to Coulomb friction are eliminated, while producing motions free of jerk discontinuities. The pressure angle is anlyzed and applied to define the positive motion.
Computerized Simulation of Generation of Internal Involute Gears and Their Assembly
Authors: Litvin F. L. , Hsiao C.-L. , Wang J.-C. , Zhou X.
Published: March 2021

The contents of the paper cover the determination of conditions : (i) of nonundercutting by axial and axial-radial generation of internal gears by shapers, and (ii) avoidance of interference by axial and axial-radial assembly.

The authors have developed computer programs for simulation of undercutting and interference, design charts and a table that allow to determine the limiting number of teeth of the cutter and pinion considering the tooth number of internal gear as known. The details of developed algorithms are given in Appendices.

The paper is illustrated with computer graphics and numerical examples.
Geometric Characteristics of the Center-Point Curve Based on the Kinematics of the Compatibility Linkage
Authors: Schaaf J. A. , Lammers J. A.
Published: March 2021

In this paper we develop a method of characterizing the center-point curves for planar four-position synthesis. We predict the five characteristic shapes of the center-point curve using the kinematic classification of the compatibility linkage obtained from a complex number formulation for planar four-position synthesis. This classification scheme is more extensive than the conventional Grashof and non-Grashof classifications in that the separate classes of change point compatibility linkages are also included. A non-Grashof compatibility linkage generates a unicursal form of the center-point curve; a Grashof compatibility linkage generates a bicursal form; a single change point compatibility linkage generates a double point form; and a double or triple change point compatibility linkage generates a circular-degenerate or a hyperbolic-degenerate form.
Optimization of Function-Generating Mechanisms Using Input-Output Curve Planning: Part I — Curve Planning and Data Preparation
Authors: Liu Zheng , Angeles Jorge
Published: March 2021

A general scheme for the optimization of one-degree-of-freedom mechanisms for function generation is proposed in this and an accompanying paper. The problem is solved here following two basic steps: i) planning input-output curves based on design requirements (input-output pairs, mobility, time ratio, etc.) and selecting data from the planned curve; and ii) setting up an optimization procedure to minimize a performance index (design error or structural error). Discussed in Part I is the first step of the optimization scheme, i.e., design-data preparation based on input-output curve planning, while, in Part II, the ensuing formulation and design strategies.
Optimization of Function-Generating Mechanisms Using Input-Output Curve Planning: Part II — Formulation and Optimization Strategies
Authors: Liu Zheng , Angeles Jorge
Published: March 2021

As a sequel to Part I, in which design-data preparation based on Input-output curve planning is discussed, Part II focuses on the second step of the optimization scheme. This step includes the basic formulation and some strategies, in the optimization procedure, for: i) transmission-quality evaluation; and ii) branch-defect elimination. Since design requirements on mobility conditions are already considered in the curve-planning phase, discussed in Part I, there is no need to introduce constraints pertaining to mobility type in the formulation, the procedure thus becoming remarkably simple.
Invariant Link Rotatability of N-Bar Kinematic Chains
Authors: Shyu J. H. , Ting Kwun-Lon
Published: March 2021

This paper proposes and proves the concept of invariant link rotatability between any two links, adjoined or not, in planar single-loop kinematic chains. It was found that in any planar single-loop chain formed by a set of links and revolute joints, the rotatability between any two links, whether they are adjoined or not, is independent of the order of links connection. Simple and general approaches were also proposed to identify the exact rotatability between any two links of a single-loop N-bar chain. When a non-revolvable link reaches the limit orientation with respect to another non-revolvable link, disregard whether they are adjoined or not, all other links become collinear or parallel to each other. This paper fully extends Ting’s rotatability laws to deal with the rotatability between two non-adjoined links.
A Path Planning Algorithm for a Free-Floating Closed-Chain Planar Manipulator
Authors: Agrawal Sunil Kumar , Garimella R.
Published: March 2021

The base of free-floating manipulators is not inertially fixed. For these manipulators, the linear and angular momentum are conserved. The linear momentum equations are holonomic while the angular momentum equations are nonholonomic. The presence of nonholonomic constraints makes the path-planning schemes, commonly used for fixed-base manipulators, unsuitable for free-floating manipulators. In this paper, we first apply inverse position and inverse rate kinematics path-planning schemes to a free-floating closed-chain planar manipulator and show that these schemes have shortcomings. Then, a working path-planning scheme is described which is based on careful study of the rate kinematics of the free-floating closed-chain manipulator. This algorithm is implemented and the graphical simulations are presented.
A New Adaptive Control Approach for Robot Manipulators
Authors: Ye Jingsheng
Published: March 2021

Dynamic equations of robot manipulators are highly nonlinear with time-varying and unknown parameters. Using the model reference adaptive control (MRAC) technique, a control scheme based on hyperstability theory is developed for robot manipulators. A new adaptive algorithm is proposed for compensating the nonlinear term in the dynamic equations and for decoupling the dynamic interaction among the joints. The main feature of the approach is that the unknown parameters are not estimated separately, but the total influences due to the modeling errors and the disturbances can be directly compensated. Simulations show good results even for large variations of parameters. A comparison of this approach with the feedback linearization method (FLM) is also presented.
Choosing an Engineering Object Data Management System
Authors: Wood Chet
Published: March 2021

An Object Database Management System (ODMS) can be a very useful component when developing applications for use in engineering and manufacturing. Choosing the right product requires a thorough analysis of the data requirements of one’s application, and an equally thorough study of the characteristics of the vendor products. Over a period of about two years, data was gathered on the products of object oriented database manufacturers and researchers. As an example of how to analyze database requirements, an overview of the requirements of our application is presented, followed by a tutorial on the elements and features provided by an ODMS. A brief description is given of each of about a dozen products. Finally, there are tables comparing specific features of a number of these systems.
New data on oribatid mites (Acari, Oribatida) phoretic on passalid beetles (Coleoptera, Passalidae) from the Afrotropical and Oriental regions, with descriptions of three new species from Congo, Gabon and Ghana

Authors: Ermilov Sergey G. , Frolov Andrey V.
Published: March 2021

The present study is based on the oribatid mites (Acari, Oribatida) phoretic on passalid beetles (Coleoptera, Scarabaeoidea, Passalidae) from the Afrotropical and Oriental regions. Nine identified mite species (phoretic on ten beetle species) are registered; of these, three species (from Congo, Gabon and Ghana) are new to science: Graptoppia (Stenoppia) boucheri sp. nov. (Oppiidae), Perscheloribates (Perscheloribates) gabonensis sp. nov. (Scheloribatidae) and Vilhenabates paraambohitra sp. nov. (Haplozetidae). An identification key to the known species of Graptoppia (Stenoppia) is given. Data on the registered phoretic relationships between Oribatida and Passalidae are summarized.
Acute toxicity and sublethal effects of metal oxide nanoparticles against the bulb mite

Authors: Korghond Gholamreza Tavakkoli , Sahebzadeh Najmeh , Allahyari Hossein , Ramroodi Sara
Published: March 2021

Crocus sativus L. (Iridaceae) known as saffron is the most commercially important medicinal food product in Iran and worldwide because of its significance for exporting commercial. However, the health of this plant is adversely threatened by abiotic and biotic stress. Bulb mite Rhizoglyphus robini Claparede (Acari: Acaridae) as abiotic stress is oligophagous and the main pest of tuber plants, commonly found in all the cultivated saffron producing areas could decrease saffron economic value. The mites tunnel through corms allowing the entry of fungal and bacterial pathogens. The widespread use of commercial pesticides in modern agriculture to protect crops from pests has caused significant public concern because of their side impacts on the environment and non-target species. Nanotechnology has been used in the production, processing, storage, packaging, and transport of agricultural products. Newly, oxide nanoparticles have been introduced as novel pesticides against pests and fertilizer. This study was conducted as an effective and environmentally-friendly method to control the growth of Rhizoglyphus robini. The lethal and sublethal effects of metal oxide nanoparticles (MNPs) including nano copper oxides (nano-CuO), nano magnesium oxide (nano-MgO), nano zinc oxide (nano-ZnO), nano titanium dioxide (nano-TiO2), and nano iron oxide (nano-Fe2O3) which their lethal concentrations ranged between 159.2 and 1036.4 mg L-1 were studied on Rhizoglyphus robini adult females. The contact effect of the tested MNPs was evaluated using the corm dip bioassay method. Assays showed that the contact toxicity of the nano-CuO treatment (229.1 mg L-1) was higher than other MNPs. To assess the sublethal effects of the MNPs, adult females were exposed to the LC25 concentration of MNPs, and life history and life-table parameters of the surviving Rhizoglyphus robini were investigated. The exposure to sublethal concentrations of the tested MNPs prolonged the egg incubation, larval period, and nymphal period significantly when compared to the control mites. Compared to other MNPs or control mite, nano-MgO and nano-TiO2 led to the longest duration of the total immature stages (11.32 and 11.32, respectively). The net reproductive rate (R0), the intrinsic rate of increase (rm), the finite rate of increase (λ), and the generation time (T) were significantly different between control and MNP treatments. The population exposed to ZnO-, MgO-, and TiO2-nanoformulations had a much lower rm value (0.164, 0.164, and 0.171 d-1, respectively) compared to the control population (0.231 d-1) and those exposed to Fe3O4- and CuO-nanoformulations (1.19 and 1.19 d-1, respectively). According to our findings, all tested MNPs, especially CuO-, ZnO-, and MgO-nano formulations, have a potential application for use in the management of Rhizoglyphus robini.
Muscle–Tendon Behavior and Kinetics in Gastrocnemius Medialis During Forefoot and Rearfoot Strike Running
Authors: Takeshita Tomonari , Noro Hiroaki , Hata Keiichiro , Yoshida Taira , Fukunaga Tetsuo , Yanagiya Toshio
Published: March 2021

The present study aimed to clarify the effect of the foot strike pattern on muscle–tendon behavior and kinetics of the gastrocnemius medialis during treadmill running. Seven male participants ran with 2 different foot strike patterns (forefoot strike [FFS] and rearfoot strike [RFS]), with a step frequency of 2.50 Hz and at a speed of 2.38 m/s for 45 seconds on a treadmill with an instrumented force platform. The fascicle behavior of gastrocnemius medialis was captured using a B-mode ultrasound system with a sampling rate of 75 Hz, and the mechanical work done and power exerted by the fascicle and tendon were calculated. At the initial contact, the fascicle length was significantly shorter in the FFS than in the RFS (P = .001). However, the fascicular velocity did not differ between strike patterns. Higher tendon stretch and recoil were observed in the FFS (P < .001 and P = .017, respectively) compared with the RFS. The fascicle in the positive phase performed the same mechanical work in both the FFS and RFS; however, the fascicle in the negative phase performed significantly greater work in the FFS than in the RFS (P = .001). RFS may be advantageous for requiring less muscular work and elastic energy in the series elastic element compared with the FFS.
Predicting Season Ticket Holder Retention Using Rich Behavioral Data
Authors: Karg Adam , Tamaddoni Ali , McDonald Heath , Ewing Michael
Published: March 2021

Season ticket holders are a vital source of revenue for professional teams, but retention remains a perennial issue. Prior research has focused on broad variables, such as relationship tenure, game attendance frequency, and renewal intention, and has generally been limited to survey data with its attenuate problems. To advance this important research agenda, the present study analyzes team-supplied behavioral data to investigate and predict retention as a loyalty outcome for a single professional team over a 3-year period. Specifically, the authors embrace a broad range of loyalty measures and team performance to predict retention and employ novel data mining techniques to improve predictive accuracy.
Exploiting the acquired vulnerability of cisplatin-resistant tumors with a hypoxia-amplifying DNA repair–inhibiting (HYDRI) nanomedicine
Authors: Chen Jing , Wang Xue , Yuan Yuan , Chen Haoting , Zhang Lingpu , Xiao Haihua , Chen Jingqi , Zhao Yongxiang , Chang Jin , Guo Weisheng , Liang Xing-Jie
Published: March 2021

Nanochemotherapy combats cisplatin resistance by exploiting increased intracellular hypoxia in cancer cells.
Spectrally encoded single-pixel machine vision using diffractive networks
Authors: Li Jingxi , Mengu Deniz , Yardimci Nezih T. , Luo Yi , Li Xurong , Veli Muhammed , Rivenson Yair , Jarrahi Mona , Ozcan Aydogan
Published: March 2021

Diffractive networks encode the spatial information of objects into power spectrum to classify images with a single-pixel detector.
Colossal anomalous Nernst effect in a correlated noncentrosymmetric kagome ferromagnet
Authors: Asaba T. , Ivanov V. , Thomas S. M. , Savrasov S. Y. , Thompson J. D. , Bauer E. D. , Ronning F.
Published: March 2021

Uranium-based ferromagnet demonstrates notable ability to convert heat to electricity.
Mechanistic Insights into Substrate Recognition and Catalysis of a New Ulvan Lyase of Polysaccharide Lyase Family 24
Authors: Xu Fei , Dong Fang , Sun Xiao-Hui , Cao Hai-Yan , Fu Hui-Hui , Li Chun-Yang , Zhang Xi-Ying , McMinn Andrew , Zhang Yu-Zhong , Wang Peng , Chen Xiu-Lan
Published: March 2021

Ulvan is a major cell wall component of green algae of the genus
Ulva.
Many marine heterotrophic bacteria can produce extracellular ulvan lyases to degrade ulvan for a carbon nutrient. In addition, ulvan has a range of physiological bioactivities based on its specific chemical structure.
An intracontinental orogen exhumed by basement-slice imbrication in the Longmenshan Thrust Belt of the Eastern Tibetan Plateau
Authors: Xue Zhenhua , Lin Wei , Chu Yang , Faure Michel , Chen Yan , Ji Wenbin , Qiu Huaning
Published: March 2021

The Longmenshan Thrust Belt in Eastern Tibet resulted from a Mesozoic orogeny and Cenozoic reworking. It is generally believed that the Cenozoic tectonics along the Longmenshan Thrust Belt are mostly inherited from the Mesozoic. Reconstructing the Mesozoic tectonics of the Longmenshan Thrust Belt is therefore important for understanding its evolutionary history. On the basis of detailed structural analysis, we recognized a Main Central Boundary that divides the Longmenshan Thrust Belt into a Southeastern Zone and a Northwestern Zone. Both zones underwent a main D1 event characterized by D1E top-to-the-SE thrusting in the Southeastern Zone and D1W top-to-the-NW/N thrusting in the Northwestern Zone. In the Southeastern Zone, a D2 top-to-the-NW/N normal faulting that cuts the D1E structures is developed along the NW boundary of the basement complexes. Newly obtained and previous geochronological data indicate that the D1E and D1W events occurred synchronously at ca. 224–219 Ma, and the D2 top-to-the-NW/N normal faulting was episodically activated at ca. 166–160 Ma, 141–120 Ma, 81–47 Ma, and 27–25 Ma. Episodic and synchronously activated top-to-the-NW normal faulting and top-to-the-SE thrusting along the northwestern and southeastern boundaries of the basement complexes, respectively, leads us to propose that the basement slices were episodically imbricated to the SE during the Late Jurassic–Early Cretaceous and Late Cretaceous–earliest Paleocene. The D1 amphibolite facies metamorphic rocks above the basement complexes recorded fast exhumation during the Late Jurassic–Early Cretaceous. We propose that the early Mesozoic northwestward basement underthrusting along a crustal “weak zone” was responsible for the D1 double-vergent thrusting and amphibolite facies metamorphism. Subsequent basement-slice imbrications reworked the Longmenshan Thrust Belt and exhumed the amphibolite facies rocks. Our results highlight the importance of basement underthrusting and imbrication in the formation and reworking of the intracontinental Longmenshan Thrust Belt in Eastern Tibet.
New chronology of the Chinese loess-paleosol sequence by leaf wax δD records during the past 800 k.y.
Authors: Wang Zheng , Liu Weiguo , Wang Hong , Cao Yunning , Hu Jing , Dong Jibao , Lu Hongxuan , Wang Huangye , Xing Meng , Liu Hu
Published: March 2021

The Chinese loess-paleosol sequences provide important archives for studying paleoenvironmental changes. However, the lack of independent and accurate time scales hinders the study between loess and other records. Asian stalagmite δ18O records indicate synchronous patterns of paleoprecipitation δ18O over large geographic regions. The record of hydrogen isotopic composition of plant wax (δDwax) in Chinese loess is also controlled by rainwater δD. Both share a common origin. The linear relationship between rainfall δ18O and δD variance provides the basis to tie together chronologies of the same climate event in different records. Here, we show a new loess chronology by correlating chronologies of marker boundaries of the prominent climate chronozones in stalagmite δ18O and summer insolation to the equivalent climate stratigraphy in the loess δDwax sequence. We first developed and tested this novel methodology with data since the last interglacial on a millennial scale, and then applied this approach to the loess δDwax sequence for the past 800 k.y. to improve the traditional chronology based on magnetic susceptibility and grain size. The new δDwax time series provides not only an improved chronology for studying paleoclimate changes during interglacial intervals, it also represents a unique database with which to better understand the links between the Asian monsoon changes in the Chinese loess and other global climate events, especially for the periods prior to 640 ka, for which stalagmite records are not available.
Supplemental Material: Ghost-dune hollows of the eastern Snake River Plain, Idaho: Their genesis, evolution, and relevance to Martian ghost-dune pits
Authors: Gaylord David , al. et
Published: March 2021

Optically stimulated luminescence, 40Ar/39Ar, and detrital zircon methods and data.
Older people’s perceptions of the impact of Dance for Health sessions in an acute hospital setting: a qualitative study
Authors: Bungay Hilary , Hughes Suzanne
Published: March 2021

Objectives

To explore the perceptions of hospitalised older people and their relatives of the impact of taking part in group dance sessions in an acute hospital setting.

Design

A qualitative descriptive approach was used.

Setting

An acute hospital trust in the East of England.

Participants

Purposive sample of dance group participants.

Intervention

Weekly music and movement sessions for frail older people on Department of Elderly Medicine Wards and the Stroke Rehabilitation Unit. Sessions take place in the ward and are facilitated by a dance artist supported by ward staff.

Results

Twenty-one semistructured interviews were conducted with older people and/or their relatives. Thematic analysis of the data identified three overarching themes: (1) dance as a physical activity, (2) dance as an opportunity for social interaction and (3) the dance group as a source of emotional support. Sessions were valued as an enjoyable way to undertake physical activity and provided an opportunity for social interaction between patients. This is important as loneliness and boredom are a common occurrence during hospitalisation and are detrimental to overall health and well-being. Patients reported an emotional impact though taking part; happiness from engaging with the group and the release of pent up emotions through the triggering of memories by the music and conversations within the group.

Conclusion

Dance for Health provides a range of physical, social and emotional benefits for hospitalised older people. Further research is required to investigate the effectiveness of group dance sessions in increasing physical activity on an acute ward and the potential psychological benefits for hospitalised older people.
Influence of language skills on the choice of terms used to describe lung sounds in a language other than English: a cross-sectional survey of staff physicians, residents and medical students
Authors: Bohadana Abraham , Azulai Hava , Jarjoui Amir , Kalak George , Rokach Ariel , Izbicki Gabriel
Published: March 2021

Introduction

The value of chest auscultation would be enhanced by the use of a standardised terminology. To that end, the recommended English terminology must be transferred to a language other than English (LOTE) without distortion.

Objective

To examine the transfer to Hebrew—taken as a model of LOTE—of the recommended terminology in English.

Design/setting

Cross-sectional study; university-based hospital.

Participants

143 caregivers, including 31 staff physicians, 65 residents and 47 medical students.

Methods

Observers provided uninstructed descriptions in Hebrew and English of audio recordings of five common sounds, namely, normal breath sound (NBS), wheezes, crackles, stridor and pleural friction rub (PFR).

Outcomes

(a) Rates of correct/incorrect classification; (b) correspondence between Hebrew and recommended English terms; c) language and auscultation skills, assessed by crossing the responses in the two languages with each other and with the classification of the audio recordings validated by computer analysis.

Results

Range (%) of correct rating was as follows: NBS=11.3–20, wheezes=79.7–87.2, crackles=58.6–69.8, stridor=67.4–96.3 and PFR=2.7–28.6. Of 60 Hebrew terms, 11 were correct, and 5 matched the recommended English terms. Many Hebrew terms were adaptations or transliterations of inadequate English terms. Of 687 evaluations, good dual-language and single-language skills were found in 586 (85.3%) and 41 (6%), respectively. However, in 325 (47.3%) evaluations, good language skills were associated with poor auscultation skills.

Conclusion

Poor auscultation skills surpassed poor language skills as a factor hampering the transfer to Hebrew (LOTE) of the recommended English terminology. Improved education in auscultation emerged as the main factor to promote the use of standardised lung sound terminology. Using our data, a strategy was devised to encourage the use of standardised terminology in non-native English-speaking countries.
Association between insulin resistance and post-ischaemic stroke outcome in patients without diabetes: protocol for a systematic review and meta-analysis
Authors: Hadwen Jeremiah , Kim Woojin , Dewar Brian , Ramsay Tim , Davis Alexandra , Dowlatshahi Dar , Shamy Michel
Published: March 2021

Introduction

Insulin resistance is an independent risk factor for atherosclerosis, coronary artery disease and ischaemic stroke. Currently, insulin resistance is not usually included in post-stroke risk stratification. This systematic review and meta-analysis intends to determine if available scientific knowledge supports an association between insulin resistance and post-stroke outcomes in patients without diabetes.

Methods and analysis

The authors will conduct a literature search in Medline, Embase, Web of Science and Cochrane Central. The review will include studies that assess the association between elevated insulin homeostasis model of insulin resistance (HOMA-IR) and post-stroke outcome (functional outcome and recurrent stroke). The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines will be used. The primary outcome will be post-stroke functional outcome (Modified Rankin Scale), and the secondary outcome will be recurrent ischaemic stroke. Comparison of outcome will be made between highest and lowest HOMA-IR range (as defined in each article included in this systematic review). Risk of bias will be assessed qualitatively. Meta-analysis will be performed if sufficient homogeneity exists between studies. Heterogeneity of outcomes will be assessed byI².

Ethics and dissemination

No human or animal subjects or samples were/will be used. The results will be published in a peer-reviewed journal, and will be disseminated at local and international neurology conferences.

PROSPERO registration number

CRD42020173608.
Clinical and cost-effectiveness of bracing in symptomatic knee osteoarthritis management: protocol for a multicentre, primary care, randomised, parallel-group, superiority trial
Authors: Holden Melanie A , Callaghan Michael , Felson David , Birrell Fraser , Nicholls Elaine , Jowett Sue , Kigozi J , McBeth John , Borrelli Belinda , Jinks Clare , Foster Nadine E , Dziedzic Krysia , Mallen Christian , Ingram Carol , Sutton Alan , Lawton Sarah , Halliday Nicola , Hartshorne Liz , Williams Helen , Browell Rachel , Hudson Hannah , Marshall Michelle , Sowden Gail , Herron Dan , Asamane Evans , Peat George
Published: March 2021

Background

Brace effectiveness for knee osteoarthritis (OA) remains unclear and international guidelines offer conflicting recommendations. Our trial will determine the clinical and cost-effectiveness of adding knee bracing (matched to patients’ clinical and radiographic presentation and with adherence support) to a package of advice, written information and exercise instruction delivered by physiotherapists.

Methods and analysis

A multicentre, pragmatic, two-parallel group, single-blind, superiority, randomised controlled trial with internal pilot and nested qualitative study. 434 eligible participants with symptomatic knee OA identified from general practice, physiotherapy referrals and self-referral will be randomised 1:1 to advice, written information and exercise instruction and knee brace versus advice, written information and exercise instruction alone. The primary analysis will be intention-to-treat comparing treatment arms on the primary outcome (Knee Osteoarthritis Outcomes Score (KOOS)-5) (composite knee score) at the primary endpoint (6 months) adjusted for prespecified covariates. Secondary analysis of KOOS subscales (pain, other symptoms, activities of daily living, function in sport and recreation, knee-related quality of life), self-reported pain, instability (buckling), treatment response, physical activity, social participation, self-efficacy and treatment acceptability will occur at 3, 6, and 12 months postrandomisation. Analysis of covariance and logistic regression will model continuous and dichotomous outcomes, respectively. Treatment effect estimates will be presented as mean differences or ORs with 95% CIs. Economic evaluation will estimate cost-effectiveness. Semistructured interviews to explore acceptability and experiences of trial interventions will be conducted with participants and physiotherapists delivering interventions.

Ethics and dissemination

North West Preston Research Ethics Committee, the Health Research Authority and Health and Care Research in Wales approved the study (REC Reference: 19/NW/0183; IRAS Reference: 247370). This protocol has been coproduced with stakeholders including patients and public. Findings will be disseminated to patients and a range of stakeholders.

Trial registration number

ISRCTN28555470.
CHILD-BRIGHT READYorNot Brain-Based Disabilities Trial: protocol of a randomised controlled trial (RCT) investigating the effectiveness of a patient-facing e-health intervention designed to enhance healthcare transition readiness in youth
Authors: Gorter Jan Willem , Amaria Khush , Kovacs Adrienne , Rozenblum Ronen , Thabane Lehana , Galuppi Barbara , Nguyen Linda , Strohm Sonya , Mahlberg Nadilein , Via-Dufresne Ley Alicia , Marelli Ariane
Published: March 2021

Introduction

Youth with brain-based disabilities (BBDs), as well as their parents/caregivers, often feel ill-prepared for the transfer from paediatric to adult healthcare services. To address this pressing issue, we developed the MyREADY TransitionTMBBD App, a patient-facing e-health intervention. The primary aim of this randomised controlled trial (RCT) was to determine whether the App will result in greater transition readiness compared with usual care for youth with BBD. Secondary aims included exploring the contextual experiences of youth using the App, as well as the interactive processes of youth, their parents/caregivers and healthcare providers around use of the intervention.

Methods and analysis

We aimed to randomise 264 youth with BBD between 15 and 17 years of age, to receive existing services/usual care (control group) or to receive usual care along with the App (intervention group). Our recruitment strategy includes remote and virtual options in response to the current requirements for physical distancing due to the COVID-19 pandemic. We will use an embedded experimental model design which involves embedding a qualitative study within a RCT. The Transition Readiness Assessment Questionnaire will be administered as the primary outcome measure. Analysis of covariance will be used to compare change in the two groups on the primary outcome measure; analysis will be intention-to-treat. Interviews will be conducted with subsets of youth in the intervention group, as well as parents/caregivers and healthcare providers.

Ethics and dissemination

The study has been approved by the research ethics board of each participating site in four different regions in Canada. We will leverage our patient and family partnerships to find novel dissemination strategies. Study findings will be shared with the academic and stakeholder community, including dissemination of teaching and training tools through patient associations, and patient and family advocacy groups.

Trial registration number

NCT03852550.
Development of a CD8 co-receptor independent T-cell receptor specific for tumor-associated antigen MAGE-A4 for next generation T-cell-based immunotherapy
Authors: Davari Kathrin , Holland Tristan , Prassmayer Laura , Longinotti Giulia , Ganley Kenneth P , Pechilis Lisa J , Diaconu Iulia , Nambiar Prashant R , Magee Michael S , Schendel Dolores J , Sommermeyer Daniel , Ellinger Christian
Published: March 2021

Background

The cancer-testis antigen MAGE-A4 is an attractive target for T-cell-based immunotherapy, especially for indications with unmet clinical need like non-small cell lung or triple-negative breast cancer.

Methods

An unbiased CD137-based sorting approach was first used to identify an immunogenic MAGE-A4-derived epitope (GVYDGREHTV) that was properly processed and presented on human leukocyte antigen (HLA)-A2 molecules encoded by the HLA-A*02:01 allele. To isolate high-avidity T cells via subsequent multimer sorting, an in vitro priming approach using HLA-A2-negative donors was conducted to bypass central tolerance to this self-antigen. Pre-clinical parameters of safety and activity were assessed in a comprehensive set of in vitro and in vivo studies.

Results

A MAGE-A4-reactive, HLA-A2-restricted T-cell receptor (TCR) was isolated from primed T cells of an HLA-A2-negative donor. The respective TCR-T-cell (TCR-T) product bbT485 was demonstrated pre-clinically to have a favorable safety profile and superior in vivo potency compared with TCR-Ts expressing a TCR derived from a tolerized T-cell repertoire to self-antigens. This natural high-avidity TCR was found to be CD8 co-receptor independent, allowing effector functions to be elicited in transgenic CD4+T helper cells. These CD4+TCR-Ts supported an anti-tumor response by direct killing of MAGE-A4-positive tumor cells and upregulated hallmarks associated with helper function, such as CD154 expression and release of key cytokines on tumor-specific stimulation.

Conclusion

The extensive pre-clinical assessment of safety and in vivo potency of bbT485 provide the basis for its use in TCR-T immunotherapy studies. The ability of this non-mutated high-avidity, co-receptor-independent TCR to activate CD8+and CD4+T cells could potentially provide enhanced cellular responses in the clinical setting through the induction of functionally diverse T-cell subsets that goes beyond what is currently tested in the clinic.
Propulsion performance and wake transitions of a customized heaving airfoil
Authors: Vineeth V. K. , Patel Devendra Kumar
Published: March 2021

The application of a flapping wing mechanism offers a vast range of development possibilities for unmanned aerial vehicles (UAVs) and autonomous underwater vehicles (AUVs). The influence of wake transitions on flapping wing mechanism’s capabilities is not fully understood particularly at low Reynolds numbers. The numerical investigation of a symmetric airfoil performing sinusoidal heaving oscillations is performed to explore the wake transitions. The influence of heaving parameters on wake transitions when exposed to a constant velocity flow is investigated. The existence of reverse von Karman vortex street, deflected wake and chaotic wake is observed. The wake deflection is found to switch its direction before transforming into a chaotic wake. The coherent structures and its evolution with the flow are presented using proper orthogonal decomposition (POD). The underlying structures and their interactions for different wake situations are identified. Correlations for the nondimensional maximum velocity in the wake in terms of frequency and amplitude is proposed. The wake dynamics is found to depend significantly on the leading edge vortices. The time-varying velocity fluctuations in the flow field are presented and discussed in detail. The velocity fluctuation contours are used to identify the regions of momentum transfer. The transient nature of the flow field is studied using the phase plot. A transition route from the periodic to chaotic regime though a quasi-periodic regime is established using time series analysis. The wake transitions are observed to be more sensitive towards heaving frequency than the heaving amplitude.
Quantum motion, coherent states and geometric phase of a generalized damped pendulum
Authors: Pedrosa I. A.
Published: March 2021

In this work, we analyze the quantum dynamics of a generalized pendulum with a time-varying mass increasing exponentially and constant gravitation. By using Lewis–Riesenfeld invariant approach and Fock states, we solve the time-dependent Schrödinger equation for this system and write its solutions in terms of solutions of the Milne–Pinney equation. We also construct coherent states for the quantized pendulum and use both Fock and coherent states to investigate some important physical proprieties of the quantized pendulum such as eigenvalues of the angular displacement and momentum, their quantum variances as well as the respective uncertainty principle. Finally, we derive the geometric, dynamical and Berry phases for the time-dependent generalized pendulum.
Blockchain Vulnerabilities in Practice
Authors: Amiet Nils
Published: March 2021

Blockchains are not invulnerable. There are known vulnerabilities in various blockchain ecosystem components. This field note describes some vulnerabilities observed in smart contracts and node software, their exploitation, and how to avoid them, with a focus on the Ethereum ecosystem.
On the Sensitivity Complexity of
k
-Uniform Hypergraph Properties
Authors: Li Qian , Sun Xiaoming
Published: March 2021

In this article, we investigate the sensitivity complexity of hypergraph properties. We present a
k
-uniform hypergraph property with sensitivity complexity
O
(
n
(⌈
k/3
⌉) for any
k
≥
3
, where
n
is the number of vertices. Moreover, we can do better when
k
≡
1
(mod 3) by presenting a
k
-uniform hypergraph property with sensitivity
O
(n⌈
k/3
⌉-1/2). This result disproves a conjecture of Babai, which conjectures that the sensitivity complexity of
k
-uniform hypergraph properties is at least Ω (
n

k/2

). We also investigate the sensitivity complexity of other symmetric functions and show that for many classes of transitive Boolean functions the minimum achievable sensitivity complexity can be
O
(N
1/3
), where
N
is the number of variables.
Influenza Virus RNA-Dependent RNA Polymerase and the Host Transcriptional Apparatus
Authors: Krischuns Tim , Lukarska Maria , Naffakh Nadia , Cusack Stephen
Published: March 2021

Influenza virus RNA-dependent RNA polymerase (FluPol) transcribes the viral RNA genome in the infected cell nucleus. In the 1970s, researchers showed that viral transcription depends on host RNA polymerase II (RNAP II) activity and subsequently that FluPol snatches capped oligomers from nascent RNAP II transcripts to prime its own transcription. Exactly how this occurs remains elusive. Here, we review recent advances in the mechanistic understanding of FluPol transcription and early events in RNAP II transcription that are relevant to cap-snatching. We describe the known direct interactions between FluPol and the RNAP II C-terminal domain and summarize the transcription-related host factors that have been found to interact with FluPol. We also discuss open questions regarding how FluPol may be targeted to actively transcribing RNAP II and the exact context and timing of cap-snatching, which is presumed to occur after cap completion but before the cap is sequestered by the nuclear cap-binding complex.
Characterization of Nanoporous Materials
Authors: Thommes M. , Schlumberger C.
Published: March 2021

Detailed analysis of textural properties, e.g., pore size and connectivity, of nanoporous materials is essential to identify correlations of these properties with the performance of gas storage, separation, and catalysis processes. The advances in developing nanoporous materials with uniform, tailor-made pore structures, including the introduction of hierarchical pore systems, offer huge potential for these applications. Within this context, major progress has been made in understanding the adsorption and phase behavior of confined fluids and consequently in physisorption characterization. This enables reliable pore size, volume, and network connectivity analysis using advanced, high-resolution experimental protocols coupled with advanced methods based on statistical mechanics, such as methods based on density functional theory and molecular simulation. If macro-pores are present, a combination of adsorption and mercury porosimetry can be useful. Hence, some important recent advances in understanding the mercury intrusion/extrusion mechanism are discussed. Additionally, some promising complementary techniques for characterization of porous materials immersed in a liquid phase are introduced.
Women's Health in the Era of Mass Incarceration
Authors: Wildeman Christopher , Lee Hedwig
Published: March 2021

Dramatic increases in criminal justice contact in the United States have rendered prison and jail incarceration common for US men and their loved ones, with possible implications for women's health. This review provides the most expansive critical discussion of research on family member incarceration and women's health in five stages. First, we provide new estimates showing how common family member incarceration is for US women by race/ethnicity and level of education. Second, we discuss the precursors to family member incarceration. Third, we discuss mechanisms through which family member incarceration may have no effect on women's health, a positive effect on women's health, and a negative effect on women's health. Fourth, we review existing research on how family member incarceration is associated with women's health. Fifth, we continue our discussion of the limitations of existing research and provide some recommendations for future research.
Carvedilol and exercise combination therapy improves systolic but not diastolic function and reduces plasma osteopontin in Col4a3−/− Alport mice
Authors: Dunkley Julian C. , Irion Camila I. , Yousefi Keyvan , Shehadeh Serene A. , Lambert Guerline , John-Williams Krista , Webster Keith A. , Goldberger Jeffrey J. , Shehadeh Lina A.
Published: March 2021

In an Alport mouse model of heart failure with preserved ejection fraction (HFpEF), exercise and carvedilol synergistically improved systolic function without affecting diastole. Carvedilol alone or in combination with exercise also improved kidney function. Molecular analyses indicate that the observed improvements in cardiorenal functions were mediated at least in part by effects on serum osteopontin and related inflammatory cytokine cascades. The work presents new potential therapeutic targets and approaches for HFpEF.