bluuebunny/crossref_metadata_2025 huggingface dataset:
High Precision Tracking of Roll-to-Roll Manufacturing Processes
Authors: Chen Zhiyi , Jiang Baoyang , Ni Jun
Published: January 2021

Methods for controlling tension and velocity in Roll-to-Roll (R2R) processes have been widely studied in literature. Such methods are very effective under normal operating conditions, but the performance will degrade when control efforts saturate the physical capability of systems. This paper presents a constrained linear-quadratic model predictive control (LQ-MPC) scheme for the purpose of reference tracking. Firstly, a discrete-time linearized model for a R2R process is derived based on the governing equations from prior studies. The model is augmented by integrating an incremental behavior into it. Then a model predictive controller is specifically designed to reach zero-offset tracking of tension and velocity references, while the encountered process constraints are enforced at the same time. The constrained control problem is reduced into a quadratic programming problem and solved by using gradient projection method. It is proved that the proposed controller can guarantee local closed-loop stability where process constraints are inactive. Simulation of a five-roller R2R system is conducted to compare the performance of a proposed controller and a typical decentralized PI controller. Results show that the proposed controller achieves better performance in terms of quick response to changing of set points and capability of decoupling the subsystems. It also demonstrates good robustness when reasonable parametric uncertainties are introduced in the system.
Multi-Functional 3D Curvilinear Self-Folding of Glassy Polymers
Authors: Lee Jae Gyeong , Won Sukyoung , Park Jeong Eun , Wie Jeong Jae
Published: January 2021

The selective light absorption of pre-stretched thermoplastic polymeric films enables wireless photothermal shape morphing from two-dimensional Euclidean geometry of films to three-dimensional (3D) curvilinear architectures. For a facile origami-inspired programming of 3D folding, black inks are printed on glassy polymers that are used as hinges to generate light-absorption patterns. However, the deformation of unpatterned areas and/or stress convolution of patterned areas hinder the creation of accurate curvilinear structures. In addition, black inks remain in the film, prohibiting the construction of transparent 3D architectures.

In this study, we demonstrate the facile preparation of transparent 3D curvilinear structures with the selection of the curvature sign and chirality via the selective light absorption of detachable tapes. The sequential removal of adhesive patterns allowed sequential folding and the control of strain responsivity in a single transparent architecture. The introduction of multiple heterogeneous non-responsive materials increased the complexity of strain engineering and functionality. External stimuli responsive kirigami-based bridge triggered the multi-material frame to build the Gaussian curvature. Conductive material casted on the film in a pattern retained the conductivity, despite local deformation. This type of tape patterning system, adopting various materials, can achieve multifunction including transparency and conductivity.
Computer-Aided Design and Additive Manufacturing of Custom Silicone Prosthetic Finger
Authors: Chen Lei , Plott Jeffery , Hildner Matthew , Mei Lillian , Shih Albert , Wensman Jeffery , Kelly Brian
Published: January 2021

Finger and partial finger amputations are one of the most frequently encountered forms of partial hand loss. Most of these amputees can benefit from prosthetic fingers, which should be both functional and aesthetic, to enhance rehabilitation by permitting a more normal professional and social life. Custom prosthetic fingers perform better than off-the-shelf ones due to better fit, comfort, and match to the patients’ physical characteristics. The conventional fabrication process for custom prosthetic fingers uses multiple impressions and molds combined with silicone injection molding to create the final shape. This process has not seen significant changes for decades and comes with a high cost and long wait time, stopping the prosthesis from benefitting the patient in a cost-effective, timely, and lifelike functional way. This study developed a new manufacturing approach for custom prosthetic fingers based on an additive manufactured custom thin-wall mold. The approach was based on optical 3D scanning of the amputees’ fingers and computer-aided design of custom finger prosthetic geometry and the corresponding thin-wall mold. Preliminary clinical study on an amputee patient shows the feasibility of this new custom molding approach and future work will clinically evaluate the performance of the prosthetic fingers created via the computer-aided design and additive manufacturing approach.
Mechanism of Debris Ejection in Atomized Dielectric-Based Electrical Discharge Machining
Authors: Tanveer Asif , Kapoor S. G.
Published: January 2021

Atomized dielectric-based electrical discharge machining (EDM) is a novel machining process in which a thin film of moving fluid resulting from a spray acts as the dielectric in the interelectrode gap. In addition to acting as the dielectric, the thin film also helps to flush the debris away from EDM crater features and requires very small quantity of fluid in doing so. This results in significantly less dielectric consumption compared to the conventional EDM while yielding higher material removal rates and better debris flushing. This paper presents a model-based investigation of the mechanism of debris flushing in atomized dielectric-based EDM. A material removal model is used to predict the amount of debris removed in terms of number of particles ejected during a single EDM discharge. The dielectric material properties and atomization spray parameters are varied in order to produce different ejection conditions and crater geometries, respectively. Particles are ejected from the bottom of crater geometries. The model captures the asymmetry in particle motion caused by the dielectric film flow and predicts the percentage of debris flushed away from the crater center. It is also observed that crater shape and size of debris particles play a role in the amount of debris flushed away.
Fabrication of Electrically Conductive Patterns on ABS Polymer Using Low-Pressure Cold Spray and Electroless Plating
Authors: Akin Semih , Jun Martin Byung-Guk , Tsai Jung-Ting , Park MinSoo , Jeong Young Hun
Published: January 2021

Previous studies have shown that metallic coatings can be successfully cold sprayed onto several polymer substrates. The electrical performance of the cold-sprayed polymers, however, is not generally sufficient enough to utilize them as an electronic device. In this paper, an environment-friendly metallization technique has been proposed to fabricate conductive metal patterns onto polymer substrates combining cold spray deposition and electroless plating to address that challenge. Copper feedstock powder was cold sprayed onto the surface of the acrylonitrile-butadiene-styrene (ABS) parts. The as-cold sprayed powders then served as the activating agent for selective electroless copper plating (ECP) to modify the surface of the polymers to be electrically conductive. A series of characterizations are conducted to investigate the morphology, analyze the surface chemistry, and evaluate the electrical performance and adhesion performance of the fabricated coatings. After 6 hours of ECP, the sheet resistance and resistivity of copper patterns on the ABS parts were measured as 2.854 mΩ/sq and 6.699 × 10−7 Ωm respectively. Moreover, simple electrical circuits were demonstrated for the metallized ABS parts through the described method. The results show that low-pressure cold spray (LPCS) and ECP processes could be combined to fabricate electrically conductive patterns on ABS polymer surfaces in an environmental-friendly way.
Modeling of Dry-EDM Plasma Discharge
Authors: Mujumdar Soham
Published: January 2021

There is a growing interest in developing the dry EDM process as a sustainable alternative to the conventional liquid dielectric-based EDM process. It is shown that the dry EDM process possesses advantages over the conventional process in terms of thermal damage, recast layer, and tool wear. However, there is a need to increase the productivity of the dry EDM process for its successful adaptation in the industry. This paper presents a model of dry EDM plasma discharge with air as the dielectric medium. The model uses global modeling (‘0D’) approach in which equations of mass balance, energy balance, and plasma expansion are solved simultaneously to obtain a time-dependent description of the plasma in terms of its composition, temperature, diameter, and heat flux to electrodes. The model includes reaction kinetics involving 622 reactions and 55 species to determine the air plasma composition. A single discharge dry EDM operation is successfully simulated using the model, and the effect of discharge current on the plasma is studied. An increase in the discharge current increases the electron density, temperature, and diameter of the plasma linearly, while heat flux to the workpiece increases exponentially. Overall, the model provides an essential tool to study the dry EDM process mechanisms at a fundamental level and devise methods for process improvements.
Polymeric Reaction Molding of Biocompatible Materials: Lessons Learned
Authors: Kosnik Sabrina , Piovesan Davide
Published: January 2021

Polymeric materials are often used as structural binders for biomedical applications. The mechanical properties of the material strongly depend on the fabrication process. To this end, we illustrate a set of casting methods for the production of samples to be tested via destructive methods. The curing process of the artifact was controlled during fabrication, and the molds were also made of polymeric materials. The fabrication of molds is illustrated where particular emphasis is posed on the manufacturing and testing of silicone molds using off-the-shelf material.

Cyanoacrylate (CA), Epoxy resin (EP) and Methacrylate ester monomers (MEMs) artifacts have been fabricated using said molds. Of the aforementioned resins, MEMs are a class of thermosetting biocompatible polymers in which fabrication is especially problematic because of the very narrow temperature window at which the monomers polymerize. This research analyzes the casting process of curable materials highlighting the setbacks of using plastic-based molds. Among the cast based manufacturing techniques, specific focus was given to the case where MEMs is made to polymerize in a silicone mold controlling the temperature of the environment. The thermal properties that the silicone-based molds require for the appropriate curing of the polymer are analyzed. It was found that due to the very high heat capacity of silicone, the regulation of the temperature within the mold is difficult often exciding the boiling point of the casted resin.
Study of Effect of Repetition Rate on Laser Shock Peening Using Finite Element Modeling
Authors: Kosaraju Sai , Zhao Xin
Published: January 2021

A two-dimensional finite element model is developed to simulate the interaction between metal samples and laser-induced shock waves. Multiple laser impacts are applied at each location to increase plastically affected depth and compressive stress. The in-depth and surface residual stress profiles are analyzed at various repetition rates and spot sizes. It is found that the residual stress is not sensitive to repetition rate until it reaches a very high level. At extremely high repetition rate (100 MHz), the delay between two shock waves is even shorter than their duration, and there will be shock wave superposition. It is revealed that the interaction of metal with shock wave is significantly different, leading to a different residual stress profile. Stronger residual stress with deeper distribution will be obtained comparing with lower repetition rate cases. The effect of repetition rate at different spot sizes is also studied. It is found that with larger laser spot, the peak compressive residual stress decreases but the distribution is deeper at extremely high repetition rates.
A Micro Arc Oxidation Composite Coating Developed on a Biocompatible Magnesium Alloy for Bone Implant Applications
Authors: Ibrahim Hamdy
Published: January 2021

The biocompatibility, mechanical properties and biodegradable nature of Mg alloys have made them attractive for biomedical applications, especially as bone implants. However, one of the main problems that limit the use of Mg alloy for several biomedical applications is their fast corrosion rates inside the body. Coating Mg-based implants is one of the most extensively studied approaches to address the fast corrosion rates of Mg alloys in the physiological environment. Micro arc oxidation (MAO) coating process has shown very promising results towards reducing the corrosion rates of Mg alloys due to the formation of a protective dense, well-adhered and wear-resistant oxide layer on the surface of the Mg alloy. In this study, the feasibility of coating an Mg-Zn-Ca-based alloy with a composite coating made using a micro-arc oxidation coating process and an immersion (dipping process) was investigated. The corrosion properties and surface characteristics of the coated alloy samples are assessed. The created protective composite coating is used to slow the corrosion rates of an Mg-Zn-Ca-based alloy. The developed composite coating resulted in a significant reduction in the corrosion rates. The results of this study show that it is possible to achieve more controlled corrosion rates of Mg-based implants towards patient-specific bone implant applications.
Incorporating Tool Contact Considerations in Tool-Path Planning for Robotic Operations
Authors: Bhatt Prahar M. , Gong Cheng , Kabir Ariyan M. , Malhan Rishi K. , Shah Brual C. , Gupta Satyandra K.
Published: January 2021

Tool-Path planning is the foundation for automating many manufacturing processes. Robotic manipulators are increasingly being considered to automate tasks that require complex tool motions. Robotic manipulators provide extra degrees of freedom and are more flexible than traditional automation technologies. However, a tool-path needs to be planned and given to the manipulator trajectory generator as input. The traditional tool-path planning considers the tool to have one contact point, known as the Tool Center Point (TCP). This underutilizes the available flexibility of the manipulator. To make use of the manipulator’s flexibility, multiple contact points or multiple TCPs can be considered. These tool contact considerations make the tool path planning problem complex and computationally challenging. In this paper, we present a novel tool path planning algorithm. Our algorithm incorporates the multiple tool contact points consideration during tool-path planning in an efficient manner to generate a high-quality tool-path in a reasonable amount of run time. We evaluated our algorithm on four different test cases. The test cases include the parts with complex geometry and tools which can have surface area for establishing contacts with the part. In these test cases, a traditional single contact tool-path will not work due to geometric constraints, and multiple tool contacts make the problem challenging. Our algorithm was able to generate tool-paths for these four test cases successfully.
Experimental and Simulation Study of Incremental Forming for Titanium Grade 2 Sheet
Authors: Mahajan Peeyush , Pal Mainak , Kumar Rakesh , Agrawal Anupam
Published: January 2021

Incremental sheet forming (ISF) process has gained massive popularity due to its die-less nature. The process shows greater flexibility in making customized sheet metal parts economically and more effectively as compared to the traditional forming processes. This paper mainly focuses on investigating the behavior of commercially pure (CP) titanium grade 2 sheet. Single point incremental forming process has been used to deform the sheet. Workpiece geometry has been chosen as conical rectangular shape, using the unidirectional spiral tool path profile. The deformation of the titanium sheet has been performed with and without the use of lubricating fluid. The finite element analysis (FEA) for the von Mises stress and sheet thickness variation has been carried out on ABAQUS® simulation software. Also, the stretching of the deformed sheet has been examined along the side wall and corner of the deformed surface. The ISF has limitation with respect to the geometrical accuracy and surface finish quality of the formed part. To study the surface quality of the deformed surface, scanning electron microscopy (SEM) has been utilized. Stress triaxiality is another important parameter to investigate the crack initiation and fracture during forming, it has been predicted using Finite element analysis.
Experimental and Numerical Investigation on Micro Friction Stir Welding of Dissimilar Metal Joints
Authors: Kishore Hreetabh , Banerjee Mainak , Rai Saruabh , Kumar Rakesh , Agrawal Anupam
Published: January 2021

Micro Friction Stir welding (μFSW) has found its broader application in the area of packaging of MEMS devices, biomedical components, and joining of micro-mechanical assemblies. This study focuses on the effect of process parameters over the joint strength while joining Al6061-T6 and pure copper sheets of 0.3 mm thickness. Also, a coupled Eulerian-Lagrangian (CEL) numerical model has been developed in the finite element suite of ABAQUS®. The boundary conditions used in the numerical simulation are kept almost similar to the experimental conditions to record thermal results. Moreover, an analytical approach for finding microhardness of welded joints using the Hall-Petch equation is also presented. The process parameters like rotational tool speed and welding traverse speed were found to be dominating in order to get better joint strength. The essential μFSW process parameters combination suggested that 1100rpm rotational speed, 20mm/min. traverse speed and 0.15mm pin depth (tool) result in superior flexural, thermal, and morphological properties of the joint. A good agreement between the experimental and simulation results was found with a maximum of 8% error in the predicted temperature values. The anticipated joint strength and surface characterization of the samples revealed a complex flow and homogeneous mixture at the pin-sheet interaction zone with higher micro-hardness values.
Experimental Analysis of Material Squeeze Factor in Two-Point Incremental Forming of AL 7075-O
Authors: Bansal Ankush , Cheng Randy , Banu Mihaela , Taub Alan , Ni Jun
Published: January 2021

In recent years, incremental sheet forming (ISF) has shown significant potential for economically fabricating sheet metal products required in low volume. Despite its advantages of reduced forming forces and higher material formability, manufacturing complex shapes with acceptable geometric accuracy is still a challenging task. Two-point ISF (TPIF) is one variant that uses a support die to a fabricate part with intricate features. In this study, effects of material squeeze factor in the TPIF process is investigated on part accuracy and formability. Material squeeze factor is defined as the amount of sheet thickness squeezed between the forming tool and support die. It is integrated as one of the processing parameters for generating a pre-defined toolpath of the forming process. However, the effective material squeeze (SFe) obtained in experiments is either zero or significantly lower than the squeeze factor programmed (SFp) in the toolpath due to machine and tool compliance. SFp values are heuristically chosen in literature studies to maintain steady contact between the sheet and die surfaces and avoid forming through degenerated SPIF rather than the “true” TPIF process. For a 67° cone, the part kept losing contact with the die surface below SFp = 30% whereas uniform contact between sheet and die surface is achieved for SFp = 40%. Also, the geometric deviation is significantly reduced from 0.61 mm to 0.39 mm along the wall region with the higher squeeze factor. Similar results are obtained for a benchmark heart shape part.
Prediction and Optimization of Surface Roughness and Cutting Force in Turning of UHMWPE by Using Taguchi Method, Response Surface Methodology and Neural Networks
Authors: Susac Florin , Stan Felicia , Fetecau Catalin , Besliu Irina
Published: January 2021

This paper reports on the optimization and prediction of the surface roughness and cutting force in the turning of UHMWPE (ultra-high molecular weight polyethylene). To identify the controllable factors in turning UHMWPE, that can minimize the variation of the surface roughness and cutting force, a three-level full factorial design, considering the feed rate, depth of cut, and cutting speed was conducted. The Taguchi method and Response Surface Methodology (RSM) were employed for establishing a relationship between the input and output parameters, whereas the significance of each parameter was analyzed using the Analysis of Variance (ANOVA). A four-layer Artificial Neural Network (ANN) model with a back-propagation algorithm and a sigmoidal transfer function and two hidden layers was developed for simultaneous prediction of surface roughness and cutting force. The results of the ANOVA of the surface roughness indicated that the feed rate is the dominant parameter followed by cutting speed and depth of cut, whereas the main cutting force is significantly affected by all three cutting parameters. The advantage of the ANN over the RSM is that the former can be used to simultaneously predict the surface roughness and cutting force, providing the most accurate estimates of the surface roughness and cutting force.
Enhancement by postfiltering for speech and audio coding in ad hoc sensor networks
Authors: Das Sneha , Bäckström Tom
Published: January 2021

Enhancement algorithms for wireless acoustic sensor networks (WASNs) are indispensable with the increasing availability and usage of connected devices with microphones. Conventional spatial filtering approaches for enhancement in WASNs approximate quantization noise with an additive Gaussian distribution, which limits performance due to the non-linear nature of quantization noise at lower bitrates. This work proposes a postfilter for enhancement based on Bayesian statistics to obtain a multidevice signal estimate, which explicitly models the quantization noise. The experiments using perceptual signal-to-noise ratio, perceptual evaluation of speech quality, and MUSHRA (multistimulus with hidden reference and anchors) scores demonstrate that the proposed postfilter can be used to enhance signal quality in ad hoc sensor networks.
Reading Between the Lines: Gender Stereotypes in Children’s Sport-Based Books
Authors: Coletti Jennifer T. , Allan Veronica , Martin Luc J.
Published: January 2021

A child’s first contact with media and culture typically comes from books they are exposed to in the home and at school. The narratives presented contribute to the early reinforcement of gender roles and norms and can greatly influence the way that young girls perceive and experience sport. The purpose of this study was to explore the narratives within sport-based books geared toward a young female audience to determine the extent to which they promote the engagement of girls in sport. A pragmatic literature search was conducted to obtain books that met our inclusion criteria. Books (n = 28) were analyzed based on the age of their intended audience (aged 3–5, 6–8, and 9–12 years) using thematic narrative analysis. Although the authors promoted the engagement of girls in sport, underlying gender stereotypes were nevertheless salient. Across the books, themes involved the emphasis of “feminine” sports as a context for diversity and learning, the need to understand development as a process, the importance of relationships, and implications pertaining to perceptions of capability as female athletes. Most importantly, the application of a critical feminist lens enabled us to identify an underlying theme—the reinforcement of gender stereotypes—that permeated the storylines and served to undermine the potential adaptive messaging intended by authors. These findings suggest the need for greater attention toward the complexity of female sport and a cultural shift in thinking toward gender equity rather than simply increasing sport access for female participants.
Optimized Genetic Tools Allow the Biosynthesis of Glycocin F and Analogues Designed To Test the Roles ofgccCluster Genes in Bacteriocin Production
Authors: Drummond Brittany J. , Loo Trevor S. , Patchett Mark L. , Norris Gillian E.
Published: January 2021

The entire 7-gene cluster for the diglycosylated bacteriocin glycocin F (GccF), including the natural promoters responsible forgccgene expression, has been ligated into theEscherichia coli-lactic acid bacteria (LAB) shuttle vector pRV610 to produce the easily modifiable 11.2-kbp plasmid pRV610gccfor the efficient production of glycocin F analogues. In contrast to the refactoring approach, chemical synthesis, or chemoenzymatic synthesis, all of which have been successfully used to probe glycocin structure and function, this plasmid can also be used to probein vivothe evolutionary constraints on glycocin scaffolds and their processing by the maturation pathway machinery, thus increasing understanding of the enzymes involved, the order in which they act, and how they are regulated.
Provenance of the El Salto Formation (early Oligocene to early Miocene), southern part of La Reforma caldera, Baja California Sur, Mexico
Authors: Ocampo-Díaz* Yam Zul Ernesto , Torres-Sánchez Sonia Alejandra , Augustsson Carita , Macías José Luis , Sosa-Ceballos Giovanni , Cisneros-Máximo Guillermo , García-Sánchez Laura , Osorio-Ocampo Susana , Avellán Denis-Ramón , Omma Jenny , Ortega-Obregón Carlos , Solari Luigi A. , González-Barba Gerardo
Published: January 2021

This study documented the stratigraphy and provenance of the El Salto Formation in southern Baja California, Mexico, which represents an early Oligocene–early Miocene forearc basin developed during the subduction of the Farallon plate, in the immediate vicinity of La Reforma caldera, central part of Baja California Sur, Mexico. In the study area, El Salto Formation consists of three stratigraphic members. The lower member is characterized by intercalations of sandstones and conglomeratic sandstones that exhibit eolian large-scale cross-stratification. U-Pb detrital zircon geochronology implies maximum depositional ages of ca. 33–31 Ma. The middle member is characterized by successions of conglomeratic sandstones and sandstones with eolian and tidal large-scale cross-stratification. The member also contains ignimbrites, tuff, and andesite deposits, and its maximum deposition age is ca. 30–28 Ma. The ignimbrite collected at the top of this member has a crystallization age of ca. 28 Ma. The upper member is characterized by conglomerates, sandstones, and shales, with maximum depositional ages ranging from 28 to 23 Ma.

Petrographically, sandstones of the El Salto Formation are composed of three petrofacies. Petrofacies A is rich in quartz with a greater contribution of felsitic volcanic lithic grains (Q55F21L24; recycled orogenic provenance). Petrofacies B is rich in lathwork and microlitic volcanic lithic fragments with minor contributions of quartz and feldspar (Q39F12L42; recycled orogenic and dissected arc), while petrofacies C is rich in microlitic volcanic fragments and lathwork with subordinate quartz and feldspar (Q21F25L54; transitional arc setting). U-Pb ages of >600 zircon grains from nine samples contained three populations: (1) 35–23 Ma (early and late Oligocene; 22% of all grains), (2) 120–60 Ma (Cretaceous; 32%), and (3) 170–140 Ma (Middle Jurassic–Early Cretaceous; 46%). Detrital zircon grains with ages of ca. 40–20 Ma showed rare earth element patterns and trace-element ratios similar to those formed in a continental arc. Volcanic rocks sampled in this work contained chemical signatures, including Nb, Pb, and Rb anomalies, that indicate their magmas were created in a subduction zone. In addition, high concentrations of heavy rare earth elements (La/Yb = 14–19) suggest that the magmas contain a component of partial melting of the mantle wedge and crust, probably as a result of asthenospheric upwelling. These features support a model in which the El Salto Formation was developed due to the rollback of the Farallon plate in the period 50–25 Ma.
Supplemental Material: Wide-blocky veins explained by dependency of crystal growth rate on fracture surface type: Insights from phase-field modeling
Authors: Spruzeniece Liene , al. et
Published: January 2021

Analytical methods, description of numerical approach, image library of results, and video files of the 2-D and 3-D simulations.
Supplemental Material: Inherited lithospheric structures control arc-continent collisional heterogeneity
Authors: Miller Meghan , al. et
Published: January 2021

Description of the methodology.
Intraperitoneal insulin administration in pigs: effect on circulating insulin and glucose levels
Authors: Dirnena-Fusini Ilze , Åm Marte Kierulf , Fougner Anders Lyngvi , Carlsen Sven Magnus , Christiansen Sverre Christian
Published: January 2021

Introduction

The effect of intraperitoneal insulin infusion has limited evidence in the literature. Therefore, the aim of the study was to investigate the pharmacokinetics and pharmacodynamics of different intraperitoneal insulin boluses. There is a lack of studies comparing the insulin appearance in the systemic circulation after intraperitoneal compared with subcutaneous insulin delivery. Thus, we also aimed for a comparison with the subcutaneous route.

Research design and methods

Eight anesthetized, non-diabetic pigs were given three different intraperitoneal insulin boluses (2, 5 and 10 U). The order of boluses for the last six pigs was randomized. Endogenous insulin and glucagon release were suppressed by repeated somatostatin analog injections. The first pig was used to identify the infusion rate of glucose to maintain stable glucose values throughout the experiment. The estimated difference between insulin boluses was compared using two-way analysis of variance (GraphPad Prism V.8).

In addition, a trial of three pigs which received subcutaneous insulin boluses was included for comparison with intraperitoneal insulin boluses.

Results

Decreased mean blood glucose levels were observed after 5 and 10 U intraperitoneal insulin boluses compared with the 2 U boluses. No changes in circulating insulin levels were observed after the 2 and 5 U intraperitoneal boluses, while increased circulating insulin levels were observed after the 10 U intraperitoneal boluses. Subcutaneously injected insulin resulted in higher values of circulating insulin compared with the corresponding intraperitoneal boluses.

Conclusions

Smaller intraperitoneal boluses of insulin have an effect on circulating glucose levels without increasing insulin levels in the systemic circulation. By increasing the insulin bolus, a major increase in circulating insulin was observed, with a minor additive effect on circulating glucose levels. This is compatible with a close to 100% first-pass effect in the liver after smaller intraperitoneal boluses. Subcutaneous insulin boluses markedly increased circulating insulin levels.
Decomposing the rural–urban gap in factors associated with childhood immunisation in sub-Saharan Africa: evidence from surveys in 23 countries
Authors: Ameyaw Edward Kwabena , Kareem Yusuf Olushola , Ahinkorah Bright Opoku , Seidu Abdul-Aziz , Yaya Sanni
Published: January 2021

Background

About 31 million children in sub-Saharan Africa (SSA) suffer from immunisation preventable diseases yearly and more than half a million children die because of lack of access to immunisation. Immunisation coverage has stagnated at 72% in SSA over the past 6 years. Due to evidence that full immunisation of children may be determined by place of residence, this study aimed at investigating the rural–urban differential in full childhood immunisation in SSA.

Methods

The data used for this study consisted of 26 241 children pooled from 23 Demographic and Health Surveys conducted between 2010 and 2018 in SSA. We performed a Poisson regression analysis with robust Standard Errors (SEs) to determine the factors associated with full immunisation status for rural and urban children. Likewise, a multivariate decomposition analysis for non-linear response model was used to examine the contribution of the covariates to the observed rural and urban differential in full childhood immunisation. All analyses were performed using Stata software V.15.0 and associations with a p<0.05 were considered statistically significant.

Results

More than half of children in urban settings were fully immunised (52.8%) while 59.3% of rural residents were not fully immunised. In all, 76.5% of rural–urban variation in full immunisation was attributable to differences in child and maternal characteristics. Household wealth was an important component contributing to the rural–urban gap. Specifically, richest wealth status substantially accounted for immunisation disparity (35.7%). First and sixth birth orders contributed 7.3% and 14.9%, respectively, towards the disparity while 7.9% of the disparity was attributable to distance to health facility.

Conclusion

This study has emphasised the rural–urban disparity in childhood immunisation, with children in the urban settings more likely to complete immunisation. Subregional, national and community-level interventions to obviate this disparity should target children in rural settings, those from poor households and women who have difficulties in accessing healthcare facilities due to distance.
Writing’s on the wall: improving the WHO Surgical Safety Checklist
Authors: Cushley Claire , Knight Tom , Murray Helen , Kidd Lawrence
Published: January 2021

Background and problem

The WHO Surgical Safety Checklist has been shown to improve patient safety as well as improving teamwork and communication in theatres. In 2009, it was made a mandatory requirement for all NHS hospitals in England and Wales. The WHO checklist is intended to be adapted to suit local settings and was modified for use in Gloucestershire Hospitals NHS Foundation Trust. In 2018, it was decided to review the use of the adapted WHO checklist and determine whether improvements in compliance and engagement could be achieved.

Aim

The aim was to achieve 90% compliance and engagement with the WHO Surgical Safety Checklist by April 2019.

Methods

In April 2018, a prospective observational audit and online survey took place. The results showed compliance for the ‘Sign In’ section of the checklist was 55% and for the ‘Time Out’ section was 91%. Engagement by the entire theatre team was measured at 58%. It was proposed to move from a paper checklist to a wall-mounted checklist, to review and refine the items in the checklist and to change the timing of ‘Time Out’ to ensure it was done immediately prior to knife-to-skin.

Results

Following its introduction in September 2018, the new wall-mounted checklist was reaudited. Compliance improved to 91% for ‘Sign In’ and to 94% for ‘Time Out’. Engagement by the entire theatre team was achieved 100% of the time. Feedback was collected, adjustments made and the new checklist was rolled out in stages across all theatres. A reaudit in December 2018 showed compliance improved further, to 99% with ‘Sign In’ and to 100% with ‘Time Out’. Engagement was maintained at 100%.

Conclusions

The aim of the project was met and exceeded. Since April 2019, the new checklist is being used across all theatres in the Trust.
Long-term survival benefit of ramipril in patients with acute myocardial infarction complicated by heart failure
Authors: Wu Jianhua , Hall Alistair S , Gale Chris P
Published: January 2021

Aims

ACE inhibition reduces mortality and morbidity in patients with heart failure after acute myocardial infarction (AMI). However, there are limited randomised data about the long-term survival benefits of ACE inhibition in this population.

Methods

In 1993, the Acute Infarction Ramipril Efficacy (AIRE) study randomly allocated patients with AMI and clinical heart failure to ramipril or placebo. The duration of masked trial therapy in the UK cohort (603 patients, mean age=64.7 years, 455 male patients) was 12.4 and 13.4 months for ramipril (n=302) and placebo (n=301), respectively. We estimated life expectancy and extensions of life (difference in median survival times) according to duration of follow-up (range 0–29.6 years).

Results

By 9 April 2019, death from all causes occurred in 266 (88.4%) patients in placebo arm and 275 (91.1%) patients in ramipril arm. The extension of life between ramipril and placebo groups was 14.5 months (95% CI 13.2 to 15.8). Ramipril increased life expectancy more for patients with than without diabetes (life expectancy difference 32.1 vs 5.0 months), previous AMI (20.1 vs 4.9 months), previous heart failure (19.5 vs 4.9 months), hypertension (16.6 vs 8.3 months), angina (16.2 vs 5.0 months) and age >65 years (11.3 vs 5.7 months). Given potential treatment switching, the true absolute treatment effect could be underestimated by 28%.

Conclusion

For patients with clinically defined heart failure following AMI, ramipril results in a sustained survival benefit, and is associated with an extension of life of up to 14.5 months for, on average, 13 months treatment duration.
Socioeconomic status and cardiovascular health in the COVID-19 pandemic
Authors: Naylor-Wardle Jeremy , Rowland Ben , Kunadian Vijay
Published: January 2021

The goals of this review are to evaluate the impact of socioeconomic (SE) status on the general health and cardiovascular health of individuals during the COVID-19 pandemic and also discuss the measures to address disparity. SE status is a strong predictor of premature morbidity and mortality within general health. A lower SE status also has implications of increased cardiovascular disease (CVD) mortality and poorer CVD risk factor profiles. CVD comorbidity is associated with a higher case severity and mortality rate from COVID-19, with both CVD and COVID-19 sharing important risk factors. The COVID-19 pandemic has adversely affected people of a lower SE status and of ethnic minority group, who in the most deprived regions are suffering double the mortality rate of the least deprived. The acute stress, economic recession and quarantine restrictions in the wake of COVID-19 are also predicted to cause a decline in mental health. This could pose substantial increase to CVD incidence, particularly with acute pathologies such as stroke, acute coronary syndrome and cardiogenic shock among lower SE status individuals and vulnerable elderly populations. Efforts to tackle SE status and CVD may aid in reducing avoidable deaths. The implementation of ‘upstream’ interventions and policies demonstrates promise in achieving the greatest population impact, aiming to protect and empower individuals. Specific measures may involve risk factor targeting restrictions on the availability and advertisement of tobacco, alcohol and high-fat and salt content food, and targeting SE disparity with healthy and secure workplaces.
Annual survival probabilities of anadromous Arctic Char remain high and stable despite interannual differences in sea ice melt date
Authors: Caza-Allard Isabeau , Mazerolle Marc J. , Harris Les N. , Malley Brendan K. , Tallman Ross F. , Fisk Aaron T. , Moore Jean-Sébastien
Published: January 2021

Throughout their range, anadromous Arctic Char (Salvelinus alpinus (Linnaeus, 1758)) support commercial, recreational, and subsistence fisheries that are important economically, socially, and culturally. However, drivers of interannual variation in survival in this species remain poorly understood. Here, we aimed to quantify the impact of environmental and biological parameters on the survival probability of anadromous Arctic Char near the community of Cambridge Bay, Nunavut, Canada. To do so, we tracked 183 Arctic Char tagged with acoustic transmitters and used capture–mark–recapture methods to estimate survival probabilities over six years. Annual survival probabilities for individuals was high, varying between 0.79 and 0.88, whereas recapture probabilities varied between 0.64 and 0.90. Interannual variation in survival probability was low and neither the environmental (air temperature and sea ice cover) nor biological (sex) variables influenced survival probability. These estimates suggest that annual survival probability is high for anadromous adult Arctic Char in the Cambridge Bay area, despite clear differences in the ice cover melt date among years. These results further our understanding of the demographic parameters of Arctic Char in the region, which will be important for future assessments of the sustainability of commercial fisheries as well as for predicting population responses to a rapidly changing Arctic.
Evaluating the effectiveness of the Safety Improvement Program in Saskatchewan using an observational before–after study with the full Bayes approach
Authors: Sacchi Emanuele , Tayebikhorami Saeid
Published: January 2021

A key step in highway safety management is to determine whether the frequency and (or) severity of collisions has been reduced after implementing a specific improvement program. This research focused on evaluating the safety performance of 50 sites that have been improved under the Saskatchewan Ministry of Highways and Infrastructure’s Safety Improvement Program (SIP). SIP projects were designed to reduce the frequency and severity of collisions on provincial highways in rural areas through the implementation of different safety countermeasures. The methodology adopted was an observational before–after study using the full Bayes approach. The results showed that SIP projects reduced total collisions by 14.8% and severe (fatal-plus-injury) collisions by 25.4%. The reduction in property-damage-only collisions was not found to be statistically significant. Crash modification factors (CMFs) for the two most frequent SIP treatments, that is, right-turn lanes and delineation lighting at intersections, were estimated and compared with the results of the literature.
Intestinal parasites of dogs (Canis lupus familiaris) in Svalbard (Norway): low prevalence and limited transmission with wildlife
Authors: Myšková Eva , Brož Marek , Kváč Martin , Sak Bohumil , Ditrich Oleg
Published: January 2021

Domesticated dogs (Canis lupus familiaris Linnaeus, 1758) are widely kept on all continents and could share parasites with free-living animals. To understand the transmission of intestinal parasites between dogs kept on the four dog stations and wildlife in Svalbard, 170 faecal samples from dogs and 203 faecal samples from wildlife, including Arctic fox (Vulpes lagopus (Linnaeus, 1758); n = 62), Svalbard reindeer (Rangifer tarandus platyrhynchus (Vrolik, 1829); n = 106), sibling vole (Microtus levis Miller, 1908; n = 63), Pink-footed Goose (Anser brachyrhynchus Baillon, 1834; n = 30), Little Auk (Alle alle (Linnaeus, 1758); n = 49), and Black-legged Kittiwake (Rissa tridactyla (Linnaeus, 1758); n = 18), were individually screened for the presence of intestinal parasites using microscopy and PCR and nucleotide sequencing methods. Additionally, the results of the study were compared with previous studies performed in the same area. The roundworm Toxascaris leonina (Linstow, 1902) was found microscopically and by PCR in a dog (n = 1). The specific DNA of three species of parasitic protists was detected in dogs from different yards. Phylogenetic analyses revealed the presence of Cryptosporidium canis Fayer, Trout, Xiao, Morgan, Lal and Dubey, 2001 (n = 1), Encephalitozoon cuniculi Levaditi, Nicolau and Schoen, 1923 genotype II (n = 4), and dog-specific Enterocytozoon bieneusi Desportes, Le Charpentier, Galian, Bernard, Cochand-Priollet, Lavergne, Ravisse and Modigliani, 1985 genotypes (n = 12). This study showed overall a low prevalence of intestinal parasites in dogs in Svalbard and possible but minimal transmission with wildlife.
$$B_{(s)}$$ to light tensor meson form factors via LCSR in HQEFT with applications to semileptonic decays
Authors: Zuo Ya-Bing , Yue Chong-Xing , Yu Bo , Kou Ying-Hui , Chen Yan , Ling Wen
Published: January 2021

In the present work, the form factors of $$B_{(s)}$$

B

(
s
)

to light P-wave tensor mesons ($$a_2(1320)$$

a
2

(
1320
)

, $$K^*_2(1430)$$

K
2
∗

(
1430
)

, $$f_2(1270)$$

f
2

(
1270
)

, $$f^\prime _2(1525)$$

f
2
′

(
1525
)

) are calculated via the light cone sum rules (LCSR) in the framework of heavy quark effective field theory (HQEFT). Firstly, the expressions of form factors in terms of the light cone distribution amplitudes (DAs) of tensor mesons are derived via the LCSR at the leading order of heavy quark expansion. It is found that the penguin type form factors can be obtained directly from the corresponding semileptonic ones, which is similar to the case of S-wave mesons. Considering the light tensor meson DAs to twist-3, we give the numerical results of form factors systematically. As applications, we investigate the branching ratios, longitudinal polarization fractions and forward-backward asymmetries of relevant semileptonic decays induced by charged current and flavor changing neutral current (FCNC) separately. Our results may be tested by more precise experiments in the future.
Neutrino masses and Hubble tension via a Majoron in MFV
Authors: Arias-Aragón Fernando , Fernández-Martínez Enrique , González-López Manuel , Merlo Luca
Published: January 2021

The recent tension between local and early measurements of the Hubble constant can be explained in a particle physics context. A mechanism is presented where this tension is alleviated due to the presence of a Majoron, arising from the spontaneous breaking of Lepton Number. The lightness of the active neutrinos is consistently explained. Moreover, this mechanism is shown to be embeddable in the minimal (Lepton) flavour violating context, providing a correct description of fermion masses and mixings, and protecting the flavour sector from large deviations from the Standard Model predictions. A QCD axion is also present to solve the Strong CP problem. The Lepton Number and the Peccei–Quinn symmetries naturally arise in the minimal (Lepton) flavour violating setup and their spontaneous breaking is due to the presence of two extra scalar singlets. The Majoron phenomenology is also studied in detail. Decays of the heavy neutrinos and the invisible Higgs decay provide the strongest constraints in the model parameter space.
Bayesian comparison of interacting modified holographic Ricci dark energy scenarios
Authors: Cid Antonella , Rodriguez-Benites Carlos , Cataldo Mauricio , Casanova Gonzalo
Published: January 2021

We perform a Bayesian model selection analysis for interacting scenarios of dark matter and modified holographic Ricci dark energy (MHRDE) with linear interacting terms. We use a combination of some of the latest cosmological data such as type Ia supernovae, cosmic chronometers, the local value of the Hubble constant, baryon acoustic oscillations measurements and cosmic microwave background through the angular scale of the sound horizon at last scattering. We find moderate/strong evidence against all the MHRDE interacting scenarios studied with respect to $$\Lambda $$
Λ
CDM when the full joint analysis is considered.