bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature Sensor Deployment for Scalable Battery Packs
Authors: Gao Mengzhu , Lai Qingzhi , Lin Xinfan
Published: January 2021

Li-ion battery systems have been widely used as an essential power source in many applications. To ensure the safety and longevity of the system, a battery pack thermal model is often used in combination with distributed temperature sensors for thermal management and monitoring purposes. Due to the limited number of sensors and sparse measurement, sensor deployment to maximize the observability of the system thermal dynamics has been a critical topic, which has attracted research attention but remains to be resolved. This paper is devoted to exploring the pattern of optimal sensor locations for scalable battery systems under different observability criteria. A battery pack thermal model is first developed based on a single cell thermal model and considering the thermal interconnection between cells in the pack. Sensor location optimization is then performed by maximizing two Gramian-based observability metrics, which quantify different aspects of system observability. Optimal sensor locations obtained under the two metrics are analyzed and compared for battery systems of different sizes. Based on the results, deployment patterns of optimal sensor locations are extracted and analyzed theoretically by correlating to the physics of the battery thermal dynamics. Moreover, the influences of critical parameters of battery packs on system observability are also analyzed and discussed.
A Cellular Automata Model for Dynamics and Control of Cardiac Arrhythmias
Authors: Gallenberger Danny , Xiong Min , Zhuang Tony Z. , Sun Kai , Tolkacheva Elena G. , Zhao Xiaopeng
Published: January 2021

As a leading cause of death in 325,000 adults per year in the United States, a significant proportion of sudden cardiac arrest (SCA) result from arrhythmias. To better understand the onset of arrhythmias and its potential treatment with more rapid and effective control approaches, a two-dimensional 50 × 50 cellular automata (CA) model is used in this study to illustrate the propagation of electrical waves across its tissue, and a constant diastolic interval (DI) control mechanism is adopted to help stabilize and prevent cardiac arrhythmias. Simulations of various scenarios including normal conduction and spiral waves in the presence of scar, normal conduction and alternans under control conditions are shown. The results validate that the CA model and constant DI control method are very efficient and effective in the study of dynamics and control of cardiac arrhythmias.
The Swirling Pendulum: Conceptualization, Modeling, Equilibria and Control Synthesis
Authors: Kadam Sujay D. , Shah Utsav , D’Souza Alrick , Shanthamurthy Prajwal Gowdru , Raj Nidhish , Banavar Ravi N. , Palanthandalam-Madapusi Harish J.
Published: January 2021

This paper introduces the swirling pendulum, a two-link, two degree-of-freedom mechanism which is under-actuated and has an unusual non-planar coupling with axis of rotation of the two links being perpendicular to each other. The swirling pendulum mechanism, while being simple to mathematically represent and easy to physically construct, exhibits several properties like loss of inertial coupling, loss of relative degree, multiple stable and unstable equilibrium points. These properties are unique as well as interesting from dynamics and controls point of view which make the swirling pendulum an excellent test-bed for testing various ideas in control and demonstrating several notions associated with systems and control theory. In this paper, we discuss the modeling of the swirling pendulum mechanism based on Lagrange’s equation along with an analysis related to equilibrium points and their stability. We also present simulation results for regulatory as well as tracking control tasks through simulations on a non-linear model using control methods like LQR, lead compensator and system inversion-based control to demonstrate the utility of the proposed mechanism in the area of systems, control and dynamics. Furthermore, we also discuss experimental results for controls applied on a real-time hardware setup.
The Effects of Trailer Towing on the Dynamics of a Lane-Keeping Controller
Authors: Vörös Illés , Takács Dénes
Published: January 2021

The main question this paper aims to address is whether a lane-keeping controller can serve as a safety feature in order to increase handling and stability of car-trailer combinations. The derivation of a nonholonomic car-trailer model is provided and its open-loop stability is analyzed. A look-ahead based lane-keeping controller is applied to the system, and a comparison is made between the closed-loop stability of an individual car and a car-trailer setup. The critical speed of the vehicle combination is shown as a function of various trailer parameters, with and without the lane-keeping controller enabled. A modified version of the controller is also tested, utilizing feedback of the trailer states. This ensures that the trailer is also kept at the center of the lane, but no improvement was found in terms of stable trailer configurations.
New Stability Analysis and Design of Discrete Time Delay Control for Nonaffine Nonlinear Systems
Authors: Reddy Suresh B.
Published: January 2021

Time Delay Control (TDC) for linear and nonlinear systems with uncertain dynamics has been widely discussed in the literature, as it has a very simple and compact form. It uses time-delayed signals for estimating unknown dynamics at an instant, and uses feedback linearization for cancellation of known and estimated unknown dynamics. While the original formulation and most of the analyses have been focused on the continuous version of the controller, its implementation is more natural in digital form. This paper extends the recently improved sufficient Bounded Input - Bounded Output (BIBO) stability conditions for continuous Time Delay Control of nonaffine nonlinear systems to discrete Time Delay Control, including simplified approximate conditions under various assumptions. Additionally. asymptotic stability is established for similar conditions. The derived conditions are contrasted with earlier results for continuous Time Delay Control. Examples are used to illustrate the differences in continuous and discrete TDC, related to performance as well as sufficient and actual conditions for stability.
Input Excitation Analysis for Black-Box Quadrotor Model System Identification
Authors: Angarita John , Doyle Daniel , Gargioni Gustavo , Black Jonathan
Published: January 2021

System identification provides a process to develop different dynamic models of varying structures based on user-defined requirements. For a quadrotor, system identification has been primarily in the field of off-white and grey-box models, but black-box models have the advantage of incorporating nonlinear aero-dynamic effects while also maintaining performance. For the identification, both a chirp and Hebert-Mackin parameter identification method waveform are used as inputs to maximize excitation while minimizing nonlinear responses. The quadrotor structure is defined by the an autoregressive with exogenous input (ARX) model, an autoregressive-moving-average (ARMAX) model, and a Box-Jenkins (BJ) models and then identified with the prediction error method. The black-box method shows that it maintains identification performance while improving upon the flexibility of different cases and ease of implementation.
Development of Wire Actuated Monolithic Soft Gripper Positioned by Robot Manipulator
Authors: Gutierrez Rafael Barreto , Garcia Martin , McDuffie Joan , Long Courtney , Tekes Ayse
Published: January 2021

This paper presents the design and development of a two fingered, monolithically designed compliant gripper mounted on a two-link robot. Rigid grippers traditionally designed by rigid links and joints might have low precision due to friction and backlash. The proposed gripper is designed as a single piece compliant mechanism consisted of several flexible links and actuated by wire through a servo motor. The gripper is attached to a two-link arm robot driven by three step motors. An additional servo motor can also rotate the base of the robot. While the robot is 3D printed using polylactic acid (PLA), the gripper is 3D printed in thermoplasticpolyurethane (TPU). Two force sensors are attached to the right and left ends of the gripper to measure grasping force. Experimental testing for grasping various objects having different sizes, shapes and weights is carried out to verify the robust performance of the proposed design. Through the experimentation, it’s been noted that the compliant gripper can successfully lift up objects at a maximum mass of 200 g and have a better performance if the objects’width is closer to the width of the gripper. The presented mechanism can be utilized as a service robot for elderly people to assist them pick and place objects or lift objects if equipped with necessary sensors.
Nonlinear Hierarchical MPC for Maximizing Aircraft Thermal Endurance
Authors: Leister Daniel D. , Koeln Justin P.
Published: January 2021

In modern high-performance aircraft, the Fuel Thermal Management System (FTMS) plays a critical role in the overall thermal energy management of the aircraft. Actuator and state constraints in the FTMS limit the thermal endurance and capabilities of the aircraft. Thus, an effective control strategy must plan and execute optimized transient fuel mass and temperature trajectories subject to these constraints over the entire course of operation. For the control of linear systems, hierarchical Model Predictive Control (MPC) has shown to be an effective approach to coordinating both short- and long-term system operation with reduced computational complexity. However, for controlling nonlinear systems, common approaches to system linearization may no longer be effective due to the long prediction horizons of upper-level controllers. This paper explores the limitations of using linear models for hierarchical MPC of the nonlinear FTMS found in aircraft. Numerical simulation results show that linearized models work well for lower-level controllers with short prediction horizons but lead to significant reductions in aircraft thermal endurance when used for upper-level controllers with long prediction horizons. Therefore, a mixed-linearity hierarchical MPC formulation is presented with a nonlinear upper-level controller and a linear lower-level controller to achieve both high performance and high computational efficiency.
Multiple Sliding Surface Controller for a Quadrotor for Improved Robustness Against Wind Disturbances
Authors: Sudakar Madhavan , Sridhar Siddharth , Kumar Manish
Published: January 2021

In this paper, we present a controller design for a quadrotor by obtaining the derivative of the actual control input using the concept of multiple sliding surfaces and Lyapunov stability analysis. The conventional sliding mode controller is highly robust. The discontinuous part of the control input suppresses disturbances well. Theoretically, however, this discontinuity causes rapid switching of the control input (chattering) which results in large energy consumption and inefficiency. The proposed control method formulates the derivative of control input (having the discontinuity) which upon integrating provides a smoother control input when compared to the classical sliding mode control. The quadrotor with our proposed controller is subjected to varying wind disturbance scenarios and its performance is bench-marked against a PID controller and a conventional sliding mode controller. A saturation function sat is used instead of the sign for the classical sliding mode controller as well as the the proposed novel controller design in all sections from 4.2. The reasoning behind this is discussed in the results section of the paper.
Visual Navigation of Wheeled Mobile Robots Using Deep Reinforcement Learning: Simulation to Real-Time Implementation
Authors: Nwaonumah Ezebuugo , Samanta Biswanath
Published: January 2021

A study is presented on applying deep reinforcement learning (DRL) for visual navigation of wheeled mobile robots (WMR), both in simulation and real-time implementation under dynamic and unknown environments. The policy gradient based asynchronous advantage actor critic (A3C), has been considered. RGB (red, green and blue) and depth images have been used as inputs in implementation of A3C algorithm to generate control commands for autonomous navigation of WMR. The initial A3C network was generated and trained progressively in OpenAI Gym Gazebo based simulation environments within robot operating system (ROS) framework for a popular target WMR, Kobuki TurtleBot2. A pre-trained deep neural network ResNet50 was used after further training with regrouped objects commonly found in laboratory setting for target-driven visual navigation of Turlebot2 through DRL. The performance of A3C with multiple computation threads (4, 6, and 8) was simulated and compared in three simulation environments. The performance of A3C improved with number of threads. The trained model of A3C with 8 threads was implemented with online learning using Nvidia Jetson TX2 on-board Turtlebot2 for mapless navigation in different real-life environments. Details of the methodology, results of simulation and real-time implementation through transfer learning are presented along with recommendations for future work.
Sensing and Classification of Ambient Vortex Wake From the Kinematics of a Bioinspired Swimming Robot Using Neural Networks
Authors: Pollard Beau , Tallapragada Phanindra
Published: January 2021

The ability of a swimming robot to extract information from a vortex field in the ambient fluid flow has immense practical applications. Such capabilities perhaps augmented with other sensors are useful to detect and avoid obstacles or potential adversaries in the fluid. This has led many researchers to attempt to sample the pressure field on the surface of a swimmer and thus extract information about the fluid flow such as the flow velocity and angle of attack. In contrast in this paper, we show through simulations, that the kinematic information of a swimmer, specifically its angular velocity, can be used to train a neural network, that can classify the vortex wake in the surrounding fluid. In effect, this classifies the type of body (or its motion) that generates the ambient wake. In practice, the angular velocity of a body can be measured with much greater accuracy than the pressure distribution on the body. We further show that a swimmer with a passive tail-like appendage can classify the vortex field with greater accuracy than a swimmer without such an appendage. Thus the results demonstrated in this paper can be of significant use in designing aquatic robots with passive appendages with improved capabilities of sensing and classifying the ambient flow.
Control Design for Automated Vehicle Emergency Safe Stop System Based on Differential Dynamic Programming
Authors: Yang Lisheng , Furukawa Tomonari , Zuo Lei , Doerzaph Zachary
Published: January 2021

This paper presents the control algorithm and system design for a newly proposed automated emergency stop system, which aims to navigate the vehicle out of its travel lane to a safe road-side location when an emergency (e.g. driver fails to take control during fallback of the Dynamic Driving Task) occurs. To address the unique requirements of such a system, control techniques based on differential dynamic programming are developed. Optimal control sequence computation is broken down into step-by-step quadratic optimization and solved iteratively. Control constraints are addressed efficiently by a tailored Projected-Newton algorithm. The iterative control algorithm is then integrated into a real-time control system which considers both computation delay and modeling errors. The system employs a novel grid-based storage structure for recording all acceptable control commands computed within the iteration and uses a high frequency estimator for self-localization. During operation, the real-time control thread will extract commands from the grid cell corresponding to current states. Simulation results show strong potential of the proposed system for addressing the engineering challenges of the automated emergency stop function. The robustness of the system in presence of computation time delay and modelling errors is also demonstrated.
How global is global health research? A large-scale analysis of trends in authorship
Authors: Dimitris Michelle C , Gittings Matthew , King Nicholas B
Published: January 2021

Many have called for greater inclusion of researchers from low- and middle-income countries (LMICs) in the conduct of global health research, yet the extent to which this occurs is unclear. Prior studies are journal-, subject-, or region-specific, largely rely on manual review, and yield varying estimates not amenable to broad evaluation of the literature. We conducted a large-scale investigation of the contribution of LMIC-affiliated researchers to published global health research and examined whether this contribution differed over time. We searched titles, abstracts, and keywords for the names of countries ever classified as low-, lower middle-, or upper middle-income by the World Bank, and limited our search to items published from 2000 to 2017 in health science-related journals. Publication metadata were obtained from Elsevier/Scopus and analysed in statistical software. We calculated proportions of publications with any, first, and last authors affiliated with any LMIC as well as the same LMIC(s) identified in the title/abstract/keywords, and stratified analyses by year, country, and countries’ most common income status. We analysed 786 779 publications and found that 86.0% included at least one LMIC-affiliated author, while 77.2% and 71.2% had an LMIC-affiliated first or last author, respectively; however, analagous proportions were only 58.7%, 36.8%, and 29.1% among 100 687 publications about low-income countries. Proportions of publications with LMIC-affiliated authors increased over time, yet this observation was driven by high research activity and representation among upper middle-income countries. Between-country variation in representation was observed, even within income status categories. We invite comment regarding these findings, particularly from voices underrepresented in this field.
Time to ACT: launching an Addiction Care Team (ACT) in an urban safety-net health system
Authors: Martin Marlene , Snyder Hannah R , Coffa Diana , Steiger Scott , Clement Joseph P , Ranji Sumant R , Azari Soraya , Nguyen Oanh K , Lum Paula J
Published: January 2021

Across the USA, morbidity and mortality from substance use are rising as reflected by increases in acute care hospitalisations for substance use complications and substance-related deaths. Patients with substance use disorders (SUD) have long and costly hospitalisations and higher readmission rates compared to those without SUD. Hospitalisation presents an opportunity to diagnose and treat individuals with SUD and connect them to ongoing care. However, SUD care often remains unaddressed by hospital providers due to lack of a systems approach and addiction medicine knowledge, and is compounded by stigma. We present a blueprint to launching an interprofessional inpatient addiction care team embedded in the hospital medicine division of an urban, safety-net integrated health system. We describe key factors for successful implementation including: (1) demonstrating the scope and impact of SUD in our health system via a needs assessment; (2) aligning improvement areas with health system leadership priorities; (3) involving executive leadership to create goal and initiative alignment; and (4) obtaining seed funding for a pilot programme from our Medicaid health plan partner. We also present challenges and lessons learnt.
Lean thinking: using 6S and visual management for efficient adverse event closure
Authors: Alzahrani Ziad
Published: January 2021

Background

We focused on a busy Adult Oncology Department having over 130 staff members, with around 70 of them being physicians with different levels of specialties. A multidisciplinary committee was formed in the department, consisting of physicians, nurses, pharmacists, a medication safety representative and a quality specialist to look after all reported incidents.

Local problem

The department staff at the institution in question in this study expressed their concern about the surging number of reported incidents, delays in closing reports within the set timeframe, ambiguity of individuals’ roles at the committee level and errors in using the safety reporting system (SRS). Accordingly, this study focused on the development of a visual aid through the creation of a functional process map to help clarify team roles and stipulate the steps for adverse event closure.

Methods

TheSort,Set-in order,Shine,Standardise,Sustain andSafety and visual management lean principles, as well as the eight lean wastes—Transportation, Inventory, Motion, Waiting, Overprocessing, Overproduction, Defect and Staff underutilisation—were introduced in early May 2016 and used during SRS committee meetings over 3 years.

Intervention

The indicators used were the average number of days for both medication and non-medication incidents from the day of reporting until the closure. The extent that the limit was exceeded was compared.

Results

The average number of days until closure showed a reduction from 67 to 37 and 134 to 61 between Periods I (2016) and III (2018) for medication and non-medication incidents, respectively.

Conclusions

The developed process map was a useful communication tool. It helped to sort process activities, team roles and streamline the process. It brought the average number of days until closure within the acceptable 45-day limit for medication incidents. Thus, using visual aids in the working environment is helpful in improving communication among the workers.
Relationship between afternoon napping and cognitive function in the ageing Chinese population
Authors: Cai Han , Su Ning , Li Wei , Li Xia , Xiao Shifu , Sun Lin
Published: January 2021

Background

Several studies have shown that afternoon napping promotes cognitive function in the elderly; on the other hand, some studies have shown opposite results. This current study further examined the relationship between afternoon napping and cognitive function in the ageing Chinese population.

Methods

A total of 2214 elderly were included (napping group: n=1534; non-napping group: n=680). They all received cognitive evaluations by the Beijing version of the Montreal Cognitive Assessment, the Mini-Mental State Examination, and the Chinese version of the Neuropsychological Test Battery. Among all the subjects, 739 elderly volunteered to take blood lipid tests.

Results

Significant differences in cognitive function and blood lipids were observed between the napping and the non-napping groups. Afternoon napping was associated with better cognitive function including orientation, language, and memory in the present study. Subjects with the habit of afternoon napping also showed a higher level of triglyceride than the non-napping subjects.

Conclusion

The results demonstrated that afternoon napping was related to better cognitive function in the Chinese ageing population.
Analysis of on-pack messages for e-liquids: a discrete choice study
Authors: Hoek Janet , Gendall Philip , Eckert Christine , Louviere Jordan , Ling Pamela , Popova Lucy
Published: January 2021

Background

Policymakers wishing to encourage smokers unable to quit to switch to using electronic nicotine delivery systems (ENDS) also need to consider how to deter ENDS use among non-smokers. We examined whether reduced-risk messages could increase ENDS’ appeal among smokers and if increased-risk messages could decrease appeal among susceptible non-smokers, occasional and former smokers.

Methodology

An online discrete choice experiment tested three attributes: information message, nicotine content (0 mg or 3 mg) and flavour (tobacco, menthol or fruit). The sample comprised 352 current smokers, 118 occasional and former smokers, and 216 ENDS-susceptible never smokers. Smokers viewed reduced-risk messages that encouraged switching to ENDS, while other groups viewed increased-risk messages that discouraged ENDS use. All groups saw a typical addiction warning. We analysed the data by estimating multinomial logit regression and adjusted latent class analysis models.

Results

Relative to no message, reduced risk-messages increased the appeal of ENDS uptake among one class of smokers (33.5%) but decreased appeal among other smokers. However, among all smokers, reduced-risk messages increased preference more than a dissuasive addiction warning. By contrast, among occasional or former smokers, and susceptible non-smokers, all information messages discouraging ENDS use, including an addiction warning, decreased preference relative to no message.

Conclusions

On-pack relative-risk messages about ENDS could make transition more attractive to smokers while increased-risk messages could deter ENDS uptake among susceptible non-smokers, occasional and former smokers. Communicating diverse messages via discrete channels could recognise heterogeneity among and between smokers and non-smokers.
Bifurcations and Exact Traveling Wave Solutions of Two Shallow Water Two-Component Systems
Authors: Li Jibin , Chen Guanrong , Zhou Yan
Published: January 2021

This paper studies two two-component shallow water wave models. From the dynamical systems approach and using the singular traveling wave theory developed by Li and Chen [2007], all possible bounded solutions (solitary wave solutions, pseudo-peakons, periodic peakons, as well as smooth periodic wave solutions) are obtained under different parameter conditions. More than six explicit exact parametric representations are derived. More interestingly, it was found that, for the two-component Camassa–Holm equations with constant vorticity, its [Formula: see text]-traveling wave system has a pseudo-peakon wave solution. In addition, its [Formula: see text]-traveling wave system has four families of uncountably infinitely many solitary wave solutions. The new results complete a recent study of Dutykh and Ionescu-Kruse [2019].
Time-Delayed Sampled-Data Feedback Control of Differential Systems Undergoing Hopf Bifurcation
Authors: Su Huan , Xu Jing
Published: January 2021

In this paper, time-delayed sampled-data feedback control technique is used to asymptotically stabilize a class of unstable delayed differential systems. Through the analysis for the distribution change of eigenvalues, an effective interval of the control parameter is obtained for a given sampling period. Here an indirect strategy is taken. Specifically, the system of continuous-time delayed feedback control is studied first by Hopf bifurcation theory. And then, the result and implicit function theorem are used to analyze the system of time-delayed sampled-data feedback control with a sufficiently small sampling period. Considering the practical criterion for the size of sampling period, the upper bound of sampling period is estimated. Finally, an application example, an unstable Mackey–Glass model, is asymptotically stabilized by introducing a blood transfusion item with time-delayed sampled-data feedback control. The blood transfusion speed and blood collection test period are derived from the main results. Some simulations and comparisons show the correctness and advantages of the main theoretical results.
Synchronization of Chaotic Circuits with Stochastically-Coupled Network Topology
Authors: Uwate Yoko , Nishio Yoshifumi , Ott Thomas
Published: January 2021

In recent years, research on synchronization between coupled chaotic circuits has attracted interest in a wide range of fields. This is because the synchronization of coupled chaotic circuits is a multidisciplinary phenomenon that occurs in various applications, such as broadband communication systems or secure communication.

In this study, we propose a coupled chaotic circuit network model with stochastic couplings. We investigate the synchronization phenomena observed for the proposed network using different network structures such as fully-coupled, random, small world and scale-free networks. We find that the same synchronization characteristics can be obtained for these networks with a dynamic topology as when the coupling strength is changed in static networks.
Urban Noise Inference Model Based on Multiple Views and Kernel Tensor Decomposition
Authors: Nie Junlan , Gao Ruibo , Kang Ye
Published: January 2021

Prediction of urban noise is becoming more significant for tackling noise pollution and protecting human mental health. However, the existing noise prediction algorithms neglected not only the correlation between noise regions, but also the nonlinearity and sparsity of the data, which resulted in low accuracy of filling in the missing entries of data. In this paper, we propose a model based on multiple views and kernel-matrix tensor decomposition to predict the noise situation at different times of day in each region. We first construct a kernel tensor decomposition model by using kernel mapping in order to speed decomposition rate and realize stable estimate the prediction system. Then, we analyze and compute the cause of the noise from multiple views including computing the similarity of regions and the correlation between noise categories by kernel distance, which improves the credibility to infer the noise situation and the categories of regions. Finally, we devise a prediction algorithm based on the kernel-matrix tensor factorization model. We evaluate our method with a real dataset, and the experiments to verify the advantages of our method compared with other existing baselines.
Enhanced Antioxidant Efficacy of Nano-Encapsulated Protorhus Longifolia Methanol Extract Stabilized with Eudragit
Authors: Mkhize Zimbili , Seboletswe Pule Silent , Paumo Hugues Kamdem , Boniface Pone Kamdem , Katata-Seru Lebogang Maureen
Published: January 2021

This study describes the synthesis of Protorhus longifolia methanolic leaf extract-loaded Eudragit nanoparticles (NPs) and assessment of their antioxidant activity comparative to the free methanolic extract. The latter was also analyzed for its total phenolic content (TPC) and total flavonoid content (TFC). The extract-loaded NPs were obtained through the emulsification solvent evaporation process and systematically characterized using the dynamic light scattering, entrapment efficiency, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The antioxidant power was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing ability of plasma (FRAP) in vitro model systems. Screening of the different classes of secondary metabolites was carried out through chemical reaction tests. Identification of the potential antioxidants was performed using the gas chromatography-mass spectrometry (GC-MS) technique and the database of National Institute Standard and Technology (NIST). The characterization techniques showed spherical-like particles having an average size of 150[Formula: see text]nm and zeta potential of [Formula: see text]22[Formula: see text]mV. The percentage of entrapped methanolic extract was determined to be 83%. The antioxidant assay demonstrated that this methodology persuaded an efficient concentration-dependent potential. This study indicates that nanoformulation of the Protorhus longifolia extracts leads to a suitable system for the enhancement of antioxidant activity. The appraisal of other pharmacological activities of the nano-encapsulated Protorhus longifolia methanol extract is under process.
Policy Note: Digital Feedback-Based Interventions for Water Conservation
Authors: Hartley Kris , Lim Nicole Sher Wen , Tortajada Cecilia
Published: January 2021

Progress in water conservation is dependent as much on human behavior as on the promise of new technologies. Digital feedback-based interventions present an opportunity to bring these two factors together, as increasingly sophisticated technologies can help change behaviors rather than simply solving problems caused by those behaviors. This paper explores the various options and opportunities for adopting feedback-based interventions — those that communicate information for the purpose of encouraging individuals to alter water consumption habits. Lessons proposed are applicable to any realm in which individual human behavior contributes to a collective environmental or social problem. Focusing on five determinants of success (design, delivery, content, integration, and commitment), this paper presents findings of related studies and fashions them into a suite of recommendations that serves as a template for practice and agenda for future research. The underlying theme — that technology is no absolute substitute for behavioral change but can be one catalyst for it — contributes to broader discussions about the relationship between human systems and the environment.
An Economic Perspective on Fiscal Sustainability of U.S. Water Utilities: What We Know and Think We Know
Authors: Ali Mohammad , Wang Jingjing , Himmelberger Heather , Thacher Jennifer
Published: January 2021

A key issue facing U.S. water utilities is that while costs are generally fixed and increasing over time, the revenue is typically variable and has generally been decreasing/dampening over time, making it harder to maintain fiscal sustainability. Based on a comprehensive review of the relevant literature, we highlight the major factors that can potentially impact the fiscal sustainability of a water utility from an economic perspective. Furthermore, using numerical examples and data from North Carolina, we critically examine which of these factors actually contribute to the fiscal unsustainability of water utilities. We conclude that decreases in demand and increases in costs are the two primary driving forces. Particularly, rate increases cannot be attributed as a determinant of fiscal unsustainability because of the inelastic nature of water demand. Finally, we also highlight strategies for U.S. water utilities to improve their fiscal sustainability.
Taking a Deep Dive Into The Batteryless Internet of Things With Shepherd
Authors: Geissdoerfer Kai , Chwalisz Mikołaj , Zimmerling Marco
Published: January 2021

Collaboration of batteryless devices is essential to their success in replacing traditional battery-based systems. Without significant energy storage, spatio-temporal fluctuations of ambient energy availability become critical for the correct functioning of these systems. We present Shepherd, a testbed for the batteryless Internet of Things (IoT) that can record and reproduce spatio-temporal characteristics of real energy environments to obtain insights into the challenges and opportunities of operating groups of batteryless sensor nodes.
Enabling Batteryless Wearable Devices by Transferring Power Through The Human Body
Authors: Shukla Rishi , Kiran Neev , Wang Rui , Gummeson Jeremy , Ivan Lee Sunghoon
Published: January 2021

Over the past few decades, we have witnessed tremendous advancements in semiconductor and MEMS technologies, leading to the proliferation of ultra-miniaturized and ultra-low-power (in micro-watt ranges) wearable devices for wellness and healthcare [1]. Most of these wearable sensors are battery powered for their operation. The use of an on-device battery as the primary energy source poses a number of challenges that serve as the key barrier to the development of novel wearable applications and the widespread use of numerous, seamless wearable sensors [5].
Monocytes in the Tumor Microenvironment
Authors: Ugel Stefano , Canè Stefania , De Sanctis Francesco , Bronte Vincenzo
Published: January 2021

Immunotherapy has revolutionized cancer treatment over the past decade. Nonetheless, prolonged survival is limited to relatively few patients. Cancers enforce a multifaceted immune-suppressive network whose nature is progressively shaped by systemic and local cues during tumor development. Monocytes bridge innate and adaptive immune responses and can affect the tumor microenvironment through various mechanisms that induce immune tolerance, angiogenesis, and increased dissemination of tumor cells. Yet monocytes can also give rise to antitumor effectors and activate antigen-presenting cells. This yin-yang activity relies on the plasticity of monocytes in response to environmental stimuli. In this review, we summarize current knowledge of the ontogeny, heterogeneity, and functions of monocytes and monocyte-derived cells in cancer, pinpointing the main pathways that are important for modeling the immunosuppressive tumor microenvironment.
Review—Ion Scattering as a Surface Analytical Tool for the Study of Passive Layers
Authors: Strehblow Hans-Henning
Published: January 2021

Among several surface analytical methods Ion Scattering is a possibility to study the composition and depth profile of passive layers. Examples are presented for Rutherford Backscattering Spectroscopy (RBS) for the investigation of thick oxide layers up to more than 100 nm on Al containing additions of other metals like Cu and low Energy Ion Scattering Spectroscopy (ISS or LEIS) for thin passive layers of a few nm thickness of binary alloys. The chemical structure of thin passive layers with a high depth resolution is obtained by ISS depth profiles, which supports the results for these films obtained by X-ray Photoelectron Spectroscopy (XPS). A reliable specimen preparation in an electrochemical cell attached to the UHV spectrometer, i.e. in a closed system is described, which helps to exclude changes and artifacts by unwanted environmental factors, which might affect the results of fundamental investigations.
Comparison of Different Procedural Approaches for Left Atrial Appendage Closure: Searching for Simplicity
Authors: Ruiz-Salmerón Rafael José , Robles-Pérez Carlos , Ronquillo-Japón María , García-Borbolla Rafael , Iglesias-Blanco Manuel , Méndez-Santos Irene , Rubio-Iglesias Carlos , Ginsburg Julia , Rodríguez-Leiras Sergio , Carrascosa-Rosillo César , Vizcaíno-Arellano Manuel , Polo-Padillo Juan
Published: January 2021

Aim. To assess procedural and long-term efficacy and safety of two alternative methods for appendage closure, conscious sedation with standard transoesophageal echo and procedure guided by rotational angiography. Background. Demand for appendage closure is increasing, and a reasonable time-response should be given to nonvalvular atrial fibrillation patients not suitable to receive anticoagulation. General anesthesia and the need for an anesthesiologist are limiting factors to improve procedure availability; it is time to introduce simpler approaches. Methods. Single center experience in appendage closure during 9 years, using three different procedural approaches: general anesthesia with echo guidance, conscious sedation with echo guidance, and rotational angiography guidance. Conscious sedation and rotational angiography-guided procedures were performed in the absence of an anesthesiologist. Procedural characteristics and follow-up events were recorded. Results. 260 consecutive appendage closure procedures were reviewed: 155 were performed under general anesthesia (59.6%), 71 were performed with conscious sedation (27.3%), and 34 were rotational angiography guided (13.1%). Device success rate for procedures guided by rotational angiography was significantly lower than that for general anesthesia and conscious sedation (91.2% versus 100% versus 98.6%,

p
=
0.001

) because there was a greater need to recapture and change device size. However, final procedural success was high and without difference between approaches (98.8% versus 97.2% versus 100%, for general anesthesia, conscious sedation, and rotational angiography, respectively); with a median follow-up of 17 months (CI 95% 13–23 month) (637.9 patients-year), there was no difference among approaches for thromboembolic (1.3 versus 1.8 versus 1.8) and major bleeding events (3.2 versus 2.8 versus 1.8), respectively. Conclusions. Appendage closure performed, either with conscious sedation with echo guidance or rotational angiography guided, is feasible, with no difference in procedural success and follow-up events compared with general anesthesia and without the limitation of the need for an anesthesiologist on-site.
Comparison of Immune Response between SARS, MERS, and COVID‐19 Infection, Perspective on Vaccine Design and Development
Authors: Ansariniya Hossein , Seifati Seyed Mohammad , Zaker Erfan , Zare Fateme
Published: January 2021

Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and Coronavirus Disease 2019 (COVID‐19) infections are the three epidemiological diseases caused by the Coronaviridae family. Perceiving the immune responses in these infections and the escape of viruses could help us design drugs and vaccines for confronting these infections. This review investigates the innate and adaptive immune responses reported in the infections of the three coronaviruses SARS, MERS, and COVID‐19. Moreover, the present study can trigger researchers to design and develop new vaccines and drugs based on immune system responses. In conclusion, due to the need for an effective and efficient immune stimulation against coronavirus, a combination of several strategies seems necessary for developing the vaccine.
QT Prolongation in Dialysis Patients: An Epidemiological Study with a Focus on Malnutrition
Authors: Shibata Masanori , Ito Isao , Tawada Hisae , Taniguchi Shinkichi
Published: January 2021

Background/Aims: QT prolongation is a known risk factor for ventricular fibrillation and ventricular tachycardia. Therefore, more refined management is necessary to reduce sudden cardiac death secondary to such arrhythmias. Methods: Electrocardiographic findings were reviewed in 224 patients, and the associations of QT prolongation with various clinical parameters were examined, including the nutritional state. Correlations were also examined between QT prolongation and body composition measurements determined by multifrequency bioelectrical impedance analysis. Results: Prolongation of the corrected QT (QTc) interval over 0.44 s was seen in 140 patients (62.5%). QT prolongation was independent of age and dialysis therapy duration and was more frequent in diabetics (70.1%) than in nondiabetics (54.2%, p = 0.014) and more frequent in women (78.8%) than in men (53.5%, p < 0.001). Serum levels of albumin (p < 0.001) and Cr (p < 0.001) and the Geriatric Nutritional Risk Index (GNRI, p < 0.001) were negatively correlated with QTc interval; no significant correlation was noted with total protein, urea nitrogen, or uric acid. Negative correlations with QTc interval were found for BMI(p < 0.01), percent total body water (%TBW; p < 0.05), and percent intracellular water (%ICW; p < 0.01) but not with the percent extracellular water/TBW ratio or edema ratio. The longer the QTc interval, the lower the fat-free mass (FFM; p < 0.01) and muscle mass (MM; p < 0.01), but there was no significant correlation with percent fat. Conclusion: These results suggest that QT prolongation is a common complication and is more frequent in women and diabetic patients. The decreases in serum albumin and Cr levels, GNRI, BMI, %TBW, %ICW, FFM, and MM together coincided with malnutrition and thus suggest a close relationship of QT prolongation with malnutrition. Management of QT prolongation may be achieved better in the future by understanding these biochemical and biophysical changes, particularly those regarding malnutrition.
Vasculitis ANCA: Alternativas de tratamiento y las expectativas en los pacientes
Authors: Aguilar-Martínez  Carolina
Published: January 2021

Background: The benefits of treating anti-neutrophil cytoplasmic autoantibody-associated vasculitis (AAV) in advancing age remains unclear with most published studies defining elderly as ≥65 years. This study aims to determine outcomes of induction immunosuppression in patients aged ≥75 years. Methods: A cohort of patients aged ≥75 years with a diagnosis of AAV between 2006 and 2018 was constructed from 2 centres. Follow-up was to 2 years or death. Analysis included multivariable Cox regression to compare mortality and end-stage renal disease (ESRD) based on receipt of induction immunosuppression therapy with either cyclophosphamide or rituximab. A systematic review of outcome studies was subsequently undertaken amongst this patient group through Pubmed, Cochrane and Embase databases from inception until October 16, 2019. Results: Sixty-seven patients were identified. Mean age was 79 ± 2.9 years and 82% (n = 55) received induction immunosuppression. Following systematic review, 4 studies were eligible for inclusion, yielding a combined total of 290 patients inclusive of our cohort. The aggregated 1-year mortality irrespective of treatment was 31% (95% CI 25–36%). Within our cohort, induction immunosuppression therapy was associated with a significantly lower 2-year mortality risk (hazard ratio [HR] 0.29 [95% CI 0.09–0.93]). The pooled HR by meta-analysis confirmed this with a significant risk reduction for death (HR 0.31 [95% CI 0.16–0.57], I2 = 0%). Treated patients had a lower pooled rate of ESRD, but was not statistically significant (HR 0.71 [95% CI 0.15–3.35]). Conclusion: This meta-analysis suggests that patients ≥75 years with AAV do benefit from induction immunosuppression with a significant survival benefit. Age alone should not be a limiting factor when considering treatment.
Die Zukunft der Anti-VEGF-A-Therapie
Authors: Strauß Olaf
Published: January 2021

Anti-vascular endothelial growth factors (anti-VEGF) have become the most common treatment modality for many retinal diseases. These include neovascular age-related macular degeneration (n-AMD), proliferative diabetic retinopathy (PDR) and retinal vein occlusions (RVO). However, these drugs are administered via intravitreal injections that are associated with sight-threatening complications. The most feared of these complications is endophthalmitis, a severe infection of the eye with extremely poor visual outcomes. Patients with retinal diseases typically have to undergo multiple injections before achieving the desired therapeutic effect. Each injection incurs the risk of the sight-threatening complications. As such, there has been great interest in developing sustained delivery platforms for anti-VEGF agents to the posterior segment of the eye. In recent years, there have been various strategies that have been conceptualised. These include non-biodegradable implants, nano-formulations and hydrogels. In this review, the barriers of drug delivery to the posterior segment of the eye will be explained. The characteristics of an ideal sustained delivery platform will then be discussed. Finally, the current available strategies will be analysed with the above-mentioned characteristics in mind to determine the advantages and disadvantages of each sustained drug delivery modality. Through the above, this review attempts to provide an overview of the sustained delivery platforms in their various phases of development.