bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards Engineering Complex Socio-Technical Systems Using Network Motifs: A Case Study on Bike-Sharing Systems
Authors: Xiao Yinshuang , Sha Zhenghui
Published: November 2020

The socio-technical system (STS) is an important topic in Systems Engineering and Design Science. Its performance is not only affected by social aspects but also influenced by various technical factors. To understand the relationships and interactions among different components and subsystems in STS, many studies have been done either at individual agent level or at the system level, yet few studies were conducted at the local structural level in such systems. Motivated by this research gap, we developed an approach to analyzing STS based on the network motif theory. In this study, we apply this approach to three bike-sharing systems (BSS) to validate its feasibility. We focus on studying the size-3 motif, the most basic building block of complex networks, and its correlations to a BSS’s rebalancing performance in three different cities, i.e., NYC, Chicago, and Los Angeles. This paper reaches three conclusions. First, both seasonal and city effects play a significant role in affecting BSS’s network structure and its local motif characteristics. Second, the rebalancing issue, i.e., the imbalance between bike returns and rentals, happened at the local transit level can be different from that observed at the system level, and vice versa. Third, the average geographical distance of size-3 trip motifs follows strong patters correlated to the motif structures as well as the number of directed links in a motif. Compared with previous studies, these insights would be beneficial to guiding system designers in engineering STS, particularly from a bottom-up manner (e.g., using mechanisms or incentives), to achieve desired system-level performance. This study also provides an in-depth understanding of the relations between local system structures and system-level performance in an STS, therefore contributes to both the design theory of complex systems and the BSS research community from a new network motif-based perspective.
Effects of Locus of Control Personality Trait on Team Performance in Cooperative Engineering Design Tasks
Authors: Avşar Alkım Z. , Grogan Paul T.
Published: November 2020

Teams in engineering design tackle problems that exceed the abilities of individuals. Improved understanding of how personality traits influence human behaviors and interaction may help create new methods and tools to support design teams. This paper seeks to understand how the Locus of Control (LOC) personality trait influences designer behaviors and team performance. A designer experiment studies 12 participant pairs controlled for categorical LOC pairing factors (internal-internal, external-external, and internal-external). Each design team completes six simplified cooperative parameter design tasks to minimize completion time, yielding 72 total data points. Regression analysis shows LOC pairing affects team efficiency in agreement with literature outside engineering design: diverse LOC traits reduce design efficiency while similarity increases team effectiveness. Results contribute to an explanatory hypothesis that LOC pairing influences designer behaviors related to action effectiveness which, subsequently, affects team performance outcomes.
Elastic Metasurfaces for Low-Frequency Flexural Wavefront Control
Authors: Lin Zhenkun , Tol Serife
Published: November 2020

Controlling elastic/acoustic wave-front via compact designs has attracted increasing research interest in past decades. The emerging of metasurface concept provides an unconventional and attractive approach in this filed. A metasurface generally consists of a single array of subwavelength-scaled patterns in the host medium, introducing an abrupt phase shift in the wave propagation path. In this paper, we explored an elastic metasurface concept to control the propagation of low-frequency flexural Lamb waves. The phase modulation based on the Snell’s law was achieved by tailoring the thickness of thin beam resonators connecting two elastic host medium. Depending on the design of the phase-modulated structure (a.k.a. metasurface), elastic waves could be steered or focused which was verified through analytical and numerical models.
Mistuning Identification for Rotating Bladed Disks Using Stationary Measurements and Reduced Order Models
Authors: Kurstak Eric , Look Karsten , D’Souza Kiran
Published: November 2020

Although full-scale representative experiments provide critical data for final validation of designs, there is increasing emphasis on computational and reduced scale experiments to test out initial design concepts. This is true in many fields, especially in the field of turbomachinery; turbomachines are complex machines that operate at high temperatures and pressures for long durations of time and it is very expensive to build prototypes and conduct full scale testing. Stationary test rigs are cheaper to design and operate than rotating test rigs, but can lack the proper boundary conditions required to mimic actual operating conditions. A key characteristic of the design that is identified from experiments for bladed disks is mistuning. Mistuning are the sector to sector differences in bladed disks due to manufacturing tolerance, operational wear, or material deviations, and can lead to vibration localization. This work provides insight in correlating stationary mistuning measurements to the mistuning observed in a rotating bladed disk. The mistuning values from bench-top tests are shown to match the mistuning values from the rotating experiments. A parametric reduced order model (PROM) is constructed using stationary mistuning values to model the fully mistuned system, complete with rotational speed effects such as stress stiffening. The PROM enables changing the mistuning and rotational speed effects in the reduced space. The natural frequencies of the computational model are compared to the experimental blade frequencies to show that the computational model is similar to the experimental system. The final model can then be used to simulate the physical experiments using time integration methods.
Evolutionary Approach to Function Model Synthesis: Development of Parameterization and Synthesis Rules
Authors: Gill Amaninder Singh , Sen Chiradeep
Published: November 2020

The goal of this paper is to develop the groundwork for automated synthesis of function models. To this end, an evolutionary algorithm based framework has been developed. A parameterization method that can completely describe any given function models has been proposed. The parameterization makes the function models compatible for use within the evolutionary algorithm framework. Validation of the parameterization method is carried out by using an evolutionary algorithm to synthesize the function models for five different electromechanical products. The algorithm converged in each case, indicating that the method is satisfactory and that function models can actually be synthesized using an evolutionary framework. In addition, the adaptation of several a priori rules for use in this framework has been proposed. These rules are categorized as grammar, logical and feature based rules. An updated evolutionary framework that incorporates these rules is also presented.
Method Selection in Human-Centered Design Teams: An Examination of Decision-Making Strategies
Authors: Rao Vivek , Kim Euiyoung , Kwon Jieun , Agogino Alice , Goucher-Lambert Kosa
Published: November 2020

Designers’ choices of methods are well known to shape project outcomes. However, questions remain about why design teams select particular methodsand how teams’ decision-making strategies are influenced by project- and process-based factors. In this work, we analyze novice design teams’ decision-making strategies underlying 297 selections of human-centered design methods over the course of three semester-long project-based engineering design courses. We propose a framework grounded in 100+ factors sourced from new product development literature that classifies design teams’ method selection strategy as either agent-, outcome-, or process-driven, with eight further subclassifications. Coding method selections with this framework, we uncover three insights about design team method selection. First, we identify fewer outcomes-based selection strategies across all phases and innovation types. Second, we observe a shift in decision-making strategy from user-focused outcomes in earlier phases to product-based outcomes in later phases. Third, we observe that decision-making strategy produces a greater heterogeneity of method selections as compared to the class average as a whole, or project type alone. These findings provide a deeper understanding of designers’ method selection behavior and have implications for effective management of design teams, development of automated design support tools to aid design teams, and curation of design method repositories, e.g., theDesignExchange.
Nonlinear Time-Series Prediction Using a Single MEMS Reservoir
Authors: Hasan Mohammad H. , Alsaleem Fadi
Published: November 2020

In this work, we show the computational potential of MEMS devices by predicting the dynamics of a 10th order nonlinear auto-regressive moving average (NARMA10) dynamical system. Modeling this system is considered complex due to its high nonlinearity and dependency on its previous values. To model the NARMA10 system, we used a reservoir computing scheme by utilizing one MEMS device as a reservoir, produced by the interaction of 100 virtual nodes. The virtual nodes are attained by sampling the input of the MEMS device and modulating this input using a random modulation mask. The interaction between virtual nodes within the system was produced through delayed feedback and temporal dependence. Using this approach, the MEMS device was capable of adequately capturing the NARMA10 response with a normalized root mean square error (NRMSE) = 6.18% and 6.43% for the training and testing sets, respectively. In practice, the MEMS device would be superior to simulated reservoirs due to its ability to perform this complex computing task in real time.
Enabling Traceability in Agri-Food Supply Chains Using an Ontological Approach
Authors: Ameri Farhad , Wallace Evan , Yoder Reid
Published: November 2020

Traceability of food products to their sources is critical for quick responses to a food emergency. US law now requires stakeholders in the agri-food supply chain to support traceability by tracking food materials they acquire and sell. However, having complete and consistent information needed to quickly investigate sources and identify affected material has proven difficult. There are multiple reasons that makes food traceability a challenging task including diversity of stakeholders and their lexicons, standards, tools and methods; unwillingness to expose information of internal operations; lack of a common understanding of steps in a supply chain; and incompleteness of data. Ontologies can address the traceability challenge by creating a shared understanding of the traceability model across stakeholders in a food supply chain. They can also support semantic mediation, data integration, and data exploration. This paper reports an on ongoing effort aimed at developing a formal ontology for supply chain traceability using use cases and data from partners in the bulk grain domain. The developed ontology was validated in VocBench environment through creating RDF triples from real datasets and executing SPARQL queries corresponding to predefined competency questions.
A Life Cycle Analysis of Laser Cutter Embodied Impacts
Authors: Moore George , Goucher-Lambert Kosa , Agogino Alice M.
Published: November 2020

There are broad claims about how makerspaces, Fab Labs, and hacker spaces are going to make production trends more sustainable and facilitate equitable access to manufacturing opportunities. Absent from most of these discussions are metrics for success: how will these personal fabrication spaces assess their status as self-sufficient, self-serving, and sustainable? Laser cutters are one of the more popular tools in personal fabrication spaces; yet there are gaps in the literature regarding their environmental impacts as compared to popular tools. Research on embodied environmental impacts is lacking for laser cutters and this study aims to fill a part of that gap by examining the embodied impacts of the Universal Laser System’s (ULS) VL-300 laser cutter. Results showed that 49.58 ReCiPe Endpoint H points were required to produce and distribute the ULS VL-300 laser cutter. Specifically, embodied impacts of the electronics — the micro-controllers required to operate the laser cutter — are responsible for the bulk (74%) of the overall laser cutter embodied impacts.
Engineering for Global Development: Characterizing the Discipline Through a Systematic Literature Review
Authors: Burleson Grace , Austin-Breneman Jesse
Published: November 2020

Over the past 50 years, researchers have repeatedly proposed the establishment of a new interdisciplinary engineering field in Engineering for Global Development (EGD), whose analytical tools and design processes result in positive social impacts and poverty alleviation in a global development context. Within each discipline and research area, a growing body of work has sought to systematically create scientific knowledge in this area. However, a recent network analysis of Human-Centered Design plus Development research indicates that sub-communities are not collaborating at a high level and therefore the overall research agenda may lack cohesion. This paper presents a descriptive analysis of EGD research within mechanical engineering along four dimensions through a systematic literature review and secondary data analysis. Results from the review and a Latent Dirichlet Allocation model indicate EGD work in mechanical engineering draws upon research methodologies from a number of other fields and has low levels of consensus on technical terminology. These results suggest consensus in the broader interdisciplinary EGD field should be examined.
A Parametric Study on the Effects of Reynolds Number on the Topology Optimization of Navier-Stokes Flows
Authors: Najmon Joel C. , Wu Tong , Tovar Andres
Published: November 2020

Fluid-flow topology optimization (FTO) allows the generation of innovative flow-channel layouts with minimal pressure drop (power dissipation) between inlet and outlet ports in a given design domain. FTO was first explored using Stokes flow with the material in the design domain modeled as a porous medium governed by Darcy’s law. More recently, Navier-Stokes flow has been implemented to consider higher Reynolds numbers. The objective of this work is to demonstrate the effect of the Reynolds number on the FTO results and generate a set of design rules. To this end, a density-based FTO algorithm and an in-house finite element analysis code for incompressible Navier-Stokes flow are developed. The optimization process is updated using the method of moving asymptotes so that the flow’s potential power is maximized. The nonlinear Navier-Stokes equations are solved using a trust region Newton’s method. Sensitivity analysis is carried out using the adjoint method. A parametric study of the underlying parameters of the Reynolds number in two numerical examples shows the effect of the fluid’s dynamic viscosity and velocity on the optimized flow channels. The results show that fluids with the same Reynolds number, but with different dynamic viscosity or velocity values, can generate significantly different flow channels.
Design of Passive Lower Limb Exoskeleton to Aid in Injury Mitigation and Muscular Efficiency
Authors: Tracey Dylan , Zhang Hao
Published: November 2020

With the duties and responsibilities of the military, they are on the cutting edge of R&D and the latest and greatest technologies. One significant problem effecting thousands of soldiers are injuries to the lower limbs, specifically the knees, as a result of high impact to the joints and muscles. Through the research of biomechanics and ergonomics during human locomotion of running, cause and effects fatigue, muscular activation during running, gait cycle force analysis, and biomimicry of kangaroos, we were able to identify lower limb exoskeletons as a viable solution to the problem. The purpose of this research was to develop a relatively inexpensive prototype of a passive lower limb exoskeleton to aid in injury mitigation and muscular efficiency for soldiers. The hypothesis was that a lower limb exoskeleton would reduce/mitigate injuries by reducing stride length and increases stride frequency to lower impact on the knees while running. The prototype was tested by one participant on a 2-mile course with two load variations tested while running. The key results were seen from the spring systems potential to increase average stride cadence/frequency by 6–14% and reduce impact on joints and muscles by increasing the number of steps and reducing high center of gravity oscillation by 13–27%. Furthermore, this study provides evidence and research that proves that a passive lower limb exoskeleton design, which increases stride frequency and reduces stride length, can mitigate injuries to the lower limbs when running with weight by reducing the impact forces on the knees and improving running economy.
A Pre-Prototyping Framework to Explore Human-Centered Prototyping Strategies During Early Design
Authors: Ahmed Salman , Demirel H. Onan
Published: November 2020

Current prototyping frameworks are often prompt-based and heavily rely on designers’ experience. The lack of systematic guidelines in prototyping activities causes unwanted variation in the quality of the prototype. Notably, there is limited, or no prototyping framework exists that enables human factors engineering (HFE) guidelines be part of the early product development process. In this paper, a pre-prototyping framework is proposed to render human-centered design strategies to guide designers before the hands-on prototyping activity starts. The methodology consists of extracting key factors related to prototyping and human factors engineering principles based on an extensive literature review. The key elements are then combined to form the prototyping categories, dimensions (theory), and tools (practice). The resulting prototyping framework can be used to develop prototyping strategies consist of theoretical guidelines and practical tools that are needed during the prototyping of human-centered products. The framework provides systematic guidance to designers in the early stages of the design process so that designers, in particular novices in ergonomics and human factors, can have a head start in building the prototypes in the right direction. Finally, a case study is presented to demonstrate a walk-through and efficacy of the proposed pre-prototyping framework.
Learning to Abstract and Compose Mechanical Device Function and Behavior
Authors: Wang Jun , Chiu Kevin , Fuge Mark
Published: November 2020

While current neural networks (NNs) are becoming good at deriving single types of abstractions for a small set of phenomena, for example, using a single NN to predict a flow velocity field, NNs are not good at composing large systems as compositions of small phenomena and reasoning about their interactions. We want to study how NNs build both the abstraction and composition of phenomena when a single NN model cannot suffice. Rather than a single NN that learns one physical or social phenomenon, we want a group of NNs that learn to abstract, compose, reason, and correct the behaviors of different parts in a system. In this paper, we investigate the joint use of Physics-Informed (Navier-Stokes equations) Deep Neural Networks (i.e., Deconvolutional Neural Networks) as well as Geometric Deep Learning (i.e., Graph Neural Networks) to learn and compose fluid component behavior. Our models successfully predict the fluid flows and their composition behaviors (i.e., velocity fields) with an accuracy of about 99%.
Enhanced Toolpath Planning for Fused Filament Fabrication
Authors: Chen Hongrui , Liu Xingchen
Published: November 2020

The slicing software process the 3D geometry into 2D slices and toolpaths for additive manufacturing processes. Most slicing software allows users to select from an array of infill patterns and to specify the overall infill volume fraction globally. However, the ability to locally control the volume fraction, and mechanical properties, is often limited. In this paper, we propose a novel toolpath enhancing algorithm to enable the local control on the volume fraction of various stock and custom infill patterns. In particular, the algorithm widens the infill pattern by directly modifying their toolpath with connected Fermat curves. By preserving the topology of the original toolpath, the connected Fermat curve not only produces predictable boosts in part performance but also minimized the printing time by eliminating extruder traversals without material deposition. The field that controls local volume fraction can be designed either manually or through optimization. The effectiveness of the proposed approach in toolpath generation is demonstrated through volume fraction fields designed by both approaches.
Multiparameter Real-World System Identification Using Iterative Residual Tuning
Authors: Allevato Adam , Pryor Mitch , Thomaz Andrea L.
Published: November 2020

In this work we consider the problem of nonlinear system identification, using data to learn multiple and often coupled parameters that allow a simulator to more accurately model a physical system and close the so-called reality gap for more accurate robot control. Our approach uses iterative residual tuning (IRT), a recently-developed derivative-free system identification technique that utilizes neural networks and visual observation to estimate parameter differences between a proposed model and a target model. We develop several modifications to the basic IRT approach and apply it to the system identification of a 5-parameter model of a marble rolling in a robot-controlled labyrinth game mechanism. We validate our technique both in simulation — where we outperform two baselines — and on a real system, where we achieve marble tracking error of 4.02% after just 5 optimization iterations.
Design of a Novel Variable Stiffness Active Ankle Foot Orthosis Using Permanent Magnets for Drop Foot Assistance
Authors: Basu Abhinaba , Jujjavarapu Sri Sadhan , Esfahani Ehsan T.
Published: November 2020

In this paper, we present the design of a novel variable stiffness ankle-foot orthosis for correcting the drop-foot condition. The proposed mechanism controls the position of permanent magnets to provide torque and stiffness assistance to the patients suffering from drop foot. A publicly available gait dataset of 20 healthy individuals is used to extract the stiffness and torque requirements of a gait cycle and the information is used to evaluate the foot orthosis. It is shown that the proposed foot orthosis can provide appropriate torque and stiffness assistance to the ankle joint during the swing and the stance phase respectively. Moreover, the spring-like nature of the repelling magnets reduces the impact forces on the patient’s joints.
Community Growth Model in Different Profit-Seeking Contexts: A Comparative Case Study of RepRap and Ultimaker
Authors: Li Zhuoxuan , Yang Maria , Seering Warren
Published: November 2020

The engagement of an online user community has been reported to be critical in the success of open design projects. However, most studies don’t consider the financial organizational contexts of their samples. Grounded in comparative case studies of the two biggest 3D printer communities — one supported by volunteers, another by a commercial firm, the paper contributes to the open design and open hardware literature with a typology of user community actions. We measured the types and intensity of different user community activities over time for the two cases. Results confirm that user community activities behave differently in profit-seeking or non-profit-seeking organizational contexts. We grounded potential causes through management team interviews as well as existing research theories. We conclude that the for-profit organizational context is associated with a difference in the design maturation process and the evolution of organizational openness.
A Methodology to Design a Variable Resistance Hand Exerciser Using a Compliant Mechanism
Authors: Komatireddy Jyothi , Midha Ashok , Lodagala Vamsi , Bagivalu Prasanna Pratheek
Published: November 2020

The design of an effective hand-exercising device is based on an existing study of the force-deflection behavior of the human hand. This paper presents a design methodology using a compliant mechanism construct, for generating the desired force-deflection profile as the output. This is made possible by the integration of a rigid cam profile segment. The compliant segments serve as the followers, and their material and geometric properties serve as design variables. The force-deflection profile utilized was developed through experimental studies conducted on the human hand, along with a mathematical model that predicts the maximum grip force as a function of the handle’s diameter. A procedure is proposed herein that would allow the use of various force-deflection profiles, to be able to change the resistance level in order to meet individual requirements. The synthesis results obtained are investigated for cam-follower non-interference using a novel pseudo-rigid-body model (PRBM) approach and verified by finite element analysis. The exercise devices generally ignore in their conceptualization and design the anatomical mechanical advantage. This methodology, owing to the nature of the experiment, duly regards the variable mechanical advantage characteristic of the hand in different positions naturally.
Enhancements to the Perfect Matching Approach for Graph Enumeration-Based Engineering Challenges
Authors: Herber Daniel R.
Published: November 2020

Graphs can be used to represent many engineering systems and decisions because of their ability to capture discrete compositional and relational information. In this article, improved methods for effectively representing and generating all graphs in a space defined by certain complex specifications are presented. These improvements are realized through enhancements to the original perfect matching-inspired approach utilizing a component catalog definition to capture the graphs of interest. These enhancements will come in many forms, including more efficient graph enumeration and labeled graph isomorphism checking, expansion of the definition of the component catalog, and the effective inclusion of new network structure constraints. Several examples are shown, including improvements to the original case studies (with up to 971× reduction in computational cost) as well as graph problems in common system architecture design patterns. The goal is to show that the work presented here and tools developed from it can play a role as the domain-independent architecture decision support tool for a variety of graph enumeration-based engineering design challenges.
American Kinesiology Association’s Role in Promoting School Physical Activity Policy
Authors: Lounsbery Monica A.F. , McKenzie Thomas L.
Published: November 2020

This paper reviews the authors’ evolution as kinesiology scholars to a public health focus via their research on school physical activity (PA) and policy. The authors present key findings from their work, including their recent focus group discussion with 20 school leaders, to substantiate their perspectives about the role that the American Kinesiology Association could play in supporting public health goals and promoting school PA policy. The authors conclude the paper by appealing to American Kinesiology Association to clearly identify PA and its promotion as a central area of study in kinesiology, strengthen its ties to public health, and advocate for putting the “physical” back in the National Physical Education Standards.
Transient cortical circuits match spontaneous and sensory-driven activity during development
Authors: Molnár Zoltán , Luhmann Heiko J. , Kanold Patrick O.
Published: November 2020

A moment in time

As the brain develops, it does not simply get bigger. Like a building that depends on temporary scaffolds as its structures are assembled, the developing brain sets up the circuits that characterize the adult brain. Molnár
et al.
review the current state of knowledge about how brain connections are built and how autonomously established patterns are reshaped by activity from the sensory periphery. With the help of a transient population of neurons, the spontaneous activity of early circuits is molded by increasing inputs from the external world. When these normal developmental interactions are disrupted, consequent miswiring drives dysfunction in the adult brain.

Science
, this issue p.
eabb2153
Behavioral state coding by molecularly defined paraventricular hypothalamic cell type ensembles
Authors: Xu Shengjin , Yang Hui , Menon Vilas , Lemire Andrew L. , Wang Lihua , Henry Fredrick E. , Turaga Srinivas C. , Sternson Scott M.
Published: November 2020

How neuron types encode behavioral states

What is the contribution of molecularly defined cell types to neural coding of stimuli and states? Xu
et al.
aimed to evaluate neural representation of multiple behavioral states in the mouse paraventricular hypothalamus. To achieve this goal, they combined deep-brain two-photon imaging with post hoc validation of gene expression in the imaged cells. The behavioral states could be well predicted by the neural response of multiple neuronal clusters. Some clusters were broadly tuned and contributed strongly to the decoding of multiple behavioral states, whereas others were more specifically tuned to certain behaviors or specific time windows of a behavioral state.

Science
, this issue p.
eabb2494
Comparative Performance of Five Commercially Available Serologic Assays To Detect Antibodies to SARS-CoV-2 and Identify Individuals with High Neutralizing Titers
Authors: Patel Eshan U. , Bloch Evan M. , Clarke William , Hsieh Yu-Hsiang , Boon Denali , Eby Yolanda , Fernandez Reinaldo E. , Baker Owen R. , Keruly Morgan , Kirby Charles S. , Klock Ethan , Littlefield Kirsten , Miller Jernelle , Schmidt Haley A. , Sullivan Philip , Piwowar-Manning Estelle , Shrestha Ruchee , Redd Andrew D. , Rothman Richard E. , Sullivan David , Shoham Shmuel , Casadevall Arturo , Quinn Thomas C. , Pekosz Andrew , Tobian Aaron A. R. , Laeyendecker Oliver
Published: November 2020

Accurate serological assays to detect antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are needed to characterize the epidemiology of SARS-CoV-2 infection and identify potential candidates for coronavirus disease 2019 (COVID-19) convalescent plasma (CCP) donation. This study compared the performances of commercial enzyme immunoassays (EIAs) with respect to detection of IgG or total antibodies to SARS-CoV-2 and neutralizing antibodies (nAbs). The diagnostic accuracy of five commercially available EIAs (Abbott, Euroimmun, EDI, ImmunoDiagnostics, and Roche) for detection of IgG or total antibodies to SARS-CoV-2 was evaluated using cross-sectional samples from potential CCP donors who had prior molecular confirmation of SARS-CoV-2 infection (
n
 = 214) and samples from prepandemic emergency department patients without SARS-CoV-2 infection (
n
 = 1,099).
Metagenome Proteins and Database Contamination
Authors: Arkhipova Irina R.
Published: November 2020

Continued influx of metagenome-derived proteins with misannotated taxonomy into conventional databases, including RefSeq, threatens to eliminate the value of taxonomy identifiers. To prevent this, urgent efforts should be undertaken by submitters of metagenomic data sets as well as by database managers.
MDM2 gene amplification as selection tool for innovative targeted approaches in PD-L1 positive or negative muscle-invasive urothelial bladder carcinoma
Authors: Brunelli Matteo , Tafuri Alessandro , Cima Luca , Cerruto Maria Angela , Milella Michele , Zivi Andrea , Buti Sebastiano , Bersanelli Melissa , Fornarini Giuseppe , Vellone Valerio Gaetano , Rebuzzi Sara Elena , Procopio Giuseppe , Verzoni Elena , Bracarda Sergio , Sabbatini Roberto , Baldessari Cinzia , Eccher Albino , Passalacqua Rodolfo , Perrucci Bruno , Giganti Maria Olga , Donini Maddalena , Panni Stefano , Tucci Marcello , Prati Veronica , Ortega Cinzia , Caliò Anna , Alongi Filippo , Munari Enrico , Pappagallo Giovanni , Iacovelli Roberto , Mosca Alessandra , Porta Camillo , Martignoni Guido , Antonelli Alessandro
Published: November 2020

Aims

According to The Cancer Genome Atlas (TCGA), around 9% of bladder carcinomas usually show abnormalities of the murine double minute 2 (MDM2) gene, but a few studies have been investigated them. We profiled MDM2 gene amplification in a series of urothelial carcinomas (UC) considering the molecular subtypes and expression of programmed death ligand 1 (PD-L1).

Methods

117 patients with muscle-invasive UC (pT2-3) without (N0) or with (N+) lymph-node metastases were revised. Only cases with availability of in toto specimens and follow-up were studied. Tissue microarray was built. p53, ER, RB1, GATA-3, CK20, CK5/6, CD44 and PD-L1 (clone sp263) immunoexpression was evaluated. Fluorescent in situ hybridisation was assessed by using the HER-2/neu, FGFR-3, CDKN2A and MDM2 probes. True (ratio 12q/CEP12 >2) MDM2 gene amplification was distinguished from polyploidy/gains (ratio <2, absolute copy number of MDM-2 >2). MDM2 and PD-L1 values were correlated to the TCGA molecular phenotypes. Statistical analysis was performed.

Results

6/50 (12%) cases (5 N0 and 1 N+) were amplified for MDM2 without matching to molecular phenotypes. Of 50, 14 (37%) cases expressed PD-L1 at 1% cut-off; 3/50 (9%) at >50% cut-off; of these, 2 cases on side of neoplasia among inflammatory cells. Only one out of six (17%) cases amplified for MDM2 showed expression (>50% cut-off) of PD-L1. MDM2 amplification was independent to all documented profiles (k test=0.3) and was prevalent in recurrent UC.

Conclusion

MDM2 amplification has been seen in both PD-L1 positive and negative muscle-invasive bladder UC independently from the TCGA molecular phenotypes. MDM2 and PD-L1 might be assessed in order to predict a better response to combo/single targeted therapies.
Ratios of negative-to-positive parity level densities in Mo isotopes
Authors: Nouri O. , Razavi R. , Rahmatinejad A. , Mohammadi S.
Published: November 2020

The ratios of negative-to-positive parity level densities in 94,96,98Mo isotopes are calculated using a microscopic formalism based on the Bardeen–Cooper–Schrieffer (BCS) model. In this calculation, the single-particle energies are obtained with the Nilsson model. Mass number, shell, and deformation effects on the parity equilibration phenomenon in these isotopes are discussed in this work.
Mobilizing Sophisticated Donors: What Candidate Facebook Posts Do Attract Intra- and Inter-District Donations?
Authors: WANG AUSTIN HORNG-EN , LAI FEI-PEI , HSU FUSHUN , WANG PETER SHAOJUI
Published: November 2020

Why do so many voters finance candidates, even out-of-district ones? We exploit two datasets from a candidate in the 2014 Taiwan City Mayor Election derived from 14,838 detail donation records and the candidate’s 296 Facebook posts during the campaign. We replicate previous findings at the district level, indicating that donations are influenced by both physical proximity and ideology. The post-level analysis shows that the neighboring effect does not build as a spillover of public policy or administrative reforms. Instead, residents donate more merely because they are closer to a campaign. Meanwhile, a candidate’s ideological posts can successfully increase donations within a few hours from a district where there are more friendly voters.
Global threshold dynamics of an age structured alcoholism model
Authors: Bentout Soufiane , Djilali Salih , Chekroun Abdenasser
Published: November 2020

We consider in this research an age-structured alcoholism model. The global behavior of the model is investigated. It is proved that the system has a threshold dynamics in terms of the basic reproduction number (BRN), where we obtained that alcohol-free equilibrium (AFE) is globally asymptotically stable (GAS) in the case [Formula: see text], but for [Formula: see text] we found that the system persists and the nontrivial equilibrium (EE) is GAS. Furthermore, the effects of the susceptible drinkers rate and the repulse rate of the recovers to alcoholics are investigated, which allow us to provide a proper strategy for reducing the spread of alcohol use in the studied populations. The obtained mathematical results are tested numerically next to its biological relevance.
Erlangmixture distribution with application on COVID-19 cases in Egypt
Authors: Abd El-Monsef M. M. E.
Published: November 2020

In this paper, a finite mixture of [Formula: see text]-Erlang distributions is proposed. Different moments, shape characteristics and parameter estimates of the proposed model are also provided. The proposed mixture has the property that it has a bounded hazard function. A special case of the mixed Erlang distribution is introduced and discussed. In addition, a predictive technique is introduced to estimate the needed number of mixture components to fit a certain data. A real data concerning the confirmed COVID-19 cases in Egypt is introduced to utilize the predictive estimation technique. Two more real datasets are used to examine the flexibility of the proposed model.
A Constant-factor Approximation Algorithm for the Asymmetric Traveling Salesman Problem
Authors: Svensson Ola , Tarnawski Jakub , Végh László A.
Published: November 2020

We give a constant-factor approximation algorithm for the asymmetric traveling salesman problem (ATSP). Our approximation guarantee is analyzed with respect to the standard LP relaxation, and thus our result confirms the conjectured constant integrality gap of that relaxation.

The main idea of our approach is a reduction to Subtour Partition Cover, an easier problem obtained by significantly relaxing the general connectivity requirements into local connectivity conditions. We first show that any algorithm for Subtour Partition Cover can be turned into an algorithm for ATSP while only losing a small constant factor in the performance guarantee. Next, we present a reduction from general ATSP instances to structured instances, on which we then solve Subtour Partition Cover, yielding our constant-factor approximation algorithm for ATSP.
Passivation-Induced Cr and Mo Enrichments of 316L Stainless Steel Surfaces and Effects of Controlled Pre-Oxidation
Authors: Lynch Benjamin , Wang Zuocheng , Ma Li , Paschalidou Eirini-Maria , Wiame Frédéric , Maurice Vincent , Marcus Philippe
Published: November 2020

Passivation mechanisms and the effects of controlled pre-oxidation, by exposure to oxygen at ultra-low pressure, on Cr and Mo surface enrichments were investigated on polycrystalline AISI 316L stainless steel surfaces with direct transfer between surface preparation and analysis by X-ray photoelectron spectroscopy and electrochemistry. Exposure to sulfuric acid at open circuit potential causes preferential dissolution of oxidized iron species, which promotes Cr3+ and Mo4+/6+ enrichments. Anodic passivation forces oxide film re-growth and Cr3+ dehydroxylation with no loss of Mo4+/6+ pre-enrichment. Ultra-low pressure pre-oxidation promotes Mo4+/6+ enrichment in the exchange outer hydroxide layer of the passive film, with no Mo0 depletion in the modified alloy region underneath the oxide film at open circuit potential, and under anodic passivation. Mo4+/6+ enrichment improves protectiveness against transient active dissolution during the active/passive transition.
Voltage Loss Analysis of Zinc-Cerium Redox Flow Batteries
Authors: Amini Kiana , Pritzker Mark D.
Published: November 2020

Redox flow batteries (RFBs) are a relatively new generation of electrochemical devices suitable for large-scale energy storage applications. The separation between the electrolyte storage tanks and the electrochemical cell in RFBs simplifies the battery scale-up and facilitates the energy/power ratio tuning. Among the different types of RFBs investigated, those based on zinc and cerium are very attractive due to the large negative and positive electrode potentials in an aqueous media. Thus, zinc-cerium RFBs are capable of providing one of the highest cell voltages (~ 2.4 V) among flow [1]. To date, Zn-Ce RFBs have primarily been investigated galvanostatically to determine their charge, voltage and energy efficiencies and attempts have been made to suppress the rate of the hydrogen evolution side reaction [2,3]. In order to further optimize the performance of these batteries and to elucidate the future pathways to enhance their efficiency, the sources of voltage loss in the battery during discharge must be identified and the role of the positive and negative half-cells in the voltage loss determined. Toward this goal, we have conducted in situ polarization and EIS experiments on a full-cell Zn-Ce RFB with reference electrodes inserted in the system. At low and intermediate current densities, the main contributor to the voltage loss during discharge is the kinetic overpotential of the negative Zn/Zn2+ half-cell. On the other hand, at high current densities, mass transfer limitations at the positive Ce3+/Ce4+ half-cell cause a large potential drop in the system. From in situ kinetic studies, we have measured an exchange current density of ~ 7.4*10−3 A cm−2 for Zn oxidation and ~ 24.2*10−3 A cm−2 for Ce4+ reduction, which supports the findings from battery operation that the kinetics of the negative electrode reaction is slow compared to that of the positive electrode at low-to-intermediate current densities. The use of an alternative mixed methanesulfonate-chloride negative electrolyte to reduce the kinetic overpotential of the negative half-cell reaction and the influence of the flow rate on the mass-transfer rate of the positive half-cell reaction have also been investigated and will be discussed in this presentation.
CPLD-Based Displacement Measurement System for Nanoscale Grating Ruler
Authors: Sun Jiyuan , Tian Chunlin
Published: November 2020

With the continuous development of science and technology, industrial production has higher and higher requirements for precision. Many high-precision measurement technologies emerge as the times require, and nanoscale grating ruler displacement measurement technology is one of them. As a kind of precision sensor, nanoscale grating ruler has important application in displacement measurement system. CPLD has the advantages of high integration and fast programming speed, which is often used to control the displacement measurement system of nanoscale grating ruler. The purpose of this paper is to deeply explore the measurement effect and related application principle of nanoscale grating ruler displacement measurement system based on CPLD technology. A set of nanoscale grating ruler displacement measurement system is designed based on CPLD technology. The output signal of grating ruler is programmed by CPLD. The x-axis displacement of the experimental platform controlled by stepping motor is measured, and the measured data are recorded by carrying out analysis and research. The results show that compared with the traditional phase difference measurement system, the measurement accuracy of the system based on CPLD is improved by 24.7%, the robustness of the measurement system is improved by 18.6%, and the measurement speed is increased by 27.3%. Therefore, this kind of nanoscale measurement precision grating ruler displacement measurement control system based on CPLD has three characteristics: high measurement accuracy, strong anti-interference ability, and high measurement motion efficiency, which can effectively meet the requirements of grating ruler displacement measurement system for high-precision manufacturing technology.
Assessment of Midwife Knowledge, Practice, and Associated Factors towards Active Management of the Third Stage of Labor at Governmental Health Institutions in Tigray Region, Northern Ethiopia, 2018
Authors: Wake Getu Engida , Wogie Girma
Published: November 2020

Introduction. Globally, postpartum hemorrhage is the most common cause of maternal mortality and morbidity, and it accounts for more than 25% of all maternal deaths. The majority of death due to postpartum hemorrhage is caused by uterine atony. Routine and correct usage of active management of the third stage of labor decreases the occurrence of postpartum hemorrhage by 60% when compared to expectant management of the third stage of labor. The purpose of this study was to assess midwife knowledge, practice, and associated factors towards active management of the third stage of labor at governmental health institutions in the Tigray region, 2018. Results. These study results showed that from the total study participants (N = 278), 170 (61.2%) were good in knowledge and 121 (43.5%) were good in practice towards active management of the third stage of labor. Training related to active management of the third stage of labor (AOR = 2.119, 95%CI = 1.141, 3.3937) and practice level of midwives (AOR = 8.089, 95%CI = 4.103, 15.950) became significantly associated with the knowledge level. The educational level of midwives (AOR = 3.811, 95%CI = 2.015, 7.210), training related to active management of the third stage of labor (AOR = 2.591, 95%CI = 1.424, 4.714), and knowledge level of midwives towards active management of the third stage of labor (AOR = 7.324, 95%CI = 3.739, 14.393) were significantly associated with the practice level. This study showed that training related to active management of the third stage of labor was significantly associated with the knowledge and practice level of midwives. The educational level and knowledge level of midwives were significantly associated with the practice level of midwives towards active management of the third stage of labor. Therefore, midwives should update their academic level and knowledge. Health institutions in collaboration with the Tigray Regional Health Bureau should arrange training for all midwives to bring change.
The Practical Influence of Climate Change on the Performance of Road Stormwater Drainage Infrastructure
Authors: Al-Ghadi Mohammed Saleh , Mohtar Wan Hanna Melini Wan , Razali Siti Fatin Mohd , El-Shafie Ahmed
Published: November 2020

The atmospheric temperature globally has risen during the last few centuries, causing global warming and climate dynamics. The impact of global warming has caused environmental effects that include increased rainfall intensity, which is recognised as the leading cause of flooding, and destruction and devastation to the surrounding environment, infrastructure, and human life. Road stormwater drainage systems are used for removing and controlling excess runoff water to the right way. However, regardless of enhanced technologies, the reliability of drainage system schemes remains a major undertaking for water and hydraulic engineers alike. In this study, a thorough evaluation of the methods employed in previous studies and research on rainfall forecasting models was undertaken. Further to that, the effect resulting from climate change on structures of drainage infrastructure is considered in addition to the methods to enhance drainage system challenges with recent models developed for advanced drainage and waterway requirements that need to be designed in consideration of climate change.