bluuebunny/crossref_metadata_2025_split huggingface dataset:
Encountering Spiking Neural Networks
Authors: Saunier Alexandre , Howes David 
Published: November 2023

AbstractOver the past two decades, the term “intelligent media” has surfaced to describe media that take on problematics of cognition, communication, and sensory perception loosely modeled after human intelligence. Taking the form of hardware‐software assemblages, these novel media demonstrate forms of autonomy that challenge human control and herald a complete redistribution of the sensible and agential. The aim of this article is to illuminate the shifting boundaries of nature and artifice as these figure in relations between humans and computational machines in the emergent computational culture of the 21st century. Its specific focus is on art‐making where the medium or materials of art have been dematerialized and figure as “intelligent” and generative in their own right. Based on a historical discussion of art‐making practices and the analysis of an artistic workshop organized by the authors, this article stakes out a much‐needed study of the other‐than‐human agency of artificial entities.
Monuments to Mestizaje and the Commemoration of Racial Democracy in Puerto Rico
Authors: Capó García Rafael V. 
Published: November 2023

AbstractIn this paper, I argue that monuments to mestizaje (miscegenation) in Puerto Rico reaffirm the myth of a harmonious mixture between the White Spaniard, Black African, and Indigenous Taíno. This racial triad, originally conceived in the nineteenth century, was institutionalized in 1956 by the Institute of Puerto Rican Culture to legitimize the reformulation of Puerto Rico's colonial status. It was meant to foster a consensus‐driven nation‐building project through a depoliticized harmonious mixture of races. I analyze ten monuments to mestizaje that privilege the white European root of Puerto Rican identity and demonstrate how their visual discourse sustains the narratives of racial democracy in Puerto Rico.
Serum butyrylcholinesterase activity in healthy dogs with and without exposure to diazinon
Authors: Almeida Sara S. F. , da Silva Rayanne H. S. , Oliveira Iago M. , Alonso Luma B. , Gonzaga Beatriz S. , Barros Alexandre C. M. , Vicente Monica C. , Melo Marília M. , Borges Naida C. , Martins Danieli B. , Botelho Ana F. M. 
Published: November 2023

AbstractBackgroundCholinesterase is a biomarker for poisonings by anticholinesterase agents, but its reference values are scarce, and possible interaction with collars containing parasiticides has not been studied.ObjectivesWe aimed to evaluate the serum cholinesterase activity of healthy dogs without a history of contact with anticholinesterase agents and healthy animals exposed to commercial collars containing organophosphate.MethodsNinety‐nine dogs were used and included healthy animals without recent exposure to anticholinesterase agents and healthy animals previously exposed to diazinon collars. Serum quantification of the enzyme butyrylcholinesterase (BuchE) through spectrophotometry was conducted on all samples. In experiment 1, BuchE activity was quantified at time 0 and 7 days after, a time when the samples were kept at −18°C. In experiment 2, sampling times were 0, 7, 14, 21, 28, and 56 days.ResultsTime 0 values were 4622.38 ± 1311.53 U/L. After 7 days, a significant decay was observed, with a mean of 3934.45 ± 1430.45 U/L. Spearman's test was performed, finding a weak correlation between ALT, creatinine, total plasma proteins, age, weight, red blood cells, platelets, leukocytes, and BuchE activities. In experiment 2, the mean at time 0 was 4753 ± 454.8 U/L. With exposure to the collar, there was a decay of up to 93% after 14 days.ConclusionsNormality values of serum BuchE in healthy dogs without a history of exposure to anticholinesterase agents were 4360.8–4883.96 U/L. Freezing serum caused a decrease in BuchE activity. Exposure to commercial collars containing diazinon also reduced BuchE activity without clinical signs, indicating that previously exposed animals should be evaluated carefully.
Optimization of a High Pressure Turbine Blade and Sector-Based Annular Rig Design for Supercritical CO2 Power Cycle Representative Testing
Authors: Tuite Logan , Braun James , Paniagua Guillermo 
Published: November 2023

Abstract
As part of the ongoing research into the design of hardware for zero emission cycles, a first-stage high-pressure turbine (HPT) blade is optimized for a 300 MWe supercritical CO2 (sCO2) power cycle using the surrogate-assisted genetic algorithm optimizer in Numeca FINE/Design three-dimensional with objectives of increasing efficiency and decreasing heat load to the blade. Supercritical CO2 property tables are constructed from NIST REFPROP data for the condensable gas simulation in FINE/Turbo. A detailed mesh sensitivity study is performed for a baseline design to identify the proper-grid refinement and efficiently allocate resources for the optimization. Seventy design variables are selected for the initial population generation. Self-organizing maps are then used to focus the design variables on the most important ones affecting the objective functions. The optimization results in approximately 3000 three-dimensional Reynolds Averaged Navier Stokes simulations of different blade shapes with increases in efficiency of up to 0.85% and decreases in heat load of 14%. Families of blade shapes are identified for experimental testing in an annular rig at the Purdue Experimental Turbine Aerothermal Laboratory. A design to adapt the annular cascade for testing optimized geometries is introduced, which features eccentric radius sectors allowing for scaled-up geometries of sCO2 optimized blade profiles to be tested at design cycle representative conditions at high Reynolds numbers in dry air. Analysis into the effects of Reynolds number, working fluid, and geometric relations are presented to prove the efficacy of the test method.
Experimental and Numerical Investigation of Flow Boiling in Additive Manufactured Foam Structures With Vapor Pathways
Authors: Broughton Justin , Torres Emanuel , Narayanan Akshith , Joshi Yogendra K. 
Published: November 2023

Abstract
The unique properties of metal foams make them potential candidates for a range of applications, including microsystem thermal management. Using additive manufacturing to create foam-type structures can improve upon prior thermal solutions by eliminating thermal interface materials and allowing for customization/local control of parameters. In the present investigation, flow boiling in additive-manufactured metal foams is investigated both experimentally and numerically. Two test samples, one with uniform structure and the other with pathways for vapor removal, are compared both experimentally and numerically. A conjugate computational fluid dynamics and heat transfer (CFD-HT) model utilizing a three-dimensional volume of fluid (VOF) model with accompanying evaporation/condensation model provided in-depth visualization of the boiling flow phenomena. The experiments generated the thermohydraulic performance over a range of heat fluxes, demonstrating that the sample incorporating dedicated vapor pathways performed better in both pressure and heat transfer performance metrics compared to the uniform foam. Additionally, negative system-level effects (i.e., hydraulic oscillations) were shown to be abated using the vapor removal structures. The numerical model yielded further insight into the factors contributing to the improved performance. Results indicated the pathways functioned as vapor removal channels, allowing the generated vapor to vent from the foam structure into the lanes. Further computational investigations demonstrated changes in flow regimes, where the addition of vapor channels caused the flow to change from churn to annular. Bubble behavior unique to the vapor pathway structure was studied, showing stagnant regions that eject vapor into the channel.
Convective Heat Transfer and Entropy Generation Analysis in Elliptic Microchannels
Authors: Su Liangbin , Yang Yongyi 
Published: November 2023

Abstract
In this paper, we investigate analytically the first and the second law characteristics of fully developed gaseous slip flow with the H1 boundary condition through elliptical microchannels. The closed-form solution of temperature distribution was obtained with the separation of variables method. Expressions for the Nusselt number, the nondimensional entropy generation rate, and the Bejan number were further deduced. The influences of crucial factors, including viscous dissipation, rarefaction, aspect ratio, and fluid axial heat conduction, have been carefully evaluated. The results indicated that viscous dissipation has a dramatic impact on heat transfer characteristics. But the rarefaction effect was found to significantly reduce the effect of the viscous dissipation on the Nusselt number, and the former may not deteriorate the heat transfer performance when considering the viscous dissipation. The main source of the entropy generation rate is controlled by fluid axial heat conduction when the Peclet number is less than one. The impacts of the viscous dissipation, the rarefaction, and the aspect ratio on entropy generation are magnified when fluid axial conduction dominates the irreversibility. The analytical solutions of the current study will make it possible to compare, evaluate, and optimize alternative elliptical microchannel heat exchanger design options.
Modeling Stiffness and Stress in Serpentine Flexures for Use in a Compliant Bone Plate
Authors: Huxman Connor , Butler Jared 
Published: November 2023

Abstract
Serpentine flexures offer several advantages for use in linear motion mechanisms, including distributed compliance to reduce stress and increase range of motion. In this work, we develop an analytical model for predicting the moment, vertical deflection, and maximum stress experienced in serpentine flexures in response to an input vertical force. Two classes of serpentines are introduced and modeled with linear motion boundary conditions enforced. Finite element analysis demonstrates a mean model error of 0.86% for these metrics across many flexure topologies. Experimental testing is performed to validate the force–deflection response of three steel serpentine compliant mechanisms. The model is able to predict the experimental stiffness data with a mean error at yield of 5.3%, compared to 6.5% with finite element analysis. Large displacement simulations show the model could remain below 10% error for deflections 3–7 times beyond the mechanisms’ deflection at yield. Finally, the model’s utility is demonstrated in the design of a novel single-piece compliant fracture fixation plate that leverages serpentine flexures to deliver controlled axial motion for long bone secondary healing. Model-derived stress-equivalent flexures are compared in their transverse and torsional rigidity. The proposed model and specific findings can be leveraged to design linear motion mechanisms that incorporate serpentine flexures across a wide range of applications.
Identification of Design Strategies and Their Effects on Performance Outcomes in Pair Parameter Design Tasks
Authors: Avşar Alkım Z. , Grogan Paul T. 
Published: November 2023

Abstract
Understanding design processes and behaviors is important for building more effective design outcomes. During design tasks, teams exhibit sequences of actions that form strategies. This article investigates patterns of design actions in a paired parameter design experiment to discover design strategies that influence outcomes. The analysis uses secondary data from a design experiment in which each pair completes a series of simplified cooperative parameter design tasks to minimize completion time. Analysis of 192 task observations uses exploratory factor analysis to identify design strategies and regression analysis to evaluate their impacts on performance outcomes. The article finds that large actions and high action size variability significantly increase completion times, leading to poor performance outcomes. However, results show that frequently changing input controllers within and among designers significantly reduces completion times, leading to higher performance outcomes. Discussion states that larger actions can introduce unexpected errors, while smaller and consistent actions enhance designers’ understanding of the effects of each action, aiding in better planning for subsequent steps. Frequent controller switching reflects effective communication and understanding within design teams, which is crucial for cooperative tasks.
Experimental Investigations on the Effects of Surface Roughness for Compressor Cascades With Different Roughness Magnitude and Location
Authors: Yu Xianjun , Zhao Shouyang , An Guangfeng , Xu Yuhang , Xu Xiaobin 
Published: November 2023

Abstract
Blade surface roughness could significantly affect the aerodynamic performance of compressors. To explore the influence of roughness magnitude and location on blade performance, experiments were conducted in a low-speed linear compressor cascade with controlled diffusion airfoils (CDA). A part-span roughness method was employed in the experiment to maintain the axial velocity–density ratio (AVDR) during the change of blade roughness magnitudes and locations. Five blade surface local roughness schemes, including the leading-edge, the fore- and aft-part of the suction surface, and the pressure surface, which were determined based on geometry sensitivity analysis, were investigated with the variation of the surface roughness magnitude between Ra = 3.1 μm to 18.8 μm. Cascade inlet and outlet flowfields and the blade surface static pressure distributions were measured, which could help to distinguish the change of blade performance characteristics and even blade surface boundary layer development state. A critical roughness effect was found, and significant blade loss increment and available incidence range reduction appear at super-critical roughness states. At the measured maxi-roughness condition, 28.4% loss increase and 41.2% incidence range reduction were reached.
Mechanical Properties of Buried Steel Pipe With Polyurethane Isolation Layer Under Strike-Slip Fault
Authors: Xue Jinghong , Ji Li 
Published: November 2023

Abstract
Long-distance buried pipelines are one of the most common and economical transportation methods for oil and gas, but the fault movement will pose a threat to the safety of pipelines. The main challenge of pipeline under strike-slip faults is to improve the ability of resistance to fault dislocation, and the main aim of the study is how to improve the critical fault displacement of pipelines with the help of polyurethane isolation layer. Three-dimensional finite element models were proposed for mechanical analysis of X80 buried steel pipe with polyurethane isolation layer under strike-slip fault. The influence of factors on the mechanical properties of pipelines were studied, such as thickness of isolation layer, internal pressure, fault displacement, diameter-thickness ratio, and the angle of pipe and fault line. The simulation results indicate that with the increase of the thickness of the isolation layer, the development of the maximum tensile and compressive strain of the pipeline is significantly reduced for the same fault displacement, resulting in a significant increase in the critical fault displacement corresponding to the three failure modes of the pipeline. As the ratio of diameter to thickness and internal pressure decrease, the critical displacements decrease. When designing and planning the pipeline, pipeline is recommended with the seismic isolation layer, large wall thickness, and the crossing-angle at 70 deg∼80 deg. The research provided a reference for judgment of earthquake resistance, failure analysis, and safety design of pipelines with polyurethane isolation layer crossing strike-slip faults.
PhyNRnet: Physics-Informed Newton–Raphson Network for Forward Kinematics Solution of Parallel Manipulators
Authors: He Chongjian , Guo Wei , Zhu Yanxia , Jiang Lizhong 
Published: November 2023

Abstract
Despite significant performance advantages, the intractable forward kinematics have always restricted the application of parallel manipulators to small posture spaces. Traditional analytical methods and Newton–Raphson method usually cannot solve this problem well due to lack of generality or latent divergence. To address this issue, this study employs recent advances in deep learning to propose a novel physics-informed Newton–Raphson network (PhyNRnet) to rapidly and accurately solve this forward kinematics problem for general parallel manipulators. The main strategy of PhyNRnet is to combine the Newton–Raphson method with the neural network, which helps to significantly improve the accuracy and convergence speed of the model. In addition, to facilitate the network optimization, semi-autoregression, hard imposition of initial/boundary conditions (I/BCs), batch normalization, etc. are developed and applied in PhyNRnet. Unlike previous data-driven paradigms, PhyNRnet adopts the physics-informed loss functions to guide the network optimization, which gives the model clear physical meaning and helps improve generalization ability. Finally, the performance of PhyNRnet is verified by three parallel manipulator paradigms with large postures, where the Newton–Raphson method has generally diverged. Besides, the efficiency analysis shows that PhyNRnet consumes only a small amount of time at each time-step, which meets the real-time requirements.
Ring Origami Spring Capable of Eversion Morphing
Authors: Zou Yu , Chen Qianying , Lu Lu , Li Xiying , Li Hongyuan , Shao Li-Hua , Duan Huiling , Lv Pengyu 
Published: November 2023

Abstract
Origami structures have been widely used in soft robots, mechanical metamaterials, architectural engineering, and biomedical engineering in recent years, benefiting from their reconfigurable shape morphing and tunable mechanical properties through folding and unfolding. In this work, we construct a new origami structure named ring origami spring (ROS) by alternately folding two perpendicularly arranged paper ribbons of the same size and connecting two ends of them. ROS can achieve an eversion morphing with four stable states, based on which both underwater locomotion and traversing water–air interface have been implemented. Theoretical models for characterizing the eversion morphing during the transition of stable states and the induced locomotion performance of ROS have been developed, and the theoretical predictions are in good agreement with the experimental results. The current work provides a new strategy for the design of origami robots, which is potentially applied in exploring complex environments.
ArcA positively regulates the expression of virulence genes and contributes to virulence of porcine Shiga toxin-producing enterotoxigenic
Escherichia coli
Authors: Jiang Fengwei , Yang Yan , Mao Zhao , Cai Wentong , Li Ganwu 
Published: November 2023

ABSTRACT

Enterotoxigenic
Escherichia coli
(ETEC) cause severe diarrhea in humans and animals. These bacteria encode two major classes of virulence factors, adhesins that promote colonization of the small intestine and enterotoxins that induce fluid secretion and thus diarrhea. Oxygen and redox sensors are regulators of virulence expression in multiple bacterial pathogens. In this study, we show that microaerobic conditions enhance the expression of virulence factors in a porcine Shiga toxin-producing ETEC (STEC/ETEC) strain. We then investigated the role of the aerobic respiration control regulator ArcA in the pathogenicity and virulence regulation in STEC/ETEC. In a mouse model, deletion of
arcA
caused less severe pathology, and the
arcA
mutant displayed lower levels of colonization and obvious weight gain of the mice compared to the wild type (WT). In a cell culture model, a lack of
arcA
reduced the adherence of STEC/ETEC to porcine intestinal epithelial cells. Furthermore, ArcA positively regulated the expression of several key virulence factors, including F18 fimbriae (
fed
), heat-labile (
eltA
) and heat-stable (
estB
) toxins, Shiga toxin 2e (
stx2e
), and hemolysin (
hlyC
), under microaerobic conditions and
in vivo
conditions. We then found that ArcA positively regulated the expression of
eltA
,
estB
, and
hlyC
by competing with a global repressor H-NS (histone-like nucleoid structuring). Mechanistically, we show that ArcA protein directly binds to the promoters of target genes, displaces H-NS silencing from the promoter and counteracts H-NS’s repression. Collectively, our data established a key role for ArcA in the pathogenicity and virulence expression of porcine STEC/ETEC.

IMPORTANCE

Enterotoxigenic
Escherichia coli
(ETEC) cause severe diarrhea in humans and animals, leading to death and huge economic loss worldwide. Thus, elucidation of ETEC’s pathogenic mechanisms will provide powerful data for the discovery of drugs serving as prevention or therapeutics against ETEC-caused diarrheal diseases. Here, we report that ArcA plays an essential role in the pathogenicity and virulence regulation in ETEC by positively regulating the expression of several key virulence factors including F18 fimbriae, heat-labile and heat-stable toxins, Shiga toxin 2e, and hemolysin, under microaerobic conditions and
in vivo
. Moreover, we found that positive regulation of several virulence genes by ArcA requires a global repressor H-NS (histone-like nucleoid structuring), implying that ArcA may exert positive effects by antagonizing H-NS. Collectively, our data established a key role for ArcA in the pathogenicity of porcine ETEC and ETEC strains isolated from human infections. Moreover, our work reveals another layer of regulation in relation to oxygen control of virulence factors in ETEC.
Metabolic and chromosomal changes in a
Bacillus subtilis whiA
mutant
Authors: Bohorquez Laura C. , de Sousa Joana , Garcia-Garcia Transito , Dugar Gaurav , Wang Biwen , Jonker Martijs J. , Noirot-Gros Marie-Françoise , Lalk Michael , Hamoen Leendert W. 
Published: November 2023

ABSTRACT

The conserved protein WhiA is present in most Gram-positive bacteria and plays a role in cell division. WhiA contains a DNA-binding motif and is a transcription regulator of the key cell division gene
ftsZ
in actinomycetes. In
Bacillus subtilis
, the absence of WhiA influences both cell division and chromosome segregation; however, the protein does not regulate any gene involved in these processes. In this study, we addressed three alternative mechanisms by which WhiA might exert its activity in
B. subtilis
and examined whether WhiA influences either (i) central carbon metabolism, (ii) fatty acid composition of the cell membrane, or (iii) chromosome organization. Mutations in glycolytic enzymes have been shown to influence both cell division and DNA replication. To measure the effect of WhiA on carbon metabolism, we tested different carbon sources and measured exometabolome fluxes. This revealed that the absence of WhiA does not affect glycolysis but does influence the pool of branched-chain fatty acid precursors. Due to the effect of WhiA on chromosome segregation, we examine chromosome organization in a ∆
whiA
mutant using chromosome conformation capture (Hi-C) analysis. This revealed a local reduction in short-range chromosome interactions. Together, these findings provide new avenues for future research into how this protein works in the non-actinomycete firmicutes.

IMPORTANCE

WhiA is a conserved DNA-binding protein that influences cell division in many Gram-positive bacteria and, in
B. subtilis,
also chromosome segregation. How WhiA works in
Bacillus subtilis
is unknown. Here, we tested three hypothetical mechanisms using metabolomics, fatty acid analysis, and chromosome confirmation capture experiments. This revealed that WhiA does not influence cell division and chromosome segregation by modulating either central carbon metabolism or fatty acid composition. However, the inactivation of WhiA reduces short-range chromosome interactions. These findings provide new avenues to study the molecular mechanism of WhiA in the future.