Potential Field Research Articles

Flexible modeling of large-scale neural network stimulation: electrical and optical extensions to The Virtual Electrode Recording Tool for EXtracellular Potentials (VERTEX).

Computational models that predict effects of neural stimulation can be used as a preliminary tool to inform in-vivo research, reducing the costs, time, and ethical considerations involved. However, current models do not support the diverse neural stimulation techniques used in-vivo, including the expanding selection of electrodes, stimulation modalities, and stimulation paradigms. To develop a more comprehensive software, we created several extensions to The Virtual Electrode Recording Tool for EXtracellular Potentials (VERTEX), the MATLAB-based neural stimulation tool from Newcastle University. VERTEX simulates input currents in a large population of multi-compartment neurons within a small cortical slice to model electric field stimulation, while recording local field potentials (LFPs) and spiking activity. Our extensions to its existing electric field stimulation framework include multiple pairs of parametrically defined electrodes and biphasic, bipolar stimulation delivered at programmable delays. To support the growing use of optogenetic approaches for targeted neural stimulation, we introduced a feature that models optogenetic stimulation through an additional VERTEX input function that converts irradiance to currents at optogenetically responsive neurons. Finally, we added extensions to allow complex stimulation protocols including paired-pulse, spatiotemporal patterned, and closed-loop stimulation. We demonstrated our novel features using VERTEX's built-in functionalities, illustrating how these extensions can be used to efficiently and systematically test diverse, targeted, and individualized stimulation patterns.

Harvesting Enhanced Blue Energy in Charged Nanochannels Using Semidiluted Polyelectrolyte Solution.

Blue energy generation in nanochannels based on salinity gradients is currently the most promising method in the area of nonconventional energy production. We used a semidiluted pure sodium carboxymethylcellulose (NaCMC)-KCl aqueous solution to study the characteristics of blue energy generation within a charged nanochannel. We solve the corresponding equations for ionic transport using a numerical technique based on the finite element method. Our analysis focused on the electric double layer (EDL) potential field, open circuit current, diffuse potential, electric conductance, maximum generated pore power, and maximum energy conversion efficiency by varying concentrations of the salt in the left-side reservoir and the bulk polyelectrolyte. The results indicate that as the polyelectrolyte concentration increases, the extent of EDL overlap considerably reduces. With an increase in polyelectrolyte concentration, the open circuit current increases, while the diffuse potential reduces. It was observed that both electrical conductance and maximal pore power improve considerably with higher polyelectrolyte concentrations. Interestingly, our modeling framework demonstrates a power density substantially higher (up to 16.31 W/m2) than earlier configurations and surpasses the established commercial limit (5 W/m2). Furthermore, our findings reveal that the reservoir salt concentration significantly affects the rate of decline in the maximum energy conversion efficiency as the polyelectrolyte concentration increases. The research paves the way for the development of high-power-density devices with several practical applications.

Optimizing Redundant Robot Kinematics and Motion Planning via Advanced D-H Analysis and Enhanced Artificial Potential Fields

Optimizing Redundant Robot Kinematics and Motion Planning via Advanced D-H Analysis and Enhanced Artificial Potential Fields

Micro-electrode array recording of extracellular electrical potentials of liquid static surface fermented Hericium erinaceus

Hericium erinaceus is a basidiomycetes fungus with previously uncharacterised extracellular electrophysiology. Here, we present results of recordings of the electrical potentials of fungal biofilms of this species using microelectrode arrays (MEAs). In particular, we focused on modelling the temporal and spatial progression of the low frequency (≤ 1 Hz) potentials. Culture media control studies showed that the electrical potential activity results from the growth and subsequent spiking behaviours of the mycelium extracellular matrices. An antifungal assay using nystatin suspension, 10,000 unit/mL in DPBS, provided evidence for the biological origin of electrical potentials due to targeting of the selective permeability of the cell membrane and subsequent cessation of electrical activity. Conversely, injection of L-glutamic acid increased the combined multi-channel mean firing rate from 0.04 Hz to 0.1 Hz. Analysis of bursting and spatial propagation of the extracellular signals are also presented.

Synergies between the circular economy and carbon emission reduction

Climate change and sustainable development drive transformation in economic development models. Carbon emission reduction and the circular economy propel climate change and sustainable development, yet it's unclear if they synergize or counteract each other. This study examines the question from theoretical and practical perspectives. Using a theory-practice framework, bibliometric and big data analyses were conducted on the Web of Science and Chinese case data, totaling 2.29GB, to explore synergies between carbon emission reduction and the circular economy. The study finds predominantly synergistic interactions between the circular economy and carbon emission reduction, with minimal offsetting effects. That is, the circular economy markedly enhances carbon emissions reduction. At the theoretical level, the two fields are gradually evolving towards in-depth research, while at the practical level, collaboration is coalescing around four areas: hot fields, potential fields, auxiliary fields and common goals. A noteworthy contribution of this study is the development of a framework that synergizes theory and practice, providing a structured approach for future research in this domain. By quantifying the synergistic and offsetting relationship between the circular economy and carbon emissions reduction through systematic big data analysis, this research offers insights essential for achieving the UN's Sustainable Development Goals. We also stress the need for diverse case studies and multi-dimensional analyses in ongoing research.

3D DNA origami pincers that multitask on giant unilamellar vesicles.

Proteins self-assemble to function in living cells. They may execute essential tasks in the form of monomers, complexes, or supramolecular cages via oligomerization, achieving a sophisticated balance between structural topology and functional dynamics. The modularity and programmability make DNA origami unique in mimicking these key features. Here, we demonstrate three-dimensional reconfigurable DNA origami pincers (DOPs) that multitask on giant unilamellar vesicles (GUVs). By programmably adjusting their pinching angle, the DOPs can dynamically control the degree of GUV remodeling. When oligomerized on the GUV to form origami cages, the DOP units interact with one another and undergo reorganization, resulting in the capture, compartmentalization, and detachment of lipid fragments. This oligomerization process is accompanied with membrane disruptions, enabling the passage of cargo across the membrane. We envisage that interfacing synthetic cells with engineered, multifunctional DNA nanostructures may help to confer customized cellular properties, unleashing the potential of both fields.

Evolution of the transtensional Barreirinhas pull-apart system in the Brazilian Equatorial margin and its correlation with the African conjugate counterpart

The Barreirinhas pull-apart system encompasses marginal basins in divergent and transform margin segments in the central sector of the Brazilian Equatorial Margin and its African conjugate counterpart. This ancient pull-apart system evolved through transtensional strike-slip motion within a highly heterogeneous crystalline basement affected by multiple rift phases. The geometry and development of pull-apart structural elements during the final rifting phase before continental breakup and the mechanisms and extent to which they were influenced by preexisting crustal heterogeneities are comprehensively addressed using an extensive database of potential field (magnetic and gravity) and 2D seismic reflection data. We also assess the lithospheric thermomechanical conditions and their influence on transtensional extension throughout Curie Point Depth, Heat Flow, and Moho depth, derived from potential field data and published seismological models. Plate reconstruction of Brazilian and African equatorial margins based on gravity patterns and comparison with sandbox analog models allow a 3D synoptic model to reveal the Barreirinhas pull-apart system evolution during the Equatorial Atlantic opening. During the rift phase I, the location of major grabens was controlled by favorably oriented Neoproterozoic shear zones, while the cooler, stronger, and thicker crust beneath cratonic areas formed the western barrier to strike-slip rift activity during rift phase II. This same geological domain anchored the onset of the pull-apart system in the last rift phase III, whose principal displacement zones developed along the extensive oceanic fracture zones linked by sigmoidal fault systems. Toward the end of the rift phase, a large asymmetric lozangle to a lazy-Z-shaped, pull-apart basin developed above low overlapping ∼90°, releasing stepover in oblique transtensional strike-slip motion.

Study of hydrogen fuel cell unmanned surface vehicle crane collision avoidance control by using an improved artificial potential field

ABSTRACT In this paper, a collision avoidance control strategy based on an enhanced Artificial Potential Field (APF) is proposed to overcome stationary and dynamic surface obstacles for Unmanned Surface Vehicle Crane (USVC) powered by hydrogen fuel cells. The proposed collision avoidance control relies on the gravitational and repulsive potential field functions. An angle limitation and speed optimisation design strategies are derived to enhance the path planning performance and guarantee the safety of the system. Finally, the simulation and experiment of USVC platform equipped with hydrogen fuel cells are developed to confirmed the effectiveness and reliability of the collision avoidance control strategy based on a novel APF under several obstacles.

An End-to-End Path Planner Combining Potential Field Method With Deep Reinforcement Learning

An End-to-End Path Planner Combining Potential Field Method With Deep Reinforcement Learning

Immunomodulatory Behavior of Tendon Magnetic Cell Sheets can be Modulated in Hypoxic Environments under Magnetic Stimulus.

Tissue environments play a crucial role in orchestrating cell behavior, guided by a complex interplay of various factors. Long lasting inflammatory signals compromise tendon homeostasis and promote tissue degeneration, while tissue oxygen levels affect local cells' responses with hypoxic environments influencing apoptosis, inflammatory mediators, and matrix production. Recent works have unveiled the therapeutic potential of pulsed electromagnetic field (PEMF) in modulating inflammatory signals expressed by human tendon cells (hTDCs), and in mitigating the hypoxia-induced effects on the regulation of inflammatory cytokines. Thus, we sought to investigate the role of hypoxic environments, namely, 1 and 2% oxygen tension, in the inflammatory profiles of magnetic cell sheets (magCSs) formed by magnetic nanoparticles internalized in contiguous hTDCs with intact cell-cell junctions and deposited matrix. We also aimed to explore the impact of PEMF over hypoxia-treated magCSs, including IL-1β-primed-magCSs, with the objective of harnessing magnetic stimulation to guide abnormal inflammatory cell responses toward efficient treatments supporting tendon regenerative potential. Our findings revealed that low oxygen tensions amplified the expression of hypoxia-associated genes and of inflammatory markers in IL-1β-primed-magCSs with an involvement of the NF-κB signaling pathway. Encouragingly, when PEMF was applied to IL-1β-primed-magCSs under hypoxic conditions, it successfully modulated inflammatory cues by favoring IL-10 and IL-4, via the NF-κB pathway. These results signify the remarkable potential of PEMF in driving proregenerative strategies and opens up new approaches in tendon therapies, highlighting the transformative impact of immunomodulatory magnetic cell sheets.

Unveiling the potential of novel 5α-reductase inhibitors via ligand based drug design, molecular docking and ADME predictions to manage BPH

Benign prostatic hyperplasia (BPH), a prevalent condition among elderly males characterized by the non-cancerous enlargement of the prostate gland is due to the increased stromal and epithelial cell numbers. The enlargement is driven by an active dihydrotestosterone (DHT), synthesized from its prohormone testosterone under the catalytic effect of 5α-reductase Type-II (5-AR2) enzyme. To reduce the increased DHT levels and ultimately to control prostate growth, inhibition of the 5-AR represent an interesting therapeutic target. The 3D crystallography structure 5-AR2, a member of the steroid 5-AR family belonging to the class of oxidoreductase has been resolved recently and opened the door to develop selective novel inhibitors of 5-AR Type-II isoform using molecular modeling techniques. The Force field and Gaussian-field three-dimensional quantitative structure–activity relationship (3D-QSAR) models have been developed using 42 selective 5-AR2 inhibitors belonging to chemical class of steroidal androstene. Partial least squares analysis produced statistically significant model with R2training = 0.9367, 0.9459 and predictability Q2test = 0.7233, 0.8595. Developed 3D-QSAR model include steric, electrostatic, hydrophobic, and hydrogen bond acceptor and donor field indicators, whereas the potential field contributions indicated the importance of steric feature in governing their biological activity. Protein-ligand interaction pattern analysis revealed that amino acid residues GLU57, ARG114, TYR91 present in the active site of 5-AR2 are crucial for lower energy complexes with good binding affinity. Identified hits were finally adjudged for their druggability by determining in-silico pharmacokinetic parameters. Further, RMSD, binding free energy calculations and post MD analysis demonstrated the enhanced binding affinity with better ΔGbind value (-79.6 ± 3.9 kcal/mol) of identified ligand A-10 than the reference molecule finasteride (-69.13 ± 4.69 kcal/mol). Combined approach of ligand-based and structure-based models have provided an improved understanding of the structural properties of androstene class that may be further used to develop novel 5-AR2 inhibitors to be useful in BPH.

Graphene-assisted remote epitaxy wrinkle-free GaN films on flexible mica

When GaN films were directly deposited onto fluorophlogopite mica substrates, spontaneous wrinkling was frequently observed in GaN films. Because of the non-uniform interface adhesion between GaN and mica, two types of delamination phenomena have been observed by scanning electron microscopy. The maximum thickness of wrinkle-free GaN films on mica substrates was ∼200 nm. Interface pinning effect occurred due to the dangling bonds caused by the damage to mica during the deposition of GaN films. To avoid the formation of dangling bonds, the surface of mica was shielded by a graphene interlayer which was transferred via a wet method. Wrinkles were eradicated after the formation of sliding contact between GaN films and fully graphene-covered mica substrates. Despite the presence of the graphene lattice, the growth of GaN epilayer remained governed by the potential field of mica, indicating that remote epitaxy occurred on a 2D mica support substrate.

Ship Trajectory Planning and Optimization via Ensemble Hybrid A* and Multi-Target Point Artificial Potential Field Model

Ship path planning is the core problem of autonomous driving of smart ships and the basis for avoiding obstacles and other ships reasonably. To achieve this goal, this study improved the traditional A* algorithm to propose a new method for ship collision avoidance path planning by combining the multi-target point artificial potential field algorithm (MPAPF). The global planning path was smoothed and segmented into multi-target sequence points with the help of an improved A* algorithm and fewer turning nodes. The improved APF algorithm was used to plan the path of multi-target points locally, and the ship motion constraints were considered to generate a path that was more in line with the ship kinematics. In addition, this method also considered the collision avoidance situation when ships meet, carried out collision avoidance operations according to the International Regulations for Preventing Collisions at Sea (COLREGs), and introduced the collision risk index (CRI) to evaluate the collision risk and obtain a safe and reliable path. Through the simulation of a static environment and ship encounter, the experimental results show that the proposed method not only has good performance in a static environment but can also generate a safe path to avoid collision in more complex encounter scenarios.

Amphiphilic Janus nanoparticles with controlled composition and wettability for pickering emulsion with controllable movement and release

Pickering emulsions represent an important class of functional materials with great potentials in field of sustainability and health, such as controlled drug release or catalysis. However, the limited tunability of the amphiphilicity and implementation of multiple components into Pickering emulsion are still challenges for reliable dynamic control. Here, a strategy to obtain a triphasic amphiphilic PS/Fe3O4@SiO2 Janus nanoparticles (JNPs) by cladding Fe3O4 NPs inside biphasic PS@SiO2 JNPs was proposed and validated. The sizes of the triphasic JNPs is in the range of 80–150 nm and water contact angle (θW) varies from 58.9° to 131.4°, indicating the wettability could be controlled at will. The formed JNPs are assembled at the oil-water interface to stabilize water-in-oil (W/O) and oil-in-water (O/W) emulsion droplets. The stabilized emulsion droplets exhibit excellent thermodynamic stability which is evidenced by the droplet viability of 50 %-80 % after 6 months or excellent salt and temperature-resistance. Moreover, the movement and demulsification are made possible with magnetic actuation of JNPs. Compared to without magnetism, the release of curcumin dissolved in water within W/O droplet was realized 70 % after 12 days, showing a promising application in controlled active material release. Taking advantage of controllable synthesis and the functionality, this proposed approach could be expanded for preparation of colloidal materials with complex chemical and incorporate additional functionality, suggesting opportunities for further applications in drug delivery, oil recovery fields, and other fields related Pickering emulsion.

Mouse Escape Behaviors and mPFC-BLA Activity Dataset: Understanding Flexible Defensive Strategies Under Threat

Responding to threats in the real world demands a sophisticated orchestration of freeze and flight behaviors dynamically modulated by the neural activity. While the medial prefrontal cortex-basolateral amygdala (mPFC-BLA) network is known to play a pivotal role in coordinating these responses, the mechanisms underlying its population dynamics remain vague. As traditional Pavlovian fear conditioning models fall short in encapsulating the breadth of natural escape behaviors, we introduce a novel dataset to bridge this gap, capturing the defensive strategies of mice against a spider robot in a natural-like environment. The adaptive escape behaviors and concurrent mPFC-BLA activity in eight mice were monitored using wireless local field potential (LFP) and video recordings, both individually and in groups. Our data offers a unique avenue to explore the neural dynamics that govern fear- and vigilance-induced threat responses in isolated and social contexts. Supplemented by detailed methodologies and validation, the dataset allows for the analysis of the transient neural oscillatory dynamics, with prospective implications for the fields of neuroscience, robotics, and artificial intelligence.

Barrow entropic cosmology with exponential potential field

In this paper, we consider an exponential potential [Formula: see text] in the framework of Barrow entropy under the constant-roll inflation and check their viability in the light of observable Planck 2020 data. By applying the first law of thermodynamics to the apparent horizon of the Universe, a modification of the Friedmann–Robertson–Walker (FRW) metric is derived in the context of Barrow entropy. We consider the early inflationary period of the universe to consist phenomenologically of a single inflationary state, that is, a state of the costant-roll inflation in which inflation is driven by an exponential potential field function. By fitting the constant-roll inflationary models to the observations, we examined the effect of the Barrow parameter [Formula: see text] on the inflation mechanism with the constant-roll parameter [Formula: see text]. As a result, we concluded that for a viable inflation, the observation limits of the inflation parameters determine that the constant-roll parameter is in the range [Formula: see text].

Photopharmacological modulation of hippocampal local field potential by caged-glutamate with MicroLED probe.

Photopharmacology is a new technique for modulating biological phenomena through the photoconversion of substances in a specific target region at precise times. Caged compounds are thought to be compatible with photopharmacology as uncaged ligands are released and function in a light irradiation-dependent manner. Here, we investigated whether a microscale light-emitting diode (MicroLED) probe is applicable for the photoconversion of caged-glutamate (caged-Glu) invivo. A needle-shaped MicroLED probe was fabricated and inserted into the mouse hippocampal dentate gyrus (DG) with a cannula for drug injection and a recording electrode for measuring the local field potential (LFP). Artificial cerebrospinal fluid (ACSF) or caged-Glu was infused into the DG and illuminated with light from a MicroLED probe. In the caged-Glu-injected DG, the LFP changed in the 10-20 Hz frequency ranges after light illumination, whereas there was no change in the ACSF control condition. The MicroLED probe is applicable for photopharmacological experiments to modulate LFP with caged-Glu invivo.

Microstructure Modeling of Transport and Kinetics in Solid State Batteries with LLZO Solid Electrolyte Fabricated Using the Freeze-Tape-Casting Method

In traditional Li-ion batteries with liquid electrolyte, the transport of lithium ions in the electrolyte and lithium in the active material within a porous electrode are studied extensively. The continuum-scale modeling of these transport phenomena considers a homogenized simulation domain consisting of liquid electrolyte and solid active material with effective transport properties accounting for the heterogeneity [1]. There have been fewer studies that consider digitized versions of the experimentally imaged microstructure in continuum-scale modeling studies, particularly to study mechanics [2]. Despite of the computational challenges, there are inherent advantages in using fully resolved microstructure modeling to improve fundamental understanding of the relevant physical and chemical phenomena in porous electrodes, such as localized degradation and stress concentration. In the case of solid electrolytes, specifically scaffold-type LLZO solid electrolytes, microstructure modeling is of even more relevance, particularly to study anisotropic transport, localized degradation phenomena, stress and deformation leading to loss of contact, and chemo-mechanics. Thus far, microstructure modeling studies on experimentally obtained microstructure consisting of solid electrolyte and active material have been quite limited [3]. The studies that have explored this realm have employed voxel-based mesh to discretize the computation domain [3]. While these methods are sufficient proof of concept, the lack of precision in defining the interface separating active material and electrolyte when using voxel-based mesh provides a source of potentially significant numerical error. Without a highly resolved interface mesh, the total interfacial area increases artificially which leads to inaccuracies in calculations of local reaction rate and overpotential. A highly resolved, smooth interface is also necessary when simulating mechanical deformation and stress field in the microstructure. In the present investigation, we model mass transport and charge transport in the active material/electrolyte microstructure to simulate concentration and potential fields with varying mesh types in order to compare their effectiveness and characterize the error that can be attributed to the mesh type chosen, particularly in the case of voxel-based meshes. Additionally, we study the effect of microstructure domain length chosen in the two directions perpendicular to the shortest length (electrode thickness) as well as boundary condition formulation on the boundaries in these axes on the simulation results. The microstructures studied in this work are derived from the image stacks of the bi/trilayer LLZO solid electrolyte fabricated using freeze-tape-casting method [4]. Overall, the present work aims to develop a better understanding of the best practices in microstructure modeling, particularly when using microstructure image stacks obtained from fabricated samples.

Phenotypic diversity in qualitative and quantitative traits for selection of high yield potential field pea genotypes

Field pea (Pisum sativum L.) needs improvement to increase productivity due to its high price and demand. However, the incidence of powdery mildew (PM) disease limits its production. This study aimed to analyze the diversity of qualitative and quantitative traits against powdery mildew resistance by utilizing cluster and principal component analysis to explore PM resistance high-yield potential field peas. Shannon–Weaver's diversity index (Hʹ) displayed high intra-genotype diversity for quantitative and qualitative aspects. Heterogeneity was identified for resistance against powdery mildew infections. Eighty-five genotypes were divided into five groups using Mohalanobis generalized distance (D2) statistics. The highest inter-cluster D2 value was observed between clusters 2 and 3 (11.89) while the lowest value was found between clusters 3 and 4 (2.06). Most of the genotypes had noticeable differences, so these could be employed in a crossing scheme. Twelve genotypes were extremely resistant, 29 genotypes were resistant, 25 genotypes were moderately resistant, 18 genotypes were fairly susceptible, and 1 genotype was susceptible to powdery mildew disease. Among 29 resistant genotypes, BFP77, BFP74, BFP63, BFP62, BFP43, and BFP80 were high yielders and, could be used directly and/or transferred through hybridization to high-yielding disease-susceptible genotypes. Among the 25 moderately resistant genotypes, BFP78, BFP45, BFP79, and BFP48 were found to be high yielders. In principal component analysis (PCA), the first four PCs with Eigen values > 1 accounted for 88.4% variability for quantitative traits. Clustering sorted genotypes into five groups, where groups 1 to 5 assembled 37, 28, 1, 8, and 11 genotypes, respectively. Genotypes of cluster 4 were identified as high yielders with its attributes. Pearson correlation significantly and positively correlated across all traits except for PM. This variation suggested that there is a mechanism to select promising genotypes for field pea breeding. Considering all features, BFP78, BFP77, BFP74, BFP63, BFP62, BFP45, BFP79, and BFP80 could be preferred as high yielders and PM resistance owing to longer pod lengths, seeds per pod and pods per plant.

Boundary Work in the Nordic Media Model: Metajournalistic Discourse on Alternative Media in Denmark, Norway, and Sweden

ABSTRACT The increasing prominence of alternative news media has been identified as a particular challenge to contemporary established journalism, next to collapsing financial models, platform dependency, falling levels of trust and increased competition. Against this background, this study examines how news editors from 23 established news organizations in Sweden, Norway, and Denmark view the rise and role of alternative news media and thereby the boundaries of the journalistic field. Combining strategic action field theory, boundary work and the concept of metajournalistic discourse, it identifies three metajournalistic discourses—We are the (real) journalists, We are in control (for now), and We are under pressure. Together, these metajournalistic discourses portray alternative news media as a challenge that largely has been overcome, and as currently insignificant actors that clearly do not represent “real journalism”. At the same time, the discourses also display concerns that alternative news media might represent potential future field ruptures via their association with broader potentially detrimental media developments, such as genre-confused media audiences or harassment of journalists.