Local Function Research Articles

Intrinsic Universality in Automata Networks III: On Symmetry versus Asynchrony

An automata network is a finite assembly of interconnected entities endowed with a set of local maps defined over a common finite alphabet. These relationships are represented through an interaction graph. Together with the local functions, an assignment known as an update scheme directs the evolution of the network by updating specific subsets of entities at discrete time steps. Despite the scrutiny of interaction graphs and update schemes, their profound impact on automata network dynamics remains largely open. This work investigates the intricate interplay between these aspects, with a focus on how update schemes can counterbalance constraints stemming from symmetric local interactions. This paper is the third of a series about intrinsic universality, a notion that assesses both dynamical and computational complexity, encompassing transient behaviors, attractors, and prediction or reachability problems. We consider four update modes—parallel, block-sequential, local clocks, and general periodic— along with several families of symmetric signed conjunctive boolean networks defined by local constraints on signs. Our main result is to show a diagonal complexity leap in this two-dimensional landscape: the stronger the local constraints the higher the level of asynchrony required to obtain intrinsic universality or increase in complexity. We also show how in some cases asynchronism allows to simulate directed interactions from undirected ones with the same local rules.

David Ferrier’s “complex whole”: Early traces of a “brain network” concept

ABSTRACT Currently, the idea that the brain is a complex network of interacting brain regions is hardly controversial. The rapid development of this field is often attributed to the emergence of powerful brain-imaging techniques and, around the millennium, the merging of the neuroscience of brain networks with modern mathematical graph theory. However, little is known about the historical roots of this concept. It is interesting to know when the first traces of a concept of brain networks can be found in the work of early neuroscientists, how this concept evolved over time, and what factors may have influenced this evolution. This study aims to set a first step in addressing these questions by a detailed analysis of David Ferrier’s classic study, The Functions of the Brain. From this analysis it will become clear that, in addition to a clear notion of localized functions in the brain, Ferrier speculated in several places about the need for several of these brain regions to communicate and interact in order to bring about higher brain functions. He referred to this perspective on the brain as a “complex whole,” which could be interpreted as an early precursor of the modern concept of brain networks.

Electron Localization Function for Noncollinear Spins.

Understanding of bonding is key to modeling materials and predicting properties thereof. A widely adopted indicator of bonds and atomic shells is the electron localization function (ELF). The building blocks of the ELF are also used in the construction of modern density functional approximations. Here, we demonstrate that the ELF breaks down when applied beyond regular nonrelativistic quantum states. We show that for tackling general noncollinear open-shell solutions, it is essential to address both the U(1) gauge invariance, i.e., invariance under a multiplication by a position dependent phase factor, and SU(2) gauge invariance, i.e., invariance under local spin rotations, conjointly. Remarkably, we find that the extended ELF also improves the description of paradigmatic collinear states.

Dynamics of an age-structured SIS epidemic model with local dispersal and general incidence functions

In this paper, an age-structured SIS epidemic model with local dispersal and general incidence functions is formulated. We first analytically derive the well-posedness of solutions, the basic reproduction number R0 and the existence of steady states. Then, we show that the disease-free steady state is global asymptotically stable if R0≤1 and disease in the model is uniformly persistent if R0>1. Moreover, we show global asymptotic stability of the endemic steady state under some cases. Finally, infection age, media coverage and spatial diffusion on the epidemic of infectious diseases are demonstrated by numerical simulations.

Numerical analysis of small-strain elasto-plastic deformation using local Radial Basis Function approximation with Picard iteration

In this paper, we discuss a von Mises plasticity model with nonlinear isotropic hardening assuming small strains in a plane strain example of internally pressurised thick-walled cylinder subjected to different loading conditions. The elastic deformation is modelled using the Navier-Cauchy equation. In regions where the von Mises stress exceeds the yield stress, corrections are made locally through a return mapping algorithm. We present a novel method that uses a Radial Basis Function-Finite Difference (RBF-FD) approach with Picard iteration to solve the system of nonlinear equations arising from plastic deformation. This technique eliminates the need to stabilise the divergence operator and avoids special positioning of the boundary nodes, while preserving the elegance of the meshless discretisation and avoiding the introduction of new parameters that would require tuning. The results of the proposed method are compared with analytical and Finite Element Method (FEM) solutions. The results show that the proposed method achieves comparable accuracy to FEM while offering significant advantages in the treatment of complex geometries without the need for conventional meshing or special treatment of boundary nodes or differential operators.

Unraveling the Role of the Skin Microbiome in Immunodermatological Diseases: Implications for Therapeutic Interventions

The skin microbiome, comprising diverse microbial communities, plays a pivotal role in maintaining cutaneous homeostasis and modulating immune responses in immunodermatological diseases. This review provides an overview of recent research investigating the interplay between the skin microbiome and autoimmune, allergic, and inflammatory skin conditions, such as psoriasis, eczema, and acne vulgaris. This literature review was conducted using PubMed, searching the keywords "skin microbiome and immunodermatological diseases," "therapeutic interventions for skin microbiota," "skin disease and microbiome-host interaction," “immune response in dermatology,” “cutaneous microbiome,” "skin microbiome and allergies," "inflammatory skin conditions and microbiome," and “immune-mediated skin diseases.” A total of 53 articles were included in this review. Current evidence suggests that alterations in the skin microbiome composition, termed dysbiosis, may contribute to disease pathogenesis and exacerbate inflammation in immunodermatological disorders. Furthermore, microbial-derived metabolites and immune-modulating factors produced by commensal bacteria can influence local immune responses and skin barrier function. Future research directions include evaluating the mechanisms by which the skin microbiome interacts with the host immune system, identifying microbial biomarkers for disease diagnosis and prognosis, and exploring microbiome-targeted therapeutic interventions, such as probiotics, microbial transplantation, and microbial metabolite supplementation. By leveraging insights from microbiome research, personalized approaches to managing immunodermatological diseases may offer novel therapeutic avenues for restoring skin immune homeostasis and improving patient outcomes.

Trace iron induced piezo-polarization field strength on piezo-promoted peroxymonosulfate activation for pollutant degradation

Advanced oxidation processes based on piezo-promoted peroxymonosulfate (PMS) activation in environmental remediation have been widely applied, but the treatment efficiency of pollutants was restricted by sluggish charge separation and low affinity of PMS. Herein, trace iron-doped layered molybdenum disulfide (Fe/MoS2) was used to degrade pollutants by piezo-promoted PMS activation. Real-time reaction site changes in carbamazepine (CBZ) degradation process were predicted by Fukui function calculation of the reaction intermediates, and the possible degradation pathways were given. Through piezoresponse force microscopy and calculation of the adsorption energy, electronic localized functions and Crystal Orbital Hamilton Population, it was verified that Fe doping improves the adsorption of oxygen-containing reactants on MoS2, enhancing the electron delocalization and piezo-polarization field, thus accelerating the piezo-promoted PMS activation kinetics. The degradation efficiency of CBZ on Fe/MoS2 (0.44 min−1) was about 22 times than that of MoS2. Piezo-promoted PMS activation strategy based on Fe/MoS2 still maintains a high removal rate in the treatment of dye and antibiotic pollutants such as ornidazole, rhodamine B, tetracycline, methyl orange, chlortetracycline. This study provides insights into the mechanism by which piezo-promoted PMS activation, and achieving high chemical efficiency for pollutants removal.

Detection of harmful gases (NO, NO2) by GaN@MoSSe heterostructures embedded with transition metal (Cu, Fe and Mn) atoms: A DFT study

Monitoring and identifying air pollutants, such as NO and NO2, is crucial due to their detrimental impact on both the environment and human health. This work employs density functional theory (DFT) with the PBE + U functional to investigate the adsorption and sensing performance of NO and NO2 on transition metal (TM)-doped GaN@MoSSe heterostructures. The adsorption energy, charge transfer, electron localization functions, charge density difference, spin density, band gaps and density of states are analyzed. The findings reveal that a transition from physisorption to chemisorption occurs after TM atoms doping. Also, when the surface is embedded with Cu, Fe and Mn atoms, there is a significant improvement in the behavior related to gas adsorption. The bandgap and its variations lead to the change in surface electrical conductivity, thereby affecting the gas sensitivity of the adsorption system. Particularly, the CuGa-GaN@MoSSe and FeGa-GaN@MoSSe systems exhibit improved gas sensitivity toward NO due to their significant band gap reduction. Meanwhile, the CuSe−MoSSe@GaN, CuGa-GaN@MoSSe, FeGa-GaN@MoSSe and MnGa-GaN@MoSSe systems also demonstrate enhanced sensing capabilities for NO2. This work offers valuable theoretical insights for exploring the potential applications of TM-GaN@MoSSe heterostructures in gas sensing.

Reactions of Ru3(CO)12 with 1,5-bis(diphenylphosphino)pentane: Synthesis, characterization, crystal structure, Hirshfeld surface and QTAIM Analysis of Ru3(CO)10(µ-dpppe)

Reactions of Ru3(CO)12 with 1,5-bis(diphenylphosphino)pentane (dpppe) in THF induced by sodium benzophenone ketyl radical anion, resulted in the expected metal cluster [Ru3(CO)11]2(µ-dpppe) (1) and Ru3(CO)10(µ-dpppe) (2) as the main products. Clusters 1 and 2 were characterized by spectroscopic methods, including Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (1H and 31P{1H} NMR).The structural features were determined using single crystal X-ray diffraction analysis. In cluster 1 and 2, the (dpppe) links two trinuclear cluster units via phosphine moieties and bridges to Ru–Ru bond, respectively. Both clusters were stabilized by the presence of C–H⋯O interactions and were further analyzed by Hirshfeld surface analysis. The bonding interactions within cluster 2 were studied using the Quantum Theory of Atoms in Molecules (QTAIM). Various local and integral topological properties of the electron density were calculated, along with the source function (SF) calculations and electron localization function (ELF) analysis.

Strangler fig–host tree associations: Insights into the ecology and management of tropical urban green spaces

Societal Impact StatementThe strangler fig is known for its hemiepiphytic growth form and conspicuous strangling behavior in the tropics worldwide. It also plays an important role in providing ecological functions in tropical urban ecosystems. This study reveals strangler figs tend to colonize large trees with suitable microsites in a large tropical botanical garden and cause some negative effects on their hosts. We advocate balanced management strategies considering ecological functions, potential risks, and overall values of stranglers and their hosts. These results provide a scientific basis for us to develop better practices for plant management in urban green spaces (especially botanical gardens with high plant biodiversity) in tropical urban ecosystems.Summary Strangler figs colonize trees in tropical cities, which contribute to a unique urban ecology and enrich local ecological functions. Understanding ecological associations between strangler figs and their host trees can improve green space management in tropical urban ecosystems. We investigated 9282 trees growing in the Xishuangbanna Tropical Botanical Garden and then analyzed the diversity, characteristics, and network of strangler figs and their host trees. We found 13 strangler fig species (319 individuals) widely colonized 67 host species, with palm hosts bearing 52% of all strangler individuals. Strangler figs had a high colonization rate in large trees with appropriate microsites (e.g., persistent palm petioles and the fork of mature trees with rough trunks). Leaf nitrogen and phosphorus content of hosts decreased significantly after strangler figs' aerial roots had entered the ground. The strangler–host network was characterized by relatively high specialization and low nestedness, and simulated management of strangler figs on large hosts and palm hosts could simplify the strangler–host network. Strangler fig colonization can be managed. Planting trees with large diameters at breast height and rough bark can increase the colonization of stranglers, while cutting off aerial roots can inhibit their establishment. The epiphytic stage is the best time to manage strangler figs. We recommend taking into consideration the trade‐offs among ecological functioning, human safety, and the multifaceted value of strangler figs and their host trees and thereby implementing comprehensive management strategies tailored to different contexts for improving green space management in the tropics.

Unveiling Carbon Cluster Coating in Graphene CVD on MgO: Combining Machine Learning Force field and DFT Modeling.

In this study, we investigate the behavior of carbon clusters (Cn, where n ranges from 16 to 26) supported on the surface of MgO. We consider the impact of doping with common impurities (such as Si, Mn, Ca, Fe, and Al) that are typically found in ores. Our approach combines density functional theory calculations with machine learning force field molecular dynamics simulations. It is found that the C21 cluster, featuring a core-shell structure composed of three pentagons isolated by three hexagons, demonstrates exceptional stability on the MgO surface and behaves as an "enhanced binding agent" on MgO-doped surfaces. The molecular dynamics trajectories reveal that the stable C21 coating on the MgO surface exhibits less mobility compared to other sizes Cn clusters and the flexible graphene layer on MgO. Furthermore, this stability persists even at temperatures up to 1100K. The analysis of the electron localization function and potential function of Cn on MgO reveals the high localization electron density between the central carbon of the C21 ring and the MgO surface. This work proposes that the C21 island serves as a superstable and less mobile precursor coating on MgO surfaces. This explanation sheds light on the experimental defects observed in graphene products, which can be attributed to the reduced mobility of carbon islands on a substrate that remains frozen and unchanged.

A DFT Computational Study of Type-I Clathrates A8Sn46-x (A = Cs or NH4, x = 0 or 2).

Semiconducting clathrates have attracted considerable interest in the field of thermoelectric materials. We report here a computational study on the crystal structure, the enthalpy of formation, and the physical properties of the following type-I clathrates: (a) experimentally studied Cs8Sn44 and hypothetical Cs8Sn46 and (b) hypothetical (NH4)8Sn46-x (x = 0 or 2). The ab initio VASP calculations for the nominal stoichiometries include the geometry optimization of the initial structural models, enthalpies of formation, and the electronic and phonon density of states. Comparison of the chemical bonding of the structural models is performed via the electron localization function. The results show that the presence and distribution of defects in the Sn framework for both Cs8Sn46-x and (NH4)8Sn46-x systems significantly alters the formation energy and its electrical properties, ranging from metallic to semiconducting behavior. In particular, one defect per six-membered Sn ring in a 3D spiro-network is the thermodynamically preferred configuration that results in the Cs8Sn44 and (NH4)8Sn44 stoichiometries with narrow-band gap semiconducting behavior. Moreover, the rotation of the ammonium cation in the polyhedral cavities is an interesting feature that may promote the use of ammonium or other small molecular cations as guests in clathrates for thermoelectric applications; this is due to the decrease in the lattice thermal conductivity.

A Study Based on the First-Principle Study of the Adsorption and Sensing Properties of Mo-Doped WSe2 for N2O, CO2, and CH4

As industry continues to develop rapidly, the greenhouse effect is becoming increasingly severe. CO2, CH4, and N2O are the three primary greenhouse gases, making their effective monitoring a crucial step in reducing emissions. This paper investigates the gas sensing performance of Mo-doped WSe2 for these three gases, through a theoretical study. First, using first-principles calculations, the doping behavior of Mo in WSe2 is examined. Subsequently, the adsorption properties of Mo-WSe2 for CO2, CH4, and N2O are analyzed by calculating adsorption energy, charge transfer, the electron localization function (ELF), Hirshfeld partition (IGMH), and the density of states (DOSs), culminating in an analysis of its sensing properties. The results indicate that when Mo is positioned above the upper Se atom, the structure is most stable. Therefore, this position is selected as the optimal adsorption site for studying the adsorption of the three gases. The adsorption energies for CO2, CH4, and N2O are 1.349 eV, −1.194 eV, and −0.528 eV, respectively, with corresponding charge transfers of 0.418, 0.450, and 0.115. In the N2O and CO2 adsorption systems, significant adsorption energy and charge transfer are observed, leading to relatively better adsorption compared to the CH4 system. Additionally, considering the adsorption performance, Mo-WSe2 demonstrates good sensor response and desorption times for N2O and CO2 at temperatures above 298 K. The findings of this research provide theoretical guidance for the application of Mo-WSe2 as a gas sensing material for detecting greenhouse gases.

Local powers of least‐squares‐based test for panel fractional Ornstein–Uhlenbeck process

In recent years, significant advancements have been made in the field of identifying financial asset price bubbles, particularly through the development of time‐series unit‐root tests featuring fractionally integrated errors and panel unit‐root tests. This study introduces an innovative approach for assessing the sign of the persistence parameter () within a panel fractional Ornstein‐Uhlenbeck process, based on the least squares estimator of . This method incorporates three distinct test statistics based on the Hurst parameter (), which can take values in the range of , be equal to , or fall within the interval of . The null hypothesis corresponds to . Based on a panel of continuous records of observations, the null asymptotic distributions are obtained when the time span () is fixed and the number of cross sections () goes to infinity. The power function of the tests is obtained under the local alternative where is close to zero in the order of . This alternative covers the departure from the unit root hypothesis from the explosive side, enabling the calculation of lower power in bubble tests. The hypothesis testing problem and the local power function are also considered when a panel of discrete‐sampled observations is available under a sequential limit, that is, the sampling interval shrinks to zero followed by the goes to infinity.

Location and function of TDP-43 in platelets, alterations in neurodegenerative diseases and arising considerations for current plasma biobank protocols

The TAR DNA Binding Protein 43 (TDP-43) has been implicated in the pathogenesis of human neurodegenerative diseases and exhibits hallmark neuropathology in amyotrophic lateral sclerosis (ALS). Here, we explore its tractability as a plasma biomarker of disease and describe its localization and possible functions in the cytosol of platelets. Novel TDP-43 immunoassays were developed on three different technical platforms and qualified for specificity, signal-to-noise ratio, detection range, variation, spike recovery and dilution linearity in human plasma samples. Surprisingly, implementation of these assays demonstrated that biobank-archived plasma samples yielded considerable heterogeneity in TDP-43 levels. Importantly, subsequent investigation attributed these differences to variable platelet recovery. Fractionations of fresh blood revealed that ≥ 95% of the TDP-43 in platelet-containing plasma was compartmentalized within the platelet cytosol. We reasoned that this highly concentrated source of TDP-43 comprised an interesting substrate for biochemical analyses. Additional characterization of platelets revealed the presence of the disease-associated phosphoserine 409/410 TDP-43 proteoform and many neuron- and astrocyte-expressed TDP-43 mRNA targets. Considering these striking similarities, we propose that TDP-43 may serve analogous functional roles in platelets and synapses, and that the study of platelet TDP-43 might provide a window into disease-related TDP-43 dyshomeostasis in the central nervous system.

A detailed TD-DFT and intermolecular interaction study of vitamin K in soluble, poorly soluble and insoluble solvents, as well as an ADME and molecular docking study

Vitamin K is one of the most important fat-soluble vitamins and while there are two main types of vitamin K in nature, known as K1 (phylloquinone) and K2 (menaquinones), there is also a synthetic type of vitamin K known as K3 (menadione). Recent studies have shown that it is crucial to know the non-covalent interactions, ADME and molecular docking of molecules in different solvent media. Therefore, we have performed some quantum chemical calculations, ADME and intra-and intermolecular interaction calculations of a number of K1, K2 and K3 such as K1-water (K1 + W), K1-methanol (K1 + M), K1-triacetin (K1 + T), K2-water (K2 + W), K2-methanol (K2 + M), K2-triacetin (K2 + T), K3-water (K3 + W), K3-methanol (K3 + M), K3-triacetin (K3 + T) performed by Density Functional Theory (DFT) and Multiwfn: A multifunctional wavefunction analyzer. Molecular structures, HOMO-LUMO energies, MEP and electronic properties have been calculated and described using DFT at the level of B3LYP/6-311G (d,p) level. The nature of the molecular interactions between vitamin K and solvents such as water, methanol and triacetin were also investigated using topological analyses such as atoms in molecule (AIM), non-covalent interaction index (NCI), reduced density gradient (RDG), Localized orbital locator (LOL) and electron localization function (ELF). In addition, FMO for electronic transitions, MEP for electrophilic and nucleophilic attack, ADME to investigate how a chemical is processed by a living organism, and Fukui functions to determine electron density are explained. Finally, molecular docking was used to determine the biological activity of the vitamin K.

Localised analytic torsion and relative analytic torsion for non compact Lie groups of type I

Let G be a (non compact) connected, simply connected, locally compact, second countable Lie group, either abelian or unimodular of type I, and let ρ be an irreducible unitary representation of G. Then, we define the analytic torsion of G localised at the representation ρ. The idea of considering localised invariants is due to Brodzki, Niblo, Plymen and Wright [5], and was exploited in [31] to define a localised eta function. Next, let Γ be a discrete co compact subgroup of G. We use the localised analytic torsion to define the relative analytic torsion of the pair (G,Γ), and we prove that the last coincides with the Lott L2 analytic torsion of a covering space. We illustrate these constructions analysing in some details two examples: the abelian case, and the case G=H, the Heisenberg group.

Insights into bismuthene and antimonene as cisplatin drug carriers: A theoretical comparative investigation

While effective targeted delivery is a challenge in nanomedicine for the delivery of anti-cancer drugs, this work focuses on the potential use of Bismuthene and antimonene nanosheets as nanocarriers for cisplatin anti-cancer using DFT methods. The results indicate that, compared to antimonene, bismuthene demonstrates significantly better physical stability, drug release rate, solubility, and biocompatibility, making it an excellent candidate for drug delivery systems. The parallel and perpendicular orientations of the anticancer drug were adsorbed on both nanosheets; the parallel configuration was the most energetically favored with an adsorption energy of −0.79 eV at the parallel site. A charge transfer from the drug to the bismuthene sheet is also revealed by the electronic charge analysis and DOS calculation, thus confirming efficient drug adsorption. Modeling a proton attack on the drug and the carrier surface near the adsorption sites was performed to model drug release, showing the stability and potential of bismuthene in this aspect of drug release mechanisms. Further, with an approach to studying its interactions with biomolecules, interactions of the drug molecule have been analyzed with amino acids, showing that drugs interact efficiently. Further assessments concerning work function, recovery time, electron localization function, and frontier molecular orbital analyses leave no doubt that bismuthene has beneficial features over antimonene. These thorough assessments present bismuthene as a more promising nanocarrier for the delivery of anti-cancer drugs and open a potential pathway to enhance the efficacy of strategies against cancer treatment.

Computational study of the supramolecular complexation of azocompounds with cucurbit[7]uril: effects on the production and release of free radicals.

An inclusion complex between 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH), a widely employed azocompound, and cucurbit[7]util (CB[7]), has shown an increased yield of radicals derived from the homolytic cleavage of the azo bond. Aimed to get insights about the formation of complexes and their effect on the yield of radicals production, complexes of CB[7] with seven azocompounds were studied by computational methods. Molecular electrostatic surfaces and structural analysis showed that the inclusion of symmetrical azocompounds inside of CB[7] depends mainly on the charge density and position of the functional groups at the main chain of the azoderivative. Analysis of non-covalent interactions and thermodynamic outcomes revealed that positively charged azocompounds with amidinium or imidazolium groups presented strong favorable interactions (multiple hydrogen bonds) with the oxygens of CB[7] portals. Additionally, carbon-centered radicals generated from the complexes (azocompounds@CB[7]) were corroborated using the electron localization function (ELF). Results evidenced that the strength of the interactions and the level of inclusion (partial or complete) between the azocompound and CB[7] determined the final orientation of the radicals (located out- or inside of the CB[7] cavity). Obtained results could be employed to design new supramolecular systems based on the properties of azocomplound@CB[7] complexes for new scientific or industrial applications. First-principles calculations at B3LYP-D3BJ/6-311g(d,p) level theory in the gas phase and in solvent (PCM, water) were performed in Gaussian 16 software package. The dispersion energy correction was included through the Grimme's dispersion with Becke-Johnson damping D3(BJ). Thermodynamical data and the minimum character of all structures were obtained from vibrational frequency calculations. NBO, Multiwfn, Chemcraft, and NCIPLOT software were used to perform population analysis, analyze outcomes, visualize data, and display non-covalent interactions respectively.

Heritability of movie-evoked brain activity and connectivity.

The neural bases of sensory processing are conserved across people, but no two individuals experience the same stimulus in exactly the same way. Recent work has established that the idiosyncratic nature of subjective experience is underpinned by individual variability in brain responses to sensory information. However, the fundamental origins of this individual variability have yet to be systematically investigated. Here, we establish a genetic basis for individual differences in sensory processing by quantifying (1) the heritability of high-dimensional brain responses to movies and (2) the extent to which this heritability is grounded in lower-level aspects of brain function. Specifically, we leverage 7T fMRI data collected from a twin sample to first show that movie-evoked brain activity and connectivity patterns are heritable across the cortex. Next, we use hyperalignment to decompose this heritability into genetic similarity in where vs. how sensory information is processed. Finally, we show that the heritability of brain activity patterns can be partially explained by the heritability of the neural timescale, a one-dimensional measure of local circuit functioning. These results demonstrate that brain responses to complex stimuli are heritable, and that this heritability is due, in part, to genetic control over stable aspects of brain function.