Model System For Interactions Research Articles

Three separate pathways in Rhizobium leguminosarum maintain phosphatidylcholine biosynthesis, which is required for symbiotic nitrogen fixation with clover.

Understanding the molecular mechanisms of symbiotic nitrogen fixation has important implications for sustainable agriculture. The presence of the phospholipid phosphatidylcholine (PC) in the membrane of rhizobia is critical for the establishment of productive nitrogen-fixing root nodules on legume plants. The reasons for the PC requirement are unknown. Here, we employed Rhizobium leguminosarum and clover as model system for a beneficial plant-microbe interaction. We found that R. leguminosarum produces PC by three distinct pathways. The relative contribution of these pathways to PC formation was determined in an array of single, double, and triple mutant strains. Several of the PC biosynthesis enzymes were purified and biochemically characterized. Most importantly, we demonstrated the essential role of PC formation by R. leguminosarum in nitrogen fixation and pinpointed a specific enzyme indispensable for plant-microbe interaction. Our study offers profound insights into bacterial PC biosynthesis and its pivotal role in biological nitrogen fixation.

Oscillations in a tumor-immune system interaction model with immune response delay.

In this paper we consider a tumor-immune system interaction model with immune response delay, in which a nonmonotonic function is used to describe immune response to the tumor burden and a time delay is used to represent the time for the immune system to respond and take effect. It is shown that the model may have one, two or three tumor equilibria, respectively, under different conditions. Time delay can only affect the stability of the low tumor equilibrium and local Hopf bifurcation occurs when the time delay passes through a critical value. The direction and stability of the bifurcating periodic solutions are also determined. Moreover, the global existence of periodic solutions is established by using a global Hopf bifurcation theorem. We also observe the existence of relaxation oscillations and complex oscillating patterns driven by the time delay. Numerical simulations are presented to illustrate the theoretical results.

Seismic performance of underground subway station structure near the strike-slip fault by the developed hybrid IBE-FEM method

To investigate the influence of strike-slip faults on the seismic responses of underground structures, based on the single-layer potential theory of the boundary element concept and the fault-site-underground structure coupling mechanisms, we proposed a hybrid indirect boundary element-finite element numerical method (IBE-FEM) to simulate efficiently the seismic response of the entire process from the near seismogenic-fault to the underground structure. Initially, based on the kinematic finite-fault model, the seismic wavefield of an overlying soft-soil sedimentary-layer site subjected to strike-slip faults with source parameters, such as rupture velocity, dip-angle, and upper-boundary burial depth, was solved using the indirect boundary element method (IBE). Subsequently, the accuracy of the IBE-FEM in predicting the site seismic wavefield was verified. On this basis, the influence laws of the source parameters and the fault-site coupling effects on the seismic performance of the structure were preliminarily investigated by establishing a numerical model of the nonlinear dynamic interaction system of a soil-underground structure. The results showed that the seismic responses of the underground structure located in the footwall far-fault region were more strongly affected by variations in the rupture velocity. The lateral deformation of the structure under the rupture velocity condition of bedrock shear-wave velocity (vs) was dramatically increased compared to sub-vs, and the lowest amplification is 59 %. Furthermore, the hanging wall and seismic damage concentration effects significantly impacted the structure located in a strike-slip fault site with a shallow-burial. This study provides a reliable and efficient analytical method for the seismic design of underground structures in complex near-fault regions.

A Systematic Process to Engineer Dependable Integration of Frame-based Input Devices in a Multimodal Input Chain: Application to Rehabilitation in Healthcare

Designing new input devices and associated interaction techniques is a key contribution in order to increase the bandwidth between users and interactive applications. In the field of Human-Computer Interaction, research and development services in industry and research laboratories in universities have been, since the invention of the mouse and the graphical user interface, proposing multiple contributions including the integration of multiple input devices in multimodal interaction technique. Those contributions, most of the time, are presented as prototypes or demonstrators providing evidence of the bandwidth increase through user studies. Such contributions however, do not provide any support to software developers for integrating them in real-life systems. When done, this integration is performed in a craft manner, outside required software engineering good practice. This paper proposes a systematic process to integrate novel input devices and associated interaction techniques to better support users' work. It exploits most recent interactive systems architectural model and formal model-based approaches for interactive systems supporting verification and validation when required. The paper focusses on Frame-based input devices which support gesture-based interactions and movements recognition but also addresses their multimodal use. This engineering approach is demonstrated on an interactive application in the area of rehabilitation in healthcare where dependability of interactions and applications is as critical as their usability.

Virtual Reality Scenario Analysis of Art Design Taking into Account Interactive Digital Media Pattern Generation Technology

In art design, 3D printing technology is crucial, and more and more creators conceive scenes using 3D modeling software to get a three-dimensional and beautiful work. Due to the large amount of noise and redundant points in the raw data collected during the modeling process, the generation speed and rendering effect of 3D models are reduced. Given the above problems, the study designed an interactive 3D lightweight modeling system based on the combination of hand-drawn sketching and laser 3D scanning based on the streamlined algorithm. The experimental results showed that when the hand-drawn speed was 300, the number of triangular slices, model size, and time required to generate the model of the hand-drawn sketching model based on the streamlined algorithm were reduced by 67.39%, 65.48%, and 63.79%, respectively. In the real-time point cloud data streamlining process of the laser 3D scanning model, the point cloud data reduction ratio and the streamlining goodness index of the point cloud streamlining algorithm are 71.99% and 3.06%, respectively. The system performance is robust, and the data processing speed and rendering effect are good.

Modeling the Nonmonotonic Immune Response in a Tumor–Immune System Interaction

Tumor–immune system interactions are very complicated, being highly nonlinear and not well understood. A large number of tumors can potentially weaken the immune system through various mechanisms such as secreting cytokines that suppress the immune response. In this paper, we propose a tumor–immune system interaction model with a nonmonotonic immune response function and adoptive cellular immunotherapy (ACI). The model has a tumor-free equilibrium and at most three tumor-presence equilibria (low, moderate and high ones). The stability of all equilibria is studied by analyzing their characteristic equations. The consideration of nonmonotonic immune response results in a series of bifurcations such as the saddle-node bifurcation, transcritical bifurcation, Hopf bifurcation and Bogdanov–Takens bifurcation. In addition, numerical simulation results show the coexistence of periodic orbits and homoclinic orbits. Interestingly, along with various bifurcations, we also found two bistable scenarios: the coexistence of a stable tumor-free as well as a high-tumor-presence equilibrium and the coexistence of a stable-low as well as a high-tumor-presence equilibrium, which can show symmetric and antisymmetric properties in a range of model parameters and initial cell concentrations. The new findings indicate that under ACI, patients can possibly reach either a stable tumor-free state or a low-tumor-presence state in the presence of nonmonotonic immune response once the immune system is activated.

Response prediction and probabilistic analysis of the vehicle-ballasted track system considering track irregularity based on long-short term memory neural network

It is necessary to efficiently and accurately predict the dynamic behavior of the train-track system subjected to massive random track geometric excitations for system evaluation and maintenance. This paper proposed an engineering practical approach for the train-track system behavior prediction by integrating the deep learning surrogate model-based long-short term memory (LSTM) and physical model of the train-ballasted track interaction (TBTI) system, and then the generalized probability density evolution method (GPDEM) is introduced to achieve the probabilistic assessment of the TBTI system under limited track irregularities, where the track irregularity probability model (TIPM) coupled with generalized-F discrepancy points sets is employed to compress the track irregularity sets to reduce the number of system responses (as training target) but without loss of the responses completeness, therefore, it can promote the efficiency and accuracy of training model. The prediction performance of the surrogate model is illustrated by comparing the time-frequency domain information, mean and standard deviation of the responses obtained by the physical model and surrogate model. The results indicated the proposed method can accurately predict the system response, especially the low and medium frequency response below 50 Hz, and improve the efficiency of stochastic analysis for the TBTI system by approximately 20 times. Furthermore, the applicability of the proposed method is further examined by investigating the influence of probability levels of track irregularity and train speeds on train performance. Its extended model is also implemented to predict the response of systems induced by any measured track irregularity in real-time, which promotes the generalization capability of the proposed surrogate model.

Naturally occurring viruses of Drosophila reduce offspring number and lifespan.

Drosophila remains a pre-eminent insect model system for host-virus interaction, but the host range and fitness consequences of the drosophilid virome are poorly understood. Metagenomic studies have reported approximately 200 viruses associated with Drosophilidae, but few isolates are available to characterize the Drosophila immune response, and most characterization has relied on injection and systemic infection. Here, we use a more natural infection route to characterize the fitness effects of infection and to study a wider range of viruses. We exposed laboratory Drosophila melanogaster to 23 naturally occurring viruses from wild-collected drosophilids. We recorded transmission rates along with two components of female fitness: survival and the lifetime number of adult offspring produced. Nine different viruses transmitted during contact with laboratory D. melanogaster, although for the majority, rates of transmission were less than 20%. Five virus infections led to a significant decrease in lifespan (D. melanogaster Nora virus, D. immigrans Nora virus, Muthill virus, galbut virus and Prestney Burn virus), and three led to a reduction in the total number of offspring. Our findings demonstrate the utility of the Drosophila model for community-level studies of host-virus interactions, and suggest that viral infection could be a substantial fitness burden on wild flies.

QuickCSGModeling: Quick CSG Operations Based on Fusing Signed Distance Fields for VR Modeling

The latest advancements in Virtual Reality (VR) enable the creation of 3D models within a holographic immersive simulation environment. In this article, we create QuickCSGModeling , a user-friendly mid-air interactive modeling system. We first prepare a dataset consisting of diverse components and precompute the discrete signed distance function (SDF) for each component. During the modeling phase, users can freely design complicated shapes with a pair of VR controllers. Based on the discrete SDF representation, any CSG-like operation (union, intersection, and subtraction) can be performed voxel-wisely. Also, we maintain a single dynamic SDF for the whole scene, whose zero-level set surface exactly encodes the most recent constructed shape. Both SDF fusion and surface extraction are implemented via GPU for a smooth user experience. A total of 34 volunteers were asked to create their favorite models using QuickCSGModeling. With a simple training, most of them can create a fascinating shape or even a descriptive scene quickly. We also discuss how to extend our system to create articulated models with hinges, where an adaptive cube subdivision has to be enforced to improve the reconstruction accuracy around the hinge part, followed by a Dual Contouring-based surface extraction. 1

A new model of ultra wideband sensors based interactive system

Camera Based Interactive Systems have found their application in various fields of human activity, such as education, industry, entertainment, healthcare, public order, etc. It could be noted that in the characteristics of such a system, certain shortcomings or weaknesses could be highlighted. To reduce these weaknesses, a new model, based on digital communication devices in the wideband radio frequency spectrum is proposed. The technology used is ultra-wideband based, through the construction of a wireless sensor network. This paper proposes a model of an ultra-wideband wireless sensor-based interactive system that implements the spatial orientation approach and the precise local positioning approach. A synthesis of the new model comprises four phases.

Testing androgen-induced immunosuppression: Environmental androgens as a model system for steroid-immune interaction.

It is well known that hormones influence and direct most facets of physiology; however, there is still contention regarding the directions of certain relationships, for example, between gonadal hormones and immunity. Among the many proposed relationships relating to gonadal-immune interactions, support for immunosuppressive effects of androgens remains prominent within physiological literature. Although ample study has been directed towardthe immunosuppressive effects of androgens, considerable disagreement remains regarding their influence on immune function. In this study, we test the hypothesis that androgens inhibit immunocompetence in the American alligator (Alligator mississippiensis). Developing alligators were incubated at female-producing temperatures with a subset of individuals being exposed to 17-α-methyltestosterone (MT) before sexual determination. 17-α-methyltestosterone is a potent androgen, not aromatizable by crocodilians, that has been found to exert masculinizing effects in exposed crocodilian populations in vivo and in vitro. Additionally, a subset of animals was exposed to a novel antigen to quantify innate and acquired immune function. We recovered no significant differences in leukocyte ratios or proportions between groups and found no significant differences in innate immune function as measured by hemolysis-hemagglutination. However, we did find significant differences in acquired immune function, where masculinized individuals expressed greater antibody titers. Our findings reject the hypothesis that androgens suppress immune function; rather, androgens may be immunoenhancing to acquired humoral responses and neutral to innate humoral immunity in crocodilians.

Photophysics of a nucleic acid-protein crosslinking model strongly depends on solvation dynamics: an experimental and theoretical study.

We present a combined experimental and theoretical study of the photophysics of 5-benzyluracil (5BU) in methanol, which is a model system for interactions between nucleic acids and proteins. A molecular dynamics study of 5BU in solution through efficient DFT-based hybrid ab initio potentials revealed a remarkable conformational flexibility - allowing the population of two main conformers - as well as specific solute-solvent interactions, which both appear as relevant factors for the observed 5BU optical absorption properties. The simulated absorption spectrum, calculated on such an ensemble, enabled a molecular interpretation of the experimental UV-Vis lowest energy band, which is also involved in the induced photo-reactivity upon irradiation. In particular, the first two excited states (mainly involving the uracil moiety) both contribute to the 5BU lowest energy absorption. Moreover, as a key finding, the nature and brightness of such electronic transitions are strongly influenced by 5BU conformation and the microsolvation of its heteroatoms.

Bridge Displacement Prediction from Dynamic Responses of a Passing Vehicle Using CNN‐GRU Networks

Dynamic displacement is an important indicator for bridge safety estimation but is difficult to measure due to economic or technological limitations. Dynamic responses of a passing vehicle include the bridge dynamic response information. This study proposes a framework utilizing artificial neural networks to efficiently and accurately predict bridge displacements from the dynamic response of a passing vehicle. The input and the output of the networks are the vehicle acceleration responses and the bridge dynamic displacement responses, respectively. The implemented framework consists of convolutional neural network (CNN) and gated recurrent units (GRU). CNN is adept at feature extraction in the microcosm of short‐term time series, revealing intricate nuances. As a complement, GRU plays a crucial role in extracting features of macroscopic long‐term time series. The CNN‐GRU network can efficiently extract higher‐order features contained in the input data. Numerical experiments are conducted using the developed vehicle‐bridge interaction (VBI) system model to obtain requisite data for training the deep neural network. The impact of the presence or absence of roadway irregularities and the number of vehicles are discussed, indicating the accuracy of the framework. Furthermore, a laboratory experiment is conducted to further assess the performance of the CNN‐GRU network. Results indicate that the CNN‐GRU network offers an effective alternative for bridge displacement measurements.

Physiotyping of Plants and Modeling the Soil Plant Atmospheric Continuum (SPAC).

This chapter presents a holistic and quantitative approach to the carbon cycle in plant systems biology. It includes (rapid) phenotyping and monitoring of physiological key interactions of plants with its respective soil and atmospheric environment (soil plant atmospheric continuum-SPAC). The approach aims at qualifying and quantifying key components of this microhabitat as influenced by a single plant or a local group of plants in order to contribute to a flux-based modelling approach. The toolset consists of plant biometry, gas exchange, metabolomics, ionomics, root exudate characterization as well as soil biological and physical-chemical characterization. The results are presented as a basic interaction and input-output model aka conceptual system model employing H. T. Odum-style plots based on empirical data.

Presenting the Interactive Control System Model in Knowledge-Based Companies

The aim of this study is to present a model of the interactive control system in knowledge-based companies. In the current research, three Type II knowledge-based manufacturing companies active in the field of advanced machinery and equipment production in East Azerbaijan Province were studied. Accordingly, this research follows a case study strategy, with data collection conducted from a defined statistical population. Additionally, the research employs a developmental research strategy. For the analysis of data obtained from questionnaires, the coding procedure, in line with statistical requirements, was conducted using the SPSS.V24 software, and the PLS.V3 structural equation software was used for both descriptive and inferential statistics, applying linear and multiple regression. The statistical population of this research includes managers of Type I and Type II knowledge-based manufacturing companies and faculty members from the University of Tehran's Department of Business Management, particularly those specializing in policy-making. The sampling method used in this study was snowball sampling. The results of the research indicate that regulatory uncertainties significantly impact the interactive control system of projects (0.896), technological uncertainties impact the interactive control system of projects (0.140), human and social uncertainties impact the interactive control system of projects (0.225), economic and market uncertainties impact the interactive control system of profit planning (0.476), environmental uncertainties impact the interactive control system of brand profitability (0.643), and strategic uncertainties impact the interactive control system of intelligence (0.821).

INVESTIGATION OF FRACTIONAL-ORDERED TUMOR-IMMUNE INTERACTION MODEL VIA FRACTIONAL-ORDER DERIVATIVE

Dynamical analysis of system of ordinary differential equations (ODEs) is an interesting topic among researchers and several tools have been discovered since so far to deal with its several other features. There are many built-in functions designed in MATLAB that researchers can use as a tool for the system of ODEs with integer order but in the similar systems have fractional-order derivative is a difficult task. Therefore, the purpose of this work is to use the Caputo fractional-order derivative to qualitatively analyze and then numerically simulate the tumor-immune system interaction model. Moreover, the Schauder fixed point theorem is used to establish the condition for the existence of at least one solution, while the Banach fixed point theorem is utilized to guarantee the existence of a unique solution. Moreover, the stability in the trajectories of considered system achieved with the aid of Ulam–Hyers (UH) stability. In addition, the numerical computations are performed using Variational Iteration Method (VIM) and the visualized results are shown using MATLAB.

Retracted: Application of Speech Interaction System Model Based on Semantic Search in English MOOC Teaching System

Retracted: Application of Speech Interaction System Model Based on Semantic Search in English MOOC Teaching System

Kratosvirus quantuckense: the history and novelty of an algal bloom disrupting virus and a model for giant virus research.

Since the discovery of the first "giant virus," particular attention has been paid toward isolating and culturing these large DNA viruses through Acanthamoeba spp. bait systems. While this method has allowed for the discovery of plenty novel viruses in the Nucleocytoviricota, environmental -omics-based analyses have shown that there is a wealth of diversity among this phylum, particularly in marine datasets. The prevalence of these viruses in metatranscriptomes points toward their ecological importance in nutrient turnover in our oceans and as such, in depth study into non-amoebal Nucleocytoviricota should be considered a focal point in viral ecology. In this review, we report on Kratosvirus quantuckense (née Aureococcus anophagefferens Virus), an algae-infecting virus of the Imitervirales. Current systems for study in the Nucleocytoviricota differ significantly from this virus and its relatives, and a litany of trade-offs within physiology, coding potential, and ecology compared to these other viruses reveal the importance of K. quantuckense. Herein, we review the research that has been performed on this virus as well as its potential as a model system for algal-virus interactions.

Shaking table test on seismic responses of asymmetrical underground subway stations

Currently, many subway stations are designed symmetrically and less attention has been paid to asymmetrical stations. The middle column of the asymmetric underground structure is offset to one side, which is not conducive to load bearing during strong earthquakes and is prone to damage. In this study, shaking table tests of a soil-symmetrical station and a soil-asymmetrical station were designed and conducted. A numerical model of the soil–structure interaction system was established, and the feasibility of the simulation method was verified. Then, the seismic responses of two kinds of stations were discussed and analysed. The results show that the dynamic response of both symmetrical and asymmetrical stations increases with the increase of the loading seismic intensity. Influenced by the size effect of the model test, there is less difference between the two models in their dynamic response. From the perspective of internal force and relative deformation, the response of the asymmetrical station is greater than that of the symmetrical station, which adequately reflects the disadvantage of asymmetrical structures in seismic design.

A Drosophila melanogaster model shows that fast growing Metarhizium species are the deadliest despite eliciting a strong immune response

ABSTRACT We used Drosophila melanogaster to investigate how differences between Metarhizium species in growth rate and mechanisms of pathogenesis influence the outcome of infection. We found that the most rapid germinators and growers in vitro and on fly cuticle were the fastest killers, suggesting that pre-penetration competence is key to Metarhizium success. Virulent strains also induced the largest immune response, which did not depend on profuse growth within hosts as virulent toxin-producing strains only proliferated post-mortem while slow-killing strains that were specialized to other insects grew profusely pre-mortem. Metarhizium strains have apparently evolved resistance to widely distributed defenses such as the defensin Toll product drosomycin, but they were inhibited by Bomanins only found in Drosophila spp. Disrupting a gene (Dif), that mediates Toll immunity has little impact on the lethality of most Metarhizium strains (an exception being the early diverged M. frigidum and another insect pathogen Beauveria bassiana). However, disrupting the sensor of fungal proteases (Persephone) allowed rapid proliferation of strains within hosts (with the exception of M. album), and flies succumbed rapidly. Persephone also mediates gender differences in immune responses that determine whether male or female flies die sooner. We conclude that some strain differences in growth within hosts depend on immune-mediated interactions but intrinsic differences in pathogenic mechanisms are more important. Thus, Drosophila varies greatly in tolerance to different Metarhizium strains, in part because some of them produce toxins. Our results further develop D. melanogaster as a tractable model system for understanding insect-Metarhizium interactions.