Exogenous Signals Research Articles

Mind your own business and communicate the same! – signaling content that makes investors interested

PurposeThis study aims to understand the impact of underlying theme in the communication on social media on funding received by early-stage start-ups.Design/methodology/approachThe study is based on empirical testing of data of 849 start-ups and more than 130K tweets. Machine learning (ML) model has been used for text classification of 130K+ tweets. Causal mediation analysis with bootstrapping is carried out for hypothesis testing.FindingsTweets addressing quality-related uncertainty are a predictor of amount of funds raised. Audience response acts as a mediator between tweets focusing on relational orientation and amount of funds raised.Research limitations/implicationsThe authors advance signaling theory by theorizing and investigating the importance of signal content. Endogenous signal of quality directly influences the start-ups outcomes, while exogenous signal helps disseminate information and influence the success.Practical implicationsEntrepreneurs should put in concerted effort to reduce uncertainty about the start-ups. Value creation is a central concept for start-ups; however, communicating value should be the dominant part of social media strategy.Originality/valueComputer-based language processing techniques have amplified the research focused on content. To the best of the authors’ knowledge, this is the first comprehensive study that explores underlying themes of communication of start-ups and their impact on acquiring funds.

Localization of Arabidopsis Glucan Synthase-Like 5, 8, and 12 to plasmodesmata and the GSL8-dependent role of PDLP5 in regulating plasmodesmal permeability

ABSTRACT Cell-to-cell communication via membranous channels called plasmodesmata (PD) plays critical roles during plant development and in response to biotic and abiotic stresses. Several enzymes and receptor-like proteins (RLPs), including Arabidopsis thaliana glucan synthase-likes (GSLs), also known as callose synthases (CALSs), and PD-located proteins (PDLPs), have been implicated in plasmodesmal permeability regulation and intercellular communication. Localization of PDLPs to punctate structures at the cell periphery and their receptor-like identity have raised the hypothesis that PDLPs are involved in the regulation of symplastic trafficking during plant development and in response to endogenous and exogenous signals. Indeed, it was shown that PDLP5 could limit plasmodesmal permeability through inducing an increase in callose accumulation at PD. However, mechanistically, how this is achieved remains to be elucidated. To address this key issue in understanding the regulation of PD, physical and functional interactions between PDLPs and GSLs (using the PDLP5–GSL8/CALS10 pair as a model) were investigated. Our results show that GSL8/CALS10 plays essential roles and is required for the function and plasmodesmal localization of PDLP5. Furthermore, it was demonstrated that the localization of PDLP5 to PD and its function in inducing callose deposition are GSL8-dependent. Importantly, our transgenic study shows that three key members of the GSL family, i.e., GSL5/CALS12, GSL8/CALS10, and GSL12/CALS3, localize to PD and co-localize with PDLP5, suggesting that GSL8/CALS10 might not be the only callose synthase with the determining role in PD regulation. These findings, together with our previous observation showing the direct interaction of GSL8/CALS10 with PDLP5, indicate the pivotal role of the GSL8/CALS10-PDLP5 interplay in regulating PD permeability. Future work is needed to investigate whether the PDLP5 functionality and localization are also disrupted in gsl5 and gsl12, or it is just gsl8-specific.

Accurate parameter estimation for safety-critical systems with unmodeled dynamics

Analysis and synthesis of safety-critical autonomous systems are carried out using models which are often dynamic. Two central features of these dynamic systems are parameters and unmodeled dynamics. Much of feedback control design is parametric in nature and as such, accurate and fast estimation of the parameters in the modeled part of the dynamic system is a crucial property for designing risk-aware autonomous systems. This paper addresses the use of a spectral lines-based approach for estimating parameters of the dynamic model of an autonomous system. Existing literature has treated all unmodeled components of the dynamic system as sub-Gaussian noise and proposed parameter estimation using Gaussian noise-based exogenous signals. In contrast, we allow the unmodeled part to have deterministic unmodeled dynamics, which are almost always present in physical systems, in addition to sub-Gaussian noise. In addition, we propose a deterministic construction of the exogenous signal in order to carry out parameter estimation. We introduce a new tool kit which employs the theory of spectral lines, retains the stochastic setting, and leads to non-asymptotic bounds on the parameter estimation error. Unlike the existing stochastic approach, these bounds are tunable through an optimal choice of the spectrum of the exogenous signal leading to accurate parameter estimation. We also show that this estimation is robust to unmodeled dynamics, a property that is not assured by the existing approach. Finally, we show that under ideal conditions with no deterministic unmodeled dynamics, the proposed approach can ensure a O˜(T) Regret, matching existing literature. Experiments are provided to support all theoretical derivations, which show that the spectral lines-based approach outperforms the Gaussian noise-based method when unmodeled dynamics are present, in terms of both parameter estimation error and Regret obtained using the parameter estimates with a Linear Quadratic Regulator in feedback.

Modeling the influence of phenotypic plasticity on maize hybrid performance

Phenotypic plasticity, the ability of an individual to alter its phenotype in response to changes in the environment, has been proposed as a target for breeding crop varieties with high environmental fitness. Here, we used phenotypic and genotypic data from multiple maize (Zea mays L.) populations to mathematically model phenotypic plasticity in response to the environment (PPRE) in inbred and hybrid lines. PPRE can be simply described by a linear model in which the two main parameters, intercept a and slope b, reflect two classes of genes responsive to endogenous (class A) and exogenous (class B) signals that coordinate plant development. Together, class A and class B genes contribute to the phenotypic plasticity of an individual in response to the environment. We also made connections between phenotypic plasticity and hybrid performance or general combining ability (GCA) of yield using 30 F1 hybrid populations generated by crossing the same maternal line with 30 paternal lines from different maize heterotic groups. We show that the parameters a and b from two given parental lines must be concordant to reach an ideal GCA of F1 yield. We hypothesize that coordinated regulation of the two classes of genes in the F1 hybrid genome is the basis for high GCA. Based on this theory, we built a series of predictive models to evaluate GCA in silico between parental lines of different heterotic groups.

An Adaptive Distributed Protocol for Finite-Time Infimum or Supremum Dynamic Consensus

In this letter, the problem of distributively tracking the minimum infimum (or maximum supremum) of a set of time-varying signals in finite-time is addressed. More specifically, each agent has access to a local time-varying exogenous signal, and all the agents are required to follow the minimum infimum (or the maximum supremum) of these signals in a distributed fashion. No assumption is made on the network size nor on the bounds of the exogenous signal derivatives. An adaptive protocol is provided which can provably solve the above problem in finite-time for multi-agent systems with undirected connected network topologies. Numerical simulations are provided to corroborate the theoretical findings.

Signature Trading: A Path-Dependent Extension of the Mean-Variance Framework with Exogenous Signals

Signature Trading: A Path-Dependent Extension of the Mean-Variance Framework with Exogenous Signals

Dahl Hysteresis Modeling and Position Control of Piezoelectric Digital Manipulator

The synthesis of a feedback controller based on a hysteresis model is challenging, mainly when the hysteresis is non-symmetric. In this letter, we propose to model a non-symmetric hysteresis of a piezoelectric actuator by using the Dahl model and design a nonlinear feedback controller for the system. For that aim, we exploit the boundedness of the system states to design an extended observer responsible for estimating the part of the system that is observable, including non-modeled terms and exogenous signals. Then, we design active disturbance rejection control that globally asymptotically stabilizes the tracking error. Finally, simulations were carried out to demonstrate the effectiveness of our approach.

The intestinal microenvironment shapes macrophage and dendritic cell identity and function

The gut comprises the largest body interface with the environment and is continuously exposed to nutrients, food antigens, and commensal microbes, as well as to harmful pathogens. Subsets of both macrophages and dendritic cells (DCs) are present throughout the intestinal tract, where they primarily inhabit the gut-associate lymphoid tissue (GALT), such as Peyer's patches and isolated lymphoid follicles. In addition to their role in taking up and presenting antigens, macrophages and DCs possess extensive functional plasticity and these cells play complementary roles in maintaining immune homeostasis in the gut by preventing aberrant immune responses to harmless antigens and microbes and by promoting host defense against pathogens. The ability of macrophages and DCs to induce either inflammation or tolerance is partially lineage imprinted, but can also be dictated by their activation state, which in turn is determined by their specific microenvironment. These cells express several surface and intracellular receptors that detect danger signals, nutrients, and hormones, which can affect their activation state. DCs and macrophages play a fundamental role in regulating T cells and their effector functions. Thus, modulation of intestinal mucosa immunity by targeting antigen presenting cells can provide a promising approach for controlling pathological inflammation. In this review, we provide an overview on the characteristics, functions, and origins of intestinal macrophages and DCs, highlighting the intestinal microenvironmental factors that influence their functions during homeostasis. Unraveling the mechanisms by which macrophages and DCs regulate intestinal immunity will deepen our understanding on how the immune system integrates endogenous and exogenous signals in order to maintain the host's homeostasis.

Влияние таргетных пробиотиков на ось «микробиота – кишечник – иммунная система

The gastrointestinal tract is a multifunctional system that performs numerous functions, including immunity. It is the basis of the body's safety, including neutralizing foreign antigens and xenobiotics, tolerance formation, or elimination. One of the most important protections for humans is the intestinal microbiota. Without symbiosis with trillions of microorganisms inhabiting the human intestine, the vital activity of the macroorganism is impossible. Therefore, the totality of the human and microbiota is considered as a superorganism. Within the framework of this paradigm, the review examines in detail numerous aspects of the interaction of the microbiota with various components of the immune system, and its role in the implementation of the immune response as a whole. In addition, the review pays attention to the problem of probiotics. Based on the understanding of the microbiota as a kind of "signaling interface" integrating exogenous and endogenous signals affecting both health and the manifestation of human diseases, the authors for the first time gave a scientific definition of "targeted probiotic therapy" as opposed to the concept of "empirical probiotic therapy" based on the principle of "one size fits all". Thus, "targeted probiotics" are safe, strain-level identifiable living microorganisms with established or suspected therapeutic targets, which, when introduced into the host body and possessing immunoregulatory, metabolic, microbiome-modulating, and other effects, can have a specific positive effect on the health (therapeutic or preventive), confirmed in randomized clinical trials. Key words: microbiota, microbiome, immune system, targeted probiotics, immunobiotics, nutraceuticals

Dynamic Min and Max Consensus and Size Estimation of Anonymous Multiagent Networks

In this article, we propose two distributed control protocols for discrete-time multiagent systems, which solve the dynamic consensus problem on the max value. In this problem, each agent is fed an exogenous reference signal and has the objective to estimate and track the instantaneous and time-varying value of the maximum among all the signals fed to the network by exploiting only local and anonymous interactions among the agents. The first protocol achieves bounded steady-state and tracking errors which can be tradedoff for convergence time. The second protocol achieves zero steady-state error and requires knowledge of an upper bound to the diameter of the graph representing the network. Modified versions of both protocols are provided to solve the dual dynamic min-consensus problem. These protocols are then exploited to solve a distributed size estimation problem in a network of anonymous agents in a dynamic setting where the size of the network is time-varying during the execution of the estimation algorithm. Numerical simulations are provided in order to corroborate the characterization of the proposed protocols.

On Input-to-State Stability of Linear Difference Equations and Its Characterization with a Lyapunov Functional

This paper investigates necessary and sufficient Lyapunov conditions for Input-to-State Stability (ISS) of Linear Difference Equations with pointwise delays and an additive exogenous signal. Grounding on recent works in the literature on necessary conditions for the exponential stability of such Difference Equations, we propose a quadratic Lyapunov functional involving the derivative of the so-called delay Lyapunov matrix of the corresponding homogeneous Difference Equation. We prove that the ISS of Linear Difference Equations is equivalent to the existence of an ISS Lyapunov functional. We apply this result to the stability and ISS analysis of hyperbolic Partial Differential Equations of conservation laws.

Light-controlled artificial transmembrane signal transduction for 'ON/OFF'-switchable transphosphorylation of an RNA model substrate.

Inspired by nature, it is of significant importance to design and construct biomimetic signaling systems to mimic natural signal transduction. Herein, we report an azobenzene/α-cyclodextrin (α-CD)-based signal transduction system with three functional modules: a light-responsive headgroup, lipid-anchored group, pro-catalyst tailgroup. The transducer can be inserted into the vesicular membrane to trigger the transmembrane translocation of molecules under the activation of light, forming a ribonuclease-like effector site and leading to the transphosphorylation of the RNA model substrate inside the vesicles. Moreover, the transphosphorylation process can be reversibly turned 'ON/OFF' over multiple cycles by the activation and deactivation of the pro-catalyst. This artificial photo-controlled signal transduction successfully constructs a signal responsive catalysis system across the membrane to utilize light to reversibly control the internal transphosphorylation process of an RNA model substrate, which might provide a new strategy for future design to utilize exogenous signals for implementing endogenous enzyme manipulation and gene regulation.

Update on the Role of Glucocorticoid Signaling in Osteoblasts and Bone Marrow Adipocytes During Aging.

Bone marrow adipose tissue (BMAT) in the skeleton likely plays a variety of physiological and pathophysiological roles that are not yet fully understood. In elucidating the complex relationship between bone and BMAT, glucocorticoids (GCs) are positioned to play a key role, as they have been implicated in the differentiation of bone marrow mesenchymal stem cells (BMSCs) between osteogenic and adipogenic lineages. The purpose of this review is to illuminate aspects of both endogenous and exogenous GC signaling, including the influence of GC receptors, in mechanisms of bone aging including relationships to BMAT. Harmful effects of GCs on bone mass involve several cellular pathways and events that can include BMSC differentiation bias toward adipogenesis and the influence of mature BMAT on bone remodeling through crosstalk. Interestingly, BMAT involvement remains poorly explored in GC-induced osteoporosis and warrants further investigation. This review provides an update on the current understanding of the role of glucocorticoids in the biology of osteoblasts and bone marrow adipocytes (BMAds).

Metagenomic and extracellular polymeric substances analysis reveals the mechanism of exogenous N-hexanoyl-L-homoserine lactone in alleviating the inhibition of perfluorooctanoic acid on anammox process

To alleviate the negative effects of perfluorooctanoic acid (PFOA) on nitrogen removal via anaerobic ammonia oxidation (anammox), an exogenous signaling factor (N-hexanoyl-L-homoserine lactone, C6-HSL) was introduced into an anammox reactor. Results showed that 2 μmol/L C6-HSL promoted the nitrogen removal efficiency of the anammox reactor under PFOA stress, with the removal efficiencies of ammonia and nitrite increasing from 79.7 ± 4.8 % and 80.8 ± 3.8 %, to 94.4 ± 4.3 % and 97.1 ± 3.8 %. Exogenous C6-HSL enhanced the compactness of the extracellular proteins, and improved the sludge hydrophobicity. Meanwhile, C6-HSL resulted in a microbial shift, with the relative abundance of Planctomycetes increasing from 30.2 % to 49.5 %. Candidatus Kuenenia stuttgartiensis replaced Candidatus Brocadia sp. BL1 as the dominant species, while the available space for other nitrogen-removing bacteria was reduced. Exogenous C6-HSL promoted the expression of anammox-related genes, such as hzsB and hdh, while denitrifying genes were down-regulated. In addition, the relative abundance of HdtS, which synthesizes AHLs, increased by 0.02446%.

A Review of Brain Activity and EEG-Based Brain-Computer Interfaces for Rehabilitation Application.

Patients with severe CNS injuries struggle primarily with their sensorimotor function and communication with the outside world. There is an urgent need for advanced neural rehabilitation and intelligent interaction technology to provide help for patients with nerve injuries. Recent studies have established the brain-computer interface (BCI) in order to provide patients with appropriate interaction methods or more intelligent rehabilitation training. This paper reviews the most recent research on brain-computer-interface-based non-invasive rehabilitation systems. Various endogenous and exogenous methods, advantages, limitations, and challenges are discussed and proposed. In addition, the paper discusses the communication between the various brain-computer interface modes used between severely paralyzed and locked patients and the surrounding environment, particularly the brain-computer interaction system utilizing exogenous (induced) EEG signals (such as P300 and SSVEP). This discussion reveals with an examination of the interface for collecting EEG signals, EEG components, and signal postprocessing. Furthermore, the paper describes the development of natural interaction strategies, with a focus on signal acquisition, data processing, pattern recognition algorithms, and control techniques.

Repeat Element Activation-Driven Inflammation: Role of NFκB and Implications in Normal Development and Cancer?

The human genome is composed of unique DNA sequences that encode proteins and unique sequence noncoding RNAs that are essential for normal development and cellular differentiation. The human genome also contains over 50% of genome sequences that are repeat in nature (tandem and interspersed repeats) that are now known to contribute dynamically to genetic diversity in populations, to be transcriptionally active under certain physiological conditions, and to be aberrantly active in disease states including cancer, where consequences are pleiotropic with impact on cancer cell phenotypes and on the tumor immune microenvironment. Repeat element-derived RNAs play unique roles in exogenous and endogenous cell signaling under normal and disease conditions. A key component of repeat element-derived transcript-dependent signaling occurs via triggering of innate immune receptor signaling that then feeds forward to inflammatory responses through interferon and NFκB signaling. It has recently been shown that cancer cells display abnormal transcriptional activity of repeat elements and that this is linked to either aggressive disease and treatment failure or to improved prognosis/treatment response, depending on cell context and the amplitude of the so-called 'viral mimicry' response that is engaged. 'Viral mimicry' refers to a cellular state of active antiviral response triggered by endogenous nucleic acids often derived from aberrantly transcribed endogenous retrotransposons and other repeat elements. In this paper, the literature regarding transcriptional activation of repeat elements and engagement of inflammatory signaling in normal (focusing on hematopoiesis) and cancer is reviewed with an emphasis on the role of innate immune receptor signaling, in particular by dsRNA receptors of the RIG-1 like receptor family and interferons/NFκB. How repeat element-derived RNA reprograms cell identity through RNA-guided chromatin state modulation is also discussed.

Crosstalk between liver macrophages and gut microbiota: An important component of inflammation-associated liver diseases.

Hepatic macrophages have been recognized as primary sensors and responders in liver inflammation. By processing host or exogenous biochemical signals, including microbial components and metabolites, through the gut-liver axis, hepatic macrophages can both trigger or regulate inflammatory responses. Crosstalk between hepatic macrophages and gut microbiota is an important component of liver inflammation and related liver diseases, such as acute liver injury (ALI), alcoholic liver disease (ALD), and nonalcoholic fatty liver disease (NAFLD). This review summarizes recent advances in knowledge related to the crosstalk between hepatic macrophages and gut microbiota, including the therapeutic potential of targeting hepatic macrophages as a component of gut microecology in inflammation-associated liver diseases.

An ethylene-responsive transcription factor and a B-box protein coordinate vegetative growth and photoperiodic flowering in chrysanthemum.

Plants employ several endogenous and exogenous signals to guarantee timely floral transitions with floral integrators. To avoid premature flowering, flowering plants must control the balance between vegetative and floral development. As a Group II member of BBX family, CmBBX8 promotes flowering by directly activating CmFTL1 in summer-flowering chrysanthemum. However, the mechanisms underlying this floral transition is yet to be elucidated. Here, we report that the chrysanthemum ERF3 homologue, CmERF3, physically interacts with CmBBX8 through yeast two-hybrid (Y2H), bimolecular fluorescence complementation (BiFC), pull-down, and luciferase complementation (LCI) assays. We found that CmERF3 was highly expressed at the vegetative stage and rarely expressed in the reproductive phase, indicating that CmERF3 may play a critical role in maintaining vegetative growth to prevent premature flowering. Rhythm analysis revealed that CmERF3 had a different response to rhythm compared to CmBBX8. Knockdown of CmERF3 facilitated floral initiation, whereas overexpression of CmERF3 delayed floral transition. We further found that CmERF3 repressed the transactivation activity of CmBBX8 on the downstream CmFTL1 gene. Collectively, our results indicatethat the CmERF3-CmBBX8 transcriptional complex is a crucial module that balances the vegetative growth and reproductive development of chrysanthemum.

Effects of exogenous bacterial quorum-sensing signal molecule/messenger N-hexanoyl-L-homoserine lactone (C-HSL) on acorn germination and plant growth of Quercus robur and Q. rubra (Fagaceae)

The effect of pre-sowing priming with N-hexanoyl-L-homoserine lactone (C6-HSL) solution (300 mg/L) on acorn germination and morpho-phenological characteristics of Quercus robur and Q. rubra was studied under laboratory conditions. After priming, 93.4% of Q. robur acorns germinated that exceeded the control by 32.2%, while the number of sprouted acorns of Q. rubra increased within error limits by 5% more than the control and amounted to 90%. According to morphological characteristics, the 47-day-old plants of Q. robur were divided into the following groups: germinated acorns, sprouts and seedlings with juvenile leaves, whereas among the plants of Q. rubra, sprouts and seedlings with true leaves were selected. A group of plants with juvenile leaves was detected only in the samples primed with C6-HSL. Priming induced differential changes in cotyledon biomass of both species and accelerated nutrient utilization by Q. robur seedlings. We observed a positive effect on the growth and biomass accumulation of Q. robur plants and a negative effect, except for plants of the third group, on those of Q. rubra. The dry weight of seedling roots of Q. robur and shoots of Q. rubra increased, respectively, by 103% and 153%. Priming of acorns with C6-HSL solution induced an increase in number, length, biomass and total area of leaves. These changes were more pronounced in Q. rubra seedlings. Alterations in the root system architecture towards formation of numerous additional lateral roots were recorded for both species. Thus, priming with C6-HSL solution activated acorn germination and stimulated growth of Q. robur plants and decelerated growth of plants of Q. rubra. Exogenous C6-HSL did not eliminate the syndrome of unfriendly seedlings of both studied oak species, but improved the viability of acorns and increased the number of seedlings.

Exploration of Gancao Xiexin decoction for treatment of Behcet disease based on network pharmacology and molecular docking.

Background:Based on network pharmacology and molecular docking, this study discusses the potential mechanism of Gancao Xiexin decoction in the treatment of Behçet disease (BD) to provide a more reliable theoretical basis for the treatment of BD.Methods:The effective components and action targets of Gancao Xiexin decoction were obtained by searching the traditional Chinese medicine systems pharmacology database and analysis platform database, and the genome annotation database platform (GeneCards) database Search BD related targets in Online Mendelian inheritance in man database, pharmacogenetics and pharmacogenomics knowledge base database, therapeutic target database and drugbank database, Venny analysis tool was used to overlap drug targets and disease targets; The “active drug active ingredient target gene” network was constructed with the help of Cytoscape 3.8.2 software, and the protein–protein interaction (PPI) network was constructed with string database; R language was used for Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of genes and genomes (KEGG) pathway enrichment analysis; Target prediction based on pubchemp platform.Results:A total of 163 active components were identified, with 730 corresponding targets, including 56 common targets of the active components and BD. GO enrichment analysis yielded 1126 entries for biological processes (BP), 17 entries for cellular components, and 89 entries for molecular functions. The significant items of BP enrichment mainly included reaction to lipopolysaccharide, reaction to bacteria-derived molecules, exogenous apoptosis signal pathways, and biological metabolism processes of reactive oxygen species. KEGG pathway enrichment analysis identified 118 significantly enriched pathways. The molecular docking technology verified that its effective components can effectively bind to the corresponding BD related target proteins.Conclusion:Gancao Xiexin decoction synergistically treats BD through multi-component, multi-target, and multi-channel mechanisms, which provides a basis for further study of the active components and mechanism of Gancao Xiexin decoction.