scholarly journals Addition of an Emotionally Stable Node in the SOSa-SPSa Model for Group Emotional Contagion of Panic in Public Health Emergency: Implications for Epidemic Emergency Responses

2020 ◽  
Vol 17 (14) ◽  
pp. 5044 ◽  
Author(s):  
Xiaoyang Ni ◽  
Haojie Zhou ◽  
Weiming Chen
Keyword(s):  
Model Simulation ◽  
Negative Emotions ◽  
Stable State ◽  
Infection Process ◽  
Infection Model ◽  
Social Stability ◽  
Stable Node ◽  
Public Events ◽  
Degree Of Risk ◽  
Group Emotions

Sentiment contagion is similar to an infectious disease that spreads in a crowd. In this study, we explore the law of emotional infection under sudden public events by SIR model. The paper adds an emotionally stable node and establishes a group emotional infection model of U-SOSPa-SPSOa model. Simulation results show that our model is reasonable and can better explain the entire contagion process by considering four groups (unsusceptible-susceptible-optimistic-pessimistic) of people. Our theoretical results show: When the pessimists were below the critical value of 0.34, the number of negative emotional groups first increased and then decreased. As the proportion increases, the emotional peak of pessimists increases. The cure probability θo has the least influence on the P(t), and at the same time, under the action of θp, the P(t) reaches the stable state first. The increase of the risk coefficient can promote the pessimist infection. When the degree of risk is low, the rate of emotional infection is increased. When the degree of risk is high, the rate of infection is slowed. Therefore, system customizers and related managers can improve the efficiency of stable groups, adjust the proportion of initial negative emotions, control the infection of the spontaneous infection process, and directly deal with negative emotions. They can carry out treatment and other means to stabilize group emotions and maintain social stability.

scholarly journals The infection rate of Daphnia magna by Pasteuria ramosa conforms with the mass-action principle

2003 ◽  
Vol 131 (2) ◽  
pp. 957-966 ◽  
Author(s):  
R. R. REGOES ◽  
J. W. HOTTINGER ◽  
L. SYGNARSKI ◽  
D. EBERT
Keyword(s):  
Daphnia Magna ◽  
Infection Rate ◽  
Infection Process ◽  
Action Principle ◽  
Mass Action ◽  
Infection Model ◽  
Susceptibility To Infection ◽  
Pasteuria Ramosa ◽  
Simple Mass ◽  
Host Parasite

In simple epidemiological models that describe the interaction between hosts with their parasites, the infection process is commonly assumed to be governed by the law of mass action, i.e. it is assumed that the infection rate depends linearly on the densities of the host and the parasite. The mass-action assumption, however, can be problematic if certain aspects of the host–parasite interaction are very pronounced, such as spatial compartmentalization, host immunity which may protect from infection with low doses, or host heterogeneity with regard to susceptibility to infection. As deviations from a mass-action infection rate have consequences for the dynamics of the host–parasite system, it is important to test for the appropriateness of the mass-action assumption in a given host–parasite system. In this paper, we examine the relationship between the infection rate and the parasite inoculum for the water flee Daphnia magna and its bacterial parasite Pasteuria ramosa. We measured the fraction of infected hosts after exposure to 14 different doses of the parasite. We find that the observed relationship between the fraction of infected hosts and the parasite dose is largely consistent with an infection process governed by the mass-action principle. However, we have evidence for a subtle but significant deviation from a simple mass-action infection model, which can be explained either by some antagonistic effects of the parasite spores during the infection process, or by heterogeneity in the hosts' susceptibility with regard to infection.

scholarly journals Csr1/Zap1 Maintains Zinc Homeostasis and Influences Virulence in Candida dubliniensis but Is Not Coupled to Morphogenesis

2015 ◽  
Vol 14 (7) ◽  
pp. 661-670 ◽  
Author(s):  
Bettina Böttcher ◽  
Katja Palige ◽  
Ilse D. Jacobsen ◽  
Bernhard Hube ◽  
Sascha Brunke
Keyword(s):  
Living Organism ◽  
Tube Formation ◽  
Infection Process ◽  
Candida Dubliniensis ◽  
Zinc Homeostasis ◽  
Growth Defect ◽  
Infection Model ◽  
Content Type ◽  
Restricted Environment ◽  
Embryonated Chicken

ABSTRACTThe supply and intracellular homeostasis of trace metals are essential for every living organism. Therefore, the struggle for micronutrients between a pathogen and its host is an important determinant in the infection process. In this work, we focus on the acquisition of zinc byCandida dubliniensis, an emerging pathogen closely related toCandida albicans. We show that the transcription factor Csr1 is essential forC. dubliniensisto regulate zinc uptake mechanisms under zinc limitation: it governs the expression of the zinc transporter genesZRT1,ZRT2, andZRT3and of the zincophore genePRA1. Exclusively, artificial overexpression ofZRT2partially rescued the growth defect of acsr1Δ/Δ mutant in a zinc-restricted environment. Importantly, we found that, in contrast to what is seen inC. albicans,Csr1(also calledZap1) is not a major regulator of dimorphism inC. dubliniensis. However, although acsr1Δ/Δ strain showed normal germ tube formation, we detected a clear attenuation in virulence using an embryonated chicken egg infection model. We conclude that, unlike inC. albicans, Csr1 seems to be a virulence factor ofC. dubliniensisthat is not coupled to filamentation but is strongly linked to zinc acquisition during pathogenesis.

scholarly journals Role of the (Mn)superoxide dismutase of Enterococcus faecalis in the in vitro interaction with microglia

Microbiology ◽  
2011 ◽  
Vol 157 (6) ◽  
pp. 1816-1822 ◽  
Author(s):  
Samuele Peppoloni ◽  
Brunella Posteraro ◽  
Bruna Colombari ◽  
Lidia Manca ◽  
Axel Hartke ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Enterococcus Faecalis ◽  
Stress Responses ◽  
Peritoneal Macrophages ◽  
Infection Process ◽  
Microglial Cells ◽  
Infection Model

Enterococcus faecalis is a significant human pathogen worldwide and is responsible for severe nosocomial and community-acquired infections. Although enterococcal meningitis is rare, mortality is considerable, reaching 21 %. Nevertheless, the pathogenetic mechanisms of this infection remain poorly understood, even though the ability of E. faecalis to avoid or survive phagocytic attack in vivo may be very important during the infection process. We previously showed that the manganese-cofactored superoxide dismutase (MnSOD) SodA of E. faecalis was implicated in oxidative stress responses and, interestingly, in the survival within mouse peritoneal macrophages using an in vivo–in vitro infection model. In the present study, we investigated the role of MnSOD in the interaction of E. faecalis with microglia, the brain-resident macrophages. By using an in vitro infection model, murine microglial cells were challenged in parallel with the wild-type strain JH2-2 and its isogenic sodA deletion mutant. While both strains were phagocytosed by microglia efficiently and to a similar extent, the ΔsodA mutant was found to be significantly more susceptible to microglial killing than JH2-2, as assessed by the antimicrobial protection assay. In addition, a significantly higher percentage of acidic ΔsodA-containing phagosomes was found and these also underwent enhanced maturation as determined by the expression of endolysosomal markers. In conclusion, these results show that the MnSOD of E. faecalis contributes to survival of the bacterium in microglial cells by influencing their antimicrobial activity, and this could even be important for intracellular killing in neutrophils and thus for E. faecalis pathogenesis.

scholarly journals A model and simulation of the emotional contagion of netizens in the process of rumor refutation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Runxi Zeng ◽  
Di Zhu
Keyword(s):  
Negative Emotions ◽  
Stable State ◽  
Emotional Contagion ◽  
Transformation Rules ◽  
Emotional Change ◽  
Model And Simulation ◽  
Emotional Model ◽  
Subjective Aspect ◽  
Emotional Value ◽  
Objective Aspect

Abstract The emotional contagion of netizens is an important factor that accelerates the spread of rumors, and it is also key to the effectiveness of rumor refutation. Based on the existing emotional model, we improved the method for calculating the emotional value and the transformation rules to simulate how the infection transforms individual emotion to group emotion during rumor refutation. The results show that the cycle and trend of netizen emotional change vary by period, but the final distribution structure presents a relatively stable state. The factors that affect the emotional changes of netizens are mainly objective and subjective aspects, both of which can promote the evolution of emotional contagion. The objective aspect depends on the speed and credibility of the rumor, and the subjective aspect depends on the degree of intimacy between netizens. After rumor refutation, emotions generally change from negative emotions to positive or immune emotions.

scholarly journals Simulation Analysis of Vertical Movement of Nitrate Nitrogen in Vadose Zone of Fluvo-aquic Soil Based on HYDRUS-1D

2021 ◽  
Vol 293 ◽  
pp. 02008
Author(s):  
Ping Jing ◽  
Hui Zhang
Keyword(s):  
Nitrate Nitrogen ◽  
Simulation Analysis ◽  
Model Simulation ◽  
Pearson Correlation ◽  
Soil Column ◽  
Wastewater Reuse ◽  
Stable State ◽  
Ground Surface ◽  
Linear Increase ◽  
Hydrus 1D

Wastewater reuse has significant social, economic and ecological benefits, and has become an important measure to alleviate the water crisis. In this paper, in the simulation analysis of soil nitrate nitrogen, the method of combining soil column leaching and model simulation is used to test the accuracy of the model. The Pearson correlation coefficient is as high as 0.99 and the Nash coefficient is also over 0.9. It shows that the simulation results of the simulation model are credible. The Hydrus-1D model is used to visually simulate the change process of Tianjin fluvo-aquic soil over time. In the simulation, the process of solute migration in the 6-18 cm of the ground surface is basically the same, and they all reach a stable state about 4 hours, and show a linear increase trend four hours ago, and then the concentration remains stable and unchanged.

scholarly journals Step-specific adaptation and trade-off over the course of an infection by GASP-mutation small colony variants

2020 ◽  
Author(s):  
Faucher Christian ◽  
Mazana Vincent ◽  
Kardacz Marion ◽  
Parthuisot Nathalie ◽  
Ferdy Jean-Baptiste ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Chronic Phase ◽  
Infection Process ◽  
Infection Model ◽  
Xenorhabdus Nematophila ◽  
Trade Off ◽  
Small Colony Variants ◽  
Trade Offs ◽  
Small Colony ◽  
Host Evolution

AbstractDuring an infection, parasites face a succession of challenges, each decisive for disease outcome. The diversity of challenges requires a series of parasite adaptations to successfully multiply and transmit from host to host. Thus, the pathogen genotypes which succeed during one step might be counter-selected in later stages of the infection. Using the bacteria Xenorhabdus nematophila and adult Drosophila melanogaster as hosts, we showed that such step-specific adaptations, here linked to GASP mutations in the X. nematophila master gene regulator lrp, exist and can trade-off with each other. We found that nonsense lrp mutations had lowered ability to resist the host immune response, while all classes of mutations in lrp were associated with a decrease in the ability to proliferate during early infection. We demonstrate that reduced proliferation of X. nematophila best explains diminished virulence in this infection model. Finally, decreased proliferation during the first step of infection is accompanied with improved proliferation during late infection, suggesting a trade-off between the adaptations to each step. Step-specific adaptations could play a crucial role in the chronic phase of infections in any diseases that show similar small colony variants (also known as SCV) to X. nematophila.ImportanceWithin-host evolution has been described in many bacterial diseases, and the genetic basis behind the adaptations stimulated a lot of interest. Yet, the studied adaptations are generally focused on antibiotic resistance, rarely on the adaptation to the environment given by the host, and the potential trade-off hindering adaptations to each step of the infection are rarely considered. Those trade-offs are key to understand intra-host evolution, and thus the dynamics of the infection. However, the understanding of these trade-offs supposes a detailed study of host-pathogen interactions at each step of the infection process, with for each step an adapted methodology. Using Drosophila melanogaster as host and the bacteria Xenorhabdus nematophila, we investigated the bacterial adaptations resulting from GASP mutations known to induce small colony variant (SCV) phenotype positively selected within-the-host over the course of an infection, and the trade-off between step-specific adaptations.

scholarly journals The Role of Legal Culture in Maintaining Social Stability and Countering Separatist Movements: Case of Ukraine

2020 ◽  
Vol 9 (1) ◽  
pp. 294
Author(s):  
Vira Kachur ◽  
Liudmyla Protosavitska ◽  
Liudmyla Zasukha ◽  
Liudmyla Golovko
Keyword(s):  
Sustainable Development ◽  
Social Relations ◽  
Security Policy ◽  
Stable State ◽  
Legal Culture ◽  
Social Stability ◽  
Political Values ◽  
Territorial Integrity ◽  
External Threats ◽  
Democratic State

This article develops hypotheses that raising the level of legal culture can serve as an effective instrument in maintaining sustainable development, social stability and territorial integrity. Legal culture should be considered as a regulator and stabilizer of social relations, both in individual countries and at the international level. It is necessary to consider legal culture in conjunction with morality, ethical, economic and political values and priorities. The study has concluded that creation of the democratic state of law and civil society is impossible without raising the level of legal culture. Creation of a strategy for raising the level of legal culture of the population is becoming a priority task, since it will allow forming the functions of the legal culture in the implementation of the national security policy in the socio-economic, political and regional spheres, preserving historical heritage and territorial integrity of Ukraine, overcoming internal and external threats to its stable state and legal development. Keywords: Legal culture, legal awareness, social stability, sustainable development

scholarly journals Identification of Genes Required for Avian Escherichia coli Septicemia by Signature-Tagged Mutagenesis

2005 ◽  
Vol 73 (5) ◽  
pp. 2818-2827 ◽  
Author(s):  
Ganwu Li ◽  
Claudia Laturnus ◽  
Christa Ewers ◽  
Lothar H. Wieler
Keyword(s):  
Escherichia Coli ◽  
Systemic Disease ◽  
Infection Process ◽  
Open Reading Frames ◽  
In Vivo Studies ◽  
Economic Losses ◽  
Extracellular Polysaccharides ◽  
Infection Model ◽  
Periplasmic Proteins

ABSTRACT Infections with avian pathogenic Escherichia coli (APEC) cause colibacillosis, an acute and largely systemic disease resulting in significant economic losses in poultry industry worldwide. Although various virulence-associated genes have been identified in APEC, their actual role in pathogenesis is still not fully understood, and, furthermore, certain steps of the infection process have not been related to previously identified factors. Here we describe the application of a signature-tagged transposon mutagenesis (STM) approach to identify critical genes required for APEC infections in vivo. Twenty pools of about 1,800 IMT5155 (O2:H5) mutants were screened in an infection model using 5-week-old chickens, and potentially attenuated mutants were subjected to a secondary screen and in vivo competition assays to confirm their attenuation. A total of 28 genes required for E. coli septicemia in chickens were identified as candidates for further characterization. Among these disrupted genes, six encode proteins involved in biosynthesis of extracellular polysaccharides and lipopolysaccharides; two encode iron transporters that have not been previously characterized in APEC in in vivo studies, and four showed similarity to membrane or periplasmic proteins. In addition, several metabolic enzymes, putative proteins with unknown function, and open reading frames with no similarity to other database entries were identified. This genome-wide analysis has identified both novel and previously known factors potentially involved in pathogenesis of APEC infection.

scholarly journals A Stochastic HIV Infection Model with Latent Infection and Antiretroviral Therapy

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Jun Liu ◽  
Yan Wang ◽  
Luju Liu ◽  
Tingting Zhao
Keyword(s):  
Hiv Infection ◽  
Stationary Distribution ◽  
Latent Infection ◽  
Infection Process ◽  
Infection Model ◽  
Rigorous Analysis ◽  
Combination Drug ◽  
Large Intensity ◽  
Hiv Infection Model ◽  
White Noises

Recent studies have demonstrated that the latent infection is a major obstacle to the viral elimination in HIV infection process. In this paper, we formulate a stochastic HIV infection model to include both latent infection and combination drug therapies. We derive that the model solution is unique and positive, and the solution is global. By constructing appropriate stochastic Lyapunov functions, the existence of an ergodic stationary distribution is obtained when the critical condition is greater than one. Furthermore, through rigorous analysis and deduction, the extinction of the virus is established under certain conditions. Numerical simulations are performed to show that small intensity of white noises can maintain the existence of a stationary distribution, while large intensity of white noises is beneficial to the extinction of the virus.

scholarly journals A ReplicativeIn VitroAssay for Drug Discovery against Leishmania donovani

2016 ◽  
Vol 60 (6) ◽  
pp. 3524-3532 ◽  
Author(s):  
Diana Tegazzini ◽  
Rosario Díaz ◽  
Fernando Aguilar ◽  
Imanol Peña ◽  
Jesús L. Presa ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Leishmania Donovani ◽  
Horse Serum ◽  
Protozoan Parasite ◽  
Infection Process ◽  
Infection Model ◽  
Content Type ◽  
Fetal Bovine

The protozoan parasiteLeishmania donovaniis the causative agent of visceral leishmaniasis, a disease potentially fatal if not treated. Current available treatments have major limitations, and new and safer drugs are urgently needed. In recent years, advances in high-throughput screening technologies have enabled the screening of millions of compounds to identify new antileishmanial agents. However, most of the compounds identifiedin vitrodid not translate their activities when tested inin vivomodels, highlighting the need to develop more predictivein vitroassays. In the present work, we describe the development of a robust replicative, high-content,in vitrointracellularL. donovaniassay. Horse serum was included in the assay media to replace standard fetal bovine serum, to completely eliminate the extracellular parasites derived from the infection process. A novel phenotypicin vitroinfection model has been developed, complemented with the identification of the proliferation of intracellular amastigotes measured by EdU incorporation.In vitroandin vivoresults for miltefosine, amphotericin B, and the selected compound 1 have been included to validate the assay.

Sign in / Sign up

Export Citation Format

Share Document