scholarly journals Mutualistic cross-feeding in microbial systems generates bistability via an Allee effect

2019 ◽  
Author(s):  
Stefan Vet ◽  
Lendert Gelens ◽  
Didier Gonze
Keyword(s):  
Allee Effect ◽  
Positive Influence ◽  
Initial Population ◽  
Explicit Model ◽  
Experimental Parameters ◽  
Initial Population Size ◽  
Strong Allee Effect ◽  
Relationship Of ◽  
Microbial Systems ◽  
Explicit Relation

ABSTRACTMutualistic interactions are characterized by the positive influence that two species exert on each other. Such mutualism can lead to bistability. Depending on the initial population size species will either survive or go extinct. Various phenomenological models have been suggested to describe bistability in mutualistic systems. However, these models do not account for interaction mediators such as nutrients. In contrast, nutrient-explicit models do not provide an intuitive understanding of what causes bistability. Here, we reduce a theoretical nutrient-explicit model of two mutualistic cross-feeders in a chemostat, uncovering an explicit relation to a growth model with an Allee effect. We show that the dilution rate in the chemostat leads to bistability by turning a weak Allee effect into a strong Allee effect. This happens as long as there is more production than consumption of cross-fed nutrients. Thanks to the explicit relationship of the reduced model with the underlying experimental parameters, these results allow to predict the biological conditions that sustain or prevent the survival of mutualistic species.

scholarly journals Agglomeration economies, congestion diseconomies, and fertility dynamics in a two-region economy

2021 ◽  
Author(s):  
Madoka Muroishi ◽  
Akira Yakita
Keyword(s):  
Population Size ◽  
Stability Condition ◽  
Fertility Rate ◽  
Model Parameters ◽  
Initial Population ◽  
Interregional Migration ◽  
Stable Path ◽  
Regional Population ◽  
Initial Population Size

AbstractUsing a small, open, two-region economy model populated by two-period-lived overlapping generations, we analyze long-term agglomeration economy and congestion diseconomy effects of young worker concentration on migration and the overall fertility rate. When the migration-stability condition is satisfied, the distribution of young workers between regions is obtainable in each period for a predetermined population size. Results show that migration stability does not guarantee dynamic stability of the economy. The stationary population size stability depends on the model parameters and the initial population size. On a stable trajectory converging to the stationary equilibrium, the overall fertility rate might change non-monotonically with the population size of the economy because of interregional migration. In each period, interregional migration mitigates regional population changes caused by fertility differences on the stable path. Results show that the inter-regional migration-stability condition does not guarantee stability of the population dynamics of the economy.

scholarly journals TO EXAMINE LEADER-MEMBER EXCHANGE AS MODERATING VARIABLE ON THE INFLUENCE OF EMPLOYEE PSYCHOLOGICAL UNCERTAINTY TOWARD EMPLOYEES’ JOB SATISFACTION AND TURNOVER INTENTION

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Muhammad Zakiy
Keyword(s):  
Job Satisfaction ◽  
Organizational Change ◽  
Turnover Intention ◽  
Negative Influence ◽  
Positive Influence ◽  
Leader Member Exchange ◽  
Member Exchange ◽  
Relationship Of ◽  
The Impact

The studies revealed that organizational change could create employee’s psychological uncertainty. However, this study argues that the quality of leader-member exchange enables to control the impact of the psychological uncertainty during the change toward employee’s attitude. This study represents job satisfaction and turnover intention as proxy of employee’s attitude for that matter. Based on social exchange theory, quality relationship of leader and employees affects on the relationship of psychological uncertainty and employee’s job satisfaction and turnover intention. This study selected private hospitals experiencing the changes of operational system for complying with national health security system. This study conducted cross-section survey for individual level-analysis. This study produces some findings. Firstly, the LMX has been failed to reduce the negative influence of psychological uncertainty towards employee’s job satisfaction, although the quality of the LMX was good. employee’s job satisfaction is more perceived as  personal afective state experienced during the organizational change. Secondly, the LMX has been successfully moderated the positive influence of the psychological uncertainty towards employee’s turnover intention.The data were collected by using questioners, distributed to the employees who worked in hospitals in Yogyakarta Province. There were 193 questioners that could be collected and analyzed by using Moderated Regression Analysis (MRA) to test the hypothesis by using SPSS application version 21. The result of the study shows that psychological uncertainty had negative correlation to employee’s job satisfaction and positive influence to psychological uncertainty toward turnover intention. Besides, LMX was proven to moderate positive influence of psychological uncertainty toward turnover intention, but it could not moderate negative influence of psychological uncertainty toward job satisfaction. 

scholarly journals The Determinant Factors of Omnichannel Service Adoption in Jakarta

2019 ◽  
pp. 1-12
Author(s):  
Wenny Rukmana ◽  
Hermawan Susyanto ◽  
Antonio . ◽  
Ina Agustini Murwani
Keyword(s):  
Structural Equation ◽  
Positive Influence ◽  
Equation Model ◽  
Moderating Effects ◽  
Service Adoption ◽  
Channel Choice ◽  
Channel Integration ◽  
Object Based ◽  
Relationship Of ◽  
The Relationship

Along with the development of technology in retail, consumers have increased their expectation about experience convenience in retail. Starting with the growth of various platform, the next development is the experience that combined both offline and online service known as Omnichannel. The Omnichannel Service Adoption is explained by Wixom Model shows the relationship of object-based beliefs, channel integration quality, perceived fluency, and internal and external usage experience as moderating effects of perceived fluency. The adoption of Omnichannel is important to deliver a consistency of data and user experience compared to multichannel. The research uses quantitative approach with Structural Equation Model (SEM) PLS for data analytic. The population is referred to Berrybenka, a prominent fashion e-commerce in Jakarta, customers. The result shows that Breadth Channel Choice, Channel Service Transparency, Content Consistency and Process Consistency have a significant and positive influence on perceived fluency. The implication and limitation of the research are also highlighted.

scholarly journals The Research of the Relationship of Preferred Musical Styles and Personal Features of Music Teachers

2019 ◽  
Vol 7 (2) ◽  
pp. 41-56 ◽  
Author(s):  
Anna A. Kharzhevskaia
Keyword(s):  
Classical Music ◽  
Music Teachers ◽  
Positive Influence ◽  
Educational Process ◽  
Personal Resources ◽  
Education Psychology ◽  
Relationship Of ◽  
The Relationship ◽  
Musical Styles ◽  
Musical Preferences

The present article researches the relationship of musical preferences of adolescence (pop, rock and rap) and modernity (classical, pop, rock, music lovers) with the display of personal features, such as empathy, emotional exhaustion, state and trait anxiety, pedagogical style and coping strategies. The musical genres and trends are considered as musical preferences and precedential musical phenomenon revealed empirically during the self-analysis by the subjects. The experimental study was carried out on the basis of Moscow Pedagogical State University and consisted of 4-5th-year students of Music Department. The connections between personal features and preferred musical styles of modernity were detected. The students considering classical music to be their favorite musical direction having a high level of personal resources. These results display the positive influence of classical music to the personal resources of future music teachers. This phenomenon demands further investigations and using in the field of musical education psychology. These results highlight necessity of detailed consideration on classical music relationship and personal features of bachelor students musical department during the educational process.

Qualitative analysis of a diffusive predator–prey model with Allee and fear effects

2021 ◽  
pp. 2150037
Author(s):  
Jia Liu
Keyword(s):  
Allee Effect ◽  
Sufficient Conditions ◽  
Allee Effects ◽  
Predator Prey ◽  
Predator Prey Model ◽  
Fear Effect ◽  
Prey Model ◽  
Strong Allee Effect ◽  
Spatially Homogeneous ◽  
Fear Effects

In this study, we consider a diffusive predator–prey model with multiple Allee effects induced by fear factors. We investigate the existence, boundedness and permanence of the solution of the system. We also discuss the existence and non-existence of non-constant solutions. We derive sufficient conditions for spatially homogeneous (non-homogenous) Hopf bifurcation and steady state bifurcation. Theoretical and numerical simulations show that strong Allee effect and fear effect have great effect on the dynamics of system.

PENGARUH KEPEMIMPINAN TRANSFORMASIONAL PADA KINERJA DENGAN KESAMAAN VISI ANTARKARYAWAN SEBAGAI VARIABEL PEMEDIASI

2013 ◽  
Vol 8 (1) ◽  
pp. 49
Author(s):  
Wisnu Prajogo
Keyword(s):  
Transformational Leadership ◽  
Employee Performance ◽  
Positive Influence ◽  
Shared Vision ◽  
Purposive Sampling ◽  
Indirect Influence ◽  
Occupational Characteristics ◽  
Relationship Of ◽  
The Relationship

This research examines the direct and indirect influence of transformational leadership to performance, with employee’s shared vision as the mediating variable. 504 respondents taken from a purposive sampling based on their occupational characteristics participated in this research. The results reveal that transformational leadership has no influence to employee performance, meanwhile transformasional leadership has positive influence to shared vision among employees, and shared vision among employees has positive influence to employee performance. This research also found that shared vision among employees has a full mediation role in the relationship of transformasional leadership and employee performance. Keywords: transformational leadership, shared vision among employees, employee performance

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