scholarly journals Evolutionary Ecological Model of Defence Activation Disorders Via the Marginal Value Theorem

2020 ◽  
Vol 17 (6) ◽  
pp. 556-578
Author(s):  
Hanson Park
Keyword(s):  
Ecological Model ◽  
Balancing Selection ◽  
Relative Proportion ◽  
Low Fertility ◽  
Marginal Value Theorem ◽  
Evolutionarily Stable Strategies ◽  
Evolutionary Mechanism ◽  
Agent Based ◽  
Marginal Value ◽  
D Values

Objective Excessive activation of defence modules leads to some dysfunctional outcomes, which can be broadly classified to defence activation disorders. Defence activation disorders have high mortality, low fertility, high prevalence and high heritability. In this study, agent-based simulation model is formulated for solving this evolutionary paradox.Methods The emotional system is considered as a superordinate cognitive module for grasping the average resource amount and the average diminishing returns of resources, based on the Marginal Value Theorem. Under the assumption, the evolutionary ecological model was proposed and analysed.Results Individuals utilising suboptimal strategies can be stably maintained in agent-based evolutionary simulation environments. Individuals were adapted to have different <i>d-values</i> according to the local niche. The simulation runs stably within the calibrated range of the variables for a long time. Agents establish locally optimal strategies based on their given <i>d-values</i>, and the relative proportion of subpopulation maintained stably in the heterogeneous habitat with the resource gradient.Conclusion This study verifies the evolutionary mechanism of defence activation disorders in computer-simulated environments by using agent-based modelling with the Marginal Value Theorem. Balancing selection appears to be a plausible evolutionary mechanism that makes the suboptimal levels of defence activation the evolutionarily stable strategies.

scholarly journals Time to fly: A comparison of marginal value theorem approximations in an agent-based model of foraging waterfowl

2017 ◽  
Vol 351 ◽  
pp. 77-86 ◽  
Author(s):  
Matt L. Miller ◽  
Kevin M. Ringelman ◽  
John M. Eadie ◽  
Jeffrey C. Schank
Keyword(s):  
Marginal Value Theorem ◽  
Agent Based Model ◽  
Agent Based ◽  
Marginal Value

Benthic community populations near two adjacent northern pulpmill discharges

1997 ◽  
Vol 35 (2-3) ◽  
pp. 381-388 ◽  
Author(s):  
G. P. Thomas ◽  
N. Munteanu
Keyword(s):  
Benthic Community ◽  
Ecological Model ◽  
Relative Proportion ◽  
Benthic Invertebrate ◽  
Treated Effluent ◽  
Spatial Confounding ◽  
Spatial Approach ◽  
Pulp And Paper Effluent ◽  
Taxonomic Groups ◽  
Benthic Invertebrate Communities

Benthic invertebrate communities were investigated as part of the federal Environmental Effects Monitoring programs conducted as required by the amended Pulp and Paper Effluent Regulations (PPER) of the federal Fisheries Act. A Refiner Mechanical (RMP) and larger Kraft pulpmill, both situated on a northern, BC reservoir, discharge secondary-treated effluent within 5 km of each other. Efforts to independently distinguish potential effects associated with these individual discharges were complicated by the proximity of the diffusers, their location within a complex ecological region of a reservoir, and the presence of temporal and spatial confounding influences. A comprehensive examination of the benthic community structure involved the combined assessment of several endpoints (total population numbers, relative proportion of taxonomic groups, and species richness). A tiered, spatial approach, based on a reservoir ecological model (Thornton et al., 1981), was adapted to assess and distinguish community structures and reservoir- and mill-related influences. Results suggested that effects associated with the two different mills could be distinguished based on subtle and distinct differences in benthic community profiles.

scholarly journals In silico characterisation of putative Plasmodium falciparum vaccine candidates in African malaria populations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
O. Ajibola ◽  
M. F. Diop ◽  
A. Ghansah ◽  
L. Amenga-Etego ◽  
L. Golassa ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Vaccine ◽  
Transmembrane Domain ◽  
Vaccine Development ◽  
Balancing Selection ◽  
Immune Recognition ◽  
African Countries ◽  
Vaccine Candidates ◽  
D Values ◽  
Tajima’S D

AbstractGenetic diversity of surface exposed and stage specific Plasmodium falciparum immunogenic proteins pose a major roadblock to developing an effective malaria vaccine with broad and long-lasting immunity. We conducted a prospective genetic analysis of candidate antigens (msp1, ama1, rh5, eba175, glurp, celtos, csp, lsa3, Pfsea, trap, conserved chrom3, hyp9, hyp10, phistb, surfin8.2, and surfin14.1) for malaria vaccine development on 2375 P. falciparum sequences from 16 African countries. We described signatures of balancing selection inferred from positive values of Tajima’s D for all antigens across all populations except for glurp. This could be as a result of immune selection on these antigens as positive Tajima’s D values mapped to regions with putative immune epitopes. A less diverse phistb antigen was characterised with a transmembrane domain, glycophosphatidyl anchors between the N and C- terminals, and surface epitopes that could be targets of immune recognition. This study demonstrates the value of population genetic and immunoinformatic analysis for identifying and characterising new putative vaccine candidates towards improving strain transcending immunity, and vaccine efficacy across all endemic populations.

Fairness, Commitment, and Inequality

2008 ◽  
pp. 1-12
Author(s):  
István Back
Keyword(s):  
Empirical Evidence ◽  
Ecological Model ◽  
Conditional Cooperation ◽  
Agent Based ◽  
Successful Strategy ◽  
Cooperative Relationships ◽  
Competitive Environments ◽  
Interaction Partners ◽  
Evolutionary Stable Strategies

Conditional cooperation is a prominent explanation of reciprocal cooperation in repeated exchange. However, empirical evidence for commitment behavior indicates that people tend to build long-term cooperative relationships characterized by largely unconditional cooperation. Using an agent-based ecological model, earlier work showed that in competitive environments commitment can be a more successful strategy than fair reciprocity. We move further in two respects. First, we add the possibility of randomly mutating strategies under evolutionary pressures. Our results show the lack of evolutionary stable strategies but we also find that commitment strategies still outperform fairness strategies on average. Our second extension introduces inequality in individual capabilities. We find that inequality shifts the balance from commitment towards fairness strategies. Our explanation is that under inequality, strategies benefit from changing interaction partners from time to time because this gives more agents access to strong partners.

Optimal Giving-Up Times and the Marginal Value Theorem

1982 ◽  
Vol 119 (4) ◽  
pp. 511-529 ◽  
Author(s):  
James N. McNair
Keyword(s):  
Marginal Value Theorem ◽  
Marginal Value
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