Stability and value of male care for offspring: is it worth only half the trouble?

Models of parental investment often assume a trade-off for males between providing care and seeking additional mating opportunities. It is not obvious, however, how such additional matings should be accounted for in a consistent population model, because deserting males might increase their fertilization success at the cost of either caring males, other deserting males or both. Here, we present a game theory model that addresses all of these possibilities in a general way. In contrast to earlier work, we find that the source of deserting males' additional matings is irrelevant to the evolutionary stability of male care. We reject the claim that fitness gains through male care are intrinsically less valuable than those through desertion, and that the former must therefore be down-weighted by 1/2 when compared with the latter.

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The trade-off between investment in weapons and fertility is mediated through spermatogenesis in the leaf-footed cactus bug Narnia femorata

10.22541/au.161046099.92330872/v1 ◽

2021 ◽

Author(s):

Katelyn Cavender ◽

Tessa Ricker ◽

Mackenzie Lyon ◽

Emily Shelby ◽

Christine Miller ◽

...

Keyword(s):

Experimental Manipulation ◽

Fertilization Success ◽

Oncopeltus Fasciatus ◽

Molecular Tools ◽

Evolutionary Potential ◽

Trade Off ◽

Trade Offs ◽

Mating Opportunities ◽

Evolutionary Trajectories ◽

Applied Knowledge

Males have the ability to compete for fertilizations through both pre-copulatory and post-copulatory intrasexual competition. Pre-copulatory competition has selected for large weapons and other adaptations to maximize access to females and mating opportunities while post-copulatory competition has resulted in ejaculate adaptations to maximize fertilization success. Negative associations between these strategies support the hypothesis that there is a trade-off between success at pre- and post-copulatory mating success. Recently, this trade-off has been demonstrated with experimental manipulation. Male leaf-footed cactus bugs, Narnia femorata, that lose a weapon by autotomy during development invest instead in large testes. While evolutionary outcomes of the trade-offs between pre- and post-copulatory strategies have been identified, less work has been done to identify proximate mechanisms by which the trade-off might occur, perhaps because the systems in which the trade-offs have been investigated are not ones that have the molecular tools required for exploring mechanism. Here we applied knowledge from a related model species for which we have developmental knowledge and molecular tools, the milkweed bug Oncopeltus fasciatus, to investigate the proximate mechanism by which autotomized N. femorata males developed larger testes. Autotomized males had evidence of a higher rate of transit amplification divisions in the spermatogonia, which would result in greater sperm numbers. Identification of mechanisms underlying a trade-off can help our understanding of the direction and constraints on evolutionary trajectories and thus the evolutionary potential under multiple forms of selection.

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How to offer mobile targeting promotion under asymmetry

Nankai Business Review International ◽

10.1108/nbri-01-2017-0004 ◽

2017 ◽

Vol 8 (3) ◽

pp. 289-303

Author(s):

Qin Wan ◽

Jing Zhu ◽

Huijing Li ◽

Lili Wang

Keyword(s):

Game Theory ◽

Price Competition ◽

Design Methodology ◽

Game Model ◽

Trade Off ◽

Content Type ◽

Equilibrium Prices ◽

Mobile Accessibility ◽

The Cost ◽

Practical Implications

Purpose Based on consumers’ geographic real-time locations, firms can utilize mobile targeting promotion (MTP) to target consumers through some applications embedded in mobile device. This paper aims to focus on two competing firms about how to make MTP strategies under asymmetric mobile accessibilities, i.e. the proportions of consumers who can be targeted by firms through apps are different. Design/methodology/approach This paper develops a game model for two competing firms. Aiming to maximizing profit, firms should consider how to utilize MTP strategies to trade off the benefit (expand market share) and the cost (intensive price competition). Findings The optimal MTP strategies and equilibrium prices have been presented under different scenarios. This paper verifies that asymmetry can make the firm with high mobile accessibility obtain extra profits. Furthermore, when unit targeting cost is relatively low, profit of the firm with low mobile accessibility increases first and decreases later with respect to its mobile accessibility. Practical implications Competing firms’ optimal MTP strategies and equilibrium prices are determined not only by unit targeting cost but also by consumers’ mobile accessibilities to firms. Firms have strong incentive to enlarge the mobile accessibility to procure more profit in monopoly context, but, under competing context, a higher mobile accessibility may not mean better for firm. Originality/value This is one of the few papers which study mobile targeting based on game theory considering unit targeting cost and asymmetric mobile accessibility simultaneously.

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The Use of a Game Theory Model to Explore the Emergence of Core/Periphery Structure in Networks and Its Symmetry

Symmetry ◽

10.3390/sym13071214 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1214

Author(s):

Ladislav Beranek ◽

Radim Remes

Keyword(s):

Game Theory ◽

Network Topology ◽

Driving Force ◽

Social Dilemma ◽

Theory Model ◽

Network Systems ◽

Complex Interactions ◽

The Subject ◽

The Cost ◽

Intense Research

In network systems characterized by complex interactions of various types, core-periphery structures can be found. In this paper, we deal with such questions as what processes can lead to the emergence of core-periphery formation, whether this structure is symmetric, and to what extent. Namely, the question of symmetry in a complex network is still the subject of intense research interest. Symmetry can relate to network topology, network relationships, and other processes on networks. To answer these questions, we modified the model of the classic social dilemma called the repeated prisoner’s dilemma (or repeated PD game) by adding the cost of maintaining relationships between the pairs of players (partners) and especially by adding the possibility of ending some relationships. We present the results of simulations that suggest that the players’ network strategy (i.e., partner selection or termination of relationships with some partners) is the driving force behind the emergence of a core-periphery structure in networks rather than the player’s strategy in PD. Our results also suggest that the formed core is symmetric, and this symmetry is a result of the symmetric interactions of core players. Our outcomes can help understand various economic or social questions related to creating centers or peripheries, including their symmetry in different network systems.

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The Effect of a Supplier’s Eco-Design on the Economic Benefits of a Supply Chain and Associated Coordination

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph182413357 ◽

2021 ◽

Vol 18 (24) ◽

pp. 13357

Author(s):

Junjun Liu ◽

Yong Geng ◽

Biao Chen ◽

Xiqiang Xia

Keyword(s):

Game Theory ◽

Decision Making ◽

Supply Chain ◽

Optimal Solution ◽

Economic Benefits ◽

Theory Model ◽

Raw Material ◽

Effort Level ◽

Decentralized Decision Making ◽

The Cost

The eco-design of upstream suppliers can reduce the environmental impact from the production process for downstream customers. To analyze the effect of suppliers’ eco-design on the economic benefits of up-downstream supply chain and the mechanisms, this study constructed a master–slave game theory model for a supplier and a manufacturer. Based on this game theory model, this study comparatively analyzes the effects on raw material/part prices, retail product prices, sale volume, revenue, and eco-design effort level under three conditions (no eco-design, decentralized decision-making with eco-design, centralized decision-making with eco-design). And to further analyze the effect of eco-design costs on the optimal solution, this article takes the supply chain of tire production as an example. This analysis could provide suggestions for the suppliers and manufacturers to develop and improve their eco-design. The main results are as follows: the supplier eco-design is beneficial to improving the overall economic benefits for suppliers and manufacturers under certain conditions, and the range in which a supplier is willing to implement eco-design in a decentralized decision-making situation is wider than that in a centralized decision-making situation; when a supplier implements an eco-design, it will transfer part of the cost to the manufacturer by raising the unit raw material/parts prices. Meanwhile, the manufacturer can reduce the production cost when the benefit of eco-design is more than the increased purchasing price, and they can decrease the retail price to expand the sales volume. Hence, consumers will benefit from lower prices. Thus, it is a multi-win situation among the suppliers, manufacturers, and consumers.

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Developing Schedule With Linear Programming (Case Study: STTF II Project Komplek Sukamukti Banjaran)

International Journal of Innovation in Enterprise System ◽

10.25124/ijies.v4i02.77 ◽

2020 ◽

Vol 4 (02) ◽

pp. 34-45

Author(s):

Naufal Dzikri Afifi ◽

Ika Arum Puspita ◽

Mohammad Deni Akbar

Keyword(s):

Linear Programming ◽

Objective Function ◽

Project Scheduling ◽

Time Limit ◽

Minimum Time ◽

Service Cost ◽

Trade Off ◽

Overtime Work ◽

The Cost

Shift to The Front II Komplek Sukamukti Banjaran Project is one of the projects implemented by one of the companies engaged in telecommunications. In its implementation, each project including Shift to The Front II Komplek Sukamukti Banjaran has a time limit specified in the contract. Project scheduling is an important role in predicting both the cost and time in a project. Every project should be able to complete the project before or just in the time specified in the contract. Delay in a project can be anticipated by accelerating the duration of completion by using the crashing method with the application of linear programming. Linear programming will help iteration in the calculation of crashing because if linear programming not used, iteration will be repeated. The objective function in this scheduling is to minimize the cost. This study aims to find a trade-off between the costs and the minimum time expected to complete this project. The acceleration of the duration of this study was carried out using the addition of 4 hours of overtime work, 3 hours of overtime work, 2 hours of overtime work, and 1 hour of overtime work. The normal time for this project is 35 days with a service fee of Rp. 52,335,690. From the results of the crashing analysis, the alternative chosen is to add 1 hour of overtime to 34 days with a total service cost of Rp. 52,375,492. This acceleration will affect the entire project because there are 33 different locations worked on Shift to The Front II and if all these locations can be accelerated then the duration of completion of the entire project will be effective

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Negotiating in the Shadow of 'Bad Faith' Refusal to Settle: A Game Theory Model of Medical Malpractice Pre-Trial Settlements and Insurance Limits

SSRN Electronic Journal ◽

10.2139/ssrn.1463655 ◽

2009 ◽

Cited By ~ 5

Author(s):

Theodore H. Frank ◽

Marie Gryphon

Keyword(s):

Game Theory ◽

Medical Malpractice ◽

Theory Model ◽

Bad Faith

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Black Hole Algorithm for Sustainable Design of Counterfort Retaining Walls

Sustainability ◽

10.3390/su12072767 ◽

2020 ◽

Vol 12 (7) ◽

pp. 2767 ◽

Cited By ~ 13

Author(s):

Víctor Yepes ◽

José V. Martí ◽

José García

Keyword(s):

Black Hole ◽

Sustainable Design ◽

Retaining Walls ◽

The Other ◽

Trade Off ◽

Construction Company ◽

Geometric Variables ◽

The Stability ◽

The Cost ◽

Black Hole Algorithm

The optimization of the cost and CO 2 emissions in earth-retaining walls is of relevance, since these structures are often used in civil engineering. The optimization of costs is essential for the competitiveness of the construction company, and the optimization of emissions is relevant in the environmental impact of construction. To address the optimization, black hole metaheuristics were used, along with a discretization mechanism based on min–max normalization. The stability of the algorithm was evaluated with respect to the solutions obtained; the steel and concrete values obtained in both optimizations were analyzed. Additionally, the geometric variables of the structure were compared. Finally, the results obtained were compared with another algorithm that solved the problem. The results show that there is a trade-off between the use of steel and concrete. The solutions that minimize CO 2 emissions prefer the use of concrete instead of those that optimize the cost. On the other hand, when comparing the geometric variables, it is seen that most remain similar in both optimizations except for the distance between buttresses. When comparing with another algorithm, the results show a good performance in optimization using the black hole algorithm.

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