scholarly journals Cheaper is not always worse: strongly protective isolates of a defensive symbiont are less costly to the aphid host

2015 ◽  
Vol 282 (1799) ◽  
pp. 20142333 ◽  
Author(s):  
Luis Cayetano ◽  
Lukas Rothacher ◽  
Jean-Christophe Simon ◽  
Christoph Vorburger
Keyword(s):  
Cost Benefit ◽  
Aphis Fabae ◽  
Parasitoid Wasps ◽  
Strain Variation ◽  
Trade Off ◽  
Black Bean ◽  
Defensive Symbiosis ◽  
Hamiltonella Defensa ◽  
The Cost ◽  
Aphid Host

Defences against parasites are typically associated with costs to the host that contribute to the maintenance of variation in resistance. This also applies to the defence provided by the facultative bacterial endosymbiont Hamiltonella defensa, which protects its aphid hosts against parasitoid wasps while imposing life-history costs. To investigate the cost–benefit relationship within protected hosts, we introduced multiple isolates of H. defensa to the same genetic backgrounds of black bean aphids, Aphis fabae , and we quantified the protection against their parasitoid Lysiphlebus fabarum as well as the costs to the host (reduced lifespan and reproduction) in the absence of parasitoids. Surprisingly, we observed the opposite of a trade-off. Strongly protective isolates of H. defensa reduced lifespan and lifetime reproduction of unparasitized aphids to a lesser extent than weakly protective isolates. This finding has important implications for the evolution of defensive symbiosis and highlights the need for a better understanding of how strain variation in protective symbionts is maintained.

scholarly journals Understanding and Encouraging Online Reviewing With a Selection-Based Review System

2019 ◽  
Vol 31 (5) ◽  
pp. 446-464
Author(s):  
Rowanne Fleck ◽  
Benjamin R Cowan ◽  
Eirini Darmanin ◽  
Yixin Wang
Keyword(s):  
Cost Benefit ◽  
Online Reviews ◽  
Review System ◽  
Personal View ◽  
Trade Off ◽  
Consumer Reviews ◽  
Online Consumer Reviews ◽  
Mobile Interface ◽  
Online Consumer ◽  
The Cost

Abstract Online consumer reviews are important for people wishing to make purchases online. However, not everyone contributes online reviews. This paper looks at consumer motivations of reviewing and rating behaviour in order to motivate the design of a mobile interface for online reviewing. An interview study found that people tend to contribute reviews and ratings based on their perception of whether they would be helpful or not to others as well as their own personal view of the usefulness of reviews and ratings when buying products. There also seems to be a cost-benefit trade-off that influences people’s decisions to review and rate: people tend to make a decision based on the perceived value of that review or rating to the community against the effort and costs of contributing. A mobile interface was designed that was intended both to reduce the cost of leaving reviews and to increase the perception of the usefulness of the reviews to others. An initial evaluation of this reviewing interface suggests that it could encourage more people to leave reviews.

Exploring the Culture of Surveillance: A Qualitative Study in Portugal

2021 ◽  
Vol 10 (1) ◽  
pp. 79-95
Author(s):  
Délcio Faustino ◽  
Maria João Simões
Keyword(s):  
Qualitative Study ◽  
Detailed Analysis ◽  
Social Inequalities ◽  
Cost Benefit ◽  
Theoretical Framework ◽  
Surveillance Culture ◽  
Trade Off ◽  
Trade Offs ◽  
The Cost ◽  
Subjective Meanings

By following the theoretical framework of the surveillance culture this article aims to detail the surveillance imaginaries and practices that individuals have, capturing differences and social inequalities among respondents. We present an in-depth look into surveillance awareness, exploring subjective meanings and the varying awareness regarding commercial, governmental, and lateral surveillance. Furthermore, a detailed analysis is made on how individuals sometimes welcome surveillance, expanding on the cost-benefit trade-off, and detailing it on three distinct trade-offs: the privacy vs. commercial gains/rewards, the privacy vs. convenience and, the privacy vs. security. Lastly, we present a section that explores and analyzes resistance to surveillance.

scholarly journals Phage loss and the breakdown of a defensive symbiosis in aphids

2013 ◽  
Vol 280 (1751) ◽  
pp. 20122103 ◽  
Author(s):  
S. R. Weldon ◽  
M. R. Strand ◽  
K. M. Oliver
Keyword(s):  
Acyrthosiphon Pisum ◽  
Bacterial Symbiont ◽  
Parasitoid Wasps ◽  
Bacterial Symbionts ◽  
Delayed Onset ◽  
Lower Weight ◽  
Terrestrial Arthropods ◽  
Defensive Symbiosis ◽  
Hamiltonella Defensa ◽  
Secondary Endosymbiont

Terrestrial arthropods are often infected with heritable bacterial symbionts, which may themselves be infected by bacteriophages. However, what role, if any, bacteriophages play in the regulation and maintenance of insect–bacteria symbioses is largely unknown. Infection of the aphid Acyrthosiphon pisum by the bacterial symbiont Hamiltonella defensa confers protection against parasitoid wasps, but only when H. defensa is itself infected by the phage A. pisum secondary endosymbiont (APSE). Here, we use a controlled genetic background and correlation-based assays to show that loss of APSE is associated with up to sevenfold increases in the intra-aphid abundance of H. defensa . APSE loss is also associated with severe deleterious effects on aphid fitness: aphids infected with H. defensa lacking APSE have a significantly delayed onset of reproduction, lower weight at adulthood and half as many total offspring as aphids infected with phage-harbouring H. defensa , indicating that phage loss can rapidly lead to the breakdown of the defensive symbiosis. Our results overall indicate that bacteriophages play critical roles in both aphid defence and the maintenance of heritable symbiosis.

Investigating the Cost-Benefit Trade-Off of Additional Planning Using Parade Game Simulation

2018 ◽  
Vol 34 (2) ◽  
pp. 04017066 ◽  
Author(s):  
S. Alireza Abbasian-Hosseini ◽  
Min Liu ◽  
Gregery Howell
Keyword(s):  
Cost Benefit ◽  
Trade Off ◽  
Game Simulation ◽  
The Cost

scholarly journals Differential Contribution of Dopaminergic Transmission at D1- and D2-like Receptors to Cost/Benefit Evaluation for Motivation in Monkeys

2020 ◽  
Author(s):  
Yukiko Hori ◽  
Yuji Nagai ◽  
Koki Mimura ◽  
Tetsuya Suhara ◽  
Makoto Higuchi ◽  
...  
Keyword(s):  
Positron Emission Tomography Imaging ◽  
Cost Benefit ◽  
Trade Off ◽  
Dopaminergic Transmission ◽  
R And D ◽  
Benefit Evaluation ◽  
Positron Emission ◽  
Reward Amount ◽  
Fundamental Insight ◽  
The Cost

AbstractIt has been widely accepted that dopamine (DA) plays a major role in motivation, yet the specific contribution of DA signaling at D1-like receptor (D1R) and D2-like receptor (D2R) to cost-benefit trade-off remains unclear. Here, by combining pharmacological manipulation of DA receptors (DARs) and positron emission tomography imaging, we assessed the relationship between the degree of D1R/D2R blockade and changes in benefit- and cost-based motivation for goal-directed behavior of macaque monkeys. We found that the degree of blockade of either D1R or D2R was associated with a reduction of relative incentive effect of reward amount, where D2R blockade had a stronger effect. Workload-discounting was selectively increased by D2R antagonism, whereas delay-discounting was similarly increased after D1R and D2R blockades. These results provide fundamental insight into the specific actions of DARs in the regulation of the cost/benefit trade-off and important implications for motivational alterations in both neurological and psychiatric disorders.

scholarly journals Dual RNA-seq in an aphid parasitoid reveals plastic and evolved adaptation to symbiont-conferred resistance

2019 ◽  
Author(s):  
Alice B. Dennis ◽  
Heidi Käch ◽  
Christoph Vorburger
Keyword(s):  
Gene Expression ◽  
Parasitoid Wasp ◽  
Aphis Fabae ◽  
Rna Seq ◽  
Aphid Parasitoid ◽  
Expression Of Genes ◽  
Study Gene Expression ◽  
Hamiltonella Defensa ◽  
Plastic Responses ◽  
Aphid Host

AbstractCoevolving taxa offer the opportunity to study the genetic basis of rapid reciprocal adaptation. We have used experimental evolution to examine adaptation in the parasitoid wasp Lysiphlebus fabarum to resistance conferred by the protective endosymbiont Hamiltonella defensa in its aphid host Aphis fabae. To examine a key stage in parasitoid infection, we have used RNA-seq to study gene expression in 4-5 day old parasitoid larvae contained in still living aphids. With this dual RNA-seq we can simultaneously view expression in individual experimentally evolved parasitoids and the aphids that house them. This gives a view of the sweeping changes in both taxa accompanying successful or unsuccessful infections. Among successful larvae, we find that experimentally evolved populations adapted to H. defensa-protected hosts differ in the expression of genes that include putative toxins and genes to cope with stress. These differences remain even when the larvae are developing in aphids possessing no defensive endosymbionts, suggesting that they are genetically based. In contrast, plastic responses between parasitoids reared in hosts with and without H. defensa are relatively small. Although aphids rely largely on their secondary endosymbionts for defense against parasitoids, we identify expression differences in aphids housing different parasitoid phenotypes. Together, these results demonstrate that wild parasitoid populations possess the genetic variation for rapid adaptation to host resistance, resulting in genetically based differences in gene expression that increase their success in parasitizing symbiont-protected host aphids.

A Study on Collaborative Design Considering Features of Design

2002 ◽  
Author(s):  
Tomoyuki Miyashita ◽  
Hiroshi Yamakawa
Keyword(s):  
Collaborative Design ◽  
Computer Software ◽  
Cost Benefit ◽  
Design System ◽  
Data Envelopment ◽  
Trade Off ◽  
Design Processes ◽  
Numerical Examples ◽  
The Cost ◽  
Cam Software

In design processes of machinery, much computer software, for examples CAD/CAE/CAM software, are used. The design processes are aided by this software. The seamless connections of the design processes are necessary for the improvement of the cost benefit of the products. However, sometimes, the conflicts among designs or design processes are occurred by the change of the design at a certain design process and these conflicts are should be noticed and solved immediately. In this research, we have developed the design system including CAD software and the developed system has some functions to find the conflicts of the change of designs and to solve the conflicts. We use Data Envelopment Analysis (DEA) to calculate the efficiency of the design and Satisficing Trade-off Method (STM) to find and solve the conflicts. We have confirmed through some fundamental numerical examples and discussed of the proposed system and method and showed the effectiveness of out study.

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