scholarly journals Experimental manipulation of Heliconius warning patterns reduces harassment of previously mated females

2018 ◽  
Author(s):  
Richard M. Merrill ◽  
Sara Neggazi ◽  
Colin R. Morrison ◽  
Rachel Crisp ◽  
W. Owen McMillan
Keyword(s):  
Significant Interaction ◽  
Local Density ◽  
Alternative Hypothesis ◽  
Experimental Manipulation ◽  
Threshold Density ◽  
Fitness Costs ◽  
Male Attraction ◽  
Female Fecundity ◽  
Risk Of Predation ◽  
Rapid Divergence

Why warning patterns are so diverse is an enduring evolutionary problem. Because predators learn to associate particular patterns with unpleasant experiences, an individual’s risk of predation should decrease as the local density of its warning pattern increases. Heliconius butterflies, however, are known for their diversity of warning patterns, and the establishment of entirely new phenotypes is difficult to explain under strict frequency-dependent selection. One possibility is that during periods of relaxed selection, drift may allow new variants to rise above a threshold density until mimicry selection takes over. We propose an alternative hypothesis where novel pattern phenotypes arise due to a conflict of interests between the sexes. It is well established that male Heliconius use warning patterns as a mating cue. This will likely be beneficial to males as it will increase the efficiency of finding mates. However, already mated females may suffer fitness costs if these cues lead to harassment by males during oviposition or foraging. When constraints imposed by predation are locally relaxed, this could lead to rapid divergence in pattern phenotypes through chase-away sexual selection. To begin to test this hypothesis, we experimentally manipulated the warning patterns of mated Heliconius erato demaphoon females and recorded their interactions with conspecific males, and the effect of male presence on laying rate. As predicted, males interacted less with mated females whose red forewing band was blacked-out, as compared to control females whose warning pattern remained intact. We also show that females lay less eggs in the presence of males, but we were unable to detect a significant interaction between warning pattern treatment and the presence of males on female fecundity. Our results suggest that male attraction to conspecific warning patterns, may impose a previously unrecognized cost on Heliconius females.

An experimental test of the effect of acute anxious arousal and anxiety sensitivity on negative reinforcement smoking

2016 ◽  
Vol 30 (7) ◽  
pp. 641-653 ◽  
Author(s):  
Samantha G Farris ◽  
Michael J Zvolensky
Keyword(s):  
Anxiety Sensitivity ◽  
Significant Interaction ◽  
Negative Reinforcement ◽  
Smoking Behavior ◽  
Experimental Manipulation ◽  
Future Research ◽  
Anxious Arousal ◽  
Smoking Topography ◽  
Biological Challenge ◽  
Before And After

Introduction: Although anxiety sensitivity has been reliably associated with smoking-anxiety comorbidity, there has not been a test of whether this construct moderates the effect of acute anxious arousal on actual smoking behavior. The present study utilized an experimental design to test the moderating role of anxiety sensitivity on laboratory-induced anxious arousal in terms of smoking urges and topography (puff style). Method: Participants were adult daily smokers ( n=90; Mage=43.6 SD =9.7); average 15.8 cigarettes per day). A between-subjects design was used; participants were randomly assigned to complete a biological challenge procedure consisting of either a single vital capacity inhalation of 35% carbon dioxide (CO2)-enriched air mixture or compressed room air. Smoking urges and smoking topography (puff behavior) were assessed before and after the challenge. Results: Results revealed a significant interaction between anxiety sensitivity and experimental condition ( b=−9.96, p=0.014), such that high anxiety sensitive smokers exposed to 35% CO2-enriched air reported significantly lower levels of smoking urges, relative to low anxiety sensitive smokers; the conditional effect of anxiety sensitivity was not observed for the room air condition. There were no significant interaction effects of experimental manipulation by anxiety sensitivity for any of the smoking topography outcomes. Discussion: The present results suggest for smokers with higher levels of anxiety sensitivity, the acute experience of anxious arousal is related to decreased subjective smoking urges. These data invite future research to explore the reasons for dampened smoking urges, including cardiorespiratory symptom severity.

S0221: Comparison of two schedules of paclitaxel as adjuvant therapy for breast cancer.

2013 ◽  
Vol 31 (18_suppl) ◽  
pp. CRA1008-CRA1008 ◽  
Author(s):  
G. Thomas Budd ◽  
William E. Barlow ◽  
Halle C. F. Moore ◽  
Timothy J. Hobday ◽  
James A. Stewart ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Interim Analysis ◽  
Significant Interaction ◽  
Cox Model ◽  
Alternative Hypothesis ◽  
Disease Free Survival ◽  
Phase Iii ◽  
Grade 5 ◽  
Two Factors ◽  
Grade 3

CRA1008 Background: S0221 is a SWOG-coordinated phase III adjuvant chemotherapy intergroup trial in node-positive and high-risk node-negative operable breast cancer which hypothesized that 1) the weekly AC+G regimen is superior to ddAC x 6 and 2) 12 weeks of weekly paclitaxel (wP) is superior to q 2 week paclitaxel x 6 (ddP). Methods: Between December 2003 and November 2010, 2,716 patients were randomized in a 2 x 2 factorial design to 1) AC+G vs ddAC and 2) P 80 mg/m2/week x 12 vs P 175 mg/m2 q 2 weeks x 6. If there was no significant interaction between the factors, the trial was powered to find a disease-free survival hazard ratio (HR) ≤ 0.82 for weekly vs q 2 week for each factor. At the first interim analysis, the AC randomization was halted for futility, and S0221 was closed to accrual 10 November 2010. S0221 reopened 15 December 2010, after which time all patients received 4 cycles of ddAC and randomization to P weekly x 12 and ddP x 6 continued. Accrual halted at a total of 3,294 in January 2012. Results: By September 7, 2012, 487 events and 340 deaths had occurred, prompting the third planned interim analysis. The Data Safety and Monitoring Committee recommended reporting the results since the futility boundary was crossed. A Cox model adjusting for the AC arms had a HR = 1.08 (95% CI 0.90-1.28; p=0.42), with the 99.5% CI excluding the original alternative hypothesis that the HR=0.82. There was no significant interaction of the two factors. Estimated 5-year progression-free survivals were 82% for weekly P and 81% for ddP. Toxicity data were available for 1,385 patients treated with ddP and 1,367 treated with weekly P. Grade 5 toxicity occurred in 4 patients on ddP and 2 on weekly P. Percent grade 3-4 toxicity per arm are shown in the Table. Conclusions: Either ddPx6 or weekly P x 12 are acceptable schedules of P administration. The differences in leukopenia likely reflect ascertainment bias against weekly P. If this is accepted, weekly P x 12 produces less overall toxicity than 6 cycles of ddP. Support: NCI grants CA32102, CA38926, CA21115, CA21076, CA77597, CA25224, CA77202, CCSRI15469, and Amgen, Inc. Clinical trial information: NCT00070564. [Table: see text]

scholarly journals Experiments confirm a dispersive phenotype associated with a natural gene drive system

2021 ◽  
Vol 8 (5) ◽  
Author(s):  
Jan-Niklas Runge ◽  
Anna K. Lindholm
Keyword(s):  
Sperm Competition ◽  
Local Density ◽  
House Mice ◽  
Gene Drive ◽  
Wild Type ◽  
Fitness Costs ◽  
Oestrus Cycle ◽  
Drive Systems ◽  
Average Body ◽  
Average Body Weight

Meiotic drivers are genetic entities that increase their own probability of being transmitted to offspring, usually to the detriment of the rest of the organism, thus ‘selfishly’ increasing their fitness. In many meiotic drive systems, driver-carrying males are less successful in sperm competition, which occurs when females mate with multiple males in one oestrus cycle (polyandry). How do drivers respond to this selection? An observational study found that house mice carrying the t haplotype, a meiotic driver, are more likely to disperse from dense populations. This could help the t avoid detrimental sperm competition, because density is associated with the frequency of polyandry. However, no controlled experiments have been conducted to test these findings. Here, we confirm that carriers of the t haplotype are more dispersive, but we do not find this to depend on the local density. t -carriers with above-average body weight were particularly more likely to disperse than wild-type mice. t -carrying mice were also more explorative but not more active than wild-type mice. These results add experimental support to the previous observational finding that the t haplotype affects the dispersal phenotype in house mice, which supports the hypothesis that dispersal reduces the fitness costs of the t .

scholarly journals Experimental manipulation of immune-mediated disease and its fitness costs for rodent malaria parasites

2008 ◽  
Vol 8 (1) ◽  
pp. 128 ◽  
Author(s):  
Gráinne H Long ◽  
Brian HK Chan ◽  
Judith E Allen ◽  
Andrew F Read ◽  
Andrea L Graham
Keyword(s):  
Experimental Manipulation ◽  
Fitness Costs ◽  
Malaria Parasites ◽  
Rodent Malaria ◽  
Immune Mediated

scholarly journals Kinship and familiarity mitigate costs of social conflict between Seychelles warbler neighbors

2017 ◽  
Vol 114 (43) ◽  
pp. E9036-E9045 ◽  
Author(s):  
Kat Bebbington ◽  
Sjouke A. Kingma ◽  
Eleanor A. Fairfield ◽  
Hannah L. Dugdale ◽  
Jan Komdeur ◽  
...  
Keyword(s):  
Body Mass ◽  
Genetic Relatedness ◽  
Social Conflict ◽  
Local Density ◽  
Fitness Costs ◽  
Telomere Attrition ◽  
Social Familiarity ◽  
Scale Population ◽  
Seychelles Warbler ◽  
Social Units

Because virtually all organisms compete with others in their social environment, mechanisms that reduce conflict between interacting individuals are crucial for the evolution of stable families, groups, and societies. Here, we tested whether costs of social conflict over territorial space between Seychelles warblers (Acrocephalus sechellensis) are mitigated by kin-selected (genetic relatedness) or mutualistic (social familiarity) mechanisms. By measuring longitudinal changes in individuals’ body mass and telomere length, we demonstrated that the fitness costs of territoriality are driven by a complex interplay between relatedness, familiarity, local density, and sex. Physical fights were less common at territory boundaries shared between related or familiar males. In line with this, male territory owners gained mass when living next to related or familiar males and also showed less telomere attrition when living next to male kin. Importantly, these relationships were strongest in high-density areas of the population. Males also had more rapid telomere attrition when living next to unfamiliar male neighbors, but mainly when relatedness to those neighbors was also low. In contrast, neither kinship nor familiarity was linked to body mass or telomere loss in female territory owners. Our results indicate that resolving conflict over territorial space through kin-selected or mutualistic pathways can reduce both immediate energetic costs and permanent somatic damage, thus providing an important mechanism to explain fine-scale population structure and cooperation between different social units across a broad range of taxa.

scholarly journals Leader or Leaderess? Consequences of Using Feminatives for the Perception of Leadership

2021 ◽  
Vol 2/2021 (35) ◽  
pp. 17-31
Author(s):  
Anna O. Kuźmińska ◽  
Keyword(s):  
Significant Interaction ◽  
Experimental Manipulation ◽  
Leadership Roles ◽  
Cognitive Representation ◽  
Experimental Conditions ◽  
Implicit Leadership ◽  
Implicit Leadership Theory ◽  
Male Ratio ◽  
The Feminine ◽  
Inclusive Instruction

According to the Implicit Leadership Theory, leadership roles are assigned in the process of social construction and depend upon the level of congruence with the cognitive representation of a leader. Previous studies show that this cognitive representation is much more likely to involve a leader being a male rather than a female. The article presents the results of an experiment aimed at tentatively verifying whether the use of the feminine forms could increase the cognitive availability of the representation of a woman as a leader. In the experiment, 135 teams (N = 307 respondents) were randomly assigned to one of two experimental conditions: 1) generic instruction (without the use of feminatives, “Please, draw a leader”), 2) inclusive instruction (using feminatives, “Please, draw a leader/leaderess”). The results showed a significant interaction between the experimental manipulation and the proportion of women in the team. The use of feminine forms increased the percentage of females drawn as leaders only in teams with a high female-to-male ratio.

scholarly journals Parasite insight: assessing fitness costs, infection risks and foraging benefits relating to gastrointestinal nematodes in wild mammalian herbivores

2018 ◽  
Vol 373 (1751) ◽  
pp. 20170197 ◽  
Author(s):  
Graeme Coulson ◽  
Jemma K. Cripps ◽  
Sarah Garnick ◽  
Verity Bristow ◽  
Ian Beveridge
Keyword(s):  
Experimental Studies ◽  
Parasite Load ◽  
Field Studies ◽  
Gastrointestinal Nematodes ◽  
Experimental Manipulation ◽  
Infection Risk ◽  
Parasitic Nematodes ◽  
Fitness Costs ◽  
Mammalian Herbivores ◽  
Technical Developments

Mammalian herbivores are typically infected by parasitic nematodes, which are acquired through direct, faecal–oral transmission. These parasites can cause significant production losses in domestic livestock, but much less is known about impacts on wild mammalian hosts. We review three elements of parasitism from the host's perspective: fitness costs of infection, risks of infection during foraging and benefits of nutritious pasture. The majority of wildlife studies have been observational, but experimental manipulation is increasing. Treatment with anthelmintics to manipulate parasite load has revealed varied impacts of parasites on fitness variables across host species, but has not produced consistent evidence for parasite-induced anorexia or impaired body condition. Some experimental studies of infection risk have manipulated faecal contamination and detected faecal avoidance by hosts. Only two field studies have explored the trade-off between infection risk and nutritional benefit generated by avoidance of contaminated patches. Overall, field studies of costs, risks and benefits of the host–parasite relationship are limited and few have examined more than one of these elements. Parasitism has much in common with predation, and future insights into anti-parasite responses by wild hosts could be gained from the conceptual and technical developments in research on anti-predator behaviour. This article is part of the Theo Murphy meeting issue ‘Evolution of pathogen and parasite avoidance behaviours’.

Experimental manipulation of female reproduction demonstrates its fitness costs in kangaroos

2014 ◽  
Vol 84 (1) ◽  
pp. 239-248 ◽  
Author(s):  
Uriel Gélin ◽  
Michelle E. Wilson ◽  
Graeme Coulson ◽  
Marco Festa-Bianchet
Keyword(s):  
Experimental Manipulation ◽  
Female Reproduction ◽  
Fitness Costs

Sex Differences in Reward and Punishment of Confederates Perceived to Be Similar or Dissimilar

1976 ◽  
Vol 42 (2) ◽  
pp. 523-529
Author(s):  
P. S. Fry
Keyword(s):  
Significant Interaction ◽  
Person Perception ◽  
Teaching Assistants ◽  
Experimental Manipulation ◽  
Personality Test ◽  
Test Results ◽  
Personality Tests ◽  
Male And Female ◽  
Graduate Teaching ◽  
Teaching Position

The experiment studied the interaction between sex of Ss and sex of similarly and dissimilarly perceived confederates in assigning rewards and punishments to confederates. Two male and 2 female confederates were introduced to male and female Ss as applicants for graduate teaching assistants. Ss and confederates were administered 4 personality tests. Ss were instructed to nominate on the basis of personality inferences, 2 candidates, one for the teaching position (reward) and one for an “errand-boy's” position (punishment). Thus, the experiment was presented as a test of Ss' accuracy in person perception. The experimental manipulation involved rigging Ss' personality test results to make confederates appear either similar or dissimilar to S. Ss' mean scores for rewards and punishments suggest that females punish other women more than men. The hypothesis of a significant interaction between sex of Ss, sex of confederates and similarity-dissimilarity was also supported.

Ab initio band theory approach to electron energy loss near edge structures

1988 ◽  
Vol 46 ◽  
pp. 506-507
Author(s):  
Xudong Weng ◽  
O.F. Sankey ◽  
Peter Rez
Keyword(s):  
Ab Initio ◽  
Local Density ◽  
Interpolation Method ◽  
Atomic Orbital ◽  
Plane Waves ◽  
Large Set ◽  
Theory Approach ◽  
Band Theory ◽  
Atomic Orbitals ◽  
Pseudopotential Calculations

Single electron band structure techniques have been applied successfully to the interpretation of the near edge structures of metals and other materials. Among various band theories, the linear combination of atomic orbital (LCAO) method is especially simple and interpretable. The commonly used empirical LCAO method is mainly an interpolation method, where the energies and wave functions of atomic orbitals are adjusted in order to fit experimental or more accurately determined electron states. To achieve better accuracy, the size of calculation has to be expanded, for example, to include excited states and more-distant-neighboring atoms. This tends to sacrifice the simplicity and interpretability of the method.In this paper. we adopt an ab initio scheme which incorporates the conceptual advantage of the LCAO method with the accuracy of ab initio pseudopotential calculations. The so called pscudo-atomic-orbitals (PAO's), computed from a free atom within the local-density approximation and the pseudopotential approximation, are used as the basis of expansion, replacing the usually very large set of plane waves in the conventional pseudopotential method. These PAO's however, do not consist of a rigorously complete set of orthonormal states.

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