Relatedness and age reduce aggressive male interactions over mating in domestic fowl

Altruistic behaviour represents a fundamental challenge in evolutionary biology. It is often best understood through kin selection, where favourable behaviour is directed towards relatives. Kin selection can take place when males cooperate to enhance the reproductive success of relatives. Here, we focus on reduced male–male competition over mating as a case of cooperation, by examining male tolerance of matings by related and unrelated competitors. A suitable model for exploring whether relatedness affects male–male interactions over mating is the domestic fowl, Gallus gallus domesticus. In this species, males form social hierarchies and dominant males commonly interrupt subdominant males’ copulation attempts. We investigated whether dominant male fowl differentially direct aggressive interactions towards unrelated and related subordinate males during mating attempts. Dominant male fowl were found to interrupt mating attempts of male relatives less often than those of unrelated males. We further tested whether male age mediates the magnitude of kin tolerance behaviour. However, we found no support for this as both young and old dominant males were less likely to interrupt related, compared to unrelated, subdominant males’ copulations during male–male interactions. Our results, consistent with kin selection, provide a rare experimental demonstration of relatedness relaxing male–male competition over mating

Relatedness and age reduce aggressive male interactions over mating in domestic fowl

Altruistic behaviour represents a fundamental challenge in evolutionary biology. It is often best understood through kin selection, where favourable behaviour is directed towards relatives. Kin selection can take place when males cooperate to enhance the reproductive success of relatives. Here, we focus on reduced male–male competition over mating as a case of cooperation, by examining male tolerance of matings by related and unrelated competitors. A suitable model for exploring whether relatedness affects male–male interactions over mating is the domestic fowl, Gallus gallus domesticus. In this species, males form social hierarchies and dominant males commonly interrupt subdominant males’ copulation attempts. We investigated whether dominant male fowl differentially direct aggressive interactions towards unrelated and related subordinate males during mating attempts. Dominant male fowl were found to interrupt mating attempts of male relatives less often than those of unrelated males. We further tested whether male age mediates the magnitude of kin tolerance behaviour. However, we found no support for this as both young and old dominant males were less likely to interrupt related, compared to unrelated, subdominant males’ copulations during male–male interactions. Our results, consistent with kin selection, provide a rare experimental demonstration of relatedness relaxing male–male competition over mating

Relatedness and age reduce aggressive male interactions over mating in domestic fowl

Altruistic behaviour represents a fundamental challenge in evolutionary biology. It is often best understood through kin selection, where favourable behaviour is directed towards relatives. Kin selection can take place when males cooperate to enhance the reproductive success of relatives. Here, we focus on reduced male–male competition over mating as a case of cooperation, by examining male tolerance of matings by related and unrelated competitors. A suitable model for exploring whether relatedness affects male–male interactions over mating is the domestic fowl, Gallus gallus domesticus. In this species, males form social hierarchies and dominant males commonly interrupt subdominant males’ copulation attempts. We investigated whether dominant male fowl differentially direct aggressive interactions towards unrelated and related subordinate males during mating attempts. Dominant male fowl were found to interrupt mating attempts of male relatives less often than those of unrelated males. We further tested whether male age mediates the magnitude of kin tolerance behaviour. However, we found no support for this as both young and old dominant males were less likely to interrupt related, compared to unrelated, subdominant males’ copulations during male–male interactions. Our results, consistent with kin selection, provide a rare experimental demonstration of relatedness relaxing male–male competition over mating

Anomalous circular polarization profiles in the He I 1083.0 nm multiplet from solar spicules

We report Stokes vector observations of solar spicules and a prominence in the He I 1083 nm multiplet carried out with the Tenerife Infrared Polarimeter. The observations show linear polarization profiles that are produced by scattering processes in the presence of a magnetic field. After a careful data reduction, we demonstrate the existence of extremely asymmetric Stokes V profiles in the spicular material that we are able to model with two magnetic components along the line of sight, and under the presence of atomic orientation in the energy levels that give rise to the multiplet. We discuss some possible scenarios that can generate the atomic orientation in spicules. We stress the importance of spectropolarimetric observations across the limb to distinguish such signals from observational artifacts.Comment: accepted for publication in Ap

Impact of a 6-wk olive oil supplementation in healthy adults on urinary proteomic biomarkers of coronary artery disease, chronic kidney disease, and diabetes (types 1 and 2): a randomized, parallel, controlled, double-blind study

Background: Olive oil (OO) consumption is associated with cardiovascular disease prevention because of both its oleic acid and phenolic contents. The capacity of OO phenolics to protect against low-density lipoprotein (LDL) oxidation is the basis for a health claim by the European Food Safety Authority. Proteomic biomarkers enable an early, presymptomatic diagnosis of disease, which makes them important and effective, but understudied, tools for primary prevention. Objective: We evaluated the impact of supplementation with OO, either low or high in phenolics, on urinary proteomic biomarkers of coronary artery disease (CAD), chronic kidney disease (CKD), and diabetes. Design: Self-reported healthy participants (n = 69) were randomly allocated (stratified block random assignment) according to age and body mass index to supplementation with a daily 20-mL dose of OO either low or high in phenolics (18 compared with 286 mg caffeic acid equivalents per kg, respectively) for 6 wk. Urinary proteomic biomarkers were measured at baseline and 3 and 6 wk alongside blood lipids, the antioxidant capacity, and glycation markers. Results: The consumption of both OOs improved the proteomic CAD score at endpoint compared with baseline (mean improvement: –0.3 for low-phenolic OO and −0.2 for high-phenolic OO; P < 0.01) but not CKD or diabetes proteomic biomarkers. However, there was no difference between groups for changes in proteomic biomarkers or any secondary outcomes including plasma triacylglycerols, oxidized LDL, and LDL cholesterol. Conclusion: In comparison with low-phenolic OO, supplementation for 6 wk with high-phenolic OO does not lead to an improvement in cardiovascular health markers in a healthy cohort. This trial was registered at www.controlled-trials.com as ISRCTN93136746

Discrete Convex Functions on Graphs and Their Algorithmic Applications

The present article is an exposition of a theory of discrete convex functions on certain graph structures, developed by the author in recent years. This theory is a spin-off of discrete convex analysis by Murota, and is motivated by combinatorial dualities in multiflow problems and the complexity classification of facility location problems on graphs. We outline the theory and algorithmic applications in combinatorial optimization problems

Personality in the Cockroach (Diploptera punctate): Evidence for Stability Across Developmental Stages Despite Age Effects on Boldness

Despite a recent surge in the popularity of animal personality studies and their wide-ranging associations with various aspects of behavioural ecology, our understanding of the development of personality over ontogeny remains poorly understood. Stability over time is a central tenet of personality; ecological pressures experienced by an individual at different life stages may, however, vary considerably, which may have a significant effect on behavioural traits. Invertebrates often go through numerous discrete developmental stages and therefore provide a useful model for such research. Here we test for both differential consistency and age effects upon behavioural traits in the gregarious cockroach Diploptera punctata by testing the same behavioural traits in both juveniles and adults. In our sample, we find consistency in boldness, exploration and sociality within adults whilst only boldness was consistent in juveniles. Both boldness and exploration measures, representative of risk-taking behaviour, show significant consistency across discrete juvenile and adult stages. Age effects are, however, apparent in our data; juveniles are significantly bolder than adults, most likely due to differences in the ecological requirements of these life stages. Size also affects risk-taking behaviour since smaller adults are both bolder and more highly explorative. Whilst a behavioural syndrome linking boldness and exploration is evident in nymphs, this disappears by the adult stage, where links between other behavioural traits become apparent. Our results therefore indicate that differential consistency in personality can be maintained across life stages despite age effects on its magnitude, with links between some personality traits changing over ontogeny, demonstrating plasticity in behavioural syndromes

Pigment Extraction from Alfalfa Leaf Protein Concentrates

The extraction and recoveries of carotenoids from alfalafa leaf protein was investigated using different organic solvent