Male sexually coercive behaviour drives increased swimming efficiency in female guppies

Sexual coercion of females by males is widespread across sexually reproducing species. It stems from a conflict of interest over reproduction and exerts selective pressure on both sexes. For females, there is often a significant energetic cost of exposure to male sexually coercive behaviours. Our understanding of the efficiency of female resistance to male sexually coercive behaviour is key to understanding how sexual conflict contributes to population level dynamics and ultimately to the evolution of sexually antagonistic traits. Overlooked within this context are plastic physiological responses of traits within the lifetime of females that could moderate the energetic cost imposed by coercive males. Here, we examined whether conflict over the frequency and timing of mating between male and female guppies Poecilia reticulata can induce changes in swimming performance and aerobic capacity in females as they work to escape harassment by males. Females exposed to higher levels of harassment over a 5-month period used less oxygen to swim at a given speed, but displayed no difference in resting metabolic rate, maximal metabolic rate, maximal sustained swimming speed or aerobic scope compared to females receiving lower levels of harassment. The observed increase in swimming efficiency is at least partially related to differences in swimming mechanics, likely brought on by a training effect of increased activity, as highly harassed females spent less time performing pectoral fin-assisted swimming. Sexual conflict results in sexually antagonistic traits that impose a variety of costs, but our results show that females can reduce costs through phenotypic plasticity. It is also possible that phenotypic plasticity in swimming physiology or mechanics in response to sexual coercion can potentially give females more control over matings and affect which male traits are under selection

Elevated systemic antibodies towards commensal gut microbiota in autoinflammatory condition

Article No. e3172Non peer reviewedPublisher PD

Study of different membrane spargers used in waste water treatment : characterisation and performance

In urban waste water treatment, a novel gas sparger based on flexible rubber membrane has been used for the last ten years. The objective of this present work is to compare two flexible membranes (the new membrane and the old membrane provided by ONDEO-DEGREMONT group) used in waste water treatment. For this purpose, the different membrane properties (hole diameter, pressure drop, critical pressure, deflection at the centerline and elasticity) have been characterized. The bubble generation at the membranes with a single orifice and with four orifices have been studied and their performances have been compared in terms of interfacial area and power consumption. From the experimental and theoretical approach, the new membrane is less elastic (or more rigid) than the old membrane. The bubble diameters generated from the new membrane remain constant with the gas velocity through the orifice, whereas they increase logarithmically for the old membrane. The inverse behaviours are observed in terms of the bubble formation frequency. Moreover, the bubbles generated from the new membrane have significantly larger sizes and lower formation frequencies than those obtained with the old one. From these results, it can be noted that the new membrane has a behaviour comparable to a rigid orifice. No coalescence phenomenon at the bubble formation is observed from the new and the old membranes with four orifices. The interfacial area and the power consumption are evaluated and show slight differences between the interfacial area provided by the old and the new membranes for one value of power consumption

Comprehensive Determination of the Hinode/EIS Roll Angle

We present a new coalignment method for the EUV Imaging Spectrometer (EIS) on board the Hinode spacecraft. In addition to the pointing offset and spacecraft jitter, this method determines the roll angle of the instrument, which has never been systematically measured, and is therefore usually not corrected. The optimal pointing for EIS is computed by maximizing the cross-correlations of the Fe XII 195.119 \r{A} line with images from the 193 \r{A} band of the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). By coaligning 3336 rasters with high signal-to-noise ratio, we estimate the rotation angle between EIS and AIA and explore the distribution of its values. We report an average value of (-0.387 $\pm$ 0.007)\deg. We also provide a software implementation of this method that can be used to coalign any EIS raster.Comment: Accepted for publication in Solar Physics, 11 pages, 7 figure

Freshwater reservoir offsets and food crusts: Isotope, AMS, and lipid analyses of experimental cooking residues

Freshwater reservoir offsets (FROs) occur when AMS dates on charred, encrusted food residues on pottery predate a pot’s chronological context because of the presence of ancient carbon from aquatic resources such as fish. Research over the past two decades has demonstrated that FROs vary widely within and between water bodies and between fish in those water bodies. Lipid analyses have identified aquatic biomarkers that can be extracted from cooking residues as potential evidence for FROs. However, lacking has been efforts to determine empirically how much fish with FROs needs to be cooked in a pot with other resources to result in significant FRO on encrusted cooking residue and what percentage of fish C in a residue is needed to result in the recovery of aquatic biomarkers. Here we provide preliminary assessments of both issues. Our results indicate that in historically-contingent, high alkalinity environments\u3c20%C from fish may result in a statistically significant FRO, but that biomarkers for aquatic resources may be present in the absence of a significant FRO

Phase transformation yield surface of anisotropic shape memory alloys

International audienceTwo theoretical investigations, i.e. a phenomenological macroscopic model and a "micro-macro" model are developed for modelling the experimental surfaces of initiation of phase transformation in shape memory alloys. A possible initial anisotropy of the materials is taken into account

Activism, affect, identification: trans documentary in France and Spain and its reception

This article explores the documentation of trans activism in France and Spain since the 2000s. The first part addresses questions surrounding the place of affect and narrative in documentary film, particularly in relation to trans issues. The second part o f the article analyses an audience case study from a screening at the International Gay and Lesbian Film Festival in Barcelona of Valérie Mitteaux's Girl or Boy, My Sex is not my Gender (2011), considering how different viewers respond to the representatio n of trans identities. The article builds on qualitative research whilst extending the exploration of sexuality and gender in previous audience studies to a consideration of documentary film, seeking to provide a more nuanced understanding of what audience claims for identification in politicised contexts mean

Male sexually coercive behaviour drives increased swimming efficiency in female guppies

Sexual coercion of females by males is widespread across sexually reproducing species. It stems from a conflict of interest over reproduction and exerts selective pressure on both sexes. For females, there is often a significant energetic cost to exposure to male sexually coercive behaviours. Our understanding of the efficiency of female resistance to male sexually coercive behaviour is key to understanding how sexual conflict contributes to population level dynamics and ultimately to the evolution of sexually antagonistic traits. Overlooked within this context are plastic physiological responses of traits within the lifetime of females that could moderate the energetic cost imposed by coercive males. Here we examined whether conflict over the frequency and timing of mating between male and female guppies Poecilia reticulata can induce changes in swimming performance and aerobic capacity in females as they work to escape harassment by males. Females exposed to higher levels of harassment over a five month period used less oxygen to swim at a given speed, but displayed no difference in resting metabolic rate, maximal metabolic rate, maximal sustained swimming speed or aerobic scope compared to females receiving lower levels of harassment. The observed increase in swimming efficiency is at least partially related to differences in swimming mechanics, likely brought on by a training effect of increased activity, as highly harassed females spent less time performing pectoral fin-assisted swimming. Sexual conflict results in sexually antagonistic traits that impose a variety of costs, but our results show that females can reduce costs through phenotypic plasticity. It is also possible that phenotypic plasticity in swimming physiology or mechanics in response to sexual coercion can potentially give females more control over matings and affect which male traits are under selection.NERCLeverhulme Early Career FellowshipLeverhulme TrustER

Aspiration of biological viscoelastic drops

Spherical cellular aggregates are in vitro systems to study the physical and biophysical properties of tissues. We present a novel approach to characterize the mechanical properties of cellular aggregates using micropipette aspiration technique. We observe an aspiration in two distinct regimes, a fast elastic deformation followed by a viscous flow. We develop a model based on this viscoelastic behavior to deduce the surface tension, viscosity, and elastic modulus. A major result is the increase of the surface tension with the applied force, interpreted as an effect of cellular mechanosensing.Comment: 4 pages, 4 figures