Freezing Behavior as a Response to Sexual Visual Stimuli as Demonstrated by Posturography

Posturographic changes in motivational conditions remain largely unexplored in the context of embodied cognition. Over the last decade, sexual motivation has been used as a good canonical working model to study motivated social interactions. The objective of this study was to explore posturographic variations in response to visual sexual videos as compared to neutral videos. Our results support demonstration of a freezing-type response in response to sexually explicit stimuli compared to other conditions, as demonstrated by significantly decreased standard deviations for (i) the center of pressure displacement along the mediolateral and anteroposterior axes and (ii) center of pressure’s displacement surface. These results support the complexity of the motor correlates of sexual motivation considered to be a canonical functional context to study the motor correlates of motivated social interactions.     

Influence du positionnement du patient sur la survenue des artefacts et l’interprétation des images de perfusion myocardique obtenues à partir d’une caméra dédiée à semi-conducteurs CZT

Myocardial perfusion imaging (MPI) can be affected by physical artefacts, such as attenuation and Compton scatter, both related to patient's morphological characteristics and his/her position during acquisition. These positional artefacts have been largely studied with classical Anger cameras. Recently, a new generation of heart-dedicated cameras has emerged, using novel cadmium–zinc–telluride (CZT) semi-conductors, with different physical characteristics and geometrical distribution. Our study aimed to investigate, in this new generation camera, the relation between patient's positioning and the occurring of physical artefacts. Plus, we examined whether these artefacts were likely to affect the interpretation made with such images.Material and methodsIn this prospective study, we included 60 patients scheduled in our unit for MPI. All of them underwent both prone and supine acquisitions, after stress test as well as at rest.ResultsAt a global population level, we observed significantly more abnormalities in supine acquisitions in territories mainly vascularized by right coronary artery, and to a lesser extent, by circumflex artery, than observed in prone acquisitions. No scoring difference was observed, regardless of position, in Summed Stress Score, Summed Rest Score or Summed Difference Score. This observation remained the same whether on a global population level, or on a BMI- and perimeter-basis level.ConclusionPosition related physical artefacts, such as attenuation and Compton scattering, are similar to those previously described with Anger cameras. These artefacts do not affect the interpretation of myocardial scans significantly, provided that both images are acquired in the same anatomical position.     

Mannose 6‐phosphonate labelling: A key for processing the therapeutic enzyme in Pompe disease

In the search of a better enzyme therapy in Pompe disease, the conjugation of mannose 6‐phosphonates to the recombinant enzyme appeared as an enhancer of its efficacy. Here, we demonstrated that the increased efficacy of the conjugated enzyme is partly due to a higher intracellular maturation because of its insensitiveness to acid phosphatases during the routing to lysosomes.     

Senescence in cell oxidative status in two bird species with contrasting life expectancy

Oxidative stress occurs when the production of reactive oxygen species (ROS) by an organism exceeds its capacity to mitigate the damaging effects of the ROS. Consequently, oxidative stress hypotheses of ageing argue that a decline in fecundity and an increase in the likelihood of death with advancing age reported at the organism level are driven by gradual disruption of the oxidative balance at the cellular level. Here, we measured erythrocyte resistance to oxidative stress in the same individuals over several years in two free-living bird species with contrasting life expectancy, the great tit (known maximum life expectancy is 15.4 years) and the Alpine swift (26 years). In both species, we found evidence for senescence in cell resistance to oxidative stress, with patterns of senescence becoming apparent as subjects get older. In the Alpine swift, there was also evidence for positive selection on cell resistance to oxidative stress, the more resistant subjects being longer lived. The present findings of inter-individual selection and intra-individual deterioration in cell oxidative status at old age in free-living animals support a role for oxidative stress in the ageing of wild animals.     

SpoIIIE mechanism of directional translocation involves target search coupled to sequence‐dependent motor stimulation

SpoIIIE/FtsK are membrane‐anchored, ATP‐fuelled, directional motors responsible for chromosomal segregation in bacteria. Directionality in these motors is governed by interactions between specialized sequence‐recognition modules (SpoIIIE‐γ/FtsK‐γ) and highly skewed chromosomal sequences (SRS/KOPS). Using a new combination of ensemble and single‐molecule methods, we dissect the series of steps required for SRS localization and motor activation. First, we demonstrate that SpoIIIE/DNA association kinetics are sequence independent, with binding specificity being uniquely determined by dissociation. Next, we show by single‐molecule and modelling methods that hexameric SpoIIIE binds DNA non‐specifically and finds SRS by an ATP‐independent target search mechanism, with ensuing oligomerization and binding of SpoIIIE‐γ to SRS triggering motor stimulation. Finally, we propose a new model that provides an entirely new interpretation of previous observations for the origin of SRS/KOPS‐directed translocation by SpoIIIE/FtsK.