Biology subjects

Mercier, S.

Publications and source records attributed to Mercier, S..

4 recordsLinked to original sources

bioRxiv2026

Predicting the Efficacy of Myopia Control Spectacle Lenses by Simulating Their Optical Effect on the Retina

Slowing myopia progression is central to addressing a growing public health concern. Myopia control spectacle lenses with diverse optical designs have been proposed for this purpose, and show varying degrees of clinical efficacy. Relating their design to their efficacy remains an open challenge. Here we show that it is possible to predict their clinical efficacy from their optical design, by reconstructing their impact on the retinal image. We simulated how several lens designs affect the retinal image using a combined lens and eye optical model. By assuming that the retina extracts specific features from the retinal image to modulate eye growth, we could predict the cumulative absolute reduction in axial elongation (CARE) of lens designs with very different rationales and microstructures. Our results show that different myopia control spectacle lenses can be compared on a common optical basis, and that their efficacy is predictable from their optical properties. This work paves the way for rational design of next-generation lenses and for adapting designs to each patient's ocular optics.

neuroscience↗

bioRxiv2025

Living with urban fear: vervet monkey response to an evolutionarily new predator

Humans have facilitated contacts between prey and predator species that have originally not co-evolved, reshuffling the prey-predator arms race. How do prey cope with an evolutionarily new predation risk? We tracked three vervet monkey troops in a South-African semi-urban habitat for 14 months to study their response to domestic dogs. We show that monkeys responded to dogs with a two-pronged behaviour: they emitted alarm calls, and became more vigilant and displayed aggressive behaviours towards the dogs. While their movement highlighted risk-prone behaviour, they appeared to have mapped and planned for risk, as they reacted more strongly when risk was unexpected. The response intensity was further modulated by risk labels typically encountered in their natural environment, but not by labels uniquely associated with dogs. This highlights that vervet monkeys responded with ingrained behaviour to this evolutionarily new threat, anticipating risk based on long-term spatial memory, but failed to integrate evolutionarily new information. TeaserVervet monkeys fear domestic dogs but fail to adjust their antipredator response by discriminating evolutionarily new risk labels.

animal behavior and cognition↗

bioRxiv2025

Behavioural flexibility and its drivers in semi-urban vervet monkeys

Phylogenetic comparisons suggest that behavioural flexibility facilitates success in urban environments. It remains less clear whether urbanization fosters cognitive skills that require flexibility, or whether successful individuals in urban environments simply apply pre-evolved skills to solve new problems. To investigate whether variation in anthropogenic experience drives behavioural flexibility required to solve a new technical problem, we presented 42 semi-urban vervet monkeys (Chlorocebus pygerythrus) with a three-phase foraging experiment. For this, we measured each monkeys tendency to "raid" human structures in their search for food to assess whether their anthropogenic experience explained individual variation in flexibility and problem-solving skills. We then used a probabilistic model to describe the series of monkeys actions when attempting to solve the foraging experiment. This allowed us to quantify three traits encompassing individuals behavioural flexibility: switch tendency between solutions, innovativeness, and learning sensitivity. We found that individuals switch tendency and innovativeness were not explained by anthropogenic experience and that the three traits were unrelated to each other. Moreover, neither switch tendency, nor innovativeness predicted the monkeys human food consumption in this habitat. Thus, our study suggests that behavioural flexibility is not driven by anthropogenic foraging experience. Contrasting with the hypothesis that urbanization selects for behavioural flexibility, our findings instead imply that vervet monkeys already had the sufficient behavioural flexibility and cognitive capacities to successfully exploit the urban habitat.

animal behavior and cognition↗

bioRxiv2018

Rare variants in the genetic background modulate the expressivity of neurodevelopmental disorders

PurposeTo assess the contribution of rare variants in the genetic background towards variability of neurodevelopmental phenotypes in individuals with rare copy-number variants (CNVs) and gene-disruptive mutations.\n\nMethodsWe analyzed quantitative clinical information, exome-sequencing, and microarray data from 757 probands and 233 parents and siblings who carry disease-associated mutations.\n\nResultsThe number of rare secondary mutations in functionally intolerant genes (second-hits) correlated with the expressivity of neurodevelopmental phenotypes in probands with 16p12.1 deletion (n=23, p=0.004) and in probands with autism carrying gene-disruptive mutations (n=184, p=0.03) compared to their carrier family members. Probands with 16p12.1 deletion and a strong family history presented more severe clinical features (p=0.04) and higher burden of second-hits compared to those with mild/no family history (p=0.001). The number of secondary variants also correlated with the severity of cognitive impairment in probands carrying pathogenic rare CNVs (n=53) or de novo mutations in disease genes (n=290), and negatively correlated with head size among 80 probands with 16p11.2 deletion. These second-hits involved known disease-associated genes such as SETD5, AUTS2, and NRXN1, and were enriched for genes affecting cellular and developmental processes.\n\nConclusionAccurate genetic diagnosis of complex disorders will require complete evaluation of the genetic background even after a candidate gene mutation is identified.

genomics↗