Biology subjects

Dore, A.

Publications and source records attributed to Dore, A..

5 recordsLinked to original sources

bioRxiv2022

Automated detection of sow posture changes with millimeter-wave radars and deep learning

Automated behavioural monitoring is increasingly required for animal welfare and precision agriculture. In pig farming, detailed analyses of sow activity are essential to identify and reduce the risks of piglets being crushed during postural changes of their mothers. Here we introduce a new, non-invasive, fast and accurate method for monitoring sow behaviour based on millimeter-wave radars and deep learning analysis. We used our method to predict postural changes in crated sows and distinguish the dangerous one that lie down abruptly from those that lie down carefully using transient postures. Two radars were placed on a metal backing above the head and the upper part of the back of each of ten sows to monitor their activity during 5 hours. We analysed the radar data with a convolutional neural network and identified five postures. The average sensitivity was 96.9% for standing, 90.8% for lying, 91.4% for nursing, 87.6% for sitting, but only 11.9% for kneeling. However, the average specificity and accuracy were greater than 92% for the five postures. Interestingly, two of the ten sows occasionally moved directly from standing to lying, without using the transient postures sitting and kneeling, thereby displaying risky behaviours for their piglets. Our radar-based classifier is more accurate, faster and require less memory than current computer vision approaches. Using more sows will improve the algorithm performance and facilitate future applications for large scale deployment in animal farming. HighlightsO_LIAutomated behavioural analysis is a major challenge for precision farming. C_LIO_LIWe developed automated detection of lactating sow postures with radars and deep learning. C_LIO_LIWe identified five postures, including transitions risky for the piglets. C_LIO_LIOur method is accurate, fast and requires less memory than computer vision. C_LIO_LIRadars thus hold considerable promises for high through-put recording of livestock activity. C_LI

animal behavior and cognition↗

bioRxiv2021

Experimental evolution under varying sex ratio and nutrient availability modulates male mating success in Drosophila melanogaster

Biased population sex ratios can alter optimal male mating strategies, and allocation to reproductive traits depends on nutrient availability. However, there is little information on how nutrition interacts with sex ratio to influence the evolution of pre-copulatory and post-copulatory traits separately. To address this omission, here we test how male mating success and reproductive investment evolve under varying sex ratios and adult diet in Drosophila melanogaster using an experimental evolution approach. We found that sex ratio and nutrient availability interacted to determine male pre-copulatory performance. Males from female-biased populations were slow to mate when they evolved on a protein-restricted diet. On the other hand, we found direct and non-interacting effects of sex ratio and nutrient availability on post-copulatory success, without interactions between them. Males that evolved on a protein-restricted diet were poor at suppressing female remating. Males that evolved under equal sex ratios fathered more offspring and were better at supressing female remating, relative to males from male-biased or female-biased populations. These results support the idea that sex ratios and nutrition interact to determine the evolution of pre-copulatory mating traits, but independently influence the evolution of post-copulatory traits.

evolutionary biology↗

bioRxiv2020

A non-invasive radar system for automated behavioural tracking: application to sheep

Automated quantification of the behaviour of freely moving animals is increasingly needed in ethology, ecology, genetics and evolution. State-of-the-art approaches often require tags to identify animals, high computational power for data collection and processing, and are sensitive to environmental conditions, which limits their large-scale utilisation. Here we introduce a new automated tracking system based on millimetre-wave radars for real time robust and high precision monitoring of untagged animals. To validate our system, we tracked 64 sheep in a standard indoor behavioural test used for genetic selection. First, we show that the proposed radar application is faster and more accurate than conventional video and infrared tracking systems. Next, we illustrate how new behavioural estimators can be derived from the radar data to assess personality traits in sheep for behavioural phenotyping. Finally, we demonstrate that radars can be used for movement tracking at larger spatial scales, in the field, by adjusting operating frequency and radiated electromagnetic power. Millimetre-wave radars thus hold considerable promises for high-throughput recording of the behaviour of animals with various sizes and locomotor modes, in different types of environments.

animal behavior and cognition↗

bioRxiv2019

Phenylethynylbenzyl-Modified Biguanides Inhibit Pancreatic Cancer Tumor Growth

We present the design and synthesis of a small library of substituted biguanidium salts and their capacity to inhibit the growth/viability of pancreatic cancer cells. We first present their in vitro and membrane activity, before we address their mechanism of action in living cells and in vivo activity. We show that phenylethynyl biguanidium salts possess higher ability to cross hydrophobic barriers, improved mitochondrial accumulation and anticancer activity. Mechanistically, the most active compound 1b, like metformin, decreases the NAD+/NADH ratio and mitochondrial respiration, but at 800-fold lower concentration. In vivo studies with, the most active, compound 1b show a significant growth inhibition of pancreatic cancer xenografts in mice, while biguanides currently in clinical trials had no activity.

cancer biology↗

bioRxiv2018

Molecular basis for high affinity agonist binding in GPCRs

A characteristic of GPCRs in the G protein-coupled state is that the affinity of the agonist often increases significantly, but the molecular basis for this is unclear. We have determined six active-state structures of the {beta}1-adrenoceptor ({beta}1AR) bound to conformation-specific nanobodies in the presence of agonists of varying efficacy. A direct comparison with structures of {beta}1AR in inactive states bound to the identical ligands showed a 24-42% reduction in the volume of the orthosteric binding site. Potential hydrogen bonds were also shorter, and there was up to a 30% increase in the number of atomic contacts between the receptor and ligand. GPCRs are highly conserved, so these factors will likely be essential in increasing the affinity of a wide range of structurally distinct agonists.\n\nOne Sentence SummaryHigh affinity agonist binding to G protein-coupled GPCRs results from an increase in the number and strength of protein-ligand interactions.

biochemistry↗