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Biology subjects

Peeters, C.

Publications and source records attributed to Peeters, C..

3 recordsLinked to original sources

Physics-Informed Neural Network Methods for Predicting Plant Height Development

Plant growth is a dynamic process affected by genes and growing environment, with all kinds of interactions between them. These complex relationships make the prediction of plant growth challenging. We propose a hybrid modelling framework that combines a logistic ordinary differential equation model with a Long Short-Term Memory (LSTM) neural network, resulting in a Physics Informed Neural Network (PINN). While PINNs have been widely applied to physical dynamical systems, their use in modelling the dynamics of plant growth systems is still largely unexplored. We illustrate the construction of a PINN on plant height data in wheat and compare its performance with alternative models for longitudinal plant data. All temporal prediction models only require time and temperature as input. Among a set of competing models, our PINN had the lowest average root mean squared error (RMSE) of prediction and the smallest standard deviation across multiple random initialisations. Therefore, we conclude that incorporating biological growth constraints into data-driven growth models can enhance prediction accuracy of longitudinal plant traits. HighlightsO_LIIntegrating plant growth equations into a temporal neural network improves plant height growth prediction over ordinary differential equations and machine learning models, especially when training data are limited. C_LI

plant biology↗

One tree, many colonies: colony structure, breeding system and colonization events of host trees in tunneling Melissotarsus ants

Ants exhibit a striking variety of lifestyles, including highly specialist or mutualist species. The minute blind workers of the African genus Melissotarsus chew tunnels in live trees to accommodate their obligate partner scale insects. Their modified legs are adapted for tunneling, but are unsuited for walking outside, confining these ants to their initial host tree. Here, we investigated whether this unique lifestyle results in complex patterns of genetic diversity at different scales, from the same tree to different populations. Using 19 microsatellite markers, we assessed their mating strategy and colony structure among and across populations in South Africa. We showed that only one queen reproduces within a colony, mated with up to three males. Yet, several inseminated dealate queens are present in colonies; one probably replaces the older queen as colonies age. The reproduction of a single queen per colony at a given time results in genetic differentiation between colonies, even those located on the same tree. Overall, we discussed how the slow process of colony digging under the bark and the lack of worker patrolling above the bark might result in reduced competition between colonies and allow several secluded colonies to cohabit in a cramped space on a tree.

evolutionary biology↗

Variability of core microbiota in newly diagnosed treatment-naïve paediatric Inflammatory Bowel Disease patients

BACKGROUND & AIMSIntestinal microbiota is considered to play a crucial role in the aetiology of inflammatory bowel disease (IBD). We aimed to describe faecal microbiota composition and dynamics in a large cohort of children with de novo (naive) IBD, in comparison to healthy paediatric controls (HC).\n\nMETHODSIn this prospective study, performed at two tertiary centres, faecal samples from newly diagnosed, treatment-naive paediatric IBD patients were collected prior to bowel cleansing for colonoscopy (t0) and 1, 3 and 6 weeks and 3 months after initiation of therapy. The microbial profiles of Crohns disease (CD) and Ulcerative colitis (UC) patients were compared with HC and linked to therapeutic response. Microbiota composition was analysed by IS-pro technology.\n\nRESULTSMicrobial profiles of 104 new IBD-patients (63 CD, 41 UC, median age 14.0 years) were compared to 61 HC (median 7.8 years). IBD was mainly characterised by decreased abundance of Alistipes finegoldi and Alistipes putredinis, which characterize a healthy state microbial core. The classifier including these core species as predictors achieved an AUC of the ROC curve of .87. Core bacteria tended to regain abundance during treatment, but did not reach healthy levels.\n\nCONCLUSIONFaecal microbiota profiles of children with de novo CD and UC can be discriminated from HC with high accuracy, mainly driven by a decreased abundance of species shaping the microbial core in the healthy state. Paediatric IBD can therefore be characterized by decreased abundance of certain bacterial species reflecting the healthy state rather than by the introduction of pathogens.

microbiology↗