A methodology to assess the impact on bees of dust from coated seeds

contribution to session IVTest methodology

A Recipe for Efficient SBIR Models: Combining Relative Triplet Loss with Batch Normalization and Knowledge Distillation

Sketch-Based Image Retrieval (SBIR) is a crucial task in multimedia retrieval, where the goal is to retrieve a set of images that match a given sketch query. Researchers have already proposed several well-performing solutions for this task, but most focus on enhancing embedding through different approaches such as triplet loss, quadruplet loss, adding data augmentation, and using edge extraction. In this work, we tackle the problem from various angles. We start by examining the training data quality and show some of its limitations. Then, we introduce a Relative Triplet Loss (RTL), an adapted triplet loss to overcome those limitations through loss weighting based on anchors similarity. Through a series of experiments, we demonstrate that replacing a triplet loss with RTL outperforms previous state-of-the-art without the need for any data augmentation. In addition, we demonstrate why batch normalization is more suited for SBIR embeddings than l2-normalization and show that it improves significantly the performance of our models. We further investigate the capacity of models required for the photo and sketch domains and demonstrate that the photo encoder requires a higher capacity than the sketch encoder, which validates the hypothesis formulated in [34]. Then, we propose a straightforward approach to train small models, such as ShuffleNetv2 [22] efficiently with a marginal loss of accuracy through knowledge distillation. The same approach used with larger models enabled us to outperform previous state-of-the-art results and achieve a recall of 62.38% at k = 1 on The Sketchy Database [30]

Biologie de la reproduction d'une espèce menacée de l'île de La Réunion (Corymborkis corymbis: Orchidaceae) : implications pour sa conservation

La connaissance de la biologie de la reproduction est une étape essentielle dans la mise en place de projets de conservation des espèces menacées. L'étude de Corymborkis corymbis, espèce protégée de l'île de La Réunion, montre que cette espèce n'est représentée que par quelques populations sur l'île. Son taux de fécondité en milieu naturel, de l'ordre de 3 %, est extrêmement faible. L'étude de son système de compatibilité montre que l'espèce est partiellement autocompatible mais pas autofertile. Des perspectives d'études à réaliser sont proposées, ainsi que des stratégies de gestion de la conservation de cette espèce.The knowledge of the reproductive biology is an essential step in the building of conservation projects of endangered species . The protected Corymborkis corymbis in La Réunion island is only represented by few populations. lts fecundity in natural conditions is very low ( around 3 % ). The study of its breeding system shows that the species is partially self-compatible but not self-fertile. This paper proposes future studies as well as management strategies of the conservation of this species

Electroswitchable red-NIR luminescence of ionic clustomesogen containing nematic liquid crystalline devices.

International audienceWe describe in this work several polyionic hybrid mol. compds. combining, by electrostatic interactions, liq. cryst. ammonium cations and tailor made molybdenum hexanuclear dianionic cluster units. All hybrids show nematic liq. cryst. behavior below 100 °C, no matter the nature of the metallic cluster apical and inner ligands. They also retain the shiny deep red photoluminescence properties of their parent cluster in the nematic phase. This nematic phase remains however quite viscous for all compds. and mixing them with com. available nematic LCs seems mandatory to integrate them into electroswitchable devices. This particularity conducted us to insert the best candidate in terms of homogeneity and stability of the clustomesogen/com. LC mixt. into a LC cell and study the behavior toward the application of an elec. stimulus. We show that the application of 30 V AC voltage allows observing a reversible modulation of the photoluminescence signal by about 52%. This work presents the first deep red photoluminescent transition metal cluster contg. device directed towards optoelectronic applications