libra UniNe
Not a member yet
28871 research outputs found
Sort by
Matters of Knowledge. Paradigms and Practices of Conservation through the Centuries
No full textÀ paraîtr
Frequency : Psychological and Methodological Considerations
Full text linkConstruction Grammar is one of the fastest-growing branches of functional syntax. Bringing together an international team of scholars, this handbook provides a complete overview of the current issues and applications in this approach. Divided into six thematic parts, it covers the fundamental notions of Construction Grammar, its conceptual origins and the basic ideas that unite its various branches, its solid empirical grounding and affinities with corpus linguistics, and the diverse perspectives in constructional scholarship. It highlights advances in discourse-related topics and applications to various domains, including multimodal communication, language learning and teaching and computational linguistics, and each chapter contains numerous illustrative examples and case studies involving a variety of languages. It also includes in-depth, empirically-grounded analyses of diverse theoretical, methodological, and interdisciplinary issues, alongside step-by-step introductions to the theory, making it essential reading for both researchers and students working in functional and cognitive approaches to linguistic analysis and syntactic theory
Le souffle créateur. Regards sur les livres d’artistes de la Bibliothèque publique de Neuchâtel
No full textÀ paraîtr
Soil Legacy Effects of Photorhabdus Bacteria Metabolites on Plant Performance and Resistance
Full text linkTHESIS DIRECTOR
Dr. RICARDO A. R. MACHADO
THESIS COMMITTEE MEMBERS
Dr. RICARDO A. R. MACHADO
Prof. TED C. J. TURLINGS
Prof. SERGIO RASMANN
Dr. IVAN HILTPOLD
Dr. CARLA MARQUES
9th OCTOBER 2025
numéro de thèse : 3215Les bactéries Photorhabdus sont des microbes puissants qui tuent les insectes et offrent une excellente opportunité pour lutter contre les ravageurs de manière écologique. Cependant, l'application de bactéries Photorhabdus par pulvérisation foliaire ou arrosage du sol sans leur vecteur nématode entomopathogène introduit des cellules bactériennes et des toxines dans le sol. Or, les effets à long terme des bactéries Photorhabdus et de leurs métabolites sur les plantes et autres organismes sont inconnus.
Dans cette étude, j'ai examiné les effets résiduels des métabolites de Photorhabdus sur la communauté microbienne du sol, la physiologie des plantes, leur performance et leur résistance aux attaques d'insectes. Pour ce faire, j'ai conditionné les sols avec : i) des cadavres d'insectes infectés par Photorhabdus ou des larves tuées mécaniquement (MK), ii) des extraits aqueux de toxines provenant de cadavres d'insectes infectés par Photorhabdus ou de larves MK, iii) des surnageants de culture de Photorhabdus sans cellules, iv) du sol autoclavé complété avec 10 % de sol vivant préalablement conditionné avec des cadavres d'insectes infectés par Photorhabdus ou des larves MK, et j'ai utilisé du sol non conditionné comme témoin. J'ai ensuite mesuré les caractéristiques de croissance des plantes et l'accumulation de biomasse chez les plantes cultivées sur les différents traitements de conditionnement du sol. Ensuite, j'ai utilisé le séquençage d'amplicons pour déterminer comment le conditionnement du sol affectait les communautés bactériennes, nématodes et fongiques. Enfin, j'ai évalué les performances des larves de Diabrotica balteata et Spodoptera frugiperda se nourrissant de plantes cultivées sur un sol conditionné, et j'ai utilisé la métabolomique pour établir le profil des réponses des plantes au niveau métabolique.
J'ai démontré que tous les traitements d'amendement du sol amélioraient considérablement la croissance des plantes, de 10 à 26 % par rapport aux plantes témoins. Cependant, aucune différence significative n'a été observée en termes de hauteur, de longueur et de largeur des feuilles, ni de nombre de racines pivotantes entre les plantes expérimentales et les plantes témoins. Des effets similaires sur la croissance des plantes ont été observés chez les plantes cultivées sur un sol amendé, soulignant le rôle des micro-organismes du sol dans ces résultats. Après analyse de la communauté microbienne du sol, l'amendement du sol avec des cadavres d'insectes infectés par Photorhabdus ou MK a considérablement modifié les communautés bactériennes et nématodes, tandis que la communauté fongique est restée stable. Il est à noter que les bactéries bénéfiques et les espèces nématodes étaient plus abondantes dans le sol amendé que dans le sol témoin, ce qui explique probablement l'amélioration de la croissance des plantes dans le sol amendé. J'ai également montré que les plantes cultivées sur des sols amendés avec des cadavres d'insectes infectés par Photorhabdus ont considérablement réduit l'alimentation des larves d'insectes d'une manière spécifique à chaque souche. Plus précisément, le poids des larves de D. balteata et S. frugiperda a été réduit respectivement de 10 à 20 % et de 10 à 59 %, soit moins que dans le sol témoin. De plus, les plantes résistantes ont accumulé respectivement douze et huit métabolites distincts dans leurs racines et leurs feuilles, dont les effets biologiques contre les insectes et les agents pathogènes sont connus.
Sur la base de ces résultats, je conclus que l'amendement du sol avec des métabolites de Photorhabdus améliore la croissance des plantes, module la communauté microbienne vers une structure favorable à la croissance des plantes et que l'amendement avec des souches sélectionnées de Photorhabdus déclenche des réponses systémiques chez les plantes contre les herbivores qui se nourrissent des racines et des feuilles.
Abstract :
Photorhabdus bacteria are potent insect-killing microbes offering a prime opportunity for environmentally benign pest control. However, applying Photorhabdus bacteria by foliar sprays or soil drenching without its entomopathogenic nematode vector introduces bacterial cells and toxins into the soil. Yet, the soil legacy effects of Photorhabdus bacteria and their metabolites on plants and other organisms are unknown. In this study, I investigated the soil legacy effects of Photorhabdus metabolites on soil microbial community, plant physiology, performance and resistance against insect attack. To achieve this, I conditioned soils with: i) Photorhabdus-infected insect cadavers or mechanically killed (MK) larvae, ii) water extracts of toxins derived from Photorhabdus-infected insect cadavers, or from MK larvae, iii) cell-free Photorhabdus culture supernatants, iv) autoclaved soil complemented with 10% of live soil previously conditioned with Photorhabdus-infected insect cadavers or MK, and used non-conditioned soil as the control. I then measured plant growth traits and biomass accumulation in plants grown on the different soil conditioning treatments. Next, I employed amplicon sequencing to determine how soil conditioning affected the bacterial, nematode, and fungal communities. Finally, I evaluated the performance of Diabrotica balteata and Spodoptera frugiperda larvae feeding on plants grown on conditioned soil, and I used metabolomics to profile plant responses at the metabolic level. I showed that all soil conditioning treatments significantly improved plant growth by 10 – 26% compared to controls. However, there were no significant differences in the height, leaf length and width, and number of crown roots of experimental plants compared to controls. Similar plant growth effects were observed in plants grown on complemented soil, underscoring the role of soil microorganisms in these results. Upon analysing the soil microbial community, soil conditioning with Photorhabdus-infected insect cadavers or MK significantly altered the bacterial and nematode communities, while the fungal community remained stable. Notably, beneficial bacteria and nematode species were more abundant in conditioned than in control soil, likely explaining the improved plant growth in conditioned soil. I also showed that plants grown on soils conditioned with Photorhabdus-infected insect cadavers significantly suppressed the feeding of insect larvae in a strain-specific manner. Specifically, D. balteata and S. frugiperda larval weights were reduced by 10 – 20% and 10 – 59% respectively, less than the control. Moreover, resistant plants accumulated twelve and eight distinct root and leaf metabolites, respectively, with known biological effects against insects and pathogens. Based on these findings, I conclude that soil conditioning with Photorhabdus metabolites improves plant growth, modulates the microbial community towards a structure that benefits plant growth and conditioning with selected Photorhabdus strains triggers plant systemic responses against root and leaf-feeding herbivores
From Forest to Zoo: Great Ape Behavior Recognition with ChimpBehave
No full textAbstract
This paper addresses the significant challenge of recognizing behaviors in non-human primates, specifically focusing on chimpanzees. Automated behavior recognition is crucial for both conservation efforts and the advancement of behavioral research. However, it is often hindered by the labor-intensive process of manual video annotation. Despite the availability of large-scale animal behavior datasets, effectively applying machine learning models across varied environmental settings remains a critical challenge due to the variability in data collection contexts and the specificity of annotations. In this paper, we introduce ChimpBehave, a novel dataset comprising over 2 h and 20 min of video (approximately 215,000 frames) of zoo-housed chimpanzees, annotated with bounding boxes and fine-grained locomotive behavior labels. Uniquely, ChimpBehave aligns its behavior classes with those in PanAf, an existing dataset collected in distinct visual environments, enabling the study of cross-dataset generalization - where models are trained on one dataset and tested on another with differing data distributions. We benchmark ChimpBehave using state-of-the-art video-based and skeleton-based action recognition models, establishing performance baselines for both within-dataset and cross-dataset evaluations. Our results highlight the strengths and limitations of different model architectures, providing insights into the application of automated behavior recognition across diverse visual settings. The dataset, models, and code can be accessed at: https://github.com/MitchFuchs/ChimpBehave
tru
Phylogenomic signatures of repeat-induced point mutations across the fungal kingdom
Full text linkFungal genome sizes exhibit more than a 100-fold variation, largely driven by the expansion of repetitive sequences such as transposable elements (TEs). Silencing mechanisms targeting TEs at the epigenetic or transcript level have independently evolved in many lineages. In fungi, repeat-induced point mutation (RIP) targets TEs by recognizing repetitive sequences and inducing mutagenesis. However, the prevalence of RIP across the fungal kingdom and the fidelity of the canonical C-to-T mutation signatures remain unclear. In this study, we address these gaps by tracking shifts in genome architecture across the fungal kingdom. We find that a striking approximately 30-fold increase in genome size within a clade of leotiomycetes is associated with the absence of several RIP-related genes, suggesting a relaxation of genome defense mechanisms during this expansion. To track the impact of genome defenses, we designed a quantitative screen for RIP-like mutation signatures. The phylum of ascomycetes was unique in showing enrichment in mutation signatures in non-coding and repetitive sequences, consistent with a phylogenetically restricted occurrence of RIP-like genome defense systems. Then, we performed a phylogeny-aware association study to identify gene functions associated with RIP-like mutation signatures. We identified a zinc-finger protein as the strongest candidate underpinning a novel mechanism of genome defenses. Our findings reveal the multifaceted drivers of genome defense systems and their close ties to genome size evolution in fungi, particularly in lineages with evidence for recent RIP activity, highlighting how proximate molecular mechanisms can shape genome evolution on deep phylogenetic scales
Spectral ratios and gaps for Steklov eigenvalues of balls with revolution-type metrics
Full text linkModelos epigramáticos en la poesía de Luis Alberto de Cuenca
Full text linkEste artículo examina un poco conocido poema de Luis Alberto de Cuenca : un soneto preliminar a Lope de Vega: el verso y la vida cuyos modelos epigramáticos estudiamos. Tras presentar el poema en cuestión, lo analizamos fijándonos tanto en sus modelos clásicos (la tradición del epigrama, y concretamente del epitafio epigramático basado en deícticos, adverbios y apelativos), por una parte, como en otros ejemplos de estilo epigramático en la obra del autor, por otra. Con este análisis, ponemos de relieve la estructura del poema, su probable inspiración y, sobre todo, su peculiar tono elegíaco, que nos sirve para explicar el uso arcaizante del adverbio «aquí» en los vv. 9 y 12.tru