Climate change is expected to modify current ecological conditions sustaining the coexistence of species within cold‐adapted plant communities. It will primarily act upon the existing structure of ...communities, whose response should depend on the functional differences governing coexistence among alpine species. We postulated that a possible trade‐off between (1) plant growth in response to temperature, (2) plant competition and (3) resistance to herbivory, modulates the rate of plant community turnover under climate change.
We reviewed the literature investigating functional traits variability within communities along elevation gradients. Despite environmental filtering, our review indicates that interspecific plant functional variation within communities does not necessarily decrease with elevation. While the diversity of traits related to abiotic affinities or competition are well documented, the variability in species resistance to herbivory within communities is poorly known.
Using a Lotka–Volterra‐based model, we simulated the impact of climate change on plant communities through (1) a direct effect on plant growth and competition and (2) an indirect effect via an increase in herbivore pressure. We showed that different shapes of trade‐offs between temperature‐related growth, competition and resistance to herbivory modulate community turnover under climate change.
We documented the existence of two independent trade‐offs axes using a detailed dataset of functional traits within two alpine grasslands in the European Alps. Plant competitive traits (i.e. leaf area and height) where negatively associated to cold tolerance, whereas traits of the leaf economic spectrum were associated to traits related to the physical resistance to herbivory.
We propose that the immediate effect of climate change on alpine plant communities will depend on existing functional variability and how functional axes trade‐off with each other. Documenting ecological constraints between plant functional axes should provide indications to anticipate winners and losers in alpine plant communities.
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•In Bucharest, future land-use demands can be met regardless of the scenario.•Simulations integrating planning show a non-sustainable loss of agricultural areas.•The mismatch between planning goals ...and demands produces high land consumption.•The method of translating strategic intentions is useful for assessments worldwide.
Urban regions worldwide revert to scenario-based simulations to understand and cope with uncertain land-use changes and future land-use demands. Whereas scenarios account for a variety of driving forces to simulate land change, spatial planning has received limited attention. To improve understanding of the potential contribution of planning to urban land change, we developed and simulated scenarios of development for Bucharest, addressing the local scale, and Bucharest-Ilfov Development Region, addressing the regional scale. The designed scenarios reflect (i) expected future land-use demands for living space, built-up areas, green space and agricultural areas, and (ii) statutory and strategic planning intentions extracted from four spatial plans and weighted based on expert opinion. All scenarios, alongside natural and socioeconomic driving forces, were simulated for both the local and the regional scales using the CLUMondo land-change model. Findings show that all future demands can be met under all scenarios, but that planning will make little contribution. Moreover, simulations highlight that integrating strategic planning intentions would produce a higher loss of agricultural lands than simulations with statutory planning intentions. Consequences of our findings for the role of planning in driving land change at various scales in multi-level planning systems are discussed.
Subjective vertical in presence of visual or auditory cues: Towards an allocentric dependence? The psychological differentiation approach initiated by Witkin and Asch (1948) on the perception of ...verticality yielded the concept of field dependence, through which observers could be distinguished from their tendency to be influenced or not by a visual frame tilt when judging the direction of gravity (i.e., subjective vertical SV). Since, field dependence has been mostly considered as a marker for a preferential sensibility to visual information with respect to other sensory modalities (e.g., vestibular or somatosensory). This pilot study aims at tackling the issue of field dependence in spatial perception from a novel perspective. We hypothesized that orientation cues issued from a same reference frame centered on near surroundings (i.e. allocentric reference frame) could lead to comparable distinctions between observers, whatever the sensory modality involved in conveying these cues. We tested 23 participants on a SV adjustment task facing two allocentric-visual or auditory-scenes. Our results show a strong correlation between SV settings in both sensory conditions where the allocentric scene was tilted. These findings suggest that individuals could differ regarding the process of spatial information issued from a same reference frame, irrespective from the sensory modality conveying the information.
Reçu le 14 décembre 2017, Accepté le 9 septembre 2019 L'étude de la perception de la verticale initiée par Witkin et Asch (1948) a abouti au concept de dépendance à l'égard du champ, distinguant les individus dans leur propension à être influencés par l'inclinaison d'un cadre visuel sur le jugement de la direction gravitaire (i.e., verticale subjective VS). Depuis, cette dépendance est souvent considérée comme révélatrice d'une sensibilité préférentielle aux informations visuelles par rapport à d'autres modalités sensorielles (e.g., vestibulaires ou somesthésiques). Ce travail pilote vise à reconsidérer la notion de dépendance à l'égard du champ dans la perception spatiale. Nous faisons l'hypothèse que des informations d'orientation issues d'un même cadre de référence centré sur l'environnement (i.e., référentiel allocentré) puissent conduire à une distinction comparable entre participants, quelle que soit la modalité sensorielle considérée. Face à deux scènes allocentrées (visuelle et sonore), 23 participants ont été testés sur une tâche d'ajustement de la VS. Nos résultats montrent une forte corrélation entre les ajustements dans les deux conditions sensorielles où la scène allocentrée était inclinée. Ceci suggère que les individus peuvent se différencier dans le traitement des informations spatiales issues d'un même cadre de référence, et ce de la même façon quelle que soit la modalité sensorielle permettant de relayer ces informations. Mots clés : perception spatiale, dépendance à l'égard du champ, cadre de référence, orientation, vision, audition -
L'étude de la perception de la verticale initiée par Witkin et Asch (1948) a abouti au concept de dépendance à l'égard du champ, distinguant les individus dans leur propension à être influencés par ...l'inclinaison d'un cadre visuel sur le jugement de la direction gravitaire (i.e., verticale subjective VS). Depuis, cette dépendance est souvent considérée comme révélatrice d'une sensibilité préférentielle aux informations visuelles par rapport à d'autres modalités sensorielles (e.g., vestibulaires ou somesthésiques). Ce travail pilote vise à reconsidérer la notion de dépendance à l'égard du champ dans la perception spatiale. Nous faisons l'hypothèse que des informations d'orientation issues d'un même cadre de référence centré sur l'environnement (i.e., référentiel allocentré) puissent conduire à une distinction comparable entre participants, quelle que soit la modalité sensorielle considérée. Face à deux scènes allocentrées (visuelle et sonore), 23 participants ont été testés sur une tâche d'ajustement de la VS. Nos résultats montrent une forte corrélation entre les ajustements dans les deux conditions sensorielles où la scène allocentrée était inclinée. Ceci suggère que les individus peuvent se différencier dans le traitement des informations spatiales issues d'un même cadre de référence, et ce de la même façon quelle que soit la modalité sensorielle permettant de relayer ces informations.
To cope with environmental challenges, plants produce a wide diversity of phytochemicals, which are also the source of numerous medicines. Despite decades of research in chemical ecology, we still ...lack an understanding of the organization of plant chemical diversity across species and ecosystems. To address this challenge, we hypothesized that molecular diversity is not only related to species diversity, but also constrained by trophic, climatic, and topographical factors. We screened the metabolome of 416 vascular plant species encompassing the entire alpine elevation range and four alpine bioclimatic regions in order to characterize their phytochemical diversity. We show that by coupling phylogenetic information, topographic, edaphic, and climatic variables, we predict phytochemical diversity, and its inherent composition, of plant communities throughout landscape. Spatial mapping of phytochemical diversity further revealed that plant assemblages found in low to midelevation habitats, with more alkaline soils, possessed greater phytochemical diversity, whereas alpine habitats possessed higher phytochemical endemism. Altogether, we present a general tool that can be used for predicting hotspots of phytochemical diversity in the landscape, independently of plant species taxonomic identity. Such an approach offers promising perspectives in both drug discovery programs and conservation efforts worldwide.
Pro-survival stress-inducible chaperone HSP110 is the only HSP for which a mutation has been found in a cancer. Multicenter clinical studies demonstrated a direct association between HSP110 ...inactivating mutation presence and excellent prognosis in colorectal cancer patients. Here, we have combined crystallographic studies on human HSP110 and in silico modeling to identify HSP110 inhibitors that could be used in colorectal cancer therapy. Two molecules (foldamers 33 and 52), binding to the same cleft of HSP110 nucleotide-binding domain, were selected from a chemical library (by co-immunoprecipitation, AlphaScreening, Interference-Biolayer, Duo-link). These molecules block HSP110 chaperone anti-aggregation activity and HSP110 association to its client protein STAT3, thereby inhibiting STAT3 phosphorylation and colorectal cancer cell growth. These effects were strongly decreased in HSP110 knockdown cells. Foldamer's 33 ability to inhibit tumor growth was confirmed in two colorectal cancer animal models. Although tumor cell death (apoptosis) was noted after treatment of the animals with foldamer 33, no apparent toxicity was observed, notably in epithelial cells from intestinal crypts. Taken together, we identified the first HSP110 inhibitor, a possible drug-candidate for colorectal cancer patients whose unfavorable outcome is associated to HSP110.
Aims
Little is yet known about the component traits that control the deployment of root architecture in most grassland species. The aim of this study was to compare patterns of root growth in ...contrasting forage legumes and to analyse their dependency to shoot development.
Methods
The parameters of a dynamic simulation model were identified for seven contrasting species in a series of greenhouse experiments in order to characterize root elongation, root branching and taproot growth. The model allowed us to explore the interactions between root development and whole plant growth.
Results
Most of the root morphogenetic parameters studied displayed significant inter-specific variability. Several traits appeared to be correlated, indicating a close association between extreme root tip diameters, the branching ability of roots and their maximal elongation rate. The species differed along two PCA axes which accounted respectively for the branching ability of fine roots and taproot development. Quite remarkably, the group of species identified for root development did not coincide with those previously identified for shoots, suggesting a degree of independence between the morphogenetic traits that control shoot and root architecture. However, both plant parts remained tightly linked through the trophic relationship represented by root biomass allocation.
Conclusions
Our results suggest that the concomitant analysis of root and shoot development is necessary to properly decipher rooting strategies in forage legumes.
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