Environment and phenology shape local adaptation in thermal performance

Populations within species often exhibit variation in traits that reflect local adaptation and further shape existing adaptive potential for species to respond to climate change. However, our mechanistic understanding of how the environment shapes trait variation remains poor. Here, we used common garden experiments to quantify thermal performance in eight populations of the marine snail Urosalpinx cinerea across thermal gradients on the Atlantic and the Pacific coasts of North America. We then evaluated the relationship between thermal performance and environmental metrics derived from time-series data. Our results reveal a novel pattern of ‘mixed’ trait performance adaptation, where thermal optima were positively correlated with spawning temperature (cogradient variation), while maximum trait performance was negatively correlated with season length (countergradient variation). This counterintuitive pattern probably arises because of phenological shifts in the spawning season, whereby ‘cold’ populations delay spawning until later in the year when temperatures are warmer compared to ‘warm’ populations that spawn earlier in the year when temperatures are cooler. Our results show that variation in thermal performance can be shaped by multiple facets of the environment and are linked to organismal phenology and natural history. Understanding the impacts of climate change on organisms, therefore, requires the knowledge of how climate change will alter different aspects of the thermal environment

French consumer preferences reveal a potential for segmentation in carrot

Gustatory differentiation is one possible means of segmentation. Consumer preferences of carrot were studied within the framework of the CosiVeg project. The characteristics of batches offered for consumer assessment enables their preferences to be evaluated. In preparation for a hedonic test of raw grated carrots that was carried out in autumn 2011, the carrot sensory space was studied in 2010 using 48 batches that were evaluated using quantative descriptive sensory analysis. The cultivars were representative of different types, Nantais, Imperator, Flakkee, coloured carrots and genetic resources. . Significant differences were observed for all criteria, allowing varieties to be grouped based on their sensory characteristics. Texture, flavor and aroma contribute to the “identity” of carrots. Overall aroma is correlated with perceptions of bitterness, sharpness and chemical aroma. Fourteen orange carrot varieties were selected for sowing in 2011. In 2010, although maximum scores were obtained for pungent and bitter attributes, this was not the case in 2011. In spite of this, the selected batches allowed the different profiles of the sensory characteristics of the carrots to be determined. Ten batches of carrot that represented a wide range of variability were tasted by a trained panel as well as a consumer panel; the product was presented as raw grated carrot. The sensory measurements obtained were used to map preferences, underlining preferences for a carrot that is juicy, aromatic and sweet. However bitter and chemical flavour carrots were not appreciated. Three types of consumer exist each having different expectations in terms of quality. Almost 20 % of people questioned are looking for a high quality product, for 33 % of consumers carrots are a staple food and they have no specific expectations and 48 % are satisfied with the current product but are potentially interested by a product that would distinguish itself as regards to quality. It means that segmentation with a high gustatory quality will be of interest for one consumer for 5

Diminished warming tolerance and plasticity in low-latitude populations of a marine gastropod

Models of species response to climate change often assume that physiological traits are invariant across populations. Neglecting potential intraspecific variation may overlook the possibility that some populations are more resilient or susceptible than others, creating inaccurate predictions of climate impacts. In addition, phenotypic plasticity can contribute to trait variation and may mediate sensitivity to climate. Quantifying such forms of intraspecific variation can improve our understanding of how climate can affect ecologically important species, such as invasive predators. Here, we quantified thermal performance (tolerance, acclimation capacity, developmental traits) across seven populations of the predatory marine snail (Urosalpinx cinerea) from native Atlantic and non-native Pacific coast populations in the USA. Using common garden experiments, we assessed the effects of source population and developmental acclimation on thermal tolerance and developmental traits of F1 snails. We then estimated climate sensitivity by calculating warming tolerance (thermal tolerance − habitat temperature), using field environmental data. We report that low-latitude populations had greater thermal tolerance than their high latitude counterparts. However, these same low-latitude populations exhibited decreased thermal tolerance when exposed to environmentally realistic higher acclimation temperatures. Low-latitude native populations had the greatest climate sensitivity (habitat temperatures near thermal limits). In contrast, invasive Pacific snails had the lowest climate sensitivity, suggesting that these populations are likely to persist and drive negative impacts on native biodiversity. Developmental rate significantly increased in embryos sourced from populations with greater habitat temperature but had variable effects on clutch size and hatching success. Thus, warming can produce widely divergent responses within the same species, resulting in enhanced impacts in the non-native range and extirpation in the native range. Broadly, our results highlight how intraspecific variation can alter management decisions, as this may clarify whether management efforts should be focused on many or only a few populations

Improving the quantification of land cover pressure on stream ecological status at the riparian scale using High Spatial Resolution Imagery

The aim of this paper is to demonstrate the interest of High Spatial Resolution Imagery (HSRI) and the limits of coarse land cover data such as CORINE Land Cover (CLC), for the accurate characterization of land cover structure along river corridors and of its functional links with freshwater ecological status on a large scale. For this purpose, we compared several spatial indicators built from two land cover maps of the Herault river corridor (southern France): one derived from the CLC database, the other derived from HSRI. The HSRI-derived map was obtained using a supervised object-based classification of multi-source remotely-sensed images (SPOT 5 XS-10 m and aerial photography-0.5 m) and presents an overall accuracy of 70 %. The comparison between the two sets of spatial indicators highlights that the HSRI-derived map allows more accuracy in the quantification of land cover pressures near the stream: the spatial structure of the river landscape is finely resolved and the main attributes of riparian vegetation can be quantified in a reliable way. The next challenge will consist in developing an operational methodology using HSRI for large-scale mapping of river corridor land cover,, for spatial indicator computation and for the development of related pressure/impact models, in order to improve the prediction of stream ecological status

Simulation of cellular irradiation with the CENBG microbeam line using GEANT4

Light-ion microbeams provide a unique opportunity to irradiate biological samples at the cellular level and to investigate radiobiological effects at low doses of high LET ionising radiation. Since 1998 a single-ion irradiation facility has been developed on the focused horizontal microbeam line of the CENBG 3.5 MV Van de Graaff accelerator. This setup delivers in air single protons and alpha particles of a few MeV onto cultured cells, with a spatial resolution of a few microns, allowing subcellular targeting. In this paper, we present results from the use of the GEANT4 toolkit to simulate cellular irradiation with the CENBG microbeam line, from the entrance to the microprobe up to the cellular medium.Comment: 6 pages, 8 figures, presented at the 2003 IEEE-NSS conference, Portland, OR, USA, October 20-24, 200

Compensatory embryonic response to allele-specific inactivation of the murine X-linked gene Hcfc1.

Early in female mammalian embryonic development, cells randomly inactivate one of the two X chromosomes to achieve overall equal inactivation of parental X-linked alleles. Hcfc1 is a highly conserved X-linked mouse gene that encodes HCF-1 - a transcriptional co-regulator implicated in cell proliferation in tissue culture cells. By generating a Cre-recombinase inducible Hcfc1 knock-out (Hcfc1(lox)) allele in mice, we have probed the role of HCF-1 in actively proliferating embryonic cells and in cell-cycle re-entry of resting differentiated adult cells using a liver regeneration model. HCF-1 function is required for both extraembryonic and embryonic development. In heterozygous Hcfc1(lox/+) female embryos, however, embryonic epiblast-specific Cre-induced Hcfc1 deletion (creating an Hcfc1(epiKO) allele) around E5.5 is well tolerated; it leads to a mixture of HCF-1-positive and -negative epiblast cells owing to random X-chromosome inactivation of the wild-type or Hcfc1(epiKO) mutant allele. At E6.5 and E7.5, both HCF-1-positive and -negative epiblast cells proliferate, but gradually by E8.5, HCF-1-negative cells disappear owing to cell-cycle exit and apoptosis. Although generating a temporary developmental retardation, the loss of HCF-1-negative cells is tolerated, leading to viable heterozygous offspring with 100% skewed inactivation of the X-linked Hcfc1(epiKO) allele. In resting adult liver cells, the requirement for HCF-1 in cell proliferation was more evident as hepatocytes lacking HCF-1 fail to re-enter the cell cycle and thus to proliferate during liver regeneration. The survival of the heterozygous Hcfc1(epiKO/+) female embryos, even with half the cells genetically compromised, illustrates the developmental plasticity of the post-implantation mouse embryo - in this instance, permitting survival of females heterozygous for an X-linked embryonic lethal allele

Rapidly assessing the risks of infectious diseases to wildlife species

Predicting the likelihood of rare events is increasingly demanded by risk managers. A key challenge is dealing with different types of uncertainty, including epistemic uncertainties (lack of knowledge), stochasticity (inherent randomness) and natural variation. One potentially catastrophic event which is impacted by high levels of all three of these uncertainty types is the transmission of livestock pathogens to wildlife, particularly for endangered species. There is often a lack of basic information, e.g. about a given pathogen's presence in local livestock populations or the susceptibility of a given wildlife species to infection by the pathogen. We adapted the OIE (World Organisation for Animal Health) risk assessment framework to rapidly assess and prioritize the risks of livestock pathogens for wildlife, taking account of epistemic uncertainties, stochasticity, seasonal movement of animals and interaction between different species at different spatial and temporal scales. We demonstrate the approach using the endangered saiga antelope (Saiga tatarica tatarica) as a case study. We conclude that, in general, transmission events are likely to be rare and limited to small geographical areas; however, their impact could be high. Brucella spp. and foot-and-mouth disease virus are among those most likely to be transmitted from livestock to the Betpak-Dala saiga population

Qualité organoleptique de la carotte : variabilité des critères sensoriels selon le type variétal

La différenciation gustative est une voie possible de segmentation. L\u27étude a porté sur la variabilité des critères sensoriels dans le matériel végétal. Trente-trois varié - tés des types Nantais, Imperator, Flakkee, de carottes de couleur et de ressources génétiques ont été caractérisées en analyse sensorielle descriptive quantitative et par des mesures physico-chimiques. Des différences significatives pour tous les critères existent et permettent de regrouper les variétés sur la base de leurs caractéristiques sensorielles. Texture, saveur et arôme contribuent à la typicité de la carotte ; l\u27arôme global est corrélé aux perceptions d\u27amer, de piquant et d\u27arôme chimique. La mesure des sucres ne permet pas d\u27évaluer la perception en bouche du sucre du fait de l\u27influence du potentiel d\u27amertume