Can microsatellite data allow identification of oleaster Plio-Pleistocene refuge zones in the Mediterranean Basin?

International audienc

The Joint European Compound Library:boosting precompetitive research

The Joint European Compound Library (JECL) is a new high-throughput screening collection aimed at driving precompetitive drug discovery and target validation. The JECL has been established with a core of over 321000 compounds from the proprietary collections of seven pharmaceutical companies and will expand to around 500000 compounds. Here, we analyse the physicochemical profile and chemical diversity of the core collection, showing that the collection is diverse and has a broad spectrum of predicted biological activity. We also describe a model for sharing compound information from multiple proprietary collections, enabling diversity and quality analysis without disclosing structures. The JECL is available for screening at no cost to European academic laboratories and SMEs through the IMI European Lead Factory (http://www.europeanleadfactory.eu/)

The Value of a virtual Kitchen to assess the activities of Daily life in Alzheimer Disease

Patients with Alzheimer\u27s disease (AD patients) experience difficulties in everyday life activities that effect independence. These difficulties can be tested using virtual reality (VR) environments that simulate real life situations. The purpose of this study was to examine the value of a virtual kitchen as an assessment tool of everyday life activities in AD patients. We focus on the assessment results obtained in a group of AD patients on a virtual kitchen designed to assess their ability to prepare a virtual cup of coffee using a virtual coffee machine. An identical real daily living task was tested. Twenty-four AD patients were matched to 32 healthy elderly controls. Significant differences in performance between research and control groups were detected on the virtual and the real tasks, with the research group performing worse. In addition, regression analyses revealed that the number of errors in the virtual test was the best predictor for the real assessment and the Instrumental Activities of Daily Living score. This provides initial support for the sensitivity and the ecological validity of the virtual kitchen as an assessment tool of everyday life activities in AD patient

Breaking of the Bancroft rule for multiple emulsions stabilized by a single stimulable polymer

International audienceWe investigated emulsions of water and toluene stabilized by (co)polymers consisting of styrene (S) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) monomer units with different compositions and structures such as a PDMAEMA homopolymer, a P(S-co-DMAEMA) random copolymer and various PS-b-PDMAEMA and PS-b-(S-co-DMAEMA) block copolymers. The model system is used to study the fundamental conditions under which the different kinds of polymer-stabilized emulsions (direct oil in water, inverse water in oil and multiple emulsions) are stabilized or destabilized by pH change (at constant temperature). Polymer properties like chain conformation at the toluene-water interface as probed by SANS and neutron reflectivity at the liquid-liquid interface, the oil-water partitioning of the polymer chains (Bancroft's rule of thumb) as determined by UV spectroscopy and interfacial tensions measured by the rising and spinning drop techniques are determined. Overall, results evidence that the curvature sign, as defined by positive and negative values as the chain segments occupy preferentially the water and toluene sides of the interface respectively, reliably predicts the emulsion kind. In contrast, the Bancroft rule failed at foreseeing the emulsion type. In the region of near zero curvature the crossover from direct to inverse emulsions occurs through the formation of either unstable coexisting direct and inverse emulsions (i) or multiple emulsions (ii). The high compact adsorption of the chains at the interface as shown by low interfacial tension values does not allow to discriminate between both cases. However, the toluene-water partitioning of the polymeric emulsifier is still a key factor driving the formation of (i) or (ii) emulsions. Interestingly, the stabilization of the multiple emulsions can be tuned to a large extent as the toluene-water polymer partitioning can be adjusted using quite a large number of physico-chemical parameters linked to polymer architecture like diblock length ratio or polymer total molar mass, for example. Moreover, we show that monitoring the oil-water partitioning aspect of the emulsion system can also be used to lower the interfacial tension at low pH to values slightly higher than 0.01 mN m-1, irrespective of the curvature sign

On the origin of the invasive olives (Olea europaea L., Oleaceae).

The olive tree (Olea europaea) has successfully invaded several regions in Australia and Pacific islands. Two olive subspecies (subspp. europaea and cuspidata) were first introduced in these areas during the nineteenth century. In the present study, we determine the origin of invasive olives and investigate the importance of historical effects on the genetic diversity of populations. Four invasive populations from Australia and Hawaii were characterized using eight nuclear DNA microsatellites, plastid DNA markers as well as ITS-1 sequences. Based on these data, their genetic similarity with native populations was investigated, and it was determined that East Australian and Hawaiian populations (subsp. cuspidata) have originated from southern Africa while South Australian populations (subsp. europaea) have mostly derived from western or central Mediterranean cultivars. Invasive populations of subsp. cuspidata showed significant loss of genetic diversity in comparison to a putative source population, and a recent bottleneck was evidenced in Hawaii. Conversely, invasive populations of subsp. europaea did not display significant loss of genetic diversity in comparison to a native Mediterranean population. Different histories of invasion were inferred for these two taxa with multiple cultivars introduced restoring gene diversity for europaea and a single successful founder event and sequential introductions to East Australia and then Hawaii for cuspidata. Furthermore, one hybrid (cuspidata x europaea) was identified in East Australia. The importance of hybridizations in the future evolution of the olive invasiveness remains to be investigated

Phylogenomics using low-depth whole genome sequencing: a case study with the olive tribe

Species trees have traditionally been inferred from a few selected markers, and genome-wide investigations remain largely restricted to model organisms or small groups of species for which sampling of fresh material is available, leaving out most of the existing and historic species diversity. The genomes of an increasing number of species, including specimens extracted from natural history collections, are being sequenced at low depth. While these datasets are widely used to analyse organelle genomes, the nuclear fraction is generally ignored. Here we evaluate different reference-based methods to infer phylogenies of large taxonomic groups from such datasets. Using the example of the Oleeae tribe, a worldwide-distributed group, we build phylogenies based on single-nucleotide polymorphisms (SNPs) obtained using two reference genomes (the olive and ash trees). The inferred phylogenies are overall congruent, yet present differences that might reflect the effect of the distance to the reference on the amount of missing data. To limit this issue, the genome complexity was reduced by using pairs of orthologous coding sequences as the reference, thus allowing combining SNPs obtained using two distinct references. Concatenated and coalescence trees based on these combined SNPs suggest events of incomplete lineage sorting and/or hybridization during the diversification of this large phylogenetic group. Our results show that genome-wide phylogenetic trees can be inferred from low-depth sequence datasets for eukaryote groups with complex genomes, and histories of reticulate evolution. This opens new avenues for large-scale phylogenomics and biogeographic analyses covering both the extant and historic diversity stored in museum collections