Flora Bellissima, an expert software to discover botany and identify plants

To promote and facilitate access to botany for protecting biodiversity indirectly is the objective of Flora Bellissima. This sofware package is based on an integrated and complete database with numerous fonctionalities, as well as on an expert system of recognition of plants called “Ophélie”. Aimed at beginners, amateurs and experts, Flora Bellissima attempts to show that it is possible to reconcile scientific rigor and popularization, in order to bring together everyone interested in botany

Electronic and physico-chemical properties of nanmetric boron delta-doped diamond structures

Heavily boron doped diamond epilayers with thicknesses ranging from 40 to less than 2 nm and buried between nominally undoped thicker layers have been grown in two different reactors. Two types of [100]-oriented single crystal diamond substrates were used after being characterized by X-ray white beam topography. The chemical composition and thickness of these so-called deltadoped structures have been studied by secondary ion mass spectrometry, transmission electron microscopy, and spectroscopic ellipsometry. Temperature-dependent Hall effect and four probe resistivity measurements have been performed on mesa-patterned Hall bars. The temperature dependence of the hole sheet carrier density and mobility has been investigated over a broad temperature range (6K<T<450 K). Depending on the sample, metallic or non-metallic behavior was observed. A hopping conduction mechanism with an anomalous hopping exponent was detected in the non-metallic samples. All metallic delta-doped layers exhibited the same mobility value, around 3.660.8 cm2/Vs, independently of the layer thickness and the substrate type. Comparison with previously published data and theoretical calculations showed that scattering by ionized impurities explained only partially this low common value. None of the delta-layers showed any sign of confinement-induced mobility enhancement, even for thicknesses lower than 2 nm.14 page

Contributions of experiment designs in photodynamic therapy: photosensitizer design, treatment analysis and optimization.

Abstract published in Photodiagnosis and Photodynamic Therapy, 8(2):137, 2011International audienceIntroduction One of the difficulties in the development of the photodynamic therapy (PDT) is inherent to the multidisciplinary feature of this treatment gathering mainly clinicians, physicists, biologists, and chemists. Another issue is the great number of biophysical and biochemical parameters involved in the design of new photosensitizers as well as in the in vivo application of this treatment. We present a global development approach based on the methodology and tools of experimental design. Three study cases are developed to assess to potential relevance of such an empirical model-based approach for the development of PDT. Methods & Results In a first study, an in vitro screening experimental design was carried out. The addressed question dealt with the determination of influent factors on the phototoxicity of a new photosensitizer based on quantum dots. Five factors were examined: the nature of quantum dots, the excitation light wavelength, the incubation time with cells, the photoactivable compound concentration and the fluence level. Relevance of each factor was finally estimated and compared to identify the significant parameters. In comparison with a typical factorial design, the total number of experiments (42 trials) was divided by 5. In a second study, an in vivo factorial experimental design was applied to detect potential synergic effects between four therapeutic factors: the phenotype of the cancer cell line, the food type, the nature of photosensitizer and the post-injection time, on the in vivo selectivity (cancer/normal tissue) of the tested photosensitizers. Results particularly pointed out the presence of a statistically significant synergic effect between these four factors and provided the optimal modalities to maximize the response in term of tumor-to-normal tissue ratio. In a third study, a Doehlert experimental design associated with a response surface model was used to determine the in vivo PDT modalities (photosensitizer concentration, irradiance and fluence) to both minimize the post-treatment growth rate of the tumor and maximize its growth delay. Only 13 experimental conditions were tested and the relevance of the optimized condition was corroborated by in vivo validation experiments. Conclusion These studies have confirmed the applicability and attractive contributions of experimental design techniques in the development and determination of optimal modalities of new photosensitizers in PDT. Their main advantages are to a priori organize experiments according to specific questions while minimizing the experimental cost and controlling as much as possible the experimental uncertainty

EuReCa ONE—27 Nations, ONE Europe, ONE Registry A prospective one month analysis of out-of-hospital cardiac arrest outcomes in 27 countries in Europe

AbstractIntroductionThe aim of the EuReCa ONE study was to determine the incidence, process, and outcome for out of hospital cardiac arrest (OHCA) throughout Europe.MethodsThis was an international, prospective, multi-centre one-month study. Patients who suffered an OHCA during October 2014 who were attended and/or treated by an Emergency Medical Service (EMS) were eligible for inclusion in the study. Data were extracted from national, regional or local registries.ResultsData on 10,682 confirmed OHCAs from 248 regions in 27 countries, covering an estimated population of 174 million. In 7146 (66%) cases, CPR was started by a bystander or by the EMS. The incidence of CPR attempts ranged from 19.0 to 104.0 per 100,000 population per year. 1735 had ROSC on arrival at hospital (25.2%), Overall, 662/6414 (10.3%) in all cases with CPR attempted survived for at least 30 days or to hospital discharge.ConclusionThe results of EuReCa ONE highlight that OHCA is still a major public health problem accounting for a substantial number of deaths in Europe.EuReCa ONE very clearly demonstrates marked differences in the processes for data collection and reported outcomes following OHCA all over Europe. Using these data and analyses, different countries, regions, systems, and concepts can benchmark themselves and may learn from each other to further improve survival following one of our major health care events

Source depth discrimination using the array invariant

International audienceIn this study, low frequency (0-500 Hz) source depth discrimination in deep water is investigated using a horizontal line array (HLA). In this con- text, propagation is dispersive and can be described by modal theory. Array invariant theory is known to allow source ranging via the modal beam-time migration pattern. This pattern is defined by the evolution of a conventional beamformer output over time. Recently, it has been shown that the array invariant and the waveguide invariant are intrinsically related. In other words, the beam-time migration pattern can be derived using waveguide invariant theory. Utilizing this dependence, we pursue the link between the two invariants to perform source depth discrimination using a HLA. Since the waveguide invariant distribution is strongly related to source depth, the beam-time migration pattern also depends on source depth and would allow for source depth discrimination to be achieved. The proposed method is suc- cessfully applied on simulated data. As the classical array invariant method, it is restricted to short signals, away from the array broadside, but it could be used with minimal environmental knowledge in a multisource context

Dislocation-Induced Birefringence in Silicon Carbide

International audienceThe dislocation-induced birefringence of Silicon Carbide (SiC) is analytically and quantitatively modelled by using the adequate SiC data. A good agreement can be obtained between theory and experiment, provided that a background residual (uniaxial) stress is added to the local dislocation-induced stress. Observations are compatible with or predictable from the Burgers vector values, so that birefringence reveals an interesting tool for probing the nature of the dislocations associated, e.g., to micropipes, also faster than and complementary to the more involved transmission electron microscopy (TEM) technique

Exploring hydrophobic sites in proteins with xenon or krypton

International audienceX-ray diffraction is used to study the binding of xenon and krypton to a variety of crystallised proteins: porcine pancreatic elastase; subtilisin Carlsberg from Bacillus licheniformis; cutinase from Fusarium solani; collagenase from Hypoderma lineatum; hen egg lysozyme, the lipoamide dehydrogenase domain from the outer membrane protein P64k from Neisseria meningitidis; urate-oxidase from Aspergillus flavus, mosquitocidal delta-endotoxin CytB from Bacillus thuringiensis and the ligand-binding domain of the human nuclear retinoid-X receptor RXR-alpha. Under gas pressures ranging from 8 to 20 bar, xenon is able to bind to discrete sites in hydrophobic cavities, ligand and substrate binding pockets, and into the pore of channel-like structures. These xenon complexes can be used to map hydrophobic sites in proteins, or as heavy-atom derivatives in the isomorphous replacement method of structure determination

Rational design of an arene ruthenium chlorin conjugate for in vivo anticancer activity

International audienceA tetranuclear p-cymene ruthenium 5,10,15,20-tetra(3-pyridyl)chlorin complex has been prepared and evaluated in vivo as dual photosensitizer and chemotherapeutic agent on mice bearing an ectopic human oral carcinoma xenograft. The in vivo study was planned using a statistical model. Optimisations of the treatment factors showed that the injected dose was critical, while the light-drug interval, fluence and fluence rate had only a modest impact. The ruthenium-chlorin conjugate was found to accumulate preferentially in the endoplasmic reticulum of KB cells. In addition, a mode of action in vivo dominated by a cytotoxic effect of the complex and not a photodynamic efficiency of the photosensitizer was suggested

A PBP2x from a clinical isolate of Streptococcus pneumoniae exhibits an alternative mechanism for reduction of susceptibility to beta-lactam antibiotics.

International audienceThe human pathogen Streptococcus pneumoniae is one of the main causative agents of respiratory tract infections. At present, clinical isolates of S. pneumoniae often exhibit decreased susceptibility toward beta-lactams, a phenomenon linked to multiple mutations within the penicillin-binding proteins (PBPs). PBP2x, one of the six PBPs of S. pneumoniae, is the first target to be modified under antibiotic pressure. By comparing 89 S. pneumoniae PBP2x sequences from clinical and public data bases, we have identified one major group of sequences from drug-sensitive strains as well as two distinct groups from drug-resistant strains. The first group includes proteins that display high similarity to PBP2x from the well characterized resistant strain Sp328. The second group includes sequences in which a signature mutation, Q552E, is found adjacent to the third catalytic motif. In this work, a PBP2x from a representative strain from the latter group (S. pneumoniae 5259) was biochemically and structurally characterized. Phenotypical analyses of transformed pneumococci show that the Q552E substitution is responsible for most of the reduction of strain susceptibility toward beta-lactams. The crystal structure of 5259-PBP2x reveals a change in polarity and charge distribution around the active site cavity, as well as rearrangement of strand beta3, emulating structural changes observed for other PBPs that confer drug resistance to Gram-positive pathogens. Interestingly, the active site of 5259-PBP2x is in closed conformation, whereas that of Sp328-PBP2x is open. Consequently, S. pneumoniae has evolved to employ the same protein in two distinct mechanisms of antibiotic resistance

Le carnyx et le casque-oiseau celtiques de Tintignac (Naves-Corrèze). Description et étude technologique.: Dossier "Tintignac"

International audienceZwei Gegenstände, die in einer kleinen Grube des gallischen Heiligtums von Tintignac deponiert waren, wurden restauriert und eingehend untersucht. Es handelt sich um eine gallischen Kriegstrompete (oder carnyx) und um einen Helm in Form des Vogels. Ihre Seltenheit (für die Carnyx) oder ihre Einmaligkeit (für den Helm), wie auch ihre komplexe Herstellung verleihen ihnen einen ungewöhnlichen Charakter. Der multidisziplinäre Forschungsansatz der Untersuchung kombiniert mehrere Methoden der Geistes- und Naturwissenschaften, darunter die Restaurierung, die Untersuchung der technologischen Aspekte, die chemischen Analysen, die Erforschung der stilistischen, symbolischen und soziokulturellen Gesichtspunkte, und schließlich die Dokumentation und die Ausstellung. Die beiden untersuchten Objekte sind aus mehreren geschmiedeten und gegossenen Elementen aus Bronze, hergestellt, die durch Weichlöten und Steckverbindungen zusammengefügt wurden. Die archäometallurgischen Analysen haben die genaue Zusammensetzung der Legierungsbestandteile der Bronze bestimmt. Die Trompete hat am oberen Ende die Form eines Wildschweinkopfes, dessen überdimensionierten Ohren Blättern ähneln, während der Helm die Form eines Vogels hat, dessen Haltung an diejenige eines Schwanes erinnert. Diese außerordentlichen Gegenstände konnten während der Kämpfe oder der auf dem Heiligtum ausgeübten Zeremonien benutzt worden sein. Diese zwei außergewöhnlichen Kultobjekte stellen gut den Wunsch der Gallier dar, den Gegner zu beeindrucken, indem ein erschreckender Anblick mit einem betäubenden Lärm vereint wird, so wie es die griechisch-römischen Autoren berichteten.Deux des objets issus d’une petite fosse du sanctuaire gaulois de Tintignac ont fait l’objet d’une restauration et d’un examen approfondi. Il s’agit d’une trompette de guerre gauloise (ou carnyx) et d’un casque en forme d’oiseau. Leur rareté (pour le carnyx) ou leur unicité (pour le casque), comme leur mode de fabrication complexe leur confèrent un caractère exceptionnel. L’approche pluridisciplinaire utilisée combine plusieurs méthodes des sciences humaines et des sciences des matériaux, dont la restauration, l’examen technologique, les études physico-chimiques, les recherches sur les aspects stylistiques, symboliques et socioculturels, et enfin la documentation et l’exposition. Les deux éléments étudiés sont constitués de plusieurs pièces de bronze martelées ou coulées assemblées par brasure ou par emboîtement. L’étude archéométallurgique a permis d’étudier précisément les alliages de bronze qui entraient dans leur composition. La trompette possède au niveau de son pavillon en forme de hure de sanglier, des oreilles démesurées semblables à des feuilles, tandis que le casque prend la forme d’un oiseau dont la posture pourrait évoquer celle d’un cygne. Ces objets extraordinaires pouvaient être utilisés lors des combats ou des cérémonies pratiquées sur le sanctuaire. La volonté des Gaulois d’impressionner l’adversaire en associant une vision frappante à un bruit assourdissant, telle que nous la rapporte les auteurs gréco-romains, est bien illustrée par ces deux objets d’exception