Mamey (Mammea americana L.) in Martinique Island : un patrimonio para ser valorizados

Introduction. Mamey (Mammea americana L., Clusiaceae) was present in Martini-que before the Spanish colonization. Its distribution area includes tropical America and the Carib-bean. A significant phenotypical diversity is observed on the island, with fruits of very uneven quality as well as various agronomic, pomological and biochemical characteristics. The aim of our work was to localize, identify and characterize trees considered of superior quality. Materials and methods. A survey carried out between April and September 2005 allowed the selection of 10 trees renowned by the people as bearing high-quality fruits. These fruits present a small number of seeds and nonadhesive pulp, and develop a sweet taste as well as a strong flavor. During the year 2006, pomological description and biochemical analysis (total soluble solids and total titrable acidity) were carried out on the fruits. Results and discussion. The biometric and biochemical characteristics measured were generally better than those cited in the literature. Some accessions stand out and present great assets for their promotion for the fresh market as well as for processing. Moreover, some tendencies emerged from the variability observed for a few characters: thus, the variability of the biochemical characteristics measured within one accession, as well as between accessions originating from the same land, is low. It is null for the seed adhesion to the pulp for fruits belonging to the same accession. Conclusion and perspectives. Our work is one of the first relating to identification and characterization of phenotypical diversity of the M. americana L. species, especially in Martinique Island. Our results are likely to pro-mote the development of a diversification network. Some highlighted trends suggest new research to be able to distinguish the role of the environmental versus genetic components in the performance of the phenotypes observed

Phonon effects on x-ray absorption and nuclear magnetic resonance spectroscopies

In material sciences, spectroscopic approaches combining ab initio calculations with experiments are commonly used to accurately analyze the experimental spectral data. Most state-of-the-art first-principle calculations are usually performed assuming an equilibrium static lattice. Yet, nuclear motion affects spectra even when reduced to the zero-point motion at 0 K. We propose a framework based on Density-Functional Theory that includes quantum thermal fluctuations in theoretical X- ray Absorption Near-Edge Structure (XANES) and solid-state Nuclear Magnetic Resonance (NMR) spectroscopies and allows to well describe temperature effects observed experimentally. Within the Born-Oppenheimer and quasi-harmonic approximations, we incorporate the nuclear motion by generating several non-equilibrium configurations from the dynamical matrix. The averaged calculated XANES and NMR spectral data have been compared to experiments in MgO, proof-of-principle compound. The good agreement obtained between experiments and calculations validates the developed approach, which suggests that calculating the XANES spectra at finite temperature by averaging individual non-equilibrium configurations is a suitable approximation. This study high- lights the relevance of phonon renormalization and the relative contributions of thermal expansion and nuclear dynamics on NMR and XANES spectra on a wide range of temperatures.Comment: 13 pages, 6 figures, 1 appendi

Reaching Beyond the Photograph, redefining the Press

Perhaps no technology has done more to alter the visual landscape of modernity than the appearance of photographs within the mass press. This visual landscape has also come to stand at the center of the formation of what we consider ‘global consciousness.’ As historian of photography Gisèle Freund remarked in 1936, ‘Photography opened a window, as it were. The faces of public personalities became familiar and things that happened all over the world were his to share. As the reader’s outlook e..

Au-delà de la photographie, vers une redefinition de la presse

Il est probable qu’aucune technologie n’a autant modifié la culture visuelle moderne que l’apparition de la photographie dans la presse grand public. Ces images se sont progressivement trouvées au cœur de la formation de ce que nous tenons pour une « conscience globale ». En 1936, l’historienne de la photographie Gisèle Freund remarque qu’« avec la photographie, une fenêtre s’ouvre sur le monde. Les visages des personnages publics, les événements qui ont lieu dans le pays même et en dehors de..

From crystalline to amorphous calcium pyrophosphates:a solid state Nuclear Magnetic Resonance perspective

Hydrated calcium pyrophosphates (CPP, Ca2P2O7·nH2O) are a fundamental family of materials among osteoarticular pathologic calcifications. In this contribution, a comprehensive multinuclear NMR (Nuclear Magnetic Resonance) study of four crystalline and two amorphous phases of this family is presented. 1H, 31P and 43Ca MAS (Magic Angle Spinning) NMR spectra were recorded, leading to informative fingerprints characterizing each compound. In particular, different 1H and 43Ca solid state NMR signatures were observed for the amorphous phases, depending on the synthetic procedure used. The NMR parameters of the crystalline phases were determined using the GIPAW (Gauge Including Projected Augmented Wave) DFT approach, based on first-principles calculations. In some cases, relaxed structures were found to improve the agreement between experimental and calculated values, demonstrating the importance of proton positions and pyrophosphate local geometry in this particular NMR crystallography approach. Such calculations serve as a basis for the future ab initio modeling of the amorphous CPP phases. Statement of significance The general concept of NMR crystallography is applied to the detailed study of calcium pyrophosphates (CPP), whether hydrated or not, and whether crystalline or amorphous. CPP are a fundamental family of materials among osteoarticular pathologic calcifications. Their prevalence increases with age, impacting on 17.5% of the population after the age of 80. They are frequently involved or associated with acute articular arthritis such as pseudogout. Current treatments are mainly directed at relieving the symptoms of joint inflammation but not at inhibiting CPP formation nor at dissolving these crystals. The combination of advanced NMR techniques, modeling and DFT based calculation of NMR parameters allows new original insights in the detailed structural description of this important class of biomaterials

Solid-state nuclear magnetic resonance: A valuable tool to explore organic-inorganic interfaces in silica-based hybrid materials

International audienc

Antinuclear factors in murine alloantisera

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65479/1/j.1399-0039.1981.tb01357.x.pd

Controlled antibody release from gelatin for on-chip sample preparation

A practical way to realize on-chip sample preparation for point-of-care diagnostics is to store the required reagents on a microfluidic device and release them in a controlled manner upon contact with the sample. For the development of such diagnostic devices, a fundamental understanding of the release kinetics of reagents from suitable materials in microfluidic chips is therefore essential. Here, we study the release kinetics of fluorophore-conjugated antibodies from (sub-) µm thick gelatin layers and several ways to control the release time. The observed antibody release is well-described by a diffusion model. Release times ranging from ~20 s to ~650 s were determined for layers with thicknesses (in the dry state) between 0.25 µm and 1.5 µm, corresponding to a diffusivity of 0.65 µm2/s (in the swollen state) for our standard layer preparation conditions. By modifying the preparation conditions, we can influence the properties of gelatin to realize faster or slower release. Faster drying at increased temperatures leads to shorter release times, whereas slower drying at increased humidity yields slower release. As expected in a diffusive process, the release time increases with the size of the antibody. Moreover, the ionic strength of the release medium has a significant impact on the release kinetics. Applying these findings to cell counting chambers with on-chip sample preparation, we can tune the release to control the antibody distribution after inflow of blood in order to achieve homogeneous cell staining

Advances in the synthesis and structure of α-canaphite: a multitool and multiscale study

α-Canaphite (CaNa2P2O7·4H2O) is a layered calcium disodium pyrophosphate tetrahydrate phase of significant geological and potential biological interest. This study overcomes the lack of a reliable protocol to synthesize pure α-canaphite by using a novel simple and reproducible approach of double decomposition in solution at room temperature. The pure α-canaphite is then characterized from the atomic to the macroscopic level using a multitool and multiscale advanced characterization strategy, providing for the first time full resolution of the α-canaphite monoclinic structure, including the hydrogen bonding network. Synchrotron X-ray diffraction and neutron diffraction are combined with multinuclear solid state NMR experimental data and computational modeling via DFT/GIPAW calculations. Among the main characteristics of the α-canaphite structure are some strong hydrogen bonds and one of the four water molecules showing a different coordination scheme. This peculiar water molecule could be the last to leave the collapsed structure on heating, leading eventually to anhydrous α-CaNa2P2O7 and could also be involved in the internal hydrolysis of pyrophosphate ions as it is the closest water molecule to the pyrophosphate ions. Relating such detailed structural data on α-canaphite to its physico-chemical properties is of major interest considering the possible roles of canaphite for biomedical applications. The vibrational spectra of α-canaphite (deuterated or not) are analyzed and Raman spectroscopy appears to be a promising tool for the identification/diagnosis of such microcrystals in vitro, in vivo or ex vivo