MALDI/MS peptide mass fingerprinting for proteome analysis: identification of hydrophobic proteins attached to eucaryote keratinocyte cytoplasmic membrane using different matrices in concert

BACKGROUND: MALDI-TOF-MS has become an important analytical tool in the identification of proteins and evaluation of their role in biological processes. A typical protocol consists of sample purification, separation of proteins by 2D-PAGE, enzymatic digestion and identification of proteins by peptide mass fingerprint. Unfortunately, this approach is not appropriate for the identification of membrane or low or high pI proteins. An alternative technique uses 1D-PAGE, which results in a mixture of proteins in each gel band. The direct analysis of the proteolytic digestion of this mixture is often problematic because of poor peptide detection and consequent poor sequence coverage in databases. Sequence coverage can be improved through the combination of several matrices. RESULTS: The aim of this study was to trust the MALDI analysis of complex biological samples, in order to identify proteins that interact with the membrane network of keratinocytes. Peptides obtained from protein trypsin digestions may have either hydrophobic or hydrophilic sections, in which case, the direct analysis of such a mixture by MALDI does not allow desorbing of all peptides. In this work, MALDI/MS experiments were thus performed using four different matrices in concert. The data were analysed with three algorithms in order to test each of them. We observed that the use of at least two matrices in concert leads to a twofold increase of the coverage of each protein. Considering data obtained in this study, we recommend the use of HCCA in concert with the SA matrix in order to obtain a good coverage of hydrophilic proteins, and DHB in concert with the SA matrix to obtain a good coverage of hydrophobic proteins. CONCLUSION: In this work, experiments were performed directly on complex biological samples, in order to see systematic comparison between different matrices for real-life samples and to show a correlation that will be applicable to similar studies. When 1D gel is needed, each band may contain a great number of proteins, each present in small amounts. To improve the proteins coverage, we have performed experiments with some matrices in concert. These experiments enabled reliable identification of proteins, without the use of Nanospray MS/MS experiments

Clone-Dependent Expression of Esca Disease Revealed by Leaf Metabolite Analysis

Grapevine trutk diseases, especially Esca, are of major concern since they gradually alter vineyards worldwide and cause heavy economic losses. The expression of Esca disease symptoms depends on several factors, including the grapevine cultivar. In this context, a possible clone-dependent expression of the Esca disease was studied. Two clones of ‘Chardonnay’ grown in the same plot were compared according to their developmental and physiological traits, metabolome, and foliar symptom expression. Analysis of their leaf metabolome highlighted differences related to symptom expression. Interestingly, the content of a few specific metabolites exhibited opposite variations in leaves of symptomatic shoots of clones 76 and 95. Altogether this study showed a clone-dependent expression of Esca disease in ‘Chardonnay’ and the relevance of GC-MS and 3D fluorescence methods to analyze the impact of the disease on the leaf metabolome

Immunosenescence patterns differ between populations but not between sexes in a long-lived mammal

International audienceIn animals, physiological mechanisms underlying reproductive and actuarial senescence remain poorly understood. Immunosenescence, the decline in the ability to display an efficient immune response with increasing age, is likely to influence both reproductive and actuarial senescence through increased risk of disease. Evidence for such a link has been reported from laboratory animal models but has been poorly investigated in the wild, where variation in resource acquisitions usually drives life-history tradeoffs. We investigated immunosenescence patterns over 7 years in both sexes of two contrasting roe deer populations (Capreolus capreolus). We first measured twelve immune markers to obtain a thorough identification of innate and adaptive components of immunity and assessed, from the same individuals, the age-dependent variation observed in parasitic infections. Although the level of innate traits was maintained at old age, the functional innate immune traits declined with increasing age in one of two populations. In both populations, the production of inflammatory markers increased with advancing age. Finally, the adaptive response declined in late adulthood. The increasing parasite burden with age we reported suggests the effective existence of immunosenescence. Age-specific patterns differed between populations but not between sexes, which indicate that habitat quality could shape agedependent immune phenotype in the wild

Reception Test of Petals for the End Cap TEC+ of the CMS Silicon Strip Tracker

The silicon strip tracker of the CMS experiment has been completed and was inserted into the CMS detector in late 2007. The largest sub system of the tracker are its end caps, comprising two large end caps (TEC) each containing 3200 silicon strip modules. To ease construction, the end caps feature a modular design: groups of about 20 silicon modules are placed on sub-assemblies called petals and these self-contained elements are then mounted onto the TEC support structures. Each end cap consists of 144 such petals, which were built and fully qualified by several institutes across Europe. Fro

Integration of the End Cap TEC+ of the CMS Silicon Strip Tracker

The silicon strip tracker of the CMS experiment has been completed and inserted into the CMS detector in late 2007. The largest sub-system of the tracker is its end cap system, comprising two large end caps (TEC) each containing 3200 silicon strip modules. To ease construction, the end caps feature a modular design: groups of about 20 silicon modules are placed on sub-assemblies called petals and these self-contained elements are then mounted into the TEC support structures. Each end cap consists of 144 petals, and the insertion of these petals into the end cap structure is referred to as TEC integration. The two end caps were integrated independently in Aachen (TEC+) and at CERN (TEC--). This note deals with the integration of TEC+, describing procedures for end cap integration and for quality control during testing of integrated sections of the end cap and presenting results from the testing

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

Le système Marius : rétro-ingénierie d'un SAGT - VRU

Le présent document doit être considéré comme un « retour d'expérience », récolement de l'ensemble des fonctions du système Marius pour l'exploitation des autoroutes de Marseille. Il est présenté comme un Cahier des Clauses Techniques Particulières, assorti de nombreux commentaires, parfois subjectifs, mais toujours argumentés, de façon à être utile aux Maîtres d'Ouvrage autant qu'aux Maîtres d’œuvre d'opérations d'exploitation dynamique.Le système Marius comprend les matériels informatiques et les logiciels (environ 200 000 lignes de code applicatif) qui permettent de piloter automatiquement ou manuellement environ 300 équipements de terrain répartis sur 150 km de chaussée (Recueils de données, Panneaux variables, Caméras, Réseau d'Appel d'Urgence, Tunnels, Bassins de rétention), et d’assurer l'aide aux opérateurs dans toutes leurs tâches de concentration/routage des informations événementielles.Les annexes du document spécifient dans le détail les données et leurs formats

Mise en place d’un inventaire spécifique du hibou des marais pour le Québec

Les populations nord-américaines du hibou des marais (Asio flammeus) sont en déclin depuis les années 1970 et le statut de l’espèce préoccupe plusieurs administrations. Les inventaires traditionnels représentent mal les patrons d’abondance de cette espèce, à cause de son comportement nomade. L’objectif de l’étude était de développer et de mettre en place un programme d’inventaire spécifique à l’espèce afin de documenter sa présence sur le territoire. Au Québec, le Saguenay–Lac-Saint-Jean semble être une région propice à la nidification de l’espèce. Nous avons sélectionné les sites d’observation en combinant les observations historiques avec les données sur les cultures fourragères. Nous avons réalisé 2 phases d’inventaire par site, de 3 visites chacune. En 2012, 7 des 8 sites étaient occupés durant la phase de migration et de formation des couples, contre 3 sur 9 l’année suivante. Durant la phase de nidification, 3 sites sur 8 étaient occupés en 2012 et 1 des 9 sites l’était en 2013. Nos résultats indiquent que la méthodologie permet de maximiser la détection de l’espèce. Deux visites par phase semblent toutefois suffisantes pour détecter la présence de l’espèce dans 1 site. Enfin, par l’intermédiaire de ce projet, les ornithologues amateurs et les agriculteurs contribuent à la préservation de l’espèce.The short-eared owl (Asio flammeus) population in North America has been declining since the 1970s and the species is of special conservation concern to several jurisdictions. Due to the nomadic nature of this species, existing survey methods are poorly adapted to determining its presence and to providing population trends. The goal of the present study was to develop and deploy a survey specifically aimed at detecting short-eared owls. The Saguenay–Lac-Saint-Jean region of Québec, which contains many suitable nesting areas for this species, was chosen for the pilot study. The location of potential survey sites was determined by combining historical observations with current agricultural land use data pertaining to forage crops. Three surveys were conducted during the migration and pair formation period, and again during the nesting period. In 2012, 7 of the 8 selected sites were occupied during the migration and pair formation period, compared to 3 out of the 9 selected sites visited in 2013. In 2012, 3 of the 8 selected sites were occupied during the nesting period, compared to 1 out of 9 in 2013. Our results show that the species-specific survey method developed maximizes the possibility of detecting short-eared owls. However, 2 visits per period were sufficient to detect the presence of the species at a given site. This project highlights how birders and farmers can make a valuable contribution to conservation efforts