281 research outputs found
Invest to Save: Report and Recommendations of the NSF-DELOS Working Group on Digital Archiving and Preservation
Digital archiving and preservation are important areas for research and development, but there is no agreed upon set of priorities or coherent plan for research in this area. Research projects in this area tend to be small and driven by particular institutional problems or concerns. As a consequence, proposed solutions from experimental projects and prototypes tend not to scale to millions of digital objects, nor do the results from disparate projects readily build on each other. It is also unclear whether it is worthwhile to seek general solutions or whether different strategies are needed for different types of digital objects and collections. The lack of coordination in both research and development means that there are some areas where researchers are reinventing the wheel while other areas are neglected.
Digital archiving and preservation is an area that will benefit from an exercise in analysis, priority setting, and planning for future research. The WG aims to survey current research activities, identify gaps, and develop a white paper proposing future research directions in the area of digital preservation. Some of the potential areas for research include repository architectures and inter-operability among digital archives; automated tools for capture, ingest, and normalization of digital objects; and harmonization of preservation formats and metadata. There can also be opportunities for development of commercial products in the areas of mass storage systems, repositories and repository management systems, and data management software and tools.
Charge Transfer and Tunable Ambipolar Effect Induced by Assembly of Cu (II) Binuclear Complexes on Carbon Nanotube Field Effect Transistor Devices
International audienceAssembly of paramagnetic Cu2 complexes with a Schiff base scaffold possessing extended electron delocalization together with a quasi-planar structure onto carbon nanotubes induces a diameter-selective charge transfer from the complex to the nanotubes leading to an interestingly large and tunable ambipolar effect. We used complementary techniques such as electron paramagnetic resonance, absorption spectroscopy, and photoluminescence to ensure the success of the assembly process and the integrity of the complex in the nanohybrid. We carried out density functional theory type calculations to rationalize the experimental results,evidencing the selective enhanced interaction of the metal complexes with one type of nanotube
Xq27 FRAXA locus is a strong candidate for dyslexia: evidence from a genome-wide scan in French families.
Dyslexia is a frequent neurodevelopmental
learning disorder. To date, nine susceptibility loci have
been identified, one of them being DYX9, located in Xq27.
We performed the first French SNP linkage study followed
by candidate gene investigation in dyslexia by studying 12
multiplex families (58 subjects) with at least two children
affected, according to categorical restrictive criteria for
phenotype definition. Significant results emerged on
Xq27.3 within DYX9. The maximum multipoint LOD
score reached 3,884 between rs12558359 and rs454992.
Within this region, seven candidate genes were investigated
for mutations in exonic sequences (CXORF1,
CXORF51, SLITRK2, FMR1, FMR2, ASFMR1, FMR1NB),
all having a role during brain development. We further
looked for 50
UTR trinucleotide repeats in FMR1 and FMR2
genes. No mutation or polymorphism co-segregating with
dyslexia was found. This finding in French families with
Dyslexia showed significant linkage on Xq27.3 enclosing
FRAXA, and consequently confirmed the DYX9 region as
a robust susceptibility locus. We reduced the previously
described interval from 6.8 (DXS1227–DXS8091) to 4 Mb
also disclosing a higher LOD score
International equatorial electrojet year : the African sector
International audienceThis paper presents the IEEY project in the African sector. The amount of our interpreted data is presently too short to allow proper scientific conclusions. Nevertheless, fist typical results illustrate our network possibilities. Some preliminary observations are briefly pre- , sented for their interest towards immediate research goals
Tuning bilayer twist using chiral counterions
From seashells to DNA, chirality is expressed at every level of biological structures. In self-assembled structures it may emerge cooperatively from chirality at the molecular scale. Amphiphilic molecules, for example, can form a variety of aggregates and mesophases that express the chirality of their constituent molecules at a supramolecular scale of micrometres (refs 1-3), Quantitative prediction of the large-scale chirality based on that at the molecular scale remains a largely unsolved problem. Furthermore, experimental control over the expression of chirality at the supramolecular level is difficult to achieve(4-7): mixing of different enantiomers usually results in phase separation(18). Here we present an experimental and theoretical description of a system in which chirality can be varied continuously and controllably ('tuned') in micrometre-scale structures. we observe the formation of twisted ribbons consisting of bilayers of gemini surfactants (two surfactant molecules covalently linked at their charged head groups). We find that the degree of twist and the pitch of the ribbons can be tuned by the introduction of opposite-handed chiral counterions in various proportions. This degree of control might be of practical value; for example, in the use of the helical structures as templates for helical crystallization of macromolecules(8,9).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62619/1/399566a0.pd
Electrical activity-triggered glucagon-like peptide-1 secretion from primary murine L-cells
Glucagon like peptide 1 (GLP-1) based therapies are now widely used for the treatment of type 2 diabetes. Developing our understanding of intestinal GLP-1 release may facilitate the development of new therapeutics aimed at targeting the GLP-1 producing L-cells. This study was undertaken to characterise the electrical activity of primary L-cells and the importance of voltage gated sodium and calcium channels for GLP-1 secretion. Primary murine L-cells were identified and purified using transgenic mice expressing a fluorescent protein driven by the proglucagon promoter. Fluorescent L-cells were identified within primary colonic cultures for patch clamp recordings. GLP-1 secretion was measured from primary colonic cultures. L-cells purified by flow cytometry were used to measure gene expression by microarray and quantitative RT-PCR. Electrical activity in L-cells was due to large voltage gated sodium currents, inhibition of which by tetrodotoxin reduced both basal and glutamine-stimulated GLP-1 secretion. Voltage gated calcium channels were predominantly of the L-type, Q-type and T-type, by expression analysis, consistent with the finding that GLP-1 release was blocked both by nifedipine and ω-conotoxin MVIIC. We observed large voltage-dependent potassium currents, but only a small chromanol sensitive current that might be attributable to KCNQ1. GLP-1 release from primary L-cells is linked to electrical activity and activation of L-type and Q-type calcium currents. The concept of an electrically excitable L-cell provides a basis for understanding how GLP-1 release may be modulated by nutrient, hormonal and pharmaceutical stimuli
<i>Gaia</i> Data Release 1. Summary of the astrometric, photometric, and survey properties
Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7.
Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release.
Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue.
Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the HIPPARCOS and Tycho-2 catalogues – a realisation of the Tycho-Gaia Astrometric Solution (TGAS) – and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of ∼3000 Cepheid and RR-Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr−1 for the proper motions. A systematic component of ∼0.3 mas should be added to the parallax uncertainties. For the subset of ∼94 000 HIPPARCOS stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr−1. For the secondary astrometric data set, the typical uncertainty of the positions is ∼10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to ∼0.03 mag over the magnitude range 5 to 20.7.
Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data
‘Sometimes there’s racism towards the French here’: xenophobic microaggressions in pre-2016 London as articulations of symbolic violence
This article discusses xenophobic microaggressions (Pierce, 1970) experienced by members of the French community in London prior to the EU-Membership Referendum in 2016. Acting at the interface of agency and passivity, implicitness and complicity, they go unseen in the social space despite their omnipresence. Through a close reading of empirical data collected as part of an ethnographic study, the article posits that these microaggressions are articulations of historically embedded anti-French ‘symbolic violence’ (Bourdieu and Wacquant, 1992; Bourdieu, 1993). The three main areas addressed are humour, intersectionality and the reproductive nature of the phenomenon (Bourdieu and Passeron, 1970; Bourdieu, 1972)
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