252 research outputs found
Applied Statistical Genetics with R for Population-Based Association Studies
Abstracts not available for BookReview
Programmable multimetallic linear nanoassemblies of ruthenium–DNA conjugates
A new ruthenium–DNA conjugates family was synthesized, made up of a ruthenium complex bound to one or two identical DNA strands of 14–58 nucleotides. The formation of controlled linear nanoassemblies containing one to seven ruthenium complexes is described
Imaging genetics: bio-informatics and bio-statistics challenges
International audienceThe IMAGEN study -- a very large European Research Project -- seeks to identify and characterize biological and environmental factors that in uence teenagers mental health. To this aim, the consortium plans to collect data for more than 2000 subjects at 8 neuroimaging centres. These data comprise neuroimaging data, behavioral tests (for up to 5 hours of testing), and also white blood samples which are collected and processed to obtain 650k single nucleotide polymorphisms (SNP) per subject. Data for more than 1000 subjects have already been collected. We describe the statistical aspects of these data and the challenges, such as the multiple comparison problem, created by such a large imaging genetics study (i.e., 650k for the SNP, 50k data per neuroimage).We also suggest possible strategies, and present some rst investigations using uni or multi-variate methods in association with re-sampling techniques. Specically, because the number of variables is very high, we rst reduce the data size and then use multivariate (CCA, PLS) techniques in association with re-sampling techniques
Solid-state single photon sources: the nanowire antenna
International audienceWe design several single-photon-sources based on the emission of a quantum dot embedded in a semiconductor (GaAs) nanowire. Through various taper designs, we engineer the nanowire ends to realize efficient metallic-dielectric mirrors and to reduce the divergence of the far-field radiation diagram. Using fully-vectorial calculations and a comprehensive Fabry-Perot model, we show that various realistic nanowire geometries may act as nanoantennas (volume of ≈0.05 λ3) that assist funnelling the emitted photons into a single monomode channel. Typically, very high extraction efficiencies above 90% are predicted for a collection optics with a numerical aperture NA=0.85. In addition, since no frequency-selective effect is used in our design, this large efficiency is achieved over a remarkably broad spectral range, 70 nm at λ=950 nm
Prediction and experimental evidence of the optimisation of the angular branching process in the thallus growth of Podospora anserina
Based upon apical growth and hyphal branching, the two main processes that
drive the growth pattern of a fungal network, we propose here a two-dimensions
simulation based on a binary-tree modelling allowing us to extract the main
characteristics of a generic thallus growth. In particular, we showed that, in
a homogeneous environment, the fungal growth can be optimized for exploration
and exploitation of its surroundings with a specific angular distribution of
apical branching. Two complementary methods of extracting angle values have
been used to confront the result of the simulation with experimental data
obtained from the thallus growth of the saprophytic filamentous fungus
Podospora anserina. Finally, we propose here a validated model that, while
being computationally low-cost, is powerful enough to test quickly multiple
conditions and constraints. It will allow in future works to deepen the
characterization of the growth dynamic of fungal network, in addition to
laboratory experiments, that could be sometimes expensive, tedious or of
limited scope.Comment: Submitted to Scientific Repor
Near-field spectroscopy of low-loss waveguide integrated microcavities
International audienceA scanning near-field spectroscopy method is used to observe loss reduction and Q-factor enhancement due to transverse-mode profile matching within photonic-crystal microcavities. Near-field measurements performed directly on cavity modes are compared with three-dimensional calculations and quantitative agreement is observed. (c) 2006 American Institute of Physics
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