1,543 research outputs found
DNA bending and the curious case of Fos/Jun
DNA bending has been implicated as an important regulatory mechanism in several processes involving protein—DNA interactions. Various methods for examining intrinsic and protein-induced DNA bending may lead to different conclusions. For the Fos and Jun transcription factors, this has resulted in controversy over whether these factors significantly bend DNA at all
Influential publications in ecological economics revisited
We revisit the analysis of Costanza et al. (2004, Ecological Economics) of influential publications in ecological economics
to discover what has changed a decade on. We examine which sources have been influential on the field
of ecological economics in the past decade, which articles in the journal Ecological Economics have had the most
influence on the field and on the rest of science, and on which areas of science the journal is having the most in-
fluence.We find that the field has matured over this period, with articles published in the journal having a greater
influence than before, an increase in citation links to environmental studies journals, a reduction in citation links
to mainstream economics journals, and possibly a shift in themes to a more applied and empirical direction.Copyright Information: © 2016 Elsevier B.V. http://www.sherpa.ac.uk/romeo/issn/0921-8009/..."Authors pre-print on any website, including arXiv and RePEC" from SHERPA/RoMEO site (as at 3/02/16)
Aspects géométriques de la fonte des flocons de neige
La fonte des flocons de neige nous permet de témoigner d'un phénomène capillaire d'une richesse et complexité inégalée. Dans ce mémoire, nous mettons de l'avant les aspects mathématiques et physiques de ce processus de fusion qui expliquent la convergence des flocons vers la goutte d'eau. À cette fin, nous proposons au lecteur une revue originale de la capillarité pour ensuite incorporer des éléments classiques de la théorie de l'élasticité afin de tenir compte de la déformation de l'interface capillaire par la structure cristalline. Nous montrons en quoi ceci explique la forme de la pellicule d'eau du flocon et les écoulements d'eau le long des dendrites. Par le fait même, ceci nous donne une façon de tenir compte de l'évolution du flocon vers la sphère. Nous terminons en exhibant le rôle de la courbure intrinsèque du substrat de glace en tant que mécanisme de frustration géométrique facilitant la transition de phase. D'un point de vue philosophique, nous montrons la tendance du flocon à atténuer ses différences de courbures au cours de sa fonte
RTIM: a Real-Time Influence Maximization Strategy
International audienceInfluence Maximization (IM) consists in finding in a network the top-k influencers who will maximize the diffusion of information. However, the exponential growth of online advertisement is due to Real-Time Bidding (RTB) which targets users on webpages. It requires complex ad placement decisions in real-time to face a high-speed stream of users. In order to stay relevant, the IM problem should be updated to answer RTB needs. While traditional IM generates a static set of influ-encers, they do not fit with an RTB environment which requires dynamic influence targeting. This paper proposes RTIM, the first IM algorithm capable of targeting users in a RTB environment. We also analyze influence scores of users in several social networks and provide a thorough experimental process to compare static versus dynamic IM solutions
Excitation of resonant plasmonic cavities by integrated waveguides for sensing applications
Optical sensors represent a large growing market which is nowadays focusing onto advancement in mobile technology. Innovations in the field of optical sensors are mostly driven by the technological advancements in the domain of micro & nanofabrication. One key to the miniaturization of optical sensors is their integration onto small chips having their own light sources and detectors. This thesis shows two separate applications of integrated optical sensors which benefit from the implementation of optical nano-structures. A first study investigates a biosensor based on a plasmonic slot waveguide cavity for the detection of changes in refractive index in femto-liter volumes. By integrating the biosensor onto a silicon-on-insulator platform, we could confine the light excitation of the cavity into a single-mode silicon strip waveguide. In a first step realized by simulation, we showed the efficient coupling of the fundamental quasi-transverse electric mode of the waveguide to the plasmonic slot waveguide cavity. We showed that the strong light confinement into the slot is an intrinsic property of the plasmonic slot waveguide which is based on the excitation of a guided wave at a metal-insulator-metal interface. We investigated the surface sensitivity of this biosensor which revealed its potential to detect single-molecules at high concentrations. Moreover, we reported a high bulk sensitivity of up to 600nm per refractive index units. In a second step, we developed a multi-step process based on electron beam lithography to fabricate the sensor. In a third step, we characterized the propagation properties of the fabricated waveguides. Finally, we measured the transmission properties of the integrated sensor has well as the far-field scattering of the plasmonic cavity. A second study focused on a new architecture of a standing-wave integrated Fourier transform spectrometer. This type of spectrometer uses nano-samplers (metallic nano-structures) to probe the intensity of a standing wave generated inside a single-mode waveguide terminated by a mirror. To enhance the well known bandwidth limitation of this type of spectrometer, we implemented a scanning mirror enabling the sub-sampling of the interferogram between each fixed nano-sampler. We fabricated a chip containing a 1D array of low delta n single-mode waveguides made out of epoxy-based "EpoCore" polymer. Equidistant metallic nano-samplers were patterned on top of the waveguides thanks to electron beam lithography. Micro-lenses were fabricated, aligned and glued to the facet of the chip to enable the free space coupling of the waveguides. We implemented a mechanical setup which included a closed-loop piezo actuated mirror to induce an additional phase shift to the interferogram. The realization of an optical setup taking care of the readout of the interferogram showed a 2D multiplexing potential of the spectrometer by realizing the simultaneous detection of independent waveguides. We also investigated the calibration procedures to overcome the fabrication uncertainties by an adapted post-processing step
Universal Mobile Information Retrieval
International audienceThe shift in human computer interaction from desktop computing to mobile interaction highly influences the needs for new designed interfaces. In this paper, we address the issue of searching for information on mobile devices, an area also known as Mobile Information Retrieval. In particular, we propose to summarize as much as possible the information retrieved by any search engine to allow universal access to information
Le réfrigérateur, un miroir social ?
Frigo à nu est un webdocumentaire ayant pour objectif de dévoiler de manière ludique l’intérieur du réfrigérateur d’un certain nombre de Français. Projet d’abord axé sur les évolutions du pouvoir d’achat et des habitudes alimentaires, il s’est rapidement transformé en un outil de réflexion sur notre rapport à la nourriture et à l’image sociale qu’elle véhicule.The web-documentary « Frigo à nu » wants to put a playful eye inside french peoples fridge. At first, the journalistics goals were to define the evolution of the eating habits in regard of the their purchasing power. But quickly the authors tranform the documentary as a tool to think about our relation with food and our social status
Accelerating hypersonic reentry simulations using deep learning-based hybridization (with guarantees)
In this paper, we are interested in the acceleration of numerical
simulations. We focus on a hypersonic planetary reentry problem whose
simulation involves coupling fluid dynamics and chemical reactions. Simulating
chemical reactions takes most of the computational time but, on the other hand,
cannot be avoided to obtain accurate predictions. We face a trade-off between
cost-efficiency and accuracy: the simulation code has to be sufficiently
efficient to be used in an operational context but accurate enough to predict
the phenomenon faithfully. To tackle this trade-off, we design a hybrid
simulation code coupling a traditional fluid dynamic solver with a neural
network approximating the chemical reactions. We rely on their power in terms
of accuracy and dimension reduction when applied in a big data context and on
their efficiency stemming from their matrix-vector structure to achieve
important acceleration factors ( to ). This paper aims
to explain how we design such cost-effective hybrid simulation codes in
practice. Above all, we describe methodologies to ensure accuracy guarantees,
allowing us to go beyond traditional surrogate modeling and to use these codes
as references.Comment: Under revie
A Review of the "Digital Turn" in the New Literacy Studies
Digital communication has transformed literacy practices and assumed great importance in the functioning of workplace, recreational, and community contexts. This article reviews a decade of empirical work of the New Literacy Studies, identifying the shift toward research of digital literacy applications. The article engages with the central theoretical, methodological, and pragmatic challenges in the tradition of New Literacy Studies, while highlighting the distinctive trends in the digital strand. It identifies common patterns across new literacy practices through cross-comparisons of ethnographic research in digital media environments. It examines ways in which this research is taking into account power and pedagogy in normative contexts of literacy learning using the new media. Recommendations are given to strengthen the links between New Literacy Studies research and literacy curriculum, assessment, and accountability in the 21st century
Glider and satellite monitoring of the variability of the suspended particle distribution and size in the Rhône ROFI
An experiment was carried out in the Gulf of Lions (NW Mediterranean) in February 2014 to assess the temporal and spatial variability of the distribution and size of suspended particulate matter (SPM) in the Rhône Region of Freshwater Influence (ROFI). A set of observations from an autonomous underwater glider, satellite ocean color data, and meteorological and hydrological time-series data highlighted the high variability of the Rhône River surface turbid plume and presence of a bottom nepheloid layer (BNL) that depended on wind and river discharge conditions. While continental winds pushed the surface plume offshore, marine winds pressed the plume at the coast and favored the sedimentation of as well as nourishment of the BNL. Moderate storm events favored breakage of the plume stratification and along-shelf transport of Rhône River particles. The spectral slopes of glider and satellite-derived light backscattering coefficients, γ, were used as a proxies of the SPM size distribution. The results clearly showed that the change of the SPM size in the nepheloid layers was induced by the flocculation of fine sediments, which became finer seaward throughout the ROFI, as well as the effect of rough weather in the breakup of flocs
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