Corpuscular description of the speed of light in a homogeneous medium

We are used to describe the detection of light in terms of particles and its propagation from the source to the detection, by waves. For instance, the slowing down of light in a transparent medium is always explained within the electromagnetic wave framework. We propose to approach that phenomenon through a purely corpuscular description. We find expression for the refractive indices which differ slightly from the usual Maxwell wave approach. We thus compare these expressions against experimental refractive indices and we show that both reproduce well the data. We show also how this corpuscular framework gives a very natural interpretation to the self focusing Kerr effect. Finally an experimental expectation of fluctuation of the speed of light is presented.Comment: 16 pages, 2 figure

Urban Agriculture: Fostering the Urban-Rural Continuum

Urban agricultural projects have been mushrooming since the end of the twentieth century, reshaping urban landscapes and even the whole urban fabric, experimenting with alternatives to the traditional urban life, sometimes creating new commons, and bringing people together. Within a city, farmers, gardeners, and their neighbors share more than just fence lines. Cities already have a huge potential for farming. Three examples can be observed in very different cities around the World: Singapore, is fully self-reliant in meat, Bamako is self-sufficient in vegetables, and in Berlin there are 80,000 community gardens on communal land and 16,000 more people are on a waiting-list [1]. And this is just the beginning; in many cities new unbuilt areas emerge in the wake of deindustrialization (derelict lands, wastelands, brownfields, etc.), or as a consequence of urban shrinking due to aging populations (as in Japan or Germany), or of emigration (as in some African mid-sized cities). These new areas are a wonderful opportunity for urban agriculture. In Detroit, thousands hectares of urban land have been given over to unemployed workers for food growing. In Britain, urban agriculture has been promoted on wastelands of 20 cities by their various councils [2]. Urban agriculture is gradually becoming a planning policy option. In Delft, the planners of the city already combine urban agriculture with several other land uses in their planning documents; in Paris, an inclusive local land development plan protects agricultural landscapes [3,4]. Urban agriculture is neither—or no more—the short-lived remnant of a rural culture nor the hipsters' latest futile craze

Urban Agriculture: Fostering the Urban-Rural Continuum

Urban agricultural projects have been mushrooming since the end of the twentieth century, reshaping urban landscapes and even the whole urban fabric, experimenting with alternatives to the traditional urban life, sometimes creating new commons, and bringing people together. Within a city, farmers, gardeners, and their neighbors share more than just fence lines. Cities already have a huge potential for farming. Three examples can be observed in very different cities around the World: Singapore, is fully self-reliant in meat, Bamako is self-sufficient in vegetables, and in Berlin there are 80,000 community gardens on communal land and 16,000 more people are on a waiting-list. And this is just the beginning; in many cities new unbuilt areas emerge in the wake of deindustrialization (derelict lands, wastelands, brownfields, etc.), or as a consequence of urban shrinking due to aging populations (as in Japan or Germany), or of emigration (as in some African mid-sized cities). These new areas are a wonderful opportunity for urban agriculture. In Detroit, thousands hectares of urban land have been given over to unemployed workers for food growing. In Britain, urban agriculture has been promoted on wastelands of 20 cities by their various councils. Urban agriculture is gradually becoming a planning policy option. In Delft, the planners of the city already combine urban agriculture with several other land uses in their planning documents; in Paris, an inclusive local land development plan protects agricultural landscapes. Urban agriculture is neither - or no more - the short-lived remnant of a rural culture nor the hipsters' latest futile craze

Collaborative model of interaction and Unmanned Vehicle Systems' interface

The interface for the next generation of Unmanned Vehicle Systems should be an interface with multi-modal displays and input controls. Then, the role of the interface will not be restricted to be a support of the interactions between the ground operator and vehicles. Interface must take part in the interaction management too. In this paper, we show that recent works in pragmatics and philosophy provide a suitable theoretical framework for the next generation of UV System's interface. We concentrate on two main aspects of the collaborative model of interaction based on acceptance: multi-strategy approach for communicative act generation and interpretation and communicative alignment

An insight into immunogenic salivary proteins of Anopheles gambiae in African children

<p>Abstract</p> <p>Background</p> <p>During blood feeding, the mosquito injects saliva into the vertebrate host. This saliva contains bioactive components which may play a role in pathogen transmission and in host-vector relationships by inducing an immune response in the vertebrate host. The evaluation of human immune responses to arthropod bites might also represent a research direction for assessing individual exposure to the bite of a malaria vector.</p> <p>Methods</p> <p>The present study examined the antibody (Ab) IgG response during the season of exposure to <it>Anopheles gambiae </it>bites in young children living in a malaria endemic area. Immunoblots were performed with <it>An. gambiae </it>saliva to detect anti-saliva Ab bands and the evolution of immunogenic bands at the peak of, and following, the transmission period.</p> <p>Results</p> <p>The results showed that anti-<it>Anopheles </it>Ab was directed against a limited number of salivary proteins (175, 115, 72 and 30 kDa bands). Specific IgG responses to mosquito salivary proteins were variable among exposed individuals; nevertheless, two major bands (175 and 72 kDa) were observed in all immune-responder children. Analysis of the intensity of immunogenic bands revealed that IgG levels against the 175 kDa band were significantly higher during the peak period compared to the end period malaria transmission.</p> <p>Conclusion</p> <p>This preliminary work supports the potential of using anti-saliva immune responses as a measure of exposure to <it>Anopheles </it>bites. The use of immunoblots coupled with evaluation of band intensity could be an adequate tool for distinguishing immunogenic salivary proteins as candidate markers of bite exposure. Furthermore, this study may open the way to design new epidemiological tools for evaluating the risk of malaria exposure.</p

On the amplitude equations for weakly nonlinear surface waves

International audienceNonlocal generalizations of Burgers' equation were derived in earlier work by Hunter [Contemp. Math. 1989], and more recently by Benzoni-Gavage and Rosini [Comput. Math. Appl. 2009], as weakly nonlinear amplitude equations for hyperbolic boundary value problems admitting linear surface waves. The local-in-time well-posedness of such equations in Sobolev spaces was proved by Benzoni-Gavage [Diff. Int. Eq. 2009] under an appropriate stability condition originally pointed out by Hunter. The latter stability condition has also been shown to be necessary for well-posedness in Sobolev spaces in a previous work of the authors in collaboration with Tzvetkov [Adv. Math. 2011]. In this article, we show how the verification of Hunter's stability condition follows from natural stability assumptions on the original hyperbolic boundary value problem, thus avoiding lengthy computations in each particular situation. When the original boundary value problem has a variational origin, we also show that the resulting amplitude equation has a Hamiltonian structure. Our analysis encompasses previous equations derived for nonlinear Rayleigh waves in elasticity

Non Parametric Learning of Sensori-Motor Maps. Application to the Control of Multi Joint Systems

Abstract: -At the light of control and learning theories, this paper addresses the question of controlling multi-joint system using sensory feedback. A generic Sensory-Motor Control Model (SMCM) is firstly presented that solves the inverse kinematics difficulty at a theoretical level. Computational implementations of SMCM requires the knowledge of sensory motor transforms that are directly dependent to the multi-joint structure that is to be controlled. To avoid the dependency of SMCM to the analytical knowledge of these transforms, a non parametric learning approach is developed to identify non linear mappings between sensory signals and motor commands involved in SMCM. The resulting adaptive SMCM (ASMCM) is intensively tested within the scope of hand-arm reaching movements. ASMCM shows to be very effective and robust at least for this task. Its generic properties and effectiveness allow to foresee wide area of application

Net Impacts in Front Office IS: a First Operationalization of Delone and McLean Model in the Banking Sector

The variable Net Impacts, a key variable in the models for information systems evaluation, is rarely operationalized according to a rigorous method and never for the banking sector. DeLone and McLean (2016) note that the challenge of developing measures to evaluate information systems is still relevant. The measurement and conceptualization of variables in real contexts is both very important and relatively absent in the literature. This research aims at operationalizing the Net Impacts construct resulting from DeLone and McLean's (2016) evaluation model for information systems, in the specific context of retail banks. It also aims at highlighting the socio‑demographic variables influencing this construct. This original work conducted with 763 people applies the Churchill paradigm (1979) to provide a reliable and valid measure of Net Impacts, inspired by the Balanced Score Card. The main result of the research concerns the empirical validation of the measure of Net Impacts. This tool consists of three categories, relating to customer satisfaction, productivity and risk and ten items, which take into account the user but also include customer perception. This three‑dimensional construct shows how the information system supports the user in a wide spectrum of work. Also, by showing that in the banking field, only the function occupied by the user influences the perception of the impact of IS, we contribute to a better knowledge of the variables related to the evaluation of IS. Thus, this instrument represents a strategic tool for monitoring and guiding efforts to increase performance. The proposed instrument is very easy for CIOs and managers to use in order to evaluate their information systems with users