Search results for "RAV"

Integration of Gravitational Torques in Cerebellar Pathways Allows for the Dynamic Inverse Computation of Vertical Pointing Movements of a Robot Arm

2008

BackgroundSeveral authors suggested that gravitational forces are centrally represented in the brain for planning, control and sensorimotor predictions of movements. Furthermore, some studies proposed that the cerebellum computes the inverse dynamics (internal inverse model) whereas others suggested that it computes sensorimotor predictions (internal forward model).Methodology/principal findingsThis study proposes a model of cerebellar pathways deduced from both biological and physical constraints. The model learns the dynamic inverse computation of the effect of gravitational torques from its sensorimotor predictions without calculating an explicit inverse computation. By using supervised …

The importance of environmental microbes for Drosophila melanogaster during seasonal macronutrient variability

2021

AbstractExperiments manipulating the nutritional environment and the associated microbiome of animals have demonstrated their importance for key fitness components. However, there is little information on how macronutrient composition and bacterial communities in natural food sources vary across seasons in nature and on how these factors affect the fitness components of insects. In this study, diet samples from an orchard compost heap, which is a natural habitat for many Drosophila species and other arthropods, were collected over 9 months covering all seasons in a temperate climate. We developed D. melanogaster on diet samples and investigated stress resistance and life-history traits as w…

Newton's Law of Universal Gravitation and Hume's Conception of Causality

2013

This article investigates the relationship between Hume’s causal philosophy and Newton’s philosophy of nature. I claim that Newton’s experimentalist methodology in gravity research is an important background for understanding Hume’s conception of causality: Hume sees the relation of cause and effect as not being founded on a priori reasoning, similar to the way that Newton criticized non-empirical hypotheses about the properties of gravity. However, according to Hume’s criteria of causal inference, the law of universal gravitation is not a complete causal law, since it does not include a reference either to contiguity or to temporal priority. It is still argued that because of the empirical…

Depositional architecture and geometric arrangement of Terravecchia Formation within the Scillato Basin (NW Sicily)

2008

Recensione: Robert Foulke, The Sea Voyage Narrative, Routledge, New York and London, 1997, pp. 244, ISBN 0-415-93894-5, in Fogli di anglistica, anno …

2008

Robert Foulke, The Sea Voyage Narrative, Routledge, New York and London, 1997, pp. 244, ISBN 0-415-93894-5. The Sea Voyage Narrative consente al lettore di immergersi nell'affascinante mondo della letteratura di mare. Robert Foulke, fine conoscitore dell'ambiente marino, mette in luce la complessità e l'aspetto proteiforme della sea literature, che non può definirsi come un vero e proprio genere letterario, ma soltanto come un'ampia categoria descrittiva. Il testo è suddiviso in sei capitoli, ciascuno dei quali analizza aspetti connessi alle esperienze di viaggi per mare in relazione con elementi narratologici e tematici di capolavori della sea literature.

Les évolutions du système d'innovation et le marché du travail des jeunes scientifiques

2004

In France, as in many other OECD countries, a sharp increase in the number of Ph.D. graduates in S&E fields from the mid-1980s to the mid-1990s was followed by a decrease in the enrolments in Ph.D. studies. Important transformations in the innovation processes were also observed on the same period. Our hypothesis is that we assist to the emergence of an intermediate scientific labour market between the traditional academic sector and the private research sector. A detailed analysis of the production processes of scientists and of the scientific careers of young scientists is first carried out in the perspective of labour economics. Then, in the perspective of the economics of innovation and…

Development of a Hybrid Method to Generate Gravito-Inertial Cues for Motion Platforms in Highly Immersive Environments

2021

Motion platforms have been widely used in Virtual Reality (VR) systems for decades to simulate motion in virtual environments, and they have several applications in emerging fields such as driving assistance systems, vehicle automation and road risk management. Currently, the development of new VR immersive systems faces unique challenges to respond to the user’s requirements, such as introducing high-resolution 360° panoramic images and videos. With this type of visual information, it is much more complicated to apply the traditional methods of generating motion cues, since it is generally not possible to calculate the necessary corresponding motion properties that are needed to …

La sage-femme, « vertueuse et experte »

2018

Dans son Instruction familière et très utile pour les accouchemens, Mme de La Marche, maîtresse jurée sage-femme de la ville et de l’Hôtel-Dieu de Paris, pose un certain nombre de questions préliminaires avant d’aborder les aspects techniques de la profession. À la première d’entre elles : « Qu’est-ce que sage-femme ? », elle répond : « C’est une femme qui doit être vertueuse et experte pour accoucher et délivrer les femmes et pour les soulager dans le temps de leur accouchement. » « Vertueus...

Mechanics and self-organization in tissue development

2021

Self-organization is an all-important feature of living systems that provides the means to achieve specialization and functionality at distinct spatio-temporal scales. Herein, we review this concept by addressing the packing organization of cells, the sorting/compartmentalization phenomenon of cell populations, and the propagation of organizing cues at the tissue level through traveling waves. We elaborate on how different theoretical models and tools from Topology, Physics, and Dynamical Systems have improved the understanding of self-organization by shedding light on the role played by mechanics as a driver of morphogenesis. Altogether, by providing a historical perspective, we show how i…

Assessing theoretical flow velocity profile and resistance in gravel bed rivers by field measurements

2018

Previous studies showed that integrating a power velocity profile, deduced applying dimensional analysis and the incomplete self-similarity condition, the flow resistance equation for open channel flow can be obtained. At first, in this paper the relationship between the Gamma function of the power velocity profile, the channel slope and the Froude number, which was already empirically introduced in a previous paper, is now theoretically deduced. Then this relationship is calibrated using the field measurements of flow velocity, water depth and bed slope carried out in 101 reaches of gravel bed rivers available by literature. The proposed relationship for estimating Gamma function and the t…