Quanta: The Originality of Einstein's Approach to Relativity?

We suggest that not only quanta may have played a role in Einstein's ideas on relativity, but that they themselves may be related to the dynamical and relativistic behaviour of the electromagnetic field exhibited in a Poincar\'e's 1900 paper, in particular to the identical transformation law of energy and frequency for bounded plane waves

Runoff vs. plurality:the effects of the electoral system on local and central government behaviour

Plurality and runoff systems oer very different incentives to parties and coalition of voters, and demand different political strategies from potential candidates and chief executives. Italian mayors and city councils are elected with a different electoral system according to the locality's population, while municipalities are otherwise treated identically in terms of funding and powers. We exploit this institutional feature to test how the presence of different electoral systems affects the central government decisions on grants, and the local government decisions on local taxes. We find evidence that the upper-tier governments favour runoff-elected mayors, and that runoff-elected mayors levy lower taxes. This is broadly consistent with the literature on runoff and plurality rule electoral systems

Air blast parameters close to a liquid propellant explosion

Equations for determining air blast parameters close to liquid propellant explosions, and estimated peak overpressure in close fiel

A Pedagogical Discussion Concerning the Gravitational Energy Radiated by Keplerian Systems

We first discuss the use of dimensional arguments (and of the quadrupolar emission hypothesis) in the derivation of the gravitational power radiated on a circular orbit. Then, we show how to simply obtain the instantaneous power radiated on a general Keplerian orbit by approximating it locally by a circle. This allows recovering with a good precision, in the case of an ellipse, the highly non trivial dependence on the eccentricity of the average power given by general relativity. The whole approach is understandable by undergraduate students.Comment: A simpler method has been used in the calculations, which requires now only standard knowledge (the radius of curvature is defined by the normal acceleration). Two figures have been added. Concerning the dimensional analysis, the comparison with electromagnetism has been detaile

Prismatic adaptation modulates oscillatory EEG correlates of motor preparation but not visual attention in healthy participants

Prismatic adaption (PA) has been proposed as a tool to induce neural plasticity and is used to help neglect rehabilitation. It leads to a recalibration of visuo-motor coordination during pointing as well as to after-effects on a number of sensorimotor and attention tasks, but whether these effects originate at a motor or attentional level remains a matter of debate. Our aim was to further characterise PA after-effects by using an approach that allows distinguishing between effects on attentional and motor processes. We recorded electroencephalography (EEG) in healthy human participants (9 females and 7 males) while performing a new double step, anticipatory attention/motor preparation paradigm before and after adaptation to rightward shifting prisms, with neutral lenses as a control. We then examined PA after-effects through changes in known oscillatory EEG signatures of spatial attention orienting and motor preparation in the alpha and beta frequency bands. Our results were twofold. First, we found PA to rightward shifting prisms to selectively affect EEG signatures of motor but not attentional processes. More specifically, PA modulated preparatory motor EEG activity over central electrodes in the right hemisphere, contralateral to the PA-induced, compensatory leftward shift in pointing movements. No effects were found on EEG signatures of spatial attention orienting over occipito-parietal sites. Second, we found the PA effect on preparatory motor EEG activity to dominate in the beta frequency band. We conclude that changes to intentional visuo-motor rather than attentional visuo-spatial processes underlie the PA after-effect of rightward deviating prisms in healthy participants