On the Asserted Clash between the Freud and the Bianchi Identities

Through a constructive method it is shown that the claim advanced in recent times about a clash that should occur between the Freud and the Bianchi identities in Einstein's general theory of relativity is based on a faulty argument.Comment: 4 pages, plain Te

L'arachide au Sénégal : un moteur en panne

L'arachide, qui a été le moteur du développement de l'économie sénégalaise jusqu'au milieu des années 1970, en fournissant la majeure partie des revenus en milieu rural et en assurant 80 % des exportations, a connu un recul important cette dernière décennie. Cette crise rappelle celle qu'ont connue les pays voisins, il y a une vingtaine d'années, et qui a conduit à la disparition de cette culture. Inquiet de cette situation, le gouvernement du Sénégal a demandé à une équipe du Cirad de déterminer les raisons de la désaffection des paysans envers l'arachide, afin de pouvoir y remédier et relancer la production. Cet ouvrage est le résultat des travaux de cette équipe. Il montre que, contrairement aux idées selon lesquelles la crise de l'arachide serait principalement une crise de l'approvisionnement des huileries, avec un repli des producteurs sur le marché informel, on assiste à une 'grève' des producteurs. Par une méthodologie originale de recensement, les auteurs démontrent que la production a été longtemps surestimée. L'enquête auprès des producteurs explique la chute des rendements par la dégradation des facteurs de production (baisse de la fertilité des sols, diminution de la qualité des semences), par la disparition des services agricoles, par une politique du prix d'achat de l'arachide qui décourage les producteurs. Relancer la production de l'arachide ne suffit plus, il faut aussi prendre en compte les potentialités agricoles du pays, chercher à mieux valoriser les autres productions et tracer une politique d'appui en milieu paysan

Not Belonging to one’s Self: Affect on Facebook’s Site Governance page

This article makes a contribution to a growing number of works that discuss affect and social media. I use Freudian affect theory to analyse user posts on the public Site Governance Facebook page. Freud’s work may help us to explore the affectivity within the user narratives and I suggest that they are expressions of alienation, dispossession and powerlessness that relate to the users’ relations with Facebook as well as to their internal and wider social relations. The article thus introduces a new angle on studies of negative user experiences that draws on psychoanalysis and critical theory

Turning to God in the Face of Ostracism: Effects of Social Exclusion on Religiousness

The present research proposes that individuals who are socially excluded can turn to religion to cope with the experience. Empirical studies conducted to test this hypothesis consistently found that socially excluded persons reported (a) significantly higher levels of religious affiliation (Studies 1, 2, and 4) and (b) stronger intentions to engage in religious behaviors (Study 2) than comparable, nonexcluded individuals. Direct support for the stress-buffering function of religiousness was also found, with a religious prime reducing the aggression-eliciting effects of consequent social rejection (Study 5). These effects were observed in both Christian and Muslim samples, revealing that turning to religion can be a powerful coping response when dealing with social rejection. Theoretical and practical implications of these findings are discussed

Semi-classical Laguerre polynomials and a third order discrete integrable equation

A semi-discrete Lax pair formed from the differential system and recurrence relation for semi-classical orthogonal polynomials, leads to a discrete integrable equation for a specific semi-classical orthogonal polynomial weight. The main example we use is a semi-classical Laguerre weight to derive a third order difference equation with a corresponding Lax pair.Comment: 11 page

Regression and the Maternal in the History of Psychoanalysis, 1900-1957

This paper examines the history of the concept of ‘regression’ as it was perceived by Sandor Ferenczi and some of his followers in the first half of the twentieth century. The first part provides a short history of the notion of ‘regression’ from the late nineteenth century to Ferenczi's work in the 1920s and 1930s. The second and third parts of the paper focus on two other thinkers on regression, who worked in Britain, under the influence of the Ferenczian paradigm – the interwar Scottish psychiatrist, Ian D. Suttie; and the British-Hungarian psychoanalyst, and Ferenczi's most important pupil, Michael Balint. Rather than a descriptive term which comes to designate a pathological mental stage, Ferenczi understood ‘regression’ as a much more literal phenomenon. For him, the mental desire to go backwards in time is a universal one, and a consequence of an inevitable traumatic separation from the mother in early childhood, which has some deep personal and cultural implications. The paper aims to show some close affinities between the preoccupation of some psychoanalysts with ‘regression’, and the growing interest in social and cultural aspects of ‘motherhood’ and ‘the maternal role’ in mid-twentieth-century British society

Quantization and noiseless measurements

In accordance with the fact that quantum measurements are described in terms of positive operator measures (POMs), we consider certain aspects of a quantization scheme in which a classical variable $f:\R^2\to \R$ is associated with a unique positive operator measure (POM) $E^f$, which is not necessarily projection valued. The motivation for such a scheme comes from the well-known fact that due to the noise in a quantum measurement, the resulting outcome distribution is given by a POM and cannot, in general, be described in terms of a traditional observable, a selfadjoint operator. Accordingly, we notice that the noiseless measurements are the ones which are determined by a selfadjoint operator. The POM $E^f$ in our quantization is defined through its moment operators, which are required to be of the form $\Gamma(f^k)$, $k\in \N$, with $\Gamma$ a fixed map from classical variables to Hilbert space operators. In particular, we consider the quantization of classical \emph{questions}, that is, functions $f:\R^2\to\R$ taking only values 0 and 1. We compare two concrete realizations of the map $\Gamma$ in view of their ability to produce noiseless measurements: one being the Weyl map, and the other defined by using phase space probability distributions.Comment: 15 pages, submitted to Journal of Physics

Robust relations between CCN and the vertical evolution of cloud drop size distribution in deep convective clouds

International audienceIn-situ measurements in convective clouds (up to the freezing level) over the Amazon basin show that smoke from deforestation fires prevents clouds from precipitating until they acquire a vertical development of at least 4 km, compared to only 1?2 km in clean clouds. The average cloud depth required for the onset of warm rain increased by ~350 m for each additional 100 cloud condensation nuclei per cm3 at a super-saturation of 0.5% (CCN0.5%). In polluted clouds, the diameter of modal liquid water content grows much slower with cloud depth (at least by a factor of ~2), due to the large number of droplets that compete for available water and to the suppressed coalescence processes. Contrary to what other studies have suggested, we did not observe this effect to reach saturation at 3000 or more accumulation mode particles per cm3. The CCN0.5% concentration was found to be a very good predictor for the cloud depth required for the onset of warm precipitation and other microphysical factors, leaving only a secondary role for the updraft velocities in determining the cloud drop size distributions. The effective radius of the cloud droplets (re) was found to be a quite robust parameter for a given environment and cloud depth, showing only a small effect of partial droplet evaporation from the cloud's mixing with its drier environment. This supports one of the basic assumptions of satellite analysis of cloud microphysical processes: the ability to look at different cloud top heights in the same region and regard their re as if they had been measured inside one well developed cloud. The dependence of re on the adiabatic fraction decreased higher in the clouds, especially for cleaner conditions, and disappeared at re?~10 µm. We propose that droplet coalescence, which is at its peak when warm rain is formed in the cloud at re~10 µm, continues to be significant during the cloud's mixing with the entrained air, canceling out the decrease in re due to evaporation