Experimental Determination of Nucleation Scaling Law for Small Charged Particles

We investigated the nucleation process at the molecular level. Controlled sticking of individual atoms onto mass selected clusters over a wide mass range has been carried out for the first time. We measured the absolute unimolecular nucleation cross sections of cationic sodium clusters Na_{n}^{+} in the range n=25-200 at several collision energies. The widely used hard sphere approximation clearly fails for small sizes: not only should vapor-to-liquid nucleation theories be modified, but also, through the microreversibility principle, cluster decay rate statistical models

Les femmes dans la vie religieuse au Moyen Âge. Un bref bilan bibliographique

Quelle a été la place des femmes dans la vie religieuse au Moyen Âge, quand on sait que le millénaire médiéval est imprégné de christianisme, que la femme est par essence inférieure à l’homme et sa sujette, donc d’abord écartée du sacerdoce ? Les images qui surgissent sont fortement contradictoires. L’ombre de grandes figures surgit. Les unes « s’élevant au dessus de leur sexe » : martyres, prophétesses, mystiques, fondatrices, savantes ; d’autres en incarnant les pires tares : les hérétiques et les sorcières. Mais qu’en est-il de l’immense troupeau discret qui cherche son salut dans des monastères toujours trop peu nombreux, les béguinages ou les tiers ordres qu’invente le bas Moyen Âge sans jamais combler, semble-t-il, ni les aspirations spirituelles ni les besoins sociaux, économiques et culturels auxquels sont censées répondre les structures d’encadrement de la vie religieuse ?What was the role of women in the religious life of the Middle Ages, a millenium impregnated with Christianity, during which women were considered by their essence inferior to and subject to men, and thus excluded from the priesthood. The images conjured up are highly contradictory. The shadows of the great appear: some « raising themselves above their sex » - martyrs, prophets, mystics, founders, scholars; others incarnating the worst vices - heretics and sorceresses. But what can we say of the immense and quiet mass who sought salvation in monasteries, always too few, in the Beguinages or Third Orders that the late Middle Ages invented without ever seeming to satisfy either the spiritual aspirations or the social, economic, and cultural needs that the structures of religious life were supposed to meet 

Synchrotron X-ray diffraction experiments with a prototype hybrid pixel detector

A prototype X-ray pixel area detector (XPAD3.1) has been used for X-ray diffraction experiments with synchrotron radiation. The characteristics of this detector are very attractive in terms of fast readout time, high dynamic range and high signal-to-noise ratio. The prototype XPAD3.1 enabled various diffraction experiments to be performed at different energies, sample-to-detector distances and detector angles with respect to the direct beam, yet it was necessary to perform corrections on the diffraction images according to the type of experiment. This paper is focused on calibration and correction procedures to obtain high-quality scientific results specifically developed in the context of three different experiments, namely mechanical characterization of nanostructured multilayers, elastic-plastic deformation of duplex steel and growth of carbon nanotubes

Advances in the treatment of prolactinomas

Prolactinomas account for approximately 40% of all pituitary adenomas and are an important cause of hypogonadism and infertility. The ultimate goal of therapy for prolactinomas is restoration or achievement of eugonadism through the normalization of hyperprolactinemia and control of tumor mass. Medical therapy with dopamine agonists is highly effective in the majority of cases and represents the mainstay of therapy. Recent data indicating successful withdrawal of these agents in a subset of patients challenge the previously held concept that medical therapy is a lifelong requirement. Complicated situations, such as those encountered in resistance to dopamine agonists, pregnancy, and giant or malignant prolactinomas, may require multimodal therapy involving surgery, radiotherapy, or both. Progress in elucidating the mechanisms underlying the pathogenesis of prolactinomas may enable future development of novel molecular therapies for treatment-resistant cases. This review provides a critical analysis of the efficacy and safety of the various modes of therapy available for the treatment of patients with prolactinomas with an emphasis on challenging situations, a discussion of the data regarding withdrawal of medical therapy, and a foreshadowing of novel approaches to therapy that may become available in the future

Mort, résurrection et aveu dans les exempla

Dans la justice des hommes les rapports entre l’aveu et la vérité sont toujours incertains, fluctuants. Au tribunal de Dieu d’où émane la Justice en soi, les rapports entre juge et justiciable sont bouleversés. Le Juge sait tout parce qu’il est précisément « l’instance absolue de vérité ». Or un groupe d’exempla échappe à ce schéma, qui rassemble ceux auxquels le jugement divin accorde de ressusciter. La communication ne retient pas, en effet, les nombreux exempla mettant en scène des revenants qui quittent un instant leur résidence, pour aller informer les vivants que la parfaite et complète contrition est indispensable, non plus que ceux dans lesquels des messagers viennent faire savoir ce qu’il en est en réalité au ciel. Sont également écartés les exempla dans lesquels l’âme sort provisoirement du corps et se trouve avoir accès à l’au-delà. On ne retient donc que les cas où le jugement impose le retour sur terre pour re-vivre. Mais le salut est-il possible s’il n’y a pas d’aveu au prêtre, d’absolution et de satisfaction postérieure ? La réponse dominante est non sauf, justement, miracle et résurrection. La résurrection peut être accordée, en outre, si l’imposture du démon est flagrante, s’il essaie de conduire les âmes en enfer et n’agit pas à visage découvert. Le pécheur peut également avoir oublié des péchés, involontairement ou non. La résurrection permet alors l’aveu qui sauve. Il existe aussi un autre grand type d’exempla, beaucoup moins nombreux, où la mort est suivie de résurrection. Ici il s’agit pour le mort d’expier et si possible de réparer non les fautes envers soi-même mais envers autrui.Ces récits de résurrection ont la même finalité que les autres exempla évoquant les rapports entre l’au-delà et l’ici-bas. Mais notre corpus a ceci d’original qu’il impose l’idée que les hommes peuvent mourir au moins deux fois. Car ce qui est nouveau ici par rapport aux résurrections opérées dans la Bible ou dans la littérature hagiographique, c’est la fin en vue de laquelle elles sont accordées. Dieu n’octroie pas le retour sur terre pour que ces chanceux comblent des désirs profanes, son seul but est de permettre à une âme réincarnée d’accéder, après pénitence sur terre, à la joie éternelle. Mais cet octroi gracieux d’une nouvelle chance ne fait que retarder le jugement définitif.In human justice the relations between confession and truth are always indistinct and fluctuating. At the court of God where real Justice comes from, the relations between judge and those to be tried are disrupted. The Judge knows everything just because he is the “absolute reference of truth”. A set of exempla, however, doesn’t fit in this framework regrouping those who by Divine Judgment are allowed to rise from the dead. As a matter of fact, the document rejects the many exempla in which ghosts are said to leave their dwelling place for a while and inform the living that a complete and sincere contrition is essential, as well as those featuring messengers who come back to reveal what heaven is really about. Equally turned down are the exempla in which the soul temporarily gets out of the body and manages to have access to the next world. The only exempla to be retained are cases in which the judgment imposes a return on earth in order to live again. But is salvation possible if there is no confession to a priest, no absolution and no later satisfaction? In most cases the answer is no, except precisely for a miracle and a resurrection. Moreover, resurrection may be granted if deception by the devil is obvious, if he tries to drive souls to hell and acts slyly. The sinner also may have forgotten some of his sins, unwittingly or not. Then resurrection allows a salvation-granting confession. There is another type of exempla, in which death is followed by resurrection. Here the dead person has to atone for and if possible compensate for the sins committed not toward his or her self but toward other people.Such narratives of resurrections serve the same purpose as the other exempla treating of relations between the beyond and this world. But the original feature of our corpus is that it imposes the idea that men may die at least twice. The new thing here, if we compare with resurrections in the Bible or in hagiographic literature, is the purpose for which resurrection is granted: God does not allow a return on earth to some lucky people just for them to fulfil profane wishes. God’s sole aim is to permit a reincarnated soul, after penance on earth, to have access to eternal happiness. Yet this gift of a second chance just delays the Last Judgment

Rhythmic Entrainment Echoes in Auditory Perception

Rhythmic entrainment echoes—rhythmic brain responses that outlast rhythmic stimulation—can demonstrate endogenous neural oscillations entrained by the stimulus rhythm. Here, we tested for such echoes in auditory perception. Participants detected a pure tone target, presented at a variable delay after another pure tone that was rhythmically modulated in amplitude. In four experiments involving 154 human (female and male) participants, we tested (1) which stimulus rate produces the strongest entrainment echo and, inspired by the tonotopical organization of the auditory system and findings in nonhuman primates, (2) whether these are organized according to sound frequency. We found the strongest entrainment echoes after 6 and 8 Hz stimulation, respectively. The best moments for target detection (in phase or antiphase with the preceding rhythm) depended on whether sound frequencies of entraining and target stimuli matched, which is in line with a tonotopical organization. However, for the same experimental condition, best moments were not always consistent across experiments. We provide a speculative explanation for these differences that relies on the notion that neural entrainment and repetition-related adaptation might exercise competing opposite influences on perception. Together, we find rhythmic echoes in auditory perception that seem more complex than those predicted from initial theories of neural entrainment. SIGNIFICANCE STATEMENT Rhythmic entrainment echoes are rhythmic brain responses that are produced by a rhythmic stimulus and persist after its offset. These echoes play an important role for the identification of endogenous brain oscillations, entrained by rhythmic stimulation, and give us insights into whether and how participants predict the timing of events. In four independent experiments involving >150 participants, we examined entrainment echoes in auditory perception. We found that entrainment echoes have a preferred rate (between 6 and 8 Hz) and seem to follow the tonotopic organization of the auditory system. Although speculative, we also found evidence that several, potentially competing processes might interact to produce such echoes, a notion that might need to be considered for future experimental design

Conducting Interface for Efficient Growth of Vertically Aligned Carbon Nanotubes: Towards Nano-Engineered Carbon Composite

International audienceVertically aligned carbon nanotubes (VACNT) are manufactured nanomaterials with excellent properties and great potential for numerous applications. Recently, research has intensified toward achieving VACNT synthesis on different planar and non-planar substrates of various natures, mainly dependent on the user-defined application. Indeed, VACNT growth has to be adjusted and optimized according to the substrate nature and shape to reach the requirements for the application envisaged. To date, different substrates have been decorated with VACNT, involving the use of diffusion barrier layers (DBLs) that are often insulating, such as SiO2 or Al2O3. These commonly used DBLs limit the conducting and other vital physico-chemical properties of the final nanomaterial composite. One interesting route to improve the contact resistance of VACNT on a substrate surface and the deficient composite properties is the development of semi-/conducting interlayers. The present review summarizes different methods and techniques for the deposition of suitable conducting interfaces and controlled growth of VACNT on diverse flat and 3-D fibrous substrates. Apart from exhibiting a catalytic efficiency, the DBL can generate a conducting and adhesive interface involving performance enhancements in VACNT composites. The abilities of different conducting interlayers are compared for VACNT growth and subsequent composite properties. A conducting interface is also emphasized for the synthesis of VACNT on carbonaceous substrates in order to produce cost-effective and high-performance nano-engineered carbon composites