Comments on the Relativity of Shape

In this talk I address three topics related to the shape of hadrons: 1. The Lorentz contraction of bound states. Few dedicated studies of this exist - I describe a recent calculation for ordinary atoms (positronium). 2. Does the A-dependence of nuclear structure functions indicate a change of proton shape in the nuclear environment? (My short answer is no.) 3. The size of Fock states contributing to processes involving large momentum transfers. End-point configurations can be transversally extended and yet sufficiently short-lived to contribute coherently to hard scattering.Comment: Talk at the Workshop on the Shape of Hadrons, 27-29 April 2006 in Athens, Greece. 11 pages, 15 figure

Test of variational transition state theory against accurate quantal results for a reaction with very large reaction-path curvature and a low barrier

We present three sets of calculations for the thermal rate constants of the collinear reaction I+HI-->IH+I: accurate quantum mechanics, conventional transition state theory (TST), and variational transition state theory (VTST). This reaction differs from previous test cases in that it has very large reaction-path curvature but hardly any tunneling. TST overestimates the accurate results by factors of 2×10^10, 2×10^4, 57, and 19 at 40, 100, 300, and 1000 K, respectively. At these same four temperatures the ratios of the VTST results to the accurate quantal ones are 0.3, 0.8, 1.1, and 1.4, respectively. We conclude that the variational transition states are meaningful, even though they are computed from a reaction-path Hamiltonian with large curvature, which is the most questionable case

The phenotype of circulating follicular-helper T cells in patients with rheumatoid arthritis defines CD200 as a potential therapeutic target

Rheumatoid arthritis (RA) is a systemic autoimmune disease primarily affecting synovial joints in which the development of autoantibodies represents a failure of normal tolerance mechanisms, suggesting a role for follicular helper T cells (TFH) in the genesis of autoimmunity. To determine whether quantitative or qualitative abnormalities in the circulating TFH cell population exist, we analysed by flow cytometry the number and profile of these cells in 35 patients with RA and 15 matched controls. Results were correlated with patient characteristics, including the presence of autoantibodies, disease activity, and treatment with biologic agents. Circulating TFH cells from patients with RA show significantly increased expression of the immunoglobulin superfamily receptor CD200, with highest levels seen in seropositive patients (P=0.0045) and patients treated with anti-TNFα agents (P=0.0008). This occurs in the absence of any change in TFH numbers or overt bias towards Th1, Th2, or Th17 phenotypes. CD200 levels did not correlate with DAS28 scores (P=0.887). Although the number of circulating TFH cells is not altered in the blood of patients with RA, the TFH cells have a distinct phenotype. These differences associate TFH cells with the pathogenesis of RA and support the relevance of the CD200/CD200R signalling pathway as a potential therapeutic target

The Role of Coaches, Institutions, and Clinicians in Addressing Athlete Mental Health

Mental health, defined by the World Health Organization as “a state of wellbeing in which every individual realizes his or her own potential, can cope with normal stresses of life, can work productively and fruitfully, and is able to make a contribution to her or his community,” is an important concern for athletes. In 2018, research findings showed that the prevalence of mental health symptoms and disorders among current elite athletes ranged from 19% for alcohol misuse to 34% for anxiety/depression, and from 16% for distress to 26% for anxiety/depression for former elite athletes.2 Research suggests that while athletes have overall better physical health than their non-athlete counterparts, they experience similar rates of mental health symptoms and disorders.https://digitalcommons.library.tru.ca/emergingdiscourses/1001/thumbnail.jp

Histoire littéraire/Histoire culturelle

Le récent Que sais-je ? de Pascal Ory sur l’histoire culturelle fait un incessant appel au dialogue entre les disciplines historiques. Mon intervention dans ce dialogue est celle d’un historien de la littérature, représentant (non autorisé) d’une discipline qui se veut à la fois pleinement historique et pleinement littéraire, donc pleinement culturelle. Avec ce paradoxe qui doit être dit d’emblée : à savoir que je ne suis pas historien patenté, et que nombre de collègues peuvent légitimement ..

Salud Camarada ! Un reportage sur la guerre d’Espagne par Mathieu Corman

La guerre d’Espagne a été un événement historique majeur. On y a vu, à juste titre, les prolégomènes de la seconde guerre mondiale. Tous les grands acteurs de la politique européenne y ont participé (les pays capitalistes-démocratiques, les pays fascistes-nazis et les pays qui se réclamaient du socialisme). Les effets du conflit n’ont pas été moins importants. Les déchirures de la société espagnole qui en ont résulté s’observent encore de nos jours. À l’époque même, par ailleurs, il s’est agi..