Heavy quarkonium: progress, puzzles, and opportunities

A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

Conformational analysis of peptides and proteins

Some major problems in the calculation of structures and properties of peptide molecules have been reviewed. Recent results from empirical calculations and extended basis set ab initio calculations have been summarized. The importance of fully flexible geometry and vibrational free energy has been discussed as has the effect of explicit Inclusion of the solvent molecules upon the conformation of peptides. Finally, the problem of "folding" a protein, i.e. predicting Its tertiary structure from Its primary sequence, has also been reviewed along with the description of a new technique which avoids the structural oversimplifications employed by other workers, at least as far as the backbone Is concerned. Although this procedure requires further Improvement, preliminary results are reported for pancreatic trypsin Inhibitor, myoglobin and serine proteases

Sobre el turismo y la movilidad en tiempos de movimiento y conjetura posdisciplinar

Si bien el turismo ha sido objeto de considerable atención académica, ha habido críticas notables sobre la naturaleza de su investigación; en particular, se le ha criticado una supuesta falta de teorización. Los debates publicados también se han centrado en su consideración como disciplina académica diferenciada. La relectura de estos debates pone el énfasis en acometer un modo de investigación posdisciplinar sobre el turismo. En este articulo sostenemos que existe una necesidad apremiante de comprender el turismo como una forma de movimiento humano dentro de un espectro mucho más amplio de las movilidades sociales y físicas. Parte de esta tarea ha sido ya realizada por disciplinas "tradicionales" como, por ejemplo, la sociología y los estudios culturales. Pero en la última década nuestra comprensión de las movilidades también se ha beneficiado en buena medida de la producción. de conocimiento debida a la transgresión de los límites disciplinares. Si los estudios de turismo quieren reflejar los actuales patrones de movilidad deben despojarse de toda aproximación ortodoxa ínter y multidisciplinar en favor de una producción, diseminación y consumo más flexible de conocimientos. Concluimos con la convicción de que estamos en el comienzo de un cambio de paradigma en los estudios del turismo, un cambio gracias al cual el turismo ya no es conceptualizado como hecho aislado sino incrustado, y por tanto mejor entendido, en un espectro más amplio de las movilidades humanas

Mild cognitive impairment: baseline and longitudinal structural MR imaging measures improve predictive prognosis.

Results of this study demonstrate that patient-specific estimates of the risk of conversion from mild cognitive impairment to Alzheimer disease can be derived from quantitative measures of brain atrophy obtained from single-time-point and serial MR imaging examinations. Purpose To assess whether single-time-point and longitudinal volumetric magnetic resonance (MR) imaging measures provide predictive prognostic information in patients with amnestic mild cognitive impairment (MCI). Materials and Methods This study was conducted with institutional review board approval and in compliance with HIPAA regulations. Written informed consent was obtained from all participants or the participants’ legal guardians. Cross-validated discriminant analyses of MR imaging measures were performed to differentiate 164 Alzheimer disease (AD) cases from 203 healthy control cases. Separate analyses were performed by using data from MR images obtained at one time point or by combining single-time-point measures with 1-year change measures. Resulting discriminant functions were applied to 317 MCI cases to derive individual patient risk scores. Risk of conversion to AD was estimated as a continuous function of risk score percentile. Kaplan-Meier survival curves were computed for risk score quartiles. Odds ratios (ORs) for the conversion to AD were computed between the highest and lowest quartile scores. Results Individualized risk estimates from baseline MR examinations indicated that the 1-year risk of conversion to AD ranged from 3% to 40% (average group risk, 17%; OR, 7.2 for highest vs lowest score quartiles). Including measures of 1-year change in global and regional volumes significantly improved risk estimates (P = 001), with the risk of conversion to AD in the subsequent year ranging from 3% to 69% (average group risk, 27%; OR, 12.0 for highest vs lowest score quartiles). Conclusion Relative to the risk of conversion to AD conferred by the clinical diagnosis of MCI alone, MR imaging measures yield substantially more informative patient-specific risk estimates. Such predictive prognostic information will be critical if disease-modifying therapies become available