On the coincidence between the Shimomuras bargaining sets and the core

A necessary condition for the coincidence of the bargaining sets dened by Shimomura (1997) and the core of a cooperative game with transferable utility is provided. To this aim, a set of payo vectors, called max-payo vectors, are introduced. This necessary condition simply checks whether these vectors are core elements of the game.max-payo vectors, core, bargaining set, cooperative games

Comparison of antimüllerian hormone levels and antral follicle count as predictor of ovarian response to controlled ovarian stimulation in good-prognosis patients at individual fertility clinics in two multicenter trials

Objective To compare antimüllerian hormone (AMH) and antral follicle count (AFC) as predictors of ovarian response to controlled ovarian stimulation at individual fertility clinics. Design Retrospective analysis of individual study center data in two multicenter trials. Centers that provided >10 patients were included in the analysis. Setting A total of 19 (n = 519 patients) and 18 study centers (n = 686 patients) participating in a long GnRH agonist trial (MERIT) and a GnRH antagonist trial (MEGASET), respectively. Patient(s) Infertile women of good prognosis. Intervention(s) Long GnRH agonist or GnRH antagonist cycles. Main Outcome Measure(s) Correlation between AMH and AFC, and oocyte yield by each study center for each trial. Results(s) Antimüllerian hormone was more strongly correlated with oocyte yield than AFC: r = 0.56 vs. r = 0.28 in the GnRH agonist cohort, and r = 0.55 vs. r = 0.33 in the GnRH antagonist cohort. The correlation was numerically higher for AMH than for AFC at a significantly higher proportion of study centers: 17 (89%) and 15 (83%) centers in the long GnRH agonist and GnRH antagonist trial, respectively. Assessment of the relative capacity of AMH and AFC for predicting oocyte yield demonstrated that AMH dominated the model: AMH, R2 = 0.29 and 0.23; AFC: R2 = 0.07 and 0.07; AMH + AFC: R2 = 0.30 and 0.23 for long GnRH agonist and GnRH antagonist trials, respectively. Conclusions(s) Antimüllerian hormone was a stronger predictor of ovarian response to gonadotropin therapy than AFC at the study center level in both randomized trials utilizing GnRH agonist and GnRH antagonist protocols. Antral follicle count provided no added predictive value beyond AMH.</p

Hydrodynamic fingering instability of driven wetting films: hindrance by diffusion

Recent experimental and theoretical efforts have revealed the existence of a fingering instability at the moving front of thin liquid films forced to spread under gravitational, rotational or surface shear stresses, as for example by using the Marangoni effect. The authors describe how the presence of a precursor film in front of the spreading macroscopic film, whether it is by prewetting the substrate or by surface diffusion or multilayer absorption, can prevent the development of the instability

Gowdy waves as a test-bed for constraint-preserving boundary conditions

Gowdy waves, one of the standard 'apples with apples' tests, is proposed as a test-bed for constraint-preserving boundary conditions in the non-linear regime. As an illustration, energy-constraint preservation is separately tested in the Z4 framework. Both algebraic conditions, derived from energy estimates, and derivative conditions, deduced from the constraint-propagation system, are considered. The numerical errors at the boundary are of the same order than those at the interior points.Comment: 5 pages, 1 figure. Contribution to the Spanish Relativity Meeting 200

El Llegat de Galton, Pearson, Fréchet i d'altres: com mesurar i interpretar l'associació estadística

Presentem en tres parts els conceptes de correlació i d'associació estadística, començant per la noció de correlació de Galton, millorada per Pearson. Utilitzem com a il.lustració les dades clàssiques de Galton i Pearson sobre heretabilitat de pares i fills respecte a l'estatura. La segona part explica com s'han d'estudiar les mateixes dades des d'una perspectiva multivariant (anàlisi de correlació canònica i de correspondències). Utilitzem també dades de Fisher. Mostrem com podem associar dades de tipus general mitjançant distàncies. La tercera part la dediquem a les distribucions bivariants. Presentem la teoria de funcions i valors propis per a dos nuclis, que s'aplica al desenvolupament diagonal d'una distribució bivariant, incloent-hi els desenvolupaments continus en termes d'integrals. Proposem una família de còpules canòniques, que permet generar distribucions bivariants.Along three parts, we present the concepts of correlation and statistical association, starting with Galton’s notion of correlation, improved by Pearson. As an illustration, we use the classic data of Galton and Pearson on heritability of parents and children regarding the stature. The second part explains how to study the same data from a multivariate perspective (canonical correlation analysis, correspondence analysis). We also use data from Fisher. We show how to associate general data sets with distances. The third part is devoted to the bivariate distributions. We present the theory of eigenfunctions and eigenvalues for two kernels, which is applied to the diagonal expansion of a bivariate distribution, including continuous expansions in terms of integrals. We propose a family of canonical copulas, which can generate bivariate distributions

A unified approach to explain contrary effects of hysteresis and smoothing in nonsmooth systems

Piecewise smooth dynamical systems make use of discontinuities to model switching between regions of smooth evolution. This introduces an ambiguity in prescribing dynamics at the discontinuity: should it be given by a limiting value on one side or other of the discontinuity, or a member of some set containing those values? One way to remove the ambiguity is to regularize the discontinuity, the most common being either to smooth out the discontinuity, or to introduce a hysteresis between switching in one direction or the other across the discontinuity. Here we show that the two can in general lead to qualitatively different dynamical outcomes. We then define a higher dimensional model with both smoothing and hysteresis, and study the competing limits in which hysteretic or smoothing effect dominate the behaviour, only the former of which correspond to Filippov's standard `sliding modes'