Perceived Centrality in Social Networks Increases Women’s Expectations of Confronting Sexism

This paper integrates the study of intergroup relations and social network cognition, predicting that women who occupy central (vs. peripheral) advice network positions are more likely to confront a coworker’s gender-biased comment. Study 1 offers correlational evidence of the predicted link between perceived advice network centrality and confronting among employed women, uniquely in advice (but not communication) networks. Study 2 replicates and investigates two possible mechanisms–perceptions of the situation as public and perceived risk of confronting. Study 3 rules out order effects and tests an additional mechanism (expectations of the network members). Study 4 is an experiment that shows people expect central (vs. peripheral) women to confront more, even when she is lower (vs. equal) power. Study 5 replicates the core hypothesis in retrospective accounts of women’s responses to real workplace gender bias. Study 6 compares multiple potential mechanisms to provide greater insight into why centrality reliably predicts confrontation

Gender, Brokerage, and Performance: A Construal Approach

We present a new theory that seeks to explain differences in the performance of men and women friendship network brokers - individuals who bridge disconnected friends. In contrast to previous audience-centered explanations, our phenomenological theory emphasizes how brokers construe (i.e., perceive and interpret) their networks. We contend that when women perceive themselves as brokers in friendship networks, they experience threat, rooted in negative stereotypes about women brokers, which undermines their performance. Using data from a cohort of MBA students, Study 1 found that women (but not men) exhibited lower performance when they perceived themselves as brokers in small-group friendship networks. Using data from a larger group of MBA students, Study 2 replicated this finding and ruled out the possibility that underlying differences in the propensity to connect those who one bridges may explain the observed gender-based difference in broker performance. Using an experimental design, Study 3 found that elevated anxiety about task performance and negative social evaluations mediated the relationship between brokerage and performance for women but not for men. Women and men differ in how they psychologically construe brokerage in friendship networks; and this difference helps account for gender differences in the performance of network brokers

Unintentional ingestion of a high dose of acenocoumarol in a young child

Acute intoxication with a vitamin K antagonist may cause serious coagulopathy. We report the accidental ingestion of a high dose of acenocoumarol in a young child. Two intravenous administrations of 5mg of vitamin K, in combination with fast and repeated administration of activated charcoal and sodium sulfate, were sufficient to prevent coagulopathy and related symptoms, despite a confirmed elevated blood acenocoumarol concentration (260 mu g/L)

Statistical mechanics of Fofonoff flows in an oceanic basin

We study the minimization of potential enstrophy at fixed circulation and energy in an oceanic basin with arbitrary topography. For illustration, we consider a rectangular basin and a linear topography h=by which represents either a real bottom topography or the beta-effect appropriate to oceanic situations. Our minimum enstrophy principle is motivated by different arguments of statistical mechanics reviewed in the article. It leads to steady states of the quasigeostrophic (QG) equations characterized by a linear relationship between potential vorticity q and stream function psi. For low values of the energy, we recover Fofonoff flows [J. Mar. Res. 13, 254 (1954)] that display a strong westward jet. For large values of the energy, we obtain geometry induced phase transitions between monopoles and dipoles similar to those found by Chavanis and Sommeria [J. Fluid Mech. 314, 267 (1996)] in the absence of topography. In the presence of topography, we recover and confirm the results obtained by Venaille and Bouchet [Phys. Rev. Lett. 102, 104501 (2009)] using a different formalism. In addition, we introduce relaxation equations towards minimum potential enstrophy states and perform numerical simulations to illustrate the phase transitions in a rectangular oceanic basin with linear topography (or beta-effect).Comment: 26 pages, 28 figure

Scaling laws and vortex profiles in 2D decaying turbulence

We use high resolution numerical simulations over several hundred of turnover times to study the influence of small scale dissipation onto vortex statistics in 2D decaying turbulence. A self-similar scaling regime is detected when the scaling laws are expressed in units of mean vorticity and integral scale, as predicted by Carnevale et al., and it is observed that viscous effects spoil this scaling regime. This scaling regime shows some trends toward that of the Kirchhoff model, for which a recent theory predicts a decay exponent $\xi=1$. In terms of scaled variables, the vortices have a similar profile close to a Fermi-Dirac distribution.Comment: 4 Latex pages and 4 figures. Submitted to Phys. Rev. Let

Relaxation equations for two-dimensional turbulent flows with a prior vorticity distribution

Using a Maximum Entropy Production Principle (MEPP), we derive a new type of relaxation equations for two-dimensional turbulent flows in the case where a prior vorticity distribution is prescribed instead of the Casimir constraints [Ellis, Haven, Turkington, Nonlin., 15, 239 (2002)]. The particular case of a Gaussian prior is specifically treated in connection to minimum enstrophy states and Fofonoff flows. These relaxation equations are compared with other relaxation equations proposed by Robert and Sommeria [Phys. Rev. Lett. 69, 2776 (1992)] and Chavanis [Physica D, 237, 1998 (2008)]. They can provide a small-scale parametrization of 2D turbulence or serve as numerical algorithms to compute maximum entropy states with appropriate constraints. We perform numerical simulations of these relaxation equations in order to illustrate geometry induced phase transitions in geophysical flows.Comment: 21 pages, 9 figure

Quasi-stationary States of Two-Dimensional Electron Plasma Trapped in Magnetic Field

We have performed numerical simulations on a pure electron plasma system under a strong magnetic field, in order to examine quasi-stationary states that the system eventually evolves into. We use ring states as the initial states, changing the width, and find that the system evolves into a vortex crystal state from a thinner-ring state while a state with a single-peaked density distribution is obtained from a thicker-ring initial state. For those quasi-stationary states, density distribution and macroscopic observables are defined on the basis of a coarse-grained density field. We compare our results with experiments and some statistical theories, which include the Gibbs-Boltzmann statistics, Tsallis statistics, the fluid entropy theory, and the minimum enstrophy state. From some of those initial states, we obtain the quasi-stationary states which are close to the minimum enstrophy state, but we also find that the quasi-stationary states depend upon initial states, even if the initial states have the same energy and angular momentum, which means the ergodicity does not hold.Comment: 9 pages, 7 figure

Slow relaxation in the two dimensional electron plasma under the strong magnetic field

We study slow relaxation processes in the point vortex model for the two-dimensional pure electron plasma under the strong magnetic field. By numerical simulations, it is shown that, from an initial state, the system undergoes the fast relaxation to a quasi-stationary state, and then goes through the slow relaxation to reach a final state. From analysis of simulation data, we find (i) the time scale of the slow relaxation increases linearly to the number of electrons if it is measured by the unit of the bulk rotation time, (ii) during the slow relaxation process, each electron undergoes an superdiffusive motion, and (iii) the superdiffusive motion can be regarded as the Levy flight, whose step size distribution is of the power law. The time scale that each electron diffuses over the system size turns out to be much shorter than that of the slow relaxation, which suggests that the correlation among the superdiffusive trajectories is important in the slow relaxation process.Comment: 11pages, 19 figures. Submitted to J. Phys. Soc. Jp