Variational objective analyses for cyclone studies

The basic analysis equations, i.e., the two horizontal momentum equations, the hydrostatic equation, and the integrated continuity equation were derived for the nonlinear vertical coordinate, nondimensionalized, and expressed in finite differences on a staggered grid. Special care was taken to transform the hydrostatic equation and the pressure gradient terms of the horizontal momentum equations to nearly eliminate truncation error over steeply sloping terrain. This formulation also eliminated explicit reference to orographically induced variations in the thermodynamic variables so that the variational adjustments are on the scale of the meteorological perturbations. The analysis equations were subjected to the Euler-Lagrange operations as expressed for finite differences and an additional set of five partial differential equations was derived, bringing to nine the number of equations in Model I. Higher order terms, terms containing observed quantities, and terms containing none of the variables to be adjusted were grouped into forcing functions and the equations were solved for the zero order terms. Zero order variables were eliminated between these equations and there resulted two diagnostic equations which take the form of general linear second order partial differential equations with nonconstant coefficients

A multivariate variational objective analysis-assimilation method. Part 2: Case study results with and without satellite data

The variational multivariate assimilation method described in a companion paper by Achtemeier and Ochs is applied to conventional and conventional plus satellite data. Ground-based and space-based meteorological data are weighted according to the respective measurement errors and blended into a data set that is a solution of numerical forms of the two nonlinear horizontal momentum equations, the hydrostatic equation, and an integrated continuity equation for a dry atmosphere. The analyses serve first, to evaluate the accuracy of the model, and second to contrast the analyses with and without satellite data. Evaluation criteria measure the extent to which: (1) the assimilated fields satisfy the dynamical constraints, (2) the assimilated fields depart from the observations, and (3) the assimilated fields are judged to be realistic through pattern analysis. The last criterion requires that the signs, magnitudes, and patterns of the hypersensitive vertical velocity and local tendencies of the horizontal velocity components be physically consistent with respect to the larger scale weather systems

H3K4 demethylase KDM5B regulates global dynamics of transcription elongation and alternative splicing in embryonic stem cells

Epigenetic regulation of chromatin plays a critical role in controlling embryonic stem (ES) cell selfrenewal and pluripotency. However, the roles of histone demethylases and activating histone modifications such as trimethylated histone 3 lysine 4 (H3K4me3) in transcriptional events such as RNA polymerase II (RNAPII) elongation and alternative splicing are largely unknown. In this study, we show that KDM5B, which demethylates H3K4me3, plays an integral role in regulating RNAPII occupancy, transcriptional initiation and elongation, and alternative splicing events in ES cells. Depletion of KDM5B leads to altered RNAPII promoter occupancy, and decreased RNAPII initiation and elongation rates at active genes and at genes marked with broad H3K4me3 domains. Moreover, our results demonstrate that spreading of H3K4me3 from promoter to gene body regions, which is mediated by depletion of KDM5B, modulates RNAPII elongation rates and RNA splicing in ES cells. We further show that KDM5B is enriched nearby alternatively spliced exons, and depletion of KDM5B leads to altered levels of H3K4 methylation in alternatively spliced exon regions, which is accompanied by differential expression of these alternatively splice exons. Altogether, our data indicate an epigenetic role for KDM5B in regulating RNAPII elongation and alternative splicing, which may support the diverse mRNA repertoire in ES cells

Toward stable 3D numerical evolutions of black-hole spacetimes

Three dimensional (3D) numerical evolutions of static black holes with excision are presented. These evolutions extend to about 8000M, where M is the mass of the black hole. This degree of stability is achieved by using growth-rate estimates to guide the fine tuning of the parameters in a multi-parameter family of symmetric hyperbolic representations of the Einstein evolution equations. These evolutions were performed using a fixed gauge in order to separate the intrinsic stability of the evolution equations from the effects of stability-enhancing gauge choices.Comment: 4 pages, 5 figures. To appear in Phys. Rev. D. Minor additions to text for clarification. Added short paragraph about inner boundary dependenc

Actions speak louder than words: outsiders' perceptions of diversity mixed messages

To attract a gender diverse workforce, many employers use diversity statements to publicly signal that they value gender diversity. However, this often represents a misalignment between words and actions (i.e., a diversity mixed message) because most organizations are male dominated, especially in board positions. We conducted 3 studies to investigate the potentially indirect effect of such diversity mixed messages through perceived behavioral integrity on employer attractiveness. In Study 1, following a 2 x 2 design, participants (N = 225) were either shown a pro gender diversity statement or a neutral statement, in combination with a gender diverse board (4 men and 4 women) or a uniform all-male board (8 men). Participants' perceived behavioral integrity of the organization was assessed. In Study 2, participants (N = 251) either read positive or negative reviews of the organization's behavioral integrity. Employer attractiveness was then assessed. Study 3 (N = 427) investigated the impact of board gender composition on perceived behavioral integrity and employer attractiveness using a bootstrapping procedure. Both the causal-chain design of Study 1 and 2, as well as the significance test of the proposed indirect relationship in Study 3, revealed that a diversity mixed message negatively affected an organization's perceived behavioral integrity, and low behavioral integrity in turn negatively impacted employer attractiveness. In Study 3, there was also evidence for a tipping point (more than 1 woman on the board was needed) with regard to participants' perceptions of the organization's behavioral integrity

Spin effects in gravitational radiation backreaction II. Finite mass effects

A convenient formalism for averaging the losses produced by gravitational radiation backreaction over one orbital period was developed in an earlier paper. In the present paper we generalize this formalism to include the case of a closed system composed from two bodies of comparable masses, one of them having the spin S. We employ the equations of motion given by Barker and O'Connell, where terms up to linear order in the spin (the spin-orbit interaction terms) are kept. To obtain the radiative losses up to terms linear in the spin, the equations of motion are taken to the same order. Then the magnitude L of the angular momentum L, the angle kappa subtended by S and L and the energy E are conserved. The analysis of the radial motion leads to a new parametrization of the orbit. From the instantaneous gravitational radiation losses computed by Kidder the leading terms and the spin-orbit terms are taken. Following Apostolatos, Cutler, Sussman and Thorne, the evolution of the vectors S and L in the momentary plane spanned by these vectors is separated from the evolution of the plane in space. The radiation-induced change in the spin is smaller than the leading-order spin terms in the momentary angular momentum loss. This enables us to compute the averaged losses in the constants of motion E, L and L_S=L cos kappa. In the latter, the radiative spin loss terms average to zero. An alternative description using the orbital elements a,e and kappa is given. The finite mass effects contribute terms, comparable in magnitude, to the basic, test-particle spin terms in the averaged losses.Comment: 12 pages, 1 figure, Phys.Rev.D15, March, 199

College Republicans and Conservative Social Identity

Through participant-observation and interviews, I explore the conservative social identity of College Republicans at a midsize, midtier public university in the United States. Using the concepts of repertoires and frames, I analyze how individuals make claims to political social identities. Specifically, I show that symbolic appeals to the free market were an essential aspect of the conservative repertoire at my field site. Furthermore, the shifting and contradictory frames used by the College Republicans in this study demonstrate that their discursive political practices were not primarily about policy preferences; they were about affirming a conservative social identity. Understanding how stated policy preferences and identity intertwine in everyday political talk has important implications for American democracy

Hollywood, Bike Messengers, and the New Economy

The sociological study of popular cinema provides an analytic entry point for exploring how economic realities are given meaning through cultural products. In this paper, I compare how two Hollywood movies about bike messengers, Quicksilver and Premium Rush, position their main characters in relationship to the new economy. Both films provide commentaries on work and social class, but, as products of unique socio-historical periods, I argue that their commentaries differ significantly. Produced in the 1980s, Quicksilver uses messengering as a form of middle-class redemption, allowing the protagonist to return to the world of capitalist finance. By contrast, as a product of the Great Recession, Premium Rush offers a utopian vision of self-determination for low-wage service workers at the same time that it reifies the uncertainty, unpredictability, and riskiness that increasingly characterize American labor. I also show that both films converge in their portrayal of women and working-class blacks

Gravity Waves, Chaos, and Spinning Compact Binaries

Spinning compact binaries are shown to be chaotic in the Post-Newtonian expansion of the two body system. Chaos by definition is the extreme sensitivity to initial conditions and a consequent inability to predict the outcome of the evolution. As a result, the spinning pair will have unpredictable gravitational waveforms during coalescence. This poses a challenge to future gravity wave observatories which rely on a match between the data and a theoretical template.Comment: Final version published in PR