Mejorar La Raza: measuring the implicit anti-black racial bias of multiracial individuals.

This dissertation sought to examine if there are implicit anti-Black racial bias differences across multiracial people who identify as Black/White compared to multiracial people who do not identify as Black/White, accounting for age, citizenship, and education level. It was also determined if age, citizenship status, and education level moderate the relationship between multiracial identity and implicit anti-Black racial bias. The theories guiding this dissertation were: Heider’s Balance Theory, Multiracial Identity Development, and White Identity Development. The data were collected from Project Implicit, a non-profit organization and international collaborative of researchers who are interested in implicit social cognition. The data analysis approach was a hierarchical multiple linear regression analysis that also tested for interaction effects. The independent variables were race (Multiracial – Black/White, Multiracial – Not Black/White), age, education level, and U.S. citizenship status. The dependent variable was overall IAT score, which measures implicit anti-Black racial bias. The results of this study suggest that multiracial people who do not identify as Black/White have more implicit anti-Black racial bias than multiracial people who do identify as Black/White. Age, citizenship status, and education level were all found to not moderate the relationship between multiracial identity and implicit anti-Black racial bias. This study begins to fill in a gap in existing literature, as little research has been done that examines the implicit racial bias and implicit anti-Black racial bias of multiracial individuals. The results of this study illustrate the importance of support for multiracial individuals (especially for multiracial people who do not identify as Black/White) in navigating implicit racial biases, implicit anti-Black racial bias, colorism, internalized racism, and horizontal racial oppression. Additionally, the results of this study contradict the idea of a “shared” multiracial experience that exists in previous research. The results of this study imply that there is a need for more individualized attention and support for multiracial individuals based on their specific racial identifications. The results also show a need for more research on implicit racial bias, implicit anti-Black racial bias and multiracial individuals based on specific racial identifications

A new model for mixing by double-diffusive convection (semi-convection): I. The conditions for layer formation

The process referred to as "semi-convection" in astrophysics and "double-diffusive convection in the diffusive regime" in Earth and planetary sciences, occurs in stellar and planetary interiors in regions which are stable according to the Ledoux criterion but unstable according to the Schwarzschild criterion. In this series of papers, we analyze the results of an extensive suite of 3D numerical simulations of the process, and ultimately propose a new 1D prescription for heat and compositional transport in this regime which can be used in stellar or planetary structure and evolution models. In a preliminary study of the phenomenon, Rosenblum et al. (2011) showed that, after saturation of the primary instability, a system can evolve in one of two possible ways: the induced turbulence either remains homogeneous, with very weak transport properties, or transitions into a thermo-compositional staircase where the transport rate is much larger (albeit still smaller than in standard convection). In this paper, we show that this dichotomous behavior is a robust property of semi-convection across a wide region of parameter space. We propose a simple semi-analytical criterion to determine whether layer formation is expected or not, and at what rate it proceeds, as a function of the background stratification and of the diffusion parameters (viscosity, thermal diffusivity and compositional diffusivity) only. The theoretical criterion matches the outcome of our numerical simulations very adequately in the numerically accessible "planetary" parameter regime, and can easily be extrapolated to the stellar parameter regime. Subsequent papers will address more specifically the question of quantifying transport in the layered case and in the non-layered case.Comment: Submitted to Ap

Guiding of Rydberg atoms in a high-gradient magnetic guide

We study the guiding of $^{87}$Rb 59D$_{5/2}$ Rydberg atoms in a linear, high-gradient, two-wire magnetic guide. Time delayed microwave ionization and ion detection are used to probe the Rydberg atom motion. We observe guiding of Rydberg atoms over a period of 5 ms following excitation. The decay time of the guided atom signal is about five times that of the initial state. We attribute the lifetime increase to an initial phase of $l$-changing collisions and thermally induced Rydberg-Rydberg transitions. Detailed simulations of Rydberg atom guiding reproduce most experimental observations and offer insight into the internal-state evolution

Tracking and data systems support for the Helios project. Volume 2: DSN support of Project Helios April 1975 - May 1976

Deep Space Network activities in the development of the Helios B mission from planning through entry of Helios 2 into first superior conjunction (end of Mission Phase II) are summarized. Network operational support activities for Helios 1 from first superior conjunction through entry into third superior conjunction are included

Chromofields of Strings and Baryons

We calculate color electric fields of quark/antiquark ($\bar{q}q$) and 3 quark ($qqq$) systems within the chromodielectric model (CDM). We explicitly evaluate the string tension of flux tubes in the $\bar{q}q$--system and analyze their profile. To reproduce results of lattice calculations we use a bag pressure $B = (320 MeV)^4$ from which an effective strong coupling constant $\alpha_s \approx 0.3$ follows. With these parameters we get a $Y$ shaped configuration for large $qqq$--systems.Comment: Contributions to QNP 2002, Quarks and Nuclear Physics, Juelich, Germany 3 pages, 10 eps figure

A Systematic Review of the Critical Factors for Success of Mobile Learning in Higher Education (University Students\u27 Perspective)

The phenomenon of the use of a mobile learning (m-Learning) platform in educational institutions is slowly gaining momentum. However, the enthusiasm with which mobile phones have been welcomed into every aspect of our lives is not yet apparent in the educational sector. To understand the reason, it is important to understand user expectations of the system. This article documents a systematic review of existing studies to find the success factors for effective m-Learning. Our systematic review collates results from 30 studies conducted in 17 countries, where 13 critical success factors were found to strongly impact m-Learning implementation. Using these results within the framework of the diffusion of innovation model for innovation adoption and the critical success factors together help us see what aspects of the innovation decision process are the likely causes of the reduced take-up of m-Learning by university students

In-medium Yang-Mills equations: a derivation and canonical quantization

The equations for Yang-Mills field in a medium are derived in a linear approximation with respect to the gauge coupling parameter and the external field. The obtained equations closely resemble the macroscopic Maxwell equations. A canonical quantization is performed for a family of Fermi-like gauges in the case of constant and diagonal (in the group indices) tensors of electric permittivity and magnetic permeability. The physical subspace is defined and the gauge field propagator is evaluated for a particular choice of the gauge. The propagator is applied for evaluation of the cross-section of ellastic quark scattering in the Born approximation. Possible applications to Cherenkov-type gluon radiation are commented briefly.Comment: 27 pages, references added, version extended with emphasis on non-Abelian gauge group impact on medium characteristics. To appear in J. Phys.

Thermohaline mixing and the photospheric composition of low-mass giant stars

We compute full evolutionary sequences of red giant branch stars close to the luminosity bump by including state of the art composition transport prescriptions for the thermohaline mixing regimes. In particular we adopt a self-consistent double-diffusive convection theory, that allows to handle the instabilities that arise when thermal and composition gradients compete against each other, and a very recent empirically motivated and parameter free asymptotic scaling law for thermohaline composition transport. In agreement with previous works, we find that during the red giant stage, a thermohaline instability sets in shortly after the hydrogen burning shell (HBS) encounters the chemical discontinuity left behind by the first dredge-up. We also find that the thermohaline unstable region, initially appearing at the exterior wing of the HBS, is unable to reach the outer convective envelope, with the consequence that no mixing of elements that produces a non-canonical modification of the stellar surface abundances occurs. Also in agreement with previous works, we find that by artificially increasing the mixing efficiency of thermohaline regions it is possible to connect both unstable regions, thus affecting the photospheric composition. However, we find that in order to reproduce the observed abundances of red giant branch stars close to the luminosity bump, thermohaline mixing efficiency has to be artificially increased by about 4 orders of magnitude from that predicted by recent 3D numerical simulations of thermohaline convection close to astrophysical environments. From this we conclude the chemical abundance anomalies of red giant stars cannot be explained on the basis of thermohaline mixing alone.Comment: 7 pages, 6 figures, accepted for publication in A&

Peer Reporting and the Perception of Fairness

Economic motives are not the only reasons for committing a (small) crime. People consider social norms and perceptions of fairness before judging a situation and acting upon it. If someone takes a bundle of printing paper from the office for private use at home, then a colleague who sees this can take action by talking to the offender or someone else (peer reporting). We investigate how fairness perception influences the decision to act upon incorrect behavior or not