Reclaiming Self-Determination: A Call for Intraracial Adoption

The wholesale marketing of Black children to suit the economic interests of others was one of the cruelest aspects of slavery. Sons and daughters who were traded away from their parents would later struggle in vain to remember their families, their customs, and their countries of origin. Even the extended families which evolved in the transient slave communities were continually fragmented as children and their caretakers were merchanted to different plantations according to the whims of White slavemasters. 1 Although due to quite different circumstances, today the Black community continues to lose its children. At present, government sponsored entities, 2 overlooking the potentially harmful consequences of transracial adoption, 3 remove Black children from their communities through transracial adoption with Whites who are unable to secure children of their own race. 4 Part I of this Note provides an overview of transracial adoption legislation leading up to the Multiethnic Placement Act (MPA) of 1994 and critiques the Act. Part II considers the effects of the transracial placement of Black children. This section focuses on the survival skills Black transracial adoptees would or would not acquire in a White home and the effect such an adoption may have on their racial identities and sense of community. Part III examines the current state of the law regarding the transracial adoption of Native American children. This section concludes that Black children should be accorded similar treatment, and moreover, that Black parents should be encouraged to adopt thereby diminishing the lengthy wait faced by adoptees ..

The influence of convective activity on the vorticity budget

The influence of convective activity on the vorticity budget was determined during the AVE VII and AVE-SESAME I periods. This was accomplished by evaluating each term in the expanded vorticity equation with twisting and tilting and friction representing the residual of all other terms. Convective areas were delineated by use of radar summary charts. The influence of convective activity was established by analyzing contoured fields of each term as well as numerical values and profiles of the various terms in convective and nonconvective areas. Vertical motion was computed by the kinematic method, and all computations were performed over the central United States using a grid spacing of 158 km. The results show that, in convective areas in particular, the residual is of comparable magnitude to the horizontal advection and divergence terms, and therefore, cannot be neglected. In convective areas, the residual term represents a sink of vorticity below 500 mb and a strong source near 300 mb. In nonconvective areas, the residual was small in magnitude at all levels, but tended to be negative (vorticity sink) at 300 mb. The local change term, over convective areas, tended to be balanced by the residual term, and appeared to be a good indicator of development (vorticity becoming more cyclonic). Finally, the shape of the vertical profiles of the term in the budget equation agreed with those found by other investigators for easterly waves, but the terms were one order of magnitude larger than those for easterly waves

Higher-dimensional resolution of dilatonic black hole singularities

We show that the four-dimensional extreme dilaton black hole with dilaton coupling constant $a= \sqrt{p/(p+2)}$ can be interpreted as a {\it completely non-singular}, non-dilatonic, black $p$-brane in $(4+p)$ dimensions provided that $p$ is {\it odd}. Similar results are obtained for multi-black holes and dilatonic extended objects in higher spacetime dimensions. The non-singular black $p$-brane solutions include the self-dual three brane of ten-dimensional N=2B supergravity and a multi-fivebrane solution of eleven-dimensional supergravity. In the case of a supersymmetric non-dilatonic $p$-brane solution of a supergravity theory, we show that it saturates a bound on the energy per unit $p$-volume.Comment: 27 pages, R/94/28, UCSBTH-94-35 (Comments added to the discussion section

Force reflecting hand controller

A universal input device for interfacing a human operator with a slave machine such as a robot or the like includes a plurality of serially connected mechanical links extending from a base. A handgrip is connected to the mechanical links distal from the base such that a human operator may grasp the handgrip and control the position thereof relative to the base through the mechanical links. A plurality of rotary joints is arranged to connect the mechanical links together to provide at least three translational degrees of freedom and at least three rotational degrees of freedom of motion of the handgrip relative to the base. A cable and pulley assembly for each joint is connected to a corresponding motor for transmitting forces from the slave machine to the handgrip to provide kinesthetic feedback to the operator and for producing control signals that may be transmitted from the handgrip to the slave machine. The device gives excellent kinesthetic feedback, high-fidelity force/torque feedback, a kinematically simple structure, mechanically decoupled motion in all six degrees of freedom, and zero backlash. The device also has a much larger work envelope, greater stiffness and responsiveness, smaller stowage volume, and better overlap of the human operator's range of motion than previous designs

POPEYE: A production rule-based model of multitask supervisory control (POPCORN)

Recent studies of relationships between subjective ratings of mental workload, performance, and human operator and task characteristics have indicated that these relationships are quite complex. In order to study the various relationships and place subjective mental workload within a theoretical framework, we developed a production system model for the performance component of the complex supervisory task called POPCORN. The production system model is represented by a hierarchial structure of goals and subgoals, and the information flow is controlled by a set of condition-action rules. The implementation of this production system, called POPEYE, generates computer simulated data under different task difficulty conditions which are comparable to those of human operators performing the task. This model is the performance aspect of an overall dynamic psychological model which we are developing to examine and quantify relationships between performance and psychological aspects in a complex environment

Centrifugal Breakout of Magnetically Confined Line-Driven Stellar Winds

We present 2D MHD simulations of the radiatively driven outflow from a rotating hot star with a dipole magnetic field aligned with the star's rotation axis. We focus primarily on a model with moderately rapid rotation (half the critical value), and also a large magnetic confinement parameter, $\eta_{\ast} \equiv B_{\ast}^2 R_{\ast}^{2} / \dot{M} V_{\infty} = 600$. The magnetic field channels and torques the wind outflow into an equatorial, rigidly rotating disk extending from near the Kepler corotation radius outwards. Even with fine-tuning at lower magnetic confinement, none of the MHD models produce a stable Keplerian disk. Instead, material below the Kepler radius falls back on to the stellar surface, while the strong centrifugal force on material beyond the corotation escape radius stretches the magnetic loops outwards, leading to episodic breakout of mass when the field reconnects. The associated dissipation of magnetic energy heats material to temperatures of nearly $10^{8}$K, high enough to emit hard (several keV) X-rays. Such \emph{centrifugal mass ejection} represents a novel mechanism for driving magnetic reconnection, and seems a very promising basis for modeling X-ray flares recently observed in rotating magnetic Bp stars like $\sigma$ Ori E.Comment: 5 pages, 3 figures, accepted by ApJ

The most rapidly rotating He-strong emission line star: HR7355

Using archival spectroscopic and photometric data, we searched for massive stars with Balmer-emission consistent with magnetically confined circumstellar material. HR 7355 is a formerly unknown He-strong star showing Balmer emission. At V=6.02 mag, it is one of the brightest objects simultaneously showing anomalous helium absorption and hydrogen emission. Among similar objects, only sigma Ori E has so far been subjected to any systematic analysis of the circumstellar material responsible for the emission. We argue that the double-wave photometric period of 0.52d corresponds to the rotation period. In tandem with the high projected equatorial velocity, v sin i=320 km/s, this short period suggests that HR 7355 is the most rapidly rotating He-strong star known to date; a class that was hitherto expected to host stars with slow to moderate rotation only.Comment: 4 pages with 2 figures. Accepted for publication as Research Note by Astronomy and Astrophysic

EVALUATING FUTURE RESERVOIR STORAGE IN THE RIO GRANDE USING NORMALIZED CLIMATE PROJECTIONS AND A WATER BALANCE MODEL

We develop and implement new tools for assessing the future of surface water supplies in downstream reaches of the Rio Grande, for which Elephant Butte Reservoir is the major storage reservoir. First, a normalization procedure is developed to adjust natural Rio Grande streamflows simulated by dynamical models in downstream reaches. The normalization accounts for upstream anthropogenic impairments to flow that are not considered in the model, thereby yielding downstream flows closer to observed values and more appropriate for use in assessments of future flows in downstream reaches. The normalization is applied to assess the potential effects of climate change on future water availability in the Rio Grande Basin at a gage just above Elephant Butte reservoir. Model simulated streamflow values were normalized force simulated flows to have the same mean and variance as observed flows over a historical baseline period, yielding normalization ratios that can be applied to future flows when water management decisions are unknown. At the gage considered in this study, the effect of the normalization is to reduce all simulated flow values by nearly 72% on average, indicative of the large fraction of natural flow diverted from the river upstream from the gage. The normalized streamflow scenarios are then implemented as the main boundary condition in a simple water balance model to analyze future policy options, using reservoir storage and downstream releases to compare management choices. It takes four years of twice the average annual inflow to fill Elephant Butte Reservoir to full operating capacity, starting from near-empty initial conditions as occurred in late 2018. In terms of increasing downstream releases and increasing reservoir storage, reducing direct reservoir evaporation was the best option from a strictly hydrologic perspective. Increasing the future inflows by reducing upstream diversions increases reservoir storage and Caballo releases, but there was also an increase in reservoir evaporation. Lastly, maintaining a minimum storage threshold for reservoir storage increases future average storage, but also leads to an increase in reservoir evaporation and a decrease in releases. Water stored in Elephant Butte Reservoir is lost via the positive correlation between increasing reservoir storage, and thus the increased surface area, and the subsequent rise in direct reservoir evaporation. Therefore, the water balance model suggests the most hydrologically efficient policy option involves reducing reservoir evaporation, although the water balance model does not consider the costs of methods to reduce evaporation

Methods for suspensions of passive and active filaments

Flexible filaments and fibres are essential components of important complex fluids that appear in many biological and industrial settings. Direct simulations of these systems that capture the motion and deformation of many immersed filaments in suspension remain a formidable computational challenge due to the complex, coupled fluid--structure interactions of all filaments, the numerical stiffness associated with filament bending, and the various constraints that must be maintained as the filaments deform. In this paper, we address these challenges by describing filament kinematics using quaternions to resolve both bending and twisting, applying implicit time-integration to alleviate numerical stiffness, and using quasi-Newton methods to obtain solutions to the resulting system of nonlinear equations. In particular, we employ geometric time integration to ensure that the quaternions remain unit as the filaments move. We also show that our framework can be used with a variety of models and methods, including matrix-free fast methods, that resolve low Reynolds number hydrodynamic interactions. We provide a series of tests and example simulations to demonstrate the performance and possible applications of our method. Finally, we provide a link to a MATLAB/Octave implementation of our framework that can be used to learn more about our approach and as a tool for filament simulation