The Texas Miracle: Racial Discrimination Alive and Well Sixty Years after Brown

The purpose of this study is to determine whether or not and how race plays a role in the funding of Texas public school districts. Beyond these determinations, we explore the legal implications that would come from evidence of a discriminatory funding system, specifically in light of Title VI of the Civil Rights Act. In this study, we use both quantitative and legal analysis. We explore population-level data containing information on the funding and racial composition of all Texas public school districts. Descriptive methods such as cross-tabulations were paired with correlation and measures of effect size to explore the relationship between race and school district funding. In our legal analysis, we review relevant legal statutes and case law, situating our quantitative findings within the larger, school finance jurisprudence context.Educatio

Non-destructive spatial heterodyne imaging of cold atoms

We demonstrate a new method for non-destructive imaging of laser-cooled atoms. This spatial heterodyne technique forms a phase image by interfering a strong carrier laser beam with a weak probe beam that passes through the cold atom cloud. The figure of merit equals or exceeds that of phase-contrast imaging, and the technique can be used over a wider range of spatial scales. We show images of a dark spot MOT taken with imaging fluences as low as 61 pJ/cm^2 at a detuning of 11 linewidths, resulting in 0.0004 photons scattered per atom.Comment: text+3 figures, submitted to Optics Letter

Dynamics and statistical mechanics of ultra-cold Bose gases using c-field techniques

We review phase space techniques based on the Wigner representation that provide an approximate description of dilute ultra-cold Bose gases. In this approach the quantum field evolution can be represented using equations of motion of a similar form to the Gross-Pitaevskii equation but with stochastic modifications that include quantum effects in a controlled degree of approximation. These techniques provide a practical quantitative description of both equilibrium and dynamical properties of Bose gas systems. We develop versions of the formalism appropriate at zero temperature, where quantum fluctuations can be important, and at finite temperature where thermal fluctuations dominate. The numerical techniques necessary for implementing the formalism are discussed in detail, together with methods for extracting observables of interest. Numerous applications to a wide range of phenomena are presented.Comment: 110 pages, 32 figures. Updated to address referee comments. To appear in Advances in Physic

Classical Region of a Trapped Bose Gas

The classical region of a Bose gas consists of all single-particle modes that have a high average occupation and are well-described by a classical field. Highly-occupied modes only occur in massive Bose gases at ultra-cold temperatures, in contrast to the photon case where there are highly-occupied modes at all temperatures. For the Bose gas the number of these modes is dependent on the temperature, the total number of particles and their interaction strength. In this paper we characterize the classical region of a harmonically trapped Bose gas over a wide parameter regime. We use a Hartree-Fock approach to account for the effects of interactions, which we observe to significantly change the classical region as compared to the idealized case. We compare our results to full classical field calculations and show that the Hartree-Fock approach provides a qualitatively accurate description of classical region for the interacting gas.Comment: 6 pages, 5 figures; updated to include new results with interaction

Cyber Bullying and Free Speech: Striking an Age-Appropriate Balance

Cyber bullying has generally been dealt with by the courts using one of two legal analyses: the “true threats” doctrine, or the Tinker substantial disruption test. This law review, the Cleveland State Law Review, recently published Anti-Cyber Bullying Statutes: Threat to Student Free Speech (referred to herein as “the Threat to Speech article”), which addressed these two theories, and argued that the current evolution of cyber bullying legislation simply goes too far. For example, Hayward states Anti-cyber bullying laws are the greatest threat to student speech because they seek to censor it anytime it occurs, using “substantial disruption” of school activities as justification and often based only on mere suspicion of potential disruption. The Threat to Speech article advocates greater protection of student speech. While we recognize that any regulation of speech by the state may raise First Amendment concerns, we are not so quick to conclude that cyber bullying regulations “chill student free speech.” Our analysis of the law leads us to the conclusion that school administrators have relatively broad discretion to regulate student speech, provided those regulations either serve legitimate pedagogical ends or protect the rights of other students and the school environment. Indeed, as we will demonstrate below, the evolution of the Supreme Court’s student free speech jurisprudence has followed the trend of granting more and more leeway to administrators. Contrary to the claims in the Threat to Speech article, in our opinion that leeway clearly extends to allowing regulation of speech which originates off campus but has a reasonable likelihood of making its way on campus. We also believe that, in addition to true threats and the Tinker substantial disruption standard described in the Threat to Speech article, school administrators may also regulate student speech consistent with the Court’s holding in Fraser—which set what we refer to as the “fundamental values standard” —and based on the fighting words doctrine

Constitutional Implications of School Punishment for Cyber Bullying

In this article, we address the scope of student free speech rights as it relates to cyber bullying. We provide a review of legal theories under which school administrators can address cyber bullying while still respecting student free speech rights and the First Amendment. Additionally, we address the jurisdiction of administrators to deal with off-campus bullying conduct

Cyber Bullying and Free Speech: Striking an Age-Appropriate Balance

Cyber bullying has generally been dealt with by the courts using one of two legal analyses: the “true threats” doctrine, or the Tinker substantial disruption test. This law review, the Cleveland State Law Review, recently published Anti-Cyber Bullying Statutes: Threat to Student Free Speech (referred to herein as “the Threat to Speech article”), which addressed these two theories, and argued that the current evolution of cyber bullying legislation simply goes too far. For example, Hayward states Anti-cyber bullying laws are the greatest threat to student speech because they seek to censor it anytime it occurs, using “substantial disruption” of school activities as justification and often based only on mere suspicion of potential disruption. The Threat to Speech article advocates greater protection of student speech. While we recognize that any regulation of speech by the state may raise First Amendment concerns, we are not so quick to conclude that cyber bullying regulations “chill student free speech.” Our analysis of the law leads us to the conclusion that school administrators have relatively broad discretion to regulate student speech, provided those regulations either serve legitimate pedagogical ends or protect the rights of other students and the school environment. Indeed, as we will demonstrate below, the evolution of the Supreme Court’s student free speech jurisprudence has followed the trend of granting more and more leeway to administrators. Contrary to the claims in the Threat to Speech article, in our opinion that leeway clearly extends to allowing regulation of speech which originates off campus but has a reasonable likelihood of making its way on campus. We also believe that, in addition to true threats and the Tinker substantial disruption standard described in the Threat to Speech article, school administrators may also regulate student speech consistent with the Court’s holding in Fraser—which set what we refer to as the “fundamental values standard” —and based on the fighting words doctrine

Wetland Bird Abundance and Safety Implications for Military Aircraft Operations

Wetlands with associated avifauna can pose a substantial hazard to aviation safety, potentially increasing bird–aircraft collision (strike) risk when located near air operations areas.We modeled year-round use by wetland avifauna of Drummond Flats Wildlife Management Area (Drummond Flats), a wetland complex located within 10 km of Vance Air Force Base (AFB), Enid, Oklahoma, USA. Our objectives were to 1) quantify seasonal avifauna abundances at Drummond Flats; 2) test a priori models reflecting use by bird species recognized as hazardous to aviation safety relative to environmental factors including flooded wetland habitat and vegetation cover; 3) use these models to predict maximal expected abundances of wetland avifauna during flood conditions; and 4) compare our findings with reported bird strikes at Vance AFB. Drought conditions influenced avian use during our study. Of the species expected to respond predictably to flooded wetland habitat, only ducks (Anatinae) occurred in numbers conducive to modeling. Using zeroinflated Poisson models, we found that duck abundance was positively associated with permanent wetland habitat type and, excluding winter, available habitat area (i.e., standing water); whereas, \u3e50% vegetation cover was negatively correlated with abundance. No model predicted \u3e97.2 ducks/ha for any habitat type, except during winter. Our models also identified potential peaks in abundance not evident from raw count data, emphasizing the benefits of this approach. Identifying factors driving abundances also enables targeted management of hazardous species. Further, we found double-sampling to be a practical method for assessing detection bias during avian surveys at wetlands. Restricting to obligate wetland species associated with Drummond Flats, we found 1 strike/184,212 flight-hours, which was an order of magnitude lower than the average for U.S. civil aircraft (1990–2014). Thus, under drought conditions, bird use of Drummond Flats likely did not elevate strike risk for Vance AFB aircraft operations. Published 2017. This article is a U.S. Government work and is in the public domain in the US

Bose-Einstein Condensation from a Rotating Thermal Cloud: Vortex Nucleation and Lattice Formation

We develop a stochastic Gross-Pitaveskii theory suitable for the study of Bose-Einstein condensation in a {\em rotating} dilute Bose gas. The theory is used to model the dynamical and equilibrium properties of a rapidly rotating Bose gas quenched through the critical point for condensation, as in the experiment of Haljan et al. [Phys. Rev. Lett., 87, 21043 (2001)]. In contrast to stirring a vortex-free condensate, where topological constraints require that vortices enter from the edge of the condensate, we find that phase defects in the initial non-condensed cloud are trapped en masse in the emerging condensate. Bose-stimulated condensate growth proceeds into a disordered vortex configuration. At sufficiently low temperature the vortices then order into a regular Abrikosov lattice in thermal equilibrium with the rotating cloud. We calculate the effect of thermal fluctuations on vortex ordering in the final gas at different temperatures, and find that the BEC transition is accompanied by lattice melting associated with diminishing long range correlations between vortices across the system.Comment: 15 pages, 12 figure