It’s Time to Talk of Other Things: of Black Power, War, and Beauty Queens

The history of military entertainment has become more popular in recent years as scholars have begun to identify the insights that studying entertainment reveals about culture and institutions. This thesis presents a piece of this growing historiography by analyzing the roles of three Miss Black America pageant winners who toured Vietnam in 1970, 1971, and 1972. Despite the variable and sometimes unclear roles of these women, they ultimately boosted the morale of black service members and became symbols of black power, black beauty, and black culture during their tours

Exploring Plant-Plant Interactions and Nutrient Manipulation as Strategies for Thorn Scrub and Thorn Forest Restoration

Restoration of thorn scrub and thorn forest communities in South Texas is hindered by harsh environmental conditions and hypercompetitive invasive grasses. The success of thorn scrub/thorn forest restoration efforts depends on increasing seedling survival and growth by reducing stress after transplantation. Four experiments evaluated initial effects of plant-plant interactions and nutrient manipulation on thorn forest restoration. High density planting along with the use of nurse plants look promising; survival was generally higher under these conditions and growth was unaffected or in the case of high-density planting, promoted. Nutrient sequestration by sorghum had little effect on seedling performance and cover of grass and other plants, but localized fertilization benefited the seedlings. Allelopathy is promising; however, field studies must be performed to confirm benefits in the field. Overall positive plant-plant interactions resulted higher survival and growth in this study and should be implemented as thorn scrub and thorn forest restoration strategies

Source amplitudes for active exterior cloaking

The active cloak comprises a discrete set of multipole sources that destructively interfere with an incident time harmonic scalar wave to produce zero total field over a finite spatial region. For a given number of sources and their positions in two dimensions it is shown that the multipole amplitudes can be expressed as infinite sums of the coefficients of the incident wave decomposed into regular Bessel functions. The field generated by the active sources vanishes in the infinite region exterior to a set of circles defined by the relative positions of the sources. The results provide a direct solution to the inverse problem of determining the source amplitudes. They also define a broad class of non-radiating discrete sources.Comment: 21 pages, 17 figure

Resonant Interactions Between Protons and Oblique Alfv\'en/Ion-Cyclotron Waves

Resonant interactions between ions and Alfv\'en/ion-cyclotron (A/IC) waves may play an important role in the heating and acceleration of the fast solar wind. Although such interactions have been studied extensively for "parallel" waves, whose wave vectors ${\bf k}$ are aligned with the background magnetic field ${\bf B}_0$, much less is known about interactions between ions and oblique A/IC waves, for which the angle $\theta$ between ${\bf k}$ and ${\bf B}_0$ is nonzero. In this paper, we present new numerical results on resonant cyclotron interactions between protons and oblique A/IC waves in collisionless low-beta plasmas such as the solar corona. We find that if some mechanism generates oblique high-frequency A/IC waves, then these waves initially modify the proton distribution function in such a way that it becomes unstable to parallel waves. Parallel waves are then amplified to the point that they dominate the wave energy at the large parallel wave numbers at which the waves resonate with the particles. Pitch-angle scattering by these waves then causes the plasma to evolve towards a state in which the proton distribution is constant along a particular set of nested "scattering surfaces" in velocity space, whose shapes have been calculated previously. As the distribution function approaches this state, the imaginary part of the frequency of parallel A/IC waves drops continuously towards zero, but oblique waves continue to undergo cyclotron damping while simultaneously causing protons to diffuse across these kinetic shells to higher energies. We conclude that oblique A/IC waves can be more effective at heating protons than parallel A/IC waves, because for oblique waves the plasma does not relax towards a state in which proton damping of oblique A/IC waves ceases

Active Exterior Cloaking

A new method of cloaking is presented. For two-dimensional quasistatics it is proven how a single active exterior cloaking device can be used to shield an object from surrounding fields, yet produce very small scattered fields. The problem is reduced to finding a polynomial which is approximately one within one disk and zero within a second disk, and such a polynomial is constructed. For the two-dimensional Helmholtz equation, it is numerically shown that three active exterior devices placed around the object suffice to produce very good cloaking.Comment: 4 pages, 3 figures, submitted to Physical Review Letter

Relationships among demographic variables, organizational culture, interpersonal self-efficacy and perceived job performance.

The goal of this study was to investigate the relationships among demographics variables (age, sex, and ethnicity), organizational culture, interpersonal self-efficacy, and perceived job performance of nonprofit human service workers. The 13 participating organizations provided services such as adoption assistance, adult daycare services, child care resource and referral help, children\u27s daycare services, family counseling, children and youth mentoring, residential care for elderly, residential care for persons with disabilities, and substance abuse treatment programs. Only 607 full-time workers filled in the questionnaire. The response rate was 54%. Findings in the present study found that self-efficacy is a major predictor of performance. This study found that to perform more effectively at the interpersonal level, nonprofit human service workers require expertise,resources, organizational and supervisor support, self-efficacy and the opportunity to engage in interpersonal interactions on job-related matters. Furthermore, the empirical results of this study support the two categories of job performance: task and contextual performance, and individual differences among workers. Sex and ethnicity had a disordinal interaction on self-ratings of contextual job performance. The findings have implications for workers, managers, policymakers, and nonprofit researchers. Suggestions are also offered to improve areas such as management and communication practices, advocating, counseling, and mentoring skills, and collaborating, supporting, volunteering, and technical skills

Real-Time Predictive Modeling and Robust Avoidance of Pedestrians with Uncertain, Changing Intentions

To plan safe trajectories in urban environments, autonomous vehicles must be able to quickly assess the future intentions of dynamic agents. Pedestrians are particularly challenging to model, as their motion patterns are often uncertain and/or unknown a priori. This paper presents a novel changepoint detection and clustering algorithm that, when coupled with offline unsupervised learning of a Gaussian process mixture model (DPGP), enables quick detection of changes in intent and online learning of motion patterns not seen in prior training data. The resulting long-term movement predictions demonstrate improved accuracy relative to offline learning alone, in terms of both intent and trajectory prediction. By embedding these predictions within a chance-constrained motion planner, trajectories which are probabilistically safe to pedestrian motions can be identified in real-time. Hardware experiments demonstrate that this approach can accurately predict pedestrian motion patterns from onboard sensor/perception data and facilitate robust navigation within a dynamic environment.Comment: Submitted to 2014 International Workshop on the Algorithmic Foundations of Robotic

Effects of lattice distortion and Jahn–Teller coupling on the magnetoresistance of La0.7Ca0.3MnO3 and La0.5Ca0.5CoO3 epitaxial films

Studies of La0.7Ca0.3MnO3 epitaxial films on substrates with a range of lattice constants reveal two dominant contributions to the occurrence of colossal negative magnetoresistance (CMR) in these manganites: at high temperatures (T → TC, TC being the Curie temperature), the magnetotransport properties are predominantly determined by the conduction of lattice polarons, while at low temperatures (T ≪ TC/, the residual negative magnetoresistance is correlated with the substrate-induced lattice distortion which incurs excess magnetic domain wall scattering. The importance of lattice polaron conduction associated with the presence of Jahn–Teller coupling in the manganites is further verified by comparing the manganites with epitaxial films of another ferromagnetic perovskite, La0.5Ca0.5CoO3. Regardless of the differences in the substrate-induced lattice distortion, the cobaltite films exhibit much smaller negative magnetoresistance, which may be attributed to the absence of Jahn–Teller coupling and the high electron mobility that prevents the formation of lattice polarons. We therefore suggest that lattice polaron conduction associated with the Jahn–Teller coupling is essential for the occurrence of CMR, and that lattice distortion further enhances the CMR effects in the manganites

Subject Perception of the Effectiveness of an Audio Slide Presentation as a Means of a Consent Review

poster abstractPrior to its initiation, the investigation was reviewed and approved by the IUPUI Institutional Review Board. In clinical research involving humans, it is extremely important that those that participate have a clear understanding of the purpose and procedures of the study as well as any risks or benefits associated with their participation. While required to be written in 8th grade language, informed consent statements may fail at fully informing the participant due to their length and legal and medical terminology required. Also, many adults have poor reading skills. This pilot study assessed subject perception as to the effectiveness of a short audiovisual slide presentation as a means of reviewing key components of the informed consent they had been asked to read. The presentation was provided in English or Spanish (approx. 10 minutes in length) based on the subject’s preference. At the end of the presentation, an anonymous questionnaire containing seven questions regarding their view of the effectiveness of the audiovisual slide presentation was given to the participant. After recording and analyzing the information obtained from the questionnaire it was demonstrated that the majority of subjects believed the presentation improved their overall ability to understand the information provided in the informed consent statement and that it did not appreciably lengthen the consenting process. The results seem to confirm the hypothesis that a presentation such as this has a positive effect in the understanding of the consenting process. This method proved successful in determining the effectiveness of an audio slide presentation as a means of a consent review. Future research may be performed to determine if preferences may vary based on demographic factors such as race or gender