Academic medical centers (AMCs) face challenges in conducting research among traditionally marginalized communities due to long-standing community mistrust. Evidence suggests that some AMC faculty and staff lack an understanding of the history of distrust and social determinants of health (SDH) affecting their communities. Wake Forest Clinical and Translational Science Institute Program in Community Engagement (PCE) aims to build bridges between communities and Wake Forest Baptist Health by equipping faculty, clinicians, administrators, and staff (FCAS) with a better understanding of SDH. The PCE collaborated with community partners to develop and implement community tours to improve cross-community AMC understanding and communication, enhance knowledge of SDH, and build awareness of community needs, priorities, and assets. Nine day-long tours have been conducted with 92 FCAS. Tours included routes through under-resourced neighborhoods and visits to community assets. Participant evaluations assessed program quality; 89% reported enhanced understanding of access-to-care barriers and how SDH affect health; 86% acknowledged the experience would improve future interactions with participants and patients; and 96% agreed they would recommend the tour to colleagues. This work supports the use of community tours as a strategy to improve cross-community AMC communication, build trust, and raise awareness of community needs, priorities, and assets.

Giant electromagnetic pulses (EMP) generated during the interaction of high-power lasers with solid targets can seriously degrade electrical measurements and equipment. EMP emission is caused by the acceleration of hot electrons inside the target, which produce radiation across a wide band from DC to terahertz frequencies. Improved understanding and control of EMP is vital as we enter a new era of high repetition rate, high intensity lasers (e.g. the Extreme Light Infrastructure). We present recent data from the VULCAN laser facility that demonstrates how EMP can be readily and effectively reduced. Characterization of the EMP was achieved using B-dot and D-dot probes that took measurements for a range of different target and laser parameters. We demonstrate that target stalk geometry, material composition, geodesic path length and foil surface area can all play a significant role in the reduction of EMP. A combination of electromagnetic wave and 3D particle-in-cell simulations is used to inform our conclusions about the effects of stalk geometry on EMP, providing an opportunity for comparison with existing charge separation models.

Placodontia were a group of marine reptiles that lived in shallow nearshore environments during the Triassic. Based on tooth morphology it has been inferred that they were durophagous, but tooth morphology differs among species: placodontoid placodonts have teeth described as hemispherical, and the teeth of more highly nested taxa within the cyamodontoid placodonts have been described as flat. In contrast, the sister taxon to the placodonts, Palatodonta bleekeri, like many other marine reptiles, has tall pointed teeth for eating soft-bodied prey. The goals of this paper are to quantify these different tooth morphologies and compare tooth shape among taxa and with a functionally “optimal” tooth. To quantify tooth morphology we measured the radius of curvature (RoC) of the occlusal surface by fitting spheres to 3D surface scans or computed microtomographic scans. Large RoCs correspond to flatter teeth, while teeth with smaller RoCs are pointier; positive RoCs have convex occlusal surfaces, and a negative RoC indicates that the occlusal surface of the tooth is concave. We found the placodontoid taxa have teeth with smaller RoCs than more highly nested taxa, and palatine teeth tend to be flatter and closer to the optimal morphology than maxillary teeth. Within one well-nested clade, the placochelyids, the rearmost palatine teeth have a more complex morphology than the predicted optimal tooth, with an overall concave occlusal surface with a small, medial cusp. These findings are in keeping with the hypothesis that placodonts were specialized durophagous predators with teeth modified to break hard prey items while resisting tooth failure.

The current study examined the influence of phonological structure and language experience on the nonword repetition performance of bilingual children. Twenty-six Spanish-dominant and 26 English-dominant Spanish–English bilingual five-year-old children were matched on current exposure to the dominant language and year of first exposure to English. Participants repeated non-wordlike nonwords in English and Spanish. The Spanish-dominant group performed better than the English-dominant group for both Spanish and English nonwords. In addition, there was a main effect for test language, where Spanish nonwords were produced more accurately than English nonwords overall. The Spanish-dominant group advantage for nonwords is interpreted as emerging from the extra practice the dominant Spanish speakers had producing multisyllabic words.

Population models for the Egyptian alfalfa weevil and alfalfa are reported, which compared favorably with field data. A mechanism for coupling the plant–herbivore trophic levels is suggested.

Frazer and Gilbert (1976) described the predation of pea aphids, Acyrthosiphon pisum (Harris), by adult coccinellids. They developed a formula to predict the predation rate as a function of temperature, predator density, and prey age-distribution and density. Gutierrez et al. (1979) extended the formula to describe several predators sharing the same prey. The following papers develop the study to cover the complete predator-prey relationship, including the dynamics of both predators and prey.

The spatial distribution of the Egyptian alfalfa weevil larvae using Iwao’s index of dispersion was examined in a California alfalfa field. The changing dispersion patterns with time were found to be influenced by both density induced competition for food and varying spatial distribution of host plants. values characteristic for both years quickly stabilized. This made possible a method for estimating leaf consumption rates by larval populations with an aggregated distribution, k being derived from . Field sampling decision rules were also determined.

The purpose of this study was to determine if different language measures resulted in the same classifications of language dominance and proficiency for a group of bilingual pre-kindergarteners and kindergarteners. Data were analyzed for 1029 Spanish–English bilingual pre-kindergarteners who spanned the full range of bilingual language proficiency. Parent questionnaires were used to quantify age of first exposure and current language use. Scores from a short test of semantic and morphosyntactic development in Spanish and English were used to quantify children's performance. Some children who were in the functionally monolingual range based on interview data demonstrated minimal knowledge of their other languages when tested. Current use accounted for more of the variance in language dominance than did age of first exposure. Results indicate that at different levels of language exposure children differed in their performance on semantic and morphosyntax tasks. These patterns suggest that it may be difficult to compare the results of studies that employ different measures of language dominance and proficiency. Current use is likely to be a useful metric of bilingual development that can be used to build a comprehensive picture of child bilingualism.

From the neodymium glass laser system Novette with two beams of 74 cm diameter and 18 kJ energy per pulse output in the nanosecond range, the design, the steps of the construction, and results of the system are reported. The two beams are synchronized to 5 psec and conversion to green light up to 78% has been realized. Conversion to four times the laser frequency is measured with more than 25% conversion. Simulation and measurement of laser beam properties at several locations permit an analysis to define the final Nova configuration. About half of Novette's experiments were to study short wave length laser–plasma interactions for the then better coupling by inverse bremsstrahlung mechanisms for inertial confinement fusion with laser intensities up to 1017 W/cm2. Experiments were divided between high density implosion research and non-local thermodynamic equilibrium plasma conditions.

This paper reports our effort to develop amorphous hydrogenated silicon carbide (a-SiC:H ) films specifically designed for MEMS applications using a semiconductor-grade organosilane known as trimethylsilane (3MS) as the precursor. In our work, the a-SiC:H films were deposited in a commercial PECVD system at a fixed temperature of 350˚C using 3MS diluted in helium (He). Films with thicknesses from ~ 100 nm to ~ 2μm, a typical range for MEMS applications, were deposited. Deposition parameters such RF power, deposition pressure, and 3MS-to-He ratio were explored to obtain films with low residual compressive stresses. Low temperature, post-deposition annealing at 450˚C was used to convert the as-deposited compressive residual stresses to moderate tensile stresses, which are desired for micromachined bridges, membranes and other anchored structures. Compositional analysis indicated that films with a Si-to-C ratio of 1 could be deposited under certain conditions. Mechanical properties such as Young's modulus and fracture strength were derived from the load-deflection behavior of micromachined freestanding membranes. Nanoindentation was used to verify the Young's modulus and determine the hardness. As expected, the films exhibit insulating properties with a relative dielectric constant at 3.90 for as-deposited films and 2.69 after annealing at 1100˚C, as determined from C-V measurements. Chemical inertness was tested in aqueous, corrosive solutions such as KOH and HNA. Prototype structures were fabricated using both surface micromachining and bulk micromachining techniques to demonstrate the potential of the a-SiC:H films for MEMS applications.

The Keck Interferometer Nuller (KIN) is one of the major scientific and technical precursors to the Terrestrial Planet Finder Interferometer (TPF-I) mission. KIN's primary objective is to measure the level of exo-zodiacal mid-infrared emission around nearby main sequence stars, which requires deep broad-band nulling of astronomical sources of a few Janskys at 10 microns. A number of new capabilitites are needed in order to reach that goal with the Keck telescopes: mid-infrared coherent recombination, interferometric operation in “split pupil” mode, N-band optical path stabilization using K-band fringe tracking and internal metrology, and eventually, active atmospheric dispersion correction. We report here on the progress made implementing these new functionalities, and discuss the initial levels of extinction achieved on the sky.

The phase stability of C-22 alloy (UNS N06022) gas tungsten arc welds was studied by aging samples at 593, 649, 704, and 760°C for times up to 6,000 hours. The tensile properties and the Charpy impact toughness of these samples were measured in the as-welded condition as well as after aging. The corrosion resistance was measured using standard immersion tests in acidic ferric sulfate (ASTM G 28 A) and 2.5% hydrochloric acid solutions at the boiling point. The microstructures of weld samples were examined using scanning electron microscopy (SEM). Precipitate volume fraction measurements were made using optical microscopy.

Degradation of the mechanical and corrosion properties of C-22 welds due to aging at all temperatures investigated was seen to occur sooner than was seen in C-22 base metal. An evaluation of the kinetics of nucleation and growth of the precipitates forming at these temperatures, however, indicated that no significant changes in TCP phase morphology would occur at temperatures below approximately 300°C.a

A significant improvement (40–60%) was reported in the low voltage (100–1000V) cathodoluminescence efficiency of ZnS phosphors coated with SiO2 by the sol-gel technique. The properties of the coatings were found to be critically dependent upon the precursor concentration, pH value and the temperature of the solution with optimum performance being obtained for a SiO2 concentration of 1.0 wt%, pH values between 7–9, and a solution temperature of 83 °C. The efficiency curves exhibited a characteristic voltage dependence which was analyzed by a one-dimensional numerical model. Enhanced low voltage efficiency was attributed to a reduction of surface recombination and the actual shape of the efficiency curve was determined by the interplay between the reduction of surface recombination and energy losses in the SiO2 coating.

Changes in the microstructure, mechanical properties and corrosion resistance of C-22 alloy were studied systematically as a function of aging temperature and aging time. Aging was performed in the temperature range 260°C to 800°C for times between 0.5 h and 40,000 h. For aging temperatures of 600°C and higher, precipitation of tetrahedral close packed (TCP) phases in C-22 alloy induce a decrease in its mechanical properties and corrosion resistance in aggressive acidic solutions. At the lower aging temperatures, long range ordering (LRO) was observed, which did not produce changes in the chemical resistance of the alloy. Arrhenius extrapolations of the high temperature data predict that C-22 alloy will be thermally stable when exposed to temperatures in the order of 300°C for times higher than 10,000 years.

The phase stability of C-22 alloy (UNS #N06022) was studied by aging samples at 593, 649, 704 and 760°C for 2000 h (2.7 mo) and 16,000 h (1.8 yr). The tensile properties and the Charpy impact toughness of these samples were measured in the mill annealed condition as well as after aging. The microstructures of samples aged 16,000 hours were examined using scanning and transmission electron microscopy (SEM and TEM). Preliminary TEM results suggest that μse forms at all temperatures investigated. Discrete carbide particles in addition to a film with very uniform thickness which appears to be μ phase formed on grain boundaries in the sample aged at 593°C. The ordered Ni2(Cr, Mo) phase was also seen in this sample. At the higher aging temperatures, mainly μ phase forms covering all the grain boundaries and also distributed throughout the bulk. Although strength increased somewhat with aging. the ductility decreased due to the formation of these grain boundary precipitates and brittle intermetallics.