The First Lunar Ranging Constraints on Gravity Sector SME Parameters

We present the first constraints on pure-gravity sector Standard-Model Extension (SME) parameters using Lunar Laser Ranging (LLR). LLR measures the round trip travel time of light between the Earth and the Moon. With 34+ years of LLR data, we have constrained six independent linear combinations of SME parameters at the level of $10^{-6}$ to $10^{-11}$. There is no evidence for Lorentz violation in the LLR dataset.Comment: 7 pages, presented at the Fourth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, August 200

More Myself: Exploring Students\u27 Perceptions of Self-Authorship Development

Increasingly, the challenges of modern adult life include the responsibility for ambiguous tasks, the need to work as a team with diverse others and the expectation to make important decisions in the face of competing interests. Research suggests that individuals able to meet these challenges demonstrate self-authorship, a way of knowing that allows them to exert control over their lives. Existing research provides insight into college students’ self-authorship and the influence of situational, environmental and personal factors on self-authorship development. However, the literature has yet to explore students’ own understanding of their self-authorship development. The purpose of this study was to explore the ways students make meaning of their self-authorship and self-authorship development. This study utilized a qualitative approach and a narrative inquiry design to collect data from recent college graduates. Eleven graduates from a public, comprehensive university in the southeast participated in the study. Participants represented a variety of ethnic backgrounds, ages, and academic disciplines. Each participated in two in-depth, semi-structured interviews. The study utilized a constant comparative approach to analysis, and open, axial, and selective coding, to identify themes that would inform the findings of the study. The findings of the study include the following: (1) nine of the eleven participants demonstrated self-authored perspectives and processes, (2) participants viewed their self-authorship development not as a series of developmental experiences or transitions, but as a singular experience of continuous development, (3) participants made meaning of their self-authorship in the context of their independence and purpose, and (4) participants’ understanding of their development provided new insight into self-authorship and its development

Summary of NASA landing-gear research

This paper presents a brief summary of the airplane landing gear research underway at NASA. The technology areas include: ground handling simulator, antiskid braking systems, space shuttle nose-gear shimmy, active control landing gear, wire brush skid landing gear, air cushion landing systems, tire/surface friction characteristics, tire mechanical properties, tire-tread materials, powered wheels for taxiing, and crosswind landing gear. This paper deals mainly with the programs on tire-tread materials, powered wheel taxiing, air cushion landing systems, and crosswind landing gear research with particular emphasis on previously unreported results of recently completed flight tests. Work in the remaining areas is only mentioned

Summary of NASA landing-gear research

Research relative to tire tread, powered-wheel taxiing, air cushion landing systems, and crosswind landing gear is discussed

An experimental and computational analysis of buoyancy driven flows by laser sheet tomography, particle image velocimetry and computational fluid dynamics

This paper contains details of a three pronged investigation into the development of a buoyant jet impinging on a wall in a closed vessel. The development of the flow was measured experimentally by particle image velocimetry (PIV) and laser sheet tomography. The experimental results are compared with a computational model of the flow calculated by the computational fluid dynamics (CFD) package PHOENICS

Nociceptive-Evoked Potentials Are Sensitive to Behaviorally Relevant Stimulus Displacements in Egocentric Coordinates.

Feature selection has been extensively studied in the context of goal-directed behavior, where it is heavily driven by top-down factors. A more primitive version of this function is the detection of bottom-up changes in stimulus features in the environment. Indeed, the nervous system is tuned to detect fast-rising, intense stimuli that are likely to reflect threats, such as nociceptive somatosensory stimuli. These stimuli elicit large brain potentials maximal at the scalp vertex. When elicited by nociceptive laser stimuli, these responses are labeled laser-evoked potentials (LEPs). Although it has been shown that changes in stimulus modality and increases in stimulus intensity evoke large LEPs, it has yet to be determined whether stimulus displacements affect the amplitude of the main LEP waves (N1, N2, and P2). Here, in three experiments, we identified a set of rules that the human nervous system obeys to identify changes in the spatial location of a nociceptive stimulus. We showed that the N2 wave is sensitive to: (1) large displacements between consecutive stimuli in egocentric, but not somatotopic coordinates; and (2) displacements that entail a behaviorally relevant change in the stimulus location. These findings indicate that nociceptive-evoked vertex potentials are sensitive to behaviorally relevant changes in the location of a nociceptive stimulus with respect to the body, and that the hand is a particularly behaviorally important site

Lithium Enhances Muscarinic Receptor–Stimulated CDP-Diacylglycerol Formation in Inositol-Depleted SK-N-SH Neuroblastoma Cells

The psychotherapeutic action of Li + in brain has been proposed to result from the depletion of cellular inositol secondary to its block of inositol monophosphatase. This action is thought to slow phosphoinositide resynthesis, thereby attenuating stimulated phosphoinositidase-mediated signal transduction in affected cells. In the present study, the effect of Li + on muscarinic receptor–stimulated formation of the immediate precursor of phosphatidylinositol, CDP-diacylglycerol (CDP-DAG), has been examined in human SK-N-SH neuroblastoma cells that have been cultured under conditions that alter the cellular content of myo -inositol. Resting neuroblastoma cells, like brain cells in vivo, were found to concentrate inositol from the culture medium, achieving an intracellular level of 60.0 ± 4 nmol/mg of protein. The addition of carbachol to [ 3 H]cytidine-prelabeled cells elicited a four- to fivefold increase in the accumulation of labeled CDP-DAG. This stimulated formation of [ 3 H]CDP-DAG was completely blocked by the addition of 10 Μ M atropine, was not dependent on the presence of Li + , nor was it affected by co-incubation with myo -inositol. This result was in sharp contrast to findings in rat brain slices, in which carbachol-stimulated formation of [ 3 H]CDP-DAG was potentiated ∼ 10-fold by Li + and substantially reduced by coincubation with inositol. The formation of [ 3 H]CDP-DAG in labeled SK-N-SH cells by carbachol was both concentration and time dependent. The order of efficacy of muscarinic ligands in stimulating [ 3 H]-CDP-DAG accumulation paralleled that established in these cells for inositol phosphate accumulation, i.e., carbachol ≥ oxotremorine-M > bethanecol ≥ arecoline > oxotremorine > pilocarpine. Extended culture of the SK-N-SH cells in an inositol-free chemically defined growth medium progressively reduced the intracellular inositol content to <5 nmol/mg of protein, a level comparable with that seen in cortical slices. In these inositol-depleted cells, Li + potentiated carbachol-stimulated [ 3 H]CDP-DAG formation, and this effect was completely reversed by coincubation with inositol (EC 50 0.2 m M ). The present study thus demonstrates, in the same cultured cell line, the effects of normal and reduced intracellular inositol levels on the ability of Li + to attenuate phosphoinositide resynthesis, as inferred from [ 3 H]CDP-DAG accumulation. The results indicate that Li + can lead to a slowing of stimulated phosphoinositide turnover in neuroblastoma cells, provided that the intracellular inositol content has been significantly reduced.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65723/1/j.1471-4159.1993.tb03289.x.pd