Reachability Maps for In Situ Operations

This work covers two programs that accomplish the same goal: creation of a "reachability map" from stereo imagery that tells where operators of a robotic arm can reach or touch the surface, and with which instruments. The programs are "marsreach" (for MER) and "phxreach." These programs make use of the planetary image geometry (PIG) library. However, unlike the other programs, they are not multi-mission. Because of the complexity of arm kinematics, the programs are specific to each mission

Interactions Between Moderate- and Long-Period Giant Planets: Scattering Experiments for Systems in Isolation and with Stellar Flybys

The chance that a planetary system will interact with another member of its host star's nascent cluster would be greatly increased if gas giant planets form in situ on wide orbits. In this paper, we explore the outcomes of planet-planet scattering for a distribution of multiplanet systems that all have one of the planets on an initial orbit of 100 AU. The scattering experiments are run with and without stellar flybys. We convolve the outcomes with distributions for protoplanetary disk and stellar cluster sizes to generalize the results where possible. We find that the frequencies of large mutual inclinations and high eccentricities are sensitive to the number of planets in a system, but not strongly to stellar flybys. However, flybys do play a role in changing the low and moderate portions of the mutual inclination distributions, and erase dynamically cold initial conditions on average. Wide-orbit planets can be mixed throughout the planetary system, and in some cases, can potentially become hot Jupiters, which we demonstrate using scattering experiments that include a tidal damping model. If planets form on wide orbits in situ, then there will be discernible differences in the proper motion distributions of a sample of wide-orbit planets compared with a pure scattering formation mechanism. Stellar flybys can enhance the frequency of ejections in planetary systems, but auto-ionization is likely to remain the dominant source of free-floating planets.Comment: Accepted for publication by Ap

Analysis and Optimization of a Dual Free Piston, Spring Assisted, Linear Engine Generator

The free piston linear engine (FPLE) generator has the potential to displace existing crankshaft driven engine technology because of its relative simplicity, higher efficiency, and increased power density. Continued interest in hybrid-electric vehicles for transportation and tightening emissions regulations has created a challenging market for conventional piston engines. Combined with rising market interest in localized power generation means there are exciting opportunities for innovative technologies that can satisfy both regulatory and commercial demands. Many groups around the world are currently working to advance the state of the FPLE, and recent success at West Virginia University will lead to a working prototype device within the next three years.;This dissertation presents the analysis and optimization of a dual free piston, spring assisted, linear engine generator (SALEG). The primary moving part is a dual piston translator driven by 2-stroke homogeneous charge compression ignition combustion cycles such that the compression stroke for one cylinder corresponds to the expansion stroke of the other. The dynamics of the translator are augmented by the addition of springs that support higher frequency operation, provide energy storage to support cyclic stability, and can be tailored to achieve a desired translator dynamic profile. Current challenges for the device involve optimization for high efficiency performance at steady state and control of the translator position and combustion events.;Using numeric simulation tools in MATLABRTM and Simulink, the dynamic behavior of the translator is modeled in conjunction with the in-cylinder thermodynamics for each engine cylinder and the linear electric alternator load. Sweeps of the primary design parameters explore the design space while demonstrating the interdependency that is characteristic of the FPLE. Then, a genetic algorithm is employed to optimize the SALEG for efficiency based on target power and practical operating constraints. It is demonstrated that low maximum stroke to bore ratio and low intake temperature are favored. Also, the design space becomes more restrictive as target power is raised, but for a range of devices as high as 25 kW, efficiency greater than 40% can be achieved.;Control mechanisms for the simulated SALEG are demonstrated and compared. These entail the control of alternator force, engine fueling, and intake conditions through the use of proportional and integral control methods. The control methods are applied to achieve resonant start-up of the device and to respond to changes in load demand and misfire. Motored, resonant hot-start is simulated for a device with natural frequency of 40 Hz, and the linear motor and controller parameters are tested. Misfire is shown to lead to rapid loss of compression, so the motored resonant control mechanism is employed to recover after misfire. A map-based controller is used to control intake temperature in response to rapid change in load. For a 50% reduction in load, intake temperature is raised by 15% (40 °C) and results in an efficiency drop from 38% to 22% at steady state. Ultimately, the simulation tool represents a platform for future investigations where experimental data and more sophisticated modeling techniques might be included to enhance the research and advancement of the free piston linear engine

Acute effects of an Avena sativa herb extract on responses to the Stroop Color-Word test

Background and aims: Extracts from oat (Avena sativa) herb may benefit cognitive performance. This study investigated whether Neuravena®, an oat herb extract, could acutely improve responses to the Stroop Color–Word test, a measure of attention and concentration and the ability to maintain task focus.  Subjects and methods: Elderly volunteers with below-average cognitive performance consumed single doses (0, 1600, and 2400 mg) of oat herb extract at weekly intervals in a double-blind, randomized, crossover comparison. Resting blood pressure (BP) was assessed before and after supplementation, and a Stroop test was performed.  Results: Significantly fewer errors were made during the color-naming component of the Stroop test after consuming the 1600-mg dose than after the 0-mg or 2400-mg doses (F (1,36)=18.85, p<0.001). In 7 subjects with suspected cognitive impairment, Stroop interference score was also improved by the 1600-mg dose compared to 0- and 2400-mg doses (F (1, 34)=2.40, p<0.01). Resting BP was unaffected by supplementation.  Conclusions: Taking 1600 mg of oat herb extract may acutely improve attention and concentration and the ability to maintain task focus in older adults with differing levels of cognitive status

Lack of Association Between 25(OH)D Levels and Incident Type 2 Diabetes in Older Women

Objective: To examine whether lower serum levels of serum 25-hydroxyvitamin (OH) D [25(OH)D] are associated with increased risk of developing type 2 diabetes. Research Design and Methods: A post hoc analysis of three nested case-control studies of fractures, colon cancer, and breast cancer that measured serum 25(OH)D levels in women participating in the Women’s Health Initiative (WHI) Clinical Trials and Observational Study who were free of prevalent diabetes at baseline. Diabetes was defined as self-report of physician diagnosis or receiving insulin or oral hypoglycemic medication. We used inverse probability weighting to make the study population representative of the WHI population as a whole. Weighted logistic regression models compared 25(OH)D levels (divided into quartiles, clinical cut points [<50, 50–<75, $\geq$75 nmol/L], or as a continuous variable) using the distribution of control subjects and adjusted for multiple confounding factors. Results: Of 5,140 women (mean age 66 years) followed for an average of 7.3 years, 317 (6.2%) developed diabetes. Regardless of the cut points used or as a continuous variable, 25(OH)D levels were not associated with diabetes incidence in either age or fully adjusted models. Nor was any relationship found between 25(OH)D and incident diabetes when evaluated by strata of BMI, race/ethnicity, or randomization status in the Calcium Vitamin D trial. Conclusions: Lower serum 25(OH)D levels were not associated with increased risk of developing type 2 diabetes in this racially and ethnically diverse population of postmenopausal women

Generation of Functional CLL-Specific Cord Blood CTL Using CD40-Ligated CLL APC

PMCID: PMC3526610This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

A Southern Hemisphere record of global trace-metal drawdown and orbital modulation of organic-matter burial across the Cenomanian–Turonian boundary (Ocean Drilling Program Site 1138, Kerguelen Plateau)

Despite its assumed global nature, there are very few detailed stratigraphic records of the late Cenomanian to the early Turonian Oceanic Anoxic Event 2 from the Southern Hemisphere. A highly resolved record of environmental changes across the Cenomanian\u2013Turonian boundary interval is presented from Ocean Drilling Program Site 1138 on the central Kerguelen Plateau (southern Indian Ocean). The new data lead to three key observations. Firstly, detailed biostratigraphy and chemostratigraphy indicate that the record of Oceanic Anoxic Event 2 is not complete, with a hiatus spanning the onset of the event. A decrease in glauconite and highly weathered clays after the onset of Oceanic Anoxic Event 2 marks the end of the hiatus interval, which can be explained by a relative sea-level rise that increased sediment accommodation space on the Kerguelen Plateau margin. This change in depositional environment controlled the timing of the delayed peak in organic-matter burial during Oceanic Anoxic Event 2 at Site 1138 compared with other Oceanic Anoxic Event 2 locations worldwide. A second key observation is the presence of cyclic fluctuations in the quantity and composition of organic matter being buried on the central Kerguelen Plateau throughout the latter stages of Oceanic Anoxic Event 2 and the early Turonian. A close correspondence between organic matter, sedimentary elemental compositions and sediments recording sea-floor oxygenation suggests that the cycles were mainly productivity-driven phenomena. Available age-control points constrain the periodicity of the coupled changes in sedimentary parameters to ca 20 to 70 ka, suggesting a link between carbon burial and astronomically forced climatic variations (precession or obliquity) in the Southern Hemisphere mid-latitudes both during, and after, Oceanic Anoxic Event 2: fluctuations that were superimposed on the impact of global-scale processes. Finally, trace-metal data from the black-shale unit at Site 1138 provide the first evidence from outside of the proto-North Atlantic region for a global drawdown of seawater trace-metal (Mo) inventories during Oceanic Anoxic Event 2

The Heavy Element Composition of Disk Instability Planets Can Range From Sub- to Super-Nebular

Transit surveys combined with Doppler data have revealed a class of gas giant planets that are massive and highly enriched in heavy elements (e.g., HD149026b, GJ436b, and HAT-P-20b). It is tempting to consider these planets as validation of core accretion plus gas capture because it is often assumed that disk instability planets should be of nebular composition. We show in this paper, to the contrary, that gas giants that form by disk instability can have a variety of heavy element compositions, ranging from sub- to super-nebular values. High levels of enrichment can be achieved through one or multiple mechanisms, including enrichment at birth, planetesimal capture, and differentiation plus tidal stripping. As a result, the metallicity of an individual gas giant cannot be used to discriminate between gas giant formation modes.Comment: Accepted by Ap

The Mock LISA Data Challenges: from Challenge 3 to Challenge 4

The Mock LISA Data Challenges are a program to demonstrate LISA data-analysis capabilities and to encourage their development. Each round of challenges consists of one or more datasets containing simulated instrument noise and gravitational waves from sources of undisclosed parameters. Participants analyze the datasets and report best-fit solutions for the source parameters. Here we present the results of the third challenge, issued in Apr 2008, which demonstrated the positive recovery of signals from chirping Galactic binaries, from spinning supermassive--black-hole binaries (with optimal SNRs between ~ 10 and 2000), from simultaneous extreme-mass-ratio inspirals (SNRs of 10-50), from cosmic-string-cusp bursts (SNRs of 10-100), and from a relatively loud isotropic background with Omega_gw(f) ~ 10^-11, slightly below the LISA instrument noise.Comment: 12 pages, 2 figures, proceedings of the 8th Edoardo Amaldi Conference on Gravitational Waves, New York, June 21-26, 200