Evidence for retrograde lithospheric subduction on Venus

Though there is no plate tectonics per se on Venus, recent Magellan radar images and topographic profiles of the planet suggest the occurrence of the plate tectonic processes of lithospheric subduction and back-arc spreading. The perimeters of several large coronae (e.g., Latona, Artemis, and Eithinoha) resemble Earth subduction zones in both their planform and topographic profile. The planform of arcuate structures in Eastern Aphrodite were compared with subduction zones of the East Indies. The venusian structures have radii of curvature that are similar to those of terrestrial subduction zones. Moreover, the topography of the venusian ridge/trench structures is highly asymmetric with a ridge on the concave side and a trough on the convex side; Earth subduction zones generally display the same asymmetry

Static feed water electrolysis subsystem development

This disclosure is directed to an electrolysis cell forming hydrogen and oxygen at spaced terminals. The anode terminal is porous and able to form oxygen within the cell and permit escape of the gaseous oxygen through the anode and out through a flow line in the presence of backpressure. Hydrogen is liberated in the cell at the opposing solid metal cathode which is permeable to hydrogen but not oxygen so that the migratory hydrogen formed in the cell is able to escape from the cell. The cell is maintained at an elevated pressure so that oxygen liberated by the cell is delivered at elevated pressure without pumping to raise the pressure of the oxygen

Involutions of knots that fix unknotting tunnels

Let K be a knot that has an unknotting tunnel tau. We prove that K admits a strong involution that fixes tau pointwise if and only if K is a two-bridge knot and tau its upper or lower tunnel.Comment: 9 pages, 3 figure

Visual-Inertial Mapping with Non-Linear Factor Recovery

Cameras and inertial measurement units are complementary sensors for ego-motion estimation and environment mapping. Their combination makes visual-inertial odometry (VIO) systems more accurate and robust. For globally consistent mapping, however, combining visual and inertial information is not straightforward. To estimate the motion and geometry with a set of images large baselines are required. Because of that, most systems operate on keyframes that have large time intervals between each other. Inertial data on the other hand quickly degrades with the duration of the intervals and after several seconds of integration, it typically contains only little useful information. In this paper, we propose to extract relevant information for visual-inertial mapping from visual-inertial odometry using non-linear factor recovery. We reconstruct a set of non-linear factors that make an optimal approximation of the information on the trajectory accumulated by VIO. To obtain a globally consistent map we combine these factors with loop-closing constraints using bundle adjustment. The VIO factors make the roll and pitch angles of the global map observable, and improve the robustness and the accuracy of the mapping. In experiments on a public benchmark, we demonstrate superior performance of our method over the state-of-the-art approaches

Music Direction for the Stage: Training for Success in Christian-based Performing Arts

The stage production music director is a position requiring highly advanced musical, managerial, and administrative skills. Many churches, Christian schools, and community groups have an interest in mounting a show or launching a performing arts ministry; however, most worship pastors, choral/instrumental conductors, and music teachers have not been adequately prepared for this specialized assignment. Of the available training resources on production and theatrical work, few address the role of the music director. Additionally, most of the literature is written for the mainstream theatrical environment. Still missing is a treatment that blends standard industry practices with the pastoral leadership and spiritual aspects of the job that are needed in Christian-based performing arts organizations. This project assessed existing literature by industry experts to ascertain the areas of study necessary for a successful career in music direction for the stage. In addition, it drew from the works of successful Christian leaders to determine the principles of pastoral leadership relevant to music direction, and the tenets of a biblically-based philosophy of ministry for the performing arts. The net result of merging these streams of study was the formation a one-semester collegiate-level curriculum that surveys the role and responsibilities of the production music director in Christian-based performing arts organizations, such as the local church, educational institutions, and community-based groups. Utilizing an in-class simulation of mounting a theatrical show, the curriculum was designed to equip students with the necessary tools to effectively meet the demands of this unique position

Shipboard and satellite observations of upper ocean velocity and transport variability in the Gulf Stream

Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 1990Acoustic doppler velocities are combined with velocity profiles generated from XBT measurements to produce estimates of the flow field between Bermuda and the eastern coast of the United States. Repeated shipboard measurements along an ascending GEOSAT subtrack between Bermuda and Cape Cod allow study of rapid Gulf Stream Variability along the track, and comparison of sea surface and velocity measurements with those computed from the GEOSAT altimeter. The shipboard data were taken during two separate cruises on the R/V Oceanus in April and December, 1989. Using mass conservation constraints and inverse techniques, the transport across the Cape Cod Bermuda track has been balanced with transport across additional ship tracks between Bermuda and Cape Hatteras, and between Bermuda and Nova Scotia. The shipboard results show evidence of a rapid barotropic mode which caused changes in transport along the Cape Cod-Bermuda track on the order of 8 Sverdrups in a week period. Comparisons of sea surface velocity and dynamic height determined from the ship's data with measurements made from the GEOSAT altimeter showed a consistent picture of the Gulf Stream location and were also consistent in showing smaller scale variations in flow. The dynamic height difference across the Gulf Stream was approximately 10% higher for the GEOSAT measurements than for the shipboard measurements, which is within the expected errors of the analysis techniques

An Instructional Designer Competency Framework for Complex Learning Designs

Learning design competency frameworks published by professional organizations, exist for typical instructional design efforts. However, a review of literature revealed a lack of frameworks available for the creation of complex learning designs (CLDs). The goal of this research was to develop a competency framework for the creation of CLDs. Quantitative and qualitative methods were employed in the four phases of the design and development research approach In phase one, a survey based on the Educational Technology Multimedia Competency Survey (ETMCS) was sent to instructional designers who self-reported as having experience creating CLDs. The purpose of phase one was to identify competencies that instructional designers felt were most important to the creation of complex, technology-mediated learning designs. The preliminary CLD framework was constructed during phase two, based on analysis of the ETMCS survey results. Measures of central tendency were used to identify competencies considered essential and desirable. Additionally, competencies were categorized into seven domains In phase three, semi-structured interviews were conducted with a subset of survey participants. The purpose was to gain deeper insight into the participant’s perception of the design complexities involved with each of the competencies included in the preliminary framework. In phase four, the preliminary framework was internally validated using an expert panel employing the Delphi method to build consensus. Three rounds were required to achieve consensus on all competencies within the framework. This consensus resulted in 79 competencies including 30 essential and 49 desirable competencies from the set identified as the preliminary framework during phase two. Several conclusions emerged from the creation of this framework. Though technology is often a trigger for many types of CLDs, specific technologies are certainly desirable, but not essential. The research also revealed that communication and collaboration competencies are almost universally essential due to the complexity of the designs which typically necessitates the formation of multi-discipline teams. Without these competencies, the team’s cross-profession effectiveness is often hindered due to differences in terminology, processes, and team member geographic location

Amyloid proteotoxicity initiates an inflammatory response blocked by cannabinoids.

The beta amyloid (Aβ) and other aggregating proteins in the brain increase with age and are frequently found within neurons. The mechanistic relationship between intracellular amyloid, aging and neurodegeneration is not, however, well understood. We use a proteotoxicity model based upon the inducible expression of Aβ in a human central nervous system nerve cell line to characterize a distinct form of nerve cell death caused by intracellular Aβ. It is shown that intracellular Aβ initiates a toxic inflammatory response leading to the cell's demise. Aβ induces the expression of multiple proinflammatory genes and an increase in both arachidonic acid and eicosanoids, including prostaglandins that are neuroprotective and leukotrienes that potentiate death. Cannabinoids such as tetrahydrocannabinol stimulate the removal of intraneuronal Aβ, block the inflammatory response, and are protective. Altogether these data show that there is a complex and likely autocatalytic inflammatory response within nerve cells caused by the accumulation of intracellular Aβ, and that this early form of proteotoxicity can be blocked by the activation of cannabinoid receptors

BLISTER Regulates Polycomb-Target Genes, Represses Stress-Regulated Genes and Promotes Stress Responses in Arabidopsis thaliana

Polycomb group (PcG) proteins are key epigenetic regulators of development. The highly conserved Polycomb repressive complex 2 (PRC2) represses thousands of target genes by trimethylating H3K27 (H3K27me3). Plant specific PcG components and functions are largely unknown, however, we previously identified the plant-specific protein BLISTER (BLI) as a PRC2 interactor. BLI regulates PcG target genes and promotes cold stress resistance. To further understand the function of BLI, we analyzed the transcriptional profile of bli-1 mutants. Approximately 40% of the up-regulated genes in bli are PcG target genes, however, bli-1 mutants did not show changes in H3K27me3 levels at all tested genes, indicating that BLI regulates PcG target genes downstream of or in parallel to PRC2. Interestingly, a significant number of BLI regulated H3K27me3 target genes is regulated by the stress hormone absciscic acid (ABA). We further reveal an overrepresentation of genes responding to abiotic stresses such as drought, high salinity, or heat stress among the up- regulated genes in bli mutants. Consistently, bli mutants showed reduced desiccation stress tolerance. We conclude that the PRC2 associated protein BLI is a key regulator of stress-responsive genes in Arabidopsis: it represses ABA-responsive PcG target genes, likely downstream of PRC2, and promotes resistance to several stresses such as cold and drought