218 research outputs found

    An Integrated Approach to Learning Communities: Designing for Place-Based, Communication-Intensive Learning

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    This article describes the design of a learning community that paired an English Composition and a Public Speaking course at the New York City College of Technology (City Tech) and explains the embedded teaching strategies: flexible scheduling, integrated assignments, and a place-based (Brooklyn) focus. These tactics, developed with the aim of engaging first-semester students in their general-education communication courses, served to orient students to City Tech and its neighboring environment. Flexible scheduling helped avoid making concessions due to time constraints and allowed for greater fairness and efficiency, while also expanding opportunities for classroom and out-of-classroom activities. Designing overlapping assignments helped students by scaffolding coursework throughout the semester, building toward increasingly challenging course objectives. The place-based focus on Brooklyn oriented students to the campus, supported their ability to find nearby places that expanded their campus experience, and gave them tools for interacting critically with their surroundings. Grounded in maker pedagogy, the semester’s final project asked students to make a shared Google Map that included their videos and summaries of their research, creating a virtual tour of downtown Brooklyn. Ultimately, these strategies supported better student success and engagement in the courses while providing a creative outlet for successful college work. Jody R. Rosen is an Assistant Professor of English and Co-Director of the OpenLab at New York City College of Technology, CUNY, where she teaches in the First-Year Learning Community program each fall semester. Her scholarship focuses on pedagogical approaches to foster community, and on Modernist narratological representations of gender and sexuality. M. Justin Davis is a Postdoctoral Fellow in the Department of Communication Studies at Northeastern University. His research explores processes related to the production, performance, and consumption of identity, cultural memory, and public mind

    Entry, Descent and Landing Systems Analysis: Exploration Class Simulation Overview and Results

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    NASA senior management commissioned the Entry, Descent and Landing Systems Analysis (EDL-SA) Study in 2008 to identify and roadmap the Entry, Descent and Landing (EDL) technology investments that the agency needed to make in order to successfully land large payloads at Mars for both robotic and exploration or human-scale missions. The year one exploration class mission activity considered technologies capable of delivering a 40-mt payload. This paper provides an overview of the exploration class mission study, including technologies considered, models developed and initial simulation results from the EDL-SA year one effort

    Long‐term memory for unfamiliar voices

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    From a sample of young male Californians, ten speakers were selected whose voices were approximately normally distributed with respect to the "easy-to-remember" versus "hard-to-remember" judgments of a group of raters. A separate group of listeners each heard one of the voices, and, after delays of 1, 2, or 4 weeks, tried to identify the voice they had heard, using an open-set, independent-judgment task. Distributions of the results did not differ from the distributions expected under the hypothesis of independent judgments. For both "heard previously" and "not heard previously" responses, there was a trend toward increasing accuracy as a function of increasing listener certainty. Overall, heard previously responses were less accurate than not heard previously responses. For heard previously responses, there was a trend toward decreasing accuracy as a function of delay between hearing a voice and trying to identify it. Information-theoretic analysis showed loss of information as a function of delay and provided means to quantify the effects of patterns of voice confusability. Signal-detection analysis revealed the similarity of results from diverse experimental paradigms. A "prototype" model is advanced to explain the fact that certain voices are preferentially selected as having been heard previously. The model also unites several previously unconnected findings in the literature on voice recognition and makes testable predictions

    Large Mass, Entry, Descent and Landing Sensitivity Results for Environmental, Performance, and Design Parameters

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    Landing on Mars has been a challenging task. Past NASA missions have shown resilience to increases in spacecraft mass by scaling back requirements such as landing site altitude, landing site location and arrival time. Knowledge of the partials relating requirements to mass is critical for mission designers to understand so that the project can retain margin throughout the process. Looking forward to new missions that will land 1.5 metric tons or greater, the current level of technology is insufficient, and new technologies will need to be developed. Understanding the sensitivity of these new technologies to requirements is the purpose of this paper

    Guidance and Control Algorithms for the Mars Entry, Descent and Landing Systems Analysis

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    The purpose of the Mars Entry, Descent and Landing Systems Analysis (EDL-SA) study was to identify feasible technologies that will enable human exploration of Mars, specifically to deliver large payloads to the Martian surface. This paper focuses on the methods used to guide and control two of the contending technologies, a mid- lift-to-drag (L/D) rigid aeroshell and a hypersonic inflatable aerodynamic decelerator (HIAD), through the entry portion of the trajectory. The Program to Optimize Simulated Trajectories II (POST2) is used to simulate and analyze the trajectories of the contending technologies and guidance and control algorithms. Three guidance algorithms are discussed in this paper: EDL theoretical guidance, Numerical Predictor-Corrector (NPC) guidance and Analytical Predictor-Corrector (APC) guidance. EDL-SA also considered two forms of control: bank angle control, similar to that used by Apollo and the Space Shuttle, and a center-of-gravity (CG) offset control. This paper presents the performance comparison of these guidance algorithms and summarizes the results as they impact the technology recommendations for future study

    Post2 End-to-End Descent and Landing Simulation for ALHAT Design Analysis Cycle 2

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    The ALHAT project is an agency-level program involving NASA centers, academia, and industry, with a primary goal to develop a safe, autonomous, precision-landing system for robotic and crew-piloted lunar and planetary descent vehicles. POST2 is used as the 6DOF descent and landing trajectory simulation for determining integrated system performance of ALHAT landing-system models and lunar environment models. This paper presents updates in the development of the ALHAT POST2 simulation, as well as preliminary system performance analysis for ALDAC-2 used for the testing and assessment of ALHAT system models. The ALDAC-2 POST2 Monte Carlo simulation results have been generated and focus on HRN model performance with the fully integrated system, as well performance improvements of AGNC and TSAR model since the previous design analysis cycl

    Expression and Comparative Genomics of Two Serum Response Factor Genes in Zebrafish

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    Serum response factor (SRF) is a single copy, highly conserved transcription factor that governs the expression of hundreds of genes involved with actin cytoskeletal organization, cellular growth and signaling, neuronal circuitry and muscle differentiation. Zebrafish have emerged as a facile and inexpensive vertebrate model to delineate gene expression, regulation, and function, and yet the study of SRF in this animal has been virtually unexplored. Here, we report the existence of two srf genes in zebrafish, with partially overlapping patterns of expression in 3 and 7 day old developing animals. The mammalian ortholog (srf1) encodes for a 520 amino acid protein expressed in adult vascular and visceral smooth muscle cells, cardiac and skeletal muscle, as well as neuronal cells. The second zebrafish srf gene (srf2), encoding for a presumptive protein of only 314 amino acids, is transcribed at lower levels and appears to be less widely expressed across adult tissues. Both srf genes are induced by the SRF coactivator myocardin and attenuated with a short hairpin RNA to mammalian SRF. Promoter studies with srf1 reveal conserved CArG boxes that are the targets of SRF-myocardin in embryonic zebrafish cells. These results reveal that SRF was duplicated in the zebrafish genome and that its protein expression in all three muscle cell types is highly conserved across vertebrate animals suggesting an ancient code for transcriptional regulation of genes unique to muscle cell lineages

    Influenza Virus (A/HK/156/97) Hemagglutinin Expressed by an Alphavirus Replicon System Protects Chickens against Lethal Infection with Hong Kong-Origin H5N1 Viruses

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    AbstractVenezuelan equine encephalitis virus replicon particles (VRP) containing the gene expressing hemagglutinin (HA) from the human Hong Kong Influenza A isolate (A/HK/156/97) were evaluated as vaccines in chicken embryos and young chicks. Expressed HA was readily detected in bird-tissue staining with anti-H5 HA antibody and in chicken cells infected with the replicon preparations following immunoprecipitation with monoclonal antibody. Birds challenged with a dose of the lethal parent virus were protected to different extents depending on the age of the bird. In ovo and 1-day-old inoculated animals that received no boost with the VRP were partially protected; birds 2 weeks of age were completely protected with a single dose of VRP

    2011 Rangeland Vegetation Assessment in the Big Desert, Upper Snake River Plain, Idaho

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    ABSTRACT To better understand long term post-fire effects in sagebrush-steppe ecosystems, vegetation data were collected at 50 randomly located sample points during the month of June 2011. In particular, field samples were acquired on June 6-7, 13-14, 21-22, and 27-28 th . Data were collected at the area known as the Big Desert using line-point intercept transects to characterize land cover. Additionally, sagebrush stem diameter measurements were taken to determine the average age of sagebrush plants. Average age estimations were used to analyze the recovery rate of sagebrush following the 2006 Crystal fire and thereby better understand fire intensity and severity at each sample site. Based upon a previous study using Local Net Primary Productivity Scaling, data collection and analysis included ten sites considered "always degraded" and ten sample sites considered "never degraded". The purpose of this data collection and analysis was to determine if a difference in land cover (by functional group) and sagebrush age existed within these two areas. Sites classified as "always degraded" had an average sagebrush plant age of 13.4 years while "never degraded" sites held a slightly higher average at 15.6 years. Grass was the most common cover type across all sites (n = 50) and rock was the least common. Areas considered "always degraded" were dominated by cheatgrass (Bromus tectorum) and litter while "never degraded" sites were dominated by shrubs and forbs. A difference in percent grass and shrub cover was found between "always degraded" and "never degraded" sites (P < 0.05)

    LDSD POST2 Simulation and SFDT-1 Pre-Flight Launch Operations Analyses

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    The Low-Density Supersonic Decelerator (LDSD) Project's first Supersonic Flight Dynamics Test (SFDT-1) occurred June 28, 2014. Program to Optimize Simulated Trajectories II (POST2) was utilized to develop trajectory simulations characterizing all SFDT-1 flight phases from drop to splashdown. These POST2 simulations were used to validate the targeting parameters developed for SFDT- 1, predict performance and understand the sensitivity of the vehicle and nominal mission designs, and to support flight test operations with trajectory performance and splashdown location predictions for vehicle recovery. This paper provides an overview of the POST2 simulations developed for LDSD and presents the POST2 simulation flight dynamics support during the SFDT-1 launch, operations, and recovery
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