126 research outputs found

    chapter 12: The Role of Mathematics in Education for Democracy 1

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72282/1/j.1744-7984.2008.00140.x.pd

    Mission Operations of the Mars Exploration Rovers

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    A document describes a system of processes involved in planning, commanding, and monitoring operations of the rovers Spirit and Opportunity of the Mars Exploration Rover mission. The system is designed to minimize command turnaround time, given that inherent uncertainties in terrain conditions and in successful completion of planned landed spacecraft motions preclude planning of some spacecraft activities until the results of prior activities are known by the ground-based operations team. The processes are partitioned into those (designated as tactical) that must be tied to the Martian clock and those (designated strategic) that can, without loss, be completed in a more leisurely fashion. The tactical processes include assessment of downlinked data, refinement and validation of activity plans, sequencing of commands, and integration and validation of sequences. Strategic processes include communications planning and generation of long-term activity plans. The primary benefit of this partition is to enable the tactical portion of the team to focus solely on tasks that contribute directly to meeting the deadlines for commanding the rover s each sol (1 sol = 1 Martian day) - achieving a turnaround time of 18 hours or less, while facilitating strategic team interactions with other organizations that do not work on a Mars time schedule

    Requesting Distant Robotic Action: An Ontology for Naming and Action Identification for Planning on the Mars Exploration Rover Mission.

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    This paper focuses on the development of a naming convention and the use of abbreviated names and a related ontology for science work and distant robotic action that comprise requests for a robotic rover during the NASA Mars Exploration Rover (MER) mission, run by the Jet Propulsion Laboratory (JPL). We demonstrate how abbreviated names and an associated ontology support sharing and identifying information among teams and software tools. An ontology of distant action must take into account a dynamic environment, changing in response to physical events and intentional actions, and reflect the influence of context on the meaning of action. The nascent domain of Martian tele-robotic science, in which specialists request work from a rover moving through a distant landscape, as well as the need to consider the interdisciplinary teams involved in completing that work, required an empirical approach. The formulation of this ontology used ethnographic methods and grounded theory to study human behavior and work practice with software tools

    Cannabinoid receptor interacting protein suppresses agonist-driven CB1 receptor internalization and regulates receptor replenishment in an agonist-biased manner

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    Cannabinoid receptor interacting protein 1a (CRIP1a) is a CB1 receptor (CB1R) distal C-terminus-associated protein that modulates CB1R signaling via G proteins, and CB1R down-regulation but not desensitization (Blume et al. [2015] Cell Signal., 27, 716-726; Smith et al. [2015] Mol. Pharmacol., 87, 747-765). In this study, we determined the involvement of CRIP1a in CB1R plasma membrane trafficking. To follow the effects of agonists and antagonists on cell surface CB(1)Rs, we utilized the genetically homogeneous cloned neuronal cell line N18TG2, which endogenously expresses both CB1R and CRIP1a, and exhibits a well-characterized endocannabinoid signaling system. We developed stable CRIP1a-over-expressing and CRIP1a-siRNA-silenced knockdown clones to investigate gene dose effects of CRIP1a on CB1R plasma membrane expression. Results indicate that CP55940 or WIN55212-2 (10 nM, 5 min) reduced cell surface CB1R by a dynamin-and clathrin-dependent process, and this was attenuated by CRIP1a over-expression. CP55940-mediated cell surface CB1R loss was followed by a cycloheximide-sensitive recovery of surface receptors (30120 min), suggesting the requirement for new protein synthesis. In contrast, WIN55212-2-mediated cell surface CB(1)Rs recovered only in CRIP1a knockdown cells. Changes in CRIP1a expression levels did not affect a transient rimonabant (10 nM)mediated increase in cell surface CB(1)Rs, which is postulated to be as a result of rimonabant effects on \u27non-agonist-driven\u27 internalization. These studies demonstrate a novel role for CRIP1a in agonist-driven CB1R cell surface regulation postulated to occur by two mechanisms: 1) attenuating internalization that is agonist-mediated, but not that in the absence of exogenous agonists, and 2) biased agonist-dependent trafficking of de novo synthesized receptor to the cell surface

    Knowing Mathematics for Teaching: Who Knows Mathematics Well Enough To Teach Third Grade, and How Can We Decide?

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    Reprinted with permission from the Fall 2005 issue of American Educator, the quarterly journal of the American Federation of Teachers, AFL-CIO.In this article, the authors describe a program of research they have been developing for more than a decade into the mathematical knowledge and skills that are used in teaching. Their research begins with examining the actual work of teaching elementary school mathematics and noting all of the challenges in this work that draw on mathematical resources; this is followed by analyzing of the nature of such mathematical knowledge and skills – how they are held and used – in the work of teaching. Through this type of analyses, they've derived a practice-based portrait of what they call “mathematical knowledge for teaching.” This article traces the development of these ideas and describes this professional knowledge of mathematics for teaching.The research reported in this paper was supported in part by grants from the U.S. Department of Education to the Consortium for Policy Research in Education (CPRE) at the University of Pennsylvania (OERI-R308A60003) and the Center for the Study of Teaching and Policy at the University of Washington (OERI-R308B70003); the National Science Foundation (REC-9979863 & REC-0129421, REC-0207649, EHR-0233456, and EHR-0335411), and the William and Flora Hewlett Foundation, and the Atlantic Philanthropies.http://deepblue.lib.umich.edu/bitstream/2027.42/65072/4/Ball_F05.pd

    Planning Considerations for a Mars Sample Receiving Facility: Summary and Interpretation of Three Design Studies

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    It has been widely understood for many years that an essential component of a Mars Sample Return mission is a Sample Receiving Facility (SRF). The purpose of such a facility would be to take delivery of the flight hardware that lands on Earth, open the spacecraft and extract the sample container and samples, and conduct an agreed-upon test protocol, while ensuring strict containment and contamination control of the samples while in the SRF. Any samples that are found to be non-hazardous (or are rendered non-hazardous by sterilization) would then be transferred to long-term curation. Although the general concept of an SRF is relatively straightforward, there has been considerable discussion about implementation planning. The Mars Exploration Program carried out an analysis of the attributes of an SRF to establish its scope, including minimum size and functionality, budgetary requirements (capital cost, operating costs, cost profile), and development schedule. The approach was to arrange for three independent design studies, each led by an architectural design firm, and compare the results. While there were many design elements in common identified by each study team, there were significant differences in the way human operators were to interact with the systems. In aggregate, the design studies provided insight into the attributes of a future SRF and the complex factors to consider for future programmatic planning

    Surface properties of Mars' polar layered deposits and polar landing sites

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    On December 3, 1999, the Mars Polar Lander and Mars Microprobes will land on the planet's south polar layered deposits near (76°S, 195°W) and conduct the first in situ studies of the planet's polar regions. The scientific goals of these missions address several poorly understood and globally significant issues, such as polar meteorology, the composition and volatile content of the layered deposits, the erosional state and mass balance of their surface, their possible relationship to climate cycles, and the nature of bright and dark aeolian material. Derived thermal inertias of the southern layered deposits are very low (50–100 J m^(−2) s^(−1/2) K^(−1)), suggesting that the surface down to a depth of a few centimeters is generally fine grained or porous and free of an appreciable amount of rock or ice. The landing site region is smoother than typical cratered terrain on ∼1 km pixel^(−1) Viking Orbiter images but contains low-relief texture on ∼5 to 100 m pixel^(−1) Mariner 9 and Mars Global Surveyor images. The surface of the southern deposits is older than that of the northern deposits and appears to be modified by aeolian erosion or ablation of ground ice

    Using automated pharmacy records to assess the management of tuberculosis.

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    We used automated pharmacy dispensing data to characterize tuberculosis (TB) management for 45 health maintenance organization (HMO) members. Pharmacy records distinguished patients treated in HMOs from those treated elsewhere. For cases treated in HMOs, they provided useful information about appropriateness of prescribed regimens and adherence to therapy
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