3,949 research outputs found

    Cotextual Android Education

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    With advances in mobile phone hardware, the demand for mobile applica- tions has risen drastically. This has resulted in mobile phones becoming a pop- ular new medium for application development. However, the body of knowledge for contextual examples and tutorials leaves much to be desired. As of January 2010, California Polytechnic State University has offered a mobile development class that teaches students how to write applications for phones running Google’s Android platform. This class aims at taking advantage of students’ current in- terest in mobile applications to teach them about difficult computer science topics. As a corollary, the class hopes to foster and encourage a sense of inde- pendence and entrepreneurship through having students design, implement, and publish their own applications to the Android Application Marketplace. The main contribution of this thesis project comes in the form of a series of detailed educational laboratory exercises and a system for grading student submissions in an automated fashion. These labs are designed to supplement the Android documentation by providing contextual examples, activities, and tutorials. It is therefore the goal of this thesis project to aid in transforming the class of mobile development students into a group of successful, practicing, mobile developers

    BIRinging Chromosomes through Cell Division—And Survivin' the Experience

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    Conventional versus highly cross-linked polyethylene in primary total knee replacement : a comparison of revision rates using data from the National Joint Registry for England, Wales, and Northern Ireland

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    There is evidence to support the use of highly cross-linked polyethylene (HXLPE) in patients undergoing total hip arthroplasty. However, the benefits for those undergoing total knee arthroplasty are uncertain, with conflicting reports based on previous cohort analyses. The purpose of the present study was to compare the revision rates following primary total knee arthroplasty with use of HXLPE as compared with conventional polyethylene (CPE) using data from the National Joint Registry (NJR) for England, Wales and Northern Ireland. We performed a retrospective analysis of primary total knee arthroplasties recorded in the NJR from 2003 to 2014. Cobalt-chromium (CoCr)-CPE and CoCr-HXLPE bearing surfaces were compared using all-cause revision, aseptic revision, and septic revision as end points. Survival analyses were conducted using rates per 100 years observed, Kaplan-Meier survival estimates, and Cox regression hazard ratios (HRs) adjusted for age, sex, American Society of Anesthesiologists (ASA) classification, body mass index (BMI), lead surgeon grade, and implant constraint. Secondary analyses compared the most commonly used HXLPEs (Zimmer Prolong, DePuy XLK, and Stryker X3) against CPE for the 3 most common total knee arthroplasty systems (NexGen, PFC Sigma, and Triathlon). In the present study of 550,658 total knee arthroplasties, the unadjusted aseptic revision rates were significantly lower following procedures performed with CPE (n = 513,744) as compared with those performed with HXLPE total knee replacements (n = 36,914) (0.29 [95% confidence interval (CI), 0.28 to 0.30] compared to 0.38 [95% CI, 0.35 to 0.42], p 35 kg/m, the "second-generation" Stryker X3 HXLPE demonstrated significantly better survival than its respective CPE, with CPE having an HR of 2.6 (95% CI, 1.2 to 5.9) (p = 0.02). Alternative bearings are marketed as having improved wear properties over traditional CoCr-CPE. This registry-based analysis demonstrated no overall survival benefit of HXLPE after a maximum duration of follow-up of 12 years. Because of their increased cost, the routine use of HXLPE bearings may not be justified. However, they may have a role in specific "higher demand" groups such as patients 35 kg/m. Therapeutic Level III. See Instructions for Authors for a complete list of levels of evidence

    Redistribution of Calving Caribou in Response to Oil Field Development on the Arctic Slope of Alaska

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    Aerial surveys were conducted annually in June 1978-87 near Prudhoe Bay, Alaska, to determine changes in the distribution of calving caribou (Rangifer tarandus granti) that accompanied petroleum-related development. With construction of an oil field access road through a calving concentration area, mean caribou density (no./sq. km) decreased from 1.41 to 0.31 (P=0.05) with 1 km and increased from 1.41 to 4.53 (P=0.04) 5-6 km from the road. Concurrently, relative caribou use of the adjacent area declined (P<0.02), apparently in response to increasing surface development. We suggest that perturbed distribution associated with roads reduced the capacity of the nearby area to sustain parturient females and that insufficient spacing of roads may have depressed overall calving activity. Use of traditional calving grounds and of certain areas therein appears to favor calf survival, principally through lower predation risk and improved foraging conditions. Given the possible loss of those habitats through displacement and the crucial importance of the reproductive process, a cautious approach to petroleum development on the Arctic Slope is warranted.Key words: Alaska, calving, caribou, disturbance, oil fieldRÉSUMÉ. Des photographies aériennes ont été prises au mois de juin chaque année de 1978 à 1987 près de la baie Prudhoe en Alaska, en vue de déterminer les changements dans la distribution des caribous (Rangifer tarandus granti) qui mettaient bas, changements accompagnant les projets de mise en valeur reliés au pétrole. Avec la construction d’une route d’accès à un champ pétrolifère à travers une zone importante de mise bas, la densité moyenne du caribou (nombre d’individus/km2) diminuait de 1,41 à 0,31 (P = 0,OS) à moins d’1 km de la route et augmentait de 1,41 à 4,53 (P = 0,04) à une distance de 516 km de la route. En même temps, l’utilisation relative de la zone adjacente par le caribou diminuait (P < 0,02), apparemment enréponse à l’augmentation de la mise en valeur de surface. On suggère que la perturbation de la distribution associée à la construction de routes diminuait la capacité de la zone environnante à supporter des femelles parturientes et qu’un espacement insuffisant des routes aurait pu faire chuter l’activité générale de mise bas. L’utilisation de terrains traditionnels de mise bas ainsi que de certaines zones à l’intérieur de ces terrains semble favoriser la survie des veaux, en particulier grâce à une baisse de la prédation et à de meilleures conditions de pâturage. Étant donné que le caribou pourrait être évincé de cet habitat et vu l’importance cruciale du processus de reproduction, on recommande une approche prudente à l’exploitation du pétrole sur le versant arctique.Mots clés: Alaska, mise bas, caribou, perturbation, champ pétrolifèr

    Planar Laser-Induced Fluorescence Velocity Measurements of Retropropulsion Jets in a Mach 12 Freestream

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106464/1/AIAA2013-2810.pd

    Investigations of Peripheral Propulsive Deceleration Jets on a Mars Science Laboratory Aeroshell

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140658/1/1.a32456.pd

    The development and flight test of a deployable precision landing system for spacecraft recovery

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    A joint NASA Dryden Flight Research Facility and Johnson Space Center program was conducted to determine the feasibility of the autonomous recovery of a spacecraft using a ram-air parafoil system for the final stages of entry from space that included a precision landing. The feasibility of this system was studied using a flight model of a spacecraft in the generic shape of a flattened biconic which weighed approximately 150 lb and was flown under a commercially available, ram-air parachute. Key elements of the vehicle included the Global Positioning System guidance for navigation, flight control computer, ultrasonic sensing for terminal altitude, electronic compass, and onboard data recording. A flight test program was used to develop and refine the vehicle. This vehicle completed an autonomous flight from an altitude of 10,000 ft and a lateral offset of 1.7 miles which resulted in a precision flare and landing into the wind at a predetermined location. At times, the autonomous flight was conducted in the presence of winds approximately equal to vehicle airspeed. Several techniques for computing the winds postflight were evaluated. Future program objectives are also presented

    Superconductivity in domains with corners

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    We study the two-dimensional Ginzburg-Landau functional in a domain with corners for exterior magnetic field strengths near the critical field where the transition from the superconducting to the normal state occurs. We discuss and clarify the definition of this field and obtain a complete asymptotic expansion for it in the large Îş\kappa regime. Furthermore, we discuss nucleation of superconductivity at the boundary
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