1,481 research outputs found
Fostering self-regulation and deep approaches to learning : end-user computing courses in higher education : a thesis presented in partial fulfillment of the requirements for the degree of Master of Education (Special Education) at Massey University, New Zealand
This thesis examines student approaches to learning and self-regulation within a higher education computing environment. Traditional end-user computing teaching methods emphasise a skills approach that does not encourage effective use of information technology as it evolves and does not consider how students approach their learning. This research was designed to promote student use of self-regulated learning to see if it would encourage deep approaches to learning. The revised two-factor Study Process Questionnaire (R-SPQ-2F) was used to measure approaches to learning, at the beginning and end of a semester, to see if students' learning had shifted towards a deeper approach. The sample was taken from two end-user computing classes in a diploma programme. The teaching of strategies to foster self-regulatory practices was introduced. Focus group discussions were held at the beginning, middle and end of the study to record student perceptions of learning. Academic journals, recording student reflection, were collected. The results from the R-SPQ-2F questionnaire showed no shift had occurred. The participants began the semester with a tendency toward a deeper learning approach, leaving little room for change. There was no difference found between approaches to learning of ethnic groupings. Qualitative results revealed deep and surface learning approaches are not necessarily mutually exclusive and may overlap, suggesting a combined approach. The course grades suggested that the adoption of teaching strategies fostering self-regulation helped student learning in the researched classes. A link was suggested between strategy use and student approaches to learning
Tethered Space Satellite-1 (TSS-1): Technical Roundabouts
In the early 1990's US and Italian scientists collaborated to study the electrodynamics of dragging a satellite on a tether through the electrically charged portion of Earth's atmosphere called the ionosphere. An electrical current induced in the long wire could be used for power and thrust generation for a satellite. Other tether uses include momentum exchange, artificial gravity, deployment of sensors or antennas, and gravity-gradient stabilization for satellites. Before the Tethered Space Satellite (TSS-1), no long tether had ever been flown, so many questions existed on how it would actually behave. The TSS consisted of a satellite with science experiments attached to a 12.5 mile long, very thin (0.10 inch diameter) copper wire assembly wound around a spool in the deployer reel mechanism. With the Space Shuttle at an altitude of 160 nautical miles above earth, the satellite was to be deployed by raising it from the Shuttle bay on a boom facing away from Earth. Once cleared of the bay, the deployer mechanism was to slowly feed out the 12-plus miles of tether. Scientific data would be collected throughout the operation, after which the satellite would be reeled back in. Pre-flight testing system level tests involved setting up a tether receiver to catch the 12.5 mile tether onto another reel as it was being unwound by the deployer reel mechanism. Testing only the reel mechanism is straightforward. This test becomes more complicated when the TSS is mounted on the flight pallet at Kennedy Space Center (KSC). The system level tests must be passed before the pallet can be installed into the Space Shuttle cargo bay. A few months before flight, the TSS payload had been integrated onto the Spacelab pallet and system level tests, including unreeling and reeling the tether, had been successfully completed. Some of this testing equipment was then shipped back to the contractor Martin Marietta. Systems-level load analyses, which cannot be run until all information about each payload is finalized, was run in parallel with the physical integration of the hardware into the Shuttle payload bay. The coupled loads analysis, as it is called, incorporates any updates to the model due to system level tests, and any changes that were found during integration. The coupled loads analysis revealed that a single bolt attaching the deployer reel mechanism to the support structure had a "negative margin" - which is an indication that it might fail during operation. Hardware certification rules do not allow for hardware to fly with negative margins, so this issue had to be resolved before the flight. Since there is conservatism in engineering analysis, there is an option to "waive" the margin requirement, and fly the experiment as is. On the other hand, a structural failure of one payload could have serious or catastrophic consequences to other payloads and possibly the mission. Minor design changes or fixes might be feasible within the payload bay prior to launch. Any major design changes that required the spooling test to validate the hardware, or for the pallet to be removed, would cause TSS not to be ready for the Shuttle launch
Tethered Space Satellite-1 (TSS-1): Wound About a Bolt
In the early 1990's US and Italian scientists collaborated to study the electrodynamics on a long tether between two satellites as it moved through the electrically charged portion of Earth's atmosphere called the ionosphere. Potential uses for the electrical current induced in the long wire include power and thrust generation for a satellite, momentum exchange, artificial gravity, deployment of sensors or antennas, and gravity-gradient stabilization. The Tethered Space Satellite (TSS) was a first-of-its-kind experiment with long tethers in space. It consisted of a satellite with science experiments attached to a 12.5 mile long, very thin (0.10 inch diameter) copper wire assembly wound around a spool in the deployer reel mechanism. The whole mechanism sits on a pallet that is installed into the Shuttle bay. At an altitude of 160 nautical miles above earth, the satellite would be deplodeployed from the Shuttle bay by raising it on a boom facing away from Earth. Once cleared of the bay, the deployer mechanism would slowly feed out the 12-plus miles of tether. Scientific data would be collected throughout the operation, after which the satellite would be reeled back in. A receiver spool to catch the 12.5 mile tether as it was being unwound by the deployer reel mechanism was set up to do the system-level test of deployer real mechanism prior to installing the loaded pallet into the Shuttle bay. The system level tests were required before the pallet could be installed into the Space Shuttle cargo bay. A few months before flight, the system level tests, including unreeling and reeling the tether, were completed at Kennedy Space Center (KSC) and the TSS payload was installed onto the Spacelab pallet. Some of this testing equipment was then shipped back to the contractor, Martin Marietta. Integration with the Shuttle began. Systems-level load analyses, which cannot be run until all information about each payload is finalized, was run in parallel with the physical integration of the hardware into the Shuttle payload bay. An analysis, called Coupled loads analysis, incorporates any updates to the model due to system level tests of all the different payloads, and any changes that were found during integration. Engineering analysis examines the worst case scenarios for the loads the hardware will see. The two times during the mission where the dynamic loads are the worst were 1) the first 10-second portion of Shuttle lift off, and 2) a 2-second time during landing when the landing gears hit the ground. The coupled loads analysis using the final verification loads showed that a single bolt attaching the deployer reel mechanism to the support structure had a "negative margin" - which is an indication that it might fail - during touch down. Hardware certification rules do not allow for hardware to fly with negative margins. A structural failure of one payload could have serious or catastrophic consequences to other payloads, or may significantly damage the Orbiter. The issue had to be resolved before the flight
Identification of sleep apnea events using discrete wavelet transform of respiration, ECG and accelerometer signals
Sleep apnea is a common sleep disorder in which patient sleep patterns are disrupted due to recurrent pauses
in breathing or by instances of abnormally low breathing.
Current gold standard tests for the detection of apnea events are costly and have the addition of long waiting times. This paper investigates the use of cheap and easy to use sensors for the identification of sleep apnea events. Combinations of respiration, electrocardiography (ECG) and acceleration signals were analysed. Results show that using features, formed using the discrete wavelet transform (DWT), from the ECG and acceleration signals provided the highest classification accuracy, with an F1 score of 0.914. However, the novel employment of just the accelerometer signal during classification provided a comparable F1 score of 0.879. By employing one or a combination of the analysed sensors a preliminary test for sleep apnea, prior to the requirement for gold standard testing, can be performed
Rocaglates induce gain-of-function alterations to eIF4A and eIF4F
Rocaglates are a diverse family of biologically active molecules that have gained tremendous interest in recent years due to their promising activities in pre-clinical cancer studies. As a result, this family of compounds has been significantly expanded through the development of efficient synthetic schemes. However, it is unknown whether all of the members of the rocaglate family act through similar mechanisms of action. Here, we present a comprehensive study comparing the biological activities of >200 rocaglates to better understand how the presence of different chemical entities influences their biological activities. Through this, we find that most rocaglates preferentially repress the translation of mRNAs containing purine-rich 5' leaders, but certain rocaglates lack this bias in translation repression. We also uncover an aspect of rocaglate mechanism of action in which the pool of translationally active eIF4F is diminished due to the sequestration of the complex onto RNA.P50 GM067041 - NIGMS NIH HHS; R24 GM111625 - NIGMS NIH HHS; R35 GM118173 - NIGMS NIH HHSPublished versio
Automatically detecting asymmetric running using time and frequency domain features
Human motion analysis technologies have been widely employed to identify injury determining factors and provide objective and quantitative feedback to athletes to help prevent injury. However, most of these technologies are: ex- pensive, restricted to laboratory environments, and can require significant post processing. This reduces their ecological validity, adoption and usefulness. In this paper, we present a novel wearable inertial sensor framework to accurately distinguish between symmetrical and asymmetrical running patterns in an unconstrained environment. The framework can automatically classify symmetry/asymmetry using Short Time Fourier Trans- form (STFT) and other time domain features in conjunction with a customized Random Forest classifier. The accuracy of the designed framework is up to 94% using 3-D accelerometer and 3-D gyroscope data from a sensor node attached on the upper back of a subject. The upper back inertial sensors data were then down-sampled by a factor of 4 to simulate utilizing low-cost inertial sensors whilst also facilitating a decrease of the computational cost to achieve near real-time application. We conclude that the proposed framework can potentially pave the way for employing low-cost sensors, such as those used in smartphones, attached on the upper back to provide injury related and performance feedback in real-time in unconstrained environments
Recruitment, growth and mortality of an Antarctic hexactinellid sponge, Anoxycalyx joubini.
Polar ecosystems are sensitive to climate forcing, and we often lack baselines to evaluate changes. Here we report a nearly 50-year study in which a sudden shift in the population dynamics of an ecologically important, structure-forming hexactinellid sponge, Anoxycalyx joubini was observed. This is the largest Antarctic sponge, with individuals growing over two meters tall. In order to investigate life history characteristics of Antarctic marine invertebrates, artificial substrata were deployed at a number of sites in the southern portion of the Ross Sea between 1967 and 1975. Over a 22-year period, no growth or settlement was recorded for A. joubini on these substrata; however, in 2004 and 2010, A. joubini was observed to have settled and grown to large sizes on some but not all artificial substrata. This single settlement and growth event correlates with a region-wide shift in phytoplankton productivity driven by the calving of a massive iceberg. We also report almost complete mortality of large sponges followed over 40 years. Given our warming global climate, similar system-wide changes are expected in the future
Airway resistance at maximum inhalation as a marker of asthma and airway hyperresponsiveness
Abstract
Background
Asthmatics exhibit reduced airway dilation at maximal inspiration, likely due to structural differences in airway walls and/or functional differences in airway smooth muscle, factors that may also increase airway responsiveness to bronchoconstricting stimuli. The goal of this study was to test the hypothesis that the minimal airway resistance achievable during a maximal inspiration (Rmin) is abnormally elevated in subjects with airway hyperresponsiveness.
Methods
The Rmin was measured in 34 nonasthmatic and 35 asthmatic subjects using forced oscillations at 8 Hz. Rmin and spirometric indices were measured before and after bronchodilation (albuterol) and bronchoconstriction (methacholine). A preliminary study of 84 healthy subjects first established height dependence of baseline Rmin values.
Results
Asthmatics had a higher baseline Rmin % predicted than nonasthmatic subjects (134 ± 33 vs. 109 ± 19 % predicted, p = 0.0004). Sensitivity-specificity analysis using receiver operating characteristic curves indicated that baseline Rmin was able to identify subjects with airway hyperresponsiveness (PC20 < 16 mg/mL) better than most spirometric indices (Area under curve = 0.85, 0.78, and 0.87 for Rmin % predicted, FEV1 % predicted, and FEF25-75 % predicted, respectively). Also, 80% of the subjects with baseline Rmin < 100% predicted did not have airway hyperresponsiveness while 100% of subjects with Rmin > 145% predicted had hyperresponsive airways, regardless of clinical classification as asthmatic or nonasthmatic.
Conclusions
These findings suggest that baseline Rmin, a measurement that is easier to perform than spirometry, performs as well as or better than standard spirometric indices in distinguishing subjects with airway hyperresponsiveness from those without hyperresponsive airways. The relationship of baseline Rmin to asthma and airway hyperresponsiveness likely reflects a causal relation between conditions that stiffen airway walls and hyperresponsiveness. In conjunction with symptom history, Rmin could provide a clinically useful tool for assessing asthma and monitoring response to treatment.
</jats:sec
Wake Encounter Analysis for a Closely Spaced Parallel Runway Paired Approach Simulation
A Monte Carlo simulation of simultaneous approaches performed by two transport category aircraft from the final approach fix to a pair of closely spaced parallel runways was conducted to explore the aft boundary of the safe zone in which separation assurance and wake avoidance are provided. The simulation included variations in runway centerline separation, initial longitudinal spacing of the aircraft, crosswind speed, and aircraft speed during the approach. The data from the simulation showed that the majority of the wake encounters occurred near or over the runway and the aft boundaries of the safe zones were identified for all simulation conditions
- …
