5,022 research outputs found

    Problem solving and creativity for undergraduate engineers: process or product?

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    Many researchers have written about the importance and complexities of developing problem solving skills and encouraging creative thinking and activity in engineering students. Whilst research suggests that established Problem Based Learning techniques are a suitable way for developing these skills it also acknowledges continued deficiencies in encouraging process skills as opposed to products or outcomes. This paper provides highlights of this previous work, and presents findings of action research in order to develop a module to improve and encourage process skills in engineering undergraduates. Lego Mindstorm robots have been used in the module to provide suitable practical activities and to stimulate student motivation

    Dynamic plantar loading index detects altered foot function in individuals with rheumatoid arthritis but not changes due to orthotic use

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    Background Altered foot function is common in individuals with rheumatoid arthritis. Plantar pressure distributions during gait are regularly assessed in this patient group; however, the association between frequently reported magnitude-based pressure variables and clinical outcomes has not been clearly established. Recently, a novel approach to the analysis of plantar pressure distributions throughout stance phase, the dynamic plantar loading index, has been proposed. This study aimed to assess the utility of this index for measuring foot function in individuals with rheumatoid arthritis.Methods Barefoot plantar pressures during gait were measured in 63 patients with rheumatoid arthritis and 51 matched controls. Additionally, 15 individuals with rheumatoid arthritis had in-shoe plantar pressures measured whilst walking in standardized footwear for two conditions: shoes-only; and shoes with prescribed custom foot orthoses. The dynamic plantar loading index was determined for all participants and conditions. Patient and control groups were compared for significant differences as were the shod and orthosis conditions.Findings The patient group was found to have a mean index of 0.19, significantly lower than the control group's index of 0.32 (p > 0.001, 95% CI [0.054, 0.197]). No significant differences were found between the shoe-only and shoe plus orthosis conditions. The loading index was found to correlate with clinical measures of structural deformity.Interpretation The dynamic plantar loading index may be a useful tool for researchers and clinicians looking to objectively assess dynamic foot function in patients with rheumatoid arthritis; however, it may be unresponsive to changes caused by orthotic interventions in this patient group.</p

    Affective Computational Model to Extract Natural Affective States of Students with Asperger Syndrome (AS) in Computer-based Learning Environment

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    This study was inspired by looking at the central role of emotion in the learning process, its impact on students’ performance; as well as the lack of affective computing models to detect and infer affective-cognitive states in real time for students with and without Asperger Syndrome (AS). This model overcomes gaps in other models that were designed for people with autism, which needed the use of sensors or physiological instrumentations to collect data. The model uses a webcam to capture students’ affective-cognitive states of confidence, uncertainty, engagement, anxiety, and boredom. These states have a dominant effect on the learning process. The model was trained and tested on a natural-spontaneous affective dataset for students with and without AS, which was collected for this purpose. The dataset was collected in an uncontrolled environment and included variations in culture, ethnicity, gender, facial and hairstyle, head movement, talking, glasses, illumination changes and background variation. The model structure used deep learning (DL) techniques like convolutional neural network (CNN) and long short-term memory (LSTM). DL is the-state-of-art tool that used to reduce data dimensionality and capturing non-linear complex features from simpler representations. The affective model provide reliable results with accuracy 90.06%. This model is the first model to detected affective states for adult students with AS without physiological or wearable instruments. For the first time, the occlusions in this model, like hand over face or head were considered an important indicator for affective states like boredom, anxiety, and uncertainty. These occlusions have been ignored in most other affective models. The essential information channels in this model are facial expressions, head movement, and eye gaze. The model can serve as an aided-technology for tutors to monitor and detect the behaviors of all students at the same time and help in predicting negative affective states during learning process

    Exact Results for the Bipartite Entanglement Entropy of the AKLT spin-1 chain

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    We study the entanglement between two domains of a spin-1 AKLT chain subject to open boundary conditions. In this case the ground-state manifold is four-fold degenerate. We summarize known results and present additional exact analytical results for the von Neumann entanglement entropy, as a function of both the size of the domains and the total system size for {\it all} four degenerate ground-states. In the large l,Ll,L limit the entanglement entropy approaches ln⁥(2)\ln(2) and 2ln⁥(2)2\ln(2) for the STz=¹1S^z_T=\pm 1 and STz=0S^z_T=0 states, respectively. In all cases, it is found that this constant is approached exponentially fast defining a length scale Ξ=1/ln⁥(3)\xi=1/\ln(3) equal to the known bulk correlation length.Comment: 11 pages, 3 figure

    Observations of Outflowing UV Absorbers in NGC 4051 with the Cosmic Origins Spectrograph

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    We present new Hubble Space Telescope (HST)/Cosmic Origins Spectrograph observations of the Narrow-Line Seyfert 1 galaxy NGC 4051. These data were obtained as part of a coordinated observing program including X-ray observations with the Chandra/High Energy Transmission Grating (HETG) Spectrometer and Suzaku. We detected nine kinematic components of UV absorption, which were previously identified using the HST/Space Telescope Imaging Spectrograph. None of the absorption components showed evidence for changes in column density or profile within the \sim 10 yr between the STIS and COS observations, which we interpret as evidence of 1) saturation, for the stronger components, or 2) very low densities, i.e., n_H < 1 cm^-3, for the weaker components. After applying a +200 km s^-1 offset to the HETG spectrum, we found that the radial velocities of the UV absorbers lay within the O VII profile. Based on photoionization models, we suggest that, while UV components 2, 5 and 7 produce significant O VII absorption, the bulk of the X-ray absorption detected in the HETG analysis occurs in more highly ionized gas. Moreover, the mass loss rate is dominated by high ionization gas which lacks a significant UV footprint.Comment: 41 pages, 10 Figures; accepted for publication in the Astrophysical Journa

    Summer Drivers of Atmospheric Variability Affecting Ice Shelf Thinning in the Amundsen Sea Embayment, West Antarctica

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    Satellite data and a 35-year hindcast of the Amundsen Sea Embayment summer climate using the Weather Research and Forecasting model are used to understand how regional and large-scale atmospheric variability affects thinning of ice shelves in this sector of West Antarctica by melting from above and below (linked to intrusions of warm water caused by anomalous westerlies over the continental shelf edge). El Nino episodes are associated with an increase in surface melt but do not have a statistically significant impact on westerly winds over the continental shelf edge. The location of the Amundsen Sea Low and the polarity of the Southern Annular Mode (SAM) have negligible impact on surface melting, although a positive SAM and eastward shift of the Amundsen Sea Low cause anomalous westerlies over the continental shelf edge. The projected future increase in El Nino episodes and positive SAM could therefore increase the risk of disintegration of West Antarctic ice shelves

    Examination of Edge Effects with Different Storage Conditions of Preplated Dimethyl Sulfoxide Nanospots in ChemLib 1,536- and 3,456-Well Assay-Ready Plates

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    For ultra-high-throughput screening, 10–30 nl of compound dissolved in 75% dimethyl sulfoxide (DMSO)/25% water (vol/vol) is spotted into 1,536- and 3,456-well ChemLib™ plates (Aurora Biotechnologies, Carlsbad, CA) and stored appropriately for a short time before screening. Although this practice eliminates the compound plating bottleneck, plated volumes of DMSO slowly evaporate from assay wells if plates are not properly stored in the interim. Since many assays are sensitive to DMSO concentrations, even slight evaporation may cause intra-plate variation and thus decrease assay quality. Using a cytochrome P450 3A4 Vivid® Blue assay (Invitrogen, Carlsbad), we investigated the rate, pattern, and quantity of evaporation over a 1-year time frame to identify best practices for long-term (i.e., 6 months or greater) storage of assay-ready compound plates. Our findings regarding evaporation at plate edges indicate that nanospots preplated in ChemLib 1,536- or 3,456-well plates are best stored at −80°C, in a bag, with or without the outer evaporation wells filled or at −20°C, in a bag, with evaporation wells filled.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63203/1/adt.2008.169.pd

    Short Circuits in Thermally Ionized Plasmas: A Mechanism for Intermittent Heating of Protoplanetary Disks

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    Many astrophysical systems of interest, including protoplanetary accretion disks, are made of turbu- lent magnetized gas with near solar metallicity. Thermal ionization of alkali metals in such gas exceeds non-thermal ionization when temperatures climb above roughly 1000 K. As a result, the conductiv- ity, proportional to the ionization fraction, gains a strong, positive dependence on temperature. In this paper, we demonstrate that this relation between the temperature and the conductivity triggers an exponential instability that acts similarly to an electrical short, where the increased conductivity concentrates the current and locally increases the Ohmic heating. This contrasts with the resistiv- ity increase expected in an ideal magnetic reconnection region. The instability acts to focus narrow current sheets into even narrower sheets with far higher currents and temparatures. We lay out the basic principles of this behavior in this paper using protoplanetary disks as our example host system, motivated by observations of chondritic meteorites and their ancestors, dust grains in protoplanetary disks, that reveal the existence of strong, frequent heating events that this instability could explain.Comment: 9 pages, 6 figures, 1 table Accepted, Ap

    NASA Light Emitting Diode Medical Applications from Deep Space to Deep Sea

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    This work is supported and managed through the NASA Marshall Space Flight Center-SBIR Program. LED-technology developed for NASA plant growth experiments in space shows promise for delivering light deep into tissues of the body to promote wound healing and human tissue growth. We present the results of LED-treatment of cells grown in culture and the effects of LEDs on patients’ chronic and acute wounds. LED-technology is also biologically optimal for photodynamic therapy of cancer and we discuss our successes using LEDs in conjunction with light-activated chemotherapeutic drugs
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