Understanding the Way Students Work: Unobtrusive Measures and the Effect of Effort on Performance

Understanding the way students use information technology in an educational setting is described as a critical factor in evaluating the effectiveness of IT use. A theoretical model, derivative of prior research, proposes three educational contexts that must be considered in evaluating performance-based effectiveness. A method of collecting information on student work patterns through unobtrusive means is presented, and a research project using the model and methods is describe

Attitudes Toward Computers: The Impact on Performance

The proliferation of personal computers throughout business environments will continue to place demands on workers at all levels to develop proficient computer skills. A variety of training mechanisms exist that allow workers to introduce, develop, and hone any needed computer skills. Identical training mechanisms, however, are nonetheless likely to result in individuals with different computer abilities (Hicks, Hicks, and Senn, 1991). Existing researchhas examined differences in demographic factors (Dambrot, Silling, and Zook; 1988) as well as differences in attitudes (Torkzadeh and Koufteros, 1993). Much of the research that has examined this area has focused on the changes in attitudes (e.g. computeranxiety) that occur due to a training intervention. Research to date, however, has not extended this effect of training on attitudes as well as to performance. The theory of reasoned action (TRA) (Fishbein and Ajzen, 1975) suggests that attitudes will influence behavior, including performance. The Technology Acceptance Model (TAM) ( Davis, Bagozzi, and Warshaw, 1989) also suggests that attitudes towards use directly influence intentions to use the computer and ultimately actual computer use. Davis et al. demonstrate that an individual\u27s initial attitudes regarding a computer\u27s ease of use and a computer\u27s usefulness influence attitudes toward use. In addition to the attitudes of computer ease of use and computer usefulness, a number of other attitudes related to computer use have been identified in the research literature. Items measuring attitudes examined in this study have been previously defined and used in other studies. The attitudes and measures used in this study were perceived usefulness , perceived ease of use (Davis et al. 1989), computer anxiety (Loyd and Gressard, 1984), anticipation of computer use (Heinssen, Glass, and Knight, 1987), fear of computer use (Heinssen et al.,1987), and attitude toward previous academic achievement. Computer anxiety has been an attitude of primary focus that corresponds closely to the concept of math anxiety (Torkzadeh and Angulo, 1992). Although computer anxiety has definitions ranging from psychological, physical or sociological discomfort to fear. The definition of anxiety in this research referred to the psychological discomfort that might come from using a computer. This discomfort might come from using something unknown, concern over making mistakes or destroying pertinent information. In addition to measuring computer anxiety, we also wanted to measure computer fear. Although extreme anxiety might become fear, there is a distinction between the two constructs. Fear was defined as a trepidation that computers would change something about the individual, such as making the person too dependent on computers. Anticipation was defined as comfort with the idea of learning and using computer skills (Harrison and Ranier, 1992). Academic achievement provided a perceived measure of a subject\u27s past performance in both math and other academic endeavors. The perceived ease of use and usefulness constructs have been well established in the work by Davis et al. (Davis, 1989; Davis, Bagozzi, and Warshaw, 1992). Perceived usefulness was defined as the degree to which a person believes that using a particular system would enhance his or her job performance . Perceived ease of use was defined as the degree to which a person believes that using a particular system would be free of effort (Davis, 1989, pg. 320)

High-Power Single-Mode 2.65-micron InGaAsSb/AlInGaAsSb Diode Lasers

Central to the advancement of both satellite and in-situ science are improvements in continuous-wave and pulsed infrared laser systems coupled with integrated miniaturized optics and electronics, allowing for the use of powerful, single-mode light sources aboard both satellite and unmanned aerial vehicle platforms. There is a technological gap in supplying adequate laser sources to address the mid-infrared spectral window for spectroscopic characterization of important atmospheric gases. For high-power applications between 2 to 3 micron, commercial laser technologies are unsuitable because of limitations in output power. For instance, existing InP-based laser systems developed for fiber-based telecommunications cannot be extended to wavelengths longer than 2 micron. For emission wavelengths shorter than 3 micron, intersubband devices, such as infrared quantum cascade lasers, become inefficient due to band-offset limitations. To date, successfully demonstrated singlemode GaSb-based laser diodes emitting between 2 and 3 micron have employed lossy metal Bragg gratings for distributed- feedback coupling, which limits output power due to optical absorption. By optimizing both the quantum well design and the grating fabrication process, index-coupled distributed-feedback 2.65-micron lasers capable of emitting in excess of 25 mW at room temperature have been demonstrated. Specifically, lasers at 3,777/cm (2.65 micron) have been realized to interact with strong absorption lines of HDO and other isotopologues of H2O. With minor modifications of the optical cavity and quantum well designs, lasers can be fabricated at any wavelength within the 2-to-3-micron spectral window with similar performance. At the time of this reporting, lasers with this output power and wavelength accuracy are not commercially available. Monolithic ridge-waveguide GaSb lasers were fabricated that utilize secondorder lateral Bragg gratings to generate single-mode emission from InGaAsSb/ AlInGaAsSb multi-quantum well structures. The device fabrication utilizes etched index-coupled gratings in the top AlGaAsSb cladding of the laser chip along the ridge waveguide, whereas commercial lasers that emit close to this wavelength include loss-coupled metal gratings that limit the output power of the laser. Semiconductor-laser-based spectrometers can be used to replace gas sensors currently used in industry and government. With the availability of high-power laser sources at mid-infrared wavelengths, sensors can target strong fundamental gas absorption lines to maximize instrument sensitivity

Causal Factors and Adverse Events of Aviation Accidents and Incidents Related to Integrated Vehicle Health Management

Causal factors in aviation accidents and incidents related to system/component failure/malfunction (SCFM) were examined for Federal Aviation Regulation Parts 121 and 135 operations to establish future requirements for the NASA Aviation Safety Program s Integrated Vehicle Health Management (IVHM) Project. Data analyzed includes National Transportation Safety Board (NSTB) accident data (1988 to 2003), Federal Aviation Administration (FAA) incident data (1988 to 2003), and Aviation Safety Reporting System (ASRS) incident data (1993 to 2008). Failure modes and effects analyses were examined to identify possible modes of SCFM. A table of potential adverse conditions was developed to help evaluate IVHM research technologies. Tables present details of specific SCFM for the incidents and accidents. Of the 370 NTSB accidents affected by SCFM, 48 percent involved the engine or fuel system, and 31 percent involved landing gear or hydraulic failure and malfunctions. A total of 35 percent of all SCFM accidents were caused by improper maintenance. Of the 7732 FAA database incidents affected by SCFM, 33 percent involved landing gear or hydraulics, and 33 percent involved the engine and fuel system. The most frequent SCFM found in ASRS were turbine engine, pressurization system, hydraulic main system, flight management system/flight management computer, and engine. Because the IVHM Project does not address maintenance issues, and landing gear and hydraulic systems accidents are usually not fatal, the focus of research should be those SCFMs that occur in the engine/fuel and flight control/structures systems as well as power systems

Single-mode 2.65 µm InGaAsSb/AlInGaAsSb laterally coupled distributed-feedback diode lasers for atmospheric gas detection.

We demonstrate index-coupled distributed-feedback diode lasers at 2.65 µm that are capable of tuning across strong absorption lines of HDO and other isotopologues of H2O. The lasers employ InGaAsSb/AlInGaAsSb multi-quantum-well structures grown by molecular beam epitaxy on GaSb, and single-mode emission is generated using laterally coupled second-order Bragg gratings etched alongside narrow ridge waveguides. We verify near-critical coupling of the gratings by analyzing the modal characteristics of lasers of different length. With an emission facet anti-reflection coating, 2-mm-long lasers exhibit a typical current threshold of 150 mA at 20 °C and are capable of emitting more than 25 mW in a single longitudinal mode, which is significantly higher than the output power reported for loss-coupled distributed-feedback lasers operating at similar wavelengths

Commercial Aircraft Integrated Vehicle Health Management Study

Statistical data and literature from academia, industry, and other government agencies were reviewed and analyzed to establish requirements for fixture work in detection, diagnosis, prognosis, and mitigation for IVHM related hardware and software. Around 15 to 20 percent of commercial aircraft accidents between 1988 and 2003 involved inalftfnctions or failures of some aircraft system or component. Engine and landing gear failures/malfunctions dominate both accidents and incidents. The IVI vl Project research technologies were found to map to the Joint Planning and Development Office's National Research and Development Plan (RDP) as well as the Safety Working Group's National Aviation Safety Strategic. Plan (NASSP). Future directions in Aviation Technology as related to IVHlvl were identified by reviewing papers from three conferences across a five year time span. A total of twenty-one trend groups in propulsion, aeronautics and aircraft categories were compiled. Current and ftiture directions of IVHM related technologies were gathered and classified according to eight categories: measurement and inspection, sensors, sensor management, detection, component and subsystem monitoring, diagnosis, prognosis, and mitigation

Severe methemoglobinemia secondary to isobutyl nitrite toxicity: the case of the ‘Gold Rush’

Isobutyl nitrite is one of the popular recreational drugs with high abuse potential that is known to cause methemoglobinemia. While inhaling this recreational drug, often referred to as a 'popper', is the typical route of administration, oral ingestion can produce a more rapid and fulminant course of methemoglobinemia. We present the case of a 69-year-old male that presented to our emergency department in extreme, life-threatening methemoglobinemia due to the ingestion of isobutyl nitrite that he obtained from an adult novelty store. The patient had a methemoglobin level above our lab cut-off of 28% and was subsequently treated with two doses of intravenous methylene blue. His hospital course was unremarkable, and he was discharged on Day 2. Methemoglobinemia is a medical emergency that requires a high index of clinical suspicion, prompt recognition, and rapid treatment

Glycan complexity dictates microbial resource allocation in the large intestine.

The structure of the human gut microbiota is controlled primarily through the degradation of complex dietary carbohydrates, but the extent to which carbohydrate breakdown products are shared between members of the microbiota is unclear. We show here, using xylan as a model, that sharing the breakdown products of complex carbohydrates by key members of the microbiota, such as Bacteroides ovatus, is dependent on the complexity of the target glycan. Characterization of the extensive xylan degrading apparatus expressed by B. ovatus reveals that the breakdown of the polysaccharide by the human gut microbiota is significantly more complex than previous models suggested, which were based on the deconstruction of xylans containing limited monosaccharide side chains. Our report presents a highly complex and dynamic xylan degrading apparatus that is fine-tuned to recognize the different forms of the polysaccharide presented to the human gut microbiota.This work was supported in part by grants to D.N.B. (BBSRC BB/G016186/1) and H.J.G. (Wellcome Trust WT097907AIA).This is the final version. It was first published by NPG at http://dx.doi.org/10.1038/ncomms848