26800 research outputs found
Sort by
Perceptions of Blind Adults on Non-Visual Mobile Text Entry
No full textText input on mobile devices without physical keys can be challenging for people who are blind or low-vision. We interview 12 blind adults about their experiences with current mobile text input to provide insights into what sorts of interface improvements may be the most beneficial. We identify three primary themes that were experiences or opinions shared by participants: the poor accuracy of dictation, difficulty entering text in noisy environments, and difficulty correcting errors in entered text. We also discuss an experimental non-visual text input method with each participant to solicit opinions on the method and probe their willingness to learn a novel method. We find that the largest concern was the time required to learn a new technique. We find that the majority of our participants do not use word predictions while typing but instead find it faster to finish typing words manually. Finally, we distill five future directions for non-visual text input: improved dictation, less reliance on or improved audio feedback, improved error correction, reducing the barrier to entry for new methods, and more fluid non-visual word predictions
Examining Student and Faculty Perspectives on Hidden Curriculum in Computing Education
No full textHidden curriculum (HC) consists of the collective behaviors, cultural norms, and assumed knowledge that students are expected to know, but never taught. For example, teamwork skills are expected during group projects, but may not have been taught explicitly. Further, knowledge such as command line tools, interview/resume skills, and time-management can fall into the HC. HC exists in a specific context and changes over time, making it hard to examine and address. My doctoral work is situated around uncovering and addressing HC in computing education. My on-going master\u27s thesis, as part of my PhD, studies HC at Michigan Technological University\u27s Computer Science Department. It examines the connections between faculty\u27s observations of students displaying HC and student\u27s experienced HC. These two, sometimes opposing, perspectives offer a complete view of HC and are often considered separately in HC research. To find commonalities between these perspectives, the study also examines near-peer mentors. A near-peer mentor is a student that takes on an instructional role; for example student teaching assistants. Faculty have a limited view of their students\u27 misconceptions and students can\u27t know what they don\u27t know. Near-peer mentors offer a perspective that serves as a midway point between faculty and student. Their perspectives might offer ways to combine student and faculty experiences and observations. The study uses survey methods to collect a snapshot of possible HC at my institution using literature as a basis. The study then uses semi-structured interviews to dive into the specifics of observations and experiences of HC The interviews and surveys include all three perspectives: student, faculty, and mentor. I will use thematic analysis to examine common HC informed by the surveys, to reveal possible themes, connections and distinctions between perspectives, and challenges
PARTICLE DISTRIBUTION IN NANOFLUIDS UNDER THE INFLUENCE OF TEMPERATURE GRADIENT
No full textA scaled thermal diffusion factor was used to predict the potential for particle migration under the influence of temperature gradient. Then an implicit finite difference model was developed to investigate whether a fluidparticle mixture exhibits particle migration or maintains a uniform distribution under unsteady temperature gradients. Using the Buongiorno model for nanofluids, conservation equations were derived and discretized. The model focused on five cases with different nanoparticles and base fluids. Results showed that certain conditions led to uniform distribution, while others indicated potential particle migration, confirming the mathematical predictions with numerical simulations
Cyanine-Based Dual-Emission Sensor for Ratiometric NAD(P)H Imaging in Cells, Renal Tissues, and Entire Organisms
No full textMonitoring the dynamic fluctuations of NADH and NADPH, key coenzymes in intracellular redox homeostasis and bioenergetics, is essential for understanding both normal physiology and disease pathology. However, precise, real-time imaging of NAD(P)H levels in complex biological systems remains a major challenge due to interference from endogenous fluorescence and the limitations of intensity-based sensors. We present a newly engineered dual-emission fluorescent sensor, sensor , which overcomes these obstacles by offering ratiometric detection with high specificity and sensitivity. The sensor features a 3-quinolinium moiety conjugated to a cyanine dye scaffold via an amine linker, enabling selective reactivity toward NAD(P)H. Upon reduction, the sensor displays a pronounced fluorescence shift with visible emission enhancement at 511 nm and a simultaneous near-infrared emission decrease at 711 nm. This ratiometric response provides a self-calibrating readout, minimizing errors from sensor concentration or excitation variability. Sensor was validated in diverse biological contexts. In live cancer cell lines (HeLa and MD-MB453), it sensitively tracked NAD(P)H alterations induced by metabolic stimulation and chemotherapy. In Drosophila melanogaster larvae, the sensor enabled in vivo imaging of redox changes under nutrient deprivation and drug exposure. Remarkably, sensor also distinguished between healthy and diseased human kidney tissues, revealing elevated NADH levels in polycystic kidney disease samples. These results demonstrate the broad utility of sensor for investigating NAD(P)H-related processes in both research and clinical diagnostics. Its dual-emission, ratiometric output, and compatibility with live cell and in vivo imaging make it a valuable platform for probing redox biology across multiple model systems
A novel distributed architecture incorporating deep learning and biased selection for vehicular communication mmWaves beamforming
No full textVehicle to Infrastructure (V2I) connectivity has historically relied on Dedicated Short Range Communication (DSRC) and more recently Cellular Vehicle to Everything (C-V2X). However, DSRC adoption has slowed due to high deployment costs, whereas C-V2X, limited to the 5.9 GHz sub 6 GHz band, provides modest data rates mainly suitable for safety critical messages. Emerging V2I services, such as high resolution sensor sharing and cooperative perception, demand multi gigabit throughput to transfer large volumes of data (4–10 GB) between vehicles and Mobile Edge Computing (MEC) servers, requirements exceeding the capacity of sub-6 GHz technologies. This study explores a novel distributed architecture utilizing a federated learning paradigm for optimizing mmWave beamforming processes in V2I communication systems. By leveraging multiple non-RF modality sensors (GPS and LiDAR) and deep learning models, this approach aims to enhance the global model\u27s adaptability and reduce the sub-6 GHz channel usage. The proposed system uses client-biased selection strategies, including MaxLoss and Heuristic Multi-Arm Bandit, to train and update the global model, demonstrating significant improvements in convergence rates and overall performance. Simulation results using the Infocom FLASH dataset validate the framework\u27s efficiency, highlighting its potential for real-world deployment in dynamic environments
Long-range quantum entanglement in dielectric mu-near-zero metamaterials
No full textEntanglement is paramount in quantum information processing. Many quantum systems suffer from spatial decoherence in distances over a wavelength and cannot be sustained over short time periods due to dissipation. However, long range solutions are required for the development of quantum information processing on chip. Photonic reservoirs mediating the interactions between qubits and their environment are suggested. Recent research takes advantage of extended wavelength inside near-zero refractive index media to solve the long-range problem along with less sensitivity on the position of quantum emitters. However, those recent proposals use plasmonic epsilon near-zero waveguides that are intrinsically lossy. Here, we propose a fully dielectric platform, compatible with the Nitrogen Vacancy (NV) diamond centers on-chip technology, to drastically improve the range of entanglement over 17 free-space wavelengths, or approximatively 12.5 µm, using mu near-zero metamaterials. We evaluate transient and steady state concurrence demonstrating an order of magnitude enhancement compared to previous works. This is, to the best of our knowledge, the first time that such a long distance is reported using this strategy. Moreover, value of the zero time delay second order correlation function g12(2)(0) are provided, showing antibunching signature correlated with a high degree of concurrence. (Figure presented.
Improved selectivity toward methanol detection via Pd-functionalized tungsten trioxide nanofiber gas sensors
No full textMethanol is a widely used yet highly toxic volatile organic compound that poses serious health hazards through inhalation or ingestion, leading to vision impairment, neurological damage, or death. Its frequent presence alongside ethanol in industrial settings and counterfeit alcoholic beverages necessitates highly selective detection strategies to prevent accidental exposure. In this study, palladium-functionalized tungsten trioxide nanofibers (Pd-WO3 NF) were synthesized to selectively detect methanol over ethanol. The nanofibers were synthesized via electrospinning followed by calcination, with Pd incorporated at varying concentrations (1–10 at %). At 350 °C, the sensor with 5 at% Pd loading demonstrated exceptional performance, achieving a response of 20.6 at 10 ppm methanol with a low detection limit (LOD) of 55 ppb, while exhibiting no measurable response to ethanol up to 50 ppm. The Pd decoration not only reduced the operating temperature of the WO3-based methanol gas sensor but also enabled high selectivity and sensitivity through defect engineering and catalytic activation. This study highlights the potential of Pd-functionalized WO3 NF for the development of advanced methanol gas sensors with low power consumption, enhanced selectivity, and robust performance
Halogenated flame retardants in the sediments of the lower Great Lakes and region-wide discoveries
No full textThis work aims to provide updated information and insights on the contamination by halogenated flame retardants (HFRs) of the Great Lakes sediments. Thirty HFRs, including polybrominated diphenyl ethers (PBDEs), dechlorane plus (DPs), and other chlorinated (CFRs) or brominated (BFRs) chemicals, were measured in 400 sediment surface grab and core segment samples from Lakes Erie and Ontario. The data were combined with those from Lakes Superior, Michigan, and Huron to provide a comprehensive region-wide analysis. Together, the target HFRs in the Great Lakes sediment amount to approximately 420 tonnes. Among the five lakes, Lake Ontario had the highest concentrations of CFRs, while Lake Erie had the largest mass accumulation of BFRs. Regression analyses identified latitude and longitude of the sites, and sediment organic content, as the most descriptive of the observed spatial distribution patterns. The data from cores indicate that the net flux has been decreasing in recent decades for most HFRs, including PBDE replacements 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (EHTBB), with average halving time of 20–65 years. However, at most locations, inputs of decabromodiphenyl ethane (DBDPE) exhibited no clear declining trend. Concentration ratios of less halogenated compounds to their respective “parents” increase with increasing sediment depth, suggesting that dehalogenation has occurred over past decades. Principal component, correlation, and hierarchical clustering analyses of the data suggest similarities and differences among HFRs in their sources and environmental behavior. These findings contribute to the scientific knowledge basis for planning future surveillance, research, and management activities in the region and beyond
Otolith microchemistry reveals contribution of hatchery-origin Walleye in Lake Oahe, South Dakota
No full textObjective: In Lake Oahe, South Dakota, recent stockings of fingerling Walleye Sander vitreus (every year from 2017 to 2019) have coincided with increased relative abundance of catchable-size Walleye. However, it is unknown if these fish originated from hatchery stockings or were produced naturally within Lake Oahe. Thus, we sought to use otolith microchemistry to delineate wild- versus hatchery-origin Walleye in Lake Oahe. Methods: In fall 2020, we collected age-0 through age-6 Walleye (n = 349) from Lake Oahe to determine fish origin during the standard gill-net survey. We used published water and otolith microchemical signatures to assign origin to collected adult Walleye. We then compared contribution of hatchery-origin fish to stocking years and locations in Lake Oahe. Additionally, we compared length at age of Walleye between both wild- and hatchery-origin fish. Results: Age-1 through age-3 Walleye represented year-classes in Lake Oahe that received Walleye stockings, and 11% (age 1, 2019 year-class, 300,000 Walleye stocked), 42% (age 2, 2018 year-class, 2,082,000 Walleye stocked), and 18% (age 3, 2017 year-class, 364,500 Walleye stocked) of the fish sampled within these age-classes were of hatchery origin. No fish were classified as hatchery origin from year-classes that did not receive Walleye stockings in Lake Oahe. Hatchery- versus wild-origin Walleye exhibited no appreciable difference in length at age for all stocked year-classes, though the stocked Walleye were consistently longer than naturally produced fish. Percent contribution for each sampling location ranged from 5% to 42% hatchery-origin Walleye. Conclusions: Otolith microchemistry provided a robust means to identify the contribution of stocked Walleye through age 3 in Lake Oahe. In general, greater stocking numbers corresponded to a higher percent contribution of hatchery-origin Walleye of a year-class. Hatchery-origin Walleye were found to contribute in higher proportion at sampling sites near stocking locations compared with sampling sites near the periphery of stocking locations. It appears that stocking fingerling Walleye has benefited lower Lake Oahe, and Walleye stocking should continue until Walleye natural recruitment becomes consistent and at a level suitable for sport fish harvest