Chirped imaging pulses in four-dimensional electron microscopy: femtosecond pulsed hole burning

The energy and time correlation, i.e. the chirp, of imaging electron pulses in dispersive propagation is measured by time-slicing (temporal hole burning) using photon-induced near-field electron microscopy. The chirp coefficient and the degree of correlation are obtained in addition to the duration of the electron pulse and its energy spread. Improving temporal and energy resolutions by time-slicing and energy-selection is discussed here and we explore their utility in imaging with time and energy resolutions below those of the generated ultrashort electron pulse. Potential applications for these imaging capabilities are discussed

Dynamical mean-field theory of Hubbard-Holstein model at half-filling: Zero temperature metal-insulator and insulator-insulator transitions

We study the Hubbard-Holstein model, which includes both the electron-electron and electron-phonon interactions characterized by $U$ and $g$, respectively, employing the dynamical mean-field theory combined with Wilson's numerical renormalization group technique. A zero temperature phase diagram of metal-insulator and insulator-insulator transitions at half-filling is mapped out which exhibits the interplay between $U$ and $g$. As $U$ ($g$) is increased, a metal to Mott-Hubbard insulator (bipolaron insulator) transition occurs, and the two insulating states are distinct and can not be adiabatically connected. The nature of and transitions between the three states are discussed.Comment: 5 pages, 4 figures. Submitted to Physical Review Letter

Reliability of a Tablet Computer-Based Dyslexia Screening Application Using an Eye-Tracking System

Purpose The early detection and management of dyslexia are crucial for preventing irreversible educational gaps and various negative consequences for affected students. However, diagnosing dyslexia is challenging because it requires a comprehensive assessment. Dyslexia screening tests that utilize fast, automated, computer-based technology can be useful for early identification and management. In this paper, we introduce a tablet computer-based dyslexia screening application that uses an eye-tracking system and verify its reliability. Methods The study included 200 participants between 8 and 13 years of age from an elementary school, all of whom underwent dyslexia screening tests twice. The screening was conducted using the VisualCamp SeeSo eye-tracking Android Software Development Kit v3.0.0, implemented on Samsung Galaxy Tab S5e tablets. The eye-tracking system measured reading speed by gaze, mean gaze fixation time, gaze fixation frequency, saccadic length, and regression ratio. To assess the reliability of the two sets of measurements, the intraclass correlation coefficient (ICC) was employed. Results Excellent reliability was found for measurements of gaze fixation frequency (ICC=0.83), gaze fixation mean time (ICC=0.82), and reading speed by gaze (ICC=0.76), and good reliability for measurements of regression ratio (ICC=0.75) and saccadic length (ICC=0.72). Conclusion This study demonstrated that the tablet computer-based dyslexia screening application reliably measured eye movements in subjects with dyslexia. Furthermore, the application proved to be highly reliable and potentially suitable for use in clinical or school settings, eliminating the need for a laboratory environment and extensive equipment

Solitary Extramedullary Plasmacytoma of the Apex of Arytenoid: Endoscopic, CT, and Pathologic Findings

Extramedullary plasmacytoma (EMP) is a rare plasma cell neoplasm that occurs mainly in the soft tissues of head and neck region, with the paranasal sinuses, nasal cavity and nasopharynx being the most common sites. Solitary EMP of the larynx is very rare but increasingly reported recently. Common sites of involvement in larynx in the order of frequency are the epiglottis, ventricles, vocal folds and ventricular folds. We report an extremely rare case of solitary EMP involving in the apex of arytenoids that was successfully treated by only surgical excision. Because solitary EMP of the apex of artytenoids is extremely rare, it should be included in the differential diagnosis for laryngeal mass. Also, solitary, small, pedunculated and localized EMP of the larynx could be completely removed by laryngeal microsurgery