42,080 research outputs found

    Passive harmonic mode-locking by mode selection in Fabry-Perot diode lasers with patterned effective index

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    We demonstrate passive harmonic mode-locking of a quantum well laser diode designed to support a discrete comb of Fabry-Perot modes. Spectral filtering of the mode spectrum was achieved using a non-periodic patterning of the cavity effective index. By selecting six modes spaced at twice the fundamental mode spacing, near-transform limited pulsed output with 2 ps pulse duration was obtained at a repetition rate of 100 GHz.Comment: 3 page

    On the road: the action learning set (ALS) journey towards becoming a research-engaged school

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    "The full report explores from a leadership perspective one approach to setting up research communities within a school – the implementation of a formal approach to action research in a large, challenging inner-city comprehensive school through the use of action learning sets (ALS), sometimes known in educational literature as ‘professional learning communities’." - Page 2

    Two species of Compsus Schoenherr, new citrus pests from Colombia (Coleoptera: Curculionidae: Entiminae)

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    Two species of the weevil genus Compsus Schoenherr (Coleoptera: Curculionidae: Entiminae) from Colombia are redescribed: C. obliquatus Hustache and C.viridivittatus (Guérin-Méneville). A key by Hustache in 1938, to 33 of the 34 recognized species of Colombian Compsus then known, is modified to include the one additional species. Habitus illustrations of males and females of the two species and illustrations of selected parts of the male and female genitalia are included. Nearly all of the specimens of these two species were collected on various species or varieties of citrus, indicating their potential as citrus pests in the future.Se redescriben dos especies de picudos del genero Compsus Schoenherr (Coleoptera: Curculionidae: Entiminae) colectadas en Colombia: C. obliquatus Hustache y C. viridivittatus (Guérin-Méneville). Se modifica la clave de identificación de Hustache de 1938 la cual incluye 33 a 34 especies conocidas de Compsus en ese entonces en Colombia. Se incluyen ilustraciones con las características físicas de machos y hembras de ambas especies e ilustraciones de partes seleccionadas de la genitalia de machos y hembras de las dos especies. Casi todos los especímenes de estas dos especies fueron colectadas en varias especies o variedades de cítricos, lo cual indica su futuro potencial como plagas de cítricos

    All-optical switching in metamaterial with high structural symmetry

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    We argue the possibility of realization of a polarization insensitive all-optical switching in a planar metamaterial composed of a 4-fold periodic array of two concentric metal rings placed on a substrate of nonlinear material. It is demonstrated that a switching may be achieved between essentially different values of transmission near the resonant frequency of the high-quality-factor Fano-shape trapped-mode excitation.Comment: 7 pages, 3 figure

    Macromia alleghaniensis (Odonata: Macromiidae): New For Michigan, with Clarifications of Northern Records

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    An Alleghany River Cruiser, Macromia alleghaniensis Williamson (Odonata: Macromiidae), collected in Cass County, Michigan on 18 June 2014, represents the first record of the species for the state, as well as the northernmost unequivocal record in North America. Other records north of 40° latitude are clarified and discussed

    All-optical memory based on the injection locking bistability of a two-color laser diode

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    We study the injection locking bistability of a specially engineered two-color semiconductor Fabry-Perot laser. Oscillation in the uninjected primary mode leads to a bistability of single mode and two-color equilibria. With pulsed modulation of the injected power we demonstrate an all-optical memory element based on this bistability, where the uninjected primary mode is switched with 35 dB intensity contrast. Using experimental and theoretical analysis, we describe the associated bifurcation structure, which is not found in single mode systems with optical injection.Comment: 5 pages, 5 figure

    Towards predicting post-editing productivity

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    Machine translation (MT) quality is generally measured via automatic metrics, producing scores that have no meaning for translators who are required to post-edit MT output or for project managers who have to plan and budget for transla- tion projects. This paper investigates correlations between two such automatic metrics (general text matcher and translation edit rate) and post-editing productivity. For the purposes of this paper, productivity is measured via processing speed and cognitive measures of effort using eye tracking as a tool. Processing speed, average fixation time and count are found to correlate well with the scores for groups of segments. Segments with high GTM and TER scores require substantially less time and cognitive effort than medium or low-scoring segments. Future research involving score thresholds and confidence estimation is suggested

    Neurodiversity Affirming Goal Writing

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    Introduction: The rise of the neurodiversity movement has started to question social communication and pragmatic therapy as we know it today. This movement started in the 1990s when Autistic people were able to connect and share ideas in online forums. These groups went on to create a social-justice movement for Autistic self-advocacy along with their own Autistic culture. This community has pointed out that some forms of pragmatic therapy can promote masking. Method: A review of the published literature and lived experiences via blogs using search terms such as “neurodiversity” and “neurodiverse response to social communication therapy” was completed to better understand this movement. A total number of 12 articles were reviewed. Results: By creating goals that are neurodivergent affirming and strength-based this can lead to greater motivation and communication successes, reduced behaviors, and help teach self-advocacy for clients with Autistic clients.https://griffinshare.fontbonne.edu/slp-posters-2023/1035/thumbnail.jp

    On the origin of radio core emission in radio-quiet quasars

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    We present a model for the radio emission from radio-quiet quasar nuclei. We show that a thermal origin for the high brightness temperature, flat spectrum point sources (known as radio ``cores'') is possible provided the emitting region is hot and optically-thin. We hence demonstrate that optically-thin bremsstrahlung from a slow, dense disk wind can make a significant contribution to the observed levels of radio core emission. This is a much more satisfactory explanation, particularly for sources where there is no evidence of a jet, than a sequence of self-absorbed synchrotron components which collectively conspire to give a flat spectrum. Furthermore, such core phenomena are already observed directly via milli-arcsecond radio imaging of the Galactic microquasar SS433 and the active galaxy NGC1068. We contend that radio-emitting disk winds must be operating at some level in radio-loud quasars and radio galaxies as well (although in these cases, observations of the radio cores are frequently contaminated/dominated by synchrotron emission from jet knots). This interpretation of radio core emission mandates mass accretion rates that are substantially higher than Eddington. Moreover, acknowledgment of this mass-loss mechanism as an AGN feedback process has important implications for the input of energy and hot gas into the inter-galactic medium (IGM) since it is considerably less directional than that from jets.Comment: to appear in ApJ Letters (4 pages
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