558 research outputs found

    Nouvelle description d’<i>Halecopsis insignis</i> de l’Éocène marin de l’Europe et les relations de ce taxon avec les Gonorynchiformes (Teleostei, Ostariophysi)

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    New description of dagger Halecopsis insignis from marine Eocene of Europe and relationships of this taxa with the Gonorynchiformes (Teleostei, Ostariophysi).The osteology of dagger Halecopsis insignis from the marine Eocene of Europe is briefly revised. The frontals are elongated and narrow at the preorbital level. The skull is latero-parietal. The mesethmoid is small and longer than broad. The lateral ethmoids are reduced. The pleurosphenoids are small and there is no orbitosphenoid. The lower jaw is short and the quadrate and the ventral branch of the preopercle very long. There are only four infraorbitals, all possessing a well developed membranodermic component. The supratemporal is strongly reduced. The extrascapular sensory commissure is enclosed in the parietals and passes also in a thin groove on the supraoccipital. The osteological characters allow to confirm that H. insignis belongs to the suborder Gonorynchoidei and to propose that it is phylogenetically lying between the family dagger Apulichthyidae, where the lateral ethmoid remains large, and the other families of this suborder, in which the membranodermic component of the infraorbitals is already lost

    Ostéologie et relations phylogénétiques des Protobramidae (Teleostei, Tselfatiiformes) du Cénomanien (Crétacé supérieur) du Liban

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    The osteology of Protobrama avus, of a new species of this genus, P. woodwardi, and of two new monospecific genera of protobramid fishes, Eusebichthys byblosi and Abisaadichthys libanicus, is studied. Protobramidae are small deep-bodied marine teleosts from the Lower Cenomanian of Lebanon. They are characterised by the gomphosis of the neural and haemal arches on the centra all along the axial skeleton, the loss of segmentation on the dorsal and anal fin rays, the small cycloid scales covering the basis of the unpaired fins, the ribs fused with the haemapophyses, the loss of epicentrals and epipleurals, the loss of epurals, the reduced number (4 or 5) of hypurals and the fusion of hypurals 3 and 4 into a dorsal hypural plate. The skull is medio-parietal. The temporal fossa is dorsally bordered by the parietal. The jaws are feebly toothed or toothless. The maxillary, which is bordering the mouth, is always toothless. The supramaxillaries are lost. The possible synonymy of the Protobramidae and Plethodidae (or Tselfatiidae) as well as the integration of the Protobramidae, the Araripichthyidae and the Ferrifronsidae into a suborder of the Protobramoidei are discussed and rejected. The analysis of the protobramid characters leads to range them as a valid family in the clupeocephalan order Tselfatiiformes near the Plethodidae

    Parent Training in Interactive Book Reading: An Investigation of Its Effects with Families at Risk

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    This study investigated the efficacy of a parent training intervention on increasing the duration, frequency and quality of interactive book reading between six parents and their children. Dependent measures included self-reports of frequency and duration of parent-child interactive reading, coding of transcripts for reading quality, children’s pre-post PPVT-R performance, consumer satisfaction questionnaires, and assessment of treatment integrity. During treatment, five of six subjects improved in reading regularity and duration. Likewise, all subjects demonstrated improvements in the quality of interactive book reading with their children. Children’s PPVT-R performance also increased upon post-testing. Consumer satisfaction and treatment integrity were favorable. Study strengths and limitations, implications for school psychological practice, and future research questions are addressed

    Parent Training in Interactive Book Reading: An Investigation of Its Effects with Families at Risk

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    This study investigated the efficacy of a parent training intervention on increasing the duration, frequency and quality of interactive book reading between six parents and their children. Dependent measures included self-reports of frequency and duration of parent-child interactive reading, coding of transcripts for reading quality, children’s pre-post PPVT-R performance, consumer satisfaction questionnaires, and assessment of treatment integrity. During treatment, five of six subjects improved in reading regularity and duration. Likewise, all subjects demonstrated improvements in the quality of interactive book reading with their children. Children’s PPVT-R performance also increased upon post-testing. Consumer satisfaction and treatment integrity were favorable. Study strengths and limitations, implications for school psychological practice, and future research questions are addressed

    Efficient out-coupling and beaming of Tamm optical states via surface plasmon polariton excitation

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    We present evidence of optical Tamm states to surface plasmon polariton (SPP) coupling. We experimentally demonstrate that for a Bragg stack with a thin metal layer on the surface, hybrid Tamm-SPP modes may be excited when a grating on the air-metal interface is introduced. Out-coupling via the grating to free space propagation is shown to enhance the transmission as well as the directionality and polarization selection for the transmitted beam. We suggest that this system will be useful on those devices, where a metallic electrical contact as well as beaming and polarization control is needed

    Modelling Defect Cavities Formed in Inverse Three-Dimensional Rod-Connected Diamond Photonic Crystals

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    Defect cavities in 3D photonic crystal can trap and store light in the smallest volumes allowable in dielectric materials, enhancing non-linearities and cavity QED effects. Here, we study inverse rod-connected diamond (RCD) crystals containing point defect cavities using plane-wave expansion and finite-difference time domain methods. By optimizing the dimensions of the crystal, wide photonic band gaps are obtained. Mid-bandgap resonances can then be engineered by introducing point defects in the crystal. We investigate a variety of single spherical defects at different locations in the unit cell focusing on high-refractive-index contrast (3.3:1) inverse RCD structures; quality factors (Q-factors) and mode volumes of the resonant cavity modes are calculated. By choosing a symmetric arrangement, consisting of a single sphere defect located at the center of a tetrahedral arrangement, mode volumes < 0.06 cubic wavelengths are obtained, a record for high index cavities.Comment: 7 pages, 8 figure

    Enhanced Optical Trapping

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    Optical tweezers have contributed substantially to the advancement of micro-manipulation. However, they do have restrictions, mainly the limited range of materials that yield to optical trapping. Here we propose a method of employing optically trapped objects to manipulate the surrounding fluid and thus particles freely diffusing within it. We create and investigate a reconfigurable active-feedback system of optically trapped actuators, capable of manipulating translational and rotational motion of one or more nearby free objects
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