420 research outputs found

    Trophoniella radesiensis Chaibi & Antit & Bouhedi & Meca & Gillet & Azzouna & Martin 2019, n. sp.

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    Trophoniella radesiensis n. sp. Chaibi and Gillet Figures 3–6 urn:lsid:zoobank.org:act: D7C85C70-87FF-4AF4-8599-A8462B3FB8B1 Material examined. Holotype: MNCN16.01 /18453, collected on 25 Nov 2015 in Radés Station, Gulf of Tunis (15°55′ N, 97°41′ W) by the first author. Paratypes: MNCN 16.01 /18454. 6 specimens, same data as for holotype; UCO T FLA 025.1specimen, same data as for holotype. Diagnosis. Body covered by sediments of different grain size (50–1000 µm of long axe) embedded on tunic, completely concealed except in posterior region. Tunic pale, dorsally smooth, ventrally rough, with large papillae, carrying sediment grains and particles. Body papillae arranged in two dorsal and four ventral rows. Branchial plate tongue-shaped. Unidentate anchylosed neurohooks from chaetiger 20. Description. Holotype with some chaetae broken, non-reproductive adult, unknown sex. 35 mm long, 4 mm wide, with 60 chaetigers; paratypes varying from 30–43 mm long and 1–4 mm wide for 43–74 chaetigers (Fig. 3 A– E). Anterior body sub-cylindrical in cross-section, tapering towards pygidium. Tunic transparent, dorsally smooth, ventrally rough with large papillae, carrying sediment grains and particles with long axes ranging from 50 to 1000 µm, totally embedded in tunic, completely concealing it dorsally and ventrally, absent in posterior region. Pale brown, slightly reddish anteriorly. Cephalic cage 12 mm long, with chaetae ca. 1.5 times longer than body width, formed by chaetigers 1–5; chaetiger 2 dorsolateral, chaetiger 3–4 lateral. Chaetal transition from cephalic cage to body chaetae gradual (Fig. 3A, 3 C–E). Body papillae similar in colour to body wall, mostly eroded, arising in two dorsal and four ventral longitudinal rows from first chaetiger to posterior end, better preserved anterior-most body region (Fig. 3A, 3 C–E). Parapodia well developed. Noto and neuropodia have four prechaetal papillae and five postchaetal papillae (Fig. 3C). Especially long papillae absent from anterior chaetigers. Gonopodial papillae not seen. Chaetiger 1 with about six notochaetae and eight neurochaetae; anterior dorsal margin with dorsal papillae, arising as a multifid cephalic veil (Fig. 4A). Chaetiger 5 widening posteriorly. Cephalic hood not exposed. Caruncle short and triangular (Fig. 4C, 4D). Branchiae cirriform, arising from tongue-shaped branchial plate, arranged in two lateral lobes (Fig. 4A, 4D), thin, long (0.5–3mm), whitish once preserved in ethanol, with ca. 60 filaments. Palp, long, corrugated, pale, as long as largest branchiae, 6 mm long (Fig. 4B, 4C). Prostomium lowcone, with two large and two small black eyes (Fig. 3D, 3E). Lateral lip expanded; dorsal and ventral lips not well developed (Fig. 3D, 3E). Notochaetae all multiarticulated capillaries; articles progressively longer towards falcate tips; medial ones in short longitudinal series, 4–7 per bundle; some yellowish some dark brown; unidentate tips (Fig. 5 A–5D). Multiarticulated capillary neurochaeta from chaetiger 2 to 5, then short unidentate neurohooks from chaetiger 6 to 19 (Fig. 6A) and anchylosed hooks from chaetiger 20 to body end (Fig. 6B), darker than preceding ones, arranged in transverse series of 4–6 units per bundle, similarly wide along their length, subdistally not or slightly expanded, with short rings continued up to a subdistal, non-annulated hyaline region, hooked, tapering to roughly pointed, unidentate tips (Fig. 5A, 6B). Pygidium simple, with single anal cirrus. No intra-specific variability in morphological characters was observed, except for lacking sediment gains in some specimens. Distribution. Known only from the type locality, Radés Station (Gulf of Tunisia, Mediterranean Sea). Collected from both soft and rocky bottoms, from 3–4 m to 10 m depth. Etymology. The species name radesiensis refers to the type locality, Radés Station.Published as part of Chaibi, Marwa, Antit, Mouna, Bouhedi, Marwa, Meca, Miguel A., Gillet, Patrick, Azzouna, Atf & Martin, Daniel, 2019, A new species of Flabelligeridae (Annelida), Trophoniella radesiensis n. sp., from Tunisia, pp. 551-561 in Zootaxa 4571 (4) on pages 554-556, DOI: 10.11646/zootaxa.4571.4.7, http://zenodo.org/record/261426

    Higher-order Hermite-Gauss modes for gravitational waves detection

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    As part of the research on thermal noise reduction in gravitational-wave detectors, we experimentally demonstrate the conversion of a fundamental TEM00 laser mode at 1064 nm to higher-order Hermite-Gaussian modes (HG) of arbitrary order via a commercially available liquid crystal spatial light modulator. We particularly studied the HG5,5/HG10,10/HG15,15 modes. A two-mirror plano-spherical cavity filters the higher-order modes spatially. We analyze the cleaned modes via a three-mirror diagnosis cavity and measure a mode purity of 96/93/78% and a conversion efficiency of 6.6%/3.7%/1.7%, respectively. A full set of simulations and mathematical proofs are also presented which shows that (i) Hermite-Gauss modes resonate in a two-mirror cavity provided mirrors are properly angled with respect to the impinging mode, and (ii) Hermite-Gauss modes resonate in triangular cavities. Hence, higher-order Hermite-Gauss modes are compatible with ground-based gravitational-wave detectors' architecture and can be employed for the mitigation of mirror thermal noise for the third generation Einstein Telescope or Cosmic Explorer

    Manual therapies for cervicogenic headache: a systematic review

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    This paper systematically reviewed randomized clinical trials (RCT) assessing the efficacy of manual therapies for cervicogenic headache (CEH). A total of seven RCTs were identified, i.e. one study applied physiotherapy ± temporomadibular mobilization techniques and six studies applied cervical spinal manipulative therapy (SMT). The RCTs suggest that physiotherapy and SMT might be an effective treatment in the management of CEH, but the results are difficult to evaluate, since only one study included a control group that did not receive treatment. Furthermore, the RCTs mostly included participant with infrequent CEH. Future challenges regarding CEH are substantial both from a diagnostic and management point of view. This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited

    Low noise amplication of an optically carried microwave signal: application to atom interferometry

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    In this paper, we report a new scheme to amplify a microwave signal carried on a laser light at λ\lambda=852nm. The amplification is done via a semiconductor tapered amplifier and this scheme is used to drive stimulated Raman transitions in an atom interferometer. Sideband generation in the amplifier, due to self-phase and amplitude modulation, is investigated and characterized. We also demonstrate that the amplifier does not induce any significant phase-noise on the beating signal. Finally, the degradation of the performances of the interferometer due to the amplification process is shown to be negligible

    Semi-automated stereoradiographic upper limb 3D reconstructions using a combined parametric and statistical model: a preliminary study

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    PURPOSE: Quantitative assessment of 3D clinical indices may be crucial for elbow surgery planning. 3D parametric modeling from bi-planar radiographs was successfully proposed for spine and lower limb clinical investigation as an alternative for CT-scan. The aim of this study was to adapt this method to the upper limb with a preliminary validation. METHODS: CT-scan 3D models of humerus, radius and ulna were obtained from 20 cadaveric upper limbs and yielded parametric models made of geometric primitives. Primitives were defined by descriptor parameters (diameters, angles...) and correlations between these descriptors were found. Using these correlations, a semi-automated reconstruction method of humerus using bi-planar radiographs was achieved: a 3D personalized parametric model was built, from which clinical parameters were computed [orientation and projections on bone surface of trochlea sulcus to capitulum (CTS) axis, trochlea sulcus anterior offset and width of distal humeral epiphysis]. This method was evaluated by accuracy compared to CT-scan and reproducibility. RESULTS: Points-to-surface mean distance was 0.9 mm (2 RMS = 2.5 mm). For clinical parameters, mean differences were 0.4-1.9 mm and from 1.7° to 2.3°. All parameters except from angle formed by CTS axis and bi-epicondylar axis in transverse plane were reproducible. Reconstruction time was about 5 min. CONCLUSIONS: The presented method provides access to morphological upper limb parameters with very low level of radiation. Preliminary in vitro validation for humerus showed that it is fast and accurate enough to be used in clinical daily practice as an alternative to CT-scan for total elbow arthroplasty pre operative evaluation

    Do fringes and trajectories shift equally in matter-wave interferometers? The example of photodetachment microscopy in a magnetic field

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    Matter-wave interferometers, either with electrons, atoms or molecules, owe their sensitivity to the accuracy of phase-shift measurements. One may, however, raise the question whether the shift undergone by interference fringes, when external forces are applied, actually differs from the shift of classical trajectories. For the case of a magnetic perturbation, we provide experimental evidence and a vector demonstration that interference patterns only undergo a global shift. The experiment is performed with the photodetachment microscope, with a uniform magnetic field superimposed over the whole volume accessible to the interfering electron. Identity of the fringe and trajectory shifts is established for any two-wave interferometer using charged particles, submitted to a magnetic field

    Characterization and limits of a cold atom Sagnac interferometer

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    We present the full evaluation of a cold atom gyroscope based on atom interferometry. We have performed extensive studies to determine the systematic errors, scale factor and sensitivity. We demonstrate that the acceleration noise can be efficiently removed from the rotation signal allowing to reach the fundamental limit of the quantum projection noise for short term measurements. The technical limits to the long term sensitivity and accuracy have been identified, clearing the way for the next generations of ultra-sensitive atom gyroscopes

    Lithological control on coastal rock cliffs erosion of Safi, Morocco

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    poster à la 8ème conférence internationale des géomorphologues, ParisThe coastline of the Safi region, between the Beddouza Cape (32°54'N - 09°28'W) and Jorf Lihoudi (32°18'N - 09°26'W), is characterised by different forms of coastal cliffs ranging from 5m to 153m high. Three different lithological units have been defined from the bottom to the top: 1) Plio-Quaternary aeolianites and coquina, 2) Cretaceous clays and sandstones, "Clay of Safi" 3) "Limestone of Dridrat" and 4) Jurassic limestones with clay, gypsum and sandstone. The aim of this study is to identify 1/ the spatial and temporal distribution of coastal instabilities with a catalog events developed from aerial photographs using the GIS (1954-2011) and 2/ the lithological controlling factor, with a special focus on Clay of Safi, using a ratio : clay layer thickness/ cliff height × 100. A conceptual model is used to define the processes acting on Safi coastal cliffs. Lithological, geomorphic, climate and anthropic parameters of 15 representative cliff sites are listed in a database. The results of aerial photographs analysis revealed a low number (10 significant erosion hotspots) of events (collapse, rock fall and landslide) that have affected cliffs during the last 60 years. Historical erosion rates range from 7 to 13 cm/yr, where they are subject to erosion. In Safi, the cliff retreat may be controlled by the proportion of clays whereby lower cliff angles are more clay-dominated. Cliffs, with a clay ratio upper than 60%, are more prone to mass movement than the others. This reflects the efficiency of continental processes. However, cliffs with less than 30% of clays ratio have no mass movement and are more subject to marine erosion. Laboratory analysis will be performed to confirm this hypothesis
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