2,196 research outputs found

    Strong lens search in the ESO public Survey KiDS

    Get PDF
    We have started a systematic search of strong lens candidates in the ESO public survey KiDS based on the visual inspection of massive galaxies in the redshift range 0.1<z<0.50.1<z<0.5. As a pilot program we have inspected 100 sq. deg., which overlap with SDSS and where there are known lenses to use as a control sample. Taking advantage of the superb image quality of VST/OmegaCAM, the colour information and accurate model subtracted images, we have found 18 new lens candidates, for which spectroscopic confirmation will be needed to confirm their lensing nature and study the mass profile of the lensing galaxies.Comment: 4 pages, 1 figure, to appear on the refereed Proceeding of the "The Universe of Digital Sky Surveys" conference held at the INAF--OAC, Naples, on 25th-28th november 2014, to be published on Astrophysics and Space Science Proceedings, edited by Longo, Napolitano, Marconi, Paolillo, Iodic

    SEAGLE - III: Towards resolving the mismatch in the dark-matter fraction in early-type galaxies between silations and observations

    Get PDF
    The central dark-matter fraction of galaxies is sensitive to feedback processes during galaxy foation. Strong gravitational lensing has been effective in the precise measurement of the dark-matter fraction inside massive early-type galaxies. Here, we compare the projected dark-matter fraction of early-type galaxies inferred from the SLACS (Sloan Lens ACS Survey) strong-lens survey with those obtained from the Evolution and Assembly of GaLaxies and their Environment (EAGLE), Illustris, and IllustrisTNG hydrodynamical silations. Previous comparisons with some silations revealed a large discrepancy, with considerably higher inferred dark-matter fractions - by factors of ≈2-3 - inside half of the effective radius in observed strong-lens galaxies as compared to silated galaxies. Here, we report good agreement between EAGLE and SLACS for the dark-matter fractions inside both half of the effective radius and the effective radius as a function of the galaxy's stellar mass, effective radius, and total mass-density slope. However, for IllustrisTNG and Illustris, the dark-matter fractions are lower than observed. This work consistently assumes a Chabrier initial mass function (IMF), which suggests that a different IMF (although not excluded) is not necessary to resolve this mismatch. The differences in the stellar feedback model between EAGLE and Illustris and IllustrisTNG are likely the dominant cause of the difference in their dark-matter fraction and density slope

    Surface alignment and anchoring transitions in nematic lyotropic chromonic liquid crystal

    Full text link
    The surface alignment of lyotropic chromonic liquid crystals (LCLCs) can be not only planar (tangential) but also homeotropic, with self-assembled aggregates perpendicular to the substrate, as demonstrated by mapping optical retardation and by three-dimensional imaging of the director field. With time, the homeotropic nematic undergoes a transition into a tangential state. The anchoring transition is discontinuous and can be described by a double-well anchoring potential with two minima corresponding to tangential and homeotropic orientation.Comment: Accepted for publication in Phys. Rev. Lett. (Accepted Wednesday Jun 02, 2010

    Properties of recombinant human cytosolic sialidase HsNEU2. The enzyme hydrolyzes monomerically dispersed GM1 ganglioside molecules

    Get PDF
    Recombinant human cytosolic sialidase (HsNEU2), expressed in Escherichia coli, was purified to homogeneity, and its substrate specificity was studied. HsNEU2 hydrolyzed 4-methylumbelliferyl alpha-NeuAc, alpha 2-->3 sialyllactose, glycoproteins (fetuin, alpha-acid glycoprotein, transferrin, and bovine submaxillary gland mucin), micellar gangliosides GD1a, GD1b, GT1b, and alpha 2-->3 paragloboside, and vesicular GM3. alpha 2-->6 sialyllactose, colominic acid, GM1 oligosaccharide, whereas micellar GM2 and GM1 were resistant. The optimal pH was 5.6, kinetics Michaelis-Menten type, V(max) varying from 250 IU/mg protein (GD1a) to 0.7 IU/mg protein (alpha(1)-acid glycoprotein), and K(m) in the millimolar range. HsNEU2 was activated by detergents (Triton X-100) only with gangliosidic substrates; the change of GM3 from vesicular to mixed micellar aggregation led to a 8.5-fold V(max) increase. HsNEU2 acted on gangliosides (GD1a, GM1, and GM2) at nanomolar concentrations. With these dispersions (studied in detailed on GM1), where monomers are bound to the tube wall or dilutedly associated (1:2000, mol/mol) to Triton X-100 micelles, the V(max) values were 25 and 72 microIU/mg protein, and K(m) was 10 and 15 x 10(-9) m, respectively. Remarkably, GM1 and GM2 were recognized only as monomers. HsNEU2 worked at pH 7.0 with an efficiency (compared with that at pH 5.6) ranging from 4% (on GD1a) to 64% (on alpha(1)-acid glycoprotein), from 7% (on GD1a) to 45% (on GM3) in the presence of Triton X-100, and from 30 to 40% on GM1 monomeric dispersion. These results show that HsNEU2 differentially recognizes the type of sialosyl linkage, the aglycone part of the substrate, and the supramolecular organization (monomer/micelle/vesicle) of gangliosides. The last ability might be relevant in sialidase interactions with gangliosides under physiological conditions

    structural connectivity analysis in children with segmental callosal agenesis

    Get PDF
    BACKGROUND AND PURPOSE: Segmental callosal agenesis is characterized by the absence of the intermediate callosal portion. We aimed to evaluate the structural connectivity of segmental callosal agenesis by using constrained spherical deconvolution tractography and connectome analysis. MATERIALS AND METHODS: We reviewed the clinical-radiologic features of 8 patients (5 males; mean age, 3.9 years). Spherical deconvolution and probabilistic tractography were performed on diffusion data. Structural connectivity analysis, including summary network metrics, modularity analysis, and network consistency measures, was applied in 5 patients and 10 age-/sex-matched controls. RESULTS: We identified 3 subtypes based on the position of the hippocampal commissure: beneath the anterior callosal remnant in 3 patients (type I), beneath the posterior callosal remnant in 3 patients (type II), and between the anterior and posterior callosal remnants in 2 patients (type III). In all patients, the agenetic segment corresponded to fibers projecting to the parietal lobe, and segmental Probst bundles were found at that level. Ectopic callosal bundles were identified in 3 patients. Topology analysis revealed reduced global connectivity in patients compared with controls. The network topology of segmental callosal agenesis was more variable across patients than that of the control connectomes. Modularity analysis revealed disruption of the structural core organization in the patients. CONCLUSIONS: Three malformative subtypes of segmental callosal agenesis were identified. Even the absence of a small callosal segment may impact global brain connectivity and modularity organization. The presence of ectopic callosal bundles may explain the greater interindividual variation in the connectomes of patients with segmental callosal agenesis

    Internal frequency conversion extreme ultraviolet interferometer using mutual coherence properties of two high-order-harmonic sources

    Get PDF
    International audienceWe report on an innovative two-dimensional imaging extreme ultraviolet (XUV) interferometer operating at 32 nm based on the mutual coherence of two laser high order harmonics (HOH) sources, separately generated in gas. We give the first evidence that the two mutually coherent HOH sources can be produced in two independent spatially separated gas jets, allowing for probing centimeter-sized objects. A magnification factor of 10 leads to a micron resolution associated with a subpicosecond temporal resolution. Single shot interferograms with a fringe visibility better than 30% are routinely produced. As a test of the XUV interferometer, we measure a maximum electronic density of 3×10^20 cm^−3 1.1 ns after the creation of a plasma on aluminum target

    Endocrine dysfunction in patients with Fabry disease

    Get PDF
    BACKGROUND: Fabry disease (FD) is a genetic disorder caused by lysosomal alpha-galactosidase-A deficiency and is characterized by the systemic accumulation of globotriaosylceramide. All endocrine glands are susceptible to globotriaosylceramide accumulation because of their high vascularization and low cellular proliferation rate. Nevertheless, this endocrine system has never been investigated in detail. OBJECTIVE: We aimed to investigate the function and morphology of the endocrine glands in FD. PATIENTS: The thyroid, gonadal, adrenal, and GH/IGF-I axes were evaluated in 18 FD patients (nine females and nine males, aged 21-64 yr) and 18 sex- and age-matched healthy subjects. STUDY DESIGN: We conducted an observational, analytical, open, prospective study. INTERVENTIONS: Ten of the 18 patients received enzyme replacement therapy (ERT) with recombinant human alpha-galactosidase-A (agalsidase beta) at a dose of 1 mg/kg body weight every 2 wk. RESULTS: FD patients had higher baseline TSH levels than controls (P &lt; 0.01). Three subjects were diagnosed with an early stage of subclinical primary hypothyroidism associated with negative antithyroid antibodies. A history of menses abnormalities, miscarriage, or assisted delivery was found in 89% of FD women. Asthenozoospermia, oligozoospermia, or both were found in all FD men through seminal fluid analysis. FD patients had significantly higher circulating ACTH and lower cortisol levels than controls (P &lt; 0.05). In patients under ERT, a suboptimal cortisol response to the 250-microg ACTH test was found in 10%, and the ACTH-stimulated cortisol peak was significantly correlated to the health status profile (P &lt; 0.05). CONCLUSION: A variety of latent endocrine dysfunctions, including life-threatening conditions, occur in patients with FD. Endocrine dysfunctions are also present in patients already receiving ERT and are in part related to their persistent poor quality of life. An endocrine work-up should be recommended in all FD patients. Adequate monitoring and hormonal therapy, when required, have to be performed in cases of subclinical endocrine dysfunction to avoid life-threatening events

    Systemic treatment of malignant gastrointestinal neuroectodermal tumour after childhood neuroblastoma: chemotherapy in malignant gastrointestinal neuroectodermal tumour

    Get PDF
    Malignant gastrointestinal neuroectodermal tumour is an extremely rare neoplasm that arises in the wall of the small bowel, stomach or large bowel in youngaged and middle-aged adults. Histologically, it is generally characterized by monomorphic cells with clear cytoplasma, S-100 protein expression, and EWSR1 gene translocation. To the best of our knowledge, we describe for the first time, the case of a young woman with a diagnosis of metastatic gastrointestinal neuroectodermal tumour arising from ileum, who had a childhood adrenal neuroblastoma with liver, bone and lymph nodes metastasis, treated with four cycles of chemotherapy with the schedule CADO-CVP (CADO: cyclophosphamide 300 mg/m2/day on days 1–5, vincristine 1,5 mg/m2/ day on days 1 and 5, and doxorubicin 60 mg/m2/day on day 5; CVP: cisplatin 40 mg/m2/day on days 1–5 and etoposide 100 mg/m2/day on days 1–5) followed by right adrenal, kidney, lymph nodes and liver lesion resection, conditioning chemotherapy (melphalan-carmustineteniposide), stem cells autologous transplantation and consecutively radiotherapy on the spine (T9 to L3) for a total of 30 Gy. For the second diagnosis of gastrointestinal neuroectodermal tumour with liver metastasis, she underwent ileal tumour resection and platinum-anthracycline based chemotherapy with initial shrinkage of liver metastasis. Unfortunately, despite the initial response and the following delivered therapies, she died for rapid progressive disease. Taking into account the late effects of past therapeutic modalities, a long-term surveillance of young child treated for neuroblastoma, is required to appreciate their overall risks of second malignancies

    Variations in the proliferative activity of the peripheral retina correlate with postnatal ocular growth in squamate reptiles

    Get PDF
    Abstract The retina is a complex, multilayered tissue responsible for the perception of visual stimuli from the environment. Contrary to mammals, the capacity for postnatal eye growth in fish and amphibians, and to a lower extent in birds, is coordinated with a progenitor population residing in the ciliary marginal zone (CMZ) at the retinal peripheral margin. However, little is known about embryonic retinogenesis and postnatal retinal growth in squamates (lizards, snakes), despite their exceptional array of ecologies and ocular morphologies. Here we address this gap by performing the first large-scale study assessing both ontogenetic and adult changes in the stem/progenitor activity of the squamate peripheral retina. Our study reveals for the first time that squamates exhibit a source of proliferating progenitors persisting post embryogenesis in a newly identified retinociliary junction anteriorly adjacent to the retina. This region is strikingly similar to the vertebrate CMZ by its peripheral location and pseudostratified nature, and shares a common pattern of slow-cycling cells, spatial differentiation gradient, and response to postnatal ocular growth. Additionally, its proliferative activity varies considerably among squamate species, in correlation with embryonic and postnatal differences in eye size and growth. Together our data indicate that squamates possess a proliferative peripheral retina that acts as a source of progenitors to compensate, at least in part, for postnatal ocular growth. Our findings also highlight the remarkable variation in activity and location of vertebrate retinal progenitors, indicating that the currently accepted scenario of reduced CMZ activity over the course of evolution is too simplistic. This article is protected by copyright. All rights reserved.Peer reviewe

    Design and Analysis of the Cis-Lunar Navigation for the ArgoMoon CubeSat Mission

    Get PDF
    In the framework of the Artemis-1 mission, 10 CubeSats will be released, including the 6U CubeSat ArgoMoon, built by the Italian company Argotec and coordinated by the Italian Space Agency. The primary goal of ArgoMoon is to capture images of the Interim Cryogenic Propulsion Stage. Then, ArgoMoon will be placed into a highly elliptical orbit around the Earth with several encounters with the Moon. In this phase, the navigation process will require a precise Orbit Determination (OD) and a Flight Path Control (FPC) to satisfy the navigation requirements. The OD will estimate the spacecraft trajectory using ground-based radiometric observables. The FPC is based on an optimal control strategy designed to reduce the dispersion with respect to the reference trajectory and minimize the total ΔV. A linear approach was used to determine the optimal targets and the number and location of the orbital maneuvers. A covariance analysis was performed to assess the expected OD performance and its robustness. The analysis results show that the reference translunar trajectory can be successfully flown and the navigation performance is strongly dependent on the uncertainties of the ArgoMoon’s Propulsion Subsystem and of the orbit injection
    • …
    corecore