601 research outputs found

    A Light Calibration System for the ProtoDUNE-DP Detector

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    A LED-based fiber calibration system for the ProtoDUNE-Dual Phase (DP) photon detection system (PDS) has been designed and validated. ProtoDUNE-DP is a 6x6x6 m3 liquid argon time-projection-chamber currently being installed at the Neutrino Platform at CERN. The PDS is based on 36 8-inch photomultiplier tubes (PMTs) and will allow triggering on cosmic rays. The system serves as prototype for the PDS of the final DUNE DP far detector in which the PDS also has the function to allow the 3D event reconstruction on non-beam physics. For this purpose an equalized PMT response is desirable to allow using the same threshold definition for all PMT groups, simplifying the determination of the trigger efficiency. The light calibration system described in this paper is developed to provide this and to monitor the PMT performance in-situ.Comment: 15 pages, 5 figure

    Intraepithelial paracrine Hedgehog signaling induces the expansion of ciliated cells that express diverse progenitor cell markers in the basal epithelium of the mouse mammary gland

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    The Hedgehog signaling pathway regulates embryo patterning and progenitor cell homeostasis in adult tissues, including epidermal appendages. A role for the Hh pathway in mammary biology and breast cancer has also been suggested. The aim of this study was to analyze Hh signaling in the mouse mammary gland through the generation of transgenic mice that express Sonic Hedgehog (Shh) under the control of the mammary-specific WAP promoter (WAP-Shh mice). To identify mammary cells capable of activating the Hh pathway we bred WAP-Shh mice to Ptch1-lacZ knock-in mice, in which the expression of a nuclear-targeted β-galactosidase reporter protein (β-gal) is driven by the endogenous Patched 1 gene regulatory region. After two cycles of induction of transgenic Shh expression, we detected areas of X-gal reactivity. Immunohistochemical analysis showed nuclear β-gal staining in clusters of mammary cells in WAP-Shh/Ptch1-lacZ bitransgenic mice. These were epithelial cells present in a basal location of displastic ducts and alveoli, adjacent to Shh-expressing luminal cells, and overexpressed epithelial basal markers keratin 5, 14 and 17 and transcription factor p63. Absence of smooth muscle actin expression and a cuboidal morphology differentiated Hh-responding cells from flat-shaped mature myoepithelial cells. Groups of cells expressing stem cell markers integrin β3 and keratins 6 and 15 were also detected within Hh-responding areas. In addition, we found that Hh-responding cells in the mammary glands of WAP-Shh/Ptch1-lacZ mice were ciliated and exhibited a low proliferation rate. Our data show the paracrine nature of hedgehog signaling in the epithelial compartment of the mouse mammary gland, where a subset of basal cells that express mammary progenitor cell markers and exhibit primary cilia is expanded in response to secretory epithelium-derived Shh.This work was supported by MCINN Grant no. SAF2006 03244, Fundación Marcelino Botín and Federación Española Cáncer de Mama (FECMA)

    Comparison of two techniques for the morphometry study on gilthead seabream (Sparus aurata) spermatozoa and evaluation of changes induced by cryopreservation

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    [EN] The development of powerful software has made possible spermatozoa morphology studies. However, some problems have emerged in relation to protocol standardization to compare results from different laboratories. This study was carried out to compare two techniques commonly used (staining vs phase contrast technique) for the morphometry study of gilthead sea bream spermatozoa using an integrated sperm analysis system (ISAS). Spermatozoa morphometry values were significantly affected by the technique used, and phase contrast technique was found to be the more accurate method, showing lower coefficients of variation on spermatozoa morphometry parameters measurements. Moreover, it has been shown that cryopreservation process produces damage in gilthead sea bream spermatozoa, causing negative effects in sperm parameters as spermatozoa morphometry (a decrease in cell volume), motility (from 95 to 68% motile cells) and viability (from 95 to 87% of live cells), being the addition of freezing medium containing cryoprotectant (DMSO) an important factor that caused the morphometry changes. (C) 2012 Elsevier Inc. All rights reserved.This work was financed by the Spanish Ministry of Science and Innovation (MICINN; AGL2007-64040-C03-00, Project SELECTBREAM). V. Gallego and I. Mazzeo were supported by predoctoral scholarships financed by the Spanish MICINN and Generalitat Valenciana, respectively. D.S. Penaranda had a postdoctoral grant from UPV.Gallego Albiach, V.; Peñaranda, D.; Marco Jiménez, F.; Mazzeo, I.; Pérez Igualada, LM.; Asturiano Nemesio, JF. (2012). Comparison of two techniques for the morphometry study on gilthead seabream (Sparus aurata) spermatozoa and evaluation of changes induced by cryopreservation. Theriogenology. 77(6):1078-1087. https://doi.org/10.1016/j.theriogenology.2011.10.010S1078108777

    Intracellular changes in Ca2+, K+ and pH after sperm motility activation in the European eel (Anguilla anguilla): Preliminary results

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    [EN] Although it is widely accepted that osmolality and ion fluxes are the main factors triggering sperm motility in fish, a complex universal mechanism for sperm motility activation does not exist in fish, and studies of marine fish species are even more scarce. Therefore, the main goal of this study was to estimate the intracellular variations in the main ions involved in sperm activation for the first time in European eel, in order to provide additional new data about this little-known process. It was observed that levels of intracellular Ca2+ and K+ sperm ions increased significantly 30 s after the hyperosmotic shock compared to baseline levels, and remained at this level until 120 s post-activation. In contrast, the intracellular pH remained constant during the first 30 s, and decreased gradually at 60 and 120 s post-activation. Our data agree with the current main theory for explaining motility activation in marine fish, in which internal fluctuations of Ca2+ and K+ seem to participate in sperm activation. In addition, fluorescent images showed that both Ca2+ and K+ were concentrated in the apical area of the sperm head, which corresponds to the location of the eel sperm mitochondria, suggesting this organelle plays an important role in sperm motility activation. (C) 2013 Elsevier B.V. All rights reserved.Funded from the European Community's 7th Framework Programme under the Theme 2 "Food, Agriculture and Fisheries, and Biotechnology", grant agreement no 245257 (Pro-Eel) and the Spanish Ministry of Science and Innovation (MICINN; AGL2010-16009). Victor Gallego has a predoctoral grant (MICINN; BES-2009-020310) and has been granted a fellowship (EEBB-I-12-05858) of the Spanish Personnel Research Training Programme to carry out this study in the Universidad de Leon (Leon, Spain). Ilaria Mazzeo had a predoctoral grant from GVA. David S. Penaranda has a contract co-financed by MICINN and UPV (PTA2011-4948-I). F. Martinez-Pastor was supported by the Ramon y Cajal program (RYC-2008-02560, MICINN).Gallego Albiach, V.; Martínez Pastor, F.; Mazzeo, I.; Peñaranda, D.; Herraez, P.; Asturiano Nemesio, JF.; Pérez Igualada, LM. (2014). Intracellular changes in Ca2+, K+ and pH after sperm motility activation in the European eel (Anguilla anguilla): Preliminary results. Aquaculture. 418:155-158. https://doi.org/10.1016/j.aquaculture.2013.10.022S15515841

    Standardization of European eel (Anguilla anguilla) sperm motility evaluation by CASA software

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    [EN] The development of powerful computer-assisted sperm analysis software has made kinetic studies of spermatozoa possible. This system has been used and validated for several species, but some technical questions have emerged regarding fish sample evaluations (i.e., frame rate, sperm dilution, chamber model, time of analysis, magnification lens, etc.). In the present study, we have evaluated the effects of different procedural and biological settings with the aim to correctly measure sperm quality parameters of the European eel. The use of different chambers did not affect the sperm motility parameters. However, regarding lens magnification, 10x was the most accurate lens, showing the least variation in the acquired data. Similarly, the frame rate setting resulted in a dramatic effect in some sperm kinetic parameters, primarily in terms of curvilinear velocity; we therefore recommend using the camera's highest available frame rate setting. Finally, the reduction in sperm motility over postactivation times suggests that sperm analysis should be performed within the first 60 seconds after activation of the European eel sperm. In conclusion, some protocol variables of sperm analysis by computer-assisted sperm analysis software can affect the measurement of eel sperm quality parameters, and should be considered before directly comparing results obtained by different laboratories. Moreover, because marine fish species show relatively similar features of sperm kinetic parameters, these results could be considered in the evaluation of the motility of sperm from other fish species. (C) 2013 Elsevier Inc. All rights reserved.This study was funded from the European Community's 7th Framework Programme under the Theme 2 "Food, Agriculture and Fisheries, and Biotechnology," grant agreement 245257 (Pro-Eel), and Generalitat Valenciana (ACOMP/2011/229). D.S.P. and P.C.F.C. have postdoctoral grants from UPV (CE-01-10) and PAC-EMBRAPA, respectively. I.M. and V.G. have predoctoral grants from Generalitat Valenciana and Spanish MICINN, respectively. The authors thank the Proiser R&D, S.L. team, who performed the task of fractioning the original sequences for the experiment described in section 3.2.Gallego Albiach, V.; Carneiro, PCF.; Mazzeo, I.; Vilchez Olivencia, MC.; Peñaranda, D.; Soler, C.; Pérez Igualada, LM.... (2013). Standardization of European eel (Anguilla anguilla) sperm motility evaluation by CASA software. Theriogenology. 79(7):1034-1040. https://doi.org/10.1016/j.theriogenology.2013.01.019S1034104079

    Using radio astronomical receivers for molecular spectroscopic characterization in astrochemical laboratory simulations: A proof of concept

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    We present a proof of concept on the coupling of radio astronomical receivers and spectrometers with chemical reactorsand the performances of the resulting setup for spectroscopy and chemical simulations in laboratory astrophysics. Several experiments including cold plasma generation and UV photochemistry were performed in a 40\,cm long gas cell placed in the beam path of the Aries 40\,m radio telescope receivers operating in the 41-49 GHz frequency range interfaced with fast Fourier transform spectrometers providing 2 GHz bandwidth and 38 kHz resolution. The impedance matching of the cell windows has been studied using different materials. The choice of the material and its thickness was critical to obtain a sensitivity identical to that of standard radio astronomical observations. Spectroscopic signals arising from very low partial pressures of CH3OH, CH3CH2OH, HCOOH, OCS,CS, SO2 (<1E-03 mbar) were detected in a few seconds. Fast data acquisition was achieved allowing for kinetic measurements in fragmentation experiments using electron impact or UV irradiation. Time evolution of chemical reactions involving OCS, O2 and CS2 was also observed demonstrating that reactive species, such as CS, can be maintained with high abundance in the gas phase during these experiments.Comment: Accepted for publication in Astronomy and Astrophysics in September 21, 2017. 16 pages, 18 figure
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