5,113 research outputs found
Les traditions mythiques sur les origines de Rome
La question des origines de Rome peut être abordée sous des angles très différents. Une des manières consiste à en étudier la présentation légendaire. Celle-ci ne se limite pas à la figure de Romulus et à son rôle de fondateur, mais remonte jusqu’à un temps mythique qui fait intervenir des peuples et des personnages de provenances très diverses. En fait, Romulus n’était pas un étranger arrivant dans une terre jusque-là inconnue et déserte, selon le modèle qu’on trouve dans les récits de fonda..
On-sky multi-wavelength phasing of segmented telescopes with the Zernike phase contrast sensor
Future Extremely Large Telescopes will adopt segmented primary mirrors with
several hundreds of segments. Cophasing of the segments together is essential
to reach high wavefront quality. The phasing sensor must be able to maintain
very high phasing accuracy during the observations, while being able to phase
segments dephased by several micrometers. The Zernike phase contrast sensor has
been demonstrated on-sky at the Very Large Telescope. We present the
multi-wavelength scheme that has been implemented to extend the capture range
from \pmlambda/2 on the wavefront to many micrometers, demonstrating that it is
successful at phasing mirrors with piston errors up to \pm4.0 micron on the
wavefront. We discuss the results at different levels and conclude with a
phasing strategy for a future Extremely Large Telescope.Comment: 17 pages, 8 figures, 2 tables. Accepted for publication in Applied
Optics; he final publised version is available on the OSA website:
http://www.opticsinfobase.org/abstract.cfm?msid=13671
Golgi apparatus casein kinase phosphorylates bioactive Ser-6 of bone morphogenetic protein 15 and growth and differentiation factor 9
AbstractBone morphogenetic protein-15 (BMP-15) and growth and differentiation factor-9 (GDF-9) are oocyte-secreted factors that play essential roles in human folliculogenesis and ovulation. Their bioactivity is tightly regulated through phosphorylation, likely to occur within the Golgi apparatus of the secretory pathway. Here we show that Golgi apparatus casein kinase (G-CK) catalyzes the phosphorylation of rhBMP-15 and rhGDF-9. rhBMP-15, in particular, is an excellent substrate for G-CK. In each protein a single residue is phosphorylated by G-CK, corresponding to the serine residue at the sixth position of the mature region of both rhBMP-15 and rhGDF-9, whose phosphorylation is required for biological activity
Person-to-Person Transmission of Andes Virus
Epidemiologic and genetic data show that person-to-person spread likely took place during the prodromal phase or shortly after it ended
Red Scliped: Evaluación del uso de tableros de selección de contenidos online en la docencia de Fisiología Animal I
Durante el curso 2013-2014 se implementó en la asignatura de Fisiología Animal I, del Grado en Biología de la Universidad de Alicante, un entorno personal de aprendizaje (EPA), a partir de la herramienta Scliped. Esta herramienta permitió desarrollar una red social de contenidos seleccionados por el profesorado, como estrategia docente para poner a disposición del alumnado recursos de excelencia que faciliten su aprendizaje. La inversión de tiempo y dinero requerida fue sensiblemente inferior a la necesaria para el desarrollo de materiales específicos equivalentes. El alumnado tuvo a su disposición un tablero de 130 contenidos seleccionados, distribuidos en 34 colecciones. Al finalizar el curso escolar 2013-2014, el EPA había recibido un total de 60.794 visitas. La evaluación del uso y conformidad del alumnado con esta herramienta mostró que, si bien opinaban que su uso era innovador, no podría sustituir la labor del profesorado. El porcentaje de adhesión a la herramienta fue bajo, tan sólo el 16% del alumnado encuestado, sin embargo, este grupo declaró que el uso de Scliped era sencillo y atractivo, que los contenidos eran pertinentes y estaban bien organizados, y que les habían facilitado el estudio y la comprensión de la materia
First assessment of the comparative toxicity of ivermectin and moxidectin in adult dung beetles: Sub-lethal symptoms and pre-lethal consequences
Among macrocyclic lactones (ML), ivermectin (IVM) and moxidectin (MOX) potentially affect all Ecdysozoan species, with dung beetles being particularly sensitive. The comparative effects of IVM and MOX on adult dung beetles were assessed for the first time to determine both the physiological sub-lethal symptoms and pre-lethal consequences. Inhibition of antennal response and ataxia were tested as two intuitive and ecologically relevant parameters by obtaining the lowest observed effect concentration (LOEC) values and interpolating other relevant toxicity thresholds derived from concentration-response curves (IC50, as the concentration of each ML where the antennal response is inhibited by half; and pLC50, as the quantity of ingested ML where partial paralysis was observed by half of treated individuals) from concentration-response curves. Both sub-lethal and pre-lethal symptoms obtained in this study coincided in that IVM was six times more toxic than MOX for adult dung beetles. Values of LOEC, IC50 and pLC50 obtained for IVM and MOX evaluated in an environmental context indicate that MOX, despite needing more time for its elimination in the faeces, would be half as harmful to dung beetles as IVM. This approach will be valuable to clarify the real impact of MLs on dung beetle health and to avoid the subsequent environmental consequences.Project CGL2015-68207-R of the Secretaría de Estado de Investigación–Ministerio de Economía y Competitividad
Label-free proteomic analysis of red blood cell membrane fractions from abdominal aortic aneurysm patients
PURPOSE: To test whether red blood cell (RBC) membrane composition is modified in abdominal aortic aneurysms (AAA) patients. EXPERIMENTAL DESIGN: RBC membrane extracts from AAA patients (aortic diameter >3 cm, n = 7) and control subjects (n = 4) were analyzed by a label-free quantitative MS-based strategy, using spectral count data. Additional validation was performed by western-blot. RESULTS: Data analysis based on spectral count from MS/MS-based experiments provided us a signature of 39 proteins differentially expressed in RBC membranes between AAA and controls (changes equal/over 1.515-fold; p-values equal/lower 0.05). MS data revealed altered levels of structural membrane proteins (e.g. spectrins and ankyrin), components of the degradation machinery (proteasome subunits), and oxidative stress related proteins (e.g. catalase and peroxiredoxin-2) among others. Decreased catalase and peroxiredoxin-2 expression in RBC membrane of AAA patients compared to controls were further validated by Western blot, confirming the proteomic results. CONCLUSIONS AND CLINICAL RELEVANCE: RBCs membrane protein composition is altered in AAA patients, which could be involved in the pathological role of RBCs in aortic tissue and become potential targets to prevent AAA progression.S
Laboratory comparison of coronagraphic concepts under dynamical seeing and high-order adaptive optics correction
The exoplanetary science through direct imaging and spectroscopy will largely
expand with the forthcoming development of new instruments at the VLT (SPHERE),
Gemini (GPI), Subaru (HiCIAO), and Palomar (Project 1640) observatories. All
these ground-based adaptive optics instruments combine extremely high
performance adaptive optics (XAO) systems correcting for the atmospheric
turbulence with advanced starlight-cancellation techniques such as coronagraphy
to deliver contrast ratios of about 10-6 to 10-7. While the past fifteen years
have seen intensive research and the development of high-contrast coronagraph
concepts, very few concepts have been tested under dynamical seeing conditions
(either during sky observation or in a realistic laboratory environment). In
this paper, we discuss the results obtained with four different coronagraphs --
phase and amplitude types -- on the High-Order Testbench (HOT), the adaptive
optics facility developed at ESO. This facility emphasizes realistic conditions
encountered at a telescope (e.g., VLT), including a turbulence generator and a
high-order adaptive optics system. It enables to evaluate the performance of
high-contrast coronagraphs in the near-IR operating with an AO-corrected PSF of
90% Strehl ratio under 0.5 arcsec dynamical seeing.Comment: Accepted for publication in MNRA
A Calcium-Dependent Chloride Current Increases Repetitive Firing in Mouse Sympathetic Neurons
Ca2+-activated ion channels shape membrane excitability in response to elevations in intracellular Ca2+. The most extensively studied Ca2+-sensitive ion channels are Ca2+-activated K+ channels, whereas the physiological importance of Ca2+-activated Cl- channels has been poorly studied. Here we show that a Ca2+-activated Cl- currents (CaCCs) modulate repetitive firing in mouse sympathetic ganglion cells. Electrophysiological recording of mouse sympathetic neurons in an in vitro preparation of the superior cervical ganglion (SCG) identifies neurons with two different firing patterns in response to long depolarizing current pulses (1 s). Neurons classified as phasic (Ph) made up 67% of the cell population whilst the remainders were tonic (T). When a high frequency train of spikes was induced by intracellular current injection, SCG sympathetic neurons reached an afterpotential mainly dependent on the ratio of activation of two Ca2+-dependent currents: the K+ [IK(Ca)] and CaCC. When the IK(Ca) was larger, an afterhyperpolarization was the predominant afterpotential but when the CaCC was larger, an afterdepolarization (ADP) was predominant. These afterpotentials can be observed after a single action potential (AP). Ph and T neurons had similar ADPs and hence, the CaCC does not seem to determine the firing pattern (Ph or T) of these neurons. However, inhibition of Ca2+-activated Cl- channels with anthracene-9′-carboxylic acid (9AC) selectively inhibits the ADP, reducing the firing frequency and the instantaneous frequency without affecting the characteristics of single- or first-spike firing of both Ph and T neurons. Furthermore, we found that the CaCC underlying the ADP was significantly larger in SCG neurons from males than from females. Furthermore, the CaCC ANO1/TMEM16A was more strongly expressed in male than in female SCGs. Blocking ADPs with 9AC did not modify synaptic transmission in either Ph or T neurons. We conclude that the CaCC responsible for ADPs increases repetitive firing in both Ph and T neurons, and it is more relevant in male mouse sympathetic ganglion neurons.This work was supported by grants PB92-0347 and PM95-0107 (from the Dirección General de Investigación Científica y Técnica, Spain) to Roberto Gallego and the Instituto de Cultura Juan Gil-Albert (Diputación de Alicante, Spain) to FdC. Our current work was supported by grants SAF2016-77575-R and RD16/0015/0019 (both from Ministerio de Economía, Innovación y Competitividad-MINEICO, Spain) to FdC and Generalitat Valenciana, PROMETEOII/2015/016 to AN. CIBERDEM is an initiative of the Instituto de Salud Carlos III
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