327 research outputs found
Comparative analysis of the immune responses induced by native versus recombinant versions of the ASP-based vaccine against the bovine intestinal parasite Cooperia oncophora
The protective capacities of a native double-domain activation-associated secreted protein (ndd-ASP)-based vaccine against the cattle intestinal nematode Cooperia oncophora has previously been demonstrated. However, protection analysis upon vaccination with a recombinantly produced antigen has never been performed. Therefore, the aim of the current study was to test the protective potential of a Pichia-produced double-domain ASP (pdd-ASP)-based vaccine against C. oncophora. Additionally, we aimed to compare the cellular and humoral mechanisms underlying the vaccine-induced responses by the native (ndd-ASP) and recombinant vaccines. Immunisation of cattle with the native C. oncophora vaccine conferred significant levels of protection after an experimental challenge infection, whereas the recombinant vaccine did not. Moreover, vaccination with ndd-ASP resulted in a higher proliferation of CD4-T cells both systemically and in the small intestinal mucosa when compared with animals vaccinated with the recombinant antigen. In terms of humoral response, although both native and recombinant vaccines induced similar levels of antibodies, animals vaccinated with the native vaccine were able to raise antibodies with greater specificity towards ndd-ASP in comparison with antibodies raised by vaccination with the recombinant vaccine, suggesting a differential immune recognition towards the ndd-ASP and pdd-ASP. Finally, the observation that animals displaying antibodies with higher percentages of recognition towards ndd-ASP also exhibited the lowest egg counts suggests a potential relationship between antibody specificity and protection
Wave characteristics on the Pacific coast of Costa Rica for energy production
The iMARES group of the University of Costa Rica has carried out a continuous measurement of the Pacific waves of Costa Rica, from which wave characteristics have been determined and how these can influence the production of electrical energy.UCR::VicerrectorÃa de Investigación::Unidades de Investigación::IngenierÃa::Instituto Investigaciones en IngenierÃa (INII
Armintxe, grotte
Le siteConnue depuis de nombreuses années, la grotte d’Armintxe s’ouvre en plein cœur de la ville de Lekeitio (Biscaye, Pays basque). L’expansion urbaine dans la seconde moitié du xxe siècle ayant obligé à colmater certaines entrées de la grotte, ce n’est qu’en juin 2016 que le groupe spéléologique ADES de Gernika a désobstrué un petit conduit proche de l’entrée d’origine (fig. 1a) et permis la localisation d’un important ensemble de gravures paléolithiques (fig. 1b).Plus aucune trace de pas..
The Effects of Stellar Rotation. I. Impact on the Ionizing Spectra and Integrated Properties of Stellar Populations
We present a sample of synthetic massive stellar populations created using
the Starburst99 evolutionary synthesis code and new sets of stellar
evolutionary tracks, including one set that adopts a detailed treatment of
rotation. Using the outputs of the Starburst99 code, we compare the
populations' integrated properties, including ionizing radiation fields,
bolometric luminosities, and colors. With these comparisons we are able to
probe the specific effects of rotation on the properties of a stellar
population. We find that a population of rotating stars produces a much harder
ionizing radiation field and a higher bolometric luminosity, changes that are
primarily attributable to the effects of rotational mixing on the lifetimes,
luminosities, effective temperatures, and mass loss rates of massive stars. We
consider the implications of the profound effects that rotation can have on a
stellar population, and discuss the importance of refining stellar evolutionary
models for future work in the study of extragalactic, and particularly
high-redshift, stellar populations.Comment: 13 pages, 8 figures; accepted for publication in the Astrophysical
Journa
Host protective ASP-based vaccine against the parasitic nematode Ostertagia ostertagi triggers NK cell activation and mixed IgG1-IgG2 response
The mucus-dwelling parasite Ostertagia ostertagi is one of the most important gastrointestinal nematodes in cattle. Our group has previously demonstrated the protective capacity of a vaccine against this parasite based on a native activation-associated secreted protein ASP1 (nASP) in combination with the saponin adjuvant QuilA. The aim of the current study was to analyse the effect of both antigen and adjuvant on the cellular and humoral vaccine-induced immune responses by comparing the native ASP to a recombinant version expressed in Pichia pastoris (pASP) and replacing QuilA by Al(OH)(3). Immunization of cattle with the protective nASP+QuilA vaccine was associated with antigen-induced proliferation of natural killer (NK) cells combined with IFN-gamma. secretion and the induction of a mixed IgG1/IgG2 antibody response. ASP-specific activation and proliferation of NK cells was also observed in mice following the same vaccination regime. Replacing QuilA by Al(OH)(3) or nASP by pASP significantly decreased the capacity of the vaccines to trigger both NK cell activation and antibody responses and failed to induce protection against a challenge infection. Reduction of the structurally anchoring disulphide bonds of the nASP completely abolished its ability to induce NK cell activation and antibody responses, highlighting the importance of protein conformation for the immunostimulatory activity
RF screening by thin resistive layers
We discuss the results of recent impedance measurements for an LHC dump kicker prototype, performed at CERN using the coaxial wire method. The kicker design includes a vacuum barrier consisting of a ceramic chamber internally coated with a thin metallic layer having good electric contact with the external beam pipe. For the bench test the coated ceramic tube was replaced by a kapton foil with a 0.2 \mu\m copper layer having the same DC resistance of 0.7 Ømega\m. The measurements show that this resistive coating provides a very effective RF screening down to frequencies below 1 MHz, where the skin depth is two orders of magnitude larger than the layer thickness and one could expect full penetration of the electromagnetic fields. We also present simulation results and analytic considerations in agreement with the measurements, showing that the return currents almost entirely flow through the copper layer down to frequencies where the reactive impedance of the kicker elements located behind it becomes comparable to the layer resistance. Finally we discuss the relevance of such coaxial wire measurements to the RF shielding by thin metallic layers in the presence of a higly relativistic proton beam
Where's Waldo? Unveiling a metal-poor extension of the Milky Way thin disc with Pristine-Gaia-synthetic
Our understanding of the Milky Way’s formation history can be refined by analyzing the information encoded in its oldest stellar populations, typically their chemical composition and orbital motion. Having access to such properties is valuable to depict a larger picture of the earliest stages of galactic formation. With the rise of Gaia, an orbital characterization of the different components of our Galaxy has been built over the years, leading to the discovery of various substructures questioning the formation processes at stake.
In that context, following previous work (Fernández-Alvar et al. 2021), we studied the presence of a metal-poor extension of the thin disc, using photometric metallicities from the Pristine survey (Starkenburg et al. 2017). Combining Gaia astrometry with Pristine photometry, we recovered two stellar populations at -2 < [Fe/H] < -1.5 : one slow-rotating (halo-like) and one fast-rotating (thin disc-like) in the MW anticentre using Gaussian mixture models coupled with a Markov-Chain-Monte-Carlo approach. We pursued our investigation with the upcoming Pristine-Gaia-synthetic catalog (Martin et al. 2023, in prep.), which gathers 1.7 million metal-poor stars with metallicities inferred from BP/RP spectrophotometry.
Our aim is to make use of this statistically significant catalog to characterize the kinematic behavior of the metal-poor MW population in a larger field of view. In this talk, I will present some preliminary results investigating the rotating metal-poor Milky Way using 3D kinematics of this all-sky sample
Evaluating a wave reanalysis node by a buoy in midwater
Las bases de datos de reanálisis de oleaje son una fuente importante de información para desarrollar
proyectos de investigación relacionados al clima marÃtimo y aplicaciones de ingenierÃa de costas. Esta fuente
de información toma todavÃa más relevancia en lugares donde se carece de registros históricos provenientes
de mediciones instrumentales, tal y como sucede en Costa Rica. No obstante, esta información, al tratarse
de un producto generado por un modelo numérico, requiere ser calibrada y validada con información
instrumental. En este trabajo se ha utilizado la información generada y disponible por la NOAA, de un
nodo de reanálisis de oleaje ubicado en aguas profundas frente a la costa del Caribe de Costa Rica, el
cual, a su vez, ha sido calibrado y validado con información medida por una boya. El producto que se
ha generado es una base de datos de oleaje calibrada desde el 2005 y en continua actualización, la cual
podrá utilizarse para distintas aplicaciones en la ingenierÃa de costas y en aproximaciones de análisis de
variabilidad climática del oleaje.The wave reanalysis is an important source of information to develop research projects related to wave climate and coastal engineering applications. This source of information is more relevant in places where it lacks historical registers coming from instrumental measurements as well as happens in Costa Rica. However, as the wave reanalysis is generated from a numerical model, it needs to be calibrated and validated with instrumental measurement. This investigation has used the wave reanalysis’s node located in deep water, coming from NOAA, in front of Caribbean’s Costa Rica coast. This information has been calibrated and validated with a buoy information. The product is a wave data base calibrated from 2005 onwards, which it is monthly updated; moreover, this information could be used in many coastal engineering applications and in wave climate variability analysis approximations.UCR::VicerrectorÃa de Investigación::Unidades de Investigación::IngenierÃa::Instituto Investigaciones en IngenierÃa (INII
Solvent and ligand effects on α-pinene epoxidation with Methyltrioxorhenium/hydrogen peroxide system (MTO/H2 O2 )
RESUMEN: Se estudiaron varios ligandos como cocatalizadores para la epoxidación de α-pineno con el sistema MTO/H2O2. La piridina es un buen cocatalizador usando diclorometano como solvente, pero se requieren grandes cantidades de piridina para obtener altos rendimientos al epóxido. El surfactante Aromox es más atractivo ya que se evita el uso de solventes clorados, los cuales son menos amigables ambientalmente. Además, se requieren cantidades relativamente pequeñas de este ligando para obtener alta actividad y selectividad al epóxido.ABSTRACT: Several ligands were studied as co-catalysts for α-pinene epoxidation with MTO/H2O2. Pyridine is an efficient co-catalyst with dichlorometane, tetrahydrofuran or ethyl acetate. However, large amounts of pyridine are
required. In contrast, with relatively small amounts of the Aromox surfactant, high activity and selectivity to α-pinene epoxide are obtained. The latter system has the additional advantage of requiring no chlorinated solvents which are environmentally less friendly
Waves Data in Costa Rica: Validating the WAVERYS Reanalysis using Waves Data
Field wave data are a relevant source of information with high impact for marine sciences and engineering. The present work compiled, in a single database, the different wave data records found in Costa Rica. Such wave data were compared with the WAVERYS reanalysis from the Copernicus Marine Environment Monitoring Service with the purpose of examining this information and its possible use in future research at both the country and regional levels. The historical wave data compilation considered records documented in different projects carried out on behalf of several governmental institutions. Statistical methods were used to analyze and compare, spatially and temporally, the information contained both in the field wave data and in the WAVERYS reanalysis. Results showed that, in the Caribbean, there are wave records between 2015 and 2017. In the Pacific, there are measurements made during the construction of Puerto Caldera between 1978 and 1985. There are also wave data obtained in different sites between 2009 to 2011 and by a recently established gauge network from 2014 onwards. It was verified that the reanalysis database has a high potential for applications in marine sciences and coastal engineering in this region of the Earth
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