Modelling wake effects using two CFD techniques

Comparativa de dos técnica de simulación de rotor: BEM (Blade Element Momentum) y MRF (Moving Reference Frame) para el perfil S809 de NRE

Hamming weights and Betti numbers of Stanley-Reisner rings associated to matroids

To each linear code over a finite field we associate the matroid of its parity check matrix. We show to what extent one can determine the generalized Hamming weights of the code (or defined for a matroid in general) from various sets of Betti numbers of Stanley-Reisner rings of simplicial complexes associated to the matroid

Comparing linear and non linear wind flow models

Assessing wind conditions on complex terrain has become a hard task as terrain complexity increases. That is why there is a need to extrapolate in a reliable manner some wind parameters that determine wind farms viability such as annual average wind speed at all hub heights as well as turbulence intensities. The development of these tasks began in the early 90´s with the widely used linear model WAsP and WAsP Engineering especially designed for simple terrain with remarkable results on them but not so good on complex orographies. Simultaneously non-linearized Navier Stokes solvers have been rapidly developed in the last decade through CFD (Computational Fluid Dynamics) codes allowing simulating atmospheric boundary layer flows over steep complex terrain more accurately reducing uncertainties. This paper describes the features of these models by validating them through meteorological masts installed in a highly complex terrain. The study compares the results of the mentioned models in terms of wind speed and turbulence intensity

Tele-repaso: repasa la lección con tu profesor por internet

TELE-REPASO es un servicio del IES Duques de Nájera de Logroño para que los alumnos y alumnas puedan realizar test de repaso de sus lecciones por internet. Las preguntas de los test han sido propuestas por los profesores y profesoras de cada asignatura. El sistema se encarga de corregir cada test y llevar cuenta de los test realizados, notas obtenidas, etc.Eje: Educación secundaria y profesional: Uso de las NTICRed de Universidades con Carreras en Informática (RedUNCI

Tele-repaso: repasa la lección con tu profesor por internet

TELE-REPASO es un servicio del IES Duques de Nájera de Logroño para que los alumnos y alumnas puedan realizar test de repaso de sus lecciones por internet. Las preguntas de los test han sido propuestas por los profesores y profesoras de cada asignatura. El sistema se encarga de corregir cada test y llevar cuenta de los test realizados, notas obtenidas, etc.Eje: Educación secundaria y profesional: Uso de las NTICRed de Universidades con Carreras en Informática (RedUNCI

Modes of action of rosemary and Debaryomyces hansenii against Aspergillus westerdijkiae in dry-cured meat matrix

Aspergillus westerdijkiae is an ochratoxin A (OTA) producer mould in dry-cured meat products. Natural strategies to control ochratoxigenic moulds using biocontrol agents (BCAs) are currently in the spotlight. The aim of this study was to test the potential antiochratoxigenic activity of rosemary leaves (R), rosemary essential oil (REO) and Debaryomyces hansenii FHSCC 253H (Dh) as BCAs against A. westerdijkiae in a dry-cured fermented sausage-based medium. The mechanisms involved in their effect were also analysed by Proteomics, using a Q-Exactive Plus. Three batches were carried out: a control without BCAs, another one with R+REO and one with Dh. R (2 g/kg) and Dh (100 μL of 10^6 cells/mL) were added to the medium and REO was added on the casing, which was put onto the medium surface to simulate the real product. Significant OTA reductions of 73.87 % and 88.26 % were provoked by R+REO and Dh, respectively. Proteomics revealed that the BCAs affected to proteins linked to OTA biosynthesis and the cell wall integrity pathway (CWI). Proteins from PKS ER domain, directly involved in mycotoxin biosynthesis, were diminished in abundance by both treatments (R+REO or Dh). R+REO altered the CWI by decreasing proteins related to the synthesis of cell surface polysaccharides and actin assembly, and increasing the cell wall protein PhiA, involved in conidiogenesis. Dh decreased the NRPS protein, indispensable for the formation of the OTB, an OTA precursor, and affected to the CWI by lowering the abundance of proteins associated with the actin binding, the synthesis of polysaccharides and the response against cell wall stress agents. Therefore, rosemary and D. hansenii FHSCC 253H are potentially useful to minimise the hazard posed by A. westerdijkiae in dry-cured fermented sausages within a HAPPCC framework.This research was funded by Foundation for Science and Technology (FCT/MCTES to CIMO, UIDB/00690/2020). Fondo Europeo de Desarrollo Regional-“Una manera de hacer Europa” (GR18056). Grant PID2019-104260GB-I00 funded by MCIN/AEI/ 10.13039/501100011033. Grant BES-2017-081340 funded by MCIN/AEI/ 10.13039/501100011033 and by “ESF Investing in your future”. Grant UNEX-AE-3394 funded by MCIN/AEI/ 10.13039/501100011033 and by “ERDF A way of making Europe”. Date of PhD graduation: 14/12/2021info:eu-repo/semantics/publishedVersio

Serial block-face scanning electron microscopy applied to study the trafficking of 8D3-coated gold nanoparticles at the blood-brain barrier

Due to the physical and physiological properties of the blood-brain barrier (BBB), the transport of neurotherapeutics from blood to brain is still a pharmaceutical challenge. We previously conducted a series of experiments to explore the potential of the anti-transferrin receptor 8D3 monoclonal antibody (mAb) to transport neurotherapeutics across the BBB. In that study, gold nanoparticles (AuNPs) were coated with the 8D3 antibody and administered intravenously to mice. Transmission electron microscopy was used and a two-dimensional (2D) image analysis was performed to detect the AuNPs in the brain capillary endothelial cells (BCECs) and brain parenchyma. In the present work, we determined that serial block-face scanning electron microscopy (SBF-SEM) is a useful tool to study the transcytosis of these AuNPs across the BBB in three dimensions and we, therefore, applied it to gain more knowledge of their transcellular trafficking. The resulting 3D reconstructions provided additional information on the endocytic vesicles containing AuNPs and the endosomal processing that occurs inside BCECs. The passage from 2D to 3D analysis reinforced the trafficking model proposed in the 2D study, and revealed that the vesicles containing AuNPs are significantly larger and more complex than described in our 2D study. We also discuss tradeoffs of using this technique for our application, and conclude that together with other volume electron microscopy imaging techniques, SBF-SEM is a powerful approach that is worth of considering for studies of drug transport across the BBB

Priming by Chemokines Restricts Lateral Mobility of the Adhesion Receptor LFA-1 and Restores Adhesion to ICAM-1 Nano-Aggregates on Human Mature Dendritic Cells

LFA-1 is a leukocyte specific β2 integrin that plays a major role in regulating adhesion and migration of different immune cells. Recent data suggest that LFA-1 on mature dendritic cells (mDCs) may function as a chemokine-inducible anchor during homing of DCs through the afferent lymphatics into the lymph nodes, by transiently switching its molecular conformational state. However, the role of LFA-1 mobility in this process is not yet known, despite that the importance of lateral organization and dynamics for LFA-1-mediated adhesion regulation is broadly recognized. Using single particle tracking approaches we here show that LFA-1 exhibits higher mobility on resting mDCs compared to monocytes. Lymphoid chemokine CCL21 stimulation of the LFA-1 high affinity state on mDCs, led to a significant reduction of mobility and an increase on the fraction of stationary receptors, consistent with re-activation of the receptor. Addition of soluble monomeric ICAM-1 in the presence of CCL21 did not alter the diffusion profile of LFA-1 while soluble ICAM-1 nano-aggregates in the presence of CCL21 further reduced LFA-1 mobility and readily bound to the receptor. Overall, our results emphasize the importance of LFA-1 lateral mobility across the membrane on the regulation of integrin activation and its function as adhesion receptor. Importantly, our data show that chemokines alone are not sufficient to trigger the high affinity state of the integrin based on the strict definition that affinity refers to the adhesion capacity of a single receptor to its ligand in solution. Instead our data indicate that nanoclustering of the receptor, induced by multi-ligand binding, is required to maintain stable cell adhesion once LFA-1 high affinity state is transiently triggered by inside-out signals.Peer ReviewedPostprint (published version

Substrate translocation involves specific lysine residues of the central channel of the conjugative coupling protein TrwB

Conjugative transfer of plasmid R388 requires the coupling protein TrwB for protein and DNA transport, but their molecular role in transport has not been deciphered. We investigated the role of residues protruding into the central channel of the TrwB hexamer by a mutational analysis. Mutations affecting lysine residues K275, K398, and K421, and residue S441, all facing the internal channel, affected transport of both DNA and the relaxase protein in vivo. The ATPase activity of the purified soluble variants was affected significantly in the presence of accessory protein TrwA or DNA, correlating with their behaviour in vivo. Alteration of residues located at the cytoplasmic or the inner membrane interface resulted in lower activity in vivo and in vitro, while variants affecting residues in the central region of the channel showed increased DNA and protein transfer efficiency and higher ATPase activity, especially in the absence of TrwA. In fact, these variants could catalyze DNA transfer in the absence of TrwA under conditions in which the wild-type system was transfer deficient. Our results suggest that protein and DNA molecules have the same molecular requirements for translocation by Type IV secretion systems, with residues at both ends of the TrwB channel controlling the opening?closing mechanism, while residues embedded in the channel would set the pace for substrate translocation (both protein and DNA) in concert with TrwA

Explosive Nucleosynthesis: What we learned and what we still do not understand

This review touches on historical aspects, going back to the early days of nuclear astrophysics, initiated by B$^2$FH and Cameron, discusses (i) the required nuclear input from reaction rates and decay properties up to the nuclear equation of state, continues (ii) with the tools to perform nucleosynthesis calculations and (iii) early parametrized nucleosynthesis studies, before (iv) reliable stellar models became available for the late stages of stellar evolution. It passes then through (v) explosive environments from core-collapse supernovae to explosive events in binary systems (including type Ia supernovae and compact binary mergers), and finally (vi) discusses the role of all these nucleosynthesis production sites in the evolution of galaxies. The focus is put on the comparison of early ideas and present, very recent, understanding.Comment: 11 pages, to appear in Springer Proceedings in Physics (Proc. of Intl. Conf. "Nuclei in the Cosmos XV", LNGS Assergi, Italy, June 2018