320 research outputs found
The Spanish SpaceWeather Service SeNMEs. A Case Study on the Sun-Earth Chain
ComunicaciĂłn presentada en el Coimbra Solar Physics Meeting, 5-9 October 2015, Coimbra, PortugalThe Spanish Space Weather Service SeNMEs, www.senmes.es, is a portal
created by the SRG-SW of the Universidad de AlcalĂĄ, Spain, to meet societal needs
of near real-time space weather services. This webpage-portal is divided in different
sections to fulfill users needs about space weather effects: radio blackouts, solar energetic
particle events, geomagnetic storms and presence of geomagnetically induced
currents.
In less than one year of activity, this service has released a daily report concerning
the solar current status and interplanetary medium, informing about the chances of a
solar perturbation to hit the Earthâs environment. There are also two different forecasting
tools for geomagnetic storms, and a daily ionospheric map. These tools allow us
to nowcast a variety of solar eruptive events and forecast geomagnetic storms and their
recovery, including a new local geomagnetic index, LDiñ, along with some specific new
scaling.
In this paper we also include a case study analysed by SeNMEs. Using different
high resolution and cadence data from space-borne solar telescopes SDO, SOHO and
GOES, along with ionospheric and geomagnetic data, we describe the Sun-Earth feature
chain for the event.MINECO project AYA2013-47735PPeer reviewe
Heterologous mammalian Akt disrupts plasma membrane homeostasis by taking over TORC2 signaling in Saccharomyces cerevisiae.
The Akt protein kinase is the main transducer of phosphatidylinositol-3,4,5-trisphosphate (PtdIns3,4,5P) signaling in higher eukaryotes, controlling cell growth, motility, proliferation and survival. By co-expression of mammalian class I phosphatidylinositol 3-kinase (PI3K) and Akt in the Saccharomyces cerevisiae heterologous model, we previously described an inhibitory effect on yeast growth that relied on Akt kinase activity. Here we report that PI3K-Akt expression in yeast triggers the formation of large plasma membrane (PM) invaginations that were marked by actin patches, enriched in PtdIns4,5P and associated to abnormal intracellular cell wall deposits. These effects of Akt were mimicked by overproduction of the PtdIns4,5P effector Slm1, an adaptor of the Ypk1 and Ypk2 kinases in the TORC2 pathway. Although Slm1 was phosphorylated in vivo by Akt, TORC2-dependent Ypk1 activation did not occur. However, PI3K-activated Akt suppressed the lethality derived from inactivation of either TORC2 or Ypk protein kinases. Thus, heterologous co-expression of PI3K and Akt in yeast short-circuits PtdIns4,5P- and TORC2-signaling at the level of the Slm-Ypk complex, overriding some of its functions. Our results underscore the importance of phosphoinositide-dependent kinases as key actors in the homeostasis and dynamics of the PM
Long-Term outcomes and durability of the mitroflow aortic bioprosthesis
[Abstract] Background. This study aims to determine the incidence and causes of structural valve deterioration (SVD) among all models of Mitroflow bioprostheses (A12/LX/DL), as well as to define their long-term clinical and hemodynamic performance.
Methods and Results. We retrospectively reviewed a series of 1023 patients who underwent aortic valve replacement with Mitroflow bioprostheses between 2001 and 2014. A small aortic root was found in 22.4% of patients. There were two cases of severe patient-prosthesis mismatch. Only 31 patients developed SVD. The rate of incidence was 8.1 cases per 1000 patient-years. Cumulative incidence of SVD was 1.4% and 3% at five and 10 years, respectively. Freedom from SVD was 97.4% and 88.2% at five and 10 years, respectively. Anticalcification phospholipid reduction treatment (PRT) for model DL was a protective factor for SVD. Multivariable analysis confirmed age <70 years and use of 19âmm valve as independent predictors of SVD. Cumulative survival was 76.6% at five years and 42.3% at 10 years (mean follow-up 3.8â±â3.1 years). In multivariable analysis, neither the use of small aortic prosthesis (pâ=â0.18) nor the occurrence of SVD (pâ=â0.85) was found to be independent predictors of long-term survival.
Conclusions. Mitroflow valves demonstrate an acceptable rate of SVD and satisfactory long-term hemodynamic performance, particularly in patients with small aortic roots, age >70 years, and cases with severe left ventricular hypertrophy. PRT might contribute to improved long-term durability
Pyrrolidine-based catalytic microporous polymers in sustainable C=N and C=C bond formation via iminium and enamine activation
ProducciĂłn CientĂficaA new set of catalytic materials having a pyrrolidine moiety confined in microporous organic polymer networks (POPs) has been attained. These catalytic polymers have been prepared by a straightforward synthesis starting from microporous polymer networks made from isatin (or a mixture of isatin and trifluoroacetophenone) and 1,3,5-triphenylbenzene. The polymers efficiently catalyzed the formation of nitrones under very mild and sustainable conditions using green solvents through an iminium ion activation mechanism. The reactions are scalable, and polymers are easily recycled. Special attention has been paid to understanding all the factors that could affect the efficiency of the confined catalysts. The electronic and conformational characteristics of the pyrrolidine moiety attached to the porous polymers, as well as other features that could affect the transport through the network, such as molecular volume and shape of reactants and products, and even hydrophilic or hydrophobic properties, have been systematically evaluated. In addition, the heterogeneous polymers are also useful in Cdouble bondC bond formation through both iminium ion and enamine activation.Gobierno de España (Agencia Estatal de InvestigaciĂłn) - (Projects CTQ2016-78779-R, PID2019-109403RB-C22, RTI2018-096328-B-I00, CTQ2017-89217-P and PID2020-118547GBI00)Junta de Castilla y LeĂłn, UniĂłn Europea y Fondo Europeo de Desarrollo Regional (FEDER) - (Project VA224P20)
Occurrence of tetracyclines and sulfonamides in manures, agricultural soils and crops from different areas in Galicia (NW Spain)
Antibiotics released to the environment are causing public health and sustainability concerns. Taking that into account, we studied the presence of tetracyclines (Tetracycline, Oxytetracycline, Chlortetracycline and Doxycycline) and sulfonamides (Sulfadiazine, Sulfamethazine, Sulfachlorpyridazine and Sulfamethoxypyridazine) in manures, soils and crops from Galicia (Spain), where a high number of cattle, pig and poultry farms exist. We used the HPLC-MS/MS technique to analyze 40 samples of cattle, pig and poultry manure, as well as 65 soil samples, and 27 vegetation samples. The presence of antibiotics was detected in 42% of the manures, 17% of the soils and 44% of crop samples, with maximum concentrations of 106.0âŻmgâŻkgâ1 for individual antibiotics in manures and 0.6âŻmgâŻkgâ1 in soils and plants. The simultaneous presence of several antibiotics was infrequent in soils (only three soils presented two or three antibiotics), and more common in manures and plants, some of them with up to five antibiotics. Pig slurries showed the highest antibiotic concentrations, as well as the highest number of different antibiotics. Crops fertilized with these slurries also showed the highest number of different antibiotics. Antibiotics were detected in 71% of grass and corn samples, and in 33% of wheat grain samples, while they were not detected in potato samples. These results can be very relevant taking into account potential environmental and public health repercussions of antibiotics in soil and water, as well as antibiotics uptake and accumulation in plants, and subsequent incorporation to the food chain.This work was supported by the Spanish Ministry of Economy and Competitiveness [grant numbers CGL2015-67333-C2-1-R and CGL2015-67333-C2-2-R]. M. Conde-Cid holds a pre-doctoral contract (FPU15/0280, Spanish Government). The sponsor had not involvement in study design; in the collection, analysis and interpretation of data; in the writing of the report, and in the decision to submit the article for publication.S
Polymorphisms in genes related to the complement system and antibody-mediated cardiac allograft rejection
[Abstract] Background. Heart transplantation (HT) is a life-saving treatment for patients with end-stage heart failure. One of the main problems after HT is the humoral response termed antibody-mediated rejection (AMR). Complement activation plays a key role in AMR contributing to graft damage. The aim of this study was to analyze genetic variants in genes related to the complement pathways that could be associated with the development of AMR.
Methods. Analysis of 51 genes related to the complement pathway was performed by next-generation sequencing in 46 HT recipients, 23 with and 23 without AMR. Statistical analysis was performed with SNPstats and R.
Results. We identified 2 single nucleotide polymorphisms, 1 in the mannose-binding lectin 2 gene (p.Gly54Asp-MBL2) and 1 in the complement factor properdin gene (p.Asn428(p=)-CFP), that showed significant association with the absence and development of AMR, respectively. Moreover, the presence of the rare allele in p.Gly54Asp-MBL2 control patients correlated with an immunodeficiency of mannose-binding lectin (6.24 ng/ml vs 207.50 ng/ml, p < 0.01), whereas the presence of the rare allele p.Asn428(p=)-CFP in patients with AMR correlated with higher levels of properdin protein (14.65 ÎŒg/ml vs 10.77 ÎŒg/ml, p < 0.05).
Conclusions. AMR is a complex phenotype affected by many recipient factors. Variants in p.Gly54Asp-MBL2 and p.Asn428(p=)-CFP genes, encoding mannose-binding lectin 2 and properdin, may influence the risk of AMR.Instituto de Salud Carlos III; PI13/0217
Tuning topological defects in magnetic stripe domains of lateral multilayers with perpendicular magnetic anisotropy
Resumen del pĂłster presentado a la VIII EdiciĂłn de la ReuniĂłn Bienal del Grupo Especializado de FĂsica del Estado SĂłlido de la Real Sociedad Española de FĂsica celebrada del en Ciudad Real del 22 al 24 de enero de 2014.Peer Reviewe
AGN variability time scales and the discrete-event model
We analyse the ultraviolet variability time scales in a sample of 15 Type 1
Active Galactic Nuclei (AGN) observed by IUE. Using a structure function
analysis, we demonstrate the existence in most objects of a maximum variability
time scale of the order of 0.02-1.00 year. We do not find any significant
dependence of these maximum variability time scales on the wavelength, but we
observe a weak correlation with the average luminosity of the objects. We also
observe in several objects the existence of long-term variability, which seems
decoupled from the short-term one. We interpret the existence of a maximum
variability time scale as a possible evidence that the light curves of Type 1
AGN are the result of the superimposition of independent events. In the
framework of the so-called discrete-event model, we study the event energy and
event rate as a function of the object properties. We confront our results to
predictions from existing models based on discrete events. We show that models
based on a fixed event energy, like supernova explosions, can be ruled out. In
their present form, models based on magnetic blobs are also unable to account
for the observed relations. Stellar collision models, while not completely
satisfactory, cannot be excluded.Comment: 13 pages, 10 figures. Accepted for publication in A&
The Starburst-AGN connection: The role of stellar clusters in AGNs
Nuclear stellar clusters are a common phenomenon in spirals and in starbursts
galaxies, and they may be a natural consequence of the star formation processes
in the central regions of galaxies. HST UV imaging of a few Seyfert 2 galaxies
have resolved nuclear starbursts in Seyfert 2 revealing stellar clusters as the
main building blocks of the extended emission. However, we do not know whether
stellar clusters are always associated with all types of nuclear activity. We
present NUV and optical images provided by HST to find out the role that
stellar clusters play in different types of AGNs (Seyferts and LLAGNs). Also
with these images, we study the circumnuclear dust morphology as a probe of the
circumnuclear environment of AGNs. Here we present a summary of the the first
results obtained for the sample of Seyferts and LLAGN galaxies.Comment: Contribution to the conference proceedings "Space Astronomy: The UV
window to the Universe", El Escorial (Spain), May 28-June 1 2007, submitted
to Ap&SS, invited ed. Gomes de Castro, A.I. Further explanations are in
Mu\~noz Marin, et al (2007) and Gonzalez Delgado et al (2007); and the full
collection of figures are at the ULR:
http://www.iaa.es/~rosa/research/LLAGNs2007/LLAGNs-HSTIma1.html
http://www.iaa.es/~manuel/publications/paper01.htm
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