546 research outputs found

    Higgs effective Hlilj vertex from heavy νR and applications to LFV

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    The European Physical Society Conference on High Energy Physics 5-12 July, 2017 VeniceWe present a new computation of the Lepton Flavor Violating effective vertex involving the Higgs boson and two leptons with different flavors. This vertex is generated from the integration to oneloop level of the heavy right handed neutrinos which are considered here within the context of the Low Scale Seesaw Models and with masses close to the TeV scale. We apply the Mass Insertion Approximation technique to compute the loop contributions from these heavy νR and derive a symple analytical formula for the Hli lj effective vertex in terms of the input Yν Yukawa coupling matrix and right handed MR neutrino masses. Some interesting phenomenological applications of this Hli lj effective vertex are also includedWe thank our respective projects: FPA2016-78645-P (MINECO(Spain)/FEDER(EU)); ITN-ELUSIVES H2020-MSCA-ITN-2015//674896 (EU); ANPCyT PICT 2013-2266 (Argentina

    Testing Supersymmetry with Lepton Flavor Violating tau and mu decays

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    In this work the following lepton flavor violating τ\tau and μ\mu decays are studied: τμμμ+\tau^- \to \mu^- \mu^- \mu^+, τeee+\tau^- \to e^- e^- e^+, μeee+\mu^- \to e^- e^- e^+, τμγ\tau^- \to \mu^- \gamma, τeγ\tau^- \to e^- \gamma and μeγ\mu^- \to e^- \gamma. We work in a supersymmetric scenario consisting of the minimal supersymmetric standard model particle content, extended by the addition of three heavy right handed Majorana neutrinos and their supersymmetric partners, and where the generation of neutrino masses is done via the seesaw mechanism. Within this context, a significant lepton flavor mixing is generated in the slepton sector due to the Yukawa neutrino couplings, which is transmited from the high to the low energies via the renormalization group equations. This slepton mixing then generates via loops of supersymmetric particles significant contributions to the rates of lj3lil_j \to 3 l_i and the correlated ljliγl_j \to l_i \gamma decays. We analize here in full detail these rates in terms of the relevant input parameters, which are the usual minimal supergravity parameters and the seesaw parameters. For the lj3lil_j \to 3 l_i decays, a full one-loop analytical computation of all the contributing supersymmetric loops is presented. This completes and corrects previous computations in the literature. In the numerical analysis compatibility with the most recent experimental upper bounds on all these τ\tau and μ\mu decays, with the neutrino data, and with the present lower bounds on the supersymmetric particle masses are required. Two typical scenarios with degenerate and hierarchical heavy neutrinos are considered. We will show here that the minimal supergravity and seesaw parameters do get important restrictions from these τ\tau and μ\mu decays in the hierarchical neutrino case.Comment: Version to appear in Physical Review

    Design tool to predict the open-hole failure strength of composite laminates subjected to in-plane loads

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    A design tool based on Whitney-Nuismer model is proposed to predict the failure strength of open-hole composite plates subjected to in-plane loads, both tensile and compressive. One of the limitations of this model is the use of characteristic distances, which have to be estimated, and which are mostly considered constant material properties. In this work, it is demonstrated that these characteristic distances are a function of the plate geometry and are not a material property. Different analytical expressions are proposed to estimate the characteristic distances by using the results of only three experimental tests. This approach enables an accurate and fast estimation of the failure strength when the parameters of the plate are modified without using numerical simulations that require a longer time to be carried out.The authors are indebted for the financial support of this work to the Ministry of Economy and Finance of Spain (project DPI2013-42240-R).Publicad

    Pathological and virological findings in patients with persistent hypertransaminasaemia of unknown aetiology

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    BACKGROUND: The histopathological spectrum and role of hepatitis viruses in cases of hypertransaminasaemia of unknown aetiology have not been correctly analysed in a sufficiently large number of patients. METHODS: We studied 1075 consecutive patients referred for liver biopsy because of elevation of alanine aminotransferase (ALT) levels for more than six months. From this population we selected those cases in whom the aetiology could not be defined from clinical, biochemical, and serological data obtained before biopsy. In these patients liver biopsies were reviewed, and hepatitis B virus (HBV)-DNA and hepatitis C virus (HCV)-RNA were assayed in serum by polymerase chain reaction (PCR). Serum hepatitis G virus (HGV)-RNA was determined by PCR in 74 patients. RESULTS: Of 1075 patients studied, the cause of the increased serum ALT levels remained elusive after appropriate testing in 109 patients (10.1%). Liver biopsies from these patients showed non-specific changes in 32.7% of cases, non-alcoholic steatohepatitis (NASH) in 15.8%, and chronic hepatitis or cirrhosis in 51.5%. HBV-DNA and/or HCV-RNA was detected more frequently in cryptogenic liver disease than in healthy blood donors (26.7% v 3.4%; p<0.001). HGV-RNA was found in only one patient. The proportion of cases with detectable HBV-DNA or HCV-RNA was 14.3% in patients with non-specific changes or NASH, 30.7% in patients with chronic hepatitis, and 61.5% in patients with cirrhosis. Cirrhosis was found more frequently in patients with positive HBV-DNA and/or HCV-RNA in serum than in those who tested negatively (p=0.005). CONCLUSIONS: In our series, patients in whom biochemical and serological data did not determine the aetiology of the disease represented 10% of all cases referred for liver biopsy for persistent elevation of serum transaminases. Approximately 50% of patients had chronic hepatitis or cirrhosis and the remainder had NASH or non-specific changes. Occult viral infections were found in a high proportion of cases in the first group and in a low percentage of patients in the second

    Gas sensor based on room temperature optical properties of Surface QDs

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    Self-organized InGaAs QDs are intensively studied for optoelectronic applications. Several approaches are in study to reach the emission wavelengths needed for these applications. The use of antimony (Sb) in either the capping layer or into the dots is one example. However, these studies are normally focused on buried QD (BQD) where there are still different controversial theories concerning the role of Sb. Ones suggest that Sb incorporates into the dot [1], while others support the hypothesis that the Sb occupies positions surrounding the dot [2] thus helping to keep their shape during the capping growth

    Ecdysone-related biomarkers of toxicity in the model organism Chironomus riparius: stage and sex-dependent variations in gene expression profiles

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    Despite being considered a model organism in toxicity studies, particularly in assessing the environmental impact of endocrine disrupting compounds (EDCs) and other chemicals, the molecular basis of development is largely unknown in Chironomus riparius. We have characterized the expression patterns of important genes involved in the ecdysone pathway from embryos to pupa, but specially during the different phases of C. riparius fourth larval instar, according to the development of genital and thoracic imaginal discs. Real-Time PCR was used to analyze: EcR and usp, two genes encoding the two dimerizing partners of the functional ecdysone receptor; E74, an early response gene induced by ecdysteroids; vg (vitellogenin), an effector gene; hsp70 and hsc70, two heat-shock genes involved in the correct folding of the ecdysone receptor; and rpL13, as a part of the ribosomal machinery. Our results show for the first time stage and sex-dependent variations in ecdysone-responsive genes, specially during the late larval stage of C. riparius. The induction in the expression of EcR and usp during the VII-VIII phase of the fourth instar is concomitant with a coordinated response in the activity of the other genes analyzed, suggesting the moment where larvae prepare for pupation. This work is particularly relevant given that most of the analyzed genes have been proposed previously in this species as sensitive biomarkers for the toxicological evaluation of aquatic ecosystems. Identifying the natural regulation of these molecular endpoints throughout the Chironomus development will contribute to a more in-depth and accurate evaluation of the disrupting effects of EDCs in ecotoxicological studies.IO's research was funded by an FPI grant from Ministerio de Ciencia e Innovación (http://www.idi.mineco.gob.es; CTM2009-07189). Research funding was provided by Ministerio de Economía y Competitividad (grant number CTM-2012-37547) and Ministerio de Ciencia e Innovación (grant number CGL2009-10868), SpainS

    Determination of a lectin protein allergen in food by on-line aptamer affinity solid-phase extraction capillary electrophoresis-mass spectrometry

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    An aptamer affinity sorbent was prepared for clean-up, preconcentration, separation and characterization of a food allergen protein by on-line aptamer affinity solid-phase extraction capillary electrophoresis-mass spectrometry (AA-SPE-CE-MS). SPE microcartridges were packed with a sorbent based on magnetic bead particles modified with an aptamer against the target lectin protein concanavalin A (Con A). After optimization of several parameters of the SPE-CE-MS method, the sample (ca. 30 µL) was loaded in separation background electrolyte (BGE, 2 M acetic acid pH 2.2), while the retained protein was eluted with 100 mM NH4OH (pH 11.2) (ca. 100 nL). The developed method was linear between 0.5 and 20 mg·L-1 and the limit of detection (LOD) was 0.25 mg·L-1, which was 100 times lower than by CE-MS. The repeatability of the method was satisfactory, with relative standard deviations (RSD) for migration times and peak areas below 1.9 and 8.1%, respectively. In addition, the microcartridges could be reused more than 25 analyses without significant loss of extraction efficiency. Finally, the applicability and versatility of the developed method were demonstrated by analyzing low levels of Con A in different food matrices (i.e. white beans, as well as chickpea, lentils, and wheat flours), leading to satisfactory results, with recoveries between 87 and 115%

    Bibliometric review in Asperger Syndrome: impact in the field of psychology and education

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    La productividad científica en Síndrome de Asperger (SA) se ha incrementado considerablemente en los últimos años desde distintos campos de la Educación y la Psicología. Incluido dentro de los Trastornos del Espectro del Autismo según el DSM-5, el SA se caracteriza por una alteración en las capacidades de relación social, comunicación y flexibilidad mental. Es objeto del presente estudio ofrecer una revisión del estado actual de la investigación en dicho ámbito e identificar las principales aportaciones científicas. La unidad de análisis se compuso por 1741 documentos extraídos de la Social Science Citation Index y revisados minuciosamente. Los resultados evidenciaron un incremento de la productividad temporal y el interés científico en las áreas de caracterización del SA, comorbilidad y tratamiento. Además, se observó una tendencia a realizar los trabajos en colaboración y un número considerable de autores clasificados como grandes productores por sus niveles de productividad superiores a los diez trabajos. La funcionalidad de esta revisión se encuentra en su valor como material de referencia para futuras líneas de investigación en tanto que abarca la identificación y análisis de los principales campos de estudio en este ámbito.The scientific productivity about Asperger Syndrome has increased dramatically in recent years from various fields of Education and Psychology. Included within the Autism Spectrum Disorder according to the DSM-5, SA is characterized by alterations in social interaction skills, communication, and mental flexibility. The aim of this study is to provide a review of the current state of research in this area and identify major scientific contributions. The unit of analysis was composed of 1741 documents taken from the Social Science Citation Index and thoroughly reviewed. The results showed an increase in temporary productivity and scientific interest in the areas of characterization of Asperger Syndrome, comorbidity and treatment. In addition, a tendency was observed to perform the investigations in collaboration and a considerable number of authors classified as big producers due to their high levels of productivity with more than ten articles. The functionality of this review is its value as a reference for future researches as long as cover the identification and analysis of the main research topics in this field

    Accurate determination of the milk protein allergen β-lactoglobulin by on-line aptamer affinity solid-phase extraction capillary electrophoresis-mass spectrometry

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    An on-line aptamer affinity solid-phase extraction capillary electrophoresis-mass spectrometry (AA-SPE-CE-MS) method was developed to purify, preconcentrate, separate, and characterize the milk allergenic protein β-lactoglobulin (β-LG) in food samples. The sorbent to pack into the SPE microcartidges was prepared by immobilizing an aptamer against β-LG onto magnetic bead particles. After optimizing the SPE-CE-MS method, the sample (ca. 75 µL) was loaded in separation background electrolyte (BGE, 2 M acetic acid pH 2.2), while a solution of 100 mM NH4OH (pH 11.2) (ca. 100 nL) was used for the protein elution. The linearity of the method ranged between 0.1 and 20 µg·mL-1 and the limit of detection (LOD) was 0.05 µg·mL-1, which was 200 times lower than by CE-MS. The method was repeatable in terms of relative standard deviation (RSD) for migration times and peak areas (< 0.5 % and 2.4 %, respectively) and microcartridge lifetime was more than 25 analyses. The applicability of the method for the determination of low levels of β-LG was shown by analyzing milk-free foods (i.e. a 100 % cocoa dark chocolate, a hypoallergenic formula for infants, and a dairy-free white bread) and milk-containing white breads. Results were satisfactory in all cases, thus demonstrating the great potential of the developed method for accurate food safety and quality control
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