Pricing tranched credit products with generalized multifactor models

The market for tranched credit products (CDOs, Itraxx tranches) is one of the fastest growing segments in the credit derivatives industry. However, some assumptions underlying the standard Gaussian onefactor pricing model (homogeneity, single factor, Normality), which is the pricing standard widely used in the industry, are probably too restrictive. In this paper we generalize the standard model by means of a two by two model (two factors and two asset classes). We assume two driving factors (business cycle and industry) with independent tStudent distributions, respectively, and we allow the model to distinguish among portfolio assets classes. In order to illustrate the estimation of the parameters of the model, an empirical application with Moody's data is also included

Electron microscopy study of CeOx–Pd/α-Al2O3 catalysts for methane dry reforming

We have investigated the interaction between Pd and Ce in a 0.47 wt % CeOx–Pd 1 wt %/ -Al2O3 catalyst that is used in the reforming reaction of CH4 with CO2. The freshly reduced catalyst was characterized by various electron microscopy techniques, such as elemental mapping, Z-contrast imaging, and electron energy-loss spectroscopy to understand the role of Ce on a microscopic scale. The high spatial resolution elemental mapping indicates that CeOx is located in close proximity of the palladium nanoparticles. High-resolution lattice images and energy-loss spectra obtained in the vicinity of the Pd particles show an anisotropic distribution of CeOx crystallites limited to the interface region between Pd and the substrate but not covering the surface of the Pd nanoparticles. Energy-loss near edge fine structure of Pd M edges reveals that the Pd nanoparticles are not oxidized.Fil: Moreno, M. S.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Wang, Feiya. National Institute for Nanotechnology; CanadáFil: Malac, M.. National Institute for Nanotechnology; CanadáFil: Kasama, T.. University of Cambridge; Reino UnidoFil: Gigola, Carlos Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Costilla, Ignacio Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Sánchez, M. D.. Universidad Nacional del Sur. Departamento de Física; Argentin

Caveolin-1 Modulates Mechanotransduction Responses to Substrate Stiffness through Actin-Dependent Control of YAP

The transcriptional regulator YAP orchestrates many cellular functions, including tissue homeostasis, organ growth control, and tumorigenesis. Mechanical stimuli are a key input to YAP activity, but the mechanisms controlling this regulation remain largely uncharacterized. We show that CAV1 positively modulates the YAP mechanoresponse to substrate stiffness through actin-cytoskeleton-dependent and Hippo-kinase-independent mechanisms. RHO activity is necessary, but not sufficient, for CAV1-dependent mechanoregulation of YAP activity. Systematic quantitative interactomic studies and image-based small interfering RNA (siRNA) screens provide evidence that this actin-dependent regulation is determined by YAP interaction with the 14-3-3 protein YWHAH. Constitutive YAP activation rescued phenotypes associated with CAV1 loss, including defective extracellular matrix (ECM) remodeling. CAV1-mediated control of YAP activity was validated in vivo in a model of pancreatitis-driven acinar-to-ductal metaplasia. We propose that this CAV1-YAP mechanotransduction system controls a significant share of cell programs linked to these two pivotal regulators, with potentially broad physiological and pathological implications. Moreno-Vicente et al. report that CAV1, a key component of PM mechanosensing caveolae, mediates adaptation to ECM rigidity by modulating YAP activity through the control of actin dynamics and phosphorylation-dependent interaction of YAP with the 14-3-3-domain protein YWHAH. Cav1-dependent YAP regulation drives two pathophysiological processes: ECM remodeling and pancreatic ADM. © 2018 The Author

Nitric oxide decreases intestinal haemorrhagic lesions in rat anaphylaxis independently of mast cell activation

The purpose of this study is to assess the role of nitric oxide (NO) in the intestinal lesions of passive anaphylaxis, since this experimental model resembles necrotizing enterocolitis. Sprague-Dawley rats were sensitized with IgE anti-dinitrophenol monoclonal antibody. Extravasation of protein-rich plasma and haemorrhagia were measured in the small intestine. Plasma histamine was measured to assess mast cell activation. The effect of exogenous NO on the lesions was assessed by using two structurally unrelated NO-donors: sodium nitroprusside and S-nitroso-Nacetyl-penicillamine (SNAP). An increased basal production of NO was observed in cells taken after anaphylaxis, associated with a reduced response to platelet-activating factor, interleukin 1beta, and IgE/DNP-bovine serum albumin complexes. The response to bacterial lipopolysaccharide and dibutyryl cyclic adenosine monophosphate (AMP) was enhanced 24 h after challenge, but at earlier times was not significantly different from that observed in controls. Treatment with either sodium nitroprusside or SNAP produced a significant reduction of the haemorrhagic lesions, which are a hallmark of rat anaphylaxis. The extravasation of protein-rich plasma was not influenced by NO-donors. The increase of plasma histamine elicited by the anaphylactic challenge was not influenced by SNAP treatment. NO-donors protect intestinal haemorrhagic lesions of rat anaphylaxis by a mechanism apparently independent of mast cell histamine release

Anti-inflammatory, pro-proliferative and antimicrobial potential of the compounds isolated from Daemonorops draco (Willd.) Blume

Ethno-pharmacological relevance: Daemonorops draco (D. draco) commonly known as “Dragon's blood” is one of the most used plants by Momok, Anak Dalam and Talang Mamak tribes from Indonesia as a remedy for wound healing. Aim of the study: This study aimed to identify the extract, fractions and compounds responsible for the anti-inflammatory and pro-proliferative activities of the D. draco resin. Additionally, the antimicrobial activity against two bacteria and one yeast species was analysed. Materials and methods: Bio-guided isolation of compounds with anti-inflammatory, pro-proliferative and antimicrobial activities from the D. draco resin was carried out by measuring: the inhibition of NF-κB and activation of Nrf2 in THP-1, HaCaT, NIH-3T3 cells; cell proliferation in NIH-3T3 and HaCaT cells; and the antimicrobial effect on E. coli, S. aureus and C. albicans. Results: Guided isolation by bioassay gave rise to the isolation and characterisation by nuclear magnetic resonance and mass spectrometry of three compounds: 1 (Bexarotene), 2 (Taspine) and 3 (2-hydroxy-1-naphthaldehyde isonicotinoyl hydrazone). All compounds showed NF-κB inhibitory activity with IC50 values of 0.10–0.13, 0.22–0.24 and 3.75–4.78 μM, respectively, while the positive control, Celastrol, had an IC50 of 7.96 μM. Likewise, all compounds showed an activating effect of Nrf2 with EC50 values of 5.34–5.43, 163.20–169.20 and 300.82–315.56 nM, respectively, while the positive control, CDDO-Me, had an EC50 of 0.11 nM. In addition, concerning the pro-proliferative activity, compound 1 (IC50 = 8.62–8.71 nM) showed a capacity of 100%, compound 2 (IC50 = 166–171 nM) showed a capacity of 75%, and compound 3 (IC50 = 469–486 nM) showed a capacity of 65%, while FSB 10% (positive control) had a pro-proliferative activity of 100% in the NIH3T3 cell lines (fibroblasts) and HaCaT (keratinocytes). Finally, all the compounds showed antimicrobial activity with MIC values of 0.12–0.16, 0.31–0.39 and 3.96–3.99 μM, respectively, in S. aureus, E. coli and C. albicans strains, while the positive control, Ofloxacin, had a MIC of 27.65 μM. Conclusion: This study managed to isolate, for the first time, three compounds (Bexarotene, Taspine and 2-hydroxy-1-naphthaldehyde isonicotinoyl hydrazone) from the resin of D. draco, with anti-inflammatory, and pro-proliferative as well as antimicrobial activitie

Participation and Influence of the libero in recepcion and defence, in volleyball U-19

El objetivo fue conocer la participación e influencia líbero en fase de ataque y defensa, en etapas de formación. La muestra fueron 6948 acciones de juego, realizadas por los jugadores de los 21 equipos del Campeonato de España Juvenil masculino. Las variables fueron: función del receptor/defensor, zona de recepción/defensa en profundidad y lateralidad, eficacia de recepción/defensa, zona donde se realiza colocación en recepción/defensa, zona hacia donde se realiza la colocación en recepción/defensa, tiempo de ataque/contraataque y eficacia de ataque/contraataque. En recepción, existió asociación significativa entre función del receptor y zona de recepción en profundidad-lateralidad, y zona donde se realiza la colocación. En defensa, existió asociación significativa entre función del defensor y zona de defensa en profundidad-lateralidad, eficacia de defensa, zona donde se realiza la colocación, zona hacia donde se realiza la colocación y tiempo de contraataque. La influencia del líbero, en estas etapas, se manifiesta más en defensa que en recepciónThe aim was to know the participation and influence of the libero in side-out phase and counter-attack, in young athletes. The sample was 6948 game actions, carried out by the players of the 21 teams that participate in the Under-19 Spanish Championship. The variables were: player that intervened in reception/dig, depth and laterality reception/dig zone, reception/dig efficacy, setting zone in reception/dig, set´s area in reception/dig, tempo of attack/counterattack and attack/counterattack efficacy. In reception, showed significant association between player that intervened in reception, depth-laterality reception zone and the setting zone. In defense, showed significant association between the player that intervened in dig and the depth-laterality dig zone, dig efficacy, setting zone, set´s area and tempo of counterattack. The influence of the participation of the libero, in young athletes, appeared more often in defense than in the receptio

La coordinación de las aproximaciones en la comprensión del concepto de límite cuando los estudiantes para profesor anticipan respuestas de estudiantes

El objetivo de este estudio es examinar en qué medida la identificación de la coordinación de las aproximaciones en el dominio y el rango de una función es considerado un avance conceptual (KDU en Simon, 2006) en la comprensión del concepto de límite de una función por futuros profesores. Veinticinco estudiantes para profesor de matemáticas anticiparon respuestas de estudiantesde bachillerato a problemas sobre el límite de una función que mostraban distintas características de la comprensión y propusieron problemas para apoyar el progreso conceptual de los estudiantes. Los resultados muestran que identificar la coordinación de las aproximaciones en el dominio y el rango como KDU permitió a los estudiantes para profesor considerar progresiones en el aprendizaje sobre las que apoyar sus propuestas de enseñanza.The aim of this study is to examine to what extent the identification of the coordination of approximations in the domain and in the range is considered a Key Developmental Understanding (KDU in Simon, 2006) by prospective teachers. 25 prospective secondary school mathematics teachers anticipated high school students’ answers to problems about the limit of a function showing different characteristics of understanding and proposed problems that would support students’ conceptual progress. Results show that identifying the coordination of the approximations in the domain and in the range as KDU allowed prospective teachers to consider progressions in students’ learning in order to support their teaching decisions.El objetivo de este estudio es examinar en qué medida la identificación de la coordinación de las aproximaciones en el dominio y el rango de una función es considerado un avance conceptual (KDU en Simon, 2006) en la comprensión del concepto de límite de una función por futuros profesores. Veinticinco estudiantes para profesor de matemáticas anticiparon respuestas de estudiantesde bachillerato a problemas sobre el límite de una función que mostraban distintas características de la comprensión y propusieron problemas para apoyar el progreso conceptual de los estudiantes. Los resultados muestran que identificar la coordinación de las aproximaciones en el dominio y el rango como KDU permitió a los estudiantes para profesor considerar progresiones en el aprendizaje sobre las que apoyar sus propuestas de enseñanza