Derivative pricing under the possibility of long memory in the supOU stochastic volatility model

We consider the supOU stochastic volatility model which is able to exhibit long-range dependence. For this model we give conditions for the discounted stock price to be a martingale, calculate the characteristic function, give a strip where it is analytic and discuss the use of Fourier pricing techniques. Finally, we present a concrete specification with polynomially decaying autocorrelations and calibrate it to observed market prices of plain vanilla options

Numerical benchmark campaign of cost action tu1404 – microstructural modelling

This paper presents the results of the numerical benchmark campaign on modelling of hydration and microstructure development of cementitious materials. This numerical benchmark was performed in the scope of COST Action TU1404 “Towards the next generation of standards for service life of cement-based materials and structures”. Seven modelling groups took part in the campaign applying different models for prediction of mechanical properties (elastic moduli or compressive strength) in cement pastes and mortars. The simulations were based on published experimental data. The experimental data (both input and results used for validation) were open to the participants. The purpose of the benchmark campaign was to identify the needs of different models in terms of input experimental data, verify predictive potential of the models and finally to provide reference cases for new models in the future. The results of the benchmark show that a relatively high scatter in the predictions can arise between different models, in particular at early ages (e.g. elastic Young’s modulus predicted at 1 d in the range 6-20 GPa), while it reduces at later age, providing relatively good agreement with experimental data. Even though the input data was based on a single experimental dataset, the large differences between the results of the different models were found to be caused by distinct assumed properties for the individual phases at the microstructural level, mainly because of the scatter in the nanoindentation-derived properties of the C-S-H phase.</jats:p

HPK1 Associates with SKAP-HOM to Negatively Regulate Rap1-Mediated B-Lymphocyte Adhesion

BACKGROUND: Hematopoietic progenitor kinase 1 (HPK1) is a Ste20-related serine/threonine kinase activated by a range of environmental stimuli including genotoxic stress, growth factors, inflammatory cytokines and antigen receptor triggering. Being inducibly recruited to membrane-proximal signalling scaffolds to regulate NFAT, AP-1 and NFkappaB-mediated gene transcription in T-cells, the function of HPK1 in B-cells to date remains rather ill-defined. METHODOLOGY/PRINCIPAL FINDINGS: By using two loss of function models, we show that HPK1 displays a novel function in regulating B-cell integrin activity. Wehi 231 lymphoma cells lacking HPK1 after shRNA mediated knockdown exhibit increased basic activation levels of Ras-related protein 1 (Rap1), accompanied by a severe lymphocyte function-associated antigen-1 (LFA-1) dependent homotypic aggregation and increased adhesion to intercellular adhesion molecule 1 (ICAM-1). The observed phenotype of enhanced integrin activity is caused downstream of Src, by a signalling module independent of PI3K and PLC, involving HPK1, SKAP55 homologue (SKAP-HOM) and Rap1-GTP-interacting adaptor molecule (RIAM). This alters actin dynamics and renders focal adhesion kinase (FAK) constitutively phosphorylated. Bone marrow and splenic B-cell development of HPK1(-/-) mice are largely unaffected, except age-related tendencies for increased splenic cellularity and BCR downregulation. In addition, naïve splenic knockout B-cells appear hyperresponsive to a range of stimuli applied ex vivo as recently demonstrated by others for T-cells. CONCLUSIONS/SIGNIFICANCE: We therefore conclude that HPK1 exhibits a dual function in B-cells by negatively regulating integrin activity and controlling cellular activation, which makes it an interesting candidate to study in pathological settings like autoimmunity and cancer

Correction to: Thermodynamic Study of the Chlorine Content of Stainless Steel (Metallurgical and Materials Transactions B, (2021), 10.1007/s11663-021-0257-1)

THIS erratum is to correct the title of Appendix A. The title contains the chemical formula of a chlorine isotope, which is written as 36CL. This is incorrect and should be changed to 36Cl. It should appear as: APPENDIX A: POTENTIAL SOURCES, ANALYSES, AND ENVIRONMENTAL IMPACT OF 36Cl REPORTED IN THE LITERATURE The original article has been corrected

Thermodynamic study of the chlorine content of stainless steel

No thermodynamic data for the solution of Cl in ferrous alloys were found in the literature. This is in accord with recent Accelerator Mass Spectroscopy (AMS) analyses which showed that Cl contents in stainless steel (SS) are in the order of a few ppb. However, based on older chemical analyses of Cl in the order of 100 ppm, SS that has been irradiated with thermal neutrons in nuclear reactors is considered a major source of the long-lived 36Cl isotope in nuclear waste. In this study, the potential Cl contamination of SS originating from production and refinement processes is investigated. Unlike ferrous alloys, blast-furnace and steelmaking slags can dissolve significant amounts of Cl. The equilibrium distribution of Cl species between slags and gas phase was calculated for various steelmaking processes using the FactSage 7.2 software and databases. The results showed that despite the high volatility of metal chlorides at high temperatures, significant fractions of Cl can be retained in the slag phase even at 1600 °C. Chloride may also be incorporated in non-metallic inclusions originating from secondary refining. Based on these results and on several further assumptions, various scenarios for explaining, and also avoiding, Cl contamination of steel are discussed

Critical evaluation of thermodynamic data for selected arsenic minerals and aqueous species with applications to natural waters

A critical evaluation of selected arsenic minerals and aqueous species and a separate review of aqueous arsenic speciation were completed recently as part of a new volume on arsenic geochemistry, mineralogy, toxicity, and microbiology (Reviews in Mineralogy and Geochemistry #79). We developed a thermodynamic network based on the most reliable and fundamental data in the arsenic system, using the most direct pathways to build the network, and checking for internal consistency at each step. Arsenolite, As2O3-cubic, is the cornerstone or anchor of the network from which thermodynamic properties of the aqueous species of arsenate and arsenite and their hydrolysis products are derived. Thermodynamic data on aqueous arsenate ions are essential for the evaluation of metal arsenate minerals and their solubilities. Very few measurements of metal arsenate and metal arsenite complexes are reported from the literature but by using a consistent chemical model and the same equation of state, several metal arsenate and metal arsenite complexes have been estimated by Marini and Accornero (2007, Environ. Geol. 52, 1343). The solubilities and solubility-product constants of several metal arsenates have been reported but many are of variable quality and in need of better measurements and further evaluation. Scorodite solubility is well characterized, consistent with recent calorimetric data at ambient temperatures. The solubility of some calcium arsenates is well characterized and there is some agreement between investigations but inconsistencies still exist and some phases are poorly characterized or not measured at all. Application of estimated metal-arsenate and metal-arsenite stability constants to waters with a wide range of composition and temperature shows that arsenite speciation is affected very little (98-99% as free forms of hydrolyzed arsenite) but that arsenate speciation can be affected substantially (24-71% of the arsenate species in the free forms). Calcium and magnesium arsenate complexes contribute 0-24%, and sodium arsenate complexes contribute 1.5-75%. These complexes should be included in speciation calculations for any waters involving arsenate species, especially water compositions with moderate or higher concentrations of sodium

Thermodynamic optimization of the system magnesium–hydrogen

On the basis of our own calorimetric data and of known equilibria data the phase equilibria in the system Mg–H have been completely calculated by means of an optimization. Both for α-MgHx and MgH2 optimized free enthalpy functions are obtained