Aspects of parameter identification in semilinear reaction-diffusion systems

This thesis provides an approach for parameter identification in general semilinear parabolic partial differential equations. The problem of of parameter identification in these equations is investigated from two different angles. On one hand, Tikhonov regularization is proposed to deal with possible non continuous dependence of the parameters on the data and on the other hand the uniqueness of a solution of the parameter identification problem is discussed. Additionally, numerical results are shown that support the theoretical findings

Cost of capital of energy efficiency projects: The case of space heating and cooling

In this paper, we develop and test the hypothesis of zero betas for energy efficiency projects related to space heating and cooling. We focus only on projects using electricity or natural gas and reason that none of their key risk factors has correlations significantly different from zero with the market portfolio or one another, whether the investor is a household or business entity. Supporting evidence from a number of European countries is presented. Our findings suggest that, in the Capital Asset Pricing Model (CAPM) framework, the cost of capital is the risk-free rate. It is argued that this discount rate needs no adjustment for country risk and is likely to be valid for other countries as well as other types of energy efficiency projects using natural gas or electricity

Present value under uncertain asset life: an evaluation of relative error

We evaluate the relative errors attributable to using the expected economic life of an asset to calculate present value instead of the correct approach of calculating the expected present value when the cessation point of the asset is uncertain. We compare the continuous-time case of exponential cash flows and exponentially distributed asset life with its discrete-time analogue of geometric cash flows and geometrically distributed asset life. We find that if the discount rate and growth rate are equal, the error is always zero. If the growth rate exceeds the discount rate, the error can easily be severe and reach 100%. If the discount rate exceeds the growth rate, the error cannot exceed 30%, but such large errors may occur for any expected asset life. In the discrete case, this error limit depends on expected asset life and is somewhat lower for shorter lives. For realistic cases, even a small percentage point difference between the discount rate and the growth rate can lead to considerable errors

Ultrafast all-optical demultiplexer based on monolithic Mach-Zehnder interferometer with integrated semiconductor optical amplifiers

A monolithically integrated and fully packaged Mach-Zehnder interferometer with semiconductor optical amplifiers (MZI-SOA) is demonstrated as polarisation-independent high-speed demultiplexer for up to 160 Gbit/s optical time division multiplexed (OTDM) data stream

A monoclinic polymorph of N-eth­oxy­carbonyl-N′-(3-phenyl-1H-1,2,4-triazol-5-yl)thio­urea

The title compound, C12H13N5O2S {systematic name: ethyl N-[N-(3-phenyl-1H-1,2,4-triazol-5-yl)carbamothio­yl]carbamate}, is a monoclinic polymorph (space group P21/c) which crystallizes with three similar independent mol­ecules in the asymmetric unit. The triazole ring makes dihedral angles of 6.6 (2), 8.4 (2) and 10.6 (2)° with the phenyl ring in the three independent molecules. The structure was previously reported [Dolzhenko et al. (2010a ▶). Acta Cryst., E46, o425] as a triclinic polymorph crystallizing in space group P . Mol­ecules in both polymorphs possess two S(6) rings generated by intra­molecular N—H⋯S and N—H⋯O hydrogen bonds, resulting in similar mol­ecular geometries. However, the two polymorphs differ in the crystal packing. In contrast to the dimers of the triclinic polymorph, mol­ecules of the monoclinic polymorph are connected by inter­molecular N—H⋯S and N—H⋯N hydrogen bonds, forming pseudosymmetric trimers arranged in sheets parallel to (302)

Significance of the Tks4 scaffold protein in bone tissue homeostasis

Abstract The main driver of osteoporosis is an imbalance between bone resorption and formation. The pathogenesis of osteoporosis has also been connected to genetic alterations in key osteogenic factors and dysfunction of bone marrow mesenchymal stem/stromal cells (BM-MSCs). Tks4 (encoded by the Sh3pxd2b gene) is a scaffold protein involved in podosome organization. Homozygous mutational inactivation of Sh3pxd2b causes Frank-ter Haar syndrome (FTHS), a genetic disease that affects bone tissue as well as eye, ear, and heart functions. To date, the role of Tks4 in adult bone homeostasis has not been investigated. Therefore, the aim of this study was to analyze the facial and femoral bone phenotypes of Sh3pxd2b knock-out (KO) mice using micro-CT methods. In addition to the analysis of the Sh3pxd2b-KO mice, the bone microstructure of an FTHS patient was also examined. Macro-examination of skulls from Tks4-deficient mice revealed craniofacial malformations that were very similar to symptoms of the FTHS patient. The femurs of the Sh3pxd2b-KO mice had alterations in the trabecular system and showed signs of osteoporosis, and, similarly, the FTHS patient also showed increased trabecular separation/porosity. The expression levels of the Runx2 and osteocalcin bone formation markers were reduced in the bone and bone marrow of the Sh3pxd2b-KO femurs, respectively. Our recent study demonstrated that Sh3pxd2b-KO BM-MSCs have a reduced ability to differentiate into osteoblast lineage cells; therefore, we concluded that the Tks4 scaffold protein is important for osteoblast formation, and that it likely plays a role in bone cell homeostasis