Color constancy from invariant wavelength ratios: An algorithm to simplify the chromatic adaptation model

In a recent article on color constancy, the chromatic adaptation model was of a novel type comprising three components separately calculated—hue, chromaticness, and lightness. The constant hue component was a simple calculation of predicted wavelength but the other two components were less direct. This article provides an algorithm to simplify the model's calculation. Calculation is far simpler and more intuitive than conventional models using complex 3 × 3 matrix transforms with their various and contentious adaptation primaries and potential disadvantages (e.g., in brightness and color gamut). The model is shown to be at least as accurate as six other (conventional) models and does not require high math skill. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 468–476, 2016     

Using a cloud-centric middleware to enable mobile hosting of Web services: mHealth use case

The unceasing growth and divergence of the mobile landscape have led to the use of smartphone and tablet devices in consuming Web services (WS) in enterprises. However, in heterogeneous WS, the shift from the mobile client consumer approach to the mobile service hosting approach is insufficiently studied. With the advancement of storage and processing capabilities of these devices, coupled with the high availability of the Web, this research focuses on the use of the mobile devices as hosts of WS in a mHealth domain. In this paper, a cloud-centric middleware technique is employed to enable access to the mobile hosts. The paper presents mobile hosting of medical data which are modeled as light-weight WS which is deployed in a real-world system. Further, a workflow authorization model is proposed to ensure privacy and the prevention of unauthorized modification of data on the mobile hosts. A data encryption technique is also put forward to enforce security and privacy of the mobile hosted data. Our current implemented project, called SOPHRA, supports mobile communication over HTTP in a Wi-Fi environment.     

An Empirical Testing of the Economic Base Theory

Most central cities must at present bargain with other units of their regions and the nation for the residents and industry they need; and their bargaining power is so weak as to threaten their viability unless aid from state and federal governments is supplied. Both in order to serve the disadvantaged residents they do attract, and to cultivate their attractiveness to other residents and to industry, cities must re-define “urban renewal” as consisting of large investments in the development of human, land, and transportation potentialities. Such investments must, as all investments, come from “surpluses” which are controlled by the states and the nation, not the cities.     

Effect of composition on the matrix transformation of the Co-Re-Cr-Ta-C alloys

Neutron diffraction measurement was performed in-situ at high temperatures on Co-Re-Ta-C alloys with and without Cr addition. This included alloys containing different C content with the C/Ta ratio varying between 0.5 and 1.0. The Co-Re-solid solution matrix of the experimental alloys is polymorphic (like in pure cobalt) and transformed from low temperature hexagonal ? phase to high temperature cubic γ phase on heating. This transformation is reversible and show hysteresis. The main alloying addition, Re, stabilizes the ? Co-phase and increases the transformation temperature to above 1273 K. The onset of the \(\varepsilon \rightleftharpoons \gamma\) transformation during heating and cooling was found to differ depending on the alloy composition. In alloys without Cr addition the transformation was not completed on cooling and the high temperature γ phase was partly retained at room temperature in metastable state with the amount depending on the cooling rate from high temperature. The diffraction and microstructural results showed that Cr is ? stabilizer (similar as Re) but the role of Ta is not clear. The C/Ta ratio has no direct effect on the matrix phase transformation. Nevertheless, it influences indirectly by determining the amount of Ta which is freely available in the matrix.     

Platelet-Released Growth Factors Influence Wound Healing-Associated Genes in Human Keratinocytes and Ex Vivo Skin Explants

Platelet-released growth factors (PRGFs) or other thrombocyte concentrate products, e.g., Platelet-Rich Fibrin (PRF), have become efficient tools of regenerative medicine in many medical disciplines. In the context of wound healing, it has been demonstrated that treatment of chronic or complicated wounds with PRGF or PRF improves wound healing in the majority of treated patients. Nevertheless, the underlying cellular and molecular mechanism are still poorly understood. Therefore, we aimed to analyze if PRGF-treatment of human keratinocytes caused the induction of genes encoding paracrine factors associated with successful wound healing. The investigated genes were Semaphorin 7A (SEMA7A), Angiopoietin-like 4 (ANGPLT4), Fibroblast Growth Factor-2 (FGF-2), Interleukin-32 (IL-32), the CC-chemokine-ligand 20 (CCL20), the matrix-metalloproteinase-2 (MMP-2), the chemokine C-X-C motif chemokine ligand 10 (CXCL10) and the subunit B of the Platelet-Derived Growth Factor (PDGFB). We observed a significant gene induction of SEMA7A, ANGPLT4, FGF-2, IL-32, MMP-2 and PDGFB in human keratinocytes after PRGF treatment. The CCL20- and CXCL10 gene expressions were significantly inhibited by PRGF therapy. Signal transduction analyses revealed that the PRGF-mediated gene induction of SEMA7A, ANGPLT4, IL-32 and MMP-2 in human keratinocytes was transduced via the IL-6 receptor pathway. In contrast, EGF receptor signaling was not involved in the PRGF-mediated gene expression of analyzed genes in human keratinocytes. Additionally, treatment of ex vivo skin explants with PRGF confirmed a significant gene induction of SEMA7A, ANGPLT4, MMP-2 and PDGFB. Taken together, these results describe a new mechanism that could be responsible for the beneficial wound healing properties of PRGF or related thrombocytes concentrate products such as PRF.     

Molecular Weight Patterns of Nägeli Amylodextrins

This research was designed to assess the utility of a four-column high performance size-exclusion chromatography (HPSEC) system to characterize starch-based carbohydrates of different sizes. Corn starches with varying amounts of amylose were treated with 16% sulfuric acid to create Nägeli amylodextrins. During treatment, sub-samples were taken at various intervals from 0–100 days. The washed, dried sub-samples were chromatographically analyzed using four Shodex lonpak columns linked in series. Chromatograms showed the progressive depolymerization of starch. Pullulan molecular weight standards were used to estimate amylodextrin molecular weights (MW). Number-average MWs of amylodextrins decreased as the original starches' amylopectin content decreased. A single HPSEC system can be effectively used to characterize carbohydrates ranging in size from starch to amylodextrins; and to monitor the acid (or enzyme) depolymerization of starches.     

Genetic Deficiency and Pharmacological Stabilization of Mast Cells Ameliorate Pressure Overload-Induced Maladaptive Right Ventricular Remodeling in Mice

Although the response of the right ventricle (RV) to the increased afterload is an important determinant of the patient outcome, very little is known about the underlying mechanisms. Mast cells have been implicated in the pathogenesis of left ventricular maladaptive remodeling and failure. However, the role of mast cells in RV remodeling remains unexplored. We subjected mast cell-deficient WBB6F1-KitW/W-v (Kit^W/Kit^W-v) mice and their mast cell-sufficient littermate controls (MC^+/+) to pulmonary artery banding (PAB). PAB led to RV dilatation, extensive myocardial fibrosis, and RV dysfunction in MC^+/+ mice. In PAB Kit^W/Kit^W-v mice, RV remodeling was characterized by minimal RV chamber dilatation and preserved RV function. We further administered to C57Bl/6J mice either placebo or cromolyn treatment starting from day 1 or 7 days after PAB surgery to test whether mast cells stabilizing drugs can prevent or reverse maladaptive RV remodeling. Both preventive and therapeutic cromolyn applications significantly attenuated RV dilatation and improved RV function. Our study establishes a previously undescribed role of mast cells in pressure overload-induced adverse RV remodeling. Mast cells may thus represent an interesting target for the development of a new therapeutic approach directed specifically at the heart.     

Thermophysical Properties of ZrB2 and ZrB2–SiC Ceramics

Thermophysical properties were investigated for zirconium diboride (ZrB₂) and ZrB₂–30 vol% silicon carbide (SiC) ceramics. Thermal conductivities were calculated from measured thermal diffusivities, heat capacities, and densities. The thermal conductivity of ZrB₂ increased from 56 W (m K)⁻¹ at room temperature to 67 W (m K)⁻¹ at 1675 K, whereas the thermal conductivity of ZrB₂–SiC decreased from 62 to 56 W (m K)⁻¹ over the same temperature range. Electron and phonon contributions to thermal conductivity were determined using electrical resistivity measurements and were used, along with grain size models, to explain the observed trends. The results are compared with previously reported thermal conductivities for ZrB₂ and ZrB₂–SiC.