Npp1 promotes atherosclerosis in ApoE knockout mice.

Ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1) generates inorganic pyrophosphate (PP(i)), a physiologic inhibitor of hydroxyapatite deposition. In a previous study, we found NPP1 expression to be inversely correlated with the degree of atherosclerotic plaque calcification. Moreover, function-impairing mutations of ENPP1, the gene encoding for NPP1, are associated with severe, artery tunica media calcification and myointimal hyperplasia with infantile onset in human beings. NPP1 and PP(i) have the potential to modulate atherogenesis by regulating arterial smooth muscle cell (SMC) differentiation and function, including increase of pro-atherogenic osteopontin (OPN) expression. Hence, this study tested the hypothesis that NPP1 deficiency modulates both atherogenesis and atherosclerotic intimal plaque calcification. Npp1/ApoE double deficient mice were generated by crossing mice bearing the ttw allele of Enpp1 (that encodes a truncation mutation) with ApoE null mice and fed with high-fat/high-cholesterol atherogenic diet. Atherosclerotic lesion area and calcification were examined at 13, 18, 23 and 28 weeks of age. The aortic SMCs isolated from both ttw/ttw ApoE(-/-) and ttw/+ ApoE(-/-) mice demonstrated decreased Opn expression. The 28-week-old ttw/ttw ApoE(-/-) and ttw/+ ApoE(-/-) had significantly smaller atherosclerotic lesions compared with wild-type congenic ApoE(-/-) mice. Only ttw/ttw but not ttw/+ mice developed artery media calcification. Furthermore in ttw/+ mice, there was a tendency towards increased plaque calcification compared to ApoE(-/-) mice without Npp1 deficiency. We conclude that Npp1 promotes atherosclerosis, potentially mediated by Opn expression in ApoE knockout mice

Density dependent diffusion models for the interaction of particle ensembles with boundaries

The transition from a microscopic model for the movement of many particles to a macroscopic continuum model for a density flow is studied. The microscopic model for the free flow is completely deterministic, described by an interaction potential that leads to a coherent motion where all particles move in the same direction with the same speed known as a flock. Interaction of the flock with boundaries, obstacles and other flocks leads to a temporary destruction of the coherent motion that macroscopically can be modeled through density dependent diffusion. The resulting macroscopic model is an advection-diffusion equation for the particle density whose diffusion coefficient is density dependent. Examples describing i) the interaction of material flow on a conveyor belt with an obstacle that redirects or restricts the material flow and ii) the interaction of flocks (of fish or birds) with boundaries and iii) the scattering of two flocks as they bounce off each other are discussed. In each case, the advection-diffusion equation is strictly hyperbolic before and after the interaction while the interaction phase is described by a parabolic equation. A numerical algorithm to solve the advection-diffusion equation through the transition is presented.Comment: 25 pages, 9 figure

Marktstrategien der Kurienbanken

With their branch networks and partners, the Florentine banks dominated international monetary transactions of the 15th century. Thanks to their presence in the main commercial centres of the continent, the merchant bankers from Tuscany dominated the cashless processing of large transfers of money from all over Europe to the Roman Curia. Kurt Weissen examines how curia bankers, such as the Alberti and the Medici, connected Germany to this payment system via Bruges and Venice. He analyses the role played by the establishment of branches in Lübeck, Cologne, Basel and Constance and the importance of cooperation with German merchant companies

Marktstrategien der Kurienbanken

With their branch networks and partners, the Florentine banks dominated international monetary transactions of the 15th century. Thanks to their presence in the main commercial centres of the continent, the merchant bankers from Tuscany dominated the cashless processing of large transfers of money from all over Europe to the Roman Curia. Kurt Weissen examines how curia bankers, such as the Alberti and the Medici, connected Germany to this payment system via Bruges and Venice. He analyses the role played by the establishment of branches in Lübeck, Cologne, Basel and Constance and the importance of cooperation with German merchant companies.Die florentinischen Banken beherrschten mit ihren Filialnetzen und Partnern die internationalen Geldgeschäfte des 15. Jahrhunderts. Dank ihrer Präsenz an den wichtigen Handelszentren des Kontinents dominierten die Händler-Bankiers aus der Toskana die bargeldlose Abwicklung der großen Geldtransfers aus ganz Europa an die römische Kurie. Kurt Weissen untersucht, wie Kurienbankiers wie die Alberti und die Medici Deutschland von Brügge und Venedig aus an dieses Zahlungssystem anschlossen. Er zeigt auf, welche Rolle dabei die Gründung eigener Niederlassungen in Lübeck, Köln, Basel und Konstanz spielten und welche Bedeutung Kooperationen mit deutschen Handelsgesellschaften zukam

A combined first and second order model for a junction with ramp buffer

Second order macroscopic traffic flow models are able to reproduce the so-called capacity drop effect, i.e., the phenomenon that the outflow of a congested region is substantially lower than the maximum achievable flow. Within this work, we propose a first order model for a junction with ramp buffer that is solely modified at the intersection so that the capacity drop is captured. Theoretical investigations motivate the new choice of coupling conditions and illustrate the difference to purely first and second order models. The numerical example considering the optimal control of the onramp merging into a main road highlights that the combined model generates similar results as the second order model

Aortic dissection associated with cogans's syndrome: deleterious loss of vascular structural integrity is associated with GM-CSF overstimulation in macrophages and smooth muscle cells

<p>Abstract</p> <p>Background</p> <p>Cogan's syndrome is a rare disorder of unknown origin characterized by inflammatory ocular disease and vestibuloauditory symptoms. Systemic vasculitis is found in about 10% of cases.</p> <p>Case presentation</p> <p>A 46-year-old female with Cogans's syndrome and a history of arterial hypertension presented with severe chest pain caused by an aneurysm of the ascending aorta with a dissection membrane located a few centimeters distal from the aortic root. After surgery, histopathological analysis revealed that vascular matrix integrity and expression of the major matrix molecules was characterized by elastolysis and collagenolysis and thus a dramatic loss of structural integrity. Remarkably, exceeding matrix deterioration was associated with massively increased levels of granulocyte macrophage colony stimulating factor (GM-CSF).</p> <p>Conclusion</p> <p>Our data suggest that the persistently increased secretion of the inflammatory mediator GM-CSF by resident inflammatory cells but also by SMC may be the trigger of aortic wall structural deterioration.</p

Durability of La0.20Sr0.25Ca0.45TiO3-based SOFC anodes : identifying sources of degradation in Ni and Pt/ceria co-impregnated fuel electrode microstructures

Funding from the University of St Andrews and HEXIS AG is acknowledged, in addition to the EPSRC Grants: EP/M014304/1 “Tailoring of Microstructural Evolution in Impregnated SOFC Electrodes” and EP/L017008/1 “Capital for Great Technologies”.Solid oxide fuel cells (SOFC) comprising LSM-YSZ/LSM composite cathodes, 6ScSZ electrolytes and La0.20Sr0.25Ca0.45TiO3 (LSCTA−) anode ‘backbone’ microstructures were prepared using thick-film ceramic processing techniques. Activation and decoration of the LSCTA− anode ‘backbone’ with electrocatalytic coatings of cerium-based oxides and metallic Ni or Pt particles was achieved using the technique of catalyst co-impregnation. SOFC containing Ni/CGO, Ni/CeO2 and Pt/CGO impregnated LSCTA anodes were tested up to ∼1000 hours by the Swiss SOFC manufacturer: HEXIS, under realistic operating conditions, including 15 redox, thermo and thermoredox cycles. The voltage degradation rates observed over the entire test period for the SOFC containing the Ni/CGO, Ni/CeO2 and Pt/CGO impregnated LSCTA− anodes were 14.9%, 7.7% and 13.4%, respectively. Post-mortem microscopic analyses indicated that CeO2 formed ubiquitous coatings upon the LSCTA− anode microstructure, allowing retention of a high population density of metallic (Ni) particles, whilst CGO formed ‘islands’ upon the microstructure and some agglomerates within the pores, leading to more facile agglomeration of metallic (Ni and Pt) nanoparticles. Correlation of the post-mortem microscopy with AC impedance analysis revealed that the agglomeration of metallic catalyst resulted in an increase in the high-frequency anode polarisation resistance, whilst agglomeration of the ceria-based component directly resulted in the development of a low-frequency process that may be attributed to combined contributions from gas conversion and chemical capacitance.PostprintPostprintPeer reviewe

Development and full system testing of novel co-impregnated La0.20Sr0.25Ca0.45TiO3 anodes for commercial combined heat and power units

Funding: Engineering and Physical Sciences Research Council. Grant Numbers: EP/J016454/1, EP/P024807/1; HEXIS AG.Over the past decade, the University of St Andrews and HEXIS AG have engaged in a highly successful collaborative project aiming to develop and upscale La0.20Sr0.25Ca0.45TiO3 (LSCTA-) anode “backbone” microstructures, impregnated with Ce0.80Gd0.20O1.90 (CG20) and metallic electrocatalysts, providing direct benefits in terms of performance and stability over the current state-of-the-art (SoA) Ni-based cermet solid oxide fuel cell (SOFC) anodes. Here, we present a brief overview of previous work performed in this research project, including short-term, durability, and poison testing of small-scale (1 cm2 area) SOFCs and upscaling to full-sized HEXIS SOFCs (100 cm2 area) in short stacks. Subsequently, recent results from short stack testing of SOFCs containing LSCTA- anodes with a variety of metallic catalyst components (Fe, Mn, Ni, Pd, Pt, Rh, or Ru) will be presented, indicating that only SOFCs containing the Rh catalyst provide comparable degradation rates to the SoA Ni/cerium gadolinium oxide anode, as well as tolerance to harsh overload conditions (which is not exhibited by SoA anodes). Finally, results from full system testing (60 cells within a 1.5 kW electrical power output HEXIS Leonardo FC40A micro-combined heat and power unit), will be outlined, demonstrating the robust and durable nature of these novel oxide electrodes, in addition to their potential for commercialization.Publisher PDFPeer reviewe

Phenols in Leaves and Bark of Fagus sylvatica as Determinants of Insect Occurrences

Beech forests play an important role in temperate and north Mediterranean ecosystems in Greece since they occupy infertile montane soils. In the last glacial maximum, Fagus sylvatica (beech) was confined to Southern Europe where it was dominant and in the last thousand years has expanded its range to dominate central Europe. We sampled four different beech forest types. We found 298 insect species associated with beech trees and dead beech wood. While F. sylvatica and Quercus (oak) are confamilial, there are great differences in richness of the associated entomofauna. Insect species that inhabit beech forests are less than one fifth of those species living in oak dominated forests despite the fact that beech is the most abundant central and north European tree. There is a distinct paucity of monophagous species on beech trees and most insect species are shared between co-occurring deciduous tree species and beech. This lack of species is attributed to the vegetation history and secondary plant chemistry. Bark and leaf biophenols from beech indicate that differences in plant secondary metabolites may be responsible for the differences in the richness of entomofauna in communities dominated by beech and other deciduous trees