Central extensions of groups of sections

If q : P -> M is a principal K-bundle over the compact manifold M, then any invariant symmetric V-valued bilinear form on the Lie algebra k of K defines a Lie algebra extension of the gauge algebra by a space of bundle-valued 1-forms modulo exact forms. In the present paper we analyze the integrability of this extension to a Lie group extension for non-connected, possibly infinite-dimensional Lie groups K. If K has finitely many connected components we give a complete characterization of the integrable extensions. Our results on gauge groups are obtained by specialization of more general results on extensions of Lie groups of smooth sections of Lie group bundles. In this more general context we provide sufficient conditions for integrability in terms of data related only to the group K.Comment: 54 pages, revised version, to appear in Ann. Glob. Anal. Geo

Dengue-2 Structural Proteins Associate with Human Proteins to Produce a Coagulation and Innate Immune Response Biased Interactome

<p>Abstract</p> <p>Background</p> <p>Dengue virus infection is a public health threat to hundreds of millions of individuals in the tropical regions of the globe. Although Dengue infection usually manifests itself in its mildest, though often debilitating clinical form, dengue fever, life-threatening complications commonly arise in the form of hemorrhagic shock and encephalitis. The etiological basis for the virus-induced pathology in general, and the different clinical manifestations in particular, are not well understood. We reasoned that a detailed knowledge of the global biological processes affected by virus entry into a cell might help shed new light on this long-standing problem.</p> <p>Methods</p> <p>A bacterial two-hybrid screen using DENV2 structural proteins as bait was performed, and the results were used to feed a manually curated, global dengue-human protein interaction network. Gene ontology and pathway enrichment, along with network topology and microarray meta-analysis, were used to generate hypothesis regarding dengue disease biology.</p> <p>Results</p> <p>Combining bioinformatic tools with two-hybrid technology, we screened human cDNA libraries to catalogue proteins physically interacting with the DENV2 virus structural proteins, Env, cap and PrM. We identified 31 interacting human proteins representing distinct biological processes that are closely related to the major clinical diagnostic feature of dengue infection: haemostatic imbalance. In addition, we found dengue-binding human proteins involved with additional key aspects, previously described as fundamental for virus entry into cells and the innate immune response to infection. Construction of a DENV2-human global protein interaction network revealed interesting biological properties suggested by simple network topology analysis.</p> <p>Conclusions</p> <p>Our experimental strategy revealed that dengue structural proteins interact with human protein targets involved in the maintenance of blood coagulation and innate anti-viral response processes, and predicts that the interaction of dengue proteins with a proposed human protein interaction network produces a modified biological outcome that may be behind the hallmark pathologies of dengue infection.</p

Nominal Stability and Swiss Monetary Regimes Over Two Centuries

This paper documents nominal stability in Switzerland from 1805 to 2013 using a data set on annual price, wage and nominal GDP changes. The trends of these indicators are estimated by an unobserved-components stochastic-volatility model in order to control for short-term fluctuations and measurement error. Based on a narrative analysis of these trends five main findings emerge. (i) Fiat currency regimes in Switzerland provided a relatively stable monetary background even compared to the metal-currency regimes before WW1. (ii) The flexible inflation targeting regime adopted in December 1999 has performed best over the last two centuries measured by today's definition of nominal stability. (iii) Fiat currency regimes without clearly communicated nominal price anchor (Bretton Woods System and monetary targeting) were characterised by an inflation bias. (iv) The metal-currency regimes (competing currencies and bimetallism before World War 1, and to some extent flexible inflation targeting, were associated with a deflation bias. (v) Persistent deflations in terms of the CPI only occurred under metallic regimes before WW2. These episodes were accompanied by falling nominal GDP, falling employment but relatively stable hourly wages

PHOTOVOLTAIC INFRARED SENSOR ARRAY IN HETEROEPITAXIAL NARROW GAP LEAD-CHALCOGENIDES ON SILICON

Linear arrays of photovoltaic IR-sensors for thermal imaging applications have been fabricated for the first time in narrow gap semiconductor layers grown heteroepitaxially on Si-substrates. Heteroepitaxy was achieved using intermediate stacked CaF2-BaF2 bilayers to overcome the large lattice- and thermal expansion mismatch between Si and lead-chalcogenides. Sensors fabricated in narrow gap PbTe have ≈ 5.7 µm cut-off wavelength at 90K and quantum efficiencies around 70%. Resistance-area products are up to 500 Ωcm2 with mean value of ≈ 150 Ωcm2 for 66 element linear arrays, well above the room temperature photon background noise limit. Sensor arrays with shorter cut-off wavelength were fabricated in the same manner in epitaxial Pb1-xEuxSe on fluoride covered Si-substrates

PHOTOVOLTAIC INFRARED SENSOR ARRAY IN HETEROEPITAXIAL NARROW GAP LEAD-CHALCOGENIDES ON SILICON

Linear arrays of photovoltaic IR-sensors for thermal imaging applications have been fabricated for the first time in narrow gap semiconductor layers grown heteroepitaxially on Si-substrates. Heteroepitaxy was achieved using intermediate stacked CaF2-BaF2 bilayers to overcome the large lattice- and thermal expansion mismatch between Si and lead-chalcogenides. Sensors fabricated in narrow gap PbTe have ≈ 5.7 µm cut-off wavelength at 90K and quantum efficiencies around 70%. Resistance-area products are up to 500 Ωcm2 with mean value of ≈ 150 Ωcm2 for 66 element linear arrays, well above the room temperature photon background noise limit. Sensor arrays with shorter cut-off wavelength were fabricated in the same manner in epitaxial Pb1-xEuxSe on fluoride covered Si-substrates