Compressive Nonparametric Graphical Model Selection For Time Series

We propose a method for inferring the conditional indepen- dence graph (CIG) of a high-dimensional discrete-time Gaus- sian vector random process from finite-length observations. Our approach does not rely on a parametric model (such as, e.g., an autoregressive model) for the vector random process; rather, it only assumes certain spectral smoothness proper- ties. The proposed inference scheme is compressive in that it works for sample sizes that are (much) smaller than the number of scalar process components. We provide analytical conditions for our method to correctly identify the CIG with high probability.Comment: to appear in Proc. IEEE ICASSP 201

Mitochondrial protein import

Transport of nuclear-encoded precursor proteins into mitochondria includes proteolytic cleavage of aminoterminal targeting sequences in the mitochondrial matrix. We have isolated the processing activity from Neurospora crassa. The final preparation (enriched ca. 10,000-fold over cell extracts) consists of two proteins, the matrix processing peptidase (MPP, 57 kd) and a processing enhancing protein (PEP, 52 kd). The two components were isolated as monomers. PEP is about 15-fold more abundant in mitochondria than MPP. It is partly associated with the inner membrane, while MPP is soluble in the matrix. MPP alone has a low processing activity whereas PEP alone has no apparent activity. Upon recombining both, full processing activity is restored. Our data indicate that MPP contains the catalytic site and that PEP has an enhancing function. The mitochondrial processing enzyme appears to represent a new type of “signal peptidase,” different from the bacterial leader peptidase and the signal peptidase of the endoplasmic reticulum

Non-destructive testing of ceramically bonded refractories - Application of ultrasound and microwaves

Quality control on refractory bricks is either mostly destructive or methods are used which require samples with a certain geometry. In a joint project between the University of Erlangen and industry the applicability of non-destructive testing methods for sintered refractory bricks was tested. Various materials with artificial flaws were measured in transmission with ultrasound (500 kc/s) as well as with microwaves (24 to 40 Gc/s) and the results were compared. Despite of good results, the testing with ultrasound proved to be unsuitable for the measurements of greater lots, because the open-pore blocks have to be coupled in water. An excellent alternative is the transmission measurement with microwaves. With both methods structural inhomogeneities as well as density differences or inclusions can be detected

Untersuchungen über die Aciditäts-Basizitätsverhältnisse in oxydischen Schmelzen I. Infrarotspektroskopische Untersuchungen über die Löslichkeit von Wasserdampf in B2O3-Schmelzen

Die Untersuchungen über die Löslichkeit von Wasserdampf in Glasschmelzen mit unterschiedlichen Basizitäten wurden auf B2O3-Schmelzen ausgedehnt. Experimentell wurde die Abhängigkeit der Löslichkeit vom Wasserdampfpartialdruck und von der Temperatur im Bereich von 700 bis 1200 °C bestimmt. Die Wassergehalte wurden infrarotspektroskopisch ermittelt. Die Präparation der Meßproben unter Verwendung einer neuentwickelten Heizpresse wird beschrieben. Im Bereich der OH-Valenzschwingungen tritt nur eine Bande bei 2,80 μm auf, deren molarer dekadischer Extinktionskoeffizient zu ε = 141 l · Mol^-1 · cm^-1 bestimmt wurde. Die Löslichkeit von Wasserdampf ist proportional der Wurzel des Partialdruckes, bei pH20 = 760 Torr und 1000 °C sind im Gleichgewicht 2 Mol-% H2O gelöst. Mit steigender Temperatur nimmt die Löslichkeit ab, die Lösungswärme beträgt -6,3 kcal/Mol H2O. Die Ergebnisse werden im Zusammenhang mit früheren Messungen und Literaturangaben über die Löslichkeit von Wasserdampf in Kieselglas und Alkalisilicatgläsern kurz diskutiert

Cyclosporin A-binding protein (cyclophilin) of Neurospora crassa

Cyclophilin (cyclosporin A-binding protein) has a dual localization in the mitochondria and in the cytosol of Neurospora crassa. The two forms are encoded by a single gene which is transcribed into mRNAs having different lengths and 5' termini (approximately 1 and 0.8 kilobases). The shorter mRNA specifies the cytosolic protein consisting of 179 amino acids. The longer mRNA is translated into a precursor polypeptide with an amino-terminal extension of 44 amino acids which is cleaved in two steps upon entry into the mitochondrial matrix. Neurospora cyclophilin shows about 60% sequence homology to human and bovine cyclophilins

On the nature of amorphous polymorphism of water

We report elastic and inelastic neutron scattering experiments on different amorphous ice modifications. It is shown that an amorphous structure (HDA') indiscernible from the high-density phase (HDA), obtained by compression of crystalline ice, can be formed from the very high-density phase (vHDA) as an intermediate stage of the transition of vHDA into its low-density modification (LDA'). Both, HDA and HDA' exhibit comparable small angle scattering signals characterizing them as structures heterogeneous on a length scale of a few nano-meters. The homogeneous structures are the initial and final transition stages vHDA and LDA', respectively. Despite, their apparent structural identity on a local scale HDA and HDA' differ in their transition kinetics explored by in situ experiments. The activation energy of the vHDA-to-LDA' transition is at least 20 kJ/mol higher than the activation energy of the HDA-to-LDA transition

Erkenntnisse über die Struktur von Alkalisilicatgläsern und -schmelzen aus dem Einbau der OH-Gruppen

Aus der Elektronentheorie ergeben sich Gesetzmäßigkeiten für die Alkaliverteilung in binären Alkalisilicatgläsern und für die Reaktion von Wasserdampf mit der Silicatschmelze. Das gelöste Wasser wird als OH-Gruppen eingebaut, deren Bindungszustand ein sehr empfindlicher Indikator für die Struktur der näheren Umgebung ist. An Hand der Infrarotspektren wasserhaltiger Gläser werden strukturelle Einzelheiten, wie Alkalischwarmbildung und Besetzungszustände der einzelnen [SiO4]-Tetraeder durch Alkaliionen, diskutiert