554 research outputs found

    Analysis of free proteinogenic intracellular amino acids of Neurospora by ion exchange chromatography

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    Analysis of free proteinogenic intracellular amino acids of Neurospora by ion exchange chromatograph

    Cyanocobalamin in mycelium of Neurospora sitophila

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    Cyonocobolamine in N. sitophil

    An improved cosmic crystallography method to detect holonomies in flat spaces

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    A new, improved version of a cosmic crystallography method for constraining cosmic topology is introduced. Like the circles-in-the-sky method using CMB data, we work in a thin, shell-like region containing plenty of objects. Two pairs of objects (quadruplet) linked by a holonomy show a specific distribution pattern, and three filters of \emph{separation, vectorial condition}, and \emph{lifetime of objects} extract these quadruplets. Each object PiP_i is assigned an integer sis_i, which is the number of candidate quadruplets including PiP_i as their members. Then an additional device of sis_i-histogram is used to extract topological ghosts, which tend to have high values of sis_i. In this paper we consider flat spaces with Euclidean geometry, and the filters are designed to constrain their holonomies. As the second filter, we prepared five types that are specialized for constraining specific holonomies: one for translation, one for half-turn corkscrew motion and glide reflection, and three for nn-th turn corkscrew motion for n=4,3,n=4, 3, and 6. {Every multiconnected space has holonomies that are detected by at least one of these five filters.} Our method is applied to the catalogs of toy quasars in flat Λ\Lambda-CDM universes whose typical sizes correspond to z5z\sim 5. With these simulations our method is found to work quite well. {These are the situations in which type-II pair crystallography methods are insensitive because of the tiny number of ghosts. Moreover, in the flat cases, our method should be more sensitive than the type-I pair (or, in general, nn-tuplet) methods because of its multifilter construction and its independence from nn.}Comment: 12 pages, 8 figures, accepted for publication in A&A (2011

    Cosmic microwave anisotropies in an inhomogeneous compact flat universe

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    The anisotropies of the cosmic microwave background (CMB) are computed for the half-turn space E_2 which represents a compact flat model of the Universe, i.e. one with finite volume. This model is inhomogeneous in the sense that the statistical properties of the CMB depend on the position of the observer within the fundamental cell. It is shown that the half-turn space describes the observed CMB anisotropies on large scales better than the concordance model with infinite volume. For most observer positions it matches the temperature correlation function even slightly better than the well studied 3-torus topology

    Effect of pyridoxal deficiency on biotin content of N. sitophila

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    Effect of pyridoxal deficiency on biotin content of N. sitophil

    Effect of biotin on lipid content of Neurospora crassa

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    Effect of biotin on lipid conten

    Numerical computation of Maass waveforms and an application to cosmology

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    We compute numerically eigenvalues and eigenfunctions of the Laplacian in a three-dimensional hyperbolic space. Applying the results to cosmology, we demonstrate that the methods learned in quantum chaos can be used in other fields of research.Comment: A version of the paper with high resolution figures is available at http://www.physik.uni-ulm.de/theo/qc/publications.htm

    Permalloy-based carbon nanotube spin-valve

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    In this Letter we demonstrate that Permalloy (Py), a widely used Ni/Fe alloy, forms contacts to carbon nanotubes (CNTs) that meet the requirements for the injection and detection of spin-polarized currents in carbon-based spintronic devices. We establish the material quality and magnetization properties of Py strips in the shape of suitable electrical contacts and find a sharp magnetization switching tunable by geometry in the anisotropic magnetoresistance (AMR) of a single strip at cryogenic temperatures. In addition, we show that Py contacts couple strongly to CNTs, comparable to Pd contacts, thereby forming CNT quantum dots at low temperatures. These results form the basis for a Py-based CNT spin-valve exhibiting very sharp resistance switchings in the tunneling magnetoresistance, which directly correspond to the magnetization reversals in the individual contacts observed in AMR experiments.Comment: 3 page

    Hot pixel contamination in the CMB correlation function?

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    Recently, it was suggested that the map-making procedure, which is applied to the time-ordered CMB data by the WMAP team, might be flawed by hot pixels. This could lead to a bias in the pixels having an angular distance of about 141 degrees from hot pixels due to the differential measuring process of the satellite WMAP. Here, the bias is confirmed, and the temperature two-point correlation function C(theta) is reevaluated by excluding the affected pixels. It is shown that the most significant effect occurs in C(theta) at the largest angles near theta = 180 degrees. Furthermore, the corrected correlation function C(theta) is applied to the cubic topology of the Universe, and it is found that such a multi-connected universe matches the temperature correlation better than the LCDM concordance model, provided the cubic length scale is close to L=4 measured in units of the Hubble length

    On the possibility for constraining cosmic topology from the celestial distribution of astronomical objects

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    We present a method to constrain cosmic topology from the distribution of astronomical objects projected on the celestial sphere. This is an extension of the 3D method introduced in Fujii & Yoshii (2011) that is to search for a pair of pairs of observed objects (quadruplet) linked by a holonomy, i.e., the method we present here is to search for a pair of celestial sphere nn-tuplets for n3n \geq 3. We find, however, that this method is impractical to apply in realistic situations due to the small signal to noise ratio. We conclude therefore that it is unrealistic to constrain the topology of the Universe from the celestial distribution, and the 3D catalogs are necessary for the purpose.Comment: 4 pages, 1 figure, accepted for publication in A&A (2011
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