Advanced Conducting Project

Contents include: Part I. The Renaissance Era Weep O Mine Eyes by John Bennet Sicut Cervus by Giovanni Pierluigi da PalestrinaPart II. The Baroque Era Cum Sancto Spiritu (from Gloria ) by Antonio VivaldiPart III. The Classical Era Lacrymosa (from Requiem ) by Wolfgang Amadeus Mozart Lebenslust by Franz SchubertPart IV. The Romantic Era Bogoroditse Devo (from All Night Vespers ) by Sergei Rachmaninoff Trois Chansons by Maurice RavelPart V. The Contemporary Era Daemon Irrepit Callidus by György Orbán Dirait-on (from Les Chansons des Roses ) by Morten Lauridsen Five Hebrew Love Songs by Eric Whitacre Even When He Is Silent by Kim Andre Arnesen

Episode of unusual high solar ultraviolet radiation over central Europe due to dynamical reduced total ozone in May 2005

In late May 2005 unusual high levels of solar ultraviolet radiation were observed over central Europe. In Northern Germany the measured irradiance of erythemally effective radiation exceeded the climatological mean by more than about 20%. An extreme low ozone event for the season coincided with high solar elevation angles and high pressure induced clear sky conditions leading to the highest value of erythemal UV-radiation ever observed over this location in May since 1994. This hereafter called "ozone mini-hole" was caused by an elevation of tropopause height accompanied with a poleward advection of ozone-poor air from the tropics. The resultant increase in UV-radiation is of particular significance for human health. Dynamically induced low ozone episodes that happen in late spring can considerably enhance the solar UV-radiation in mid latitudes and therefore contribute to the UV-burden of people living in these regions

Eigensolutions of the Wigner--Eisenbud problem for a cylindrical nanowire within finite volume method

We present a finite volume method for computing a representative range of eigenvalues and eigenvectors of the Schrödinger operator on a three dimensional cylindrically symmetric bounded domain with mixed boundary conditions. More specifically, we deal with a semiconductor nanowire which consists of a dominant host material and contains heterostructure features such as double-barriers or quantum dots. The three dimensional Schrödinger operator is reduced to a family of two dimensional Schrödinger operators distinguished by a centrifugal potential. Ultimately, we numerically treat them by means of a finite volume method. We consider a uniform, boundary conforming Delaunay mesh, which additionally conforms to the material interfaces. The 1/r singularity is eliminated by approximating r at the vertexes of the Voronoi boxes. We study how the anisotropy of the effective mass tensor acts on the uniform approximation of the first K eigenvalues and eigenvectors and their sequential arrangement. There exists an optimal uniform Delaunay discretization with matching anisotropy. This anisotropic discretization yields best accuracy also in the presence of a mildly varying scattering potential, shown exemplarily for a nanowire resonant tunneling diode. For potentials with 1/r singularity one retrieves the theoretically established first order convergence, while the second order convergence is recovered only on uniform grids with an anisotropy correction

A Morphological and Multicolor Survey for Faint QSOs in the Groth-Westphal Strip

Quasars representative of the populous faint end of the luminosity function are frustratingly dim with m~24 at intermediate redshift; moreover groundbased surveys for such faint QSOs suffer substantial morphological contamination by compact galaxies having similar colors. In order to establish a more reliable ultrafaint QSO sample, we used the APO 3.5-m telescope to take deep groundbased U-band CCD images in fields previously imaged in V,I with WFPC2/HST. Our approach hence combines multicolor photometry with the 0.1" spatial resolution of HST, to establish a morphological and multicolor survey for QSOs extending about 2 magnitudes fainter than most extant groundbased surveys. We present results for the "Groth-Westphal Strip", in which we identify 10 high likelihood UV-excess candidates having stellar or stellar-nucleus+galaxy morphology in WFPC2. For m(606)<24.0 (roughly B<24.5) the surface density of such QSO candidates is 420 (+180,-130) per square degree, or a surface density of 290 (+160,-110) per square degree with an additional V-I cut that may further exclude compact emission line galaxies. Even pending confirming spectroscopy, the observed surface density of QSO candidates is already low enough to yield interesting comparisons: our measures agree extremely well with the predictions of several recent luminosity function models.Comment: 29 pages including 6 tables and 7 figures. As accepted for publication in The Astronomical Journal (minor revisions

Infrared properties of Mg1−x_{1-x}Alx(_x(B1−y_{1-y}Cy_{y})2_2 single crystals in the normal and superconducting state

The reflectivity $R (\omega)$ of $ab$-oriented Mg$_{1-x}$Al$_x$(B$_{1-y }$C$_y$)$_2$ single crystals has been measured by means of infrared microspectroscopy for $1300<\omega<17000$ cm$^{-1}$. An increase with doping of the scattering rates in the $\pi$ and $\sigma$ bands is observed, being more pronounced in the C doped crystals. The $\sigma$-band plasma frequency also changes with doping due to the electron doping, while the $\pi$-band one is almost unchanged. Moreover, a $\sigma\to\sigma$ interband excitation, predicted by theory, is observed at $\omega_{IB} \simeq 0.47$ eV in the undoped sample, and shifts to lower energies with doping. By performing theoretical calculation of the doping dependence $\omega_{IB}$, the experimental observations can be explained with the increase with electron doping of the Fermi energy of the holes in the $\sigma$-band. On the other hand, the $\sigma$ band density of states seems not to change substantially. This points towards a $T_c$ reduction driven mainly by disorder, at least for the doping level studied here. The superconducting state has been also probed by infrared synchrotron radiation for $30<\omega<150$ cm$^{-1}$ in one pure and one C-doped sample. In the undoped sample ($T_c$ = 38.5 K) a signature of the $\pi$-gap only is observed. At $y$ = 0.08 ($T_c$ = 31.9 K), the presence of the contribution of the $\sigma$-gap indicates dirty-limit superconductivity in both bands.Comment: 12 pages, 9 figure

High quality factor GaAs microcavity with buried bullseye defects

The authors acknowledge financial support from the State of Bavaria, as well as from the DFG within the Project Schn1376/3.1: Polariton based single-photon sources, and from the Danish Research Council for Technology and Production (Sapere Aude LOQIT, DFF4005-00370).The development of high quality factor solid-state microcavities with low mode volumes has paved the way towards on-chip cavity quantum electrodynamics experiments and the development of high-performance nanophotonic devices. Here, we report on the implementation of a new kind of solid-state vertical microcavity, which allows for confinement of the electromagnetic field in the lateral direction without deep etching. The confinement originates from a local elongation of the cavity layer imprinted in a shallow etch and epitaxial overgrowth technique. We show that it is possible to improve the quality factor of such microcavities by a specific in-plane bullseye geometry consisting of a set of concentric rings with sub wavelength dimensions. This design results in a smooth effective lateral photonic potential and therefore in a reduction of lateral scattering losses, which makes it highly appealing for experiments in the framework of exciton-polariton physics demanding tight spatial confinement.PostprintPeer reviewe

Cell permeable stapled peptide inhibitor of Wnt signaling that targets β-catenin protein‒protein interactions

The Wnt signaling pathway plays a critical role in cell proliferation and differentiation, thus it is often associated with diseases such as cancers. Unfortunately, although attractive, developing anti-cancer strategy targeting Wnt signaling has been challenging given that the most attractive targets are involved in protein-protein interactions (PPIs). Here, we develop a stapled peptide inhibitor that targets the interaction between β-catenin and T cell factor/lymphoid enhancer-binding factor transcription factors, which are crucially involved in Wnt signaling. Our integrative approach combines peptide stapling to optimize proteolytic stability, with lessons learned from cell-penetrating peptide (CPP) design to maximize cellular uptake resulting in NLS-StAx-h, a selective, cell permeable, stapled peptide inhibitor of oncogenic Wnt signaling that efficiently inhibits β-catenin-transcription factor interactions. We expect that this type of integrative strategy that endows stapled peptides with CPP features will be generally useful for developing inhibitors of intracellular PPIs