An Investigative Study of Gurney Flaps on a NACA 0036 Airfoil

This project examined the effect of Gurney flaps on a 2D, 2-ft chord NACA 0036 airfoil in the Cal Poly 3’x4’ low speed wind tunnel at 25 m/s. It also covered the numerical simulation of the experiment in computational fluid dynamics (CFD). During the study, problems with the wind tunnel data were seen. After a careful diagnosis, the problem was traced to dirty flow conditioners which were subsequently replaced. Five Gurney flaps at 1, 2, 3, 4, and 5% of the chord were tested. The Gurney flaps had the effect of eliminating the lift reversal effect and lowering the profile drag at low angles of attack, ranging from 4-27%. The optimal Gurney flap appeared to be 2% of the chord. CFD modeling of the problem had limited success, with the best results coming from Mentor’s k-w SST turbulence model. This model reproduced the non-linear lift curve, and captured the trend in rising drag fairly well, but failed to predict the correct point of separation. Attempts to model the Gurney flap in CFD were unsuccessful

Reanalysis of the GALLEX solar neutrino flux and source experiments

After the completion of the gallium solar neutrino experiments at the Laboratori Nazionali del Gran Sasso (GALLEX}: 1991-1997; GNO: 1998-2003) we have retrospectively updated the GALLEX results with the help of new technical data that were impossible to acquire for principle reasons before the completion of the low rate measurement phase (that is, before the end of the GNO solar runs). Subsequent high rate experiments have allowed the calibration of absolute internal counter efficiencies and of an advanced pulse shape analysis for counter background discrimination. The updated overall result for GALLEX (only) is (73.4 +7.1 -7.3) SNU. This is 5.3% below the old value of (77.5 + 7.5 -7.8) SNU (PLB 447 (1999) 127-133) with a substantially reduced error. A similar reduction is obtained from the reanalysis of the 51Cr neutrino source experiments of 1994/1995.Comment: Accepted by Physics Letters B January 13, 201

Detailed characterization of the O-linked glycosylation of the neuropilin-1 c/MAM-domain

Neuropilins are involved in angiogenesis and neuronal development. The membrane proximal domain of neuropilin-1, called c or MAM domain based on its sequence conservation, has been implicated in neuropilin oligomerization required for its function. The c/MAM domain of human neuropilin-1 has been recombinantly expressed to allow for investigation of its propensity to engage in molecular interactions with other protein or carbohydrate components on a cell surface. We found that the c/MAM domain was heavily O-glycosylated with up to 24 monosaccharide units in the form of disialylated core 1 and core 2 O-glycans. Attachment sites were identified on the chymotryptic c/MAM peptide ETGATEKPTVIDSTIQSEFPTY by electron-transfer dissociation mass spectrometry (ETD-MS/MS). For highly glycosylated species consisting of carbohydrate to about 50 %, useful results could only be obtained upon partial desialylation. ETD-MS/MS revealed a hierarchical order of the initial O-GalNAc addition to the four different glycosylation sites. These findings enable future functional studies about the contribution of the described glycosylations in neuropilin-1 oligomerization and the binding to partner proteins as VEGF or galectin-1. As a spin-off result the sialidase from Clostridium perfringens turned out to discriminate between galactose- and N-acetylgalactosamine-linked sialic acid

A psychophysiology practical as part of the medical psychology course

Die Vermittlung der Zusammenhänge zwischen psychologischen Funktionen und körperlichen Veränderungen sowie deren Relevanz für die Entstehung und Aufrechterhaltung von Krankheiten stellt ein zentrales Ziel der Ausbildung in Medizinischer Psychologie dar. Zur Veranschaulichung dieser Zusammenhänge führten wir ein Psychophysiologie-Praktikum im ersten vorklinischen Semester ein. Die Studierenden führten in Vierergruppen mit Hilfe ausführlicher schriftlicher Instruktionen jeweils ca. 30 Minuten andauernde praktische Übungen durch, die die folgenden Themen behandelten: (1) Stress (abhängige Variable: Herzrate), (2) "Lügendetektor" (abhängige Variable: Hautleitwertsreaktionen), (3) Biofeedback (abhängige Variable: Hauttemperatur) und (4) Elektroenzephalogramm (abhängige Variable: Amplituden der vier klassischen Frequenzbänder). Die praktischen Übungen wurden durch theoretische Gruppenarbeiten und einen Termin zur Zusammenfassung der Ergebnisse der Übungen ergänzt. Die studentische Evaluation des Praktikums war durchweg positiv. So wurde das Praktikum als Bereicherung des Kurses angesehen, und der selbstbeurteilte Kenntnisstand auf dem Gebiet der Psychophysiologie zeigte eine signifikante Verbesserung. Diese Ergebnisse sowie unsere Eindrücke während des Praktikums bekräftigten unseren Entschluss, ein Psychophysiologie-Praktikum als Teil des Kurses der Medizinischen Psychologie und Medizinischen Soziologie fest zu etablieren.Teaching in medical psychology aims at establishing an understanding of the relationships between psychological functions and bodily reactions and of the relevance of these interactions for the development and maintenance of diseases. To illustrate these relationships, a psychophysiology practical was introduced in the first semester. Students performed practical 30-minute exercises in groups of four on the basis of comprehensive written instructions. The following topics were covered: (1) stress (dependent variable: heart rate), (2) "lie detection" (dependent variable: skin conductance response), (3) biofeedback (dependent variable: skin temperature), and (4) electroencephalogram (dependent variable: amplitude in the four classical frequency bands). The practical exercises were complemented by theoretical group work and a summary of the results of the exercises. Students evaluated the practical positively. It was considered a benefit to the course, and the self-rated knowledge in the area of psychophysiology increased significantly. These results, as well as our experiences during the practical, have reinforced our decision to establish a psychophysiology practical as part of the medical psychology/medical sociology course

Vom neuronalen Einzelfahrschein zur kortikalen Netzkarte : audio-visuelle Objekterkennung in der Großhirnrinde

Die Wahrnehmung von Objekten gelingt uns jeden Tag unzählige Male – zumeist rasend schnell und problemlos. Obwohl fast immer mehrere unserer Sinne gleichzeitig bei ihrer Wahrnehmung angesprochen werden, erscheinen uns diese Objekte dennoch als ganzheitlich und geschlossen. Für die neuronale Verarbeitung eines bellenden Hundes zum Beispiel empfängt die Großhirnrinde zumindest Eingangsdaten des Seh- und des Hörsystems. Sie werden auf getrennten Pfaden und in spezialisierten Arealen mit aufsteigender Komplexität analysiert. Dieses Funktionsprinzip der parallel verteilten Verarbeitung stellt die Wissenschaftler aber auch vor das so genannte »Bindungsproblem«: Wo und wie werden die Details wieder zu einem Ganzen – zu einer neuronalen Repräsentation – zusammengefügt? Am Institut für medizinische Psychologie der Universitätsklinik Frankfurt untersuchen Neurokognitionsforscher die crossmodale Objekterkennung mit einer Kombination modernster Verfahren der Hirnforschung und kommen dabei den Ver - arbeitungspfaden in der Großhirnrinde auf die Spur

Density Functional Theory for the Photoionization Dynamics of Uracil

Photoionization dynamics of the RNA base Uracil is studied in the framework of Density Functional Theory (DFT). The photoionization calculations take advantage of a newly developed parallel version of a multicentric approach to the calculation of the electronic continuum spectrum which uses a set of B-spline radial basis functions and a Kohn-Sham density functional hamiltonian. Both valence and core ionizations are considered. Scattering resonances in selected single-particle ionization channels are classified by the symmetry of the resonant state and the peak energy position in the photoelectron kinetic energy scale; the present results highlight once more the site specificity of core ionization processes. We further suggest that the resonant structures previously characterized in low-energy electron collision experiments are partly shifted below threshold by the photoionization processes. A critical evaluation of the theoretical results providing a guide for future experimental work on similar biosystems

Influence of boundary conditions on quantum escape

It has recently been established that quantum statistics can play a crucial role in quantum escape. Here we demonstrate that boundary conditions can be equally important - moreover, in certain cases, may lead to a complete suppression of the escape. Our results are exact and hold for arbitrarily many particles.Comment: 6 pages, 3 figures, 1 tabl