Edge local complementation for logical cluster states

A method is presented for the implementation of edge local complementation in graph states, based on the application of two Hadamard operations and a single controlled-phase (CZ) gate. As an application, we demonstrate an efficient scheme to construct a one-dimensional logical cluster state based on the five-qubit quantum error-correcting code, using a sequence of edge local complementations. A single physical CZ operation, together with local operations, is sufficient to create a logical CZ operation between two logical qubits. The same construction can be used to generate any encoded graph state. This approach in concatenation may allow one to create a hierarchical quantum network for quantum information tasks.Comment: 15 pages, two figures, IOP styl

ENOBIO - First tests of a dry electrophysiology electrode using carbon nanotubes

We describe the development and first tests of Enobio, a dry electrode sensor concept for biopotential applications. In the proposed electrodes, the tip of the electrode is covered with a forest of multi-walled CNTs that can be coated with Ag/AgCl to provide ionic-electronic transduction. The CNT brush-like structure is to penetrate the outer layers of the skin improving electrical contact as well as increae the contact surface area. In this paper, we report the results of the first tests of this concept -- immersion on saline solution and pig skin signal detection. These indicate performance on a par with state of the art research-oriented wet electrodes.Comment: Submitted and accepted at the 28th IEEE EMBS International Conference, New York City, August 31st-September 3rd, 2006. Figures updated with proper filtering and averagin

Eine verbesserte fluorimetrische Cortisolbestimmung im Serum

Die fluorimetrische Methode zur Bestimmung von Serumcortisol wurde durch blasenfreie Füllung einer Spezialküvette mittels Pumpvorrichtung, durch Benützung eines Spectralfluorimeters, sowie Verlegung des Meßzeitpunktes (80 min) und durch optimale Anregung (464 nm) und Emissionsmessung (522 nm) verbessert. Empfindlichkeit (<1 µg Cortisol/100 ml), Richtigkeit, Genauigkeit, Reproduzierbarkeit von Tag zu Tag (VK=6–7%) und Störfaktoren der Methode werden angegeben. Mit dieser Methode wurden Normalberciche für die 9 Uhr-Nüchterncortisolwerte und die i.v. ACTH-Belastung ermittelt. Bei NNR-insuffizienten Patienten (M. Addison; Zustand nach Operation eines Hypophysentumors; total Adrenalektomierte) wurden i.v. ACTH-Belastungen durchgeführt, wobei sich bereits beim 9 Uhr-Nüchterncortisolwert eine diagnostisch gut brauchbare Trennung gegenüber dem Normalbereich ergab. Unter Dexamethasonsubstitution wurden bei NNR-Insuffizienz sehr niedrige Cortisolspiegel gemessen, was für die Spezifität der Methode spricht. Dic Bestimmung des 24 Std-Rhythmus der Cortisolwerte bei NNR-Insuffizienten zeigte, daß besonders in den frühen Morgenstunden im Vergleich zu Normalpersonen erniedrigte Cortisolspiegel bestehen. Daraus wird ein besserer Verteilungsvorschlag für die Cortisol-substitution abgeleitet.The fluorimetric determination of serum cortisol was improved 1. using a pumpdevice to fill a special microcuvette avoiding the development of small bubbles, 2. using a recording spectrofluorometer with optimal absorption (464 nm) and emission (522 nm), and 3. allowing for maximal fluorescence of cortisol (80 min). Sensitivity (<1 µg cortisol/100 ml), accuracy, precision and specificity of the method are reported. Normal values of 9.00 a.m. serum cortisol (9.7–32.0 µg/100 ml) and of values before and after ACTH infusion tests were determined. For adrenal insufficiency (Addisons disease, total adrenalectomy, or after hypophysectomy) the 9.00 a.m. values of serum cortisol were generally satisfactory for diagnosis. In partial adrenal insufficiency ACTH infusion tests had to be performed. Very low levels of serum cortisol (2–4 µg/100 ml) were obtained, when patients with adrenal insufficiency were substituted with dexamethasone for three days, proving the specificity of the method. Determination of circadian rhythms of serum cortisol in patients with adrenal insufficiency on cortisol substitutive therapy in divided doses demonstrated cortisol levels far below the normal values during the carly morning hours. This situation should be improved by dividing the cortisol dose as follows: 6 a.m.: 10 mg, 10 a.m.: 5 mg, 2 p.m.: 5 mg and 8 p.m. or later: 10 mg cortisol

Globular Clusters as Candidates for Gravitational Lenses to Explain Quasar-Galaxy Associations

We argue that globular clusters (GCs) are good candidates for gravitational lenses in explaining quasar-galaxy associations. The catalog of associations (Bukhmastova 2001) compiled from the LEDA catalog of galaxies (Paturel 1997) and from the catalog of quasars (Veron-Cetty and Veron 1998) is used. Based on the new catalog containing 8382 pairs, we show that one might expect an increased number of GCs around irregular galaxies of types 9 and 10 from the hypothesis that distant compact sources are gravitationally lensed by GCs in the halos of foreground galaxies. The King model is used to determine the central surface densities of 135 GCs in the Milky Way. The distribution of GCs in central surface density was found to be lognormal.Comment: 22 pages, 4 figure

HD 181068: A Red Giant in a Triply-Eclipsing Compact Hierarchical Triple System

Hierarchical triple systems comprise a close binary and a more distant component. They are important for testing theories of star formation and of stellar evolution in the presence of nearby companions. We obtained 218 days of Kepler photometry of HD 181068 (magnitude of 7.1), supplemented by groundbased spectroscopy and interferometry, which show it to be a hierarchical triple with two types of mutual eclipses. The primary is a red giant that is in a 45-day orbit with a pair of red dwarfs in a close 0.9-day orbit. The red giant shows evidence for tidally-induced oscillations that are driven by the orbital motion of the close pair. HD 181068 is an ideal target for studies of dynamical evolution and testing tidal friction theories in hierarchical triple systems.Comment: 22 pages, including supporting on-line material. This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science Vol. 332 no. 6026 pp. 216-218 (8 April 2011), doi:10.1126/science.1201762. http://www.sciencemag.org/content/332/6026/216.ful

Cartoon Computation: Quantum-like computing without quantum mechanics

We present a computational framework based on geometric structures. No quantum mechanics is involved, and yet the algorithms perform tasks analogous to quantum computation. Tensor products and entangled states are not needed -- they are replaced by sets of basic shapes. To test the formalism we solve in geometric terms the Deutsch-Jozsa problem, historically the first example that demonstrated the potential power of quantum computation. Each step of the algorithm has a clear geometric interpetation and allows for a cartoon representation.Comment: version accepted in J. Phys.A (Letter to the Editor

Diagnostische Bedeutung der Proteinbindung von Plasmacortisol, bestimmt durch Dextrangelfiltration

1. Mittels Dextrangelfiltration wurde nach Inkubation von markiertem Cortisol und Plasma der proteingebundene und der sog. freie Anteil (%) des endogenen Plasmacortisols ermittelt und bei gleichzeitiger fluorimetrischer Bestimmung der 11-OHCS auch die Menge proteingebundenen, bzw. sog. freien Cortisols (µg-%) berechnet. 2. Die diagnostische Brauchbarkeit der Methode wurde bei Patienten mit Nebennierenrindeninsuffizienz, mit Hypophysentumoren, nach Hypophysektomie, mit Cushing-Syndrom mit der fluorimetrischen Bestimmung der 11-OHCS verglichen. Die einfache Bestimmung der Cortisolbindung war bei hypophysektomierten Patienten der Bestimmung der 11-OHCS überlegen und entsprach der aufwendigeren ACTH-Belastung. 3. Falsch hohe fluorimetrische 11-OHCS-Spiegel im Plasma unter Spirolacton- oder Oestrogenbehandlung und in der Gravidität lassen sich durch Bestimmung der Cortisolbindung klären. Bei Schilddrüsenüberfunktion war das sog. freie Cortisol im Plasma relativ und absolut vermehrt, bei Schilddrüsenunterfunktion fand sich eine Zunahme des plasmaproteingebundenen Cortisols.1. Following incubation of labeled cortisol and plasma the percentages of protein bound and socalled free endogenous cortisol were determined by means of dextran gel filtration. 2. The diagnostic value of this method was compared with fluorimetric determinations of 11-OHCS for patients with adrenal insufficiency, Cushing-Syndrome, pituitary tumors and after hypophysectomy. In hypophysectomized patients the simple determination of protein bound cortisol was found to correlate well with diagnostic ACTH-infusion tests and to be more sensitive than fluorimetric determinations of 11-OHCS in 9 a.m. plasma. 3. Falsely elevated fluorimetric values of plasma 11-OHCS in patients treated with spirolactone or estrogens, resp. during pregnancy may be recognized through determination of cortisol binding. — In thyrotoxicosis socalled free cortisol was elevated, both relatively and absolutely; in hypothyroidism an increase of protein bound cortisol was found