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

Algebraic invariants of five qubits

The Hilbert series of the algebra of polynomial invariants of pure states of five qubits is obtained, and the simplest invariants are computed.Comment: 4 pages, revtex. Short discussion of quant-ph/0506073 include

Short-period volcanic gas precursors to phreatic eruptions: Insights from Poás Volcano, Costa Rica

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A molecular analysis of the Afrotropical Baetidae

Recent work on the Afrotropical Baetidae has resulted in a number of important taxonomic changes: several polyphyletic genera have been split and more than 30 new Afrotropical genera have been established. In order to test their phylogenetic relevance and to clarify the suprageneric relationships, we reconstructed the first comprehensive molecular phylogeny of the Afrotropical Baetidae. We sequenced a total of ca. 2300 bp from nuclear (18S) and mitochondrial (12S and 16S) gene regions from 65 species belonging to 26 genera. We used three different approaches of phylogeny reconstruction: direct optimization, maximum parsimony and maximum likelihood. The molecular reconstruction indicates the Afrotropical Baetidae require a global revision at a generic as well as suprageneric level. Only four of the 12 genera were monophyletic when represented by more than one species in the analysis. Historically, two conflicting concepts of the suprageneric classification of Afrotropical Baetidae were proposed. One was based on the gathering of sister genera into complexes and the other on the division of the family into a restricted number of subfamilies. According to our reconstruction, neither is completely satisfactory: the major complexes of genera present in Africa are either paraphyletic or polyphyletic and the division of the Afrotropical Baetidae into two subfamilies is probably too simplified

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

Genome-wide linkage scan for athlete status in 700 British female DZ twin pairs

Association studies, comparing elite athletes with sedentary controls, have reported a number of genes that may be related to athlete status. The present study reports the first genome wide linkage scan for athlete status. Subjects were 4488 adult female twins from the TwinsUK Adult Twin Registry (793 monozygotic [MZ] and 1000 dizygotic [DZ] complete twin pairs, and single twins). Athlete status was measured by asking the twins whether they had ever competed in sports and what was the highest level obtained. Twins who had competed at the county or national level were considered elite athletes. Using structural equation modeling in Mx, the heritability of athlete status was estimated at 66%. Seven hundred DZ twin pairs that were successfully genotyped for 1946 markers (736 microsatellites and 1210 SNPs) were included in the linkage analysis. Identical-by-descent probabilities were estimated in Merlin for a 1 cM grid, taking into account the linkage disequilibrium of correlated SNPs. The linkage scan was carried out in Mx using the π-approach. Suggestive linkages were found on chromosomes 3q22-q24 and 4q31-q34. Both areas converge with findings from previous studies using exercise phenotypes. The peak on 3q22-q24 was found at the SLC9A9 gene. The region 4q31-q34 overlaps with the region for which suggestive linkages were found in two previous linkage studies for physical fitness (FABP2 gene; Bouchard et al., 2000) and physical activity (UCP1 gene; Simonen et al., 2003). Future association studies should further clarify the possible role of these genes in athlete status

The New ‘Hidden Abode’: Reflections on Value and Labour in the New Economy

In a pivotal section of Capital, volume 1, Marx (1976: 279) notes that, in order to understand the capitalist production of value, we must descend into the ‘hidden abode of production’: the site of the labour process conducted within an employment relationship. In this paper we argue that by remaining wedded to an analysis of labour that is confined to the employment relationship, Labour Process Theory (LPT) has missed a fundamental shift in the location of value production in contemporary capitalism. We examine this shift through the work of Autonomist Marxists like Hardt and Negri, Lazaratto and Arvidsson, who offer theoretical leverage to prize open a new ‘hidden abode’ outside employment, for example in the ‘production of organization’ and in consumption. Although they can open up this new ‘hidden abode’, without LPT's fine-grained analysis of control/resistance, indeterminacy and structured antagonism, these theorists risk succumbing to empirically naive claims about the ‘new economy’. Through developing an expanded conception of a ‘new hidden abode’ of production, the paper demarcates an analytical space in which both LPT and Autonomist Marxism can expand and develop their understanding of labour and value production in today's economy. </jats:p

Sulfur degassing at Erta Ale (Ethiopia) and Masaya (Nicaragua) volcanoes: Implications for degassing processes and oxygen fugacities of basaltic systems

We investigate the relationship between sulfur and oxygen fugacity at Erta Ale and Masaya volcanoes. Oxygen fugacity was assessed utilizing Fe3+/∑Fe and major element compositions measured in olivine‐hosted melt inclusions and matrix glasses. Erta Ale melts have Fe3+/∑Fe of 0.15–0.16, reflecting fO2 of ΔQFM 0.0 ± 0.3, which is indistinguishable from fO2 calculated from CO2/CO ratios in high‐temperature gases. Masaya is more oxidized at ΔQFM +1.7 ± 0.4, typical of arc settings. Sulfur isotope compositions of gases and scoria at Erta Ale (δ34Sgas − 0.5‰; δ34Sscoria + 0.9‰) and Masaya (δ34Sgas + 4.8‰; δ34Sscoria + 7.4‰) reflect distinct sulfur sources, as well as isotopic fractionation during degassing (equilibrium and kinetic fractionation effects). Sulfur speciation in melts plays an important role in isotope fractionation during degassing and S6+/∑S is 0.67 in Masaya melt inclusions. No change is observed in Fe3+/∑Fe or S6+/∑S with extent of S degassing at Erta Ale, indicating negligible effect on fO2, and further suggesting that H2S is the dominant gas species exsolved from the S2−‐rich melt (i.e., no redistribution of electrons). High SO2/H2S observed in Erta Ale gas emissions is due to gas re‐equilibration at low pressure and fixed fO2. Sulfur budget considerations indicate that the majority of S injected into the systems is emitted as gas, which is therefore representative of the magmatic S isotope composition. The composition of the Masaya gas plume (+4.8‰) cannot be explained by fractionation effects but rather reflects recycling of high δ34S oxidized sulfur through the subduction zone