Local permutations of products of Bell states and entanglement distillation

We present new algorithms for mixed-state multi-copy entanglement distillation for pairs of qubits. Our algorithms perform significantly better than the best known algorithms. Better algorithms can be derived that are tuned for specific initial states. The new algorithms are based on a characterization of the group of all locally realizable permutations of the 4^n possible tensor products of n Bell states.Comment: 6 pages, 1 figur

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

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

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

Nearby debris disk systems with high fractional luminosity reconsidered

By searching the IRAS and ISO databases we compiled a list of 60 debris disks which exhibit the highest fractional luminosity values (fd>10^-4) in the vicinity of the Sun (d<120pc). Eleven out of these 60 systems are new discoveries. Special care was taken to exclude bogus disks from the sample. We computed the fractional luminosity values using available IRAS, ISO, and Spitzer data, and analysed the galactic space velocities of the objects. The results revealed that stars with disks of high fractional luminosity often belong to young stellar kinematic groups, providing an opportunity to obtain improved age estimates for these systems. We found that practically all disks with fd>5x10^-4 are younger than 100Myr. The distribution of the disks in the fractional luminosity versus age diagram indicates that (1) the number of old systems with high fd is lower than was claimed before; (2) there exist many relatively young disks of moderate fractional luminosity; and (3) comparing the observations with a current theoretical model of debris disk evolution a general good agreement could be found.Comment: 47 pages, 6 figures, AASTeX preprint (accepted for publication in the Astrophysical Journal); refined the text parts of table 6 and

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

Ultrasound characteristics of endometrial cancer as defined by the International Endometrial Tumor Analysis (IETA) consensus nomenclature - A prospective multicenter study

OBJECTIVES: To describe the sonographic features of endometrial cancer in relation to stage, grade, and histological type using the International Endometrial Tumor Analysis (IETA) terminology. METHODS: Prospective multicenter study on 1714 women with endometrial cancer undergoing a standardized transvaginal grayscale and Doppler ultrasound examination by an experienced ultrasound examiner using a high-end ultrasound system. Clinical and sonographic data were entered into a web-based protocol. We assessed how strongly sonographic characteristics, according to IETA, were associated to outcome at hysterectomy, i.e. tumor stage, grade, and histological type. RESULTS: After excluding 176 women (no or delayed hysterectomy, final diagnosis other than endometrial cancer, or incomplete data), 1538 women were included in our statistical analysis. Median age was 65 years (range 27-98), and median BMI 28.4 (range 16-67), 1378 (89.7%) women were postmenopausal, and 1296 (84.2%) reported abnormal vaginal bleeding. Grayscale and color Doppler features varied according to grade and stage. High-risk tumors (stage 1A, grade 3 or non-endometrioid or ≥ stage 1B) were less likely to have regular endometrial myometrial border (difference of -23%, 95% CI -27 to -18%), whilst they were larger (mean endometrial thickness; difference of +9 mm, 95% CI +8 to +11 mm), more frequently had non-uniform echogenicity (difference of +10%, 95% CI +5 to +15%), a multiple, multifocal vessel pattern (difference of +21%, 95% CI +16 to +26%), and a moderate or high color score (difference of +22%, 95% CI +18 to +27%), than low-risk tumors. CONCLUSION: Grayscale and color Doppler ultrasound features are associated with grade and stage, and differ between high and low risk endometrial cancer

Association of MC1R Variants and host phenotypes with melanoma risk in CDKN2A mutation carriers: a GenoMEL study

&lt;p&gt;&lt;b&gt;Background&lt;/b&gt; Carrying the cyclin-dependent kinase inhibitor 2A (CDKN2A) germline mutations is associated with a high risk for melanoma. Penetrance of CDKN2A mutations is modified by pigmentation characteristics, nevus phenotypes, and some variants of the melanocortin-1 receptor gene (MC1R), which is known to have a role in the pigmentation process. However, investigation of the associations of both MC1R variants and host phenotypes with melanoma risk has been limited.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Methods&lt;/b&gt; We included 815 CDKN2A mutation carriers (473 affected, and 342 unaffected, with melanoma) from 186 families from 15 centers in Europe, North America, and Australia who participated in the Melanoma Genetics Consortium. In this family-based study, we assessed the associations of the four most frequent MC1R variants (V60L, V92M, R151C, and R160W) and the number of variants (1, &#8805;2 variants), alone or jointly with the host phenotypes (hair color, propensity to sunburn, and number of nevi), with melanoma risk in CDKN2A mutation carriers. These associations were estimated and tested using generalized estimating equations. All statistical tests were two-sided.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Results&lt;/b&gt; Carrying any one of the four most frequent MC1R variants (V60L, V92M, R151C, R160W) in CDKN2A mutation carriers was associated with a statistically significantly increased risk for melanoma across all continents (1.24 × 10−6 &#8804; P &#8804; .0007). A consistent pattern of increase in melanoma risk was also associated with increase in number of MC1R variants. The risk of melanoma associated with at least two MC1R variants was 2.6-fold higher than the risk associated with only one variant (odds ratio = 5.83 [95% confidence interval = 3.60 to 9.46] vs 2.25 [95% confidence interval = 1.44 to 3.52]; Ptrend = 1.86 × 10−8). The joint analysis of MC1R variants and host phenotypes showed statistically significant associations of melanoma risk, together with MC1R variants (.0001 &#8804; P &#8804; .04), hair color (.006 &#8804; P &#8804; .06), and number of nevi (6.9 × 10−6 &#8804; P &#8804; .02).&lt;/p&gt; &lt;p&gt;&lt;b&gt;Conclusion&lt;/b&gt; Results show that MC1R variants, hair color, and number of nevi were jointly associated with melanoma risk in CDKN2A mutation carriers. This joint association may have important consequences for risk assessments in familial settings.&lt;/p&gt