Fast rate estimation of an unitary operation in SU(d)

We give an explicit procedure based on entangled input states for estimating a $SU(d)$ operation $U$ with rate of convergence $1/N^2$ when sending $N$ particles through the device. We prove that this rate is optimal. We also evaluate the constant $C$ such that the asymptotic risk is $C/N^2$. However other strategies might yield a better const ant $C$.Comment: 8 pages, 1 figure Rewritten version, accepted for publication in Phys. Rev. A. The introduction is richer, the "tool section" on group representations has been suppressed, and a section proving that the 1/N^2 rate is optimum has been adde

Psychometric properties of Basic Empathy Scale among female juvenile delinquents and school youths

Research on empathy often distinguishes between affective and cognitive empathy, but there is limited knowledge regarding the application or measurement of these two dimensions of empathy among female youth, especially forensic samples of female youth. The main aim of the present study was to examine the psychometric properties of the Basic Empathy Scale (BES) among a Portuguese sample of female youths (N = 377), composed of incarcerated female juvenile offenders (n = 103) and school youths (n = 274). The two-factor structure of the BES obtained a good fit among the school sample, but the fit among the forensic sample was poor. Both samples demonstrated adequate psychometric properties in terms of Cronbach's alpha, omega coefficient, mean inter item correlations, corrected item-total correlation range, and criterion validity. However, some caution is advised when using the BES with female youth involved in the juvenile justice system, particularly with incarcerated female youth. (C) 2017 Elsevier Ltd. All rights reserved.European Social Fund (POPH/FSE)info:eu-repo/semantics/publishedVersio

Cyclosporine augments hepatic regenerative response in rats

A number of mechanisms participate in the hepatic injury that occurs during and following liver transplantation. A normal allograft regenerative response is probably essential for a successful transplant outcome. In this study, the effect of cyclosporine, a potent immunosuppressant used routinely after liver transplantation, on the regenerative response of the liver after partial hepatectomy was investigated. Male Wistar rats were pretreated for one week with either cyclosporine or the olive oil vehicle and were subjected to either a two-thirds partial hepatectomy or a sham operation. Animals were sacrificed at various times postoperatively and the remnant livers were weighed to determine the liver weight to body weight ratio, two biochemical measures of a regenerative response (cytosolic ornithine decarboxylase activity and thymidine kinase activity), and the hepatic content of estrogen and androgen receptors, as the content of these receptors has been shown to modulate, at least in part, the subsequent hepatic regenerative response. The preoperative hepatic cytosol content of ornithine decarboxylase, thymidine kinase, and estrogen receptor was significantly greater (P<0.05) in rats pretreated with cyclosporine than in those treated with the vehicle alone. A significant increase in ornithine decarboxylase and thymidine kinase activities occurred after partial hepatectomy in both the cyclosporine-pretreated and vehicle-pretreated animals. The absolute levels for each parameter were also greater in the cyclosporine-treated animals than in the vehicle-treated controls at 24 hr after partial hepatectomy (P<0.05). The pattern of change in the hepatic cytosolic content of estrogen and androgen receptors in both groups of animals was comparable with those described previously for regenerating liver. These data suggest that cyclosporine may predispose the liver to respond to either a regenerative signal or perceived need and thereby fortuitously enhance liver graft performance after successful surgical implantation. © 1989 Plenum Publishing Corporation

Magnetic Properties of J-J-J' Quantum Heisenberg Chains with Spin S=1/2, 1, 3/2 and 2 in a Magnetic Field

By means of the density matrix renormalization group (DMRG) method, the magnetic properties of the J-J-J$^{\prime}$ quantum Heisenberg chains with spin $S=1/2$, 1, 3/2 and 2 in the ground states are investigated in the presence of a magnetic field. Two different cases are considered: (a) when $J$ is antiferromagnetic and $J^{\prime}$ is ferromagnetic (i.e. the AF-AF-F chain), the system is a ferrimagnet. The plateaus of the magnetization are observed. It is found that the width of the plateaus decreases with increasing the ferromagnetic coupling, and disappears when $$ passes over a critical value. The saturated field is observed to be independent of the ferromagnetic coupling; (b) when $J$ is ferromagnetic and $J^{\prime}$ is antiferromagnetic (i.e. the F-F-AF chain), the system becomes an antiferromagnet. The plateaus of the magnetization are also seen. The width of the plateaus decreases with decreasing the antiferromagnetic coupling, and disappears when $J^{\prime}/J$ passes over a critical value. Though the ground state properties are quite different, the magnetization plateaus in both cases tend to disappear when the ferromagnetic coupling becomes more dominant. Besides, no fundamental difference between the systems with spin half-integer and integer has been found.Comment: 8 pages, 9 figures, to be published in J. Phys.: Condens. Matte

Galois cohomology of certain field extensions and the divisible case of Milnor-Kato conjecture

We prove the "divisible case" of the Milnor-Bloch-Kato conjecture (which is the first step of Voevodsky's proof of this conjecture for arbitrary prime l) in a rather clear and elementary way. Assuming this conjecture, we construct a 6-term exact sequence of Galois cohomology with cyclotomic coefficients for any finite extension of fields whose Galois group has an exact quadruple of permutational representations over it. Examples include cyclic groups, dihedral groups, the biquadratic group Z/2\times Z/2, and the symmetric group S_4. Several exact sequences conjectured by Bloch-Kato, Merkurjev-Tignol, and Kahn are proven in this way. In addition, we introduce a more sophisticated version of the classical argument known as "Bass-Tate lemma". Some results about annihilator ideals in Milnor rings are deduced as corollaries.Comment: LaTeX 2e, 17 pages. V5: Updated to the published version + small mistake corrected in Section 5. Submitted also to K-theory electronic preprint archives at http://www.math.uiuc.edu/K-theory/0589

A Survey for Transient Astronomical Radio Emission at 611 MHz

We have constructed and operated the Survey for Transient Astronomical Radio Emission (STARE) to detect transient astronomical radio emission at 611 MHz originating from the sky over the northeastern United States. The system is sensitive to transient events on timescales of 0.125 s to a few minutes, with a typical zenith flux density detection threshold of approximately 27 kJy. During 18 months of around-the-clock observing with three geographically separated instruments, we detected a total of 4,318,486 radio bursts. 99.9% of these events were rejected as locally generated interference, determined by requiring the simultaneous observation of an event at all three sites for it to be identified as having an astronomical origin. The remaining 3,898 events have been found to be associated with 99 solar radio bursts. These results demonstrate the remarkably effective RFI rejection achieved by a coincidence technique using precision timing (such as GPS clocks) at geographically separated sites. The non-detection of extra-solar bursting or flaring radio sources has improved the flux density sensitivity and timescale sensitivity limits set by several similar experiments in the 1970s. We discuss the consequences of these limits for the immediate solar neighborhood and the discovery of previously unknown classes of sources. We also discuss other possible uses for the large collection of 611 MHz monitoring data assembled by STARE.Comment: 24 pages, 6 figures; to appear in PAS

Winning versus losing during gambling and its neural correlates

Humans often make decisions which maximize an internal utility function. For example, humans often maximize their expected reward when gambling and this is considered as a "rational" decision. However, humans tend to change their betting strategies depending on how they "feel". If someone has experienced a losing streak, they may "feel" that they are more likely to win on the next hand even though the odds of the game have not changed. That is, their decisions are driven by their emotional state. In this paper, we investigate how the human brain responds to wins and losses during gambling. Using a combination of local field potential recordings in human subjects performing a financial decision-making task, spectral analyses, and non-parametric cluster statistics, we investigated whether neural responses in different cognitive and limbic brain areas differ between wins and losses after decisions are made. In eleven subjects, the neural activity modulated significantly between win and loss trials in one brain region: the anterior insula ($p=0.01$). In particular, gamma activity (30-70 Hz) increased in the anterior insula when subjects just realized that they won. Modulation of metabolic activity in the anterior insula has been observed previously in functional magnetic resonance imaging studies during decision making and when emotions are elicited. However, our study is able to characterize temporal dynamics of electrical activity in this brain region at the millisecond resolution while decisions are made and after outcomes are revealed