Orbital and spin correlations in Ca2−x_{2-x}Srx_xRuO4_4: A mean field study

The alloy Ca$_{2-x}$Sr$_x$RuO$_4$ exhibits a complex phase diagram with peculiar magnetic metallic phases. In this paper some aspects of this alloy are discussed based on a mean field theory for an effective Kugel-Khomskii model of localized orbital and spin degrees of freedom. This model results from an orbital selective Mott transition which in the three-band system localized two orbitals while leaving the third one itinerant. Special attention is given to the region around a structure quantum phase transition at $x \approx 0.5$ where the crystal lattice changes from tetragonal to orthorhombic symmetry while leaving the system metallic. This transition yields, a change from ferromagnetic to antiferromagnetic spin correlations. The complete mean field phase diagram for this transition is given including orbital and spin order. The anisotropy of spin susceptibility, a consequence of spin-orbit coupling and orbital correlation, is a tell-tale sign of one of these phases. In the predominantly antiferromagnetic phase we describe a metamagnetic transition in a magnetic field and show that coupling of the itinerant band to the localized degrees of freedom yields an anomalous longitudinal magnetoresistance transition. Both phenomena are connected with the evolution of the ferromagnetic and antiferromagnetic domains in the external magnetic field and agree qualitatively with the experimental findings.Comment: 12 pages, accepted for publication in EPJ

Additional J/ΨJ/\Psi Suppression from High Density Effects

At high energies the saturation effects associated to the high parton density should modify the behavior of the observables in proton-nucleus and nucleus-nucleus scattering. In this paper we investigate the saturation effects in the nuclear $J/\Psi$ production and estimate the modifications in the energy dependence of the cross section as well as in the length of the nuclear medium. In particular, we calculate the ratio of $J/\Psi$ to Drell-Yan cross sections and show that it is strongly modified if the high density effects are included. Moreover, our results are compared with the data from the NA50 Collaboration and predictions for the RHIC and LHC kinematic regions are presented. We predict an additional $J/\Psi$ suppression associated to the high density effects.Comment: 13 pages, 5 figures, version to be published in Eur. Phys. J.

Sea Power and China's Strategic Choices

China's national goals have shifted from the need to guarantee its survival during the country's revolutionary days to the current state of securing stable economic development. This shift marks a full transition for China, changing from a closed country to a developing one that is irrevocably integrated with the rest of the world. Today, while this subject is a common discourse in scholarly and political circles, the international community is still coming to grips with the meaning and impact of China's evolving role on the world stage. It is not an easy issue and extends beyond economics

A pre-evaluation of British public opinion on the London 2012 Olympics based on sport participation types

As recalled by Girginov and Hills (2008), one ambitious aim in staging the London 2010 Olympics concerns sports development and participation legacy. According to them, this objective comes from both the IOC‟s will to create positive legacies from the Games and the promotion of sports-for-all in the host country, and the bid committee and the UK government‟s will to “use the games to inspire the country‟s people to become more physically active” (p.2092). However, as observed by Coalter (2004), the positive impact of major events on sports participation is not automatic and moreover Olympic “legacies are constructed and not given” (Girginov & Hills, 2008, p.2092). The aim of this study is to provide a pre-evaluation of the London Olympics in relation to sport participation patterns in order to first identify the critical issues influencing British people‟s engagement into the Games and second to create the basis for a longitudinal analysis of their impact. In order to evaluate people‟s perceptions of London 2012, we used Social Representation Theory (Moscovici, 1984), as social representations characterise a form of socially elaborated and shared knowledge, with practical consequences which contribute to the construction of a common reality among social groups

TRECVID: evaluating the effectiveness of information retrieval tasks on digital video

TRECVID is an annual exercise which encourages research in information retrieval from digital video by providing a large video test collection, uniform scoring procedures, and a forum for organizations interested in comparing their results. TRECVID benchmarking covers both interactive and manual searching by end users, as well as the benchmarking of some supporting technologies including shot boundary detection, extraction of some semantic features, and the automatic segmentation of TV news broadcasts into non-overlapping news stories. TRECVID has a broad range of over 40 participating groups from across the world and as it is now (2004) in its 4th annual cycle it is opportune to stand back and look at the lessons we have learned from the cumulative activity. In this paper we shall present a brief and high-level overview of the TRECVID activity covering the data, the benchmarked tasks, the overall results obtained by groups to date and an overview of the approaches taken by selective groups in some tasks. While progress from one year to the next cannot be measured directly because of the changing nature of the video data we have been using, we shall present a summary of the lessons we have learned from TRECVID and include some pointers on what we feel are the most important of these lessons

Book Review: Perspectivas (7th edition)

Review of Kiddle, Mary Ellen, Branda Wegmann and Sandra Schreffler. Perspectivas (7th edition). Boston: Heinle and Heinle, 2002. pp. 372. ISBN 0-03-033936-

Data incongruence and the problem of avian louse phylogeny

Recent studies based on different types of data (i.e. morphological and molecular) have supported conflicting phylogenies for the genera of avian feather lice (Ischnocera: Phthiraptera). We analyse new and published data from morphology and from mitochondrial (12S rRNA and COI) and nuclear (EF1-) genes to explore the sources of this incongruence and explain these conflicts. Character convergence, multiple substitutions at high divergences, and ancient radiation over a short period of time have contributed to the problem of resolving louse phylogeny with the data currently available. We show that apparent incongruence between the molecular datasets is largely attributable to rate variation and nonstationarity of base composition. In contrast, highly significant character incongruence leads to topological incongruence between the molecular and morphological data. We consider ways in which biases in the sequence data could be misleading, using several maximum likelihood models and LogDet corrections. The hierarchical structure of the data is explored using likelihood mapping and SplitsTree methods. Ultimately, we concede there is strong discordance between the molecular and morphological data and apply the conditional combination approach in this case. We conclude that higher level phylogenetic relationships within avian Ischnocera remain extremely problematic. However, consensus between datasets is beginning to converge on a stable phylogeny for avian lice, at and below the familial rank

For the conscientious objector, it is better to die than to kill

Article discussing conscientious objection. References Buddhism, Gandhi, pacifism and the Christian church and both world war

The role of trust as a mediator in the relationship between technology factors and intention to accept internet banking in Nigeria

This study had been carried out to investigate factors that influence the intention to accept internet banking and examined the mediating role of trust between technology factors and the intention to accept an internet banking. This study reviewed related technology acceptance theories and trust models. The decomposed theory of planned behaviour, innovation diffusion theory and trustworthiness technology were adopted. The aforementioned adopted models suggested five main factors namely; perceived behaviour control, attitude, subjective norm, trust and intention to accept internet banking. This was a quantitative research method. Questionnaire was adopted to 559 bank customers within Lagos, Port-harcourt and Abuja in Nigeria. The response rate is 55.85%, representing 391 worth questionnaires. SPSS and AMOS version 20 tools were utilized to analyze the data in reference to descriptive statistics, standardized regression and mediation effects. The initial model without mediation analyzes revealed 71% variance (R2) in customer intent to accept internet banking. However, when modified with trust mediating factors, the results revealed 74% variance, implying that trust contributed a 3% to the model. Consequently serves as a partial mediator towards the intention to accept internet banking in Nigeria. As a result, thorough understanding of this may assist practitioners in analyzing reason(s) for slow pace in acceptance of the technology, provide efficient measures to improving customers’ acceptance and provide an insight for academia about internet usage in Nigeria. Future studies can be directed towards replicating the use of this model in other locations and different analytical techniques