8,685 research outputs found

    Competing Valence Bond States of Spin-3/2 Fermions on a Strongly Coupled Ladder

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    We study the possible ground state configurations of two strongly coupled chains of charge neutral spin-3/2 fermionic atoms interacting via short range van der Waals interaction. The coupling between the two chains is realized by relatively large hopping amplitude. Exploiting that such a ladder configuration can be mapped to an effective one-band model we analyze the emerging ground states of the system. We show that various spatially inhomogeneous states, valence bond states, plaquette states compete depending on the filling and the ratio of the interaction strengths in the singlet and quintet scattering channel. We find that a Luttinger liquid state is the ground state of the strongly coupled ladder in an extended region of the parameter space, and we also show that a topologically nontrivial charge Haldane state can emerge in the strongly coupled ladder at quarter and three-quarter fillings.Comment: 9 pages, 8 figure

    Investigation of effects of two environmental heavy metals in a combined exposure model on the nervous system in rats

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    In the present study, the interaction of inhalational and oral exposure to manganese and lead was investigated. Young adult male Wistar rats (2 x 10 per group) were treated orally with MnCl2 (15 and 60 mg/kg b.w.) or Pb acetate (80 and 320 mg/kg) for 3 or 6 weeks. Then, one half of the groups was further treated by intratracheal instillation of nanoparticulate MnO2 (2.63 mg/kg) or PbO (2 mg/kg) for an equal period of time. Body weight gain and signs of general toxicity were regularly checked. Finally, the rats’ motor behavior was tested in an open field box, and their spontaneous and evoked cortical electrical activity was recorded in urethane anesthesia. MnO2 nanoparticles caused disproportionately strong reduction of body weight gain but with Pb the weight effect was more dependent on dose. In the open field test, Mn caused hypomotility, more strongly after 6 weeks oral plus 6 weeks intratracheal than after 6 weeks oral treatment. Pb-treated rats showed increased ambulation but less rearing and somewhat longer local activity. Spontaneous cortical activity was shifted to higher frequencies after oral Mn application, but this change was not intensified by subsequent nanoparticle application. Oral Pb had an opposite effect. Cortical evoked potentials showed latency lengthening. In several cases, the effect of Mn and Pb was about as strong after 3 weeks oral plus 3 weeks intratracheal as after 6 weeks oral administration, although the summed dose was ca. two times lower in the former case. There can be a more-than-additive interaction between the amounts of heavy metals entering the organism in different routes and chemical forms

    How does consumer behaviour change? Examples from energy conservation

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    A global consumer society is rapidly overshooting ecological limits, there is a dire need to find new ways to change consumer behaviour. Yet history knows few succesful examples of reducing consumption. However, since the 1970s, there is a long legacy of work on energy conservation, which we use to identify three key factors that influence consumer behaviour: consumer awareness, contextual factors and community. Drawing on evidence from a European research project called CHANGING BEHAVIOUR, we discuss where previous efforts to change energy behaviour have succeeded in making a difference. We highlight ways in which sociotechnical systems shaping consumption can be changed and emerging ways in which consumers can join forces to achieve greater power and reach. This analysis has implications for attempts to build a more sustainable consumer society, including, but not limited to, the need to reduce primary energy consumption and greenhouse gas emissions

    Implicit rating: A potential new method to alert crisis on the interbank lending market

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    A new measure called “implicit rating” is introduced which might be a component of an early warning system. The proposed methodology relies on the aggregation of experts’ knowledge hidden in the transactional data of the interbank market of unsecured loans. Banks are simultaneously assessing the creditworthiness of each other which is reflected in the partner limits and in the interest rates. In the Hungarian interbank market the overall trading volume and the average interest rate did not show any negative trends before the crisis of 2008, however the average implicit partner limit started to decrease several months earlier, hence it might serve as a stress indicator

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