Conductance of deformable molecules with interaction

Zero temperature linear response conductance of molecules with Coulomb interaction and with various types of phonon modes is analysed together with local occupation, local moment, charge fluctuations and fluctuations of molecular deformation. Deformation fluctuations are quantitatively related to charge fluctuations which exhibit similarity also to static charge susceptibility.Comment: 4 pages, color figure

Patient education and disease activity: A study among rheumatoid arthritis patients

Objective: To determine whether patients experiencing high disease activity derive more benefit from patient education than those experiencing low disease activity. - \ud Methods: Data from a randomized study on the effects of a program of patient education were analyzed retrospectively. Four subgroups were studied: the high disease activity subgroup of patients who had participated in the educational program, the complementary low disease activity subgroup, the high disease activity subgroup of controls, and its low disease activity complement. Patients with erythrocyte sedimentation rate >28 mm/first hour were classified as having high disease activity. Effects on frequency of physical exercises, endurance exercises, and relaxation exercises and effects on health status (Modified Health Assessment Questionnaire, Dutch Arthritis Impact Measurement Scales [AIMS]) were measured. - \ud Results: There were no significant differences between the adherence parameters of the various pairs of groups. Four months after the educational program began, anxiety and depression scores on the Dutch-AIMS had increased among participating patients who were experiencing high disease activity and decreased among those who were experiencing low disease activity. - \ud Conclusions: Patients experiencing high disease activity did not derive more benefit from patient education than those experiencing low disease activity. On the contrary, an increase of anxiety and depression is found in these patients. Further study is needed to confirm our findings

Entanglement and transport through correlated quantum dot

We study quantum entanglement in a single-level quantum dot in the linear-response regime. The results show, that the maximal quantum value of the conductance 2e^2/h not always match the maximal entanglement. The pairwise entanglement between the quantum dot and the nearest atom of the lead is also analyzed by utilizing the Wootters formula for charge and spin degrees of freedom separately. The coexistence of zero concurrence and the maximal conductance is observed for low values of the dot-lead hybridization. Moreover, the pairwise concurrence vanish simultaneously for charge and spin degrees of freedom, when the Kondo resonance is present in the system. The values of a Kondo temperature, corresponding to the zero-concurrence boundary, are also provided.Comment: Presented on the International Conference "Nanoelectronics '06", 7-8 January 2006, Lancaster, U

Some exact results for the multicomponent t-J model

We present a generalization of the Sutherland's multicomponent model. Our extension includes both the ferromagnetic and the antiferromagnetic t-J model for any value of the exchange coupling J and the hopping parameter t. We prove rigorously that for one dimensional chains the ground-state of the generalized model is non-degenerate. As a consequence, the ordering of energy levels of the antiferromagnetic t-J model is determined. Our result rigorously proves and extends the analysis carried out by Sutherland in establishing the phase diagram of the model as a function of the number of components.Comment: 11 pages, RevTeX 3.0, no figure

Formulae for zero-temperature conductance through a region with interaction

The zero-temperature linear response conductance through an interacting mesoscopic region attached to noninteracting leads is investigated. We present a set of formulae expressing the conductance in terms of the ground-state energy or persistent currents in an auxiliary system, namely a ring threaded by a magnetic flux and containing the correlated electron region. We first derive the conductance formulae for the noninteracting case and then give arguments why the formalism is also correct in the interacting case if the ground state of a system exhibits Fermi liquid properties. We prove that in such systems, the ground-state energy is a universal function of the magnetic flux, where the conductance is the only parameter. The method is tested by comparing its predictions with exact results and results of other methods for problems such as the transport through single and double quantum dots containing interacting electrons. The comparisons show an excellent quantitative agreement.Comment: 18 pages, 18 figures; to appear in Phys. Rev.

Perception of Nuclear Energy and Coal in France and the Netherlands

This study focuses on the perception of large scale application of nuclear energy and coal in the Netherlands and France. The application of these energy-sources and the risks and benefits are judged differently by various group in society. In Europe, France has the highest density of nuclear power plants and the Netherlands has one of the lowest. In both countries scientists and social scientists completed a questionnaire assessing the perception of the large scale application of both energy sources. Furthermore, a number of variables relating to the socio cultural and political circumstances were measured. The results indicate that the French had a higher risk perception and a more negative attitude toward nuclear power than the Dutch. But they also assess the benefits of the use of nuclear power to be higher. Explanations for these differences are discussed

Oxygen transport and consumption in germinating seeds

Three mathematical models were formulated to describe the oxygen con-sumption of seeds during germination. These models were fitted to measure-ment data of oxygen consumption curves for individual germinating seeds of Savoy cabbage, barley and sugar beet provided by Fytagoras. The first model builds on a logistic growth model for the increasing population of mitochondria in the embryo during growth. The other two take the anatomy and physiologi-cal properties of the seed into account. One describes the oxygen uptake during the germination phase only. An extension of this model is capable of fitting the complete oxygen consumption curve, including the initial ‘repair’ phase in which the embryonic cells recover from their dormant state before extensive cell division and growth commences. Keywords: Modelling, seed germination, cellular respiration, oxygen transpor

A new CT-based method to quantify radiation-induced lung damage in patients

SummaryA new method to assess radiation-induced lung toxicity (RILT) using CT-scans was developed. It is more sensitive in detecting damage and corresponds better to physician-rated radiation pneumonitis than routinely-used methods. Use of this method may improve lung toxicity assessment and thereby facilitate development of more accurate predictive models for RILT

NRG approach to the transport through a finite Hubbard chain connected to reservoirs

We study the low-energy properties of a Hubbard chain of finite size N_C connected to two noninteracting leads using the numerical renormalization group (NRG) method. The results obtained for N_C = 3 and 4 show that the low-lying eigenstates have one-to-one correspondence with the free quasi-particle excitations of a local Fermi liquid. It enables us to determine the transport coefficients from the fixed-point Hamiltonian. At half-filling, the conductance for even N_C decreases exponentially with increasing U showing a tendency towards the development of a Mott-Hubbard gap. In contrast, for odd N_C, the Fermi-liquid nature of the low-energy states assures perfect transmission through the Kondo resonance. Our formulation to deduce the conductance from the fixed-point energy levels can be applied to various types of interacting systems.Comment: One typo found in Eq.(3) in previous version has been correcte