533 research outputs found

    Parameter studies on optimal absorption and electrophoretic resonances in lossy media

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    This paper summarizes and elaborates on some new results on the optimal absorption in small spherical suspensions based on electrophoretic (plasmonic) resonances and lossy surrounding media. The main application here is to study the physical limitations for radio frequency absorption in gold nanoparticle (GNP) suspensions and its potential to achieve GNP targeted hyperthermia in cancer therapy. Numerical parameter studies are included to demonstrate the analysis approach

    Higher CSF/serum free-T4 ratio is associated with improvement of quality of life during treatment with L-thyroxine

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    Up to 20% of individuals with primary hypothyroidism treated with L-thyroxine still suffer from severe symptoms. These are supposedly brain derived and involve both cognitive and emotional domains. Previously, no consistent relationship has been found between thyroid hormones (TH) or TSH levels in blood and quality of life (QoL). Recently, we reported an association between cerebrospinal fluid (CSF)/serum free-thyroxine (f-T4) ratio and QoL, in juvenile hypothyroid patients. Here, we investigated if CSF/serum f-T4 ratio and QoL estimates correlate also during L-thyroxine treatment. Moreover, the CSF biomarker neurogranin (Ng) was used as a biomarker for synaptic function and integrity in clinical research. Ng is partially controlled by TH and therefore we investigated the relationship between QoL parameters and Ng levels. Patients diagnosed with primary hypothyroidism were investigated using vital parameters, serum and CSF analyses of TH, TSH, Ng and QoL questionnaires. Similar procedures were performed after 6 months of treatment. The most marked associations with QoL were found for CSF/serum f-T4 ratio, which was strongly related to several QoL parameters such as the mental subscore of SF-36 (r = 0.83, p <.0005). Ng, which did not differ from that in our healthy controls, was lower in some patients during treatment and higher in others. However, the change in Ng during treatment was significantly correlated with QoL parameters including the mental subscore of SF-36 (r = −0.86, p <.0001). In addition, the CSF/serum f-T4 ratio correlated with the change in Ng (r = −0.75, p =.001). Our results suggest that the ratio between CSF and serum f-T4 is an important biomarker for QoL during treatment of patients with primary hypothyroidism, so far in research, but in the future maybe also in clinical settings. Moreover, this ratio also correlates with the changes in Ng levels during L-thyroxine treatment, further supporting the impact of the TH balance between serum and CSF on QoL

    r-modes in Relativistic Superfluid Stars

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    We discuss the modal properties of the rr-modes of relativistic superfluid neutron stars, taking account of the entrainment effects between superfluids. In this paper, the neutron stars are assumed to be filled with neutron and proton superfluids and the strength of the entrainment effects between the superfluids are represented by a single parameter η\eta. We find that the basic properties of the rr-modes in a relativistic superfluid star are very similar to those found for a Newtonian superfluid star. The rr-modes of a relativistic superfluid star are split into two families, ordinary fluid-like rr-modes (ror^o-mode) and superfluid-like rr-modes (rsr^s-mode). The two superfluids counter-move for the rsr^s-modes, while they co-move for the ror^o-modes. For the ror^o-modes, the quantity κσ/Ω+m\kappa\equiv\sigma/\Omega+m is almost independent of the entrainment parameter η\eta, where mm and σ\sigma are the azimuthal wave number and the oscillation frequency observed by an inertial observer at spatial infinity, respectively. For the rsr^s-modes, on the other hand, κ\kappa almost linearly increases with increasing η\eta. It is also found that the radiation driven instability due to the rsr^s-modes is much weaker than that of the ror^o-modes because the matter current associated with the axial parity perturbations almost completely vanishes.Comment: 14 pages, 4 figures. To appear in Physical Review

    A phenomenological equation of state for isospin asymmetric nuclear matter

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    A phenomenological momentum-independent (MID) model is constructed to describe the equation of state (EOS) for isospin asymmetric nuclear matter, especially the density dependence of the nuclear symmetry energy Esym(ρ)E_{\text{\textrm{sym}}}(\rho). This model can reasonably describe the general properties of the EOS for symmetric nuclear matter and the symmetry energy predicted by both the sophisticated isospin and momentum dependent MDI model and the Skyrme-Hartree-Fock approach. We find that there exists a nicely linear correlation between KsymK_{\mathrm{sym}} and LL as well as between J0/K0J_{0}/K_{0} and K0K_{0}, where LL and KsymK_{\mathrm{sym}} represent, respectively, the slope and curvature parameters of the symmetry energy at the normal nuclear density ρ0\rho_{0} while K0K_{0} and J0J_{0} are, respectively, the incompressibility and the third-order derivative parameter of symmetric nuclear matter at ρ0\rho_{0}. These correlations together with the empirical constraints on K0K_{0}, LL and Esym(ρ0)E_{\text{\textrm{sym}}}(\rho_{0}) lead to an estimation of -477 MeV Ksat,2241\leq K_{\mathrm{sat,2}}\leq -241 MeV for the second-order isospin asymmetry expansion coefficient for the incompressibility of asymmetric nuclear matter at the saturation point.Comment: 9 pages, 4 figures, contribution to Special Topic on Large-Scale Scientific Facilities (LSSF) in Science in China Series G: Physics, Mechanics & Astronom

    Toward Human-Carnivore Coexistence: Understanding Tolerance for Tigers in Bangladesh

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    Fostering local community tolerance for endangered carnivores, such as tigers (Panthera tigris), is a core component of many conservation strategies. Identification of antecedents of tolerance will facilitate the development of effective tolerance-building conservation action and secure local community support for, and involvement in, conservation initiatives. We use a stated preference approach for measuring tolerance, based on the ‘Wildlife Stakeholder Acceptance Capacity’ concept, to explore villagers’ tolerance levels for tigers in the Bangladesh Sundarbans, an area where, at the time of the research, human-tiger conflict was severe. We apply structural equation modeling to test an a priori defined theoretical model of tolerance and identify the experiential and psychological basis of tolerance in this community. Our results indicate that beliefs about tigers and about the perceived current tiger population trend are predictors of tolerance for tigers. Positive beliefs about tigers and a belief that the tiger population is not currently increasing are both associated with greater stated tolerance for the species. Contrary to commonly-held notions, negative experiences with tigers do not directly affect tolerance levels; instead, their effect is mediated by villagers’ beliefs about tigers and risk perceptions concerning human-tiger conflict incidents. These findings highlight a need to explore and understand the socio-psychological factors that encourage tolerance towards endangered species. Our research also demonstrates the applicability of this approach to tolerance research to a wide range of socio-economic and cultural contexts and reveals its capacity to enhance carnivore conservation efforts worldwide

    GPML: an XML-based standard for the interchange of genetic programming trees

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    We propose a Genetic Programming Markup Language (GPML), an XML based standard for the interchange of genetic programming trees, and outline the benefits such a format would bring in allowing the deployment of trained genetic programming (GP) models in applications as well as the subsidiary benefit of allowing GP researchers to directly share trained trees. We present a formal definition of this standard and describe details of an implementation. In addition, we present a case study where GPML is used to implement a model predictive controller for the control of a building heating plant

    Solving the chemical master equation using sliding windows

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    <p>Abstract</p> <p>Background</p> <p>The chemical master equation (CME) is a system of ordinary differential equations that describes the evolution of a network of chemical reactions as a stochastic process. Its solution yields the probability density vector of the system at each point in time. Solving the CME numerically is in many cases computationally expensive or even infeasible as the number of reachable states can be very large or infinite. We introduce the sliding window method, which computes an approximate solution of the CME by performing a sequence of local analysis steps. In each step, only a manageable subset of states is considered, representing a "window" into the state space. In subsequent steps, the window follows the direction in which the probability mass moves, until the time period of interest has elapsed. We construct the window based on a deterministic approximation of the future behavior of the system by estimating upper and lower bounds on the populations of the chemical species.</p> <p>Results</p> <p>In order to show the effectiveness of our approach, we apply it to several examples previously described in the literature. The experimental results show that the proposed method speeds up the analysis considerably, compared to a global analysis, while still providing high accuracy.</p> <p>Conclusions</p> <p>The sliding window method is a novel approach to address the performance problems of numerical algorithms for the solution of the chemical master equation. The method efficiently approximates the probability distributions at the time points of interest for a variety of chemically reacting systems, including systems for which no upper bound on the population sizes of the chemical species is known a priori.</p
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