26,555 research outputs found

    The BIOEXPLOIT Project

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    The EU Framework 6 Integrated Project BIOEXPLOIT concerns the exploitation of natural plant biodiversity for the pesticide-free production of food. It focuses on the pathogens Phytophthora infestans, Septoria tritici, Blumeria graminis, Puccinia spp. and Fusarium spp. and on the crops wheat, barley, tomato and potato. The project commenced in October 2005, comprises 45 laboratories in 12 countries, and is carried out by partners from research institutes, universities, private companies and small-medium enterprises. The project has four strategic objectives covered in eight sub-projects. These objectives relate to (i) understanding the molecular components involved in durable disease resistance, (ii) exploring and exploiting the natural biodiversity in disease resistance, (iii) accelerating the introduction of marker-assisted breeding and genetic engineering in the EU plant breeding industry, and (iv) coordinating and integrating resistance breeding research, providing training in new technologies, disseminating the results, and transferring knowledge and technologies to the industry

    Light meson radial Regge trajectories

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    A new physical mechanism is suggested to explain the universal depletion of high meson excitations. It takes into account the appearance of holes inside the string world sheet due to qqˉq\bar{q} pair creation when the length of the string exceeds the critical value R11.4R_1 \simeq 1.4 fm. It is argued that a delicate balance between large NcN_c loop suppression and a favorable gain in the action, produced by holes, creates a new metastable (predecay) stage with a renormalized string tension which now depends on the separation r. This results in smaller values of the slope of the radial Regge trajectories, in good agreement with the analysis of experimental data in [Ref.3]Comment: 25 pages, 1 figur

    The ccˉc\bar c interaction above threshold and the radiative decay X(3872)J/ψγX(3872)\rightarrow J/\psi\gamma

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    Radiative decays of X(3872)X(3872) are studied in single-channel approximation (SCA) and in the coupled-channel (CC) approach, where the decay channels DDˉD\bar D^* are described with the string breaking mechanism. In SCA the transition rate Γ~2=Γ(23P1ψγ)=71.8\tilde{\Gamma}_2=\Gamma(2\,{}^3P_1 \rightarrow \psi\gamma)=71.8~keV and large Γ~1=Γ(23P1J/ψγ)=85.4\tilde{\Gamma}_1=\Gamma(2\,{}^3P_1\rightarrow J/\psi\gamma)=85.4~keV are obtained, giving for their ratio the value Rψγ~=Γ~2Γ~1=0.84\tilde{R_{\psi\gamma}}=\frac{\tilde{\Gamma}_2}{\tilde{\Gamma}_1}=0.84. In the CC approach three factors are shown to be equally important. First, the admixture of the 13P11\,{}^3P_1 component in the normalized wave function of X(3872)X(3872) due to the CC effects. Its weight cX(ER)=0.200±0.015c_{\rm X}(E_{\rm R})=0.200\pm 0.015 is calculated. Secondly, the use of the multipole function g(r)g(r) instead of rr in the overlap integrals, determining the partial widths. Thirdly, the choice of the gluon-exchange interaction for X(3872)X(3872), as well as for other states above threshold. If for X(3872)X(3872) the gluon-exchange potential is taken the same as for low-lying charmonium states, then in the CC approach Γ1=Γ(X(3872)J/ψγ)3\Gamma_1= \Gamma(X(3872)\rightarrow J/\psi\gamma) \sim 3~keV is very small, giving the large ratio Rψγ=B(X(3872)ψ(2S)γ)B(X(3872)J/ψγ)1.0R_{\psi\gamma}=\frac{\mathcal{B}(X(3872)\rightarrow \psi(2S)\gamma)}{\mathcal{B}(X(3872)\rightarrow J/\psi\gamma)}\gg 1.0. Arguments are presented why the gluon-exchange interaction may be suppressed for X(3872)X(3872) and in this case Γ1=42.7\Gamma_1=42.7~keV, Γ2=70.5\Gamma_2= 70.5~keV, and Rψγ=1.65R_{\psi\gamma}=1.65 are predicted for the minimal value cX(min)=0.185c_{\rm X}({\rm min})=0.185, while for the maximal value cX=0.215c_{\rm X}=0.215 we obtained Γ1=30.8\Gamma_1=30.8~keV, Γ2=73.2\Gamma_2=73.2~keV, and Rψγ=2.38R_{\psi\gamma}=2.38, which agrees with the LHCb data.Comment: 12 pages, no figure

    Integral resource capacity planning for inpatient care services based on hourly bed census predictions

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    The design and operations of inpatient care facilities are typically largely historically shaped. A better match with the changing environment is often possible, and even inevitable due to the pressure on hospital budgets. Effectively organizing inpatient care requires simultaneous consideration of several interrelated planning issues. Also, coordination with upstream departments like the operating theater and the emergency department is much-needed. We present a generic analytical approach to predict bed census on nursing wards by hour, as a function of the Master Surgical Schedule (MSS) and arrival patterns of emergency patients. Along these predictions, insight is gained on the impact of strategic (i.e., case mix, care unit size, care unit partitioning), tactical (i.e., allocation of operating room time, misplacement rules), and operational decisions (i.e., time of admission/discharge). The method is used in the Academic Medical Center Amsterdam as a decision support tool in a complete redesign of the inpatient care operations

    Scheduling microCHPs in a group of houses

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    The increasing penetration of renewable energy sources, the demand for more energy efficient electricity production and the increase in distributed electricity generation causes a shift in the way electricity is produced and consumed. The downside of these changes in the electricity grid is that network stability and controllability become more difficult compared to the old situation. The new network has to accommodate various means of production, consumption and buffering and needs to offer control over the energy flows between these three elements.\ud In order to offer such a control mechanism we need to know more about the individual aspects. In this paper we focus on the modelling of distributed production. Especially, we look at the use of microCHP (Combined Heat and Power) appliances in a group of houses.\ud The problem of planning the production runs of the microCHP is modelled via an ILP formulation, both for a single house and for a group of houses.\u

    Pauli-Potential and Green Function Monte-Carlo Method for Many-Fermion Systems

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    The time evolution of a many-fermion system can be described by a Green's function corresponding to an effective potential, which takes anti-symmetrization of the wave function into account, called the Pauli-potential. We show that this idea can be combined with the Green's Function Monte Carlo method to accurately simulate a system of many non-relativistic fermions. The method is illustrated by the example of systems of several (2-9) fermions in a square well.Comment: 12 pages, LaTeX, 4 figure

    On the microCHP scheduling problem

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    In this paper both continuous and discrete models for the microCHP (Combined Heat and Power) scheduling problem are derived. This problem consists of the decision making to plan runs for a specific type of distributed electricity\ud generators, the microCHP. As a special result, one model variant of the problem, named n-DSHSP-restricted, is proven to be NP-complete in the strong sense. This shows the necessity of the development of heuristics for the scheduling of microCHPs, in case multiple generators are combined in a so-called fleet

    The leptonic widths of high ψ\psi-resonances in unitary coupled-channel model

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    The leptonic widths of high ψ\psi-resonances are calculated in a coupled-channel model with unitary inelasticity, where analytical expressions for mixing angles between (n+1)3S1(n+1)\,^3S_1 and n3D1n\,^3D_1 states and probabilities ZiZ_i of the ccˉc\bar c component are derived. Since these factors depend on energy (mass), different values of mixing angles θ(ψ(4040))=27.7\theta(\psi(4040))=27.7^\circ and θ(ψ(4160))=29.5\theta(\psi(4160))=29.5^\circ, Z1(ψ(4040))=0.76Z_1\,(\psi(4040))=0.76, and Z2(ψ(4160))=0.62Z_2\,(\psi(4160))=0.62 are obtained. It gives the leptonic widths Γee(ψ(4040))=Z11.17=0.89\Gamma_{ee}(\psi(4040))=Z_1\, 1.17=0.89~keV, Γee(ψ(4160))=Z20.76=0.47\Gamma_{ee}(\psi(4160))=Z_2\, 0.76=0.47~keV in good agreement with experiment. For ψ(4415)\psi(4415) the leptonic width Γee(ψ(4415))= 0.55\Gamma_{ee}(\psi(4415))=~0.55~keV is calculated, while for the missing resonance ψ(4510)\psi(4510) we predict M(ψ(4500))=(4515±5)M(\psi(4500))=(4515\pm 5)~MeV and Γee(ψ(4510))0.50\Gamma_{ee}(\psi(4510)) \cong 0.50~keV.Comment: 10 pages, 6 references corrected, some new material adde

    Effect of disorder on the conductance of a Cu atomic point contact

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    We present a systematic study of the effect of the disorder in copper point contacts. We show that peaks in the conductance histogram of copper point contacts shift upon addition of nickel impurities. The shift increases initially linerarly with the nickel concentration, thus confirming that it is due to disorder in the nanowire, in accordance with predictions. In general, this shift is modelled as a resistance R_s which is placed in series with the contact resistance R_c. However, we obtain different R_s values for the two peaks in the histogram, R_s being larger for the peak at higher conductance.Comment: 6 pages, 4 figure
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