21,865 research outputs found
The BIOEXPLOIT Project
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
Strong coupling constant from bottomonium fine structure
From a fit to the experimental data on the fine structure, the
two-loop coupling constant is extracted. For the 1P state the fitted value is
at the scale GeV, which corresponds to the QCD constant MeV (n_f = 4) and \alpha_s(\mu_2) = 0.40 \pm 0.02(exp)\pm 0.02(th)\mu_2 = 1.02 \pm 0.2\alpha_s(1.0) \approx 0.40\alpha_s\alpha_s$ are found to be about 15%.Comment: 18 pages LaTe
The leptonic widths of high -resonances in unitary coupled-channel model
The leptonic widths of high -resonances are calculated in a
coupled-channel model with unitary inelasticity, where analytical expressions
for mixing angles between (n+1)\,^3S_1 and n\,^3D_1 states and
probabilities of the component are derived. Since these factors
depend on energy (mass), different values of mixing angles
and ,
, and are obtained. It gives
the leptonic widths ~keV,
~keV in good agreement with
experiment. For the leptonic width
~keV is calculated, while for the missing
resonance we predict ~MeV and
~keV.Comment: 10 pages, 6 references corrected, some new material adde
Higher excitations of the and mesons
The masses of higher and excitations are shown to decrease
due to the string contribution, originating from the rotation of the QCD string
itself: it lowers the masses by 45 MeV for and by 65 MeV for . An additional decrease MeV takes place if the current mass
of the light (strange) quark is used in a relativistic model. For
and the calculated masses agree with the
experimental values for and , and the masses of
, , , and are in
agreement with the new BaBar data. For the yet undiscovered resonances we
predict the masses MeV, MeV,
MeV, and MeV. We show that
for the states with and () are almost
completely unmixed (), which implies that the mixing
angles between the states with S=1 and S=0 () are for L=2 and for L=3.Comment: 22 pages, no figures, 4 tables Two references and corresponding
discussion adde
The heavy-quark pole masses in the Hamiltonian approach
From the fact that the nonperturbative self-energy contribution
to the heavy meson mass is small: ; MeV \cite{ref.01}, strong restrictions on the pole
masses and are obtained. The analysis of the and the
spectra with the use of relativistic (string) Hamiltonian gives
(2-loop) GeV and (2-loop) GeV which
correspond to the running mass GeV and GeV. The masses
and , which define the heavy quarkonia spin structure, are shown to
be by MeV larger than the pole ones.Comment: 18 pages, no figures, 8 table
Light meson radial Regge trajectories
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 pair creation when the length of the
string exceeds the critical value fm. It is argued that a
delicate balance between large 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 interaction above threshold and the radiative decay
Radiative decays of are studied in single-channel approximation
(SCA) and in the coupled-channel (CC) approach, where the decay channels are described with the string breaking mechanism. In SCA the transition
rate ~keV and
large ~keV
are obtained, giving for their ratio the value
. In the
CC approach three factors are shown to be equally important. First, the
admixture of the component in the normalized wave function of
due to the CC effects. Its weight is calculated. Secondly, the use of the multipole function
instead of in the overlap integrals, determining the partial widths.
Thirdly, the choice of the gluon-exchange interaction for , as well as
for other states above threshold. If for the gluon-exchange potential
is taken the same as for low-lying charmonium states, then in the CC approach
~keV is very small,
giving the large ratio .
Arguments are presented why the gluon-exchange interaction may be suppressed
for and in this case ~keV, ~keV, and
are predicted for the minimal value , while for the maximal value we obtained
~keV, ~keV, and , which
agrees with the LHCb data.Comment: 12 pages, no figure
Health Planner Pigs as an Instrument for Monitoring and Evaluation of Animal Health Care on Pig Farms
In order to support animal health care on pig farms a Health Planner Pigs has been developed. In 1998 the practical value of the system was tested under field condition on pig farms. The Health Planner proved to be a valuable instrument for monitoring and evaluating animal health on pig farms. Due to the promising results of the field experiment, the Dutch Farmers Organisation (LTO-Nederland) in 1999 adopted the system and coordinates its adaptation and introduction into practice. In 2001, veterinarians and farm advisers has been educated in using the Health Planner. Some parts of the Health Planner will be automised and linked to existing farm management information systems. In 2002, farmers will be educated in the use of it.Farm Management, Livestock Production/Industries,
Flexible nurse staffing based on hourly bed census predictions
Workload on nursing wards depends highly on patient arrivals and patient lengths of stay, which are both inherently variable. Predicting this workload and staffing nurses accordingly is essential for guaranteeing quality of care in a cost effective manner. This paper introduces a stochastic method that uses hourly census predictions to derive efficient nurse staffing policies. The generic analytic approach minimizes staffing levels while satisfying so-called nurse-to-patient ratios. In particular, we explore the potential of flexible staffing policies which allow hospitals to dynamically respond to their fluctuating patient population by employing float nurses. The method is applied to a case study of the surgical inpatient clinic of the Academic Medical Center (AMC) Amsterdam. This case study demonstrates the method's potential to study the complex interaction between staffing requirements and several interrelated planning issues such as case mix, care unit partitioning and size, and surgical block planning. Inspired by the numerical results, the AMC decided that this flexible nurse staffing methodology will be incorporated in the redesign of the inpatient care operations during the upcoming years
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