37,407 research outputs found
Combined production of broilers and fruits
Combined production of broilers and fruit trees is a subject often discussed in organic fruit
production in Denmark. Very little research has been carried out on this type of production
system. In organic production in Denmark, nearly no pesticides are allowed, so the need
for alternative pest control is large. Apple sawfly (Hoplocampa testudinea) and pear midge
(Contarinia pyrivora) cause big crop losses in apples and pears respectively, in unsprayed
organic fruit production. Both insects infest fruitlets and cause these to drop prematurely
after which the pests pupate in the topsoil. In the present experiment a research orchard
with the varieties ‘Discovery’ and ‘Conference’ were used as outdoor area for broilers to
minimise the population of sawflies and pear midges, and to reduce the need for weeding
and manuring. The trees were kept unsprayed. Fruit yield and fruit quality were assessed
at harvest. White sticky traps were placed in the test area in order to measure the
occurrence of sawfly over time. The infestation of pear midge was investigated counting
the infested fruitlets in clusters on trees at the centre of the plots. The catch of apple
sawflies was reduced in the combined apple and broiler production, but no significant
effect on the yield or the fruit quality was seen. Experiences from on-farm research show
that combining fruit and egg-production is one way to reduce the problem with apple
sawfly, but poultry alone is not a sufficient way of controlling sawflies. The welfare and
health of the broilers were excellent under fruit trees
Fluid Dynamical Description of the Chiral Transition
We investigate the dynamics of the chiral transition in an expanding
quark-anti-quark plasma. The calculations are made within a linear sigma model
with explicit quark and antiquark degrees of freedom. We solve numerically the
classical equations of motion for chiral fields coupled to the fluid dynamical
equations for the plasma. Fast initial growth and strong oscillations of the
chiral field and strong amplification of long wavelength modes of the pion
field are observed in the course of the chiral transition.Comment: 9 pages LaTeX, 4 postscript figure
Null-Wave Giant Gravitons from Thermal Spinning Brane Probes
We construct and analyze thermal spinning giant gravitons in type II/M-theory
based on spherically wrapped black branes, using the method of thermal probe
branes originating from the blackfold approach. These solutions generalize in
different directions recent work in which the case of thermal (non-spinning)
D3-brane giant gravitons was considered, and reveal a rich phase structure with
various new properties. First of all, we extend the construction to M-theory,
by constructing thermal giant graviton solutions using spherically wrapped M2-
and M5-branes. More importantly, we switch on new quantum numbers, namely
internal spins on the sphere, which are not present in the usual extremal limit
for which the brane world volume stress tensor is Lorentz invariant. We examine
the effect of this new type of excitation and in particular analyze the
physical quantities in various regimes, including that of small temperatures as
well as low/high spin. As a byproduct we find new stationary dipole-charged
black hole solutions in AdS_m X S^n backgrounds of type II/M-theory. We finally
show, via a double scaling extremal limit, that our spinning thermal giant
graviton solutions lead to a novel null-wave zero-temperature giant graviton
solution with a BPS spectrum, which does not have an analogue in terms of the
conventional weakly coupled world volume theory.Comment: v1: 31p
An isolated epizootic of hemorrhagic-like fever in cats caused by a novel and highly virulent strain of feline calicivirus.
An isolated epizootic of a highly fatal feline calicivirus (FCV) infection, manifested in its severest form by a systemic hemorrhagic-like fever, occurred over a 1-month period among six cats owned by two different employees and a client of a private veterinary practice. The infection may have started with an unowned shelter kitten that was hospitalized during this same period for a severe atypical upper respiratory infection. The causative agent was isolated from blood and nasal swabs from two cats; the electron microscopic appearance was typical for FCV and capsid gene sequencing showed it to be genetically similar to other less pathogenic field strains. An identical disease syndrome was recreated in laboratory cats through oral inoculation with tissue culture grown virus. During the course of transmission studies in experimental cats, the agent was inadvertently spread by caretakers to an adjoining room containing a group of four normal adult cats. One of the four older cats was found dead and a second was moribund within 48-72h in spite of symptomatic treatment; lesions in these animals were similar to those of the field cats but with the added feature of severe pancreatitis. The mortality in field cats, deliberately infected laboratory cats, and inadvertently infected laboratory cats ranged from 33-50%. This new isolate of calicivirus, named FCV-Ari, was neutralized at negligible to low titer by antiserum against the universal FCV-F9 vaccine strain. Cats orally immunized with FCV-F9, and then challenge-exposed shortly thereafter with FCV-Ari, developed a milder self-limiting form of disease, indicating partial protection. However, all of the field cats, including the three that died, had been previously immunized with parenteral FCV-F9 vaccine. FCV-Ari caused a disease that was reminiscent of Rabbit Hemorrhagic Disease, a highly fatal calicivirus infection of older rabbits
Continuous and discrete flows on operator algebras
Let be a centrally ergodic W* dynamical system. When is
not a factor, we show that, for each , the crossed product induced by
the time automorphism is not a factor if and only if there exist
a rational number and an eigenvalue of the restriction of to
the center of , such that . In the C* setting, minimality seems to
be the notion corresponding to central ergodicity. We show that if
is a minimal unital C* dynamical system and is either prime
or commutative but not simple, then, for each , the crossed product
induced by the time automorphism is not simple if and only if
there exist a rational number and an eigenvalue of the restriction of
to the center of , such that .Comment: 7 page
Anomalous surface waves from Lop Nor nuclear explosions: Observations and numerical modeling
Surface waves from the Chinese test site of Lop Nor are analyzed using long-period and broadband stations located at regional and teleseismic distances and at different azimuths. For most azimuths, strong Love waves between 0.02 and 0.045 Hz are observed with an amplitude of up to 10 times that of the Rayleigh waves. In addition, an anomalous early Rayleigh wave train is observed at some stations in western Europe. Due to a particularly favorable station and source configuration, it is possible to isolate the areas where the anomalies are created. The high-amplitude Love waves must be attributed to either source effects or path effects immediately north of Lop Nor. The early wave train is shown to be due to a partial energy conversion between Love and Rayleigh waves, probably at the Tornquist Zone. To estimate the possible contribution from surface wave conversions to the observed anomalies, numerical simulations are carried out with the indirect boundary element method. The simulations show that a relatively small variation of crustal thickness can induce Rayleigh to Love wave conversions between 0.02 and 0.1 Hz frequency. The calculated amplitudes of the Love waves are significant (up to 35% of the amplitude of the incoming Rayleigh waves), but they are too small to fit the observed amplitude anomaly. The observed converted waves and the numerical results nevertheless indicate that surface wave conversions can be significant across strong lateral crustal heterogeneities. In particular, the conversions due to changes in crustal thickness are located in the period interval which is routinely used for estimation of Ms
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