16,734 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
Inflammation and changes in cytokine levels in neurological feline infectious peritonitis.
Feline infectious peritonitis (FIP) is a progressive, fatal, predominantly Arthus-type immune-mediated disease that is triggered when cats are infected with a mutant enteric coronavirus. The disease presents variably with multiple organ failure, seizures, generalized effusion, or shock. Neurological FIP is clinically and pathologically more homogeneous than systemic 'wet' or 'dry' FIP; thus, comparison of cytokine profiles from cats with neurological FIP, wet FIP, and non-FIP neurological disease may provide insight into some baseline characteristics relating to the immunopathogenesis of neurological FIP. This study characterizes inflammation and changes in cytokines in the brain tissue of FIP-affected cats. Cellular infiltrates in cats with FIP included lymphocytes, plasma cells, neutrophils, macrophages, and eosinophils. IL-1 beta, IL-6, IL-12, IL-18, TNF-alpha, macrophage inhibitory protein (MIP)-1 alpha, and RANTES showed no upregulation in the brains of control cats, moderate upregulation in neurological FIP cats, and very high upregulation in generalized FIP cats. Transcription of IFN-gamma appeared upregulated in cats with systemic FIP and slightly downregulated in neurological FIP. In most cytokines tested, variance was extremely high in generalized FIP and much less in neurological FIP. Principal components analysis was performed in order to find the least number of 'components' that would summarize the cytokine profiles in cats with neurological FIP. A large component of the variance (91.7%) was accounted for by levels of IL-6, MIP-1 alpha, and RANTES. These findings provide new insight into the immunopathogenesis of FIP and suggest targets for immune therapy of this disease
Field efficacy of new compounds to replace copper for scab control in organic apple production
Efficacy of compounds was investigated in field experiments in Denmark and the Netherlands according to EPPO guidelines. Some Yucca extracts and potassium bicarbonate had an efficacy similar to sulphur on leaves. Addition of sulphur to Yucca 1 and to potassium bicarbonate increased the level of efficacy to that of copper. This confirms results from earlier years. Although a dose increase resulted in better efficacy, this was more prominent for Yucca1 than for potassium bicarbonate
The productivity and financial impacts of eight types of environmental enrichment for broiler chickens
Reduced mobility in broilers can contribute to leg health problems. Environmental enrichment has been suggested as one approach to combat this through stimulating increased physical activity. Past studies have tested the effect of environmental enrichments on bird behaviour, health and welfare, but few have estimated their financial impacts. This study tested the impact of eight types of environmental enrichment on enterprise net margin, accounting for direct intervention costs plus indirect effects via changes to bird mortality, weight, feed intake, feed conversion ratio, and foot pad dermatitis. The trial used 58 pens each containing approximately 500 broilers (Ross 308) at a stocking density of 40 kg/m2. The environmental enrichments were: roughage, vertical panels, straw bales, elevated platforms (5 and 30 cm), increased distances between feed and water (7 and 3.5 m) and stocking density reduced to 34 kg/m2, plus a control group. Mortality was recorded daily and feed intake and weight weekly. Footpad dermatitis was assessed on day 35. Only one intervention improved financial performance (3.5 m between feed and water) above the control, suggesting that most environmental enrichment would have a negative financial impact due to the additional intervention costs, unless consumers were willing to pay a price premium
Inducing spin-dependent tunneling to probe magnetic correlations in optical lattices
We suggest a simple experimental method for probing antiferromagnetic spin
correlations of two-component Fermi gases in optical lattices. The method
relies on a spin selective Raman transition to excite atoms of one spin species
to their first excited vibrational mode where the tunneling is large. The
resulting difference in the tunneling dynamics of the two spin species can then
be exploited, to reveal the spin correlations by measuring the number of doubly
occupied lattice sites at a later time. We perform quantum Monte Carlo
simulations of the spin system and solve the optical lattice dynamics
numerically to show how the timed probe can be used to identify
antiferromagnetic spin correlations in optical lattices.Comment: 5 pages, 5 figure
Quantification of trypsin with a radioimmunoassay in herring larvae (Clupea harengus) compared with a highly sensitive fluorescence technique to determine tryptic enzyme activity
Enzymatic activity and quantity of the protease trypsin were measured in individual herring larvae (Clupea harengus L.). The enzymatic activity assay was done using a fluorescence technique, and a radioimmunoassay was used for quantification of trypsin. The results are compared and the differences between the techniques discussed. Both methods gave similar results, as high or low values in trypsin quantity were reflected in high or low values of tryptic activity. Quantity and activity were linearly and positively correlated, but small differences between methods were found at the lowest detection limits. Both techniques reflect high variability between individual larvae
Ptychographic X-ray computed tomography of extended colloidal networks in food emulsions
As a main structural level in colloidal food materials, extended colloidal
networks are important for texture and rheology. By obtaining the 3D
microstructure of the network, macroscopic mechanical properties of the
material can be inferred. However, this approach is hampered by the lack of
suitable non-destructive 3D imaging techniques with submicron resolution.
We present results of quantitative ptychographic X-ray computed tomography
applied to a palm kernel oil based oil-in-water emulsion. The measurements were
carried out at ambient pressure and temperature. The 3D structure of the
extended colloidal network of fat globules was obtained with a resolution of
around 300 nm. Through image analysis of the network structure, the fat globule
size distribution was computed and compared to previous findings. In further
support, the reconstructed electron density values were within 4% of reference
values.Comment: 19 pages, 4 figures, to be published in Food Structur
Observations of electron gyroharmonic waves and the structure of the Io torus
Narrow-banded emissions were observed by the Planetary Radio Astronomy experiment on the Voyager 1 spacecraft as it traversed the Io plasma torus. These waves occur between harmonics of the electron gyrofrequency and are the Jovian analogue of electrostatic emissions observed and theoretically studied for the terrestrial magnetosphere. The observed frequencies always include the component near the upper hybrid resonant frequency, (fuhr) but the distribution of the other observed emissions varies in a systematic way with position in the torus. A refined model of the electron density variation, based on identification of the fuhr line, is included. Spectra of the observed waves are analyzed in terms of the linear instability of an electron distribution function consisting of isotropic cold electrons and hot losscone electrons. The positioning of the observed auxiliary harmonics with respect to fuhr is shown to be an indicator of the cold to hot temperature ratio. It is concluded that this ratio increases systematically by an overall factor of perhaps 4 or 5 between the inner and outer portions of the torus
Canted antiferromagnetism in phase-pure CuMnSb
We report the low-temperature properties of phase-pure single crystals of the
half-Heusler compound CuMnSb grown by means of optical float-zoning. The
magnetization, specific heat, electrical resistivity, and Hall effect of our
single crystals exhibit an antiferromagnetic transition at and a second anomaly at a temperature . Powder and single-crystal neutron diffraction establish an
ordered magnetic moment of ,
consistent with the effective moment inferred from the Curie-Weiss dependence
of the susceptibility. Below , the Mn sublattice displays
commensurate type-II antiferromagnetic order with propagation vectors and
magnetic moments along (magnetic space group ).
Surprisingly, below , the moments tilt away from by
a finite angle , forming a canted antiferromagnetic
structure without uniform magnetization consistent with magnetic space group
. Our results establish that type-II antiferromagnetism is not the
zero-temperature magnetic ground state of CuMnSb as may be expected of the
face-centered cubic Mn sublattice.Comment: 14 pages, 15 figure
Tsirelson's problem and Kirchberg's conjecture
Tsirelson's problem asks whether the set of nonlocal quantum correlations
with a tensor product structure for the Hilbert space coincides with the one
where only commutativity between observables located at different sites is
assumed. Here it is shown that Kirchberg's QWEP conjecture on tensor products
of C*-algebras would imply a positive answer to this question for all bipartite
scenarios. This remains true also if one considers not only spatial
correlations, but also spatiotemporal correlations, where each party is allowed
to apply their measurements in temporal succession; we provide an example of a
state together with observables such that ordinary spatial correlations are
local, while the spatiotemporal correlations reveal nonlocality. Moreover, we
find an extended version of Tsirelson's problem which, for each nontrivial Bell
scenario, is equivalent to the QWEP conjecture. This extended version can be
conveniently formulated in terms of steering the system of a third party.
Finally, a comprehensive mathematical appendix offers background material on
complete positivity, tensor products of C*-algebras, group C*-algebras, and
some simple reformulations of the QWEP conjecture.Comment: 57 pages, to appear in Rev. Math. Phy
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