10,210 research outputs found
How can private standard accelerate the development of organic production?
It is possible to use private standards to increase the speed in development of organic production in a wide range of areas and to do that on a solid scientific basis. KRAV has recently improved the standard performance in reducing climate impact of the production and the methodology from this work will be possible to use in several areas such as reduction of environmental impact, animal welfare and reduction of health risk for consumers
It is obvious, though, that we need to get more knowledge on how consumers value our extra requirements in the standard and their willingness to pay for these since this is of crucial importance to motivate the producers to accept more stringent standards
Expected and Predicted Realignments: The FF/DM Exchange Rate During the EMS
An empirical model of time-varying realignment risk in an exchange rate target zone is developed. Expected rates of devaluation are estimated as the difference between interest race differentials and estimated expected rates of depreciation within the exchange rate band, using French Franc/Deutsche Mark data during the European Monetary System. The behavior of estimated expected rates of depreciation accord well with the theoretical model of Bertola-Svensson (1990) . We are also able to predict actual realignments with some success.
Superdeformed bands in neutron-rich Sulfur isotopes suggested by cranked Skyrme-Hartree-Fock calculations
On the basis of the cranked Skyrme-Hartree-Fock calculations in the
three-dimensional coordinate-mesh representation, we suggest that, in addition
to the well-known candidate 32S, the neutron-rich nucleus 36S and the drip-line
nuclei,48S and 50S, are also good candidates for finding superdeformed
rotational bands in Sulfur isotopes. Calculated density distributions for the
superdeformed states in 48S and 50S exhibit superdeformed neutron skinsComment: 18 pages including 10 ps figure
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Trade and ethnozoological use of African lorisiformes in the last 20 years
Trade in primates is considered a major impediment to primate conservation globally. The bushmeat trade in West and Central Africa is considered largely unsustainable and represents one of the main threats to biodiversity. Furthermore, the use of primates in traditional practices and medicine includes a third of the African primate species. Little is known about the trade in the African mainland lorisiforms; pottos, angwantibos and galagos. Aiming to fill this knowledge gap we created an online survey, conducted a literature review, and analyzed CITES trade records, focusing on the last two decades. We obtained 188 questionnaire responses from researchers and people working in 31 different countries in sub-Saharan Africa. We found a total of 33 publications reporting on trade in African lorisiforms, and CITES records indicate that almost 2000 lorisiforms were traded internationally from African range countries. Fifty-three percent of respondents provided meaningful details about aspects of the trade in African lorisiforms from 50% of the range countries. Galagos were reported by respondents in larger numbers than pottos and angwantibos, and mainly occurred in the pet trade. Pottos were the most frequently mentioned taxon in the literature, when all trade types were combined. Across all of the sources (online survey, literature and CITES database), trade in pottos and angwantibos was reported from 12 countries, and galagos from 23 countries. Trade was reported to occur mainly within rural settings (64%), potentially indicating that demand is not high enough to fuel long distance trading. However, as seen in the Asian lorisiforms, once quantitative studies were conducted, the threat that trade posed became alarmingly apparent and is now considered a major impediment to their conservation. Our insight into the trade of African lorisiforms should be followed up with concerted studies, with an emphasis on quantifying trade to the species level
An analysis of the Bayesian track labelling problem
In multi-target tracking (MTT), the problem of assigning labels to tracks (track labelling) is vastly covered in literature, but its exact mathematical formulation, in terms of Bayesian statistics, has not been yet looked at in detail. Doing so, however, may help us to understand how Bayes-optimal track labelling should be performed or numerically approximated. Moreover, it can help us to better understand and tackle some practical difficulties associated with the MTT problem, in particular the so-called ``mixed labelling'' phenomenon that has been observed in MTT algorithms. In this memorandum, we rigorously formulate the optimal track labelling problem using Finite Set Statistics (FISST), and look in detail at the mixed labeling phenomenon. As practical contributions of the memorandum, we derive a new track extraction formulation with some nice properties and a statistic associated with track labelling with clear physical meaning. Additionally, we show how to calculate this statistic for two well-known MTT algorithms
Housing, Feeding and Management of Calves and Replacement Heifers in Swedish Dairy Herds
A questionnaire was sent to 1500 randomly selected dairy herds in Sweden, asking for general information about the herds, including routines from birth to first calving and also routines at breeding, calving and during the grazing period. Fifty-eight percent of the questionnaires were returned. The preweaned calves were kept in individual calf pens in 68% and in group housing systems in 28% of the herds. Pens with slatted floors were the main housing system for replacement heifers from weaning to breeding, and tie stalls from breeding to first calving. Whole milk was used in 44% and milk replacements in 42% of the herds. The calves received, as a median, 2.5 litres of milk per meal and 2 meals per day. The median age at weaning was 8 weeks. Age was the single most common criteria used for deciding both weaning and breeding time. The median age when the heifers were first turned out to pasture was 6 months. Prophylactic anthelmintic treatment was used by 65% of the herds. The most common diet for replacement heifers before calving was a combination of grain, hay and silage
Journal Staff
The aluminum–zinc-vacancy (Al Zn −V Zn ) complex is identified as one of the dominant defects in Al-containing n -type ZnO after electron irradiation at room temperature with energies above 0.8 MeV. The complex is energetically favorable over the isolated V Zn , binding more than 90% of the stable V Zn ’s generated by the irradiation. It acts as a deep acceptor with the (0/− ) energy level located at approximately 1 eV above the valence band. Such a complex is concluded to be a defect of crucial and general importance that limits the n -type doping efficiency by complex formation with donors, thereby literally removing the donors, as well as by charge compensation
ON THE GEOMETRY OF THE X-RAY EMITTING REGION IN SEYFERT GALAXIES
For the first time, detailed radiative transfer calculations of Comptonized
X-ray and gamma-ray radiation in a hot pair plasma above a cold accretion disk
are performed using two independent codes and methods. The simulations include
both energy and pair balance as well as reprocessing of the X- and gamma-rays
by the cold disk. We study both plane-parallel coronae as well as active
dissipation regions having shapes of hemispheres and pill boxes located on the
disk surface. It is shown, contrary to earlier claims, that plane-parallel
coronae in pair balance have difficulties in selfconsistently reproducing the
ranges of 2-20 keV spectral slopes, high energy cutoffs, and compactnesses
inferred from observations of type 1 Seyfert galaxies. Instead, the
observations are consistent with the X-rays coming from a number of individual
active regions located on the surface of the disk.
A number of effects such as anisotropic Compton scattering, the reflection
hump, feedback to the soft photon source by reprocessing, and an active region
in pair equilibrium all conspire to produce the observed ranges of X-ray
slopes, high energy cutoffs, and compactnesses. The spread in spectral X-ray
slopes can be due to a spread in the properties of the active regions such as
their compactnesses and their elevations above the disk surface. Simplified
models invoking isotropic Comptonization in spherical clouds are no longer
sufficient when interpreting the data.Comment: 9 pages, 3 postscript figures, figures can be obtained from the
authors via e-mail: [email protected]
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