636 research outputs found
Kappa-contraction from to
We present contraction prescription of the quantum groups: from to
. Our strategy is different then one chosen in ref. [P. Zaugg,
J. Phys. A {\bf 28} (1995) 2589]. We provide explicite prescription for
contraction of and generators of and arrive at
Hopf algebra .Comment: 3 pages, plain TEX, harvmac, to be published in the Proceedings of
the 4-th Colloqium Quantum Groups and Integrable Systems, Prague, June 1995,
Czech. J. Phys. {\bf 46} 265 (1996
Sainfoin – New Data on Anthelmintic Effects and Production in Sheep and Goats
Gastrointestinal nematodes (GIN) are one of the most important problems affecting health and therefore performance and welfare in small ruminant husbandry. The control of these parasites in the past strongly relied on the repeated use of anthelmintic drugs. This has led to nematode populations which are resistant to most of the currently available anthelmintics. Furthermore customer’s demands for organic and residue free animal products are increasing. The aforementioned problems have given a strong impetus for the development of new non-chemical strategies to control GIN. Previous research has pointed out the anthelmintic potential of sainfoin (Onobrychis viciifolia) and other tanniferous (CT) feed sources in goats and lambs infected with GIN. A recent Swiss experiment focussed on the use of sainfoin and field bean (Vicia faba, cv. Scirocco) as single CT sources as well as in combination for additional synergic effects, to reduce periparturient GIN egg rise of ewes in late gestation and early lactation. Another experiment with Alpine goats concentrated on the influence of sainfoin on milk performance and cheese quality. The results of these experiments will be presented and discussed in connection with previous knowledge on (i) anthelmintic effects of sainfoin and (ii) the influence of sainfoin administration on performance
Size matters in quantitative radar monitoring of animal migration: estimating monitored volume from wingbeat frequency
This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Quantitative radar studies are an important component of studying the movements of birds. Whether a bird, at a certain distance from the radar, is detected or not depends on its size. The volume monitored by the radar is therefore different for birds of different sizes. Consequently, an accurate quantification of bird movements recorded by small-scale radar requires an accurate determination of the monitored volume for the objects in question, although this has tended to be ignored. Here, we demonstrate the importance of sensitivity settings for echo detection on the estimated movement intensities of birds of different sizes. The amount of energy reflected from a bird and detected by the radar receiver (echo power) depends not only on the bird's size and on the distance from the radar antenna, but also on the beam shape and the bird's position within this beam. We propose a method to estimate the size of a bird based on the wingbeat frequency, retrieved from the echo-signal, independent of the absolute echo power. The estimated bird-size allows calculation of size-specific monitored volumes, allowing accurate quantification of movement intensities. We further investigate the importance of applying size-specific monitored volumes to quantify avian movements instead of using echo counts. We also highlight the importance of accounting for size-specific monitored volume of small scale radar systems, and the necessity of reporting technical information on radar parameters. Applying this framework will increase the quality and validity of quantitative radar monitoring.COST – European Cooperation in Science and Technolog
Lipid Emulsion Containing High Amounts of n3 Fatty Acids (Omegaven) as Opposed to n6 Fatty Acids (Intralipid) Preserves Insulin Signaling and Glucose Uptake in Perfused Rat Hearts
BACKGROUND:
It is currently unknown whether acute exposure to n3 fatty acid–containing fish oil–based lipid emulsion Omegaven as opposed to the n6 fatty acid–containing soybean oil–based lipid emulsion Intralipid is more favorable in terms of insulin signaling and glucose uptake in the intact beating heart.
METHODS:
Sprague–Dawley rat hearts were perfused in the working mode for 90 minutes in the presence of 11 mM glucose and 1.2 mM palmitate bound to albumin, the first 30 minutes without insulin followed by 60 minutes with insulin (50 mU/L). Hearts were randomly allocated to 100 µM Intralipid, 100 µM Omegaven, or no emulsion (insulin treatment alone) for 60 minutes. Glycolysis and glycogen synthesis were measured with the radioactive tracer [5-3H]glucose, and glucose uptake was calculated. Phosphorylation of protein phosphatase 2A (PP2A), protein kinase Akt, and phosphofructokinase (PFK)-2 was measured by immunoblotting. Glycolytic metabolites were determined by enzymatic assays. Mass spectrometry was used to establish acylcarnitine profiles. Nuclear factor κB (NFκB) nuclear translocation served as reactive oxygen species (ROS) biosensor.
RESULTS:
Insulin-mediated glucose uptake was decreased by Intralipid (4.9 ± 0.4 vs 3.7 ± 0.3 μmol/gram dry heart weight [gdw]·min; P = .047) due to both reduced glycolysis and glycogen synthesis. In contrast, Omegaven treatment did not affect insulin-mediated glycolysis or glycogen synthesis and thus preserved glucose uptake (5.1 ± 0.3 vs 4.9 ± 0.4 μmol/gdw·min; P = .94). While Intralipid did not affect PP2A phosphorylation status, Omegaven resulted in significantly enhanced tyrosine phosphorylation and inhibition of PP2A. This was accompanied by increased selective threonine phosphorylation of Akt and the downstream target PFK-2 at S483. PFK-1 activity was increased when compared with Intralipid as measured by the ratio of fructose 1,6-bisphosphate to fructose 6-phosphate (Omegaven 0.60 ± 0.11 versus Intralipid 0.47 ± 0.09; P = .023), consistent with increased formation of fructose 2,6-bisphosphate by PFK2, its main allosteric activator. Omegaven lead to accumulation of acylcarnitines and fostered a prooxidant response as evidenced by NFκB nuclear translocation and activation.
CONCLUSIONS:
Omegaven as opposed to Intralipid preserves glucose uptake via the PP2A–Akt–PFK pathway in intact beating hearts. n3 fatty acids decelerate β-oxidation causing accumulation of acylcarnitine species and a prooxidant response, which likely inhibits redox-sensitive PP2A and thus preserves insulin signaling and glucose uptake
Bicrossproduct structure of -Poincare group and non-commutative geometry
We show that the -deformed Poincar\'e quantum algebra proposed for
elementary particle physics has the structure of a Hopf agebra bicrossproduct
U(so(1,3))\cobicross T. The algebra is a semidirect product of the classical
Lorentz group acting in a deformed way on the momentum sector .
The novel feature is that the coalgebra is also semidirect, with a backreaction
of the momentum sector on the Lorentz rotations. Using this, we show that the
-Poincar\'e acts covariantly on a -Minkowski space, which we
introduce. It turns out necessarily to be deformed and non-commutative. We also
connect this algebra with a previous approach to Planck scale physics.Comment: 12 pages. Revision: minor typos correcte
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Study of Disease and Physiology in the 1979 Homing Study Hatchery Stocks: A Supplement to "Imprinting Salmon and Steelhead Trout for Homing", 1979 by Slatick, Gilbreath, and Walch.
The National Marine Fisheries Service (NMFS), under contract to the Bonneville Power Administration, is conducting research on imprinting salmon and steelhead for homing (Slatick et al. 1979, 1980; Novotny and Zaugg 1979). The studies were begun with little background knowledge of the effects of disease or certain physiological functions on imprinting and homing in salmonids. Consequently, work aimed at filling this void was begun by the authors in 1978 (Novotny and Zaugg 1979) and continued in 1979. In 1979, we examined random samples of normal populations of homing test fish at the hatcheries to determine the physiological readiness to migrate and adapt to seawater and general fish health. At the Manchester Marine Experimental Station, Manchester, Washington, we determined the survival of samples of the test fish maintained in marine net-pens after release from the hatcheries. Hatcheries and stocks sampled are listed in Table 1
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Study of Disease and Physiology in the 1978 Homing Study Hatchery Stocks: A Supplement to "Imprinting Salmon and Steelhead Trout for Homing" by Slatick, Novotny, and Gilbreath, January 1979.
The main functions of the National Marine Fisheries Service (NMFS) Aquaculture Task biologists and contractual scientists involved in the 1978 homing studies were primarily a surveillance of fish physiology, disease, and relative survival during culture in marine net-pens, to determine if there were any unusual factors that might effect imprinting and homing behavior. The studies were conducted with little background knowledge of the implications of disease and physiology on imprinting and homing in salmonids. Hatcheries and stocks sampled are listed in Table 1. The health status of the stocks was quite variable as could be expected. The Dworshak and Wells Hatcheries steelhead suffered from some early stresses in seawater, probably osmoregulatory. The incidences of latent BKD in the Wells and Chelan Hatcheries steelhead and Kooskia Hatchery spring chinook salmon were extremely high, and how these will effect survival in the ocean is not known. Gill enzyme activity in the Dworshak and Chelan Hatcheries steelhead at release was low. Of the steelhead, survival in the Tucannon Hatchery stock will probably be the highest, with Dworshak Hatchery stock the lowest. The analyses conducted by the veterinary pathologist indicate that overall there was no evidence of serious pathological conditions that might be disastrous to any given stock, but at this time it is also difficult to interpret the results of certain types of clinical pathology that have either not been previously reported or extensively studied. For example, if the 77% incidence of basophillic granular organisms in the gills of the Carson coho salmon does represent an infestation of microsporidian protozoan parasites, is the intensity of infestation severe enough to cause irreparable damage that might affect survival? The results of the viral assays are questionable because the Rangen Laboratory is the only one that found evidence of viruses in these stocks (however, the veterinary pathologist did find evidence of a pox-type virus in one kidney from the Kooskia Hatchery spring chinook salmon). Secondly, even if the virus identification were substantiated, we cannot be sure of the significance of positive test results. However, this variation is food for thought in how survival of individual stocks might be improved in the future through a closer examination of dietary and environmental requirements, and monitoring the incidence of sub-clinical diseases by random sub-sampling of populations
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