953 research outputs found

    The Ideal Intersection Property for Groupoid Graded Rings

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    We show that if a groupoid graded ring has a certain nonzero ideal property, then the commutant of the center of the principal component of the ring has the ideal intersection property, that is it intersects nontrivially every nonzero ideal of the ring. Furthermore, we show that for skew groupoid algebras with commutative principal component, the principal component is maximal commutative if and only if it has the ideal intersection property

    The effects of pre-slaughter selection of reindeer bulls (Rangifer tarandus tarandus L.) on technological and sensory meat quality, blood metabolites and abomasal lesions

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    Thirty reindeer bulls (age 1 1/2 years) were subjected to different pre-slaughter treatments to study the effects on ultimate pH values, muscle glycogen content, blood metabolites and abomasal lesions. Gathering and herding into a grazing corral were followed by various selection procedures. Before starting these, a control group of 10 reindeer were captured by lasso and slaughtered outside the grazing corral. Ten reindeer were then selected by hand from a small group of animals (100-150 head) in a small selection corral. Another 10 reindeer were selected from a large herd of about 1000-2000 animals, by the traditional technique of using a lasso. During a 6-hour selection, animals were captured and slaughtered after 1.5 hours (n = 2), 3-5 hours (n = 2), 5 hours (n = 3) and 6 hours (n=3) respectively. The results showed the technique of using a lasso to be stressful and glycogen-depleting, as the two lasso captured groups (the control group and the reindeer exposed to the protracted lasso selection) had the highest ultimate pH values and lowest muscle glycogen values measured. By contrast, the selection procedure where reindeer were captured by hand, was not found to be detrimental to glycogen content and ultimate pH values. Nevertheless, both selection techniques expose the reindeer to acute stress during the capture and manual restraint, which in the present study was reflected in high plasma Cortisol values in all treatment groups. The frequency of abomasal lesions was highest in the group of reindeer subjected to the prolonged selection procedure. No connection between technological and sensory meat quality was found in this study. The technique of selecting animals by hand ought to be further developed so that existing practical problems can be solved. The technique could then be recommended for wider use

    Pre-slaughter handling of reindeer bulls {Rangifer tarandus tarandus L.) — effects on technological and sensory meat quality, blood metabolites and muscular and abomasal lesions

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    Forty-one reindeer bulls (age 1 1/2 years) were subjected to different pre-slaughter treatments: herding for a short distance to a grazing corral, selection by use of a lasso, lorry transport and helicopter herding for 1, 2 and 3 days respectively. As control, 9 reindeer were shot without previous handling (in the mountains). The results indicated the traditional selection technique of using a lasso to be the most stressful and glycogen-depleting handling procedure so far studied. In the lasso-selected reindeer the lowest glycogen values and the highest ultimate pH values in the meat were measured. The values of the measured parameters indicating stress (aspartate aminotransferase (ASAT), urea, Cortisol and abomasal lesions) were also highest in these reindeer. By contrast, the modern method of herding by helicopter was not found to be detrimental to glycogen content, ultimate pH, the measured blood metabolites, or the frequency of abomasal lesions. In all treatment groups degenerative lesions were observed in the skeletal muscles. No relarionship between technological and sensory meat quality characteristics and skeletal muscle lesions in reindeer could, however, be found in this study. The study confirmed an earlier finding that a 'stress-flavour' could develop in reindeer meat after intensive pre-slaughter handling of the animals. Further study of when and how such "stress-flavour" develops ought to be undertaken

    A new low mass for the Hercules dSph: the end of a common mass scale for the dwarfs?

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    We present a new mass estimate for the Hercules dwarf spheroidal galaxy (dSph), based on the revised velocity dispersion obtained by Aden et al. (2009, arXiv:0908.3489). The removal of a significant foreground contamination using newly acquired Stromgren photometry has resulted in a reduced velocity dispersion. Using this new velocity dispersion of 3.72 +/- 0.91 km/s, we find a mass of M_300=1.9^{+1.1}_{-0.8} 10^6 M_sun within the central 300 pc, which is also the half-light radius, and a mass of M_433=3.7_{-1.6}^{+2.2} 10^6 M_sun within the reach of our data to 433 pc, significantly lower than previous estimates. We derive an overall mass-to-light ratio of M_433/L=103^{+83}_{-48} M_sun/L_sun. Our mass estimate calls into question recent claims of a common mass scale for dSph galaxies. Additionally, we find tentative evidence for a velocity gradient in our kinematic data of 16 +/- 3 km/s/kpc, and evidence of an asymmetric extension in the light distribution at about 0.5 kpc. We explore the possibility that these features are due to tidal interactions with the Milky Way. We show that there is a self-consistent model in which Hercules has an assumed tidal radius of r_t = 485 pc, an orbital pericentre of r_p = 18.5 +/- 5 kpc, and a mass within r_t of M_{tid,r_t}=5.2 +/- 2.7 10^6 M_sun. Proper motions are required to test this model. Although we cannot exclude models in which Hercules contains no dark matter, we argue that Hercules is more likely to be a dark matter dominated system which is currently experiencing some tidal disturbance of its outer parts.Comment: 10 pages, 3 figures, Accepted for publication by ApJ

    A field study of management stress in reindeer (Rangifer tarandus L)

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    The impact of stress was studied in semidomesticated reindeer subjected to various herding and handling methods. In herded and handled animals, stress lesions were found, such as abomasal haemorrhage, muscular and myocardial degeneration and marked changes in blood constituents. The degree of change was dependent of the magnitude of stress the animal had been exposed to. Manual handling and restraint was found to be one of the major stress factors. There were evident indications of a cumulative effect of repeated stress events. The use of motor vehicles (helicopter and snow-scooter), for herding and transporting the animals, was found to be an important stress factor. It is concluded that various herding and handling methods studied in the present investigation led to varying degrees of deleterious effects on the health of the animals and a poorer meatquality from slaughtered animals. Hence herding should be undertaken as carefully as possible, the time taken for manual handling should be minimized, and the corrals be so constructed as to cause a minimum of disturbance, capture and restraint. Transportation should be undertaken very cautiously with as little manual handling as possible during loading and unloading. To obtain a good meat quality, animals to be slaughtered should be subjected to a minimum of handling, i.e. slaughter should take place as quickly as possible. Transportation of live animals to slaughterhouses and the keeping of animals in corrals, pens or crates whilst awaiting slaughter will result in a lowered meat quality and should therefore be avoided.En fåltstudie av stress hos ren i samband med olika hanteringsformer.Abstract in Swedish / Sammanfatning: Betydelsen av stress hos ren studerades i hjordar i vilka olika typer av samlings- och hanteringsmetoder anvandes. I samtliga hjordar som utsatts for olika former av drivning forelag hos slaktdjur skador betingade av stress i form av magblodningar, muskelsonderfall och forandringar i blodbilden. De funna skadorna och forandringarna var beroende av den grad av stress som djuren utsatts for. Manuell hantering och inskrankning av djurens rorelsefrihet befanns vara en av de huvudsakliga stressfaktorerna. Det forelag åvenledes en stark indikation på en kumulativ effekt av upprepad stress. Anvandning av motorfordon (helikopter, snoskoter) vid drivning samt vågtransport av levande djur befanns vara betydande stressfaktorer. Det kan fastslås att de olika hanteringsformerna inneburit olika grader av stress. Graden av stresspåverkan innebår olika grader av negativa effekter dels allmånt for djurens hålsotillstånd dels for en forsåmrad kottkvalitet. Sålunda bor drivningar foretagas så forsiktigt som mojligt och tiden for manuell hantering goras så kort som mpjlig. Dårtill bor gårdor konstrueras så att yttre storning, manuell hantering och begrånsning av djurens rorelsefrihet minimeras. Transporter bor genomforas med forsiktighet och med undvikande av manuell hantering vid lastning och lossning. Slakt bor foretagas omedelbart, dvs vid gårdan. Transport av levande djur, samt hållandet av djur i gårdor eller fillor i vantan på slakt innebår att kottkvaliteten forsåmras och bor således undvikas.Kenttâtutkimus porojen stressistâ erilaisten kâsittelymuotojen yhteydessà.Abstract in Finnish / Yhteenveto: Stressin merkitystâ poroissa tutkitaan laumoissa, joissa kàytetààn erilaisia kokoamis - ja kàsittelymenetelmià. Kaikissa laumoissa, jotka olivat joutuneet alttiiksi erilaisille ajomuodoille, oli teuraselàimissâ stressin aiheuttamia vammoja mahaverenvuotojen, lihasrappeutumien ja verikuvan muutosten muodossa. Lôydetyt vammat ja muutokset olivat stressin aiheuttamat siina suhteessa kuin elaimet olivat siihen joutuneet. Kàsin pitely ja elàinten liikuntavapauden rajoittuminen havaittiin olevan yksi pààsiallisista stressintekijôistà. Oli esillà myôs voimakas osoitus kasvavan vaikutuksen toistuvasta stressistâ. Moottoriajoneuvojen (helikopteri, moottori-kelkka) kàyttô ajossa sekà elàvien elàinten tiekuljetus nayttivàt olevan merkittàvià stressitekijôità. Voidaan todeta, ettà erilaiset kasittelymuodot ovat aiheuttaneet stressin erilaisia asteita. Stressin vaikutuksen taso aiheutti eri asteisia negatiivisia vaikutuksia osittain huonontuneeseen lihan laatuun. Nainollen pitàà ajot suorittaa niin varovaisesti kuin mahdollista ja aika kàsin pitelyyn tehtàvà niin lyhyeksi kuin mahdollista. Sen lisàksi pitàà aidât rakentaa niin, ettà ulkoista hàirintàà, kàsin pitelyà ja elàinten liikuntavapauden rajoitusta vàhennetààn. Kuljetukset pitàà suorittaa varovaisuudella ja koettaa vàlttàà kàsin pitelyà kuormauksessa ja purkauksessa. Teurastaminen pitàà suorittaa vâlittômàsti, toisin sanoen aidan luona. Elàvien elàinten kuljetus, sekà elàinten pitàminen aitauksissa tai tarhoissa teurastamista odotellessa aiheuttaa lihalaadun huonontumiseen ja pitàà nàin ollen vàlttàà

    Skew Category Algebras Associated with Partially Defined Dynamical Systems

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    We introduce partially defined dynamical systems defined on a topological space. To each such system we associate a functor ss from a category GG to \Top^{\op} and show that it defines what we call a skew category algebra A⋊σGA \rtimes^{\sigma} G. We study the connection between topological freeness of ss and, on the one hand, ideal properties of A⋊σGA \rtimes^{\sigma} G and, on the other hand, maximal commutativity of AA in A⋊σGA \rtimes^{\sigma} G. In particular, we show that if GG is a groupoid and for each e \in \ob(G) the group of all morphisms e→ee \rightarrow e is countable and the topological space s(e)s(e) is Tychonoff and Baire, then the following assertions are equivalent: (i) ss is topologically free; (ii) AA has the ideal intersection property, that is if II is a nonzero ideal of A⋊σGA \rtimes^{\sigma} G, then I∩A≠{0}I \cap A \neq \{0\}; (iii) the ring AA is a maximal abelian complex subalgebra of A⋊σGA \rtimes^{\sigma} G. Thereby, we generalize a result by Svensson, Silvestrov and de Jeu from the additive group of integers to a large class of groupoids.Comment: 16 pages. This article is an improvement of, and hereby a replacement for, version 1 (arXiv:1006.4776v1) entitled "Category Dynamical Systems and Skew Category Algebras

    Ultimate pH values in reindeer meat with particular regard to animal sex and age, muscle and transport distance

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    The distribution of ultimate pH values and the frequency of high pH values in three reindeer muscles (AL longissimus, M. biceps femoris and M. triceps brachii) from bulls, cows and calves after short and long distance transport were studied. About 3400 reindeer carcasses from 12 different herds were included in this study. The post mortem processes in reindeer meat seemed to develop very rapidly, and therefore an early measurement (approx. 15h post mortem) of ultimate pH can be done without electrical stimulation of the carcasses. In a comparison between muscles, M. triceps brachii had a higher ultimate pH value than M. longissimus and M. biceps femoris. Meat from reindeer calves had higher ultimate pH values than meat from adult animals, indicating that calves are more susceptible to stress than adult animals and hence deplete their energy stores more readily. Road transport by lorry did not cause any increase in ultimate pH values in bulls and calves. Reindeer cows, however, did have an increase in ultimate pH, while more borderline cases of DFD (5.80<pH<6.20) were observed when cows were transported over more than 500 km. The physical condition and energy balance of the animals before transport were suggested to determine their ability to tolerate transport stress

    Work disability before and after a major cardiovascular event: a ten-year study using nationwide medical and insurance registers

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    We examined the trajectories of work disability before and after IHD and stroke events. New IHD (n = 13521) and stroke (n = 7162) cases in 2006-2008 were retrieved from nationwide Swedish hospital records and their annual work disability days five years before and after the date of diagnosis were retrieved from a nationwide disability register. There was no pre-event differences in disability days between the IHD and stroke cases and five years prior to the event, they were close to those observed in the general population. In the first post-event year, the adjusted mean days increased to 83.9 (95% CI 80.6-86.5) in IHD; to 179.5 (95% CI 172.4-186.8) in stroke, a six-fold increase in IHD and 14-fold in stroke. Work disability leveled off among the IHD cases but not among those who had stroke. The highest disability levels for the fifth post-event year after a stroke event was associated with pre-existing diabetes (146.9), mental disorder (141.2), non-employment (137.0), and immigrant status (117.9). In a working-age population, the increase in work disability after a cardiovascular event decreases close to the pre-event level in IHD but remains particularly high after stroke; among patients with comorbid depression or diabetes, immigrants, and those not in employment

    Local Destabilization of the Metal-Binding Region in Human Copper−Zinc Superoxide Dismutase by Remote Mutations Is a Possible Determinant for Progression of ALS

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    More than 100 distinct mutations in the gene CuZnSOD encoding human copper–zinc superoxide dismutase (CuZnSOD) have been associated with familial amyotrophic lateral sclerosis (fALS), a fatal neuronal disease. Many studies of different mutant proteins have found effects on protein stability, catalytic activity, and metal binding, but without a common pattern. Notably, these studies were often performed under conditions far from physiological. Here, we have used experimental conditions of pH 7 and 37 °C and at an ionic strength of 0.2 M to mimic physiological conditions as close as possible in a sample of pure protein. Thus, by using NMR spectroscopy, we have analyzed amide hydrogen exchange of the fALS-associated I113T CuZnSOD variant in its fully metalated state, both at 25 and 37 °C, where ^(15)N relaxation data, as expected, reveals that CuZnSOD I113T exists as a dimer under these conditions. The local dynamics at 82% of all residues have been analyzed in detail. When compared to the wild-type protein, it was found that I113T CuZnSOD is particularly destabilized locally at the ion binding sites of loop 4, the zinc binding loop, which results in frequent exposure of the aggregation prone outer β-strands I and VI of the β-barrel, possibly enabling fibril or aggregate formation. A similar study (Museth, A. K., et al. (2009) Biochemistry, 48, 8817–8829) of amide hydrogen exchange at pH 7 and 25 °C on the G93A variant also revealed a selective destabilization of the zinc binding loop. Thus, a possible scenario in ALS is that elevated local dynamics at the metal binding region can result in toxic species from formation of new interactions at local β-strands
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