406 research outputs found

    Some aspects on the impact of parasitic infections in animals used as laboratory animals and their impact on the parasites

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    A deworming field trial with ivermectin (MSD) in reindeer

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    This paper is to be regarded as a follow-up under field conditions of Nordkvist et al. (1983) as far as ivermectin is concerned. 54 reindeer calves (29 males + 25 females), as far as possible of normal size, were selected November 15th, 1982 from a reindeer herd belonging to Maskaure sameby, Arvidsjaur. The calves were individually branded, by means of ear tags and weighed. 29 calves (15 males + 14 females) were treated with ivermectin (Ivomec 1% MSD) at a dose rate of 1 ml per calf (roughly corresponding to 200 meg ivermectin per kg body weight), subcutaneous injection. Remaining 25 calves (14 males + 11 females) served as untreated controls. The entire group of calves was then returned to the herd for free grazing during winter. During the winter 3 treated calves were found dead, all three of them had been suffering from keratoconjunctivitis. If any of the control animals had succumbed during the same time is not known. On April 21st, 1983 (approx. 150 days post treatment) 44 calves (24 treated + 20 controls) were weighed. 5 treated and 5 controls were randomly selected for slaughter. Carcasses and organs were thoroughly examined from a parasitological and, as far as lungs were concerned, pathological point of view. The efficacy of the treatment was 100(M> or nearly 100% against Oedemagena tarandi, Cephenemyia trompe, Dictyocaulus viviparus, Elaphostrongylus rangiferi, and nematode eggs in faeces. The efficacy against gastrointestinal nematodes was, probably due to date of treatment, somewhat difficult to judge (Tab 1). A statistical analysis of the weight changes, relative to initial weights, (Tab. 2) supports the statements — that all animals had lost weight — that treated males had lost significantly less of their body weights than control males — That weight change of treated females did not differ significantly from that of control females — that the average weight loss of the entire treated group was significantly less than that of the control group.Ett fältavmaskningsförsök med ivermectin (MSD) på renar.Abstract in Swedish / Sammanfattning: 54 renkalvar (29 m + 25 f) såvitt mojligt av normal storlek, utvaldes den 25 november 1982 ur en renhjord tillhorig Maskaure sameby, Arjeplog. Kalvarna mdividmårktes med oronknappar och vågdes. Av dessa behandlades 29 kalvar (15 0*0" + 14 $9) med ivermectin (Ivomec, 1% MSD), 1 ml per kalv, subkutan injektion. Resterande 25 kalvar fungerade som obehandlade kontrolldjur. Den 21 april 1983 (efter 147 dagar) vågdes ånyo 44 (24 behandlade + 20 kontroller) av de ursprungliga djuren. 5 renar i vardera gruppen slaktades och kropp och organ undersoktes parasitologiskt. Effekten av behandlingen var 100% eller nåstintill mot Oedemagena tarandi, Cephenemyia trompe, Dictyocaulus viviparus, Elaphostrongulus rangiferi samt vad gällde forekomsten av nematodågg i tracken. Effekten på mag-tarmnematoder var, med hånsyn till behandlingstidpunkten, svårbedomd. Effekten på trichostrongylida lopmagsmaskar var också svårbedomd och diskuteras i texten. Den relativa forandringen av renarnas kroppsvikt, dvs forandringen i forhållande till ursprungsvikten, har beråknats och statistiskt bearbetats. Det kunde då konstateras — att samtliga renar hade forlorat i vikt — att den genomsnittliga viktforlusten hos de behandlade hankalvarna var signifikant lågre ån hos de obehandlade hankalvarna — att den genomsnittliga viktforlusten hos de behandlade honkalvarna ime skiljde sig statistiskt från viktforlusten hos de obehandlade honkalvarna — att den genomsnittliga viktforlusten i hela den behandlade gruppen var signifikant lagre ån i den obehandlade gruppen.Kenttätutkimus porojen matokuurista Ivermectinillä (MSD).Abstract in Finnish / Yhteenveto: Arjeplogissa Maskauren lappalaiskylåån kuuluvasta porotokasta valittiin 25. marraskuuta 1982 54 porovasaa (29 m + 25 f) mikåli mahdollista normaalikokoa. Vasat yksilomerkittiin korvanastoilla ja punnittiin. Nåistå kåsiteltiin 29 vasaa (15 m + 14 f) ivermectinillå (Ivomec, 1 % MSD), 1 ml vasaa kohden, ruiskutcttuna nahan alle. Loput 25 vasaa toimivat kåsittelemåttominå tarkkailuelåiminå. 21 huhtikuuta 1983 (147 påivån jålkeen) punnittiin uudelleen 44 (24 kåsiteltyå + 20 tarkkailuelåintå) alkuperåisistå elåimistå. Joka ryhmåstå teurastettiin 5 poroa ja ruho ja sisåelimet tutkittiin parasitoloogisesti. Kåsittelyn vaikutus oli 100% tai låhes tåydellinen seuraavia kohtaan: Oedemagena tarandi, Cephenemyia trompe, Dictyocaulus viviparus, Elapohostrongylus rangiferi sekå myoskin mitå tulee matojen munien esiintymiseen sonnassa. Vaikutus maha - ja suolistomatoihin oli, kåsittelyn ajankohdan huomioonottaen, vaikeasti ratkaistavissa. Vaikutus juoksutusmahoihin (trichostrongylida) oli myos vaikeasti ratkaistavissa ja siitå keskustellaan tekstisså. Porojen ruhojen painon suhteellinen muutos, t.s. muutos suhteessa alkuperåispainoon on arvioitu ja tilastollisesti kåsitelty. Voitiin silloin todeta — ettå kaikki porot olivat kevcntyneet painossaan, — ettå kåsiteltyjen urosvasojen keskimååråinen painonvåhennys oli merkitsevåsti alhaisempi kuin kåsittelemåttomien urosvasojen, — ettå kåsiteltyjen naarasvasoien keskimååråinen painonvåhennys ei eronnut tilastollistesti kåsittelemåttomien naarasvasojen painonvåhennyksestå, — ettå koko kåsitellyn ryhmån keskimååråinen painonvåhennys oli merkitsevåsti alhaisempi kuin kåsittelemåttomåsså ryhmåsså

    A comparative study on the efficacy of four anthelmintics on some important reindeer parasites

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    Four anthelmintic preparations were tested against some of the most important parasites of reindeer, i.e. warble fly (Oedemagena tarandi), nostril fly (Cephenemyia trompe), brainworm (Elaphostrongylus rangiferi), and lungworm (Dictyocaulus viviparus). Their efficacy against intestinal nematodes was also registered. Test drugs were Fenthion (Bayer), Fenbendazole (Hoechst), Mebendazole (Janssen), and Ivermectin (Merk Sharp & Dohme). Against O. tarandi and C. trompe Ivermectin was 100% effective and Fenthion 86 and 100% respectively. The efficacy of Fen- and Mebendazole against these parasites was not significant. Against E. rangiferi the benzimidazole compounds were highly effective, with Mebendazole a bit ahead. Ivermectin had a moderate effect and Fenthion had no effect on this parasite. Against D. viviparus Fenbendazole, Mebendazole and Ivermectin were of equal, moderate-high effectiveness. No drug had a complete effect on the «arrested» larvae of D. viviparus. Fenthion had no effect at all. Fenbendazole and Ivermectin were both 100% effective against intestinal nematodes. Mebendazole was less effective and Fenthion had no effects. Ivermectin is considered to be the overall most effective anthelmintic in this test.En jamforande studie av effekten av fyra anthelmintika mot några betydelsesfulla parasiter hos ren.Abstract in Swedish / Sammandrag: Fyra antiparasitmedel har prôvats mot några av renens viktigaste parasiter, nàmligen hudkorm (Oedemagena tarandi), svalgkorm (Cephenemyia trompe), hjårnmask (Elaphostrongylus rangiferi) och lungmask (Dictyocaulus viviparus). Vidare har medlens effekt på mag- tarmnematoder (Trichostongylider) också noterats. De prôvade medicinerna var Fenthion (Bayer), Mebendazole (Leo/Janssen), Fenbendazole (Hoechst) och Ivermectin (Merck Sharp & Dohme). Mot hud- och svalgkorm var Ivermectin 100% effektivt medan for Fenthion effekten var 86 resp 100%. Effekten av Fen- och Mebendazole mot de båda parasiterna var inte signifikant. Mot hjårnmask noterades mycket hôg effekt av Mebendazole och aven Fenbendazole medan Ivermectin hade något såmre effekt med den valda doseringen. Fenthion hade ingen effekt på denna parasit. Mot lungmask visade Fenbendazole och Ivermectin god effekt medan Mebendazole visade något lagre effekt. Inget av preparaten hade dock fullgod verkan på de vilande inaktiva 5:te stadiets larverna av denna parasit. Fenthion hade ingen effekt. Mot mag-tarmnematoder var Fenbendazole och Ivermectin 100% effektiva medan Mebendazole hade en något làgre, delvis undertryckande effekt. Fenthion hade ingen effekt. Ivermectin får anses vara det allmånt sett effektivaste maskmedlet i denna undersokning.Vertailevatutkielma neljan loislaakeaineen vaikutuksesta muutamia tarkeita porojen loisia vastaan.Abstract in Finnish / Yhteenveto: On kokeiltu neljaa loislaakeainetta muutamia porojen tarkeinpia loisia vastaan, nimittain kurmua (Oedemagena tarandi), saulakkaa (Cephenemyia trompe), aivomatoa (Elaphostrongylus rangiferi) ja keuhkomatoa (Dictyocaulus viviparus). Edelleen on laakeaineiden vaikutus maha- ja suolistomatoihin (Trichostrongyliidit) myoskin pantu merkille. Kokeillut laakeaineet olivat Fenthion (Bayer), Mebendazole (Leo/Janssen), Fenbendazole (Hoechst) ja Ivermectin (Merck - Sharp and Dohme). Kurmua ja saulakkaa vastaan oli Ivermectin 100% tehokas, kun taas Fenthionin vaikutus oli toisessa 86 ja toisessa 100%. Fen- ja Mebendazolen vaikutus molempia loisia vastaan ei ollut merkittava. Mebendazolen ja myos Fenbendazolen vaikutus aivomatoa vastaan havaittiin hyvin korkeaksi, kun taas Ivermectinilla oli jonkin verran huonompi vaikutus valitulla annostuksella. Fenthionilla ei ollut mitaan vaikutusta tata loista vastaan. Keuhkomatoa vastaan osoitti Fenbendazole ja Ivermectin hyvan vaikutuksen, kun taas Mebendazolella oli jonkin verran heikompi vaikutus. Kuitenkaan ei millaan laakevalmisteista ollut taystehokasta vaikutusta taman loisen lepaaviin tehottomiin 5:asteen toukkiin. Fenthionilla ei ollut mitaan vaikutusta. Fenbendazole ja Ivermectin maha- ja suolistomatoja vastaan olivat 100% tehokkaita, kun taas Mebendazolella oli jonkin verran alhaisempi, osittain vaimentava vaikutus. Fenthionilla ei ollut mitaan vaikutusta

    Real-time Chern-Simons term for hypermagnetic fields

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    If non-vanishing chemical potentials are assigned to chiral fermions, then a Chern-Simons term is induced for the corresponding gauge fields. In thermal equilibrium anomalous processes adjust the chemical potentials such that the coefficient of the Chern-Simons term vanishes, but it has been argued that there are non-equilibrium epochs in cosmology where this is not the case and that, consequently, certain fermionic number densities and large-scale (hypermagnetic) field strengths get coupled to each other. We generalise the Chern-Simons term to a real-time situation relevant for dynamical considerations, by deriving the anomalous Hard Thermal Loop effective action for the hypermagnetic fields, write down the corresponding equations of motion, and discuss some exponentially growing solutions thereof.Comment: 13 page

    Detection of Babesia divergens in southern Norway by using an immunofluorescence antibody test in cow sera

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    <p>Abstract</p> <p>Background</p> <p>The incidence of bovine babesiosis, caused by <it>Babesia divergens </it>(Apicomplexa: Piroplasmida) has decreased markedly since the 1930 s, but may re-emerge as a consequence of climate change and changes in legislation and pasturing practices. This is a potentially serious disease, with both economical and animal welfare consequences. Therefore, there is a need to survey the distribution of <it>B. divergens</it>.</p> <p>Methods</p> <p>We tested sera from 306 healthy pastured cows from 24 farms along the southern Norwegian coast by using an indirect immunofluorescence IgG antibody test (IFAT). Fractions of seropositive cows were compared by calculating 95% CI.</p> <p>Results</p> <p>The results of this test showed that 27% of the sera were positive for <it>B. divergens </it>antibodies. The fraction of antibody-positive sera that we detected showed a two-humped distribution, with a high fraction of positives being found in municipalities in the western and eastern parts of the study area, while the municipalities between these areas had few or no positive serum samples.</p> <p>Conclusions</p> <p>Neither the farmers' observations nor the Norwegian Dairy Herd Recording System give an adequate picture of the distribution of bovine babesiosis. Serological testing of cows by using IFAT is a convenient way of screening for the presence of <it>B. divergens </it>in an area.</p

    Constraining photon-axion oscillations using quasar spectra

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    Using quasar spectra from the SDSS survey, we constrain the possibility of photon-axion oscillations as a source of dimming of high redshift objects. Such a process has been suggested as an explanation of the apparent faintness of distant Type Ia supernovae. For most combinations of magnetic field strengths and plasma densities along the line of sight, large beam attenuations in broad band filters would also lead to significant differential attenuation, not observed in the quasar sample. However, this conservative study does not exclude the possibility of 0.1 mag dimming of Type Ia supernovae for average plasma densities n_e = 10^(-8) cm^(-3). NIR and MIR spectroscopic studies of high-z sources may be used put further constrains or provide indirect evidence for the existence of a very light axion.Comment: 14 pages, 8 figure

    The Cosmic Microwave Background and Helical Magnetic Fields: the tensor mode

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    We study the effect of a possible helicity component of a primordial magnetic field on the tensor part of the cosmic microwave background temperature anisotropies and polarization. We give analytical approximations for the tensor contributions induced by helicity, discussing their amplitude and spectral index in dependence of the power spectrum of the primordial magnetic field. We find that an helical magnetic field creates a parity odd component of gravity waves inducing parity odd polarization signals. However, only if the magnetic field is close to scale invariant and if its helical part is close to maximal, the effect is sufficiently large to be observable. We also discuss the implications of causality on the magnetic field spectrum.Comment: We have corrected a normalisation error which was pointed out to us by Antony Lewis. It enhances our limits on the magnetic fields by (2\pi)^{3/4} ~

    Magnetic fields in the early universe in the string approach to MHD

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    There is a reformulation of magnetohydrodynamics in which the fundamental dynamical quantities are the positions and velocities of the lines of magnetic flux in the plasma, which turn out to obey equations of motion very much like ideal strings. We use this approach to study the evolution of a primordial magnetic field generated during the radiation-dominated era in the early Universe. Causality dictates that the field lines form a tangled random network, and the string-like equations of motion, plus the assumption of perfect reconnection, inevitably lead to a self-similar solution for the magnetic field power spectrum. We present the predicted form of the power spectrum, and discuss insights gained from the string approximation, in particular the implications for the existence or not of an inverse cascade.Comment: 12 pages, 2 figure

    Full characterization of vibrational coherence in a porphyrin chromophore by two-dimensional electronic spectroscopy

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    In this work we present experimental and calculated two-dimensional electronic spectra for a 5,15-bisalkynyl porphyrin chromophore. The lowest energy electronic Qy transition couples mainly to a single 380 cm–1 vibrational mode. The two-dimensional electronic spectra reveal diagonal and cross peaks which oscillate as a function of population time. We analyze both the amplitude and phase distribution of this main vibronic transition as a function of excitation and detection frequencies. Even though Feynman diagrams provide a good indication of where the amplitude of the oscillating components are located in the excitation-detection plane, other factors also affect this distribution. Specifically, the oscillation corresponding to each Feynman diagram is expected to have a phase that is a function of excitation and detection frequencies. Therefore, the overall phase of the experimentally observed oscillation will reflect this phase dependence. Another consequence is that the overall oscillation amplitude can show interference patterns resulting from overlapping contributions from neighboring Feynman diagrams. These observations are consistently reproduced through simulations based on third order perturbation theory coupled to a spectral density described by a Brownian oscillator model

    The stochastic gravitational wave background from turbulence and magnetic fields generated by a first-order phase transition

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    We analytically derive the spectrum of gravitational waves due to magneto-hydrodynamical turbulence generated by bubble collisions in a first-order phase transition. In contrast to previous studies, we take into account the fact that turbulence and magnetic fields act as sources of gravitational waves for many Hubble times after the phase transition is completed. This modifies the gravitational wave spectrum at large scales. We also model the initial stirring phase preceding the Kolmogorov cascade, while earlier works assume that the Kolmogorov spectrum sets in instantaneously. The continuity in time of the source is relevant for a correct determination of the peak position of the gravitational wave spectrum. We discuss how the results depend on assumptions about the unequal-time correlation of the source and motivate a realistic choice for it. Our treatment gives a similar peak frequency as previous analyses but the amplitude of the signal is reduced due to the use of a more realistic power spectrum for the magneto-hydrodynamical turbulence. For a strongly first-order electroweak phase transition, the signal is observable with the space interferometer LISA.Comment: 46 pages, 17 figures. Replaced with revised version accepted for publication in JCA
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