Efficacy of orally administered oxolinic acid and Vetoquinol, an oxolinic acid ester, for the treatment furunculosis in Atlantic salmon Salmo salar held seawater

This study was performed to determine the efficacy of orally administered oxolinic acid and Vetoquinol, an oxolinic acid ester, in the treatment of experimental induced furunculosis in Atlantic salmon Salmo salar held in seawater. Two strains of the causative bacterium Aeromonas salmonicida subsp. salmonicida, 1 sensitive (VI-88/09/03175) and 1 resistant (3475/90) to oxolinic acid, were used. In 2 trials, cohabitational challenges were performed by introducing 8 fish challenged in advance by an intraperitoneal injection of 2.2 x 10(4) colony forming units of strain 3475/90 (Trial 1) or strain VI-88/09/03175 (Trial 2) to 10 aquaria each containing 40 healthy fish. The treatment groups in both trials consisted of 4 groups receiving either oxolinic acid (2 groups) or Vetoquinol (2 groups) and 1 control group. An unchallenged, unmedicated group was used to determine the natural mortality in the population. The recommended therapeutic dose of 25 mg oxolinic acid kg(-1) fish at Days 1, 2, 4, 6, 8 and 10 following initiation of treatment was used. Oral medication initiated at Day 10 (Trial 1) or Day 11 (Trial 2) following challenge significantly (p < 0.05) lowered the specific mortality in all drug-treated groups compared to the untreated control groups. Mortality in Vetoquinol-treated groups was significantly (p < 0.05) lower than in oxolinic acid-treated groups in Trial 1 whereas no significant (p < 0.05) difference in survival rate was found between the medicated groups in Trial 2

Changes in plasma and liver glutathione levels in Atlantic salmon Salmo salar suffering from infectious salmon anemia (ISA)

The levels of reduced glutathione (GSH) in plasma and liver in healthy Atlantic salmon Salmo salar and salmon suffering from infectious salmon anaemia (ISA) were measured using high-performance liquid chromatography (HPLC). The infected salmon had an increased level of plasma GSH Compared to controls, the mean values being 72.31 +/- 11.56 and 52.8 +/- 2.92 muM, respectively. The increased GSH level in plasma was found to be significant (p < 0.0001, unpaired t-test) and may be a result of intracellular release. The hepatic GSH level was significantly lower in the infected salmons compared to controls (p < 0,0001, unpaired t-test) and the mean values were calculated to be 1618.7 +/- 543.7 and 2512.1 +/- 326.9 nmol g-1 liver (wet wt), respectively. A decrease in hepatic GSH of up to 70 % in diseased fish compared to controls was observed. Such low levels of GSH in the liver may affect the capability of this organ in the transformation and excretion of xenobiotics from the body

Arkeologisk og botanisk undersøkelse av hus i røysfelt øst på Forsandmoen. Forsand gnr. 241 bnr. 6, Sandnes k. (del av id. 64670)

Oppdragsgiver: StatnettI tidsrommet 24.08-02.10.2020 gjennomførte Arkeologisk Museum, UiS, en utgravning på garden Forsand gnr. 241, bnr. 6, i Sandnes kommune. Det ble åpnet opp et areal på til sammen 3522,1 m2 fordelt på to felt, begge innenfor kulturminnefelt id. 64670. Bakgrunnen for undersøkelsen lengst øst på Forsandmoen var Statnetts etablering av ny høyspentmast og demontering av gammel mast. Innenfor planområdet for demontering av den gamle masta ble det verken funnet røyser eller bosettingsspor. Anleggene registrert som små røyser på den tuete markoverflata viste seg å være oppspadde masser knyttet til etableringa av den gamle høyspentmasta. Innenfor anleggsområdet for ny strømmast var det registrert ei langrøys (id. 64670-5). I det avdekka arealet i dyrka mark ble det ikke funnet bevarte spor etter røyser. Det ble derimot funnet bosettingsspor i undergrunnen i form av fire identifiserte langhus. Tre av bygningene er datert til yngre romertid/folkevandringstid. Hus 2 og 3 er datert til yngre romertid, mens Hus 3 er datert til første del av folkevandringstid. Hus 1 skiller seg ut fra øvrige hus på Forsandmoen i konstruksjonsform (se Fig. 1). I Hus 3 var det bevarte lag tolket som rester av gulvlag, med høy forekomst av leirkarskår. Bosettingssporene fortsetter utenfor det vesle arealet avdekket for etablering av nytt mastefeste, med høyest konsentrasjon av bosettingsspor mot sørøstlig hjørne av undersøkelsesområdet. Området for bosettingsspor er således ikke avgrenset og vi må kunne anta at det utgravde feltet lengst øst på moen, på nordsida av fylkesveien, kun representerer del av et større bosettingsområde innenfor og utenfor de registrerte røysene synlige på dagens markoverflate

Water masses constrain the distribution of deep-sea sponges in the North Atlantic Ocean and Nordic Seas

Water masses are bodies of water with distinctive physical and biogeochemical properties. They impart vertical structure to the deep ocean, participate in circulation, and can be traced over great distances, potentially influencing the distributions of deep-sea fauna. The classic potential temperature-salinity (theta-s) diagram was used to investigate deep-sea sponge (demosponge genus Geodia) association with water masses over the North Atlantic Ocean and Nordic Seas. A novel analysis was conducted, based on sampling the curvature of climatological mean theta-s curves at sponge locations. Sponges were particularly associated with turning points in the theta-s curves, indicative of intermediate and deep water masses. Arctic geodiid species (G. hentscheli and G. parva) were associated with Arctic intermediate and deep waters in the Nordic Seas, and with dense overflows into the northern North Atlantic. Boreal species (G. atlantica, G. barretti, G. macandrewii, and G. phlegraei) were associated with upper and intermediate water masses in the Northeast Atlantic and with upper, Atlantic-derived waters in the Nordic Seas. Taken together with distributional patterns, a link with thermohaline currents was also inferred. We conclude that water masses and major current pathways structure the distribution of a key deep-sea benthic faunal group on an ocean basin scale. This is most likely because of a combination of the physical constraints they place on the dispersal of early life-history stages, ecophysiological adaptation (evolved tolerances) to specific water masses, and the benefits to filter-feeders of certain phenomena linked to water column structure (e.g. nepheloid layers, internal waves/ tides, density-driven currents)

Effects of novel ingredients on growth performance in european sea bass, dicentrarchus labrax

publishedVersio

A high-throughput multiplexing and selection strategy to complete bacterial genomes

Background: Bacterial whole-genome sequencing based on short-read technologies often results in a draft assembly formed by contiguous sequences. The introduction of long-read sequencing technologies permits those contiguous sequences to be unambiguously bridged into complete genomes. However, the elevated costs associated with long-read sequencing frequently limit the number of bacterial isolates that can be long-read sequenced. Here we evaluated the recently released 96 barcoding kit from Oxford Nanopore Technologies (ONT) to generate complete genomes on a high-throughput basis. In addition, we propose an isolate selection strategy that optimizes a representative selection of isolates for long-read sequencing considering as input large-scale bacterial collections. Results: Despite an uneven distribution of long reads per barcode, near-complete chromosomal sequences (assembly contiguity = 0.89) were generated for 96 Escherichia coli isolates with associated short-read sequencing data. The assembly contiguity of the plasmid replicons was even higher (0.98), which indicated the suitability of the multiplexing strategy for studies focused on resolving plasmid sequences. We benchmarked hybrid and ONT-only assemblies and showed that the combination of ONT sequencing data with short-read sequencing data is still highly desirable (i) to perform an unbiased selection of isolates for long-read sequencing, (ii) to achieve an optimal genome accuracy and completeness, and (iii) to include small plasmids underrepresented in the ONT library. Conclusions: The proposed long-read isolate selection ensures the completion of bacterial genomes that span the genome diversity inherent in large collections of bacterial isolates. We show the potential of using this multiplexing approach to close bacterial genomes on a high-throughput basis.Peer reviewe

The order parameter-entropy relation in some universal classes: experimental evidence

The asymptotic behaviour near phase transitions can be suitably characterized by the scaling of $\Delta s/Q^2$ with $\epsilon=1-T/T_c$, where $\Delta s$ is the excess entropy and $Q$ is the order parameter. As $\Delta s$ is obtained by integration of the experimental excess specific heat of the transition $\Delta c$, it displays little experimental noise so that the curve $\log(\Delta s/Q^2)$ versus $\log\epsilon$ is better constrained than, say, $\log\Delta c$ versus $\log\epsilon$. The behaviour of $\Delta s/Q^2$ for different universality classes is presented and compared. In all cases, it clearly deviates from being a constant. The determination of this function can then be an effective method to distinguish asymptotic critical behaviour. For comparison, experimental data for three very different systems, Rb2CoF4, Rb2ZnCl4 and SrTiO3, are analysed under this approach. In SrTiO3, the function $\Delta s/Q^2$ does not deviate within experimental resolution from a straight line so that, although Q can be fitted with a non mean-field exponent, the data can be explained by a classical Landau mean-field behaviour. In contrast, the behaviour of $\Delta s/Q^2$ for the antiferromagnetic transition in Rb2CoF4 and the normal-incommensurate phase transition in Rb2ZCl4 is fully consistent with the asymptotic critical behaviour of the universality class corresponding to each case. This analysis supports, therefore, the claim that incommensurate phase transitions in general, and the A$_2$BX$_4$ compounds in particular, in contrast with most structural phase transitions, have critical regions large enough to be observable.Comment: 13 pp. 9 ff. 2 tab. RevTeX. Submitted to J. Phys.: Cond. Matte

Spin-lattice instability to a fractional magnetization state in the spinel HgCr2O4

Magnetic systems are fertile ground for the emergence of exotic states when the magnetic interactions cannot be satisfied simultaneously due to the topology of the lattice - a situation known as geometrical frustration. Spinels, AB2O4, can realize the most highly frustrated network of corner-sharing tetrahedra. Several novel states have been discovered in spinels, such as composite spin clusters and novel charge-ordered states. Here we use neutron and synchrotron X-ray scattering to characterize the fractional magnetization state of HgCr2O4 under an external magnetic field, H. When the field is applied in its Neel ground state, a phase transition occurs at H ~ 10 Tesla at which each tetrahedron changes from a canted Neel state to a fractional spin state with the total spin, Stet, of S/2 and the lattice undergoes orthorhombic to cubic symmetry change. Our results provide the microscopic one-to-one correspondence between the spin state and the lattice distortion

Switching between dynamic states in intermediate-length Josephson junctions

The appearance of zero-field steps (ZFS’s) in the current-voltage characteristics of intermediate-length overlap-geometry Josephson tunnel junctions described by a perturbed sine-Gordon equation (PSGE) is associated with the growth of parametrically excited instabilities of the McCumber background curve (MCB). A linear stability analysis of a McCumber solution of the PSGE in the asymptotic linear region of the MCB and in the absence of magnetic field yields a Hill’s equation which predicts how the number, locations, and widths of the instability regions depend on the junction parameters. A numerical integration of the PSGE in terms of truncated series of time-dependent Fourier spatial modes verifies that the parametrically excited instabilities of the MCB evolve into the fluxon oscillations characteristic of the ZFS’s. An approximate analysis of the Fourier mode equations in the presence of a small magnetic field yields a field-dependent Hill’s equation which predicts that the major effect of such a field is to reduce the widths of the instability regions. Experimental measurements on Nb-NbxOy-Pb junctions of intermediate length, performed at different operating temperatures in order to vary the junction parameters and for various magnetic field values, verify the physical existence of switching from the MCB to the ZFS’s. Good qualitative, and in many cases quantitative, agreement between analytic, numerical, and experimental results is obtained

Generalized calculation of magnetic coupling constants for Mott-Hubbard insulators: Application to ferromagnetic Cr compounds

Using a Rayleigh-Schr\"odinger perturbation expansion of multi-band Hubbard models, we present analytic expressions for the super-exchange coupling constants between magnetic transition metal ions of arbitrary separation in Mott-Hubbard insulators. The only restrictions are i) all ligand ions are closed shell anions and ii) all contributing interaction paths are of equal length. For short paths, our results essentially confirm the Goodenough-Kanamori-Anderson rules, yet in general there does not exist any simple rule to predict the sign of the magnetic coupling constants. The most favorable situation for ferromagnetic coupling is found for ions with less than half filled d shells, the (relative) tendency to ferromagnetic coupling increases with increasing path length. As an application, the magnetic interactions of the Cr compounds Rb$_2$CrCl$_4$, CrCl$_3$, CrBr$_3$ and CrI$_3$ are investigated, all of which except CrCl$_3$ are ferromagnets.Comment: 13 pages, 6 eps figures, submitted to Phys Rev