Incomplete Release of Citrate During Acid Precipitation of Casein

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Sialic Acid as an Index of the κ-Casein Content of Bovine Skimmilk

Summary The sialic acid content of skimmilk proteins has been examined, using a modification of Warren's thiobarbituric acid method. Lactose interferes with this method and was removed by thorough washing of the proteins. κ -casein and proteose-peptone appear to be the only two skimmilk proteins containing significant amounts of sialic acid. Treatments with DEAE cellulose almost completely removed the low concentrations of sialic acid present in α s - and β -caseins, and examination of these caseins by starch gel electrophoresis indicates that such removal involved traces of κ -casein. Since the stability of α s - κ -casein mixtures in the presence of calcium appeared to be directly related to the sialic acid content of the mixture at all levels below the 0.37% (uncorrected for moisture) needed to give complete stability, it is concluded that sialic acid measurements can be used as an index of the intact κ -casein content of such mixtures. Proteose-peptone is precipitated by 12% TCA, but remains in solution at pH 4.5, so analysis of sialic acid can also be used as an index of the κ -casein concentration of whole acid casein. Values of 0.26–0.59% sialic acid were obtained in washed whole acid caseins prepared from individual lots of milk, indicating that the proportion of κ -casein is variable. The sialic acid content of κ -casein appears to be close to 2.3%; on this basis, the proportion of κ -casein in whole acid casein varies between 11–26%

Quantifying the AGN-driven outflows in ULIRGs (QUADROS) III: Measurements of the radii and kinetic powers of 8 near-nuclear outflows

As part of the Quantifying ULIRG AGN-driven Outflows (QUADROS) project to quantify the impact of active galactic nuclei (AGN)-driven outflows in rapidly evolving galaxies in the local Universe, we present observations of eight nearby ultraluminous infrared galaxies (ULIRGs, 0.04 < z < 0.2) taken with the Intermediate-dispersion Spectrograph and Imaging System on the William Herschel Telescope (WHT), and also summarize the results of the project as a whole. Consistent with Rose et al. (2018), we find that the outflow regions are compact (0.08 < R[O III] < 1.5 kpc), and the electron densities measured using the [S II], [O II] trans-auroral emission-line ratios are relatively high (2.5 < log ne (cm−3) < 4.5, median log ne (cm−3) ∼ 3.1). Many of the outflow regions are also significantly reddened (median E(B − V) ∼ 0.5). Assuming that the deprojected outflow velocities are represented by the fifth percentile velocities (v05) of the broad, blueshifted components of [O III] λ5007, we calculate relatively modest mass outflow rates (0.1 < M < ˙ 20 M yr−1, median M˙ ∼ 2 M yr−1), and find kinetic powers as a fraction of the AGN bolometric luminosity (F˙ = E/L ˙ bol) in the range 0.02 < F <˙ 3 per cent (median F˙ ∼ 0.3 per cent). The latter estimates are in line with the predictions of multi-stage outflow models, or single-stage models in which only a modest fraction of the initial kinetic power of the inner disc winds is transferred to the larger scale outflows. Considering the QUADROS sample as a whole, we find no clear evidence for correlations between the properties of the outflows and the bolometric luminosities of the AGN, albeit based on a sample that covers a relatively small range in Lbol. Overall, our results suggest that there is a significant intrinsic scatter in outflow properties of ULIRGs for a given AGN luminosit

Quantifying the AGN-driven outflows in ULIRGs (QUADROS) I: VLT/Xshooter observations of 9 nearby objects

Although now routinely incorporated into hydrodynamic simulations of galaxy evolution, the true importance of the feedback effect of the outflows driven by active galactic nuclei (AGNs) remains uncertain from an observational perspective. This is due to a lack of accurate information on the densities, radial scales and level of dust extinction of the outflow regions. Here we use the unique capabilities of VLT/Xshooter to investigate the warm outflows in a representative sample of nine local (0.06 < z < 0.15) Ultraluminous Infrared Galaxies (ULIRGs) with AGNs and, for the first time, accurately quantify the key outflow properties. We find that the outflows are compact (0.06 < R[O III] < 1.2 kpc), significantly reddened (median E(B − V) ∼ 0.5 magnitudes), and have relatively high electron densities (3.4 < log10 ne (cm−3) < 4.8). It is notable that the latter densities – obtained using trans-auroral [S II] and [O II] emission-line ratios – exceed those typically assumed for the warm, emission-line outflows in active galaxies, but are similar to those estimated for broad and narrow absorption line outflow systems detected in some type 1 AGN. Even if we make the most optimistic assumptions about the true (deprojected) outflow velocities, we find relatively modest mass outflow rates (0.07 < M < ˙ 14 M yr−1) and kinetic powers measured as a fraction of the AGN bolometric luminosities (4 × 10−4 < E/L ˙ BOL < 0.8 per cent). Therefore, although warm, AGN-driven outflows have the potential to strongly affect the star formation histories in the inner bulge regions (r ∼ 1 kpc) of nearby ULIRGs, we lack evidence that they have a significant impact on the evolution of these rapidly evolving systems on larger scales

Relaxation and Landau-Zener experiments down to 100 mK in ferritin

Temperature-independent magnetic viscosity in ferritin has been observed from 2 K down to 100 mK, proving that quantum tunneling plays the main role in these particles at low temperature. Magnetic relaxation has also been studied using the Landau-Zener method making the system crossing zero resonant field at different rates, alpha=dH/dt, ranging from 10^{-5} to 10^{-3} T/s, and at different temperatures, from 150 mK up to the blocking temperature. We propose a new Tln(Delta H_{eff}/tau_0 alpha) scaling law for the Landau-Zener probability in a system distributed in volumes, where Delta H_{eff} is the effective width of the zero field resonance.Comment: 13 pages, 4 postscript figure

Highlighting when animals expend excessive energy for travel using dynamic body acceleration

Travel represents a major cost for many animals so there should be selection pressure for it to be efficient – at minimum cost. However, animals sometimes exceed minimum travel costs for reasons that must be correspondingly important. We use Dynamic Body Acceleration (DBA), an acceleration-based metric, as a proxy for movement-based power, in tandem with vertical velocity (rate of change in depth) in a shark (Rhincodon typus) to derive the minimum estimated power required to swim at defined vertical velocities. We show how subtraction of measured DBA from the estimated minimum power for any given vertical velocity provides a “proxy for power above minimum” metric (PPAmin), highlighting when these animals travel above minimum power. We suggest that the adoption of this metric across species has value in identifying where and when animals are subject to compelling conditions that lead them to deviate from ostensibly judicious energy expenditure

The evolution of the 3D shape of the broad-lined Type Ic SN 2014ad

We present optical spectropolarimetry and spectroscopy of the broad-lined Type Ic (Ic-bl) SN 2014ad. Our spectropolarimetric observations cover seven epochs, from −2 to 66 d after V-band maximum, and the spectroscopic data were acquired from −2 to +107 d. The photospheric velocity estimates showed ejecta speeds similar to those of SN 1998bw and other SNe associated with gamma-ray bursts (GRBs). The spectropolarimetric data revealed aspherical outer ejecta and a nearly spherical interior. The polarization associated with O I λ7774 and the Ca II infrared triplet suggests a clumpy and highly asymmetrical distribution of these two species within the ejecta. Furthermore, it was shown that the two line forming regions must have been spatially distinct and oxygen was found to have higher velocities than calcium. Another oxygen line-forming region was also identified much closer to the core of the explosion and distributed in a spherical shell. It is difficult to reconcile the geometry of the deeper ejecta with a jet driven explosion, but the high ejecta velocities of SN 2014ad are typical of those observed in SNe Ic-bl with GRBs and the behaviour of the oxygen and calcium line-forming regions is consistent with fully jet-driven models. The metallicity of the host galaxy of SN 2014ad was also calculated and compared to that of the hosts of other SNe Ic-bl with and without GRBs, but due to the overlap in the two populations no conclusion could be drawn

Movements of common bream Abramis brama in a highly-connected, lowland wetland reveal spatially discrete sub-populations with diverse migration strategies

1. Freshwater ecosystems are increasingly characterised by high levels of fragmentation that restrict the movements of mobile fauna. Yet studies also suggest the migratory behaviours of potamodromous fishes can be highly variable in barrier-free systems, where differing migratory behaviours enable populations to exploit a wide range of food and space resources. This intra-population divergence in spatial and temporal resource use is important to our ecological understanding of distribution patterns and population structure. 2. Common bream Abramis brama (‘bream’) is a potentially strong model species for testing the importance of divergent migration patterns in lowland rivers, but existing studies have been largely restricted to spatially confined and/or anthropogenically- modified systems. This study’s principal focus was to examine the diversity of bream migration behaviour in a highly-connected, lowland system using passive acoustic telemetry, which provided continuous, multi-year data on the movements of 181 bream across a tidally-influenced, lowland wetland in eastern England (~60 km of continuous river length plus numerous interconnected shallow lakes and dykes). Tracked bream were grouped according to their initial location and timing of tagging. 3. Bream migratory behaviours varied considerably between tagging groups, but with greater consistency within groups. There was little mixing of groups outside of spawning periods, with season and tidal phase being significant predictors of movements. Rates of movement and swimming speeds were highest in spring, with movements also generally occurring in the direction of tidal flows. 4. For fish tagged just prior to spawning, there was considerable diversity in their post- spawning movements, with some remaining in the immediate vicinity and others that moved to areas ~ 25 km away. These spatially discrete patterns remained until the following spawning period, with high individual consistency in movement behaviour between years. 5. These results suggest this lowland fish population is comprised of several distinct, semi-independent subpopulations that only share space resources in their spawning period. This indicates the importance of connectivity in lowland freshwater systems for enabling and maintaining high phenotypic diversity in the migration behaviours of potamodromous fishes

Actors and networks or agents and structures: towards a realist view of information systems

Actor-network theory (ANT) has achieved a measure of popularity in the analysis of information systems. This paper looks at ANT from the perspective of the social realism of Margaret Archer. It argues that the main issue with ANT from a realist perspective is its adoption of a `flat' ontology, particularly with regard to human beings. It explores the value of incorporating concepts from ANT into a social realist approach, but argues that the latter offers a more productive way of approaching information systems

A method for isolating and culturing placental cells from failed early equine pregnancies

Early pregnancy loss occurs in 6–10% of equine pregnancies making it the main cause of reproductive wastage. Despite this, reasons for the losses are known in only 16% of cases. Lack of viable conceptus material has inhibited investigations of many potential genetic and pathological causes. We present a method for isolating and culturing placental cells from failed early equine pregnancies. Trophoblast cells from 18/30 (60%) failed equine pregnancies of gestational ages 14–65 days were successfully cultured in three different media, with the greatest growth achieved for cells cultured in AmnioChrome™ Plus. Genomic DNA of a suitable quality for molecular assays was also isolated from 29/30 of these cases. This method will enable future investigations determining pathologies causing EPL