Nonclassical states in strongly correlated bosonic ring ladders

We study the ground state of a bosonic ring ladder under a gauge flux in the vortex phase, corresponding to the case where the single-particle dispersion relation has two degenerate minima. By combining exact diagonalization and an approximate fermionization approach we show that the ground state of the system evolves from a fragmented state of two single-particle states at weak interparticle interactions to a fragmented state of two Fermi seas at large interactions. Fragmentation is inferred from the study of the eigenvalues of the reduced single-particle density matrix as well as from the calculation of the fidelity of the states. We characterize these nonclassical states by the momentum distribution, the chiral currents and the current-current correlations

Electron-Electron Bremsstrahlung Emission and the Inference of Electron Flux Spectra in Solar Flares

Although both electron-ion and electron-electron bremsstrahlung contribute to the hard X-ray emission from solar flares, the latter is normally ignored. Such an omission is not justified at electron (and photon) energies above $\sim 300$ keV, and inclusion of the additional electron-electron bremsstrahlung in general makes the electron spectrum required to produce a given hard X-ray spectrum steeper at high energies. Unlike electron-ion bremsstrahlung, electron-electron bremsstrahlung cannot produce photons of all energies up to the maximum electron energy involved. The maximum possible photon energy depends on the angle between the direction of the emitting electron and the emitted photon, and this suggests a diagnostic for an upper cutoff energy and/or for the degree of beaming of the accelerated electrons. We analyze the large event of January 17, 2005 observed by RHESSI and show that the upward break around 400 keV in the observed hard X-ray spectrum is naturally accounted for by the inclusion of electron-electron bremsstrahlung. Indeed, the mean source electron spectrum recovered through a regularized inversion of the hard X-ray spectrum, using a cross-section that includes both electron-ion and electron-electron terms, has a relatively constant spectral index $\delta$ over the range from electron kinetic energy $E = 200$ keV to $E = 1$ MeV. However, the level of detail discernible in the recovered electron spectrum is not sufficient to determine whether or not any upper cutoff energy exists.Comment: 7 pages, 5 figures, submitted to Astrophysical Journa

Individual variation and intraclass correlation in arachidonic acid and eicosapentaenoic acid in chicken muscle

Chicken meat with reduced concentration of arachidonic acid (AA) and reduced ratio between omega-6 and omega-3 fatty acids has potential health benefits because a reduction in AA intake dampens prostanoid signaling, and the proportion between omega-6 and omega-3 fatty acids is too high in our diet. Analyses for fatty acid determination are expensive, and finding the optimal number of analyses to give reliable results is a challenge. The objective of the present study was i) to analyse the intraclass correlation of different fatty acids in five meat samples, of one gram each, within the same chicken thigh, and ii) to study individual variations in the concentrations of a range of fatty acids and the ratio between omega-6 and omega-3 fatty acid concentrations among fifteen chickens. Fifteen newly hatched broilers were fed a wheat-based diet containing 4% rapeseed oil and 1% linseed oil for three weeks. Five muscle samples from the mid location of the thigh of each chicken were analysed for fatty acid composition. The intraclass correlation (sample correlation within the same animal) was 0.85-0.98 for the ratios of total omega-6 to total omega-3 fatty acids and of AA to eicosapentaenoic acid (EPA). This indicates that when studying these fatty acid ratios, one sample of one gram per animal is sufficient. However, due to the high individual variation between chicken for these ratios, a relatively high number of animals (minimum 15) are required to obtain a sufficiently high power to reveal significant effects of experimental factors (e.g. feeding regimes). The present experiment resulted in meat with a favorable concentration ratio between omega-6 and omega-3 fatty acids. The AA concentration varied from 1.5 to 2.8 g/100 g total fatty acids in thigh muscle in the fifteen broilers, and the ratio between AA and EPA concentrations ranged from 2.3 to 3.9. These differences among the birds may be due to genetic variance that can be exploited by breeding for lower AA concentration and/or a more favorable AA/EPA ratio to produce meat with health benefits

Bovine milk in human nutrition – a review

Milk and milk products are nutritious food items containing numerous essential nutrients, but in the western societies the consumption of milk has decreased partly due to claimed negative health effects. The content of oleic acid, conjugated linoleic acid, omega-3 fatty acids, short- and medium chain fatty acids, vitamins, minerals and bioactive compounds may promote positive health effects. Full-fat milk has been shown to increase the mean gastric emptying time compared to half-skimmed milk, thereby increasing the gastrointestinal transit time. Also the low pH in fermented milk may delay the gastric emptying. Hence, it may be suggested that ingesting full-fat milk or fermented milk might be favourable for glycaemic (and appetite?) regulation. For some persons milk proteins, fat and milk sugar may be of health concern. The interaction between carbohydrates (both natural milk sugar and added sugar) and protein in milk exposed to heat may give products, whose effects on health should be further studied, and the increasing use of sweetened milk products should be questioned. The concentration in milk of several nutrients can be manipulated through feeding regimes. There is no evidence that moderate intake of milk fat gives increased risk of diseases

Dietary intake of menaquinone-4 may determine hepatic and pancreatic menaquinone-4 in chickens

Objective: The aim of this study was to determine the biological effects of natural dietary intake of vitamin K as phylloquinone (K1) and menaquinone-4 (MK-4) and a control diet also containing menadione (K3) on levels of K1 and total MK-4 (menaquinone-4) and menaquinone-4-2,3-epoxide (MK-4O) in liver and pancreas, and on femur bending resistance in a fast-growing animal model. Design: Chickens were fed four wheat-based diets from day 11 to day 22 after hatching. The diets contained different combinations of fat sources: rapeseed oil, animal rendered fat, soybean oil and hydrogenated soybean oil. Concentration of K1 in the three experimental diets was 120 ng/g whereas MK-4 levels were 23, 52 and 63 ng/g respectively. The control diet contained 157 ng K1/g, 75 ng MK-4/g and 2.250 ng K3/g. Results: Growth rates and femur strength confirmed adequate supply of nutrients and vitamin K in the test groups. There were no significant differences in femur bending resistance among the test groups, but these were higher than the control. K1, MK-4 and MK-4O were found in liver. In pancreas, mainly MK-4O was found with small amounts of MK-4, but none had content of K1. In the test groups the hepatic levels of MK-4 and MK-4O reflected the dietary intake of MK-4. Conclusion: The chickens were in good health with good bone resistance without supplements of K3in the feed, but at least a natural content of 23 ng MK-4/g feed. Liver and pancreas appears to use MK-4 in different ways

Selenium Requirements and Metabolism in Poultry

As counteract against deficiency in livestock, dietary treatments are supplemented with selenium (Se), usually as the inorganic form sodium selenite (SS). Since Se is considered as toxic as well as an essential element, SS is added to prevent an increase of Se in edible chicken parts. However, in many countries, populations suffer from suboptimal Se intake and even Se deficiency, by increasing the use of organic Se sources such as Se‐enriched yeast or wheat in animal feed, there will be a subsequent increase in meat and egg products for human consumption. One could argue that the chickens do not need the extra pool of Se in muscles, as the inorganic form will be sufficient to meet the chickens Se requirements. Since the feed is fortified with selenite, the chickens will always have adequate access to the essential trace element. However, global gene set functional enrichment analysis revealed statistically significant enrichment of a number of biological processes that were dependent on the Se feed sources, such as cell growth, organ development and protein metabolism in favour of organic Se

Linking an Early Triassic delta to antecedent topography: Source-to-sink study of the southwestern Barents Sea margin

Present-day catchments adjacent to sedimentary basins may preserve geomorphic elements that have been active through long intervals of time. Relicts of ancient catchments in present-day landscapes may be investigated using mass-balance models and can give important information about upland landscape evolution and reservoir distribution in adjacent basins. However, such methods are in their infancy and are often difficult to apply in deep-time settings due to later landscape modification. The southern Barents Sea margin of N Norway and NW Russia is ideal for investigating source-to-sink models, because it has been subject to minor tectonic activity since the Carboniferous, and large parts have eluded significant Quaternary glacial erosion. A zone close to the present-day coast has likely acted as the boundary between basin and catchments since the Carboniferous. Around the Permian-Triassic transition, a large delta system started to prograde from the same area as the present-day largest river in the area, the Tana River, which has long been interpreted to show features indicating that it was developed prior to present-day topography. We performed a source-to-sink study of this ancient system in order to investigate potential linkages between present-day geomorphology and ancient deposits. We investigated the sediment load of the ancient delta using well, core, two-dimensional and three-dimensional seismic data, and digital elevation models to investigate the geomorphology of the onshore catchment and surrounding areas. Our results imply that the present-day Tana catchment was formed close to the Permian-Triassic transition, and that the Triassic delta system has much better reservoir properties compared to the rest of Triassic basin infill. This implies that landscapes may indeed preserve catchment geometries for extended periods of time, and it demonstrates that source-to-sink techniques can be instrumental in predicting the extent and quality of subsurface reservoirs.publishedVersio

Lithological influence on sill geometry in sedimentary basins : Controls and recognition in reflection seismic data

Peer reviewe

Linking sediment supply variations and tectonic evolution in deep time, source-to-sink systems—The Triassic Greater Barents Sea Basin

Triassic strata in the Greater Barents Sea Basin are important records of geodynamic activity in the surrounding catchments and sediment transport in the Arctic basins. This study is the first attempt to investigate the evolution of these source areas through time. Our analysis of sediment budgets from subsurface data in the Greater Barents Sea Basin and application of the BQART approach to estimate catchment properties shows that (1) during the Lower Triassic, sediment supply was at its peak in the basin and comparable to that of the biggest modern-day river systems, which are supplied by tectonically active orogens; (2) the Middle Triassic sediment load was significantly lower but still comparable to that of the top 10 largest modern rivers; (3) during the Upper Triassic, sediment load increased again in the Carnian; and (4) there is a large mismatch (70%) between the modeled and estimated sediment load of the Carnian. These results are consistent with the Triassic Greater Barents Sea Basin succession being deposited under the influence of the largest volcanic event ever at the Permian-Triassic boundary (Siberian Traps) and concurrent with the climatic changes of the Carnian Pluvial Event and the final stages of the Northern Ural orogeny. They also provide a better understanding of geodynamic impacts on sedimentary systems and improve our knowledge of continental-scale sediment transport. Finally, the study demonstrates bypass of sediment from the Ural Mountains and West Siberia into the adjacent Arctic Sverdrup, Chukotka, and Alaska Basins in Late Carnian and Late Norian time.publishedVersio