Lie algebras with given properties of subalgebras and elements

Results about the following classes of finite-dimensional Lie algebras over a field of characteristic zero are presented: anisotropic (i.e., Lie algebras for which each adjoint operator is semisimple), regular (i.e., Lie algebras in which each nonzero element is regular in the sense of Bourbaki), minimal nonabelian (i.e., nonabelian Lie algebras all whose proper subalgebras are abelian), and algebras of depth 2 (i.e., Lie algebras all whose proper subalgebras are abelian or minimal nonabelian).Comment: 8 pages; v3: added proofs; fixed a list of algebras of depth 2 in Theorem 7; the statement of Theorem 5 is weakened, the former statement added as conjecture; to appear in Proceedings of the Conference "Algebra - Geometry - Mathematical Physics" (Mulhouse, 2011), Springer Proc. Math. Sta

Molluscs from a shallow-water whale-fall and their affinities with adjacent benthic communities on the Swedish west coast

We conducted a species-level study of molluscs associated with a 5-m long carcass of a minke whale at a depth of 125 m in the Kosterfjord (North Sea, Sweden). The whale-fall community was quantitatively compared with the community commonly living in the surrounding soft-bottom sediments. Five years after the deployment of the dead whale at the sea floor, the sediments around the carcass were dominated by the bivalve Thyasira sarsi, which is known to contain endosymbiotic sulphur-oxidizing bacteria, while background sediments were dominated by another thyasirid, T. equalis, less dependent on chemosynthesis for its nutrition. The Kosterfjord samples were further compared at the species level with mollusc abundance data derived from the literature, including samples from different marine settings of the west coast of Sweden (active methane seep, fjords, coastal and open marine environments). The results show high similarity between the Kosterfjord whale-fall community and the community that developed in one of the Swedish fjords (Gullmar Fjord) during hypoxic conditions. This study indicates that at shallow-water whale-falls, the sulphophilic stage of the ecological succession is characterized by generalist chemosynthetic bivalves commonly living in organic-rich, sulphidic environments. © 2014 Taylor & Francis

Goats excel at learning and remembering a highly novel cognitive task

PMCID: PMC398717

SIM(2) and supergraphs

We construct Feynman rules and Supergraphs in SIM(2) superspace. To test our methods we perform a one-loop calculation of the effective action of the SIM(2) supersymmetric Wess-Zumino model including a term which explicitly breaks Lorentz invariance. The renormalization of the model is also discussed.Comment: 28 page

Single-phase mixing through a narrow gap

Mixing through narrow gaps connecting adjacent flow paths is an important mass and heat transfer process for many thermo-hydraulic applications. Such flows are considered balanced when the inlet flow speeds of adjacent subchannels are matched. In the present work, experimental observations are presented for balanced and unbalanced flows including the mixing coefficients and flow visualization within the gap. The large coherent structures are identified, with frequency in general agreement with those reported by previous investigators. To utilize Proper Orthogonal Decomposition (POD) for the discrete data yielded by PIV, we employ method of Singular Value Decomposition (SVD). The bulk of the mixing is attributed to the dominant modes and demonstrate that mixing rates estimated from velocity measurements are in fair agreement with mixing coefficients based on tracer concentration measurements

Generation of superoxide and singlet oxygen from α-tocopherolquinone and analogues.

Three potential routes to generation of reactive oxygen species from a tocopherolquinone have been identified. The quinone of the water-soluble vitamin E analogue Trolox C (Trol-Q) is reduced by hydrated electron and isopropanol a hydroxyalkyl radical, and the resulting semiquinone reacts with molecular oxygen to form superoxide with a second order rate constant of 1.3 x 108 dm3 mol-1 s-1, illustrating the potential for redox cycling. Illumination (UV-A, 355 nm) of the quinone of 2,2,5,7,8-pentamethyl-6-hydroxychromanol (PMHC-Q) leads to a reactive short-lived (ca 10-6 s) triplet state, able to oxidise tryptophan with a second order rate constant greater than 109 dm3 mol-1 s-1. The triplet states of these quinones sensitize singlet oxygen formation with quantum yields of about 0.8. Such potentially damaging reactions of a tocopherolquinone may in part account for the recent findings that high levels of dietary vitamin E supplementation lack any beneficial effect and may lead to slightly enhanced levels of overall mortality

Recent high-energy marine events in the sediments of the Lagoa de Óbidos and Martinhal (Portugal): Recognition, age and likely causes

© 2012 Author(s) - This work is distributed under the Creative Commons Attribution 3.0 License.This article has been made available through the Brunel Open Access Publishing Fund.A key issue in coastal hazards research is the need to distinguish sediments deposited by past extreme storms from those of past tsunamis. This study contributes to this aim by investigating patterns of sedimentation associated with extreme coastal flood events, in particular, within the Lagoa de Óbidos (Portugal). The recent stratigraphy of this coastal lagoon was studied using a wide range of techniques including visual description, grain-size analysis, digital and x-ray photography, magnetic susceptibility and geochemical analysis. The sequence was dated by 14C, 210Pb and Optically Stimulated Luminescence. Results disclose a distinctive coarser sedimentary unit, within the top of the sequence studied, and shown in quartz sand by the enrichment of elements with marine affinity (e.g., Ca and Na) and carbonates. The unit fines upwards and inland, thins inland and presents a sharp erosive basal contact. A noticeable post-event change in the sedimentary pattern was observed. The likely agent of sedimentation is discussed here and the conceivable association with the Great Lisbon tsunami of AD 1755 is debated, while a comparison is attempted with a possibly synchronous deposit from a tsunami in Martinhal (Algarve, Portugal). The possibility of a storm origin is also discussed in the context of the storminess of the western Portuguese coast and the North Atlantic Oscillation. This study highlights certain characteristics of the sedimentology of the deposits that may have a value in the recognition of extreme marine inundation signatures elsewhere in the world.This article is made available through the Brunel Open Access Publishing Fund

Brain Tumor Synthetic Segmentation in 3D Multimodal MRI Scans

The magnetic resonance (MR) analysis of brain tumors is widely used for diagnosis and examination of tumor subregions. The overlapping area among the intensity distribution of healthy, enhancing, non-enhancing, and edema regions makes the automatic segmentation a challenging task. Here, we show that a convolutional neural network trained on high-contrast images can transform the intensity distribution of brain lesions in its internal subregions. Specifically, a generative adversarial network (GAN) is extended to synthesize high-contrast images. A comparison of these synthetic images and real images of brain tumor tissue in MR scans showed significant segmentation improvement and decreased the number of real channels for segmentation. The synthetic images are used as a substitute for real channels and can bypass real modalities in the multimodal brain tumor segmentation framework. Segmentation results on BraTS 2019 dataset demonstrate that our proposed approach can efficiently segment the tumor areas. In the end, we predict patient survival time based on volumetric features of the tumor subregions as well as the age of each case through several regression models