3D attributed models for addressing environmental and engineering geoscience problems in areas of urban regeneration : a case study in Glasgow, UK

The City of Glasgow is situated on and around the lower floodplain and inner estuary of the River Clyde in the west of Scotland, UK. Glasgow’s urban hinterland once was one of Europe’s leading centres of heavy industry, and of ship building in particular. The industries were originally fed by locally mined coal and ironstone. In common with many European cities, the heavy industries declined and Glasgow was left with a legacy of industrial dereliction, widespread undermining, and extensive vacant and contaminated sites, some the infilled sites of clay pits and sand and gravel workings

Metallic ferromagnetism without exchange splitting

In the band theory of ferromagnetism there is a relative shift in the position of majority and minority spin bands due to the self-consistent field due to opposite spin electrons. In the simplest realization, the Stoner model, the majority and minority spin bands are rigidly shifted with respect to each other. Here we consider models at the opposite extreme, where there is no overall shift of the energy bands. Instead, upon spin polarization one of the bands broadens relative to the other. Ferromagnetism is driven by the resulting gain in kinetic energy. A signature of this class of mechanisms is that a transfer of spectral weight in optical absorption from high to low frequencies occurs upon spin polarization. We show that such models arise from generalized tight binding models that include off-diagonal matrix elements of the Coulomb interaction. For certain parameter ranges it is also found that reentrant ferromagnetism occurs. We examine properties of these models at zero and finite temperatures, and discuss their possible relevance to real materials

Pedestrian Solution of the Two-Dimensional Ising Model

The partition function of the two-dimensional Ising model with zero magnetic field on a square lattice with m x n sites wrapped on a torus is computed within the transfer matrix formalism in an explicit step-by-step approach inspired by Kaufman's work. However, working with two commuting representations of the complex rotation group SO(2n,C) helps us avoid a number of unnecessary complications. We find all eigenvalues of the transfer matrix and therefore the partition function in a straightforward way.Comment: 10 pages, 2 figures; eqs. (101) and (102) corrected, files for fig. 2 fixed, minor beautification

Rigorous results on superconducting ground states for attractive extended Hubbard models

We show that the exact ground state for a class of extended Hubbard models including bond-charge, exchange, and pair-hopping terms, is the Yang "eta-paired" state for any non-vanishing value of the pair-hopping amplitude, at least when the on-site Coulomb interaction is attractive enough and the remaining physical parameters satisfy a single constraint. The ground state is thus rigorously superconducting. Our result holds on a bipartite lattice in any dimension, at any band filling, and for arbitrary electron hopping.Comment: 12 page

The NF-κB subunit c-Rel regulates Bach2 tumour suppressor expression in B-cell lymphoma

The REL gene, encoding the NF-κB subunit c-Rel, is frequently amplified in B-cell lymphoma and functions as a tumour-promoting transcription factor. Here we report the surprising result that c-rel–/– mice display significantly earlier lymphomagenesis in the c-Myc driven, Eμ-Myc model of B-cell lymphoma. c-Rel loss also led to earlier onset of disease in a separate TCL1-Tg-driven lymphoma model. Tumour reimplantation experiments indicated that this is an effect intrinsic to the Eμ-Myc lymphoma cells but, counterintuitively, c-rel–/– Eμ-Myc lymphoma cells were more sensitive to apoptotic stimuli. To learn more about why loss of c-Rel led to earlier onset of disease, microarray gene expression analysis was performed on B cells from 4-week-old, wild-type and c-rel–/– Eμ-Myc mice. Extensive changes in gene expression were not seen at this age, but among those transcripts significantly downregulated by the loss of c-Rel was the B-cell tumour suppressor BTB and CNC homology 2 (Bach2). Quantitative PCR and western blot analysis confirmed loss of Bach2 in c-Rel mutant Eμ-Myc tumours at both 4 weeks and the terminal stages of disease. Moreover, Bach2 expression was also downregulated in c-rel–/– TCL1-Tg mice and RelA Thr505Ala mutant Eμ-Myc mice. Analysis of wild-type Eμ-Myc mice demonstrated that the population expressing low levels of Bach2 exhibited the earlier onset of lymphoma seen in c-rel–/– mice. Confirming the relevance of these findings to human disease, analysis of chromatin immunoprecipitation sequencing data revealed that Bach2 is a c-Rel and NF-κB target gene in transformed human B cells, whereas treatment of Burkitt's lymphoma cells with inhibitors of the NF-κB/IκB kinase pathway or deletion of c-Rel or RelA resulted in loss of Bach2 expression. These data reveal a surprising tumour suppressor role for c-Rel in lymphoma development explained by regulation of Bach2 expression, underlining the context-dependent complexity of NF-κB signalling in cancer

Design and placement of synthetic sex pheromone traps for cacao mirids in Ghana

Cacao mirids (Sahlbergella singularis, Distantiella theobroma and Bryocoropsis laticollis) were captured in pheromone traps releasing a 2:1 blend of the sex pheromone components of the two first named species in a series of five experiments on cacao (Theobroma cacao) plantations in Ghana. A total of 835 cacao mirids were caught, all male, 95% of which were S. singularis, 3%D. theobroma and 2%B. laticollis. Two sticky trap and two water trap designs made from locally available materials were as effective for capturing S. singularis and total mirids as the best sticky trap from previously reported studies. Coating the outer surface of a large water trap with sticker increased the catch 4.4×, and 2.7× for a cylindrical sticky trap. Sticker on the outside of the water trap also increased the inside catch of S. singularis by 76% and total mirids by 71%. The numbers of S. singularis and D. theobroma trapped increased with increasing trap elevation and were highest around canopy level. Those traps caught an average 12× more mirids than traps at 1.8 m, the height recommended currently. Therefore, largewater traps coated with sticker and aligned with the cacao canopy should raise the current capture rates of pheromone traps for cacao mirids about 50×, which may be sufficient for effective pest management by mass trapping without synthetic insecticides

Correlated hopping of electrons: Effect on the Brinkman-Rice transition and the stability of metallic ferromagnetism

We study the Hubbard model with bond-charge interaction (`correlated hopping') in terms of the Gutzwiller wave function. We show how to express the Gutzwiller expectation value of the bond-charge interaction in terms of the correlated momentum-space occupation. This relation is valid in all spatial dimensions. We find that in infinite dimensions, where the Gutzwiller approximation becomes exact, the bond-charge interaction lowers the critical Hubbard interaction for the Brinkman-Rice metal-insulator transition. The bond-charge interaction also favors ferromagnetic transitions, especially if the density of states is not symmetric and has a large spectral weight below the Fermi energy.Comment: 5 pages, 3 figures; minor changes, published versio

Modern cosmologies from empty Kaluza-Klein solutions in 5D

We show that the empty five-dimensional solutions of Davidson-Sonnenschtein-Vozmediano, {\em Phys. Rev.} {\bf D32} (1985)1330, in the "old" Kaluza-Klein gravity, under appropriate interpretation can generate an ample variety of cosmological models in 4D, which include the higher-dimensional modifications to general relativity predicted by "modern" versions of noncompactified 5D gravity as, e.g., induced-matter and braneworld theories. This is the first time that these solutions are investigated in a systematic way as embeddings for cosmological models in 4D. They provide a different formulation, which is complementary to the approaches used in current versions of 5D relativity.Comment: Accepted for publication in JHE

Automatic structures for semigroup constructions

We survey results concerning automatic structures for semigroup constructions, providing references and describing the corresponding automatic structures. The constructions we consider are: free products, direct products, Rees matrix semigroups, Bruck-Reilly extensions and wreath products.Comment: 22 page