Spin-Glass Model for Inverse Freezing

We analyze the Blume-Emery-Griffiths model with disordered magnetic interaction displaying the inverse freezing phenomenon. The behaviour of this spin-1 model in crystal field is studied throughout the phase diagram and the transition and spinodal lines for the model are computed using the Full Replica Symmetry Breaking Ansatz that always yelds a thermodynamically stable phase. We compare the results both with the quenched disordered model with Ising spins on lattice gas - where no reentrance takes place - and with the model with generalized spin variables recently introduced by Schupper and Shnerb [Phys. Rev. Lett. 93, 037202 (2004)]. The simplest version of all these models, known as Ghatak-Sherrington model, turns out to hold all the general features characterizing an inverse transition to an amorphous phase, including the right thermodynamic behavior.Comment: 6 pages, 4 figures, to appear in the Proceeding for the X International Workshop on Disordered Systems (2006), Molveno, Ital

High resolution structural evidence suggests the Sarcoplasmic Reticulum forms microdomains with acidic stores (lysosomes) in the heart

Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP) stimulates calcium release from acidic stores such as lysosomes and is a highly potent calcium-mobilising second messenger. NAADP plays an important role in calcium signalling in the heart under basal conditions and following β-adrenergic stress. Nevertheless, the spatial interaction of acidic stores with other parts of the calcium signalling apparatus in cardiac myocytes is unknown. We present evidence that lysosomes are intimately associated with the sarcoplasmic reticulum (SR) in ventricular myocytes; a median separation of 20 nm in 2D electron microscopy and 3.3 nm in 3D electron tomography indicates a genuine signalling microdomain between these organelles. Fourier analysis of immunolabelled lysosomes suggests a sarcomeric pattern (dominant wavelength 1.80 μm). Furthermore, we show that lysosomes form close associations with mitochondria (median separation 6.2 nm in 3D studies) which may provide a basis for the recently-discovered role of NAADP in reperfusion-induced cell death. The trigger hypothesis for NAADP action proposes that calcium release from acidic stores subsequently acts to enhance calcium release from the SR. This work provides structural evidence in cardiac myocytes to indicate the formation of microdomains between acidic and SR calcium stores, supporting emerging interpretations of NAADP physiology and pharmacology in heart

TOPAZ1, a Novel Germ Cell-Specific Expressed Gene Conserved during Evolution across Vertebrates

BACKGROUND: We had previously reported that the Suppression Subtractive Hybridization (SSH) approach was relevant for the isolation of new mammalian genes involved in oogenesis and early follicle development. Some of these transcripts might be potential new oocyte and granulosa cell markers. We have now characterized one of them, named TOPAZ1 for the Testis and Ovary-specific PAZ domain gene. PRINCIPAL FINDINGS: Sheep and mouse TOPAZ1 mRNA have 4,803 bp and 4,962 bp open reading frames (20 exons), respectively, and encode putative TOPAZ1 proteins containing 1,600 and 1653 amino acids. They possess PAZ and CCCH domains. In sheep, TOPAZ1 mRNA is preferentially expressed in females during fetal life with a peak during prophase I of meiosis, and in males during adulthood. In the mouse, Topaz1 is a germ cell-specific gene. TOPAZ1 protein is highly conserved in vertebrates and specifically expressed in mouse and sheep gonads. It is localized in the cytoplasm of germ cells from the sheep fetal ovary and mouse adult testis. CONCLUSIONS: We have identified a novel PAZ-domain protein that is abundantly expressed in the gonads during germ cell meiosis. The expression pattern of TOPAZ1, and its high degree of conservation, suggests that it may play an important role in germ cell development. Further characterization of TOPAZ1 may elucidate the mechanisms involved in gametogenesis, and particularly in the RNA silencing process in the germ lin

Local Abundance Patterns of Noctuid Moths in Olive Orchards: Life-History Traits, Distribution Type and Habitat Interactions

Local species abundance is related to range size, habitat characteristics, distribution type, body size, and life-history variables. In general, habitat generalists and polyphagous species are more abundant in broad geographical areas. Underlying this, local abundance may be explained from the interactions between life-history traits, chorological pattern, and the local habitat characteristics. The relationship within taxa between life-history traits, distribution area, habitat characteristics, and local abundance of the noctuid moth (Lepidoptera: Noctuidae) assemblage in an olive orchard, one of the most important agro-ecosystems in the Mediterranean basin, was analyzed. A total of 66 species were detected over three years of year-round weekly samplings using the light-trap method. The life-history traits examined and the distribution type were found to be related to the habitat-species association, but none of the biological strategies defined from the association to the different habitats were linked with abundance. In contrast to general patterns, dispersal ability and number of generations per year explained differences in abundance. The relationships were positive, with opportunistic taxa that have high mobility and several generations being locally more abundant. In addition, when the effect of migrant species was removed, the distribution type explained abundance differences, with Mediterranean taxa (whose baricenter is closer to the studied area) being more abundant

BCAT1 controls metabolic reprogramming in activated human macrophages and is associated with inflammatory diseases

This work was supported by the Medical Research Council (MR/M004716/1 and MR/N01121X/1 to J.B.) and by Kidney Research UK (RP9/2013 to J.B.). D.C. is supported by the Institute Pasteur, Fondazione Cenci Bolognetti. C.M. is supported by the British Hearth Foundation Fellowship (FS/12/3829640)