Biomineral Proteins from Mytilus edulis Mantle Tissue Transcriptome

The common blue mussel, Mytilus edulis, has a bimineralic shell composed of approximately equal proportions of the two major polymorphs of calcium carbonate: calcite and aragonite. The exquisite biological control of polymorph production is the focus of research interest in terms of understanding the details of biomineralisation and the proteins involved in the process of complex shell formation. Recent advances in ease and availability of pyrosequencing and assembly have resulted in a sharp increase in transcriptome data for invertebrate biominerals. We have applied Roche 454 pyrosequencing technology to profile the transcriptome for the mantle tissue of the bivalve M. edulis. A comparison was made between the results of several assembly programs: Roche Newbler assembler versions 2.3, 2.5.2 and 2.6 and MIRA 3.2.1 and 3.4.0. The Newbler and MIRA assemblies were subsequently merged using the CAP3 assembler to give a higher consensus in alignments and a more accurate estimate of the true size of the M. edulis transcriptome. Comparison sequence searches show that the mantle transcripts for M. edulis encode putative proteins exhibiting sequence similarities with previously characterised shell proteins of other species of Mytilus, the Bivalvia Pinctada and haliotid gastropods. Importantly, this enhanced transcriptome has detected several transcripts that encode proteins with sequence similarity with previously described shell biomineral proteins including Shematrins and lysine-rich matrix proteins (KRMPs) not previously found in Mytilus. © 2013 The Author(s)

Connected clusters: landscaping study

This study presents evidence from five dynamic, city region-based climate innovation clusters. Here businesses, academics, communities and government work together to deliver low-carbon innovation. We believe this concentration of resources, expertise and initiative is our best chance of meeting the Paris climate targets while also reaping social and economic benefits that come with the development and delivery of cleantech solutions. Climate-KIC’s ConnectedClusters project is an alliance of five city regions – Birmingham, Edinburgh, Frankfurt, London and Valencia – committed to sharing, replicating and scaling what works in developing innovation ecosystems for delivering effective climate action. Between now and 2020, the project will work hard to accelerate and enable transformation of the places we live into clean, prosperous and thriving cities and regions by developing new collaborative approaches to technology, procurement, investment and training. ConnectedClusters will help inform a transition away from product and technology innovation in isolation, towards a systemic, regionally-embedded approach to climate innovation. Paris shows that for our continued prosperity, transformation on a scale never witnessed before is imperative. Only by working together can we achieve that change

Ba6−3x Nd8+2x Ti18O54 Tungsten Bronze: A New High-Temperature n-Type Oxide Thermoelectric

Semiconducting Ba6−3x Nd8+2x Ti18O54 ceramics (with x = 0.00 to 0.85) were synthesized by the mixed oxide route followed by annealing in a reducing atmosphere; their high-temperature thermoelectric properties have been investigated. In conjunction with the experimental observations, atomistic simulations have been performed to investigate the anisotropic behavior of the lattice thermal conductivity. The ceramics show promising n-type thermoelectric properties with relatively high Seebeck coefficient, moderate electrical conductivity, and temperature-stable, low thermal conductivity; For example, the composition with x = 0.27 (i.e., Ba5.19Nd8.54Ti18O54) exhibited a Seebeck coefficient of S 1000K = 210 µV/K, electrical conductivity of σ 1000K = 60 S/cm, and thermal conductivity of k 1000K = 1.45 W/(m K), leading to a ZT value of 0.16 at 1000 K

Regulation of Hemolysin Expression and Virulence of Staphylococcus aureus by a Serine/Threonine Kinase and Phosphatase

Exotoxins, including the hemolysins known as the alpha (α) and beta (β) toxins, play an important role in the pathogenesis of Staphylococcus aureus infections. A random transposon library was screened for S. aureus mutants exhibiting altered hemolysin expression compared to wild type. Transposon insertions in 72 genes resulting in increased or decreased hemolysin expression were identified. Mutations inactivating a putative cyclic di-GMP synthetase and a serine/threonine phosphatase (Stp1) were found to reduce hemolysin expression, and mutations in genes encoding a two component regulator PhoR, LysR family transcriptional regulator, purine biosynthetic enzymes and a serine/threonine kinase (Stk1) increased expression. Transcription of the hla gene encoding α toxin was decreased in a Δstp1 mutant strain and increased in a Δstk1 strain. Microarray analysis of a Δstk1 mutant revealed increased transcription of additional exotoxins. A Δstp1 strain is severely attenuated for virulence in mice and elicits less inflammation and IL-6 production than the Δstk1 strain. In vivo phosphopeptide enrichment and mass spectrometric analysis revealed that threonine phosphorylated peptides corresponding to Stk1, DNA binding histone like protein (HU), serine-aspartate rich fibrinogen/bone sialoprotein binding protein (SdrE) and a hypothetical protein (NWMN_1123) were present in the wild type and not in the Δstk1 mutant. Collectively, these studies suggest that Stk1 mediated phosphorylation of HU, SrdE and NWMN_1123 affects S. aureus gene expression and virulence

Biomineralization: Elemental and organic influence in carbonate systems

Biomineralization is the accumulation of minerals by organisms especially into biological structures. The biomineral structures perform a wide range of interrelated functions including support and mobility in the vertebrate skeleton and many others. In the biosphere, there are at least 60 different minerals, calcium phosphate, calcium carbonate, and silica are the most abundant. The physical and material properties of these biocomposites can be ultimately determined using the variety of biomineral ultrastructures and chemical compositions, in combination with organic components. The organic components influence the mineral even at the level of the unit cell. Biomineral are produced under strict biological means, in which crystallization rate influenced the final composition of the biomineral. Biomineralization process, focusing on marine invertebrates, have been provided with a view of understanding and interpreting climate data recorded by their chemical and isotopic composition. The carbonate systems that are considered includes corals, bivalves, brachiopods, coccoliths, and foraminifera

Design issues for socially intelligent user-interfaces: a discourse analysis of a data-to-text system for summarizing clinical data

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The structure and function of the LH2 (B800–850) complex from the purple photosynthetic bacterium Rhodopseudomonas acidophila strain 10050

27 pages, 11 figures, 2 tables.-- PMID: 9481143 [PubMed].The major light-absorbing pigments in purple photosynthetic bacteria are the bacteriochlorophylls (a and b) (BChl) and the carotenoids. These pigments are noncovalently attached to two types of integral membrane protein forming the reaction centers and the light-harvesting or antenna complexes (Hawthornthwaite and Cogdell, 1991; Hunter, 1995; Zuber and Cogdell, 1995). Photosynthesis in purple bacteria usually begins with the absorption of a photon in the light-harvesting system. The absorbed energy is then rapidly (in less than ~100 ps) and efficiently transferred to the reaction center (~95% quantum efficiency). In the reaction center this energy is used to drive the initial charge separation reaction and the energy is then "trapped" (Feher and Okamura, 1978; Feher et al., 1989; Deisenhofer et al., 1995). The combination of antenna complexes with a reaction center constitutes the photosynthetic unit (PSU). For most commonly studied purple bacteria the number of PSUs per cell and their size are variable. Depending on such factors as the light-intensity at which cells are grown, the size of the PSU can vary from about 30 BChls per reaction center up to 200-300 BChls per reaction center (Aagaard and Sistrom, 1972; Drews, 1985). This arrangement of reaction centers surrounded by an antenna system ensures that each reaction center is kept well supplied with incoming solar energy and effectively acts to increase their cross-sectional area for photon capture. It is interesting to note that in most species the same pigments are found in both reaction centers and antenna complexes, and it is the protein that determines which function a given pigment is destined to fulfil.When BChl a is dissolved in an organic solvent such as 7:2 v/v acetone:methanol its NIR absorption band is located at 772 nm. This is the typical Qy absorption band of monomeric BChl a. However, when the BChl a is non-covalently bound into an antenna complex, this NIR absorption band is red shifted between 800-940 nm, depending on the species (Fig. 1) (Thornber et al., 1978; Hawthornthwaite and Cogdell, 1991). In most species this red shift is associated with an increase in spectral complexity, with several peaks/shoulders clearly visible in the in vivo absorption spectrum. This red shift arises from pigment-pigment and pigment-protein interactions within the antenna complexes and is regularly used to both identify them and judge their integrity.Since they are integral membrane proteins, the isolation of a purple bacterial antenna complex begins with the solubilization of the photosynthetic membrane with a suitable detergent (Cogdell and Thorber, 1979; Hawthornthwaite and Cogdell, 1991). Very often the solubilized complexes are then initially fractionated by sucrose gradient centrifugation (Fig. 2). In most species this fractionation reveals two types of antenna complex, called LH1 and LH2. LH1 forms the so called "core" complex. It is closely associated with the reaction center and forms a stoichiometric complex with it (usually ~32 BChls per reaction center (Gall, 1995; Karrasch et al., 1995; Zuber and Cogdell, 1995). LH2, also sometimes called the "variable" or "peripheral" antenna complex, is the topic for the remainder of this review. Readers who want to obtain more information on the overall subject of the structure and function of the bacterial PSU should consult the following general reviews (Somsen et al., 1993; Blankenship et al., 1995; Loach and Parkes-Loach, 1995; Cogdell et al., 1996; Papiz et al., 1996).Some of the work described in this review was supported by grants from the BBSRC, the EU and the Human Frontiers of Science Programme. RJC would like to thank the Alexander von Humboldt Foundation for financial support during the writing of this review.Peer reviewe