Effect of spin-orbit coupling on the excitation spectrum of Andreev billiards

We consider the effect of spin-orbit coupling on the low energy excitation spectrum of an Andreev billiard (a quantum dot weakly coupled to a superconductor), using a dynamical numerical model (the spin Andreev map). Three effects of spin-orbit coupling are obtained in our simulations: In zero magnetic field: (1) the narrowing of the distribution of the excitation gap; (2) the appearance of oscillations in the average density of states. In strong magnetic field: (3) the appearance of a peak in the average density of states at zero energy. All three effects have been predicted by random-matrix theory.Comment: 5 pages, 4 figure

Production of alkenes and novel secondary products by P450 OleT JE using novel H2O2-generating fusion protein systems

Jeotgalicoccus sp. 8456 OleTJE (CYP152L1) is a fatty acid decarboxylase cytochrome P450 that uses hydrogen peroxide (H2O2) to catalyse production of terminal alkenes, which are industrially important chemicals with biofuel applications. We report enzyme fusion systems in which Streptomyces coelicolor alditol oxidase (AldO) is linked to OleTJE. AldO oxidizes polyols (including glycerol), generating H2O2 as a co-product and facilitating its use for efficient OleTJE-dependent fatty acid decarboxylation. AldO activity is regulatable by polyol substrate titration, enabling control over H2O2 supply to minimise oxidative inactivation of OleTJE and prolong activity for increased alkene production. We also use these fusion systems to generate novel products from secondary turnover of 2-OH and 3-OH myristic acid primary products, expanding the catalytic repertoire of OleTJE

The mitochondrial genome of the hexactinellid sponge Aphrocallistes vastus: Evidence for programmed translational frameshifting

<p>Abstract</p> <p>Background</p> <p>Mitochondrial genomes (mtDNA) of numerous sponges have been sequenced as part of an ongoing effort to resolve the class-level phylogeny of the Porifera, as well as to place the various lower metazoan groups on the animal-kingdom tree. Most recently, the partial mtDNA of two glass sponges, class Hexactinellida, were reported. While previous phylogenetic estimations based on these data remain uncertain due to insufficient taxon sampling and accelerated rates of evolution, the mtDNA molecules themselves reveal interesting traits that may be unique to hexactinellids. Here we determined the first complete mitochondrial genome of a hexactinellid sponge, <it>Aphrocallistes vastus</it>, and compared it to published poriferan mtDNAs to further describe characteristics specific to hexactinellid and other sponge mitochondrial genomes.</p> <p>Results</p> <p>The <it>A. vastus </it>mtDNA consisted of a 17,427 base pair circular molecule containing thirteen protein-coding genes, divergent large and small subunit ribosomal RNAs, and a reduced set of 18 tRNAs. The <it>A. vastus </it>mtDNA showed a typical hexactinellid nucleotide composition and shared a large synteny with the other sequenced glass sponge mtDNAs. It also contained an unidentified open reading frame and large intergenic space region. Two frameshifts, in the <it>cox3 </it>and <it>nad6 </it>genes, were not corrected by RNA editing, but rather possessed identical shift sites marked by the extremely rare tryptophan codon (UGG) followed by the common glycine codon (GGA) in the +1 frame.</p> <p>Conclusion</p> <p>Hexactinellid mtDNAs have shown similar trends in gene content, nucleotide composition, and codon usage, and have retained a large gene syntenty. Analysis of the mtDNA of <it>A. vastus </it>has provided evidence diagnostic for +1 programmed translational frameshifting, a phenomenon disparately reported throughout the animal kingdom, but present in the hexactinellid mtDNAs that have been sequenced to date.</p

A microbial platform for renewable propane synthesis based on a fermentative butanol pathway

Background Propane (C3H8) is a volatile hydrocarbon with highly favourable physicochemical properties as a fuel, in addition to existing global markets and infrastructure for storage, distribution and utilization in a wide range of applications. Consequently, propane is an attractive target product in research aimed at developing new renewable alternatives to complement currently used petroleum-derived fuels. This study focuses on the construction and evaluation of alternative microbial biosynthetic pathways for the production of renewable propane. The new pathways utilize CoA intermediates that are derived from clostridial-like fermentative butanol pathways and are therefore distinct from the first microbial propane pathways recently engineered in Escherichia coli. Results We report the assembly and evaluation of four different synthetic pathways for the production of propane and butanol, designated a) atoB-adhE2 route, b) atoB-TPC7 route, c) nphT7-adhE2 route and d) nphT7-TPC7 route. The highest butanol titres were achieved with the atoB-adhE2 (473 ± 3 mg/L) and atoB-TPC7 (163 ± 2 mg/L) routes. When aldehyde deformylating oxygenase (ADO) was co-expressed with these pathways, the engineered hosts also produced propane. The atoB-TPC7-ADO pathway was the most effective in producing propane (220 ± 3 μg/L). By (i) deleting competing pathways, (ii) including a previously designed ADOA134F variant with an enhanced specificity towards short-chain substrates and (iii) including a ferredoxin-based electron supply system, the propane titre was increased (3.40 ± 0.19 mg/L). Conclusions This study expands the metabolic toolbox for renewable propane production and provides new insight and understanding for the development of next-generation biofuel platforms. In developing an alternative CoA-dependent fermentative butanol pathway, which includes an engineered ADO variant (ADOA134F), the study addresses known limitations, including the low bio-availability of butyraldehyde precursors and poor activity of ADO with butyraldehyde

Antibacterial nanocomposites based on Ag NPs and HMDSO deposited by atmospheric pressure plasma

The development of new multifunctional coatings with antimicrobial properties has a special interest in several applications for pharmaceutical and medical products. This work reports on the deposition of antimicrobial coatings based on silver nanoparticles (Ag NPs) embedded in an organosilicon film onto woven and nonwoven textiles. The Ag nanoparticles admixed with hexamethyldisiloxane (HMDSO) vapours are introduced by means of an atomizer system in the remote discharge of an atmospheric pressure plasma source operating in argon. The chemical properties and the surface morphology of the coatings with antimicrobial potential are discussed.This work was performed within the M-ERA-NET project PlasmaTex, contract 31/2016/ UEFISCDI. The financial support from the Ministry of Research and Innovation under the Nucleus contract 4N/2016 is gratefully acknowledged.info:eu-repo/semantics/publishedVersio

Sand in the wheels, or oiling the wheels, of international finance? : New Labour's appeal to a 'new Bretton Woods'

Tony Blair’s political instinct typically is to associate himself only with the future. As such, his explicit appeal to ‘the past’ in his references to New Labour’s desire to establish a “new Bretton Woods” is sufficient in itself to arouse some degree of analytical curiosity (see Blair 1998a). The fact that this appeal was made specifically in relation to Bretton Woods is even more interesting. The resonant image of the international economic context established by the original Bretton Woods agreements invokes a style and content of policy-making which Tony Blair typically dismisses as neither economically nor politically consistent with his preferred vision of the future (see Blair 2000c, 2001b)

The role of ADP-ribosylation in regulating DNA interstrand crosslink repair

ADP-ribosylation by ADP-ribosyltransferases (ARTs) has a well-established role in DNA strand break repair by promoting enrichment of repair factors at damage sites through ADP-ribose interaction domains. Here we exploit the simple eukaryote Dictyostelium to uncover a role for ADP-ribosylation in regulating DNA interstrand crosslink repair and redundancy of this pathway with non-homologous end-joining (NHEJ). In silico searches identify a protein that contains a permutated macrodomain (Aprataxin/APLF-and-PNKP-Like protein; APL). Structural analysis reveals permutated macrodomains retain features associated with ADP-ribose interactions and APL is capable of binding poly-ADP-ribose through its macrodomain. APL is enriched in chromatin in response to cisplatin, an agent that induces DNA interstrand crosslinks (ICLs). This is dependent on the macrodomain of APL, and the ART Adprt2, indicating a role for ADP-ribosylation in the cellular response to cisplatin. Although adprt2− cells are sensitive to cisplatin, ADP-ribosylation is evident in these cells due to redundant signalling by the DSB-responsive ART Adprt1a, promoting NHEJ-mediated repair. These data implicate ADP-ribosylation in DNA ICL repair and identify NHEJ can function to resolve this form of DNA damage in the absence of Adprt2

Freshwater Sponges Have Functional, Sealing Epithelia with High Transepithelial Resistance and Negative Transepithelial Potential

Epithelial tissue — the sealed and polarized layer of cells that regulates transport of ions and solutes between the environment and the internal milieu — is a defining characteristic of the Eumetazoa. Sponges, the most ancient metazoan phylum [1], [2], are generally believed to lack true epithelia [3], [4], [5], but their ability to occlude passage of ions has never been tested. Here we show that freshwater sponges (Demospongiae, Haplosclerida) have functional epithelia with high transepithelial electrical resistance (TER), a transepithelial potential (TEP), and low permeability to small-molecule diffusion. Curiously, the Amphimedon queenslandica sponge genome lacks the classical occluding genes [5] considered necessary to regulate sealing and control of ion transport. The fact that freshwater sponge epithelia can seal suggests that either occluding molecules have been lost in some sponge lineages, or demosponges use novel molecular complexes for epithelial occlusion; if the latter, it raises the possibility that mechanisms for occlusion used by sponges may exist in other metazoa. Importantly, our results imply that functional epithelia evolved either several times, or once, in the ancestor of the Metazoa

The re-regulation of broadcasting: Or the mill owners’ triumph

Discusses the driving forces behind the Communications Bill 2001 of Great Britain. Terms of the bill; Arguments concerning the re-regulation