Quantum walks of correlated particles

Quantum walks of correlated particles offer the possibility to study large-scale quantum interference, simulate biological, chemical and physical systems, and a route to universal quantum computation. Here we demonstrate quantum walks of two identical photons in an array of 21 continuously evanescently-coupled waveguides in a SiOxNy chip. We observe quantum correlations, violating a classical limit by 76 standard deviations, and find that they depend critically on the input state of the quantum walk. These results open the way to a powerful approach to quantum walks using correlated particles to encode information in an exponentially larger state space

A Klebsiella pneumoniae antibiotic resistance mechanism that subdues host defences and promotes virulence

Klebsiella pneumoniae is an important cause of multidrug-resistant infections worldwide. Recent studies highlight the emergence of multidrug-resistant K.\ua0pneumoniae strains which show resistance to colistin, a last-line antibiotic, arising from mutational inactivation of the mgrB regulatory gene. However, the precise molecular resistance mechanisms of mgrB-associated colistin resistance and its impact on virulence remain unclear. Here, we constructed an mgrB gene K.\ua0pneumoniae mutant and performed characterisation of its lipid A structure, polymyxin and antimicrobial peptide resistance, virulence and inflammatory responses upon infection. Our data reveal that mgrB mutation induces PhoPQ-governed lipid A remodelling which confers not only resistance to polymyxins, but also enhances K. pneumoniae virulence by decreasing antimicrobial peptide susceptibility and attenuating early host defence response activation. Overall, our findings have important implications for patient management and antimicrobial stewardship, while also stressing antibiotic resistance development is not inexorably linked with subdued bacterial fitness and virulence

Novel Method For The Production Of Polyunsaturated Fatty Acids (Patent US 2006/0246556 A1)

The present invention relates to an improved process for the specific production of poly-unsaturated omega-3 and omega-6 fatty acids and a process for the production of triglycerides having an increased content of unsaturated fatty acids, in particular omega-3 and omega-6 fatty acids having at least two double bonds and a 20 or 22 carbon atom chain length. The invention relates to the production of a transgenic organism, preferably a transgenic plant or a transgenic microorganism, hav-ing an increased content of fatty acids, oils or lipids containing C20- or C22-fatty acids with a delta-5, 7, 8, 10 double bond, respectively due to the expression of a delta-8-desaturase and a delta-9-elon-gase from organisms such as plants preferably Algae like Isochrysis galbana or Euglena gracilis. In addition the invention relates to a process for the production of poly unsaturated fatty acids such as Eicosapentaenoic, Arachidonic, Docosapentaenoic or Doosahexaenoic acid through the co-expression of a delta-8-desaturase, a delta-9-elongase and a delta-5 desaturase in organisms such as microorganisms or plants. The invention additionally relates to the use of specific nucleic acid sequences encoding for the aforementioned proteins with delta-8-desaturase-, delta-9-elongase- or delta-5-desaturase-activity, nucleic acid constructs, vectors and organisms containing said nucleic acid sequences. The invention further relates to unsaturated fatty acids and triglycerides having an increased content of at least 1% by weight of unsaturated fatty acids and use thereof

Quantum walk on distinguishable non-interacting many-particles and indistinguishable two-particle

We present an investigation of many-particle quantum walks in systems of non-interacting distinguishable particles. Along with a redistribution of the many-particle density profile we show that the collective evolution of the many-particle system resembles the single-particle quantum walk evolution when the number of steps is greater than the number of particles in the system. For non-uniform initial states we show that the quantum walks can be effectively used to separate the basis states of the particle in position space and grouping like state together. We also discuss a two-particle quantum walk on a two- dimensional lattice and demonstrate an evolution leading to the localization of both particles at the center of the lattice. Finally we discuss the outcome of a quantum walk of two indistinguishable particles interacting at some point during the evolution.Comment: 8 pages, 7 figures, To appear in special issue: "quantum walks" to be published in Quantum Information Processin

Novel Method For The Production Of Polyunsaturated Fatty Acids (Patent WO 2004/057001 A2)

The present invention relates to an improved process for the specific production of poly-unsaturated omega-3 and omega-6 fatty acids and a process for the production of triglycerides having an increased content of unsaturated fatty acids, in particular omega-3 and omega-6 fatty acids having at least two double bonds and a 20 or 22 carbon atom chain length. The invention relates to the produc-tion of a transgenic organism, preferably a transgenic plant or a transgenic microorganism, hav-ing an increased content of fatty acids, oils or lipids containing C20- or C22- fatty acids with a delta-5, 7, 8, 10 double bond, respectively due to the expression of a delta-8-desaturase and a delta-9- elon-gase from organisms such as plants preferably Algae like Isochrysis galbana or Euglena gracilis. In addition the invention relates to a process for the production of poly unsaturated fatty acids such as Eicosapentaenoic, Arachidonic, Docosapentaenoic or Docosahexaenoic acid through the co- expression of a delta -8-desaturase, a delta-9-elongase and a delta-5 desaturase in organisms such as microorganisms or plants.The invention additionally relates to the use of specific nucleic acid sequences encoding for the aforementioned proteins with delta-8-desaturase-, delta-9-elongase- or delta-5-desaturase-activity, nucleic acid constructs, vectors and organisms containing said nucleic acid sequences. The invention further relates to unsaturated fatty acids and triglycerides having an increased content of at least 1 % by weight of unsaturated fatty acids and use thereof

Proinflammatory bacterial peptidoglycan as a cofactor for the development of central nervous system autoimmune disease

Upon stimulation by microbial products through TLR, dendritic cells (DC) acquire the capacity to prime naive T cells and to initiate a proinflammatory immune response. Recently, we have shown that APC within the CNS of multiple sclerosis (MS) patients contain peptidoglycan (PGN), a major cell wall component of Gram-positive bacteria, which signals through TLR and NOD. In this study, we report that Staphylococcus aureus PGN as a single component can support the induction of experimental autoimmune encephalomyelitis (EAE) in mice, an animal model for MS. Mice immunized with an encephalitogenic myelin oligodendrocyte glycoprotein peptide in IFA did not develop EAE. In contrast, addition of PGN to the emulsion was sufficient for priming of autoreactive Th1 cells and development of EAE. In vitro studies demonstrate that PGN stimulates DC-mediated processes, reflected by increased Ag uptake, DC maturation, Th1 cell expansion, activation, and proinflammatory cytokine production. These data indicate that PGN-mediated interactions result in proinflammatory stimulation of Ag-specific effector functions, which are important in the development of EAE. These PGN-mediated processes may occur both within the peripheral ly

Universal digital quantum simulation with trapped ions

A digital quantum simulator is an envisioned quantum device that can be pro- grammed to efficiently simulate any other local system. We demonstrate and investigate the digital approach to quantum simulation in a system of trapped ions. Using sequences of up to 100 gates and 6 qubits, the full time dynamics of a range of spin systems are digitally simulated. Interactions beyond those naturally present in our simulator are accurately reproduced and quantitative bounds are provided for the overall simulation quality. Our results demon- strate the key principles of digital quantum simulation and provide evidence that the level of control required for a full-scale device is within reach.Comment: 12 pages, 4 figures (main article) + 31 pages, 9 figures (supplementary online material

Lipoglycans Contribute to Innate Immune Detection of Mycobacteria

Innate immune recognition is based on the detection, by pattern recognition receptors (PRRs), of molecular structures that are unique to microorganisms. Lipoglycans are macromolecules specific to the cell envelope of mycobacteria and related genera. They have been described to be ligands, as purified molecules, of several PRRs, including the C-type lectins Mannose Receptor and DC-SIGN, as well as TLR2. However, whether they are really sensed by these receptors in the context of a bacterium infection remains unclear. To address this question, we used the model organism Mycobacterium smegmatis to generate mutants altered for the production of lipoglycans. Since their biosynthesis cannot be fully abrogated, we manipulated the biosynthesis pathway of GDP-Mannose to obtain some strains with either augmented (∼1.7 fold) or reduced (∼2 fold) production of lipoglycans. Interestingly, infection experiments demonstrated a direct correlation between the amount of lipoglycans in the bacterial cell envelope on one hand and the magnitude of innate immune signaling in TLR2 reporter cells, monocyte/macrophage THP-1 cell line and human dendritic cells, as revealed by NF-κB activation and IL-8 production, on the other hand. These data establish that lipoglycans are bona fide Microbe-Associated Molecular Patterns contributing to innate immune detection of mycobacteria, via TLR2 among other PRRs

Comparative study of the extracellular proteome of Sulfolobus species reveals limited secretion

Although a large number of potentially secreted proteins can be predicted on the basis of genomic distribution of signal sequence-bearing proteins, protein secretion in Archaea has barely been studied. A proteomic inventory and comparison of the growth medium proteins in three hyperthermoacidophiles, i.e., Sulfolobus solfataricus, S. acidocaldarius and S. tokodaii, indicates that only few proteins are freely secreted into the growth medium and that the majority originates from cell envelope bound forms. In S. acidocaldarius both cell-associated and secreted α-amylase activities are detected. Inactivation of the amyA gene resulted in a complete loss of activity, suggesting that the same protein is responsible for the a-amylase activity at both locations. It is concluded that protein secretion in Sulfolobus is a limited process, and it is suggested that the S-layer may act as a barrier for the free diffusion of folded proteins into the medium