General Bootstrap Equations in 4D CFTs

We provide a framework for generic 4D conformal bootstrap computations. It is based on the unification of two independent approaches, the covariant (embedding) formalism and the non-covariant (conformal frame) formalism. We construct their main ingredients (tensor structures and differential operators) and establish a precise connection between them. We supplement the discussion by additional details like classification of tensor structures of n-point functions, normalization of 2-point functions and seed conformal blocks, Casimir differential operators and treatment of conserved operators and permutation symmetries. Finally, we implement our framework in a Mathematica package and make it freely available.Comment: 57 page

A non commutative sewing lemma

In a preceding paper [E.J.ofProb.34,860-892,(2006)], we proved a sewing lemma which was a key result for the study of Holder continuous functions. In this paper we give a non-commutative version of this lemma with some applications.Comment: 11 page

Crystal Structure of the P Pilus Rod Subunit PapA

P pili are important adhesive fibres involved in kidney infection by uropathogenic Escherichia coli strains. P pili are assembled by the conserved chaperone-usher pathway, which involves the PapD chaperone and the PapC usher. During pilus assembly, subunits are incorporated into the growing fiber via the donor-strand exchange (DSE) mechanism, whereby the chaperone's G1 β-strand that complements the incomplete immunoglobulin-fold of each subunit is displaced by the N-terminal extension (Nte) of an incoming subunit. P pili comprise a helical rod, a tip fibrillum, and an adhesin at the distal end. PapA is the rod subunit and is assembled into a superhelical right-handed structure. Here, we have solved the structure of a ternary complex of PapD bound to PapA through donor-strand complementation, itself bound to another PapA subunit through DSE. This structure provides insight into the structural basis of the DSE reaction involving this important pilus subunit. Using gel filtration chromatography and electron microscopy on a number of PapA Nte mutants, we establish that PapA differs in its mode of assembly compared with other Pap subunits, involving a much larger Nte that encompasses not only the DSE region of the Nte but also the region N-terminal to it. Author Summary. Bacterial adhesion to a host is a crucial step that determines the onset of bacterial infection. It is mediated through recognition of a receptor on the host cell surface by a protein called an adhesin displayed on the surface of the bacterium. Many adhesins are displayed at the tip of specialized organelles called pili, some of which are assembled by the ubiquitous chaperone-usher pathway. In this pathway, each pilus subunit is assisted in folding by a chaperone. The resulting chaperone-subunit complex is targeted to a pore located in the outer membrane, called the usher, that serves as assembly platform. There, pilus subunits dissociate from the chaperone and polymerize, resulting in a surface organelle, the pilus, that protrudes out of the usher. Here, we have determined the structure of the major subunit of the P pilus, PapA. The P pilus, produced in uropathogenic Escherichia coli, displays the adhesin PapG responsible for targeting the bacterium to the kidney epithelium. We have determined the structure of PapA either bound to its cognate chaperone, PapD, or bound to another PapA subunit. These structures provide a view of PapA before and after its assembly in the pilus and shed light on the mechanism of PapA assembly.National Institutes of Health (DE 09761, GM040388, DE 09161); Committee of Scientific Research (3 PO4A 003 24, 2 P05A 137 24); Foundation for Polish Science (SUBSYDIUM PROFESORSKIE award); Swedish Rheumatism Association; Nanna Svartz Foundation; King Gustaf V Foundatio

CTRANSPORT: Multi-agent-based simulation

Pollution nowadays is a really important issue that must be solved. Big cities suffer from overcrowding which result in traffic congestion and a lot of air pollution. Adapting to the idea of cities bike lane expansion, we design a Multi-agent simulation to distribute among the users green energy vehicles; concretely bikes, scooters and electric cars.Pollution nowadays is a really important issue that must be solved. Big cities suffer from overcrowding which result in traffic congestion and a lot of air pollution. Adapting to the idea of cities bike lane expansion, we design a Multi-agent simulation to distribute among the users green energy vehicles; concretely bikes, scooters and electric cars