Pedro J Silva

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In this article we derive the full interacting effective actions for supersymmetric D-branes in arbitrary bosonic type II supergravity backgrounds. The actions are presented in terms of component fields up to second order in fermions. As one expects, the actions are built from the supercovariant derivative operator and the κ-symmetry projector. The results(More)
We consider 1/2 BPS excitations of AdS5 × S 5 geometries in type IIB string theory that can be mapped into free fermion configurations according to the prescription of Lin, Lunin and Maldacena (LLM). It is shown that whenever the fermionic probability density exceeds one or is negative, closed timelike curves appear in the bulk. A violation of the Pauli(More)
During heme biosynthesis, coproporphyrinogen III oxidase catalyzes the conversion of two propionate substituents from the highly reactive substrate coproporphyrinogen III into vinyl substituents, yielding protoporphyrinogen IX. Although the crystal structure of this important enzyme has recently been reported, the reaction mechanism of this intriguing(More)
A nitrate reductase was solubilized with Triton X-100 from the membranes of Pseudomonas chlororaphis DSM 50135 grown microaerobically in the presence of nitrate. Like other membrane-bound nitrate reductases, it contains three subunits, of 129, 66 (64) and 24 kDa, referred to in the literature as alpha, beta and gamma, respectively. Electrocatalytic studies(More)
In this work we define a new limiting procedure that extends the usual thermodynamics treatment of Black Hole physics, to the supersymmetric regime. This procedure is inspired on equivalent statistical mechanics derivations in the dual CFT theory, where the BPS partition function at zero temperature is obtained by a double scaling limit of temperature and(More)
In this article, we describe giant gravitons in AdS5 × S5 moving along generic trajectories in AdS5. The giant graviton dynamics is solved by proving that the D3-brane effective action reduces to that of a massive point particle in AdS5 and therefore the solutions are in one to one correspondence with timelike geodesics of AdS5. All these configurations are(More)
We derive the actions for type II Green-Schwarz strings up to second order in the fermions, for general bosonic backgrounds. We base our work on the so-called normal coordinate expansion. The resulting actions are κ-symmetric and, for the case of surviving background supersymmetries, supersymmetric. We first obtain the type IIa superstring action from the(More)
We show that the supertube configurations exist in all supersymmetric type IIA backgrounds which are purely geometrical and which have, at least, one flat direction. In other words, they exist in any spacetime of the form R1,1 × M8, with M8 any of the usual reduced holonomy manifolds. These generalised supertubes preserve 1/4 of the supersymmetries(More)
The consecutive structural genes for the iron-sulfur flavoenzyme sulfide dehydrogenase, sudB and sudA, have been identified in the genome of Pyrococcus furiosus. The translated sequences encode a heterodimeric protein with an α-subunit, SudA, of 52598 Da and a β-subunit, SudB, of 30686 Da. The α-subunit carries a FAD, a putative nucleotide binding site for(More)