Understanding the Evolutionary Relationships and Major Traits of \u3cem\u3eBacillus\u3c/em\u3e through Comparative Genomics

Background: The presence of Bacillus in very diverse environments reflects the versatile metabolic capabilities of a widely distributed genus. Traditional phylogenetic analysis based on limited gene sampling is not adequate for resolving the genus evolutionary relationships. By distinguishing between core and pan-genome, we determined the evolutionary and functional relationships of known Bacillus. Results: Our analysis is based upon twenty complete and draft Bacillus genomes, including a newly sequenced Bacillus isolate from an aquatic environment that we report for the first time here. Using a core genome, we were able to determine the phylogeny of known Bacilli, including aquatic strains whose position in the phylogenetic tree could not be unambiguously determined in the past. Using the pan-genome from the sequenced Bacillus, we identified functional differences, such as carbohydrate utilization and genes involved in signal transduction, which distinguished the taxonomic groups. We also assessed the genetic architecture of the defining traits of Bacillus, such as sporulation and competence, and showed that less than one third of the B. subtilis genes are conserved across other Bacilli. Most variation was shown to occur in genes that are needed to respond to environmental cues, suggesting that Bacilli have genetically specialized to allow for the occupation of diverse habitats and niches. Conclusions: The aquatic Bacilli are defined here for the first time as a group through the phylogenetic analysis of 814 genes that comprise the core genome. Our data distinguished between genomic components, especially core vs. pan-genome to provide insight into phylogeny and function that would otherwise be difficult to achieve. A phylogeny may mask the diversity of functions, which we tried to uncover in our approach. The diversity of sporulation and competence genes across the Bacilli was unexpected based on previous studies of the B. subtilis model alone. The challenge of uncovering the novelties and variations among genes of the non-subtilis groups still remains. This task will be best accomplished by directing efforts toward understanding phylogenetic groups with similar ecological niches

Omniscient foliations and the geometry of cosmological spacetimes

We identify certain general geometric conditions on a foliation of a spacetime (M,g) by timelike curves that will impede the existence of null geodesic lines, especially if (M,g) possesses a compact Cauchy hypersurface. The absence of such lines, in turn, yields well-known restrictions on the geometry of cosmological spacetimes, in the context of Bartnik's splitting conjecture. Since the (non)existence of null lines is actually a conformally invariant property, such conditions only need to apply for some suitable conformal rescaling of g.Comment: 19 pages, no figure

Vortex motion channeling effects in Nb with mesoscopic arrays of Ni lines

Ordered arrays of submicrometric Ni lines have been fabricated in sputtered Nb films. Magnetotransport R(H) and (I, V) curves were measured close to the critical temperature using a cross-shape bridge that allows us to apply current in two directions: parallel or perpendicular to the lines. The experimental results show anisotropic vortex motion with clear channeling effects. In R(H) data, magnetic features appear but they are absent in the (I, V) curves

Propuesta de una campaña de acción social, para la concientización y prevención de accidentes de tránsito mediante la utilización de un producto multimedia en la parroquia Pastocalle, cantón Latacunga en el periodo 2012

Today there is much talk of preventing traffic accidents in Ecuador, but it is clear that there is not a real awareness about the consequences of traffic accidents occur in the country, as we see daily and inform us serious accidents, which unfortunately blood stain on our country roads, which are generated by three main causes: reckless driver, speeding and drunkenness. The key word in terms of road safety, prevention, prevention is achieved by promoting social culture as a motivator and driver of social change, such as training programs, education campaigns and development of knowledge, skills, to build capacity and change attitudes and skills is a challenge and a priority in relation to road safety.Hoy en día se habla mucho de prevención de accidentes de tránsito en el Ecuador, pero es evidente que no existe una verdadera conciencia, sobre las consecuencias que producen los accidentes de tránsito en el país, ya que todos los días vemos y nos informamos de graves accidentes de tránsito, que lamentablemente tiñen de sangre las carreteras de nuestro país, las que se generan por tres causas principales: imprudencia del conductor, exceso de velocidad y embriaguez. La palabra clave en cuanto a la seguridad vial, es la prevención, la prevención se logra promoviendo una cultura social, como elemento motivador e impulsor de cambios sociales, como programas de formación, campañas de educación y desarrollo de conocimientos, habilidades, para generar capacidades y actitudes de cambio y competencias, es un reto y una prioridad en lo referente a la seguridad vial

Vortex phases in superconducting Nb thin films with periodic pinning

Magnetotransport properties have been used to investigate vortex phases in Nb films with periodic arrays of magnetic pinning centers. This kind of samples show a continuous glass transition similar to that observed in Nb plain films, but the periodic pinning yields different critical exponents and enhanced glass transition temperature at the matching field

Experimental adiabatic vortex ratchet effect in Nb films with asymmetric pinning trap

Nb films grown on top of an array of asymmetric pinning centers show a vortex ratchet effect. A net flow of vortices is induced when the vortex lattice is driven by fluctuating forces on an array of pinning centers without reflection symmetry. This effect occurs in the adiabatic regime and it could be mimiced only by reversible DC driven forces