Topology of Conical Intersection Seams and the Geometric Phase.

In this paper, we demonstrate two topological properties of crossing seams, that is, the sets of points in the -dimensional space of nuclear coordinates where two electronic eigenstates are degenerate. We shall examine the typical case of states of the same spin with accidental degeneracies, whereby the crossing seam is of dimension - 2. The first property we demonstrate is that a crossing seam has no boundary, therefore, it must either extend asymptotically to infinite values of one or more coordinates or wrap on itself.

Phylogenomic analysis of the understudied species reveals a poly- and paraphyletic genus.

Understanding the evolutionary relationships between the species in the family has been a persistent challenge in bacterial systematics due to high recombination rates in these species. Previous studies of this family have focused on and . However, previously understudied species are gaining new attention, with now recognized as a common human pathogen and with and being unique in the bacterial world as multicellular organisms.

Acquisition, co-option, and duplication of the rtx toxin system and the emergence of virulence in Kingella.

The bacterial genus Kingella includes two pathogenic species, namely Kingella kingae and Kingella negevensis, as well as strictly commensal species. Both K. kingae and K.

Pathogenic determinants of disease.

is an emerging pediatric pathogen and is increasingly recognized as a leading etiology of septic arthritis, osteomyelitis, and bacteremia and an occasional cause of endocarditis in young children. The pathogenesis of disease begins with colonization of the upper respiratory tract followed by breach of the respiratory epithelial barrier and hematogenous spread to distant sites of infection, primarily the joints, bones, and endocardium. As recognition of as a pathogen has increased, interest in defining the molecular determinants of pathogenicity has grown.

CosR Is a Global Regulator of the Osmotic Stress Response with Widespread Distribution among Bacteria.

Bacteria accumulate small, organic compounds called compatible solutes via uptake from the environment or biosynthesis from available precursors to maintain the turgor pressure of the cell in response to osmotic stress. The halophile has biosynthesis pathways for the compatible solutes ectoine (encoded by ) and glycine betaine (encoded by ), four betaine-carnitine-choline transporters (encoded by to ), and a second ProU transporter (encoded by ). All of these systems are osmotically inducible with the exception of Previously, it was shown that CosR, a MarR-type regulator, was a direct repressor of in species.

Quorum Sensing Regulators AphA and OpaR Control Expression of the Operon Responsible for Biosynthesis of the Compatible Solute Ectoine.

To maintain the turgor pressure of the cell under high osmolarity, bacteria accumulate small organic compounds called compatible solutes, either through uptake or biosynthesis. , a marine halophile and an important human and shellfish pathogen, has to adapt to abiotic stresses such as changing salinity. contains multiple compatible solute biosynthesis and transporter systems, including the operon required for ectoine biosynthesis.

CRISPR-Cas systems are present predominantly on mobile genetic elements in Vibrio species.

Background: Bacteria are prey for many viruses that hijack the bacterial cell in order to propagate, which can result in bacterial cell lysis and death. Bacteria have developed diverse strategies to counteract virus predation, one of which is the clustered regularly interspaced short palindromic repeat (CRISPR) and CRISPR associated (Cas) proteins immune defense system. Species within the bacterial family Vibrionaceae are marine organisms that encounter large numbers of phages.