153 research outputs found
Strings on Bubbling Geometries
We study gauge theory operators which take the form of a product of a trace
with a Schur polynomial, and their string theory duals. These states represent
strings excited on bubbling AdS geometries which are dual to the Schur
polynomials. These geometries generically take the form of multiple annuli in
the phase space plane. We study the coherent state wavefunction of the lattice,
which labels the trace part of the operator, for a general Young tableau and
their dual description on the droplet plane with a general concentric ring
pattern. In addition we identify a density matrix over the coherent states on
all the geometries within a fixed constraint. This density matrix may be used
to calculate the entropy of a given ensemble of operators. We finally recover
the BMN string spectrum along the geodesic near any circle from the ansatz of
the coherent state wavefunction.Comment: 41 pages, 12 figures, published version in JHE
The antimicrobial effects of the alginate oligomer OligoG CF-5/20 are independent of direct bacterial cell membrane disruption
Concerns about acquisition of antibiotic resistance have led to increasing demand for new antimicrobial therapies. OligoG CF-5/20 is an alginate oligosaccharide previously shown to have antimicrobial and antibiotic potentiating activity. We investigated the structural modification of the bacterial cell wall by OligoG CF-5/20 and its effect on membrane permeability. Binding of OligoG CF-5/20 to the bacterial cell surface was demonstrated in Gram-negative bacteria. Permeability assays revealed that OligoG CF-5/20 had virtually no membrane-perturbing effects. Lipopolysaccharide (LPS) surface charge and aggregation were unaltered in the presence of OligoG CF-5/20. Small angle neutron scattering and circular dichroism spectroscopy showed no substantial change to the structure of LPS in the presence of OligoG CF-5/20, however, isothermal titration calorimetry demonstrated a weak calcium-mediated interaction. Metabolomic analysis confirmed no change in cellular metabolic response to a range of osmolytes when treated with OligoG CF-5/20. This data shows that, although weak interactions occur between LPS and OligoG CF-5/20 in the presence of calcium, the antimicrobial effects of OligoG CF-5/20 are not related to the induction of structural alterations in the LPS or cell permeability. These results suggest a novel mechanism of action that may avoid the common route in acquisition of resistance via LPS structural modification
Visuospatial Integration: Paleoanthropological and Archaeological Perspectives
The visuospatial system integrates inner and outer functional processes, organizing spatial, temporal, and social interactions between the brain, body, and environment. These processes involve sensorimotor networks like the eyeâhand circuit, which is especially important to primates, given their reliance on vision and touch as primary sensory modalities and the use of the hands in social and environmental interactions. At the same time, visuospatial cognition is intimately connected with memory, self-awareness, and simulation capacity. In the present article, we review issues associated with investigating visuospatial integration in extinct human groups through the use of anatomical and behavioral data gleaned from the paleontological and archaeological records. In modern humans, paleoneurological analyses have demonstrated noticeable and unique morphological changes in the parietal cortex, a region crucial to visuospatial management. Archaeological data provides information on handâtool interaction, the spatial behavior of past populations, and their interaction with the environment. Visuospatial integration may represent a critical bridge between extended cognition, self-awareness, and social perception. As such, visuospatial functions are relevant to the hypothesis that human evolution is characterized by changes in brainâbodyâenvironment interactions and relations, which enhance integration between internal and external cognitive components through neural plasticity and the development of a specialized embodiment capacity. We therefore advocate the investigation of visuospatial functions in past populations through the paleoneurological study of anatomical elements and archaeological analysis of visuospatial behaviors
Correlations vs connectivity in R-charge
The holographic relation between quantum correlations and connectivity of
spacetime is explored for single R-charged AdS black holes and their
half-BPS limits (superstars). In a two boundary set-up, the wormhole between
both universes reduces to a designable and computable quantum mechanical
correlation between the dual microscopic degrees of freedom in the BPS limit.
This quantum connectivity is seen as a naked singularity by a single sided
observer. In a single boundary set-up, as a small step towards the description
of entangled black holes, we describe quantum teleportation between two labs in
different locations of the transverse 5-sphere using entangled gravitons in a
reference state that provides a classical channel between both labs.Comment: 53 pages + appendices, 29 figures v2: few corrections and added a
conclusion sectio
Progetto aziendale di sorveglianza delle infezioni associate alle pratiche assistenziali.
Progetto INF-OSS. Progetto Nazionale sui programmi aziendali di controllo del rischio infettivo
Il rischio infettivo per gli operatori nella pratica odontoiatrica: aspetti epidemiologici e preventivi
Atti
- âŠ