1,048 research outputs found
A note on the Gauss decomposition of the elliptic Cauchy matrix
Explicit formulas for the Gauss decomposition of elliptic Cauchy type
matrices are derived in a very simple way. The elliptic Cauchy identity is an
immediate corollary.Comment: 5 page
Monomeric adiponectin modulates nitric oxide release and calcium movements in porcine aortic endothelial cells in normal/high glucose conditions.
AIMS:
Perivascular adipose tissue can be involved in the process of cardiovascular pathology through the release of adipokines, namely adiponectins. Monomeric adiponectin has been shown to increase coronary blood flow in anesthetized pigs through increased nitric oxide (NO) release and the involvement of adiponectin receptor 1 (AdipoR1). The present study was therefore planned to examine the effects of monomeric adiponectin on NO release and Ca2+ transients in porcine aortic endothelial cells (PAEs) in normal/high glucose conditions and the related mechanisms.
MAIN METHODS:
PAEs were treated with monomeric adiponectin alone or in the presence of intracellular kinases blocker, AdipoR1 and Ca2+-ATPase pump inhibitors. The role of Na+/Ca2+ exchanger was examined in experiments performed in zero Na+ medium. NO release and intracellular Ca2+ were measured through specific probes.
KEY FINDINGS:
In PAE cultured in normal glucose conditions, monomeric adiponectin elevated NO production and [Ca2+]c. Similar effects were observed in high glucose conditions, although the response was lower and not transient. The Ca2+ mobilized by monomeric adiponectin originated from an intracellular pool thapsigargin- and ATP-sensitive and from the extracellular space. Moreover, the effects of monomeric adiponectin were prevented by kinase blockers and AdipoR1 inhibitor. Finally, in normal glucose condition, a role for Na+/Ca2+ exchanger and Ca2+-ATPase pump in restoring Ca2+ was found.
SIGNIFICANCE:
Our results add new information about the control of endothelial function elicited by monomeric adiponectin, which would be achieved by modulation of NO release and Ca2+ transients. A signalling related to Akt, ERK1/2 and p38MAPK downstream AdipoR1 would be involved
Theory of unitarity bounds and low energy form factors
We present a general formalism for deriving bounds on the shape parameters of
the weak and electromagnetic form factors using as input correlators calculated
from perturbative QCD, and exploiting analyticity and unitarity. The values
resulting from the symmetries of QCD at low energies or from lattice
calculations at special points inside the analyticity domain can beincluded in
an exact way. We write down the general solution of the corresponding Meiman
problem for an arbitrary number of interior constraints and the integral
equations that allow one to include the phase of the form factor along a part
of the unitarity cut. A formalism that includes the phase and some information
on the modulus along a part of the cut is also given. For illustration we
present constraints on the slope and curvature of the K_l3 scalar form factor
and discuss our findings in some detail. The techniques are useful for checking
the consistency of various inputs and for controlling the parameterizations of
the form factors entering precision predictions in flavor physics.Comment: 11 pages latex using EPJ style files, 5 figures; v2 is version
accepted by EPJA in Tools section; sentences and figures improve
Multivalued Fields on the Complex Plane and Conformal Field Theories
In this paper a class of conformal field theories with nonabelian and
discrete group of symmetry is investigated. These theories are realized in
terms of free scalar fields starting from the simple systems and scalar
fields on algebraic curves. The Knizhnik-Zamolodchikov equations for the
conformal blocks can be explicitly solved. Besides of the fact that one obtains
in this way an entire class of theories in which the operators obey a
nonstandard statistics, these systems are interesting in exploring the
connection between statistics and curved space-times, at least in the two
dimensional case.Comment: (revised version), 30 pages + one figure (not included), (requires
harvmac.tex), LMU-TPW 92-1
Transmission or Within-Host Dynamics Driving Pulses of Zoonotic Viruses in Reservoir-Host Populations.
Progress in combatting zoonoses that emerge from wildlife is often constrained by limited knowledge of the biology of pathogens within reservoir hosts. We focus on the host-pathogen dynamics of four emerging viruses associated with bats: Hendra, Nipah, Ebola, and Marburg viruses. Spillover of bat infections to humans and domestic animals often coincides with pulses of viral excretion within bat populations, but the mechanisms driving such pulses are unclear. Three hypotheses dominate current research on these emerging bat infections. First, pulses of viral excretion could reflect seasonal epidemic cycles driven by natural variations in population densities and contact rates among hosts. If lifelong immunity follows recovery, viruses may disappear locally but persist globally through migration; in either case, new outbreaks occur once births replenish the susceptible pool. Second, epidemic cycles could be the result of waning immunity within bats, allowing local circulation of viruses through oscillating herd immunity. Third, pulses could be generated by episodic shedding from persistently infected bats through a combination of physiological and ecological factors. The three scenarios can yield similar patterns in epidemiological surveys, but strategies to predict or manage spillover risk resulting from each scenario will be different. We outline an agenda for research on viruses emerging from bats that would allow for differentiation among the scenarios and inform development of evidence-based interventions to limit threats to human and animal health. These concepts and methods are applicable to a wide range of pathogens that affect humans, domestic animals, and wildlife.National Institutes of HealthThis is the author accepted manuscript. It is currently under an indefinite embargo pending publication by the Public Library of Science
Hypothesis: Somatic Mosaicism and Parkinson Disease
Letter to the EditorFil: Perandones, Carlos Edgardo. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Pellene, L. A. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Giugni, J. C.. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Calvo, D. S.. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Raina, G. B.. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Cuevas, S. M.. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Mata, I. F.. University of Washington; Estados UnidosFil: Zabetian, C. P.. University of Washington; Estados UnidosFil: Caputo, Mariela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Servicio de Huellas Digitales Genéticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Corach, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Servicio de Huellas Digitales Genéticas; ArgentinaFil: Micheli, Federico. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Servicio de Huellas Digitales Genéticas; ArgentinaFil: Radrizzani Helguera, Martin. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin
Mosaicism of alpha-synuclein gene rearrangements: Report of two unrelated cases of early-onset parkinsonism
Dear Sir,
In genetics, the term ‘mosaicism’ describes the situation in which groups of cells have a
different genetic composition to other cells in an organism. Somatic gene rearrangements
due to multiplication or deletion of genes (copy number variation) and/or sections of
chromosomes can lead to mosaicism.
The presence of multiple copies of the alpha-synuclein gene (SNCA) is known to be
associated with Parkinson’s disease (PD) and the severity of symptoms increases with the
number of copies of the gene [1]. While the features of PD associated with duplication of
SNCA are usually (but not always) typical of the condition [2–3], patients with triplicate
copies have atypical features, including rapidly evolving symptoms, severe cognitive
impairment, limited response to levodopa, more severe symptoms of dementia and more..
Coral-Bacterial Communities before and after a Coral Mass Spawning Event on Ningaloo Reef
Bacteria associated with three coral species, Acropora tenuis, Pocillopora damicornis and Tubastrea faulkneri, were assessed before and after coral mass spawning on Ningaloo Reef in Western Australia. Two colonies of each species were sampled before and after the mass spawning event and two additional samples were collected for P. damicornis after planulation. A variable 470 bp region of the 16 S rRNA gene was selected for pyrosequencing to provide an understanding of potential variations in coral-associated bacterial diversity and community structure. Bacterial diversity increased for all coral species after spawning as assessed by Chao1 diversity indicators. Minimal changes in community structure were observed at the class level and data at the taxonomical level of genus incorporated into a PCA analysis indicated that despite bacterial diversity increasing after spawning, coral-associated community structure did not shift greatly with samples grouped according to species. However, interesting changes could be detected from the dataset; for example, α-Proteobacteria increased in relative abundance after coral spawning and particularly the Roseobacter clade was found to be prominent in all coral species, indicating that this group may be important in coral reproduction
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