2,078 research outputs found
Observation of a peaking structure in the J/ψφmass spectrum from B±→J/ψφK±decays
A peaking structure in the J/ψφmass spectrum near threshold is observed in B±→J/ψφK±decays, produced in pp collisions at √s=7TeVcollected with the CMS detector at the LHC. The data sample, selected on the basis of the dimuon decay mode of the J/ψ, corresponds to an integrated luminosity of 5.2fb−1. Fitting the structure to an S-wave relativistic Breit–Wigner lineshape above a three-body phase-space nonresonant component gives a signal statistical significance exceeding five standard deviations. The fitted mass and width values are m =4148.0 ±2.4 (stat.) ±6.3 (syst.) MeVand Γ=28+15−11(stat.) ±19 (syst.) MeV, respectively. Evidence for an additional peaking structure at higher J/ψφmass is also reported
Las telas transgresoras de la araña Anancy en el archipiélago de San Andrés, Vieja Providencia y Santa Catalina (Colombia) y en la provincia Atlántica de Limón (Costa Rica)
Anti-Advanced glycation end-product and free radical scavenging activity of plants from the yucatecan flora
Background: Formation and accumulation of advanced glycation end-products (AGE) is recognized as a major pathogenic process in diabetic complications, atherosclerosis and cardiovascular diseases. In addition, reactive oxygen species and free radicals have also been reported to participate in AGE formation and in cell damage. Natural products with antioxidant and antiAGE activity have great therapeutic potential in the treatment of diabetes, hypertension and related complications. Objective: to test ethanolic extracts and aqueous-traditional preparations of plants used to treat diabetes, hypertension and obesity in Yucatecan traditional medicine for their anti-AGE and free radical scavenging activities. Materials and Methods: ethanolic extracts of leaves, stems and roots of nine medicinal plants, together with their traditional preparations, were prepared and tested for their anti-AGE and antioxidant activities using the inhibition of advanced glycation end products and DPPH radical scavenging assays, respectively. Results: the root extract of C. fistula (IC50= 0.1 mg/mL) and the leaf extract of P. auritum (IC50= 0.35 mg/mL) presented significant activity against vesperlysine and pentosidine-like AGE. Although none of the aqueous traditional preparations showed significant activity in the anti-AGE assay, both the traditional preparations and the ethanolic extracts of E. tinifolia, M. zapota, O. campechianum and P. auritum showed significant activity in the DPPH reduction assay. <65Conclusions: the results suggest that the metabolites responsible for the detected radical-scavenging activity are different to those involved in inhibiting AGE formation; however, the extracts with antioxidant activity may contain other metabolites which are able to prevent AGE formation through a different mechanism
The nuclear energy density functional formalism
The present document focuses on the theoretical foundations of the nuclear
energy density functional (EDF) method. As such, it does not aim at reviewing
the status of the field, at covering all possible ramifications of the approach
or at presenting recent achievements and applications. The objective is to
provide a modern account of the nuclear EDF formalism that is at variance with
traditional presentations that rely, at one point or another, on a {\it
Hamiltonian-based} picture. The latter is not general enough to encompass what
the nuclear EDF method represents as of today. Specifically, the traditional
Hamiltonian-based picture does not allow one to grasp the difficulties
associated with the fact that currently available parametrizations of the
energy kernel at play in the method do not derive from a genuine
Hamilton operator, would the latter be effective. The method is formulated from
the outset through the most general multi-reference, i.e. beyond mean-field,
implementation such that the single-reference, i.e. "mean-field", derives as a
particular case. As such, a key point of the presentation provided here is to
demonstrate that the multi-reference EDF method can indeed be formulated in a
{\it mathematically} meaningful fashion even if does {\it not} derive
from a genuine Hamilton operator. In particular, the restoration of symmetries
can be entirely formulated without making {\it any} reference to a projected
state, i.e. within a genuine EDF framework. However, and as is illustrated in
the present document, a mathematically meaningful formulation does not
guarantee that the formalism is sound from a {\it physical} standpoint. The
price at which the latter can be enforced as well in the future is eventually
alluded to.Comment: 64 pages, 8 figures, submitted to Euroschool Lecture Notes in Physics
Vol.IV, Christoph Scheidenberger and Marek Pfutzner editor
A Real Space Description of Magnetic Field Induced Melting in the Charge Ordered Manganites: I. The Clean Limit
We study the melting of charge order in the half doped manganites using a
model that incorporates double exchange, antiferromagnetic superexchange, and
Jahn-Teller coupling between electrons and phonons. We primarily use a real
space Monte Carlo technique to study the phase diagram in terms of applied
field and temperature , exploring the melting of charge order with
increasing and its recovery on decreasing . We observe hysteresis in
this response, and discover that the `field melted' high conductance state can
be spatially inhomogeneous even without extrinsic disorder. The hysteretic
response plays out in the background of field driven equilibrium phase
separation. Our results, exploring , , and the electronic parameter
space, are backed up by analysis of simpler limiting cases and a Landau
framework for the field response. This paper focuses on our results in the
`clean' systems, a companion paper studies the effect of cation disorder on the
melting phenomena.Comment: 16 pages, pdflatex, 11 png fig
Altered protein expression and protein nitration pattern during d-galactosamine-induced cell death in human hepatocytes: a proteomic analysis
BACKGROUND/AIMS:
Hepatic injury by d-galactosamine (d-GalN) is a suitable experimental model of hepatocellular injury. The induction of oxidative and nitrosative stress participates during d-GalN-induced cell death in cultured rat hepatocytes. This study aimed to identify protein expression changes during the induction of apoptosis and necrosis by d-GalN in cultured human hepatocytes.
METHODS:
A proteomic approach was used to identify the proteins involved and those altered by tyrosine nitration. A high dose of d-GalN (40 mM) was used to induce apoptosis and necrosis in primary culture of human hepatocytes. Cellular lysates prepared at different times after addition of d-GalN were separated by two-dimensional electrophoresis. Gel spots with an altered expression and those matching nitrotyrosine-immunopositive proteins were excised and analyzed by mass spectrometry.
RESULTS:
d-GalN treatment upregulated microsomal cytochrome b5, fatty acid binding protein and manganese superoxide dismutase, and enhanced annexin degradation. d-GalN increased tyrosine nitration of four cytosolic (Hsc70, Hsp70, annexin A4 and carbonyl reductase) and three mitochondrial (glycine amidinotransferase, ATP synthase beta chain, and thiosulfate sulfurtransferase) proteins in human hepatocytes.
CONCLUSIONS:
The results provide evidences that oxidative stress and nitric oxide-derived reactive oxygen intermediates induce specific alterations in protein expression that may be critical for the induction of apoptosis and necrosis by d-GalN in cultured human hepatocytes
Toward a taxonomy of newspaper information quality: An experimental model and test applied to Venezuela dimensions found in information quality
The quality of information from communication media is a topic that has been dealt
with by various theorists through the analysis of the final products of information.
This research work offers an analysis model of the quality of information of printed
news media by the use of three indexes of categories and structured dimensions
that will allow for the assessment and evaluation of the quality of information from
the media, and the identification of the incidence of political-economic conditions
of the journalistic environment’s macro-environment. For this, an experimental test
of two Venezuelan media outlets was performed. Their use allowed us to conclude
that political polarization and discourse of social confrontation, as well as economic
factors such as inflation and pay scales had a proportionally direct effect on the quality
of information products
A Real Space Description of Field Induced Melting in the Charge Ordered Manganites: II. the Disordered Case
We study the effect of A site disorder on magnetic field induced melting of
charge order (CO) in half doped manganites using a Monte-Carlo technique.
Strong A-site disorder destroys CO even without an applied field. At moderate
disorder, the zero field CO state survives but has several intriguing features
in its field response. Our spatially resolved results track the broadening of
the field melting transition due to disorder and explain the unusual dependence
of the melting scales on bandwidth and disorder. In combination with our
companion paper on field melting of charge order in clean systems we provide an
unified understanding of CO melting across all half doped manganites.Comment: 9 pages, pdflatex, 10 embedded png fig
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Using the NANA toolkit at home to predict older adults' future depression
Background: Depression is currently underdiagnosed among older adults. As part of the Novel Assessment of Nu-trition and Aging (NANA) validation study, 40 older adults self-reported their mood using a touchscreen computer over three, one-week periods. Here, we demonstrate the potential of these data to predict future depression status.
Methods: We analysed data from the NANA validation study using a machine learning approach. We applied the least absolute shrinkage and selection operator with a logistic model to averages of six measures of mood, with depression status according to the Geriatric Depression Scale 10 weeks later as the outcome variable. We tested multiple values of the selection parameter in order to produce a model with low deviance. We used a cross-validation framework to avoid overspecialisation, and receiver operating characteristic curve (ROC) analysis to determine the quality of the fitted model.
Results: The model we report contained coefficients for two variables: sadness and tiredness, as well as a constant. The cross-validated area under the ROC curve for this model was 0.88 (CI: 0.69–0.97).
Limitations: While results are based on a small sample, the methodology for the selection of variables appears suitable for the problem at hand, suggesting promise for a wider study and ultimate deployment with older adults at increased risk of depression.
Conclusions: We have identified self-reported scales of sadness and tiredness as sensitive measures which have the potential to predict future depression status in older adults, partially addressing the problem of underdiagnosis
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