617 research outputs found
Limits on the integration constant of the dark radiation term in Brane Cosmology
We consider the constraints from primordial Helium abundances on the constant
of integration of the dark radiation term of the brane-world generalized
Friedmann equation derived from the Randall-Sundrum Single brane model. We
found that -- using simple, approximate and semianalytical Method -- that the
constant of integration is limited to be between -8.9 and 2.2 which limits the
possible contribution from dark radiation term to be approximately between -27%
to 7% of the background photon energy density.Comment: 8 page
Physiological levels of lipoxin A4 inhibit ENaC and restore airway surface liquid height in cystic fibrosis bronchial epithelium.
In cystic fibrosis (CF), the airway surface liquid (ASL) is depleted. We previously demonstrated that lipoxin A4 (LXA4) can modulate ASL height (ASLh) through actions on Cl(-) transport. Here, we report novel effects of lipoxin on the epithelial Na(+) channel ENaC in this response. ASL dynamics and ion transport were studied using live-cell confocal microscopy and short-circuit current measurements in CF (CuFi-1) and non-CF (NuLi-1) cell cultures. Low physiological concentrations of LXA4 in the picomolar range produced an increase in ASLh which was dependent on inhibition of an amiloride-sensitive Na(+) current and stimulation of a bumetanide-sensitive Cl(-) current. These ion transport and ASLh responses to LXA4 were blocked by Boc-2 an inhibitor of the specific LXA4 receptor ALX/FPR2. LXA4 affected the subcellular localization of its receptor and enhanced the localization of ALX/FPR2 at the apical membrane of CF cells. Our results provide evidence for a novel effect of low physiological concentrations of LXA4 to inhibit airway epithelial Na(+) absorption that results in an ASL height increase in CF airway epithelia
Whatâs in a name? Unpacking âCommunity Blankâ terminology in reproductive, maternal, newborn and child health: a scoping review
Introduction: Engaging the community as actors within reproductive, maternal, newborn and child health (RMNCH) programmes (referred to as âcommunity blankâ) has seen increased implementation in recent years. While evidence suggests these approaches are effective, terminology (such as âcommunity engagement,â âcommunity participation,â âcommunity mobilisation,â and âsocial accountabilityâ) is often used interchangeably across published literature, contributing to a lack of conceptual clarity in practice. The purpose of this review was to describe and clarify varying uses of these terms in the literature by documenting what authors and implementers report they are doing when they use these terms. Methods: Seven academic databases (PubMed/MEDLINE, Embase, CINAHL, PsycINFO, Scopus, Web of Science, Global Health), two grey literature databases (OAIster, OpenGrey) and relevant organisation websites were searched for documents that described âcommunity blankâ terms in RMNCH interventions. Eligibility criteria included being published between 1975 and 1 October 2021 and reports or studies detailing the activities used in âcommunity blank.â Results: A total of 9779 unique documents were retrieved and screened, with 173 included for analysis. Twenty-four distinct âcommunity blankâ terms were used across the documents, falling into 11 broader terms. Use of these terms was distributed across time and all six WHO regions, with âcommunity mobilisationâ, âcommunity engagementâ and âcommunity participationâ being the most frequently used terms. While 48 unique activities were described, only 25 activities were mentioned more than twice and 19 of these were attributed to at least three different âcommunity blankâ terms. Conclusion: Across the literature, there is inconsistency in the usage of âcommunity blankâ terms for RMNCH. There is an observed interchangeable use of terms and a lack of descriptions of these terms provided in the literature. There is a need for RMNCH researchers and practitioners to clarify the descriptions reported and improve the documentation of âcommunity blankâ implementation. This can contribute to a better sharing of learning within and across communities and to bringing evidence-based practices to scale. Efforts to improve reporting can be supported with the use of standardised monitoring and evaluation processes and indicators. Therefore, it is recommended that future research endeavours clarify the operational definitions of âcommunity blankâ and improve the documentation of its implementation.University College DublinWorld Health Organizatio
Rational sequences for the conductance in quantum wires from affine Toda field theories
We analyse the expression for the conductance of a quantum wire which is
decribed by an integrable quantum field theory. In the high temperature regime
we derive a simple formula for the filling fraction. This expression involves
only the inverse of a matrix which contains the information of the asymptotic
phases of the scattering matrix and the solutions of the constant thermodynamic
Bethe ansatz equations. Evaluating these expressions for minimal affine Toda
field theory we recover several sequences of rational numbers, which are
multiples of the famous Jain sequence for the filling fraction occurring in the
context of the fractional quantum Hall effect. For instance we obtain for -minimal affine Toda field theory. The matrices
involved have in general non-rational entries and are not part of previous
classification schemes based on integral lattices.Comment: 9 pages Latex, version to appear in Journal of Physics
Exercise and Oxidative Damage in Nucleoid DNA Quantified Using Single Cell Gel Electrophoresis: Present and Future Application
High intensity exercise can enhance the production of reactive oxygen and nitrogen free radical species, which may cause a number of perturbations to cellular integrity, including deoxyribonucleic acid (DNA) modification. In the absence of adequate DNA repair, it is theoretically possible that several biological disorders may ensue, in addition to premature aging. This striking hypothesis and supposition can only be realized in the presence of sound methodology for the quantification of DNA damage and repair. The alkaline single-cell gel electrophoresis or âcomet assayâ is a simple and reliable method for measuring the components of DNA stability in eukaryotic cells. The assay is commonly used in research associated with genotoxicology and in human bio-monitoring studies concerned with gene-environment interactions; but is currently less appreciated and under-utilized in the domain of exercise science. No exercise related study for example, has incorporated the comet assay combined with fluorescent in situ hybridization methodology to detect and investigate whole genome, telomeric DNA, or gene region-specific DNA damage and repair in cells. Our laboratory and others have used the comet assay in conjunction with lesion-specific endonucleases to measure DNA strand breaks and oxidized bases to confirm that high intensity exercise can damage and destabilize DNA. Thus, the primary function of this review is to highlight recent advances and innovation with the comet assay, in order to enhance our future understanding of the complex interrelationship between exercise and DNA modification in eukaryotic cells. A brief synopsis of the current literature addressing DNA stability as a function of continuous aerobic exercise is also included
A Geometric Approach to CP Violation: Applications to the MCPMFV SUSY Model
We analyze the constraints imposed by experimental upper limits on electric
dipole moments (EDMs) within the Maximally CP- and Minimally Flavour-Violating
(MCPMFV) version of the MSSM. Since the MCPMFV scenario has 6 non-standard
CP-violating phases, in addition to the CP-odd QCD vacuum phase \theta_QCD,
cancellations may occur among the CP-violating contributions to the three
measured EDMs, those of the Thallium, neutron and Mercury, leaving open the
possibility of relatively large values of the other CP-violating observables.
We develop a novel geometric method that uses the small-phase approximation as
a starting point, takes the existing EDM constraints into account, and enables
us to find maximal values of other CP-violating observables, such as the EDMs
of the Deuteron and muon, the CP-violating asymmetry in b --> s \gamma decay,
and the B_s mixing phase. We apply this geometric method to provide upper
limits on these observables within specific benchmark supersymmetric scenarios,
including extensions that allow for a non-zero \theta_QCD.Comment: 34 pages, 16 eps figures, to appear in JHE
Additional roles of a peripheral loopâloop interaction in the Neurospora VS ribozyme
Many RNAs contain tertiary interactions that contribute to folding the RNA into its functional 3D structure. In the VS ribozyme, a tertiary loopâloop kissing interaction involving stemâloops I and V is also required to rearrange the secondary structure of stemâloop I such that nucleotides at the base of stem I, which contains the cleavageâligation site, can adopt the conformation required for activity. In the current work, we have used mutants that constitutively adopt the catalytically permissive conformation to search for additional roles of the kissing interaction in vitro. Using mutations that disrupt or restore the kissing interaction, we find that the kissing interaction contributes âŒ1000-fold enhancement to the rates of cleavage and ligation. Large Mg2+-dependent effects on equilibrium were also observed: in the presence of the kissing interaction cleavage is favored >10-fold at micromolar concentrations of Mg2+; whereas ligation is favored >10-fold at millimolar concentrations of Mg2+. In the absence of the kissing interaction cleavage exceeds ligation at all concentrations of Mg2+. These data provide evidence that the kissing interaction strongly affects the observed cleavage and ligation rate constants and the cleavageâligation equilibrium of the ribozyme
Leptogenesis in a Realistic Supersymmetric Model of Inflation with a Low Reheat Temperature
We discuss leptogenesis in a realistic supersymmetric model of inflation with
a low reheat temperature 1-10 GeV. The lepton asymmetry is generated by a
decaying right handed sneutrino, which is produced after inflation during
preheating. The inflationary model is based on a simple variant of the
Next-to-Minimal Supersymmetric Standard model (NMSSM) which solves the \mu
problem, called \phiNMSSM, where the additional singlet \phi plays the role of
the inflaton in hybrid (or inverted hybrid) type models. The model is invariant
under an approximate Peccei-Quinn symmetry which also solves the strong CP
problem, and leads to an invisible axion with interesting cosmological
consequences. We show how the baryon number of the universe and the nature of
cold dark matter are determined by the same parameters controlling the strong
CP problem, the \mu problem and the neutrino masses and mixing angles.Comment: 17 page, latex, 1 eps fi
Drivers for Rift Valley fever emergence in Mayotte: A Bayesian modelling approach
Rift Valley fever (RVF) is a major zoonotic and arboviral hemorrhagic fever. The conditions leading to RVF epidemics are still unclear, and the relative role of climatic and anthropogenic factors may vary between ecosystems. Here, we estimate the most likely scenario that led to RVF emergence on the island of Mayotte, following the 2006â2007 African epidemic. We developed the first mathematical model for RVF that accounts for climate, animal imports and livestock susceptibility, which is fitted to a 12-years dataset. RVF emergence was found to be triggered by the import of infectious animals, whilst transmissibility was approximated as a linear or exponential function of vegetation density. Model forecasts indicated a very low probability of virus endemicity in 2017, and therefore of re-emergence in a closed system (i.e. without import of infected animals). However, the very high proportion of naive animals reached in 2016 implies that the island remains vulnerable to the import of infectious animals. We recommend reinforcing surveillance in livestock, should RVF be reported is neighbouring territories. Our model should be tested elsewhere, with ecosystem-specific data
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