28,014 research outputs found
Comparing Exchange Market Pressure in West and Southern African Countries
We compare the performance of Cape Verde and Mozambique concerning financial credibility as measured by Exchange Market Pressure, an institutional feature that has often been overlooked in the literature as a relevant institution for economies. Drawing on previous research by Macedo et al. (2009), we expand their analysis and, using several definitions of “financial credibility”, all related to different angles on Exchange Market Pressure indices, we conclude that - against reasonable benchmarks in their respective regions - financial credibility has been very good for Cape Verde and fairly good for Mozambique. JEL codes: C22, E44, F31, F33Exchange Rate Regime, Exchange Market Pressure, EGARCH
Analytical study of tunneling times in flat histogram Monte Carlo
We present a model for the dynamics in energy space of multicanonical
simulation methods that lends itself to a rather complete analytic
characterization. The dynamics is completely determined by the density of
states. In the \pm J 2D spin glass the transitions between the ground state
level and the first excited one control the long time dynamics. We are able to
calculate the distribution of tunneling times and relate it to the
equilibration time of a starting probability distribution. In this model, and
possibly in any model in which entering and exiting regions with low density of
states are the slowest processes in the simulations, tunneling time can be much
larger (by a factor of O(N)) than the equilibration time of the probability
distribution. We find that these features also hold for the energy projection
of single spin flip dynamics.Comment: 7 pages, 4 figures, published in Europhysics Letters (2005
Big Data as a Technology-to-think-with for Scientific Literacy
This research aimed to identify indications of scientific literacy resulting
from a didactic and investigative interaction with Google Trends Big Data
software by first-year students from a high-school in Novo Hamburgo, Southern
Brazil. Both teaching strategies and research interpretations lie on four
theoretical backgrounds. Firstly, Bunge's epistemology, which provides a
thorough characterization of Science that was central to our study. Secondly,
the conceptual framework of scientific literacy of Fives et al. that makes our
teaching focus precise and concise, as well as supports one of our
methodological tool: the SLA (scientific literacy assessment). Thirdly, the
"crowdledge" construct from dos Santos, which gives meaning to our study when
as it makes the development of scientific literacy itself versatile for paying
attention on sociotechnological and epistemological contemporary phenomena.
Finally, the learning principles from Papert's Constructionism inspired our
educational activities. Our educational actions consisted of students, divided
into two classes, investigating phenomena chose by them. A triangulation
process to integrate quantitative and qualitative methods on the assessments
results was done. The experimental design consisted in post-tests only and the
experimental variable was the way of access to the world. The experimental
group interacted with the world using analyses of temporal and regional plots
of interest of terms or topics searched on Google. The control class did
'placebo' interactions with the world through on-site observations of
bryophytes, fungus or whatever in the schoolyard. As general results of our
research, a constructionist environment based on Big Data analysis showed
itself as a richer strategy to develop scientific literacy, compared to a free
schoolyard exploration.Comment: 23 pages, 2 figures, 8 table
Deformation and rigidity results for the 2k-Ricci tensor and the 2k-Gauss-Bonnet curvature
We present several deformation and rigidity results within the classes of
closed Riemannian manifolds which either are -Einstein (in the sense that
their -Ricci tensor is constant) or have constant -Gauss-Bonnet
curvature. The results hold for a family of manifolds containing all non-flat
space forms and the main ingredients in the proofs are explicit formulae for
the linearizations of the above invariants obtained by means of the formalism
of double forms.Comment: 30 pages; no figure
Induced pluripotent stem cells, a giant leap for mankind therapeutic applications
Induced pluripotent stem cells (iPSC) technology has propelled the field of stem
cells biology, providing new cells to explore the molecular mechanisms of
pluripotency, cancer biology and aging. A major advantage of human iPSC,
compared to the pluripotent embryonic stem cells, is that they can be generated
from virtually any embryonic or adult somatic cell type without destruction of
human blastocysts. In addition, iPSC can be generated from somatic cells
harvested from normal individuals or patients, and used as a cellular tool to
unravel mechanisms of human development and to model diseases in a manner
not possible before. Besides these fundamental aspects of human biology and
physiology that are revealed using iPSC or iPSC-derived cells, these cells hold an
immense potential for cell-based therapies, and for the discovery of new or
personalized pharmacological treatments for many disorders. Here, we review
some of the current challenges and concerns about iPSC technology. We
introduce the potential held by iPSC for research and development of novel
health-related applications. We briefly present the efforts made by the scientific
and clinical communities to create the necessary guidelines and regulations to
achieve the highest quality standards in the procedures for iPSC generation,
characterization and long-term preservation. Finally, we present some of the
audacious and pioneer clinical trials in progress with iPSC-derived cells.info:eu-repo/semantics/publishedVersio
Evidence that the degree of band 3 phosphorylation modulates human erythrocytes nitric oxide efflux – in vitro model of hyperfibrinogenemia
© 2011 – IOS Press and the authors. All rights reservedRecent evidence has shown that plasma fibrinogen, a major cardiovascular risk factor, interacts with the erythrocyte membrane and acts to influence blood flow via erythrocyte nitric oxide (NO) modulation. In the present pioneer in-vitro study, whole blood samples were harvested from healthy subjects and aliquots were incubated in the absence (control aliquots) and presence of fibrinogen at different degrees of band 3 phosphorylation, and the levels of NO, nitrite, nitrate and S-nitroglutathione (GSNO) were determined.
Hyperfibrinogenemia interferes with erythrocyte NO mobilization without changing its efflux in a way that seems to be dependent of the degree of band 3 phosphorylation. In presence of higher fibrinogen concentrations the NO efflux is reinforced when band 3 is phosphorylated (p < 0.001). Higher levels of nitrite, nitrate and GSNO were documented (p < 0.05). However, the mechanisms by which fibrinogen signalling modulates erythrocyte function remain to be clarified and are currently under study. These conditions may be considered an approach to be followed in blood storage for transfusions.This study was supported by grants from the FCT - Fundação para a Ciência e a Tecnologia (project reference PTDC/SAU-OSM/73449/2006
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