5,100 research outputs found
FOREIGN DIRECT INVESTMENT AND ECONOMIC GROWTH IN ROMANIA’S DEVELOPMENT REGION NORTH-EAST
One of integration’s advantages it is represented by the increasing grade of economic opening toward the rest of the world, with benefic effects over intercepted foreign direct flows, reciprocal flows of working force and work productivity. Given this context and taking into account analyses presented in our research, I appreciate that North – East Developing Region will further attract larger flows of foreign direct investments, flows that will in turn accelerate, through chain effect, the process of regional development.foreign direct investments, economic growth, development regions, regional dissimilitude, competitive advantages
A biophysical observation model for field potentials of networks of leaky integrate-and-fire neurons
We present a biophysical approach for the coupling of neural network activity
as resulting from proper dipole currents of cortical pyramidal neurons to the
electric field in extracellular fluid. Starting from a reduced threecompartment
model of a single pyramidal neuron, we derive an observation model for
dendritic dipole currents in extracellular space and thereby for the dendritic
field potential that contributes to the local field potential of a neural
population. This work aligns and satisfies the widespread dipole assumption
that is motivated by the "open-field" configuration of the dendritic field
potential around cortical pyramidal cells. Our reduced three-compartment scheme
allows to derive networks of leaky integrate-and-fire models, which facilitates
comparison with existing neural network and observation models. In particular,
by means of numerical simulations we compare our approach with an ad hoc model
by Mazzoni et al. [Mazzoni, A., S. Panzeri, N. K. Logothetis, and N. Brunel
(2008). Encoding of naturalistic stimuli by local field potential spectra in
networks of excitatory and inhibitory neurons. PLoS Computational Biology 4
(12), e1000239], and conclude that our biophysically motivated approach yields
substantial improvement.Comment: 31 pages, 4 figure
Rigorous coherent-structure theory for falling liquid films: Viscous dispersion effects on bound-state formation and self-organization
We examine the interaction of two-dimensional solitary pulses on falling
liquid films. We make use of the second-order model derived by Ruyer-Quil and
Manneville [Eur. Phys. J. B 6, 277 (1998); Eur. Phys. J. B 15, 357 (2000);
Phys. Fluids 14, 170 (2002)] by combining the long-wave approximation with a
weighted residuals technique. The model includes (second-order) viscous
dispersion effects which originate from the streamwise momentum equation and
tangential stress balance. These effects play a dispersive role that primarily
influences the shape of the capillary ripples in front of the solitary pulses.
We show that different physical parameters, such as surface tension and
viscosity, play a crucial role in the interaction between solitary pulses
giving rise eventually to the formation of bound states consisting of two or
more pulses separated by well-defined distances and travelling at the same
velocity. By developing a rigorous coherent-structure theory, we are able to
theoretically predict the pulse-separation distances for which bound states are
formed. Viscous dispersion affects the distances at which bound states are
observed. We show that the theory is in very good agreement with computations
of the second-order model. We also demonstrate that the presence of bound
states allows the film free surface to reach a self-organized state that can be
statistically described in terms of a gas of solitary waves separated by a
typical mean distance and characterized by a typical density
Susceptibility loci CNVs with incomplete penetrance accurate diagnosis with uncertain prognosis
Chromosomal microarray analysis (CMA) is the first-tier test for developmental delay, autism spectrum disorders, and congenital abnormalities in postnatal diagnosis and for ultrasound abnormalities in prenatal diagnosis.
The detection of variants with clinical significance by CMA, when compared to karyotype, can increase up to 10-20% in postnatal diagnosis and up to 5-18% in prenatal diagnosis. Nevertheless CMA also detects incomplete penetrance neuro-Susceptibility Loci Copy Number Variants (SL-CNV), which although having clinical significance have an uncertain prognosis.
The aim of this study is to identify from the literature a set of SLCNV, and the corresponding penetrance for each variant, determining their occurrence in our cohort of postnatal samples ran between January 2012 and August 2018 and prenatal samples ran between January 2015 and August 2018.
We have established a 21 SL-CNV set, and from a total of 835 postnatal samples and 317 prenatal samples we have identified 36 and 11 cases, respectively, with a variant in one of the 21 established SLCNV.
The percentage of cases with a SL-CNV is relatively similar between postnatal samples (4.5%) and prenatal samples (3.5%), although the reason of referral for the two groups is not completely overlapping and also the total number of prenatal samples represents about half of the time span of the postnatal samples, which might have underestimated their occurrence. The estimated penetrance for each of the established SL-CNV present some inter-publication variability, especially concerning samples with different phenotypes. Nevertheless some variants show concordance.
Estimating the penetrance for SL-CNV, and their clinical impact for the patient or carriers in the family, is a complex task. Only time, analysis of larger cohorts, and future knowledge of genotype-environment-phenotype interactions will overcome this difficulty, decreasing uncertainty for the around 4% of patients diagnosed by CMA.info:eu-repo/semantics/publishedVersio
Metallothioneins in the clam Ruditapes decussatus: an overview
The clam Ruditapes decussatus is a suspension-feeding bivalve mollusc widely distributed in European waters and in the Mediterranean. Due to is economic importance it is heavily harvested in many countries, and particularly in Portugal. Its ability to accumulate high metal concentrations along with its economic importance was the main reason for its selection as a bioindicator. Metallothionein (MT) concentrations in the clams R. decussatus followed by gel filtration chromatography, differential pulse polarography and SDS-PAGE, after Cd exposure, revealed that MT is induced in different tissues (whole soft tissues, gills, digestive gland and remaining tissues) but the level of MT induction is tissue dependent. MT from the gills and the digestive gland give a more sensitive response to assess the effects of metal exposure directly from the water or from the food than in the whole soft tissues. MT levels were also measured in the gills, digestive gland and remaining tissues of R. decussatus collected in the Ria Formosa lagoon (Portugal) from areas of different metal load and during the period of sexual differentiation of the clam. Data revealed that there were significant differences of MT concentrations among sites and season but not among sex. Purification of MT from the digestive gland of R. decussatus revealed four MT isoforms. The molecular weight of one of these isoforms, determined by SDS-PAGE, was of the same order of magnitude as that of MT from other bivalve species. Similarly the amino acid sequence of the beta domain of the MT of the digestive gland of the clam also shows some degree of similarity with the similar MT sequence from mussels and oysters. It is, therefore suggested that there is some degree of similarity in the MT structure among these species.info:eu-repo/semantics/publishedVersio
Rate of Convergence of Phase Field Equations in Strongly Heterogeneous Media towards their Homogenized Limit
We study phase field equations based on the diffuse-interface approximation
of general homogeneous free energy densities showing different local minima of
possible equilibrium configurations in perforated/porous domains. The study of
such free energies in homogeneous environments found a broad interest over the
last decades and hence is now widely accepted and applied in both science and
engineering. Here, we focus on strongly heterogeneous materials with
perforations such as porous media. To the best of our knowledge, we present a
general formal derivation of upscaled phase field equations for arbitrary free
energy densities and give a rigorous justification by error estimates for a
broad class of polynomial free energies. The error between the effective
macroscopic solution of the new upscaled formulation and the solution of the
microscopic phase field problem is of order for a material given
characteristic heterogeneity . Our new, effective, and reliable
macroscopic porous media formulation of general phase field equations opens new
modelling directions and computational perspectives for interfacial transport
in strongly heterogeneous environments
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