1,205 research outputs found
Constraints on the active tectonics of the Friuli/NW Slovenia area from CGPS measurements and three-dimensional kinematic modeling
We use site velocities from continuous GPS (CGPS) observations and kinematic
modeling to investigate the active tectonics of the Friuli/NW Slovenia area. Data from 42
CGPS stations around the Adriatic indicate an oblique collision, with southern Friuli
moving NNW toward northern Friuli at the relative speed of 1.6 to 2.2 mm/a. We
investigate the active tectonics using 3DMove, a three-dimensional kinematic model tool.
The model consists of one indenter-shaped fault plane that approximates the Adriatic
plate boundary. Using the ‘‘fault-parallel flow’’ deformation algorithm, we move the
hanging wall along the fault plane in the direction indicated by the GPS velocities. The
resulting strain field is used for structural interpretation. We identify a pattern of
coincident strain maxima and high vorticity that correlates well with groups of
hypocenters of major earthquakes (including their aftershocks) and indicates the
orientation of secondary, active faults. The pattern reveals structures both parallel and
perpendicular to the strike of the primary fault. In the eastern sector, which shows more
complex tectonics, these two sets of faults probably form an interacting strike-slip
system
The mean field infinite range p=3 spin glass: equilibrium landscape and correlation time scales
We investigate numerically the dynamical behavior of the mean field 3-spin
spin glass model: we study equilibrium dynamics, and compute equilibrium time
scales as a function of the system size V. We find that for increasing volumes
the time scales increase like . We also present an
accurate study of the equilibrium static properties of the system.Comment: 6 pages, 9 figure
Intranasal rapamycin ameliorates Alzheimer-like cognitive decline in a mouse model of Down syndrome
Background: Down syndrome (DS) individuals, by the age of 40s, are at increased risk to develop Alzheimer-like dementia, with deposition in brain of senile plaques and neurofibrillary tangles. Our laboratory recently demonstrated the disturbance of PI3K/AKT/mTOR axis in DS brain, prior and after the development of Alzheimer Disease (AD). The aberrant modulation of the mTOR signalling in DS and AD age-related cognitive decline affects crucial neuronal pathways, including insulin signaling and autophagy, involved in pathology onset and progression. Within this context, the therapeutic use of mTOR-inhibitors may prevent/attenuate the neurodegenerative phenomena. By our work we aimed to rescue mTOR signalling in DS mice by a novel rapamycin intranasal administration protocol (InRapa) that maximizes brain delivery and reduce systemic side effects. Methods: Ts65Dn mice were administered with InRapa for 12 weeks, starting at 6 months of age demonstrating, at the end of the treatment by radial arms maze and novel object recognition testing, rescued cognition. Results: The analysis of mTOR signalling, after InRapa, demonstrated in Ts65Dn mice hippocampus the inhibition of mTOR (reduced to physiological levels), which led, through the rescue of autophagy and insulin signalling, to reduced APP levels, APP processing and APP metabolites production, as well as, to reduced tau hyperphosphorylation. In addition, a reduction of oxidative stress markers was also observed. Discussion: These findings demonstrate that chronic InRapa administration is able to exert a neuroprotective effect on Ts65Dn hippocampus by reducing AD pathological hallmarks and by restoring protein homeostasis, thus ultimately resulting in improved cognition. Results are discussed in term of a potential novel targeted therapeutic approach to reduce cognitive decline and AD-like neuropathology in DS individuals
Hydrologically induced slope deformations detected by GPS and clinometric surveys in the Cansiglio Plateau, southern Alps
Changes in groundwater or surface water level may cause observable deformation of the drainage basins in different ways. We describe an active slope deformation monitored with GPS and tiltmeter stations in a karstic limestone plateau in southeastern Alps (Cansiglio Plateau). The observed transient GPS deformation clearly correlates with the rainfall. Both GPS and tiltmeter equipments react instantly to heavy rains displaying abrupt offsets, but with different time constants, demonstrating the response to different catchment volumes. The GPS movement is mostly confined in the horizontal plane (SSW direction) showing a systematic tendency to rebound in the weeks following the rain. Four GPS stations concur to define a coherent deformation pattern of a wide area (12
75km2), concerning the whole southeastern slope of the plateau. The plateau expands and rebounds radially after rain by an amount up to a few centimeters and causing only small vertical deformation. The effect is largest where karstic features are mostly developed, at the margin of the plateau where a thick succession of Cretaceous peritidal carbonates faces the Venetian lowland. Acouple of tiltmeters installed in a cave at the top of the plateau, detect a much faster deformation, that has the tendency to rebound in less than 6h. The correlation to rainfall is less straightforward, and shows a more complex behavior during rainy weather. The different responses demonstrate a fast hydrologic flow in the more permeable epikarst for the tiltmeters, drained by open fractures and fissures in the neighborhood of the cave, and a rapid tensile dislocation of the bedrock measured at the GPS stations that affect the whole slope of the mountain. In the days following the rain, both tiltmeter and GPS data show a tendency to retrieve the displacement which is consistent with the phreatic discharge curve. We propose that hydrologically active fractures recharged by rainfall are the most likely features capable to induce the observed strain variations
Optimal two-stage spatial sampling design for estimating critical parameters of SARS-CoV-2 epidemic: Efficiency versus feasibility
The COVID-19 pandemic presents an unprecedented clinical and healthcare challenge for the many medical researchers who are attempting to prevent its worldwide
spread. It also presents a challenge for statisticians involved in designing appropriate
sampling plans to estimate the crucial parameters of the pandemic. These plans are
necessary for monitoring and surveillance of the phenomenon and evaluating health
policies. In this respect, we can use spatial information and aggregate data regarding
the number of verifed infections (either hospitalized or in compulsory quarantine)
to improve the standard two-stage sampling design broadly adopted for studying
human populations. We present an optimal spatial sampling design based on spatially balanced sampling techniques. We prove its relative performance analytically
in comparison to other competing sampling plans, and we also study its properties
through a series of Monte Carlo experiments. Considering the optimal theoretical
properties of the proposed sampling plan and its feasibility, we discuss suboptimal
designs that approximate well optimality and are more readily applicable
HySIA: Tool for Simulating and Monitoring Hybrid Automata Based on Interval Analysis
We present HySIA: a reliable runtime verification tool for nonlinear hybrid
automata (HA) and signal temporal logic (STL) properties. HySIA simulates an HA
with interval analysis techniques so that a trajectory is enclosed sharply
within a set of intervals. Then, HySIA computes whether the simulated
trajectory satisfies a given STL property; the computation is performed again
with interval analysis to achieve reliability. Simulation and verification
using HySIA are demonstrated through several example HA and STL formulas.Comment: Appeared in RV'17; the final publication is available at Springe
4D Spin Glasses in Magnetic Field Have a Mean Field like Phase
By using numerical simulations we show that the 4D Edwards Anderson
spin glass in magnetic field undergoes a mean field like phase transition. We
use a dynamical approach: we simulate large lattices (of volume ) and work
out the behavior of the system in limit where both and go to infinity,
but where the limit is taken first. By showing that the dynamic
overlap converges to a value smaller than the static one we exhibit replica
symmetry breaking. The critical exponents are compatible with the ones obtained
by mean field computations.Comment: Physrev format, 5 ps figures include
A general method to determine replica symmetry breaking transitions
We introduce a new parameter to investigate replica symmetry breaking
transitions using finite-size scaling methods. Based on exact equalities
initially derived by F. Guerra this parameter is a direct check of the
self-averaging character of the spin-glass order parameter. This new parameter
can be used to study models with time reversal symmetry but its greatest
interest concerns models where this symmetry is absent. We apply the method to
long-range and short-range Ising spin glasses with and without magnetic field
as well as short-range multispin interaction spin glasses.Comment: 5 pages, 4 figures, Revtex fil
Numerical Simulations of the 4D Edwards-Anderson Spin Glass with Binary Couplings
We present numerical results that allow a precise determination of the
transition point and of the critical exponents of the 4D Edwards-Anderson Spin
Glass with binary quenched random couplings. We show that the low T phase
undergoes Replica Symmetry Breaking. We obtain results on large lattices, up to
a volume : we use finite size scaling to show the relevance of our
results in the infinite volume limit.Comment: 18 pages + 17 figures, revised bibliography and minor typos. Added
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