5,472 research outputs found
Communication Between Process and Structure: Modelling and Simulating Message Reference Networks with COM/TE
Focusing on observable message signs and referencing structures, communication processes can be described and analysed as message reference networks which are characterized by dynamic pattern evolution. Computational simulation provides a way of obtaining insights into the factors driving such processes. Our paper describes a theoretical framework for communication-oriented modelling — the COM approach — that is centred around the notion of social visibility as a reputation mechanism. The approach contrasts with agent-based social networks on the one hand, and with bibliometric document networks on the other. In introducing our simulation environment COM/TE, typical properties of message reference networks are discussed in terms of a case study which deals with the impact of different media and styles of communication on emergent patterns of social visibility.Communication, Communication-Oriented Modelling, Message Sign, Dynamic Networks, Bottom-up Approach, Temporality, Social Visibility, Reputation, Socionics
Interpreting Soft Sediment Deformation and Mass Transport Deposits as Seismites in the Dead Sea Depocenter
Peer reviewedPublisher PD
On fractional Choquard equations
We investigate a class of nonlinear Schrodinger equations with a generalized
Choquard nonlinearity and fractional diffusion. We obtain regularity,
existence, nonexistence, symmetry as well as decays properties.Comment: revised version, 22 page
On small-noise equations with degenerate limiting system arising from volatility models
The one-dimensional SDE with non Lipschitz diffusion coefficient is widely
studied in mathematical finance. Several works have proposed asymptotic
analysis of densities and implied volatilities in models involving instances of
this equation, based on a careful implementation of saddle-point methods and
(essentially) the explicit knowledge of Fourier transforms. Recent research on
tail asymptotics for heat kernels [J-D. Deuschel, P.~Friz, A.~Jacquier, and
S.~Violante. Marginal density expansions for diffusions and stochastic
volatility, part II: Applications. 2013, arxiv:1305.6765] suggests to work with
the rescaled variable : while
allowing to turn a space asymptotic problem into a small- problem
with fixed terminal point, the process satisfies a SDE in
Wentzell--Freidlin form (i.e. with driving noise ). We prove a
pathwise large deviation principle for the process as
. As it will become clear, the limiting ODE governing the
large deviations admits infinitely many solutions, a non-standard situation in
the Wentzell--Freidlin theory. As for applications, the -scaling
allows to derive exact log-asymptotics for path functionals of the process:
while on the one hand the resulting formulae are confirmed by the CIR-CEV
benchmarks, on the other hand the large deviation approach (i) applies to
equations with a more general drift term and (ii) potentially opens the way to
heat kernel analysis for higher-dimensional diffusions involving such an SDE as
a component.Comment: 21 pages, 1 figur
Quasielastic Versus Inelastic and Deep Inelastic Lepton Scattering in Nuclei at x > 1
We have made a thorough investigation of the nuclear structure function W_2A
in the region of 0.8 < x < 1.5 and Q^2 < 20 GeV^2, separating the quasielastic
and inelastic plus deep inelastic contributions. The agreement with present
experimental data is good giving support to the results for both channels.
Predictions are made in yet unexplored regions of x and Q^2 to assert the
weight of the quasielastic or inelastic channels. We find that at Q^2 < 4 GeV^2
the structure function is dominated by the quasielastic contributions for x <
1.5, while for values of Q^2 > 15 GeV^2 and the range of x studied the
inelastic channels are over one order of magnitude bigger than the quasielastic
one. The potential of the structure function at x > 1 as a source of
information on nuclear correlations is stressed once more.Comment: 17 pages, LaTeX, 13 PostScript figures, final version to be published
in Nuclear Physics
Communication between process and structure : modelling and simulating message reference networks with COM/TE
Focusing on observable message signs and referencing structures, communication processes can be described and analysed as message reference networks which are characterized by dynamic pattern evolution. Computational simulation provides a way of obtaining insights into the factors driving such processes. Our paper describes a theoretical framework for communication-oriented modelling — the COM approach — that is centred around the notion of social visibility as a reputation mechanism. The approach contrasts with agent-based social networks on the one hand, and with bibliometric document networks on the other. In introducing our simulation environment COM/TE, typical properties of message reference networks are discussed in terms of a case study which deals with the impact of different media and styles of communication on emergent patterns of social visibility
Opioid receptor signaling, analgesic and side effects induced by a computationally designed pH-dependent agonist
Novel pain killers without adverse effects are urgently needed. Opioids induce central and intestinal side effects such as respiratory depression, sedation, addiction, and constipation. We have recently shown that a newly designed agonist with a reduced acid dissociation constant (pK(a)) abolished pain by selectively activating peripheral mu-opioid receptors (MOR) in inflamed (acidic) tissues without eliciting side effects. Here, we extended this concept in that pK(a) reduction to 7.22 was achieved by placing a fluorine atom at the ethylidene bridge in the parental molecule fentanyl. The new compound (FF3) showed pH-sensitive MOR affinity, [S-35]-GTP gamma S binding, and G protein dissociation by fluorescence resonance energy transfer. It produced injury-restricted analgesia in rat models of inflammatory, postoperative, abdominal, and neuropathic pain. At high dosages, FF3 induced sedation, motor disturbance, reward, constipation, and respiratory depression. These results support our hypothesis that a ligand's pK(a) should be close to the pH of injured tissue to obtain analgesia without side effects
Non-perturbative dynamics of hot non-Abelian gauge fields: beyond leading log approximation
Many aspects of high-temperature gauge theories, such as the electroweak
baryon number violation rate, color conductivity, and the hard gluon damping
rate, have previously been understood only at leading logarithmic order (that
is, neglecting effects suppressed only by an inverse logarithm of the gauge
coupling). We discuss how to systematically go beyond leading logarithmic order
in the analysis of physical quantities. Specifically, we extend to
next-to-leading-log order (NLLO) the simple leading-log effective theory due to
Bodeker that describes non-perturbative color physics in hot non-Abelian
plasmas. A suitable scaling analysis is used to show that no new operators
enter the effective theory at next-to-leading-log order. However, a NLLO
calculation of the color conductivity is required, and we report the resulting
value. Our NLLO result for the color conductivity can be trivially combined
with previous numerical work by G. Moore to yield a NLLO result for the hot
electroweak baryon number violation rate.Comment: 20 pages, 1 figur
Low-cost reusable instrumentation for laparoendoscopic single-site nephrectomy : assessment in a porcine model
Purpose: To test different sets of prebent instruments and a new reusable access device for laparoendoscopic single-site (LESS) surgery. Materials and Methods: Three surgeons with previous experience in LESS performed 12 nephrectomies in six pigs. In all procedures, a multichannel access device (X-CONE_) and a 5-mm extra-long telescope were used. Four sets of prebent instruments with different profiles (S-portal_) were tested: Standard (one straight scissorsand one curved grasper), Cuschieri, Carus, and Leroy set (each of them consisting of two curved instruments with different configurations). Assessment was performed based on both objective (procedure time; time to
manage the pedicle; time to free kidney) and subjective parameters (entry=exit of instruments; triangulation; dissection up=down; dissection lateral; retraction; interdependence). The subjective assessment tool used was a Likert type scale (1¼easy to 5¼prohibitive). The access device was assessed by using objective (time to completeinsertion of device after skin incision) and subjective (significant air leakage, movement constraint) parameters.
Results: Time to insertion of the X-CONE was <1 minute in all the cases. Surgeons reported significant insufflant leakage in 58% of cases. The procedure was completed in 10=12 (83%) cases. Mean operative time was 8.3_4.2 minutes, being lower for the Carus group (4.5 min) and higher for the standard group (13 min). Among thedifferent sets, the standard one obtained the best mean scores for all subjective parameters. Conclusions: X-CONE allows easy abdominal access, and its reusable properties represent cost savings for LESS compared with disposable devices. Prebent instruments might also represent attractive low-cost tools for LESS
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