35,812 research outputs found
Performance Analysis and Design of Maximum Ratio Combining in Channel-Aware MIMO Decision Fusion
In this paper we present a theoretical performance analysis of the maximum
ratio combining (MRC) rule for channel-aware decision fusion over
multiple-input multiple-output (MIMO) channels for (conditionally) dependent
and independent local decisions. The system probabilities of false alarm and
detection conditioned on the channel realization are derived in closed form and
an approximated threshold choice is given. Furthermore, the channel-averaged
(CA) performances are evaluated in terms of the CA system probabilities of
false alarm and detection and the area under the receiver operating
characteristic (ROC) through the closed form of the conditional moment
generating function (MGF) of the MRC statistic, along with Gauss-Chebyshev (GC)
quadrature rules. Furthermore, we derive the deflection coefficients in closed
form, which are used for sensor threshold design. Finally, all the results are
confirmed through Monte Carlo simulations.Comment: To appear in IEEE Transactions on Wireless Communication
Quantized vortices in two dimensional solid 4He
Diagonal and off-diagonal properties of 2D solid 4He systems doped with a
quantized vortex have been investigated via the Shadow Path Integral Ground
State method using the fixed-phase approach. The chosen approximate phase
induces the standard Onsager-Feynman flow field. In this approximation the
vortex acts as a static external potential and the resulting Hamiltonian can be
treated exactly with Quantum Monte Carlo methods. The vortex core is found to
sit in an interstitial site and a very weak relaxation of the lattice positions
away from the vortex core position has been observed. Also other properties
like Bragg peaks in the static structure factor or the behavior of vacancies
are very little affected by the presence of the vortex. We have computed also
the one-body density matrix in perfect and defected 4He crystals finding that
the vortex has no sensible effect on the off-diagonal long range tail of the
density matrix. Within the assumed Onsager Feynman phase, we find that a
quantized vortex cannot auto-sustain itself unless a condensate is already
present like when dislocations are present. It remains to be investigated if
backflow can change this conclusion.Comment: 4 pages, 3 figures, LT26 proceedings, accepted for publication in
Journal of Physics: Conference Serie
Trichothecenes NIV and DON modulate the maturation of murinedendritic cells
Nivalenol (NIV) and Deoxynivalenol (DON), mycotoxins of the trichothecene family are considered very common food contaminants. In this work, we investigated whether the immunotoxic effects ascribed to these trichothecenes may be mediated by perturbations in the activity of dendritic cells (DCs). Murine bone marrow-derived DCs were used to evaluate the effects of NIV and DON on the LPS-induced maturation process.We found that the expression of the class II MHC and of the accessory CD11c molecules, but not of the costimulatory CD86 marker, was down-regulated by NIV and DON exposure in LPS-treated DCs, as well as nitric oxide (NO) production. Interestingly, NIV, but not DON, induced DC necrosis. Moreover, the analysis of the cytokine pattern showed that IL-12 and IL-10 expressions induced by LPS exposure were suppressed by both trichothecenes in a dose-dependent fashion. On the other hand, the secretion of the proinflammatory cytokine TNFa was increased as a direct consequence of DON and NIV exposure. Taken together, our data indicated that the immunotoxicity of NIV and DON was related to the capacity of both trichothecenes to interfere with phenotypic and functional features of maturing DCs
Mycotoxins nivalenol and deoxynivalenol differently modulate cytokine mRNA expression in Jurkat T cells.
Deoxynivalenol (DON) and its hydroxylated form nivalenol (NIV) are Fusarium mycotoxins that occur in cereal grains alone or in
combination. Several studies have shown that these metabolites affect lymphocyte functions. However, the molecular mechanisms
underlying their activities are still partially known. To address this issue, we examined the influence of NIV and DON in modulating
IFNc, IL-2 and IL-8 mRNA levels in Jurkat T cells. In PMA/ionomycin stimulated cells, pre-incubated with increasing concentrations of NIV, transcription was induced in the range 0.06â2 lM; higher concentrations of NIV were found non-stimulating (4 lM) or inhibitory (8 lM) for IFNc and IL-2 whereas IL-8 was still induced. DON administration elicited a similar profile for IL-8 and IFNc, whilst IL-2 mRNA was induced in a broader range of concentrations. Combination of NIV and DON at 1:1 and 1:10 ratios essentially restored the cytokine transcriptional pattern observed with NIV alone but the level of transcripts, with the exception of IL-8, peaked at lower concentrations suggesting interactive effects. Moreover both mycotoxins caused inhibition of cell proliferation, mediated by induction of apoptosis, confirming previous results and highlighting the usefulness of Jurkat as a T-cell model to study the effects of mycotoxins on the immune functions in humans
A new formulation of oral viscous budesonide in treating of paediatric eosinophilic oesophagitis: a pilot study
OBJECTIVES:
Oral viscous budesonide is a recent therapeutic option for eosinophilic oesophagitis (EoE) compared with dietary restriction and inhaled steroids. This single-centre, open-label, not blinded study aims to evaluate the efficacy and safety of a new, preprepared oral viscous budesonide suspension (PVB) in children and adolescents with EoE.
METHODS:
We treated 36 children with PVB (29 boys; median age 12 years) with EoE diagnosed according to European Society for Paediatric Gastroenterology Hepatology and Nutrition guidelines. Patients <150 and >150 cm height received 2 and 4 mg PVB daily, respectively, for 12 weeks. Upper gastrointestinal endoscopy was performed at baseline, after 12 weeks of therapy and 24 weeks after the end of therapy. Baseline and post-treatment scores were calculated for symptoms, endoscopy, and histology. Serum cortisol was performed at baseline, 12, and 36 weeks.
RESULTS:
At the end of PVB trial, endoscopy showed macroscopic remission in 32 patients (88.9%), whereas at histology median pre- and post-treatment peak eosinophil count/high power field (HPF) markedly decreased from 42.2 (range: 15-100) to 2.9 (range: 0-30); moreover, mean symptom and histology scores impressively improved compared with baseline (Pâ<â0.01). At 24 weeks after the end of PVB therapy, endoscopy showed oesophageal relapse in 21 patients (58.3%), whereas 15 (41.7%) were still in remission. Seven children (19.4%) with positive multichannel intraluminal impedance-pH were treated also with proton pump inhibitors. No significant difference between pre-/post-treatment morning cortisol levels occurred.
CONCLUSIONS:
The new PVB suspension presented in the present study is effective and safe for treating children with proven EoE. Larger placebo-controlled clinical trials would provide more information about dosing, efficacy, and long-term safety of this formulation, specifically designed for the oesophagus
Strong coupling expansion of chiral models
A general precedure is outlined for an algorithmic implementation of the
strong coupling expansion of lattice chiral models on arbitrary lattices. A
symbolic character expansion in terms of connected values of group integrals on
skeleton diagrams may be obtained by a fully computerized approach.Comment: 2 pages, PostScript file, contribution to conference LATTICE '9
Computation of microdosimetric distributions for small sites
Object of this study is the computation of microdosimetric functions for sites which are too small to permit experimental determination of the distributions by Rossi-counters. The calculations are performed on simulated tracks generated by Monte-Carlo techniques.
The first part of the article deals with the computational procedure. The second part presents numerical results for protons of energies 0.5, 5, 20 MeV and for site diameters of 5, 10, 100 nm
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