6,330 research outputs found
A Formal Framework for Modeling Trust and Reputation in Collective Adaptive Systems
Trust and reputation models for distributed, collaborative systems have been
studied and applied in several domains, in order to stimulate cooperation while
preventing selfish and malicious behaviors. Nonetheless, such models have
received less attention in the process of specifying and analyzing formally the
functionalities of the systems mentioned above. The objective of this paper is
to define a process algebraic framework for the modeling of systems that use
(i) trust and reputation to govern the interactions among nodes, and (ii)
communication models characterized by a high level of adaptiveness and
flexibility. Hence, we propose a formalism for verifying, through model
checking techniques, the robustness of these systems with respect to the
typical attacks conducted against webs of trust.Comment: In Proceedings FORECAST 2016, arXiv:1607.0200
Models Predicting Postpartum Glucose Intolerance Among Women with a History of Gestational Diabetes Mellitus: a Systematic Review
Purpose of Review: Despite the crucial role that prediction models play in guiding early risk stratifcation and timely intervention to prevent type 2 diabetes after gestational diabetes mellitus (GDM), their use is not widespread in clinical practice. The purpose of this review is to examine the methodological characteristics and quality of existing prognostic models predicting postpartum glucose intolerance following GDM. Recent Findings. A systematic review was conducted on relevant risk prediction models, resulting in 15 eligible publications from research groups in various countries. Our review found that traditional statistical models were more common than machine learning models, and only two were assessed to have a low risk of bias. Seven were internally validated, but none were externally validated. Model discrimination and calibration were done in 13 and four studies, respectively. Various predictors were identifed, including body mass index, fasting glucose concentration during pregnancy, maternal age, family history of diabetes, biochemical variables, oral glucose tolerance test, use of insulin in pregnancy, postnatal fasting glucose level, genetic risk factors, hemoglobin A1c, and weight. Summary: The existing prognostic models for glucose intolerance following GDM have various methodological shortcomings, with only a few models being assessed to have low risk of bias and validated internally. Future research should prioritize the development of robust, high-quality risk prediction models that follow appropriate guidelines, in order to advance this area and improve early risk stratifcation and intervention for glucose intolerance and type 2 diabetes among women who have had GDM.Yitayeh Belsti, Lisa Moran, Demelash Woldeyohannes Handiso, Vincent Versace, Rebecca Goldstein, Aya Mousa, Helena Teede, Joanne Enticot
Histone Acetylation-Mediated Regulation of the Hippo Pathway
The Hippo pathway is a signaling cascade recently found to play a key role in tumorigenesis therefore understanding the mechanisms that regulate it should open new opportunities for cancer treatment. Available data indicate that this pathway is controlled by signals from cell-cell junctions however the potential role of nuclear regulation has not yet been described. Here we set out to verify this possibility and define putative mechanism(s) by which it might occur. By using a luciferase reporter of the Hippo pathway, we measured the effects of different nuclear targeting drugs and found that chromatin-modifying agents, and to a lesser extent certain DNA damaging drugs, strongly induced activity of the reporter. This effect was not mediated by upstream core components (i.e. Mst, Lats) of the Hippo pathway, but through enhanced levels of the Hippo transducer TAZ. Investigation of the underlying mechanism led to the finding that cancer cell exposure to histone deacetylase inhibitors induced secretion of growth factors and cytokines, which in turn activate Akt and inhibit the GSK3 beta associated protein degradation complex in drug-affected as well as in their neighboring cells. Consequently, expression of EMT genes, cell migration and resistance to therapy were induced. These processes were suppressed by using pyrvinium, a recently described small molecule activator of the GSK 3 beta associated degradation complex. Overall, these findings shed light on a previously unrecognized phenomenon by which certain anti-cancer agents may paradoxically promote tumor progression by facilitating stabilization of the Hippo transducer TAZ and inducing cancer cell migration and resistance to therapy. Pharmacological targeting of the GSK3 beta associated degradation complex may thus represent a unique approach to treat cancer. © 2013 Basu et al
An upper limit on hypertriton production in collisions of Ar(1.76 AGeV)+KCl
A high-statistic data sample of Ar(1.76 AGeV)+KCl events recorded with HADES
is used to search for a hypertriton signal. An upper production limit per
centrality-triggered event of x on the level is
derived. Comparing this value with the number of successfully reconstructed
hyperons allows to determine an upper limit on the ratio
, which is confronted with statistical and
coalescence-type model calculations
Peripheral non-viral MIDGE vector-driven delivery of β-endorphin in inflammatory pain
<p>Abstract</p> <p>Background</p> <p>Leukocytes infiltrating inflamed tissue produce and release opioid peptides such as β-endorphin, which activate opioid receptors on peripheral terminals of sensory nerves resulting in analgesia. Gene therapy is an attractive strategy to enhance continuous production of endogenous opioids. However, classical viral and plasmid vectors for gene delivery are hampered by immunogenicity, recombination, oncogene activation, anti-bacterial antibody production or changes in physiological gene expression. Non-viral, non-plasmid minimalistic, immunologically defined gene expression (MIDGE) vectors may overcome these problems as they carry only elements needed for gene transfer. Here, we investigated the effects of a nuclear localization sequence (NLS)-coupled MIDGE encoding the β-endorphin precursor proopiomelanocortin (POMC) on complete Freund's adjuvant-induced inflammatory pain in rats.</p> <p>Results</p> <p>POMC-MIDGE-NLS injected into inflamed paws appeared to be taken up by leukocytes resulting in higher concentrations of β-endorphin in these cells. POMC-MIDGE-NLS treatment reversed enhanced mechanical sensitivity compared with control MIDGE-NLS. However, both effects were moderate, not always statistically significant or directly correlated with each other. Also, the anti-hyperalgesic actions could not be increased by enhancing β-endorphin secretion or by modifying POMC-MIDGE-NLS to code for multiple copies of β-endorphin.</p> <p>Conclusion</p> <p>Although MIDGE vectors circumvent side-effects associated with classical viral and plasmid vectors, the current POMC-MIDGE-NLS did not result in reliable analgesic effectiveness in our pain model. This was possibly associated with insufficient and variable efficacy in transfection and/or β-endorphin production. Our data point at the importance of the reproducibility of gene therapy strategies for the control of chronic pain.</p
Inclusive dielectron production in proton-proton collisions at 2.2 GeV beam energy
Data on inclusive dielectron production are presented for the reaction p+p at
2.2 GeV measured with the High Acceptance DiElectron Spectrometer (HADES). Our
results supplement data obtained earlier in this bombarding energy regime by
DLS and HADES. The comparison with the 2.09 GeV DLS data is discussed. The
reconstructed e+e- distributions are confronted with simulated pair cocktails,
revealing an excess yield at invariant masses around 0.5 GeV/c2. Inclusive
cross sections of neutral pion and eta production are obtained
Production of Sigma{\pm}pi?pK+ in p+p reactions at 3.5 GeV beam energy
We study the production of Sigma^+-pi^+-pK^+ particle quartets in p+p
reactions at 3.5 GeV kinetic beam energy. The data were taken with the HADES
experiment at GSI. This report evaluates the contribution of resonances like
Lambda(1405$, Sigma(1385)^0, Lambda(1520), Delta(1232), N^* and K^*0 to the
Sigma^+- pi^-+ p K+ final state. The resulting simulation model is compared to
the experimental data in several angular distributions and it shows itself as
suitable to evaluate the acceptance corrections properly.Comment: 15 pages, 5 figure
Baryonic resonances close to the Kbar-N threshold: the case of Sigma(1385)^+ in pp collisions
We present results of an exclusive measurement of the first excited state of
the Sigma hyperon, Sigma(1385)^+, produced in p+p -> Sigma^+ + K^+ + n at 3.5
GeV beam energy. The extracted data allow to study in detail the invariant mass
distribution of the Sigma(1385)^+. The mass distribution is well described by a
relativistic Breit-Wigner function with a maximum at m_0 = 1383.2 +- 0.9
MeV/c^2 and a width of 40.2 +- 2.1 MeV/c^2. The exclusive production
cross-section comes out to be 22.27 +- 0.89 +- 1.56 +3.07 -2.10 mu b. Angular
distributions of the Sigma(1385)^+ in different reference frames are found to
be compatible with the hypothesis that 33 % of Sigma(1385)^+ result from the
decay of an intermediate Delta^{++} resonance.Comment: 12 pages; 12 figures; submitted to PR
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