609 research outputs found
Modelling and Simulation of Adaptive Multi-Agent Systems with Stochastic Nets-within-Nets
No full textThis study centers on self-adapting multi-agent systems modeled utilizing the SONAR framework. Our key focus is on forecasting the costs and benefits of adaptation during execution within the MAPE loop (monitor, analyse, plan, and execute). Analyzing these adaptation processes is intricate due to SONAR enabling second-order activities, such as structural adaptation involving agent interaction protocols or the organizational network itself. We forecast these dynamic processes using a stochastic run-time model (e.g., the environment has a stochastic representation). Since SONAR is conceptualized with HORNETS (a nets-within-nets formalism), we necessitate “probabilistic” HORNETS. To illustrate our approach’s effectiveness, we showcase a small case study of a self-modifying MAS organization and provide an analysis of adaptation dynamics
Immunomodulating effects of environmentally realistic copper concentrations in Mytilus edulis adapted to naturally low salinities.
No full textThe possibility to assess organisms’ health condition and biological effects of chemicals is a fundamental requirement for the achievement of the Good Environmental Status (GES) as defined in the Marine Strategy Framework Directive (EU). In this respect, the role of natural environmental stressors, possibly acting as confounding factors, should be carefully considered, especially at low doses of exposure. Organisms from the Baltic Sea have adapted to the ambient salinity regime, however energetically costly osmoregulating processes may have an impact on the capability to respond to additional stress such as contamination. In the present study, immune responses of Mytilus spp, adapted to salinities of 12 ‰ (LS) and 20 ‰ (MS) were compared after short-term exposure (1, 7 and 13 days) to low copper concentrations (5, 9 and 16 μg/L Cu). In brief, LS mussels accumulated markedly more copper than MS mussels, and exhibited a strong correlation between bacterial clearance and phagocytic activity. The greatest separating factor of LS and MS was the proportion of granulocytes and hyalinocytes while functional parameters (phagocytic activity and bacterial clearance) were merely affected by salinity, but rather by copper exposure. The overall results demonstrated that immune responses may be suitable biomarkers for the assessment of ecosystem health in brackish waters (10 to 20 ‰ S), and that the impact of salinity on physiological processes should be accounted for
A “Symbolic” Representation of Object-Nets
No full textIn this contribution, we extend the concept of a Petri net morphism to Elementary Object Systems (Eos). Eos are a net-within-nets formalism, that is, we allow the tokens of a Petri net to be Petri nets again. This nested structure has the consequence that even systems defined by very small Petri nets have a quite huge reachability graph. In this contribution, we use automorphism to describe symmetries of the Petri net topology. Since these symmetries carry over to markings as well, this leads to a condensed state space, too
A distributed optimization algorithm for Nash bargaining in multi-agent systems
No full textIn this paper, we consider a multi-objective optimization problem over networks in which agents aim to maximize their own objective function, while satisfying both local and coupling constraints. This set up includes, e.g., the computation of optimal steady states in multi-agent control systems. Since fairness is a key feature required for the solution, we resort to Cooperative Game Theory and search for the Nash bargaining solution among all the efficient (or Pareto optimal) points of a bargaining game. We propose a negotiation mechanism among the agents to compute such a solution in a distributed way. The problem is reformulated as the maximization of a properly weighted sum of the objective functions. The proposed algorithm is then a two step procedure in which local estimates of the Nash bargaining weights are updated online and existing distributed optimization algorithms are applied. The proposed method is formally analyzed for a particular case, while numerical simulations are provided to corroborate the theoretical findings and to demonstrate its efficacy
Systematic review and exploratory meta-analysis of the efficacy, safety, and biological effects of psychostimulants and atomoxetine in patients with schizophrenia or schizoaffective disorder
No full textObjective Our aim was to summarize the efficacy and safety of atomoxetine, amphetamines, and methylphenidate in schizophrenia.Methods We undertook a systematic review, searching PubMed/Scopus/Clinicaltrials.gov for double-blind, randomized, placebo-controlled studies of psychostimulants or atomoxetine in schizophrenia published up to 1 January 2017. A meta-analysis of outcomes reported in two or more studies is presented.Results We included 22 studies investigating therapeutic effects of stimulants (k=14) or measuring symptomatic worsening/relapse prediction after stimulant challenge (k=6). Six studies of these two groups plus one additional study investigated biological effects of psychostimulants or atomoxetine. No effect resulted from interventional studies on weight loss (k=1), smoking cessation (k=1), and positive symptoms (k=12), and no improvement was reported with atomoxetine (k=3) for negative symptoms, with equivocal findings for negative (k=6) and mood symptoms (k=2) with amphetamines. Attention, processing speed, working memory, problem solving, and executive functions, among others, showed from no to some improvement with atomoxetine (k=3) or amphetamines (k=6). Meta-analysis did not confirm any effect of stimulants in any symptom domain, including negative symptoms, apart from atomoxetine improving problem solving (k=2, standardized mean difference (SMD)=0.73, 95% CI=0.10-1.36, p=0.02, I2=0%), and trending toward significant improvement in executive functions with amphetamines (k=2, SMD=0.80, 95% CI=-1.68 to +0.08, p=0.08, I2=66%). In challenge studies, amphetamines (k=1) did not worsen symptoms, and methylphenidate (k=5) consistently worsened or predicted relapse. Biological effects of atomoxetine (k=1) and amphetamines (k=1) were cortical activation, without change in β-endorphin (k=1), improved response to antipsychotics after amphetamine challenge (k=2), and an increase of growth hormone-mediated psychosis with methylphenidate (k=2). No major side effects were reported (k=6).Conclusions No efficacy for stimulants or atomoxetine on negative symptoms is proven. Atomoxetine or amphetamines may improve cognitive symptoms, while methylphenidate should be avoided in patients with schizophrenia. Insufficient evidence is available to draw firm conclusions
Effects of the Lattice Expansion on the Reactivity of a 1D Oxide
No full textBy means of scanning tunneling microscopy (STM) and density functional theory (DFT) calculations, we characterize at the single-atom level the mechanism of the water formation reaction on the (10 × 2)-O/Rh(110) surface, a prototype of a one-dimensional (1D) oxide where the lattice expansion and the segmentation of the surface play a fundamental role. When the reaction is imaged in the 238−263 K temperature range (35 s/image acquisition time), a peculiar comblike propagation mechanism for the reaction front is found. Fast STM measurements (33 ms/image) prove that this mechanism holds also at room temperature, being therefore an intrinsic characteristic of the reaction on the 1D oxide. DFT calculations explain the observed behavior as due to the interplay between the lattice expansion in the initial surface and its relaxation during the reaction that leads to varying configurations for the reactants
APPLICATION OF LONG HIGH CAPACITY GAS-INSULATED LINES IN STRUCTURES
No full textThis brochure gives information on the application of long high capacity Gas-Insulated Lines (GIL) in structures like bridges or tunnels. It is written as a guide for technical experts involved in all aspects of GIL, but also can be used for general information on GIL technology.
Basic information is included about published doc-uments, the properties of insulating gases, technical data, and standard design dimensions and specifications.
It explains the planning steps and requirements con-cerning route planning and the possibilities and limits given by the GIL.
The existing GILs in structures have been identi¬fied world-wide for tunnels, above ground installations, directly buried installations, and bridges; for tunnels and bridges specific requirements, e. g. seismic, electromag¬netic fields and grounding, are explained and discussed for different types of bridges and tunnels.
Project execution and the handling of large scale pro-jects including the operation, maintenance and repair process are covered, as well as life cycle assessment, safety analysis and detailed cost analysis
Fertility outcome after radical vaginal trachelectomy: A prospective study of 212 patients
No full textObjective: For treatment in patients with early-stage cervical cancer, radical vaginal trachelectomy (RVT) as a fertility-preserving surgery can be put on a par with radical hysterectomy as to oncologic safety. Our aim was to investigate the fertility concerns and outcome. Methods: Prospective collection of fertility data of patients treated with RVT. The data were collected on personal communication, by telephone, or e-mail correspondence. Descriptive statistical analysis was performed. Results: Between March 2005 and April 2010, 212 patients were followed up after RVT. Only 76 patients (35.9%) were seeking parenthood currently. Sixty pregnancies occurred in 50 women. Five patients (8.3%) had first-trimester miscarriage, 3 had second-trimester miscarriage (5.0%), 2 patients decided for pregnancy termination (3.3%), and 1 patient (1.7%) had an ectopic pregnancy. Three women (5.0%) delivered prematurely before 28th weeks of gestation, 15 (25.0%) delivered between 28 and 36 weeks, and 27 women (45.0%) reached full term. Four pregnancies are ongoing. Conclusions: Preservation of childbearing function is a great advantage for patients with early-stage cervical cancer. Many patients do not seek parenthood immediately. We see no impairment of fertility and have solid data on pregnancy outcome. Premature labor is the main problem in pregnancy after RVT. Copyright copy; 2011 by IGCS and ESGO
Radical vaginal trachelectomy (RVT) combined with laparoscopic lymphadenectomy: Prospective study of 225 patients with early-stage cervical cancer
No full textObjective: The aim of the study was to prove the surgical and oncological safety of radical vaginal trachelectomy (RVT) and laparoscopic lymphadenectomy for patients with early-stage cervical cancer who are seeking parenthood. Methods: A database of 225 patients with early-stage cervical cancer and intention to treat by RVTafter laparoscopic lymphadenectomy was prospectively maintained. A total of 212 patients were treated according to the protocol. The procedure was preformed in a standardized manner, and life table analysis was applied. Results: In the cohort of patients treated according to protocol, 8 recurrences occurred and 4 patients died from recurrence. The median follow-up time was 37 months (range, 0-171 months). The 5-year recurrence-free and overall survival was 94.4% and 97.4%, respectively. Perioperative and short-term postoperative complications were rare (2.8% and 7.5%, respectively). No severe long-term complications occurred. Conclusions: Radical vaginal trachelectomy combined with laparoscopic lymphadenectomy is a safe method for treatment of patients with early-stage cervical cancer who are seeking parenthood
- …
