142 research outputs found

    Equilibria-based Probabilistic Model Checking for Concurrent Stochastic Games

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    Probabilistic model checking for stochastic games enables formal verification of systems that comprise competing or collaborating entities operating in a stochastic environment. Despite good progress in the area, existing approaches focus on zero-sum goals and cannot reason about scenarios where entities are endowed with different objectives. In this paper, we propose probabilistic model checking techniques for concurrent stochastic games based on Nash equilibria. We extend the temporal logic rPATL (probabilistic alternating-time temporal logic with rewards) to allow reasoning about players with distinct quantitative goals, which capture either the probability of an event occurring or a reward measure. We present algorithms to synthesise strategies that are subgame perfect social welfare optimal Nash equilibria, i.e., where there is no incentive for any players to unilaterally change their strategy in any state of the game, whilst the combined probabilities or rewards are maximised. We implement our techniques in the PRISM-games tool and apply them to several case studies, including network protocols and robot navigation, showing the benefits compared to existing approaches

    Evaluating the Effectiveness of Coagulation–Flocculation Treatment Using Aluminum Sulfate on a Polluted Surface Water Source: A Year-Long Study

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    \ua9 2024 by the authors.Safeguarding drinking water is a major public health and environmental concern because it is essential to human life but may contain pollutants that can cause illness or harm the environment. Therefore, continuous research is necessary to improve water treatment methods and guarantee its quality. As part of this study, the effectiveness of coagulation–flocculation treatment using aluminum sulfate (Al2(SO4)3) was evaluated on a very polluted site. Samplings were taken almost every day for a month from the polluted site, and the samples were characterized by several physicochemical properties, such as hydrogen potential (pH), electrical conductivity, turbidity, organic matter, ammonium (NH+4), phosphate (PO43−), nitrate (NO3−), nitrite (NO2−), calcium (Ca2+), magnesium (Mg2+), total hardness (TH), chloride (Cl−), bicarbonate (HCO3−), sulfate (SO42−), iron (Fe3+), manganese (Mn2+), aluminum (Al3+), potassium (K+), sodium (Na+), complete alkalimetric titration (TAC), and dry residue (DR). Then, these samples were treated with Al2(SO4)3 using the jar test method, which is a common method to determine the optimal amount of coagulant to add to the water based on its physicochemical characteristics. A mathematical model had been previously created using the support vector machine method to predict the dose of coagulant according to the parameters of temperature, pH, TAC, conductivity, and turbidity. This Al2(SO4)3 treatment step was repeated at the end of each month for a year, and a second characterization of the physicochemical parameters was carried out in order to compare them with those of the raw water. The results showed a very effective elimination of the various pollutions, with a very high rate, thus demonstrating the effectiveness of the Al2(SO4)3. The physicochemical parameters measured after the treatment showed a significant reduction in the majority of the physicochemical parameters. These results demonstrated that the coagulation–flocculation treatment with Al2(SO4)3 was very effective in eliminating the various pollutions present in the raw water. They also stress the importance of continued research in the field of water treatment to improve the quality of drinking water and protect public health and the environment

    Equilibria-based probabilistic model checking for concurrent stochastic games

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    Probabilistic model checking for stochastic games enables formal verification of systems that comprise competing or collaborating entities operating in a stochastic environment. Despite good progress in the area, existing approaches focus on zero-sum goals and cannot reason about scenarios where entities are endowed with different objectives. In this paper, we propose probabilistic model checking techniques for concurrent stochastic games based on Nash equilibria. We extend the temporal logic rPATL (probabilistic alternating-time temporal logic with rewards) to allow reasoning about players with distinct quantitative goals, which capture either the probability of an event occurring or a reward measure. We present algorithms to synthesise strategies that are subgame perfect social welfare optimal Nash equilibria, i.e., where there is no incentive for any players to unilaterally change their strategy in any state of the game, whilst the combined probabilities or rewards are maximised. We implement our techniques in the PRISM-games tool and apply them to several case studies, including network protocols and robot navigation, showing the benefits compared to existing approaches

    Mast cell tryptase stimulates myoblast proliferation; a mechanism relying on protease-activated receptor-2 and cyclooxygenase-2

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    <p>Abstract</p> <p>Background</p> <p>Mast cells contribute to tissue repair in fibrous tissues by stimulating proliferation of fibroblasts through the release of tryptase which activates protease-activated receptor-2 (PAR-2). The possibility that a tryptase/PAR-2 signaling pathway exists in skeletal muscle cell has never been investigated. The aim of this study was to evaluate whether tryptase can stimulate myoblast proliferation and determine the downstream cascade.</p> <p>Methods</p> <p>Proliferation of L6 rat skeletal myoblasts stimulated with PAR-2 agonists (tryptase, trypsin and SLIGKV) was assessed. The specificity of the tryptase effect was evaluated with a specific inhibitor, APC-366. Western blot analyses were used to evaluate the expression and functionality of PAR-2 receptor and to assess the expression of COX-2. COX-2 activity was evaluated with a commercial activity assay kit and by measurement of PGF<sub>2</sub>α production. Proliferation assays were also performed in presence of different prostaglandins (PGs).</p> <p>Results</p> <p>Tryptase increased L6 myoblast proliferation by 35% above control group and this effect was completely inhibited by APC-366. We confirmed the expression of PAR-2 receptor <it>in vivo </it>in skeletal muscle cells and in satellite cells and <it>in vitro </it>in L6 cells, where PAR-2 was found to be functional. Trypsin and SLIGKV increased L6 cells proliferation by 76% and 26% above control, respectively. COX-2 activity was increased following stimulation with PAR-2 agonist but its expression remained unchanged. Inhibition of COX-2 activity by NS-398 abolished the stimulation of cell proliferation induced by tryptase and trypsin. Finally, 15-deoxy-Δ-<sup>12,14</sup>-prostaglandin J<sub>2 </sub>(15Δ-PGJ<sub>2</sub>), a product of COX-2-derived prostaglandin D<sub>2</sub>, stimulated myoblast proliferation, but not PGE<sub>2 </sub>and PGF<sub>2</sub>α.</p> <p>Conclusions</p> <p>Taken together, our data show that tryptase can stimulate myoblast proliferation and this effect is part of a signaling cascade dependent on PAR-2 activation and on the downstream activation of COX-2.</p

    Identifying work ability promoting factors for home care aides and assistant nurses

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    <p>Abstract</p> <p>Background</p> <p>In workplace health promotion, all potential resources needs to be taken into consideration, not only factors relating to the absence of injury and the physical health of the workers, but also psychological aspects. A dynamic balance between the resources of the individual employees and the demands of work is an important prerequisite. In the home care services, there is a noticeable trend towards increased psychosocial strain on employees at work. There are a high frequency of work-related musculoskeletal disorders and injuries, and a low prevalence of sustainable work ability. The aim of this research was to identify factors promoting work ability and self-efficacy in care aides and assistant nurses within home care services.</p> <p>Methods</p> <p>This study is based on cross-sectional data collected in a municipality in northern Sweden. Care aides (n = 58) and assistant nurses (n = 79) replied to a self-administered questionnaire (response rate 46%). Hierarchical multiple regression analyses were performed to assess the influence of several independent variables on self-efficacy (model 1) and work ability (model 2) for care aides and assistant nurses separately.</p> <p>Results</p> <p>Perceptions of personal safety, self-efficacy and musculoskeletal wellbeing contributed to work ability for assistant nurses (R<sup>2</sup>adj of 0.36, <it>p </it>< 0.001), while for care aides, the safety climate, seniority and age contributed to work ability (R<sup>2</sup>adj of 0.29, <it>p </it>= 0.001). Self-efficacy was associated with the safety climate and the physical demands of the job in both professions (R<sup>2</sup>adj of 0.24, <it>p </it>= 0.003 for care aides), and also by sex and age for the assistant nurses (R<sup>2</sup>adj of 0.31, <it>p </it>< 0.001).</p> <p>Conclusions</p> <p>The intermediate factors contributed differently to work ability in the two professions. Self-efficacy, personal safety and musculoskeletal wellbeing were important for the assistant nurses, while the work ability of the care aides was associated with the safety climate, but also with the non-changeable factors age and seniority. All these factors are important to acknowledge in practice and in further research. Proactive workplace interventions need to focus on potentially modifiable factors such as self-efficacy, safety climate, physical job demands and musculoskeletal wellbeing.</p

    Chromium Stress Mitigation by Polyamine-Brassinosteroid Application Involves Phytohormonal and Physiological Strategies in Raphanus sativus L.

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    Brassinosteroids (BRs) and polyamines (PAs) are well-established growth regulators playing key roles in stress management among plants. In the present study, we evaluated the effects of epibrassinolide (EBL, an active BR) and spermidine (Spd, an active PA) on the tolerance of radish to oxidative stress induced by Cr (VI) metal. Our investigation aimed to study the impacts of EBL (10−9 M) and/or Spd (1 mM) on the biochemical and physiological responses of radish (Raphanus sativus L.) under Cr-stress. Applications of EBL and/or Spd were found to improve growth of Cr-stressed seedlings in terms of root length, shoot length and fresh weight. Our data also indicated that applications of EBL and Spd have significant impacts, particularly when applied together, on the endogenous titers of PAs, free and bound forms of IAA and ABA in seedlings treated with Cr-stress. Additionally, co-applications of EBL and Spd modulated more remarkably the titers of antioxidants (glutathione, ascorbic acid, proline, glycine betaine and total phenol) and activities of antioxidant enzymes (guaicol peroxidase, catalase, superoxide dismutase and glutathione reductase) in Cr-stressed plants than their individual applications. Attenuation of Cr-stress by EBL and/or Spd (more efficient with EBL and Spd combination) was also supported by enhanced values of stress indices, such as phytochelatins, photosynthetic pigments and total soluble sugars, and reduction in malondialdehyde and H2O2 levels in Cr-treated seedlings. Diminution of ROS production and enhanced ROS scavenging capacities were also noted for EBL and/or Spd under Cr-stress. However, no significant reduction in Cr uptake was observed for co-application of EBL and Spd when compared to their individual treatments in Cr-stressed seedlings. Taken together, our results demonstrate that co-applications of EBL and Spd are more effective than their independent treatments in lowering the Cr-induced oxidative stress in radish, leading to improved growth of radish seedlings under Cr-stress

    Nuclear Importation of Mariner Transposases among Eukaryotes: Motif Requirements and Homo-Protein Interactions

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    Mariner-like elements (MLEs) are widespread transposable elements in animal genomes. They have been divided into at least five sub-families with differing host ranges. We investigated whether the ability of transposases encoded by Mos1, Himar1 and Mcmar1 to be actively imported into nuclei varies between host belonging to different eukaryotic taxa. Our findings demonstrate that nuclear importation could restrict the host range of some MLEs in certain eukaryotic lineages, depending on their expression level. We then focused on the nuclear localization signal (NLS) in these proteins, and showed that the first 175 N-terminal residues in the three transposases were required for nuclear importation. We found that two components are involved in the nuclear importation of the Mos1 transposase: an SV40 NLS-like motif (position: aa 168 to 174), and a dimerization sub-domain located within the first 80 residues. Sequence analyses revealed that the dimerization moiety is conserved among MLE transposases, but the Himar1 and Mcmar1 transposases do not contain any conserved NLS motif. This suggests that other NLS-like motifs must intervene in these proteins. Finally, we showed that the over-expression of the Mos1 transposase prevents its nuclear importation in HeLa cells, due to the assembly of transposase aggregates in the cytoplasm
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