Vertigo: Comparing Structural Models of Imperfect Behavior in Experimental Games

This paper investigates learning in games with one-sided incomplete information using laboratory data from a game which we call the game of Vertigo. The predicted Bayes-Nash equilibrium behavior of the agents in this type of game generates overly strong restrictions on the data, including the zero likelihood problem: certain actions should never be observed. To circumvent statistical problems, and to allow for deviations from perfectly rational behavior, we introduce the possibility of players making errors when choosing their actions. We compare two competing models depending on whether players take the errors in actions into consideration when formulating their strategies. We also investigate possible deviations from Bayes's rule, producing too fast or too slow an updating rule. In total, we get six models of sophisticated and unsophisticated strategy formation on the first dimension, and fast, slow, or no updating on the second. We apply a fully Bayesian structural econometric approach to compare the statistical performance of these six models, and to obtain posterior estimates of several nuisance parameters governing the errors in actions. The two models where players are unsophisticated and either use no updating at all, or use dampened updating, have a much higher likelihood than any of the others

Computational Issues in the Statistical Design and Analysis of Experimental Games

One goal of experimental economics is to provide data to identify models that best describe the behavior of experimental subjects and, more generally, human economic behavior. We discuss here what we think are the three main steps required to make experimental investigations of economic games as statistically informative as possible: finding the solution of the experimental game under the postulated equilibrium or other economic models, selecting from a potential class of experimental designs the optimal one for discriminating between those models, and choosing an optimal stopping rule that indicates when to stop sampling data and accept one model as the best explanation of the data. Each step can be computationally intensive. We offer an algorithmic presentation of the necessary computations in each of the three steps and illustrate these procedures by examples from our research on learning models in experimental games with incomplete information. These three steps of experimental design and analysis are not limited to experimental games, but the computational burden of implementing these algorithms in other experimental environments - for example, market experiments - requires further considerations with which we have not dealt

The Use of Ceramic Waste Powder (CWP) in Making Eco-Friendly Concretes

The global production of ceramic waste powder (CWP), which is produced during the final polishing process of ceramic tiles, exceeds 22 billion tons. The disposal of CWP in landfills will cause significant environmental problems (i.e., soil, air, and groundwater pollution). CWP is characterized by its chemical composition that is mainly composed of silica (SiO2) and alumina (Al2O3). Both minerals represent more than 80% of the CWP composition. CWP has potentials to be used as an ingredient to partially or entirely replacing Portland cement to make eco-friendly concretes. This chapter summarizes the effect of using CWP in making eco-friendly concretes, with a particular focus on using CWP as a partial cement replacement in conventional-vibrated concrete (CVC) and self-compacting concrete (SCC), and the production of zero-cement alkali-activated concrete (AAC)

Serological evidence of association between Helicobacter pylori infection and coronary artery disease

Background: Studies have reported relationship between chronic  Helicobacter pylori infection and coronary artery disease (CAD). The  cytotoxin-associated gene A product (CagA) is an immunodominant protein which indicates infection with virulent H. pylori strains. Significant  associations of CagA-positive H. pylori strains with coronary artery disorders have been widely reported. H. pylori is also known to produce different heat shock proteins (HSPs) which can stimulate the production of specific  antibody against microbial proteins and capable of eliciting autoimmune reaction against human tissue expressing HSPs such as vascular  endothelial cells. The objectives of this study are to investigate the  association between H. pylori and CagA with coronary atherosclerosis and CAD, and to determine the possible role of H. pylori HSP60 protein in increasing the risk of CAD development. Methods: This study included 70 patients with stable angina and 70 age and gender-matched controls. Each group was evaluated by clinical history, physical examination, cardiac echocardiography (ECHO) and electrocardiography (ECG) with and without exercise. Fasting blood glucose, total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL) and triglycerides (TG) were estimated by automated enzymatic methods. H. pylori IgG, CagA IgG and HSP60 IgG were measured by enzyme-linked immunosorbent assay (ELISA) for both groups. Results: The seroprevalence of H. pylori infection was high in both groups; 75.7% in case and 68.6% in control (p=0.346). Serum IgG levels were significantly higher for CagA (p=0.028) and HSP60 (p<0.001) in cases than in controls. There was significant association between H. pylori and CagA IgGs in cases (p=0.007) but no association in controls (p=0.700). Higher HSP60 IgG level was significantly associated with both positive H. pylori IgG (p<0.001) and CagA IgG (p<0.001) in cases but no significant association was found with H. pylori (p=0.815) or CagA (p=0.332) IgG levels in the control group. Serum values were significantly higher for TC (p<0.001), TG (p<0.001) and LDL (p=0.004) while value for HDL was significantly lower (p<0.001) in H. pylori IgG-positive subjects (case and control). Conclusion: There is serological evidence that H. pylori infection may pose a significant risk factor for CAD. Since H. pylori can be eliminated by specific treatment, this may be a good preventive approach for CAD.Key words: H. pylori, coronary artery disease, CagA, HSP60, serology

Assessment of left ventricular recovery in Tako-Tsubo cardiomyopathy using 2D strain echocardiography

Contre la désertification De la convention internationale à l'élaboration participative des programmes d'action nationaux Comme toutes les conventions internationales, la convention sur la désertification est un texte consensuel qui n'indique pas de façon explicite comment mettre en oeuvre toutes ses dispositions. Pourtant, chaque pays affecté est tenu d'élaborer et d'appliquer des programmes d'action nationaux qui doivent être appliqués par les acteurs les plus concernés, les communautés locales. Cet ouvrage propose une démarche pour l'élaboration participative de ces programmes d'action. Il est la synthèse des résultats et des recommandations de la Conférence sous-régionale de vulgarisation de la Convention de lutte contre la désertification et de mise en oeuvre du Plan d'action du RIOD (Réseau international des ONG sur la désertification) en mai 1996. Cette conférence s'inscrivait dans une série de quatre rencontres sous-régionales préconisées afin de faire connaître la convention à un plus grand nombre d'acteurs. Masse Lo - Yacine Diagne - Emmanuel Seck - Série Etudes et recherches n° 190-191 ISBN : 92-9130-0187 - Enda-Editions - Boîte Postale 3370 - Dakar - SENEGAL Tél.: (221) 22-42-29 Télécopie : (221) 23-51-57 E-mail : [email protected]. Prix : 100 FF frais de port inclus pour les pays du Nord - 2 000 FCFA (frais de port : 800 FCFA) pour les pays du SudDe la convention international

Investigating the residual effect of silver nanoparticles gel as an intra-canal medicament on dental pulp stromal cells

Background The aim of this study was to evaluate the indirect effects of residual silver nanoparticles (AgNPs) gel on human dental pulp stromal cells (DPSCs). Methods Ninety-five dentin discs (4x4x1 mm) were prepared from freshly extracted human single-rooted teeth following institutional ethical approval and informed consent. Samples were cleaned, autoclaved, and treated with: 1.5%NaOCl, Saline and 17% EDTA then randomly assigned to 5 groups that received 50 μl of one of the following treatments: 0.01%AgNPs, 0.015%AgNPs, 0.02%AgNPs, Calcium hydroxide (Ca (OH)2) or no treatment for 1 week. Discs were washed with Saline and 17%EDTA then seeded with DPSCs and incubated for 3 and 7 days. At 24 hours unattached cells were collected and counted. At each time point cytotoxicity (LDH assay), cell viability (live/dead staining and confocal microscopy) and cell proliferation (WST1 assay) were assessed. All experiments were repeated a minimum of 3 times using DPSCs isolated from 3 different donors for each time point assessed (n = 9/group). Statistical analysis was done using One-Way ANOVA followed by Tukey’s test and Kruskal Wallis followed by post-hoc comparisons with significance set at p ≤ 0.05. Results After 24 hours, the percentage of DPSCs attachment ranged between 92.66% ±4.54 and 95.08% ±1.44 with no significant difference between groups (P = 0.126). Cell viability was ≥92% at 24 hours for all groups. However this percentage dropped to less than 60% at 3 days then started to rise again at 7 days. There was no significant difference in cytotoxicity between different groups at all time points except for 0.01%AgNPs group which had the highest cytotoxicity. DPSCs proliferation increased significantly from 3 to 7 days in all groups except for Ca (OH)2 which showed lower proliferation rates at both 3 (45.89%) and 7 days (79.25%). Conclusion Dentin discs treated for 7 days with concentrations of AgNPs gel (0.01–0.02%) allowed more than 90% DPSCs cell attachment after 24 hours. The cytotoxicity and proliferation of DPSCs in response to AgNPs gel were comparable to those with calcium hydroxide. This suggests that AgNPs gel may represent a promising future candidate for clinical use in regenerative endodontics. However, its effects may be concentration-dependent warranting further investigation

Economical Experiments: Bayesian Efficient Experimental Design

We propose and implement a Bayesian optimal design procedure. Our procedure takes as its primitives a class of models, a class of experimental designs, and priors on the nuisance parameters of those models. We select the experimental design that maximizes the information (in the sense of Kullback-Liebler) from the experiment. We sequentially sample with the given design and models until all but one of the models has viable posterior odds. A model which has low posterior odds in a small collection of models will have an even lower posterior odds when compared to a larger class, and hence we can dismiss it. The procedure can be used sequentially by introducing new models and comparing them to the models that survived earlier rounds of experiments. The emphasis is not on running as many experiments as possible, but rather on choosing experimental designs to distinguish between models in the shortest possible time period. The first stage of optimal design is illustrated with a simple experimental game with one-sided incomplete information

Antiviral activity of chitosan nanoparticles for controlling plant-infecting viruses

Chitosan nanoparticles (ChiNPs) are a potentially effective means for controlling numerous plant diseases. This study firstly describes the antiviral capabilities of ChiNPs to control plant viral diseases compared to its bulk form. Bean yellow mosaic virus (BYMV) was used as a model plant virus affecting faba bean plants and many other legumes. The antiviral effectiveness of ChiNPs and chitosan were evaluated as a curative application method, using six dosage rates (50, 100, 200, 250, 300 and 400 mg/L). Results indicated that ChiNPs curatively applied 48 h post virus inoculation entirely inhibit the disease infectivity and viral accumulation content at 300 mg/L and 400 mg/L. The virus titre was greatly alleviated within the plant tissues by 7.71% up to100% depending on ChiNP dosage rates. However, chitosan used in its bulk-based material form revealed a relatively low to an intermediate reduction in virus infectivity by 6.67% up to 48.86%. Interestingly, ChiNPs affect the virus particle’s integrity by producing defective and incomplete BYMV viral particles, defeating their replication and accumulation content within the plant tissues. Simultaneously, ChiNP applications were appreciably shown to promote the pathogenesis-related (PR-1) gene and other defence-related factors. The mRNA of the PR-1 gene was markedly accumulated in treated plants, reaching its maximum at 400 mg/L with 16.22-fold relative expression change over the untreated control. Further, the total phenol dynamic curve was remarkably promoted for 30 days in response to ChiNP application, as compared to the untreated control. Our results provide the first report that chitosan-based nanomaterials have a superior effect in controlling plant viruses as an antiviral curing agent, suggesting that they may feasibly be involved in viral disease management strategies under field conditions without serious health concerns and environmental costs. Significance: • Our findings show that chitosan nanoparticles have a powerful curing antiviral activity against BYMV disease. These findings open the door for the use of eco-friendly nano-based tools in controlling numerous plant viruses. The use of eco-friendly nano-based materials could result in a successful integrative control strategy for plant viruses under field conditions, negating the need for the conventional measure used to control most of the insect-transmitted plant viruses, that is insecticide application against vector insects

Vertigo: Comparing Structural Models of Imperfect Behavior in Experimental Games

This paper investigates learning in games with one-sided incomplete information using laboratory data from a game which we call the game of Vertigo. The predicted Bayes-Nash equilibrium behavior of the agents in this type of game generates overly strong restrictions on the data, including the zero likelihood problem: certain actions should never be observed. To circumvent statistical problems, and to allow for deviations from perfectly rational behavior, we introduce the possibility of players making errors when choosing their actions. We compare two competing models depending on whether players take the errors in actions into consideration when formulating their strategies. We also investigate possible deviations from Bayes's rule, producing too fast or too slow an updating rule. In total, we get six models of sophisticated and unsophisticated strategy formation on the first dimension, and fast, slow, or no updating on the second. We apply a fully Bayesian structural econometric approach to compare the statistical performance of these six models, and to obtain posterior estimates of several nuisance parameters governing the errors in actions. The two models where players are unsophisticated and either use no updating at all, or use dampened updating, have a much higher likelihood than any of the others