780 research outputs found
Fictitious Play: A Statistical Study of Multiple Economic Experiments
This paper illustrates the use of a full Bayesian procedure to update an experimenter's belief over various economic behavioral hypotheses using data from a variety of (potentially very different) experiments. Our example uses experimental data to update our belief as to whether individuals select strategies according to fictitious play. We endow the experimenter with priors over the events that players act according to fictitious play and according to the Cournot process. We then numerically compute the likelihood function for each experiment by replicating the experimental design and running the experiment with robots that behave according to each of our hypotheses. Updating experiment by experiment shows that some of the experiments favor Cournot, but most of them favor fictitious play as the more likely hypothesis. This illustrates the limitations of a classical procedure that can take only one experiment into consideration since some of the experiments may be misleading. Indeed, when we did the overall updating using 9 experiments, we found that, for any priors, the overall posterior put probability very close to one on the individuals acting according to fictitious play. Given the heterogeneity in the payoffs and design of the experiments that we combine for that overall posterior, it is clear that there is no classical procedure that would offer the same type of information
Modification of bacterial cell membrane to accelerate decolorization of textile wastewater effluent using microbial fuel cells: role of gamma radiation
The aim of the present work was to increase bacterial adhesion on anode via inducing membrane modifications to enhance textile wastewater treatment in Microbial Fuel Cell (MFC). Real textile wastewater was used in mediator-less MFCs for bacterial enrichment. The enriched bacteria were pre-treated by exposure to 1 KGy gamma radiation and were tested in MFC setup. Bacterial cell membrane permeability and cell membrane charges were measured using noninvasive dielectric spectroscopy measurements. The results show that pre-treatment using gamma radiation resulted in biofilm formation and increased cell permeability and exopolysaccharide production; this was reflected in both MFC performance (average voltage 554.67 mV) and decolorization (96.42%) as compared to 392.77 mV and 60.76% decolorization for non-treated cells. At the end of MFC operation, cytotoxicity test was performed for treated wastewater using a dermal cell line, the results obtained show a decrease in toxicity from 24.8 to 0 (v/v%) when cells were exposed to gamma radiation. Fourier-transform infrared (FTIR) spectroscopy showed an increase in exopolysaccharides in bacterial consortium exposed to increasing doses of gamma radiation suggesting that gamma radiation increased exopolysaccharide production, providing transient media for electron transfer and contributing to accelerating MFC performance. Modification of bacterial membrane prior to MFC operation can be considered highly effective as a pre-treatment tool that accelerates MFC performance
Long-term changes and community structure of macrobenthic Arthropoda and mollusca in Bardawill lagoon
EnLagoons are among the most productive aquatic ecosystems which for thousands of years have been exploited by man. Bardawil Lagoon is a small, hyper saline lagoon in an arid area located in the middle of Sinai’s Mediterranean coast. Long-term changes,community structure, biodiversity, biomass and abundance of Arthropoda and Mollusca were studied. Orchestia gammarella, Chironomidae larvae and Balanus perfera were recorded as dominant taxa within 15 identified Arthropoda species. The western area of the lagoon maintained the highest standing crop as a result of the flourishing of Chironomidae larvae. Arthropoda are weakly represented in the middle and eastern areas. The standing crop of the total Arthropoda shows an obvious increase from 253 and 298 indiv.m-2 during 1984 and 1986 to 711 indiv.m-2 during the present study.Branchiodonta variabilis was the dominant of 9 molluscan species. Spatially there was a tendency towards a decrease in abundance westwards. The population density of Mollusca had highly reduced from 1028 indiv.m-2 in 1984 to 671 indiv.m-2 during the present study.The present study shows that Arthropoda and Mollusca assemblages undergo dramatic changes. There is no sign of presence of 20 previously listed species in the lagoon.On the other hand, 9 species have been recorded for the first time
Fictitious Play: A Statistical Study of Multiple Economic Experiments
This paper illustrates the use of a full Bayesian procedure to update an experimenter's belief over various economic behavioral hypotheses using data from a variety of (potentially very different) experiments. Our example uses experimental data to update our belief as to whether individuals select strategies according to fictitious play. We endow the experimenter with priors over the events that players act according to fictitious play and according to the Cournot process. We then numerically compute the likelihood function for each experiment by replicating the experimental design and running the experiment with robots that behave according to each of our hypotheses. Updating experiment by experiment shows that some of the experiments favor Cournot, but most of them favor fictitious play as the more likely hypothesis. This illustrates the limitations of a classical procedure that can take only one experiment into consideration since some of the experiments may be misleading. Indeed, when we did the overall updating using 9 experiments, we found that, for any priors, the overall posterior put probability very close to one on the individuals acting according to fictitious play. Given the heterogeneity in the payoffs and design of the experiments that we combine for that overall posterior, it is clear that there is no classical procedure that would offer the same type of information
The effect of serum angiotensin II and angiotensin II type 1 receptor gene polymorphism on pediatric lupus nephritis
Background: Angiotensin II (Ang II) is found to perpetuate inflammation and visceral damage in systemic lupus erythematosus (SLE). It mediates most of its actions through Ang II receptor type I (AT1) whose gene polymorphism A1166C (CC genotype) seems to have pathogenic effects. Objective: To measure serum Ang II and the frequency of AT1 receptor CC genotype among a group of Egyptian patients with pediatric onset lupus nephritis (pLN). Methods: This is a case-control cross sectional study which included 24 patients with pLN and 24 age and sex-matched healthy subjects as controls. Clinical evaluation and routine laboratory markers for SLE patients were done. SLE disease activity index (SLEDAI) and the British Isles Lupus Assessment Group (BILAG)-2004 renal score were measured. Serum Ang II was measured by enzyme linked immunosorbent assay and detection of ATI receptor CC genotype by polymerase chain reaction were done for both patients and controls. Results: Patients had significantly higher serum Ang II than the controls (p=0.0001). The frequency of AT1 receptor CC genotype was significantly higher among patients as compared to the control group (p=0.008). Both serum Ang II and AT1 receptor CC genotype were comparable between patients with proliferative LN class III and IV and those with LN class II (p>0.05). Serum Ang II did not correlate significantly with SLEDAI or BILAG-renal score (p>0.05). Conclusion: Serum Ang II and AT1 receptor CC genotype seem to have pathogenic role in pLN but with no deleterious effects on the phenotype of LN for further assessment.Keywords: Lupus nephritis; Angiotensin II; Angiotensin II type 1 receptor; Polymorphism; Pediatrics
Impact of maternal gestational diabetes on neutrophil functions of full term neonates
Background: Maternal gestational diabetes is associated with an inflammatory environment that may contribute to fetal and placental inflammatory profile changes. Few studies investigated the effect of maternal gestational diabetes on neonatal innate immunity.Objectives: Our objective was to study neutrophil number and function in neonates born to mothers with gestational diabetes.Methods: Neutrophil number (complete blood count) and functions [CD11b, CD62L and Dihydrorhodamine 123 (DHR) by flow cytometry] were assessed in the cord blood of 30 full term neonates born to gestational diabetic mothers on insulin during pregnancy and another 15 born to healthy mothers as controls.Results: The mean total leucocytic and absolute neutrophil count were significantly lower in neonates of diabetics than in normal neonates (13.55± 2.51 and 17.89± 3.66 p> 0.001; 9.01±1.59 and 14.18±3.44 p>0.001 respectively). Mean CD11b, CD62L and DHR were lower among neonates of diabetic mothers than normal neonates (82.48± 8.09 & 87.85± 4.87 p < 0.05; 8.63±4.41 and 24.98±10.47 p <0.001; 68.71± 10.24 and 79.57±8.64 p< 0.001 respectively). Unlike the control neonates, neonates of gestational diabetic mothers had positive correlation between the functional neutrophil parameters (r0.39 p<0.05).Conclusion: Gestational diabetes affects cord blood neutrophil count and functions leading to high susceptibility to infection.Keywords: Gestational, diabetes mellitus, neutrophil
Neutrophil functions in late preterm neonates with respiratory distress syndrome
Background: Studies that have addressed the effects of respiratory distress syndrome (RDS) on neutrophil function suggested that neutrophil functions other than the generation of the respiratory burst are not impaired. Yet, results have been confusing and in some cases contradictory.Objectives: The aim of this cross-sectional controlled study is to assess neutrophil number and function in late preterm neonates with RDS.Methods: Thirty patients underwent clinical and laboratory evaluation including complete blood counts and tests of neutrophil functions (CD11b, CD62L and Dihydrorhodamine 123 by flowcytometry) in comparison to 15 healthy term controls. RDS was assessed clinically and radiologically (chest x-ray).Results: Fifty percent of patients (12 females and 18 males) had grade II respiratory distress followed by grade III then grade I. DHR, CD 11b and CD62L results were lower among the patients group (mean ± SD: 62.1± 12.23, 63.22 ± 11.41, 15.03 ± 8.7 respectively). There were no significant correlations between neutrophils count, DHR, CD11b and CD62L. Only CD11b was significantly lower with higher grades of RDS.Conclusion: Neonates with RDS show variable affection of neutrophil functions. Further studies are recommended to elucidate the exact mechanisms by which RDS can affect neutrophil functions and whether these effects are associated with increased incidence of infections.Keywords: Neutrophils, function, respiratory distress syndrome, late preterm, innate immunity, infections, adhesion molecule
Influence of Different Decontamination Approaches on Bone Substitute Adhesion to Peri-Implantitis Affected Implant Surfaces: An SEM Proof of Principle Study
Background: During healing, clot blended graft materials may retract away from implant surfaces creating microgaps that compromise re-osseointegration. The present study aimed to evaluate different surface decontamination materials’ effect on adhesion of the graft materials to peri-implantitis affected parts, a factor that can resist clot blended graft retraction improving re-osseointegration. Methods: Eighteen peri-implantitis affected implants diagnosed as hopeless and designated for removal contributed in this prospective, masked trial. Samples were randomly distributed into three groups, each of six implants. Group one (G1) was coated with hydroxyapatite of a micro particle size of 250 to 1000 µm after saline surface decontamination for two minutes. Group two (G2) peri-implantitis affected parts were treated with the graft material following two minutes of chlorhexidine gluconate 0.12% (CHX) surface treatment. Group three (G3) implants were coated with the graft material after citric acid (CA) (pH = 1) surface conditioning for two minutes. Implants in all groups were agitated in phosphate-buffered saline (PBS) by using an automatic tissue processor agitator for three minutes. Implants were prepared for surface scanning evaluation. Results: Scanning electron microscopy (SEM) observation of G1 saline treated control implants were devoid of bone particles adherent to peri-implantitis affected surfaces. The surface area covered by grafted particles in G2 was statistically higher than that of G1 (P<0.01). Group three (CA-treated) showed nearly complete coverage of peri-implantitis affected parts by the graft material covering 88.8% of examined surface areas which was statistically higher than that of G2 (P<0.05). Conclusion: Citric acid implant surface conditioning could improve implant re-osseointegration through enhancement of the graft adhesion to the implant surface. Smear layer barrier effect seemed to be the most important factor that compromised graft adhesion to preri-implantitis affected parts of the implant surfaces
Typical behavior of relays in communication channels
The typical behavior of the relay-without-delay channel under low-density parity-check coding and its multiple-unit generalization, termed the relay array, is studied using methods of statistical mechanics. A demodulate-and- forward strategy is analytically solved using the replica symmetric ansatz which is exact in the system studied at Nishimori's temperature. In particular, the typical level of improvement in communication performance by relaying messages is shown in the case of a small and a large number of relay units. © 2007 The American Physical Society
Amelioration of The Dielectric Properties of Ceramic Insulators Using Nano-alumina
Outdoor HV porcelain insulators face various environmental stresses that cause their degradation. Consequently, amelioration of their insulating properties becomes a target of recent researches to survive higher voltage levels. Investigating the impact of the addition of 0, 5, 10, and 15 wt. % nano- alumina (NA) on the dielectric and physical characteristics of porcelain materials at elevated sintering temperatures is the aim of this study. Porcelain specimens were synthesized from kaolin, feldspar, and quartz as available low-cost raw materials. The specimens were sintered at 1100, 1200, 1300, and 1400°C for 2 h. For some specimens, the microstructure and phases formed were identified using scanning electron microscopy and X-ray diffraction techniques. The changes that occur upon heating (include melting, phase transition, sublimation, and decomposition) were identified by Differential Thermogravimetric Analysis. The dielectric strength, relative permittivity, and loss tangent of different samples were measured at a large scale of frequencies. Breakdown strength values of different samples were verified by applying the Finite Element Method. The best electrical and physical properties were achieved at 1300ºC. At this temperature the porcelain sample containing 5 wt. % NA presented optimum physical characteristics as well as good insulating properties assent the feasibility of producing electro-technical porcelai
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