Ambiguity aversion as a route to randomness in a duopoly game

The global dynamics is investigated for a duopoly game where the perfect foresight hypothesis is relaxed and firms are worst-case maximizers. Overlooking the degree of product substitutability as well as the sensitivity of price to quantity, the unique and globally stable Cournot-Nash equilibrium of the complete-information duopoly game, loses stability when firms are not aware if they are playing a duopoly game, as it is, or an oligopoly game with more than two competitors. This finding resembles Theocharis' condition for the stability of the Cournot-Nash equilibrium in oligopolies without uncertainty. As opposed to complete-information oligopoly games, coexisting attractors, disconnected basins of attractions and chaotic dynamics emerge when the Cournot-Nash equilibrium loses stability. This difference in the global dynamics is due to the nonlinearities introduced by the worst-case approach to uncertainty, which mirror in bimodal best-reply functions. Conducted with techniques that require a symmetric setting of the game, the investigation of the dynamics reveals that a chaotic regime prevents firms from being ambiguity averse, that is, firms are worst-case maximizers only in the quantity-expectation space. Therefore, chaotic dynamics are the result and at the same time the source of profit uncertainty

Magnetoelectric composite bilayer film by electrophoretic deposition

In the recent years the interest of the research community towards multiferroic composite materials was growing fast [1,2]. A number of papers relates to bulk materials while less attention is focused on films. Electrophoretic deposition (EPD) was applied to prepare magnetoelectric (ME) composite bilayer thick films based on perovskite phase and spinel cobalt ferrite as some of the best piezoelectric and magnetostrictive oxides belong these crystal groups. The co-deposition of titanium oxide (TO) and cobalt ferrite (CFO) nanoparticles and the deposition of niobium-doped lead titanate zirconate (PZTN) were made from colloidal suspensions in ethanol keeping constant voltage and recording the current. Good adhesion and compaction of the green film were achieved by optimization of deposition voltage and time while high density of the film and minimized interphase reactions occurred after sintering. The deposited volume, the mixing of dielectric and magnetic phases and the density and ordering of the films have been verified by electron scanning microscopy after heat treatment. No reactions between the different phases was found. The piezoelectric properties were measured on the sintered films. [1] N.A. Spaldin, M. Fiebig, Science 309 (2005) 391. [2] R. Ramesh, N.A. Spaldin, Nat. Mater. 6 (2007) 21

Effects of Starter Cultures and Type of Casings on the Microbial Features and Volatile Profile of Fermented Sausages

In the literature, the effect of the type of casing on fermented sausages is quite unexplored, while several studies are focused on the impact of starter cultures. Therefore, this paper studied the effect of three commercial starter cultures and two casings (natural or collagen) on Italian fermented sausages. Physico-chemical parameters (aw, pH, weight loss), microbiota, aroma profile and sensory analysis were evaluated. Results showed that collagen casings promoted a higher reduction of pH and weight loss. Concerning the microbiota, samples with natural casing had higher counts of lactic acid bacteria, while yeast proliferation was promoted in those with collagen. Regardless of the starters and casings applied, levels of enterococci and Enterobacteriaceae were low (≤2 log CFU/g). The aroma profile was significantly affected by casing: despite the starter applied, the presence of collagen casing favoured acid accumulation (mainly acetate and butanoate) and reduction of ketones. Sensory analysis highlighted significant differences only for odour, colour intensity and sourness. The differences observed suggest that collagen casings may provide a greater availability of oxygen. Overall, casings rather than starter cultures impact the microbial and sensorial features of fermented sausages

Structure analysis of cobalt ferrite/titania-silica composite

Magnetodielectric bulk composite of a magnetic phase in dielectric matrix have been studied. Silica coated titania powder was produced by elctrocoagulation and used as dielectric matrix; while the cobalt ferrite powder was selected as magnetic filler. This study aims at tailoring the magnetic and dielectric phases and their interfaces in order to obtain new electromagnetic properties. The microstructure of sintered titaniasilica/cobalt ferrite composites has been related to compositional modifications in terms of silica/titania weight ratio and titania-silica/cobalt ferrite volume ratio. The crystalline structure was studied by XRD analysis supported also by EDS investigationand image analysis performed on the electron micrographs. The image analysis supported the XRD and EDS interpretations, and contributed to evaluate the effective volume contentof the phases after heat treatment

Magnetoelectric composite bilayer films by electrophoretic deposition

In the recent years the interest of the research community towards multiferroic composite materials was growing fast [1,2]. A number of papers relates to bulk materials while less attention is focused on films. Electrophoretic deposition (EPD) was applied to prepare magnetoelectric (ME) composite bilayer thick films based on piezoelectric phases and cobalt ferrite. The deposition/co-depositionwere made from colloidal suspensions in ethanolkeeping constant voltage and recording the current. Good adhesion and compaction of the green film were achieved by optimization of deposition voltage and time while high density of the film and minimized interphase reactions occurred after sintering. The chemical activity between the two layers was controlled through the batches composition and it could lead to the synthesis of complex engineered structures.The deposited volume, the mixing of dielectric and magnetic phases and the density and ordering of the films have been verified by electron scanning microscopy after heat treatment. The piezoelectric properties were measured on the sintered films. [1] N.A. Spaldin, M. Fiebig, Science 309 (2005) 391. [2] R. Ramesh, N.A. Spaldin, Nat. Mater. 6 (2007) 21

Reconstruction of the Terminal of an Abandoned Fractured Unipolar Coronary Sinus Lead: a Feasible Solution to Restore Effective Cardiac Resynchronization Therapy

AbstractComplications related to coronary sinus lead are not infrequent in recipients of cardiac resynchronization devices. We describe the case of a patient with a biventricular implantable cardioverter defibrillator with persistent phrenic nerve stimulation, previous coronary sinus lead fracture, and severe left subclavian vein stenosis. The reimplantation of a new coronary sinus lead on the left side, ipsilateral to the original implant, was unsuccessful. In order to avoid more complex and risky procedures, we performed the repair of the fractured abandoned lead with the reconstruction of the unipolar lead terminal. Effective biventricular pacing was obtained with satisfactory electrical parameters and it was maintained at twelve months follow-up

Predicting the initial rate of water absorption in clay bricks

The effect of product characteristics and processing conditions on the initial rate of water absorption of fifteen clay bricks was investigated and the influence of porosimetric parameters (amount, size and tortuosity of pores) as well as of phase composition (amount of calcium-silicates and amorphous phase) was established. The suction behaviour of bricks, which may be brought back to the models of Gummerson et al. (1981) and Hoffman and Niesel (1988), was also evaluated on the basis of both the product microstructure and the liquid physical properties. According to the model of Beltran et al. (1988), which reveled to be sufficiently reliable, the values of the capillary coefficient Ks were calculated and their correlation with the experimental ones has been provided. For a given liquid and in the same experimental conditions, the results indicate that varying in a controlled way the product microstructure (i.e. decreasing the pore size, increasing the pore tortuosity and/or controlling the amorphous/new formed phases ratio) should allow to design materials having a most suitable behaviour

Simple ions control the elasticity of calcite gels via interparticle forces

Suspensions of calcite in water are employed in many industrial fields such as paper filling, pharmaceutics, heritage conservation or building construction, where the rheological properties of the paste need to be controlled. We measure the impact of simple ions such as calcium, sodium or hydroxide on the elasticity of a nanocalcite paste, which behaves as a colloidal gel. We confront our macroscopic measurements to DLVO interaction potentials, based on chemical speciations and measurements of the zeta potential. By changing the ion type and concentration, we go beyond the small repulsion regime and span two orders of magnitude in shear modulus. Upon addition of calcium hydroxide, we observe a minimum in shear modulus, correlated to a maximum in the DLVO energy barrier, due to two competing effects: Calcium adsorption onto calcite surface rises the zeta potential and consequently the electrostatic repulsion, while increasing salt concentration induces stronger electrostatic screening. We also demonstrate that the addition of sodium hydroxide completely screens the surface charge and leads to a more rigid paste. A second important result is that carbonation of the calcite suspensions by the atmospheric CO 2 leads to a convergent high elasticity of the colloidal gels, whatever their initial value, also well rationalized by DLVO theory and resulting from a decrease in zeta potential and in surface charge density

Survival, growth, and biogenic amine production of Enterococcus faecium FC12 in response to extracts and essential oils of Rubus fruticosus and Juniperus oxycedrus

Enterococci are lactic acid bacteria (LAB) usually found as food contaminants in fermented products such as cheeses and fermented sausages. Due to their antibiotic resistance, the presence of virulence factors, and the ability to produce biogenic amines (BAs), the determination of these bacteria is crucial to assure food quality and safety. BAs production and consequent accumulation in foods can cause toxicological eects on human health. Plant phenolic compounds are promising alternatives to chemical preservatives and reflect consumers’ demand for “green” solutions. In this study, the antimicrobial eect of blackberry (Rubus fruticosus) leaves and prickly juniper (Juniperus oxycedrus) needles, both as phenolic extracts (PE) and essential oils (EO), were evaluated against Enterococcus faecium FC12, a known tyramine-producing strai