Optimal Control Problems Arising In Marketing Models

The diffusion in time of a new product in a monopolistic or oligopolistic market can be described by a system of evolution equations (PDE, ODE, DDE) containing one or more control parameters (advertising, prices, plant locations, ...). The productors choose the control parameters in order to maximize their (discounted) prots. Hence an optimal control problems (in the case of a monopoly) or a dynamic game (in the case of an oligopoly) has to be solved. A specic model is proposed and an exhaustive description of its solution is given.

Optimal marketing decision in a duopoly: a stochastic approach

Let us consider two new perfect substitute durable products which are produced and sold in a market by two competing firms. Looking at a potential buyer, we build a stochastic rule by which she purchases the good from one of the two firms (so that she becomes an adopter). The model is considered discrete in time and space. The probability of transition from the non adopter state to the adopter one depends on an imitation mechanism (word-ofmouth) as well as on the pricing and advertising policies of the producers/sellers. It is assumed that only actual information about the market determine the evolution in the subsequent time step so that a Markov process arises. Both firms maximize their expected discounted profits by choosing optimal marketing strategies. Suitable equilibria are characterized and, because of the lack of convexity in the model, the simulated annealing algorithm is proposed to compute them.

Co-selection of antibiotic and heavy metal resistance in freshwater bacteria

Antibiotic resistant bacteria are found in most environments, especially in highly anthropized waters. A direct correlation between human activities (e.g., pollution) and spread and persistence of antibiotic resistant bacteria (ARB) and resistance genes (ARGs) within the resident bacterial communities appears more and more obvious. Furthermore, the threat posed for human health by the presence of ARB and ARGs in these environments is enhanced by the risk of horizontal gene transfer of resistance genes to human pathogens. Although the knowledge on the spread of antibiotic resistances in waters is increasing, the understanding of the driving factors determining the selection for antibiotic resistance in the environment is still scarce. Antibiotic pollution is generally coupled with contamination by heavy metals (HMs) and other chemicals, which can also promote the development of resistance mechanisms, often through co-selecting for multiple resistances. The co-selection of heavy metal resistance genes and ARGs in waters, sediments, and soils, increases the complexity of the ecological role of ARGs, and reduces the effectiveness of control actions. In this mini-review we present the state-of-the-art of the research on antibiotic- and HM-resistance and their connection in the environment, with a focus on HM pollution and aquatic environments. We review the spread and the persistence of HMs and/or ARB, and how it influences their respective gene co-selection. In the last chapter, we propose Lake Orta, a system characterized by an intensive HM pollution followed by a successful restoration of the chemistry of the water column, as a study-site to evaluate the spread and selection of HMs and antibiotic resistances in heavily disturbed environments

Coinfection by Ureaplasma spp., Photobacterium damselae and an Actinomyces-like microorganism in a bottlenose dolphin (Tursiops truncatus) with pleuropneumonia stranded along the Adriatic coast of Italy

A case of pleuropneumonia is reported in an adult male bottlenose dolphin (Tursiops truncatus) found stranded in 2014 along the Central Adriatic coast of Italy. A severe pyogranulomatous pneumonia and thoracic lymphadenopathy were present at necropsy. Numerous Splendore-Hoeppli bodies were found microscopically scattered throughout the lung. Histochemical evidence of Actinomyces-like organisms was obtained from the pulmonary parenchyma, with a strain of Photobacterium damselae subsp. piscicida and Ureaplasma spp. being also isolated from the same tissue. For the latter, a genome fragment of approximately 1400 bp from the 16s rDNA was amplified and sequenced. BLAST analysis revealed 100% identity with an uncultured Ureaplasma spp. (JQ193826.1)

Theoretical and Numerical Study on Buongiorno’s Model with a Couette Flow of a Nanofluid in a Channel with an Embedded Cavity

In the present paper, the fluid flow and heat transfer of a nanofluid are numerically investigated. More specifically, reference is made to a nanofluid, described by means of Buongiorno’s model, subjected to Couette flow. The considered domain consists of a channel that displays a cavity shortly after the inlet section. The transport model for the nanofluid, that is the mass conservation, momentum, and nanoparticles equation, is written in a dimensionless form and solved by employing the software package Comsol Multiphysics. Many ideas emerged from this work: the visualization of the velocity stream function, the dimensionless temperature, and nanoparticle concentration fields are provided, as a function of the governing parameters: Reynolds, Peclet, Lewis, Brownian diffusivity number, and thermophoretic diffusivity number. Concerning the nanofluid typical effects, the thermophoretic diffusion seems to affect the solution much more than the Brownian diffusion. The Nusselt number on the upper wall is calculated as well, and the results show that it proves to be, in most of the considered cases, an increasing function of the Reynolds number. Moreover, concerning the Nusselt number, the Brownian diffusion effects are shown to be negligible

The meiofauna as neglected carriers of antibiotic resistant and pathogenic bacteria in freshwater ecosystems

The World Health Organization considers antibiotic resistance as one of the main threats to human and other animals? health. Despite the measures used to limit the spread of antibiotic resistance, the efforts made are not enough to tackle this problem. Thus, it has becomeimportant to understand how bacteria acquire and transmit antibiotic resistant genes (ARGs), in particular in the environment, giventhe close connection between the latter and human and animal health, as defined by the One-Healthconcept. Aquatic ecosystems areoften strongly impacted by anthropogenic activities, making them a source for ARGs and antibiotic resistant bacteria (ARB). Althoughfreshwater meiofauna have been the object of active research, few studies have focused on the relationship between the spread of an-tibiotic resistance and these organisms. In this review, we investigated freshwatermeiofaunaas carriers of resistances since they playa central role in the aquatic environments and can harbor human and animal potential pathogens. We assessed if these animals couldcontribute to the spread of ARGs and of potentially pathogenic bacteria. Only four taxa (Rotifera, Chironomidae, Cladocera, Copepoda)were found to be the subject of studies focused on antibiotic resistance. The studies we analyzed, although with some limitations,demonstrated that ARGs and ARB can be found in these animals, and several of them showed the presence of potentially pathogenicbacteria for humans and animals within their microbiome. Thus, meiofauna can be considered a source and a reservoir, even if neglected,of ARGs and ARB for the freshwater environments.However, further studies are needed to evaluate the impact of the meiofauna on thespread and persistence of antibiotic resistance in these ecosystems.Fil: Sathicq, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; Argentina. Consiglio Nazionale delle Ricerche; ItaliaFil: Sbaffi, Tomasa. Consiglio Nazionale delle Ricerche; ItaliaFil: Borgomaneiro, Giulia. Consiglio Nazionale delle Ricerche; ItaliaFil: Di Cesare, Andrea. Consiglio Nazionale delle Ricerche; ItaliaFil: Sabatino, Raffaella. Consiglio Nazionale delle Ricerche; Itali

Financial sector pro-cyclicality: lessons from the crisis

We analyze the main forces affecting financial system pro-cyclicality (the fact that developments in the financial sector can amplify business cycle fluctuations). We first review some major structural developments in financial markets that may influence pro-cyclicality and that have been overlooked in earlier analyses. We then examine three issues that are center stage in the current debate: capital regulation, accounting standards and managers’ incentives. After reviewing the institutional set-up and the key mechanisms at work, we critically examine a series of proposals designed to mitigate pro-cyclicality.pro-cyclicality, financial accelerator, capital requirements, leverage, accounting standards, incentives

Bacteriophages limitedly contribute to the antimicrobial resistome of microbial communities in wastewater treatment plants

Bacteriophages are known as players in the transmission of antimicrobial resistance genes (ARGs) by horizontal gene transfer. In this study, we characterized the bacteriophage community and the associated ARGs to estimate the potential for phages to spread ARGs in aquatic ecosystems analyzing the intra- and extracellular DNA isolated from two wastewater treatment plants (WWTPs) by shotgun metagenomics. We compared the phage antimicrobial resistome with the bacterial resistome and investigated the effect of the final disinfection treatment on the phage community and its resistome. Phage community was mainly composed by Siphoviridae and other members of the order Caudovirales. The final disinfection only marginally affected the composition of the phage community, and it was not possible to measure its effect on the antimicrobial resistome. Indeed, only three phage metagenome-assembled genomes (pMAGs) annotated as Siphoviridae, Padoviridae, and Myoviridae were positive for putative ARGs. Among the detected ARGs, i.e., dfrB6, rpoB mutants, and EF-Tu mutants, the first one was not annotated in the bacterial MAGs. Overall, these results demonstrate that bacteriophages limitedly contribute to the whole antimicrobial resistome. However, in order to obtain a comprehensive understanding of the antimicrobial resistome within a microbial community, the role of bacteriophages needs to be investigated

Presenza e distribuzione di batteri antibiotico-resistenti nelle acque del Lago Maggiore

Not availableRicerche sull\u27evoluzione del Lago Maggiore. Aspetti limnologici. Programma triennale 2013-2015. Campagna 2013. Presenza e distribuzione di batteri antibiotico-resistenti nelle acque del Lago Maggiore. Valutazione della presenza di geni di antibiotico-resistenza (ABR). Quantificazione dei geni di resistenza alle tetracicline

Mitotic cell death induction by targeting the mitotic spindle with tubulin-inhibitory indole derivative molecules

Tubulin-targeting molecules are widely used cancer therapeutic agents. They inhibit microtubule-based structures, including the mitotic spindle, ultimately preventing cell division. The final fates of microtubule-inhibited cells are however often heterogeneous and difficult to predict. While recent work has provided insight into the cell response to inhibitors of microtubule dynamics (taxanes), the cell response to tubulin polymerization inhibitors remains less well characterized. Arylthioindoles (ATIs) are recently developed tubulin inhibitors. We previously identified ATI members that effectively inhibit tubulin polymerization in vitro and cancer cell growth in bulk cell viability assays. Here we characterise in depth the response of cancer cell lines to five selected ATIs. We find that all ATIs arrest mitotic progression, yet subsequently yield distinct cell fate profiles in time-lapse recording assays, indicating that molecules endowed with similar tubulin polymerization inhibitory activity in vitro can in fact display differential efficacy in living cells. Individual ATIs induce cytological phenotypes of increasing severity in terms of damage to the mitotic apparatus. That differentially triggers MCL-1 down-regulation and caspase-3 activation, and underlies the terminal fate of treated cells. Collectively, these results contribute to define the cell response to tubulin inhibitors and pinpoint potentially valuable molecules that can increase the molecular diversity of tubulin-targeting agents