8,258 research outputs found

    Frequently hypercyclic translation semigroups

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    Frequent hypercyclicity for translation C0C_0-semigroups on weighted spaces of continuous functions is investigated. The results are achieved by establishing an analogy between frequent hypercyclicity for the translation semigroup and for weighted pseudo-shifts and by characterizing frequent hypercyclic weighted pseudo-shifts in spaces of vanishing sequences. Frequent hypercylic translation semigroups in weighted LpL^p-spaces are also characterized

    Analyticity of a class of degenerate evolution equations on the canonical simplex of Rd\R^d arising from Fleming--Viot processes

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    We study the analyticity of the semigroups generated by a class of degenerate second order differential operators in the space C(Sd)C(S_d), where SdS_d is the canonical simplex of Rd\R^d. The semigroups arise from the theory of Fleming--Viot processes in population genetics.Comment: 32 page

    Correlating yeast cell stress physiology to changes in the cell surface morphology:atomic force microscopic studies

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    Yeasts are unicellular haploid fungi that help us to bake bread and ferment alcoholic beverages, but in some cases, they can cause infections that are sometimes fatal. Over 1000 different known species of yeasts are widely distributed in nature[1]. Although the majority of these (e.g., Saccharomyces cerevisiae) live in the general environment, a few species (e.g., Candida) are associated with humans and sometimes become pathogenic[1]. This occurs when our immune system weakens and Candida yeasts start to grow in an uncontrolled way, thereby causing candidiasis and nosocomial infections that result in high patient morbidity and mortality rates[2]

    The dynamics of socially responsible product differentiation and the habit formation of socially responsible consumers

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    In our model of socially responsible (SR) product differentiation two duopolists (a zero profit socially concerned producer and a profit maximizing producer) compete over prices and (costly) “socially and environmentally responsible” features of their products under a given law of motion of consumer’s habits. In a continuous time model in which the location of the zero profit socially responsible entrant is fixed and the profit maximizing producer (PMP) limits himself to price competition without SR imitation, we show that the optimal dynamic PMP’s price is always lower than his optimal static price since the PMP knows that, by leaving too much market share to his competitor, he will reinforce the habit of socially responsible consumption and loose further market share in the future. We also inspect the properties of equilibria when the PMP can imitate the entrant’s SR and we find that, in this case, the threshold triggering a PMP strategy of SR imitation and minimum price differentiation is higher in the dynamic than in the static case, depending on the PMP’s shadow cost of changes in consumer social responsibility.product differentiation, social responsibility, fair trade

    What information could the main actors of liquid biopsy provide? A representative case of non-small cell lung cancer (NSCLC)

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    In non-small cell lung cancer (NSCLC), there is a consensus regarding the use of liquid biopsy, generally, to detect "druggable" mutations and, in particular, to monitor tyrosine kinase inhibitor (TKI) treatments. However, whether circulating tumor cells (CTCs) are better tools than cell-free DNA (cfDNA), is still a matter of debate, mainly concerning which antigen(s) we should use to investigating simultaneously both epithelial and epithelial-to-mesenchymal transient (EMT) phenotype in the same sample of CTCs. To address this item, we exploited here a single-tube liquid biopsy, to detect both epithelial cell adhesion molecule (EpCAM)-positive CTCs and EpCAM-low/negative CTCs, because down-modulation of EpCAM is considered the first step in EMT. Furthermore, we analyzed the DNA from CTCs of four different phenotypes (ctcDNA), according to their EpCAM expression and cytokeratin pattern, and circulating tumor DNA (ctDNA) by droplet digital PCR (ddPCR), in order to disclose activating and resistancedriving mutations. Liquid biopsy reflected spatial and temporal heterogeneity of the tumor under treatment pressure. We provide the proof-of-concept that the complementary use of ctDNA and ctcDNA represents a reliable, minimally invasive and dynamic tool for a more comprehensive view of tumor evolution
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