Trichothecenes NIV and DON modulate the maturation of murinedendritic cells

Nivalenol (NIV) and Deoxynivalenol (DON), mycotoxins of the trichothecene family are considered very common food contaminants. In this work, we investigated whether the immunotoxic effects ascribed to these trichothecenes may be mediated by perturbations in the activity of dendritic cells (DCs). Murine bone marrow-derived DCs were used to evaluate the effects of NIV and DON on the LPS-induced maturation process.We found that the expression of the class II MHC and of the accessory CD11c molecules, but not of the costimulatory CD86 marker, was down-regulated by NIV and DON exposure in LPS-treated DCs, as well as nitric oxide (NO) production. Interestingly, NIV, but not DON, induced DC necrosis. Moreover, the analysis of the cytokine pattern showed that IL-12 and IL-10 expressions induced by LPS exposure were suppressed by both trichothecenes in a dose-dependent fashion. On the other hand, the secretion of the proinflammatory cytokine TNFa was increased as a direct consequence of DON and NIV exposure. Taken together, our data indicated that the immunotoxicity of NIV and DON was related to the capacity of both trichothecenes to interfere with phenotypic and functional features of maturing DCs

Mycotoxins nivalenol and deoxynivalenol differently modulate cytokine mRNA expression in Jurkat T cells.

Deoxynivalenol (DON) and its hydroxylated form nivalenol (NIV) are Fusarium mycotoxins that occur in cereal grains alone or in combination. Several studies have shown that these metabolites affect lymphocyte functions. However, the molecular mechanisms underlying their activities are still partially known. To address this issue, we examined the influence of NIV and DON in modulating IFNc, IL-2 and IL-8 mRNA levels in Jurkat T cells. In PMA/ionomycin stimulated cells, pre-incubated with increasing concentrations of NIV, transcription was induced in the range 0.06–2 lM; higher concentrations of NIV were found non-stimulating (4 lM) or inhibitory (8 lM) for IFNc and IL-2 whereas IL-8 was still induced. DON administration elicited a similar profile for IL-8 and IFNc, whilst IL-2 mRNA was induced in a broader range of concentrations. Combination of NIV and DON at 1:1 and 1:10 ratios essentially restored the cytokine transcriptional pattern observed with NIV alone but the level of transcripts, with the exception of IL-8, peaked at lower concentrations suggesting interactive effects. Moreover both mycotoxins caused inhibition of cell proliferation, mediated by induction of apoptosis, confirming previous results and highlighting the usefulness of Jurkat as a T-cell model to study the effects of mycotoxins on the immune functions in humans

Order and chaos: interactive computational activities for the classroom

It has long been believed that typical students learn better through contemporary approaches to questions originated by physics problems that allow experiments. This belief motivated us to develop interactive computational didactic materials about contemporaneous mathematics that can be used both in the classroom and in mathematics clubs in school. Dynamical Systems, the study of how physical systems evolve with time, inspired the activities developed. They share a key goal of understanding the order/chaos relationship in natural phenomena, human behaviour and social systems. Another goal to achieve is to give mathematics an experimental/laboratorial component, which rarely is present. In fact, all the interactive computational didactic materials developed include simulations and the capability to generate wonderful pictures, from which students can enjoy the beauty of mathematics.The first author was supported by the Centre of Research in Mathematics and Applications, University of Évora, through the FCT Pluriannual Funding Program. The second author was supported by FEDER Funds through "Programa Operacional Factores de Competitividade – COMPETE" and by Portuguese Funds through FCT -"Fundação para a Ciência e a Tecnologia", within the Project PEst-C/MAT/UI0013/2011

A K-Theoretic Proof of Boutet de Monvel's Index Theorem for Boundary Value Problems

We study the C*-closure A of the algebra of all operators of order and class zero in Boutet de Monvel's calculus on a compact connected manifold X with non-empty boundary. We find short exact sequences in K-theory 0->K_i(C(X))->K_i(A/K)->K_{1-i}(C_0(T*X'))->0, i= 0,1, which split, where K denotes the compact ideal and T*X' the cotangent bundle of the interior of X. Using only simple K-theoretic arguments and the Atiyah-Singer Index Theorem, we show that the Fredholm index of an elliptic element in A is given as the composition of the topological index with mapping K_1(A/K)->K_0(C_0(T*X')) defined above. This relation was first established by Boutet de Monvel by different methods.Comment: Title slightly changed. Accepted for publication in Journal fuer die reine und angewandte Mathemati

Solid wastes wastewater and remediation costs in an urban slum: The case study of A Gypsy Camp in Napoli (S Italy)

Slums represent a sort of black box within the urban environment, generating multiple impacts, that are often acknowledged, but forgotten by urban planners and policy-makers when envisioning the future of cities, due to the dimension of social exclusion in which slum dwellers live. These criticalities pose a further threat to urban sustainability. The first problem is revealed by the lack of quantifications about many environmental and socio-economic factors, as well as by a general lack of understanding about slums as systems. This study is aimed at overcoming the present knowledge weakness, developing a preliminary site-specific system representation of a slum as a system. In particular, a case study of a Gypsy camp in Napoli (S Italy) was chosen for such a purpose. Focusing on solid waste, an approximate evaluation of informal waste picking activity was performed. Basic parameters of generated wastewater, which is dispersed in the environment due to the absence of any sewerage infrastructure, are accounted according to environmental engineering standards. In addition, considering a second abandoned camp (Brecce Sant'Erasmo, Napoli, Italy), specific-site remediation costs were calculated. Results evidence the necessity of a better understanding of resources flows within slums. A first planning action for the studied area would be to separate the areas for waste processing with respect to living areas. Basic infrastructures for solid waste and wastewater management are also necessary to improve the life quality of slum dwellers, while reducing the existing impacts. Finally, also a study to detail atmospheric emissions characteristics would be desirable. Specific upgrading solutions are indicated on the basis of the existing literature. They include planning and monitoring actions, together with the development of engineered solutions for waste and wastewater management

Quaternionic polynomials with multiple zeros: A numerical point of view

In the ring of quaternionic polynomials there is no easy solution to the problem of finding a suitable definition of multiplicity of a zero. In this paper we discuss different notions of multiple zeros available in the literature and add a computational point of view to this problem, by taking into account the behavior of the well known Newton's method in the presence of such roots.COMPETE reference number POCI-01-0145-FEDER-006683; FCT/MEC's financial support through national funding and by the ERDF through the Operational Programme on ``Competitiveness and Internationalization -- COMPETE 2020" under the PT2020 Partnership Agreementinfo:eu-repo/semantics/publishedVersio