Browsing by Issue Date, starting with "2012-10-18"
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- Protein and DNA nanoparticulate multiantigenic vaccines against H. pylori: In vivo evaluationPublication . Figueiredo, Lara; Calado, Cecília; Almeida, António J.; Gonçalves, Lídia M. D.Immunisation against H. pylori is an attractive option for antibiotic resistance and reinfection situations. Strain genetic heterogeneity, and low immunogenicity of protein antigens and DNA alone are nonetheless obstacles to this approach. We developed multigenic H. pylori DNA-nanoparticle and protein-nanoparticle vaccines based on pathogenic relevance. Six antigens were chosen for the vaccine construction: CagA, VacA, HpaA, UreB, HomB and GroEL. Different combinations of CS/DS and CS/Alg /TPP nanoparticles with DNA and chimeric proteins were produced as vaccine systems. Immune responses were evaluated after i.m. and oral immunisation of BALB/c mice. Oral vaccination successfully stimulated mucosal immunity while i.m. immunisation efficiently elicited a more equilibrated cellular/humoral immune response.
- Autonomic activities in the execution of scientific workflows: evaluation of the AWARD frameworkPublication . Assunção, Luis; Gonçalves, Carlos Jorge de Sousa; Cunha, José C.Workflows have been successfully applied to express the decomposition of complex scientific applications. However the existing tools still lack adequate support to important aspects namely, decoupling the enactment engine from tasks specification, decentralizing the control of workflow activities allowing their tasks to run in distributed infrastructures, and supporting dynamic workflow reconfigurations. We present the AWARD (Autonomic Workflow Activities Reconfigurable and Dynamic) model of computation, based on Process Networks, where the workflow activities (AWA) are autonomic processes with independent control that can run in parallel on distributed infrastructures. Each AWA executes a task developed as a Java class with a generic interface allowing end-users to code their applications without low-level details. The data-driven coordination of AWA interactions is based on a shared tuple space that also enables dynamic workflow reconfiguration. For evaluation we describe experimental results of AWARD workflow executions in several application scenarios, mapped to the Amazon (Elastic Computing EC2) Cloud.
- The importance of Helicobacter pylori's genetic variability for the construction of an efficient vaccinePublication . Vaz, Filipa; Couto, Andreia; Calado, CecíliaHelicobacter pylori is responsible for several gastric diseases. The main constraints of vaccine trials against this pathogen are mainly due to the bacterium high antigenic variability and to down-regulation of the host immune responses. To counteract these factors we propose a DNA vaccine able to induce a balanced humoural and citotoxic specific immune responses, based on multi-antigens. The selection of the antigens NapA, HpaA, VacA and HomB were conducted based on immunoproteomic data and the protein role on infection and pathogenesis. A fragment of each target-antigen was selected by in silico methods based on the maximization of the gene conservation and antigenicity. The set of these small fragments will be presented as a vaccine based on several conserved epitopes of multi-antigenic targets, and consequently representative of the bacterium antigenic variability.
- Modelling, monitoring and control of plasmid bioproduction in Escherichia coli culturesPublication . Lopes, Marta B.; Scholtz, Teresa; Silva, Daniel; Santos, Inês; Silva, Tito; Sampaio, Pedro; Couto, Andreia; Lopes, Vitor V.; Calado, CecíliaAn integrated approach for modelling, monitoring and control the plasmid bioproduction in Escherichia coli cultures is presented. In a first stage, by the implementation of a kinetic model for E. coli cultures, a better bioprocess understanding was reached, concerning the availability of nutrients and products along the bioprocess, and their effects on the plasmid production. Results presented may provide significant help for future modelling and monitoring implementation. In a second stage, FTIR spectroscopy coupled with chemometrics, namely PLS regression, shows its potential as a high-throughput technique for simultaneously estimating the key variables involved in the plasmid production process by E. coli cultures run under distinct conditions. Finally, owing to online monitoring and process control, an NIR fibre optic probe and chemometrics provided promising results concerning the control of biomass and carbon sources in E. coli cultures.