Effect of antibodies on the expression of Plasmodium falciparum circumsporozoite protein gene

Antibodies are known to play an important role in the control of malaria infection. However, they can modulate parasite development enhancing infection. The effect of anti-Plasmodium antibodies on the expression of circumsporozoite protein gene (csp) was investigated. Plasmodium falciparum 3D7 in vitro cultures were submitted to: i) anti- circumsporozoite protein monoclonal antibody (anti-CSP-mAb) [1μg/ml, 0.1μg/ml, 0.01μg/ml and 0.001μg/ml] and ii) purified IgG Fab fragment from a pool of malaria patients [1mg/ml and 1μg/ml]; and compared to control cultures. After 24h the number of ring infected erythrocytes was determined in order to calculate invasion efficacy. At 48h culture supernatant was collected, and the amount of circumsporozoite protein determined by ELISA, parasitaemia was calculated and cells were processed for RNA preparation. Expression of csp gene was quantified using Real time RT-PCR. There was an increase in parasite growth when treated with lower anti-CSP-mAb concentration, which was associated with lower csp expression, while 1μg/ml anti-CSP-mAb treatment presented a growth inhibitory effect accompanied by high csp expression

Multi-scalar tachyon potential on non-BPS domain walls

We have considered the multi-scalar and multi-tachyon fields living on a 3d domain wall embedded in a 5d dimensional Minkowski spacetime. The effective action for such a domain wall can be found by integrating out the normal modes as vibrating modes around the domain wall solution of a truncated 5d supergravity action. The multi-scalar tachyon potential are good enough to modeling assisted inflation scenario with multi-tachyon fields. The tachyon condensation are also briefly addressed.Comment: version to appear in JHEP, 18 pages, 3 figure

Uma abordagem da historicidade das representações sociais An approach to the historicity of social representations

O artigo pretende enfatizar a historicidade das representações sociais como aspecto fundamental para a compreensão de seus processos de generatividade e de estabilização de conteúdos. Para tanto, considera que as representações sociais são resultado, de um lado, da reapropriação de conteúdos advindos de períodos cronológicos distintos e, de outro, daqueles gerados por novos contextos. Assim, são apresentados aspectos de reciprocidade entre representações sociais e a perspectiva da história das mentalidades enfatizando que os processos de objetivação e de ancoragem, formadores das representações sociais, são privilegiados para a investigação dessa historicidade.<br>The article aims to emphasize the historicity of the social representations as a basic aspect for the understanding of their processes of generativity and of stabilization of contents. For so, it considers social representations as the consequence, on the one hand, of the appropriation of contents from chronological different periods and, on the other hand, from those contents produced by new contexts. Therefore, the article presents some aspects of the reciprocity between social representations and history of mentalities in order to emphasize that the processes of objectivation and anchorage, which are constitutive of the social representations, are privileged processes for the investigation of this historicity