Investigations into the existence of life in other parts of the cosmos find strong parallels with studies of the origin and evolution of life on our own planet. In this way, astrobiology and paleobiology are married by their common interest in disentangling the interconnections between life and the surrounding environment. In this way, a cross-point of both sciences is paleometry, which involves a myriad of imaging and geochemical techniques, usually non-destructive, applied to the investigation of the fossil record. In the last decades, paleometry has benefited from an unprecedented technological improvement, thus solving old questions and raising new ones. This advance has been paralleled by conceptual approaches and discoveries fuelled by technological evolution in astrobiological research. In this context, we present some new data and review recent advances on the employment of paleometry to investigations on paleobiology and astrobiology in Brazil in areas such biosignatures in Ediacaran microbial mats, biogenicity tests on enigmatic Ediacaran structures, research on Ediacaran metazoan biomineralization, fossil preservation in Cretaceous insects and fish, and finally the experimental study on the decay of fish to test the effect of distinct types of sediment on soft-tissue preservation, as well as the effects of early diagenesis on fish bone preservation.

Acute Chagas disease outbreaks are related to the consumption of food or drink contaminated by triatomine feces, thus making oral infection an important route of transmission. Both vector-borne and oral infections trigger important cardiac manifestations in the host that are related to a dysregulated immune response. The aims of this work were to evaluate possible alterations of lymphocyte CD4+/CD8+ sub-populations, Th1 and Th2 cytokines, nitrite concentrations and cardiac histopathology. One group of male Wistar rats was intraperitoneally infected (I.P.) with 1×105 metacyclic trypomastigotes of the T. cruzi Y strain, and another group of Wistar rats was orally infected (O.I.) with 8×105 metacyclic trypomastigotes of the same strain. The intraperitoneal infection triggered statistically enhanced parasite and peritoneal macrophage numbers, increased concentrations of NO and IL-12 and elevated cardiac inflammatory foci when compared with the oral infection. However, proliferation of CD4+ and CD8+ T cells were not statistically different for oral and intraperitoneal routes.

We report the determination of the age of the Galactic thin disk by means of Th/Eu nucleocosmochronology. This method is only weakly dependent on stellar evolutions models, therefore allowing an important verification of the most used dating techniques, which are the fitting of isochrones to the oldest Galactic open clusters, and the calculation of white dwarf cooling sequences. This work builds upon our previous determination (del Peloso et al. 2005a, 2005b), by including 7 new objects to the sample which was originally composed of 19 disk dwarfs/subgiants of F5 to G8 spectral types – a 37% extension. The obtained result, (8.8±1.7)Gyr, corroborates the most recent white dwarf ages determined via cooling sequence calculations, which indicate a low age ($\widetilde{<}10~\mbox{Gyr}$) for the disk.