Taxonomic changes have frequently occurred in the anuran genus Pseudopaludicola as a consequence of high morphological similarity among its species. The present work reports karyotypic analysis of three Pseudopaludicola species sampled in their type locality and four Pseudopaludicola populations from distinct localities, aiming at contributing to the systematics of this genus. Chromosomes were stained with Giemsa or submitted to the silver staining (Ag-NOR) and C-banding techniques. The karyotype was 2nϭ22 in P. mineira, Pseudopaludicola sp. and two populations of P. saltica. The chromosome pair 8 was heteromorphic in P. saltica, characterizing a XX/XY sex-determination system with telocentric X and submetacentric Y. Highly similar karyotypes with 2nϭ18 chromosomes were observed in P. canga, P. aff. canga from Barreirinhas, State of Maranhão, Uberlândia, State of Minas Gerais and Icém, State São Paulo. The high similarity among the karyotypes 2nϭ18 suggested that the populations of P. aff. canga belong to the group 'pusilla', the same group of P. canga. The data demonstrated also that P. aff. canga from Barreirinhas (northeast region) is cytogenetically identical to P. canga with regarding the NOR site position in pair 3 and the presence of a heterochromatic block in the pair 2, whereas P. aff. canga from Uberlândia and Icém (southeast) had the NOR in the pair 9. Moreover, the cytogenetic data discriminated P. mineira and Pseudopaludicola sp. from the previously analyzed species with 22 chromosomes, and suggested that Pseudopaludicola sp. is an undescribed species. Sexual heteromorphic chromosomes are fi rstly reported in Pseudopaludicola and the data indicated the need of an extensive taxonomic review in this genus.

I describe here a new species of Pseudopaludicola (P. serrana) found in the southern limits of the Espinhaço mountain range in the state of Minas Gerais, Brazil. This new species is related to P. saltica and P. murundu and can be diagnosed by the following combination of characters: (1) long hindlimbs and absence of T-shaped terminal phalanges, (2) single, dark, and subgular vocal sac with dark longitudinal folds in males; (3) immaculate to light brown, nuptial pads in males that cover the external part of finger I; (4) SVL/HL greater than 2.7; and (5) advertisement call with dominant frequency above 5 kHz, pulse duration range between 13 and 23 ms, and mean interval between notes of 177 ms. Tadpoles and the advertisement call are also described.

The aim of this investigation is focused on the evaluation of distinctive coatings commonly applied in the automotive industry. The resulting corrosion behavior is analyzed by using electrochemical impedance spectroscopy (EIS), equivalent circuit (EC) and potentiodynamic polarization curves. The novelty concerns a comparison between tricationic phosphate (TCP), cataphoretic electrodeposition (CED) of an epoxy layer, TCP + CED and HDG (hot-dip galvanized) + TCP + CED multi-coatings. Both the naturally deposited and defect-induced damage (incision) coatings are examined. The experimental impedance parameters and corrosion current densities indicate that multi-coating system (HDG + TCP + CED layers) provides better protection. Both planar and porous electrode behaviors are responsible to predict the corrosion mechanism of the majority of samples examined. Although induced-damage samples reveal that corrosion resistances decreased up to 10×, when compared with no damaged samples, the same trend of the corrosion protection is maintained, i.e., TCP < CED < TCP + CED < HDG + TCP + CED. It is also found that the same trend verified by using electrochemical parameters is also observed when samples are subjected under salt spray condition (500 h). It is also found that porous electrode behavior is not a deleterious aspect to corrosion resistance. It is more intimately associated with initial thickness coating, while corrosion resistance is associated with adhesion of the CED layer on TCP coating. The results of relative cost-to-efficiency to relative coating density ratios are associated with fact that a CED coating is necessary to top and clear coating applications and the TCP + CED and the HDG/TCP + CED coating systems exhibit the best results.

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Primeiramente a DEUS, a quem sou infinitamente grato por tudo que me aconteceu durante esta fase tão importante da minha vida. À Profa. Dra. Shirlei Maria Recco Pimentel, por ter aberto as portas de seu laboratório e me aceitado no curso de mestrado mesmo sem nenhuma experiência acadêmica prévia, o que demonstrou uma grande confiança em mim, fato que me comoveu profundamente. Agradeço ainda, pela sua competente orientação e experiência de vida.