Paleontologia e evolução a problemática da espécie em Paleozoologia

The concept of species in Paleontology is of paramount importance since the correct taxonomic determinations are essential to establish the age of the beds where fossils are collected. Particularly since 1940, the concept of species from a biological context, corresponding to the variability of a set of interpopulation compatibility, led us to a new approach, in which a typological conception has been replaced by a populationist one. If the notion of species is not necessarily identical for all living organisms, the greater the difficulties of interpretation in the private world of cephalopod fossils. The latter, lend themselves well to population systematics, and where this concept of species rests primarily on the morphological similarities. Thus, the introduction of general ideas analyse "typological species", "biological species", the problem of the definition of a "population" in Paleontology, and also the importance of the biometric analysis of fossil associations. The classic examples of polymorphism amd polytypism, in existing or extinct organisms, show that the concept of fossil species, observed in a well-defined period of its lifetime, is no different from that of biological species. The study of the evolution of fossil organisms allow us to understand the modelities of evolution and the mechanisms of speciation here synthesized and fully documented, namely the anagenesis or sequential evolution and the cladogenesis or divergent evoltuion; these mechanisms are the basis of the synthetic or gradualist theory of evolution developed by Dobzhansky, Mayr, Huxley, Rensch and impson. This summary ends with a reference to the theory of punctuated (or intermittent) equilibria proposed by Gould and Eldredge, who presented a more objective interpretation of morphological gaps, considered as elements of evolution itself. The interdisciplinary collaboration between zoologists, geneticists and paleontologists, is compulsory in this domain. Paleozoology has a key role since it conveys the dynamism and depth to the dimension of space-time duality.

Characterization of the volatile fraction emitted by phloems of four pinus species by solid-phase microextraction and gas chromatography–mass spectrometry

Pine forests constitute some of the most important renewable resources supplying timber, paper and chemical industries, among other functions. Characterization of the volatiles emitted by different Pinus species has proven to be an important tool to decode the process of host tree selection by herbivore insects, some of which cause serious economic damage to pines. Variations in the relative composition of the bouquet of semiochemicals are responsible for the outcome of different biological processes, such as mate finding, egg-laying site recognition and host selection. The volatiles present in phloem samples of four pine species, P. halepensis, P. sylvestris, P. pinaster and P. pinea, were identified and characterized with the aim of finding possible host-plant attractants for native pests, such as the bark beetle Tomicus piniperda. The volatile compounds emitted by phloem samples of pines were extracted by headspace solid-phase micro extraction, using a 2 cm 50/30 mm divinylbenzene/carboxen/polydimethylsiloxane table flex solid-phase microextraction fiber and its contents analyzed by high-resolution gas chromatography, using flame ionization and a non polar and chiral column phases. The components of the volatile fraction emitted by the phloem samples were identified by mass spectrometry using time-of-flight and quadrupole mass analyzers. The estimated relative composition was used to perform a discriminant analysis among pine species, by means of cluster and principal component analysis. It can be concluded that it is possible to discriminate pine species based on the monoterpenes emissions of phloem samples.

Fucosyltransferase IX: characterization and biological role

α3/4-Fucosyltransferases (α3/4-FUTs) are glycosyltransferases (GTs) that catalyze the transfer of fucose in an α3/4-linkage onto the N-acetylglucosamine residue from acceptors containing the type II or type I (Galβ4/3GlcNAc, respectively) structures, thus synthesizing the fucosylated Lewis (Le) carbohydrate determinants. Fucosyltransferase IX (FUT9), the most recently identified member of the family, presents the higher divergence from the other FUTs and its sequence is the only highly conserved among species. FUT9 synthesizes the Lewisx (Lex) epitope (Galβ4(Fucα3)GlcNAc). Recent evidence has suggested that it is the enzyme responsible for the synthesis of Lex in the mouse brain. Lex expression has been described in glycoproteins, proteoglycans and glycolipids from the central nervous system (CNS) of diverse species, including rodents and humans.

Ditopic molecular architectures for the recognition of anionic species

Dissertation presented to obtain the Ph.D degree in Chemistry

Establishment of environmental and biological bases to optimise the production of the European clam Ruditapes decussatus (Linnaeus, 1758)

Dissertação para obtenção do Grau de Doutor em Ambiente

Landscape composition and climatic parameters significant in the spread of an invasive species (Pine wood Nematode)

Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente

Electron driven reactions in sulphur containing biological prototypes

The interaction of ionising radiation with living tissues may direct or indirectly generate several secondary species with relevant genotoxic potential. Due to recent findings that electrons with energies below the ionisation threshold can effectively damage DNA, radiation-induced damage to biological systems has increasingly come under scrutiny. The exact physico-chemical processes that occur in the first stages of electron induced damage remain to be explained. However, it is also known that free electrons have a short lifetime in the physiological medium. Hence, electron transfer processes studies represent an alternative approach through which the role of "bound" electrons as a source of damage to biological tissues can be further explored. The thesis work consists of studying dissociative electron attachment (DEA) and electron transfer to taurine and thiaproline. DEA measurements were executed in Siedlce University with Prof. Janina Kopyra under COST action MP1002 (Nanoscale insights in ion beam cancer therapy). The electron transfer experiments were conducted in a crossed atom(potassium)-molecule beam arrangement. In these studies the anionic fragmentation patterns were obtained. The results of both mechanisms are shown to be significantly different, unveiling that the damaging potential of secondary electrons can be underestimated. In addition, sulphur atoms appear to strongly influence the dissociation process, demonstrating that certain reactions can be controlled by substitution of sulphur at specific molecular sites.

Biological colonization on majolica glazed tiles: biodeterioration, bioreceptivity and mitigation strategies

The impact of microbial activity on the deterioration of cultural heritage is a well-recognized global problem. Glazed wall tiles constitute an important part of the worldwide cultural heritage. When exposed outdoors, biological colonization and consequently biodeterioration may occur. Few studies have dealt with this issue, as shown in the literature review on biodiversity, biodeterioration and bioreceptivity of architectural ceramic materials. Due to the lack of knowledge on the biodeteriogens affecting these assets, the characterization of microbial communities growing on Portuguese majolica glazed tiles, from Pena National Palace (Sintra, Portugal) and another from Casa da Pesca (Oeiras, Portugal) was carried out by culture and molecular biology techniques. Microbial communities were composed of microalgae, cyanobacteria, bacteria and fungi, including a new fungal species (Devriesia imbrexigena) described for the first time. Laboratory-based colonization experiments were performed to assess the biodeterioration patterns and bioreceptivity of glazed wall tiles produced in laboratory. Microorganisms previously identified on glazed tiles were inoculated on pristine and artificially aged tile models and incubated under laboratory conditions for 12 months. Phototrophic microorganisms were able to grow into glaze fissures and the tested fungus was able to form oxalates over the glaze. The bioreceptivity of artificially aged tiles was higher for phototrophic microorganisms than pristine tile models. A preliminary approach on mitigation strategies based on in situ application of commercial biocides and titanium dioxide (TiO2) nanoparticles on glazed tiles demonstrated that commercial biocides did not provide long term protection. In contrast, TiO2 treatment caused biofilm detachment. In addition, the use of TiO2 thin films on glazed wall tiles as a protective coating to prevent biological colonization was analysed under laboratorial conditions. Finally, conservation notes on tiles exposed to biological colonization were presented.