Identification of mating type genes in the bipolar basidiomycetous yeast rhodosporidium toruloides: first insight into the MAT Locus structure of the sporidiobolales

Eukaryotic Cell, Vol.7, Nº6

A new dinosaur tracksite in the Lower Cretaceous of Portugal

A new Lower Cretaceous (Aptian-Albian) dinosaur tracksite at the Olhos de Água beach is described. It is the first vertebrate fossil finding ever found in the concerned unit, and yielded 128 tracks in 17 trackways within an area of ca. 80 square metres. Three tridactyl footprint morphotypes have been recognized: - Type I ("Iguanodontipus-like") - trackways D, F, K, J and P; - Type 2 (large theropod), although larger in size, typically from a Grallator-like theropod footprint, i.e , A, B, G, H and 0 trackways; - Type 3 (medium size theropod); M is the only track of this type. There are other, poorly preserved, unidentified trackways. The theropod, swinging trackway B was produced by an animal that was limping. The theropod track M starts eastwards but drastically changes westwards, speeding up at the same time; this dinosaur decided to turn around and run in the opposite direction. This site shows three main trackway directions: to the South, to the East, and westwards. Except for the trackway 0, large theropods A, B, G and H walked southwards. Perpendicularly to the se, ornithopods, small theropods and unidentified trackmakers walked towards East (5) and West (7). The segregation oftrackmakers and directions, with large theropod traekways southwards and other dinosaurs' west or eastwards, may mean that large theropods patrolled a walkway area to an important resource, most probably water, often frequented by ornithopods and smaller theropods. There is no evidence of social behavior or gregarism: footprints' overposition shows that the large, southwards walking theropods passed on different occasions. Three trackway sequences can be established by chronologic order.

The thickness of the transport layer in stratified geomorphic flows

River Flow 2010

Urban sprawl analysis and modeling in Asmara, Eritreia: Application of Geospatial Tools

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Land cover dynamics in Savanna Ecosystem of Borena Ethiopia

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Integrated study by NMR and X-ray Crystallography on the analysis of the molecular interactions in heme-binding proteins

Dissertação para obtenção do Grau de Doutor em Bioquímica, Especialidade Bioquímica Estrutural

Structural and functional studies of PpcA: a key protein in the electron transfer pathways of Geobacter sulfurreducens

Dissertação para obtenção do Grau de Doutor em Bioquímica, ramo de Biotecnologia

The determinants of SMEs capital structure: Overcoming supply constraints

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Corporate networks in Poland: Interlocking directorates and business systems

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Image processing methodology for assessment of drilling induced damage in CFRP

Dissertação para obtenção do Grau de Mestre em Engenharia Mecânica

Cell division and chromosome segregation in Staphylococcus aureus

Dissertação para a obtenção do grau de doutor em Biologia pelo Instituto de Tecnologia Química e Biológica. Universidade Nova de Lisboa

Exploring profitability diversity through financial statement analysis

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Follow the red road of triheme cytochromes in Geobacter sulfurreducens

The bacterium Geobacter sulfurreducens (Gs) is capable of oxidizing a large variety of compounds relaying electrons out of the cytoplasm and across the membrane in a process designated as extracellular electron transfer. The Gs genome was fully sequenced and a family composed by five periplasmic triheme cytochromes c7 (designated PpcA-E) was identified. These cytochromes play an important role in the reduction of extracellular acceptors. They contain approximately 70 amino acids, three heme groups with bis-histidinyl axial coordination, and share between 57 and 77% sequence identity. The triheme cytochrome PpcA is highly abundant in Gs and is most likely the reservoir of electrons destined for outer surface. In addition to its role in electron transfer pathways this protein can perform e-/H+ energy transduction, a process that is disrupted when the strictly conserved aromatic residue phenylalanine 15 is replaced by a leucine (PpcAF15L). This Thesis focuses on the expression, purification and characterization of these proteins using Nuclear Magnetic Resonance and ultraviolet-visible spectroscopy. The orientations of the heme axial histidine ring planes and the orientation of the heme magnetic axis were determined for each Gs triheme cytochrome. The comparison of the orientations obtained in solution with the crystal structures available showed significant differences. The results obtained provide the paramagnetic constraints to include in the future refinement of the solution structure in the oxidized state. In this work was also determined the solution structure and the pH-dependent conformational changes of the PpcAF15L allowing infer the structural origin for e-/H+ energy transduction mechanism as shown by PpcA. Finally, the backbone and side chain NH signals of PpcA were used to map interactions between this protein and the putative redox partner 9,10-anthraquinone-2,6-disulfonate (AQDS). In this work a molecular interaction was identified for the first time between PpcA and AQDS, constituting the first step toward the rationalization of the Gs respiratory chain.

Functional genomic analysis of heat stress in Vitis vinifera

Grapevine (Vitis vinifera) is one of most agro-economically important fruit crops worldwide, with a special relevance in Portugal where over 300 varieties are used for wine production. Due to global warming, temperature stress is currently a serious issue affecting crop production especially in temperate climates. Mobile genetic elements such as retrotransposons have been shown to be involved in environmental stress induced genetic and epigenetic modifications. In this study, sequences related to Grapevine Retrotransposon 1 (Gret1) were utilized to determine heat induced genomic and transcriptomic modifications in Touriga Nacional, a traditional Portuguese grapevine variety. For this purpose, growing canes were treated to 42 oC for four hours and leaf genomic DNA and RNA was utilized for various techniques to observe possible genomic alterations and variation in transcription levels of coding and non-coding sequences between non-treated plants and treated plants immediately after heat stress (HS-0 h) or after a 24 hour recovery period (HS-24 h). Heat stress was found to induce a significant decrease in Gret1 related sequences in HS-24 h leaves, indicating an effect of heat stress on genomic structure. In order to identify putative heat induced DNA modifications, genome wide approaches such as Amplified Fragment Length Polymorphism were utilized. This resulted in the identification of a polymorphic DNA fragment in HS-0 h and HS-24 h leaves whose sequence mapped to a genomic region flanking a house keeping gene (NADH) that is represented in multiple copies in the Vitis vinifera genome. Heat stress was also found to affect the transcript levels of various non-coding and gene coding sequences. Accordingly, quantitative real time PCR results established that Gret1 related sequences are up regulated immediately after heat stress whereas the level of transcript of genes involved in identification and repair of double strand breaks are significantly down regulated in HS-0 h plants. Taken together, the results of this work demonstrated heat stress affects both genomic integrity and transcription levels.