Bottom-up regulation of phytoplankton in the Guadiana estuary

Tese dout., Ciências do Mar (Ecologia Marinha), Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2010

Applying the ecohydrology approach to the Guadiana estuary and coastal areas: lessons learned from dam impacted ecosystems

Ecohydrology is a scientific concept applied to problem- solving in environmental issues. It recognises that the present practice of relying nearly exclusively on engineering fixes to solve environmental problems is failing to restore the aquatic environment to a level that can sustain the quality of life that people are demanding. Ecohydrology is based on the ability of science to quantify and explain the relationships between hy- drological processes and biotic dynamics at a catchment scale and to manipulate these processes to increase the robustness of the aquatic system and thus its ability to cope with human- induced stresses. The concept was developed by the UNESCO International Hydrologic Programme (IHP) and the Man and Biosphere Programme (MAB).

Long-term changes in fish communities of the Ria Formosa coastal lagoon (southern Portugal) based on two studies made 20 years apart

Fish communities of the Ria Formosa coastal lagoon (south Portugal) were sampled on a monthly basis with a beach seine at 4 sites, during two different time periods: 1980-1986 and 2001-2002. Community indices, species ranking and multivariate analysis were used in order to identify changes in the fish community between the two time periods. A total of 153,511 fish representing 57 taxa were recorded. Although species composition was very similar for both sampling periods, multivariate analysis performed on annual species abundance in number and weight revealed differences in fish community structure between the two periods. Structural changes in fish community were related mostly to a sharp decrease in the abundance of Mugilidae from 1980-1986 to 2001-2002. These changes were probably associated to a decrease in organic matter contents and nutrients concentrations due to improvements in sewage treatment and better water circulation inside the lagoon. The changes in fish community structure are more evident in the inner areas of the lagoon than near the inlet. The association between changes in sewage patterns and changes in the ichthyofaunal community structure reinforces the importance of fish communities as a biological indicator of human induced changes in marine systems. (c) 2007 Elsevier Ltd. All rights reserved.

Molecular cloning, full-length sequence and preliminary characterization of a 56-kDa protein induced by human interferons

Among the various proteins which are induced when human cells are are treatened with interferon, a predominant protein of unknown function, with molecular mass 56 kDa, has been observed. With the aim of exploring the molecular basis of the regulation of this protein and of its mRNA, in order to understand its biological functionand its possible contribution to the various antiviral and non-antiviral actions exerted by interferons.

Development of a Piggybac based direct reprogramming system for derivation of integration free induced pluripotent stem cells

Induced pluripotent stem cells (iPSc) have great potential for applications in regenerative medicine, disease modeling and basic research. Several methods have been developed for their derivation. The original method of Takahashi and Yamanaka involved the use of retroviral vectors which result in insertional mutagenesis, presence in the genome of potential oncogenes and effects of residual transgene expression on differentiation bias of each particular iPSc line. Other methods have been developed, using different viral vectors (adenovirus and Sendai virus), transient plasmid transfection, mRNA transduction, protein transduction and use of small molecules. However, these methods suffer from low efficiencies; can be extremely labor intensive, or both. An additional method makes use of the piggybac transposon, which has the advantage of inserting its payload into the host genome and being perfectly excised upon re-expression of the transposon transposase. Briefly, a policistronic cassette expressing Oct4, Sox2, Klf4 and C-Myc flanked by piggybac terminal repeats is delivered to the cells along with a plasmid transiently expressing piggybac transposase. Once reprogramming occurs, the cells are re-transfected with transposase and subclones free of tranposon integrations screened for. The procedure is therefore very labor intensive, requiring multiple manipulations and successive rounds of cloning and screening. The original method for reprogramming with the the PiggyBac transposon was created by Woltjen et al in 2009 (schematized here) and describes a process with which it is possible to obtain insert-free iPSc. Insert-free iPSc enables the establishment of better cellular models of iPS and adds a new level of security to the use of these cells in regenerative medicine. Due to the fact that it was based on several low efficiency steps, the overall efficiency of the method is very low (<1%). Moreover, the stochastic transfection, integration, excision and the inexistence of an active way of selection leaves this method in need of extensive characterization and screening of the final clones. In this work we aime to develop a non-integrative iPSc derivation system in which integration and excision of the transgenes can be controlled by simple media manipulations, avoiding labor intensive and potentially mutagenic procedures. To reach our goal we developed a two vector system which is simultaneously delivered to original population of fibroblasts. The first vector, Remo I, carries the reprogramming cassette and GFP under the regulation of a constitutive promoter (CAG). The second vector, Eneas, carries the piggybac transposase associated with an estrogen receptor fragment (ERT2), regulated in a TET-OFF fashion, and its equivalent reverse trans-activator associated with a positive-negative selection cassette under a constitutive promoter. We tested its functionality in HEK 293T cells. The protocol is divided in two the following steps: 1) Obtaining acceptable transfection efficiency into human fibroblasts. 2) Testing the functionality of the construct 3) Determining the ideal concentration of DOX for repressing mPB-ERT2 expression 4) Determining the ideal concentration of TM for transposition into the genome 5) Determining the ideal Windows of no DOX/TM pulse for transposition into the genome 6) 3, 4 and 5) for transposition out of the genome 7) Determination of the ideal concentration of GCV for negative selection We successfully demonstrated that ENEAS behaved as expected in terms of DOX regulation of the expression of mPB-ERT2. We also demonstrated that by delivering the plasmid into 293T HEK cells and manipulating the levels of DOX and TM in the medium, we could obtain puromycin resistant lines. The number of puromycin resistant colonies obtained was significantly higher when DOX as absent, suggesting that the colonies resulted from transposition events. Presence of TM added an extra layer of regulation, albeit weaker. Our PCR analysis, while not a clean as would be desired, suggested that transposition was indeed occurring, although a background level of random integration could not be ruled out. Finally, our attempt to determine whether we could use GVC to select clones that had successfully mobilized PB out of the genome was unsuccessful. Unexpectedly, 293T HEK cells that had been transfected with ENEAS and selected for puromycin resistance were insensitive to GCV.

Evaluation of the human factor in the scheduling of smart appliances in smart grids

Recently there has been an increase of interest in implementing a new set of home appliances, known as Smart Appliances that integrate Information Technologies, the Internet of Things and the ability of communicating with other devices. While Smart Appliances are characterized as an important milestone on the path to the Smart Grid, by being able to automatically schedule their loads according to a tariff or reflecting the power that is generated using renewable sources, there is not a clear understanding on the impact that the behavior of such devices will have in the comfort levels of users, when they shift their working periods to earlier, or later than, a preset time. Given these considerations, in this work we analyse the results of an assessment survey carried out to a group of Home Appliance users regarding their habits when dealing with these machines and the subjective impact in quality caused by either finishing its programs before or after the time limit set by the user. The results of this work are expected to be used as input for the evaluation of load scheduling algorithms running in energy management systems. © 2014 Springer International Publishing.