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Institution

Instituto Superior Técnico

Education
About: Instituto Superior Técnico is a based out in . It is known for research contribution in the topics: Catalysis & Finite element method. The organization has 10085 authors who have published 30226 publications receiving 667524 citations. The organization is also known as: IST & Instituto Superior Tecnico.


Papers
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Journal ArticleDOI
TL;DR: The information emerging from this genome expression profiling and the detailed investigation of the biological role of candidate genes, as targets of phenol toxicity or as determinants of Phenol resistance in P. putida KT2440, will allow more rationale strategies for developing bacteria with greater solvent tolerance with impact in bioremediation and whole‐cell biotransformations in media with organic solvents.
Abstract: To gain insight into the global mechanism underlying phenol toxicity and tolerance in bacteria, we have generated a two-dimensional protein reference map and used it to identify variations in protein expression levels in Pseudomonas putida KT2440 following exposure to sub-lethal inhibitory concentrations of this solvent. Inspection of the two-dimensional gel electrophoresis gels revealed that 1 h following sudden cell exposure to two different concentrations of phenol, leading to the inhibition of exponential growth (600 mg/L) or to growth arrest for, at least, 4 h before inhibited growth resumption (800 mg/L), the amount of 68 proteins was increased while the amount of 13 proteins was reduced. The up-regulated proteins include proteins involved in the: (i) oxidative stress response (AhpC, SodB,Tpx and Dsb); (ii) general stress reponse (UspA, HtpG, GrpE and Tig); (iii) energetic metabolism (AcnB, AtpH, Fpr, AceA, NuoE, and MmsA-1); (iv) fatty acid biosynthesis (FabB, AccC-1 and FabBx1); (v) inhibition of cell division (MinD); (vi) cell envelope biosynthesis (LpxC, VacJ, and MurA); (vii) transcription regulation (OmpR and Fur); and (viii) transport of small molecules (TolC, BraC, AotJ, AapJ, FbpA and OprQ). Among the down-regulated proteins are those involved in nucleotide biosynthesis (PurM, PurL, PyrH and Dcd) and cell motility (FliC). The information emerging from this genome expression profiling and the detailed investigation of the biological role of candidate genes, as targets of phenol toxicity or as determinants of phenol resistance in P. putida KT2440, will allow more rationale strategies for developing bacteria with greater solvent tolerance with impact in bioremediation and whole-cell biotransformations in media with organic solvents.

221 citations

Posted Content
TL;DR: Marian is an efficient and self-contained Neural Machine Translation framework with an integrated automatic differentiation engine based on dynamic computation graphs that can achieve high training and translation speed.
Abstract: We present Marian, an efficient and self-contained Neural Machine Translation framework with an integrated automatic differentiation engine based on dynamic computation graphs. Marian is written entirely in C++. We describe the design of the encoder-decoder framework and demonstrate that a research-friendly toolkit can achieve high training and translation speed.

220 citations

Journal ArticleDOI
TL;DR: In this paper, the authors discuss the interpretation of scales for attitude measuring and give a survey of data analysis techniques under the proper ordinal understanding of Likert scales, which are used in survey studies for attitude measurement.
Abstract: Likert scales are widely used in survey studies for attitude measuring. In particular, the questionnaires propagated by the SERVQUAL approach are based on Likert scales. Though the problem of attitude suggests an ordinal interpretation of Likert scales, attitude survey data are often evaluated with techniques designed for cardinal measurements. The present paper discusses the interpretation of scales for attitude measuring and gives a survey of data analysis techniques under the proper ordinal understanding.

220 citations

Proceedings ArticleDOI
16 Jun 2000
TL;DR: Omni-directional images provide the means of having adequate representations to support both accurate or qualitative navigation, since landmarks remain visible in all images, as opposed to a small field-of-view standard camera.
Abstract: We describe a method for visual based robot navigation with a single omni-directional (catadioptic) camera. We show how omni-directional images can be used to generate the representations needed for two main navigation modalities: Topological Navigation and Visual Path Following. Topological Navigation relies on the robot's qualitative global position, estimated from a set of omni-directional images obtained during a training stage (compressed using PCA). To deal with illumination changes, an eigenspace approximation to the Hausdorff measure is exploited. We present a method to transform omni-directional images to Bird's Eye Views that correspond to scaled orthographic views of the ground plane. These images are used to locally control the orientation of the robot, through visual servoing. Visual Path Following is used to accurately control the robot along a prescribed trajectory, by using bird's eye views to track landmarks on the ground plane. Due to the simplified geometry of these images, the robot's pose can be estimated easily and used for accurate trajectory following. Omni-directional images facilitate landmark based navigation, since landmarks remain visible in all images, as opposed to a small field-of-view standard camera. Also, omni-directional images provide the means of having adequate representations to support both accurate or qualitative navigation. Results are described in the paper.

220 citations

Journal ArticleDOI
TL;DR: In this paper, the authors describe the H2RES model for optimisation of integration of hydrogen usage with intermittent renewable energy sources on the example of an isolated island in the Madeira archipelago, Porto Santo.
Abstract: While the energy supply of most islands depends mainly on expensive oil derivatives’ importation, the others are linked by usually a weak electricity grid connection to the mainland. Due to high energy costs the islands are proving to be excellent test beds for the introduction of new technologies, and some islands are trying to become so-called renewable islands, to satisfy their energy demand mainly or entirely from indigenous and renewable sources, thus increasing the security of supply, and employment opportunities, without necessarily increasing the costs. Islands that have energy sources, such as hydro or geothermal energy, can easily integrate them into the power system, but those with mainly intermittent renewable energy sources are confronted with the necessity of energy storage. The most promising technologies are reversible hydro where geography allows, and storing hydrogen where it does not. The stored hydrogen can later be used for electricity production, and also for transport. This paper describes the H2RES model for optimisation of integration of hydrogen usage with intermittent renewable energy sources on the example of an isolated island in the Madeira archipelago, Porto Santo. It shows that it is possible to significantly increase the penetration of renewable energy sources, albeit at a relatively high cost, with hydrogen storage technology. The H2RES model, which includes reversible hydro and batteries as storage technologies, can serve as a valuable tool for island energy planning.

220 citations


Authors

Showing all 10288 results

NameH-indexPapersCitations
Joao Seixas1531538115070
A. Gomes1501862113951
Amartya Sen149689141907
António Amorim136147796519
Joao Varela133141192438
Pietro Faccioli132137889795
João Carvalho126127877017
Pedro Jorge12477668658
Pedro Silva12496174015
A. De Angelis11853454469
Hermine Katharina Wöhri11662955540
Helena Santos114105854286
P. Conde Muiño10955856133
Joao Saraiva10751953340
J. N. Reddy10692666940
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202341
2022354
20212,263
20202,433
20192,327
20182,190