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Publicações

2024

Simplified model(s) of the GRAVITY plus adaptive optics system(s) for performance prediction

Autores
Berdeu, A; Le Bouquin, JB; Melia, G; Bourgès, L; Berger, JP; Bourdarot, G; Paumard, T; Eisenhauer, F; Straubmeier, C; Garcia, P; Hönig, S; Millour, F; Kreidberg, L; Defrere, D; Soulez, F; Shimizu, T;

Publicação
ADAPTIVE OPTICS SYSTEMS IX

Abstract
In the context of the GRAVITY+ upgrade, the adaptive optics (AO) systems of the GRAVITY interferometer are undergoing a major lifting. The current CILAS deformable mirrors (DM, 90 actuators) will be replaced by ALPAO kilo-DMs (43x43, 1432 actuators). On top of the already existing 9x9 Shack-Hartmann wavefront sensors (SH-WFS) for infrared (IR) natural guide star (NGS), new 40x40 SH-WFSs for visible (VIS) NGS will be deployed. Lasers will also be installed on the four units of the Very Large Telescope to provide a laser guide star (LGS) option with 30x30 SH-WFSs and with the choice to either use the 9x9 IR-WFSs or 2x2 VIS-WFSs for low order sensing. Thus, four modes will be available for the GRAVITY+ AO system (GPAO): IR-NGS, IR-LGS, VIS-NGS and VIS-LGS. To prepare the instrument commissioning and help the observers to plan their observations, a tool is needed to predict the performances of the different modes and for different observing conditions (NGS magnitude, science object magnitude, turbulence conditions,...). We developed models based on a Mar ' echal approximation to predict the Strehl ratio of the four GPAO modes in order to feed the already existing tool that simulates the GRAVITY performances. Waiting for commissioning data, our model was validated and calibrated using the TIPTOP toolbox, a Point Spread Function simulator based on the computation of Power Spectrum Densities. In this work, we present our models of the NGS modes of GPAO and their calibration with TIPTOP.

2024

The leaf idioblastome of the medicinal plant Catharanthus roseus is associated with stress resistance and alkaloid metabolism

Autores
Guedes, JG; Ribeiro, R; Carqueijeiro, I; Guimaraes, AL; Bispo, C; Archer, J; Azevedo, H; Fonseca, NA; Sottomayor, M;

Publicação
JOURNAL OF EXPERIMENTAL BOTANY

Abstract
Catharanthus roseus leaves produce a range of monoterpenoid indole alkaloids (MIAs) that include low levels of the anticancer drugs vinblastine and vincristine. The MIA pathway displays a complex architecture spanning different subcellular and cell type localizations, and is under complex regulation. As a result, the development of strategies to increase the levels of the anticancer MIAs has remained elusive. The pathway involves mesophyll specialized idioblasts where the late unsolved biosynthetic steps are thought to occur. Here, protoplasts of C. roseus leaf idioblasts were isolated by fluorescence-activated cell sorting, and their differential alkaloid and transcriptomic profiles were characterized. This involved the assembly of an improved C. roseus transcriptome from short- and long-read data, IDIO+. It was observed that C. roseus mesophyll idioblasts possess a distinctive transcriptomic profile associated with protection against biotic and abiotic stresses, and indicative that this cell type is a carbon sink, in contrast to surrounding mesophyll cells. Moreover, it is shown that idioblasts are a hotspot of alkaloid accumulation, suggesting that their transcriptome may hold the key to the in-depth understanding of the MIA pathway and the success of strategies leading to higher levels of the anticancer drugs. Catharanthus mesophyll idioblasts are a hotspot of alkaloid accumulation. The idioblast transcriptome is associated with stress responses and provides a roadmap towards the increase of anticancer alkaloid levels.

2024

The Role of Batteries in Maximizing Green Hydrogen Production with Power Flow Tracing

Autores
Dudkina E.; Villar J.; Bessa R.J.; Crisostomi E.;

Publicação
4th International Conference on Smart Grid and Renewable Energy, SGRE 2024 - Proceedings

Abstract
Hydrogen is currently getting more and more attention in the European climate strategy as a promising enabling technology to decarbonize industry, transport sector and to provide a long-term, high-capacity energy storage solution. However, to truly contribute to the reduction of CO2 emissions, hydrogen must be produced respecting a principle of additionality, to ensure that it is produced using renewable energy sources and that its production does not decrease the green energy supplied to other loads. This study tracks the share of renewables generation in the energy mix used to produce hydrogen by applying a power flow tracing technique integrated with an optimal power flow analysis. This method allows the minimization of the system operation costs, while maximizing the green hydrogen production and considering the additionality principle. The system cost function is also modified to include the sizing and allocation of conventional batteries in the grid, and assess their ability to further increase the share of green energy in hydrogen production.

2024

Points of interest in the city of Barcelos in Portugal through augmented reality

Autores
Pereira M.; Silva J.C.; Pinheiro M.; Carvalho S.; Santos G.;

Publicação
Internet of Things and Cyber-Physical Systems

Abstract
Barcelos is a historic city in Portugal with many tourist attractions, attracting more and more visitors who come to the city with the aim of exploring it. The main objective of this article is to boost tourism in the city of Barcelos, specifically highlighting tourist, historical and leisure spots, based on the development of a mobile application using augmented reality technologies and geolocation. This application intends to allow the users to know historical points of interest in Barcelos, as well as interact with a certain point. The results of this investigation were evaluated by testing the application by end users, with the aim of identifying whether the application meets their needs, in particular the promotion of tourist and historical points.

2024

Quantum advantage in temporally flat measurement-based quantum computation

Autores
de Oliveira, M; Barbosa, LS; Galvao, EF;

Publicação
QUANTUM

Abstract
Several classes of quantum circuits have been shown to provide a quantum computational advantage under certain assumptions. The study of ever more restricted classes of quantum circuits capable of quantum advantage is motivated by possible simplifications in experimental demonstrations. In this paper we study the efficiency of measurement-based quantum computation with a completely flat temporal ordering of measurements. We propose new constructions for the deterministic computation of arbitrary Boolean functions, drawing on correlations present in multi-qubit Greenberger, Horne, and Zeilinger (GHZ) states. We characterize the necessary measurement complexity using the Clifford hierarchy, and also generally decrease the number of qubits needed with respect to previous constructions. In particular, we identify a family of Boolean functions for which deterministic evaluation using non-adaptive MBQC is possible, featuring quantum advantage in width and number of gates with respect to classical circuits.

2024

Does Technological Innovativeness Influence Users' Experiences With Virtual Reality Tourism?

Autores
Sousa, N; Jorge, F; Teixeira, MS; Losada, N; Alen, E; Guttentag, D;

Publicação
INTERNATIONAL JOURNAL OF TOURISM RESEARCH

Abstract
Immersive experiences offered by virtual reality (VR) have the power to impact tourists' decision-making and on-site experiences. However, prior research has focused on explaining VR's acceptance by tourists as a function of technological capacity, rather than user characteristics, such as innovativeness. This research intends to fill the existing knowledge gap regarding the role of technological innovativeness on VR experiences. To do so, this study examines whether individuals' technological innovativeness influences their perceptions of a VR tourism experience and, in turn, their intention to recommend the experience. The study provides a VR experience to 405 tourists at a winery. The results reveal that the tourists' technological innovativeness influences their perception of enjoyment, experience quality, and satisfaction. These findings suggest that, when developing or distributing VR content, the technological innovativeness of the audience is important to consider. The findings have theoretical and practical value, with direct implications for tourism professionals and policymakers.

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