3,928 research outputs found
Impact of Estimation Uncertainty in PMU-Based Resynchronization of Continental Europe Synchronous Areas
Power system stability is a task that every system operator (SO) is required to achieve daily to ensure an uninterruptible power supply. Especially at the transmission level, for each SO it is of utmost importance to ensure proper exchange of information with other SOs, mainly in case of contingencies. However, in the last years, two major events led to the splitting of Continental Europe into two synchronous areas. These events were caused by anomalous conditions which involved in one case the fault of a transmission line and in the other a fire outage in proximity to high-voltage lines. This work analyzes these two events from the measurement point of view. In particular, we discuss the possible impact of estimation uncertainty on control decisions based on measurements of instantaneous frequency. For this purpose, we simulate five different configurations of phasor measurement units (PMUs), as characterized by different signal models, processing routines, and estimation accuracy in the presence of off-nominal or dynamic conditions. The objective is to establish the accuracy of the frequency estimates in transient conditions, more specifically during the resynchronization of the Continental Europe area. Based on this knowledge, it is possible to set more suitable conditions for resynchronization operations: the idea is to consider not only the frequency deviation between the two areas but also to take into account the respective measurement uncertainty. As confirmed by the analysis of the two real-world scenarios, such an approach would allow for minimizing the probability of adverse or even dangerous conditions such as dampened oscillations and inter-modulations
Terminology in the Digital World
UIDB/03213/2020
UIDP/03213/2020This Special Issue is dedicated to the 2nd International Conference on “Multilingual digital terminology today: Design, representation formats, and management systems” (MDTT 2023), which took place in Lisbon, Portugal, from 29 to 30 June, 2023publishersversionpublishe
Organizational culture and lean practices: analysis through a real case study
Nowadays, lean researchers are focused on the role of organizational culture and contingencies factors in the success and sustainability of lean management. This research aims at contributing to the academia debate by analysing through a deep case study whether organizational culture based on lean management can enable companies in overcoming differences related to the national culture. Moreover, the study wants to provide evidences that companies can leverage on lean practice in order to spread organizational culture among different country-based plants
enquĂŞte sur la perception du trouble dysmorphique corporel
UIDB/03213/2020
UIDP/03213/2020This study explores the notion of referent in terminology, focusing on body dysmorphic disorder (BDD). We delve into the relationship between object, concept, referent, and term, highlighting their interdependence and their impact on the perception of this pathology. With a questionnaire, we analyze the denominative variants of BDD and examine how these terms shape the mental representations of this medical condition, often generating negative connotations.publishersversionpublishe
Identification of G-quadruplex DNA/RNA binders: Structure-based virtual screening and biophysical characterization
Background
Recent findings demonstrated that, in mammalian cells, telomere DNA (Tel) is transcribed into telomeric repeat-containing RNA (TERRA), which is involved in fundamental biological processes, thus representing a promising anticancer target. For this reason, the discovery of dual (as well as selective) Tel/TERRA G-quadruplex (G4) binders could represent an innovative strategy to enhance telomerase inhibition.
Methods
Initially, docking simulations of known Tel and TERRA active ligands were performed on the 3D coordinates of bimolecular G4 Tel DNA (Tel2) and TERRA (TERRA2). Structure-based pharmacophore models were generated on the best complexes and employed for the virtual screening of ~ 257,000 natural compounds. The 20 best candidates were submitted to biophysical assays, which included circular dichroism and mass spectrometry at different K+ concentrations.
Results
Three hits were here identified and characterized by biophysical assays. Compound 7 acts as dual Tel2/TERRA2 G4-ligand at physiological KCl concentration, while hits 15 and 17 show preferential thermal stabilization for Tel2 DNA. The different molecular recognition against the two targets was also discussed.
Conclusions
Our successful results pave the way to further lead optimization to achieve both increased selectivity and stabilizing effect against TERRA and Tel DNA G4s.
General significance
The current study combines for the first time molecular modelling and biophysical assays applied to bimolecular DNA and RNA G4s, leading to the identification of innovative ligand chemical scaffolds with a promising anticancer profile. This article is part of a Special Issue entitled "G-quadruplex" Guest Editor: Dr. Concetta Giancola and Dr. Daniela Montesarchio
The use of image analysis as a new approach to assess behaviour classification in a pig barn
The aim of this study was to develop an innovative method for measuring the activity level of pigs in a barn in real time. An infrared-sensitive camera was placed over two pens of the piggery, images were recorded for 24 h a day for eight days during the fattening period, and the activity and occupation indices were calculated every second in real time using software. In the laboratory, the recorded images were visually labelled to score the animals' behaviour adopting the Martin and Bateson's Scan sampling method, and to find a relation with the automatically measured activity index. Pigs' behaviour was assigned in the following way, 0 - no activity, 1 - fighting or struggling, 2 - biting one another, 3 - abnormal behaviour as nuzzling or suckling one another (interacting pigs), 4 - feed assumption time. Pigs spent most of the time lying inactively (82–90% of the time), following a diurnal rhythm with peaks related to the feeding administration routine; fighting episodes occurred very rarely (0.05–0.10% of the time). Based on the analysis of the automatically measured group activity index compared to the manual labelling, a relation was found between the activity index and the behaviour types (no activity, nuzzling and feeding). The novelty presented in this study was the development of on-line tools to monitor farm animals continuously during their life, in a fully automatic way, with objective measures and criteria without imposing additional stress to the animals
Checkpoint Inhibition in Myeloma: Opportunities and Challenges
Despite major improvements in the treatment landscape, most multiple myeloma (MM) patients eventually succumb to the underlying malignancy. Immunotherapy represents an attractive strategy to achieve durable remissions due to its specificity and capacity for long term memory. Activation of immune cells is controlled by a balance of agonistic and inhibitory signals via surface and intracellular receptors. Blockade of such inhibitory immune receptors (termed as “immune checkpoints”) including PD-1/PD-L1 has led to impressive tumor regressions in several cancers. Preclinical studies suggest that these immune checkpoints may also play a role in regulating tumor immunity in MM. Indeed, myeloma was among the first tumors wherein therapeutic efficacy of blockade of PD-1 axis was demonstrated in preclinical models. Expression of PD-L1 on tumor and immune cells also correlates with the risk of malignant transformation. However, early clinical studies of single agent PD-1 blockade have not led to meaningful tumor regressions. Immune modulatory drugs (IMiDs) are now the mainstay of most MM therapies. Interestingly, the mechanism of immune activation by IMiDs also involves release of inhibitory checkpoints, such as Ikaros-mediated suppression of IL-2. Combination of PD-1 targeted agents with IMiDs led to promising clinical activity, including objective responses in some patients refractory to IMiD therapy. However, some of these studies were transiently halted in 2017 due to concern for a possible safety signal with IMiD-PD1 combination. The capacity of the immune system to control MM has been further reinforced by recent success of adoptive cell therapies, such as T cells redirected by chimeric-antigen receptors (CAR-Ts). There remains an unmet need to better understand the immunologic effects of checkpoint blockade, delineate mechanisms of resistance to these therapies and identify optimal combination of agonistic signaling, checkpoint inhibitors as well as other therapies including CAR-Ts, to realize the potential of the immune system to control and prevent MM
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