Discrete and continuous symmetries in multi-Higgs-doublet models

We consider the Higgs sector of multi-Higgs-doublet models in the presence of simple symmetries relating the various fields. We construct basis invariant observables which may in principle be used to detect these symmetries for any number of doublets. A categorization of the symmetries into classes is required, which we perform in detail for the case of two and three Higgs doublets.Comment: 13 pages, RevTex, references adde

Charge breaking bounds in the Zee model

We study the possibility that charge breaking minima occur in the Zee model. We reach very different conclusions from those attained in simpler, two Higgs doublet models, and the reason for this is traced back to the existence of cubic terms in the potential. A scan of the Zee model's parameter space shows that CB is restricted to a narrow region of values of the parameters

Minkowski space structure of the Higgs potential in 2HDM: II. Minima, symmetries, and topology

We continue to explore the consequences of the recently discovered Minkowski space structure of the Higgs potential in the two-Higgs-doublet model. Here, we focus on the vacuum properties. The search for extrema of the Higgs potential is reformulated in terms of 3-quadrics in the 3+1-dimensional Minkowski space. We prove that 2HDM cannot have more than two local minima in the orbit space and that a twice-degenerate minimum can arise only via spontaneous violation of a discrete symmetry of the Higgs potential. Investigating topology of the 3-quadrics, we give concise criteria for existence of non-contractible paths in the Higgs orbit space. We also study explicit symmetries of the Higgs potential/lagrangian and their spontaneous violation from a wider perspective than usual.Comment: 27 pages, 5 figure

Basis invariant conditions for supersymmetry in the two-Higgs-doublet model

The minimal supersymmetric standard model involves a rather restrictive Higgs potential with two Higgs fields. Recently, the full set of classes of symmetries allowed in the most general two Higgs doublet model was identified; these classes do not include the supersymmetric limit as a particular class. Thus, a physically meaningful definition of the supersymmetric limit must involve the interaction of the Higgs sector with other sectors of the theory. Here we show how one can construct basis invariant probes of supersymmetry involving both the Higgs sector and the gaugino-higgsino Higgs interactions.Comment: RevTex, 11 pages, v2-small section adde

Blink : observing thin slices of behavior to determine users' expectation towards task difficulty

This work aims to address the following question: is it possible to infer the users' expectations regarding task difficulty by watching them just before the actual start? We present a study where people acting as evaluators determined users’ expectations based on non-linguistic social signals in a 20 seconds video clip. The evaluations were performed using a five-point scale and the average error of the evaluations was of one point. Preliminary results suggest what type of signals was used by the evaluators to determine the users’ expected difficulty with the task.Este trabalho é financiado por Fundos FEDER através do Programa Operacional Factores de Competitividade – COMPETE e por Fundos Nacionais através da FCT – Fundação para a Ciência e a Tecnologia no âmbito do projecto PTDC/EIA-EIA/098634/200

Thin slices of interaction : predicting users’ task difficulty within 60 sec

We report on an exploratory study where the first 60 seconds of the video recording of a user interaction are used to predict the user’s experienced task difficulty. This approach builds on previous work on “thin slices” of human-human behavior, and applies it to humancomputer interaction. In the scenario of interacting with a photocopy machine, automated video coding showed that the Activity and Emphasis predicted 46.6% of the variance of task difficulty. This result closely follows reported results on predicting negotiation outcomes from conversational dynamics using similar variables on the speech signal.The project is funded by FEDER (Fundo Europeu de Desenvolvimento Regional) through COMPETE (Programa Operacional Factores de Competitividade) and by National funds through FCT (Fundação para a Ciência e a Tecnologia) in the context of the project PTDC/EIA-EIA/098634/2008

The role of Polypharmacology and Cholinesterase inhibitors

Publisher Copyright: © 2023 NOVA School of Science and Technology. ChemistrySelect published by Wiley-VCH GmbH.Alzheimer's disease (AD) is a devastating syndrome that accounts for 60–70 % of all dementia cases, putting an enormous burden on global healthcare and economy. Unfortunately, there is no cure for AD, and the currently approved drugs are limited in their effects. Given the various pathological mechanisms behind AD, the “one-target, one-drug” paradigm for drug design became obsolete, and a new paradigm, polypharmacology, emerged. Consequently, a greater focus has been put towards multi-target directed ligands (MTDLs), as these can regulate several targets operating in the disease network. Parallel to that, cholinesterase inhibitors have regained popularity after decades of being considered only symptomatic agents with no disease-modifying properties. In this review, the current AD hypotheses and therapeutic targets, the concept of polypharmacology in AD pathology and the importance of cholinesterases in the pathogenesis and biochemical processes of AD are discussed, with a final overview of the current development in cholinesterase-based MTDLs.publishersversionpublishe

Rhinitis: Epidemiological Knowledge in Portugal

Nas últimas décadas verificou-se, nos paises Ocidentais, um aumento substancial na prevalência de rinite alérgica, sendo o subdiagnóstico e o subtratamento diliculdades acrescidas para a qualidade de vida dos doentes com esta doença inflamatória crónica.É objectivo deste trabalho de revisão, apresentar dados epidemiológicos nacionais referentes à prevalência de rinite, caracterizando alguns factores de risco, realçando-se o problema da falta de diagnóstico desta situação c1ínica tão prevalente no nosso pais

Integration of touch attention mechanisms to improve the robotic haptic exploration of surfaces

This text presents the integration of touch attention mechanisms to improve the efficiency of the action-perception loop, typically involved in active haptic exploration tasks of surfaces by robotic hands. The progressive inference of regions of the workspace that should be probed by the robotic system uses information related with haptic saliency extracted from the perceived haptic stimulus map (exploitation) and a “curiosity”-inducing prioritisation based on the reconstruction's inherent uncertainty and inhibition-of-return mechanisms (exploration), modulated by top-down influences stemming from current task objectives, updated at each exploration iteration. This work also extends the scope of the top-down modulation of information presented in a previous work, by integrating in the decision process the influence of shape cues of the current exploration path. The Bayesian framework proposed in this work was tested in a simulation environment. A scenario made of three different materials was explored autonomously by a robotic system. The experimental results show that the system was able to perform three different haptic discontinuity following tasks with a good structural accuracy, demonstrating the selectivity and generalization capability of the attention mechanisms. These experiments confirmed the fundamental contribution of the haptic saliency cues to the success and accuracy of the execution of the tasks

Extending Inferential Group Analysis in Type 2 Diabetic Patients with Multivariate GLM Implemented in SPM8

BACKGROUND: Although voxel based morphometry studies are still the standard for analyzing brain structure, their dependence on massive univariate inferential methods is a limiting factor. A better understanding of brain pathologies can be achieved by applying inferential multivariate methods, which allow the study of multiple dependent variables, e.g. different imaging modalities of the same subject. OBJECTIVE: Given the widespread use of SPM software in the brain imaging community, the main aim of this work is the implementation of massive multivariate inferential analysis as a toolbox in this software package. applied to the use of T1 and T2 structural data from diabetic patients and controls. This implementation was compared with the traditional ANCOVA in SPM and a similar multivariate GLM toolbox (MRM). METHOD: We implemented the new toolbox and tested it by investigating brain alterations on a cohort of twenty-eight type 2 diabetes patients and twenty-six matched healthy controls, using information from both T1 and T2 weighted structural MRI scans, both separately - using standard univariate VBM - and simultaneously, with multivariate analyses. RESULTS: Univariate VBM replicated predominantly bilateral changes in basal ganglia and insular regions in type 2 diabetes patients. On the other hand, multivariate analyses replicated key findings of univariate results, while also revealing the thalami as additional foci of pathology. CONCLUSION: While the presented algorithm must be further optimized, the proposed toolbox is the first implementation of multivariate statistics in SPM8 as a user-friendly toolbox, which shows great potential and is ready to be validated in other clinical cohorts and modalities