Browsing by Issue Date, starting with "2020-12-03"
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- Oligomerization Profile of Human Transthyretin Variants with Distinct AmyloidogenicityPublication . Frangolho, Ana; Correia, Bruno E.; Vaz, Daniela C.; Almeida, Zaida L.; Brito, Rui M. M.One of the molecular hallmarks of amyloidoses is ordered protein aggregation involving the initial formation of soluble protein oligomers that eventually grow into insoluble fibrils. The identification and characterization of molecular species critical for amyloid fibril formation and disease development have been the focus of intense analysis in the literature. Here, using photo-induced cross-linking of unmodified proteins (PICUP), we studied the early stages of oligomerization of human transthyretin (TTR), a plasma protein involved in amyloid diseases (ATTR amyloidosis) with multiple clinical manifestations. Upon comparison, the oligomerization processes of wild-type TTR (TTRwt) and several TTR variants (TTRV30M, TTRL55P, and TTRT119M) clearly show distinct oligomerization kinetics for the amyloidogenic variants but a similar oligomerization mechanism. The oligomerization kinetics of the TTR amyloidogenic variants under analysis showed a good correlation with their amyloidogenic potential, with the most amyloidogenic variants aggregating faster (TTRL55P > TTRV30M > TTRwt). Moreover, the early stage oligomerization mechanism for these variants involves stepwise addition of monomeric units to the growing oligomer. A completely different behavior was observed for the nonamyloidogenic TTRT119M variant, which does not form oligomers in the same acidic conditions and even for longer incubation times. Thorough characterization of the initial steps of TTR oligomerization is critical for better understanding the origin of ATTR cytotoxicity and developing novel therapeutic strategies for the treatment of ATTR amyloidosis.
- Prevalence of Childhood Obesity in Portugal: A Narrative Review of the LiteraturePublication . Frade, Fátima; Carteiro, Dora; Pereira, Fátima; Marques, Joana; Graça Frade, João ManuelBackground: The number of childhood obesity cases has been increasing in several countries around the world. In view of all the associated complications at an early stage of child development, it becomes urgent to understand this problem in depth. Objective: The aim of this work was to describe the prevalence of childhood obesity in Portugal and analyze the trend of its evolution in recent years. Materials and Methods: This is a narrative review of the literature in the databases on the following platforms: Academic Google, Scientific Electronic Library Online (SciELO), EBSCO Host, and Biblioteca Virtual em Saúde (BVS). The keywords used were: Prevalence, Pediatric Obesity, Child Overweight, and Portugal. Results and Discussion: Data on the prevalence of childhood obesity in Portugal are presented, describing the results of studies conducted at national and district level, in the different age groups and by sex. Conclusions: The data reveal that the prevalence of overweight in Portugal ranges between 20 and 40%, and of obesity between 10 and 15%, which reinforces the urgent need for monitoring and implementing preventive measures.
- The Value of Information Searching against Fake NewsPublication . Martins, José; Pinto, AlbertoInspired by the Daley-Kendall and Goffman-Newill models, we propose an Ignorant-Believer-Unbeliever rumor (or fake news) spreading model with the following characteristics: (i) a network contact between individuals that determines the spread of rumors; (ii) the value (cost versus benefit) for individuals who search for truthful information (learning); (iii) an impact measure that assesses the risk of believing the rumor; (iv) an individual search strategy based on the probability that an individual searches for truthful information; (v) the population search strategy based on the proportion of individuals of the population who decide to search for truthful information; (vi) a payoff for the individuals that depends on the parameters of the model and the strategies of the individuals. Furthermore, we introduce evolutionary information search dynamics and study the dynamics of population search strategies. For each value of searching for information, we compute evolutionarily stable information (ESI) search strategies (occurring in non-cooperative environments), which are the attractors of the information search dynamics, and the optimal information (OI) search strategy (occurring in (eventually forced) cooperative environments) that maximizes the expected information payoff for the population. For rumors that are advantageous or harmful to the population (positive or negative impact), we show the existence of distinct scenarios that depend on the value of searching for truthful information. We fully discuss which evolutionarily stable information (ESI) search strategies and which optimal information (OI) search strategies eradicate (or not) the rumor and the corresponding expected payoffs. As a corollary of our results, a recommendation for legislators and policymakers who aim to eradicate harmful rumors is to make the search for truthful information free or rewarding.