Singly generated quasivarieties and residuated structures

A quasivariety K of algebras has the joint embedding property (JEP) iff it is generated by a single algebra A. It is structurally complete iff the free countably generated algebra in K can serve as A. A consequence of this demand, called "passive structural completeness" (PSC), is that the nontrivial members of K all satisfy the same existential positive sentences. We prove that if K is PSC then it still has the JEP, and if it has the JEP and its nontrivial members lack trivial subalgebras, then its relatively simple members all belong to the universal class generated by one of them. Under these conditions, if K is relatively semisimple then it is generated by one K-simple algebra. It is a minimal quasivariety if, moreover, it is PSC but fails to unify some finite set of equations. We also prove that a quasivariety of finite type, with a finite nontrivial member, is PSC iff its nontrivial members have a common retract. The theory is then applied to the variety of De Morgan monoids, where we isolate the sub(quasi)varieties that are PSC and those that have the JEP, while throwing fresh light on those that are structurally complete. The results illuminate the extension lattices of intuitionistic and relevance logics

Será que o brasileiro está poupando o suficiente para se aposentar?

This article answers the question: how much wealth should a Brazilian accumulate along time to sustain his (her) consumption during retirement? Using a life-cycle model, we simulate scenarios for different household incomes, family size, and life circumstances, to obtain the additional saving effort needed by future beneficiaries of the Regime Geral de Previdência Social (RGPS). Given the current high replacement rates, we show that more than 95% of the population needs no additional savings during their working age, because they will enjoy an increase in their “free” per capita income during retirement. In other words, surprisingly, a low voluntary saving rate is the right decision from the perspective of an average Brazilian that plans a smooth consumption, in the belief that current social security arrangements will persist. Were it not for the very high banking spread, it would be optimal for the average Brazilian to borrow in the working age to increase his (her) consumption level.Este artigo responde à pergunta: qual o acúmulo de patrimônio necessário para que um brasileiro possa manter o seu padrão de consumo na aposentadoria? Baseado na Teoria do Ciclo de Vida, simulamos diferentes cenários de renda domiciliar, tamanho de família e circunstâncias de vida, para determinar a poupança complementar necessária aos futuros beneficiários do Regime Geral de Previdência Social (RGPS). Mantidas as elevadas taxas de reposição, demonstramos que mais de 95% da população não necessita poupar durante a vida ativa, pois desfrutarão de um aumento da renda “livre” per capita na aposentadoria. Ou seja, surpreendentemente, uma baixa taxa de poupança voluntária é a reação correta da perspectiva do brasileiro médio que planeja um consumo estável, crente na manutenção do arranjo previdenciário vigente. Não fosse o altíssimo spread bancário, seria ótimo para o brasileiro médio se endividar na fase ativa para elevar seu nível de consumo

A modal theorem-preserving translation of a class of three-valued logics of incomplete information

International audienceThere are several three-valued logical systems that form a scattered landscape, even if all reasonable connectives in three-valued logics can be derived from a few of them. Most papers on this subject neglect the issue of the relevance of such logics in relation with the intended meaning of the third truth-value. Here, we focus on the case where the third truth-value means unknown, as suggested by Kleene. Under such an understanding, we show that any truth-qualified formula in a large range of three-valued logics can be translated into KD as a modal formula of depth 1, with modalities in front of literals only, while preserving all tautologies and inference rules of the original three-valued logic. This simple information logic is a two-tiered classical propositional logic with simple semantics in terms of epistemic states understood as subsets of classical interpretations. We study in particular the translations of Kleene, Gödel, ᴌukasiewicz and Nelson logics. We show that Priest’s logic of paradox, closely connected to Kleene’s, can also be translated into our modal setting, simply by exchanging the modalities possible and necessary. Our work enables the precise expressive power of three-valued logics to be laid bare for the purpose of uncertainty management

Solution-processed, Self-organized Organic Single Crystal Arrays with Controlled Crystal Orientation

A facile solution process for the fabrication of organic single crystal semiconductor devices which meets the demand for low-cost and large-area fabrication of high performance electronic devices is demonstrated. In this paper, we develop a bottom-up method which enables direct formation of organic semiconductor single crystals at selected locations with desired orientations. Here oriented growth of one-dimensional organic crystals is achieved by using self-assembly of organic molecules as the driving force to align these crystals in patterned regions. Based upon the self-organized organic single crystals, we fabricate organic field effect transistor arrays which exhibit an average field-effect mobility of 1.1 cm2V−1s−1. This method can be carried out under ambient atmosphere at room temperature, thus particularly promising for production of future plastic electronics

Afatinib therapy in case of EGFR G724S emergence as resistance mechanism to osimertinib

Osimertinib is a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) used both as the first-line treatment of EGFR-mutated non-small cell lung cancer patients and in second-line after T790M-positive disease progression to first- or second-generation TKIs. Unfortunately, patients unavoidably experience disease progression to osimertinib and the current research is focused on resistance mechanisms and the relative therapeutic strategy. We report the case of a patient with advanced EGFR-mutated (exon 19 deletion and T790M-positive) non-small cell lung cancer who developed disease progression to osimertinib characterized by the loss of T790M concurrently with the emergence of G724S EGFR mutation, which was tackled by subsequent afatinib treatment. Next-generation sequencing molecular study of rebiopsy at time of progression to osimertinib revealed the persistence of EGFR exon 19 deletion, loss of T790M with a new G724S EGFR mutation; other concomitant mechanisms were excluded. Retrospective analysis of cell-free DNA revealed the emergence of G724S EGFR mutation four months before the radiologically-proven disease progression. The patient, after chemotherapy, was treated with afatinib with clinical and radiological benefit. Our case report contributes to increase the knowledge on acquired resistance mechanisms to osimertinib treatment, and it shows, for the first time, the efficacy of afatinib in the case of T790M loss and emergence of G724S EGFR mutation. Anti-Cancer Drugs 32: 758-762 Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved

3D printed PEDOT:PSS-based conducting and patternable eutectogel electrodes for machine learning on textiles

The proliferation of medical wearables necessitates the development of novel electrodes for cutaneous electrophysiology. In this work, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) is combined with a deep eutectic solvent (DES) and polyethylene glycol diacrylate (PEGDA) to develop printable and biocompatible electrodes for long-term cutaneous electrophysiology recordings. The impact of printing parameters on the conducting properties, morphological characteristics, mechanical stability and biocompatibility of the material were investigated. The optimised eutectogel formulations were fabricated in four different patterns —flat, pyramidal, striped and wavy— to explore the influence of electrode geometry on skin conformability and mechanical contact. These electrodes were employed for impedance and forearm EMG measurements. Furthermore, arrays of twenty electrodes were embedded into a textile and used to generate body surface potential maps (BSPMs) of the forearm, where different finger movements were recorded and analysed. Finally, BSPMs for three different letters (B, I, O) in sign-language were recorded and used to train a logistic regressor classifier able to reliably identify each letter. This novel cutaneous electrode fabrication approach offers new opportunities for long-term electrophysiological recordings, online sign-language translation and brain-machine nterfaces.Fil: Ruiz Mateos Serrano, Ruben. University of Cambridge; Reino UnidoFil: Aguzin, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Mitoudi Vagourdi, Eleni. University of Cambridge; Estados UnidosFil: Tao, Xudong. University of Cambridge; Reino UnidoFil: Naegele, Tobias E.. University of Cambridge; Reino UnidoFil: Jin, Amy T.. University of Cambridge; Reino UnidoFil: Lopez Larrea, Naroa. Universidad del País Vasco; EspañaFil: Picchio, Matías Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Alban Paccha, Marco Vinicio. University of Cambridge; Estados UnidosFil: Minari, Roque Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Mecerreyes, David. Universidad del País Vasco; EspañaFil: Dominguez Alfaro, Antonio. University of Cambridge; Reino UnidoFil: Malliaras, George G.. University of Cambridge; Estados Unido

Dipping-Induced Azimuthal Helix Orientation in Langmuir-Blodgett Monolayers of α-Helical Amphiphilic Diblock Copolypeptides

The azimuthal helix orientation of the rigid-rod amphiphilic diblock copolypeptides (PLGA-b-PMLGSLGs) of poly(α-L-glutamic acid) (PLGA) and poly(γ-methyl-L-glutamate-ran-γ-stearyl-L-glutamate) with 30 mol % of stearyl substituents (PMLGSLG) in Langmuir-Blodgett (LB) monolayers was investigated using polarized transmission Fourier transform infrared spectroscopy. The relative position of dipping with respect to the previous transfer position can be used to manipulate the azimuthal orientation of the helices parallel to or tilted by an angle of 45° with respect to the dipping direction in the transferred films. The study of the azimuthal order for the LB monolayers of PLGA-b-PMLGSLGs of various block lengths revealed that the observed effect arises mainly from the deformation of the PMLGSLG top brush layer, induced by the flow orientation around the transfer region. In those cases where the PMLGSLG block is tilted by a sufficiently large angle with respect to the surface normal, high azimuthal order parameters of 0.5-0.75 were obtained.