Brain-Inspired Intelligent Systems for Daily Assistance

The fields of machine learning and cognitive computing have been in the last decade revolutionised with neural-inspired algorithms (e.g., deep ANNs and deep RL) and brain-intelligent systems that assist in many real-world learning tasks from robot monitoring and interaction at home to complex decision-making about emotions and behaviours in humans and animals. While there are remarkable advances in these brain-inspired algorithms and systems, they need to be trained with huge data sets, and their results lack flexibility to adapt to diverse learning tasks and sustainable performance over long periods of time. To address these challenges, it is essential to gain an analytical understanding of the principles that allow biological inspired intelligent systems to leverage knowledge and how they can be translated to hardware for daily assistance and practical applications. This special issue brings researchers from interdesciplinary domains to report their latest research work on algorithms and neural-inspired systems that flexibly adapt to new learning tasks, learn from the environment using multimodal signals (e.g., neural, physiological, and kinematic), and produce autonomous adaptive agencies, which utilise cognitive and affective data, within a social neuroscientific framework. In this special issue, we have selected five papers out of fourteen high-quality papers after a careful reviewing process, which brings the acceptance rate to 35.7 percent. The five papers are representative of the current state-of-the-art in this area

Distributed Path Computation without Transient Loops: An Intermediate Variables Approach

Paths with loops, even transient ones, pose significant stability problems in networks. As a result, much effort has been devoted over the past thirty years to designing distributed algorithms capable of avoiding loops. We present a new algorithm, Distributed path computation with Intermediate Variables (DIV), that guarantees that no loops, transient or steady-state, can ever form. DIV’s novelty is in that it is not restricted to shortest paths, can easily handle arbitrary sequences of changes and updates, and provably outperforms earlier approaches in several key metrics. In addition, when used with distance-vector style path computation algorithms, DIV also prevents counting-to-infinity; hence further improving convergence. The paper introduces DIV and its key properties. Simulation quantifying its performance gains are also presented

Transmission Losses in Left-handed Materials

We numerically analyze the origin of the transmission losses in left-handed structures. Our data confirms that left handed structures can have very good transmission properties, in spite of the expectable dispersion of their effective permeability and refraction index. The large permittivity of the metallic components improves the transmission. High losses, observed in recent experiments, could be explained by the absorption of the dielectric board

Specific gene correction of the AGXT gene and direct cell reprogramming for the treatment of Primary Hyperoxaluria Type 1

P428 Primary Hyperoxaluria Type 1 (PH1) is an inherited rare metabolic liver disease caused by the deficiency in the alanine: glyoxylate aminotransferase enzyme (AGXT), involved in the glyoxylate metabolism. The only potentially curative treatment is organ transplantation. Thus, the development of new therapeutic approaches for the treatment of these patients appears as a priority.We propose the combination of site-specific gene correction and direct cell reprogramming for the generation of autologous phenotypically healthy induced hepatocytes (iHeps) from skin-derived fibroblast of PH1 patients. For the correction of AGXT mutations, we have designed specific gene editing tools to address gene correction by two different strategies, assisted by CRISPR/Cas9 system. Accurate specific point mutation correction (c.853T-C) has been achieved by homologydirected repair (HDR) with ssODN harbouring wild-type sequence. In the second strategy, an enhanced version ofAGXTcDNAhas been inserted near the transcription start codon of the endogenous gene, constituting an almost universal correction strategy for PH1 mutations. Direct reprogramming of fibroblasts has been conducted by overexpression of hepatic transcription factors and in vitro culture in defined media. In vitro characterization of healthy induced hepatocytes (iHeps) has demonstrated hepatic function of the reprogrammed cells. PH1 patient fibroblasts and , ,

Radiative Lifetimes of Single Excitons in Semiconductor Quantum Dots- Manifestation of the Spatial Coherence Effect

Using time correlated single photon counting combined with temperature dependent diffraction limited confocal photoluminescence spectroscopy we accurately determine, for the first time, the intrinsic radiative lifetime of single excitons confined within semiconductor quantum dots. Their lifetime is one (two) orders of magnitude longer than the intrinsic radiative lifetime of single excitons confined in semiconductor quantum wires (wells) of comparable confining dimensions. We quantitatively explain this long radiative time in terms of the reduced spatial coherence between the confined exciton dipole moment and the radiation electromagnetic field.Comment: 4 pages, 3 figure

Relation between incidence of Fusarium graminearum in seeds, emergence and occurrence of giberela in wheat seedlings

Com o objetivo de verificar o comportamento de 30 genótipos de trigo em relação à emergência e à incidência de giberela em plântulas provenientes de sementes portadoras de Fusarium graminearum, foram instalados experimentos de laboratório e casa-de-vegetação. Em laboratório, as sementes utilizadas para os experimentos de emergência e incidência de giberela foram analisadas para sanidade pelo método do papel de filtro com congelamento. Em casa-de-vegetação, as sementes foram distribuídas em caixas de plástico, contendo areia tratada com brometo de metila. O delineamento utilizado foi o de blocos casualizados, constituído de 30 tratamentos com quatro repetições de 50 sementes, perfazendo um total de 200 sementes/tratamento. As avaliações da emergência de plântulas e da incidência de giberela foram feitas aos sete, 14 e 21 dias após a semeadura (DAS), contando-se o número de plântulas emergidas e retirando-se as plântulas sintomáticas, as quais foram submetidas a câmara úmida, por 24 horas, em laboratório. Não houve diferença significativa da incidência do patógeno na emergência das plântulas. Não foi constatada correlação entre a incidência de giberela nas plântulas e o nível de resistência dos genótipos, bem como entre incidência de giberela nas plântulas e a incidência do patógeno nas sementes.In order to verify the behavior of 30 genotypes of wheat in relation to the emergence and incidence of giberela in wheat seedlings from seeds contaminated with F. graminearum, experiments were carried out under laboratory and greenhouse conditions. In the laboratory, seeds were analyzed for health using freezer blotter test. In the greenhouse, seeds were sowed in plastic boxes filled with sand treated with methyl bromide. Statistical design was randomized blocks with 30 treatments, four replications of 50 seeds (200 seeds/treatment). Emergence of seedlings and giberela incidence were evaluated at seven, 14 and 21 days after sowing. Symptomatic seedlings were removed and submitted to humid chambers for 24 hours under laboratory conditions. There was no significant difference in the incidence of the pathogen in the emergence of seedlings. There was no correlation between the incidence of F. graminearum in the genotypes and incidence of giberela in seedlings, nor between the incidence of giberela in seedlings and the incidence of the pathogen in the seeds

Delay-induced Synchronization Phenomena in an Array of Globally Coupled Logistic Maps

We study the synchronization of a linear array of globally coupled identical logistic maps. We consider a time-delayed coupling that takes into account the finite velocity of propagation of the interactions. We find globally synchronized states in which the elements of the array evolve along a periodic orbit of the uncoupled map, while the spatial correlation along the array is such that an individual map sees all other maps in his present, current, state. For values of the nonlinear parameter such that the uncoupled maps are chaotic, time-delayed mutual coupling suppress the chaotic behavior by stabilizing a periodic orbit which is unstable for the uncoupled maps. The stability analysis of the synchronized state allows us to calculate the range of the coupling strength in which global synchronization can be obtained.Comment: 8 pages, 7 figures, changed content, added reference

Chemistry of the interaction between an alkoxysilane-based impregnation treatment and cementitious phases

Chemical compatibility with a wide range of materials is among the features that has driven the use of alkoxysilanes as consolidants in built structures. Such compatibility is particularly important in cementitious materials where the reaction with portlandite may generate C-S-H gel, one of the main hydration phases of OPC. The cementitious matrix is a complex system, however, and the reaction of its many phases with alkoxysilanes, while poorly understood, may determine treatment efficacy. This article describes a detailed study of the individual interactions between an oligomeric alkoxysilane-based impregnation treatment previously shown to interact with the portlandite present in cement paste and the cementitious phases generated in ordinary portland cement hydration. The findings show that both portlandite and C-S-H gel interact with the silicon oligomers in the hydrolysed impregnation treatment to generate a C-S-H gel (in the case of portlandite) and a rise in C-S-H gel mean chain length (MCL). Ettringite is also altered in the presence of alkoxysilanes, transforming to gypsum and AH(3). Its transformation generates a tetrahedral aluminium that is taken up into a high silicon gel sourced from the treatment to form an amorphous aluminosilicate gel. Monocarboaluminate and katoite also partially decompose in the interaction with the product, whereas gibbsite remains unaffected

Questions of perfect lenses by left handed materials

We consider questions about the much discussed "perfect lenses" made by left handed materials. The transmission and reflection from a slab of left handed materials are investigated and the coefficients are obtained by the standard transfer matrix method. Possible limitations on such superlenses are explored. It is shown that the quality of the lenses can be significantly affected by the absorption that is necessarily present in the materials.Comment: 3 figure