Higher physical fitness levels are associated with less language decline in healthy ageing

Healthy ageing is associated with decline in cognitive abilities such as language. Aerobic fitness has been shown to ameliorate decline in some cognitive domains, but the potential benefits for language have not been examined. In a cross-sectional sample, we investigated the relationship between aerobic fitness and tip-of-the-tongue states. These are among the most frequent cognitive failures in healthy older adults and occur when a speaker knows a word but is unable to produce it. We found that healthy older adults indeed experience more tip-of-the-tongue states than young adults. Importantly, higher aerobic fitness levels decrease the probability of experiencing tip-of-the-tongue states in healthy older adults. Fitness-related differences in word finding abilities are observed over and above effects of age. This is the first demonstration of a link between aerobic fitness and language functioning in healthy older adults

Topological representations of matroid maps

The Topological Representation Theorem for (oriented) matroids states that every (oriented) matroid can be realized as the intersection lattice of an arrangement of codimension one homotopy spheres on a homotopy sphere. In this paper, we use a construction of Engstr\"om to show that structure-preserving maps between matroids induce topological mappings between their representations; a result previously known only in the oriented case. Specifically, we show that weak maps induce continuous maps and that the process is a functor from the category of matroids with weak maps to the homotopy category of topological spaces. We also give a new and conceptual proof of a result regarding the Whitney numbers of the first kind of a matroid.Comment: Final version, 21 pages, 8 figures; Journal of Algebraic Combinatorics, 201

Verification of Magnitude and Phase Responses in Fixed-Point Digital Filters

In the digital signal processing (DSP) area, one of the most important tasks is digital filter design. Currently, this procedure is performed with the aid of computational tools, which generally assume filter coefficients represented with floating-point arithmetic. Nonetheless, during the implementation phase, which is often done in digital signal processors or field programmable gate arrays, the representation of the obtained coefficients can be carried out through integer or fixed-point arithmetic, which often results in unexpected behavior or even unstable filters. The present work addresses this issue and proposes a verification methodology based on the digital-system verifier (DSVerifier), with the goal of checking fixed-point digital filters w.r.t. implementation aspects. In particular, DSVerifier checks whether the number of bits used in coefficient representation will result in a filter with the same features specified during the design phase. Experimental results show that errors regarding frequency response and overflow are likely to be identified with the proposed methodology, which thus improves overall system's reliability

Argamassas multifuncionais para armazenamento de calor, despoluição do ar e auto-limpeza, processo para a sua preparação e utilização

Patente Portuguesa n.º PT 106935A presente invenção diz respeito a argamassas, para aplicação no revestimento interior e exterior de sistemas construtivos, que compreende misturas, em diferentes proporções, de microcápsulas de materiais de mudança de fase (PCM) e nanopartículas de dióxido de titânio, juntamente com um ou mais ligantes, à base de cal, cimento ou gesso, agregados, água e outros materiais auxiliares. A invenção diz também respeito a um processo para a elaboração das referidas argamassas por mistura prévia e homogeneização, em seco, dos componentes sólidos, com posterior mistura com água e homogeneização numa máquina misturadora. A argamassa de acordo com a invenção é utilizada no revestimento interior e exterior de sistemas construtivos, com o objectivo de poupar energia, melhorar a qualidade do ar e assegurar auto-limpeza.Fundação para a Ciência e a Tecnologia (FCT

Papel de nano-aditivos na funcionalização de argamassas

A manutenção da qualidade do ar no interior dos edifícios é um dos aspetos mais relevantes da construção sustentável e tem forte impacto no nível de conforto dos utilizadores. A introdução de nano-aditivos em materiais de construção permite modificar propriedades fundamentais destes materiais convencionais, com o objetivo de proporcionar novas funcionalidades. Neste trabalho apresentam-se os resultados obtidos com o desenvolvimento de argamassas funcionais que pretendem melhorar a qualidade do ar interior e contribuir para a poupança energética dos edifícios. As formulações foram optimizadas com vista à sua aplicação em construção nova ou reabilitação

One-note samba: the biogeographical history of the relict Brazilian butterfly Elkalyce cogina

[Aim] Biogeographically puzzling taxa represent an opportunity to understand the processes that have shaped current species distributions. The systematic placement and biogeographical history of Elkalyce cogina, a small lycaenid butterfly endemic to Brazil and neighbouring Argentina, are long-standing puzzles. We use molecular tools and novel biogeographical and life history data to clarify the taxonomy and distribution of this butterfly.[Location] South America, with emphasis on the Atlantic Rain Forest and Cerrado biomes (Brazil and Argentina).[Methods] We gathered a data set of 71 Polyommatini (Lycaenidae) samples, including representatives of all described subtribes and/or sections. Among these, we contributed new sequences for E. cogina and four additional relevant taxa in the target subtribes Everina, Lycaenopsina and Polyommatina. We inferred a molecular phylogeny based on three mitochondrial genes and four nuclear markers to assess the systematic position and time of divergence of E. cogina. Ancestral geographical ranges were estimated with the R package BioGeoBEARS. To investigate heterogeneity in clade diversification rates, we used Bayesian analysis of macroevolutionary mixtures (bamm).[Results] Our results confirm the hypothesis that E. cogina belongs to the subtribe Everina and not Lycaenopsina, but unexpectedly recovered it as the sister group to the rest of Everina, with an estimated divergence time of approximately 10 Ma. Ancestral geographical range reconstruction points to an old colonization from Asia, the centre of diversity for the Everina, to the New World. The Neotropical Polyommatina lineage diversified to produce almost 100 species in multiple genera, whereas the E. cogina lineage did not diversify at all. Such lack of diversification is unique among the seven Everina/Polyommatina lineages that colonized the New World. We also show that the larvae of E. cogina feed on Fabaceae, supporting the identification of this host-plant family as the ancestral state for the whole group.[Main conclusions] The age and biogeographical reconstruction of the Elkalyce lineage are similar to those of the Neotropical lineage of Polyommatina and suggest that both travelled via the route proposed by Vladimir Nabokov (Asia-Beringia-North America-South America). This coincidence suggests that the climatic conditions at c. 10 Ma favoured dispersal from Asia to the Neotropics and that later events may have erased traces of these butterfly lineages in North America.Funding was provided by the Spanish Ministerio de Economía y Competitividad (project CGL2013-48277-P). G.T. is supported by the grant BP-A00275 (AGAUR-Generalitat de Catalunya), Marie Curie Actions FP7-PEOPLE-2013-IOF (project 622716) and the grant 1.50.1617.2013 at Saint Petersburg State University; L.A.K. was supported by CAPES (3200-14-0); A.V.L.F. thanks ICMBio for research permits (SISBIO no. 10802-5), CNPq (fellowship 302585/2011-7 and grant 564954/2010-1), RedeLep-SISBIOTA-Brasil/CNPq (563332/2010-7), the National Science Foundation (DEB-1256742), BR-BoL (MCT/CNPq/FNDCT 50/2010) and FAPESP (grant 2012/50260-6 and BIOTA-FAPESP Programs 2011/50225-3 and 2013/50297-0).Peer Reviewe

Testing General Relativity with Current Cosmological Data

Deviations from general relativity, such as could be responsible for the cosmic acceleration, would influence the growth of large scale structure and the deflection of light by that structure. We clarify the relations between several different model independent approaches to deviations from general relativity appearing in the literature, devising a translation table. We examine current constraints on such deviations, using weak gravitational lensing data of the CFHTLS and COSMOS surveys, cosmic microwave background radiation data of WMAP5, and supernova distance data of Union2. Markov Chain Monte Carlo likelihood analysis of the parameters over various redshift ranges yields consistency with general relativity at the 95% confidence level.Comment: 11 pages; 7 figures; typographical errors corrected; this is the published versio