52 research outputs found

    Simplification and Shift in Cognition of Political Difference: Applying the Geometric Modeling to the Analysis of Semantic Similarity Judgment

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    Perceiving differences by means of spatial analogies is intrinsic to human cognition. Multi-dimensional scaling (MDS) analysis based on Minkowski geometry has been used primarily on data on sensory similarity judgments, leaving judgments on abstractive differences unanalyzed. Indeed, analysts have failed to find appropriate experimental or real-life data in this regard. Our MDS analysis used survey data on political scientists' judgments of the similarities and differences between political positions expressed in terms of distance. Both distance smoothing and majorization techniques were applied to a three-way dataset of similarity judgments provided by at least seven experts on at least five parties' positions on at least seven policies (i.e., originally yielding 245 dimensions) to substantially reduce the risk of local minima. The analysis found two dimensions, which were sufficient for mapping differences, and fit the city-block dimensions better than the Euclidean metric in all datasets obtained from 13 countries. Most city-block dimensions were highly correlated with the simplified criterion (i.e., the left–right ideology) for differences that are actually used in real politics. The isometry of the city-block and dominance metrics in two-dimensional space carries further implications. More specifically, individuals may pay attention to two dimensions (if represented in the city-block metric) or focus on a single dimension (if represented in the dominance metric) when judging differences between the same objects. Switching between metrics may be expected to occur during cognitive processing as frequently as the apparent discontinuities and shifts in human attention that may underlie changing judgments in real situations occur. Consequently, the result has extended strong support for the validity of the geometric models to represent an important social cognition, i.e., the one of political differences, which is deeply rooted in human nature

    Molecular Dynamics Simulations Suggest that Electrostatic Funnel Directs Binding of Tamiflu to Influenza N1 Neuraminidases

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    Oseltamivir (Tamiflu) is currently the frontline antiviral drug employed to fight the flu virus in infected individuals by inhibiting neuraminidase, a flu protein responsible for the release of newly synthesized virions. However, oseltamivir resistance has become a critical problem due to rapid mutation of the flu virus. Unfortunately, how mutations actually confer drug resistance is not well understood. In this study, we employ molecular dynamics (MD) and steered molecular dynamics (SMD) simulations, as well as graphics processing unit (GPU)-accelerated electrostatic mapping, to uncover the mechanism behind point mutation induced oseltamivir-resistance in both H5N1 “avian” and H1N1pdm “swine” flu N1-subtype neuraminidases. The simulations reveal an electrostatic binding funnel that plays a key role in directing oseltamivir into and out of its binding site on N1 neuraminidase. The binding pathway for oseltamivir suggests how mutations disrupt drug binding and how new drugs may circumvent the resistance mechanisms

    The genome of the Trinidadian guppy, Poecilia reticulata, and variation in the Guanapo population

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    For over a century, the live bearing guppy, Poecilia reticulata, has been used to study sexual selection as well as local adaptation. Natural guppy populations differ in many traits that are of intuitively adaptive significance such as ornamentation, age at maturity, brood size and body shape. Water depth, light supply, food resources and predation regime shape these traits, and barrier waterfalls often separate contrasting environments in the same river. We have assembled and annotated the genome of an inbred single female from a high-preda- tion site in the Guanapo drainage. The final assembly comprises 731.6 Mb with a scaffold N50 of 5.3 MB. Scaffolds were mapped to linkage groups, placing 95% of the genome assembly on the 22 autosomes and the X-chromosome. To investigate genetic variation in the population used for the genome assembly, we sequenced 10 wild caught male individu- als. The identified 5 million SNPs correspond to an average nucleotide diversity (π) of 0.0025. The genome assembly and SNP map provide a rich resource for investigating adap- tation to different predation regimes. In addition, comparisons with the genomes of other Poeciliid species, which differ greatly in mechanisms of sex determination and maternal resource allocation, as well as comparisons to other teleost genera can begin to reveal how live bearing evolved in teleost fish

    A produção de plosivas por crianças de três anos falantes do português brasileiro Infant voices: the production of plosives by three-year-olds

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    OBJETIVO: apresentar as características fonético-acústicas de produção das consoantes plosivas vozeadas e não-vozeadas por crianças de três anos. MÉTODOS: análise qualitativa baseada na inspeção das características fonético-acústicas de eventos fônicos ocorridos no intervalo de obstrução, na liberação da plosão e na transição para a vogal e análise quantitativa das medidas do Voice Onset Time (VOT), de três repetições das seis consoantes plosivas do Português Brasileiro (PB), por quatro crianças, sendo três meninos e uma menina, falantes nativos do PB, por meio de análise fonético-acústica, em espectrograma de banda larga. Os achados foram comparados com estimativas de valores para a faixa adulta de falante nativo do PB. RESULTADOS: as crianças apresentaram produções semelhantes às que são encontradas na fala adulta, tanto para as plosivas vozeadas como para as não-vozeadas, bilabiais, alveolares e velares. Apresentaram também plosivas vozeadas com interrupção de barra de sonoridade e ocorrência de VOT positivo, e qualidade diferenciada de burst. Para as não-vozeadas, ocorreram a presença da breathy vowel no período de obstrução das plosivas e a presença de aspiração no segmento correspondente ao VOT positivo, para os três pontos de articulação pesquisados. CONCLUSÃO: as diferenças encontradas na produção das plosivas vozeadas, quanto às características da barra de sonoridade e qualidade do burst, a presença da breathy vowel nas plosivas não-vozeadas e aspiração, caracterizam a produção das plosivas nessa faixa etária. A diversidade das medidas acústicas, verificada pelos valores dos desvios-padrão sugerem que as crianças realizaram diversas tentativas, com diferentes ajustes para produzir tais sons.<br>PURPOSE: to present the phonetic-acoustic features of the production of both voiced and voiceless plosives by three-year-old children. METHODS: qualitative analysis based on the inspection of phonetic-acoustic characteristics of phonic events occurring in the obstruction interval, in the burst, and in the transition to the vowel as well as quantitative analysis of the measures of the voice onset time (VOT), of three repetitions of the six plosive consonants of Brazilian Portuguese (BP) by four native-speaker children in the three-year-old age bracket, three boys and one girl, by means of an acoustic-phonetic analysis, in a wide-band spectrogram. The findings were compared to estimates of values for the adult group of native speakers of Brazilian Portuguese (BP). RESULTS: the children showed production of plosives with VOT similar to that of adult speech both for voiced and unvoiced plosives, bilabials, alveolars and velars. They also showed productions dissimilar to adults, such as voiced plosives with interruption of the voice bar and positive VOT, besides a particular quality of burst. As regards the unvoiced plosives, there were episodes of breathy vowel during obstruction as well as of aspiration in the segment corresponding to positive VOT, in the three articulation points under study. CONCLUSION: differences found in the production of voiced plosives as regards spectral features of the voice bar and burst quality as well as the occurrence of breathy vowel in unvoiced plosives along with aspiration, characterize the production of plosives in this age bracket. The diversity of acoustic measures, observed by the values of shunting line-standards, suggest that children made several attempts, with various degrees of adjustment, to produce such sounds
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