811 research outputs found

    Behavioral modeling of GaN-based power amplifiers: impact of electrothermal feedback on the model accuracy and identification

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    In this article, we discuss the accuracy of behavioral models in simulating the intermodulation distortion (IMD) of microwave GaN-based high-power amplifiers in the presence of strong electrothermal (ET) feedback. Exploiting an accurate self-consistent ET model derived from measurements and thermal finite-element method simulations, we show that behavioral models are able to yield accurate results, provided that the model identification is carried out with signals with wide bandwidth and large dynamics

    Enhanced Recognition of Vocal Emotions in Individuals With Naturally Good Musical Abilities

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    Music training is widely assumed to enhance several nonmusical abilities, including speech perception, executive functions, reading, and emotion recognition. This assumption is based primarily on cross-sectional comparisons between musicians and nonmusicians. It remains unclear, however, whether training itself is necessary to explain the musician advantages, or whether factors such as innate predispositions and informal musical experience could produce similar effects. Here, we sought to clarify this issue by examining the association between music training, music perception abilities and vocal emotion recognition. The sample (N = 169) comprised musically trained and untrained listeners who varied widely in their musical skills, as assessed through self-report and performance-based measures. The emotion recognition tasks required listeners to categorize emotions in nonverbal vocalizations (e.g., laughter, crying) and in speech prosody. Music training was associated positively with emotion recognition across tasks, but the effect was small. We also found a positive association between music perception abilities and emotion recognition in the entire sample, even with music training held constant. In fact, untrained participants with good musical abilities were as good as highly trained musicians at recognizing vocal emotions. Moreover, the association between music training and emotion recognition was fully mediated by auditory and music perception skills. Thus, in the absence of formal music training, individuals who were “naturally” musical showed musician-like performance at recognizing vocal emotions. These findings highlight an important role for factors other than music training (e.g., predispositions and informal musical experience) in associations between musical and nonmusical domains. (PsycInfo Database Record (c) 2020 APA, all rights reserved

    Influence of decreasing nutrient path length on the development of engineered cartilage

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    SummaryObjectiveChondrocyte-seeded agarose constructs of 4mm diameter (2.34mm thickness) develop spatially inhomogeneous material properties with stiffer outer edges and a softer central core suggesting nutrient diffusion limitations to the central construct region [Guilak F, Sah RL, Setton LA. Physical regulation of cartilage metabolism. In: Mow VC, Hayes WC, Eds. Basic Orthopaedic Biomechanics, Philadelphia 1997;179–207.]. The effects of reducing construct thickness and creating channels running through the depth of the thick constructs were examined.MethodsIn Study 1, the properties of engineered cartilage of 0.78mm (thin) or 2.34mm (thick) thickness were compared. In Study 2, a single nutrient channel (1mm diameter) was created in the middle of each thick construct. In Study 3, the effects of channels on larger 10mm diameter, thick constructs were examined.ResultsThin constructs developed superior mechanical and biochemical properties than thick constructs. The channeled constructs developed significantly higher mechanical properties vs control channel-free constructs while exhibiting similar glycosaminoglycan (GAG) and collagen content. Collagen staining suggested that channels resulted in a more uniform fibrillar network. Improvements in constructs of 10mm diameter were similarly observed.ConclusionsThis study demonstrated that more homogeneous tissue-engineered cartilage constructs with improved mechanical properties can be achieved by reducing their thickness or incorporating macroscopic nutrient channels. Our data further suggests that these macroscopic channels remain open long enough to promote this enhanced tissue development while exhibiting the potential to refill with cell elaborated matrix with additional culture time. Together with reports that <3mm defects in cartilage heal in vivo and that irregular holes are associated with clinically used osteochondral graft procedures, we anticipate that a strategy of incorporating macroscopic channels may aid the development of clinically relevant engineered cartilage with functional properties

    Creation of the department of physical education of the São Paulo state (1925-1932)

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    O artigo aborda a criação do Departamento de Educação Física do Estado de São Paulo (DEF-SP), procurando analisar os debates que fomentaram sua implantação, identificar as posições assumidas pelos sujeitos que contribuíram para isso e examinar as iniciativas implementadas durante seu primeiro ano de funcionamento. A criação do DEF-SP esteve relacionada aos debates próprios dos campos esportivo e intelectual paulistas, em intersecção com disputas e tensões sobre a identidade nacional. Foi promovida por figuras do universo esportivo, como cronistas e atletas, e por médicos. A justificativa para sua criação apresentou teor eugenista, sendo a manifestação esportiva interpretada como uma forma de desenvolver o vigor físico e moral da população49171264286This paper focuses on the creation of the Departamento de Educação Física do Estado de São Paulo [Department of Physical Education of São Paulo State] (DEF-SP). Its objectives are: a) to analyze the debates that led to the creation of the DEF-SP; b) to identify the positions assumed by the subjects who contributed to its creation; c) to verify the initiatives that were implemented in its first year of activity. The creation of the DEF-SP was linked to the debates of the sports field of São Paulo in intersection with disputes and tensions about the national identity. It was promoted by sports figures, such as sports journalist, athletes and also by doctors. The justification for its creation presented a eugenic content, and the sport was interpreted as means to develop physical and moral vigor of the populatio

    Lack of effect of cell-wall targeted antibacterials on biofilm formation and antifungal susceptibility of Candidaspecies

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    The use of central venous catheters (CVC) and broad-spectrum antibacterials are among the main risk factors for the development of candidemia in patients admitted to intensive care units (ICU). It is known that some antibacterials increase the resistance of these yeasts to azole antifungals. Thus, the aim of this research was to determine whether yeast present in CVC colonizations previously exposed to cell-wall targeted antibacterials benefit from a reduction in susceptibility to fluconazole and voriconazole, facilitating their ability to form biofilms. Candida albicans, C. tropicalis, C. glabrata, C. parapsilosis and C. guilhermondii were seeded into antibacterial (cefepime, meropenem, vancomycin, and piperacillin-tazobactam) gradient plates produced in Mueller-Hinton Agar. The susceptibility to fluconazole and voriconazole and the biofilm formation of the yeasts were tested before and after exposure to the antibacterials. None of the antibacterials exerted a significant effect on the in vitro susceptibility of the yeasts to the antifungal agents or on their ability to form biofilms. These results suggest that increased candidemia in ICU patients is not attributable to possible alterations in the yeasts, but is more likely caused by a weakening of the patient's general condition after long exposure to infection
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