Objectives Bilateral vocal fold immobility (BVFI) is a rare and life‐threatening condition in which both vocal folds are fixed, resulting in airway obstruction associated with life‐threatening respiratory compromise. Treatment of BVFI is largely surgical and remains an unsatisfactory compromise between voice, breathing, and swallowing. No comparisons between currently employed techniques currently exist. We sought to employ computational fluid dynamics (CFD) modeling to delineate the optimal surgical approach for BVFI. Methods Utilizing clinical computed tomography of BVFI subjects, coupled with image analytics employing CFD models and subject pulmonary function data, we compared the airflow features in the baseline pathologic states and changes seen between endoscopic cordotomy, endoscopic suture lateralization, and posterior cricoid expansion. Results CFD modeling demonstrated that the greatest airflow velocity occurs through the posterior glottis on inspiration and anterior glottis on expiration in both the normal condition and in BVFI. Glottic airflow velocity and resistance were significantly higher in the BVFI condition compared to normal. Geometric indices (cross‐sectional area of airway) were lower in posterior cricoid expansion surgery when compared to alternate surgical approaches. CFD measures (airflow velocity and resistance) improved with all surgical approaches but were superior with posterior cricoid expansion. Conclusion CFD modeling can provide discrete, quantitative assessment of the airflow through the laryngeal inlet, and offers insights into the pathophysiology and changes that occur after surgery for BVFI. Level of Evidence NA. Laryngoscope, 130:E57–E64, 2020

O presente ensaio buscará explorar um assunto essencial no ensino de Geografia para jovens: o processo de construção e apreensão de conceitos. Utilizando uma base teórica sócio construtivista, este estudo compreende que o aprendizado de conceitos geográficos está diretamente associado à formação de uma consciência espacial através do diálogo, interação e reflexão do aluno com seu espaço de vivência. E esses dois elementos –a consciência espacial e o espaço de vivência- podem ser mobilizados com o uso de letras de músicas em situações de aprendizagem. O artigo explorará inicialmente alguns aportes teóricos sobre o ensino de Geografia e suas novas concepções e as possibilidades dadas ao ensino de conteúdos geográficos com o uso de músicas. Com os indicativos das diretrizes educacionais vigentes em âmbito nacional, destaca-se a importância do estudo de conceitos como eixos do conhecimento e da aprendizagem e, nesse caminho metodológico, faz-se a proposição de um conjunto de letras musicais agrupadas por fichas de atividade válidas para o estudo de conceitos geográficos em turmas de Ensino Médio, letras essas que discorrem sobre lugares, regiões, territórios e paisagens diversas, trazendo os elementos cotidianos atrelados às relações sociais materializadas no espaço geográfico.

Categorification of some integer sequences are obtained by enumerating the number of sections in the Auslander–Reiten quiver of algebras of finite representation type.

This study examines the turbulence characteristics of the boundary layer over New York City. Understanding the urban boundary layer characteristics is key to forecasting weather in cities, where most people live. Although extensive research into urban boundary layer (UBL) processes have been carried out in the past decades, majority of these studies focussed on the urban surface layer; our understanding of urban mixed layer characteristics is still incomplete. Here we use Doppler lidar observations from multiple sites in New York City to study turbulent properties in the UBL and their relationship to the heterogeneous urban surface. All three sites were influenced by different levels of urbanization. Our analysis shows vertical stratification in momentum transport during non-neutral stability periods. The analysis over multiple sites reveal a degree of homogeneity in mixed layer characteristics, especially during extreme heat episodes. The spectral analysis show high variability in normalized energy density at different heights.

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