RESUMO Objetivou-se descrever comparativamente as artérias responsáveis pela irrigação dos lobos tímicos cervicais e torácicos dos javalis, determinando-se também as características morfológicas do referido órgão nessa espécie, a ponto de correlacioná-las evolutivamente com os demais representantes da família Suidae. Os lobos tímicos cervicais direito e esquerdo receberam ramos distribuídos pelas artérias carótidas comuns direita e esquerda e cervicais superficiais direita e esquerda e, por vezes, pelas artérias torácica externa esquerda e subclávia esquerda. Essa característica vascular foi mantida ao longo da evolução, estando presente em linhagens e raças mais recentes de suídeos. A irrigação dos lobos tímicos torácicos direito e esquerdo foi realizada predominantemente por ramos diretos e indiretos ipsilaterais e contralaterais das artérias torácicas internas direita e esquerda, e também por ramos da artéria subclávia esquerda. Ramos diretos das artérias cervicais superficiais direita e esquerda e ramos diretos da artéria torácica interna direita foram encontrados para o lobo tímico médio, sendo essa uma descrição única nessa espécie, o que demonstra uma característica evolutiva primitiva nesse ancestral.

ABSTRACT The objective of this study was to comparatively describe the arteries responsible for the irrigation of the cervical and thoracic thymus lobes of Boars, also determining the morphological characteristics of this body in this species to the point of evolutionarily correlating them with other representatives of the Suidae family. The left and right cervical thymic lobes received branches distributed by common right and left, superficial right and left carotid arteries, and neck and, sometimes, the outer left chest and left subclavian arteries. This feature was vascular maintained throughout evolution and is present in more recent strains and breeds of swine. Irrigation of the right and left thoracic thymic lobes was performed predominantly by direct and indirect ipsilateral and contralateral branches of the right and left internal thoracic arteries and also by branches of the left subclavian artery. Direct branches of the right and left superficial cervical artery and right branches of the right internal thoracic artery were found for the average thymic lobe, this being a unique description in this species, demonstrating a primitive feature in this evolutionary ancestor.

By means of dimensional selection of natural lignocellulosic fibers, based on precise diameter measurements, it was recently possible to obtain fibers with relatively higher tensile strength. The present article overviews works on the statistical evaluation, through the Weibull analysis, of the ultimate tensile stress of eight lignocellulosic fibers: sisal, ramie, curaua, jute, bamboo, coir, piassava and buriti. It is shown that, for all of these fibers, the tensile strength holds an inverse relationship with the fiber diameter. Statistically this relationship conforms to a hyperbolic type of analytical equation, which discloses the possibility of unusually high strength fibers to be selected in association with very small diameters. A structural analysis using scanning electron microscopy offered an explanation to the strengthening mechanisms responsible for the superior performance of these dimensionally selected fibers.