and the gastric glands of larvae/postlarvae (from hatching until 45 days posthatching) of three fish species (two teleostean and a chondrostean) were investigated using conventional histochemical methods (periodic acid schiff –PAS-, diastase-PAS; alcian blue pH 0.5, 1 and 2.5) in order to distinguish neutral and acidic (carboxylated and sulphated) glycoconjugates, as well as bromophenol blue reaction for identification of proteins. Additionally, the presence and distribution of sugar residues in the oligosaccharide side chains of glycoconjugates were investigated using horseradish peroxidase (HPR)-conjugated lectins (Con A, DBA, WGA and UEA-I). Most mucous cells (digestive, epidermal and branchial) of Siberian sturgeon, Acipenser baeri, sea bream, Sparus aurata and Senegal sole, Solea senegalensis larvae were PAS- and alcian blue- (pH 2.5 and 0.5) positive, with small variations between organs/tissues and species. Bromophenol blue reaction (general proteins) was positive in a minority of the mucous cells, usually in those cells which were PAS-negative. Proteins rich in sulphydryl (-SH) and/or disulphide (-S-S-) groups related with the glycoprotein nature of the glycoconjugates present in mucous cells were also observed. Epidermal, branchial and digestive mucous cells of all studied larvae did not contain glycogen or lipids

The aim of the present study was to investigate the sequence of shell bone formation in the embryos of the Pleurodira, Podocnemis unifilis. Their bones and cartilage were collected and cleared before staining. The shell was also examined by obtaining a series of histological slices. All the bony elements of the plastron have independent ossification centers, which subsequently join together and retain two fontanelles until the period of hatching. This turtle has a mesoplastra, which is characteristic of the Podocnemididae. The carapace begins to form concurrently with the ossification of the ribs at the beginning of stage 20. All the plates, except the suprapygal, initiate ossification during the embryonic period. The main purpose of the histological investigation was to highlight the relationship between the formation of the carapace and ribs with that of the neural plates. The costal and neural plates were found not to independent ossification centers, but to be closely related to components of the endoskeleton, originating as expansions of the perichondral collar of the ribs

O plexo braquial é um conjunto de nervos com origem na região medular cervicotorácica que inerva o membro torácico e adjacências. Seu estudo em diferentes espécies é importante não apenas como uma fonte de conhecimento morfológico, mas, também, por facilitar o diagnóstico de disfunções neuromusculares decorrentes de diversas patologias. O objetivo foi descrever as origens e ramificações do plexo braquial do Mazama gouazoubira. Foram utilizados três espécimes, pertencentes ao acervo científico do Laboratório de Ensino e Pesquisa em Animais Silvestres da Universidade Federal de Uberlândia (UFU); eles foram fixados em formaldeído a 3,7% e dissecados. No M. gouazoubira, o plexo braquial resultou de conexões entre os ramos dos três últimos nervos espinhais cervicais, C6, C7 e C8, e do primeiro torácico T1, e teve como derivações os nervos supraescapular, subescapulares cranial e caudal, axilar, musculocutâneo, mediano, ulnar, radial, peitorais, toracodorsal, torácico longo e torácico lateral. Os músculos inervados pelos nervos do plexo braquial foram o supraespinhal, infraespinhal, subescapular, redondo maior, redondo menor, deltoide, cleidobraquial, coracobraquial, bíceps braquial, braquial, tríceps braquial, ancôneo, flexor superficial dos dedos, flexor profundo dos dedos, flexor radial do carpo, flexor ulnar do carpo, extensor radial do carpo, ulnar lateral, extensor oblíquo do carpo, extensores dos dedos, peitoral superficial, peitoral profundo, serrátil ventral e oblíquo externo do abdome.

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Recent studies have demonstrated the existence of a relationship between a structures susceptibility to second-order effects and its natural period of vibration ([Formula: see text]) given that both these properties are fundamentally dependent on the structure stiffness and mass properties. The main advantage of the use of this characteristic is that [Formula: see text] can be obtained easily by the existing structural analysis software. In this study, different formulations are developed in order to propose an amplification factor ([Formula: see text]) to multiply first-order analysis results and satisfactorily obtain results of a second-order analysis. These formulations are based on D’Alembert’s principle, Rayleighs method, and the use of generalized coordinates to represent the dynamic displacement of flexible structures. It is observed that [Formula: see text] provides values closer to and in fact, more conservatively than, those obtained by the conventional simplified methods currently used by structural design engineers. Thus, the amplification factor [Formula: see text], which is based on the natural period of vibration, is proposed to be used as (i) an indicator of a structure susceptibility to second-order effects and (ii) an amplification factor to describe the second-order effects on reinforced concrete frames.

Cold-formed steel may be used to frame the walls, floors, and roofs of modern buildings. The individual cold-formed steel members (studs) have sheathing attached to provide appropriate architectural enclosures. This sheathing also serves to brace the coldformed steel studs under load. This thesis is dedicated to the study of sheathed coldformed steel walls under axial loads. Current design methods are highly developed regarding the design of isolated coldformed steel members such as columns and beams, but cold-formed steel wall studs that rely on sheathing for bracing are not fully addressed. A series of tests on single columns with sheathing, and full-scale walls with sheathing are completed herein and compared with previous design methods adopted by the American Iron and Steel Institute (AISI) Specification. The comparison shows that previous design methods lead to overly conservative strength prediction. This is particularly true for the case of dissimilar sheathing, e.g. oriented strand board on one face and gypsum board on the other face of the stud. The sheathing supplies beneficial restraint to the wall studs and the stiffness of this sheathing-based restraint is characterized experimentally and analytically herein. The lateral bracing stiffness and resistance supplied by the fastener-sheathing combination that braces the stud is explored, taking into account typical design variables as well as the influence of humidity and construction flaws. For the first time, the lateral bracing stiffness is correctly divided into a local fastener and global diaphragm stiffness. While local stiffness considers the damage around the fastener connection, the diaphragm stiffness considers the shear stiffness of the whole sheathing. vi "I don't know what I may seem to the world; but as to myself I seem to have been only like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me"

The objective of the present study was to analyze chondrogenesis and the ossification pattern of the limbs of Melanosuchus niger in order to contribute with possible discussions on homology and the fusion pattern of autopodial elements and phylogeny. In the Reserva Extrativista do Lago Cuniã, Rondônia, Brazil, six nests were marked and two eggs removed from each nest at 24-hour intervals until hatching. Embryos were cleared using KOH; bone tissue was stained with alizarin red S and cartilage with Alcian blue. Routine staining with HE was also performed. In the pectoral girdle, the scapula showed ossification centers before the coracoid process. In the pelvic girdle, the ilium and the ischium were condensed as a single cartilage, although ossification took place through two separate centers, forming distinct elements in the adult. The pubis developed from an independent cartilaginous center with free end, which reflects its function in breathing. In the initial stages, the stylopodium and the zeugopodium developed from the condensation of a Y-shaped cartilage in the limbs, and differentiation of the primary axis and digital arch were observed. The greatest changes were observed in the mesopodia. In their evolution, Crocodylia underwent a vast reduction in the number of autopodial elements as a consequence of fusions and ossification of some elements. This study shows that the chondrogenesis and ossification sequences are dissociated. Moreover, the differences between M. niger and other species show clear variation in the patterns for these events in Alligatoridae.

No abstract