External Morphology and Ultrastructure of Tegumental Glands of Aegla platensis (Crustacea, Anomura, Aeglidae) Pleopods: Might They Play A Role in Egg Attachment?

Egg incubation on the female abdomen is the parental care behavior observed in aeglids, in which eggs are kept adhered to maternal pleopods and maintained, cleaned and aerated. In A. platensis, egg attachment occurs with the aid of pleopodal setae, which are twisted around their axis in the distal region, forming the funiculus, and pleopodal glands, which are responsible for the production of the adhesive substance that seems to be involved in egg fixation to pleopodal setae. Those glands are acini formed by secretory cells arranged concentrically around a central duct, giving them a rosette appearance. Two types of secretory cells were observed, those that produce electron-lucid vesicles and those having electron-dense ones. Both kinds of vesicles are released in a duct whose opening pore is located on the pleopodal surface and constitute the adhesive substance that coats eggs and pleopodal setae, ensuring egg fixation to the female body and maternal care maintenance. This study investigates the internal and external morphology of Aegla platensis pleopods, to understand the egg attachment process and identify the structures involved in this phenomenon. Three microscopy techniques are used: scanning electron microscopy (SEM), transmission electron microscopy (TEM), and optical microscopy (OM)

The evolutionary origin of bilaterian smooth and striated myocytes

The dichotomy between smooth and striated myocytes is fundamental for bilaterian musculature, but its evolutionary origin is unsolved. In particular, interrelationships of visceral smooth muscles remain unclear. Absent in fly and nematode, they have not yet been characterized molecularly outside vertebrates. Here, we characterize expression profile, ultrastructure, contractility and innervation of the musculature in the marine annelid Platynereis dumerilii and identify smooth muscles around the midgut, hindgut and heart that resemble their vertebrate counterparts in molecular fingerprint, contraction speed and nervous control. Our data suggest that both visceral smooth and somatic striated myocytes were present in the protostome-deuterostome ancestor and that smooth myocytes later co-opted the striated contractile module repeatedly for example, in vertebrate heart evolution. During these smooth-to-striated myocyte conversions, the core regulatory complex of transcription factors conveying myocyte identity remained unchanged, reflecting a general principle in cell type evolutio

Impacto de edificações do tipo "construído para alugar" na estratégia e no uso dos espaços urbanos

Esta pesquisa investiga o impacto de edificações do tipo “construído para alugar” na estética e no uso dos espaços urbanos consolidados e predominantemente residenciais, a partir da avaliação de diferentes grupos de indivíduos. O problema da pesquisa reside na inserção destas estruturas e de suas atividades comerciais em ambientes construídos sem que se saiba seu real impacto na qualidade visual e de uso do ambiente construído. Assim, o objetivo é analisar e comparar níveis de satisfação e preferências estéticas de cenas, nos períodos diurno e noturno, com edificações do tipo “construído para alugar” e cenas com as edificações substituídas, considerando que podem existir diferenças entre as avaliações de indivíduos com diferentes tipos e níveis de formação acadêmica e diferentes níveis de familiaridade. Também, é objetivo identificar os níveis de satisfação com a localização das diferentes atividades das edificações tipo “construído para alugar”, nos entornos predominantemente residenciais, e averiguar se esta tipologia é satisfatória para o desempenho das atividades que abriga, de acordo com diferentes grupos de indivíduos relacionados à estas estruturas. Para tanto, são selecionados nove exemplares localizados na cidade de Porto Alegre-RS. Os métodos de coleta de dados fazem parte dos utilizados na área de estudos Ambiente e Comportamento, sistematizados por meio de levantamentos de arquivo e levantamentos de campo, questionários e entrevistas. A análise de dados é realizada através de testes estatísticos não-paramétricos. Os resultados desta investigação demonstram que a estética das cenas urbanas é avaliada de acordo com o nível de estímulo visual e ordenamento de tais cenas, independentemente do nível de formação ou familiaridade dos indivíduos. Ainda, revelam que a tipologia “construído para alugar” não impacta de maneira positiva na estética dos seus entornos, principalmente para os moradores destes entornos, pois sua aparência tende a carecer de estímulo visual e de relação ordenada com seus entornos. Por outro lado, os resultados demonstram que as atividades comerciais destas edificações, em especial as de primeiras necessidades e de consumo imediato, são percebidas como muito adequadas para os entornos residências, devido à existência de demanda e a sua contribuição para o movimento qualitativo de pessoas nos espaços urbanos. Em complemento, os resultados revelam que as edificações são muito satisfatórias quanto aos espaços internos devido à flexibilidade e quantidade de espaço, e suas localizações têm influência no desempenho de suas atividades, que ocorrem de maneira satisfatória. Contudo, a tipologia tende a possuir acesso para usuários e áreas de estacionamento insatisfatórias, além de apresentar problemas relacionados ao conforto térmico. Por fim, espera-se que os dados obtidos possam contribuir para a qualificação dos espaços urbanos, objetivando atender melhor às necessidades dos indivíduos quanto à estética e ao uso do ambiente construído.This research investigates the impact of "built for rent" buildings on aesthetics and on use of consolidated and predominantly residential urban spaces, based on the evaluation of different groups of individuals. The research problem deals with the insertion of these structures and their commercial activities in built environments without the knowledge of their real impact on the visual quality and use of the built environment. Therefore, the objective is to analyze and compare satisfaction levels and aesthetic preferences of scenes, during day and night periods, of “built for rent” buildings, and scenes with substituted buildings, considering that there may be differences between the evaluations from individuals with different types and levels of education, and different levels of familiarity. The research also intends to identify levels of satisfaction with location of the different activities of "built for rent" buildings within predominantly residential environments, and to investigate if this typology is satisfactory for the performance of its activities, according to different groups of individuals related to these structures. For this purpose, nine buildings located in the city of Porto Alegre-RS are selected. Data gathering procedures are part of those in the Environment and Behavior area of study, which includes archival records, field surveys, questionnaires and interviews. The data analysis was carried out through non-parametric statistical tests. The results of this research demonstrate that urban scenes are evaluated according to the level of visual stimulus and ordering of such scenes, regardless of the level of academic education or familiarity of the individuals. Furthermore, they reveal that the "built for rent" typology does not have a positive impact on the aesthetics of their environments, especially for the residents of these environments, since its appearance tends to lack visual stimulation and orderly relation with their surroundings. On the other hand, the results show that commercial activities of these buildings, especially those of first necessity and of immediate consumption, are perceived as very suitable for residential environments, due to the existence of demand and the contribution to the qualitative movement of people in the urban spaces. In addition, the results show that the interior area of the buildings are very adequate for their activities, due to the flexibility and quantity of space, and their locations have influence the performance of their activities, which occur in a satisfactory way. However, the typology tends to have an unsatisfactory access and parking areas for its users, as well as presents problems related to internal thermal comfort. In conclusion, it is expected that the results obtained can contribute to the qualification of urban spaces, aiming to better meet the needs of individuals regarding to aesthetics and the use of urban space

Monoamines in the pedal plexus of the land snail Megalobulimus oblongus (Gastropoda, Pulmonata)

In molluscs, the number of peripheral neurons far exceeds those found in the central nervous system. Although previous studies on the morphology of the peripheral nervous system exist, details of its organization remain unknown. Moreover, the foot of the terrestrial species has been studied less than that of the aquatic species. As this knowledge is essential for our experimental model, the pulmonate gastropod Megalobulimus oblongus, the aim of the present study was to investigate monoamines in the pedal plexus of this snail using two procedures: glyoxylic acid histofluorescence to identify monoaminergic structures, and the unlabeled antibody peroxidase anti-peroxidase method using antiserum to detect the serotonergic component of the plexus. Adult land snails weighing 48-80 g, obtained from the counties of Barra do Ribeiro and Charqueadas (RS, Brazil), were utilized. Monoaminergic fibers were detected throughout the pedal musculature. Blue fluorescence (catecholamines, probably dopamine) was observed in nerve branches, pedal and subepithelial plexuses, and in the pedal muscle cells. Yellow fluorescence (serotonin) was only observed in thick nerves and in muscle cells. However, when immunohistochemical methods were used, serotonergic fibers were detected in the pedal nerve branches, the pedal and subepithelial plexuses, the basal and lateral zones of the ventral integument epithelial cells, in the pedal ganglion neurons and beneath the ventral epithelium. These findings suggest catecholaminergic and serotonergic involvement in locomotion and modulation of both the pedal ganglion interneurons and sensory information. Knowledge of monoaminergic distribution in this snail´s foot is important for understanding the pharmacological control of reflexive responses and locomotive behavior