Biology and behaviour of the neotropical ant-mimicking spider Aphantochilus rogersi (Araneae: Aphantochilidae): nesting, maternal care and ontogeny of ant-hunting techniques

Aphantochilus rogersi is an ant-mimicking spider that preys exclusively on cephalotine ants. The spiders oviposit in close proximity to nests of the model ant Zacryptocerus pusillus, and emergent spiderlings tend to remain in the vicinity of natal egg sacs. Females of A. rogersi actively defend their egg sacs against approaching workers of Z. pusillus, but the latter may sometimes destroy the eggs. Feeding specialization on these ants is confirmed by more than 300 observations of young and adult A. rogersi carrying ant corpses in the held. Although A. rogersi possesses several behavioural traits which may reduce the risk of being injured by ants during subjugation, field and laboratory observations showed that social defence by Z. pusillus may cause mutilation to the spiders. Tests in captivity revealed an ontogenetic change in the prey-capture techniques employed by A. rogersi. Early-instar spiderlings can apparently only seize the ant's petiole tightly if they are able to approach the ant from the front. As the ant is paralysed, the spiderling positions itself vertically in relation to the substratum. Larger spiders, on the other hand, attack ants most frequently from behind, and seem better equipped to seize the ant's petiole firmly with their larger chelicerae. Owing to their greater strength, late-instar spiders are able to Lift the struggling ant aloft. The selection of a suitable oviposition site, the mother's ability to defend herself and the eggs from nearby ants, and the capacity to capture and subdue ants safely from emergence to maturity, are regarded as crucial traits inherent in the mimetic and feeding specialization by A. rogersi.242464365

Formação pedagógica de professores de nutrição: uma omissão consentida? Teacher training for nutrition professors: a tacitly accepted omission?

Apesar dos novos papéis preconizados pelas Diretrizes Curriculares Nacionais aos profissionais de Nutrição, pouca atenção tem sido dada ao desenvolvimento docente para atuação nos novos cenários. O objetivo deste ensaio é o de discutir um dos desafios à formação do nutricionista, a prática docente e a formação pedagógica do professor da área da saúde, para pensar formas de oportunizar um ensino de melhor qualidade, com base em autores que discutem a docência universitária. Identificam-se como causas da resistência docente às mudanças, a desvalorização das atividades de ensino e a supremacia das atividades de pesquisa nas universidades. O estudo permitiu sugerir a necessidade de reflexão por parte dos professores de Nutrição sobre as questões da docência universitária e sobre o desenvolvimento docente em uma perspectiva crítica e reflexiva, que possa ancorar mudanças pedagógicas necessárias à formação de nutricionistas.<br>Despite the new roles called in for the National Curricular Guidelines for teachers in nutrition courses, little attention has been paid to the professional development of the nutrition professional acting as a teacher. Based on the work of authors who discuss university teaching, this essay discusses some of the challenges involved in training nutritionists, such as teaching practice and teacher training for the professor in the health field, with the goal of providing higher-quality teaching. The devaluation of teaching and the supremacy of research at universities have been identified as the causes of teachers' resistance to change. This study reveals the need for professors of nutrition to reflect on the questions of university teaching and teacher development from a critical and reflective perspective which can anchor the pedagogical changes needed to train the nutritionist

Cytogenetics of three Brazilian species of Eleutherodactylus (Anura, Leptodactylidae) with 22 chromosomes and re-analysis of multiple translocations in E. binotatus

In this paper, we provide a cytogenetic analysis of Eleutherodactylus guentheri, E. parvus and E. binotatus. All of the species had a diploid chromosomal number of 2n = 22. The karyotypes of E. guentheri and E. parvus were very similar and differed only slightly in the morphology of pair 2. These two species also had an NOR-bearing secondary constriction on the long arms of pair 6. The karyotype of E. binotatus differed from those of E. guentheri and E. parvus in the morphology and size of the chromosomes, in the number of chromosomal arms, in the NOR location (detected on the short arms of pair 1), and in the pattern of heterochromatin. These results reinforce the differences between E. guentheri and E. binotatus and support the existence of two species group. Five individuals of E. binotatus showed morphs for pairs 2 and 3. These morphs probably arose from the translocation of a segment from one chromosome of pair 3 to a homologue of pair 2. In addition, some mitotic metaphases of E. binotatus showed spontaneous chromosomal breaks which suggested that there were sites of fragility. Meiotic diakinesis showed multiple chromosomal rings, indicating the occurrence of multiple translocations, as previously reported by other investigators. These data suggest that, in addition to fission and fusion, other chromosomal rearrangements were probably involved in the differentiation of the karyotypes of these species of Eleutherodactylus, especially E. binotatus