SummaryThe passage of seeds through hydration and dehydration cycles (HD cycles) can be essential for the acquisition of tolerance and survival to abiotic stress conditions. Since seeds of species from semi-arid ecosystems naturally undergo discontinuous hydration when they germinate, the aim of this study was to compare the seed germination of Xiquexique gounellei subsp. gounellei (Cactaceae) from different populations growing in the Caatinga, a Tropical Dry Forest in Northeastern Brazil, submitted to water deficit after HD cycles. We collected seeds from two populations growing in the municipalities of Canindé de São Francisco and Sousa. We subjected the seeds to 0, 1, 2 and 3 HD cycles and placed them to germinate at osmotic potentials 0.0, -0.2, -0.4, -0.6, -0.8 and -1.0 MPa. From the results of this study, we observed that the two populations do not respond significantly to HD cycles, however the population of Canindé de São Francisco showed a higher germinability in a shorter period, as well as a higher germination speed. Although the two populations grow in the same ecosystem, we observed different germinative behaviour between the populations. Differences in seed germination from the two populations may be related to the phenotypic plasticity of the species influenced by genotypic variation and differences in seasonality and microhabitat conditions in which the populations are growing.

Desiccation tolerance mechanisms are one of the main factors related to the ability to survive water deficit conditions imposed by abiotic stress. Thus, the objective of this work was to evaluate the desiccation tolerance and the influence of water deficit on the initial development of Tabebuia aurea (Silva Manso) Benth. & Hook.f. ex S. Moore. The seedlings were divided into two treatments the control and those that were submitted to 50% desiccation. The control groups received water daily over a period of 30 days, while the groups that underwent water deficit had water suspension for 14 days, totaling two cycles of water deficit over a period of 30 days. The results of this study indicate that seedlings of T. aurea survive desiccation and present less development, whether of the stem, roots, number of leaves, stem diameter when subjected to desiccation and consequent water deficit. Thus, these results indicate that the reduction in early development is related to the perception and attenuation of stressful conditions imposed by the abiotic environment during development.

Estratégias precisam ser elaboradas para o retorno das atividades presenciais nas instituições educacionais. Diante disso, para a diminuir o contágio pela SARS-CoV-2 e suas variantes, bem como os vírus da gripe H1N1, H3N2 (Darwin) e Cepa B, esse trabalho teve como objetivo realizar a construção de um modelo de mapa risco de contaminação aos vírus que possa ser adaptado para as diferentes instituições, e que possibilite a visualização das áreas nos quais os riscos são maiores e menores, para que possam ser traçados estratégias para o controle das doenças. O mapa de risco foi construído utilizando como modelo a Universidade Federal de Sergipe (UFS) no campus universitário Professor Alberto Carvalho, localizado na cidade de Itabaiana, Sergipe, Brasil. Após a construção do mapa, foram adicionados os graus de risco de baixo, médio e alta intensidade de contaminação pelos vírus, tendo como resultado as áreas de maiores riscos: salas de aula, banheiros, vivência, laboratórios e o auditório, isto está relacionado com o alto número de pessoas circulando nesses locais e o contato frequente com maçanetas, corrimão, vidrarias, bancadas e locais com baixa circulação de ar. Por fim, o mapa de risco serve de guia para identificar as áreas de maiores riscos e que possam ser traçadas, por partes administrativas das instituições, estratégias para minimizar tais problemáticas.