Leaf characters of populations of the aquatic macrophyte Montrichardia linifera were studied using geometric morphometrics to compare variation with traditional circumscriptions of the two recognized species. Two hundred and ten individuals were sampled from seven populations in the delta region of the Rio Parnaíba, north‐east Brazil. Six landmarks of the leaf blade were digitized from images and analysed with MorphoJ software. Procrustes‐aligned configurations were studied using principal component analysis and canonical variates analysis in the pooled data and individual populations. Sinus shape variation was studied using landmark configurations of the posterior lobe basiscopic lamina. Covariation of leaf blade shape, basiscopic lamina shape, secondary vein number and petiole ligule length was investigated with partial least squares analysis. Allometry of these variables with leaf blade centroid size was investigated using multivariate regression, linear modelling and analysis of covariance. Measured variables varied continuously over the ranges previously reported for the two species. The characters of the two species morphotypes covaried and were only partly influenced by allometric effects. Symmetric shape variables predominated, but a distinctive left‐ and right‐handed asymmetry occurred in all populations. Genetic and ecological studies are needed to investigate the significant inter‐population differences further. The study offers a methodology for a broader combined morphometric/molecular investigation. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 170, 554–572.

RESUMONa aplicação dos conteúdos da disciplina Ciências Naturais à teoria não deveria ser desvinculada da prática, pois esta metodologia é imprescindível para construção do conhecimento científico dos alunos. Assim, objetivouse investigar a viabilidade de aulas práticas para alunos do 7º ano do Ensino Fundamental, em duas escolas estaduais no município de Parnaíba, Piauí, como estratégias para facilitar o ensino-aprendizagem em conteúdo de Botânica. Foram aplicados questionários antes e após cada aula prática para verificar a construção de conhecimento. Os resultados demonstraram aumento no número de respostas corretas após as aulas práticas nas duas escolas alvo da pesquisa. Concluiu-se que o ensino de ciências, pode ser melhorado a partir de iniciativas simples, como realização de aula prática dentro da sala ou usando os espaços verdes da escola. PALAVRAS-CHAVE:Construção do conhecimento científico, Ensino de botânica, Metodologia de ensino. PRACTICAL AS A STRATEGY FOR KNOWLEDGE IN BOTANY IN ELEMENTARY EDUCATION ABSTRACTWhen teaching the subject area of Natural Science, theoretical and practical aspects should not be separated, since both viewpoints are essential for ensuring that the students acquire a well-formed foundation of scientific knowledge. The objective of this study was therefore to investigate the viability of practical classes for students in the seventh year of Basic Education, in two state schools of the municipality of Parnaíba, Piauí, as a strategy for facilitating teaching and learning in the subject area of Botany. Questionnaires were used before and after each practical class to study the acquisition of the students' knowledge. The results demonstrated an increase in the number of correct answers after the practical classes, in the two schools studied. Our conclusion is that scientific teaching can be improved by simple initiatives such as carrying out practical sessions within the classroom or by using the green spaces within the school..

Background: Natural naphthoquinones have shown diversified biological activities including antibacterial, antifungal, antimalarial, and cytotoxic activities. However, they are also compounds with acute cytotoxicity, immunotoxicity, carcinogenesis, and cardio- and hepatotoxicity, then the modification at their redox center is an interesting strategy to overcome such harmful activity. Objective: In this study, four novel semisynthetic hydrazones, derived from the isomers α- and β-lapachones (α and β, respectively) and coupled with the drugs hydralazine (HDZ) and isoniazid (ACIL), were prepared, evaluated by electrochemical methods and assayed for anticancer activity. Method: The semisynthetic hydrazones were obtained and had their molecular structures established by NMR, IR, and MS. Anticancer activity was evaluated by cell viability determined by reduction of 3-(4,5-dimethyl-2-thiazol)-2,5-diphenyl-2H-tetrazolium bromide (MTT). The electrochemical studies, mainly cyclic voltammetry, were performed, in aprotic and protic media. Result: The study showed that the compounds 2, 3, and 4 were active against at least one of the cancer cell lines evaluated, being compounds 3 and 4 the most cytotoxic. Toward HL-60 cells, compound 3 was 20x more active than β-lapachone, and 3x more cytotoxic than doxorubicin. Furthermore, 3 showed an SI value of 39.62 for HL-60 cells. Compound 4 was active against all cancer cells tested, with IC50 values in the range 2.90–12.40 μM. Electrochemical studies revealed a profile typical of self-protonation and reductive cleavage, dependent on the supporting electrolyte. Conclusion: These results therefore indicate that compounds 3 and 4 are strong candidates as prototypes of new antineoplastic drugs.

The most widely used vaccines were messenger RNA (mRNA), viral vector, and inactivated virus with two‐dose schedules. In Brazil, the CoronaVac (Sinovac) was the first vaccine approved for emergency use, and the third dose was administered, preferably, with the BNT162b2 vaccine. We evaluated antibody levels after 6 months of the booster dose with BNT162B2 in previous recipients of CoronaVac and whether a subsequent severe acute respiratory syndrome coronavirus 2 (SARS‐COV‐2) infection enhances the antibody response. We analyze the humoral response (spike [S] IgM for the SARS‐CoV‐2 and IgG for the S and nucleocapsid [N] proteins) in samples collected before the third dose and 6 months after the third dose. The presence of antibodies was measured by using Abbott Architect i2000SR. The IgM and IgG antispikes were stimulated mainly 30 days after the third dose (30d/3D), with a decline over time. The IgG anti‐N was stimulated predominantly in 90d/3D and 180d/3D. The N IgG levels were 50 and 35 times higher in the positive polymerase chain reaction (PCR) group in 90d/3D and 180d/3D, respectively. The S IgG titers were 1.5 times elevated in the positive PCR group, in 180d/3D. The BNT162b2 boosted the S IgG levels, decreasing after 60 days. The booster shot induced IgM and IgG antibodies against spike protein. Infection after vaccination increased antibodies against protein N.

We evaluated the longitudinal dynamics of antibody response to the SARS-CoV-2 vaccine CoronaVac and the effect of a booster dose of BNT162b2 vaccine. We found a robust antibody response after the second dose of Coro-naVac that wanes over time. The response was recovered by BNT162b2, which boosted anti-spike antibody titers.

The study consists of a taxonomic treatment of the Araceae of Ceará, a state lying within Brazil's semi-arid region. The aroid flora shows greater similarity to those of central Brazil and Amazonia than to the Atlantic forest. Most species occur in humid forest fragments - the "florestas serranas". Geophytes are also found in caatinga and dry forest (Taccarum ulei) and lithophytes on rock outcrops in dry forest (Philodendron acutatum). Floating aquatics occur in ponds and lakes throughout the state (Pistia stratiotes, Lemna aequinoctialis, Lemna minuta, Spirodela intermedia, Wolffia columbiana, Wolffiella welwitschii), and freshwater helophytes (Montrichardia linifera) along river margins. 28 taxa (species and varieties) in 19 genera are described and most are illustrated:Anthurium (three spp.), Caladium (one sp.), Dieffenbachia (one sp.), Dracontium (one sp.), Lemna (two spp.), Monstera (two spp., one with two varieties), Montrichardia (one sp.), Philodendron (four spp.), Pistia (one sp.), Scaphispatha (one sp.), Spathicarpa (one sp.), Spathiphyllum (one sp.), Spirodela (one sp.), Syngonium (one sp.), Taccarum (one sp.), Wolffia (one sp.), Wolffiella (one sp.), Xanthosoma (two spp.), Zomicarpa (one sp.). New records for Ceará are Dieffenbachia aglaonematifolia, Dracontium nivosum, Monstera adansonii var. laniata, Philodendron sp. aff. ruthianum and the naturalized exotic Typhonium roxburghii. An identification key and data on geographic distribution and conservation status are provided.

This is the fi rst taxonomic study of the family Araceae in the state of Piauí, Northeast Brazil. The survey was conducted in four coastal municipalities (Ilha Grande, Luiz Correia, Cajueiro da Praia and Parnaíba) of the state. Eight species were recorded in six genera: Lemna aequinoctialis Welw., L. valdiviana Phil., Montrichardia linifera (Arruda) Schott, Pistia stratiotes L., Wolffi ella lingulata (Hegelm.) Hegelm., W. oblonga (Phil.) Hegelm., Taccarum ulei Engl. & K. Krause and Spathicarpa gardneri Schott. Of these, two are geophytes (T. ulei, S. gardneri) and the others are aquatic macrophytes. Descriptions, illustrations, phenology and habitat information are given for each species as well as a key to their identifi cation.

Pilocarpus microphyllus Stapf ex Wardlew. (jaborandi) is native to the North and Northeast regions of Brazil. Intensive exploitation for the extraction of pilocarpine, a valuable alkaloid for the pharmaceutical industry, has killed off or brought about a loss of vigor of naturally occurring plant populations. As a result, the species is officially listed as an endangered species of the Brazilian flora. Genetic diversity is required for the adaptation of populations to environmental changes, and maintaining it is a central objective for biological conservation. ISSRs are dominant markers widely used in genetic diversity studies of endangered species, allowing for the identification of genotypes and cultivars, as well as helping in phylogenetic studies based on DNA fingerprinting. This study presents an ISSR primer selection for genetic structure analyses of natural populations and cultivated collections of P. microphyllus.