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Weeds interfere negatively on development, yield and quality of soybeans (Glycine max). Inadequate weed control by herbicide use can select for resistant or tolerant biotypes, leading to a shift in the weed flora. An example is the increase of incidence of morning glory (Ipomoea spp.) in soybeans growing areas in South Brazil. The aim of this study was to determine the competitiveness of soybeans intercropped with I. triloba, I. indivisa and I. purpurea through a replacement experiments series. Greenhouse experiments were conducted in a completely randomized design with four replications. The first experiment was carried out aiming to get the plant population while total plant dry mass remained constant. Other experiments were done under replacement series experiments with soybeans and morning glory ratios of 100:0, 75:25, 50:50, 25:75 and 100:0 using the 250 plant m-2 defined by the preliminary experiment. Leaf area, root and shoots dry mass were assessed. Diagrams along with index interpretation were used to performed a competitiveness analysis. Soybeans showed greater competitiveness as I. triloba, I. purpurea and I. indivisa species for the leaf area, root and shoots dry mass variables. Intraspecific competition prevails between soybean plants whilst interspecific competition prevails for morning glory. As plantas daninhas interferem negativamente no desenvolvimento, na produtividade e na qualidade da soja. O controle inadequado das plantas daninhas pelo uso de herbicidas pode selecionar biótipos resistentes e/ou plantas tolerantes, provocando mudança na flora de plantas daninhas. Objetivou-se com este trabalho determinar a competitividade da soja em convivência com plantas de I. triloba, I. indivisa e I. purpurea, por meio de experimentos em série de substituição. Os experimentos foram realizados em casa de vegetação, no delineamento inteiramente casualizado com quatro repetições. O primeiro experimento foi realizado com a finalidade de obter a população de plantas a partir da qual a massa seca total das plantas permanecesse constante; já os demais experimentos foram realizados em série de substituição com proporções entre soja e corda-de-viola de 100:0, 75:25, 50:50, 25:75 e 100:0, com população definida no experimento preliminar de 250 plantas m-2. As variáveis avaliadas foram área foliar, massa de matéria seca de raiz e massa de matéria seca da parte aérea. A análise da competitividade foi feita por diagramas de competitividade e por interpretações dos índices. Os resultados indicam a soja como competidor superior às espécies de cordas-de-viola (I. triloba, I. indivisa e I. purpurea) para as variáveis área foliar, massa de matéria seca de raiz e massa de matéria seca da parte aérea e que para soja predomina a competição intraespecífica, enquanto para as cordas-de-viola prevalece a competição interespecífica.

Diabetes mellitus (DM) is associated with brain alterations that may contribute to cognitive dysfunctions. Chlorogenic acid (CGA) and caffeine (CA), abundant in coffee (CF), are natural compounds that have showed important actions in the brain. The present study aimed to evaluate the effect of CGA, CA, and CF on acetylcholines- terase (AChE), Na ? ,K ? -ATPase, aminolevulinate dehydra- tase (d-ALA-D) activities and TBARS levels from cerebral cortex, as well as memory and anxiety in streptozotocin- induced diabetic rats. Animals were divided into eight groups (n = 5-10): control; control/CGA 5 mg/kg; control/CA 15 mg/kg; control/CF 0.5 g/kg; diabetic; diabetic/CGA 5 mg/kg; diabetic/CA 15 mg/kg; and diabetic/CF 0.5 g/kg. Our results demonstrated an increase in AChE activity and TBARS levels in cerebral cortex, while d-ALA-D and Na ? , K ? -ATPase activities were decreased in the diabetic rats when compared to control water group. Furthermore, a memory deficit and an increase in anxiety in diabetic rats were observed. The treatment with CGA and CA prevented the increase in AChE activity in diabetic rats when compared to the diabetic water group. CGA, CA, and CF intake par- tially prevented cerebral d-ALA-D and Na ? ,K ? -ATPase activity decrease due to diabetes. Moreover, CGA prevented diabetes-induced TBARS production, improved memory, and decreased anxiety. In conclusion, among the compounds studied CGA proved to be a compound which acts better in the prevention of brain disorders promoted by DM.