Avaliação de cultivares de alfafa nas condições de cerrado no Estado de Minas Gerais.

O objetivo deste trabalho foi avaliar o potencial forrageiro de cultivares de alfafa na região de Cerrado do Estado de Minas Gerais. O delineamento experimental foi o de blocos ao acaso, com três repetições. Durante os períodos de seca e das águas, foram observadas diferenças significativas entre as cultivares quanto ao potencial de produção de forragem, teor de proteína bruta, relação folha/caule e tolerância a pragas e doenças. As cultivares Crioula e P 30 destacam-se das demais em relação ao potencial produtivo e resistência a pragas e doenças e são recomendadas para a região dos Cerrados da Zona Metalúrgica de Minas Gerais

Seagrass and submerged aquatic vegetation (VAS) habitats off the Coast of Brazil: state of knowledge, conservation and main threats

Seagrass meadows are among the most threatened ecosystems on earth, raising concerns about the equilibrium of coastal ecosystems and the sustainability of local fisheries. The present review evaluated the current status of the research on seagrasses and submerged aquatic vegetation (SAV) habitats off the coast of Brazil in terms of plant responses to environmental conditions, changes in distribution and abundance, and the possible role of climate change and variability. Despite an increase in the number of studies, the communication of the results is still relatively limited and is mainly addressed to a national or regional public; thus, South American seagrasses are rarely included or cited in global reviews and models. The scarcity of large-scale and long-term studies allowing the detection of changes in the structure, abundance and composition of seagrass habitats and associated species still hinders the investigation of such communities with respect to the potential effects of climate change. Seagrass meadows and SAV occur all along the Brazilian coast, with species distribution and abundance being strongly influenced by regional oceanography, coastal water masses, river runoff and coastal geomorphology. Based on these geomorphological, hydrological and ecological features, we characterised the distribution of seagrass habitats and abundances within the major coastal compartments. The current conservation status of Brazilian seagrasses and SAV is critical. The unsustainable exploitation and occupation of coastal areas and the multifold anthropogenic footprints left during the last 100 years led to the loss and degradation of shoreline habitats potentially suitable for seagrass occupation. Knowledge of the prevailing patterns and processes governing seagrass structure and functioning along the Brazilian coast is necessary for the global discussion on climate change. Our review is a first and much-needed step toward a more integrated and inclusive approach to understanding the diversity of coastal plant formations along the Southwestern Atlantic coast as well as a regional alert the projected or predicted effects of global changes on the goods and services provided by regional seagrasses and SAV

Synthesis of novel polybutadiene-graft-poly(sodium methacrylate) amphiphilic copolymers as precursors for liquid crystalline graft copolymers

Well-defined polybutadiene-graft-poly(tert-butyl methacrylate) (PBD-g-PtBMA) copolymers were prepared by reaction of PtBMA chains end-capped with a tert-butyl 4-vinylbenzoate (tBVB) anion, with the selectively hydrosilylated 1,2-units of anionically synthesized PBD. Substitution of the tBVB anion for the anion of living PtBMA chains is required for the formation of the expected C-silylation product instead of the unstable O-silylation one. Subsequent hydrolysis of the poly(tert-butyl methacrylate) grafts followed by neutralization of the carboxylic acid groups by sodium hydroxide leads to amphiphilic polybuta-diene-graft-poly(sodium methacrylate) (PBD-g-PNaMA) graft copolymers. These copolymers form unimeric micelles in water, as observed by dynamic light scattering (DLS). Non-covalent liquid crystalline graft copo-lymers were prepared by cation exchange between PBD-g-PNaMA copolymers and an ammonium containing smectic mesogen. These copolymers form a smectic mesophase which is microphase separated from PBD

Antibacterial activity of 15-deoxygoyazensolide isolated from the stems of Minasia alpestris (Asteraceae) against oral pathogens

This work reports the isolation of the sesquiterpene lactone 15-deoxygoyazensolide from the stems of Minasia alpestris and the evaluation of its antimicrobial activity against the following oral pathogens: Enterococcus faecalis, Streptococcus salivarius, Streptococcus sobrinus, Streptococcus mutans, Streptococcus mitis, Streptococcus sanguinis, and Lactobacillus casei. Despite the cytotoxicity and genotoxicity of other sesquiterpene lactones of the furanoheliangolide-type, our results revealed that this compound exhibits low antibacterial activity against the evaluated oral pathogens; however, an interesting selectivity against E. faecalis (minimum inhibitory concentration [MIC] = 40 mu g mL(-1)) and S. sobrinus (MIC = 60 mu g mL(-1)) was observed.FAPESP[Process 07/54241-8]CAPE