Efeito da Convivencia de Echinochloa Cruz-Galli (L.) Beauv (Capim-Arroz) com Plantas de Arroz em Diferentes Niveis de Nitrogenio e Fosforo

Foram conduzidos, ao ar livre, em caixas com 47 kg de solo, dois experimentos para determinar os efeitos do capim-arroz (Echinochloa crus-galli (L.) Beauv.) no crescimento e producao de plantas de arroz (Oryza sativa L.). Utilizando-se o fatorial como delineamento experimental, foram estudadas as variaveis adubcao nitrogenada x densidade populacional de capim-arroz (1o experimento) e adubação fosfatada x densidade populacional de capim-arroz (2o experimento). Os resultados demonstraram que as adubacoes (N ou P2O5) nao tiveram qualquer influencia na convivencia entre as populacoes de arroz e capim-arroz. Por outro lado, o capim-arroz se mostrou altamente prejudicial ao arroz, em todas as medidas de crescimento avaliadas: peso seco e verde da parte aarea, perfilhamento, numero e peso das paniculas do arroz, o que mostra que os prejuizos aumentaram em funcao do aumento da densidade populacional do capim-arroz.Made available in DSpace on 2011-04-09T12:18:15Z (GMT). No. of bitstreams: 1 pab06fev91.pdf: 350938 bytes, checksum: 8a5af893e29cc6189e7be30f1a2145b3 (MD5) Previous issue date: 2001-09-13199

Anti-Mycobacterium tuberculosis activity of fungus Phomopsis stipata

Our purpose was to determine the anti-Mycobacterium tuberculosis activity of the metabolites produced by the endophitic fungus Phomopsis stipata (Lib.) B. Sutton, (Diaporthaceae), cultivated in different media. The antimycobacterial activity was assessed through the Resazurin Microtiter Assay (REMA) and the cytotoxicity test performed on macrophage cell line. The extracts derived from fungi grown on Corn Medium and Potato Dextrose Broth presented the smallest values of Minimum Inhibitory Concentration (MIC) and low cytotoxicity, which implies a high selectivity index. This is the first report on the chemical composition and antitubercular activity of metabolites of P. stipata, as well as the influence of culture medium on these properties

CO2 acts as a signalling molecule in populations of the fungal pathogen Candida albicans

10.1371/journal.ppat.1001193PLoS Pathogens611e100119

Ultrafast optical spectroscopy of strongly correlated materials and high-temperature superconductors: a non-equilibrium approach

In the last two decades non-equilibrium spectroscopies have evolved from avant-garde studies to crucial tools for expanding our understanding of the physics of strongly correlated materials. The possibility of obtaining simultaneously spectroscopic and temporal information has led to insights that are complementary to (and in several cases beyond) those attainable by studying the matter at equilibrium. From this perspective, multiple phase transitions and new orders arising from competing interactions are benchmark examples where the interplay among electrons, lattice and spin dynamics can be disentangled because of the different timescales that characterize the recovery of the initial ground state. For example, the nature of the broken-symmetry phases and of the bosonic excitations that mediate the electronic interactions, eventually leading to superconductivity or other exotic states, can be revealed by observing the sub-picosecond dynamics of impulsively excited states. Furthermore, recent experimental and theoretical developments have made it possible to monitor the time-evolution of both the single-particle and collective excitations under extreme conditions, such as those arising from strong and selective photo-stimulation. These developments are opening the way for new, non-equilibrium phenomena that can eventually be induced and manipulated by short laser pulses. Here, we review the most recent achievements in the experimental and theoretical studies of the non-equilibrium electronic, optical, structural and magnetic properties of correlated materials. The focus will be mainly on the prototypical case of correlated oxides that exhibit unconventional superconductivity or other exotic phases. The discussion will also extend to other topical systems, such as iron-based and organic superconductors, (Formula presented.) and charge-transfer insulators. With this review, the dramatically growing demand for novel experimental tools and theoretical methods, models and concepts, will clearly emerge. In particular, the necessity of extending the actual experimental capabilities and the numerical and analytic tools to microscopically treat the non-equilibrium phenomena beyond the simple phenomenological approaches represents one of the most challenging new frontiers in physics