Surface structure of Hevea leaves and its importance for the interaction with fungal plant pathogens and for plant systematics.

Resumo apresentado no XXI Congresso Brasileiro de Fitopatologia, Salvador, 1988

Anti-cyanobacterial activity of Moringa oleifera seeds

Filtrates from crushed Moringa oleifera seeds were tested for their effects on growth and Photosystem II efficiency of the common bloom-forming cyanobacterium Microcystis aeruginosa. M. aeruginosa populations exhibited good growth in controls and treatments with 4- and 8-mg crushed Moringa seeds per liter, having similar growth rates of 0.50 (±0.01) per day. In exposures of 20- to 160-mg crushed Moringa seeds L−1, growth rates were negative and on average −0.23 (±0.05) .day−1. Presumably, in the higher doses of 20- to 160-mg crushed seeds per liter, the cyanobacteria died, which was supported by a rapid drop in the Photosystem II efficiency (ΦPSII), while the ΦPSII was high and unaffected in 0, 4, and 8 mg L−1. High-density populations of M. aeruginosa (chlorophyll-a concentrations of ∼270 µg L−1) were reduced to very low levels within 2 weeks of exposure to ≥80-mg crushed seeds per liter. At the highest dosage of 160 mg L−1, the ΦPSII dropped to zero rapidly and remained nil during the course of the experiment (14 days). Hence, under laboratory conditions, a complete wipeout of the bloom could be achieved. This is the first study that yielded evidence for cyanobactericidal activity of filtrate from crushed Moringa seeds, suggesting that Moringa seed extracts might have a potential as an effect-oriented measure lessening cyanobacterial nuisance

Ultrastructure of acridone alkaloid idioblasts in roots and cell cultures of Ruta graveolens

Histological analysis of Ruta graveolens L. roots and in vitro grown cell suspensions revealed idioblasts with vacuoles containing clusters of droplets thought to be the storage compartment of acridone alkaloids. These idioblasts contained numerous vacuoles of varying sizes rather than the large, single, central vacuole characteristic of most adjacent parenchyma cells. The structure of idioblasts in roots and suspension cultures was identical. Treatment of suspension cultures with fungal elicitors known to increase alkaloid accumulation greatly did not affect the structure of idioblasts

Traumatic dental injuries as reported during school hours in Bergen

Aims: To identify existing guidelines for managing traumatic dental injuries (TDIs) in the schools of Bergen, to ascertain the frequency of occurrence of such injuries, and to estimate the need for further information among teachers and school administrators. Material and methods: The study, undertaken among teachers and school administrators of elementary and lower secondary schools in Bergen municipality, was questionnaire-based and included a cross section of staff. The structured short questionnaire included items registering TDIs during 2009, existence of routines or guidelines for managing TDIs, previous relevant training, and request for TDI education or information. The statistical methods included frequency tables and logistic regression analysis. Results: The response rate was 73%. The incidence proportion of TDIs was measured to 0.74% of children at risk, varying according to children's classes (peak at third class: 1.68% of children in the population). No schools had adequate written guidelines for handling TDIs. Previous education on the subject was scarce. In 20 schools, there was no perceived need for TDI-related education or information. The schools’ routines for TDI reporting, who was in charge of the reporting, acquired TDI education and expressed need for TDI information or education, did not influence the number of reported TDI cases. Conclusion: This study has produced reliable information that schools in the municipality of Bergen could improve ways of reporting and managing TDIs. As teachers with skills in handling TDIs could help to improve the prognosis for injured teeth, some types of educational intervention in schools should be launched

Synthesis of acetyldimethyl(phenyl)silane and its enantioselective conversion into (R)-(1-hydroxyethyl)dimethyl(phenyl)silane by plant cell suspension culytures of Symphytum officinale L. and Ruta graveolens L.

Starting from chlorodimethyl(phenyl)silane (3), acetyldimethyl(phenyl)silane (l) was prepared by a two-step synthesis in a total yield of 90% [PhMe$_2$SiCl (3)-> PhMe$_2$SiCCOMe)=CH$_2$ (4)-> PhMe$_2$SiC(O)Me (1)]. The prochiral acetylsilane 1 was transfonned enantioselectively into (R)-(1-hydroxyethyl)dimethyl(phenyl)silane [(R)-2] using plant cell Suspension cultures of Symphytum officinale L. or Ruta graveolens L. Under preparative conditions (300-mg scale, not optimized), (R)-2 was isolated in 15% (Symphytum) and 9% yield (Ruta), respectively. The enantiomeric purities of the products were 81% ee (Syrnphytum) and 60% ee (Ruta), respectively