Medida Rápida e Simultânea dos Tempos de Relaxação Longitudinal e Transversal por RMN-CWFP.

bitstream/CNPDIA/10475/1/CT66_2005.pd

Neutrality of narrative discussion in annual reports of UK listed companies

This paper reports the results of an investigation into the neutrality of the narrative discussion of financial performance and position, as evidenced in 179 annual reports of UK listed companies. Neutrality of narrative discussion was determined by comparing the average proportions of good and bad news contained in the narrative and statutory accounts sections of the annual reports. The results of a comparison of the proportion of good news in the two sections of the annual reports suggest that the narrative sections contained a significantly higher proportion of good news than the statutory accounts sections. Comparison of proportions of bad news, however, indicates that the narrative sections contained a significantly lower proportion of bad news compared to the statutory accounts sections. Finally, the results also suggest that the proportion of good news as compared to bad news in the narrative sections is significantly higher than the proportion of good news compared to bad news in the statutory accounts section. The results are consistent with the suggestion that company management highlights good news in narrative discussions. The implications of the findings for company management, users, auditors and regulators are discussed

Composition and biological activity of the essential oil peruvian lantana camara

The composition of the essential oil from Lantana camara L. (Verbenaccae) obtained by hydrodistillation of the aerial parts was examined by GC, GC/MS, and (13)C-NMR. The GC analysis showed that carvone is the most abundant monoterpene 75.9%, together with limonene 16.9%, accounting for 92.8% of the oil. The major components were also tested by (13)C-NMR analysis of the essential oil. The L. camara oil was assayed against several microorganisms, showing moderate antibacterial activity against the human pathogen Staphylococcus aureus (MIC 200 mu g/ml). High antioxidant activity evaluated by the Trolox equivalent antioxidant capacity assay (TEAC) was found (29.0 mmol Trolox/kg) and relative low anti-inflammatory activity due to its weak ability for inhibiting lipoxygenase (IC(50) = 81.5 mu g/ml)

Mycotoxin production from fungi isolated from grapes

Aims: In order to assess the potential for producing mycotoxins, fungi were isolated from wine producing grapes. Methods and Results: The isolates were identified and Penicillium expansum, the most well recognized mycotoxin producer, was analysed for mycotoxin production by TLC. Many of the strains produced patulin and/or citrinin, often depending on whether they were grown on a grape or yeast extract sucrose media. Conclusions: Citrinin was produced by all strains grown in the yeast extract sucrose medium, but only one strain (from 51) was able to produce this compound in grape juice medium. Patulin was produced in the yeast extract medium by 20 strains and in grape juice medium by 33 strains. Significance and Impact of the Study: The presence of mycotoxins in wine producing grapes is discussed. Grapes contamination with patulin seems not to contribute to wine contamination, and no ochratoxin producing fungi was identified.The British Council, Conselho de Reitores das Universidades Portuguesas (CRUP) - Windsor Programme - grant no 29/00

ESR, raman and conductivity studies on fractionated poly(2-methoxyaniline-5-sulfonic acid)

Synthesis methods used to produce poly(2-methoxyaniline-5-sulfonic acid) (PMAS), a water soluble, self-doped conducting polymer, have been shown to form two distinctly different polymer fractions with molecular weights of approximately 2 kDa and 8 -10 kDa. The low molecular weight (LMWT) PMAS fraction is redox inactive and non-conducting while the high molecular weight (HMWT) PMAS is electro-active with electrical conductivities of 0.94 0.05 S cm-1. Previous investigations have illustrated the different photochemical and electrochemical properties of these fractions, but have not correlated these properties with the structural and electronic interactions that drive them. Incomplete purification of the PMAS mixture, typically via bag dialysis, has been shown to result in a mixture of approximately 50:50 HMWT:LMWT PMAS with electrical conductivity significantly lower at approximately 0.10 to 0.26 S cm-1. The difference between the electrical conductivities of these fractions has been investigated by the controlled addition of the non-conducting LMWT PMAS fraction into the HMWT PMAS composite film with the subsequent electronic properties investigated by solid-state ESR and Raman spectroscopies. These studies illustrate strong electronic intereactions of the insulating LMWT PMAS with the emeraldine salt HMWT PMAS to substantially alter the population of the electronic charge carriers in the conducting polymer. ESR studies on these mixtures, when compared to HMWT PMAS, exhibited a lower level of electron spin in the presence of LMWT PMAS indicative of the the formation of low spin bipolarons without a change the oxidation state of the conducting HMWT fraction

Avaliação de genótipos de trigo quanto à reação a Pyricularia oryzae em campo.

A brusone, causada por Pyricularia oryzae, é umas das doenças mais limitantes da cultura do trigo, afetando diretamente a espiga e podendo causar danos de até 100%. Fungicidas não têm proporcionado controle satisfatório da doença. O uso da resistência genética, por ser mais econômico, seria o método mais desejável para controle. Porém, poucas fontes de resistência ao patógeno são conhecidas. O objetivo deste trabalho foi avaliar genótipos de trigo em campo quanto à reação a P. oryzae buscando identificar fontes de resistência. Quarenta e nove genótipos, do banco de germoplasma da Embrapa Trigo, foram semeados no campo experimental da Embrapa Soja, em Londrina, PR. As parcelas tinham três linhas de 3 m com 0,2 m entre linhas e cerca de 80 sementes m linear-1 . Na área do experimento foi instalado um sistema de irrigação para fornecer umidade, favorecendo a ocorrência da doença. O sistema foi acionado automaticamente quatro vezes ao dia, permanecendo ligado por sete minutos. O delineamento experimental foi blocos casualizados com duas repetições. A partir do início do espigamento os genótipos foram monitorados quanto a ocorrência da brusone. Espigas com sintomas foram marcadas semanalmente e ao final do ciclo de cada genótipo foram contadas as espigas sadias e as com sintomas para determinação da incidência (%). Trinta e seis genótipos apresentaram incidência igual ou menor que 10%, sendo 19 de ciclo tardio, 12 de ciclo médio e dois de ciclo precoce. Em estudo repetido no próximo ano, se confirmados os baixos valores de incidência, esses genótipos poderão ser utilizados em programas de melhoramento