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Biomedical subjects

D Mara

Publications and source records attributed to D Mara.

4 recordsLinked to original sources
PubMed2005

Research on waste stabilization ponds in the United Kingdom: sludge accumulation in pilot-scale primary facultative ponds.

Three pilot-scale facultative ponds, located at Esholt wastewater treatment works in Bradford, West Yorkshire, UK were operated in parallel for 53 months, each with different BOD loadings and hydraulic retention times. Measurements of the sludge accumulation were made at 6-monthly intervals commencing at 3 months after start-up. In addition grab sludge samples were collected and analysed for total solids, volatile solids and faecal coliforms. After the first year of operation the sludge accumulation rate was 0.74 m3 yr(-1) for all three ponds (p=816), independent of BOD loading and HRT; the per capita accumulation rates were within the range 0.08-0.16 m3 person(-1) yr(-1). Evidence of degradation was found in the sludge from the percentage of volatile solids in the dry solids, but insignificant removal of faecal coliforms.

Animals↗
PubMed2001

Resveratrol and a novel tyrosinase in Carignan grape juice.

Polyphenol levels in wines are affected by the wine-making process. Resveratrol is one polyphenol which has been the subject of a commendable amount of recent research. In this work, we found that resveratrol is immediately degraded by tyrosinase. A novel tyrosinase was purified from Carignan grapes. The purification process included salting out and separation on a cation-exchange column, followed by gel filtration. Tyrosinase was purified in a homogeneous form by SDS-PAGE and was characterized: its specific activity toward 3-(3,4-dihydroxyphenyl)-L-alanine (DOPA) increased by a factor of 24 with an overall recovery of 3% of initial activity. The apparent molecular mass of the purified tyrosinase was 40 kDa as determined by SDS-PAGE, and 42 kDa as determined by gel filtration. Its activity was optimal at pH 6 and at 25 degrees C. The enzyme exhibited high activity toward phenylenediamine, epicatechin, pyrogallol, DOPA, and resveratrol. Tyrosinase activity was inhibited by KCN, thiourea, and SO(2). Resveratrol levels were stable following the removal of proteins from the juice, suggesting that early spraying of grapes with SO(2) is an important factor affecting the final amount of resveratrol in wine.

Antioxidants↗
PubMed1997

Social drinking and laughter.

Pairs of observers monitored drinking and laughter in groups of social drinkers (N = 56). A significant correlation of .27 was found between units of alcohol consumed and laughter scores.

Adolescent↗