Although dihydrofolic acid can be formed enzymatically, in the presence of adenosine triphosphate, from 2-amino4-hydroxy-6hydroxymethyldihydropteridine and p-aminobenzoylglutamic acid (3, 4), Brown, Weisman, and Molnar (4) have postulated that dihydropteroic acid, instead of p-aminobenzoylglutamic acid, is the normal intermediate in dihydrofolate synthesis in Escherichia coli. They have present...

Laboratory studies were conducted to verify the influence of photophase on diapause incidence in the Neotropical brown stink bug, Euschistus heros (Fabr., 1798), fed with soybean [Glycine max (L.)] Merrill pods. Nymphs were maintained at three different photophases: 10 h, 12 h, and 14 h, with constant temperature of 25 +/- 1 degree C and relative humidity of 65 +/- 5%. With 14 h, approximately ...

The discovery of the hypertrophy of the rat brown adipose tissue which is induced by prolonged cold exposure [l] has been followed by many ultrastructural and biochemical studies upon this tissue which presents the peculiarity to contain a great number of mitochondrial [2]. Chronic cold exposure increases the mitochondrial diameter [3], the number of cristae [4] or the concentration of inner me...

A study of the histology and histochemical reactions for lipase, alkaline phosphatase, acid phosphatase, adenosine triphosphatase, succinic dehydrogenase, lactic dehydrogenase, phospholipids, cholesterol, sulphydryl groups, and water-insoluble aldehydes and ketones in the brown and yellow adipose tissue of the bat {Hipposideros speoris) revealed that the two types of adipose tissue differ in hi...

Boron deficiency and phytohormone interactions have been studied in unfertilized cotton (Gossypium hirsutum) ovules grown in vitro. Such ovules required exogenous indoleacetic acid and/or gibberellic acid for fiber elongation. Boron also was required for maintenance of fiber elongation and normal morphogenesis throughout 14 days of culture. The amount of exogenous boron necessary for maximum fi...

Arachidonic acid (AA) is a polyunsaturated fatty acid that stimulates the proliferation of many cellular types. We studied the mitogenic potential of AA in rat brown preadipocytes in culture and the signaling pathways involved. AA is a potent mitogen which induces 4-fold DNA synthesis in brown preadipocytes. The AA mitogenic effect increases by NE addition. AA also increases the mitogenic actio...

Sodium uptake rates were measured in wild and hatchery reared Norwegian brown trout (Salmo trutta) exposed to media of a range of pH. Sodium uptake was strongly dependent on external acidity, being reduced in media of low pH. Wild fish from the naturally acid R. Tovdal (S. Norway) were more tolerant of acid media than hatchery reared fish. The effects of increasing external sodium concentration...

Treatment of effluents containing phenols such as textile dyes with fungal laccases is usually limited to the acid to neutral pH range and moderate temperatures. Here we demonstrate for the first time that spore-bound laccases which are stable at high temperatures and pH values can be used for phenolic dye decolorisation. Laccase containing spores from Bacillus SF were immobilized on alumina pe...