In the light, photosynthesis provides carbon for metabolism and growth. In the dark, plant growth depends on carbon reserves that were accumulated during previous light periods. Many plants accumulate part of their newly-fixed carbon as starch in their leaves in the day and remobilise it to support metabolism and growth at night. The daily rhythms of starch accumulation and degradation are dyna...

The volatile gas isoprene is emitted in teragrams per annum quantities from the terrestrial biosphere and exerts a large effect on atmospheric chemistry. Isoprene is made primarily from recently fixed photosynthate; however, alternate carbon sources play an important role, particularly when photosynthate is limiting. We examined the relative contribution of these alternate carbon sources under ...

A new approach for pulse labelling of plants using the short-lived positron emitting radioisotope carbon-11 (halflife: 20.4 min) as 11 CO 2 is reported together with its application to measuring [ 11 C]isoprene emissions from intact leaves capturing information associated with: (1) rate of emission; (2) the relative contribution of recently fixed carbon to isoprene biosynthesis; and (3) the tra...

Thiobacillus ferrooxidans was used in fixed-film bioreactors to oxidize ferrous sulfate to ferric sulfate. Glass beads, ion-exchange resin, and activated-carbon particles were tested as support matrix materials. Activated carbon was tested in both a packed-bed bioreactor and a fluidized-bed bioreactor; the other matrix materials were used in packed-bed reactors. Activated carbon displayed the m...

Adsorption by granular activated carbon (GAC) has been widely employed to remove various synthetic organic contaminants (SOCs) from water supplies [1]. A factor complicating the design and effectiveness of activated carbon for the treatment of potable waters is the presence of naturally occurring dissolved organic matter (NOM) in natural waters. The presence of NOM can significantly reduce the ...

Electrochemical glucose enzyme biosensors have been prepared on carbon film electrodes made from carbon film electrical resistors. Evaluation and characterisation of these electrodes in phosphate buffer saline solution has been carried out with and without pretreatment by cycling in perchloric acid or at fixed applied potential. Both pretreatments led to a reduction in the carbon surface oxidat...

In recent years, several radiopharmaceuticals have been developed for imaging regional cerebral blood flow (rCBF) such as 75Se labelled PIPSE and MOSE, ²º¹TI labelled DDC and 99mTc labelled HMPAO. HMPAO with two asymmetric carbon atoms (At the 3 and 9 positions), produces d,1 and meso isomers, only one of which is retained in the brain. Rapid intracellular conversion of 99mTc-d,1-HMPAO to...

Rates of photosynthesis, sucrose synthesis, starch accumulation and degradation were measured in sugar beet (Beta vulgaris L.) and bean (Phaseolus vulgaris L.) plants under a square-wave light regime and under a sinusoidal regime that simulated the natural daylight period. Photosynthesis rate increased in a measured manner in direct proportion to the increasing light level. In contrast to this ...