We observed diurnal and seasonal patterns of leaf-scale gas exchange within the crown of a Dipterocarpus sublamellatus Foxw. tree growing in a lowland dipterocarp forest at Pasoh, Peninsular Malaysia. Observations were carried out nine times over 6 years, from September 2002 to December 2007. Observation periods included both wet and mild-dry periods, and natural and saturated photosynthetic ph...

Complete submergence of plants prevents direct O(2) and CO(2) exchange with air. Underwater photosynthesis can result in marked diurnal changes in O(2) supply to submerged plants. Dynamics in pO(2) had not been measured directly for submerged rice (Oryza sativa), but in an earlier study, radial O(2) loss from roots showed an initial peak following shoot illumination. O(2) dynamics in shoots and...

Whole-plant diurnal C exchange analysis provided a noninvasive estimation of daily net C gain in transgenic tobacco (Nicotiana tabacum L.) plants deficient in leaf cytosolic pyruvate kinase (PKc-). PKc- plants cultivated under a low light intensity (100 &mgr;mol m-2 s-1) were previously shown to exhibit markedly reduced root growth, as well as delayed shoot and flower development when compared ...

surface ozone (surface o3)is a secondary pollutant and there are only limited studies on ozone in south india. studies have revealed a strong correlation between higher ozone levels and warmer days. surface o3 along with its precursors like no2, co and ch4 are being measured at kanyakumari (8.0780° n, 77.5410° e), tamilnadu, india and in this paper we present the summer time variation of ozone ...

11 Anthropogenic and biogenic controls on the surface-atmosphere exchange of CO2 are explored 12 for three different environments. Similarities are seen between suburban and woodland sites during 13 summer, when photosynthesis and respiration determine the diurnal pattern of the CO2 flux. In 14 winter, emissions from human activities dominate urban and suburban fluxes; building emissions 15 inc...

Once dissolved uranium (U) from tailings deposits enters adjacent streams, subsequent downstream transport is affected by the rate at which U is immobilised in sediments, thereby lowering its concentration in stream water. For aqueous phases immobilisation includes adsorption onto sediments and suspended solids, as well as precipitation and co-precipitation as insoluble compounds, all mechanism...

Natural variability in seawater pH and associated carbonate chemistry parameters is in part driven by biological activities such as photosynthesis and respiration. The amplitude of these variations is expected to increase with increasing seawater carbon dioxide (CO2) concentrations in the future, because of simultaneously decreasing buffer capacity. Here, we address this experimentally during a...

The budget of atmospheric CO2 is widely studied using records of temporal and spatial variations of concentrations, d C and dO values. However, the number and diversity of sources and sinks prevents these alone from fully constraining the budget. Molecules containing two rare isotopes can serve as additional tracers and potentially provide additional, independent, constraints. We present data d...

The filamentous cyanobacterium Arthrospira platensis has a long history of use as a food supply and it has been used by the European Space Agency in the MELiSSA project, an artificial microecosystem which supports life during long-term manned space missions. This study assesses progress in the field of cyanobacterial shotgun proteomics and light/dark diurnal cycles by focusing on Arthrospira pl...

The green alga Chlamydomonas reinhardtii is a useful model organism for investigating diverse biological processes, such as photosynthesis and chloroplast biogenesis, flagella and basal body structure/function, cell growth and division, and many others. We combined a highly synchronous photobioreactor culture system with frequent temporal sampling to characterize genome-wide diurnal gene expres...