Large enrichments in fatty acid H/H ratios distinguish respiration from aerobic fermentation in yeast .

Shifts in the hydrogen stable isotopic composition (H/H ratio) of lipids relative to water (lipid/water H-fractionation) at natural abundances reflect different sources of the central cellular reductant, NADPH, in bacteria. Here, we demonstrate that lipid/water H-fractionation (ε) can also constrain the relative importance of key NADPH pathways in eukaryotes. We used the metabolically flexible yeast a microbial model for respiratory and fermentative metabolism in industry and medicine, to investigate ε.

Mixoplankton and mixotrophy: future research priorities.

Phago-mixotrophy, the combination of photoautotrophy and phagotrophy in mixoplankton, organisms that can combine both trophic strategies, have gained increasing attention over the past decade. It is now recognized that a substantial number of protistan plankton species engage in phago-mixotrophy to obtain nutrients for growth and reproduction under a range of environmental conditions. Unfortunately, our current understanding of mixoplankton in aquatic systems significantly lags behind our understanding of zooplankton and phytoplankton, limiting our ability to fully comprehend the role of mixoplankton (and phago-mixotrophy) in the plankton food web and biogeochemical cycling.

Human settlement of East Polynesia earlier, incremental, and coincident with prolonged South Pacific drought.

The timing of human colonization of East Polynesia, a vast area lying between Hawai'i, Rapa Nui, and New Zealand, is much debated and the underlying causes of this great migration have been enigmatic. Our study generates evidence for human dispersal into eastern Polynesia from islands to the west from around AD 900 and contemporaneous paleoclimate data from the likely source region. Lake cores from Atiu, Southern Cook Islands (SCIs) register evidence of pig and/or human occupation on a virgin landscape at this time, followed by changes in lake carbon around AD 1000 and significant anthropogenic disturbance from c.