Thursday, October 6, 2011
Wednesday, October 5, 2011
A new leaf turns in carbon science
“A new insight into global photosynthesis. The chemical process governing how ocean and land plants absorb and release carbon dioxide, has been revealed in research that will assist scientists to more accurately assess future climate change.”
In a paper published in Nature, a team of US, Dutch and Australian scientists have estimated that the global rate of photosynthesis, the chemical process governing the way ocean and land plants absorb and release CO2, occurs 25% faster than previously thought.
Understanding the exchange of gases, including CO2 and water vapour is especially significant to science because of its relevance to global management of carbon emissions. Photo: UMCES
From analysing more than 30 years of data collected by Scripps Institution of Oceanography, UC San Diego including air samples collected and analysed by CSIRO and the Bureau of Meteorology from the Cape Grim Air Pollution Monitoring Station, scientists have deduced the mean rate of photosynthesis over several decades and identified the El Nino-Southern Oscillation phenomenon as a regulator of the type of oxygen atoms found in CO2 from the far north to the south pole.
“Our analysis suggests that current estimates of global primary production are too low and the refinements we propose represent a new benchmark for models to simulate carbon cycling through plants,” says co-author, Dr Colin Allison, an atmospheric chemist at CSIRO’s Aspendale laboratories.
The study, led by Dr Lisa Welp from the Scripps Institution of Oceanography, California, traced the path of oxygen atoms in CO2 molecules, which tells researchers how long the CO2 has been in the atmosphere and how fast it had passed through plants. From this, they estimated that the global rate of photosynthesis is about 25 percent faster than previously thought.
“It’s difficult to measure the rate of photosynthesis for forests, let alone the entire globe. For a single leaf it’s straightforward, you just put it in an instrument chamber and measure the CO2 decreasing in the chamber air,” said Dr Welp.
“But you cannot do that for an entire forest. What we have done is to use a naturally occurring marker, an oxygen isotope, in atmospheric CO2 that allows us to track how often it ended up inside a plant leaf, and from oxygen isotopic CO2 data collected around the world we can estimate the mean global rate of photosynthesis over the last few decades.”
In other studies, analysis of water and oxygen components found in ocean sediments and ice cores have provided scientists with a ‘big picture’ insight into carbon cycling over millions of years, but the search for the finer details of exchanges or uptake through ocean algae and terrestrial plant leaves has been out of reach.
The authors said that their new estimate of the rate of global photosynthesis will help guide other estimates of plant activity, such as the capacity of forests and crops to grow and fix carbon, and help re-define how scientists measure and model the cycling of CO2 between the atmosphere and plants on land and in the ocean.
Dr Allison said understanding the exchange of gases, including CO2 and water vapour, in the biosphere – oceans, land and atmosphere – is especially significant to climate science, and to policymakers, because of its relevance to global management of carbon emissions.
“Quantifying this global production, centred on the exchange of growth-promoting CO2 and water vapour, has been historically difficult because there are no direct measurements at scales greater than leaf levels.
“Inferences drawn from atmospheric measurements provide an estimate of ecosystem exchanges and satellite-based observations can be used to estimate overall primary production, but as a result of this new research we have re-defined the rate of biospheric carbon exchange between atmosphere, land and ocean.
“These results can be used to validate the biospheric components included in carbon cycle models and, although still tentative, may be useful in predicting future climate change,” Dr Allison said.
CSIRO’s Dr Roger Francey was a co-author on the project, led by Scripps’ Drs Welp and Ralph Keeling. Other co-authors of the study are Harro Meijer from the University of Groningen in the Netherlands; Alane Bollenbacher, Stephen Piper and Martin Wahlen from Scripps; and Kei Yoshimura from the University of Tokyo, Japan.
Dr Allison said a critical element of the research was access to long data sets at multiple locations, such as Cape Grim, Mauna Loa and South Pole, extending back to 1977 when Cape Grim was established in Tasmania’s north-west, together with more recent samples from facilities such as Christmas Island, Samoa, California and Alaska. The Cape Grim Baseline Air Pollution Station provides vital information about changes to the atmospheric composition of the Southern Hemisphere.
“Dr Allison said understanding the exchange of gases, including CO2 and water vapour, in the biosphere – oceans, land and atmosphere – is especially significant to climate science, and to policymakers, because of its relevance to global management of carbon emissions.”
Robot Culture Machine Efficiently Grows Biological Cells Without Human Intervention
Robotic Cell Factory This robotic cell factory can churn out 500 cell cultures a month. © Fraunhofer IPM
The tedious, carpal-tunnel-inducing pipette work of cell biologists may soon be relegated to robots, thanks to a new cell factory developed in Germany. This could free humans to perform new studies and ask new questions, as automated equipment takes over the time-consuming task of growing, feeding and observing cells in the lab.
Cell cultures are one of the most important tools in biology, used to study a huge host of diseases and cellular functions. But cells are delicate, and for now they must be cultivated by hand, grown in petri dishes and nurtured with a special broth until there are enough cells to transfer to even more petri dishes. The transfer is done via pipette so the cells aren’t harmed.
Many robots aren’t equipped with a gentle enough touch to pull this off, and the humid, warm conditions cells need to grow are not very friendly to electronics. But now, researchers at three different Fraunhofer Institutes have developed a system that can automate this entire process, using several different robots and machines.
One robot is designed to move around the first-generation cell cultures, called multititer plates, among various spots. Then an automated microscope checks the cells to assess their growth, adjusting the light and focus as needed, and the images are fed into a computer system. Special software determines how many cell colonies are present on the plates, and if there are enough, another robot is tasked with picking them up. Using a hollow needle, it chooses cells measuring between 100 and 200 micrometers and transfers them to a new container for continued growth.
The system can produce about 500 cell cultures a month, according to a news release from Fraunhofer. Biologists can even train the system to recognize certain cell types, based on their physical characteristics. The whole thing is big enough to fill a small lab.
Fraunhofer already has a cell factory of a different sort, producing sheets of human skin. That process is also controlled by robots and computers that monitor the cells’ health and growth. But this new one is based on a modular design, so it can be adapted for various uses — for instance, if a lab only wants to automate one part of the cell culture process.
Researchers set up a prototype at the Max Planck Institute, where biologists will use it to determine protein functions, according to Fraunhofer Research News. Let's hope nothing goes wrong and the robots do not use their new skills to create a new legion of multicellular servants.
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