This week in science (#40)
Recent results from the European satellite Planck have challenged what was previously reported as the discovery of the century. The signal detected by BICEP2, a South Pole based experiment, and attributed to an extremely rapid expansion during the first moments of the Universe (inflation), seems to have a much simpler explanation: dust. While the judge is still out, and the absence of evidence is not evidence of absence, any extraordinary claims about the very first instants of the Universe will have to be backed by extraordinary proof.
In a press release boldly entitled “Rethinking the Origins of the Universe” it is claimed that scientist Laura Merisini-Houghton has “proven, mathematically, that black holes can never come into being in the first place”. The reason being the inclusion of quantum effects (namely Hawking radiation) in the process of stellar mass Black Hole formation. This process is usually only discussed in the framework of Einstein’s general relativity. The press release has been criticized for a number of reasons: overhyping a result that is not peer-reviewed yet, generalizing the result to all kinds of black holes, and finally extending the implications of the finding to the first moments of the Universe (a topic that is not discussed in the paper itself). While definitely a potentially exciting development, skepticism is recommended.
It’s all well and good that industrious scientists are breaking Moore’s Law for DNA-sequencing, but what of the genetic end-products, proteins? Current methods for protein determination are expensive, limited in scope, often require purification and aren’t amenable to scaling. Researchers in the Church Lab at Harvard are changing that, starting with the area of protein-protein interaction. By specifically tagging proteins with DNA-barcodes, spreading and immobilizing the bulk sample, and then amplifying the DNA tags, researchers could then “sequence” co-localized proteins. Through statistical leveraging (i.e. taking 1 million samples per mm^2), researchers built protein interaction profiles for GPCRs1 and antibodies.
Read more (Technical) : Nature Article
G protein-coupled receptors, a protein family of receptors that sense molecules outside the cell and activate inside signal transduction pathways and, ultimately, cellular responses↩
At the beginning of the month, Gomes, et al released a statistical model for the spreading risk of the Ebola Virus (EVD) from West Africa. UK, Belgium, France, and US were at the highest risk, with a lower-bound of 5% (the US had an upper-bound of 18%) at the projection cut-off date of September 22, 2014. On Septemeber 30, the CDC announced the first detected case on US soil in Dallas, Texas. While the now-quarantined passenger flew from Liberia on September 20, he was not contagious en route, displaying symptoms 4 days later. Healthcare workers are currently working around the clock tracking everyone who came into contact with the patient for testing, a luxury unavailable in West Africa where workers are still under-staffed and under-supplied, despite hundreds of millions of dollars in promised foreign aid.
This study demonstrates the predictive power of well-designed models and is a sobering reminder that the global community is still at risk from EVD, which is projected to reach hundreds of thousands of cases in West Africa by January 2015.
Last week, researchers at Cornell University and Rothamsted Research, UK, published experimental results that demonstrate improved photosynthetic activity in Nature (News & Views). Modern plants have CO2-fixing enzymes (a complex known as Rubisco) that can’t readily distinguish between CO2 and O2. This leads to inefficiency and requires large concentrations of Rubisco, making it the most prevalent enzyme on the planet.
Lin, et al replaced tobacco’s native Rubisco large subunit gene with that found in a highly-efficient cyanobacteria (along with genes to aid complex assembly). Increases in Rubisco turnover compared to wildtype were seen, but at high CO2 concentrations. Still, this is a huge step towards boosting crop yields and especially important as the UN projects a 2x production increase is necessary by 2050.