The Extended Reach of Australian Drought
Total Page：16
File Type：pdf, Size：1020Kb
Selections from the RESEARCH HIGHLIGHTS scientific literature ASTROPHYSICS Rare element from space The element tellurium A. TOENSING/GETTY probably originated in exploding stars, or supernovae, through a process by which nuclei rapidly capture neutrons and become heavier. Ian Roederer of the Carnegie Observatories in Pasadena, California, and his colleagues used the Hubble Space Telescope to detect signs of tellurium in three ancient stars in the halo of the Milky Way. Tellurium is the heaviest element for which production by rapid neutron capture, called the r-process, can be CLIMATE SCIENCE predicted using laboratory data. The authors report that the The extended reach of Australian drought observed levels of tellurium match earlier predictions The Big Dry, a prolonged drought that affected whereas in the northwest it was associated with made for the r-process in the southeast Australia from 1997 to 2011, was a decreased frequency of tropical cyclones. Solar System. They conclude more extensive than previously thought. The authors say that the northwest drought that tellurium and other Gavan McGrath at the University of Western coincided with and probably exacerbated the heavy elements are produced Australia in Crawley and his colleagues one in the southeast. predominantly by this process. analysed satellite data from across the The findings suggest that distinct climatic Astrophys. J. 747, L8 (2012) continent and found evidence of decreased factors such as decadal cyclone trends and water storage, rainfall and plant growth changes in ocean circulation can combine to BIODIVERSITY throughout the country between 2002 and create a continental-scale drought. 2010. In the southeast, the drought correlated Geophys. Res. Lett. http://dx.doi. New amphibians with an irregular Indian Ocean circulation, org/10.1029/2011GL050263 (2012) with no limbs A family of limbless encompassing seven new They also warn that these adaptive evolution. Peter amphibians has been species of the caecilian order and other creatures in this Armbruster at Georgetown discovered in the soils of of amphibians. An analysis region of India are threatened University in Washington northeastern India. of the animals’ genomes and by deforestation and rapid DC and his colleagues report Sathyabhama Das Biju at cranial anatomy showed that population growth. that over roughly 20 years, the the University of Delhi and these Chikilidae (pictured Proc. R. Soc. B http://dx.doi. insect (Aedes albopictus) has his colleagues unearthed with a clutch of eggs) — which org/10.1098/rspb.2012.0150 adapted to differences in the more than 500 examples measure up to 25 centimetres (2012) timing of winter onset across in length — probably first roughly 15° of latitude. appeared during the early EVOLUTION The authors measured the Cretaceous period, about day length required to induce 140 million years ago. Invasive mosquito winter-time dormancy in S. D. BIJU The animals’ closest adapts fast mosquitoes across various known relatives are in latitudes in the US and Japan Africa. The authors Since arriving in the United between 2005 and 2008, and suggest that, historically, States from Japan in 1985, the compared the measurements caecilians are likely to have invasive Asian tiger mosquito with those taken about 20 years been geographically has spread across the country’s earlier. They found a response restricted, with low eastern reaches, providing to seasonal change that is rates of speciation. a natural demonstration of among the fastest documented 8 | NATURE | VOL 483 | 1 MARCH 2012 © 2012 Macmillan Publishers Limited. All rights reserved RESEARCH HIGHLIGHTS THIS WEEK adaptation in nature. Lunar Reconnaissance Other traits, such as body Orbiter, Thomas Watters of size, did not show a pattern of the Smithsonian Institution COMMUNITY The most viewed adaptation in either country. in Washington DC and his CHOICE papers in science The findings support the idea colleagues spotted graben — that, in a changing climate, long, narrow blocks of rock MOLECULAR BIOLOGY animals evolve mainly by that drop down and form adapting to changes in trenches as the Moon’s crust is Noncoding RNAs decapped seasonal shifts. stretched. Some of the graben Am. Nat. http://dx.doi. are as shallow as one metre, ✪ HIGHLY READ Long RNA molecules have recently been org/10.1086/664709 (2012) suggesting that, in geological on www.cell.com discovered that seem to regulate genes terms, they are fresh. 22 Jan–21 Feb rather than code for proteins, but little is MICROBIOLOGY The authors suggest that known about how they do this. Loss of a their findings are inconsistent protective cap from these long noncoding RNAs (lncRNAs) New species with models that predict seems to be a crucial step in regulating a specific type of spring forth that the primordial Moon gene in yeast. was completely molten Like protein-encoding messenger RNAs, lncRNAs have Microorganisms and would have a cap that protects the molecule from decomposing. By in a Siberian hot contracted so preventing loss of the cap in budding yeast, Jeff Coller and his spring have been much that local colleagues at Case Western Reserve University in Cleveland, caught in the extensional Ohio, found that many lncRNAs function at genomic act of diverging pressures regions near highly regulated genes that respond to specific to form two would have environmental cues such as sugars and iron. One family of species. been quashed. these ‘inducible’ genes — the GAL system, which enables ARIZONA STATE UNIV./GSFC/NASA STATE ARIZONA Rachel Instead, cells to metabolize a sugar called galactose — is regulated by Whitaker at the graben lncRNAs that must lose their caps for the cell to activate the the University of may reflect an sugar-processing genes. Illinois in Urbana- environment of Mol. Cell 45, 279–291 (2012) Champaign and her team weaker contractions that sequenced the genomes of 12 resulted from the early Moon strains of Sulfolobus islandicus having only a molten exterior. is known to improve synaptic — an archaeon living in hot Nature Geosci. http://dx.doi. plasticity. org/10.1038/ngeo1387 (2012) springs around a volcano on The authors hope that FGL REN YUGAO Russia’s Kamchatka Peninsula. could provide a starting point The sequences show that the NEUROSCIENCE for the development of drugs microbes belong to two groups that boost cognition. — dubbed red and blue — and Cognitive boost to PLoS Biol. 10, e1001262 (2012) that genes are exchanged more brain connections readily within than between PALAEOECOLOGY the groups. This means that By sensitizing the process each group of microbes meets by which neurons normally Ancient forest the classic definition of a alter the strength of their preserved in ash biological species. connections, a molecule The authors think that derived from a neuronal Volcanic ash buried a swampy physiological differences protein improves learning and forest roughly 298 million between the two populations memory in rats. years ago, preserving a could be preventing gene flow. José Esteban at the wealth of detail about the For instance, strains of the red Autonomous University of region’s flora. Scientists have looked like feather dusters and group replicate faster and to Madrid and his colleagues uncovered the fossilized plants reached heights of 25 metres higher densities than do those studied the effects of the in what is now northern China. or more. The team also found of the blue group. molecule, FGL, on rats and on Jun Wang at the Chinese fossils of vines and three PLoS Biol. 10, e1001265 (2012) slices of the rat hippocampus, Academy of Sciences species of Noeggerathiales a brain region involved in Nanjing, Hermann — small spore-bearing trees GEOLOGY in learning and memory. Pfefferkorn at the University thought to be close relatives of They showed that FGL of Pennsylvania in the earliest ferns. Stretch marks caused persistent activation Philadelphia and their team Proc. Natl Acad. Sci USA on the Moon of signalling molecules in reconstructed the ancient http://dx.doi.org/10.1073/ hippocampal neurons. This set ecosystem by analysing the pnas.1115076109 (2012) The Moon has been stretched in motion a chain of molecular positions of individual plants For a longer story on this within the past 50 million events that increased the across three sites (an artist’s research, see go.nature.com/ years — a surprising and efficiency with which a type impression pictured) that eklwre relatively recent sign of of receptor called AMPA cover a combined area of more extensional tectonics for a was inserted into neuronal than 1,000 square metres. NATURE.COM body that has been around for connections, or synapses. The Besides sporting a broad, low For the latest research published by 4.5 billion years. incorporation of additional canopy of tree ferns, the peat Nature visit: Using a camera on NASA’s AMPA receptors into synapses forest contained trees that www.nature.com/latestresearch 1 MARCH 2012 | VOL 483 | NATURE | 9 © 2012 Macmillan Publishers Limited. All rights reserved.