You are hereFeed aggregator

Feed aggregator


Q&A Jane Harding: Individual approach

Nature - Wed, 07/23/2014 - 00:00

Q&A Jane Harding: Individual approach

Nature. doi:10.1038/511S82a

Author: Smriti Mallapaty

Jane Harding is deputy vice-chancellor for research and professor of neonatology at the University of Auckland, which is New Zealand's most well-funded university under the Performance-Based Research Fund. She discusses the country's approach to assessing science and measuring impact, and describes why she prefers a model that grades the individual not the research group.

Categories: Literature

Universality of core promoter elements?

Nature - Wed, 07/23/2014 - 00:00

Universality of core promoter elements?

Nature 511, 7510 (2014). doi:10.1038/nature13587

Authors: Matthias Siebert & Johannes Söding

Arising from B. J. Venters & B. F. Pugh Nature502, 53–58 (2013); doi:10.1038/nature12535How cells locate the regions to initiate transcription is an open question, because core promoter elements (CPEs) are found in only a small fraction of core promoters. A recent study measured 159,117 DNA binding regions of transcription factor IIB (TFIIB) by ChIP-exo (chromatin immunoprecipitation with lambda exonuclease digestion followed by high-throughput sequencing) in human cells, found four degenerate CPEs—upstream and downstream TFIIB recognition elements (BREu and BREd), TATA and initiator element (INR)—in nearly all of them, and concluded that these regions represent sites of transcription initiation marked by universal CPEs. We show that the claimed universality of CPEs is explained by the low specificities of the patterns used and that the same match frequencies are obtained with two negative controls (randomized sequences and scrambled patterns). Our analyses also cast doubt on the biological significance of most of the 150,753 non-messenger-RNA-associated ChIP-exo peaks, 72% of which lie within repetitive regions. There is a Retraction accompanying this Brief Communication Arising by Venters, B. J. & Pugh, B. F. Nature511,http://dx.doi.org/10.1038/nature13588 (2014).

Categories: Literature

Correction

Nature - Wed, 07/23/2014 - 00:00

Correction

Nature 511, 7510 (2014). http://www.nature.com/doifinder/10.1038/511407a

The Comment 'Polio eradication hinges on child health in Pakistan' (Nature511, 285–287; 2014 ) accidentally referred to Abbottabad as a village instead of a city.

Categories: Literature

Correction

Nature - Wed, 07/23/2014 - 00:00

Correction

Nature 511, 7510 (2014). http://www.nature.com/doifinder/10.1038/511410e

The Outlook article 'Fat chance' (Nature511, S14–S15; 10.1038/511S14a2014) incorrectly stated that ice cream is part of a ketogenic diet. In fact, this diet is high in fat but low in carbohydrate so does not include high-sugar foods.

Categories: Literature

Earth science: Rain on the parade

Nature - Wed, 07/23/2014 - 00:00

Earth science: Rain on the parade

Nature 511, 7510 (2014). doi:10.1038/511413a

Authors: Alison M. Anders

An analysis of landforms in the Bolivian Andes suggests that surface uplift has shaped the climate and landscape. This contrasts with previous work suggesting that climate controls topography and deformation along the mountain range.

Categories: Literature

Population biology: Fur seals signal their own decline

Nature - Wed, 07/23/2014 - 00:00

Population biology: Fur seals signal their own decline

Nature 511, 7510 (2014). doi:10.1038/511414a

Authors: Tim Coulson & Sonya Clegg

Data on three generations of Antarctic fur seals suggest that climate change is reducing the survival of less-fit individuals with low genetic variation, but that overall seal numbers are falling. See Letter p.462

Categories: Literature

50 & 100 Years Ago

Nature - Wed, 07/23/2014 - 00:00

50 & 100 Years Ago

Nature 511, 7510 (2014). doi:10.1038/511416a

50 Years AgoAs regards technical development, very high frequency, “VHF”, is undoubtedly the radio system of the future. The possibility of stereophonic broadcasting on some regular scheduled basis is just beginning to show above the horizon. Even to-day, some 6 million people who have

Categories: Literature

Solid-state physics: Siphoning spins

Nature - Wed, 07/23/2014 - 00:00

Solid-state physics: Siphoning spins

Nature 511, 7510 (2014). doi:10.1038/511418a

Authors: Joo-Von Kim

Topological insulators are materials known for their remarkable electron-transport properties. They now emerge as excellent sources of electron spins for manipulating tiny magnets. See Letter p.449

Categories: Literature

Spin-transfer torque generated by a topological insulator

Nature - Wed, 07/23/2014 - 00:00

Spin-transfer torque generated by a topological insulator

Nature 511, 7510 (2014). doi:10.1038/nature13534

Authors: A. R. Mellnik, J. S. Lee, A. Richardella, J. L. Grab, P. J. Mintun, M. H. Fischer, A. Vaezi, A. Manchon, E.-A. Kim, N. Samarth & D. C. Ralph

Magnetic devices are a leading contender for the implementation of memory and logic technologies that are non-volatile, that can scale to high density and high speed, and that do not wear out. However, widespread application of magnetic memory and logic devices will require the development of efficient mechanisms for reorienting their magnetization using the least possible current and power. There has been considerable recent progress in this effort; in particular, it has been discovered that spin–orbit interactions in heavy-metal/ferromagnet bilayers can produce strong current-driven torques on the magnetic layer, via the spin Hall effect in the heavy metal or the Rashba–Edelstein effect in the ferromagnet. In the search for materials to provide even more efficient spin–orbit-induced torques, some proposals have suggested topological insulators, which possess a surface state in which the effects of spin–orbit coupling are maximal in the sense that an electron’s spin orientation is fixed relative to its propagation direction. Here we report experiments showing that charge current flowing in-plane in a thin film of the topological insulator bismuth selenide (Bi2Se3) at room temperature can indeed exert a strong spin-transfer torque on an adjacent ferromagnetic permalloy (Ni81Fe19) thin film, with a direction consistent with that expected from the topological surface state. We find that the strength of the torque per unit charge current density in Bi2Se3 is greater than for any source of spin-transfer torque measured so far, even for non-ideal topological insulator films in which the surface states coexist with bulk conduction. Our data suggest that topological insulators could enable very efficient electrical manipulation of magnetic materials at room temperature, for memory and logic applications.

Categories: Literature

Zircons reveal magma fluxes in the Earth’s crust

Nature - Wed, 07/23/2014 - 00:00

Zircons reveal magma fluxes in the Earth’s crust

Nature 511, 7510 (2014). doi:10.1038/nature13532

Authors: Luca Caricchi, Guy Simpson & Urs Schaltegger

Magma fluxes regulate the planetary thermal budget, the growth of continents and the frequency and magnitude of volcanic eruptions, and play a part in the genesis and size of magmatic ore deposits. However, because a large fraction of the magma produced on the Earth does not erupt at the surface, determinations of magma fluxes are rare and this compromises our ability to establish a link between global heat transfer and large-scale geological processes. Here we show that age distributions of zircons, a mineral often present in crustal magmatic rocks, in combination with thermal modelling, provide an accurate means of retrieving magma fluxes. The characteristics of zircon age populations vary significantly and systematically as a function of the flux and total volume of magma accumulated in the Earth’s crust. Our approach produces results that are consistent with independent determinations of magma fluxes and volumes of magmatic systems. Analysis of existing age population data sets using our method suggests that porphyry-type deposits, plutons and large eruptions each require magma input over different timescales at different characteristic average fluxes. We anticipate that more extensive and complete magma flux data sets will serve to clarify the control that the global heat flux exerts on the frequency of geological events such as volcanic eruptions, and to determine the main factors controlling the distribution of resources on our planet.

Categories: Literature

Climate change selects for heterozygosity in a declining fur seal population

Nature - Wed, 07/23/2014 - 00:00

Climate change selects for heterozygosity in a declining fur seal population

Nature 511, 7510 (2014). doi:10.1038/nature13542

Authors: Jaume Forcada & Joseph Ivan Hoffman

Global environmental change is expected to alter selection pressures in many biological systems, but the long-term molecular and life history data required to quantify changes in selection are rare. An unusual opportunity is afforded by three decades of individual-based data collected from a declining population of Antarctic fur seals in the South Atlantic. Here, climate change has reduced prey availability and caused a significant decline in seal birth weight. However, the mean age and size of females recruiting into the breeding population are increasing. We show that such females have significantly higher heterozygosity (a measure of within-individual genetic variation) than their non-recruiting siblings and their own mothers. Thus, breeding female heterozygosity has increased by 8.5% per generation over the last two decades. Nonetheless, as heterozygosity is not inherited from mothers to daughters, substantial heterozygote advantage is not transmitted from one generation to the next and the decreasing viability of homozygous individuals causes the population to decline. Our results provide compelling evidence that selection due to climate change is intensifying, with far-reaching consequences for demography as well as phenotypic and genetic variation.

Categories: Literature

Receptor binding by H10 influenza viruses

Nature - Wed, 07/23/2014 - 00:00

Receptor binding by H10 influenza viruses

Nature 511, 7510 (2014). doi:10.1038/nature13443

Authors: Sebastien G. Vachieri, Xiaoli Xiong, Patrick J. Collins, Philip A. Walker, Stephen R. Martin, Lesley F. Haire, Ying Zhang, John W. McCauley, Steven J. Gamblin & John J. Skehel

H10N8 follows H7N9 and H5N1 as the latest in a line of avian influenza viruses that cause serious disease in humans and have become a threat to public health. Since December 2013, three human cases of H10N8 infection have been reported, two of whom are known to have died. To gather evidence relating to the epidemic potential of H10 we have determined the structure of the haemagglutinin of a previously isolated avian H10 virus and we present here results relating especially to its receptor-binding properties, as these are likely to be major determinants of virus transmissibility. Our results show, first, that the H10 virus possesses high avidity for human receptors and second, from the crystal structure of the complex formed by avian H10 haemagglutinin with human receptor, it is clear that the conformation of the bound receptor has characteristics of both the 1918 H1N1 pandemic virus and the human H7 viruses isolated from patients in 2013 (ref. 3). We conclude that avian H10N8 virus has sufficient avidity for human receptors to account for its infection of humans but that its preference for avian receptors should make avian-receptor-rich human airway mucins an effective block to widespread infection. In terms of surveillance, particular attention will be paid to the detection of mutations in the receptor-binding site of the H10 haemagglutinin that decrease its avidity for avian receptor, and could enable it to be more readily transmitted between humans.

Categories: Literature

Costs of Urban Light Pollution Highlighted in Citizen Science Effort

Yale Environment 360 - Tue, 07/22/2014 - 11:01

A recently launched citizen science project aims to highlight the environmental, social, and financial impacts of excessive nighttime lighting in cities around

Click to Enlarge

Shanghai, China, at night the world. The project, called Cities at Night, enlists people to help identify the cities pictured in thousands of blindingly lit photos taken by astronauts orbiting the earth. Organizers hope that when residents and officials see the bright photos of their cities at night, they will be prompted to cut nighttime light use and energy consumption. Widespread artificial lighting has made light pollution a growing problem in urban areas by disrupting behavioral patterns of people and wildlife, wasting millions of dollars in energy costs, and adding greenhouse gases to the atmosphere. Some solutions are relatively inexpensive and straightforward, the organizers say, such as using shields to direct light down to street-level, which can allow a city to use lower-wattage streetlights.

Categories: Environmental News

The wrong kind of carbon cut

Nature - Tue, 07/22/2014 - 00:00

The wrong kind of carbon cut

Nature 511, 7510 (2014). doi:10.1038/511383a

The repeal of Australia’s carbon-pricing scheme — the first time a nation has reversed action on climate change — sets a worrying example for other countries mulling steps to reduce emissions.

Categories: Literature

Delegates mourn MH17 passengers

Nature - Tue, 07/22/2014 - 00:00

Delegates mourn MH17 passengers

Nature 511, 7510 (2014). http://www.nature.com/doifinder/10.1038/511391a

Authors: Katia Moskvitch & Edward Susman

AIDS conference tries to draw inspiration from lost scientists.

Categories: Literature

Anger as Australia dumps carbon tax

Nature - Tue, 07/22/2014 - 00:00

Anger as Australia dumps carbon tax

Nature 511, 7510 (2014). http://www.nature.com/doifinder/10.1038/511392a

Author: Quirin Schiermeier

Climate experts decry demise of emissions-control system.

Categories: Literature

Gene-hunt gain for mental health

Nature - Tue, 07/22/2014 - 00:00

Gene-hunt gain for mental health

Nature 511, 7510 (2014). http://www.nature.com/doifinder/10.1038/511393a

Author: Sara Reardon

Flood of genetic locations linked to schizophrenia helps spark financial boost to research field.

Categories: Literature

China plans super collider

Nature - Tue, 07/22/2014 - 00:00

China plans super collider

Nature 511, 7510 (2014). http://www.nature.com/doifinder/10.1038/511394a

Author: Elizabeth Gibney

Proposals for two accelerators could see country become collider capital of the world.

Categories: Literature

Schizophrenia: Genesis of a complex disease

Nature - Tue, 07/22/2014 - 00:00

Schizophrenia: Genesis of a complex disease

Nature 511, 7510 (2014). doi:10.1038/nature13645

Authors: Jonathan Flint & Marcus Munafò

The largest genome-wide analysis of schizophrenia performed so far has identified more than 100 genetic regions that contribute to disease risk, establishing new leads for understanding this form of mental illness. See Article p.421

Categories: Literature

Biological insights from 108 schizophrenia-associated genetic loci

Nature - Tue, 07/22/2014 - 00:00

Biological insights from 108 schizophrenia-associated genetic loci

Nature 511, 7510 (2014). doi:10.1038/nature13595

Authors:

Schizophrenia is a highly heritable disorder. Genetic risk is conferred by a large number of alleles, including common alleles of small effect that might be detected by genome-wide association studies. Here we report a multi-stage schizophrenia genome-wide association study of up to 36,989 cases and

Categories: Literature

Secondary Links