Science

The best in science news, commentary, and research
  • [Editorial] Passing the CEO baton
    [Feb 2015]

    s I retire from the office of chief executive of the American Association for the Advancement of Science (AAAS) and pass the baton to my very capable successor, physicist and former U.S. congressman Rush Holt, I have been reflecting on changes over the past decades both within the scientific enterprise and in its relationship with the rest of society. Many trends are cause for celebration, but others require remedial attention. On the positive side, new technologies have enabled new and very important scientific questions to be confronted, and a rise in collaborative, multidisciplinary science has fueled a remarkable pace of discovery. Science is also becoming more global in character as more countries invest in science and technology and fortify their infrastructures and science capacities. Science has never been more productive. And yet, the overall climate for science is more difficult than I have ever seen in my scientific career. This stunning state of contradiction indicates that there has never been a greater need, or a greater opportunity, for an international organization such as AAAS, whose mission is to advance science and serve society. Author: Alan I. Leshner
    Categories: Journal Articles
  • [In Brief] This week's section
    [Feb 2015]

    In science news around the world, molecular diagnostics company Myriad Genetics ends a long battle to defend its controversial patents on genetic tests for cancer risk, police search the Max Planck Institute for Biological Cybernetics in response to accusations of animal mistreatment by activists, researchers funded by the pharmaceutical company Roche—which makes Tamiflu—found that the drug helps combat influenza, a fire at the Russian Academy of Sciences destroys a significant portion of its documents, and the U.K. House of Commons votes overwhelmingly to allow researchers to pursue a fertility treatment called mitochondrial DNA replacement therapy. Also, the European Commission's former (and first) chief science adviser, microbiologist Anne Glover, tells reporters she doesn't regret saying that opposing genetically modified crops is a form of madness. And the first Science Ball opens its doors to debutantes and doctorates in Vienna, home of the waltz and of balls.
    Categories: Journal Articles
  • [In Depth] Seafloor grooves record the beat of the ice ages
    [Feb 2015]

    In addition to carving up the continents, the ice ages also tattoo the sea floor with rhythmic patterns, according to two studies published this week. At seafloor spreading centers, plates of ocean crust diverge and magma erupts in the gap, building new crust onto the plates' trailing edges. Parallel to these spreading centers are "abyssal hills": long, 100-meter-high ridges on the diverging plates, separated by valleys. It turns out that these periodic grooves reflect the timing of the ice ages. Ice ages are driven mainly by periodic variations in Earth's orbit and spin that alter sunlight in the Northern Hemisphere. During these periods, ice sheets trap so much frozen water that sea levels can drop a hundred meters or more. This reduces the pressure on the ocean floor and, in turn, speeds up the eruptions at the spreading centers—thickening the ocean plates and creating the abyssal hills, researchers say. The periodic strength of the eruptions helps explain the long-debated origin of the abyssal hills. Also intriguing is the question of whether emissions from seafloor volcanoes could be a feedback that helps bring about the end of ice ages. Author: Eric Hand
    Categories: Journal Articles
  • [In Depth] U.S. House reveals ambitious biomedical innovation plan
    [Feb 2015]

    Since last April, a bipartisan team in the U.S. House of Representatives has led a high-profile initiative to speed the development of new medical treatments. Last week, the initiative bore its first fruit: a sweeping draft proposal released by Energy and Commerce Committee Chair Fred Upton (R–MI) that would overhaul many policies at the National Institutes of Health and the Food and Drug Administration. But Upton's draft had a bumpy rollout. His partner in the initiative, Diana DeGette (D–CO), announced that she did not endorse it. And although the document is attracting praise from many industry and research advocacy groups, some are concerned that it neglects basic research funding while extending overly generous terms to drug companies. Author: Kelly Servick
    Categories: Journal Articles
  • [In Depth] Misfire aside, signs of cosmic inflation could come soon
    [Feb 2015]

    When the biggest discovery in cosmology in years officially unraveled last Friday, nobody was surprised. Nevertheless, cosmologists remain optimistic that such a discovery may come soon. Last March, cosmologists using a specialized telescope at the South Pole called BICEP2 reported that they had detected faint pinwheel-like swirls in the afterglow of the big bang—the cosmic microwave background—that would be direct evidence of cosmic inflation, a bizarre exponential growth spurt thought to have blown up the infant universe. But in September, data from Europe's Planck spacecraft suggested the signal was an artifact of dust in our galaxy. Now, a joint analysis by the BICEP and Planck teams confirms the dust explanation. Still, a gaggle of experiments in the works will have sensitivity to see a signal half as strong as the now-discredited one. And researchers are planning for a $100 million network of telescopes, to be deployed next decade, that would be 10 times more sensitive still. Evidence for inflation may come within a few years. Author: Adrian Cho
    Categories: Journal Articles
  • [In Depth] Africa's soil engineers: Termites
    [Feb 2015]

    Although we all tend to think about large mammals as being the big dominant drivers of what's happening in the savanna, termites and their mounds are proving ever more influential. Indigenous people have long used soil from termite mounds for farming. Studies have long shown termites, by retrieving vegetation, help concentrate nitrogen, phosphorous, and organic material in the mounds. These nutrient islands are the savanna's supermarkets, supporting both plant-eating and predatory insects, as well as spiders, lizards, and large grazers, such as elephants. They occur in polka-dot arrays, spaced to maximize the number of mounds while minimizing territorial conflicts. By modeling the interactions of termites, rainfall, soil, and plants, researchers now show that the termite mounds are an insurance policy against climate change, protecting the vegetation on them from water scarcity. Author: Elizabeth Pennisi
    Categories: Journal Articles
  • [In Depth] Japanese neutrino physicists think really big
    [Feb 2015]

    Japan has already made its mark in research into the wispy, elementary particles known as neutrinos. In the mid-1980s, the Kamiokande detector conducted groundbreaking observations of neutrinos emanating from the sun, the atmosphere, and a supernova. The work later won a Nobel Prize in physics. In the mid-1990s, observations at that detector's larger successor, Super-Kamiokande, demonstrated that neutrinos have mass, upsetting previous theories. Now Japanese physicists are thinking really big with a plan to build Hyper-Kamiokande, which would be the largest neutrino detector ever. Researchers believe this behemoth will allow them to determine the remaining unknown properties of neutrinos, study the early universe, and probe why matter is more common than antimatter. Scientists from 13 countries this past weekend formally launched a protocollaboration to develop a detailed design they can take to funding agencies in hopes of getting the $800 million or so needed to build the detector. They hope to start construction in 2018 and start taking data in 2025. Author: Dennis Normile
    Categories: Journal Articles
  • [In Depth] Budget for 2016 accentuates the practical
    [Feb 2015]

    "Making it real" is the key message that U.S. scientists should take from the 2016 budget that President Barack Obama submitted to Congress this week. His proposed $4 trillion budget shatters the spending caps from a 10-year agreement reached in 2011 to reduce the federal deficit, using revenues from higher taxes on the wealthy. But the overall 7.2% increase allocated for all discretionary spending exceeds the percentage allocated to most agencies that support academic research, with the emphasis on applied research that addresses pressing societal problems. The White House had already announced initiatives on precision medicine and fighting antibiotic resistance, and the president's new budget also contains large increases in such areas as advanced manufacturing, energy technologies, and climate monitoring and mitigation. The budget debate now moves to Congress, which is likely to resist most of the spending increases. A yearlong battle is likely, with scientists as interested bystanders. Author: Jeffrey Mervis
    Categories: Journal Articles
  • [In Depth] Biomedical initiatives get top billing in budget rollout
    [Feb 2015]

    Days before the release of the overall federal budget request, the White House began talking up two new flagship scientific efforts. The $215 million Precision Medicine Initiative, first mentioned in President Barack Obama's 20 January State of the Union address, aims to advance personalized medicine in part by assembling a database containing genetic and medical information from at least 1 million Americans. The other is a roughly $1.2 billion multiagency effort to combat the mounting public health crisis of antibiotic-resistant infections. The National Institutes of Health, which would receive an overall 3.3% increase to $31.3 billion, would play a key role in both campaigns. The two initiatives have drawn encouraging words from members of Congress in both parties. Authors: Jocelyn Kaiser, Kelly Servick
    Categories: Journal Articles
  • [Feature] A classroom experiment
    [Feb 2015]

    The National Science Foundation (NSF) has poured half a billion dollars into the Robert Noyce Teacher Scholarship Program since it was launched in 2003. The program is meant to draw those with STEM (science, technology, engineering, and math) degrees into teaching at high-needs public schools, on the assumption that students would learn more science and math if they were taught by those who know and love the subjects. Several thousand Noyce-trained teachers have been placed in these schools. But so far the program hasn't moved the needle on student achievement, or even on the overall supply of well-prepared STEM teachers. The reasons are complicated. And many of the factors that will ultimately determine the success or failure of the program, including attitudes toward the teaching profession and the myriad factors that affect how students learn, lie outside NSF's power to control. Author: Jeffrey Mervis
    Categories: Journal Articles
  • [Policy Forum] Where is Silicon Valley?
    [Feb 2015]

    Although economists, politicians, and business leaders have long emphasized the importance of entrepreneurship (1, 2), defining and characterizing entrepreneurship has been elusive (3, 4). Researchers have been unable to systematically connect the type of high-impact entrepreneurship found in regions such as Silicon Valley with the overall incidence of entrepreneurship in the population (5–7). This has important implications: Researchers arrive at alternative conclusions about roles and patterns of entrepreneurship (8–10), and policy-makers are given conflicting recommendations about whether or how to promote entrepreneurship for economic and social progress (11, 12). Authors: Jorge Guzman, Scott Stern
    Categories: Journal Articles
  • [Perspective] There goes the macrophage neighborhood
    [Feb 2015]

    The lymph node is a highly structured organ optimized for generating adaptive immune responses. Lymph fluid carrying pathogens and their antigens from infected tissue is first distributed into a large cavity just beneath the node's surface, which is populated by a dense layer of specialized macrophages. These subcapsular sinus (SCS) macrophages filter incoming lymph, capture pathogens, and relay pathogen-derived antigen to B cells in subjacent follicles, provoking them to produce antibodies (see the figure). At the original infection site, migratory dendritic cells (DCs) are activated, acquire antigen, and deliver it to the node through the lymph, generating a secondary wave of immune cell activation. Until now, this influx of DCs has been viewed as beneficial to the host, as they activate T cells within the node's paracortex. However, on page 667 of this issue, Gaya et al. (1) demonstrate that incoming DCs can be harmful. These cells can disrupt the SCS macrophage layer and reduce the host's ability to mount a humoral (antibody) response to a secondary pathogen. Author: Heather D. Hickman
    Categories: Journal Articles
  • [Perspective] Taking temperature at the nanoscale
    [Feb 2015]

    Measuring temperature has become commonplace since Fahrenheit, Celsius, and others introduced thermometers and temperature scales in the 18th century. However, the definition of temperature is not at all obvious, as it is now described as a statistical quantity given by the rate of change of entropy with respect to the internal energy of a system with volume and number of particles held constant. This is by itself not an easy concept to grasp. In addition, determining temperature raises thermodynamical questions when considering systems with further and further reduced dimensions (1). Consequently, measuring temperature at the nanoscale constitutes a challenge in many fields of science and technology. On page 629 of this issue, Mecklenburg et al. (2) report how they have elegantly met this challenge. Author: Christian Colliex
    Categories: Journal Articles
  • [Perspective] Our skewed sense of space
    [Feb 2015]

    The hippocampus is the brain region where spatial maps of our surroundings are encoded. A specific location will activate a set of neurons called place cells to represent the particular place. What happens as the number of environments encountered increases? Does the hippocampus continually create and store distinct independent “maps” for each locale, or can place cells be recruited for more than one map to generalize across locales? It appears that both mechanisms contribute in unique ways. Author: György Buzsáki
    Categories: Journal Articles
  • [Perspective] A Me6Age for pluripotency
    [Feb 2015]

    Cell-fate decisions are orchestrated by global changes in gene expression, some of which are driven by epigenetic alterations, often including methylation of DNA. Embryonic stem cells (ESCs) have been used to decipher many of the critical factors underlying cell-fate decisions. Mouse ESCs exist in several different pluripotent states, notably naïve or ground-state ESCs and primed epiblast stem cells (EpiSCs), which resemble pre- and post-implantation–stage embryos, respectively (1, 2). New research now reveals another role for nucleic acid methylation in stem cell–fate determination, but of RNA rather than DNA—at position six of the adenosine base (m6A). Two recent papers, by Geula et al. (3) in Science Express and Batista et al. (4), show that m6A is involved in regulating stem cell maintenance and cell-fate decisions through its modulation of RNA stability and translation. Authors: Hendrik G. Stunnenberg, Michiel Vermeulen, Yaser Atlasi
    Categories: Journal Articles
  • [Perspective] The coordination chemistry of nanocrystal surfaces
    [Feb 2015]

    In the 1990s, when quantum confined colloidal semiconductor nanocrystals (NCs, or quantum dots) were first synthesized with narrow size distributions, there was an explosion of effort to harness their bright and narrow luminescence for optoelectronic devices and fluorescence labeling (1). However, the surfactant ligands that stabilized NCs also influenced their electronic structure and optical properties. Encapsulating the NC cores within an insulating inorganic shell reduced the effect of surface structure on charge recombination (2) and forced the radiative recombination of photoexcited charges. These structures greatly increased the photoluminescence quantum yield (PLQY) and enabled their recent use in liquid crystal displays. However, PLQYs of core-shell nanocrystals remain sensitive to their surfaces and if NCs are to be useful within electrical devices, such as photovoltaic (PV) cells, the complex relation between their surface structure and their frontier orbital structure must be better understood. Author: Jonathan Owen
    Categories: Journal Articles
  • [Perspective] How a virus travels the world
    [Feb 2015]

    In November and December 2014, highly pathogenic avian influenza (HPAI) viruses of the H5 subtype originating from China were detected in poultry and wild birds in various countries of Asia and Europe, and, for the first time, in North America. These incursions of newly emerging HPAI H5 viruses constitute a threat to animal and potentially human health and raise questions about the routes of transmission. Authors: Josanne H. Verhagen, Sander Herfst, Ron A. M. Fouchier
    Categories: Journal Articles
  • [Book Review] Surrounded by science
    [Feb 2015]

    The natural history museum is an example of a 19th-century invention that still has momentum in the 21st century. In a way, the continued presence of museums in our modern world is as surprising as if one were to see a fleet of horse-drawn carriages hurtling down the highway at 75 mph. Life on Display, by historians Karen A. Rader and Victoria E. M. Cain, focuses on the evolution of U.S. science and nature museums from the late 19th century to the early 21st century, stitching together a number of surprising insights into an excellent history. Author: Kirk R. Johnson
    Categories: Journal Articles
  • [Book Review] Breaking bad science
    [Feb 2015]

    London newsstands can strike Americans as remarkable, both for the number of different papers being sold and for their alarming headlines. Most U.S. cities are lucky to have a single daily newspaper—shrinking in both physical size and circulation—with fairly staid contents. In contrast, Britain has about 10 daily newspapers that contend for a national audience. Their circulations are also slipping, but the fact that they are competing for readers makes their coverage colorful by American standards. Author: Joel Best
    Categories: Journal Articles
  • [Books et al.] Books Received
    [Feb 2015]

    A listing of books received at Science during the week ending 30 January 2015.
    Categories: Journal Articles