Recursos de Sanidad, Biomedicina y Salud
 
 

Noticias Externas del Wednesday 07 de March de 2012

NEJM
 
New England Journal of Medicine, Volume 366, Issue 10, Page 932-942, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 957-959, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 960-961, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 904-913, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 914-924, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 963-966, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 893-903, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 967-969, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 883-892, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 966, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 970, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 970, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 925-931, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 962-963, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 944-954, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 956-957, March 2012.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 943, March 2012.
 
 
New England Journal of Medicine, Volume 0, Issue 0, Ahead of Print.
 
 
New England Journal of Medicine, Volume 366, Issue 10, Page 970, March 2012.
 
 
New England Journal of Medicine, Volume 0, Issue 0, Ahead of Print.
 
The New York Times
 
In only the second surgery of its kind, Mr. Lyles’s cancerous windpipe was replaced in November with a synthetic one that had been seeded with his own cells.
 
 
In the hospital, people who aren't employees fit into one of two categories: patient or visitor. But when visiting relatives or friends become ill on a hospital floor, it's not easy to care for them.
 
National Institutes of Health (NIH)
 
Notice NOT-HG-12-011 from the NIH Guide for Grants and Contracts
 
 
Notice NOT-OD-12-071 from the NIH Guide for Grants and Contracts
 
 
Notice NOT-OD-12-077 from the NIH Guide for Grants and Contracts
 
 
Funding Opportunity RFA-DK-12-005 from the NIH Guide for Grants and Contracts. This Funding Opportunity Announcement (FOA) invites applications from institutions to coordinate a NIDDK Short-Term Education Program for Underrepresented Persons (STEP-UP) that targets high school students. STEP-UP is a national program designed to provide eight to twelve weeks of summer research education and training for students underrepresented in biomedical research on a national basis, including individuals from disadvantaged backgrounds, individuals from underrepresented racial and ethnic groups, and individuals with disabilities. STEP-UP aims to expose students to and increase interest in NIDDK mission areas including diabetes, endocrinology, metabolism, nutrition, obesity, and digestive, liver, urologic, kidney, and hematologic diseases.
 
 
Funding Opportunity RFA-DK-12-001 from the NIH Guide for Grants and Contracts. This FOA invites applications for continuation the Integrated Islet Distribution Program (IIDP) that provides for the distribution of human cadaveric islets for biomedical research. It solicits a single coordinating center that will subcontract with qualified islet isolation facilities to prepare and distribute human islets. The Coordinating Center will manage an application process to establish eligibility to receive islets, maintain a roster of investigators approved to receive islets, implement a notification system informing investigators of human islet availability, implement a partial cost recovery system through fees collected from islet recipients, and develop a system to monitor and improve the quality of islets distributed. Human islets are an essential resource for diabetes research, both to advance our understanding of human islet cell biology and to develop therapies for the treatment of diabetes. The coordinating center will provide an indispensible research service to the medical community by providing access to human islets and foster improved standardization and quality of this precious research resource.
 
The New York Times
 
The lobbying group for seniors reported an overall rise in the cost of drugs in recent years despite a decrease in the price of generic drugs.
 
 
The drug, Surfaxin, which helps premature babies with their breathing, won approval on its fifth try.
 
 
Concerned about Idaho’s high skin cancer rate, state lawmakers are considering legislation that would restrict tanning salon use among minors.
 
 
Doctors have been fielding reports from patients that statins leave them feeling "fuzzy," and unable to remember small and big things.
 
 
Studies suggest that narcolepsy is far more common than most doctors realize, and it is frequently misdiagnosed.
 
 
India’s mass production of generic versions of drugs patented elsewhere helps poor people with treatment that would otherwise be too costly, but drug companies say the knockoffs stifle innovation.
 
The Wall Street Journal
 
Authorities investigating the importation of low-cost foreign pharmaceuticals into the U.S. have identified a supply chain that may have allowed fake cancer drugs to reach U.S. clinics.
 
National Institutes of Health (NIH)
 
HIV-positive children older than 1 year who were treated after showing moderate HIV-related symptoms did not experience greater cognitive or behavior problems compared to peers treated when signs of their infection were still mild, according to a study funded by the National Institutes of Health. But both groups of HIV-positive children lagged behind HIV-negative children in these areas, suggesting that the first year of life may present a critical treatment window for minimizing impairments in brain development due to HIV.
 
The New York Times
 
With the help of a little oil and some bold seasonings, these kohlrabi sticks deliver big flavor.
 
CORDIS
 
Investigadores de la Universidad de Nottingham (Reino Unido) han diseñado una técnica innovadora que permite estudiar las raíces de las plantas. Los resultados de su trabajo, publicados en la revista Plant Physiology, darán lugar a mejores técnicas de fitogenética con las que obtener nuevas variedades de cultivos y mayores tasas de productividad. Este nuevo método está basado en la misma tecnología de rayos X que se emplea en las exploraciones de tomografía computarizada (TAC) habituales en hospitales. Quality validation date: 2012-03-07
 
 
Investigadores británicos han descubierto que en los últimos 100 000 años la actividad humana y el cambio climático han provocado la extinción de una parte de la gran fauna del planeta. Presentado en Proceedings of the National Academy of Sciences (PNAS), el estudio aclara la manera en la que la presión ejercida sobre la megafauna influye en los grandes animales vivos. Investigadores de la Universidad de Cambridge (Reino Unido) estudiaron las extinciones producidas durante el Cuaternario superior, que abarca los últimos 700 000 años, y sobre todo las producidas en los últimos 100 000 años. Quality validation date: 2012-03-07
 
 
A los científicos dedicados al desarrollo de dispositivos protésicos para personas con lesiones en la médula espinal o con amputaciones les agradará conocer los resultados de un nuevo estudio financiado con fondos europeos en el que se pone de manifiesto que el encéfalo es más flexible y aprende mejor de lo que se creía hasta ahora. Un equipo de científicos de Portugal y Estados Unidos ha publicado un artículo en Nature en el que se explica que se puede enseñar al encéfalo una tarea que normalmente no realizaría gracias a un proceso denominado plasticidad. El equipo descubrió que los mismos circuitos encefálicos utilizados para aprender capacidades motoras como montar en bicicleta o conducir un coche pueden utilizarse para controlar tareas exclusivamente mentales, incluso las arbitrarias. Quality validation date: 2012-03-07
 
Nature
 

Lessons of a triple disaster

Nature 483, 7388 (2012). doi:10.1038/483123a

The aftermath of the biggest earthquake in Japan's history, and the tsunami and nuclear disaster that followed, offers a map for preparing for the next catastrophe.

 
 

Political science

Nature 483, 7388 (2012). doi:10.1038/483123b

The practice of science cannot be, nor should it be, entirely apolitical.

 
 

Gold in the text?

Nature 483, 7388 (2012). doi:10.1038/483124a

Publishers and scientists should do more to foster the mining of research literature by computer.

 
 

No theory is too special to question

Nature 483, 7388 (2012). http://www.nature.com/doifinder/10.1038/483125a

Author: Giovanni Amelino-Camelia

The flurry of research that followed the claim of faster-than-light neutrinos was far from a waste of time, says Giovanni Amelino-Camelia.

 
 

Oceanography: Tsunamis collide and grow taller

Nature 483, 7388 (2012). doi:10.1038/483126a

Ridges and mountains on the sea floor dangerously amplified the eastward-bound segments of the tsunami that devastated Japan's Tohoku coast (pictured) last year.Satellite observations made on 11 March at different locations over the Pacific Ocean suggest that tsunami height increased as the wavefront raced

 
 

HIV: A race to kill or be killed

Nature 483, 7388 (2012). doi:10.1038/483126b

HIV's prime cellular victim can itself kill affected cells during the early days of infection. And it seems that the more vigorous this response by CD4 T cells is, the greater an HIV-positive person's chance is of being able to maintain a relatively low viral

 
 

Environmental Science: Oil-sands pollution quantified

Nature 483, 7388 (2012). doi:10.1038/483126c

Air pollution caused by crude-oil extraction from Canadian oil sands is comparable to that measured over mid-sized cities or in the vicinity of large coal-burning power plants.Chris McLinden of Environment Canada in Toronto and his colleagues used satellite observations to determine how the mining

 
 

Immunology: Fighting viruses antibody-free

Nature 483, 7388 (2012). doi:10.1038/483126d

Neutralizing antibodies were thought to be essential to helping the body fight off viruses, but it turns out that this is not always the case.Antibodies are made by immune cells called B cells. A team led by Matteo Iannacone and Ulrich von Andrian at

 
 

Materials Science: Competition looms for graphene

Nature 483, 7388 (2012). doi:10.1038/483127a

Graphene — atomically thick sheets of carbon atoms arranged in a honeycomb pattern — has received much attention for its exceptional electrical properties, thought to arise from its hexagonal symmetry. But Daniel Malko and his colleagues at the University of Erlangen-Nuremberg in Germany propose that

 
 

Cell Biology: Sperm steer with calcium

Nature 483, 7388 (2012). doi:10.1038/483127b

How winding a sperm's path is depends on the degree to which the concentration of calcium ions in the sperm changes.Eggs attract sperm by sending out chemical cues that activate calcium-ion release in the sperm's tail, or flagellum. When Luis Alvarez and Benjamin Kaupp

 
 

Neuroscience: Behind marijuana memory lapse

Nature 483, 7388 (2012). doi:10.1038/483127c

Marijuana hampers short-term memory by activating a signalling pathway between neurons and non-neuronal cells called astrocytes, work in mice suggests. This is surprising because astrocytes have mostly been considered to be just support cells.Giovanni Marsicano at the French National Institute of Health and Medical

 
 

Virology: Bats can carry flu too

Nature 483, 7388 (2012). doi:10.1038/483127d

Fruit bats in Guatemala harbour a strain of influenza virus, researchers report — expanding the known mammalian reservoir for the largely bird-borne influenza A.Suxiang Tong of the US Centers for Disease Control and Prevention in Atlanta, Georgia, and her colleagues screened 316 bats from

 
 

Microbiology: Unintended antimicrobial effects

Nature 483, 7388 (2012). doi:10.1038/483127e

Highly read on rsbl.royalsocietypublishing.org in JanuaryAs antibiotic resistance in microorganisms has risen, some scientists have suggested that short, synthetic amino-acid chains, or peptides, that kiWll invading pathogens could make a new therapeutic weapon. But Michelle Habets and Michael Brockhurst at the University of

 
 

Seven days: 2–8 March 2012

Nature 483, 7388 (2012). http://www.nature.com/doifinder/10.1038/483128a

The week in science: China’s research-budget boost; UN meets Millennium Development goals in water and poverty; and the NIH launches an online registry for genetic tests.

 
 

Earthquake hazards: Putting seismic research to most effective use

Nature 483, 7388 (2012). doi:10.1038/483147a

Author: Hiroo Kanamori

Today's tools and geophysical knowledge could be utilized more effectively for earthquake hazard mitigation, says Hiroo Kanamori.

 
 

Seismology: Why giant earthquakes keep catching us out

Nature 483, 7388 (2012). doi:10.1038/483149a

Author: Thorne Lay

A spate of huge earthquakes in the past seven years has provided humbling lessons, says Thorne Lay.

 
 

Energy policy: The nuclear landscape

Nature 483, 7388 (2012). doi:10.1038/483151a

Author: Peter Bradford

The accident at Fukushima has convinced many nations to phase out nuclear power. Economics will be the deciding force, says Peter Bradford.

 
 

Energy: Plumbing the depths

Nature 483, 7388 (2012). doi:10.1038/483154a

Author: Amanda Mascarelli

A chronicle of events preceding the Deepwater Horizon oil spill in the Gulf of Mexico has a thriller-like edge, finds Amanda Mascarelli.

 
 

Books in brief

Nature 483, 7388 (2012). doi:10.1038/483155a

A crackle of erudite energy leaps from this lively commingling of art, culture and science. In 28 essays, biologist Gerald Weissmann explores the complex territory of modern biology and epigenetics in this era of social media. In each, Weissmann finds links between research and elements

 
 

Photography: Force of nature

Nature 483, 7388 (2012). doi:10.1038/483156a

Authors: Stefan Michalowski & Georgia Smith

Stefan Michalowski and Georgia Smith thrill to artist Berenice Abbott's 'portraits' of physical forces.

 
 

Q&A: Jazz experimentalist

Nature 483, 7388 (2012). doi:10.1038/483157a

Author: Jascha Hoffman

Vijay Iyer is a New York jazz pianist who has academic roots in physics and music cognition. As he releases Accelerando — a follow-up to his 2009 world number one jazz album Historicity — he talks about the bodily origins of rhythm, the science of improvisation and the social function of music.

 
 

Future pandemics: Step up funding for flu prevention

Nature 483, 7388 (2012). doi:10.1038/483158a

Author: Simon N. Williams

Experts on pandemic influenza need to convince governments and the public that, although the 2009–10 'swine flu' pandemic proved to be relatively mild, the threat posed by future flu pandemics is severe and warrants more investment in public education and research (Nature482,

 
 

Degraded ecosystems: Keep jellyfish numbers in check

Nature 483, 7388 (2012). doi:10.1038/483158b

Authors: Anthony J. Richardson, Daniel Pauly & Mark J. Gibbons

It may be unclear whether jellyfish numbers are rising globally (Nature482, 20–21; 201210.1038/482020a), but this should not distract us from taking urgent action to control populations in those degraded ecosystems where particular species have undeniably increased.You

 
 

Genetics research: Clinical standards not practical in the lab

Nature 483, 7388 (2012). doi:10.1038/483158c

Author: Klaus Lindpaintner

Gholson Lyon calls for more rigorous standards in genetics research so that results can be disclosed to subjects and their families as valid clinical diagnostic information (Nature482, 300–301; 2012). This well-intentioned proposal is impractical because it would add

 
 

Sugar: an excess of anything can harm

Nature 483, 7388 (2012). doi:10.1038/483158d

Author: Richard C. Cottrell

As director-general of the World Sugar Research Organisation, I wish to point out some shortcomings in the latest discussion of sugar's impact on health (Nature482, 27–29; 2012).Robert Lustig and colleagues incorrectly say that sugar consumption has tripled

 
 

Retirement: Sticking around

Nature 483, 7388 (2012). doi:10.1038/nj7388-233a

Author: Virginia Gewin

Academics who delay retirement could create roadblocks for early-career researchers.

 
 

The postdoc dilemma

Nature 483, 7388 (2012). doi:10.1038/nj7388-235a

Author: Gaston Small

Balancing a career and the obligations of a full-time job can be deceptively difficult, says Gaston Small.

 
 

Bread

Nature 483, 7388 (2012). doi:10.1038/483238a

Author: Eliza Blair

A taste of history.

 
 

Social science: Human reproductive assistance

Nature 483, 7388 (2012). doi:10.1038/483160a

Authors: Kim Hill & A. Magdalena Hurtado

What is the biological explanation for menopause, and for female survival beyond it? A study suggests that competition for help in ancestral societies may have been key to the evolution of this unusual human trait.

 
 

Physical chemistry: Single molecules filmed dancing on a table top

Nature 483, 7388 (2012). doi:10.1038/483161a

Authors: Misha Y. Ivanov

By ripping an electron away from a molecule and then slamming it back again, the motion of nuclei in a molecule has been tracked with extremely high temporal and spatial resolution. See Letter p.194

 
 

50 & 100 years ago

Nature 483, 7388 (2012). doi:10.1038/483162a

From the fermentation broth of a strain of Fusidium a hitherto unrecorded antibiotic, for which the name 'fusidic acid' is proposed, has been isolated ... The activity was determined by the agar cup-plate method using Staphylococcus aureus as test organism ... From the

 
 

Cell biology: The sensation of stretch

Nature 483, 7388 (2012). doi:10.1038/483163a

Authors: Philip A. Gottlieb & Frederick Sachs

Piezo proteins have been shown to form large ion channels that serve a sensory function in fruitflies. The findings help to explain how Piezos convert mechanical force into biological signals. See Article p.176 & Letter p.209

 
 

Genomics: Gorilla gorilla gorilla

Nature 483, 7388 (2012). doi:10.1038/483164a

Authors: Richard A Gibbs & Jeffrey Rogers

The gorilla genome reveals that genetic similarities among humans and the apes are more complex than expected, and allows a fresh assessment of the evolutionary mechanisms that led to the primate species seen today. See Article p.169

 
 

Geochemistry: A rusty carbon sink

Nature 483, 7388 (2012). doi:10.1038/483165a

Authors: Tim I. Eglinton

The finding that reactive iron species may have a role in stabilizing organic matter in ocean sediments underlines the tight coupling between the biogeochemical cycles of carbon and iron. See Letter p.198

 
 

Ageing: Sorting out the sirtuins

Nature 483, 7388 (2012). doi:10.1038/nature10950

Authors: David B. Lombard & Richard A. Miller

Debates over the role of sirtuin proteins in ageing are maturing into functional assessments of the individual proteins. It seems that overexpression of a specific sirtuin can extend lifespan in male mice. See Letter p.218

 
 

Materials science: Continuity through dispersity

Nature 483, 7388 (2012). doi:10.1038/483167a

Authors: Richard A Register

By making polymers whose central blocks have a range of lengths, materials have been prepared that contain separate, intermeshed domains extending throughout the material — a highly desirable structure.

 
 

Insights into hominid evolution from the gorilla genome sequence

Nature 483, 7388 (2012). doi:10.1038/nature10842

Authors: Aylwyn Scally, Julien Y. Dutheil, LaDeana W. Hillier, Gregory E. Jordan, Ian Goodhead, Javier Herrero, Asger Hobolth, Tuuli Lappalainen, Thomas Mailund, Tomas Marques-Bonet, Shane McCarthy, Stephen H. Montgomery, Petra C. Schwalie, Y. Amy Tang, Michelle C. Ward, Yali Xue, Bryndis Yngvadottir, Can Alkan, Lars N. Andersen, Qasim Ayub, Edward V. Ball, Kathryn Beal, Brenda J. Bradley, Yuan Chen, Chris M. Clee, Stephen Fitzgerald, Tina A. Graves, Yong Gu, Paul Heath, Andreas Heger, Emre Karakoc, Anja Kolb-Kokocinski, Gavin K. Laird, Gerton Lunter, Stephen Meader, Matthew Mort, James C. Mullikin, Kasper Munch, Timothy D. O’Connor, Andrew D. Phillips, Javier Prado-Martinez, Anthony S. Rogers, Saba Sajjadian, Dominic Schmidt, Katy Shaw, Jared T. Simpson, Peter D. Stenson, Daniel J. Turner, Linda Vigilant, Albert J. Vilella, Weldon Whitener, Baoli Zhu, David N. Cooper, Pieter de Jong, Emmanouil T. Dermitzakis, Evan E. Eichler, Paul Flicek, Nick Goldman, Nicholas I. Mundy, Zemin Ning, Duncan T. Odom, Chris P. Ponting, Michael A. Quail, Oliver A. Ryder, Stephen M. Searle, Wesley C. Warren, Richard K. Wilson, Mikkel H. Schierup, Jane Rogers, Chris Tyler-Smith & Richard Durbin

Gorillas are humans’ closest living relatives after chimpanzees, and are of comparable importance for the study of human origins and evolution. Here we present the assembly and analysis of a genome sequence for the western lowland gorilla, and compare the whole genomes of all extant

 
 

Experimental verification of Landauer’s principle linking information and thermodynamics

Nature 483, 7388 (2012). doi:10.1038/nature10872

Authors: Antoine Bérut, Artak Arakelyan, Artyom Petrosyan, Sergio Ciliberto, Raoul Dillenschneider & Eric Lutz

In 1961, Rolf Landauer argued that the erasure of information is a dissipative process. A minimal quantity of heat, proportional to the thermal energy and called the Landauer bound, is necessarily produced when a classical bit of information is deleted. A direct consequence of this logically irreversible transformation is that the entropy of the environment increases by a finite amount. Despite its fundamental importance for information theory and computer science, the erasure principle has not been verified experimentally so far, the main obstacle being the difficulty of doing single-particle experiments in the low-dissipation regime. Here we experimentally show the existence of the Landauer bound in a generic model of a one-bit memory. Using a system of a single colloidal particle trapped in a modulated double-well potential, we establish that the mean dissipated heat saturates at the Landauer bound in the limit of long erasure cycles. This result demonstrates the intimate link between information theory and thermodynamics. It further highlights the ultimate physical limit of irreversible computation.

 
 

Field-driven photoemission from nanostructures quenches the quiver motion

Nature 483, 7388 (2012). doi:10.1038/nature10878

Authors: G. Herink, D. R. Solli, M. Gulde & C. Ropers

Strong-field physics, an extreme limit of light–matter interaction, is expanding into the realm of surfaces and nanostructures from its origin in atomic and molecular science. The attraction of nanostructures lies in two intimately connected features: local intensity enhancement and sub-wavelength confinement of optical fields. Local intensity enhancement facilitates access to the strong-field regime and has already sparked various applications, whereas spatial localization has the potential to generate strong-field dynamics exclusive to nanostructures. However, the observation of features unattainable in gaseous media is challenged by many-body effects and material damage, which arise under intense illumination of dense systems. Here, we non-destructively access this regime in the solid state by employing single plasmonic nanotips and few-cycle mid-infrared pulses, making use of the wavelength-dependence of the interaction, that is, the ponderomotive energy. We investigate strong-field photoelectron emission and acceleration from single nanostructures over a broad spectral range, and find kinetic energies of hundreds of electronvolts. We observe the transition to a new regime in strong-field dynamics, in which the electrons escape the nanolocalized field within a fraction of an optical half-cycle. The transition into this regime, characterized by a spatial adiabaticity parameter, would require relativistic electrons in the absence of nanostructures. These results establish new degrees of freedom for the manipulation and control of electron dynamics on femtosecond and attosecond timescales, combining optical near-fields and nanoscopic sources.

 
 

Imaging ultrafast molecular dynamics with laser-induced electron diffraction

Nature 483, 7388 (2012). doi:10.1038/nature10820

Authors: Cosmin I. Blaga, Junliang Xu, Anthony D. DiChiara, Emily Sistrunk, Kaikai Zhang, Pierre Agostini, Terry A. Miller, Louis F. DiMauro & C. D. Lin

Establishing the structure of molecules and solids has always had an essential role in physics, chemistry and biology. The methods of choice are X-ray and electron diffraction, which are routinely used to determine atomic positions with sub-ångström spatial resolution. Although both methods are currently limited to probing dynamics on timescales longer than a picosecond, the recent development of femtosecond sources of X-ray pulses and electron beams suggests that they might soon be capable of taking ultrafast snapshots of biological molecules and condensed-phase systems undergoing structural changes. The past decade has also witnessed the emergence of an alternative imaging approach based on laser-ionized bursts of coherent electron wave packets that self-interrogate the parent molecular structure. Here we show that this phenomenon can indeed be exploited for laser-induced electron diffraction (LIED), to image molecular structures with sub-ångström precision and exposure times of a few femtoseconds. We apply the method to oxygen and nitrogen molecules, which on strong-field ionization at three mid-infrared wavelengths (1.7, 2.0 and 2.3 μm) emit photoelectrons with a momentum distribution from which we extract diffraction patterns. The long wavelength is essential for achieving atomic-scale spatial resolution, and the wavelength variation is equivalent to taking snapshots at different times. We show that the method has the sensitivity to measure a 0.1 Å displacement in the oxygen bond length occurring in a time interval of ∼5 fs, which establishes LIED as a promising approach for the imaging of gas-phase molecules with unprecedented spatio-temporal resolution.

 
 

Preservation of organic matter in sediments promoted by iron

Nature 483, 7388 (2012). doi:10.1038/nature10855

Authors: Karine Lalonde, Alfonso Mucci, Alexandre Ouellet & Yves Gélinas

The biogeochemical cycles of iron and organic carbon are strongly interlinked. In oceanic waters, organic ligands have been shown to control the concentration of dissolved iron. In soils, solid iron phases shelter and preserve organic carbon, but the role of iron in the preservation of organic matter in sediments has not been clearly established. Here we use an iron reduction method previously applied to soils to determine the amount of organic carbon associated with reactive iron phases in sediments of various mineralogies collected from a wide range of depositional environments. Our findings suggest that 21.5 ± 8.6 per cent of the organic carbon in sediments is directly bound to reactive iron phases. We further estimate that a global mass of (19–45) × 1015 grams of organic carbon is preserved in surface marine sediments as a result of its association with iron. We propose that these associations between organic carbon and iron, which are formed primarily through co-precipitation and/or direct chelation, promote the preservation of organic carbon in sediments. Because reactive iron phases are metastable over geological timescales, we suggest that they serve as an efficient ‘rusty sink’ for organic carbon, acting as a key factor in the long-term storage of organic carbon and thus contributing to the global cycles of carbon, oxygen and sulphur.

 
 

Corrigendum: The Amazon basin in transition

Nature 483, 7388 (2012). doi:10.1038/nature10943

Authors: Eric A. Davidson, Alessandro C. de Araújo, Paulo Artaxo, Jennifer K. Balch, I. Foster Brown, Mercedes M. C. Bustamante, Michael T. Coe, Ruth S. DeFries, Michael Keller, Marcos Longo, J. William Munger, Wilfrid Schroeder, Britaldo S. Soares-Filho, Carlos M. Souza & Steven C. Wofsy

Nature481, 321–328 (2012)In the ‘Natural and anthropogenic climatic variation’ section of this Review, we incorrectly referred to the North Atlantic Oscillation as a contributor to the 2005 Amazonian droughts. We should instead have referred to the Atlantic

 
 

The BAH domain of ORC1 links H4K20me2 to DNA replication licensing and Meier–Gorlin syndrome

Nature 484, 7392 (2012). doi:10.1038/nature10956

Authors: Alex J. Kuo, Jikui Song, Peggie Cheung, Satoko Ishibe-Murakami, Sayumi Yamazoe, James K. Chen, Dinshaw J. Patel & Or Gozani

The recognition of distinctly modified histones by specialized ‘effector’ proteins constitutes a key mechanism for transducing molecular events at chromatin to biological outcomes. Effector proteins influence DNA-templated processes, including transcription, DNA recombination and DNA repair; however, no effector functions have yet been identified within the mammalian machinery that regulate DNA replication. Here we show that ORC1—a component of ORC (origin of replication complex), which mediates pre-DNA replication licensing—contains a bromo adjacent homology (BAH) domain that specifically recognizes histone H4 dimethylated at lysine 20 (H4K20me2). Recognition of H4K20me2 is a property common to BAH domains present within diverse metazoan ORC1 proteins. Structural studies reveal that the specificity of the BAH domain for H4K20me2 is mediated by a dynamic aromatic dimethyl-lysine-binding cage and multiple intermolecular contacts involving the bound peptide. H4K20me2 is enriched at replication origins, and abrogating ORC1 recognition of H4K20me2 in cells impairs ORC1 occupancy at replication origins, ORC chromatin loading and cell-cycle progression. Mutation of the ORC1 BAH domain has been implicated in the aetiology of Meier–Gorlin syndrome (MGS), a form of primordial dwarfism, and ORC1 depletion in zebrafish results in an MGS-like phenotype. We find that wild-type human ORC1, but not ORC1–H4K20me2-binding mutants, rescues the growth retardation of orc1 morphants. Moreover, zebrafish depleted of H4K20me2 have diminished body size, mirroring the phenotype of orc1 morphants. Together, our results identify the BAH domain as a novel methyl-lysine-binding module, thereby establishing the first direct link between histone methylation and the metazoan DNA replication machinery, and defining a pivotal aetiological role for the canonical H4K20me2 mark, via ORC1, in primordial dwarfism.

 
 

The 2.8 Å crystal structure of the dynein motor domain

Nature 484, 7394 (2012). doi:10.1038/nature10955

Authors: Takahide Kon, Takuji Oyama, Rieko Shimo-Kon, Kenji Imamula, Tomohiro Shima, Kazuo Sutoh & Genji Kurisu

Dyneins are microtubule-based AAA+ motor complexes that power ciliary beating, cell division, cell migration and intracellular transport. Here we report the most complete structure obtained so far, to our knowledge, of the 380-kDa motor domain of Dictyostelium discoideum cytoplasmic dynein at 2.8 Å

 
 

Corrigendum: Modernization: One step at a time

Nature 495, 7440 (2013). doi:10.1038/nature10977

Author: Zhiguo Xu

Nature480, S90–S92 (2011)A quote attributed to Yi Rao in this Outlook article incorrectly implied that he criticized the use of traditional Chinese medicine (TCM) techniques. Instead, Rao’s intention was to question attitudes that apply different standards to