This press release contains:
· Summaries of newsworthy papers:
Virology: Cancer drugs may help wipe out hiding HIV
Astrophysics: An exoplanetary system on a level plane
Biodiversity: Protected tropical forest under threat
Immunology: Malnutrition-linked inflammation of the gut
Physics: Higgs excitation
Physics: Switching to a new way of controlling electronics
Quantum physics: Quantum light filter
And finally... Snakes on the plain
· Geographical listing of authors
 Virology: Cancer drugs may help wipe out hiding HIV (pp 482-485; N&V)
HIV-1 infections that evade pharmaceutical attack by hiding inside cells can be ‘flushed out’ using a cancer drug, research in this week’s Nature suggests. This study provides the first evidence in patients that the drug vorinostat can disrupt so-called proviral latency of HIV-1, which represents a major barrier to curing HIV-1 infection. These findings may pave the way to an approach for testing new methods of directly attacking and eradicating latent HIV infection.
HIV infection can persist within a small population of cells without expressing any viral genes, which means that it is difficult to target with antivirals therapies. It has previously been shown in cell cultures that induction of virus gene expression in cells latently infected with HIV-1 can be achieved with a family of drugs known as histone deacetylase inhibitors, such as vorinostat. David Margolis and co-workers report the disruption of latent HIV infection in HIV-positive patients after a single dose of vorinostat, observing nearly a fivefold mean increase in HIV RNA expression. The authors note that vorinostat has some toxic effects that need to be considered when weighing up the risks and benefits of attempts to eradicate HIV infection using this and similar drugs.
David Margolis (University of North Carolina at Chapel Hill, NC, USA)
Tel: +1 919 966 6388; E-mail: [email protected]
Steven Deeks (University of California, San Francisco, CA, USA) N&V author
E-mail: [email protected]
 Astrophysics: An exoplanetary system on a level plane (pp 449-453; N&V)
A collection of exoplanets orbiting their star in a configuration that is similar to the Solar System’s is described in this week’s Nature. This observation sheds light on the conditions that determine the architecture of a planetary system.
In our Solar System, the Sun’s equator and the planets’ orbital planes are nearly aligned, presumably a consequence of their formation from a single spinning gaseous disk. Many exoplanet systems do not display this arrangement, and isolated ‘hot Jupiters’ — giant planets that orbit close to their parent stars — are often misaligned, some even with retrograde orbits. It has been suspected that the high obliquities are the result of the same dynamical interactions that produce hot Jupiters.
Roberto Sanchis-Ojeda and colleagues report an analysis of transits of planets over starspots on the Sun-like star Kepler-30, a system that has no hot Jupiters. They show that its three planets’ orbits are aligned with the stellar equator. These findings suggest that high orbital tilts, known as obliquities, are confined to systems that experienced disruptive dynamical interactions.
Roberto Sanchis-Ojeda (Massachusetts Institute of Technology, Cambridge, MA, USA)
Tel: +1 617 899 5040; E-mail: [email protected]
Daniel Fabrycky (University of California, Santa Cruz, CA, USA) co-author
Tel: +1 831 459 3539; E-mail: [email protected]
Drake Deming (University of Maryland, College Park, MD, USA) N&V author
Tel: +1 301 405 8053; E-mail: [email protected]
 Biodiversity: Protected tropical forest under threat (AOP)
A large number of tropical forest protected areas are experiencing a decline in biodiversity, according to an analysis in Nature this week. These reserves are supposed to represent a final refuge for threatened species and natural ecosystem processes, as concerns about human impacts on tropical biodiversity grow. The study indicates that tropical protected areas are often intimately linked ecologically to their surrounding habitats, and the fate of protected areas is determined by environmental changes both within and outside of the reserves.
To evaluate how protected areas are functioning, William Laurance and co-authors assemble a large data set on changes over the past 20 to 30 years, from 60 tropical reserves across the globe. Their assessment reveals great variation in the state of these reserves, with about half experiencing substantial losses of biodiversity. Habitat disruption, hunting and forest-product exploitation are the strongest predictors of declining reserve health. The authors assert that efforts to maintain biodiversity should not be limited to reducing pressures within the reserves, as changes outside of the protected areas also affect biodiversity.
William Laurance (James Cook University, Cairns, Australia)
Tel: +61 7 4038 1518 or: +61 7 4042 1819; E-mail: [email protected]
 Immunology: Malnutrition-linked inflammation of the gut (pp 477-481; N&V)
An enzyme involved in uptake of dietary amino acids is shown to have a critical role in the regulation of inflammation in the colon. A study in this week’s Nature finds that following intestinal injury mice with a defective version of angiotensin-converting enzyme 2 (ACE2) are more prone to colitis. This inflammation is associated with amino acid deficiency and a shift in the microbes residing in the intestine, and can be corrected with administration of amino acids. ACE2 is known to have a role in blood pressure regulation via the body’s renin-angiotensin system (RAS), but the amino acid transporting function ACE2 is RAS-independent.
Josef Penninger and colleagues provide a molecular explanation for how malnutrition, one of the major health issues in the world, can cause a marked increase in susceptibility to intestinal inflammation. Their data indicate that the essential amino acid tryptophan and its metabolite nicotinamide are key regulators of gut microbiota and susceptibility to inflammation. They find that ACE2 can control the composition of microbes in the intestine and propensity to colitis through the regulation of amino acid metabolism. Mice deficient in ACE2 show impaired tryptophan metabolism and develop colitis, but treatment with nicotinamide or tryptophan alleviates these symptoms.
Josef Penninger (Austrian Academy of Sciences, Vienna, Austria)
Tel: +43 1 79044 ext. 4700; E-mail: [email protected]
Fiona Powrie (University of Oxford, UK) N&V author
Tel: +44 1865 285 494; E-mail: [email protected]
 Physics: Higgs excitation (pp 454-458)
Evidence for a Higgs-type excitation ― not to be confused with a Higgs boson ― in an ultracold atomic system presented in this week’s Nature may assist the study of relativistic field theories. A Higgs excitation is of crucial importance in the standard model of elementary particles, where it is thought to be responsible for mass. The latest findings indicate that this type of excitation also has an observable signature in quantum many-body systems.
In relativistic field theory, a process known as spontaneous symmetry breaking leads to excitations that underlie a range of phenomena ― not just in high-energy particle physics, but also in condensed matter systems. Whether the Higgs-type excitation could be observed in a low-dimensional atomic system was a matter of debate. Manuel Endres and colleagues answer the question, identifying a Higgs-type excitation in a two-dimensional ultracold atomic gas. They find that the excitation has a finite mass, which shows a characteristic reduction near a quantum phase transition.
This observation represents a first step in exploring emergent relativistic models with ultracold atomic gases, the authors suggest.
Manuel Endres (Max-Planck-Institut für Quantenoptik, Garching, Germany)
Tel: +49 89 32905 214; E-mail: [email protected]
 Physics: Switching to a new way of controlling electronics (pp 459-462; N&V)
A new concept in transistors, a vital component of modern electronics, is presented in this week’s Nature. Transistors can be regarded as a type of switch and are the building blocks of logic circuits. The demonstrated device may lead to electronic applications with new features such as combined electrical and optical control and low-power consumption.
In a conventional silicon transistor, the voltage-controlled switching mechanism is provided by a nanometre-sized conducting channel near the surface. Masaki Nakano and colleagues operate their device based on a fundamentally different mechanism: a voltage controls the electronic properties of the whole device, which is made from vanadium dioxide instead of silicon. Voltages of just 1 V, at room temperature, switch the material from insulating to metallic. The authors anticipate that practical applications of this achievement could include the remote transmission of electrical signals.
Masaki Nakano (RIKEN Advanced Science Institute, Wako, Japan)
Tel: +81 48 462 1111 ext. 6123; E-mail: [email protected]
Jochen Mannhart (Max Planck Institute for Solid State Research, Stuttgart, Germany) N&V author
Tel: +49 711 689 1650; E-mail: [email protected]
 Quantum physics: Quantum light filter (AOP; N&V)
An unusual atomic medium that can control single photons (individual quanta of light) is demonstrated in this week’s Nature. The approach opens possibilities for quantum-by-quantum control of light fields, such as deterministic quantum logic, which could represent a major advance towards all-optical quantum information processing.
Achieving strong nonlinear interactions between photons is a long-standing goal in optical science and engineering, as it would enable control of individual light quanta; however, photons do not normally interact in this way in conventional optical materials. Vladan Vuletić and colleagues show that a cold, dense gas of atoms in Rydberg states (highly excited levels) can be nonlinear under certain conditions. The cloud can act as a single photon filter that converts a light beam into a stream of single photons by absorbing photon pairs while remaining transparent to single photons.
The authors suggest that their findings may pave the way for applications that require control of light quanta, including single-photon switching and exploring the quantum dynamics of strongly interacting photonic many-body systems.
Vladan Vuletić (Massachusetts Institute of Technology, Cambridge, MA, USA)
Tel: +1 617 324 1174; E-mail: [email protected]
Thad Walker (University of Wisconsin, Madison, WI, USA) N&V author
Tel: +1 608 262 4093; E-mail: [email protected]
 And finally... Snakes on the plain (AOP)
Analysis of a fossilized terrestrial snake known as Coniophis, reported in Nature this week, sheds new light on the question of whether snakes evolved on land or in the sea. Coniophis is found to represent a transitional snake, with a snake-like body and a lizard-like head. The findings indicate that snakes evolved their modern skulls on land.
The Late-Cretaceous-period (approximately 70 million years ago) Coniophis has been described previously, but Nicholas Longrich and colleagues take a new look at some long-neglected remains. Observation of a lizard-like head suggests that early snakes were burrowers that had long bodies before evolving the highly flexible skull that is characteristic of modern snakes. The authors also provide insight into the evolution of snake feeding; considering its small size, tooth shape and skull structure (unlike modern snakes, Coniophis lacks the ability to swallow large prey whole), they propose that Coniophis preyed on small animals.
Evolution of a new method of locomotion, and adaptations that facilitate the ingestion of larger prey were probably a key evolutionary step that promoted the diversification of snakes, the authors conclude.
Nicholas Longrich (Yale University, New Haven, CT, USA)
Tel: +1 203 824 1279; E-mail: [email protected]
ALSO IN THIS ISSUE…
 Inland thinning of West Antarctic Ice Sheet steered along subglacial rifts (pp 468-471)
 Dissecting the genomic complexity underlying medulloblastoma
 Subgroup-specific structural variation across 1,000 medulloblastoma genomes
GEOGRAPHICAL LISTING OF AUTHORS…
The following list of places refers to the whereabouts of authors on the papers numbered in this release. For example, London: 4 - this means that on paper number four, there will be at least one author affiliated to an institute or company in London. The listing may be for an author's main affiliation, or for a place where they are working temporarily. Please see the PDF of the paper for full details.
Vienna: 3, 4, 11
Santa Cruz: 3
Boa Vista: 3
São Paulo: 3, 11
Toronto: 10, 11
Calgary: 3, 11
Montreal: 3, 11
Prince George: 3
CENTRAL AFRICAN REPUBLIC
San Pedro: 3
Ceske Budejovice: 3
DEMOCRATIC REPUBLIC OF CONGO
Berlin: 3, 10
Freiburg: 4, 10
Heidelberg: 10, 11
Munich: 5, 10
Nuremberg: 10, 11
Würzburg: 3, 10
New Delhi: 3
West Kalimantan: 3
Tsukuba: 4, 6
Utrecht: 3, 4
PAPUA NEW GUINEA
Río Piedras: 3
San Juan: 3
Nakhon Pathom: 3
Cambridge: 3, 9, 10
Newcastle-upon-Tyne: 10, 11
UNITED STATES OF AMERICA
Little Rock: 11
La Jolla: 11
Los Angeles: 3, 11
Moffett Field: 2
Mountain View: 2
Palo Alto: 10
Pasadena: 5, 7
San Diego: 1, 3, 11
San Francisco: 11
Santa Cruz: 2
Stanford: 3, 11
New Haven: 3, 8
District of Columbia
Pompano Beach: 3
Takoma Park: 3
Boston: 1, 3, 10, 11
Cambridge: 2, 5, 7, 8, 10, 11
Ann Arbor: 11
St. Louis: 3, 11
New York: 3, 11
Stony Brook: 3
Chapel Hill: 1
Durham: 3, 11
New Florence: 3
White Horse Junction: 1
Fort Worth: 3
Seattle: 3, 11
From North America and Canada
Neda Afsarmanesh, Nature New York
Tel: +1 212 726 9231; E-mail: [email protected]
From Japan, Korea, China, Singapore and Taiwan
Eiji Matsuda, Nature Tokyo
Tel: +81 3 3267 8751; E-mail: [email protected]
From the UK
Rebecca Walton, Nature London
Tel: +44 20 7843 4502; E-mail: [email protected]
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