Climate Newsprint

[Report] Copper-catalyzed asymmetric addition of olefin-derived nucleophiles to ketones

Science Magazine - Thu, 07/07/2016 - 23:00
Enantioenriched alcohols found in an array of bioactive natural products and pharmaceutical agents are often synthesized by asymmetric nucleophilic addition to carbonyls. However, this approach generally shows limited functional-group compatibility, requiring the use of preformed organometallic reagents in conjunction with a stoichiometric or substoichiometric amount of chiral controller to deliver optically active alcohols. Herein we report a copper-catalyzed strategy for the stereoselective nucleophilic addition of propargylic and other alkyl groups to ketones, using easily accessible (poly)unsaturated hydrocarbons as latent carbanion equivalents. Our method features the catalytic generation of highly enantioenriched organocopper intermediates and their subsequent diastereoselective addition to ketones, allowing for the effective construction of highly substituted stereochemical dyads with excellent stereocontrol. Moreover, this process is general, scalable, and occurs at ambient temperature. Authors: Yang Yang, Ian B. Perry, Gang Lu, Peng Liu, Stephen L. Buchwald
Categories: Climate Newsprint

[Report] Thermally stable single-atom platinum-on-ceria catalysts via atom trapping

Science Magazine - Thu, 07/07/2016 - 23:00
Catalysts based on single atoms of scarce precious metals can lead to more efficient use through enhanced reactivity and selectivity. However, single atoms on catalyst supports can be mobile and aggregate into nanoparticles when heated at elevated temperatures. High temperatures are detrimental to catalyst performance unless these mobile atoms can be trapped. We used ceria powders having similar surface areas but different exposed surface facets. When mixed with a platinum/aluminum oxide catalyst and aged in air at 800°C, the platinum transferred to the ceria and was trapped. Polyhedral ceria and nanorods were more effective than ceria cubes at anchoring the platinum. Performing synthesis at high temperatures ensures that only the most stable binding sites are occupied, yielding a sinter-resistant, atomically dispersed catalyst. Authors: John Jones, Haifeng Xiong, Andrew T. DeLaRiva, Eric J. Peterson, Hien Pham, Sivakumar R. Challa, Gongshin Qi, Se Oh, Michelle H. Wiebenga, Xavier Isidro Pereira Hernández, Yong Wang, Abhaya K. Datye
Categories: Climate Newsprint

[Report] Tail use improves performance on soft substrates in models of early vertebrate land locomotors

Science Magazine - Thu, 07/07/2016 - 23:00
In the evolutionary transition from an aquatic to a terrestrial environment, early tetrapods faced the challenges of terrestrial locomotion on flowable substrates, such as sand and mud of variable stiffness and incline. The morphology and range of motion of appendages can be revealed in fossils; however, biological and robophysical studies of modern taxa have shown that movement on such substrates can be sensitive to small changes in appendage use. Using a biological model (the mudskipper), a physical robot model, granular drag measurements, and theoretical tools from geometric mechanics, we demonstrate how tail use can improve robustness to variable limb use and substrate conditions. We hypothesize that properly coordinated tail movements could have provided a substantial benefit for the earliest vertebrates to move on land. Authors: Benjamin McInroe, Henry C. Astley, Chaohui Gong, Sandy M. Kawano, Perrin E. Schiebel, Jennifer M. Rieser, Howie Choset, Richard W. Blob, Daniel I. Goldman
Categories: Climate Newsprint

[Report] Phototactic guidance of a tissue-engineered soft-robotic ray

Science Magazine - Thu, 07/07/2016 - 23:00
Inspired by the relatively simple morphological blueprint provided by batoid fish such as stingrays and skates, we created a biohybrid system that enables an artificial animal—a tissue-engineered ray—to swim and phototactically follow a light cue. By patterning dissociated rat cardiomyocytes on an elastomeric body enclosing a microfabricated gold skeleton, we replicated fish morphology at 110 scale and captured basic fin deflection patterns of batoid fish. Optogenetics allows for phototactic guidance, steering, and turning maneuvers. Optical stimulation induced sequential muscle activation via serpentine-patterned muscle circuits, leading to coordinated undulatory swimming. The speed and direction of the ray was controlled by modulating light frequency and by independently eliciting right and left fins, allowing the biohybrid machine to maneuver through an obstacle course. Authors: Sung-Jin Park, Mattia Gazzola, Kyung Soo Park, Shirley Park, Valentina Di Santo, Erin L. Blevins, Johan U. Lind, Patrick H. Campbell, Stephanie Dauth, Andrew K. Capulli, Francesco S. Pasqualini, Seungkuk Ahn, Alexander Cho, Hongyan Yuan, Ben M. Maoz, Ragu Vijaykumar, Jeong-Woo Choi, Karl Deisseroth, George V. Lauder, L. Mahadevan, Kevin Kit Parker
Categories: Climate Newsprint

[Report] Higher-order organization of complex networks

Science Magazine - Thu, 07/07/2016 - 23:00
Networks are a fundamental tool for understanding and modeling complex systems in physics, biology, neuroscience, engineering, and social science. Many networks are known to exhibit rich, lower-order connectivity patterns that can be captured at the level of individual nodes and edges. However, higher-order organization of complex networks—at the level of small network subgraphs—remains largely unknown. Here, we develop a generalized framework for clustering networks on the basis of higher-order connectivity patterns. This framework provides mathematical guarantees on the optimality of obtained clusters and scales to networks with billions of edges. The framework reveals higher-order organization in a number of networks, including information propagation units in neuronal networks and hub structure in transportation networks. Results show that networks exhibit rich higher-order organizational structures that are exposed by clustering based on higher-order connectivity patterns. Authors: Austin R. Benson, David F. Gleich, Jure Leskovec
Categories: Climate Newsprint

[Report] S-Acylation of the cellulose synthase complex is essential for its plasma membrane localization

Science Magazine - Thu, 07/07/2016 - 23:00
Plant cellulose microfibrils are synthesized by a process that propels the cellulose synthase complex (CSC) through the plane of the plasma membrane. How interactions between membranes and the CSC are regulated is currently unknown. Here, we demonstrate that all catalytic subunits of the CSC, known as cellulose synthase A (CESA) proteins, are S-acylated. Analysis of Arabidopsis CESA7 reveals four cysteines in variable region 2 (VR2) and two cysteines at the carboxy terminus (CT) as S-acylation sites. Mutating both the VR2 and CT cysteines permits CSC assembly and trafficking to the Golgi but prevents localization to the plasma membrane. Estimates suggest that a single CSC contains more than 100 S-acyl groups, which greatly increase the hydrophobic nature of the CSC and likely influence its immediate membrane environment. Authors: Manoj Kumar, Raymond Wightman, Ivan Atanassov, Anjali Gupta, Charlotte H. Hurst, Piers A. Hemsley, Simon Turner
Categories: Climate Newsprint

[Report] Climate-driven regime shift of a temperate marine ecosystem

Science Magazine - Thu, 07/07/2016 - 23:00
Ecosystem reconfigurations arising from climate-driven changes in species distributions are expected to have profound ecological, social, and economic implications. Here we reveal a rapid climate-driven regime shift of Australian temperate reef communities, which lost their defining kelp forests and became dominated by persistent seaweed turfs. After decades of ocean warming, extreme marine heat waves forced a 100-kilometer range contraction of extensive kelp forests and saw temperate species replaced by seaweeds, invertebrates, corals, and fishes characteristic of subtropical and tropical waters. This community-wide tropicalization fundamentally altered key ecological processes, suppressing the recovery of kelp forests. Authors: Thomas Wernberg, Scott Bennett, Russell C. Babcock, Thibaut de Bettignies, Katherine Cure, Martial Depczynski, Francois Dufois, Jane Fromont, Christopher J. Fulton, Renae K. Hovey, Euan S. Harvey, Thomas H. Holmes, Gary A. Kendrick, Ben Radford, Julia Santana-Garcon, Benjamin J. Saunders, Dan A. Smale, Mads S. Thomsen, Chenae A. Tuckett, Fernando Tuya, Mathew A. Vanderklift, Shaun Wilson
Categories: Climate Newsprint

[Report] Structural basis for membrane anchoring of HIV-1 envelope spike

Science Magazine - Thu, 07/07/2016 - 23:00
HIV-1 envelope spike (Env) is a type I membrane protein that mediates viral entry. We used nuclear magnetic resonance to determine an atomic structure of the transmembrane (TM) domain of HIV-1 Env reconstituted in bicelles that mimic a lipid bilayer. The TM forms a well-ordered trimer that protects a conserved membrane-embedded arginine. An amino-terminal coiled-coil and a carboxyl-terminal hydrophilic core stabilize the trimer. Individual mutations of conserved residues did not disrupt the TM trimer and minimally affected membrane fusion and infectivity. Major changes in the hydrophilic core, however, altered the antibody sensitivity of Env. These results show how a TM domain anchors, stabilizes, and modulates a viral envelope spike and suggest that its influence on Env conformation is an important consideration for HIV-1 immunogen design. Authors: Jyoti Dev, Donghyun Park, Qingshan Fu, Jia Chen, Heather Jiwon Ha, Fadi Ghantous, Tobias Herrmann, Weiting Chang, Zhijun Liu, Gary Frey, Michael S. Seaman, Bing Chen, James J. Chou
Categories: Climate Newsprint

[Report] Cilia-based flow network in the brain ventricles

Science Magazine - Thu, 07/07/2016 - 23:00
Cerebrospinal fluid conveys many physiologically important signaling factors through the ventricular cavities of the brain. We investigated the transport of cerebrospinal fluid in the third ventricle of the mouse brain and discovered a highly organized pattern of cilia modules, which collectively give rise to a network of fluid flows that allows for precise transport within this ventricle. We also discovered a cilia-based switch that reliably and periodically alters the flow pattern so as to create a dynamic subdivision that may control substance distribution in the third ventricle. Complex flow patterns were also present in the third ventricles of rats and pigs. Our work suggests that ciliated epithelia can generate and maintain complex, spatiotemporally regulated flow networks. Authors: Regina Faubel, Christian Westendorf, Eberhard Bodenschatz, Gregor Eichele
Categories: Climate Newsprint

[Report] Reengineering chimeric antigen receptor T cells for targeted therapy of autoimmune disease

Science Magazine - Thu, 07/07/2016 - 23:00
Ideally, therapy for autoimmune diseases should eliminate pathogenic autoimmune cells while sparing protective immunity, but feasible strategies for such an approach have been elusive. Here, we show that in the antibody-mediated autoimmune disease pemphigus vulgaris (PV), autoantigen-based chimeric immunoreceptors can direct T cells to kill autoreactive B lymphocytes through the specificity of the B cell receptor (BCR). We engineered human T cells to express a chimeric autoantibody receptor (CAAR), consisting of the PV autoantigen, desmoglein (Dsg) 3, fused to CD137-CD3ζ signaling domains. Dsg3 CAAR-T cells exhibit specific cytotoxicity against cells expressing anti-Dsg3 BCRs in vitro and expand, persist, and specifically eliminate Dsg3-specific B cells in vivo. CAAR-T cells may provide an effective and universal strategy for specific targeting of autoreactive B cells in antibody-mediated autoimmune disease. Authors: Christoph T. Ellebrecht, Vijay G. Bhoj, Arben Nace, Eun Jung Choi, Xuming Mao, Michael Jeffrey Cho, Giovanni Di Zenzo, Antonio Lanzavecchia, John T. Seykora, George Cotsarelis, Michael C. Milone, Aimee S. Payne
Categories: Climate Newsprint

[New Products] New Products

Science Magazine - Thu, 07/07/2016 - 23:00
A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.
Categories: Climate Newsprint

[Working Life] The questions that opened doors

Science Magazine - Thu, 07/07/2016 - 23:00
Author: Carlos A. Aguilar-Trigueros
Categories: Climate Newsprint

Estimated cost of Hinkley Point C nuclear plant rises to £37bn

The Guardian Climate Change - Thu, 07/07/2016 - 19:57

Critics point to volatility of scheme but energy department says price ‘will not affect bill payers’

The total lifetime cost of the planned Hinkley Point C nuclear power plant could be as high as £37bn, according to an assessment published by the UK government. The figure was described as shocking by critics of the scheme, who said it showed just how volatile and uncertain the project had become, given that the same energy department’s estimate 12 months earlier had been £14bn.

The latest prediction comes amid increasing speculation about the future of the controversial project in Somerset, whose existence has been put in further doubt by post-Brexit financial jitters.

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Categories: Climate Newsprint

June swoon: US breaks another monthly temperature record

The Guardian Climate Change - Thu, 07/07/2016 - 17:14

Average temperature of 71.8F is 3.3F above 20th-century average for the month and comes amid a string of climate- and weather-related calamities

The US experienced its warmest ever June last month, with a scorching summer set to compound a string of climate-related disasters that have already claimed dozens of lives and cost billions of dollars in damage this year.

Worldwide, heat records have been broken for 13 months in a row, an unprecedented streak of warmth that has stunned climate scientists and heightened concerns over the future livability of parts of the planet.

Related: Arctic sea ice crashes to record low for June

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Categories: Climate Newsprint

Australia's vast kelp forests devastated by marine heatwave, study reveals

The Guardian Climate Change - Thu, 07/07/2016 - 17:00

About 90% of forests off the western coast were wiped out between 2011 and 2013, posing a threat to biodiversity and the marine economy, say scientists

A hundred kilometres of kelp forests off the western coast of Australia were wiped out by a marine heatwave between 2010 and 2013, a new study has revealed.

About 90% of the forests that make up the north-western tip of the Great Southern Reef disappeared over the period, replaced by seaweed turfs, corals, and coral fish usually found in tropical and subtropical waters.

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Categories: Climate Newsprint

Arctic sea ice crashes to record low for June

The Guardian Climate Change - Thu, 07/07/2016 - 15:19

From mid-June onwards, ice cover disappeared at an average rate of 29,000 miles a day, about 70% faster than the typical rate of ice loss, experts say

The summer sea ice cover over the Arctic raced towards oblivion in June, crashing through previous records to reach a new all-time low.

The Arctic sea ice extent was a staggering 260,000 sq km (100,000 sq miles) below the previous record for June, set in 2010. And it was 1.36m sq km (525,000 sq miles) below the 1981-2010 long-term average, according to the National Snow and Ice Data Center.

Related: Arctic sea ice fell to record low for May

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Categories: Climate Newsprint

Christiana Figueres nominated for post of UN secretary general

The Guardian Climate Change - Thu, 07/07/2016 - 14:15

UN’s former climate change chief, who was a key architect of the Paris climate agreement, joins long list of candidates to succeed Ban Ki-moon

One of the chief architects of the global accord on climate change signed last year in Paris has been nominated for the post of secretary general of the United Nations.

Christiana Figueres, executive secretary of the UN framework convention on climate change (UNFCCC), won plaudits from around the world at the successful conclusion of the Paris talks in December. The summit saw all of the world’s nations agree for the first time to a binding commitment to avoid dangerous levels of global warming.

Related: Paris climate deal: key points at a glance

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Categories: Climate Newsprint

Climate scientists are under attack from frivolous lawsuits | Lauren Kurtz

The Guardian Climate Change - Thu, 07/07/2016 - 10:00

Climate Science Legal Defense Fund is forced to defend climate scientists against constant frivolous lawsuits

Today’s climate scientists have a lot more to worry about than peer review. Organizations with perverse financial incentives harass scientists with lawsuit after lawsuit, obstructing research and seeking to embarrass them with disclosures of private information.

On June 14th, an Arizona court ruled that thousands of emails from two prominent climate scientists must be turned over to the Energy & Environment Legal Institute (E&E), a group that disputes the 97% expert consensus on human-caused climate change and argues against action to confront it. E&E and its attorneys are funded by Peabody Coal, Arch Coal, and Alpha Natural Resources, coal corporations with billions of dollars in revenue.

[a]lternative methods of communications have been and remain available to Professors Hughes and Overpeck and any other similarly situated persons should they desire to correspond in confidence regarding research projects and like endevours [sic].

open records requests are increasingly being used to harass and intimidate scientists and other academic researchers, or to disrupt and delay their work.

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Categories: Climate Newsprint

Fracking 'will break UK climate targets unless rules are made stricter'

The Guardian Climate Change - Thu, 07/07/2016 - 08:30

Government advisers also say more action would be needed to cut emissions in other areas to cope with full-scale fracking

Shale gas production will break the UK’s climate change targets unless there is stricter regulation now, according to the government’s official advisers.

More action to cut carbon emissions in other areas would also be needed to cope with full-scale fracking, despite the government already struggling to meet existing commitments.

Related: UK lacks policies to meet more than half its carbon emissions cuts – report

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Categories: Climate Newsprint

Climate change plagues Madagascar's poor: 'The water rose so fast'

The Guardian Climate Change - Thu, 07/07/2016 - 08:00

Severe droughts and floods have had a devastating impact on the island’s rural poor, who are reliant on small-scale farming or fishing

Angenie, 21, lives in a country many people think of as an ecological paradise, home to a unique diversity of plants and animals. Yet within the past three years she has witnessed droughts and floods so severe she has had to flee her home to escape them – twice.

Angenie grew up in southern Madagascar where, as a child, she remembers “things being green”. But for the past few years a severe drought, blamed on the devastating effects of El Niño, has gripped the southern region. “The land got dry, really dry,” she says. “It got to the point we were not able to grow anything. People ate only dried cassava or cactus fruit.”

Related: Madagascar's vanilla farmers face volatile times after poor harvest

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Categories: Climate Newsprint
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