Feed aggregator

Days before Trump takes office, Obama gives another $500 million to UN Green Climate Fund

Climate Depot - 6 hours 24 min ago
Via: https://thinkprogress.org/500-million-to-gcf-306414ccc909#.nhpgh0on4 Days before Trump takes office, State Department gives $500 million to UN Green Climate Fund The announcement is expected to prompt a backlash. A woman works her computer at the Green Climate Fund stand at the COP21, United Nations Climate Change Conference, Monday, Nov. 30, 2015 in Le Bourget, north of Paris. CREDIT: AP Photo/Michel [...]

Polymeric phase V of carbon dioxide has not been recovered at ambient pressure and has a unique structure [Letters (Online Only)]

PNAS Early Edition Articles - 6 hours 42 min ago
In their high-pressure study of solid CO2, Yong et al. (1) claim: (i) that they recovered the polymeric phase V (CO2-V) at ambient pressure and 191 K, and (ii) that CO2-V may exist in different crystal structures. We demonstrate below that neither of these claims is supported by their data....

Reply to Datchi et al.: Recovered phase CO2-V at low temperature and a newly predicted 3D-extended CO2 phase [Letters (Online Only)]

PNAS Early Edition Articles - 6 hours 49 min ago
In their letter, Datchi et al. (1) question (i) the recoverability of CO2-V at low pressure and (ii) the identification of CO2-V as a Pna21 structure in our paper (2). We argue below that both of Datchi et al.’s (1) claims are incorrect. Regarding Datchi et al.’s (1) first claim,...

Zero-index structures as an alternative platform for quantum optics [Applied Physical Sciences]

PNAS Early Edition Articles - 7 hours 19 min ago
Vacuum fluctuations are one of the most distinctive aspects of quantum optics, being the trigger of multiple nonclassical phenomena. Thus, platforms like resonant cavities and photonic crystals that enable the inhibition and manipulation of vacuum fluctuations have been key to our ability to control light–matter interactions (e.g., the decay of...

Elemental sulfur aerosol-forming mechanism [Earth, Atmospheric, and Planetary Sciences]

PNAS Early Edition Articles - 7 hours 19 min ago
Elemental sulfur aerosols are ubiquitous in the atmospheres of Venus, ancient Earth, and Mars. There is now an evolving body of evidence suggesting that these aerosols have also played a role in the evolution of early life on Earth. However, the exact details of their formation mechanism remain an open...

Bilateral recruitment of prefrontal cortex in working memory is associated with task demand but not with age [Neuroscience]

PNAS Early Edition Articles - 7 hours 19 min ago
Elderly adults may master challenging cognitive demands by additionally recruiting the cross-hemispheric counterparts of otherwise unilaterally engaged brain regions, a strategy that seems to be at odds with the notion of lateralized functions in cerebral cortex. We wondered whether bilateral activation might be a general coping strategy that is independent...

Unlocking Tn3-family transposase activity in vitro unveils an asymetric pathway for transposome assembly [Biochemistry]

PNAS Early Edition Articles - 7 hours 19 min ago
The Tn3 family is a widespread group of replicative transposons that are notorious for their contribution to the dissemination of antibiotic resistance and the emergence of multiresistant pathogens worldwide. The TnpA transposase of these elements catalyzes DNA breakage and rejoining reactions required for transposition. It also is responsible for target...

Iron isotopes reveal distinct dissolved iron sources and pathways in the intermediate versus deep Southern Ocean [Environmental Sciences]

PNAS Early Edition Articles - 7 hours 19 min ago
As an essential micronutrient, iron plays a key role in oceanic biogeochemistry. It is therefore linked to the global carbon cycle and climate. Here, we report a dissolved iron (DFe) isotope section in the South Atlantic and Southern Ocean. Throughout the section, a striking DFe isotope minimum (light iron) is...

Thermal-driven domain and cargo transport in lipid membranes [Chemistry]

PNAS Early Edition Articles - 7 hours 19 min ago
Domain migration is observed on the surface of ternary giant unilamellar vesicles held in a temperature gradient in conditions where they exhibit coexistence of two liquid phases. The migration localizes domains to the hot side of the vesicle, regardless of whether the domain is composed of the more ordered or...

Catalytic oxidation of Li2S on the surface of metal sulfides for Li-S batteries [Chemistry]

PNAS Early Edition Articles - 7 hours 19 min ago
Polysulfide binding and trapping to prevent dissolution into the electrolyte by a variety of materials has been well studied in Li−S batteries. Here we discover that some of those materials can play an important role as an activation catalyst to facilitate oxidation of the discharge product, Li2S, back to the...

An RNA-based signature enables high specificity detection of circulating tumor cells in hepatocellular carcinoma [Medical Sciences]

PNAS Early Edition Articles - 7 hours 19 min ago
Circulating tumor cells (CTCs) are shed into the bloodstream by invasive cancers, but the difficulty inherent in identifying these rare cells by microscopy has precluded their routine use in monitoring or screening for cancer. We recently described a high-throughput microfluidic CTC-iChip, which efficiently depletes hematopoietic cells from blood specimens and...

Repair shielding of platinum-DNA lesions in testicular germ cell tumors by high-mobility group box protein 4 imparts cisplatin hypersensitivity [Biochemistry]

PNAS Early Edition Articles - 7 hours 19 min ago
Cisplatin is the most commonly used anticancer drug for the treatment of testicular germ cell tumors (TGCTs). The hypersensitivity of TGCTs to cisplatin is a subject of widespread interest. Here, we show that high-mobility group box protein 4 (HMGB4), a protein preferentially expressed in testes, uniquely blocks excision repair of...

{alpha}-Synuclein binds and sequesters PIKE-L into Lewy bodies, triggering dopaminergic cell death via AMPK hyperactivation [Neuroscience]

PNAS Early Edition Articles - 7 hours 19 min ago
The abnormal aggregation of fibrillar α-synuclein in Lewy bodies plays a critical role in the pathogenesis of Parkinson’s disease. However, the molecular mechanisms regulating α-synuclein pathological effects are incompletely understood. Here we show that α-synuclein binds phosphoinositide-3 kinase enhancer L (PIKE-L) in a phosphorylation-dependent manner and sequesters it in Lewy...

Measurement of cortical elasticity in Drosophila melanogaster embryos using ferrofluids [Developmental Biology]

PNAS Early Edition Articles - 7 hours 19 min ago
Many models of morphogenesis are forced to assume specific mechanical properties of cells, because the actual mechanical properties of living tissues are largely unknown. Here, we measure the rheology of epithelial cells in the cellularizing Drosophila embryo by injecting magnetic particles and studying their response to external actuation. We establish...

A natural product inhibits the initiation of {alpha}-synuclein aggregation and suppresses its toxicity [Neuroscience]

PNAS Early Edition Articles - 7 hours 19 min ago
The self-assembly of α-synuclein is closely associated with Parkinson’s disease and related syndromes. We show that squalamine, a natural product with known anticancer and antiviral activity, dramatically affects α-synuclein aggregation in vitro and in vivo. We elucidate the mechanism of action of squalamine by investigating its interaction with lipid vesicles,...

Active MLKL triggers the NLRP3 inflammasome in a cell-intrinsic manner [Immunology and Inflammation]

PNAS Early Edition Articles - 7 hours 19 min ago
Necroptosis is a physiological cell suicide mechanism initiated by receptor-interacting protein kinase-3 (RIPK3) phosphorylation of mixed-lineage kinase domain-like protein (MLKL), which results in disruption of the plasma membrane. Necroptotic cell lysis, and resultant release of proinflammatory mediators, is thought to cause inflammation in necroptotic disease models. However, we previously showed...

Prion replication without host adaptation during interspecies transmissions [Microbiology]

PNAS Early Edition Articles - 7 hours 19 min ago
Adaptation of prions to new species is thought to reflect the capacity of the host-encoded cellular form of the prion protein (PrPC) to selectively propagate optimized prion conformations from larger ensembles generated in the species of origin. Here we describe an alternate replicative process, termed nonadaptive prion amplification (NAPA), in...

Recognition of protein-linked glycans as a determinant of peptidase activity [Biochemistry]

PNAS Early Edition Articles - 7 hours 19 min ago
The vast majority of proteins are posttranslationally altered, with the addition of covalently linked sugars (glycosylation) being one of the most abundant modifications. However, despite the hydrolysis of protein peptide bonds by peptidases being a process essential to all life on Earth, the fundamental details of how peptidases accommodate posttranslational...

High Coulombic efficiency aluminum-ion battery using an AlCl3-urea ionic liquid analog electrolyte [Chemistry]

PNAS Early Edition Articles - 7 hours 19 min ago
In recent years, impressive advances in harvesting renewable energy have led to a pressing demand for the complimentary energy storage technology. Here, a high Coulombic efficiency (∼99.7%) Al battery is developed using earth-abundant aluminum as the anode, graphite as the cathode, and a cheap ionic liquid analog electrolyte made from...

Loss of GET pathway orthologs in Arabidopsis thaliana causes root hair growth defects and affects SNARE abundance [Plant Biology]

PNAS Early Edition Articles - 7 hours 19 min ago
Soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE) proteins are key players in cellular trafficking and coordinate vital cellular processes, such as cytokinesis, pathogen defense, and ion transport regulation. With few exceptions, SNAREs are tail-anchored (TA) proteins, bearing a C-terminal hydrophobic domain that is essential for their membrane integration. Recently, the...
Syndicate content