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Sidewinding snakes and robots turn with template [Engineering]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
Many organisms move using traveling waves of body undulation, and most work has focused on single-plane undulations in fluids. Less attention has been paid to multiplane undulations, which are particularly important in terrestrial environments where vertical undulations can regulate substrate contact. A seemingly complex mode of snake locomotion, sidewinding, can...

Mutagenesis of mating pheromone system in yeast [Genetics]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
The diversification of sex pheromones is regarded as one of the causes of prezygotic isolation that results in speciation. In the fission yeast Schizosaccharomyces pombe, the molecular recognition of a peptide pheromone by its receptor plays an essential role in sexual reproduction. We considered that molecular coevolution of a peptide-mating...

Non-native species increase floral diversity [Ecology]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
Plants are commonly listed as invasive species, presuming that they cause harm at both global and regional scales. Approximately 40% of all species listed as invasive within Britain are plants. However, invasive plants are rarely linked to the national or global extinction of native plant species. The possible explanation is...

The genome of Mycobacterium lepromatosis [Microbiology]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
Mycobacterium lepromatosis is an uncultured human pathogen associated with diffuse lepromatous leprosy and a reactional state known as Lucio's phenomenon. By using deep sequencing with and without DNA enrichment, we obtained the near-complete genome sequence of M. lepromatosis present in a skin biopsy from a Mexican patient, and compared it...

ATP synthase essential in malaria life cycle [Colloquium Paper]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
Mitochondrial ATP synthase is driven by chemiosmotic oxidation of pyruvate derived from glycolysis. Blood-stage malaria parasites eschew chemiosmosis, instead relying almost solely on glycolysis for their ATP generation, which begs the question of whether mitochondrial ATP synthase is necessary during the blood stage of the parasite life cycle. We knocked...

Evidence for indigenous nitrogen on Mars [Earth, Atmospheric, and Planetary Sciences]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
The Sample Analysis at Mars (SAM) investigation on the Mars Science Laboratory (MSL) Curiosity rover has detected oxidized nitrogen-bearing compounds during pyrolysis of scooped aeolian sediments and drilled sedimentary deposits within Gale crater. Total N concentrations ranged from 20 to 250 nmol N per sample. After subtraction of known N...

Synergistic regulation of PDE4B by PKA-C{beta} and p65 [Pharmacology]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
Phosphodiesterase 4B (PDE4B) plays a key role in regulating inflammation. Roflumilast, a phosphodiesterase (PDE)4-selective inhibitor, has recently been approved for treating severe chronic obstructive pulmonary disease (COPD) patients with exacerbation. However, there is also clinical evidence suggesting the development of tachyphylaxis or tolerance on repeated dosing of roflumilast and the...

Structural mechanisms of human RecQ helicases [Biochemistry]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
RecQ helicases are a widely conserved family of ATP-dependent motors with diverse roles in nearly every aspect of bacterial and eukaryotic genome maintenance. However, the physical mechanisms by which RecQ helicases recognize and process specific DNA replication and repair intermediates are largely unknown. Here, we solved crystal structures of the...

Gram-positive bactericidal activity of auranofin [Microbiology]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
Infections caused by antibiotic-resistant bacteria are a rising public health threat and make the identification of new antibiotics a priority. From a cell-based screen for bactericidal compounds against Mycobacterium tuberculosis under nutrient-deprivation conditions we identified auranofin, an orally bioavailable FDA-approved antirheumatic drug, as having potent bactericidal activities against both replicating...

Trichodesmium spp. gene sparse genome [Evolution]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
Understanding the evolution of the free-living, cyanobacterial, diazotroph Trichodesmium is of great importance because of its critical role in oceanic biogeochemistry and primary production. Unlike the other >150 available genomes of free-living cyanobacteria, only 63.8% of the Trichodesmium erythraeum (strain IMS101) genome is predicted to encode protein, which is 20–25%...

Racemic crystallography of a key TB protein [Biochemistry]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
Protein 3D structure can be a powerful predictor of function, but it often faces a critical roadblock at the crystallization step. Rv1738, a protein from Mycobacterium tuberculosis that is strongly implicated in the onset of nonreplicating persistence, and thereby latent tuberculosis, resisted extensive attempts at crystallization. Chemical synthesis of the...

Cooperation between IFI16 and cGAS [Microbiology]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
Interferon γ-inducible protein 16 (IFI16) and cGMP-AMP synthase (cGAS) have both been proposed to detect herpesviral DNA directly in herpes simplex virus (HSV)-infected cells and initiate interferon regulatory factor-3 signaling, but it has been unclear how two DNA sensors could both be required for this response. We therefore investigated their...

Area burned is unaffected by mountain pine beetle [Sustainability Science]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
In the western United States, mountain pine beetles (MPBs) have killed pine trees across 71,000 km2 of forest since the mid-1990s, leading to widespread concern that abundant dead fuels may increase area burned and exacerbate fire behavior. Although stand-level fire behavior models suggest that bark beetle-induced tree mortality increases flammability...

Plexin D1 regulates visceral adipose tissue growth [Developmental Biology]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
Genome-wide association studies have implicated PLEXIN D1 (PLXND1) in body fat distribution and type 2 diabetes. However, a role for PLXND1 in regional adiposity and insulin resistance is unknown. Here we use in vivo imaging and genetic analysis in zebrafish to show that Plxnd1 regulates body fat distribution and insulin...

Early sedentary communities in the Maya lowlands [Anthropology]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
Our archaeological investigations at Ceibal, a lowland Maya site located in the Pasión region, documented that a formal ceremonial complex was built around 950 B.C. at the onset of the Middle Preclassic period, when ceramics began to be used in the Maya lowlands. Our refined chronology allowed us to trace...

Mre11 toxicity in the absence of Sae2 [Genetics]

PNAS Early Edition Articles - Mon, 03/23/2015 - 13:04
The Mre11–Rad50–Xrs2/NBS1 (MRX/N) nuclease/ATPase complex plays structural and catalytic roles in the repair of DNA double-strand breaks (DSBs) and is the DNA damage sensor for Tel1/ATM kinase activation. Saccharomyces cerevisiae Sae2 can function with MRX to initiate 5′-3′ end resection and also plays an important role in attenuation of DNA...

Flashback 1958: Arctic Ice Sheet Will Envelope NYC, Chicago

Climate Depot - Mon, 03/23/2015 - 12:21

Watch Six-Year-Old’s Gripping Video on Climate Change

Climate Depot - Mon, 03/23/2015 - 12:18

Jerry Brown: Opposition on climate change ‘borders on the immoral’ – Ted Cruz’s skepticism ‘unfit to be running for office’

Climate Depot - Mon, 03/23/2015 - 12:02

While warning us of ‘rising oceans’ in SOTU, did Obama just buy a beachfront mansion?

Climate Depot - Mon, 03/23/2015 - 11:55
While warning us of ‘rising oceans’ in SOTU, did Obama just buy a beachfront mansion? http://wattsupwiththat.com/2015/03/21/while-warning-us-of-rising-oceans-in-sotu-did-obama-just-buy-a-beachfront-mansion Story submitted by Eric Worrall Rumours are flying that the owner of a beachfront mansion in Hawaii, which was once used to film the hit TV series “Magnum PI”, is none other than President Obama – the same President [...]
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