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Gamma motor neurons survive and exacerbate alpha motor neuron degeneration in ALS [Neuroscience]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
The molecular and cellular basis of selective motor neuron (MN) vulnerability in amyotrophic lateral sclerosis (ALS) is not known. In genetically distinct mouse models of familial ALS expressing mutant superoxide dismutase-1 (SOD1), TAR DNA-binding protein 43 (TDP-43), and fused in sarcoma (FUS), we demonstrate selective degeneration of alpha MNs (α-MNs)...

Dopamine release from the locus coeruleus to the dorsal hippocampus promotes spatial learning and memory [Neuroscience]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
Dopamine neurotransmission in the dorsal hippocampus is critical for a range of functions from spatial learning and synaptic plasticity to the deficits underlying psychiatric disorders such as attention-deficit hyperactivity disorder. The ventral tegmental area (VTA) is the presumed source of dopamine in the dorsal hippocampus. However, there is a surprising...

Sox2+ progenitors in sharks link taste development with the evolution of regenerative teeth from denticles [Evolution]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
Teeth and denticles belong to a specialized class of mineralizing epithelial appendages called odontodes. Although homology of oral teeth in jawed vertebrates is well supported, the evolutionary origin of teeth and their relationship with other odontode types is less clear. We compared the cellular and molecular mechanisms directing development of...

Cosmc is an X-linked inflammatory bowel disease risk gene that spatially regulates gut microbiota and contributes to sex-specific risk [Immunology and Inflammation]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
Inflammatory bowel disease (IBD) results from aberrant immune stimulation against a dysbiotic mucosal but relatively preserved luminal microbiota and preferentially affects males in early onset disease. However, factors contributing to sex-specific risk and the pattern of dysbiosis are largely unexplored. Core 1 β3GalT-specific molecular chaperone (Cosmc), which encodes an X-linked...

Electrotonic coupling of excitable and nonexcitable cells in the heart revealed by optogenetics [Physiology]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
Electrophysiological studies of excitable organs usually focus on action potential (AP)-generating cells, whereas nonexcitable cells are generally considered as barriers to electrical conduction. Whether nonexcitable cells may modulate excitable cell function or even contribute to AP conduction via direct electrotonic coupling to AP-generating cells is unresolved in the heart: such...

Unexpected central role of the androgen receptor in the spontaneous regeneration of myelin [Neuroscience]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
Lost myelin can be replaced after injury or during demyelinating diseases in a regenerative process called remyelination. In the central nervous system (CNS), the myelin sheaths, which protect axons and allow the fast propagation of electrical impulses, are produced by oligodendrocytes. The abundance and widespread distribution of oligodendrocyte progenitors (OPs)...

Light affects salt stress-induced transcriptional memory of P5CS1 in Arabidopsis [Plant Biology]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
To cope with environmental stresses, plants often adopt a memory response upon primary stress exposure to facilitate a quicker and stronger reaction to recurring stresses. However, it remains unknown whether light is involved in the manifestation of stress memory. Proline accumulation is a striking metabolic adaptation of higher plants during...

Simultaneous dimension reduction and adjustment for confounding variation [Systems Biology]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
Dimension reduction methods are commonly applied to high-throughput biological datasets. However, the results can be hindered by confounding factors, either biological or technical in origin. In this study, we extend principal component analysis (PCA) to propose AC-PCA for simultaneous dimension reduction and adjustment for confounding (AC) variation. We show that...

Genetic, immunological, and clinical features of patients with bacterial and fungal infections due to inherited IL-17RA deficiency [Genetics]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
Chronic mucocutaneous candidiasis (CMC) is defined as recurrent or persistent infection of the skin, nails, and/or mucosae with commensal Candida species. The first genetic etiology of isolated CMC—autosomal recessive (AR) IL-17 receptor A (IL-17RA) deficiency—was reported in 2011, in a single patient. We report here 21 patients with complete AR...

Growth hormone-releasing hormone receptor antagonists inhibit human gastric cancer through downregulation of PAK1-STAT3/NF-{kappa}B signaling [Cell Biology]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
Gastric cancer (GC) ranks as the fourth most frequent in incidence and second in mortality among all cancers worldwide. The development of effective treatment approaches is an urgent requirement. Growth hormone-releasing hormone (GHRH) and GHRH receptor (GHRH-R) have been found to be present in a variety of tumoral tissues and...

Measuring spectroscopy and magnetism of extracted and intracellular magnetosomes using soft X-ray ptychography [Biophysics and Computational Biology]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
Characterizing the chemistry and magnetism of magnetotactic bacteria (MTB) is an important aspect of understanding the biomineralization mechanism and function of the chains of magnetosomes (Fe3O4 nanoparticles) found in such species. Images and X-ray absorption spectra (XAS) of magnetosomes extracted from, and magnetosomes in, whole Magnetovibrio blakemorei strain MV-1 cells...

Artemisia annua mutant impaired in artemisinin synthesis demonstrates importance of nonenzymatic conversion in terpenoid metabolism [Plant Biology]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
Artemisinin, a sesquiterpene lactone produced by Artemisia annua glandular secretory trichomes, is the active ingredient in the most effective treatment for malaria currently available. We identified a mutation that disrupts the amorpha-4,11-diene C-12 oxidase (CYP71AV1) enzyme, responsible for a series of oxidation reactions in the artemisinin biosynthetic pathway. Detailed metabolic...

Janus effect of antifreeze proteins on ice nucleation [Chemistry]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
The mechanism of ice nucleation at the molecular level remains largely unknown. Nature endows antifreeze proteins (AFPs) with the unique capability of controlling ice formation. However, the effect of AFPs on ice nucleation has been under debate. Here we report the observation of both depression and promotion effects of AFPs...

Estimating uncertainty in respondent-driven sampling using a tree bootstrap method [Statistics]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
Respondent-driven sampling (RDS) is a network-based form of chain-referral sampling used to estimate attributes of populations that are difficult to access using standard survey tools. Although it has grown quickly in popularity since its introduction, the statistical properties of RDS estimates remain elusive. In particular, the sampling variability of these...

Direct evidence of interaction-induced Dirac cones in a monolayer silicene/Ag(111) system [Physics]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
Silicene, analogous to graphene, is a one-atom-thick 2D crystal of silicon, which is expected to share many of the remarkable properties of graphene. The buckled honeycomb structure of silicene, along with enhanced spin-orbit coupling, endows silicene with considerable advantages over graphene in that the spin-split states in silicene are tunable...

An NAD+-dependent transcriptional program governs self-renewal and radiation resistance in glioblastoma [Cell Biology]

PNAS Early Edition Articles - Wed, 12/07/2016 - 15:14
Accumulating evidence suggests cancer cells exhibit a dependency on metabolic pathways regulated by nicotinamide adenine dinucleotide (NAD+). Nevertheless, how the regulation of this metabolic cofactor interfaces with signal transduction networks remains poorly understood in glioblastoma. Here, we report nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting step in NAD+ synthesis, is highly expressed...

Greens freak out over Trump’s EPA pick: Call him ‘Dangerous’ – ‘Existential threat to the planet’

Climate Depot - Wed, 12/07/2016 - 15:13
Excerpts Via: https://www.politicopro.com/energy/whiteboard/2016/12/dems-greens-slam-pruitt-nomination-080774 Dems, greens slam Pruitt nomination By Alex Guillén 12/07/2016 03:53 PM EDT Oklahoma Attorney General Scott Pruitt’s expected nomination to head EPA today drew sharp criticism from green groups and environmental advocates in Congress, including former presidential candidate Bernie Sanders, who said he would oppose the “sad and dangerous” move. … Dan Pfeiffer, [...]

Celebrate! Trump to pick ‘ardent opponent’ of Obama climate agenda to run EPA

Climate Depot - Wed, 12/07/2016 - 14:38
U.S. President-Elect Donald Trump will pick an ardent opponent of President Barack Obama’s measures to stem climate change to head the Environmental Protection Agency, a Trump transition team source said on Wednesday. Trump’s choice, Oklahoma Attorney General Scott Pruitt, has enraged environmental activists, but he fits with the Republican president-elect’s promise to cut the agency [...]

Bravo! Trump appoints ‘a fierce critic of the EPA’ — to head EPA!

Climate Depot - Wed, 12/07/2016 - 14:33
Pruitt became the top prosecutor for Oklahoma, which has extensive oil reserves, in 2011, and has challenged the EPA multiple times since, including in a pending lawsuit to throw out the EPA’s Clean Power Plan. The plan is the centerpiece of Obama’s climate change strategy and requires states to curb carbon output.

Cheers! Trump picks leading EPA critic to head agency

Climate Depot - Wed, 12/07/2016 - 14:21
Donald Trump intends to nominate a chief critic of the EPA to be its next head, a source confirmed Wednesday. Oklahoma Attorney General Scott Pruitt will be named the next Environmental Protection Agency administrator, the source said. Pruitt, who was elected in the 2010 tea party wave, has filed lawsuits targeting the environmental policies of [...]
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