Proceedings of the Natural Academy of Sciences
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SLC family HCO3- pump in diatoms [Environmental Sciences]
[Jan 2013]
Photosynthesis in marine diatoms is a vital fraction of global primary production empowered by CO2-concentrating mechanisms. Acquisition of HCO3− from seawater is a critical primary step of the CO2-concentrating mechanism, allowing marine photoautotrophic eukaryotes to overcome CO2 limitation in alkaline high-salinity water. However, little is known about molecular mechanisms governing...
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Mass spectrometry for brain tumor diagnosis [Medical Sciences]
[Jan 2013]
The main goal of brain tumor surgery is to maximize tumor resection while preserving brain function. However, existing imaging and surgical techniques do not offer the molecular information needed to delineate tumor boundaries. We have developed a system to rapidly analyze and classify brain tumors based on lipid information acquired...
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Model-based fMRI locates fronto-parietal functions [Neuroscience]
[Jan 2013]
In this study, we used model-based functional MRI (fMRI) to locate two functions of the fronto-parietal network: declarative memory retrievals and updating of working memory. Because regions in the fronto-parietal network are by definition coherently active, locating functions within this network is difficult. To overcome this problem, we applied model-based...
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Quantum phase transition of charge order in NbSe2 [Physics]
[Jan 2013]
The competition between proximate electronic phases produces a complex phenomenology in strongly correlated systems. In particular, fluctuations associated with periodic charge or spin modulations, known as density waves, may lead to exotic superconductivity in several correlated materials. However, density waves have been difficult to isolate in the presence of chemical...
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Calling patterns in human communication dynamics [Social Sciences]
[Jan 2013]
Modern technologies not only provide a variety of communication modes (e.g., texting, cell phone conversation, and online instant messaging), but also detailed electronic traces of these communications between individuals. These electronic traces indicate that the interactions occur in temporal bursts. Here, we study intercall duration of communications of the 100,000...
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BCR-ABL1 expression in multiple myeloma cells [Biological Sciences]
[Jan 2013]
Cancer cell lines (CCLs) are widely used to provide investigators with unlimited cell stocks, enabling experimental repetition and cumulative data assemblage. In numerous instances, cancer genes were first identified in CCL. Hence, the recent report in PNAS (1) that a classic multiple myeloma (MM) cell line, NCI-H929, bears cytogenetic rearrangement...
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Multiple myeloma cells with BCR-ABL fusion [Biological Sciences]
[Jan 2013]
MacLeod et al. question whether our lot of H929 multiple myeloma (MM) plasma cells were contaminated with K562 chronic myeloid leukemia (CML) cells (1). Before addressing this issue, we want to state that the central purpose of our paper was to demonstrate that hypothesis-directed proteomics using immunoprecipitation (IP)–liquid chromatography–tandem mass...
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Do crows reason about causes or agents? [Biological Sciences]
[Jan 2013]
In a recent issue of PNAS, Taylor et al. (1) claimed that New Caledonian crows can reason about hidden causal agents (HCAs). Crows first experienced three trials in the HCA condition: they saw a human enter a hide within their aviary; a stick being poked from the hide toward a...
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The devil is not in association or distraction [Biological Sciences]
[Jan 2013]
We agree with the suggestion by Boogert et al. (1) that manipulating the animacy of the predictor cue would be a useful follow-up to our recent study on causal reasoning in New Caledonian crows (2). However, it is important to note that the data presented in our paper cannot be...
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Nascent-Seq analysis of cycling gene expression [Cell Biology]
[Jan 2013]
Rhythmic mRNA expression is a hallmark of circadian biology and has been described in numerous experimental systems including mammals. A small number of core clock gene mRNAs and a much larger number of output mRNAs are under circadian control. The rhythmic expression of core clock genes is regulated at the...
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Low Smg1 enhances tumor development [Developmental Biology]
[Jan 2013]
SMG1 is a member of the phosphoinositide kinase-like kinase family of proteins that includes ATM, ATR, and DNA-PK, proteins with known roles in DNA damage and cellular stress responses. SMG1 has a well-characterized role in nonsense-mediated decay as well as suggested roles in the DNA damage response, resistance to oxidative...
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Biosynthesis of antibiotics in shipworm gills [Microbiology]
[Jan 2013]
Shipworms are marine wood-boring bivalve mollusks (family Teredinidae) that harbor a community of closely related Gammaproteobacteria as intracellular endosymbionts in their gills. These symbionts have been proposed to assist the shipworm host in cellulose digestion and have been shown to play a role in nitrogen fixation. The genome of one...
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Input-specific and size-dependent spine shrinkage [Neuroscience]
[Jan 2013]
Refinement of neural circuits in the mammalian cerebral cortex shapes brain function during development and in the adult. However, the signaling mechanisms underlying the synapse-specific shrinkage and loss of spiny synapses when neural circuits are remodeled remain poorly defined. Here, we show that low-frequency glutamatergic activity at individual dendritic spines...
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Quantifying the fuzzy coat of human Tau fibrils [Neuroscience]
[Jan 2013]
The structure and properties of amyloid-like Tau fibrils accumulating in neurodegenerative diseases have been debated for decades. Although the core of Tau fibrils assembles from short β-strands, the properties of the much longer unstructured Tau domains protruding from the fibril core remain largely obscure. Applying immunogold transmission EM, and force-volume...
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Evidence for causal complementarity [Psychological and Cognitive Sciences]
[Jan 2013]
Language production and spatial attention are the most salient lateralized cerebral functions, and their complementary specialization has been observed in the majority of the population. To investigate whether the complementary specialization has a causal origin (the lateralization of one function causes the opposite lateralization of the other) or rather is...
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MZ B cells as source of protective HIV antibodies [Immunology]
[Jan 2013]
A series of potent, broadly neutralizing HIV antibodies have been isolated from B cells of HIV-infected individuals. VRC01 represents a subset of these antibodies that mediate neutralization with a restricted set of IGHV genes. The memory B cells expressing these antibodies were isolated years after infection; thus, the B-cell subpopulation...
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Sortase-mediated modification of {alpha}DEC205 [Immunology]
[Jan 2013]
A monoclonal antibody against the C-type lectin DEC205 (αDEC205) is an effective vehicle for delivery of antigens to dendritic cells through creation of covalent αDEC205–antigen adducts. These adducts can induce antigen-specific T-cell immune responses or tolerance. We exploit the transpeptidase activity of sortase to install modified peptides and protein-sized antigens...
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BCC cancer stem cells [Medical Sciences]
[Jan 2013]
Smoothened antagonists directly target the genetic basis of human basal cell carcinoma (BCC), the most common of all cancers. These drugs inhibit BCC growth, but they are not curative. Although BCC cells are monomorphic, immunofluorescence microscopy reveals a complex hierarchical pattern of growth with inward differentiation along hair follicle lineages....
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LRP-6 and DKK-1 regulate fibrogenesis [Medical Sciences]
[Jan 2013]
Fibrosis of vital organs is a major public health problem with limited therapeutic options. Mesenchymal cells including microvascular mural cells (pericytes) are major progenitors of scar-forming myofibroblasts in kidney and other organs. Here we show pericytes in healthy kidneys have active WNT/β-catenin signaling responses that are markedly up-regulated following kidney...
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Cardiomyocyte proliferation in human heart growth [Medical Sciences]
[Jan 2013]
The human heart is believed to grow by enlargement but not proliferation of cardiomyocytes (heart muscle cells) during postnatal development. However, recent studies have shown that cardiomyocyte proliferation is a mechanism of cardiac growth and regeneration in animals. Combined with evidence for cardiomyocyte turnover in adult humans, this suggests that...
Categories: Journal Articles