Proceedings of the Natural Academy of Sciences

Proceedings of the National Academy of Sciences RSS feed -- current issue
  • Treg signature changes in visceral adipose tissue [Immunology and Inflammation]
    [Jan 2015]

    A unique population of Foxp3+CD4+ regulatory T (Treg) cells resides in visceral adipose tissue (VAT) of lean mice, especially in the epididymal fat depot. VAT Tregs are unusual in their very high representation within the CD4+ T-cell compartment, their transcriptome, and their repertoire of antigen-specific T-cell receptors. They are important...
    Categories: Journal Articles
  • Cationic particles enhance lung antibody response [Immunology and Inflammation]
    [Jan 2015]

    Pulmonary immunization enhances local humoral and cell-mediated mucosal protection, which are critical for vaccination against lung-specific pathogens such as influenza or tuberculosis. A variety of nanoparticle (NP) formulations have been tested preclinically for pulmonary vaccine development, yet the role of NP surface charge on downstream immune responses remains poorly understood....
    Categories: Journal Articles
  • Intracellular osteopontin and NK cell homeostasis [Immunology and Inflammation]
    [Jan 2015]

    Natural killer (NK) cells play an essential role in the immune response to infection and cancer. After infection or during homeostatic expansion NK cells express a developmental program that includes a contraction phase followed by the formation of long-lived mature memory-like cells. Although this NK cell response pattern is well...
    Categories: Journal Articles
  • B-cell responses to VZV vaccine in twins [Immunology and Inflammation]
    [Jan 2015]

    Adaptive immune responses in humans rely on somatic genetic rearrangements of Ig and T-cell receptor loci to generate diverse antigen receptors. It is unclear to what extent an individual’s genetic background affects the characteristics of the antibody repertoire used in responding to vaccination or infection. We studied the B-cell repertoires...
    Categories: Journal Articles
  • Granular impact cratering by liquid drops [Physics]
    [Jan 2015]

    When a granular material is impacted by a sphere, its surface deforms like a liquid yet it preserves a circular crater like a solid. Although the mechanism of granular impact cratering by solid spheres is well explored, our knowledge on granular impact cratering by liquid drops is still very limited....
    Categories: Journal Articles
  • Measuring the effectiveness of peer review [Social Sciences]
    [Jan 2015]

    Peer review is the main institution responsible for the evaluation and gestation of scientific research. Although peer review is widely seen as vital to scientific evaluation, anecdotal evidence abounds of gatekeeping mistakes in leading journals, such as rejecting seminal contributions or accepting mediocre submissions. Systematic evidence regarding the effectiveness—or lack...
    Categories: Journal Articles
  • The search for what sets humans apart [News Feature]
    [Jan 2015]

    Despite our intuition that humans are a species distinct from other animals, attempts to define what makes us unique continue to confound. In a quiet room, away from the bustle of their daycare playmates, two 3 year olds pull a rope that’s wrapped around a board, which sits inside a...
    Categories: Journal Articles
  • Ribosomal proteins control vacuole trafficking [Plant Biology]
    [Jan 2015]

    The vacuole is the most prominent compartment in plant cells and is important for ion and protein storage. In our effort to search for key regulators in the plant vacuole sorting pathway, ribosomal large subunit 4 (rpl4d) was identified as a translational mutant defective in both vacuole trafficking and normal...
    Categories: Journal Articles
  • In This Issue [This Week in PNAS]
    [Jan 2015]

    Isotope distributions within deep Earth Relatively little is known about the carbon budget and the dynamics that shape the budget within Earth’s interior and core. The major processes that formed Earth, such as accretion, magma–ocean formation, and the violent impact that created the Moon, may have resulted in significant losses...
    Categories: Journal Articles
  • Assessing maize genetic erosion [Biological Sciences]
    [Jan 2015]

    Dyer et al. (1) report a rapid decline in maize varieties grown by Mexican farmers, arguing that their results are in contrast with previously reported work. We believe that the support for this rapid decline is weak, and that the contrast with previously reported work is false. Dyer et al....
    Categories: Journal Articles
  • Wake-up call for crop conservation science [Biological Sciences]
    [Jan 2015]

    We strongly concur with Brush et al. (1) regarding the urgency for a new generation of studies (2), but reject claims that our findings are unsupported and our comparisons false, a misperception that could delay adequate academic and policy responses. First, spurious or not, it is not our interpretation that...
    Categories: Journal Articles
  • Hyperlocomotion vs. lack of habituation [Biological Sciences]
    [Jan 2015]

    Locomotion, described as “the combination of forward progression carrying the animal from one location to the next, and stopping/scanning involving investigation of particular locations” (1), is an innate behavior heavily used as a defining phenotypic trait in animal studies related to motor disorders, including Parkinson’s disease. Hence, it is important...
    Categories: Journal Articles
  • Hyperlocomotion [Biological Sciences]
    [Jan 2015]

    We would like to thank Konsolaki and Skaliora for their interest in our paper (1). In their view, our interpretation for the increased locomotion found in the knockout animals is incorrect because, as they argue, it could be a result of different reactions to exposure to novel environments, or to...
    Categories: Journal Articles
  • How many scientific papers are not original? [Computer Sciences]
    [Jan 2015]

    Is plagiarism afflicting science? In PNAS, Citron and Ginsparg (1) count the number of authors who are submitting articles containing text already appearing elsewhere. They report disturbing numbers of authors resorting to copying, particularly in some countries where 15% of submissions are detected as containing duplicated material. I am on...
    Categories: Journal Articles
  • V-ATPases and fusion? [Biochemistry]
    [Jan 2015]

    At the dawn of the 20th century, Metchnikoff (1) fed particles of litmus to various eukaryotic cells. The endocytosed particles changed color from blue to red, indicating their residence in acidifying endosomes. This acidification is driven by a highly conserved multisubunit H+ pump, the vacuolar ATPase (V-ATPase). Acidification activates luminal...
    Categories: Journal Articles
  • Evidence on the origin of carnivorous plants [Evolution]
    [Jan 2015]

    Carnivorous plants have fascinated scientists and the general public since the pioneering studies of Charles Darwin (1). No doubt part of their wide appeal is that carnivorous plants have turned the evolutionary tables on animals, consuming them as prey, with the green predators often equipped with remarkable lures, traps, stomachs,...
    Categories: Journal Articles
  • Urea nucleation from aqueous solution [Chemistry]
    [Jan 2015]

    Despite its ubiquitous character and relevance in many branches of science and engineering, nucleation from solution remains elusive. In this framework, molecular simulations represent a powerful tool to provide insight into nucleation at the molecular scale. In this work, we combine theory and molecular simulations to describe urea nucleation from...
    Categories: Journal Articles
  • Iron isotope fractionation by phytoplankton bloom [Earth, Atmospheric, and Planetary Sciences]
    [Jan 2015]

    The supply and bioavailability of dissolved iron sets the magnitude of surface productivity for ∼40% of the global ocean. The redox state, organic complexation, and phase (dissolved versus particulate) of iron are key determinants of iron bioavailability in the marine realm, although the mechanisms facilitating exchange between iron species (inorganic...
    Categories: Journal Articles
  • Synthetic lethality of GLS and Hsp90 inhibition [Cell Biology]
    [Jan 2015]

    The mammalian target of rapamycin complex 1 (mTORC1) integrates multiple signals from growth factors, nutrients, and cellular energy status to control a wide range of metabolic processes, including mRNA biogenesis; protein, nucleotide, and lipid synthesis; and autophagy. Deregulation of the mTORC1 pathway is found in cancer as well as genetic...
    Categories: Journal Articles
  • Evolution of intermolecular interactions [Evolution]
    [Jan 2015]

    Many cellular functions depend on highly specific intermolecular interactions, for example transcription factors and their DNA binding sites, microRNAs and their RNA binding sites, the interfaces between heterodimeric protein molecules, the stems in RNA molecules, and kinases and their response regulators in signal-transduction systems. Despite the need for complementarity between...
    Categories: Journal Articles