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News Feature: Tracing gold’s cosmic origin story [Earth, Atmospheric, and Planetary Sciences] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Ken Croswell
Desperate phone calls made in the dead of night rarely convey good news, much less first word of a major scientific discovery. Alex Ji made such a call in 2015 from atop a mountain in Chile, where he was using one of the world’s largest telescopes. “This was actually the first time that I had taken data on a telescope ever,” says Ji, then a graduate student at the Massachusetts Institute of Technology
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Liquid-crystal-based topological photonics [Physics] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Hamed Abbaszadeh, Michel Fruchart, Wim van Saarloos, Vincenzo Vitelli
Liquid crystals are complex fluids that allow exquisite control of light propagation thanks to their orientational order and optical anisotropy. Inspired by recent advances in liquid-crystal photo-patterning technology, we propose a soft-matter platform for assembling topological photonic materials that holds promise for protected unidirectional waveguides, sensors, and lasers. Crucial to our approach
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Glycoconjugate pathway connections revealed by sequence similarity network analysis of the monotopic phosphoglycosyl transferases [Biophysics and Computational Biology] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Katherine H. O’Toole, Barbara Imperiali, Karen N. Allen
The monotopic phosphoglycosyl transferase (monoPGT) superfamily comprises over 38,000 nonredundant sequences represented in bacterial and archaeal domains of life. Members of the superfamily catalyze the first membrane-committed step in en bloc oligosaccharide biosynthetic pathways, transferring a phosphosugar from a soluble nucleoside diphosphosugar to a membrane-resident polyprenol phosphate. The
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Interpretations of ground-state symmetry breaking and strong correlation in wavefunction and density functional theories [Physics] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 John P. Perdew, Adrienn Ruzsinszky, Jianwei Sun, Niraj K. Nepal, Aaron D. Kaplan
Strong correlations within a symmetry-unbroken ground-state wavefunction can show up in approximate density functional theory as symmetry-broken spin densities or total densities, which are sometimes observable. They can arise from soft modes of fluctuations (sometimes collective excitations) such as spin-density or charge-density waves at nonzero wavevector. In this sense, an approximate density functional
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Creating self-assembled arrays of mono-oxo (MoO3)1 species on TiO2(101) via deposition and decomposition of (MoO3)n oligomers [Chemistry] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Nassar Doudin, Greg Collinge, Pradeep Kumar Gurunathan, Mal-Soon Lee, Vassiliki-Alexandra Glezakou, Roger Rousseau, Zdenek Dohnálek
Hierarchically ordered oxides are of critical importance in material science and catalysis. Unfortunately, the design and synthesis of such systems remains a key challenge to realizing their potential. In this study, we demonstrate how the deposition of small oligomeric (MoO3)1–6 clusters—formed by the facile sublimation of MoO3 powders—leads to the self-assembly of locally ordered arrays of immobilized
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Evolution in the weak-mutation limit: Stasis periods punctuated by fast transitions between saddle points on the fitness landscape [Evolution] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Yuri Bakhtin, Mikhail I. Katsnelson, Yuri I. Wolf, Eugene V. Koonin
A mathematical analysis of the evolution of a large population under the weak-mutation limit shows that such a population would spend most of the time in stasis in the vicinity of saddle points on the fitness landscape. The periods of stasis are punctuated by fast transitions, in lnNe/s time (Ne, effective population size; s, selection coefficient of a mutation), when a new beneficial mutation is fixed
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Designing angle-independent structural colors using Monte Carlo simulations of multiple scattering [Engineering] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Victoria Hwang, Anna B. Stephenson, Solomon Barkley, Soeren Brandt, Ming Xiao, Joanna Aizenberg, Vinothan N. Manoharan
Disordered nanostructures with correlations on the scale of visible wavelengths can show angle-independent structural colors. These materials could replace dyes in some applications because the color is tunable and resists photobleaching. However, designing nanostructures with a prescribed color is difficult, especially when the application—cosmetics or displays, for example—requires specific component
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Rational policymaking during a pandemic [Immunology and Inflammation] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Loïc Berger, Nicolas Berger, Valentina Bosetti, Itzhak Gilboa, Lars Peter Hansen, Christopher Jarvis, Massimo Marinacci, Richard D. Smith
Policymaking during a pandemic can be extremely challenging. As COVID-19 is a new disease and its global impacts are unprecedented, decisions are taken in a highly uncertain, complex, and rapidly changing environment. In such a context, in which human lives and the economy are at stake, we argue that using ideas and constructs from modern decision theory, even informally, will make policymaking a more
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Coronavirus replication-transcription complex: Vital and selective NMPylation of a conserved site in nsp9 by the NiRAN-RdRp subunit [Microbiology] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-02-09 Heiko Slanina, Ramakanth Madhugiri, Ganesh Bylapudi, Karin Schultheiß, Nadja Karl, Anastasia Gulyaeva, Alexander E. Gorbalenya, Uwe Linne, John Ziebuhr
RNA-dependent RNA polymerases (RdRps) of the Nidovirales (Coronaviridae, Arteriviridae, and 12 other families) are linked to an amino-terminal (N-terminal) domain, called NiRAN, in a nonstructural protein (nsp) that is released from polyprotein 1ab by the viral main protease (Mpro). Previously, self-GMPylation/UMPylation activities were reported for an arterivirus NiRAN-RdRp nsp and suggested to generate
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The hygiene hypothesis, the COVID pandemic, and consequences for the human microbiome [Microbiology] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-02-09 B. Brett Finlay, Katherine R. Amato, Meghan Azad, Martin J. Blaser, Thomas C. G. Bosch, Hiutung Chu, Maria Gloria Dominguez-Bello, Stanislav Dusko Ehrlich, Eran Elinav, Naama Geva-Zatorsky, Philippe Gros, Karen Guillemin, Frédéric Keck, Tal Korem, Margaret J. McFall-Ngai, Melissa K. Melby, Mark Nichter, Sven Pettersson, Hendrik Poinar, Tobias Rees, Carolina Tropini, Liping Zhao, Tamara Giles-Vernick
The COVID-19 pandemic has the potential to affect the human microbiome in infected and uninfected individuals, having a substantial impact on human health over the long term. This pandemic intersects with a decades-long decline in microbial diversity and ancestral microbes due to hygiene, antibiotics, and urban living (the hygiene hypothesis). High-risk groups succumbing to COVID-19 include those with
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In This Issue Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-19 National Academy of Sciences
ENVIRONMENTAL SCIENCES Plumbojarosite, an insoluble lead–iron hydroxysulfate mineral. Image credit: Wikimedia Commons/John Sobolewski (JSS), licensed under CC BY 3.0. Reducing lead bioavailability in soil Childhood exposure to lead can lead to long-term adverse health effects. A significant source of lead exposure in children is contaminated soil and dust. Because of...
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Reply to Stuchlik et al.: The Younger Dryas onset at 12.87 ky B.P. is still ȷustified if the Laacher See eruption is considered [Physical Sciences] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Hai Cheng, Haiwei Zhang, Jonathan Baker, Ashish Sinha, Hanying Li, Jingyao Zhao, Xiyu Dong, Youwei Li, Xue Jia, Baoyun Zong, Yanjun Cai
We thank Stuchlík et al. for their comments (1) on our paper (2). First, for the sake of clarity, we note that Stuchlík et al. may have inadvertently stated “δ18O records in several ice cores from Greenland and Antarctica that were originally dated by the radiocarbon method.” This is obviously incorrect, as ice-core δ18O series are not radiocarbon-dated. We are also intrigued by their comment that
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Longitudinal shear stress response in human endothelial cells to atheroprone and atheroprotective conditions [Systems Biology] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Mano R. Maurya, Shakti Gupta, Julie Yi-Shuan Li, Nassim E. Ajami, Zhen B. Chen, John Y.-J. Shyy, Shu Chien, Shankar Subramaniam
The two main blood flow patterns, namely, pulsatile shear (PS) prevalent in straight segments of arteries and oscillatory shear (OS) observed at branch points, are associated with atheroprotective (healthy) and atheroprone (unhealthy) vascular phenotypes, respectively. The effects of blood flow-induced shear stress on endothelial cells (ECs) and vascular health have generally been studied using human
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Multiple domain interfaces mediate SARM1 autoinhibition [Neuroscience] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Chen Shen, Mihir Vohra, Pengfei Zhang, Xianrong Mao, Matthew D. Figley, Jian Zhu, Yo Sasaki, Hao Wu, Aaron DiAntonio, Jeffrey Milbrandt
Axon degeneration is an active program of self-destruction mediated by the protein SARM1. In healthy neurons, SARM1 is autoinhibited and, upon injury autoinhibition is relieved, activating the SARM1 enzyme to deplete NAD+ and induce axon degeneration. SARM1 forms a homomultimeric octamer with each monomer composed of an N-terminal autoinhibitory ARM domain, tandem SAM domains that mediate multimerization
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Long-range structural defects by pathogenic mutations in most severe glucose-6-phosphate dehydrogenase deficiency [Medical Sciences] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Naoki Horikoshi, Sunhee Hwang, Cornelius Gati, Tsutomu Matsui, Carlos Castillo-Orellana, Andrew G. Raub, Adriana A. Garcia, Fatemeh Jabbarpour, Alexander Batyuk, Joshua Broweleit, Xinyu Xiang, Andrew Chiang, Rachel Broweleit, Esteban Vöhringer-Martinez, Daria Mochly-Rosen, Soichi Wakatsuki
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common blood disorder, presenting multiple symptoms, including hemolytic anemia. It affects 400 million people worldwide, with more than 160 single mutations reported in G6PD. The most severe mutations (about 70) are classified as class I, leading to more than 90% loss of activity of the wild-type G6PD. The crystal structure of G6PD reveals
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Identification of the Younger Dryas onset was confused by the Laacher See volcanic eruption [Physical Sciences] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Evžen Stuchlík, Daniel Vondrák, Zuzana Hořická, Jolana Hrubá, Ana Mijovilovich, Günther Kletetschka
Cheng et al. (1) provide data on oxygen-isotope δ18O in nine speleothems of Younger Dryas (YD) age from caves situated in several continents between 42°27′ N and 21°05′ S and dated by the U-Th method. They compare this data with δ18O records in several ice cores from Greenland and Antarctica that were originally dated by the radiocarbon method. While the presented YD records of δ18O and their bowl-shaped
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A short ORF-encoded transcriptional regulator [Genetics] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Minseob Koh, Insha Ahmad, Yeonjin Ko, Yuxiang Zhang, Thomas F. Martinez, Jolene K. Diedrich, Qian Chu, James J. Moresco, Michael A. Erb, Alan Saghatelian, Peter G. Schultz, Michael J. Bollong
Recent technological advances have expanded the annotated protein coding content of mammalian genomes, as hundreds of previously unidentified, short open reading frame (ORF)-encoded peptides (SEPs) have now been found to be translated. Although several studies have identified important physiological roles for this emerging protein class, a general method to define their interactomes is lacking. Here
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PIAS1 modulates striatal transcription, DNA damage repair, and SUMOylation with relevance to Huntington’s disease [Neuroscience] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Eva L. Morozko, Charlene Smith-Geater, Alejandro Mas Monteys, Subrata Pradhan, Ryan G. Lim, Peter Langfelder, Marketta Kachemov, Austin Hill, Jennifer T. Stocksdale, Pieter R. Cullis, Jie Wu, Joseph Ochaba, Ricardo Miramontes, Anirban Chakraborty, Tapas K. Hazra, Alice Lau, Sophie St-cyr, Iliana Orellana, Lexi Kopan, Keona Q. Wang, Sylvia Yeung, Blair R. Leavitt, Jack C. Reidling, X. William Yang,
DNA damage repair genes are modifiers of disease onset in Huntington’s disease (HD), but how this process intersects with associated disease pathways remains unclear. Here we evaluated the mechanistic contributions of protein inhibitor of activated STAT-1 (PIAS1) in HD mice and HD patient-derived induced pluripotent stem cells (iPSCs) and find a link between PIAS1 and DNA damage repair pathways. We
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Results from a 2020 field experiment encouraging voting by mail [Political Sciences] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Daniel J. Hopkins, Marc Meredith, Anjali Chainani, Nathaniel Olin, Tiffany Tse
The ability to cast a mail ballot can safeguard the franchise. However, because there are often additional procedural protections to ensure that a ballot cast in person counts, voting by mail can also jeopardize people’s ability to cast a recorded vote. An experiment carried out during the COVID-19 pandemic illustrates both forces. Philadelphia officials randomly sent 46,960 Philadelphia registrants
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Impact of transnational land acquisitions on local food security and dietary diversity [Sustainability Science] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Marc F. Müller, Gopal Penny, Meredith T. Niles, Vincent Ricciardi, Davide Danilo Chiarelli, Kyle Frankel Davis, Jampel Dell’Angelo, Paolo D’Odorico, Lorenzo Rosa, Maria Cristina Rulli, Nathaniel D. Mueller
Foreign investors have acquired approximately 90 million hectares of land for agriculture over the past two decades. The effects of these investments on local food security remain unknown. While additional cropland and intensified agriculture could potentially increase crop production, preferential targeting of prime agricultural land and transitions toward export-bound crops might affect local access
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Growth hormone-releasing hormone agonists ameliorate chronic kidney disease-induced heart failure with preserved ejection fraction [Medical Sciences] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Wei Zheng, Fan Li, Zhanyu Ding, Hao Liu, Lei Zhu, Cong Xu, Jiawei Li, Qi Gao, Yanxing Wang, Zhenglin Fu, Chao Peng, Xiumin Yan, Xueliang Zhu, Yao Cong
The radial spoke (RS) heads of motile cilia and flagella contact projections of the central pair (CP) apparatus to coordinate motility, but the morphology is distinct for protozoa and metazoa. Here we show the murine RS head is compositionally distinct from that of Chlamydomonas. Our reconstituted murine RS head core complex consists of Rsph1, Rsph3b, Rsph4a, and Rsph9, lacking Rsph6a and Rsph10b,
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Live-cell epigenome manipulation by synthetic histone acetylation catalyst system [Biochemistry] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Yusuke Fujiwara, Yuki Yamanashi, Akiko Fujimura, Yuko Sato, Tomoya Kujirai, Hitoshi Kurumizaka, Hiroshi Kimura, Kenzo Yamatsugu, Shigehiro A. Kawashima, Motomu Kanai
Chemical modifications of histones, such as lysine acetylation and ubiquitination, play pivotal roles in epigenetic regulation of gene expression. Methods to alter the epigenome thus hold promise as tools for elucidating epigenetic mechanisms and as therapeutics. However, an entirely chemical method to introduce histone modifications in living cells without genetic manipulation is unprecedented. Here
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Synaptotagmin-1-, Munc18-1-, and Munc13-1-dependent liposome fusion with a few neuronal SNAREs [Biochemistry] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Karolina P. Stepien, Josep Rizo
Neurotransmitter release is governed by eight central proteins among other factors: the neuronal SNAREs syntaxin-1, synaptobrevin, and SNAP-25, which form a tight SNARE complex that brings the synaptic vesicle and plasma membranes together; NSF and SNAPs, which disassemble SNARE complexes; Munc18-1 and Munc13-1, which organize SNARE complex assembly; and the Ca2+ sensor synaptotagmin-1. Reconstitution
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Native American fire management at an ancient wildland-urban interface in the Southwest United States [Environmental Sciences] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Christopher I. Roos, Thomas W. Swetnam, T. J. Ferguson, Matthew J. Liebmann, Rachel A. Loehman, John R. Welch, Ellis Q. Margolis, Christopher H. Guiterman, William C. Hockaday, Michael J. Aiuvalasit, Jenna Battillo, Joshua Farella, Christopher A. Kiahtipes
The intersection of expanding human development and wildland landscapes—the “wildland–urban interface” or WUI—is one of the most vexing contexts for fire management because it involves complex interacting systems of people and nature. Here, we document the dynamism and stability of an ancient WUI that was apparently sustainable for more than 500 y. We combine ethnography, archaeology, paleoecology
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Bifurcation of excited state trajectories toward energy transfer or electron transfer directed by wave function symmetry [Chemistry] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Paola S. Oviedo, Luis M. Baraldo, Alejandro Cadranel
This work explores the concept that differential wave function overlap between excited states can be engineered within a molecular chromophore. The aim is to control excited state wave function symmetries, so that symmetry matches or mismatches result in differential orbital overlap and define low-energy trajectories or kinetic barriers within the excited state surface, that drive excited state population
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Structurally silent peptide anchor modifications allosterically modulate T cell recognition in a receptor-dependent manner [Immunology and Inflammation] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Angela R. Smith, Jesus A. Alonso, Cory M. Ayres, Nishant K. Singh, Lance M. Hellman, Brian M. Baker
Presentation of peptides by class I MHC proteins underlies T cell immune responses to pathogens and cancer. The association between peptide binding affinity and immunogenicity has led to the engineering of modified peptides with improved MHC binding, with the hope that these peptides would be useful for eliciting cross-reactive immune responses directed toward their weak binding, unmodified counterparts
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Multiple cannabinoid signaling cascades powerfully suppress recurrent excitation in the hippocampus [Neuroscience] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Kyle R. Jensen, Coralie Berthoux, Kaoutsar Nasrallah, Pablo E. Castillo
Recurrent excitatory neural networks are unstable. In the hippocampus, excitatory mossy cells (MCs) receive strong excitatory inputs from dentate granule cells (GCs) and project back onto the proximal dendrites of GCs. By targeting the ipsi- and contralateral dentate gyrus (DG) along the dorsoventral axis of the hippocampus, MCs form an extensive recurrent excitatory circuit (GC-MC-GC) whose dysregulation
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Discovery of a hidden transient state in all bromodomain families [Biophysics and Computational Biology] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Lluís Raich, Katharina Meier, Judith Günther, Clara D. Christ, Frank Noé, Simon Olsson
Bromodomains (BDs) are small protein modules that interact with acetylated marks in histones. These posttranslational modifications are pivotal to regulate gene expression, making BDs promising targets to treat several diseases. While the general structure of BDs is well known, their dynamical features and their interplay with other macromolecules are poorly understood, hampering the rational design
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Moireless correlations in ABCA graphene [Applied Physical Sciences] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Alexander Kerelsky, Carmen Rubio-Verdú, Lede Xian, Dante M. Kennes, Dorri Halbertal, Nathan Finney, Larry Song, Simon Turkel, Lei Wang, Kenji Watanabe, Takashi Taniguchi, James Hone, Cory Dean, Dmitri N. Basov, Angel Rubio, Abhay N. Pasupathy
Atomically thin van der Waals materials stacked with an interlayer twist have proven to be an excellent platform toward achieving gate-tunable correlated phenomena linked to the formation of flat electronic bands. In this work we demonstrate the formation of emergent correlated phases in multilayer rhombohedral graphene––a simple material that also exhibits a flat electronic band edge but without the
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Discrete TrkB-expressing neurons of the dorsomedial hypothalamus regulate feeding and thermogenesis [Neuroscience] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Jessica Houtz, Guey-Ying Liao, Juan Ji An, Baoji Xu
Mutations in the TrkB neurotrophin receptor lead to profound obesity in humans, and expression of TrkB in the dorsomedial hypothalamus (DMH) is critical for maintaining energy homeostasis. However, the functional implications of TrkB-fexpressing neurons in the DMH (DMHTrkB) on energy expenditure are unclear. Additionally, the neurocircuitry underlying the effect of DMHTrkB neurons on energy homeostasis
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Experienced well-being rises with income, even above $75,000 per year [Psychological and Cognitive Sciences] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Matthew A. Killingsworth
What is the relationship between money and well-being? Research distinguishes between two forms of well-being: people’s feelings during the moments of life (experienced well-being) and people’s evaluation of their lives when they pause and reflect (evaluative well-being). Drawing on 1,725,994 experience-sampling reports from 33,391 employed US adults, the present results show that both experienced
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DNA origami demonstrate the unique stimulatory power of single pMHCs as T cell antigens [Biophysics and Computational Biology] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Joschka Hellmeier, Rene Platzer, Alexandra S. Eklund, Thomas Schlichthaerle, Andreas Karner, Viktoria Motsch, Magdalena C. Schneider, Elke Kurz, Victor Bamieh, Mario Brameshuber, Johannes Preiner, Ralf Jungmann, Hannes Stockinger, Gerhard J. Schütz, Johannes B. Huppa, Eva Sevcsik
T cells detect with their T cell antigen receptors (TCRs) the presence of rare agonist peptide/MHC complexes (pMHCs) on the surface of antigen-presenting cells (APCs). How extracellular ligand binding triggers intracellular signaling is poorly understood, yet spatial antigen arrangement on the APC surface has been suggested to be a critical factor. To examine this, we engineered a biomimetic interface
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Accumulation of styrene oligomers alters lipid membrane phase order and miscibility [Biophysics and Computational Biology] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Mattia I. Morandi, Monika Kluzek, Jean Wolff, André Schroder, Fabrice Thalmann, Carlos M. Marques
Growth of plastic waste in the natural environment, and in particular in the oceans, has raised the accumulation of polystyrene and other polymeric species in eukyarotic cells to the level of a credible and systemic threat. Oligomers, the smallest products of polymer degradation or incomplete polymerization reactions, are the first species to leach out of macroscopic or nanoscopic plastic materials
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Surface boulder banding indicates Martian debris-covered glaciers formed over multiple glaciations [Earth, Atmospheric, and Planetary Sciences] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Joseph S. Levy, Caleb I. Fassett, John W. Holt, Reid Parsons, Will Cipolli, Timothy A. Goudge, Michelle Tebolt, Lily Kuentz, Jessica Johnson, Fairuz Ishraque, Bronson Cvijanovich, Ian Armstrong
Glacial landforms, including lobate debris aprons, are a global water ice reservoir on Mars preserving ice from past periods when high orbital obliquity permitted nonpolar ice accumulation. Numerous studies have noted morphological similarities between lobate debris aprons and terrestrial debris-covered glaciers, an interpretation supported by radar observations. On Earth and Mars, these landforms
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Structure and assembly of the diiron cofactor in the heme-oxygenase-like domain of the N-nitrosourea-producing enzyme SznF [Biophysics and Computational Biology] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Molly J. McBride, Sarah R. Pope, Kai Hu, C. Denise Okafor, Emily P. Balskus, J. Martin Bollinger, Amie K. Boal
In biosynthesis of the pancreatic cancer drug streptozotocin, the tridomain nonheme-iron oxygenase SznF hydroxylates Nδ and Nω′ of Nω-methyl-l-arginine before oxidatively rearranging the triply modified guanidine to the N-methyl-N-nitrosourea pharmacophore. A previously published structure visualized the monoiron cofactor in the enzyme’s C-terminal cupin domain, which promotes the final rearrangement
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Quantum phases of Rydberg atoms on a kagome lattice [Physics] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Rhine Samajdar, Wen Wei Ho, Hannes Pichler, Mikhail D. Lukin, Subir Sachdev
We analyze the zero-temperature phases of an array of neutral atoms on the kagome lattice, interacting via laser excitation to atomic Rydberg states. Density-matrix renormalization group calculations reveal the presence of a wide variety of complex solid phases with broken lattice symmetries. In addition, we identify a regime with dense Rydberg excitations that has a large entanglement entropy and
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The Tiger Rattlesnake genome reveals a complex genotype underlying a simple venom phenotype [Evolution] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Mark J. Margres, Rhett M. Rautsaw, Jason L. Strickland, Andrew J. Mason, Tristan D. Schramer, Erich P. Hofmann, Erin Stiers, Schyler A. Ellsworth, Gunnar S. Nystrom, Michael P. Hogan, Daniel A. Bartlett, Timothy J. Colston, David M. Gilbert, Darin R. Rokyta, Christopher L. Parkinson
Variation in gene regulation is ubiquitous, yet identifying the mechanisms producing such variation, especially for complex traits, is challenging. Snake venoms provide a model system for studying the phenotypic impacts of regulatory variation in complex traits because of their genetic tractability. Here, we sequence the genome of the Tiger Rattlesnake, which possesses the simplest and most toxic venom
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Acceleration of catalysis in dihydrofolate reductase by transient, site-specific photothermal excitation [Chemistry] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Rachel Kozlowski, Jing Zhao, R. Brian Dyer
We have studied the role of protein dynamics in chemical catalysis in the enzyme dihydrofolate reductase (DHFR), using a pump–probe method that employs pulsed-laser photothermal heating of a gold nanoparticle (AuNP) to directly excite a local region of the protein structure and transient absorbance to probe the effect on enzyme activity. Enzyme activity is accelerated by pulsed-laser excitation when
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Autoinhibitory elements of the Chd1 remodeler block initiation of twist defects by destabilizing the ATPase motor on the nucleosome [Biochemistry] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Ilana M. Nodelman, Zhongtian Shen, Robert F. Levendosky, Gregory D. Bowman
Chromatin remodelers are ATP (adenosine triphosphate)-powered motors that reposition nucleosomes throughout eukaryotic chromosomes. Remodelers possess autoinhibitory elements that control the direction of nucleosome sliding, but underlying mechanisms of inhibition have been unclear. Here, we show that autoinhibitory elements of the yeast Chd1 remodeler block nucleosome sliding by preventing initiation
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Photopatterned biomolecule immobilization to guide three-dimensional cell fate in natural protein-based hydrogels [Applied Biological Sciences] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Ivan Batalov, Kelly R. Stevens, Cole A. DeForest
Hydrogel biomaterials derived from natural biopolymers (e.g., fibrin, collagen, decellularized extracellular matrix) are regularly utilized in three-dimensional (3D) cell culture and tissue engineering. In contrast to those based on synthetic polymers, natural materials permit enhanced cytocompatibility, matrix remodeling, and biological integration. Despite these advantages, natural protein-based
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Synthetic protein conjugate vaccines provide protection against Mycobacterium tuberculosis in mice [Immunology and Inflammation] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Cameron C. Hanna, Anneliese S. Ashhurst, Diana Quan, Joshua W. C. Maxwell, Warwick J. Britton, Richard J. Payne
The global incidence of tuberculosis remains unacceptably high, with new preventative strategies needed to reduce the burden of disease. We describe here a method for the generation of synthetic self-adjuvanted protein vaccines and demonstrate application in vaccination against Mycobacterium tuberculosis. Two vaccine constructs were designed, consisting of full-length ESAT6 protein fused to the TLR2-targeting
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Environment-based object values learned by local network in the striatum tail [Neuroscience] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Jun Kunimatsu, Shinya Yamamoto, Kazutaka Maeda, Okihide Hikosaka
Basal ganglia contribute to object-value learning, which is critical for survival. The underlying neuronal mechanism is the association of each object with its rewarding outcome. However, object values may change in different environments and we then need to choose different objects accordingly. The mechanism of this environment-based value learning is unknown. To address this question, we created
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Pathogenic role of delta 2 tubulin in bortezomib-induced peripheral neuropathy [Neuroscience] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Maria Elena Pero, Cristina Meregalli, Xiaoyi Qu, Grace Ji-eun Shin, Atul Kumar, Matthew Shorey, Melissa M. Rolls, Kurenai Tanji, Thomas H. Brannagan, Paola Alberti, Giulia Fumagalli, Laura Monza, Wesley B. Grueber, Guido Cavaletti, Francesca Bartolini
The pathogenesis of chemotherapy-induced peripheral neuropathy (CIPN) is poorly understood. Here, we report that the CIPN-causing drug bortezomib (Bort) promotes delta 2 tubulin (D2) accumulation while affecting microtubule stability and dynamics in sensory neurons in vitro and in vivo and that the accumulation of D2 is predominant in unmyelinated fibers and a hallmark of bortezomib-induced peripheral
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Distinct electrophysiological signatures of task-unrelated and dynamic thoughts [Psychological and Cognitive Sciences] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Julia W. Y. Kam, Zachary C. Irving, Caitlin Mills, Shawn Patel, Alison Gopnik, Robert T. Knight
Humans spend much of their lives engaging with their internal train of thoughts. Traditionally, research focused on whether or not these thoughts are related to ongoing tasks, and has identified reliable and distinct behavioral and neural correlates of task-unrelated and task-related thought. A recent theoretical framework highlighted a different aspect of thinking—how it dynamically moves between
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Evolution and demise of passive margins through grain mixing and damage [Earth, Atmospheric, and Planetary Sciences] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 David Bercovici, Elvira Mulyukova
How subduction—the sinking of cold lithospheric plates into the mantle—is initiated is one of the key mysteries in understanding why Earth has plate tectonics. One of the favored locations for subduction triggering is at passive margins, where sea floor abuts continental margins. Such passive margin collapse is problematic because the strength of the old, cold ocean lithosphere should prohibit it from
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Self-inhibition effect of metal incorporation in nanoscaled semiconductors [Chemistry] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Bin Zhu, Ding Yi, Yuxi Wang, Hongyu Sun, Gang Sha, Gong Zheng, Erik C. Garnett, Bozhi Tian, Feng Ding, Jia Zhu
There has been a persistent effort to understand and control the incorporation of metal impurities in semiconductors at nanoscale, as it is important for semiconductor processing from growth, doping to making contact. Previously, the injection of metal atoms into nanoscaled semiconductor, with concentrations orders of magnitude higher than the equilibrium solid solubility, has been reported, which
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Positive epistasis between disease-causing missense mutations and silent polymorphism with effect on mRNA translation velocity [Biophysics and Computational Biology] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Robert Rauscher, Giovana B. Bampi, Marta Guevara-Ferrer, Leonardo A. Santos, Disha Joshi, David Mark, Lisa J. Strug, Johanna M. Rommens, Manfred Ballmann, Eric J. Sorscher, Kathryn E. Oliver, Zoya Ignatova
Epistasis refers to the dependence of a mutation on other mutation(s) and the genetic context in general. In the context of human disorders, epistasis complicates the spectrum of disease symptoms and has been proposed as a major contributor to variations in disease outcome. The nonadditive relationship between mutations and the lack of complete understanding of the underlying physiological effects
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The joint dynamics of investor beliefs and trading during the COVID-19 crash [Economic Sciences] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Stefano Giglio, Matteo Maggiori, Johannes Stroebel, Stephen Utkus
We analyze how investor expectations about economic growth and stock returns changed during the February−March 2020 stock market crash induced by the COVID-19 pandemic, as well as during the subsequent partial stock market recovery. We surveyed retail investors who are clients of Vanguard at three points in time: 1) on February 11–12, around the all-time stock market high, 2) on March 11–12, after
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Pervasive cropland in protected areas highlight trade-offs between conservation and food security [Sustainability Science] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Varsha Vijay, Paul R. Armsworth
Global cropland expansion over the last century caused widespread habitat loss and degradation. Establishment of protected areas aims to counteract the loss of habitats and to slow species extinctions. However, many protected areas also include high levels of habitat disturbance and conversion for uses such as cropland. Understanding where and why this occurs may realign conservation priorities and
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IMITATION SWITCH is required for normal chromatin structure and gene repression in PRC2 target domains [Genetics] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Masayuki Kamei, Abigail J. Ameri, Aileen R. Ferraro, Yael Bar-Peled, Fangzhou Zhao, Christina L. Ethridge, Kathleen Lail, Mojgan Amirebrahimi, Anna Lipzen, Vivian Ng, Igor V. Grigoriev, Robert J. Schmitz, Yi Liu, Zachary A. Lewis
Polycomb Group (PcG) proteins are part of an epigenetic cell memory system that plays essential roles in multicellular development, stem cell biology, X chromosome inactivation, and cancer. In animals, plants, and many fungi, Polycomb Repressive Complex 2 (PRC2) catalyzes trimethylation of histone H3 lysine 27 (H3K27me3) to assemble transcriptionally repressed facultative heterochromatin. PRC2 is structurally
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Mdm2 phosphorylation by Akt regulates the p53 response to oxidative stress to promote cell proliferation and tumorigenesis [Cell Biology] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-26 Loretah Chibaya, Baktiar Karim, Hong Zhang, Stephen N. Jones
We have shown previously that phosphorylation of Mdm2 by ATM and c-Abl regulates Mdm2-p53 signaling and alters the effects of DNA damage in mice, including bone marrow failure and tumorigenesis induced by ionizing radiation. Here, we examine the physiological effects of Mdm2 phosphorylation by Akt, another DNA damage effector kinase. Surprisingly, Akt phosphorylation of Mdm2 does not alter the p53-mediated
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Symmetrical arrangement of proteins under release-ready vesicles in presynaptic terminals [Neuroscience] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-02-02 Abhijith Radhakrishnan, Xia Li, Kirill Grushin, Shyam S. Krishnakumar, Jun Liu, James E. Rothman
Controlled release of neurotransmitters stored in synaptic vesicles (SVs) is a fundamental process that is central to all information processing in the brain. This relies on tight coupling of the SV fusion to action potential-evoked presynaptic Ca2+ influx. This Ca2+-evoked release occurs from a readily releasable pool (RRP) of SVs docked to the plasma membrane (PM). The protein components involved
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Wireless, soft electronics for rapid, multisensor measurements of hydration levels in healthy and diseased skin [Engineering] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-02-02 Kyeongha Kwon, Heling Wang, Jaeman Lim, Keum San Chun, Hokyung Jang, Injae Yoo, Derek Wu, Alyssa Jie Chen, Carol Ge Gu, Lindsay Lipschultz, Jong Uk Kim, Jihye Kim, Hyoyoung Jeong, Haiwen Luan, Yoonseok Park, Chun-Ju Su, Yui Ishida, Surabhi R. Madhvapathy, Akihiko Ikoma, Jean Won Kwak, Da Som Yang, Anthony Banks, Shuai Xu, Yonggang Huang, Jan-Kai Chang, John A. Rogers
Precise, quantitative measurements of the hydration status of skin can yield important insights into dermatological health and skin structure and function, with additional relevance to essential processes of thermoregulation and other features of basic physiology. Existing tools for determining skin water content exploit surrogate electrical assessments performed with bulky, rigid, and expensive instruments
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Nonlinear elasticity and damping govern ultrafast dynamics in click beetles [Applied Physical Sciences] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-02-02 Ophelia Bolmin, John J. Socha, Marianne Alleyne, Alison C. Dunn, Kamel Fezzaa, Aimy A. Wissa
Many small animals use springs and latches to overcome the mechanical power output limitations of their muscles. Click beetles use springs and latches to bend their bodies at the thoracic hinge and then unbend extremely quickly, resulting in a clicking motion. When unconstrained, this quick clicking motion results in a jump. While the jumping motion has been studied in depth, the physical mechanisms
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Self-organized biotectonics of termite nests [Biophysics and Computational Biology] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-02-02 Alexander Heyde, Lijie Guo, Christian Jost, Guy Theraulaz, L. Mahadevan
The termite nest is one of the architectural wonders of the living world, built by the collective action of workers in a colony. Each nest has several characteristic structural motifs that allow for efficient ventilation, cooling, and traversal. We use tomography to quantify the nest architecture of the African termite Apicotermes lamani, consisting of regularly spaced floors connected by scattered
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Using data-driven approaches to improve delivery of animal health care interventions for public health [Sustainability Science] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-02-02 Stella Mazeri, Jordana L. Burdon Bailey, Dagmar Mayer, Patrick Chikungwa, Julius Chulu, Paul Orion Grossman, Frederic Lohr, Andrew D. Gibson, Ian G. Handel, Barend M. deC. Bronsvoort, Luke Gamble, Richard J. Mellanby
Rabies kills ∼60,000 people per year. Annual vaccination of at least 70% of dogs has been shown to eliminate rabies in both human and canine populations. However, delivery of large-scale mass dog vaccination campaigns remains a challenge in many rabies-endemic countries. In sub-Saharan Africa, where the vast majority of dogs are owned, mass vaccination campaigns have typically depended on a combination
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The natural axis of transmitter receptor distribution in the human cerebral cortex [Neuroscience] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-19 Alexandros Goulas, Jean-Pierre Changeux, Konrad Wagstyl, Katrin Amunts, Nicola Palomero-Gallagher, Claus C. Hilgetag
Transmitter receptors constitute a key component of the molecular machinery for intercellular communication in the brain. Recent efforts have mapped the density of diverse transmitter receptors across the human cerebral cortex with an unprecedented level of detail. Here, we distill these observations into key organizational principles. We demonstrate that receptor densities form a natural axis in the
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Thermodynamics of interfaces extended to nanoscales by introducing integral and differential surface tensions [Chemistry] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-19 W. Dong
As a system shrinks down in size, more and more molecules are found in its surface region, so surface contribution becomes a large or even a dominant part of its thermodynamic potentials. Surface tension is a venerable scientific concept; Gibbs defined it as the excess of grand potential of an inhomogeneous system with respect to its bulk value per interface area [J. W. Gibbs, “The Collected Works”
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Astrocytic cAMP modulates memory via synaptic plasticity [Neuroscience] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-19 Zhiwen Zhou, Kazuki Okamoto, Junya Onodera, Toshimitsu Hiragi, Megumi Andoh, Masahito Ikawa, Kenji F. Tanaka, Yuji Ikegaya, Ryuta Koyama
Astrocytes play a key role in brain homeostasis and functions such as memory. Specifically, astrocytes express multiple receptors that transduce signals via the second messenger cAMP. However, the involvement of astrocytic cAMP in animal behavior and the underlying glial–neuronal interactions remains largely unknown. Here, we show that an increase in astrocytic cAMP is sufficient to induce synaptic
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Systematic analysis of differential rhythmic liver gene expression mediated by the circadian clock and feeding rhythms [Systems Biology] Proc. Natl. Acad. Sci. U.S.A. (IF 9.412) Pub Date : 2021-01-19 Benjamin D. Weger, Cédric Gobet, Fabrice P. A. David, Florian Atger, Eva Martin, Nicholas E. Phillips, Aline Charpagne, Meltem Weger, Felix Naef, Frédéric Gachon
The circadian clock and feeding rhythms are both important regulators of rhythmic gene expression in the liver. To further dissect the respective contributions of feeding and the clock, we analyzed differential rhythmicity of liver tissue samples across several conditions. We developed a statistical method tailored to compare rhythmic liver messenger RNA (mRNA) expression in mouse knockout models of