Extensive mitochondrial diversity within a single Amerindian tribe.

abstract：:Asexual freshwater planarians reproduce by tearing themselves into two pieces by a process called binary fission. The resulting head and tail pieces regenerate within about a week, forming two new worms. Understanding this process of ripping oneself into two parts poses a challenging biomechanical problem. Because pla...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Malinowski PT,Cochet-Escartin O,Kaj KJ,Ronan E,Groisman A,Diamond PH,Collins ES

更新日期：2017-10-10 00:00:00

abstract：:Interspersed repeated sequences (Alu and Kpn) were used as probes to detect a set of Not I restriction fragments of human chromosome 21 from the hybrid cell line WAV17. Forty different Not I fragments, ranging in size from less than 0.05 megabase (Mb) to 7.0 Mb, were identified. The total length of these fragments was...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Sainz J,Pevny L,Wu Y,Cantor CR,Smith CL

更新日期：1992-02-01 00:00:00

abstract：:The cytoplasmic Myc protein (c-Myc) regulates various human genes and is dysregulated in many human cancers. Phosphorylation mediates the protein activation of c-Myc and is essential for the function of this transcription factor in normal cell behavior and tumor growth. To date, however, the targeting of Myc as a ther...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Fan-Minogue H,Cao Z,Paulmurugan R,Chan CT,Massoud TF,Felsher DW,Gambhir SS

更新日期：2010-09-07 00:00:00

abstract：:Genomes exhibit diverse patterns of species-specific GC content, GC and AT skews, codon bias, and mutation bias. Despite intensive investigations and the rapid accumulation of sequence data, the causes of these a priori different genome biases have not been agreed on and seem multifactorial and idiosyncratic. We show ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Vetsigian K,Goldenfeld N

更新日期：2009-01-06 00:00:00

abstract：:Many groups of insects are specialists in exploiting sensory cues to locate food resources or conspecifics. To achieve orientation, bees and ants analyze the polarization pattern of the sky, male moths orient along the females' odor plume, and cicadas, grasshoppers, and crickets use acoustic signals to locate singing ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Poulet JF,Hedwig B

更新日期：2005-10-25 00:00:00

abstract：:Mannan-binding protein (MBP), a Ca2+-dependent mammalian lectin specific for mannose and N-acetylglucosamine, is an important serum component associated with innate immunity. MBP activates complement and functions as a direct opsonin on binding to mannooligosaccharide-bearing pathogens. We have found that MBP recogniz...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ma Y,Uemura K,Oka S,Kozutsumi Y,Kawasaki N,Kawasaki T

更新日期：1999-01-19 00:00:00

abstract：:The assembly and composition of human excision nuclease were investigated by electrophoretic mobility shift assay and DNase I footprinting. Individual repair factors or any combination of up to four repair factors failed to form DNA-protein complexes of high specificity and stability. A stable complex of high specific...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Wakasugi M,Sancar A

更新日期：1998-06-09 00:00:00

abstract：:Helminthosporoside is a host-specific toxin produced by Helminthosporium sacchari, both in culture and in infected sugarcane tissue. The susceptibility of any given clone of sugarcane to disease is invariably associated with the presence of a toxin-binding protein. This report presents evidence for the presence of the...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Strobel GA,Hess WM

更新日期：1974-04-01 00:00:00

abstract：:IL-33, a cytokine of the IL-1 family, is closely associated with type II T cell responses. Here, we report an unexpected proinflammatory role of IL-33 in inflammatory arthritis. IL-33 was expressed in synovial fibroblasts from patients with rheumatoid arthritis (RA). Expression was markedly elevated in vitro by inflam...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Xu D,Jiang HR,Kewin P,Li Y,Mu R,Fraser AR,Pitman N,Kurowska-Stolarska M,McKenzie AN,McInnes IB,Liew FY

更新日期：2008-08-05 00:00:00

abstract：:Alfalfa mosaic virus (AlMV) coat protein is involved in systemic infection of host plants, and a specific mutation in this gene prevents the virus from moving into the upper uninoculated leaves. The coat protein also is required for different viral functions during early and late infection. To study the role of the co...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Spitsin S,Steplewski K,Fleysh N,Belanger H,Mikheeva T,Shivprasad S,Dawson W,Koprowski H,Yusibov V

更新日期：1999-03-02 00:00:00

abstract：:Helicases are molecular motor enzymes that unwind and translocate nucleic acids. One of the central questions regarding helicase activity is whether the process of coupling ATP hydrolysis to DNA unwinding requires an oligomeric form of the enzyme. We have applied a pre-steady-state kinetics approach to address this qu...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Nanduri B,Byrd AK,Eoff RL,Tackett AJ,Raney KD

更新日期：2002-11-12 00:00:00

abstract：:Cultured skin fibroblasts from patients with Menkes disease, an X-linked disorder involving a defect in copper metabolism, were analyzed for copper concentration by means of atomic absorption spectrophotometry. These cultures consistently exhibited elevated copper concentrations (mean = 335.5 ng of copper per mg of pr...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Goka TJ,Stevenson RE,Hefferan PM,Howell RR

更新日期：1976-02-01 00:00:00

abstract：:In a subclone derived from mouse L(tk-) cells, we found a plasmid present in a high copy number (greater than 5000 copies per cell) that was stably maintained extrachromosomally without any cytopathic effect to the host cells. This plasmid, termed L factor, has two forms: 5.3 and 5.5 kilobase pairs. DNA sequencing and...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kusano T,Uehara H,Saito H,Segawa K,Oishi M

更新日期：1987-04-01 00:00:00

abstract：:Brain function depends on adaptive self-organization of large-scale neural assemblies, but little is known about quantitative network parameters governing these processes in humans. Here, we describe the topology and synchronizability of frequency-specific brain functional networks using wavelet decomposition of magne...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Bassett DS,Meyer-Lindenberg A,Achard S,Duke T,Bullmore E

更新日期：2006-12-19 00:00:00

abstract：:From the types of ring chromosomes induced in x-irradiated Chinese hamster ovary (CHO) cells, we deduce the existence of switches in the polarity of chromosomal DNA; if there is a continuous DNA double helix along the full length of the chromosome then the polarity switches imply 3'-3' and 5'-5' phosphodiester linkage...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Wolff S,Lindsley DL,Peacock WJ

更新日期：1976-03-01 00:00:00

abstract：:The development of seeds in flowering plants is placed under complex interactions between maternal tissues, the embryo, and the endosperm. The endosperm plays a major role in the regulation of seed size. In Arabidopsis thaliana, endosperm size depends on the coordination of the genetic pathway HAIKU (IKU) with epigene...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Li J,Nie X,Tan JL,Berger F

更新日期：2013-09-17 00:00:00

abstract：:Many materials phenomena are governed by the interaction between chemistry and mechanics. However, it was only in the second half of the 20th century that the theory of open system elasticity by Francis Larché and John W. Cahn concatenated the fields of solid mechanics and alloy chemistry. As the theory's central mate...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Shi S,Markmann J,Weissmüller J

更新日期：2018-10-23 00:00:00

abstract：:Aire induces ectopic expression of peripheral tissue antigens (PTAs) in thymic medullary epithelial cells, which promotes immunological tolerance. Beginning with a broad screen of histone peptides, we demonstrate that the mechanism by which this single factor controls the transcription of thousands of genes involves r...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Koh AS,Kuo AJ,Park SY,Cheung P,Abramson J,Bua D,Carney D,Shoelson SE,Gozani O,Kingston RE,Benoist C,Mathis D

更新日期：2008-10-14 00:00:00

abstract：:Protein homeostasis is critically important for cell viability. Key to this process is the refolding of misfolded or aggregated proteins by molecular chaperones or, alternatively, their degradation by proteases. In most prokaryotes and in chloroplasts and mitochondria, protein degradation is performed by the caseinoly...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Vahidi S,Ripstein ZA,Bonomi M,Yuwen T,Mabanglo MF,Juravsky JB,Rizzolo K,Velyvis A,Houry WA,Vendruscolo M,Rubinstein JL,Kay LE

更新日期：2018-07-10 00:00:00

abstract：:Bacterial mutants have been isolated, called groN, that block phage development by interference with the action of the product of the phage N gene. lambdatrp phages, which depend on the N product for the synthesis of tryptophan enzymes, do not make these enzymes in groN bacteria. Two type of phage mutants have been is...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Georgopoulos CP

更新日期：1971-12-01 00:00:00

abstract：:Two issues long debated among Pacific and American prehistorians are (i) whether there was a pre-Columbian introduction of chicken (Gallus gallus) to the Americas and (ii) whether Polynesian contact with South America might be identified archaeologically, through the recovery of remains of unquestionable Polynesian or...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Storey AA,Ramírez JM,Quiroz D,Burley DV,Addison DJ,Walter R,Anderson AJ,Hunt TL,Athens JS,Huynen L,Matisoo-Smith EA

更新日期：2007-06-19 00:00:00

abstract：:Genes encoding thymidylate synthetase from Bacillus subtilis bacteriophages were cloned in Escherichia coli. Chimeric plasmids pCD1 and pCD3 were constructed from site-specific endonuclease digests of bacteriophage phi3T DNA cloned in pMB9 in E. coli. Similar cloning techniques with bacteriophage beta22 DNA yielded ch...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Duncan CH,Wilson GA,Young FE

更新日期：1978-08-01 00:00:00

abstract：:Archaea of the phylum Thaumarchaeota are among the most abundant prokaryotes on Earth and are widely distributed in marine, terrestrial, and geothermal environments. All studied Thaumarchaeota couple the oxidation of ammonia at extremely low concentrations with carbon fixation. As the predominant nitrifiers in the oce...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Könneke M,Schubert DM,Brown PC,Hügler M,Standfest S,Schwander T,Schada von Borzyskowski L,Erb TJ,Stahl DA,Berg IA

更新日期：2014-06-03 00:00:00

abstract：:A fundamental property of ecosystems is a tradeoff between the number and size of habitats: as the number of habitats within a fixed area increases, the average area per habitat must decrease. This tradeoff is termed the "area-heterogeneity tradeoff." Theoretical models suggest that the reduction in habitat sizes unde...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ben-Hur E,Kadmon R

更新日期：2020-03-03 00:00:00

abstract：:Absorbance changes of C-550 and cytochrome b(559), and fluorescence-yield changes were measured during irradiation of chloroplasts at -196 degrees . The photo-reduction of C-550 proceeded more rapidly than the photo-oxidation of cytochrome b(559), and the fluorescence-yield change had similar kinetics to the cytochrom...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Butler WL

更新日期：1972-11-01 00:00:00

abstract：:A single animal group can display different types of collective motion at different times. For a one-dimensional individual-based model of self-organizing group formation, we show that repeated switching between distinct ordered collective states can occur entirely because of stochastic effects. We introduce a framewo...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kolpas A,Moehlis J,Kevrekidis IG

更新日期：2007-04-03 00:00:00

abstract：:Previous studies have shown that the immunosuppressive and carcinogenic polycyclic aromatic hydrocarbon 7,12-dimethylbenz(a)anthracene (DMBA) impairs Ca(2+)-dependent transmembrane signaling in human and murine lymphocytes. The purpose of the present studies was to analyze potential mechanisms of immunosuppression by ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Archuleta MM,Schieven GL,Ledbetter JA,Deanin GG,Burchiel SW

更新日期：1993-07-01 00:00:00

abstract：:Chronic fatigue immune dysfunction syndrome (CFIDS) is a recently recognized illness characterized by debilitating fatigue as well as immunological and neurological abnormalities [Straus, S.E. (1988) J. Inf. Dis. 157, 405-412]. Once thought to be caused by Epstein-Barr virus, it is now thought to have a different but ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： DeFreitas E,Hilliard B,Cheney PR,Bell DS,Kiggundu E,Sankey D,Wroblewska Z,Palladino M,Woodward JP,Koprowski H

更新日期：1991-04-01 00:00:00

abstract：:The coding sequence for Anabaena 7120 glutamine synthetase [L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.1] are shown to be contained within a 7.5-kilobase-pair (kbp) HindIII fragment that has been cloned by plaque hybridization. The hybridization probe for the cyanobacterial gene was a recombinant plasmid conta...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Fisher R,Tuli R,Haselkorn R

更新日期：1981-06-01 00:00:00

abstract：:Ab initio multi-reference second-order perturbation theory computations are used to explore the photochemical behavior of two ion pairs constituted by a chloride counterion interacting with either a rhodopsin or bacteriorhodopsin chromophore model (i.e., the 4-cis-gamma-methylnona-2,4,6,8-tetraeniminium and all-trans-...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Cembran A,Bernardi F,Olivucci M,Garavelli M

更新日期：2005-05-03 00:00:00