Ultraconserved words point to deep language ancestry across Eurasia.

abstract：:The underlying causes of late-Holocene climate variability in the tropics are incompletely understood. Here we report a 1,500-year reconstruction of climate history and glaciation in the Venezuelan Andes using lake sediments. Four glacial advances occurred between anno Domini (A.D.) 1250 and 1810, coincident with sola...

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

authors： Polissar PJ,Abbott MB,Wolfe AP,Bezada M,Rull V,Bradley RS

更新日期：2006-06-13 00:00:00

abstract：:A general model is proposed for genetic recombination. Its essential new feature is the hypothesis that recombination is initiated by a single-strand (or asymmetric) transfer, which may, after isomerization, become a two-strand (or symmetric) exchange. The likelihood of this transition from asymmetric to symmetric str...

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

authors： Meselson MS,Radding CM

更新日期：1975-01-01 00:00:00

abstract：:Immunoglobulin heavy-chain variable region (TH) gene segments located closest to the joining (JH) gene segments are preferentially rearranged during ontogeny, indicating that chromosomal position influences the frequency of rearrangement. In addition, certain VH gene segments are repeatedly rearranged, suggesting that...

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

authors： Lawler AM,Kearney JF,Kuehl M,Gearhart PJ

更新日期：1989-09-01 00:00:00

abstract：:The Etruscans, the only preclassical European population that has been genetically characterized so far, share only two haplotypes with their modern geographic counterparts, the Tuscans, who, nonetheless, appear to be their closest relatives. We modeled 10 demographic scenarios spanning the last 2,500 years and tested...

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

authors： Belle EM,Ramakrishnan U,Mountain JL,Barbujani G

更新日期：2006-05-23 00:00:00

abstract：:Previous studies have shown that the helical RecA nucleoprotein filament formed on a circular single strand of DNA causes the progressive, directional transfer of a complementary strand from naked linear duplex DNA to the nucleoprotein filament, even when the duplex contains a sizable heterologous insertion. Since Rec...

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

authors： Jwang B,Radding CM

更新日期：1992-08-15 00:00:00

abstract：:The chief impediment to the precise biochemical identification of transfer factor and its mechanism of action has been the lack of a reproducible in vitro assay. We now report on a method by which dialysates containing transfer factor of proven in vivo potency can convert nonimmune lymphocytes to immune responsiveness...

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

authors： Ascher MS,Schneider WJ,Valentine FT,Lawrence HS

更新日期：1974-04-01 00:00:00

abstract：:In Salmonella typhimurium, the CobU, CobS, CobT, and CobC proteins have been proposed to catalyze the late steps in adenosylcobalamin biosynthesis, which define the nucleotide loop assembly pathway. This paper reports the in vitro assembly of the nucleotide loop of adenosylcobalamin from its precursors adenosylcobinam...

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

authors： Maggio-Hall LA,Escalante-Semerena JC

更新日期：1999-10-12 00:00:00

abstract：:A promoterless trp-lac fusion fragment was inserted near one end of the bacterial transposon Tn5 in the correct orientation to fuse lacZ gene expression to promoters outside Tn5. The resulting transposon, Tn5 lac, retains the kanamycin-resistance gene of Tn5 and transposes in Escherichia coli at 6% the frequency of Tn...

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

authors： Kroos L,Kaiser D

更新日期：1984-09-01 00:00:00

abstract：:Conventional asymmetric PCR is inefficient and difficult to optimize because limiting the concentration of one primer lowers its melting temperature below the reaction annealing temperature. Linear-After-The-Exponential (LATE)-PCR describes a new paradigm for primer design that renders assays as efficient as symmetric...

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

authors： Sanchez JA,Pierce KE,Rice JE,Wangh LJ

更新日期：2004-02-17 00:00:00

abstract：:Understanding the approach to faulting in continental rocks is critical for identifying processes leading to fracturing in geomaterials and the preparation process of large earthquakes. In situ dynamic X-ray imaging and digital volume correlation analysis of a crystalline rock core, under a constant confining pressure...

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

authors： Renard F,McBeck J,Kandula N,Cordonnier B,Meakin P,Ben-Zion Y

更新日期：2019-08-13 00:00:00

abstract：:Delta 5-3-Ketosteroid isomerase (EC 5.3.3.1) promotes an allylic rearrangement involving intramolecular proton transfer via a dienolic intermediate. This enzyme enhances the catalytic rate by a factor of 10(10). Two residues, Tyr-14, the general acid that polarizes the steroid 3-carbonyl group and facilitates enolizat...

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

authors： Zhao Q,Abeygunawardana C,Talalay P,Mildvan AS

更新日期：1996-08-06 00:00:00

abstract：:Thrombospondin, a 450-kDa multinodular glycoprotein with lectin-type activity, is found in human platelets, endothelial cells, fibroblasts, smooth muscle cells, monocytes, and granular pneumocytes. Thrombospondin interacts with heparin, fibrinogen, fibronectin, collagen, histidine-rich glycoprotein, and plasminogen. R...

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

authors： Asch AS,Leung LL,Shapiro J,Nachman RL

更新日期：1986-05-01 00:00:00

abstract：:In response to vascular injury, vascular smooth muscle cells (VSMCs) may switch from a contractile to a proliferative phenotype thereby contributing to neointima formation. Previous studies showed that the long noncoding RNA (lncRNA) NEAT1 is critical for paraspeckle formation and tumorigenesis by promoting cell proli...

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

authors： Ahmed ASI,Dong K,Liu J,Wen T,Yu L,Xu F,Kang X,Osman I,Hu G,Bunting KM,Crethers D,Gao H,Zhang W,Liu Y,Wen K,Agarwal G,Hirose T,Nakagawa S,Vazdarjanova A,Zhou J

更新日期：2018-09-11 00:00:00

abstract：:IL-27-induced type 1 regulatory T (Tr1) cells suppress autoimmunity by producing IL-10. Signal transducer and activator of transcription (STAT) 1 and STAT3 have been described as key transcription factors that promote IL-10 secretion from Tr1 cells induced by IL-27. However, the molecular pathways for negatively regul...

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

authors： Wu C,Pot C,Apetoh L,Thalhamer T,Zhu B,Murugaiyan G,Xiao S,Lee Y,Rangachari M,Yosef N,Kuchroo VK

更新日期：2013-05-07 00:00:00

abstract：:Signal transduction by two-component systems involves phosphorylation and thereby activation of the response regulator by the cognate histidine kinase. Bifunctional histidine kinases have two opposing activities: depending on the environmental stimuli they either promote phosphorylation or stimulate the rapid dephosph...

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

authors： Kramer G,Weiss V

更新日期：1999-01-19 00:00:00

abstract：:The crystal structures of Escherichia coli thymidylate kinase (TmpK) in complex with P1-(5'-adenosyl)-P5-(5'-thymidyl)pentaphosphate and P1-(5'-adenosyl)P5-[5'-(3'-azido-3'-deoxythymidine)] pentaphosphate have been solved to 2.0-A and 2.2-A resolution, respectively. The overall structure of the bacterial TmpK is very ...

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

authors： Lavie A,Ostermann N,Brundiers R,Goody RS,Reinstein J,Konrad M,Schlichting I

更新日期：1998-11-24 00:00:00

abstract：:State transition in photosynthesis is a short-term balancing mechanism of energy distribution between photosystem I (PSI) and photosystem II (PSII). When PSII is preferentially excited (state 2), a pool of mobile light-harvesting complex II (LHCII) antenna proteins is thought to migrate from PSII to PSI, but biochemic...

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

authors： Takahashi H,Iwai M,Takahashi Y,Minagawa J

更新日期：2006-01-10 00:00:00

abstract：:The replication initiator protein of plasmid R6K preferentially repressed transcription initiated in vitro from the promoter of the initiator protein cistron. DNase I protection experiments revealed that the sequences in the region of the promoter recognized by the initiator protein partially overlapped the sequences ...

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

authors： Kelley W,Bastia D

更新日期：1985-05-01 00:00:00

abstract：:Clear-cut inherited Mendelian traits, such as familial adenomatous polyposis or hereditary nonpolyposis colorectal cancer, account for <4% of colorectal cancers. Another 20% of all colorectal cancers are thought to occur in individuals with a significant inherited multifactorial susceptibility to colorectal cancer tha...

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

authors： Fearnhead NS,Wilding JL,Winney B,Tonks S,Bartlett S,Bicknell DC,Tomlinson IP,Mortensen NJ,Bodmer WF

更新日期：2004-11-09 00:00:00

abstract：:Experimental work in animals has shown that memory formation depends on a cascade of molecular events. Here we show that variability of human memory performance is related to variability in genes encoding proteins of this signaling cascade, including the NMDA and metabotrobic glutamate receptors, adenylyl cyclase, CAM...

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

authors： de Quervain DJ,Papassotiropoulos A

更新日期：2006-03-14 00:00:00

abstract：:Dyskeratosis congenita is a premature aging syndrome characterized by muco-cutaneous features and a range of other abnormalities, including early greying, dental loss, osteoporosis, and malignancy. Dyskeratosis congenita cells age prematurely and have very short telomeres. Patients have mutations in genes that encode ...

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

authors： Vulliamy T,Beswick R,Kirwan M,Marrone A,Digweed M,Walne A,Dokal I

更新日期：2008-06-10 00:00:00

abstract：:P201 is a short (eight-residue) nonacidic peptide that comprises a strong transcriptional activating region when tethered to DNA in yeast. Here we identify the mediator protein Gal11 as an essential target of P201. Deletion of Gal11, which modestly decreases activation elicited by the typical acidic yeast activator, a...

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

authors： Lu Z,Ansari AZ,Lu X,Ogirala A,Ptashne M

更新日期：2002-06-25 00:00:00

abstract：:We have examined the extent of tyrosine phosphorylation of talin, a component of the cytoskeleton localized in the focal adhesions and, therefore, a potential substrate of p60v-src, the transforming protein of Rous sarcoma virus. p60v-src is a tyrosine kinase that induces high levels of phosphotyrosine and the disorga...

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

authors： Pasquale EB,Maher PA,Singer SJ

更新日期：1986-08-01 00:00:00

abstract：:Immune responses of the malaria vector mosquito Anopheles gambiae were monitored systematically by the induced expression of five RNA markers after infection challenge. One newly isolated marker encodes a homologue of the moth Gram-negative bacteria-binding protein (GNBP), and another corresponds to a serine protease-...

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

authors： Dimopoulos G,Richman A,Müller HM,Kafatos FC

更新日期：1997-10-14 00:00:00

abstract：:Some aspects of pattern formation in developing embryos can be described by nonlinear reaction-diffusion equations. An important class of these models accounts for diffusion and degradation of a locally produced single chemical species. At long times, solutions of such models approach a steady state in which the conce...

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

authors： Gordon PV,Sample C,Berezhkovskii AM,Muratov CB,Shvartsman SY

更新日期：2011-04-12 00:00:00

abstract：:Cell-free extracts of Arbacia eggs (Arbacia punctulata) apparently do not contain an enzymatic system for the reduction of ribonucleotides to deoxyribonucleotides. However, during an interval of 5 hr after fertilization at 23 degrees , an enzymatic system is produced that is capable of catalyzing the reduction of CDP ...

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

authors： Noronha JM,Sheys GH,Buchanan JM

更新日期：1972-08-01 00:00:00

abstract：:Many cyanobacteria alter their phycobilisome composition in response to changes in light wavelength in a process termed complementary chromatic adaptation. Mutant strains FdR1 and FdR2 of the filamentous cyanobacterium Fremyella diplosiphon are characterized by aberrant chromatic adaptation. Instead of adjusting to di...

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

authors： Chiang GG,Schaefer MR,Grossman AR

更新日期：1992-10-15 00:00:00

abstract：:To study the protein structure-function relationship, we propose a method to efficiently create three-dimensional maps of structure space using a very large dataset of > 30,000 Structural Classification of Proteins (SCOP) domains. In our maps, each domain is represented by a point, and the distance between any two poi...

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

authors： Osadchy M,Kolodny R

更新日期：2011-07-26 00:00:00

abstract：:Let X(0) be an unknown M by N matrix. In matrix recovery, one takes n < MN linear measurements y(1),…,y(n) of X(0), where y(i) = Tr(A(T)iX(0)) and each A(i) is an M by N matrix. A popular approach for matrix recovery is nuclear norm minimization (NNM): solving the convex optimization problem min ||X||*subject to y(i) ...

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

authors： Donoho DL,Gavish M,Montanari A

更新日期：2013-05-21 00:00:00

abstract：:Based on the DNA sequence of the symbiotic plasmid of Rhizobium strain NGR234, we predicted potential rearrangements generated by homologous recombination. All predicted rearrangements were identified experimentally by using a PCR-based methodology. Thus, the predicted and the actual dynamic maps of the replicon coinc...

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

authors： Flores M,Mavingui P,Perret X,Broughton WJ,Romero D,Hernández G,Dávila G,Palacios R

更新日期：2000-08-01 00:00:00