The signal environment is more important than diet or chemical specialization in the evolution of warning coloration.

abstract：:Mitochondrial DNA from several mammalian species has been digested with a site-specific restriction endonuclease (HaeIII) from Haemophilus aegyptius. A quantitative analysis of the resulting specific fragments indicates that the mtDNA of any individual mammal is predominantly a single molecular clone. Gel analysis of ...

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

authors： Potter SS,Newbold JE,Hutchison CA 3rd,Edgell MH

更新日期：1975-11-01 00:00:00

abstract：:Single-stranded (ss) RNA viruses infect all domains of life. To date, for most ssRNA virions, only the structures of the capsids and their associated protein components have been resolved to high resolution. Qβ, an ssRNA phage specific for the conjugative F-pilus, has a T = 3 icosahedral lattice of coat proteins assem...

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

authors： Gorzelnik KV,Cui Z,Reed CA,Jakana J,Young R,Zhang J

更新日期：2016-10-11 00:00:00

abstract：:Metabolic, infectious, and tumor cell-intrinsic noxae can all evoke the endoplasmic reticulum (ER) stress response in tumor cells, which is critical for tumor cell growth and cancer progression. Evidence exists that the ER stress response can drive a proinflammatory program in tumor cells and macrophages but, to our k...

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

authors： Mahadevan NR,Rodvold J,Sepulveda H,Rossi S,Drew AF,Zanetti M

更新日期：2011-04-19 00:00:00

abstract：:The spindle checkpoint ensures the accuracy of chromosome segregation during mitosis. The protein serine/threonine kinase, Mps1, is a critical component of the spindle checkpoint in human cells and regulates the kinetochore localization of key checkpoint proteins. The kinase activity of Mps1 is required for the spindl...

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

authors： Kang J,Chen Y,Zhao Y,Yu H

更新日期：2007-12-18 00:00:00

abstract：:The guanosine hydrazide 1 yields a stable supramolecular hydrogel based on the formation of a guanine quartet (G-quartet) in presence of metal cations. The effect of various parameters (concentration, nature of metal ion, and temperature) on the properties of this gel has been studied. Proton NMR spectroscopy is shown...

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

authors： Sreenivasachary N,Lehn JM

更新日期：2005-04-26 00:00:00

abstract：:In classical evolutionary theory, traits evolve because they facilitate organismal survival and/or reproduction. We discuss a different type of evolutionary mechanism that relies upon differential dispersal. Traits that enhance rates of dispersal inevitably accumulate at expanding range edges, and assortative mating b...

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

authors： Shine R,Brown GP,Phillips BL

更新日期：2011-04-05 00:00:00

abstract：:Bufonid anurans of the genus Atelopus contain both steroidal bufadienolides and various guanidinium alkaloids of the tetrodotoxin class. The former inhibit sodium-potassium ATPases, whereas the latter block voltage-dependent sodium channels. The structure of one guanidinium alkaloid, zetekitoxin AB, has remained a mys...

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

authors： Yotsu-Yamashita M,Kim YH,Dudley SC Jr,Choudhary G,Pfahnl A,Oshima Y,Daly JW

更新日期：2004-03-30 00:00:00

abstract：:Aged rats, displaying impairments in spatial learning and memory associated with marked cellular atrophy of forebrain cholinergic neurons, received intracerebroventricular infusions of one of the four neurotrophins nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3), or neurotrop...

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

authors： Fischer W,Sirevaag A,Wiegand SJ,Lindsay RM,Björklund A

更新日期：1994-08-30 00:00:00

abstract：:Sessile marine organisms are prolific sources of biologically active natural products. However, these compounds are often found in highly variable amounts, with the abiotic and biotic factors governing their production remaining poorly understood. We present an approach that permits monitoring of in vivo natural produ...

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

authors： Esquenazi E,Jones AC,Byrum T,Dorrestein PC,Gerwick WH

更新日期：2011-03-29 00:00:00

abstract：:Fas, a member of the tumor necrosis factor receptor family, can induce apoptosis when activated by Fas ligand binding or anti-Fas antibody crosslinking. Genetic studies have shown that a defect in Fas-mediated apoptosis resulted in abnormal development and function of the immune system in mice. A point mutation in the...

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

authors： Chu K,Niu X,Williams LT

更新日期：1995-12-05 00:00:00

abstract：:Despite the growing interest in collective phenomena such as "swarm intelligence" and "wisdom of the crowds," little is known about the mechanisms underlying decision-making in vertebrate animal groups. How do animals use the behavior of others to make more accurate decisions, especially when it is not possible to ide...

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

authors： Ward AJ,Sumpter DJ,Couzin ID,Hart PJ,Krause J

更新日期：2008-05-13 00:00:00

abstract：:As chips further shrink toward smaller scales, fabrication processes based on the self-assembly of individual particles into patterns or structures are often sought. One of the most popular techniques for two-dimensional assembly (self-assembled monolayers) is based on capillary forces acting on particles placed at a ...

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

authors： Aubry N,Singh P,Janjua M,Nudurupati S

更新日期：2008-03-11 00:00:00

abstract：:The neonatal Fc receptor for IgG (FcRn) is a distant member of the MHC class I protein family. It binds IgG and albumin in a pH-dependent manner and protects these from catabolism by diverting them from a degradative fate in lysosomes. In addition, FcRn-mediated IgG transport across epithelial barriers is responsible ...

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

authors： Qiao SW,Kobayashi K,Johansen FE,Sollid LM,Andersen JT,Milford E,Roopenian DC,Lencer WI,Blumberg RS

更新日期：2008-07-08 00:00:00

abstract：:Regulation of cardiac contraction by neurotransmitters and hormones is often correlated with regulation of the L-type Ca2(+)-channel current (ICa) through the opposite actions of two second messengers, cyclic AMP and cyclic GMP. While cyclic AMP stimulation of ICa is mediated by the activation of cyclic AMP-dependent ...

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

authors： Méry PF,Lohmann SM,Walter U,Fischmeister R

更新日期：1991-02-15 00:00:00

abstract：:Apolipoprotein E (apoE) secreted by macrophages in the artery wall exerts an important protective effect against the development of atherosclerosis, presumably through its ability to promote lipid efflux. Previous studies have shown that increases in cellular free cholesterol levels stimulate apoE transcription in mac...

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

authors： Laffitte BA,Repa JJ,Joseph SB,Wilpitz DC,Kast HR,Mangelsdorf DJ,Tontonoz P

更新日期：2001-01-16 00:00:00

abstract：:A sensitive assay for detection of eukaryotic RNA polymerase II has been developed. This assay depends on the ability of polymerase II to elongate a small RNA primer, oligo(U), hybridized to a single-stranded homopolymeric DNA template, poly(dA). The poly(dA).oligo(U)-dependent RNA polymerase II from calf thymus has b...

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

authors： Fradkin LG,Leong K,Morrow CD,Berk AJ,Dasgupta A

更新日期：1985-12-01 00:00:00

abstract：:MAC5 is a component of the conserved MOS4-associated complex. It plays critical roles in development and immunity. Here we report that MAC5 is required for microRNA (miRNA) biogenesis. MAC5 interacts with Serrate (SE), which is a core component of the microprocessor that processes primary miRNA transcripts (pri-miRNAs...

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

authors： Li S,Li M,Liu K,Zhang H,Zhang S,Zhang C,Yu B

更新日期：2020-09-22 00:00:00

abstract：:Different strains of Newcastle disease virus vary in their ability to induce cell fusion. When administered to cells at high multiplicities of infection some strains induce cell fusion within three hours. This type of fusion is apparently caused by the virus particles in the inoculum, since it can be induced by noninf...

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

authors： Bratt MA,Gallaher WR

更新日期：1969-10-01 00:00:00

abstract：:Although neural circuits mediating various simple behaviors have been delineated, those generating more complex behaviors are less well described. The discrete structure of avian song control nuclei promises that circuits controlling complex behaviors, such as birdsong, can also be understood. To this end, we develope...

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

authors： Mooney R,Konishi M

更新日期：1991-05-15 00:00:00

abstract：:Blunting immunopathology without abolishing host defense is the foundation for safe and effective modulation of infectious and autoimmune diseases. Sphingosine 1-phosphate receptor 1 (S1PR1) agonists are effective in treating infectious and multiple autoimmune pathologies; however, mechanisms underlying their clinical...

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

authors： Teijaro JR,Studer S,Leaf N,Kiosses WB,Nguyen N,Matsuki K,Negishi H,Taniguchi T,Oldstone MB,Rosen H

更新日期：2016-02-02 00:00:00

abstract：:The postdevelopmental basis of cellular identity and the unique cellular output of a particular neuron type are of particular interest in the nervous system because a detailed understanding of circuits responsible for complex processes in the brain is impeded by the often ambiguous classification of neurons in these c...

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

authors： Schulz DJ,Goaillard JM,Marder EE

更新日期：2007-08-07 00:00:00

abstract：:Many membrane channels and receptors exhibit adaptive, or desensitized, response to a strong sustained input stimulus. A key mechanism that underlies this response is the slow, activity-dependent removal of responding molecules to a pool which is unavailable to respond immediately to the input. This mechanism is imple...

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

authors： Friedlander T,Brenner N

更新日期：2009-12-29 00:00:00

abstract：:The nucleotide sequences of the complementary strands of two human diversity region (D) minigenes, D2 and D4, show stretches of homology with two human variable region kappa chain (V kappa) genes, NG9 and HK101, respectively, in the first complementarity-determining region. In one V kappa sequence, the homology includ...

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

authors： Chen PP,Kabat EA,Wu TT,Fong S,Carson DA

更新日期：1985-04-01 00:00:00

abstract：:Mature larvae of Sarcophaga argyrostoma fail to form puparia when kept in contact with water, but pupariate after having been subsequently exposed to dryness for 30 hr. They become increasingly more sensitive to injected ecdysone the longer the exposure to dry conditions. A second wet treatment halts the production of...

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

authors： Zdarek J,Fraenkel G

更新日期：1970-09-01 00:00:00

abstract：:A major barrier to the design of immunotherapeutics and vaccines for cancer is the idiosyncratic nature of many tumor antigens and the possibility that T cells may be tolerant of broadly distributed antigens. We have devised an experimental strategy that exploits species differences in protein sequences to circumvent ...

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

authors： Theobald M,Biggs J,Dittmer D,Levine AJ,Sherman LA

更新日期：1995-12-19 00:00:00

abstract：:An oligomeric intermediate in the biosynthetic pathway of peptidoglycan was isolated from B. megaterium. The oligomer has been identified as [disaccharide(pentapeptide)]12 pyrophosphoryl undecaprenol. ...

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

authors： Fuchs-Cleveland E,Gilvarg C

更新日期：1976-11-01 00:00:00

abstract：:Markov chain Monte Carlo (MCMC) or the Metropolis-Hastings algorithm is a simulation algorithm that has made modern Bayesian statistical inference possible. Nevertheless, the efficiency of different Metropolis-Hastings proposal kernels has rarely been studied except for the Gaussian proposal. Here we propose a unique ...

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

authors： Yang Z,Rodríguez CE

更新日期：2013-11-26 00:00:00

abstract：:The key enzyme for transcription of protein-encoding genes in eukaryotes is RNA polymerase II (RNAPII). The recruitment of this enzyme during transcription initiation and its passage along the template during transcription elongation is regulated through the association and dissociation of several complexes. Elongator...

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

authors： Nelissen H,Fleury D,Bruno L,Robles P,De Veylder L,Traas J,Micol JL,Van Montagu M,Inzé D,Van Lijsebettens M

更新日期：2005-05-24 00:00:00

abstract：:Phosphorylation plays a critical role in controlling the function of cytoskeletal assemblies but no direct method yet exists to measure the phosphorylation state of proteins at the level of individual molecules and assemblies. Herein, we apply scanning transmission electron microscopy in combination with electron ener...

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

authors： Leapman RD,Gallant PE,Reese TS,Andrews SB

更新日期：1997-07-22 00:00:00

abstract：:beta1,4-Galactosyltransferase (beta4GalT-I) participates in both glycoconjugate biosynthesis (ubiquitous activity) and lactose biosynthesis (mammary gland-specific activity). In somatic tissues, transcription of the mammalian beta4GalT-I gene results in a 4.1-kb mRNA and a 3.9-kb mRNA as a consequence of initiation at...

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

authors： Charron M,Shaper JH,Shaper NL

更新日期：1998-12-08 00:00:00