An auxin-driven polarized transport model for phyllotaxis.

abstract：:Early abstract reasoning has typically been characterized by a "relational shift," in which children initially focus on object features but increasingly come to interpret similarity in terms of structured relations. An alternative possibility is that this shift reflects a learned bias, rather than a typical waypoint a...

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

authors： Carstensen A,Zhang J,Heyman GD,Fu G,Lee K,Walker CM

更新日期：2019-07-09 00:00:00

abstract：:In Drosophila, heterochromatin protein 1 (HP1) suppresses the expression of euchromatic genes that are artificially translocated adjacent to heterochromatin by expanding heterochromatin structure into neighboring euchromatin. The purpose of this study was to determine whether HP1 functions as a transcriptional repress...

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

authors： Hwang KK,Eissenberg JC,Worman HJ

更新日期：2001-09-25 00:00:00

abstract：:Bacteria use membrane-integral sensor histidine kinases (HK) to perceive stimuli and transduce signals from the environment to the cytosol. Information on how the signal is transmitted across the membrane by HKs is still scarce. Combining both liquid- and solid-state NMR, we demonstrate that structural rearrangements ...

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

authors： Salvi M,Schomburg B,Giller K,Graf S,Unden G,Becker S,Lange A,Griesinger C

更新日期：2017-03-21 00:00:00

abstract：:Molecular beacons are DNA probes that form a stem-and-loop structure and possess an internally quenched fluorophore. When they bind to complementary nucleic acids, they undergo a conformational transition that switches on their fluorescence. These probes recognize their targets with higher specificity than probes that...

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

authors： Bonnet G,Tyagi S,Libchaber A,Kramer FR

更新日期：1999-05-25 00:00:00

abstract：:To identify genes important for hair-cell function, we conducted a mutagenic screen in zebrafish. Larvae from one mutant line, ru848, were unresponsive to acoustic stimuli and unable to balance. The mutation results in a 90% reduction in hair-cell number and partial retinal degeneration by 5 days postfertilization. We...

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

authors： Starr CJ,Kappler JA,Chan DK,Kollmar R,Hudspeth AJ

更新日期：2004-02-24 00:00:00

abstract：:This paper describes a variety of statistical methods for obtaining precise quantitative estimates of the similarities and differences in the structures of semantic domains in different languages. The methods include comparing mean correlations within and between groups, principal components analysis of interspeaker c...

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

authors： Romney AK,Moore CC,Batchelder WH,Hsia TL

更新日期：2000-01-04 00:00:00

abstract：:The major protein constituent of human plasma high density lipoproteins has been isolated and its complete amino-acid sequence determined. The protein, designated apolipoprotein-glutamine-I by the presence of carboxyl-terminal glutamine, is a single polypeptide chain of 245 amino-acid residues, including three residue...

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

authors： Baker HN,Delahunty T,Gotto AM Jr,Jackson RL

更新日期：1974-09-01 00:00:00

abstract：:The mammalian target of rapamycin (mTOR) is a central regulator of cell growth and proliferation in response to growth factor and nutrient signaling. Consequently, this kinase is implicated in metabolic diseases including cancer and diabetes, so there is great interest in understanding the complete spectrum of mTOR-re...

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

authors： Wang BT,Ducker GS,Barczak AJ,Barbeau R,Erle DJ,Shokat KM

更新日期：2011-09-13 00:00:00

abstract：:An endonucleolytic activity is associated with purified PM(2) bacteriophages. It converts the double-stranded supercoiled PM(2) DNA mostly into the linear form that sediments as a homogenous peak in alkaline sucrose gradients. The same activity is found in intact or detergent-lysed phages. Optimal activity is observed...

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

authors： Laval F

更新日期：1974-12-01 00:00:00

abstract：:Bacteriophage lambda integrates into the chromosome of its Escherichia coli host by means of a site-specific recombination between a locus on the phage chromosome (phage att site) and a locus on the bacterial chromosome (bacterial att site). The nucleotide sequence of four lambda att sites altered in site-specific rec...

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

authors： Hoess RH,Landy A

更新日期：1978-11-01 00:00:00

abstract：:In contrast to the Hox genes in arthropods and vertebrates, those in molluscs show diverse expression patterns with differences reported among lineages. Here, we investigate 2 phylogenetically distant molluscs, a gastropod and a polyplacophoran, and show that the Hox expression in both species can be divided into 2 ca...

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

authors： Huan P,Wang Q,Tan S,Liu B

更新日期：2020-01-07 00:00:00

abstract：:Deciphering the electron transfer reactivity characteristics of amyloid β-peptide copper complexes is an important task in connection with the role they are assumed to play in Alzheimer's disease. A systematic analysis of this question with the example of the amyloid β-peptide copper complex by means of its electroche...

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

authors： Balland V,Hureau C,Savéant JM

更新日期：2010-10-05 00:00:00

abstract：:A minimalist Cys2His2 zinc finger peptide, Lys-Tyr-Ala-Cys-Ala-Ala-Cys-Ala-Ala-Ala-Phe-Ala-Ala-Lys-Ala-Ala-Leu-Ala- Ala-His-Ala-Ala-Ala-His-Ala-Lys, has been synthesized. Metal binding studies using Co2+ as a probe indicated that this peptide forms a 1:1 peptide/metal complex with a dissociation constant comparable to...

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

authors： Michael SF,Kilfoil VJ,Schmidt MH,Amann BT,Berg JM

更新日期：1992-06-01 00:00:00

abstract：:The effects of temperature and of the action of a purified phospholipase C enzyme preparation on human red blood cell membranes has been investigated by chemical analyses, circular dichroism, and proton magnetic resonance measurements. The results indicate that a substantial fraction of the phospholipids and the prote...

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

authors： Glaser M,Simpkins H,Singer SJ,Sheetz M,Chan SI

更新日期：1970-03-01 00:00:00

abstract：:Ellagic acid, a naturally occurring plant phenol, inhibits the activity of the direct-acting mutagen N-methyl-N-nitrosourea (MeNU) in Salmonella typhimurium TA100. Ellagic acid at 0.10, 0.25, 0.50, and 1.00 mM inhibited the mutagenicity of MeNU (0.40 mM) by 3%, 13%, 45%, and 60%, respectively. Ellagic acid (3 mM) also...

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

authors： Dixit R,Gold B

更新日期：1986-11-01 00:00:00

abstract：:Steroidogenic factor-1 (SF-1) and liver receptor homologue-1 (LRH-1) belong to the fushi tarazu factor 1 subfamily of nuclear receptors. SF-1 is an essential factor for sex determination during development and regulates adrenal and gonadal steroidogenesis in the adult, whereas LRH-1 is a critical factor for developmen...

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

authors： Wang W,Zhang C,Marimuthu A,Krupka HI,Tabrizizad M,Shelloe R,Mehra U,Eng K,Nguyen H,Settachatgul C,Powell B,Milburn MV,West BL

更新日期：2005-05-24 00:00:00

abstract：:Let Lambda=SL(2)(Z) be the modular group and let c(n)(Lambda) be the number of congruence subgroups of Lambda of index at most n. We prove that lim(n--> infinity )(log c(n)(Lambda)/((log n)(2)/log log n))=(3-2(sqrt)2)/4. The proof is based on the Bombieri-Vinogradov "Riemann hypothesis on the average" and on the solut...

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

authors： Goldfeld D,Lubotzky A,Nikolov N,Pyber L

更新日期：2004-09-14 00:00:00

abstract：:Newborns are at increased risk of jaundice, a condition in which excess bilirubin accumulates in blood. Left untreated, jaundice can lead to neurological impairment and death. Jaundice resulting from unconjugated hyperbilirubinemia is easily treated with exposure to blue light, and phototherapy systems have been devel...

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

authors： Keahey PA,Simeral ML,Schroder KJ,Bond MM,Mtenthaonnga PJ,Miros RH,Dube Q,Richards-Kortum RR

更新日期：2017-12-19 00:00:00

abstract：:Daily rhythmic processes are coordinated by circadian clocks, which are present in numerous central and peripheral tissues. In mammals, two circadian clocks, the food-entrainable oscillator (FEO) and methamphetamine-sensitive circadian oscillator (MASCO), are "black box" mysteries because their anatomical loci are unk...

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

authors： Pendergast JS,Oda GA,Niswender KD,Yamazaki S

更新日期：2012-08-28 00:00:00

abstract：:Mechanisms underlying age-related obesity and insulin resistance are generally unknown. Here, we report age-related adipose vascular changes markedly modulated fat mass, adipocyte functions, blood lipid composition, and insulin sensitivity. Notably, VEGF expression levels in various white adipose tissues (WATs) underw...

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

authors： Honek J,Seki T,Iwamoto H,Fischer C,Li J,Lim S,Samani NJ,Zang J,Cao Y

更新日期：2014-10-14 00:00:00

abstract：:Natural environments are filled with multiple, often competing, signals. In contrast, biological systems are often studied in "well-controlled" environments where only a single input is varied, potentially missing important interactions between signals. Catabolite repression of galactose by glucose is one of the best-...

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

authors： Escalante-Chong R,Savir Y,Carroll SM,Ingraham JB,Wang J,Marx CJ,Springer M

更新日期：2015-02-03 00:00:00

abstract：:We find that histidine residues in proteins are major targets for reaction with the lipid peroxidation product 4-hydroxynon-2-enal (HNE). Reaction of insulin (which contains no sulfhydryl groups) with HNE leads to the generation of HNE-protein adducts, which are converted to radioactive derivatives upon subsequent tre...

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

authors： Uchida K,Stadtman ER

更新日期：1992-05-15 00:00:00

abstract：:The exemplary search capabilities of flying insects have established them as one of the most diverse taxa on Earth. However, we still lack the fundamental ability to quantify, represent, and predict trajectories under natural contexts to understand search and its applications. For example, flying insects have evolved ...

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

authors： Kaushik PK,Renz M,Olsson SB

更新日期：2020-06-02 00:00:00

abstract：:Studies of the accelerated aging disorder Hutchinson-Gilford progeria syndrome (HGPS) can potentially reveal cellular defects associated with physiological aging. HGPS results from expression and abnormal nuclear envelope association of a farnesylated, truncated variant of prelamin A called "progerin." We surveyed the...

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

authors： Chang W,Wang Y,Luxton GWG,Östlund C,Worman HJ,Gundersen GG

更新日期：2019-02-26 00:00:00

abstract：:The nanoscale distributions of electron density and electric fields in GaAs semiconductor devices are displayed with NMR experiments. The spectra are sensitive to the changes to the nuclear-spin Hamiltonian that are induced by perturbations delivered in synchrony with a line-narrowing pulse sequence. This POWER (pertu...

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

authors： Kempf JG,Miller MA,Weitekamp DP

更新日期：2008-12-23 00:00:00

abstract：:In this note the Weierstrass integral J is taken as L, the Riemann integral of length. Here M(n), n > 1, is a compact, connected manifold of class C(infinity) with a positive definite Riemann structure. Presentations (phi, U(phi)) in M(n) and geodesics (with the aid of the Euler-Riemann equations) are defined in Morse...

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

authors： Morse M

更新日期：1977-06-01 00:00:00

abstract：:Vibrio cholerae, the causative agent of cholera, has reservoirs in fresh and brackish water where it interacts with virulent bacteriophages. Phages are the most abundant biological entity on earth and coevolve with bacteria. It was reported that concentrations of phage and V. cholerae inversely correlate in aquatic re...

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

authors： Silva-Valenzuela CA,Camilli A

更新日期：2019-01-29 00:00:00

abstract：:To identify the binding domain for dihydropyridine Ca2+ antagonists, skeletal muscle Ca2+ channels were photolabeled with [3H](+)-PN200-110 and [3H]azidopine. Regions of alpha 1 photolabeled by these ligands were then identified by antibody mapping of proteolytic fragments. Approximately 50% of the specific labeling b...

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

authors： Striessnig J,Murphy BJ,Catterall WA

更新日期：1991-12-01 00:00:00

abstract：:We have isolated, by molecular cloning and genetic complementation of a listeriolysin-negative mutant, a gene required for the expression of this virulence factor in Listeria monocytogenes. The mutant strain SLCC53, which was nonhemolytic and avirulent, harbored a deletion of 450 base pairs located approximately 1500 ...

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

authors： Leimeister-Wächter M,Haffner C,Domann E,Goebel W,Chakraborty T

更新日期：1990-11-01 00:00:00

abstract：:The lymphocyte differentiation (Ly) antigen phenotype of cytotoxic effector T cells specific for H-2 mutant alloantigens was determined. Cytotoxic effectors generated in primary mixed lymphocyte culture and specific for H-2Kba and H-2Dda alloantigens are sensitive to both anti-Ly-1 and anti-Ly-2 serum plus complement....

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

authors： Wettstein PJ,Bailey DW,Mobraaten LE,Klein J,Frelinger JA

更新日期：1979-07-01 00:00:00