Abstract:
:We consider many-body problems in classical mechanics where a wide range of time scales limits what can be computed. We apply the method of optimal prediction to obtain equations that are easier to solve numerically. We demonstrate by examples that optimal prediction can reduce the amount of computation needed to obtain a solution by several orders of magnitude.
journal_name
Proc Natl Acad Sci U S Aauthors
Kast APdoi
10.1073/pnas.97.12.6253keywords:
subject
Has Abstractpub_date
2000-06-06 00:00:00pages
6253-7issue
12eissn
0027-8424issn
1091-6490pii
97/12/6253journal_volume
97pub_type
杂志文章abstract::In clinical trials comparing two treatments, one would often like to control the probability of erroneous decision while minimizing not the total sample size but the number of patients given the inferior treatment. To do this obviously requires that one use a datadependent allocation rule for the two treatments rather...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 临床试验,杂志文章
doi:10.1073/pnas.69.10.2993
更新日期:1972-10-01 00:00:00
abstract::Using chimeric recombinants transfected into HeLa cells and a transient expression assay, we demonstrate that the 5'-flanking region of the pS2 gene from position -428 to position -324 exhibits both constitutive and estrogen-inducible enhancer activity. The estrogen-inducible activity, but not the constitutive activit...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.86.4.1218
更新日期:1989-02-01 00:00:00
abstract::The effect of Zn2+ on a voltage-dependent, transient potassium current (IA) in acutely dissociated neurons from the suprachiasmatic nucleus was studied with the whole-cell patch-clamp technique. At micromolar concentrations, Zn2+ markedly potentiated IA activated from a holding potential of -60 mV, which is the restin...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.90.24.11806
更新日期:1993-12-15 00:00:00
abstract::In addition to tRNA and 5S RNA, Escherichia coli contains several other small, stable RNA species; these are M1, 10Sa, 6S, and 4.5S RNA. Although these RNAs are initially synthesized as precursor molecules, relatively little is known about their maturation. The data presented here show that 3' exoribonucleolytic trimm...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.95.6.2856
更新日期:1998-03-17 00:00:00
abstract::Translation of injected mRNA in oocytes of Xenopus laevis has been used as a highly sensitive and quantitative assay for interferon mRNA. Injection into oocytes of polyadenylylated RNA extracted from poly(I).poly(C)-induced human diploid fibroblasts (FS-4) leads to the synthesis of biologically active human fibroblast...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.74.8.3409
更新日期:1977-08-01 00:00:00
abstract::Patients with primary (AL) cardiac amyloidosis suffer from progressive cardiomyopathy with a median survival of less than 8 months and a 5-year survival of <10%. Contributing to this poor prognosis is the fact that these patients generally do not tolerate standard heart failure therapies. The molecular mechanisms unde...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0912263107
更新日期:2010-03-02 00:00:00
abstract::The eyes of some aquatic animals form images through reflective optics. Shrimp, lobsters, crayfish, and prawns possess reflecting superposition compound eyes, composed of thousands of square-faceted eye units (ommatidia). Mirrors in the upper part of the eye (the distal mirror) reflect light collected from many ommati...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1722531115
更新日期:2018-03-06 00:00:00
abstract::Distinct subsets of thymic epithelial cells (TECs) support T-cell development and selection. Isolated TECs contain multicellular complexes that enclose many viable thymocytes. However, the functions of those TECs, termed thymic nurse cells (TNCs), are unclear and the idea that TNCs are present in vivo is questioned. H...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1213069109
更新日期:2012-12-11 00:00:00
abstract::The three-dimensional organization of HLA antigens has been investigated by spectroscopic and immunochemical techniques. Measurement of the circular dichroism shows that in papain-solubilized HLA the heavy chain as well as the previously studied light chain (beta 2-microglobulin) consists predominantly of beta-pleated...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.76.8.3844
更新日期:1979-08-01 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
pub_type: 杂志文章
doi:10.1073/pnas.092263499
更新日期:2002-06-25 00:00:00
abstract::The field of perceptual learning has identified changes in perceptual templates as a powerful mechanism mediating the learning of statistical regularities in our environment. By measuring threshold-vs.-contrast curves using an orientation identification task under varying levels of external noise, the perceptual templ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1417056111
更新日期:2014-11-25 00:00:00
abstract::L-2-hydroxyglutarate (L-2HG) has emerged as a putative oncometabolite that is capable of inhibiting enzymes involved in metabolism, chromatin modification, and cell differentiation. However, despite the ability of L-2HG to interfere with a broad range of cellular processes, this molecule is often characterized as a me...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1614102114
更新日期:2017-02-07 00:00:00
abstract::Phosphorylation of ADP to ATP was induced in nonrespiring submitochondrial particles (SMP) from rat liver by the application of electric pulses with field strengths of 10-35 kV/cm and a decay time of 60 mus. In all cases respiration was inhibited completely by using cyanide or rotenone. Newly formed ATP was measured b...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.78.12.7473
更新日期:1981-12-01 00:00:00
abstract::Poliovirus RNA polymerase requires a host factor to initiate RNA synthesis in vitro. The host factor was previously purified to near homogeneity from HeLa cells but was not assigned an enzymatic activity. This report describes the purification of a terminal uridylyltransferase that can act as host factor. By all crite...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.2.221
更新日期:1986-01-01 00:00:00
abstract::Physical and gene mapping studies reveal that chloroplast DNA from geranium (Pelargonium hortorum) has sustained a number of extensive duplications and inversions, resulting in a genome arrangement radically unlike that of other plants. At 217 kilobases in size, the circular chromosome is about 50% larger than the typ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.84.3.769
更新日期:1987-02-01 00:00:00
abstract::Selective culling in populations of most organisms is rank-order: individuals of low rank on a scale of potential fitnesses tend to be eliminated during early development, whereas surviving adults (whose number reflects the carrying capacity of the environment) are generally drawn from the distribution's upper end. Ha...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.86.6.2117
更新日期:1989-03-01 00:00:00
abstract::Cell aggregates are a tool for in vitro studies of morphogenesis, cancer invasion, and tissue engineering. They respond to mechanical forces as a complex rather than simple liquid. To change an aggregate's shape, cells have to overcome energy barriers. If cell shape fluctuations are active enough, the aggregate sponta...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0902085106
更新日期:2009-10-13 00:00:00
abstract::Histone methylation has an important role in transcriptional regulation. However, unlike H3K4 and H3K9 methylation, the role of H4K20 monomethylation (H4K20me-1) in transcriptional regulation remains unclear. Here, we show that Wnt3a specifically stimulates H4K20 monomethylation at the T cell factor (TCF)-binding elem...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1009353108
更新日期:2011-02-22 00:00:00
abstract::Hox5 genes (Hoxa5, Hoxb5, Hoxc5) are exclusively expressed in the lung mesenchyme during embryogenesis, and the most severe phenotypes result from constitutive loss of function of all three genes. Because Hox5 triple null mutants exhibit perinatal lethality, the contribution of this paralogous group to postembryonic l...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1807067115
更新日期:2018-11-06 00:00:00
abstract::The kinetics for hydrogen exchange at individual base pairs in self-complementary deoxydodecanucleotide duplexes have been estimated from NMR saturation recovery measurements on the resolved imino protons as a function of temperature. The imino protons of dA . dT base pairs in the center of the fully alternating d(C-G...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.80.8.2184
更新日期:1983-04-01 00:00:00
abstract::Ca2+, pheromones, sweet taste compounds, and the main neurotransmitters glutamate and gamma-aminobutyric acid activate G protein-coupled receptors (GPCRs) that constitute the GPCR family 3. These receptors are dimers, and each subunit has a large extracellular domain called a Venus flytrap module (VFTM), where agonist...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.162138699
更新日期:2002-08-20 00:00:00
abstract::It has long been recognized that a suite of proteins exists in coral skeletons that is critical for the oriented precipitation of calcium carbonate crystals, yet these proteins remain poorly characterized. Using liquid chromatography-tandem mass spectrometry analysis of proteins extracted from the cell-free skeleton o...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1301419110
更新日期:2013-03-05 00:00:00
abstract::Proliferating-cell nuclear antigen (PCNA) mediates the replication of simian virus 40 (SV40) DNA by reversing the effects of a protein that inhibits the elongation reaction. Two other protein fractions, activator I and activator II, were also shown to play important roles in this process. We report that activator II i...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.86.19.7361
更新日期:1989-10-01 00:00:00
abstract::An investigation by paramagnetic resonance spectroscopy of the photoreduction of ferredoxin, oxygenically by water and anoxygenically by a direct electron donor to photosystem I, led to the unexpected findings that different reductive mechanisms may be involved. Ferredoxin photoreduced by water was not reoxidized in t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.77.5.2676
更新日期:1980-05-01 00:00:00
abstract::cDNA clones corresponding to the polypeptide that has been shown to be an endogenous diazepam binding inhibitor and may act as a physiological ligand for the benzodiazepine/beta-carboline receptor have been isolated from bacteriophage lambda recombinant libraries from rat hypothalamus, total brain, and liver. The clon...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.19.7221
更新日期:1986-10-01 00:00:00
abstract::Arabidopsis thaliana endosperm, a transient tissue that nourishes the embryo, exhibits extensive localized DNA demethylation on maternally inherited chromosomes. Demethylation mediates parent-of-origin-specific (imprinted) gene expression but is apparently unnecessary for the extensive accumulation of maternally biase...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1306164110
更新日期:2013-05-07 00:00:00
abstract::The AF-6 protein is a multidomain protein that contains two potential Ras-binding domains within its N terminus. Because of this feature, AF-6 has been isolated in both two-hybrid and biochemical approaches and is postulated to be a potential Ras-effector protein. Herein, we show that it is specifically the first Ras-...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.97.16.9064
更新日期:2000-08-01 00:00:00
abstract::The observed intensities of the reflections from the body-centered cubic phase of lipid systems are shown to be incompatible with a recently reported model consisting of straight, indefinitely long rods. ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.78.8.4683
更新日期:1981-08-01 00:00:00
abstract::Levels and subcellular distribution of connexin 43 (Cx43), a gap junction protein, were studied in hamster leukocytes before and after activation with endotoxin (lipopolysaccharide, LPS) both in vitro and in vivo. Untreated leukocytes did not express Cx43. However, Cx43 was clearly detectable by indirect immunofluores...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.15.7011
更新日期:1995-07-18 00:00:00
abstract::The gel filtration behavior, in the presence of detergents, of membrane-bound IgM from normal mouse spleen B lymphocytes was compared to that of secretory IgM from mouse plasma cells. The proteins were labeled either by surface radioiodination or biosynthetically with radioactive amino acids. Cell lysates were fractio...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.76.11.5515
更新日期:1979-11-01 00:00:00