Abstract:
:New data are reported on the influence of size on the velocity threshold for real movement. As the length of a narrow stimulus object increases, width remaining constant, the velocity threshold also increases. These findings are discussed in relation to some psychophysical experiments on contrast and some physiological experiments on motion.
journal_name
Proc Natl Acad Sci U S Aauthors
Mates B,Graham CHdoi
10.1073/pnas.65.3.516subject
Has Abstractpub_date
1970-03-01 00:00:00pages
516-20issue
3eissn
0027-8424issn
1091-6490journal_volume
65pub_type
杂志文章abstract::The distribution of enkephalin-like immunoreactivity within the avian retina was studied by immunofluorescence and immunoperoxidase techniques with antiserum to [Met5]enkephalin and [Leu5]enkephalin. Formaldehyde-fixed retinae were sectioned and incubated in antiserum to either [Met5]- or [Leu5]enkephalin. Specificity...
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.76.6.3010
更新日期:1979-06-01 00:00:00
abstract::We have constructed and characterized a polyoma virus-based plasmid that is maintained as an autonomously replicating extrachromosomal element (episome) in mouse embryonic stem (ES) cells. Plasmid pMGD20neo contains the polyoma origin of replication harboring a mutated enhancer (PyF101), a modified polyoma early regio...
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.92.5.1292
更新日期:1995-02-28 00:00:00
abstract::This paper reviews food (especially cereal) production trends and prospects for the world and its main regions. Despite fears to the contrary, in recent years we have seen continued progress toward better methods of feeding humanity. Sub-Saharan Africa is the sole major exception. Looking to the future, this paper arg...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.96.11.5929
更新日期:1999-05-25 00:00:00
abstract::Aminoacyl-tRNAs are generally formed by direct attachment of an amino acid to tRNAs by aminoacyl-tRNA synthetases, but Gln-tRNA is an exception to this rule. Gln-tRNA(Gln) is formed by this direct pathway in the eukaryotic cytosol and in protists or fungi mitochondria but is formed by an indirect transamidation pathwa...
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.0712299105
更新日期:2008-04-29 00:00:00
abstract::Cytotoxic T lymphocytes (CTLs) recognize antigens in the context of major histocompatibility complex (MHC) class I gene products. The T-cell receptor (TCR) that mediates this MHC-restricted antigen recognition recognizes short peptide fragments rather than the intact antigen. Presentation of peptides to the TCR may th...
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.86.2.617
更新日期:1989-01-01 00:00:00
abstract::Gliogenesis in animal development is spatiotemporally regulated so that correct numbers of glia are present to support various neuronal functions. During Drosophila embryonic development, the glial regulatory gene, glial cell missing/glial cell deficient (gcm/glide), promotes glial cell fate and differentiation. Here ...
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.0808899106
更新日期:2009-04-21 00:00:00
abstract::The gamma-aminobutyrate-synthesizing enzyme glutamate decarboxylase (GAD; L-glutamate 1-carboxy-lyase, EC 4.1.1.15) is a major target of autoantibodies associated with both early and late stages of pancreatic beta-cell destruction and development of type 1 diabetes. We have used five monoclonal anti-islet-cell antibod...
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.90.7.2832
更新日期:1993-04-01 00:00:00
abstract::In eukaryotes, microtubules are essential for cellular plasticity and dynamics. Here we show that P300/CBP-associated factor (PCAF), a kinetochore-associated acetyltransferase, acts as a negative modulator of microtubule stability through acetylation of EB1, a protein that controls the plus ends of microtubules. PCAF ...
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.1202639109
更新日期:2012-10-09 00:00:00
abstract::Several authors have considered Markov processes defined by the motion of a particle on a fixed line with a random velocity(1, 6, 8, 10) or a random diffusivity.(5, 12) A "random evolution" is a natural but apparently new generalization of this notion. In this note we hope to show that this concept leads to simple and...
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.62.2.305
更新日期:1969-02-01 00:00:00
abstract::MicroRNAs are predicted to regulate approximately 30% of all human genes by targeting sequences in their 3' UTR. Polymorphisms in 3' UTR of several genes have been reported to affect gene expression, but the mechanism is not fully understood. Here, we demonstrate that 829C-->T, a naturally occurring SNP, near the miR-...
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.0706217104
更新日期:2007-08-14 00:00:00
abstract::The role of various adhesion molecules in lymphocyte homing to the brain and in inflammatory autoimmune disease of the central nervous system (CNS) was examined in mice. Activated T cell lines and clones expressed CD44 and integrin alpha4, but not L-selectin, and entered the CNS independent of their antigen specificit...
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.96.12.6896
更新日期:1999-06-08 00:00:00
abstract::The production of the staphylococcal exotoxin toxic shock syndrome toxin-1 (TSST-1) by Staphylococcus aureus has been associated with essentially all cases of menstruation-associated toxic shock syndrome (TSS). In this work, we show that the human vaginal isolate Lactobacillus reuteri RC-14 produces small signaling mo...
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.1017431108
更新日期:2011-02-22 00:00:00
abstract::The with-no-lysine (K) (WNK) kinases are an atypical family of protein kinases that regulate ion transport across cell membranes. Mutations that result in their overexpression cause hypertension-related disorders in humans. Of the four mammalian WNKs, only WNK1 is expressed throughout the body. We report that WNK1 inh...
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.1617649113
更新日期:2016-12-13 00:00:00
abstract::This article emphasizes the role played by a remarkable pointwise inequality satisfied by fractionary derivatives in order to obtain maximum principles and Lp-decay of solutions of several interesting partial differential equations. In particular, there are applications to quasigeostrophic flows, in two space variable...
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.2036515100
更新日期:2003-12-23 00:00:00
abstract::Methionine sulfoxide reductase A (MsrA) catalyzes the reduction of methionine sulfoxide to methionine and is specific for the S epimer of methionine sulfoxide. The enzyme participates in defense against oxidative stresses by reducing methionine sulfoxide residues in proteins back to methionine. Because oxidation of 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.1101275108
更新日期:2011-06-28 00:00:00
abstract::In normal adult rats anesthetized with urethane, intravenous injections of beta-endorphin (30--150 micrograms kg-1) induced a transient fall of blood pressure followed by a small hypertension and a prolonged hypotension. Prior administration of naloxone completely blocked these effects, whereas naloxone, given 1 hr af...
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.75.12.6240
更新日期:1978-12-01 00:00:00
abstract::Heavy electronic states originating from the f atomic orbitals underlie a rich variety of quantum phases of matter. We use atomic scale imaging and spectroscopy with the scanning tunneling microscope to examine the novel electronic states that emerge from the uranium f states in URu(2)Si(2). We find that, as the tempe...
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.1005892107
更新日期:2010-06-08 00:00:00
abstract::The insulin and glucagon responses to 10 mM glucose and 10 mM arginine were studied in pancreata isolated from nondiabetic diabetes-prone and diabetes-resistant BB/W rats at 60, 80, and 140 days of age and in diabetic BB/W rats on the 1st and 14th days of their diabetes. In the former group the insulin response to glu...
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.83.24.9749
更新日期:1986-12-01 00:00:00
abstract::The environmental impact of using recombinant bovine somatotropin (rbST) in dairy production was examined on an individual cow, industry-scale adoption, and overall production system basis. An average 2006 U.S. milk yield of 28.9 kg per day was used, with a daily response to rbST supplementation of 4.5 kg per cow. Rat...
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.0802446105
更新日期:2008-07-15 00:00:00
abstract::Immunoglobulin- or multiple myeloma-associated amyloidosis has been distinguished by the tissue deposition of Congophilic, fibrillar protein consisting of light chains or light-chain fragments (AL amyloidosis). We now report the isolation and characterization of another form of immunoglobulin-associated amyloid obtain...
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.87.17.6542
更新日期:1990-09-01 00:00:00
abstract::A density-shift method is described for analyzing insulin receptor synthesis and turnover in cultured cells labeled with "heavy" amino acids (2H, 13C, and 15N). Solubilized newly synthesized heavy and old "light" receptors are separated by isopycnic banding on CsCl gradients and then quantitated. Insulin receptor synt...
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.77.1.285
更新日期:1980-01-01 00:00:00
abstract::Protein tyrosine phosphorylation in purified synaptic vesicles from rat forebrain has been studied in the presence of Mn2+ and orthovanadate. High levels of endogenous protein tyrosine phosphorylation were observed. Four major phosphoproteins, with apparent molecular masses of 105, 94, 38, and 30 kDa, were shown to co...
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.85.3.762
更新日期:1988-02-01 00:00:00
abstract::A special methionine tRNA (tRNAi) is universally required to initiate translation. Amongst species a tRNAi structural conservation is most apparent in the anticodon and T arms of the molecule but extends into the variable loop and the 3' strand of the D stem. This suggested that they could share a similar ancestral or...
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.82.14.4587
更新日期:1985-07-01 00:00:00
abstract::Transgenic mice harboring the int-2/Fgf-3 protooncogene under transcriptional control of the mouse mammary tumor virus (MMTV) promoter/enhancer exhibit a dramatic, benign hyperplasia of the mammary gland. In one int-2 transgenic line (TG.NX), this growth disturbance is evoked by pregnancy and regresses after parturiti...
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.92.6.2268
更新日期:1995-03-14 00:00:00
abstract::GM54VA human cells transformed by simian virus 40 (SV40) were fused with peritoneal macrophages obtained from three different mouse strains. All 27 hybrid clones studied were positive for SV40 tumor antigen in 100% of their cells and contained human chromosome 17. Human chromosome 17 was the only human chromosome pres...
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.74.1.315
更新日期:1977-01-01 00:00:00
abstract::Voltage gating of hyperpolarization-activated cation (HCN) channels is potentiated by direct binding of cAMP to a cytoplasmic cAMP-sensing domain (CSD). When unliganded, the CSD inhibits hyperpolarization-dependent opening of the HCN channel gate; cAMP binding relieves this autoinhibition so that opening becomes more ...
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.1012750108
更新日期:2011-01-11 00:00:00
abstract::Ischemia of the myocardium and lower limbs is a common consequence of arterial disease and a major source of morbidity and mortality in modernized countries. Inducing neovascularization for the treatment of ischemia is an appealing therapeutic strategy for patients for whom traditional treatment modalities cannot be p...
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.1117885109
更新日期:2012-01-31 00:00:00
abstract::G proteins are activated when they associate with G protein-coupled receptors (GPCRs), often in response to agonist-mediated receptor activation. It is generally thought that agonist-induced receptor-G protein association necessarily promotes G protein activation and, conversely, that activated GPCRs do not interact w...
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.2003787117
更新日期:2020-09-01 00:00:00
abstract::Cell-mediated immunity is critical for host resistance to tuberculosis. T lymphocytes recognizing antigens presented by the major histocompatibility complex (MHC) class I and class II molecules have been found to be necessary for control of mycobacterial infection. Mice genetically deficient in the generation of MHC c...
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.96.26.15190
更新日期:1999-12-21 00:00:00
abstract::Helodermin is a vasoactive intestinal peptide-like peptide in the salivary gland venom of the lizard Heloderma suspectum. Helodermin-like immunofluorescence was observed in the parafollicular (C) cells in several mammals and in the C cell homologues of the chicken ultimobranchial gland. Thus, helodermin-like peptides ...
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.86.4.1357
更新日期:1989-02-01 00:00:00