Abstract:
:The notion of stability of a local ring arises naturally in investigating completed moduli spaces via geometric invariant theory. A scheme corresponding to a boundary point of a moduli space of nonsingular varieties cannot have unstable singular points. This paper reports some results concerning the stability of surface singularities. If a two-dimensional Cohen-Macaulay local ring R is semistable, its multiplicity must be less than seven and either equal to or 1 less than its embedding dimension. If the multiplicity of R is equal to its embedding dimension, the singularity of R must be a simple or cyclic elliptic singularity or the nonnormal limit of such a singularity. The results for the case when the multiplicity of R is less than its embedding dimension are still incomplete; the possible singularities that may arise when the multiplicity of R is equal to 2 or 3 are described.
journal_name
Proc Natl Acad Sci U S Aauthors
Shah Jdoi
10.1073/pnas.75.9.4085subject
Has Abstractpub_date
1978-09-01 00:00:00pages
4085-6issue
9eissn
0027-8424issn
1091-6490journal_volume
75pub_type
杂志文章abstract::Cereal agriculture originated with the domestication of barley and early forms of wheat in the Fertile Crescent. There has long been speculation that barley was domesticated more than once. We use differences in haplotype frequency among geographic regions at multiple loci to infer at least two domestications of barle...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 历史文章,杂志文章
doi:10.1073/pnas.0611377104
更新日期:2007-02-27 00:00:00
abstract::The phosphoprotein (NS) of vesicular stomatitis virus is an indispensable subunit of the virion-associated RNA polymerase (L). NS consists of a highly acidic NH2-terminal domain and a basic COOH-terminal domain. Unlike the latter, the amino acid sequences of the NH2-terminal regions are highly dissimilar among differe...
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.85.21.7977
更新日期:1988-11-01 00:00:00
abstract::Huntington's disease (HD) is a progressive neurodegenerative disease caused by a glutamine expansion within huntingtin protein. The exact pathological mechanisms determining disease onset and progression remain unclear. However, aggregates of insoluble mutant huntingtin (mhtt), a hallmark of HD, are readily detected 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.0707842104
更新日期:2007-10-16 00:00:00
abstract::The phenotype of several erythromycin-resistant mutants of Chlamydomonas reinhardi was further characterized in terms of the electrophoretic properties of their chloroplast ribosomal proteins. In mutant ery-M2d a single protein of the large (52 S) subunit has altered properties, which probably result from a change in ...
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.69.12.3779
更新日期:1972-12-01 00:00:00
abstract::Cofilin-actin rods are inclusion-like structures that are induced by certain chemical or physical stresses in cultured cells, and the rods formed in neurons are thought to be associated with neurodegeneration. Here, we cloned an Aplysia cofilin homolog and overexpressed it in cultured neurons. Overexpressed cofilin fo...
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.0507675102
更新日期:2005-11-01 00:00:00
abstract::The C-C chemokine receptor 5 (CCR5) plays a crucial role in facilitating the entry of macrophage-tropic strains of the HIV-1 into cells, but the mechanism of this phenomenon is completely unknown. To explore the role of CCR5-derived signal transduction in viral entry, we introduced mutations into two cytoplasmic domai...
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.94.10.5061
更新日期:1997-05-13 00:00:00
abstract::We demonstrate how a conventional confocal spinning-disk (CSD) microscope can be converted into a doubly resolving image scanning microscopy (ISM) system without changing any part of its optical or mechanical elements. Making use of the intrinsic properties of a CSD microscope, we illuminate stroboscopically, generati...
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.1315858110
更新日期:2013-12-24 00:00:00
abstract::Two photochromic activators of the electrogenic membrane of the electroplax of Electrophorus electricus are described. Trans-3,3'-bis[alpha-(trimethylammonium)methyl]azobenzene dibromide (Bis-Q), one of the most potent ever reported, is active at concentrations of less than 10(-7) M. Its cis isomer, which is obtained ...
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.68.8.1820
更新日期:1971-08-01 00:00:00
abstract::Whole-genome duplication (WGD) is believed to be a significant source of major evolutionary innovation. Redundant genes resulting from WGD are thought to be lost or acquire new functions. However, the rates of gene loss and thus temporal process of genome reshaping after WGD remain unclear. The WGD shared by all teleo...
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.1507669112
更新日期:2015-12-01 00:00:00
abstract::(2'-5')Oligoadenylate synthetase [(2'-5')A synthetase], which synthesizes a series of oligoadenylates ppp-(A2'p)n5'A [collectively referred to as (2'-5')A], has been described previously in rat liver cells, where its concentration varied with the growth status of this organ--i.e., it decreased during the early phase 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.80.15.4609
更新日期:1983-08-01 00:00:00
abstract::Individuals with developmental dyslexia vary in their ability to improve reading skills, but the brain basis for improvement remains largely unknown. We performed a prospective, longitudinal study over 2.5 y in children with dyslexia (n = 25) or without dyslexia (n = 20) to discover whether initial behavioral or brain...
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.1008950108
更新日期:2011-01-04 00:00:00
abstract::Central nervous system (CNS) trauma can result in tissue disruption, neuronal and axonal degeneration, and neurological dysfunction. The limited spontaneous CNS repair in adulthood and aging is often insufficient to overcome disability. Several investigations have demonstrated that targeting HDAC activity can protect ...
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.0907935106
更新日期:2009-11-17 00:00:00
abstract::Dysfunction of gap junctions (GJs) caused by mutations in connexin26 (Cx26) and Cx30 accounts for nearly half of all cases of hereditary nonsyndromic deafness cases. Although it is widely held that GJs connecting supporting cells in the organ of Corti mainly provide ionic pathways for rapid removal of K+ around the ba...
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.0501859102
更新日期:2005-10-18 00:00:00
abstract::Synthesis of the 31-amino acid, inner membrane protein MgtS (formerly denoted YneM) is induced by very low Mg2+ in a PhoPQ-dependent manner in Escherichia coli Here we report that MgtS acts to increase intracellular Mg2+ levels and maintain cell integrity upon Mg2+ depletion. Upon development of a functional tagged de...
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.1703415114
更新日期:2017-05-30 00:00:00
abstract::Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system postulated to be a cell-mediated autoimmune disease in which interferon gamma (IFN-gamma) plays an important role. There is increased IFN-gamma secretion in MS, and IFN-gamma administration induces exacerbations of disease. We foun...
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.94.2.599
更新日期:1997-01-21 00:00:00
abstract::We have established a recombinant inbred strain of mouse named spontaneous crescentic glomerulonephritis-forming mouse/Kinjoh or SCG/Kj. Mice of this strain spontaneously develop rapidly progressive glomerulonephritis. This strain of mice was derived from (BXSB/Mp x MRL/Mp-lpr/lpr)F1 hybrid mice by brother x sister ma...
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.90.8.3413
更新日期:1993-04-15 00:00:00
abstract::When rat pancreatic polynucleosomes were poly(ADP-ribosyl)ated with purified calf thymus poly(ADP-ribose) polymerase and examined by electron microscopy, a relaxation of their native zigzag structure was observed. At high ionic strengths control nucleosomes condensed into 250-A-thick fibers, but poly(ADP-ribosyl)ated ...
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.79.11.3423
更新日期:1982-06-01 00:00:00
abstract::Interindividual differences in hepatic metabolism, which are mainly due to genetic polymorphism in its gene, have a large influence on individual drug efficacy and adverse reaction. Hepatocyte-like cells (HLCs) differentiated from human induced pluripotent stem (iPS) cells have the potential to predict interindividual...
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.1413481111
更新日期:2014-11-25 00:00:00
abstract::Leptin is a pivotal regulator of energy and glucose homeostasis, and defects in leptin signaling result in obesity and diabetes. The ATP-sensitive potassium (K(ATP)) channels couple glucose metabolism to insulin secretion in pancreatic β-cells. In this study, we provide evidence that leptin modulates pancreatic β-cell...
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.1216351110
更新日期:2013-07-30 00:00:00
abstract::We have previously shown that nuclear transcripts of the multifunctional enzyme, carbamoyl-phosphate synthetase, aspartate transcarbamylase, dihydroorotase RNA can be released from nuclei of Syrian hamster cells as compact ribonucleoprotein (RNP) particles that sediment at the 200S region in a sucrose gradient. The 20...
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.86.2.466
更新日期:1989-01-01 00:00:00
abstract::We use the inverse scattering method to determine the weak limit of solutions of the Korteweg-deVries equation as dispersion tends to zero. The limit, valid for all time, is characterized in terms of a quadratic programming problem which can be solved with the aid of function theoretic methods. For large t, the soluti...
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.76.8.3602
更新日期:1979-08-01 00:00:00
abstract::The interaction between the ribosomal-stalk protein L7/12 (L12) and initiation factor 2 (IF2) is essential for rapid subunit association, but the underlying mechanism is unknown. Here, we have characterized the L12-IF2 interaction on Escherichia coli ribosomes using site-directed mutagenesis, fast kinetics, and molecu...
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.1802001115
更新日期:2018-05-01 00:00:00
abstract::Fossil glycoproteins of the soluble organic matrix are present in an 80-million-year-old mollusk shell from the Late Cretaceous Period. Discrete molecular weight components, as determined by gel electrophoresis, are preserved. The fossil organic matrix was compared with the organic matrix of a living representative sp...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 历史文章,杂志文章
doi:10.1073/pnas.73.8.2541
更新日期:1976-08-01 00:00:00
abstract::ERK6, a mitogen-activated protein (MAP) kinase-related serine/threonine kinase, is highly expressed in human skeletal muscle and appears to function as a signal transducer during differentiation of myoblasts to myotubes. In transfected 293 cells, activation of the 45-kDa enzyme results in tyrosine-phosphorylated 46- 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.93.9.4355
更新日期:1996-04-30 00:00:00
abstract::Cerebellar development occurs mainly postnatally and implies cell proliferation and migration. Hepatocyte growth factor (HGF) and Met are involved in mediating these responses in other tissues and are coexpressed in the cerebellum. Here we show that Met is localized in granule cell precursors and that cultures of thes...
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.222362099
更新日期:2002-11-12 00:00:00
abstract::Pseudohypoaldosteronism type II is a salt-sensitive form of hypertension with hyperkalemia in humans caused by mutations in the with-no-lysine kinase 4 (WNK4). Several studies have shown that WNK4 modulates the activity of the renal Na(+)Cl(-) cotransporter, NCC. Because the renal consequences of WNK4 carrying pseudoa...
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.1200947109
更新日期:2012-05-15 00:00:00
abstract::Paleoanthropologists and vertebrate paleontologists have for decades debated the etiology of tooth wear and its implications for understanding the diets of human ancestors and other extinct mammals. The debate has recently taken a twist, calling into question the efficacy of dental microwear to reveal diet. Some argue...
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.1509491112
更新日期:2015-08-25 00:00:00
abstract::Nonhomologous integration vectors have been used to demonstrate the feasibility of insertional mutagenesis in haploid tachyzoites of the protozoan parasite Toxoplasma gondii. Mutant clones resistant to 5-fluorouracil were identified at a frequency of approximately 10(-6) (approximately 2 x 10(-5) of the stable transfo...
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.92.12.5749
更新日期:1995-06-06 00:00:00
abstract::Quiescent BALB/c 3T3 cells exposed briefly to a platelet-derived growth factor (PDGF) become "competent" to replicate their DNA but do not "progress" into S phase unless incubated with growth factors contained in platelet-poor plasma. Plasma from hypophysectomized rats is deficient in progression activity; it does not...
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.76.3.1279
更新日期:1979-03-01 00:00:00
abstract::Bacteriophage lambda encodes a number of genes involved in the recombinational repair of DNA double-strand breaks. The product of one of these genes, rap, has been purified. Truncated Rap proteins that copurify with the full-length form are derived, at least in part, from a rho-dependent transcription terminator locat...
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.95.23.13507
更新日期:1998-11-10 00:00:00