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Creator | Title | Description | Subject | Date |
| 226 |
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Capecchi, Mario R.; Mansour, Suzanne L.; Thomas, Kirk R. | Disruption of the proto-oncogene int-2 in mouse embryo-derived stem cells: a general strategy for targeting mutations to non-selectable genes. | Gene targeting--homologous recombination of DNA sequences residing in the chromosome with newly introduced DNA sequences--in mouse embryo-derived stem cells promises to provide a means to generate mice of any desired genotype. We describe a positive nd negative selection procedure that enriches 2,00... | Animals; Clone Cells; Restriction Mapping; Stem Cells | 1988-11-24 |
| 227 |
 |
Davidson, Diane W. | Cecropia and its biotic defenses | In all the world, the genus Cecropia is unrivaled for the number of myrmecophytes, or true "antplants" counted among its species (McKey & Davidson, 1993). Based on the proportion of Cecropia species producing Mullerian bodies in at least some parts of their distribution, myrmecophytes comprise the ... | Myrmecophytes; Mullerian bodies; Pearl bodies | 2005 |
| 228 |
 |
Gesteland, Raymond F.; Weiss, Robert B. | Efficient shine- Dalgarno sequence but not translation is necessary for LacZ mRNA stability in Escherichia coli | The 5' ends of many bacterial transcripts are important in determining mRNA stability. A series of Shine-Dalgarno (SD) sequence changes showed that the complementarity of the SD sequence to the anti-SD sequence of 16S rRNA correlates with lacZ mRNA stability in Escherichia coli. Several initiation c... | Protein Biosynthesis; Ribosomes; Escherichia coli; Shine-Dalgarno Sequence | 1994 |
| 229 |
 |
Clayton, Dale H. | Common grackle anting with lime fruit and its effect on ectoparasites | Anting is stereotyped behavior in which birds ex- pose themselves to fluid-secreting ants or other pun- gent substances. During "active" anting a bird crush- es an ant in the bill and rubs it frenetically through its plumage (Rothschild and Clay 1952). During "passive" anting a bird entices ants to ... | Quiscalus quiscala; Columbicola columbae; Anting; Ectoparasites | 1993 |
| 230 |
 |
Coley, Phyllis D. | New cytotoxic cinnamic acid derivatives from leaves of Bonamia trichantha | Bioassay-guided fractionation of the methanolic extract of the young leaves of Bonamia trichantha led to the isolation of four new cinnamic acid derivatives trichanthins A-D (l-4).Their structures were established by spectroscopic methods. All compounds were tested in cytotoxic assays against the MC... | Bonamia trichantha; Cinnamic acid; Caffeic acid ester; p-Coumaric acid ester: Farnesol; Z-(l l)-hexadecen-l-ol; Cytotoxicity | 2006 |
| 231 |
 |
Sperry, John S. | Water transport in vesselless angiosperms: conducting efficiency and cavitation safety | Two structure-function hypotheses were tested for vesselless angiosperm wood. First, vesselless angiosperm wood should have much higher flow resistance than conifer wood because angiosperm tracheids lack low-resistance torus-margo pits. Second, vesselless wood ought to be exceptionally safe from cav... | | 2007 |
| 232 |
 |
Capecchi, Mario R.; Bernstein, Kenneth E.; Thomas, Kirk R. | Targeting genes for self-excision in the germ line | A procedure is described that directs the self-induced deletion of DNA sequences as they pass through the male germ line of mice. The testes-specific promoter from the angiotensin-converting enzyme gene was used to drive expression of the Cre-recombinase gene. Cre was linked to the selectable marker... | Cre-recombinase; Hoxa3; Chimeric mice | 1999-06-15 |
| 233 |
 |
Goller, Franz | Vocal gestures of shared syllable types in cardinals | In songbirds, songs are learned by memorization and copying of tutor song and such copies can be remarkably accurate. However, it is not known whether acoustic similarity is generated by equally similar vocal gestures. We studied syringeal and respiratory motor patterns of syllable types shared by u... | Cardinalis cardinalis; Vocal gestures; Birdsong syllables; Song syllables | 1997 |
| 234 |
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Capecchi, Mario R. | Polypeptide chain termination in vitro: isolation of a release factor. | The growing polypeptide chain remains bound to the ribosome-messenger RNA complex through the sRNA carrying the last amino acid incorporated into the polypeptide chain.' On completion of the polypeptide chain a mechanism must exist for releasing it from the protein-synthesizing machinery. To date, m... | Carbon Isotopes; Phenylalanine; Proteins | 1967-09-01 |
| 235 |
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Carrier, David R. | Coupled evolution of breathing and locomotion as a game of leapfrog | Because the increase in metabolic rate related to locomotor activity places demands on the cardiorespiratory apparatus, it is not surprising that the evolution of breathing and of locomotion are coupled. As the respiratory faculty becomes more refined, increasingly aerobic life strategies can be exp... | Evolution; Coupled evolution; Breathing; Locomotion; Cardiorespiratory apparatus | 2006 |
| 236 |
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Clayton, Dale H. | Feather-busting bacteria | I ONCE HAD A COLLEAGUE who delighted in the aphorism, which he proudly coined himself, "If it's too small to see with the naked eye, it ain't there." Sadly, this view may as well be true for ornithologists who study birds only through unaided eyes, binoculars, or spotting scopes. But birds can also ... | Columba livia; Columbiformes; Ectoparasites; Bacteria; Plumage | 1999 |
| 237 |
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Olivera, Baldomero M.; ; McIntosh, J. Michael | Localization of [125I] ω-conotoxin GVIA binding in human hippocampus and cerebellum | THE peptide toxin ω-conotoxin GVIA (ω-CgTx) has been shown to be a high affinity ligand for N-type calcium channels in the brain. We have employed [125I]ω-CgTx to localize N-type channels in human hippocampus and cerebellum using autoradiography. Ten micron thick slidemounted tissue sections of... | Conotoxins; Peptide toxins | 1993 |
| 238 |
 |
Adler, Frederick R. | Recent rapid increases in the right whale (Eubalaena australis) population off southern Brazil | Right whales (Eubalaena australis) that gather on a wintering ground off southern Brazil have been aerial surveyed and photographically identified since 1987. As of 2003 the Brazilian Right Whale Catalogue has 315 different individual whales of which 31 were resighted in other years (23 females, 3 y... | | 2005 |
| 239 |
 |
Sperry, John S. | Evolution of water transport and xylem structure | Land plants need water to replace the evaporation that occurs while atmospheric CO2 is diffusing into photosynthetic tissue. The water-for-carbon exchange rate is poor, and evolutionary history indicates a progression of innovations for cheap water transport--beginning in order with capillary sucti... | Cavitation; Vessels; Plants | 2003 |
| 240 |
 |
Clayton, Dale H.; Rogers, Alan R. | Genetic analysis of lice supports direct contact between modern and archaic humans | Parasites can be used as unique markers to investigate host evolutionary history, independent of host data. Here we show that modern human head lice, Pediculus humanus, are composed of two ancient lineages, whose origin predates modern Homo sapiens by an order of magnitude (ca. 1.18 million years). | Pediculus humanus; Head lice; Molecular phylogeny; Phthirus | 2004 |
| 241 |
 |
Olivera, Baldomero M.; Hillyard, David R. | Conotoxins | Many successful animal and plant families have developed distinctive biochemical strategies; one of the more unusual examples is found in a group of marine gastropods, the cone snails (Conus) (1). These animals have evolved a specialized biochemistry of small constrained peptides, the conotoxins. Th... | Conotoxins | 1991 |
| 242 |
 |
Ehleringer, James R. | Fuentes de aqua utilizadas por las plantas desérticas y su importancia en planes de manejo y restauración ecológica | El agua es el factor más importante que afecta a la productividad primaria y la estructura de la vegetación en ecosistemas áridos. Dado que las especies de plantas pueden diferir en sus capacidades de utilizar distintas fuentes de agua, el conocimiento de estos aspectos es fundamental para los ... | Fuentes de agua; Isótopos estables; 8-H; 5 l sO; Zonas áridas; Plantas desérticas; Relaciones hídricas; Restauración ecológica; Desierto de Atacama; Atacama Desert; Stable isotopes; Water sources; Arid regions; Ecological restoration; Water relations; Water supplies | 2000 |
| 243 |
 |
Coley, Phyllis D.; Kursar, Thomas A. | Food quality, competition, and parasitism influence feeding preference in a neotropical lepidopteran | We surveyed Lepidoptera found on 11 species of Inga (Fabaceae:Mimosoideae) co-existing on Barro Colorado Island, Panama, to evaluate factors influencing diet choice. Of the 47 species of caterpillars (747 individuals) recorded, each fed on a distinct set of Inga. In the field, 96% of the individuals... | Competition; Electivity; Gelechiid; Herbivore growth; Fabaceae; Inga; Leaf expansion; Leafing phenology; Lipidoptera; Panama; Parasitism; Plant quality | 2006 |
| 244 |
 |
Bohs, Lynn A. | Ethnobotany of the genus Cyphomandra (Solanaceae) | Plants of the genus Cyphomandra (Solanaceae) have long been utilized for their edible fruits in their native Latin America. The best-known species is the domesticated tree tomato or tamarillo, Cyphomandra betacea. This species, popular as a raw or cooked fruit, is widely cultivated in Andean South ... | Cyphomandra; Cyphomandra betacea; Alkaloids | 1989 |
| 245 |
 |
Capecchi, Mario R. | Yeast super-suppressors are altered tRNAs capable of translating a nonsense codon in vitro. | tRNA isolated from two different yeast super-suppressor strains translates a known nonsense mutation in vitro, whereas tRNA from a closely related nonsuppressing strain does not. Suppression was assayed by translation of RNA isolated from an amber coat mutant of bacteriophage Qbeta (GB11) in a prote... | Codon; Escherichia coli; Protein Biosynthesis | 1975-11 |
| 246 |
 |
Olivera, Baldomero M. | Bacteriophage Mu DNA replication in vitro | An in vitro system for bacteriophage Mu DNA replication using lysates on cellophane discs is described. Mu replication was monitored by DNA hybridization. Using a thermoinducible Mu Iysogen, 30-50% of all DNA synthesis in vitro was Mu-specific. | Bacteriophage Mu | 1983 |
| 247 |
 |
Adler, Frederick R. | Is space necessary? Interference competition and limits to biodiversity | A single trade-off between competitive ability and mortality has been shown to support an arbitrarily large number of species in models of interference competition in spatially structured populations. We show that this results not from spatial structure, but instead from the assumption that a small ... | Mortality rate; Competitive ability; Seed size | 2000 |
| 248 |
 |
Sperry, John S. | Analysis of circular bordered pit function I. Angiosperm vessels with homogenous pit membranes | A model predicted pit and vessel conductivity, the air-seed pressure for cavitation, and the implosion pressure causing vessel collapse. Predictions were based on measurements from 27 angiosperm species with circular bordered pits and air-seed pressures of 0.2-11.3 MPa. Vessel implosion pressure exc... | Functional wood anatomy; hydraulic architecture; plant biomechanics | 2004 |
| 249 |
 |
Sperry, John S. | Evaluation of Murray's law in Psilotum nudum (Psilotaceae), an analogue of ancestral vascular plants | Previous work has shown that the xylem of seed plants follows Murray's law when conduits do not provide structural support to the plant. Here, compliance with Murray's law was tested in the stem photosynthesizer Psilotum nudum, a seedless vascular plant. Psilotum nudum was chosen because the central... | Conduit furcation number; hydraulic architecture; Murray's law | 2005 |
| 250 |
 |
Bastiani, Michael | Central projections of the stretch receptor neurons of crayfish: structure, variation, and postembryonic growth | Each stretch receptor neuron (SR) of the crayfish abdomen projects from its peripherally located soma an axon that enters the CNS through the second nerve (N2) of its segmental ganglion. CoZ+ backfills of N2 revealed that this axon bifurcates, sending one branch to the brain and the other to the te... | Abdomen; Axon; Ganglion | 1988 |
