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Filters: Date: "2000" Department: "Biology" Collection: "ir_uspace"
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CreatorTitleDescriptionSubjectDate
1 Hultine, KevinCarbon and nitrogen allocation to male and female reproduction in Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca, Pinaceae)We measured carbon (respiration, photosynthesis, and production) and nitrogen allocation to male and female cones of Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca) to quantify gender-specific: (1) resource allocation to reproduction, and (2) contribution to carbon costs of reproducti...Gender; photosynthesis; resource allocation2000
2 Ehleringer, James R.Carbon isotope discrimination and water relations of oak hybrid populations in southwestern UtahThe evergreen oak Quercus turbinella and the deciduous Q. gambelii form natural hybrids in southwestern Utah and northern Arizona. Hybrid individuals also are found in northern Utah in a region where only Q. gambelii currently exists, indicating that Q. turbinella has recently retreated southward. ...Quercus turbinella; Oak hybrids; Leaf structure; Leaf nitrogen; Carbon isotope discrimination; Water potential; Oak ecology2000
3 Ehleringer, James R.Carbon isotope ratios in belowground carbon cycle processesAnalyses of carbon isotope ratios (δ13C) in soil organic matter (SOM) and soil respired CO2 provide insights into dynamics of the carbon cycle. δ13C analyses do not provide direct measures of soil CO2 efflux rates but are useful as a constraint in carbon cycle models. In many cases, δ13C analyses...Below ground processes; Ecosystems; Carbon cycle; Carbon isotope ratio; Ecosystem processes; Global change; Soil organic carbon; Soil organic matter2000
4 Beckerle, Mary C.Characterization of the interaction between zyxin and members of the Ena/Vasodilator-stimulated Phosphoprotein family of proteinsZyxin contains a proline-rich N-terminal domain that is similar to the C-terminal domain in the ActA protein of the bacteria, Listeria monocytogenes. We screened the entire amino acid sequence of human zyxin for Menainteracting peptides and found that, as with ActA, proline-rich sequences were the s...Zyxin; Actin; Listeria monocytogenes; Proline-rich repeats; Cell spreading2000
5 Olivera, Baldomero M.Distinction among neuronal subtypes of voltage-activated sodium channels by μ-conotoxin PIIIAThe functional properties of most sodium channels are too similar to permit identification of specific sodium channel types underlying macroscopic current. Such discrimination would be particularly advantageous in the nervous system in which different sodium channel family isoforms are coexpressed i...Conotoxins; m-conotoxin2000
6 Ehleringer, James R.Fuentes de aqua utilizadas por las plantas desérticas y su importancia en planes de manejo y restauración ecológicaEl 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 supplies2000
7 Adler, Frederick R.Genetic and phylogenetic consequences of island biogeographyIsland biogeography theory predicts that the number of species on an island should increase with island size and decrease with island distance to the mainland. These predictions are generally well supported in comparative and experimental studies. These ecological, equilibrium predictions arise as a...Extinction; Genetic divergence; Island isolation; Migration; Speciation2000
8 Carrier, David R.Human flight and exercise in microgravityEarly experimenters in human flight learned, sometimes with fatal consequences, that the human body lacks the muscular power to fly (1). Indeed, the power demands are so great that only relatively small animals (less than 12 kg) are able to fly actively due to the interplay of morphologic scaling (m...Human flight; Microgravity2000
9 Farmer, Colleen G.; Carrier, David R.Integration of ventilation and locomotion in archosaursMovements of the pelvis have recently been found to contribute to ventilation in both crocodilians and birds. Alligators have a kinetic pelvis in which the ischiopubic and ischiotruncus muscles rotate the pubic bones ventrally to increase abdominal volume and thereby facilitate inspiration. In birds...Archosaurs; Theropods; Integration; Ventilation; Pelvic aspiration; Cuirassal breathing2000
10 Ehleringer, James R.Intra- and interspecific variation for summer precipitation use in pinyon-juniper woodlandsIn the arid southwest of North America, winter precipitation penetrates to deep soil layers, whereas summer"monsoon" precipitation generally wets only surface layers. Use of these spatially separated water sources was determined for three dominant tree species of the pinyon-juniper ecosystem at six ...D/H ratios; Juniperus osteosperma; Pinus edulis; pinyon-juniper ecosystem; plant water sources; precipitation use; Quercus gambelii; roots; Photosynthetic gas exchange; Monsoon2000
11 Adler, Frederick R.Is space necessary? Interference competition and limits to biodiversityA 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 size2000
12 Olivera, Baldomero M.; McIntosh, J. MichaelIsolation and characterization of a novel Conus peptide with apparent antinociceptive activityCone snails are tropical marine mollusks that envenomate prey with a complex mixture of neuropharmacologically active compounds. We report the discovery and biochemical characterization of a structurally unique peptide isolated from the venom of Conus marmoreus. The new peptide, mr10a, potently incr...Conotoxins; Conus peptides; Conus marmoreus; mr10a; antinociceptive activity2000
13 Capecchi, Mario R.Lack of angiotensin II-facilitated erythropoiesis causes anemia in angiotensin-converting enzyme-deficient miceWhile nephrologists often observe reduced hematocrit associated with inhibitors of angiotensin-converting enzyme (ACE), the basis for this effect is not well understood. We now report that two strains of ACE knockout mice have a normocytic anemia associated with elevated plasma erythropoietin level...2000
14 Davidson, Diane W.Microtopography of microbiotic crusts on the Colorado Plateau, and distribution of component organismsWe analyzed the microtopography of microbiotic soil crusts at 3 sites on the Colorado Plateau of southern Utah and investigated distributions of cyanobacteria and several lichens in distinctive microhabitats created by this topography. At all 3 sites the long axes of linear soil mounds were oriented...Microtopography; Microbiotic crusts; Colorado Plateau; Cryptobiotic soil; Colonization; Nonrandom orientation; Exposure; Collema; Disturbance history; Microhabitat2000
15 Clayton, Dale H.Molecular phylogeny of the dove genus Zenaida: mitochondrial and nuclear DNA sequencesWe reconstructed a phylogeny for the seven species of doves in the genus Zenaida on the basis of a combined analysis of mitochondria (ND2 and cytochrome b) and nuclear (fibrinogen intron 7) DNA sequences. This phylogeny, which is completely resolved, is well supported with all nodes showing greater...Molecular phylogeny; Dove; Nuclear DNA2000
16 Jorgensen, ErikMutations in synaptojanin disrupt synaptic vesicle recyclingSynaptojanin is a polyphosphoinositide phosphatase that is found at synapses and binds to proteins implicated in endocytosis. For these reasons, it has been proposed that synaptojanin is involved in the recycling of synaptic vesicles. Here, we demonstrate that the unc-26 gene encodes the Caenorhab...2000
17 Jorgensen, ErikMutations in β-spectrin disrupt axon outgrowth and sarcomere structureB-Spectrin is a major component of the membrane skeleton, a structure found at the plasma membrane of most animal cells. B-Spectrin and the membrane skeleton have been proposed to stabilize cell membranes, generate cell polarity, or localize specific membrane proteins. We demonstrate that the Caen...2000
18 Olivera, Baldomero M.; McIntosh, J. MichaelNuclear magnetic resonance solution conformation of α-conotoxin AuIB, an α3ß4 subtype-selective neuronal nicotinic acetylcholine receptor antagonistThe neuronal nicotinic acetylcholine receptors constitute a highly diverse group, with subtypes consisting of pentameric combinations of α and ß subunits. α-Conotoxins are a homologous series of small peptides that antagonize these receptors. We present the three-dimensional solution structure ...Conotoxins; a-conotoxin AuIB2000
19 Farmer, Colleen G.Parental care: the key to understanding endothermy and other convergent features in birds and mammalsBirds and mammals share a number of features that are remarkably similar but that have evolved independently. One of these characters, endothermy, has been suggested to have played a cardinal role in avian and mammalian evolution. I hypothesize that it is parental care, rather than endothermy, that ...Evolution; Metabolism; Convergence2000
20 Olivera, Baldomero M.Single amino acid substitutions in ĸ-conotoxin PVIIA disrupt interaction with the Shaker K+ channelĸ-Conotoxin PVIIA (ĸ-PVIIA), a 27-amino acid peptide with three disulfide cross-links, isolated from the venom of Conus purpurascens, is the first conopeptide shown to inhibit the Shaker K1 channel (Terlau, H., Shon, K., Grilley, M., Stocker, M., Stühmer, W., and Olivera, B. M. (1996) Nature ...Conotoxins; k-conotoxin PVIIA; Shaker K+ channels; Conus purpurascens2000
21 Clayton, Dale H.Testing species limits of non-echolocating Philippine swiftlets (Collocalia spp.) using molecular genetic dataSwiftlets are small, insectivorous birds that are distributed from the Indian Ocean, through southeast Asia and north Australia, to the Pacific. About 22 species of swiflets nest in caves or other dark places, where they navigate using a crude form of echolocation (Chantler and Driessens 1995). Thr...2000
22 Goller, FranzTracheal length changes and upper vocal tract resonances during zebra finch songUpper vocal tract resonances in singing birds could be modified by beak opening, laryngeal adjustments and tracheal length changes.Sonomicrometry; Syringeal; Tracheal shortening2000
23 Sperry, John S.Vulnerability to xylem cavitation and the distribution of sonoran desert vegetationWe studied 15 riparian and upland Sonoran desert species to evaluate how the limitation of xylem pressure (Vx) by cavitation corresponded with plant distribution along a moisture gradient. Riparian species were obligate riparian trees (Fraxinus velutina, Populus fremontii, and Salix gooddingii), nat...Comparative approach; species distribution; xylem conducting efficency2000
24 Ehleringer, James R.Water and nitrogen uptake patterns following moisture pulses in a cold desert communityVariation in the ability to utilize pulses of both water and nitrogen (N) is one possible mechanism allowing the coexistence of species in the cold desert community on the Colorado Plateau. We simulated 25-mm precipitation events and used stable isotope tracers (2H and 15N) to follow water and N upt...Colorado Plateau; Desert perennials; Nitrogen uptake patterns; Pulse utilization; Resource partitioning; Stable isotopes; Water uptake patterns2000
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