UScholar Works
 
Filters: Date: "1983" Department: "Biology" Collection: "ir_uspace"
1 - 25 of 15
Number of results to display per page
CreatorTitleDescriptionSubjectDate
1 Beckerle, Mary C.Analysis of the roles of microtubules and actin in erythrophore intracellular motilityThe Holocentrus erythrophore, a red pigment cell, represents a model system for the study of organized intracellular transport. We have investigated the possibility that microtubules and actin are integral components of the pigment translocating motility machine.Actin; Actomyosin; Erythrophore; Pigment1983
2 Sperry, John S.Anatomy of the palm Rhapis excelsa, IX. Xylem structure of the leaf insertionSTEMS OF PERENNIAL PLANTS, particularly trees, represent a considerable investment in biomass. Trees can survive even under the most adverse conditions, but only if the hydraulic integrity of the stem is preserved. A very important and vulnerable part of the stem is the xylem. As water is pulled int...Palm stems; Palm stem anatomy; Palm leaves; Leaf insertion; Vessel network; Vessel-length distribution; Primary vascular stem tissue; Hydraulic architechture; Water column1983
3 Olivera, Baldomero M.Bacteriophage Mu DNA replication in vitroAn 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 Mu1983
4 Seger, JonConditional relatedness, recombination, and the chromosome numbers of insectsIf two polymorphic loci are out of phase equilibrium, a homozygote at one of these loci is more highly related to its kin, at the other locus, than is an equivalent heterozygote. As a result, selection can favor (1) phenotypic responses to relative heterozygosity, and (2) increased recombination bet...Coefficients of relatedness; Conditional relatedness1983
5 Olivera, Baldomero M.; Gray, William RobertConotoxin MI: disulfide bonding and conformational statesThe toxic peptide from Conus magus venom (conotoxin MI) is a 14-amino acid peptide (McIntosh, M., Cruz, L. J., Hunkapiller, M. W., Gray, W. R., and Olivera, B. M. (1982) Arch. Biochem. Biophys. 218, 329-334) which inhibits the acetylcholine ceptor. In this work we have confirmed the primary structu...Conotoxins; Disulfide bonding; Venom; Conus magus1983
6 Bastiani, MichaelGuidance of neuronal growth cones: selective fasciculation in the grasshopper embryoOne of the central questions of developmental neurobiology concerns how the diversity and specificity of individual neurons are generated during embryonic development. One major component of neuronal diversity is the complex axonal morphology of individual neurons, largely generated early in develop...Neurons; Filopodia; Axon1983
7 Coley, Phyllis D.Herbivory and defensive characteristics of tree species in a lowland tropical forestRate of herbivory and defensive characteristics of young and mature leaves were measured for saplings of 46 canopy tree species in a lowland tropical rain forest (Barro Colorado Island, Panama). Grazing rates were determined in the field for sample periods in the early wet, late wet, and dry seasons...Fiber; Herbivory; Life history; Panama; Phenolics; Plant growth; Spatial distribution; Tannins; Temporal distribution; Treefall gaps; Tropical forest1983
8 Coley, Phyllis D.Intraspecific variation in herbivory on two tropical tree speciesLevels of herbivory on young and mature leaves were determined for two tree species, Trichilia cipo (Meliaceae) and Cecropia insignis (Moraceae), in a lowland rain forest of Panama. Saplings of both species were studied in light gaps, and in addition, Trichilia was studied in the understory.Cecropia insignis; Trichilia cipo; Herbivory; Intraspecific variation; Panama; Temporal distribution; Treefall gaps; Tropical forest; Understory1983
9 Bastiani, MichaelLoss of axons in the cat optic nerve following fetal unilateral enucleation: an electron microscopic analysisBetween the 48th day of gestation (E-48) and maturity, the number of axons in the cat optic nerve is reduced by approximately 50%. On the basis of an electron microscopic assay, the axon population of the E-48 nerve was estimated to be 328,000. In contrast, estimates from two normal adults were 159,...Ganglion cell death; Retinofugal projection; Retinal ganglion cell axons1983
10 Blair, David F.Metal centers of cytochrome c oxidase: structures and interactionsStudies directed toward the elucidation of the structures of the metal centers in cytochrome c oxidase are reviewed. Progress towards an understanding of the interactions between these centers and their spatial distributions within the protein will also be presented. Our studies are based primarily...1983
11 Sperry, John S.Observations on the structure and function of hydathodes in Blechnum lehmaniiThe fronds of many ferns in the Polypodiaceae (Ogura, 1972) and Cyatheaceae (Weiler, cited in Lippmann, 1925) possess swollen vein endings associated with specialized adaxial epidermal cells. Their structure is similar in all ferns (Gardiner, 1883; Potonie, 1892; Poirault, 1893; Goebel, 1930; Gutten...Hydathodes; Blechnum lehmannii; Root pressure; Secretion1983
12 Bastiani, MichaelPathfinding by neuronal growth cones in grasshopper embryos I. Divergent choices made by the growth cones of sibling neuronsWe are interested in how the growth cones of identified neurons navigate in the central nervous system of the grasshopper embryo. The behavior of identified growth cones was observed as a function of developmental time by (i) periodically removing embryos from synchronized clutches of eggs and (i...Neuropil; Axonal; Cell1983
13 Bastiani, MichaelPathfinding by neuronal growth cones in grasshopper embryos: II. Selective fasciculation onto specific axonal pathwaysIn the previous paper (Raper, J. A., M. Bastiani, and C. S. Goodman (1983) J. Neurosci. 3: 20-30) we showed that the growth cones of two sibling neurons, the G and C cells, follow the same route in the developing grasshopper neuropil until they reach a stereotypic choice point. Here their growth con...Neurons; Axons; Neuropil1983
14 Olivera, Baldomero M.Poly(ADP-ribosylation) of a DNA topoisomeraseA DNA topoisomerase activity, copurifying with poly(ADP-ribose) synthetase from calf thymus, >95% inhibited if extensive poly(ADP-ribosylation) is allowed to occur. The inhibited DNA topoisomerase, which has drastically different elution properties on hydroxylapatite, can be reactivated by mild alka...Nicotinic acid; ADP-ribosylation; Turnover cycle; Synthetases1983
15 Coley, Phyllis D.Uprooting and snapping of trees: structural determinants and ecological consequencesThe influence of mechanical and architectural properties of trees on growth rates, mortality rates, and relative probabilities of snapping and uprooting were examined on Barro Colorado Island, Republic of Panama. Of 310 fallen trees, 70% snapped, 25% uprooted, and 5% broke off at ground level. Stepw...Snapping; Uprooting1983
1 - 25 of 15