Life Sciences Commons^™

A Method For Estimating Marine Habitat Values Based On Fish Guilds, With Comparisons Between Sites In The Southern California Bight, Alan Bond, John Stephens, Daniel Pondella, James Allen, Mark Helvey

Alan B. Bond

Habitat valuation is an essential tool for tracking changes in habitat quality and in adjudicating environmental mitigation. All current methods for estimating habitat values of coastal marine sites rely heavily on the opinion of experts or on data variables that can readily be manipulated to influence the outcome. As a result, unbiased, quantitative comparisons between the values of different marine habitats are generally unavailable. We report here on a robust, objective technique for the valuation of marine habitats that makes use of data that are commonly gathered in surveys of marine fish populations: density, fidelity, and mean size. To insure …

Monogenic Control Of Iris Coloration In The January Tetra (Hemigrammus Hyanuary Characidae), Jack Frankel

Jack Frankel

Analysis Of Age And Growth In Two Eastern Pacific Groupers (Serranidae: Epinephelinae), Matthew Craig, Daniel Pondella, John Hafner

Daniel Pondella

In an attempt to characterize species specific-growth rates of two Eastern Pacific groupers, individuals from two sympatric species, Epinephelus labriformis (n = 173), and Cephalopholis panamensis (n = 127), were collected at various localities in Mexico and the Galápagos archipelago in 1997 and 1998. Sagittal otoliths were removed, and age of each individual was determined by direct visual inspection of annuli present following sectioning. Length/weight relationships were determined, and growth curves were generated using the von Bertalanffy growth model. The two species demonstrated similar growth rates, yet, as determined by the von Bertalanffy parameters, E. labriformis tended towards a larger …

Action Of Repeat-Induced Point Mutation On Both Strands Of A Duplex And On Tandem Duplications Of Various Sizes In Neurospora, Michael Watters, Thomas Randall, Brian Margolin, Eric Selker, David Stadler

Michael Watters

In Neurospora crassa, DNA sequence duplications are detected and altered efficiently during the sexual cycle by a process known as RIP (repeat-induced point mutation). Affected sequences are subjected to multiple GC-to-AT mutations. To explore the pattern in which base changes are laid down by RIP we examined two sets of strains. First, we examined the products of a presumptive spontaneous RIP event at the mtr locus. Results of sequencing suggested that a single RIP event produces two distinct patterns of change, descended from the two strands of an affected DNA duplex. Equivalent results were obtained using an exceptional tetrad from …

The Saccharomyces Cerevisiae Ubiquitin-Proteasome System, Mark Hochstrasser, Phoebe Johnson, Cassandra Arendt, Alexander Amerik, Sowmya Swaminathan, Rob Swanson, Shyr-Jiann Li, Jeffrey Laney, Robin Pals-Rylaarsdam, Jonathan Nowak, Pamela Connerly, M. Yanagida, K. Nasmyth, M. Tyers, R. Hunt, J. Diffley

Rob Swanson

Our studies of the yeast ubiquitin-proteasome pathway have uncovered a number of general principles that govern substrate selectivity and proteolysis in this complex system. Much of the work has focused on the destruction of a yeast transcription factor, MAT alpha 2. The alpha 2 protein is polyubiquitinated and rapidly degraded in alpha-haploid cells. One pathway of proteolytic targeting, which depends on two distinct endoplasmic reticulum-localized ubiquitin-conjugating enzymes, recognizes the hydrophobic face of an amphipathic helix in alpha 2. Interestingly, degradation of alpha 2 is blocked in a/alpha-diploid cells by heterodimer formation between the alpha 2 and a1 homeodomain proteins. The …

Phd Thesis (Doctorat De Spécialité): Université De Ouagadougou, 1999. Dr. Mamoudou H. Dicko. Purification Et Propriétés Physico-Chimiques Des Enzymes De Curculigo Pilosa, Gladiolus Klattianus Et Boscia Senegalensis Catalysant L'Hydrolyse Des Polysaccharides (Amidon Et Béta-Glucanes), Mamoudou H. Dicko Prof.

Pr. Mamoudou H. DICKO, PhD

The objective of this study was the research of novel and inexpensive sources of polysaccharides degrading enzymes such as amylases and glucanases from local plants in order to justify their biotechnological applications. The isolation of two l3-amylases and an endo-1,3-ß-D-glucanase was reached using common protein purification methods such as buffer extraction, ammonium sulfate fractionation, ionexchange and gel filtration chromatographies. The methods used were simple and easily reproducible, suggesting the possibilfty of large-scale production. ln the crude extract of Curculigo pilosa tuber, only ß-amylase was detected as starch degrading enzyme and its activity was approximately 282 Uig of fresh material. The …

The C. Elegans Homeodomain Gene Unc-42 Regulates Chemosensory And Glutamate Receptor Expression, Renee Baran, Rachel Aronoff, Gian Garriga

Renee Baran

Genes that specify cell fate can influence multiple aspects of neuronal differentiation, including axon guidance, target selection and synapse formation. Mutations in the unc-42 gene disrupt axon guidance along the C. elegans ventral nerve cord and cause distinct functional defects in sensory-locomotory neural circuits. Here we show that unc-42 encodes a novel homeodomain protein that specifies the fate of three classes of neurons in the Caenorhabditis elegans nervous system: the ASH polymodal sensory neurons, the AVA, AVD and AVE interneurons that mediate repulsive sensory stimuli to the nematode head and anterior body, and a subset of motor neurons that innervate …

A Method For Estimating Marine Habitat Values Based On Fish Guilds, With Comparisons Between Sites In The Southern California Bight, Alan B. Bond, John S. Stephens, Daniel J. Pondella Ii, James M. Allen, Mark Helvey

Daniel Pondella

Habitat valuation is an essential tool for tracking changes in habitat quality and in adjudicating environmental mitigation. All current methods for estimating habitat values of coastal marine sites rely heavily on the opinion of experts or on data variables that can readily be manipulated to influence the outcome. As a result, unbiased, quantitative comparisons between the values of different marine habitats are generally unavailable. We report here on a robust, objective technique for the valuation of marine habitats that makes use of data that are commonly gathered in surveys of marine fish populations: density, fidelity, and mean size. To insure …

Genome-Wide Bioinformatic And Molecular Analysis Of Introns In Saccharomyces Cerevisiae, Marc Spingola, Leslie Grate, David Haussler, Manuel Ares

Marc Spingola

Oviposition Preference And Offspring Performance Of Eurosta Solidaginis On Genotypes Of Solidago Altissima, Warren Abrahamson, T. Craig, J. Itami, J. Horner

Warren G. Abrahamson, II

No abstract provided.

Growing Pollen Tubes Possess A Constitutive Alkaline Band In The Clear Zone And A Growth-Dependent Acidic Tip, Joseph Kunkel, J, Feijo, J. Sainhas, G. Hackett, P. Hepler

Joseph Kunkel

Using both the proton selective vibrating electrode to probe the extracellular currents and ratiometric wide-field fluorescence microscopy with the indicator 2′,7′-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF)-dextran to image the intracellular pH, we have examined the distribution and activity of protons (H+) associated with pollen tube growth. The intracellular images reveal that lily pollen tubes possess a constitutive alkaline band at the base of the clear zone and an acidic domain at the extreme apex. The extracellular observations, in close agreement, show a proton influx at the extreme apex of the pollen tube and an efflux in the region that corresponds to the position of …

Episodic Reproduction In Two Fire-Prone Palms, Serenoa Repens And Sabal Etonia (Palmae), Warren Abrahamson

Warren G. Abrahamson, II

No abstract provided.

Influence Of Plant Genotype And Early-Season Water Deficits On Oviposition Preference And Offspring Performance In Eurosta Solidaginis (Diptera: Tephritidae), Warren Abrahamson, J. Horner

Warren G. Abrahamson, II

No abstract provided.

Host-Plant Genotype And Other Herbivores Influence Goldenrod Stem Galler Preference And Performance, Warren Abrahamson, J. Cronin

Warren G. Abrahamson, II

No abstract provided.