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Iowa State University

1994

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Articles 1 - 12 of 12

Full-Text Articles in Life Sciences

Using Biodiversity Data To Assess Species--Habitat Relationships In Glacier National Park, Montana, Diane M. Debinski, Peter F. Brussard Nov 1994

Using Biodiversity Data To Assess Species--Habitat Relationships In Glacier National Park, Montana, Diane M. Debinski, Peter F. Brussard

Diane M. Debinski

Biodiversity surveys are becoming increasingly popular. However, standard analysis techniques for these data have not yet been developed. This paper explores the use of multivariate ordination techniques for assessing species—habitat relationships using biodiversity data. The research was conducted in Glacier National Park, Montana, and birds and butterflies were chosen as the taxonomic groups of study. Biodiversity assessment sites were established throughout a range of habitats and monitored from 1987 through 1989. Presence/absence sampling over the total number of sampling sites was used to classify species commonness and rarity. Approximately 86% of the historically recorded butterflies and 70% of the historically …

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A Nuclear Juvenile Hormone-Binding Protein From Larvae Of Manduca Sexta: A Putative Receptor For The Metamorphic Action Of Juvenile Hormone, Subba R. Palli, Kazushige Touhara, Jean-Philippe Charles, Bryony C. Bonning, Jeffrey K. Atkinson, Stephen C. Trowell, Kiyoshi Hiruma, Walter G. Goodman, Themis Kyriakides, Glenn D. Prestwich, Bruce D. Hammock, Lynn M. Ridiford Jun 1994

A Nuclear Juvenile Hormone-Binding Protein From Larvae Of Manduca Sexta: A Putative Receptor For The Metamorphic Action Of Juvenile Hormone, Subba R. Palli, Kazushige Touhara, Jean-Philippe Charles, Bryony C. Bonning, Jeffrey K. Atkinson, Stephen C. Trowell, Kiyoshi Hiruma, Walter G. Goodman, Themis Kyriakides, Glenn D. Prestwich, Bruce D. Hammock, Lynn M. Ridiford

Bryony C. Bonning

A 29-kDa nuclear juvenile hormone (JH)-binding protein from the epidermis of Manduca sexta larvae was purified by using the photoaffinity analog for JH II ([3H]epoxyhomofarnesyldiazoacetate) and partially sequenced. A 1.1-kb cDNA was isolated by using degenerate oligonucleotide primers for PCR based on these sequences. The cDNA encoded a 262-amino acid protein that showed no similarity with other known proteins, except for short stretches of the interphotoreceptor retinoid-binding protein, rhodopsin, and human nuclear protein p68. Recombinant baculovirus containing this cDNA made a 29-kDa protein that was covalently modified by [3H]epoxyhomofarnesyldiazoacetate and specifically bound the natural enantiomer of JH I (Kd = …

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The Phosphate Transporter From Pea Mitochondria (Isolation And Characterization In Proteolipid Vesicles), Cecilia A. Mcintosh, David J. Oliver May 1994

The Phosphate Transporter From Pea Mitochondria (Isolation And Characterization In Proteolipid Vesicles), Cecilia A. Mcintosh, David J. Oliver

David J. Oliver

The phosphate transporter from mitochondria will exchange matrix phosphate for cytosolic phosphate and facilitate either phosphate/proton symport or phosphate/hydroxyl ion antiport. The phosphate transported into the matrix by this carrier is either used for ATP synthesis or exchanges back out to the cytosol on the dicarboxylate transporter, permitting entry of malate and succinate into the matrix. The phosphate transporter was solubilized from etiolated pea (Pisum sativum L. cv Alaska) mitochondrial membranes with Triton X-114, purified approximately 500-fold by hydroxylapatite chromatography, and reconstituted into azolectin vesicles that were preloaded with 0.1 or 10 mM phosphate. Phosphate transport was measured as the …

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Insect Control By Use Of Recombinant Baculoviruses Expressing Juvenile Hormone Esterase, Bryony C. Bonning, Bruce D. Hammock Jan 1994

Insect Control By Use Of Recombinant Baculoviruses Expressing Juvenile Hormone Esterase, Bryony C. Bonning, Bruce D. Hammock

Bryony C. Bonning

Anti-juvenile hormone activity, and the resulting cessation of feeding, has long been considered by the agricultural chemical industry as a means for insect control. Juvenile hormone esterase (JHE) contributes to the decline in JH titer at certain times during larval development. This chapter reviews the efforts made to develop a fast acting recombinant baculovirus insecticide by creating a virus which will express artificially high levels of JHE in the insect at inappropriate times. The findings are discussed in the light of our current understanding of the regulation of larval development and the role of JHE. Prospects for the newly developed, …

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Predicting Modes Of Toxic Action From Chemical Structure: An Overview, Steven P. Bradbury Jan 1994

Predicting Modes Of Toxic Action From Chemical Structure: An Overview, Steven P. Bradbury

Steven P. Bradbury

In the field of environmental toxicology, and especially aquatic toxicology, quantitative structure activity relationships (QSARs) have developed as scientifically-credible tools for predicting the toxicity of chemicals when little or no empirical data are available. A basic and fundamental understanding of toxicological principles has been considered crucial to the continued acceptance and application of these techniques as biologically relevant. As a consequence, there has been an evolution of QSAR development and application from that of a chemical-class perspective to one that is more consistent with assumptions regarding modes of toxic action. The assessment of a compound’s likely mode of toxic action …

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Influence Of Summer Storms On The Solution Geochemistry In A Coastal Plain Hydrosequence, Jeffrey M. Novak, C. Lee Burras Jan 1994

Influence Of Summer Storms On The Solution Geochemistry In A Coastal Plain Hydrosequence, Jeffrey M. Novak, C. Lee Burras

C. Lee Burras

An understanding of factors which influence wetland soil solution chemistry is important for soil solutions are known to influence some chemical properties of surface waters. The influence of summer storms on the solution geochemistry in a South Carolina riverine wetland soil was evaluated by comparing pore water collected 2,4 hr after five summer storm events with pore water acquired during five nonstorm periods. Pore water was collected by tension lysimeters buried at 15 to 152 cm in two locations along a hydrologic gradient. Samples of rain, throughfall and stream water were also collected. Overall, summer storms had no significant influence …

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Induced Lsoflavonoids In Diverse Populations Of Astragalus Cicer, Andrew W. Lenssen, Susan S. Martin, Charley E. Townsend Jan 1994

Induced Lsoflavonoids In Diverse Populations Of Astragalus Cicer, Andrew W. Lenssen, Susan S. Martin, Charley E. Townsend

Andrew W. Lenssen

lsoflavonoids were induced in mature leaves of the legume Asbagalus cicer L. by spores of the fungus Bipoaris zeicola. The five major elicited compounds included two isoflavans (mucronulatol and astraciceran), two isoflavones (cajanin and acicerone), and a pterocarpan (maackiain). Only occasional traces of these compounds were detected in controls. Among 41 populations originating in Europe or Russia, mean total elicited isoflavonoid content differed 12-fold. Mucronulatol was the predominant compound elicited, comprising 20-70% of total isoflavonoids. Significant interpopulational differences existed for each isoflavonoid, but no geographic patterns of total or relative proportions of the five compounds were discernible.

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Acicerone: An Isoflavone From Astragalus Cicer, Andrew W. Lenssen, Susan S. Martin, Charley E. Townsend, Bruce Hawkins Jan 1994

Acicerone: An Isoflavone From Astragalus Cicer, Andrew W. Lenssen, Susan S. Martin, Charley E. Townsend, Bruce Hawkins

Andrew W. Lenssen

A new isoflavone isolated from fungus-inoculated roots of Astragalus cicer has been identified as 6-hydroxy- 7-methoxy-3’,4’-methylenedioxyisoflavone (acicerone).

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Cell Surface Charge And Initial Attachment Characteristics Of Rough Strains Of Listeria Monocytogenes, James S. Dickson Jan 1994

Cell Surface Charge And Initial Attachment Characteristics Of Rough Strains Of Listeria Monocytogenes, James S. Dickson

James S. Dickson

The relative negative surface charge and hydrophobicity of four bacterial strains were evaluated by gravity flow and spin column methods. There was no significant difference between the two methods, indicating that spin column chromatography is an acceptable alternative method of determining cell surface charge or hydrophobicity. Six strains of Listeria monocytogenes which exhibited rough colony appearance were evaluated for surface charge and hydrophobicity and their ability to contaminate beef muscle tissue. With one exception, all of the rough strains exhibited greater net negative surface charge and reduced ability to contaminate beef during the initial stages of attachment. Since greater net …

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Antimicrobial Effects Of Trisodium Phosphate Against Bacteria Attached To Beef Tissue, James S. Dickson, C. G. Nettles Cutter, G. R. Siragusa Jan 1994

Antimicrobial Effects Of Trisodium Phosphate Against Bacteria Attached To Beef Tissue, James S. Dickson, C. G. Nettles Cutter, G. R. Siragusa

James S. Dickson

Sliced beef tissue was artificially contaminated with Salmonella typhimurium, Listeria monocytogenes and Escherichia coli OI57:H7. The contaminated tissue was immersed in 8, 10 and 12% solutions of trisodium phosphate at 25, 40 and 55°C with contact times of up to 3 min. The concentration of the trisodium phosphate solution was not a significant factor in reducing the populations of the bacteria on either lean or adipose tissue. Reductions in bacterial populations of I to 1.5 loglocycles were obtained on lean tissue contaminated with the gram-negative pathogens, although less reduction in population was seen with L. monocytogenes. Greater reductions in bacterial …

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Temporal Response Of Rabbits To B-Adrenergic Agonist Feeding: Tissue Weight, Calpain And Calpastatin Activities, And Nucleic Acid And Protein Concentration, T. D. Pringle, Steven M. Lonergan, C. R. Calkins, S. J. Jones, P. S. Miller, M. Koohmaraie Jan 1994

Temporal Response Of Rabbits To B-Adrenergic Agonist Feeding: Tissue Weight, Calpain And Calpastatin Activities, And Nucleic Acid And Protein Concentration, T. D. Pringle, Steven M. Lonergan, C. R. Calkins, S. J. Jones, P. S. Miller, M. Koohmaraie

Steven M. Lonergan

Forty-eight crossbred rabbits were used in three replications of a 2 x 4 factorial arrangement to investigate the short-term responses of tissue accretion, calpains and calpastatin activity, and nucleic acid and protein concentrations to 6- adrenergic agonist (BAA) feeding. Rabbits were fed a 17% CP diet with or without 7 ppm of L644,969 and slaughtered after 1, 4, 8, or 16 d of treatment. Empty body dressing percentage and biceps femoris weight (as a percentage of empty body weight [EBWI) were significantly higher in the treated rabbits than in the controls after 16 d of treatment. Heart and liver weights …

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Field Identification Of Birdseye In Sugar Maple (Acer Saccharum Marsh.), Douglas D. Stokke, Don C. Bragg Jan 1994

Field Identification Of Birdseye In Sugar Maple (Acer Saccharum Marsh.), Douglas D. Stokke, Don C. Bragg

Douglas D. Stokke

Birdseye grain distortions in sugar maple must be identified to capture the full value of a timber sale throughout the economic range of birdseye's occurrence. Even when relatively common, birdseye veneer typically makes up less than 1 percent of the harvested volume, but may account for one-half of the value of the sale. With prices recently reaching $50,000 per Mbf for prime logs, omission of birdseye (when present) from cruise data could cause significant economic loss for the forest landowner. But figured wood can sometimes be detected in standing timber (Pillow 1955). Field identification of birdseye sugar maple is critical …

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