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Articles 1 - 25 of 25
Full-Text Articles in Life Sciences
Long-Toed Salamanders In Harvested And Intact Douglas-Fir Forests Of Western Montana, George P. Naughton, Colin B. Henderson, Kerry R. Foresman, Rex L. Mcgraw Ii
Long-Toed Salamanders In Harvested And Intact Douglas-Fir Forests Of Western Montana, George P. Naughton, Colin B. Henderson, Kerry R. Foresman, Rex L. Mcgraw Ii
Biological Sciences Faculty Publications
There is little known about how timber harvest practices have affected terrestrial amphibians in the northern Rocky Mountains. Especially lacking is information on the effects of revised harvest methods that fall within the framework of environmental or New Forestry. We estimated the relative abundance of a common forest amphibian, the long-toed salamander (Ambystoma macrodactylum) captured in pitfall arrays on intact, environmentally harvested, and overstory-removal harvested sites in mixed-conifer forests of western Montana. Pitfall data from 1994 through 1996 showed that previously logged sites contained significantly fewer long-toed salamanders regardless of harvest method used. The number of salamanders captured …
Characterization Of Borrelia Burgdorferi Blya And Blyb Proteins: A Prophage-Encoded Holin-Like System, Christopher J. Damman, Christian H. Eggers, D. Scott Samuels
Characterization Of Borrelia Burgdorferi Blya And Blyb Proteins: A Prophage-Encoded Holin-Like System, Christopher J. Damman, Christian H. Eggers, D. Scott Samuels
Biological Sciences Faculty Publications
The conserved cp32 plasmid family of Borrelia burgdorferi was recently shown to be packaged into a bacteriophage particle (C. H. Eggers and D. S. Samuels, J. Bacteriol. 181:7308-7313, 1999), This plasmid encodes BlyA, a 7.4-kDa membrane-interactive protein, and BlyB, an accessory protein, which were previously proposed to comprise a hemolysis system. Our genetic and biochemical evidence suggests that this hypothesis is incorrect and that BlyA and BlyB function instead as a prophage-encoded holin or holin-like system for this newly described bacteriophage, An Escherichia coli mutant containing the blyAB locus that was defective for the normally cryptic host hemolysin SheA was …
Sensitivity Of Species Habitat-Relationship Model Performance To Factors Of Scale, J. W. Karl, P. J. Heglund, E. O. Garton, J. M. Scott, N. M. Wright, Richard L. Hutto
Sensitivity Of Species Habitat-Relationship Model Performance To Factors Of Scale, J. W. Karl, P. J. Heglund, E. O. Garton, J. M. Scott, N. M. Wright, Richard L. Hutto
Biological Sciences Faculty Publications
Researchers have come to different conclusions about the usefulness of habitat-relationship models for predicting species presence or absence. This difference frequently stems from a failure to recognize the effects of spatial scales at which the models are applied. We examined the effects of model complexity, spatial data resolution, and scale of application on the performance of bird habitat relationship (BHR) models on the Craig Mountain Wildlife Management Area and on the Idaho portion of the U.S. Forest Service's Northern Region. We constructed and tested BHR models for 60 bird species detected on the study areas. The models varied by three …
Hemin-Binding Surface Protein From Bartonella Quintana, James A. Carroll, Sherry A. Coleman, Laura S. Smitherman, Michael F. Minnick
Hemin-Binding Surface Protein From Bartonella Quintana, James A. Carroll, Sherry A. Coleman, Laura S. Smitherman, Michael F. Minnick
Biological Sciences Faculty Publications
Bartonella quintana, the agent of trench fever and a cause of endocarditis and bacillary angiomatosis in humans, has the highest reported in vitro hemin requirement for any bacterium. We determined that eight membrane-associated proteins from B. quintana bind hemin and that a similar to 25-kDa protein (HbpA) was the dominant hemin binding protein. Like many outer membrane proteins, HbpA partitions to the detergent phase of a Triton X-114 extract of the cell and is heat modifiable, displaying an apparent molecular mass shift from approximately 25 to 30 kDa when solubilized at 100 degreesC. Immunoblots of purified outer and inner membranes …
Comparison Of Coastal Fringe And Interior Forests As Reserves For Marbled Murrelets On Vancouver Island, Alan E. Burger, Volker Bahn, Angeline R.M. Tillmanns
Comparison Of Coastal Fringe And Interior Forests As Reserves For Marbled Murrelets On Vancouver Island, Alan E. Burger, Volker Bahn, Angeline R.M. Tillmanns
Biological Sciences Faculty Publications
Much of the protected habitat available to the threatened Marbled Murrelet Brachyramphus marmoratus and other old-growth associated species in the Pacific Northwest is in narrow strips along the coast (e.g., parks and scenic fringes). Using data over two years from three watersheds on southwest Vancouver Island, we show that such shoreline strip forests represent suboptimal habitat for murrelets. Murrelet detections, including circling and subcanopy behaviors, were significantly lower at 30 coastal stations (20–250 m from the shoreline edge) than at 30 interior stations (1.5–21.0 km inland). Densities of predators were significantly higher at the coastal stations. The coastal trees were …
Monitoring Bacterial Transport By Stable Isotope Enrichment Of Cells, William Holben, Peggy H. Ostrom
Monitoring Bacterial Transport By Stable Isotope Enrichment Of Cells, William Holben, Peggy H. Ostrom
Biological Sciences Faculty Publications
Understanding the transport and behavior of bacteria in the environment has broad implications in diverse areas, ranging from agriculture to groundwater quality, risk assessment, and bioremediation. The ability to reliably track and enumerate specific bacterial populations in the context of native communities and environments is key to developing this understanding. We report a novel bacterial tracking approach, based on altering the stable carbon isotope value (delta C-13) Of bacterial cells, which provides specific and sensitive detection and quantification of those cells in environmental samples. This approach was applied to the study of bacterial transport in saturated porous media. The transport …
Facilitation May Buffer Competitive Effects: Indirect And Diffuse Interactions Among Salt Marsh Plants, Ragan M. Callaway, Steven C. Pennings
Facilitation May Buffer Competitive Effects: Indirect And Diffuse Interactions Among Salt Marsh Plants, Ragan M. Callaway, Steven C. Pennings
Biological Sciences Faculty Publications
Direct interactions among plant species may be highly modified by indirect or diffuse effects within a multispecies community. We investigated the direct and diffuse effects of two salt marsh perennials, Monanthechloe littoralis and Arthrocnemum subterminale, on winter annuals and the perennial herb Limonium californicum in a salt marsh in central California. In permanent plots, Monanthechloe had expanded substantially in the upper marsh over the past 13 yr, while Arthrocnemum and all annual species had decreased. These dynamics suggest that Monanthechloe may directly outcompete most other species in the upper marsh. In contrast, Arthrocnemum is known to facilitate some annual species. …
Tid1/Rdh54 Promotes Colocalization Of Rad51 And Dmc1 During Meiotic Recombination, Stephen L. Gasior
Tid1/Rdh54 Promotes Colocalization Of Rad51 And Dmc1 During Meiotic Recombination, Stephen L. Gasior
Biological Sciences Faculty Publications
Two RecA homologs, Rad51 and Dmc1, assemble as cytologically visible complexes (foci) at the same sites on meiotic chromosomes. Time course analysis confirms that co-foci appear and disappear as the single predominant form. A large fraction of co-foci are eliminated in a red1 mutant, which is expected as a characteristic of the interhomolog-specific recombination pathway. Previous studies suggested that normal Dmc1 loading depends on Rad51. We show here that a mutation in TID1/RDH54, encoding a RAD54 homolog, reduces Rad51-Dmc1 colocalization relative to WT. A rad54 mutation, in contrast, has relatively little effect on RecA homolog foci except when strains also …
Regional Variation In Recruitment Of Hemlock Seedlings And Saplings In The Upper Great Lakes, Usa, Thomas P. Rooney, Ronald J. Mccormick, Stephen L. Solheim, Donald M. Waller
Regional Variation In Recruitment Of Hemlock Seedlings And Saplings In The Upper Great Lakes, Usa, Thomas P. Rooney, Ronald J. Mccormick, Stephen L. Solheim, Donald M. Waller
Biological Sciences Faculty Publications
Mature eastern hemlock–northern hardwood forest cover decreased drastically in the upper Midwest following European settlement and has yet to rebound substantially. Previous studies show that stands retaining substantial hemlock canopy coverage have low hemlock seedling and sapling densities. Results from various geographically restricted studies suggest several possible mechanisms that could cause low seedling or sapling density. We examined the relative importance of these proposed mechanisms in the Southern Superior Uplands Section of the Laurentian Forest Province. We surveyed 294- m2 plots in 100 hemlock stands in northern Wisconsin and western upper Michigan to assess how these proposed mechanisms affect the …
A Biochemical Mechanism For Nonrandom Mutations And Evolution, Barbara E. Wright
A Biochemical Mechanism For Nonrandom Mutations And Evolution, Barbara E. Wright
Biological Sciences Faculty Publications
No abstract provided.
Outcrossing Rate And Inbreeding Depression In The Perennial Yellow Bush Lupine, Lupinus Arboreus (Fabaceae), Pamela Kittelson, John L. Maron
Outcrossing Rate And Inbreeding Depression In The Perennial Yellow Bush Lupine, Lupinus Arboreus (Fabaceae), Pamela Kittelson, John L. Maron
Biological Sciences Faculty Publications
Little is known about the breeding systems of perennial Lupinus species. We provide information about the breeding system of the perennial yellow bush lupine, Lupinus arboreus, specifically determining self-compatibility, outcrossing rate, and level of inbreeding depression. Flowers are self-compatible, but autonomous self-fertilization rarely occurs; thus selfed seed are a product of facilitated selfing. Based on four isozyme loci from 34 maternal progeny arrays of seeds we estimated an outcrossing rate of 0.78. However, when we accounted for differential maturation of selfed seeds, the outcrossing rate at fertilization was lower, ∼0.64. Fitness and inbreeding depression of 11 selfed and outcrossed families …
The Impacts Of A Nonindigenous Marine Predator In A California Bay, Edwin D. Grosholz, Gregory M. Ruiz, Cheryl A. Dean, Kim A. Shirley, John L. Maron, Peter G. Connors
The Impacts Of A Nonindigenous Marine Predator In A California Bay, Edwin D. Grosholz, Gregory M. Ruiz, Cheryl A. Dean, Kim A. Shirley, John L. Maron, Peter G. Connors
Biological Sciences Faculty Publications
Coastal marine ecosystems worldwide are being altered rapidly by the invasion of nonindigenous species. Unlike terrestrial and freshwater systems, the impacts of an invading species have never been quantified on multiple trophic levels for a marine food web. We measured the impact of the nonindigenous green crab, Carcinus maenas, on a coastal marine food web in central California and found that this predator exerted strong “top-down” control, significantly reducing the abundances of several of the 20 invertebrate species monitored over a 9-yr period. Densities of native clams, Nutricola tantilla and Nutricola confusa, and native shore crabs, Hemigrapsus oregonensis, showed 5-fold …
Integrating Development With Evolution: A Case Study With Beetle Horns, Douglas J. Emlen
Integrating Development With Evolution: A Case Study With Beetle Horns, Douglas J. Emlen
Biological Sciences Faculty Publications
No abstract provided.
Disruption Of The Borrelia Burgdorferi Gac Gene, Encoding The Naturally Synthesized Gyra C-Terminal Domain, Scott W. Knight, Betsy J. Kimmel, Christian H. Eggers, D. Scott Samuels
Disruption Of The Borrelia Burgdorferi Gac Gene, Encoding The Naturally Synthesized Gyra C-Terminal Domain, Scott W. Knight, Betsy J. Kimmel, Christian H. Eggers, D. Scott Samuels
Biological Sciences Faculty Publications
The C-terminal domain of the A subunit of DNA gyrase, which we term Gac, is naturally synthesized in Borrelia burgdorferi as an abundant DNA-binding protein. Full-length GyrA, which includes the C-terminal domain, is also synthesized by the spirochete and functions as a subunit of DNA gyrase, We have disrupted synthesis of Gac as an independent protein and demonstrated that it is not essential for growth in a coumarin-resistant background. We detected no alterations in DNA maintenance, condensation, or topology In B. burgdorferi lacking this small DNA-binding protein.
Periphyton Production On Wood And Sediment: Substratum-Specific Response To Laboratory And Whole-Lake Nutrient Manipulations, Yvonne Vadeboncoeur, David M. Lodge
Periphyton Production On Wood And Sediment: Substratum-Specific Response To Laboratory And Whole-Lake Nutrient Manipulations, Yvonne Vadeboncoeur, David M. Lodge
Biological Sciences Faculty Publications
Substratum heterogeneity is a large source of variability in periphyton production, but the influence of substratum on periphyton response to experimental manipulations is rarely measured. Using laboratory and whole-lake experiments, we compared area-specific primary production of periphyton on wood (epixylon) and sediment (epipelon), and tested whether periphyton on the 2 substrata responded differently to water-column fertilization. In the laboratory, natural periphyton assemblages on wood or sediment were exposed to 1 of 6 treatments in a fully factorial (light [250, 70, or 10 μmol m−2 s−1] × nutrient [control or + N and P]) experiment. We measured 14 …
The Advantages Of Clonal Integration Under Different Ecological Conditions: A Community-Wide Test, Steven C. Pennings, Ragan M. Callaway
The Advantages Of Clonal Integration Under Different Ecological Conditions: A Community-Wide Test, Steven C. Pennings, Ragan M. Callaway
Biological Sciences Faculty Publications
The "connectedness" of clonal plants has been shown to promote survival and growth in a variety of single-species, single-factor studies, but experiments comparing the relative advantages of clonality across multiple habitats and species are rare, raising the concern that generalizations about the benefits of clonality might be biased by the particular species or habitat studied. We studied the importance of clonal integration in southeastern USA salt marsh plants, using all six of the common clonal species in the community, by following the success of intact and severed clonal fragments invading three habitat treatments. Clonal integration was most important for growth …
A Bacteriophage-Like Particle From Bartonella Bacilliformis, Kent D. Barbian, Michael F. Minnick
A Bacteriophage-Like Particle From Bartonella Bacilliformis, Kent D. Barbian, Michael F. Minnick
Biological Sciences Faculty Publications
Bartonella bacilliformis and Bartonella henselae, the respective agents of Oroya fever and cat-scratch disease in humans, are known to produce bacteriophage-like particles (BLPs) that package 14 kbp segments of the host chromosome. Data from this study suggest that other Bartonella species including Bartonella quintana, Bartonella doshiae and Bartonella grahamii also contain similar BLPs, as evidenced by the presence of a 14 kbp extrachromosomal DNA element in their genomes, whereas Bartonella elizabethae and Bartonella clarridgeiae do not. A purification scheme utilizing chloroform, DNase I and centrifugation was devised to isolate BLPs from B. bacilliformis. Intact BLPs were observed by transmission electron …
Stress And Developmental Stability: Vegetation Removal Causes Increased Fluctuating Asymmetry In Shrews, Alexander V. Badyaev, Kerry R. Foresman, Miguel V. Fernandes
Stress And Developmental Stability: Vegetation Removal Causes Increased Fluctuating Asymmetry In Shrews, Alexander V. Badyaev, Kerry R. Foresman, Miguel V. Fernandes
Biological Sciences Faculty Publications
Environmental stress can increase phenotypic variation in populations by affecting developmental stability of individuals. While such increase in variation results from individual differences in ability to buffer stress, groups of individuals and different traits may have different sensitivity to stressful conditions. For example, the sex that is under stronger directional selection for faster growth may be more sensitive to stressful conditions during development. On an individual level, stress-induced variation in a trait may be related to the strength of stabilizing selection that acts on the trait. We experimentally examined sensitivity of mandibular development to stress in a free-living population of …
Genetic Variation Among Endosymbionts Of Widely Distributed Vestimentiferan Tubeworms, Carol A. Di Meo, Ami E. Wilbur, William E. Holben, Robert A. Feldman, Robert C. Vrijenhoek, S. Craig Cary
Genetic Variation Among Endosymbionts Of Widely Distributed Vestimentiferan Tubeworms, Carol A. Di Meo, Ami E. Wilbur, William E. Holben, Robert A. Feldman, Robert C. Vrijenhoek, S. Craig Cary
Biological Sciences Faculty Publications
Vestimentiferan tubeworms thriving in sulfidic deep-sea hydrothermal vents and cold seeps are constrained by their nutritional reliance on chemoautotrophic endosymbionts. In a recent phylogenetic study using 16S ribosomal DNA, we found that endosymbionts from vent and seep habitats form two distinct clades,vith little variation within each clade. In the present study, we used two different approaches to assess the genetic variation among biogeographically distinct vestimentiferan symbionts, DNA sequences were obtained for the noncoding, internal transcribed spacer (ITS) regions of the rRNA operons of symbionts associated with six different genera of vestimentiferan tubeworms. ITS sequences from endosymbionts of host genera collected …
Structure Of A Rat Α1-Macroglobulin Receptor-Binding Domain Dimer, Tsan Xiao, Dianne L. Decamp, Stephen R. Sprang
Structure Of A Rat Α1-Macroglobulin Receptor-Binding Domain Dimer, Tsan Xiao, Dianne L. Decamp, Stephen R. Sprang
Biological Sciences Faculty Publications
α-Macroglobulin inhibits a broad spectrum of proteinases by forming macromolecular cages inside which proteinases are cross-linked and trapped. Upon formation of a complex with proteinase, α-macroglobulin undergoes a large conformational change that results in the exposure of its receptor-binding domain (RBD). Engagement of this domain by α-macroglobulin receptor permits clearance of the α-macroglobulin: proteinase complex from circulation. The crystal structure of rat α1-macroglobulin RBD has been determined at 2.3 Å resolution. The RBD is composed of a nine-stranded β-sandwich and a single α-helix that has been implicated as part of the receptor binding site and that lies on …
Evidence For Microbial Fe(Iii) Reduction In Anoxic, Mining-Impacted Lake Sediments (Lake Coeur D’Alene, Idaho), David E. Cummings, Anthony W. March, Benjamin Bostick, Stefan Spring, Frank Caccavo Jr., Scott Fendorf, Frank Rosenzweig
Evidence For Microbial Fe(Iii) Reduction In Anoxic, Mining-Impacted Lake Sediments (Lake Coeur D’Alene, Idaho), David E. Cummings, Anthony W. March, Benjamin Bostick, Stefan Spring, Frank Caccavo Jr., Scott Fendorf, Frank Rosenzweig
Biological Sciences Faculty Publications
Mining-impacted sediments of Lake Coeur d'Alene, Idaho, contain more than 10% metals on a dry weight basis, approximately 80% of which is iron. Since iron (hydr)oxides adsorb toxic, ore-associated elements, such as arsenic, iron (hydr)oxide reduction may in part control the mobility and bioavailability of these elements. Geochemical and microbiological data were collected to examine the ecological role of dissimilatory Fe(III)-reducing bacteria in this habitat. The concentration of mild-acid-extractable Fe(II) increased with sediment depth up to 50 g kg−1, suggesting that iron reduction has occurred recently. The maximum concentrations of dissolved Fe(II) in interstitial water (41 mg liter …
Absence Of Insect Juvenile Hormones In The American Dog Tick, Dermacentor Veriabilis (Say) (Acari: Ixodidae), And In Ornithodoros Parkeri Cooley (Acari: Argasidae), P. A. Neese, Daniel E. Sonenshine, V. L. Kallapur, C. S. Apperson, R. M. Roe
Absence Of Insect Juvenile Hormones In The American Dog Tick, Dermacentor Veriabilis (Say) (Acari: Ixodidae), And In Ornithodoros Parkeri Cooley (Acari: Argasidae), P. A. Neese, Daniel E. Sonenshine, V. L. Kallapur, C. S. Apperson, R. M. Roe
Biological Sciences Faculty Publications
Synganglia, salivary gland, midgut, ovary, fat body and muscle alone and in combination from the ixodid tick, Dermacentor variabilis (Say), or the argasid tick, Ornithodoros parkeri Cooley, were incubated in vitro in separate experiments with L-[methyl-3H]methionine and farnesoic acid or with [1-14C]acetate. Life stages examined in D. variabilis were 3 and 72 h old (after ecdysis) unfed nymphs, partially fed nymphs (18 and 72 h after attachment to the host), fully engorged nymphs (2 d after detachment from host), 3 and 72 h old (after eclosion) unfed females, partially fed unmated females (12–168 …
Response Of The Tick Dermacentor Variabilis (Acari: Ixodidae) To Hemocoelic Inoculation Of Borrelia Burgdorferi (Spirochetales), Robert Johns, Daniel E. Sonenshine, Wayne L. Hynes
Response Of The Tick Dermacentor Variabilis (Acari: Ixodidae) To Hemocoelic Inoculation Of Borrelia Burgdorferi (Spirochetales), Robert Johns, Daniel E. Sonenshine, Wayne L. Hynes
Biological Sciences Faculty Publications
When Borrelia burgdorferi B31 low passage strain spirochetes were directly injected into the hemocoel of Dermacentor variabilis(Say) females, the bacteria were cleared from the hemocoel within < 24 h. Viable spirochetes were not found in hemolymph, salivary gland, or ovary tissues by subculturing or by IFA. The hemocyte population increased ≈6 times within the first 6 h after inoculation compared with the uninoculated controls. In contrast, the soluble total hemolymph protein content decreased inversely with the increase in hemocytes. Borreliacidal activity was demonstrated with cell-free hemolymph from D. variabilis. In vitro antimicrobial assays using hemolymph from borrelia-challenged and nonchallenged ticks resulted in 72% spirochete reductions compared with only 11.5%, respectively, within 1 h. Additional evidence of induced antimicrobial hemolymph protein activity was demonstrated by SDS-PAGE, which revealed upregulation of a lysozyme-like peptide (≈ 15 kDa) (22% increase) and the induction of a ≈ 5.8 kDa peptide in the B. burgdorferi-challenged ticks. In contrast with the nonvector borne Bacillus subtilis …
Estuarine Relationships Between Zooplankton Community Structure And Trophic Gradients, Gyung Soo Park, Harold G. Marshall
Estuarine Relationships Between Zooplankton Community Structure And Trophic Gradients, Gyung Soo Park, Harold G. Marshall
Biological Sciences Faculty Publications
Zooplankton and water quality parameters were investigated at eight mesohaline stations in the lower Chesapeake Bay and Elizabeth River from January through December 1994 to identify the changes of zooplankton community structure with increased eutrophication. The total micro- and mesozooplankton biomass decreased with the increase of eutrophication. However, the relative proportion of microzooplankton increased with increased eutrophication. Within highly eutrophied waters, the small oligotrichs (m) and rotifers dominated the total zooplankton biomass (as carbon). However, tintinnids, copepod nauplii and mesozooplankton significantly decreased with the increase of eutrophication. These patterns were consistent throughout the seasons and had significant relationships statistically. These …
Hyaluronidases Of Gram-Positive Bacteria, Wayne L. Hynes, Sheryl Lynne Walton
Hyaluronidases Of Gram-Positive Bacteria, Wayne L. Hynes, Sheryl Lynne Walton
Biological Sciences Faculty Publications
Bacterial hyaluronidases, enzymes capable of breaking down hyaluronate, are produced by a number of pathogenic Gram-positive bacteria that initiate infections at the skin or mucosal surfaces. Since reports of the hyaluronidases first appeared, there have been numerous suggestions as to the role of the enzyme in the disease process. Unlike some of the other more well studied virulence factors, much of the information on the role of hyaluronidase is speculative, with little or no data to substantiate proposed roles. Over the last 5 years, a number of these enzymes from Gram-positive organisms have been cloned, and the nucleotide sequence determined. …