Open Access. Powered by Scholars. Published by Universities.®

Biology Commons™

Open Access. Powered by Scholars. Published by Universities.®

2006

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 61 - 90 of 536

Full-Text Articles in Biology

The Effects Of Carotenoid And Food Availability On Resistance To A Naturally Occurring Parasite (Gyrodactylus Turnbulli) In Guppies (Poecilia Reticulata), Gita R. Kolluru, Gregory F. Grether, Sandra H. South, Eric Dunlop, Andrea Cardinali, Linda Liu, Andreah Carapiet Oct 2006

The Effects Of Carotenoid And Food Availability On Resistance To A Naturally Occurring Parasite (Gyrodactylus Turnbulli) In Guppies (Poecilia Reticulata), Gita R. Kolluru, Gregory F. Grether, Sandra H. South, Eric Dunlop, Andrea Cardinali, Linda Liu, Andreah Carapiet

Biological Sciences

Dietary carotenoids have been shown to confer immunological benefits to some species of animals in which males also use these pigments to attract mates. Thus, the potential exists for an allocation trade-off between the sexual and immunological functions of carotenoids. Food availability may also influence immune system function. The present study examined the effects of carotenoid and food availability on the resistance of male guppies (Poecilia reticulata Peters) from four wild populations to the parasite Gyrodactylus turnbulli Harris. Intermediate levels of carotenoid ingestion resulted in the lowest parasite loads, which suggests that carotenoids strengthen parasite resistance at low levels …

Go to article

Quantitative Profiling Of Arabidopsis Polar Glycerolipids In Response To Phosphorus Starvation. Roles Of Phospholipases Dζ1 And Dζ2 In Phosphatidylcholine Hydrolysis And Digalactosyldiacylglycerol Accumulation In Phosphorus-Starved Plants, Xuemin Wang, Maoyin Li, Ruth Welti Oct 2006

Quantitative Profiling Of Arabidopsis Polar Glycerolipids In Response To Phosphorus Starvation. Roles Of Phospholipases Dζ1 And Dζ2 In Phosphatidylcholine Hydrolysis And Digalactosyldiacylglycerol Accumulation In Phosphorus-Starved Plants, Xuemin Wang, Maoyin Li, Ruth Welti

Biology Department Faculty Works

Phosphorus is an essential macronutrient that often limits plant growth and development. Under phosphorus-limited conditions, plants undergo substantial alterations in membrane lipid composition to cope with phosphorus deficiency. To characterize the changes in lipid species and to identify enzymes involved in plant response to phosphorus starvation, 140 molecular species of polar glycerolipids were quantitatively profiled in rosettes and roots of wild-type Arabidopsis (Arabidopsis thaliana) and phospholipase D knockout mutants pldζ1, pldζ2, and pldζ1pldζ2. In response to phosphorus starvation, the concentration of phospholipids was decreased and that of galactolipids was increased. Phospholipid lost in phosphorus-starved Arabidopsis rosettes was replaced by an …

Go to article

A Scoping Paper : Matters Relevant To The Development Of A Sustainable Allocation And Growout Modul For Western Lobster Pueruli, Department Of Fisheries Western Australia Oct 2006

A Scoping Paper : Matters Relevant To The Development Of A Sustainable Allocation And Growout Modul For Western Lobster Pueruli, Department Of Fisheries Western Australia

Fisheries Management Papers

This Scoping Paper has been prepared as a first step in the development of a management framework for a commercial western rock lobster puerulus growout aquaculture industry in Western Australia. The purpose of this Scoping Paper is to identify and scope the issues associated with the development of such an industry and to identify matters which should be considered in the development of a management framework.

Go to article

Consumers Limit The Abundance And Dynamics Of A Perennial Shrub With A Seed Bank, Matthew J. Kauffman, John L. Maron Oct 2006

Consumers Limit The Abundance And Dynamics Of A Perennial Shrub With A Seed Bank, Matthew J. Kauffman, John L. Maron

Biological Sciences Faculty Publications

For nearly 30 years, ecologists have argued that predators of seeds and seedlings seldom have population-level effects on plants with persistent seed banks and density-dependent seedling survival. We parameterized stage-based population models that incorporated density dependence and seed dormancy with data from a 5.5-year experiment that quantified how granivorous mice and herbivorous voles influence bush lupine (Lupinus arboreus) demography. We asked how seed dormancy and density-dependent seedling survival mediate the impacts of these consumers in dune and grassland habitats. In dune habitat, mice reduced analytical lambda (the intrinsic rate of population growth) by 39%, the equilibrium number of above-ground plants …

Go to article

Frequent Fire Alters Nitrogen Transformations In Ponderosa Pine Stands Of The Inland Northwest, Thomas H. Gremer, Anna Sala Oct 2006

Frequent Fire Alters Nitrogen Transformations In Ponderosa Pine Stands Of The Inland Northwest, Thomas H. Gremer, Anna Sala

Biological Sciences Faculty Publications

Recurrent, low-severity fire in ponderosa pine (Pinus ponderosa)linterior Douglas-fir (Pseudotsuga menziesii var. glauca) forests is thought to have directly influenced nitrogen (N) cycling and availability. However, no studies to date have investigated the influence of natural fire intervals on soil processes in undisturbed forests, thereby limiting our ability to understand ecological processes and successional dynamics in this important ecosystem of the Rocky Mountain West. Here, we tested the standing hypothesis that recurrent fire in ponderosa pine/Douglas-fir forests of the Inland Northwest decreases total soil N, but increases N turnover and nutrient availability. We compared soils in stands unburned over the …

Go to article

Mig-5/Dsh Controls Cell Fate Determination And Cell Migration In C. Elegans, Timothy Walston, Chaobo Guo, Rui Proenca, Mingfu Wu, Michael Herman, Jeff Hardin, Edward Hedgecock Oct 2006

Mig-5/Dsh Controls Cell Fate Determination And Cell Migration In C. Elegans, Timothy Walston, Chaobo Guo, Rui Proenca, Mingfu Wu, Michael Herman, Jeff Hardin, Edward Hedgecock

School of Biological Sciences: Faculty Publications

Cell fate determination and cell migration are two essential events in the development of an organism. We identify mig-5, a Dishevelled family member, as a gene that regulates several cell fate decisions and cell migrations that are important during C. elegans embryonic and larval development. In offspring from mig-5 mutants, cell migrations are defective during hypodermal morphogenesis, QL neuroblast migration, and the gonad arm migration led by the distal tip cells (DTCs). In addition to abnormal migration, DTC fate is affected, resulting in either an absent or an extra DTC. The cell fates of the anchor cell in hermaphrodites …

Go to article

Invasion Through Quantitative Effects: Intense Shade Drives Native Decline And Invasive Success, Kurt O. Reinhart, Julie Gurnee, Reyes Tirado, Ragan M. Callaway Oct 2006

Invasion Through Quantitative Effects: Intense Shade Drives Native Decline And Invasive Success, Kurt O. Reinhart, Julie Gurnee, Reyes Tirado, Ragan M. Callaway

Biological Sciences Faculty Publications

The effects of invasive nonnative species on community composition are well documented. However, few studies have determined the mechanisms by which invaders drive these changes. The literature indicates that many nonnative plant species alter light availability differently than natives in a given community, suggesting that shading may be such a mechanism. We compared light quantity (photosynthetically active radiation, PAR) and quality (red : far-red ratio, R:Fr) in riparian reaches heavily invaded by a nonnative tree (Acer platanoides) to that in an uninvaded forest and experimentally tested the effects of our measured differences in PAR and R:Fr on the …

Go to article

Year-Round Diet Of The Marsh Rice Rat, Oryzomys Palustris, In Virginia Tidal Marshes, Robert K. Rose, Shannon W. Mcgurk Oct 2006

Year-Round Diet Of The Marsh Rice Rat, Oryzomys Palustris, In Virginia Tidal Marshes, Robert K. Rose, Shannon W. Mcgurk

Virginia Journal of Science

The marsh rice rat, Oryzomys palustris, is the dominant semi-aquatic rodent living in tidal marshes of the Virginia coastal plain. Described as highly carnivorous, this species is known to consume a range of animal foods, including crustaceans, mollusks, fish, and arthropods, as well as some plant foods. Analysis of stomach contents from rice rats collected from Eastern Shore tidal marshes throughout an annual cycle revealed that all 103 stomachs contained dicots, 82 percent had monocots, 61 percent had crabs and insects, and 38 percent had snails. Thirty-eight percent of stomachs contained foods in all five categories, no stomach was …

Go to article

Minutes: Council Meeting Oct 2006

Minutes: Council Meeting

Virginia Journal of Science

Minutes of the VAS Council meeting Friday May 26, 2006, 8 - 9:40 AM, at Skelton Conference Center Inn, Virginia Tech, Blacksburg VA. Minutes were edited for publication.

Go to article

Effects Of Long-Term Hypoxia On Enzymes Of Carbohydrate Metabolism In The Gulf Killifish, Fundulus Grandis, Bernard Rees Oct 2006

Effects Of Long-Term Hypoxia On Enzymes Of Carbohydrate Metabolism In The Gulf Killifish, Fundulus Grandis, Bernard Rees

Biological Sciences Faculty Publications

The goal of the current study was to generate a comprehensive, multi-tissue perspective of the effects of chronic hypoxic exposure on carbohydrate metabolism in the Gulf killifish Fundulus grandis. Fish were held at approximately 1.3 mg l(-1) dissolved oxygen (approximately 3.6 kPa) for 4 weeks, after which maximal activities were measured for all glycolytic enzymes in four tissues (white skeletal muscle, liver, heart and brain), as well as for enzymes of glycogen metabolism (in muscle and liver) and gluconeogenesis (in liver). The specific activities of enzymes of glycolysis and glycogen metabolism were strongly suppressed by hypoxia in white skeletal muscle, …

Go to article

Resistance To Pressure-Induced Dilatation In Femoral But Not Saphenous Artery: Physiological Role Of Latch?, Christopher Call, Shaojie Han, John E. Speich, Thomas J. Eddinger, Paul H. Ratz Oct 2006

Resistance To Pressure-Induced Dilatation In Femoral But Not Saphenous Artery: Physiological Role Of Latch?, Christopher Call, Shaojie Han, John E. Speich, Thomas J. Eddinger, Paul H. Ratz

Biological Sciences Faculty Research and Publications

We recently determined that the ability of the femoral artery (FA) to maintain higher levels of tonic isometric stress compared with the saphenous artery (SA) was due to differential expression of motor proteins permitting latch-bridge formation in FA and not SA. Arteries under pressure in vivo are not constrained to contract isometrically. Thus the significance of latch-bridge formation in arterial physiology remains to be determined. To address this translational question, diameter changes of pressurized FA and SA were compared. The reduction in lumen diameter induced by KCl at 80 mmHg (isobaric active constriction; IAC) was greater at 30 s than …

Go to article

Spinobulbar Neurons In Lamprey: Cellular Properties And Synaptic Interactions, James F. Einum, James T. Buchanan Oct 2006

Spinobulbar Neurons In Lamprey: Cellular Properties And Synaptic Interactions, James F. Einum, James T. Buchanan

Biological Sciences Faculty Research and Publications

An in vitro preparation of the nervous system of the lamprey, a lower vertebrate, was used to characterize the properties of spinal neurons with axons projecting to the brain stem [i.e., spinobulbar (SB) neurons)]. To identify SB neurons, extracellular electrodes on each side of the spinal cord near the obex recorded the axonal spikes of neurons impaled with sharp intracellular microelectrodes in the rostral spinal cord. The ascending spinal neurons (n = 144) included those with ipsilateral (iSB) (63/144), contralateral (cSB) (77/144), or bilateral (bSB) (4/144) axonal projections to the brain stem. Intracellular injection of biocytin revealed that the …

Go to article

An Automated Method For Rapid Identification Of Putative Gene Family Members In Plants, Ronald L. Frank, Ajay Mane, Fikret Erçal Sep 2006

An Automated Method For Rapid Identification Of Putative Gene Family Members In Plants, Ronald L. Frank, Ajay Mane, Fikret Erçal

Biological Sciences Faculty Research & Creative Works

Background: Gene duplication events have played a significant role in genome evolution, particularly in plants. Exhaustive searches for all members of a known gene family as well as the identification of new gene families has become increasingly important. Subfunctionalization via changes in regulatory sequences following duplication (adaptive selection) appears to be a common mechanism of evolution in plants and can be accompanied by purifying selection on the coding region. Such negative selection can be detected by a bias toward synonymous over nonsynonymous substitutions. However, the process of identifying this bias requires many steps usually employing several different software programs. We …

Go to article

Waterfowl Management Plan, Lake Restoration Task Force, Wade Worthen, Wes Dripps Sep 2006

Waterfowl Management Plan, Lake Restoration Task Force, Wade Worthen, Wes Dripps

Furman Lake Restoration Book Gallery

A six page document submitted by The Lake Restoration Task Force. The document lists the members of the task force, gives an overview of waterfowl overpopulation at the Furman Lake, goals for the future, and the strategy to solve this problem. The document provides a specific implementation plan and concludes with an assessment of the plan.

Go to article

Testing An Ecophysiological Mechanism Of Morphological Plasticity In Pupfish And Its Relevance To Conservation Efforts For Endangered Devils Hole Pupfish, Sean C. Lema, Gabrielle A. Nevitt Sep 2006

Testing An Ecophysiological Mechanism Of Morphological Plasticity In Pupfish And Its Relevance To Conservation Efforts For Endangered Devils Hole Pupfish, Sean C. Lema, Gabrielle A. Nevitt

Biological Sciences

Imperiled species that have been translocated or established in captivity can show rapid alterations in morphology and behavior, but the proximate mechanisms of such phenotypic changes are rarely known. Devils Hole pupfish (Cyprinodon diabolis) are endemic to a single desert pool and are characterized by a small body, large head and eyes, and lack of pelvic fins. To lessen the risk of extinction, additional populations of C. diabolis were established in artificial refuges. Yet, pupfish in these refuges rapidly shifted to a larger body, smaller head and eyes, and greater body depth. Here we examined how food availability …

Go to article

Low Cell Ph Depresses Peak Power In Rat Skeletal Muscle Fibres At Both 30°C And 15°C: Implications For Muscle Fatigue, Shannon T. Knuth, H. L. W. Dave, Jim R. Peters, Robert H. Fitts Sep 2006

Low Cell Ph Depresses Peak Power In Rat Skeletal Muscle Fibres At Both 30°C And 15°C: Implications For Muscle Fatigue, Shannon T. Knuth, H. L. W. Dave, Jim R. Peters, Robert H. Fitts

Biological Sciences Faculty Research and Publications

Historically, an increase in intracellular H+ (decrease in cell pH) was thought to contribute to muscle fatigue by direct inhibition of the cross-bridge leading to a reduction in velocity and force. More recently, due to the observation that the effects were less at temperatures closer to those observed in vivo, the importance of H+ as a fatigue agent has been questioned. The purpose of this work was to re-evaluate the role of H+ in muscle fatigue by studying the effect of low pH (6.2) on force, velocity and peak power in rat fast-and slow-twitch muscle fibres …

Go to article

Reflections On Wallace, Charles H. Smith Sep 2006

Reflections On Wallace, Charles H. Smith

DLPS Faculty Publications

An unpublished paper has recently come to light, which shows that even at an early age, Alfred Russel Wallace was bold enough to approach the scientific establishment with his ideas.

Go to article

Comparative Sequence Analysis And Tissue Localization Of Members Of The Slc6 Family Of Transporters In Adult Drosophila Melanogaster, Matthew S. Thimgan, Jonathan S. Berg, Ann E. Stuart Sep 2006

Comparative Sequence Analysis And Tissue Localization Of Members Of The Slc6 Family Of Transporters In Adult Drosophila Melanogaster, Matthew S. Thimgan, Jonathan S. Berg, Ann E. Stuart

Biological Sciences Faculty Research & Creative Works

The SLC6 family comprises proteins that move extracellular neurotransmitters, amino acids and osmolytes across the plasma membrane into the cytosol. In mammals, deletion of SLC6 family members has dramatic physiologic consequences, but in the model organism Drosophila melanogaster, little is known about this family of proteins. Therefore, in this study we carried out an initial analysis of 21 known or putative SLC6 family members from the Drosophila genome. Protein sequences from these genes segregated into either well-defined subfamilies, including the novel insect amino acid transporter subfamily, or into a group of weakly related sequences not affiliated with a recognized …

Go to article

Direct And Correlated Effects Of Selection On Flight After Exposure To Thermal Stress In Drosophila Melanogaster, Robert A. Krebs, Kimberly A. Thompson Sep 2006

Direct And Correlated Effects Of Selection On Flight After Exposure To Thermal Stress In Drosophila Melanogaster, Robert A. Krebs, Kimberly A. Thompson

Biological, Geological, and Environmental Faculty Publications

To demonstrate how insects may adapt to ecologically relevant levels of heat stress, we performed artificial selection on the ability of Drosophila melanogaster to fly after an exposure to a high but non-lethal thermal stress. Both tolerance and intolerance to heat stress arose very quickly, as only a few generations of selection were necessary to cause significant separation between high and low lines for heat tolerance. Estimates of heritability based on the lines artificially selected for increased flight ability ranged from 0.024 to 0.052, while estimates of heritability based on the lines selected for the inability to fly after heat …

Go to article

In Situ Muscle Power Differs Without Varying In Vitro Mechanical Properties In Two Insect Leg Muscles Innervated By The Same Motor Neuron, Anna N. Ahn, Kenneth Meijer, Robert J. Full Sep 2006

In Situ Muscle Power Differs Without Varying In Vitro Mechanical Properties In Two Insect Leg Muscles Innervated By The Same Motor Neuron, Anna N. Ahn, Kenneth Meijer, Robert J. Full

All HMC Faculty Publications and Research

The mechanical behavior of muscle during locomotion is often predicted by its anatomy, kinematics, activation pattern and contractile properties. The neuromuscular design of the cockroach leg provides a model system to examine these assumptions, because a single motor neuron innervates two extensor muscles operating at a single joint. Comparisons of the in situ measurements under in vivo running conditions of muscle 178 to a previously examined muscle (179) demonstrate that the same inputs (e.g. neural signal and kinematics) can result in different mechanical outputs. The same neural signal and kinematics, as determined during running, can result in different mechanical functions, …

Go to article

Diversity Of The Ig Repertoire Is Maintained With Age In Spite Of Reduced Germinal Centre Cells In Human Tonsil Lymphoid Tissue, G. R. Kolar, D. Mehta, P. C. Wilson, J. D. Capra Sep 2006

Diversity Of The Ig Repertoire Is Maintained With Age In Spite Of Reduced Germinal Centre Cells In Human Tonsil Lymphoid Tissue, G. R. Kolar, D. Mehta, P. C. Wilson, J. D. Capra

Biological Sciences Faculty Research & Creative Works

Humans and almost all species studied to date exhibit a decreased responsiveness to immunization and increased autoimmunity with age. While this has been observed clinically for decades, only recently has an understanding of the molecular basis for these changes begun to be appreciated. Studies of the B-cell aspects of these changes in ageing mice and the very few reports in ageing humans have not been conclusive. Here we examine the nucleotide sequence of over 1250 VH transcripts from the tonsils of individuals of various ages for changes to the VH4 immunoglobulin repertoire. An exhaustive examination of VH, DH and JH …

Go to article

Broad Specificity Of Mammalian Adenylyl Cyclase For Interaction With 2',3'-Substituted Purine- And Pyrimidine Nucleotide Inhibitors, Tung-Chung Mou, Andreas Gille, Srividya Suryanarayana, Mark Richter, Roland Seifert, Stephen R. Sprang Sep 2006

Broad Specificity Of Mammalian Adenylyl Cyclase For Interaction With 2',3'-Substituted Purine- And Pyrimidine Nucleotide Inhibitors, Tung-Chung Mou, Andreas Gille, Srividya Suryanarayana, Mark Richter, Roland Seifert, Stephen R. Sprang

Biological Sciences Faculty Publications

Membrane adenylyl cyclases (mACs) play an important role in signal transduction and are therefore potential drug targets. Earlier, we identified 2',3'-O-(N-methylanthraniloyl) (MANT)-substituted purine nucleotides as a novel class of highly potent competitive mAC inhibitors (Ki values in the 10 nM range). MANT nucleotides discriminate among various mAC isoforms through differential interactions with a binding pocket localized at the interface between the C1 and C2 domains of mAC. In this study, we examine the structure/activity relationships for 2',3'-substituted nucleotides and compare the crystal structures of mAC catalytic domains (VC1:IIC2) bound to MANT-GTP, MANT-ATP, and 2',3'-(2,4,6-trinitrophenyl) (TNP)-ATP. TNP-substituted purine and pyrimidine nucleotides …

Go to article

Behavioural Responses Of Blue Petrel Chicks (Halobaena Caerulea) To Food-Related And Novel Odours In A Simple Wind Tunnel, Gregory B. Cunningham, Richard W. Van Buskirk, Mark J. Hodges, Henri Weimerskirch, Gabrielle A. Nevitt Sep 2006

Behavioural Responses Of Blue Petrel Chicks (Halobaena Caerulea) To Food-Related And Novel Odours In A Simple Wind Tunnel, Gregory B. Cunningham, Richard W. Van Buskirk, Mark J. Hodges, Henri Weimerskirch, Gabrielle A. Nevitt

Biology Faculty/Staff Publications

No abstract provided.

Go to article

Utilization Of Sea Scallop (Placopecten Magellanicus Gmelin) Microsatellite Markers For Phylogenetic Applications In Bay Scallops (Argopecten Irradians Lamarck), Lilliana E.J. Kim, James J. Campanella, Paul Ax Bologna Sep 2006

Utilization Of Sea Scallop (Placopecten Magellanicus Gmelin) Microsatellite Markers For Phylogenetic Applications In Bay Scallops (Argopecten Irradians Lamarck), Lilliana E.J. Kim, James J. Campanella, Paul Ax Bologna

Department of Biology Faculty Scholarship and Creative Works

In previous research, microsatellite markers have been used to geographically and phylogenetically characterize and identify populations of sea scallops (Placopecten magellanicus Gmelin). Given that sea scallops are a closely related species to bay scallops (Argopecten irradians Lamarck), we have investigated whether the flanking DNA sequences of sea scallop microsatellite loci have been conserved in the bay scallop. We found that in all seven sets of published sea scallop PCR primers (Pma130, -132, -135, -180, -200, -212, and -275) that were tested with bay scallop DNA, there was sequence conservation and amplification of microsatellite regions. Our initial phylogenetic analyses, …

Go to article

Expression Of The Primary Carbohydrate Component Of The Bordetella Bronchiseptica Biofilm Matrix Is Dependent On Growth Phase But Independent Of Bvg Regulation, Yasuhiko Irie, Andrew Preston, Ming H. Yuk Sep 2006

Expression Of The Primary Carbohydrate Component Of The Bordetella Bronchiseptica Biofilm Matrix Is Dependent On Growth Phase But Independent Of Bvg Regulation, Yasuhiko Irie, Andrew Preston, Ming H. Yuk

Biology Faculty Publications

We previously showed that the Bvg virulence control system regulates biofilm formation in Bordetella bronchiseptica (Y. Irie, S. Mattoo, and M. H. Yuk, J. Bacteriol. 186:5692-5698, 2004). Analyses of the extracellular components of B. bronchiseptica biofilm matrix revealed that the major sugar component in the matrix was xylose, and linkage analysis indicated a majority of it to be in a 4-linked polymeric form. The production of xylose was independent of Bvg regulation but instead was dependent on bacterial growth phase. In addition, N-acetyl-glucosamine in the matrix was found to be important for the initial development of the biofilm. These …

Go to article

Secondary Metabolic Gene Cluster Silencing In Aspergillus Nidulans, J. W. Bok, D. Noordermeer, Shubha Kale Ireland, N. P. Keller Sep 2006

Secondary Metabolic Gene Cluster Silencing In Aspergillus Nidulans, J. W. Bok, D. Noordermeer, Shubha Kale Ireland, N. P. Keller

Faculty and Staff Publications

In contrast to most primary metabolism genes, the genes involved in secondary metabolism and certain nutrient utilization pathways are clustered in fungi. Recently a nuclear protein, LaeA, was found to be required for the transcription of several secondary metabolite gene clusters in Aspergillus nidulans. Here we show that LaeA regulation does not extend to nutrient utilization or the spoC1 sporulation clusters. One of the secondary metabolite clusters regulated by LaeA contains the positive regulatory (i.e. aflR) and biosynthetic genes required for biosynthesis of sterigmatocystin (ST), a carcinogenic toxin. Analysis of ST gene cluster expression indicates LaeA regulation of the cluster …

Go to article

Microbial Growth And Biofilm Formation In Geologic Media Is Detected With Complex Conductivity Measurements, Caroline A. Davis, Estella A. Atekwana, Eliot A. Atekwana, Lee D. Slater, Silvia Rossbach, Melanie R. Mormile Sep 2006

Microbial Growth And Biofilm Formation In Geologic Media Is Detected With Complex Conductivity Measurements, Caroline A. Davis, Estella A. Atekwana, Eliot A. Atekwana, Lee D. Slater, Silvia Rossbach, Melanie R. Mormile

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Complex conductivity measurements (0.1-1000 Hz) were obtained from biostimulated sand-packed columns to investigate the effect of microbial growth and biofilm formation on the electrical properties of porous media. Microbial growth was verified by direct microbial counts, pH measurements, and environmental scanning electron microscope imaging. Peaks in imaginary (interfacial) conductivity in the biostimulated columns were coincident with peaks in the microbial cell concentrations extracted from sands. However, the real conductivity component showed no discernible relationship to microbial cell concentration. We suggest that the observed dynamic changes in the imaginary conductivity (σ″) arise from the growth and attachment of microbial cells and …

Go to article

Rana Ocellata Linnaeus, 1758 (Currently Leptodactylus Ocellatus; Amphibia, Anura): Proposed Conservation Of Usage Of The Specific Name By The Designation Of A Neotype, W. Ronald Heyer, Ulisses Caramaschi, Rafael O. De Sá Sep 2006

Rana Ocellata Linnaeus, 1758 (Currently Leptodactylus Ocellatus; Amphibia, Anura): Proposed Conservation Of Usage Of The Specific Name By The Designation Of A Neotype, W. Ronald Heyer, Ulisses Caramaschi, Rafael O. De Sá

Biology Faculty Publications

The purpose of this application, under Article 75.6 of the Code, is to conserve the usage of the specific name of Rana ocellata Linnaeus, 1758 for a species of leptodactylid frog from South America by the designation of a neotype. Prevailing usage of the name is threatened by the identity of the type specimen which is a different species than that which is currently known as Leptodactylus ocellatus. It is proposed that all name-bearing types be set aside and a neotype designated in accord with prevailing usage.

Go to article

Characterization Of Mmp37p, A Saccharomyces Cerevisiae Mitochondrial Matrix Protein With A Role In Mitochondrial Protein Import, Michelle R. Gallas, Mary Kathryn Dienhart, Rosemary A. Stuart, Roy M. Long Sep 2006

Characterization Of Mmp37p, A Saccharomyces Cerevisiae Mitochondrial Matrix Protein With A Role In Mitochondrial Protein Import, Michelle R. Gallas, Mary Kathryn Dienhart, Rosemary A. Stuart, Roy M. Long

Biological Sciences Faculty Research and Publications

Many mitochondrial proteins are encoded by nuclear genes and after translation in the cytoplasm are imported via translocases in the outer and inner membranes, the TOM and TIM complexes, respectively. Here, we report the characterization of the mitochondrial protein, Mmp37p (YGR046w) and demonstrate its involvement in the process of protein import into mitochondria. Haploid cells deleted of MMP37 are viable but display a temperature-sensitive growth phenotype and are inviable in the absence of mitochondrial DNA. Mmp37p is located in the mitochondrial matrix where it is peripherally associated with the inner membrane. We show that Mmp37p has a role in the …

Go to article

Censusing And Measuring Lianas: A Quantitative Comparison Of The Common Methods, Stefan A. Schnitzer, Saara J. Dewalt, Jérôme Chave Sep 2006

Censusing And Measuring Lianas: A Quantitative Comparison Of The Common Methods, Stefan A. Schnitzer, Saara J. Dewalt, Jérôme Chave

Biological Sciences Faculty Research and Publications

Lianas contribute to many aspects of tropical forest diversity and dynamics, and interest in liana ecology has grown substantially in recent years. Methods to census lianas and estimate biomass, however, differ among studies, possibly hindering attempts to compare liana communities. At Nouragues Research Station (French Guiana), we tested the extent to which liana abundance, basal area, and estimated biomass differed depending on stem diameter measurement location, inclusion of ramets, inclusion of lianas rooted within versus passing through the plot, and plot shape. We found that the mean per plot abundance and basal area of lianas were significantly greater when lianas …

Go to article

First Prev Next Last