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Biological Sciences Faculty Publications

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Articles 1261 - 1290 of 1571

Full-Text Articles in Life Sciences

Threshold Evolution In Exotic Populations Of A Polyphenic Beetle, Armin P. Moczek, John Hunt, Douglas J. Emlen, Leigh W. Simmons May 2002

Threshold Evolution In Exotic Populations Of A Polyphenic Beetle, Armin P. Moczek, John Hunt, Douglas J. Emlen, Leigh W. Simmons

Biological Sciences Faculty Publications

Polyphenic development is thought to play an important role in the evolution of phenotypic diversity and morphological novelties, yet the evolution of polyphenisms has rarely been documented in natural populations. Here we compare the morphologies of male dung beetles (Onthophagus taurus; Coleoptera: Scarabaeidae) from populations introduced to Australia and the eastern United States. Males in this species express two alternative morphologies in response to larval feeding conditions. Males encountering favourable conditions grow larger than a threshold body size and develop a pair of horns on their heads, whereas males that encounter poor conditions do not reach this threshold size and …

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The Fitness Consequences Of Interspecific Eavesdropping Between Plants, Richard Karban, John L. Maron May 2002

The Fitness Consequences Of Interspecific Eavesdropping Between Plants, Richard Karban, John L. Maron

Biological Sciences Faculty Publications

Although many ecologists have discounted the possibility of communication between plants, recent work demonstrates that wild tobacco plants with experimentally clipped sagebrush neighbors suffer less leaf herbivory than tobacco controls with unclipped neighbors. In this report, we examine the fitness consequences of resistance induced by eavesdropping. Annual tobacco plants with clipped sagebrush neighbors produced more flowers and seed-bearing capsules than plants with unclipped neighbors although these performance measures varied considerably over the five years of the study. Tobacco plants with clipped neighbors also suffered more frost damage than controls in one year. There was no indication that eavesdropping was more …

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Cost Of Defense In The Context Of Plant Competition: Brassica Rapa May Grow And Defend, David H. Siemens, Shannon H. Garner, Thomas Mitchell-Olds, Ragan M. Callaway Feb 2002

Cost Of Defense In The Context Of Plant Competition: Brassica Rapa May Grow And Defend, David H. Siemens, Shannon H. Garner, Thomas Mitchell-Olds, Ragan M. Callaway

Biological Sciences Faculty Publications

Theory on costs of plant defense against herbivory in stressful environments predicts that costs should increase when competition is intense. This amplifies a fundamental dilemma that plants are thought to face: allocate limited resources to grow fast enough to compete, or invest these resources in secondary metabolites to maintain defense. We studied costs associated with genetic and environmental variation in secondary metabolite production of Brassica rapa in the presence and absence of the generalist competitor Lolium perenne. We used experimental quantitative genetics (artificial selection) to manipulate genetic variation, and herbivore-induction treatments to produce environmental variation in myrosinase and glucosinolate …

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Crystallization Of Complex Between Soluble Domains Of Adenylyl Cyclase And Activated Gs Alpha, John J. Tesmer, Roger K. Sunahara, David A. Fancy, Alfred G. Gilman, Stephen R. Sprang Jan 2002

Crystallization Of Complex Between Soluble Domains Of Adenylyl Cyclase And Activated Gs Alpha, John J. Tesmer, Roger K. Sunahara, David A. Fancy, Alfred G. Gilman, Stephen R. Sprang

Biological Sciences Faculty Publications

No abstract provided.

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Glass Capillary Tube Feeding: A Method For Infecting Nymphal Ixodes Scapularis (Acari: Ixodidae) With The Lyme Disease Spirochete Borrelia Burgdorferi, Anne H. Broadwater, Daniel E. Sonenshine, Wayne L. Hynes, Shane Ceraul, Aravinda M. De Silva Jan 2002

Glass Capillary Tube Feeding: A Method For Infecting Nymphal Ixodes Scapularis (Acari: Ixodidae) With The Lyme Disease Spirochete Borrelia Burgdorferi, Anne H. Broadwater, Daniel E. Sonenshine, Wayne L. Hynes, Shane Ceraul, Aravinda M. De Silva

Biological Sciences Faculty Publications

We evaluated an artificial capillary feeding method to infect nymphal Ixodes scapularis (Say) ticks with Borrelia burgdorferi, the causative agent of Lyme disease. Thirty to 70% of the nymphs were infected after feeding for 2.5 h from glass capillary tubes filled with a solution of spirochetes. Capillary infection was stable and persisted in the nymphs for at least 10 d after feeding. Capillary feeding also maintained natural vector competence patterns because I. scapularis ticks acquired infection unlike Dermacentor variablis (Say), which did not become infected. Capillary infected I. scapularis nymphs were capable of transmitting the infection to naive mice …

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Autotrophic Picoplankton: Their Presence And Significance In Marine And Freshwater Ecosystems, Harold G. Marshall Jan 2002

Autotrophic Picoplankton: Their Presence And Significance In Marine And Freshwater Ecosystems, Harold G. Marshall

Biological Sciences Faculty Publications

No abstract provided.

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Resistance Of The Tick Dermacentor Variabilis (Acari: Ixodidae) Following Challenge With The Bacterium Escherichia Coli (Enterobacteriales: Enterobacteriaceae), Shane M. Ceraul, Daniel E. Sonenshine, Wayne L. Hynes Jan 2002

Resistance Of The Tick Dermacentor Variabilis (Acari: Ixodidae) Following Challenge With The Bacterium Escherichia Coli (Enterobacteriales: Enterobacteriaceae), Shane M. Ceraul, Daniel E. Sonenshine, Wayne L. Hynes

Biological Sciences Faculty Publications

In addition to a soluble response, many invertebrates control bacterial infections by means of phagocytosis or melanotic encapsulation. In some insects, Escherichia coli growth is reported to be inhibited by aggregation/encapsulation. Soluble and phagocytic responses to bacterial challenge have been reported in ticks, but evidence of an aggregation/encapsulation response was reported only for inanimate (araldite) implants. Ticks were challenged by direct inoculation of bacteria into the hemocoel cavity. By plating, no viable E. coli were detected 6 h postinoculation. A direct fluorescence assay (DFA) revealed aggregated bacteria 1 h postinoculation. Furthermore, DFA showed aggregated bacteria at 6, 24, and 48 …

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In Vivo Effect Of Leukemia Inhibitory Factor (Lif) And An Anti-Lif Polyclonal Antibody On Murine Embryo And Fetal Development Following Exposure At The Time Of Transcervical Blastocyst Transfer, Michael H. Mitchell, R. James Swanson, Sergio Oehninger Jan 2002

In Vivo Effect Of Leukemia Inhibitory Factor (Lif) And An Anti-Lif Polyclonal Antibody On Murine Embryo And Fetal Development Following Exposure At The Time Of Transcervical Blastocyst Transfer, Michael H. Mitchell, R. James Swanson, Sergio Oehninger

Biological Sciences Faculty Publications

Leukemia inhibitory factor (LIF) enhances in vitro murine preimplantation development in a time- and dose-dependent fashion. Knockout experiments have demonstrated that endometrial LIF is essential for in vivo murine implantation. We assessed the impact of LIF and an anti-LIF polyclonal antibody (pab) on in vivo development and developed a novel and successful nonsurgical method of embryo transfer for this species, a transcervical blastocyst transfer technique. The objectives of this study were to evaluate the effects of LIF and the anti-LIF pab on 1) implantation, resorption, pregnancy, and viability rates and 2) the overall structural and skeletal development. Two-cell embryos were …

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Rickettsial Infection In Dermacentor Variabilis (Acari : Ixodidae) Inhibits Transovarial Transmission Of A Second Rickettsia, Kevin R. Macaluso, Daniel E. Sonenshine, Shane M. Ceraul, Abdu F. Azad Jan 2002

Rickettsial Infection In Dermacentor Variabilis (Acari : Ixodidae) Inhibits Transovarial Transmission Of A Second Rickettsia, Kevin R. Macaluso, Daniel E. Sonenshine, Shane M. Ceraul, Abdu F. Azad

Biological Sciences Faculty Publications

This study examined the ability of ticks to maintain multiple species of spotted fever group rickettsiae via transovarial transmission. Using a capillary feeding method, previously established Rickettsia montana- and Rickettsia rhipicephali-infected cohorts of Dermacentor variabilis (Say) were exposed to R. rhipicephali and R. montana, respectively, in two reciprocal challenge experiments. Eggs collected from individual females, for two successive generations, of each cohort were assessed for rickettsial infection by polymerase chain reaction for each challenge experiment. Assessment of the eggs from challenged ticks identified that both R. montana- and R. rhipicephali-infected ticks were refractory to their …

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Isoetes Toximontana (Isoetaceae), A New Quillwort With Green Megaspores From The Northern Cape Of South Africa, Lytton John Musselman, J. P. Roux Jan 2002

Isoetes Toximontana (Isoetaceae), A New Quillwort With Green Megaspores From The Northern Cape Of South Africa, Lytton John Musselman, J. P. Roux

Biological Sciences Faculty Publications

Isoetes toximontana is only the second quillwort reported from the Northern Cape region in South Africa. It occurs in shallow water on the Gifberg. Megaspores are uniformly tuberculate on the proximal surface; their distal surfaces may have occasional rugi along with bullae. They are olive green when dry. Microspores are brown and aculeate. Preliminary field studies suggest that an unexpected diversity of quillworts is found in this region.

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Distribution Of The Euryhaline Squid Lolliguncula Brevis In Chesapeake Bay: Effects Of Selected Abiotic Factors, I. K. Bartol, R. Mann, M. Vecchione Jan 2002

Distribution Of The Euryhaline Squid Lolliguncula Brevis In Chesapeake Bay: Effects Of Selected Abiotic Factors, I. K. Bartol, R. Mann, M. Vecchione

Biological Sciences Faculty Publications

The majority of cephalopods are thought to have limitations arising from physiology and locomotion that exclude them from shallow, highly variable, euryhaline environments. The brief squid Lolliguncula brevis may be a notable exception because it tolerates low salinities, withstands a wide range of environmental conditions, and swims readily in shallow water. Little is known about the distribution of L. brevis in Chesapeake Bay, a diverse and highly variable estuary. Therefore, a survey of L. brevis was conducted in the Virginia portion of Chesapeake Bay from 1993 to 1997 using a 9.1 m otter trawl, and the effects of selected factors …

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Evidence For Infanticide In Bottlenose Dolphins Of The Western North Atlantic, Dale G. Dunn, Susan G. Barco, D. Ann Pabst, William A. Mclellan Jan 2002

Evidence For Infanticide In Bottlenose Dolphins Of The Western North Atlantic, Dale G. Dunn, Susan G. Barco, D. Ann Pabst, William A. Mclellan

Biological Sciences Faculty Publications

Nine bottlenose dolphin (Tursiops truncatus) calves that stranded in Virginia in 1996 and 1997 died of severe blunt-force trauma. Injuries were concentrated on the head and chest and multiple rib fractures, lung lacerations, and soft tissue contusions were prominent. Skeletal and/or soft tissue trauma occurred bilaterally in all of the calves. One had a bite wound across the left mandible that exhibited deep punctures consistent with the tooth placement in an adult bottlenose dolphin. The lesions were not compatible with predation, boat strike, fisheries interactions, rough-surf injury, or blast injury. However, they were similar to traumatic injuries described in stranded …

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Percent G+C Profiling Accurately Reveals Diet-Related Differences In The Gastrointestinal Microbial Community Of Broiler Chickens, Juha H. A. Apajalahti, Anu Kettunen, Michael R. Bedford, William E. Holben Dec 2001

Percent G+C Profiling Accurately Reveals Diet-Related Differences In The Gastrointestinal Microbial Community Of Broiler Chickens, Juha H. A. Apajalahti, Anu Kettunen, Michael R. Bedford, William E. Holben

Biological Sciences Faculty Publications

Broiler chickens from eight commercial farms in Southern Finland were analyzed for the structure of their gastrointestinal microbial community by a nonselective DNA-based method, percent G+C-based profiling. The bacteriological impact of the feed source and in-farm whole-wheat amendment of the diet was assessed by percent G+C profiling. Also, a phylogenetic 16S rRNA gene (rDNA)-based study was carried out to aid in interpretation of the percent G+C profiles. This survey showed that most of the 16S rDNA sequences found could not be assigned to any previously known bacterial genus or they represented an unknown species of one of the taxonomically heterogeneous …

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Isolation And Characterization Of A Novel As(V)-Reducing Bacterium: Implications For Arsenic Mobilization And The Genus Desulfitobacterium, Allison Niggemyer, Stefan Spring, Erko Stackebrandt, Frank Rosenzweig Dec 2001

Isolation And Characterization Of A Novel As(V)-Reducing Bacterium: Implications For Arsenic Mobilization And The Genus Desulfitobacterium, Allison Niggemyer, Stefan Spring, Erko Stackebrandt, Frank Rosenzweig

Biological Sciences Faculty Publications

Dissimilatory arsenate-reducing bacteria have been implicated in the mobilization of arsenic from arsenic-enriched sediments. An As(V)-reducing bacterium, designated strain GBFH, was isolated from arsenic-contaminated sediments of Lake Coeur d'Alene, Idaho. Strain GBFH couples the oxidation of formate to the reduction of As(V) when formate is supplied as the sole carbon source and electron donor. Additionally, strain GBFH is capable of reducing As(V), Fe(III), Se(VI), Mn(IV) and a variety of oxidized sulfur species. 16S ribosomal DNA sequence comparisons reveal that strain GBFH is closely related to Desulfitobacterium hafniense DCB-2T and Desulfitobacterium frappieri PCP-1T. Comparative physiology demonstrates that D …

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Facilitation And Competition On Gradients In Alpine Plant Communities, Philippe Choler, Richard Michalet, Ragan M. Callaway Dec 2001

Facilitation And Competition On Gradients In Alpine Plant Communities, Philippe Choler, Richard Michalet, Ragan M. Callaway

Biological Sciences Faculty Publications

We conducted a neighbor removal experiment in natural alpine plant communities of the southwestern Alps to test for the relative importance of competitive and facilitative interactions along elevational and topographical gradients. The experimental sites were chosen to encompass most of the floristic diversity observed along gradients of elevation and topography, which are the two main ecological gradients associated with alpine plant communities in the western Alps. The effects of neighbor removal on the survival, aboveground biomass, and reproduction of five target species were tested at each of six experimental sites. Using biomass data, we calculated relative competitive index (RCI) and …

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Structural And Functional Analysis Of Interhelical Interactions In The Human Immunodeficiency Virus Type 1 Gp41 Envelope Glycoprotein By Alanine-Scanning Mutagenesis, Min Lu, Marisa O. Stoller, Shilong Wang, Jie Liu, Melinda B. Fagan, Jack H. Nunberg Nov 2001

Structural And Functional Analysis Of Interhelical Interactions In The Human Immunodeficiency Virus Type 1 Gp41 Envelope Glycoprotein By Alanine-Scanning Mutagenesis, Min Lu, Marisa O. Stoller, Shilong Wang, Jie Liu, Melinda B. Fagan, Jack H. Nunberg

Biological Sciences Faculty Publications

Membrane fusion by human immunodeficiency virus type 1 (HIV-1) is promoted by the refolding of the viral envelope glycoprotein into a fusion-active conformation. The structure of the gp41 ectodomain core in its fusion-active state is a trimer of hairpins in which three antiparallel carboxyl-terminal helices pack into hydrophobic grooves on the surface of an amino-terminal trimeric coiled coil. In an effort to identify amino acid residues in these grooves that are critical for gp41 activation, we have used alanine-scanning mutagenesis to investigate the importance of individual side chains in determining the biophysical properties of the gp41 core and the membrane …

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Swimming Mechanics And Behavior Of The Shallow-Water Brief Squid Lolliguncula Brevis, Ian K. Bartol, Mark R. Patterson, Roger Mann Nov 2001

Swimming Mechanics And Behavior Of The Shallow-Water Brief Squid Lolliguncula Brevis, Ian K. Bartol, Mark R. Patterson, Roger Mann

Biological Sciences Faculty Publications

Although squid are among the most versatile swimmers and rely on a unique locomotor system, little is known about the swimming mechanics and behavior of most squid, especially those that swim at low speeds in inshore waters. Shallow-water brief squid Lolliguncula brevis, ranging in size from 1.8 to 8.9 cm. in dorsal mantle length (DML), were placed in flumes and videotaped, and the data were analyzed using motion-analysis equipment. Flow visualization and force measurement experiments were also performed in water tunnels. Mean critical swimming speeds (Ucrit) ranged from 15.3 to 22.8 cm s-1, and mean …

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The Standardized Fish Bioassay Procedure For Detecting And Culturing Actively Toxic Pfiesteria, Used By Two Reference Laboratories For Atlantic And Gulf Coast States, Joann M. Burkholder, Harold G. Marshall, David W. Seaborn, Nora J. Deamer-Melia Oct 2001

The Standardized Fish Bioassay Procedure For Detecting And Culturing Actively Toxic Pfiesteria, Used By Two Reference Laboratories For Atlantic And Gulf Coast States, Joann M. Burkholder, Harold G. Marshall, David W. Seaborn, Nora J. Deamer-Melia

Biological Sciences Faculty Publications

In the absence of purified standards of toxins from Pfiesteria species, appropriately conducted fish bioassays are the "gold standard" that must be used to detect toxic strains of Pfiesteria slop. from natural estuarine water or sediment samples and to culture actively toxic Pfiesteria. In this article, we describe the standardized steps of our fish bioassay as an abbreviated term for a procedure that includes two sets of trials with fish, following the Henle-Koch postulates modified for toxic rather than infectious agents. This procedure was developed in 1991, and has been refined over more than 12 years of experience in …

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Structure Of The Rgrgs Domain Of P115rhogef, Zhe Chen, Clark D. Wells, Paul C. Sternweis, Stephen R. Sprang Sep 2001

Structure Of The Rgrgs Domain Of P115rhogef, Zhe Chen, Clark D. Wells, Paul C. Sternweis, Stephen R. Sprang

Biological Sciences Faculty Publications

p115RhoGEF, a guanine nucleotide exchange factor for Rho GTPase, is also a GTPase activating protein (GAP) for G12 and G13 heterotrimeric Gα subunits. Near its N-terminus, p115RhoGEF contains a domain (rgRGS) with remote sequence identity to RGS (regulators of G protein signaling) domains. The rgRGS domain is necessary but not sufficient for the GAP activity of p115RhoGEF. The 1.9 Å resolution crystal structure of the rgRGS domain shows structural similarity to RGS domains but possesses a C-terminal extension that folds into a layer of helices that pack against the hydrophobic core of the domain. Mutagenesis experiments show that …

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Transduction By Phi Bb-1, A Bacteriophage Of Borrelia Burgdorferi, Christian H. Eggers, Betsy J. Kimmel, James L. Bono, Abdallah F. Elias, Patricia Rosa, D. Scott Samuels Aug 2001

Transduction By Phi Bb-1, A Bacteriophage Of Borrelia Burgdorferi, Christian H. Eggers, Betsy J. Kimmel, James L. Bono, Abdallah F. Elias, Patricia Rosa, D. Scott Samuels

Biological Sciences Faculty Publications

We previously described a bacteriophage of the Lyme disease agent Borrelia burgdorferi designated phi BB-1. This phage packages the host complement of the 32-kb circular plasmids (cp32s), a group of homologous molecules found throughout the genus Borrelia. To demonstrate the ability of phi BB-1 to package and transduce DNA, a kanamycin resistance cassette was inserted into a cloned fragment of phage DNA, and the resulting construct was transformed into B. burgdorferi CA-11.2A cells. The kan cassette recombined into a resident cp32 and was stably maintained. The cp32 containing the kan cassette was packaged by phi BB-1 released from this B. …

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Restoring Enriched Grasslands: Effects Of Mowing On Species Richness, Productivity, And Nitrogen Retention, John L. Maron, Robert L. Jefferies Aug 2001

Restoring Enriched Grasslands: Effects Of Mowing On Species Richness, Productivity, And Nitrogen Retention, John L. Maron, Robert L. Jefferies

Biological Sciences Faculty Publications

Species-rich grasslands that become enriched with nitrogen often suffer decreases in species richness, increases in plant biomass, and invasion by weedy exotic species. Suitable techniques to restore enriched grasslands and reestablish native communities are increasingly needed. Here we report results of a 5-yr experiment in enriched coastal prairie grasslands (Bodega Marine Reserve, Bodega Bay, California, USA), to determine the combined effects of mowing and biomass removal on total soil nitrogen, net rates of mineralization, nitrogen retention, and species richness and biomass. We mowed and removed plant biomass from plots in areas where the N-fixing shrub, bush lupine (Lupinus arboreus …

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Establishing A Direct Role For The Bartonella Bacilliformis Invasion-Associated Locus B (Ialb) Protein In Human Erythrocyte Parasitism, Sherry A. Coleman, Michael F. Minnick Jul 2001

Establishing A Direct Role For The Bartonella Bacilliformis Invasion-Associated Locus B (Ialb) Protein In Human Erythrocyte Parasitism, Sherry A. Coleman, Michael F. Minnick

Biological Sciences Faculty Publications

The invasion-associated locus A and B genes (ialAB) of Bartonella bacilliformis were previously shown to confer an erythrocyte-invasive phenotype upon Escherichia coli, indirectly implicating their role in virulence. We report the first direct demonstration of a role for ialB as a virulence factor in B, bacilliformis. The presence of a secretory signal sequence and amino acid sequence similarity to two known outer membrane proteins involved in virulence suggested that IalB was an outer membrane protein, To develop an antiserum for protein localization, the ialB gene was cloned in frame into an expression vector with a six-histidine tag and under control …

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Assembly Of Reca-Like Recombinases: Distinct Roles For Mediator Proteins In Mitosis And Meiosis, Stephen L. Gasior Jul 2001

Assembly Of Reca-Like Recombinases: Distinct Roles For Mediator Proteins In Mitosis And Meiosis, Stephen L. Gasior

Biological Sciences Faculty Publications

Members of the RecA family of recombinases from bacteriophage T4, Escherichia coli, yeast, and higher eukaryotes function in recombination as higher-order oligomers assembled on tracts of single-strand DNA (ssDNA). Biochemical studies have shown that assembly of recombinase involves accessory factors. These studies have identified a class of proteins, called recombination mediator proteins, that act by promoting assembly of recombinase on ssDNA tracts that are bound by ssDNA-binding protein (ssb). In the absence of mediators, ssb inhibits recombination reactions by competing with recombinase for DNA-binding sites. Here we briefly review mediated recombinase assembly and present results of new in vivo experiments. …

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Isoetes Mattaponica (Isoetaceae), A New Diploid Quillwort From Freshwater Tidal Marshes Of Virginia, Lytton John Musselman, W. Carl Taylor, Rebecca D. Bray Jul 2001

Isoetes Mattaponica (Isoetaceae), A New Diploid Quillwort From Freshwater Tidal Marshes Of Virginia, Lytton John Musselman, W. Carl Taylor, Rebecca D. Bray

Biological Sciences Faculty Publications

Isoetes mattaponica is a rare quillwort of freshwater tidal rivers of eastern Virginia with a somatic chromosome number of 2n = 22. Megaspores have low rugulate muri on both the proximal and distal surfaces; the girdle is broad. Microspores are echinate-spinose with ornamented spines. Isoetes mattaponica may be one of the parents of several polyploids in the Southeastern United States.

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C2 Domains From Different Ca2+ Signaling Pathways Display Functional And Mechanistic Diversity, E. A. Nalefski, M. A. Wisner, J. Z. Chen, S. R. Sprang, M. Fukuda, K. Mikoshiba, J. J. Falke Mar 2001

C2 Domains From Different Ca2+ Signaling Pathways Display Functional And Mechanistic Diversity, E. A. Nalefski, M. A. Wisner, J. Z. Chen, S. R. Sprang, M. Fukuda, K. Mikoshiba, J. J. Falke

Biological Sciences Faculty Publications

The ubiquitous C2 domain is a conserved Ca2+-triggered membrane-docking module that targets numerous signaling proteins to membrane surfaces where they regulate diverse processes critical for cell signaling. In this study, we quantitatively compared the equilibrium and kinetic parameters of C2 domains isolated from three functionally distinct signaling proteins: cytosolic phospholipase A2-α (cPLA2-α), protein kinase C-β (PKC-β), and synaptotagmin-IA (Syt-IA). The results show that equilibrium C2 domain docking to mixed phosphatidylcholine and phosphatidylserine membranes occurs at micromolar Ca2+ concentrations for the cPLA2-α C2 domain, but requires 3- and 10-fold higher Ca2+ …

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Experimental Model Of Human Body Louse Infection Using Green Fluorescent Protein-Expressing Bartonella Quintana, Pierre-Edouard Fournier, Michael F. Minnick, Hubert Lepidi, Eric Salvo, Didier Raoult Mar 2001

Experimental Model Of Human Body Louse Infection Using Green Fluorescent Protein-Expressing Bartonella Quintana, Pierre-Edouard Fournier, Michael F. Minnick, Hubert Lepidi, Eric Salvo, Didier Raoult

Biological Sciences Faculty Publications

A laboratory colony of human body lice was experimentally infected by feeding on rabbits made artificially bacteremic with a green fluorescent protein-expressing Bartonella quintana. B. quintana was detected in the gut and feces until death but not in the eggs. The life span of the lice was not modified. The rabbit model should provide valuable clues to the role of lice in the transmission of B. quintana.

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Antibody Binding And Neutralization Of Primary And T-Cell Line-Adapted Isolates Of Human Immunodeficiency Virus Type 1, Joanne York, Kathryn E. Follis, Meg Trahey, Phillipe N. Nyambi, Susan Zolla-Pazner, Jack H. Nunberg Mar 2001

Antibody Binding And Neutralization Of Primary And T-Cell Line-Adapted Isolates Of Human Immunodeficiency Virus Type 1, Joanne York, Kathryn E. Follis, Meg Trahey, Phillipe N. Nyambi, Susan Zolla-Pazner, Jack H. Nunberg

Biological Sciences Faculty Publications

The relative resistance of human immunodeficiency virus type 1 (HIV-1) primary isolates (PIs) to neutralization by a wide range of antibodies remains a theoretical and practical barrier to the development of an effective HIV vaccine. One model to account for the differential neutralization sensitivity between Pls and laboratory (or T-cell line-adapted [TCLA]) strains of HN suggests that the envelope protein (Env) complex is made more accessible to antibody binding as a consequence of adaptation to growth in established cell lines. Here, we revisit this question using genetically related PI and TCLA viruses and molecularly cloned env genes. By using complementary …

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Life-History Evolution In Guppies. Vii. The Comparative Ecology Of High- And Low-Predation Environments, David Reznick, Mark J. Butler Iv, Helen Rodd Feb 2001

Life-History Evolution In Guppies. Vii. The Comparative Ecology Of High- And Low-Predation Environments, David Reznick, Mark J. Butler Iv, Helen Rodd

Biological Sciences Faculty Publications

Prior research has demonstrated a strong association between the species of predators that co-occur with guppies and the evolution of guppy life histories. The evolution of these differences in life histories has been attributed to the higher mortality rates experienced by guppies in high-predation environments. Here, we evaluate whether there might be indirect effects of predation on the evolution of life-history patterns and whether there are environmental differences that are correlated with predation. To do so, we quantified features of the physical and chemical environment and the population biology of guppies from seven high-and low-predation localities. We found that high-predation …

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Development Of Microsatellite Multiplexes For Wild Goats Using Primers Designed From Domestic Bovidae, Celia Maudet, Gordon Luikart, Pierre Taberlet Jan 2001

Development Of Microsatellite Multiplexes For Wild Goats Using Primers Designed From Domestic Bovidae, Celia Maudet, Gordon Luikart, Pierre Taberlet

Biological Sciences Faculty Publications

Many wild goat taxa (Capra spp.) are endangered and would benefit from the availability of molecular tools that are useful for population management and conservation. We developed microsatellite DNA markers useful in all wild goat species, by using a cross-species amplification approach. Seventy-five microsatellite primer pairs designed from domestic cattle (Bos taurus), sheep (Ovis aries) and goat (Capra hircus) were tested oil three distantly related Capra species: C. ibex ibex, C. [i.] sibirica, and C. pyrenaica. On average, 90% of the domestic ungulate primers amplified a microsatellite PCR product in the …

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Infection And Transovarial Transmission Of Rickettsiae In Dermacentor Variabilis Acquired By Artificial Feeding, K. R. Macaluso, Daniel E. Sonenshine, Shane M. Ceraul, A. F. Azad Jan 2001

Infection And Transovarial Transmission Of Rickettsiae In Dermacentor Variabilis Acquired By Artificial Feeding, K. R. Macaluso, Daniel E. Sonenshine, Shane M. Ceraul, A. F. Azad

Biological Sciences Faculty Publications

In this study we examined the efficiency of an in vitro feeding technique using glass microcapillaries as a method of establishing rickettsiae-infected lines of ticks. To quantify the volume ingested by ticks during microcapillary feeding, the incorporation of radiolabeled amino acids in tick gut and hemolymph was calculated. Fifteen of 18 ticks consumed between 0.06 μl and 6.77μl. However, ingestion of fluid was not correlated to weight gain during capillary feeding. Uninfected and partially fed laboratory-reared female Dermacentor variabilis ticks were exposed to either Rickettsia montana- or Rickettsia rhipicephali-infected Vero cells via microcapillary tubes, returned to rabbit hosts, …

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