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Full-Text Articles in Life Sciences

Possible Nonconductive Role Of Geobacter Sulfurreducens Pilus Nanowires In Biofilm Formation, Gemma Reguera, Rachael B. Pollina, Julie S. Nicoll, Derek Lovley Dec 2006

Possible Nonconductive Role Of Geobacter Sulfurreducens Pilus Nanowires In Biofilm Formation, Gemma Reguera, Rachael B. Pollina, Julie S. Nicoll, Derek Lovley

Derek Lovley

Geobacter sulfurreducens required expression of electrically conductive pili to form biofilms on Fe(III) oxide surfaces, but pili were also essential for biofilm development on plain glass when fumarate was the sole electron acceptor. Furthermore, pili were needed for cell aggregation in agglutination studies. These results suggest that the pili of G. sulfurreducens also have a structural role in biofilm formation.


Bmc Infectious Diseases, Frances Cirino, Wilmore C. Webley, Corrie West, Nancy L. Croteau, Chester Andrzejewski Jr, Elizabeth S. Stuart Nov 2006

Bmc Infectious Diseases, Frances Cirino, Wilmore C. Webley, Corrie West, Nancy L. Croteau, Chester Andrzejewski Jr, Elizabeth S. Stuart

Wilmore C Webley

No abstract provided.


Role Of Red Gsu In Stress Response And Fe(Iii) Reduction In Geobacter Sulfurreducens, Laurie N. Didonato, Sara A. Sullivan, Barbara A. Methѐ, Kelly P. Nevin, Reg England, Derek Lovley Oct 2006

Role Of Red Gsu In Stress Response And Fe(Iii) Reduction In Geobacter Sulfurreducens, Laurie N. Didonato, Sara A. Sullivan, Barbara A. Methѐ, Kelly P. Nevin, Reg England, Derek Lovley

Kelly Nevin

Geobacter species are key members of the microbial community in many subsurface environments in which dissimilatory metal reduction is an important process. The genome of Geobacter sulfurreducens contains a gene designated relGsu, which encodes a RelA homolog predicted to catalyze both the synthesis and the degradation of guanosine 3′,5′-bispyrophosphate (ppGpp), a regulatory molecule that signals slow growth in response to nutrient limitation in bacteria. To evaluate the physiological role of RelGsu in G. sulfurreducens, a relGsu mutant was constructed and characterized, and ppGpp levels were monitored under various conditions in both the wild-type and relGsu mutant strains. In ...


Implicating An Introduced Generalist Parasitoid In The Invasive Browntail Moth's Enigmatic Demise, Joseph Elkinton, D. Parry, G. Boettner Oct 2006

Implicating An Introduced Generalist Parasitoid In The Invasive Browntail Moth's Enigmatic Demise, Joseph Elkinton, D. Parry, G. Boettner

Joseph Elkinton

Recent attention has focused on the harmful effects of introduced biological control agents on nontarget species. The parasitoid Compsilura concinnata is a notable example of such biological control gone wrong. Introduced in 1906 primarily for control of gypsy moth, Lymantria dispar, this tachinid fly now attacks more than 180 species of native Lepidoptera in North America. While it did not prevent outbreaks or spread of gypsy moth, we present reanalyzed historical data and experimental findings suggesting that parasitism by C. concinnata is the cause of the enigmatic near-extirpation of another of North America's most successful invaders, the browntail moth ...


Cardiac Myosin Missense Mutations Cause Dilated Cardiomyopathy In Mouse Models And Depress Molecular Motor Function, Joachim Schmitt, Edward Debold, Ferhaan Ahmad, Amy Armstrong, Andrea Frederico, David Conner, Ulrike Mende, Martin Lohse, David Warshaw, Christine Seidman, J. Seidman Sep 2006

Cardiac Myosin Missense Mutations Cause Dilated Cardiomyopathy In Mouse Models And Depress Molecular Motor Function, Joachim Schmitt, Edward Debold, Ferhaan Ahmad, Amy Armstrong, Andrea Frederico, David Conner, Ulrike Mende, Martin Lohse, David Warshaw, Christine Seidman, J. Seidman

Edward P. Debold

Dilated cardiomyopathy (DCM) leads to heart failure, a leading cause of death in industrialized nations. Approximately 30% of DCM cases are genetic in origin, with some resulting from point mutations in cardiac myosin, the molecular motor of the heart. The effects of these mutations on myosin's molecular mechanics have not been determined. We have engineered two murine models characterizing the physiological, cellular, and molecular effects of DCM-causing missense mutations (S532P and F764L) in the α-cardiac myosin heavy chain and compared them with WT mice. Mutant mice developed morphological and functional characteristics of DCM consistent with the human phenotypes. Contractile ...


Biofilm And Nanowire Production Leads To Increased Current In Geobacter Sulfurreducens Fuel Cells, Gemma Reguera, Kelly P. Nevin, Julie S. Nicoll, Sean F. Covalla, Trevor L. Woodard, Derek Lovley Aug 2006

Biofilm And Nanowire Production Leads To Increased Current In Geobacter Sulfurreducens Fuel Cells, Gemma Reguera, Kelly P. Nevin, Julie S. Nicoll, Sean F. Covalla, Trevor L. Woodard, Derek Lovley

Derek Lovley

Geobacter sulfurreducens developed highly structured, multilayer biofilms on the anode surface of a microbial fuel cell converting acetate to electricity. Cells at a distance from the anode remained viable, and there was no decrease in the efficiency of current production as the thickness of the biofilm increased. Genetic studies demonstrated that efficient electron transfer through the biofilm required the presence of electrically conductive pili. These pili may represent an electronic network permeating the biofilm that can promote long-range electrical transfer in an energy-efficient manner, increasing electricity production more than 10-fold.


Biofilm And Nanowire Production Leads To Increased Current In Geobacter Sulfurreducens Fuel Cells, Gemma Reguera, Kelly P. Nevin, Julie S. Nicoll, Sean F. Covalla, Trevor L. Woodard, Derek Lovley Aug 2006

Biofilm And Nanowire Production Leads To Increased Current In Geobacter Sulfurreducens Fuel Cells, Gemma Reguera, Kelly P. Nevin, Julie S. Nicoll, Sean F. Covalla, Trevor L. Woodard, Derek Lovley

Kelly Nevin

Geobacter sulfurreducens developed highly structured, multilayer biofilms on the anode surface of a microbial fuel cell converting acetate to electricity. Cells at a distance from the anode remained viable, and there was no decrease in the efficiency of current production as the thickness of the biofilm increased. Genetic studies demonstrated that efficient electron transfer through the biofilm required the presence of electrically conductive pili. These pili may represent an electronic network permeating the biofilm that can promote long-range electrical transfer in an energy-efficient manner, increasing electricity production more than 10-fold.


Tests Of Parallel Molecular Evolution In A Long-Term Experiment With Escherichia Coli, Margaret Riley, Robert Woods, Dominique Schneider, Cynthia L. Winkworth, Richard E. Lenski Jun 2006

Tests Of Parallel Molecular Evolution In A Long-Term Experiment With Escherichia Coli, Margaret Riley, Robert Woods, Dominique Schneider, Cynthia L. Winkworth, Richard E. Lenski

Margaret Riley

The repeatability of evolutionary change is difficult to quantify because only a single outcome can usually be observed for any precise set of circumstances. In this study, however, we have quantified the frequency of parallel and divergent genetic changes in 12 initially identical populations of Escherichia coli that evolved in identical environments for 20,000 cell generations. Unlike previous analyses in which candidate genes were identified based on parallel phenotypic changes, here we sequenced four loci (pykF, nadR, pbpA-rodA, and hokB/sokB) in which mutations of unknown effect had been discovered in one population, and then we compared the substitution ...


Detection Of Chlamydia In The Peripheral Blood Cells Of Normal Donors Using In Vitro Culture, Immunofluorescence Microscopy And Flow Cytometry Techniques, Frances Cirino, Wilmore Webley, Corrie West, Nancy L. Croteau, Chester Andrzejewski Jr., Elizabeth S. Stuart Feb 2006

Detection Of Chlamydia In The Peripheral Blood Cells Of Normal Donors Using In Vitro Culture, Immunofluorescence Microscopy And Flow Cytometry Techniques, Frances Cirino, Wilmore Webley, Corrie West, Nancy L. Croteau, Chester Andrzejewski Jr., Elizabeth S. Stuart

Wilmore C Webley

BACKGROUND: Chlamydia trachomatis (Ct) and Chlamydia pneumoniae (Cp) are medically significant infectious agents associated with various chronic human pathologies. Nevertheless, specific roles in disease progression or initiation are incompletely defined. Both pathogens infect established cell lines in vitro and polymerase chain reaction (PCR) has detected Chlamydia DNA in various clinical specimens as well as in normal donor peripheral blood monocytes (PBMC). However, Chlamydia infection of other blood cell types, quantification of Chlamydia infected cells in peripheral blood and transmission of this infection in vitro have not been examined.

METHODS: Cp specific titers were assessed for sera from 459 normal human ...


Two Putative C-Type Multiheme Cytochromes Required For The Expression Of Omcb, And Outer Membrane Protein Essential For Optimal Fe(Iii) Reduction In Geobacter Sulfurreducens, Byoung-Chan Kim, Xinlei Qian, Ching Leang, Maddalena V. Coppi, Derek Lovley Jan 2006

Two Putative C-Type Multiheme Cytochromes Required For The Expression Of Omcb, And Outer Membrane Protein Essential For Optimal Fe(Iii) Reduction In Geobacter Sulfurreducens, Byoung-Chan Kim, Xinlei Qian, Ching Leang, Maddalena V. Coppi, Derek Lovley

Derek Lovley

Deletion of two homologous Geobacter sulfurreducens c-type cytochrome genes, omcG and omcH, decreased the rate of Fe(III) reduction and decreased the level of an outer membrane cytochrome critical for Fe(III) reduction, OmcB, without affecting its transcription. Expression of either gene restored Fe(III) reduction and OmcB expression, suggesting functional similarity.


Dna Microarray And Proteomic Analyses Of The Rpos Regulon In Geobacter Sulfurreducens, Carol Giometti, Cinthia Núñez, Sandra Tollaksen, Abraham Esteve-Núñez, Tripti Khare, Winston Lin, Derek Lovley, Barbara Methѐ Jan 2006

Dna Microarray And Proteomic Analyses Of The Rpos Regulon In Geobacter Sulfurreducens, Carol Giometti, Cinthia Núñez, Sandra Tollaksen, Abraham Esteve-Núñez, Tripti Khare, Winston Lin, Derek Lovley, Barbara Methѐ

Derek Lovley

The regulon of the sigma factor RpoS was defined in Geobacter sulfurreducens by using a combination of DNA microarray expression profiles and proteomics. An rpoS mutant was examined under steady-state conditions with acetate as an electron donor and fumarate as an electron acceptor and with additional transcriptional profiling using Fe(III) as an electron acceptor. Expression analysis revealed that RpoS acts as both a positive and negative regulator. Many of the RpoS-dependent genes determined play roles in energy metabolism, including the tricarboxylic acid cycle, signal transduction, transport, protein synthesis and degradation, and amino acid metabolism and transport. As expected, RpoS ...


Notch1 Augments Nf- ĸb Activity By Facilitating Its Nuclear Retention, H. M. Shin, Lisa Minter, O.H. Cho, S. Gottipati, A.H. Fauq, T.E. Golde, G.E. Sonenshein, B.A. Osborne Jan 2006

Notch1 Augments Nf- ĸb Activity By Facilitating Its Nuclear Retention, H. M. Shin, Lisa Minter, O.H. Cho, S. Gottipati, A.H. Fauq, T.E. Golde, G.E. Sonenshein, B.A. Osborne

Lisa Minter

Notch1 specifically upregulates expression of the cytokine interferon-gamma in peripheral T cells through activation of NF-kappaB. However, how Notch mediates NF-kappaB activation remains unclear. Here, we examined the temporal relationship between Notch signaling and NF-kappaB induction during T-cell activation. NF-kappaB activation occurs within minutes of T-cell receptor (TCR) engagement and this activation is sustained for at least 48 h following TCR signaling. We used gamma-secretase inhibitor (GSI) to prevent the cleavage and subsequent activation of Notch family members. We demonstrate that GSI blocked the later, sustained NF-kappaB activation, but did not affect the initial activation of NF-kappaB. Using biochemical approaches ...


Correlations Among Traits Associated With Herbivore Resistance And Pollination: Implications For Pollination And Nectar Robbing In A Distylous Plant, Rebecca E. Irwin, Lynn Adler Jan 2006

Correlations Among Traits Associated With Herbivore Resistance And Pollination: Implications For Pollination And Nectar Robbing In A Distylous Plant, Rebecca E. Irwin, Lynn Adler

Lynn Adler

Plants interact simultaneously with a diversity of visitors, including herbivores and pollinators. Correlations among traits associated with herbivory and pollination may constrain the degree to which plants can evolve in response to any one interactor. Using the distylous plant, Gelsemium sempervirens, we tested the hypothesis that traits typically associated with pollination (distyly) and herbivore resistance (secondary compounds) were phenotypically correlated and examined how these traits influenced plant interactions with floral visitors. The flowers of G. sempervirens are visited by pollinators and a nectar robber, and the leaves and flowers express gelsemine, an alkaloid that is deterrent and sometimes toxic to ...


A High-Resolution Map Of Arabidopsis Recombinant Inbred Lines By Whole-Genome Array Hybridization, Samuel P. Hazen, T. S. Singer, Y. Fan, H. S. Chang, T. Zhu, S. P. Briggs Jan 2006

A High-Resolution Map Of Arabidopsis Recombinant Inbred Lines By Whole-Genome Array Hybridization, Samuel P. Hazen, T. S. Singer, Y. Fan, H. S. Chang, T. Zhu, S. P. Briggs

Samuel P Hazen

Recombinant populations were the basis for Mendel's first genetic experiments and continue to be key to the study of genes, heredity, and genetic variation today. Genotyping several hundred thousand loci in a single assay by hybridizing genomic DNA to oligonucleotide arrays provides a powerful technique to improve precision linkage mapping. The genotypes of two accessions of Arabidopsis were compared by using a 400,000 feature exon-specific oligonucleotide array. Around 16,000 single feature polymorphisms (SFPs) were detected in ~8,000 of the ~26,000 genes represented on the array. Allelic variation at these loci was measured in a recombinant ...


Multifunctionality And Mechanical Origins: Ballistic Jaw Propulsion In Trap-Jaw Ants, Sheila Patek, J. E. Baio, B. L. Fisher, A. V. Suarez Jan 2006

Multifunctionality And Mechanical Origins: Ballistic Jaw Propulsion In Trap-Jaw Ants, Sheila Patek, J. E. Baio, B. L. Fisher, A. V. Suarez

Sheila Patek

Extreme animal movements are usually associated with a single, high-performance behavior. However, the remarkably rapid mandible strikes of the trap-jaw ant, Odontomachus bauri, can yield multiple functional outcomes. Here we investigate the biomechanics of mandible strikes in O. bauri and find that the extreme mandible movements serve two distinct functions: predation and propulsion. During predatory strikes, O. bauri mandibles close at speeds ranging from 35 to 64 m·s−1 within an average duration of 0.13 ms, far surpassing the speeds of other documented ballistic predatory appendages in the animal kingdom. The high speeds of the mandibles assist in ...


The Role Of Arp2/3 And Scar/Wave Complexes In Polar Growth Of The Apical Cell Of The Moss Physcomitrella, Rs Quatrano, Pf Perroud, P Harries, M Bezanilla, Ah Pan, P Klueh, D Cove Jan 2006

The Role Of Arp2/3 And Scar/Wave Complexes In Polar Growth Of The Apical Cell Of The Moss Physcomitrella, Rs Quatrano, Pf Perroud, P Harries, M Bezanilla, Ah Pan, P Klueh, D Cove

Magdalena Bezanilla

No abstract provided.


Mutations In Arabidopsis Yellow Stripe-Like1 And Yellow Stripe-Like3 Reveal Their Roles In Metal Ion Homeostasis And Loading Of Metal Ions In Seeds, Elsbeth Walker, B. M. Waters, H. H. Chu, R. J. Didonato, L. A. Roberts, R. B. Eisley, B. Lahner, D. E. Salt Jan 2006

Mutations In Arabidopsis Yellow Stripe-Like1 And Yellow Stripe-Like3 Reveal Their Roles In Metal Ion Homeostasis And Loading Of Metal Ions In Seeds, Elsbeth Walker, B. M. Waters, H. H. Chu, R. J. Didonato, L. A. Roberts, R. B. Eisley, B. Lahner, D. E. Salt

Elsbeth Walker

Here, we describe two members of the Arabidopsis (Arabidopsis thaliana) Yellow Stripe-Like (YSL) family, AtYSL1 and AtYSL3. The YSL1 and YSL3 proteins are members of the oligopeptide transporter family and are predicted to be integral membrane proteins. YSL1 and YSL3 are similar to the maize (Zea mays) YS1 phytosiderophore transporter (ZmYS1) and the AtYSL2 iron (Fe)-nicotianamine transporter, and are predicted to transport metal-nicotianamine complexes into cells. YSL1 and YSL3 mRNAs are expressed in both root and shoot tissues, and both are regulated in response to the Fe status of the plant. β-Glucuronidase reporter expression, driven by YSL1 and YSL3 ...


A Comparison Of Vineland Apple Rootstocks And M.26 Emla In The 1996 Mcintosh Rootstock Trial, Wesley Autio, James Krup, Jon Clements Jan 2006

A Comparison Of Vineland Apple Rootstocks And M.26 Emla In The 1996 Mcintosh Rootstock Trial, Wesley Autio, James Krup, Jon Clements

Wesley Autio

No abstract provided.


Several New Dwarfing Rootstocks Compared To Lovell In The 2002 Nc-140 Peach Rootstock Trial, Wesley Autio, James Krupa Jan 2006

Several New Dwarfing Rootstocks Compared To Lovell In The 2002 Nc-140 Peach Rootstock Trial, Wesley Autio, James Krupa

Wesley Autio

No abstract provided.


Cg.4814, Cg.7707, G.30, And Supporter 4 Versus M.26 Emla And M.7 Emla In The 1999 Nc-140 Semidwarf Apple Rootstock Trial, Wesley Autio Jan 2006

Cg.4814, Cg.7707, G.30, And Supporter 4 Versus M.26 Emla And M.7 Emla In The 1999 Nc-140 Semidwarf Apple Rootstock Trial, Wesley Autio

Wesley Autio

No abstract provided.


G.16 Versus M.9 In The 1998 Nc-140 Apple Rootstock Trial, Wesley Autio, Jon Clements, James Krupa Jan 2006

G.16 Versus M.9 In The 1998 Nc-140 Apple Rootstock Trial, Wesley Autio, Jon Clements, James Krupa

Wesley Autio

No abstract provided.


Do Surfactants Affect Response To Chemical Thinners?, James Krupa, Wesley Autio Jan 2006

Do Surfactants Affect Response To Chemical Thinners?, James Krupa, Wesley Autio

Wesley Autio

No abstract provided.


Chemical Thinning Of Apples Using Ethephon: Another Unsuccessful Year, Wesley Autio, James Krupa Jan 2006

Chemical Thinning Of Apples Using Ethephon: Another Unsuccessful Year, Wesley Autio, James Krupa

Wesley Autio

No abstract provided.


Alternative Fungicides For Management Of Sooty Blotch And Flyspeck, Daniel Cooley, Wesley Autio, Arthur Tuttle, James Krupa Jan 2006

Alternative Fungicides For Management Of Sooty Blotch And Flyspeck, Daniel Cooley, Wesley Autio, Arthur Tuttle, James Krupa

Wesley Autio

No abstract provided.


G.16 Versus M.9 And B.9 In The 2002 Massachusetts-New Jersey Cameo Rootstock Trial, Jon Clements, Wesley Autio Jan 2006

G.16 Versus M.9 And B.9 In The 2002 Massachusetts-New Jersey Cameo Rootstock Trial, Jon Clements, Wesley Autio

Wesley Autio

No abstract provided.


New Cg Rootstocks, G.16, And Supporter 1, 2, And 3 Versus M.9 And M.26 Emla In The 1999 Nc-140 Dwarf Apple Rootstock Trial, Wesley Autio, Jon Clements, James Krups Jan 2006

New Cg Rootstocks, G.16, And Supporter 1, 2, And 3 Versus M.9 And M.26 Emla In The 1999 Nc-140 Dwarf Apple Rootstock Trial, Wesley Autio, Jon Clements, James Krups

Wesley Autio

No abstract provided.


Chemical Thinning Of Apples Using Ethephon, Wesley Autio, James Krupa Jan 2006

Chemical Thinning Of Apples Using Ethephon, Wesley Autio, James Krupa

Wesley Autio

No abstract provided.


Naphthalene Acetic Acid And Apogee Control Growth In The Tops Of Dwarf Apple Trees, Wesley Autio, James Krupa, Jon Clements Jan 2006

Naphthalene Acetic Acid And Apogee Control Growth In The Tops Of Dwarf Apple Trees, Wesley Autio, James Krupa, Jon Clements

Wesley Autio

No abstract provided.


Naphthalene Acetic Acid Can Differentially Reduce Growth In The Tops Of Dwarf Apple Trees, Results From 2005, Wesley Autio, James Krupa, Jon Clements Jan 2006

Naphthalene Acetic Acid Can Differentially Reduce Growth In The Tops Of Dwarf Apple Trees, Results From 2005, Wesley Autio, James Krupa, Jon Clements

Wesley Autio

No abstract provided.


B.9, M.9, And M.26 Strains And New Polish And Piau Rootstocks In The 2002 Nc-140 Apple Rootstock Trial, Wesley Autio, James Krupa Jan 2006

B.9, M.9, And M.26 Strains And New Polish And Piau Rootstocks In The 2002 Nc-140 Apple Rootstock Trial, Wesley Autio, James Krupa

Wesley Autio

No abstract provided.