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Fast Microtubule Dynamics In Meiotic Spindles Measured By Single Molecule Imaging: Evidence That The Spindle Environment Does Not Stabilize Microtubules, Thomas J. Maresca, D. J. Needleman, A. Groen, R. Ohi, L. Mirny, T. Mitchison 2010 University of Massachusetts - Amherst

Fast Microtubule Dynamics In Meiotic Spindles Measured By Single Molecule Imaging: Evidence That The Spindle Environment Does Not Stabilize Microtubules, Thomas J. Maresca, D. J. Needleman, A. Groen, R. Ohi, L. Mirny, T. Mitchison

Thomas J. Maresca

Metaphase spindles are steady-state ensembles of microtubules that turn over rapidly and slide poleward in some systems. Since the discovery of dynamic instability in the mid-1980s, models for spindle morphogenesis have proposed that microtubules are stabilized by the spindle environment. We used single molecule imaging to measure tubulin turnover in spindles, and nonspindle assemblies, in Xenopus laevis egg extracts. We observed many events where tubulin molecules spend only a few seconds in polymer and thus are difficult to reconcile with standard models of polymerization dynamics. Our data can be quantitatively explained by a simple, phenomenological model—with only one adjustable parameter—in …


Evolution Of A Unique Predatory Feeding Apparatus: Functional Anatomy, Development And A Genetic Locus For Jaw Laterality In Lake Tanganyika Scale-Eating Cichlids, R. Craig Albertson, T. A. Stewart 2010 University of Massachusetts - Amherst

Evolution Of A Unique Predatory Feeding Apparatus: Functional Anatomy, Development And A Genetic Locus For Jaw Laterality In Lake Tanganyika Scale-Eating Cichlids, R. Craig Albertson, T. A. Stewart

R. Craig Albertson

Background While bilaterality is a defining characteristic of triploblastic animals, several assemblages have managed to break this symmetry in order to exploit the adaptive peaks garnered through the lateralization of behaviour or morphology. One striking example of an evolved asymmetry in vertebrates comes from a group of scale-eating cichlid fishes from Lake Tanganyika. Members of the Perissodini tribe of cichlid fishes have evolved dental and craniofacial asymmetries in order to more effectively remove scales from the left or right flanks of prey. Here we examine the evolution and development of craniofacial morphology and laterality among Lake Tanganyika scale-eating cichlids. Results …


A Look At The Fruit Thinning Weather In 2010, Wesley Autio, Jon Clements 2010 University of Massachusetts - Amherst

A Look At The Fruit Thinning Weather In 2010, Wesley Autio, Jon Clements

Wesley Autio

No abstract provided.


2009 Nc-140 Peach Rootstock Trial In Massachusetts, Wesley Autio, Jon Clements, James Krupa 2010 University of Massachusetts - Amherst

2009 Nc-140 Peach Rootstock Trial In Massachusetts, Wesley Autio, Jon Clements, James Krupa

Wesley Autio

No abstract provided.


New Nc-140 Apple Rootstock Trials Planted In Massachusetts And New Jersey In The Spring Of 2010, Wesley Autio, James Krupa, Jon Clements 2010 University of Massachusetts - Amherst

New Nc-140 Apple Rootstock Trials Planted In Massachusetts And New Jersey In The Spring Of 2010, Wesley Autio, James Krupa, Jon Clements

Wesley Autio

No abstract provided.


Using Heading Vs. Notching With Or Without Ba Application To Induce Branching In Non-Feathered, First-Leaf Apple Trees, Jon Clements, Wesley Autio 2010 University of Massachusetts - Amherst

Using Heading Vs. Notching With Or Without Ba Application To Induce Branching In Non-Feathered, First-Leaf Apple Trees, Jon Clements, Wesley Autio

Wesley Autio

No abstract provided.


Metabolic Response Of Geobacter Sulfurreducens Towards Electron Donor/Acceptor Variation, Derek Lovley, Tae Hoon Yang, Maddalena V. Coppi, Jun Sun 2010 University of Massachusetts - Amherst

Metabolic Response Of Geobacter Sulfurreducens Towards Electron Donor/Acceptor Variation, Derek Lovley, Tae Hoon Yang, Maddalena V. Coppi, Jun Sun

Derek Lovley

Background Geobacter sulfurreducens is capable of coupling the complete oxidation of organic compounds to iron reduction. The metabolic response of G. sulfurreducens towards variations in electron donors (acetate, hydrogen) and acceptors (Fe(III), fumarate) was investigated via 13C-based metabolic flux analysis. We examined the 13C-labeling patterns of proteinogenic amino acids obtained from G. sulfurreducens cultured with 13C-acetate. Results Using 13C-based metabolic flux analysis, we observed that donor and acceptor variations gave rise to differences in gluconeogenetic initiation, tricarboxylic acid cycle activity, and amino acid biosynthesis pathways. Culturing G. sulfurreducens cells with Fe(III) as the electron acceptor and acetate as the electron …


Evolution Of Electron Transfer Out Of The Cell: Comparative Genomics Of Six Geobacter Genomes, Jessica E. Butler, Nelson D. Young, Derek Lovley 2010 University of Massachusetts - Amherst

Evolution Of Electron Transfer Out Of The Cell: Comparative Genomics Of Six Geobacter Genomes, Jessica E. Butler, Nelson D. Young, Derek Lovley

Derek Lovley

Background: Geobacter species grow by transferring electrons out of the cell - either to Fe(III)-oxides or to manmade substances like energy-harvesting electrodes. Study of Geobacter sulfurreducens has shown that TCA cycle enzymes, inner-membrane respiratory enzymes, and periplasmic and outer-membrane cytochromes are required. Here we present comparative analysis of six Geobacter genomes, including species from the clade that predominates in the subsurface. Conservation of proteins across the genomes was determined to better understand the evolution of Geobacter species and to create a metabolic model applicable to subsurface environments. Results: The results showed that enzymes for acetate transport and oxidation, and for …


Interference With Histidyl-Trna Synthetase By A Crispr Spacer Sequence As A Factor In The Evolution Of Pelobacter Carbinolicus, Derek Lovley, Muktak Aklujkar 2010 University of Massachusetts - Amherst

Interference With Histidyl-Trna Synthetase By A Crispr Spacer Sequence As A Factor In The Evolution Of Pelobacter Carbinolicus, Derek Lovley, Muktak Aklujkar

Derek Lovley

BACKGROUND: Pelobacter carbinolicus, a bacterium of the family Geobacteraceae, cannot reduce Fe(III) directly or produce electricity like its relatives. How P. carbinolicus evolved is an intriguing problem. The genome of P. carbinolicus contains clustered regularly interspaced short palindromic repeats (CRISPR) separated by unique spacer sequences, which recent studies have shown to produce RNA molecules that interfere with genes containing identical sequences. RESULTS: CRISPR spacer #1, which matches a sequence within hisS, the histidyl-tRNA synthetase gene of P. carbinolicus, was shown to be expressed. Phylogenetic analysis and genetics demonstrated that a gene paralogous to hisS in the genomes of Geobacteraceae is …


Constraint-Based Modeling Analysis Of The Metabolism Of Two Pelobacter Species, Derek Lovley, Jun Sun, Shelly A. Haveman, Olivia Bui, Tom R. Fahland 2010 University of Massachusetts - Amherst

Constraint-Based Modeling Analysis Of The Metabolism Of Two Pelobacter Species, Derek Lovley, Jun Sun, Shelly A. Haveman, Olivia Bui, Tom R. Fahland

Derek Lovley

BACKGROUND: Pelobacter species are commonly found in a number of subsurface environments, and are unique members of the Geobacteraceae family. They are phylogenetically intertwined with both Geobacter and Desulfuromonas species. Pelobacter species likely play important roles in the fermentative degradation of unusual organic matters and syntrophic metabolism in the natural environments, and are of interest for applications in bioremediation and microbial fuel cells. RESULTS: In order to better understand the physiology of Pelobacter species, genome-scale metabolic models for Pelobacter carbinolicus and Pelobacter propionicus were developed. Model development was greatly aided by the availability of models of the closely related Geobacter …


De Novo Assembly Of The Complete Genome Of An Enhanced Electricity-Producing Variant Of Geobacter Sulfurreducens Using Only Short Reads, Derek Lovley, Harish Nagarajan, Jessica E. Butler, Anna Klimes, Yu Qiu, Karsten Zengler, Joy Ward, Nelson D. Young, Barbara A. Methe, Bernhard Ø. Palsson, Christian L. Barrett 2010 University of Massachusetts - Amherst

De Novo Assembly Of The Complete Genome Of An Enhanced Electricity-Producing Variant Of Geobacter Sulfurreducens Using Only Short Reads, Derek Lovley, Harish Nagarajan, Jessica E. Butler, Anna Klimes, Yu Qiu, Karsten Zengler, Joy Ward, Nelson D. Young, Barbara A. Methe, Bernhard Ø. Palsson, Christian L. Barrett

Derek Lovley

State-of-the-art DNA sequencing technologies are transforming the life sciences due to their ability to generate nucleotide sequence information with a speed and quantity that is unapproachable with traditional Sanger sequencing. Genome sequencing is a principal application of this technology, where the ultimate goal is the full and complete sequence of the organism of interest. Due to the nature of the raw data produced by these technologies, a full genomic sequence attained without the aid of Sanger sequencing has yet to be demonstrated. We have successfully developed a four-phase strategy for using only next-generation sequencing technologies (Illumina and 454) to assemble …


Genome-Wide Gene Regulation Of Biosynthesis And Energy Generation By A Novel Transcriptional Repressor In Geobacter Species, Derek Lovley, Toshiyuki Ueki 2010 University of Massachusetts - Amherst

Genome-Wide Gene Regulation Of Biosynthesis And Energy Generation By A Novel Transcriptional Repressor In Geobacter Species, Derek Lovley, Toshiyuki Ueki

Derek Lovley

Geobacter species play important roles in bioremediation of contaminated environments and in electricity production from waste organic matter in microbial fuel cells. To better understand physiology of Geobacter species, expression and function of citrate synthase, a key enzyme in the TCA cycle that is important for organic acid oxidation in Geobacter species, was investigated. Geobacter sulfurreducens did not require citrate synthase for growth with hydrogen as the electron donor and fumarate as the electron acceptor. Expression of the citrate synthase gene, gltA, was repressed by a transcription factor under this growth condition. Functional and comparative genomics approaches, coupled with genetic …


The Genome Of Geobacter Bemidjiensis, Exemplar For The Subsurface Clade Of Geobacter Species That Predominate In Fe(Iii)-Reducing Subsurface Enviorments, Muktak Aklujkar, Nealson D. Young, Dawn Holmes, Milind Chavan, Carla Risso, Hajnalka E. Kiss, Cliff S. Han, Miriam L. Land, Derek Lovley 2010 University of Massachusetts - Amherst

The Genome Of Geobacter Bemidjiensis, Exemplar For The Subsurface Clade Of Geobacter Species That Predominate In Fe(Iii)-Reducing Subsurface Enviorments, Muktak Aklujkar, Nealson D. Young, Dawn Holmes, Milind Chavan, Carla Risso, Hajnalka E. Kiss, Cliff S. Han, Miriam L. Land, Derek Lovley

Derek Lovley

BACKGROUND: Geobacter species in a phylogenetic cluster known as subsurface clade 1 are often the predominant microorganisms in subsurface environments in which Fe(III) reduction is the primary electron-accepting process. Geobacter bemidjiensis, a member of this clade, was isolated from hydrocarbon-contaminated subsurface sediments in Bemidji, Minnesota, and is closely related to Geobacter species found to be abundant at other subsurface sites. This study examines whether there are significant differences in the metabolism and physiology of G. bemidjiensis compared to non-subsurface Geobacter species. RESULTS: Annotation of the genome sequence of G. bemidjiensis indicates several differences in metabolism compared to previously sequenced non-subsurface …


Welcome To A New Kind Of Tension: Translating Kinetochore Mechanics Into A Wait-Anaphase Signal, Thomas J. Maresca, E. D. Salmon 2010 University of Massachusetts - Amherst

Welcome To A New Kind Of Tension: Translating Kinetochore Mechanics Into A Wait-Anaphase Signal, Thomas J. Maresca, E. D. Salmon

Thomas J. Maresca

Recent high-resolution studies of kinetochore structure have transformed the way researchers think about this crucial macro-molecular complex, which is essential for ensuring chromosome segregation occurs faithfully during cell division. Kinetochores mediate the interaction between chromosomes and the plus-ends of dynamic spindle microtubules and control the timing of anaphase onset by regulating the spindle assembly checkpoint (SAC). There is much debate in the SAC research community as to whether mitotic cells sense only microtubule attachment at the kinetochore, or both attachment and tension, before committing to anaphase. In this Commentary, we present a brief history of the tension-versus-attachment debate, summarize recent …


Anhang: Auszüge Aus Dem Späteren Leben Von Professor Dr. Otto Vogl, Otto Vogl 2010 University of Massachusetts - Amherst

Anhang: Auszüge Aus Dem Späteren Leben Von Professor Dr. Otto Vogl, Otto Vogl

Otto Vogl

No abstract provided.


Evaluation Of Measurement Procedures Used To Determine The Bulk Density Of Distillers Dried Grains With Solubles (Ddgs), Clairmont L. Clementson, Klein E. Ileleji, Kurt A. Rosentrater 2010 Purdue University

Evaluation Of Measurement Procedures Used To Determine The Bulk Density Of Distillers Dried Grains With Solubles (Ddgs), Clairmont L. Clementson, Klein E. Ileleji, Kurt A. Rosentrater

Kurt A. Rosentrater

The production of corn-based ethanol in the U.S. has been dramatically increasing in recent years, and consequently so has the quantity of co-products, especially distillers dried grains with solubles (DDGS), generated from this industrial sector. DDGS is sold as a commodity for animal feed, and like corn, its bulk physical and chemical properties are quality attributes that can be used in trading by merchandisers. Consistency in product quality has been a cause for concern in the industry, and the lack of standard methods for physical and chemical property determination potentially confounds the issue, especially when results of attributes measured by …


The Carboxyl-Terminal Segment Of Apolipoprotein A-V Undergoes A Lipid-Induced Conformational Change, Kasuen Mauldin, B. L. Lee, M. Oleszczuk, B. D. Sykes, R. O. Ryan 2010 University of California - Berkeley

The Carboxyl-Terminal Segment Of Apolipoprotein A-V Undergoes A Lipid-Induced Conformational Change, Kasuen Mauldin, B. L. Lee, M. Oleszczuk, B. D. Sykes, R. O. Ryan

Kasuen Mauldin

Apolipoprotein (apo) A-V is a 343-residue, multidomain protein that plays an important role in regulation of plasma triglyceride homeostasis. Primary sequence analysis revealed a unique tetraproline sequence (Pro293-Pro296) near the carboxyl terminus of the protein. A peptide corresponding to the 48-residue segment beyond the tetraproline motif was generated from a recombinant apoA-V precursor wherein Pro295 was replaced by Met. Cyanogen bromide cleavage of the precursor protein, followed by negative affinity chromatography, yielded a purified peptide. Nondenaturing polyacrylamide gel electrophoresis verified that apoA-V(296-343) solubilizes phospholipid vesicles, forming a relatively heterogeneous population of reconstituted high-density lipoprotein with Stokes’ diameters>17 nm. At …


Effect Of Dipterinyl Calcium Pentahydrate On Hepatitis B Virus Replication In Transgenic Mice, P Moheno, John D. Morrey, D Fuchs 2010 Utah State University

Effect Of Dipterinyl Calcium Pentahydrate On Hepatitis B Virus Replication In Transgenic Mice, P Moheno, John D. Morrey, D Fuchs

John D. Morrey

Dipterinyl calcium pentahydrate (DCP) has previously been shown to inhibit MDA-MB-231 human breast cancer xenographs in nude mice in a manner correlated with increases in plasma IL-12 and IL-4 concentrations, and decreases in plasma IL-6 levels. DCP also inhibits indoleamine 2,3-dioxygenase (IDO), an immuno-inhibitory enzyme, in human PBMCs (Peripheral Blood Mononuclear Cells).


Assessing Changes In Vascular Permeability In A Hamster Model Of Viral Hemorrhagic Fever, B B. Gowen, J G. Julander, N R. London, M H. Wong, D Larson, John D. Morrey, D Y. Li, M Bray 2010 Utah State University

Assessing Changes In Vascular Permeability In A Hamster Model Of Viral Hemorrhagic Fever, B B. Gowen, J G. Julander, N R. London, M H. Wong, D Larson, John D. Morrey, D Y. Li, M Bray

John D. Morrey

A number of RNA viruses cause viral hemorrhagic fever (VHF), in which proinflammatory mediators released from infected cells induce increased permeability of the endothelial lining of blood vessels, leading to loss of plasma volume, hypotension, multi-organ failure, shock and death. The optimal treatment of VHF should therefore include both the use of antiviral drugs to inhibit viral replication and measures to prevent or correct changes in vascular function. Although rodent models have been used to evaluate treatments for increased vascular permeability (VP) in bacterial sepsis, such studies have not been performed for VHF.


Development Of A New Tacaribe Arenavirus Infection Model And Its Use To Explore Antiviral Activity Of A Novel Aristeromycin Analog, B B. Gowen, M H. Wong, D Larson, W Ye, K H. Jung, E J. Sefing, R Skirpstunas, D F. Smee, John D. Morrey, S W. Schneller 2010 Utah State University

Development Of A New Tacaribe Arenavirus Infection Model And Its Use To Explore Antiviral Activity Of A Novel Aristeromycin Analog, B B. Gowen, M H. Wong, D Larson, W Ye, K H. Jung, E J. Sefing, R Skirpstunas, D F. Smee, John D. Morrey, S W. Schneller

John D. Morrey

A growing number of arenaviruses can cause a devastating viral hemorrhagic fever (VHF) syndrome. They pose a public health threat as emerging viruses and because of their potential use as bioterror agents. All of the highly pathogenic New World arenaviruses (NWA) phylogenetically segregate into clade B and require maximum biosafety containment facilities for their study. Tacaribe virus (TCRV) is a nonpathogenic member of clade B that is closely related to the VHF arenaviruses at the amino acid level. Despite this relatedness, TCRV lacks the ability to antagonize the host interferon (IFN) response, which likely contributes to its inability to cause …


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