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Role Of Propionates In Substrate Binding To Heme Oxygenase From Neisseria Meningitidis: A Nuclear Magnetic Resonance Study, Dungeng Peng, Li Hua Ma, Kevin M. Smith, Xuhong Zhang, Michihiko Sato, Gerd N. La Mar Sep 2012

Role Of Propionates In Substrate Binding To Heme Oxygenase From Neisseria Meningitidis: A Nuclear Magnetic Resonance Study, Dungeng Peng, Li Hua Ma, Kevin M. Smith, Xuhong Zhang, Michihiko Sato, Gerd N. La Mar

Faculty Publications

Heme oxygenase (HO) cleaves hemin into biliverdin, iron, and CO. For mammalian HOs, both native hemin propionates are required for substrate binding and activity. The HO from the pathogenic bacterium Neisseria meningitidis (NmHO) possesses a crystallographically undetected C-terminal fragment that by solution 1H nuclear magnetic resonance (NMR) is found to fold and interact with the active site. One of the substrate propionates has been proposed to form a salt bridge to the C-terminus rather than to the conventional buried cationic side chain in other HOs. Moreover, the C-terminal dipeptide Arg208His209 cleaves spontaneously over ∼24 h at a rate dependent on …

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Formation And Stabilization Of Combustion-Generated, Environmentally Persistent Radicals On Ni(Ii)O Supported On A Silica Surface, Eric Vejerano, Slawomir M. Lomnicki, Barry Dellinger Sep 2012

Formation And Stabilization Of Combustion-Generated, Environmentally Persistent Radicals On Ni(Ii)O Supported On A Silica Surface, Eric Vejerano, Slawomir M. Lomnicki, Barry Dellinger

Faculty Publications

Previous studies have indicated environmentally persistent free radicals (EPFRs) are formed when hydroxyl- and chlorine-substituted aromatics chemisorbed on Cu(II)O and Fe(III)2O3 surfaces and were stabilized through their interactions with the surface metal cation. The current study reports our laboratory investigation on the formation and stabilization of EPFRs on a Ni(II)O surface. The EPFRs were produced by the chemisorption of adsorbates on the supported metal oxide surface and transfer of an electron from the adsorbate to the metal center, resulting in reduction of the metal cation. Depending on the temperature and the nature of the adsorbate, more than one type of …

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Life History Theory And Social Psychology, Donald F. Sacco, Karol Osipowicz Sep 2012

Life History Theory And Social Psychology, Donald F. Sacco, Karol Osipowicz

Faculty Publications

No abstract provided.

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Defining The Role Of Ultrasound In Drug Delivery, William G. Pitt Sep 2012

Defining The Role Of Ultrasound In Drug Delivery, William G. Pitt

Faculty Publications

Ultrasound is a very effective modality for drug delivery because energy that is noninvasively transmitted through the skin can be focused on a specific location and employed to release drug at that site. Most of the drug delivery techniques employ one or both of the results of ultrasonic insonation – the generation of thermal energy, called hyperthermia, or the oscillation of gas bubbles, called acoustic cavitation. Cavitation perturbs cell membrane structures via several modes and increases the permeability to drugs or other solutes. Microconvection, caused by stable cavitation, shears cell membranes. The shock waves and fluid jets of inertial cavitation …

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Resource-Based Habitat Associations In A Neotropical Liana Community, James W. Dalling, Stefan A. Schnitzer, Claire Baldeck, Kyle E. Harms, Robert John, Scott A. Mangan, Elena Lobo, Joseph B. Yavitt, Stephen P. Hubbell Sep 2012

Resource-Based Habitat Associations In A Neotropical Liana Community, James W. Dalling, Stefan A. Schnitzer, Claire Baldeck, Kyle E. Harms, Robert John, Scott A. Mangan, Elena Lobo, Joseph B. Yavitt, Stephen P. Hubbell

Faculty Publications

Summary: 1.Lianas are a conspicuous element of many tropical forests, accounting for up to 40% of woody stem density and 20% of species richness in seasonal forests. However, lianas have seldom been surveyed at sufficiently large spatial scales to allow an assessment of the importance of habitat variables in structuring liana communities. 2.We compare the association patterns of 82 liana species and an equivalent sample of tree species on the 50ha Forest Dynamics Project plot on Barro Colorado Island, Panama, with topographic habitat variables (high and low plateau, slope, swamp and streamside), and thirteen mapped soil chemical variables. In addition, …

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Correlated Evolution Of Beak Morphology And Song In The Neotropical Woodcreeper Radiation, Elizabeth Perrault Derryberry, Nathalie Seddon, Santiago Claramunt, Joseph Andrew Tobias, Adam Baker, Alexandre Aleixo, Robb Thomas Brumfield Sep 2012

Correlated Evolution Of Beak Morphology And Song In The Neotropical Woodcreeper Radiation, Elizabeth Perrault Derryberry, Nathalie Seddon, Santiago Claramunt, Joseph Andrew Tobias, Adam Baker, Alexandre Aleixo, Robb Thomas Brumfield

Faculty Publications

Mating signals may diversify as a byproduct of morphological adaptation to different foraging niches, potentially driving speciation. Although many studies have focused on the direct influence of ecological and sexual selection on signal divergence, the role of indirect mechanisms remains poorly understood. Using phenotypic and molecular datasets, we explored the interplay between morphological and vocal evolution in an avian radiation characterized by dramatic beak variation, the Neotropical woodcreepers (Dendrocolaptinae). We found evidence of a trade-off between the rate of repetition of song syllables and frequency bandwidth: slow paced songs had either narrow or wide frequency bandwidths, and bandwidth decreased as …

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Adipogenesis, Kelesha Sarjeant, Jacqueline M. Stephens Sep 2012

Adipogenesis, Kelesha Sarjeant, Jacqueline M. Stephens

Faculty Publications

Adipose tissue is an important site for lipid storage, energy homeostasis, and whole-body insulin sensitivity. It is important to understand the mechanisms involved in adipose tissue development and function, which can be regulated by the endocrine actions of various peptide and steroid hormones. Recent studies have revealed that white and brown adipocytes can be derived from distinct precursor cells. This review will focus on transcriptional control of adipogenesis and its regulation by several endocrine hormones. The general functions and cellular origins of adipose tissue and how the modulation of adipocyte development pertains to metabolic disease states will also be considered. …

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Dnt1 Acts As A Mitotic Inhibitor Of The Spindle Checkpoint Protein Dma1 In Fission Yeast, Yamei Wang, Wen Zhu Li, Alyssa E. Johnson, Zhou Qing Luo, Xue Li Sun, Anna Feoktistova, W. Hayes Mcdonald, Ian Mcleod, John R. Yates, Kathleen L. Gould, Dannel Mccollum, Quan Wen Jin Sep 2012

Dnt1 Acts As A Mitotic Inhibitor Of The Spindle Checkpoint Protein Dma1 In Fission Yeast, Yamei Wang, Wen Zhu Li, Alyssa E. Johnson, Zhou Qing Luo, Xue Li Sun, Anna Feoktistova, W. Hayes Mcdonald, Ian Mcleod, John R. Yates, Kathleen L. Gould, Dannel Mccollum, Quan Wen Jin

Faculty Publications

The Schizosaccharomyces pombe checkpoint protein Dma1 couples mitotic progression with cytokinesis and is important in delaying mitotic exit and cytokinesis when kinetochores are not properly attached to the mitotic spindle. Dma1 is a ubiquitin ligase and potential functional relative of the human tumor suppressor Chfr. Dma1 delays mitotic exit and cytokinesis by ubiquitinating a scaffold protein (Sid4) of the septation initiation network, which, in turn, antagonizes the ability of the Polo-like kinase Plo1 to promote cell division. Here we identify Dnt1 as a Dma1-binding protein. Several lines of evidence indicate that Dnt1 inhibits Dma1 function during metaphase. First, Dnt1 interacts …

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A Conserved Two-Component Regulatory System, Pids/Pidr, Globally Regulates Pigmentation And Virulence-Related Phenotypes Of Burkholderia Glumae, Hari Sharan Karki, Inderjit Kaur Barphagha, Jong Hyun Ham Sep 2012

A Conserved Two-Component Regulatory System, Pids/Pidr, Globally Regulates Pigmentation And Virulence-Related Phenotypes Of Burkholderia Glumae, Hari Sharan Karki, Inderjit Kaur Barphagha, Jong Hyun Ham

Faculty Publications

Burkholderia glumae is a rice pathogenic bacterium that causes bacterial panicle blight. Some strains of this pathogen produce dark brown pigments when grown on casamino-acid peptone glucose (CPG) agar medium. A pigment-positive and highly virulent strain of B.glumae, 411gr-6, was randomly mutagenized with mini-Tn5gus, and the resulting mini-Tn5gus derivatives showing altered pigmentation phenotypes were screened on CPG agar plates to identify the genetic elements governing the pigmentation of B.glumae. In this study, a novel two-component regulatory system (TCRS) composed of the PidS sensor histidine kinase and the PidR response regulator was identified as an essential regulatory factor for pigmentation. Notably, …

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Inferring The Evolutionary History Of Divergence Despite Gene Flow In A Lizard Species, Scincella Lateralis (Scincidae), Composed Of Cryptic Lineages, Nathan D. Jackson, Christopher C. Austin Sep 2012

Inferring The Evolutionary History Of Divergence Despite Gene Flow In A Lizard Species, Scincella Lateralis (Scincidae), Composed Of Cryptic Lineages, Nathan D. Jackson, Christopher C. Austin

Faculty Publications

Although recent radiations are fruitful for studying the process of speciation, they are difficult to characterize and require the use of multiple loci and analytical methods that account for processes such as gene flow and genetic drift. Using multilocus sequence data, we combine hierarchical cluster analysis, coalescent species tree inference, and isolation-with-migration analysis to investigate evolutionary relationships among cryptic lineages of North American ground skinks. We also estimate the extent that gene flow has accompanied or followed diversification, and also attempt to account for and minimize the influence of gene flow when reconstructing relationships. The data best support seven largely …

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Sperm Cryopreservation In Live-Bearing Xiphophorus Fishes: Offspring Production From Xiphophorus Variatus And Strategies For Establishment Of Sperm Repositories, Huiping Yang, Rafael Cuevas-Uribe, Markita G. Savage, Ronald B. Walter, Terrence R. Tiersch Sep 2012

Sperm Cryopreservation In Live-Bearing Xiphophorus Fishes: Offspring Production From Xiphophorus Variatus And Strategies For Establishment Of Sperm Repositories, Huiping Yang, Rafael Cuevas-Uribe, Markita G. Savage, Ronald B. Walter, Terrence R. Tiersch

Faculty Publications

Cryopreservation of sperm from Xiphophorus fishes has produced live young in three species: X. hellerii, X. couchianus, and X. maculatus. In this study, the goal was to establish protocols for sperm cryopreservation and artificial insemination to produce live young in X. variatus, and to identify needs for repository development. The objectives were to: 1) collect basic biological characteristics of males; 2) cryopreserve sperm from X. variatus, 3) harvest live young from cryopreserved sperm, and 4) discuss the requirements for establishment of sperm repositories. The 35 males used in this study had a body weight of 0.298±0.096g (mean±SD), body length of …

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Seeing The Seafloor Discoveries Of The Rvib Nathaniel B. Palmer Multibeam Systems, Frank O. Nitsche, Julia S. Wellner, Philip Bart, Suzanne O'Hara, Kathleen Gavahan Sep 2012

Seeing The Seafloor Discoveries Of The Rvib Nathaniel B. Palmer Multibeam Systems, Frank O. Nitsche, Julia S. Wellner, Philip Bart, Suzanne O'Hara, Kathleen Gavahan

Faculty Publications

The detailed seafloor topography around Antarctica was virtually unknown until RVIB Nathaniel B. Palmer and other ships started to collect multibeam swath measurements in the 1990s. These new, high-resolution bathymetric data allowed the creation of topographic maps of the Antarctic continental shelf and rise with unprecedented detail. The multibeam data revealed glacial morphological features that allowed reconstruction of paleo-ice flow and maximum ice extent of the formerly glaciated continental margin. Furthermore, these data provided the basis for new insights into the continent's tectonic evolution and defined the nature of marine biological habitats in polar regions. © 2012 by The Oceanography …

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A New Us Polar Research Vessel For The Twenty-First Century, Robert B. Dunbar, Jon Alberts, Carin Ashjian, Vernon Asper, Dale Chayes, Eugene Domack, Hugh Ducklow, Bruce Huber, Lawrence Lawver, Daniel Oliver, Doug Russell, Craig R. Smith, Maria Vernet Sep 2012

A New Us Polar Research Vessel For The Twenty-First Century, Robert B. Dunbar, Jon Alberts, Carin Ashjian, Vernon Asper, Dale Chayes, Eugene Domack, Hugh Ducklow, Bruce Huber, Lawrence Lawver, Daniel Oliver, Doug Russell, Craig R. Smith, Maria Vernet

Faculty Publications

Scientific and political interests at the poles are significant and rapidly increasing, driven in part by the effects of climate change and emerging geopolitical realities. The polar regions provide important services to global ecosystems and humankind, ranging from food and energy to freshwater and biodiversity. Yet the poles are experiencing changes at rates that far outpace the rest of the planet. Coastal Arctic communities are impacted by climate change through coastal erosion, sea level rise, ice loss, and altered marine food webs, threatening the future of their subsistence lifestyle. Climate change has dramatically increased the melt rate of ice sheets …

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Stable Bifurcations In Semelparous Leslie Models, J. M. Cushing, Shandelle M. Henson Sep 2012

Stable Bifurcations In Semelparous Leslie Models, J. M. Cushing, Shandelle M. Henson

Faculty Publications

In this paper, we consider nonlinear Leslie models for the dynamics of semelparous age-structured populations. We establish stability and instability criteria for positive equilibria that bifurcate from the extinction equilibrium at R0=1. When the bifurcation is to the right (forward or super-critical), the criteria consist of inequalities involving the (low-density) between-class and within-class competition intensities. Roughly speaking, stability (respectively, instability) occurs if between-class competition is weaker (respectively, stronger) than within-class competition. When the bifurcation is to the left (backward or sub-critical), the bifurcating equilibria are unstable. We also give criteria that determine whether the boundary of the positive cone is …

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Estimates Of Body Mass For Fossil Giant Ground Squirrels, Genus Paenemarmota, H. Thomas Goodwin, Kelsey M. Bullock Sep 2012

Estimates Of Body Mass For Fossil Giant Ground Squirrels, Genus Paenemarmota, H. Thomas Goodwin, Kelsey M. Bullock

Faculty Publications

Paenemarmota Hibbard and Schultz, 1948 includes 3 species of giant ground squirrels within Marmotini (Rodentia, Sciuridae) from the Late Miocene and Pliocene of central and western North America. We developed skeletal and dental models for estimating body mass across modern species of Marmotini and apply these models to Paenemarmota. The most reliable models for estimating body mass of modern species (on the basis of length and width of femur, lengths of p4 and P4) generally yielded lower estimates of body mass for Paenemarmota than less reliable models (on the basis of lengths of m1, m2, M1, and M2). Models that …

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Emotional Psychological And Related Problems Among Truant Youths: An Exploratory Latent Class Analysis, Richard Dembo, Rhissa Briones-Robinson, Rocío Aracelis Ungaro, Laura M. Gulledge, Lora M. Karas, Ken C. Winters, Steven Belenko, Paul Greenbaum Sep 2012

Emotional Psychological And Related Problems Among Truant Youths: An Exploratory Latent Class Analysis, Richard Dembo, Rhissa Briones-Robinson, Rocío Aracelis Ungaro, Laura M. Gulledge, Lora M. Karas, Ken C. Winters, Steven Belenko, Paul Greenbaum

Faculty Publications

Latent class analysis was conducted on the psychosocial problems experienced by truant youths. Data were obtained from baseline interviews completed on 131 youths and their parents/guardians involved in a NIDA-funded, Brief Intervention Project. Results identified two classes of youths: Class 1(n=9) - youths with low levels of delinquency, mental health and substance abuse issues; and Class 2(n=37) - youths with high levels of these problems. Comparison of these two classes on their urine analysis test results and parent/guardian reports of traumatic events found significant (p<.05) differences between them that were consistent with their problem group classification. Our results have important implications for research and practice.

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Bioactive Trace Metal Distributions And Biogeochemical Controls In The Southern Ocean, Christopher Measures, Mariko Hatta, Maxime Grand Sep 2012

Bioactive Trace Metal Distributions And Biogeochemical Controls In The Southern Ocean, Christopher Measures, Mariko Hatta, Maxime Grand

Faculty Publications

Extensive sampling in many regions of the Southern Ocean has demonstrated that surface water concentrations of dissolved Fe are low enough to limit phytoplankton growth. In contrast, there is currently no evidence that other bioactive elements (e.g., Mn, Zn, Co) are similarly limiting. Although atmospheric input of dissolved Fe to Southern Ocean surface waters appears to be low, resuspension of sediments from shallow regions around islands and the Antarctic coastline can inject significant amounts of Fe into the surrounding waters, stimulating primary production and providing a natural laboratory for studying the response of biological systems to natural Fe fertilization processes. …

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Database Of Diazotrophs In Global Ocean: Abundance, Biomass And Nitrogen Fixation Rates, Y.-W. Luo, S.C. Doney, L.A. Anderson, M. Benavides, I. Berman-Frank, A. Bode, S. Bonnet, K. H. Boström, D. Böttjer, D.G. Capone, E.J. Carpenter, Y.L. Chen, M.J. Church, J.E. Dore, L.I. Falcón, A. Fernández, R.A. Foster, K. Furuya, F. Gómez, K. Gundersen, A.M. Hynes, D.M. Karl, S. Kitajima, R.J. Langlois, J. Laroche, R.M. Letelier, E. Marañón, D.J. Mcgillicuddy Jr., P.H. Moisander, C.M. Moore, B. Mouriño-Carballido, M.R. Mulholland, J.A. Needoba, K.M. Orcutt, A.J. Poulton, E. Rahav, P. Raimbault, A.P. Rees, L. Riemann, T. Shiozaki, A. Subramaniam, T. Tyrell, K.A. Turk-Kubo, M. Varela, T.A. Villareal, E.A. Webb, A.E. White, J. Wu, J.P. Zehr Aug 2012

Database Of Diazotrophs In Global Ocean: Abundance, Biomass And Nitrogen Fixation Rates, Y.-W. Luo, S.C. Doney, L.A. Anderson, M. Benavides, I. Berman-Frank, A. Bode, S. Bonnet, K. H. Boström, D. Böttjer, D.G. Capone, E.J. Carpenter, Y.L. Chen, M.J. Church, J.E. Dore, L.I. Falcón, A. Fernández, R.A. Foster, K. Furuya, F. Gómez, K. Gundersen, A.M. Hynes, D.M. Karl, S. Kitajima, R.J. Langlois, J. Laroche, R.M. Letelier, E. Marañón, D.J. Mcgillicuddy Jr., P.H. Moisander, C.M. Moore, B. Mouriño-Carballido, M.R. Mulholland, J.A. Needoba, K.M. Orcutt, A.J. Poulton, E. Rahav, P. Raimbault, A.P. Rees, L. Riemann, T. Shiozaki, A. Subramaniam, T. Tyrell, K.A. Turk-Kubo, M. Varela, T.A. Villareal, E.A. Webb, A.E. White, J. Wu, J.P. Zehr

Faculty Publications

Marine N2 fixing microorganisms, termed diazotrophs, are a key functional group in marine pelagic ecosystems. The biological fixation of dinitrogen (N2) to bioavailable nitrogen provides an important new source of nitrogen for pelagic marine ecosystems and influences primary productivity and organic matter export to the deep ocean. As one of a series of efforts to collect biomass and rates specific to different phytoplankton functional groups, we have constructed a database on diazotrophic organisms in the global pelagic upper ocean by compiling about 12 000 direct field measurements of cyanobacterial diazotroph abundances (based on microscopic cell counts or …

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A Novel Allosteric Inhibitor Of Macrophage Migration Inhibitory Factor (Mif), Fengwei Bai, Oluwatoyin A. Asojo, Pier Cirillo, Mihai Ciustea, Michel Ledzidet, Paul A. Aristoff, Lin Leng, Raymond A. Koski, Thomas J. Powell, Richard Bucala, Karen G. Anthony Aug 2012

A Novel Allosteric Inhibitor Of Macrophage Migration Inhibitory Factor (Mif), Fengwei Bai, Oluwatoyin A. Asojo, Pier Cirillo, Mihai Ciustea, Michel Ledzidet, Paul A. Aristoff, Lin Leng, Raymond A. Koski, Thomas J. Powell, Richard Bucala, Karen G. Anthony

Faculty Publications

Macrophage migration inhibitory factor (MIF) is a catalytic cytokine and an upstream mediator of the inflammatory pathway. MIF has broad regulatory properties, dysregulation of which has been implicated in the pathology of multiple immunological diseases. Inhibition of MIF activity with small molecules has proven beneficial in a number of disease models. Known small molecule MIF inhibitors typically bind in the tautomerase site of the MIF trimer, often covalently modifying the catalytic proline. Allosteric MIF inhibitors, particularly those that associate with the protein by noncovalent interactions, could reveal novel ways to block MIF activity for therapeutic benefit and serve as chemical …

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Current Status Of Boron Neutron Capture Therapy Of High Grade Gliomas And Recurrent Head And Neck Cancer, Rolf F. Barth, M. Graca H. Vicente, Otto K. Harling, W. S. Kiger, Kent J. Riley, Peter J. Binns, Franz M. Wagner, Minoru Suzuki, Teruhito Aihara, Itsuro Kato, Shinji Kawabata Aug 2012

Current Status Of Boron Neutron Capture Therapy Of High Grade Gliomas And Recurrent Head And Neck Cancer, Rolf F. Barth, M. Graca H. Vicente, Otto K. Harling, W. S. Kiger, Kent J. Riley, Peter J. Binns, Franz M. Wagner, Minoru Suzuki, Teruhito Aihara, Itsuro Kato, Shinji Kawabata

Faculty Publications

Boron neutron capture therapy (BNCT) is a biochemically targeted radiotherapy based on the nuclear capture and fission reactions that occur when non-radioactive boron-10, which is a constituent of natural elemental boron, is irradiated with low energy thermal neutrons to yield high linear energy transfer alpha particles and recoiling lithium-7 nuclei. Clinical interest in BNCT has focused primarily on the treatment of high grade gliomas, recurrent cancers of the head and neck region and either primary or metastatic melanoma. Neutron sources for BNCT currently have been limited to specially modified nuclear reactors, which are or until the recent Japanese natural disaster, …

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The First Record Of A Trans-Oceanic Sister-Group Relationship Between Obligate Vertebrate Troglobites, Prosanta Chakrabarty, Matthew P. Davis, John S. Sparks Aug 2012

The First Record Of A Trans-Oceanic Sister-Group Relationship Between Obligate Vertebrate Troglobites, Prosanta Chakrabarty, Matthew P. Davis, John S. Sparks

Faculty Publications

We show using the most complete phylogeny of one of the most species-rich orders of vertebrates (Gobiiformes), and calibrations from the rich fossil record of teleost fishes, that the genus Typhleotris, endemic to subterranean karst habitats in southwestern Madagascar, is the sister group to Milyeringa, endemic to similar subterranean systems in northwestern Australia. Both groups are eyeless, and our phylogenetic and biogeographic results show that these obligate cave fishes now found on opposite ends of the Indian Ocean (separated by nearly 7,000 km) are each others closest relatives and owe their origins to the break up of the southern supercontinent, …

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Mammalian Per2 Regulates Akt Activation And Dna Damage Response, Xiaoming Yang, Xuezhong He, Zhengguan Yang, Esmaiel Jabbari Aug 2012

Mammalian Per2 Regulates Akt Activation And Dna Damage Response, Xiaoming Yang, Xuezhong He, Zhengguan Yang, Esmaiel Jabbari

Faculty Publications

PER2 is a key mammalian circadian clock protein. It also has a tumor suppressive function. Down regulation of PER2 in the cultured cancer cells accelerates cell proliferation, while overexpression of PER2 inhibits cell growth and induces apoptosis. The Per2 mutant mice have a cancer prone phenotype and an altered DNA damage response. Here we report that PER2 regulates AKT activity. Cells with down-regulated PER2 expression have prolonged high levels of AKT T308 phosphorylation after growth factor stimulation or DNA damage. PER2 down-regulation delays DNA damage induced Chk2 activation and overrides DNA damage induced apoptosis and cell cycle arrest.

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The Structure Of The Bfrb-Bfd Complex Reveals Protein-Protein Interactions Enabling Iron Release From Bacterioferritin, Huili Yao, Yan Wang, Scott Lovell, Ritesh Kumar, Anatoly M. Ruvinsky, Kevin P. Battaile, Ilya A. Vakser, Mario Rivera Aug 2012

The Structure Of The Bfrb-Bfd Complex Reveals Protein-Protein Interactions Enabling Iron Release From Bacterioferritin, Huili Yao, Yan Wang, Scott Lovell, Ritesh Kumar, Anatoly M. Ruvinsky, Kevin P. Battaile, Ilya A. Vakser, Mario Rivera

Faculty Publications

Ferritin-like molecules are unique to cellular iron homeostasis because they can store iron at concentrations much higher than those dictated by the solubility of Fe3+. Very little is known about the protein interactions that deliver iron for storage or promote the mobilization of stored iron from ferritin-like molecules. Here, we report the X-ray crystal structure of Pseudomonas aeruginosa bacterioferritin (Pa-BfrB) in complex with bacterioferritin-associated ferredoxin (Pa-Bfd) at 2.0 Å resolution. As the first example of a ferritin-like molecule in complex with a cognate partner, the structure provides unprecedented insight into the complementary interface that enables the [2Fe-2S] cluster of Pa-Bfd …

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Identification Of Oxidized Amino Acid Residues In The Vicinity Of The Mn 4Cao 5 Cluster Of Photosystem Ii: Implications For The Identification Of Oxygen Channels Within The Photosystem, Laurie K. Frankel, Larry Sallans, Patrick A. Limbach, Terry M. Bricker Aug 2012

Identification Of Oxidized Amino Acid Residues In The Vicinity Of The Mn 4Cao 5 Cluster Of Photosystem Ii: Implications For The Identification Of Oxygen Channels Within The Photosystem, Laurie K. Frankel, Larry Sallans, Patrick A. Limbach, Terry M. Bricker

Faculty Publications

As a light-driven water-plastoquinone oxidoreductase, Photosystem II produces molecular oxygen as an enzymatic product. Additionally, under a variety of stress conditions, reactive oxygen species are produced at or near the active site for oxygen evolution. In this study, Fourier-transform ion cyclotron resonance mass spectrometry was used to identify oxidized amino acid residues located in several core Photosystem II proteins (D1, D2, CP43, and CP47) isolated from spinach Photosystem II membranes. While the majority of these oxidized residues (81%) are located on the oxygenated solvent-exposed surface of the complex, several residues on the CP43 protein ( 354E, 355T, 356M, and 357R) …

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Breast Tumour Initiating Cell Fate Is Regulated By Microenvironmental Cues From An Extracellular Matrix, Sharmistha Saha, Pang-Kuo Lo, Xinrui Duan, Hexin Chen, Qian Wang Aug 2012

Breast Tumour Initiating Cell Fate Is Regulated By Microenvironmental Cues From An Extracellular Matrix, Sharmistha Saha, Pang-Kuo Lo, Xinrui Duan, Hexin Chen, Qian Wang

Faculty Publications

Cancer stem cells, also known as tumour-initiating cells (TICs), are identified as highly tumorigenic population within tumours and hypothesized to be main regulators in tumour growth, metastasis and relapse. Evidence also suggests that a tumour microenvironment plays a critical role in the development and progression of cancer, by constantly modulating cell–matrix interactions. Scientists have tried to characterize and identify the TIC population but the actual combination of extracellular components in deciphering the fate of TICs has not been explored. The basic unanswered question is the phenotypic stability of this TIC population in a tissue extracellular matrix setting. The in vivo …

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Predicting Decadal Trends And Transient Responses Of Radiocarbon Storage And Fluxes In A Temperate Forest Soil, C. A. Sierra, S. E. Trumbore, E. A. Davidson, Serita D. Frey, K. E. Savage, F. M. Hopkins Aug 2012

Predicting Decadal Trends And Transient Responses Of Radiocarbon Storage And Fluxes In A Temperate Forest Soil, C. A. Sierra, S. E. Trumbore, E. A. Davidson, Serita D. Frey, K. E. Savage, F. M. Hopkins

Faculty Publications

Representing the response of soil carbon dynamics to global environmental change requires the incorporation of multiple tools in the development of predictive models. An important tool to construct and test models is the incorporation of bomb radiocarbon in soil organic matter during the past decades. In this manuscript, we combined radiocarbon data and a previously developed empirical model to explore decade-scale soil carbon dynamics in a temperate forest ecosystem at the Harvard Forest, Massachusetts, USA. We evaluated the contribution of different soil C fractions to both total soil CO2 efflux and microbially respired C. We tested the performance of the …

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Asymmetric Syntheses Of 8-Oxabicyclo[3,2,1]Octanes: A Cationic Cascade Cyclization, Bin Li, Yu Jun Zhao, Yin Chang Lai, Teck Peng Loh Aug 2012

Asymmetric Syntheses Of 8-Oxabicyclo[3,2,1]Octanes: A Cationic Cascade Cyclization, Bin Li, Yu Jun Zhao, Yin Chang Lai, Teck Peng Loh

Faculty Publications

High octane: A novel and practical syntheses of 8-oxabicyclo[3.2.1]octanes using a cationic cascade cyclization reaction has been developed (see scheme; TIPS=triisopropylsilyl). The diastereomer of the cyclization product isolated depends upon whether the acetal or aldehyde substrate is used. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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Expanding And Testing A Computational Method For Predicting The Ground State Reduction Potentials Of Organic Molecules On The Basis Of Empirical Correlation To Experiment, Eugene J. Lynch, Amy L. Speelman, Bryce A. Curry, Charles S. Murillo, Jason G. Gillmore Aug 2012

Expanding And Testing A Computational Method For Predicting The Ground State Reduction Potentials Of Organic Molecules On The Basis Of Empirical Correlation To Experiment, Eugene J. Lynch, Amy L. Speelman, Bryce A. Curry, Charles S. Murillo, Jason G. Gillmore

Faculty Publications

A method for predicting the ground state reduction potentials of organic molecules on the basis of the correlation of computed energy differences between the starting S-0 and one-electron-reduced D-0 species with experimental reduction potentials in acetonitrile has been expanded to cover 3.5 V of potential range and 74 compounds across 6 broad families of molecules. Utilizing the conductor-like polarizable continuum model of implicit solvent allows a global correlation that is computationally efficient and has improved accuracy, with r(2) > 0.98 in all cases and root mean square deviation errors of(mean absolute deviationsmV) for either B3LYP/6-311+G(d,p) or B3LYP//6-31G(d) with an appropriate choice …

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The Role Of Individual Behavior Type In Mediating Indirect Interactions, Blaine D. Griffen, Benjamin J. Toscano, John Gatto Aug 2012

The Role Of Individual Behavior Type In Mediating Indirect Interactions, Blaine D. Griffen, Benjamin J. Toscano, John Gatto

Faculty Publications

Trait-mediated indirect interactions (TMII) play an important role in structuring natural communities, and numerous studies have experimentally demonstrated their presence in a variety of systems. However, these studies have largely examined the presence or absence of traits that are responsible for these interactions, without considering natural variation between individuals in the extent to which these traits are manifested. We used a well-documented TMII to investigate the importance of individual behavior type for determining the strength of the TMII. The toadfish Opsanus tau has an indirect positive influence on bivalve survival because the mud crab Panopeus herbstii, a consumer of bivalves, …

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Temperature Responses Of Carbon Monoxide And Hydrogen Uptake By Vegetated And Unvegetated Volcanic Cinders, Caitlin E. King, Gary M. King Aug 2012

Temperature Responses Of Carbon Monoxide And Hydrogen Uptake By Vegetated And Unvegetated Volcanic Cinders, Caitlin E. King, Gary M. King

Faculty Publications

Ecosystem succession on a large deposit of volcanic cinders emplaced on Kilauea Volcano in 1959 has resulted in a mosaic of closed-canopy forested patches and contiguous unvegetated patches. Unvegetated and unshaded surface cinders (Bare) experience substantial diurnal temperature oscillations ranging from moderate (16°C) to extreme (55°C) conditions. The surface material of adjacent vegetated patches (Canopy) experiences much smaller fluctuations (14-25°C) due to shading. To determine whether surface material from these sites showed adaptations by carbon monoxide (CO) and hydrogen (H2) consumption to changes in ambient temperature regimes accompanying succession, we measured responses of CO and H2 uptake to short-term variations …

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