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Articles 1 - 30 of 127

Full-Text Articles in Life Sciences

Sustainable Intensification Of Livestock Systems Using Forage Legumes In The Anthropocene, José C. B. Dubeux Jr., D. M. Jaramillo, E. R. S. Santos, L. Garcia, L. M. D. Queiroz, K. R. Trumpp Nov 2023

Sustainable Intensification Of Livestock Systems Using Forage Legumes In The Anthropocene, José C. B. Dubeux Jr., D. M. Jaramillo, E. R. S. Santos, L. Garcia, L. M. D. Queiroz, K. R. Trumpp

IGC Proceedings (1997-2023)

Sustainable intensification of livestock systems implies greater efficiency in resource utilization resulting in greater output of products and other ecosystem services per unit of resource input. Strategies to improve resource use efficiency include diversification of plant and ruminant species with complementary resource use. Forages that have root systems with contrasting architecture and exploring different soil layers with complementary use of resource acquisition (e.g., nutrients, water) could enhance primary productivity. Belowground interactions with soil microbiota (e.g., mycorrhizae) is key to enhance resource utilization. Forages with complementary canopy characteristics that helps enhancing light interception and utilization could also lead to greater resource …

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An Artifact In Intracellular Cytokine Staining For Studying T Cell Responses And Its Alleviation., Zheng Gong, Qing Li, Jiayuan Shi, Guangwen Ren Jan 2022

An Artifact In Intracellular Cytokine Staining For Studying T Cell Responses And Its Alleviation., Zheng Gong, Qing Li, Jiayuan Shi, Guangwen Ren

Faculty Research 2022

Intracellular cytokine staining (ICS) is a widely employed ex vivo method for quantitative determination of the activation status of immune cells, most often applied to T cells. ICS test samples are commonly prepared from animal or human tissues as unpurified cell mixtures, and cell-specific cytokine signals are subsequently discriminated by gating strategies using flow cytometry. Here, we show that when ICS samples contain Ly6G+ neutrophils, neutrophils are ex vivo activated by an ICS reagent - phorbol myristate acetate (PMA) - which leads to hydrogen peroxide (H2O2) release and death of cytokine-expressing T cells. This artifact …

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Space Systems: Emerging Technologies And Operations, Randall K. Nichols, Candice M. Carter, John-Paul Hood, Mark J. Jackson, Siny M. J. Joseph, Haley Larson, Wayne D. Lonstein, Randall Mai, Robert Mccreight, Hans C. Mumm, Michael L. Oetken, Michael J. Pritchard, Julie J. H. C. Ryan, Suzanne E. Sincavage, William Slofer Jan 2022

Space Systems: Emerging Technologies And Operations, Randall K. Nichols, Candice M. Carter, John-Paul Hood, Mark J. Jackson, Siny M. J. Joseph, Haley Larson, Wayne D. Lonstein, Randall Mai, Robert Mccreight, Hans C. Mumm, Michael L. Oetken, Michael J. Pritchard, Julie J. H. C. Ryan, Suzanne E. Sincavage, William Slofer

NPP eBooks

SPACE SYSTEMS: EMERGING TECHNOLOGIES AND OPERATIONS is our seventh textbook in a series covering the world of UASs / CUAS/ UUVs. Other textbooks in our series are Drone Delivery of CBNRECy – DEW Weapons: Emerging Threats of Mini-Weapons of Mass Destruction and Disruption (WMDD); Disruptive Technologies with applications in Airline, Marine, Defense Industries; Unmanned Vehicle Systems & Operations On Air, Sea, Land; Counter Unmanned Aircraft Systems Technologies and Operations; Unmanned Aircraft Systems in the Cyber Domain: Protecting USA’s Advanced Air Assets, 2nd edition; and Unmanned Aircraft Systems (UAS) in the Cyber Domain Protecting USA's Advanced Air Assets, 1st edition. …

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Biodegradation Of Rubber Particles In Soil: Using Acclimated Bacteria Isolated From Kansas Soil To Degrade Cryogrinds In Slurry, Shane Graham Jan 2022

Biodegradation Of Rubber Particles In Soil: Using Acclimated Bacteria Isolated From Kansas Soil To Degrade Cryogrinds In Slurry, Shane Graham

Williams Honors College, Honors Research Projects

This study investigated the viability of bioremediating rubber cryogrind using enriched indigenous bacteria. To begin the experiment, soils from three highway roadside locations in Kansas, KS 96 and West, KS 400 and 143rd, and 199th, were collected and transported to the lab to be studied. An initial soil characterization was run on the soil samples using distilled (DI) water mixture and 0.01 M CaCl2 to assess conductivity. The soils were tested to gather a baseline of the relationship between pH and conductivity and the impact of its distance from the roadside. Bacteria were isolated from …

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Comprehensive Characterization Of 536 Patient-Derived Xenograft Models Prioritizes Candidatesfor Targeted Treatment., Hua Sun, Song Cao, R Jay Mashl, Chia-Kuei Mo, Simone Zaccaria, Michael C Wendl, Sherri R Davies, Matthew H Bailey, Tina M Primeau, Jeremy Hoog, Jacqueline L Mudd, Dennis A Dean, Rajesh Patidar, Li Chen, Matthew A Wyczalkowski, Reyka G Jayasinghe, Fernanda Martins Rodrigues, Nadezhda V Terekhanova, Yize Li, Kian-Huat Lim, Andrea Wang-Gillam, Brian A Van Tine, Cynthia X Ma, Rebecca Aft, Katherine C Fuh, Julie K Schwarz, Jose P Zevallos, Sidharth V Puram, John F Dipersio, Nci Pdxnet Consortium, Brandi Davis-Dusenbery, Matthew J Ellis, Michael T Lewis, Michael A Davies, Meenhard Herlyn, Bingliang Fang, Jack A Roth, Alana L Welm, Bryan E Welm, Funda Meric-Bernstam, Feng Chen, Ryan C Fields, Shunqiang Li, Ramaswamy Govindan, James H Doroshow, Jeffrey A Moscow, Yvonne A Evrard, Jeffrey Chuang, Benjamin J Raphael, Li Ding, Carol J Bult, Peter N Robinson Aug 2021

Comprehensive Characterization Of 536 Patient-Derived Xenograft Models Prioritizes Candidatesfor Targeted Treatment., Hua Sun, Song Cao, R Jay Mashl, Chia-Kuei Mo, Simone Zaccaria, Michael C Wendl, Sherri R Davies, Matthew H Bailey, Tina M Primeau, Jeremy Hoog, Jacqueline L Mudd, Dennis A Dean, Rajesh Patidar, Li Chen, Matthew A Wyczalkowski, Reyka G Jayasinghe, Fernanda Martins Rodrigues, Nadezhda V Terekhanova, Yize Li, Kian-Huat Lim, Andrea Wang-Gillam, Brian A Van Tine, Cynthia X Ma, Rebecca Aft, Katherine C Fuh, Julie K Schwarz, Jose P Zevallos, Sidharth V Puram, John F Dipersio, Nci Pdxnet Consortium, Brandi Davis-Dusenbery, Matthew J Ellis, Michael T Lewis, Michael A Davies, Meenhard Herlyn, Bingliang Fang, Jack A Roth, Alana L Welm, Bryan E Welm, Funda Meric-Bernstam, Feng Chen, Ryan C Fields, Shunqiang Li, Ramaswamy Govindan, James H Doroshow, Jeffrey A Moscow, Yvonne A Evrard, Jeffrey Chuang, Benjamin J Raphael, Li Ding, Carol J Bult, Peter N Robinson

Faculty Research 2021

Development of candidate cancer treatments is a resource-intensive process, with the research community continuing to investigate options beyond static genomic characterization. Toward this goal, we have established the genomic landscapes of 536 patient-derived xenograft (PDX) models across 25 cancer types, together with mutation, copy number, fusion, transcriptomic profiles, and NCI-MATCH arms. Compared with human tumors, PDXs typically have higher purity and fit to investigate dynamic driver events and molecular properties via multiple time points from same case PDXs. Here, we report on dynamic genomic landscapes and pharmacogenomic associations, including associations between activating oncogenic events and drugs, correlations between whole-genome duplications …

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Fos Rescues Neuronal Differentiation Of Sox2-Deleted Neural Stem Cells By Genome-Wide Regulation Of Common Sox2 And Ap1(Fos-Jun) Target Genes., Miriam Pagin, Mattias Pernebrink, Mattia Pitasi, Federica Malighetti, Chew Yee Ngan, Sergio Ottolenghi, Giulio Pavesi, Claudio Cantù, Silvia K Nicolis Jul 2021

Fos Rescues Neuronal Differentiation Of Sox2-Deleted Neural Stem Cells By Genome-Wide Regulation Of Common Sox2 And Ap1(Fos-Jun) Target Genes., Miriam Pagin, Mattias Pernebrink, Mattia Pitasi, Federica Malighetti, Chew Yee Ngan, Sergio Ottolenghi, Giulio Pavesi, Claudio Cantù, Silvia K Nicolis

Faculty Research 2021

The transcription factor SOX2 is important for brain development and for neural stem cells (NSC) maintenance. Sox2-deleted (Sox2-del) NSC from neonatal mouse brain are lost after few passages in culture. Two highly expressed genes, Fos and Socs3, are strongly downregulated in Sox2-del NSC; we previously showed that Fos or Socs3 overexpression by lentiviral transduction fully rescues NSC's long-term maintenance in culture. Sox2-del NSC are severely defective in neuronal production when induced to differentiate. NSC rescued by Sox2 reintroduction correctly differentiate into neurons. Similarly, Fos transduction rescues normal or even increased numbers of immature neurons expressing beta-tubulinIII, but not …

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Synthesis Of Thresholds Of Ocean Acidification Impacts On Echinoderms, N. Bednaršek, P. Calosi, R. A. Feely, R. Ambrose, M. Byrne, Kit Yu Karen Chan, S. Dupont, J. L. Padilla-Gamiño, J. I. Spicer, F. Kessouri, M. Roethler, M. Sutula, S. B. Weisberg May 2021

Synthesis Of Thresholds Of Ocean Acidification Impacts On Echinoderms, N. Bednaršek, P. Calosi, R. A. Feely, R. Ambrose, M. Byrne, Kit Yu Karen Chan, S. Dupont, J. L. Padilla-Gamiño, J. I. Spicer, F. Kessouri, M. Roethler, M. Sutula, S. B. Weisberg

Biology Faculty Works

Assessing the vulnerability of marine invertebrates to ocean acidification (OA) requires an understanding of critical thresholds at which developmental, physiological, and behavioral traits are affected. To identify relevant thresholds for echinoderms, we undertook a three-step data synthesis, focused on California Current Ecosystem (CCE) species. First, literature characterizing echinoderm responses to OA was compiled, creating a dataset comprised of >12,000 datapoints from 41 studies. Analysis of this data set demonstrated responses related to physiology, behavior, growth and development, and increased mortality in the larval and adult stages to low pH exposure. Second, statistical analyses were conducted on selected pathways to identify …

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Disruptive Technologies With Applications In Airline & Marine And Defense Industries, Randall K. Nichols, Hans C. Mumm, Wayne Lonstein, Suzanne Sincavage, Candice M. Carter, John-Paul Hood, Randall Mai, Mark Jackson, Bart Shields Feb 2021

Disruptive Technologies With Applications In Airline & Marine And Defense Industries, Randall K. Nichols, Hans C. Mumm, Wayne Lonstein, Suzanne Sincavage, Candice M. Carter, John-Paul Hood, Randall Mai, Mark Jackson, Bart Shields

NPP eBooks

Disruptive Technologies With Applications in Airline, Marine, Defense Industries is our fifth textbook in a series covering the world of Unmanned Vehicle Systems Applications & Operations On Air, Sea, and Land. The authors have expanded their purview beyond UAS / CUAS / UUV systems that we have written extensively about in our previous four textbooks. Our new title shows our concern for the emergence of Disruptive Technologies and how they apply to the Airline, Marine and Defense industries. Emerging technologies are technologies whose development, practical applications, or both are still largely unrealized, such that they are figuratively emerging into prominence …

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The Organic Synthesis Of Anthranilic Acid Derivatives As Potential Active Antibiotics, Paul Chappell Apr 2020

The Organic Synthesis Of Anthranilic Acid Derivatives As Potential Active Antibiotics, Paul Chappell

Student Scholars Day Posters

The objective of this research project was to synthesize multiple derivatives of anthranilic acid. These derivatives will then be tested for antibiotic activity against Staphylococcus aureus and Escherichia coli (E. coli). As bacteria become more resistant to penicillin-based antibiotics, the exploration of anthranilic acid-based antibiotics could serve an important role for future medical use. This research project included data collection via 1H-NMR, 12C-NMR, TLC, MP, and IR to determine purity for biological testing.

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Computational Tools For Analyzing Correlations Between Microbial Biological Diversity And Ecosystems, Behzad Torkian Apr 2020

Computational Tools For Analyzing Correlations Between Microbial Biological Diversity And Ecosystems, Behzad Torkian

Theses and Dissertations

Metagenomics has developed into a reliable mechanism to analyze microbial diversity of microbial communities in the recent years. Through the use of next-generation sequencing, metagenomic studies can generate billions of short sequencing reads that are processed by computational tools. However, with the rapid adoption of metagenomics, a large amount of data has been produced. This high level of data production requires the development of computational tools and pipelines to manage data scalability and performance. In this thesis, we developed several tools that will aid in the exploration of the large amount of DNA sequence data, and we further developed a …

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The Zinc Transporter Zipt-7.1 Regulates Sperm Activation In Nematodes, Yanmei Zhao, Chieh-Hsiang Tan, Amber Krauchunas, Andrea Scharf, Nicholas Dietrich, Kurt Warnhoff, Zhiheng Yuan, Marina Druzhinina, Sam Guoping Gu, Long Miao, Andrew Singson, Ronald E Ellis, Kerry Kornfeld Jun 2018

The Zinc Transporter Zipt-7.1 Regulates Sperm Activation In Nematodes, Yanmei Zhao, Chieh-Hsiang Tan, Amber Krauchunas, Andrea Scharf, Nicholas Dietrich, Kurt Warnhoff, Zhiheng Yuan, Marina Druzhinina, Sam Guoping Gu, Long Miao, Andrew Singson, Ronald E Ellis, Kerry Kornfeld

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Sperm activation is a fascinating example of cell differentiation, in which immotile spermatids undergo a rapid and dramatic transition to become mature, motile sperm. Because the sperm nucleus is transcriptionally silent, this transition does not involve transcriptional changes. Although Caenorhabditis elegans is a leading model for studies of sperm activation, the mechanisms by which signaling pathways induce this transformation remain poorly characterized. Here we show that a conserved transmembrane zinc transporter, ZIPT-7.1, regulates the induction of sperm activation in Caenorhabditis nematodes. The zipt-7.1 mutant hermaphrodites cannot self-fertilize, and males reproduce poorly, because mutant spermatids are defective in responding to activating …

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The Pacific Salmon Explorer: A Data Driven Look At Salmon Populations And Their Habitats, Katrina Connors, Eileen Jones, Leah Honka, Katy Kellock, Eric Hertz, Brian E. Riddell Apr 2018

The Pacific Salmon Explorer: A Data Driven Look At Salmon Populations And Their Habitats, Katrina Connors, Eileen Jones, Leah Honka, Katy Kellock, Eric Hertz, Brian E. Riddell

Salish Sea Ecosystem Conference

The lack of a centralized, standardized, and easily accessible repository of information on the state of natural resources, and threats to them, can undermine efforts to make informed, transparent, and evidenced-based management and conservation decisions. This is the case with Pacific salmon in British Columbia (BC), where a lack of information on the current status of salmon population and their habitats is undermining public confidence in the ability of government agencies to sustainability manage Pacific salmon populations. In an effort to provide broader public access to salmon datasets, the Pacific Salmon Foundation embarked on a major initiative to synthesize the …

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A Metadata Reporting Framework (Frames) For Synthesis Of Ecohydrological Observations, Danielle S. Christianson, Charuleka Varadharajan, Bradley O. Christoffersen, Matteo Detto, Boris Faybishenko, Bruno O. Gimenez, Val Hendrix, Kolby J. Jardine, Robinson Negron-Juarez, Gilberto Z. Pastorello Nov 2017

A Metadata Reporting Framework (Frames) For Synthesis Of Ecohydrological Observations, Danielle S. Christianson, Charuleka Varadharajan, Bradley O. Christoffersen, Matteo Detto, Boris Faybishenko, Bruno O. Gimenez, Val Hendrix, Kolby J. Jardine, Robinson Negron-Juarez, Gilberto Z. Pastorello

Biology Faculty Publications and Presentations

Metadata describe the ancillary information needed for data preservation and independent interpretation, comparison across heterogeneous datasets, and quality assessment and quality control (QA/QC). Environmental observations are vastly diverse in type and structure, can be taken across a wide range of spatiotemporal scales in a variety of measurement settings and approaches, and saved in multiple formats. Thus, well-organized, consistent metadata are required to produce usable data products from diverse environmental observations collected across field sites. However, existing metadata reporting protocols do not support the complex data synthesis and model-data integration needs of interdisciplinary earth system research. We developed a metadata reporting …

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Inhibition Of Post-Transcriptional Steps In Ribosome Biogenesis Confers Cytoprotection Against Chemotherapeutic Agents In A P53-Dependent Manner, Russell T Sapio, Anastasiya N Nezdyur, Matthew Krevetski, Leonid Anikin, Vincent J Manna, Natalie Minkovsky, Dimitri G Pestov Aug 2017

Inhibition Of Post-Transcriptional Steps In Ribosome Biogenesis Confers Cytoprotection Against Chemotherapeutic Agents In A P53-Dependent Manner, Russell T Sapio, Anastasiya N Nezdyur, Matthew Krevetski, Leonid Anikin, Vincent J Manna, Natalie Minkovsky, Dimitri G Pestov

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

The p53-mediated nucleolar stress response associated with inhibition of ribosomal RNA transcription was previously shown to potentiate killing of tumor cells. Here, we asked whether targeting of ribosome biogenesis can be used as the basis for selective p53-dependent cytoprotection of nonmalignant cells. Temporary functional inactivation of the 60S ribosome assembly factor Bop1 in a 3T3 cell model markedly increased cell recovery after exposure to camptothecin or methotrexate. This was due, at least in part, to reversible pausing of the cell cycle preventing S phase associated DNA damage. Similar cytoprotective effects were observed after transient shRNA-mediated silencing of Rps19, but not …

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Can We Predict Ectotherm Responses To Climate Change Using Thermal Performance Curves And Body Temperatures?, Brent J Sinclair, Katie E Marshall, Mary A Sewell, Danielle L Levesque, Christopher S Willett, Stine Slotsbo, Yunwei Dong, Christopher D G Harley, David J Marshall, Brian S Helmuth, Raymond B Huey Nov 2016

Can We Predict Ectotherm Responses To Climate Change Using Thermal Performance Curves And Body Temperatures?, Brent J Sinclair, Katie E Marshall, Mary A Sewell, Danielle L Levesque, Christopher S Willett, Stine Slotsbo, Yunwei Dong, Christopher D G Harley, David J Marshall, Brian S Helmuth, Raymond B Huey

Biology Publications

Thermal performance curves (TPCs), which quantify how an ectotherm's body temperature (Tb ) affects its performance or fitness, are often used in an attempt to predict organismal responses to climate change. Here, we examine the key - but often biologically unreasonable - assumptions underlying this approach; for example, that physiology and thermal regimes are invariant over ontogeny, space and time, and also that TPCs are independent of previously experienced Tb. We show how a critical consideration of these assumptions can lead to biologically useful hypotheses and experimental designs. For example, rather than assuming that TPCs are fixed during ontogeny, one …

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Chemical Activation Of A Food Deprivation Signal Extends Lifespan., Mark Lucanic, Theo Garrett, Ivan Yu, Fernando Calahorro, Azar Asadi Shahmirzadi, Aaron Miller, Matthew S Gill, Robert E. Hughes, Lindy Holden-Dye, Gordon J. Lithgow Oct 2016

Chemical Activation Of A Food Deprivation Signal Extends Lifespan., Mark Lucanic, Theo Garrett, Ivan Yu, Fernando Calahorro, Azar Asadi Shahmirzadi, Aaron Miller, Matthew S Gill, Robert E. Hughes, Lindy Holden-Dye, Gordon J. Lithgow

Natural Sciences and Mathematics | Student Professional Publications

Model organisms subject to dietary restriction (DR) generally live longer. Accompanying this lifespan extension are improvements in overall health, based on multiple metrics. This indicates that pharmacological treatments that mimic the effects of DR could improve health in humans. To find new chemical structures that extend lifespan, we screened 30 000 synthetic, diverse drug-like chemicals in Caenorhabditis elegans and identified several structurally related compounds that acted through DR mechanisms. The most potent of these NP1 impinges upon a food perception pathway by promoting glutamate signaling in the pharynx. This results in the overriding of a GPCR pathway involved in the …

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Hunting, Food Subsidies, And Mesopredator Release: The Dynamics Of Crop-Raiding Baboons In A Managed Landscape, Rachel A. Taylor, Sadie J. Ryan, Justin S. Brashares, Leah R. Johnson Apr 2016

Hunting, Food Subsidies, And Mesopredator Release: The Dynamics Of Crop-Raiding Baboons In A Managed Landscape, Rachel A. Taylor, Sadie J. Ryan, Justin S. Brashares, Leah R. Johnson

Integrative Biology Faculty and Staff Publications

The establishment of protected areas or parks has become an important tool for wildlife conservation. However, frequent occurrences of human-wildlife conflict at the edges of these parks can undermine their conservation goals. Many African protected areas have experienced concurrent declines of apex predators alongside increases in both baboon abundance and the density of humans living near the park boundary. Baboons then take excursions outside of the park to raid crops for food, conflicting with the human population. We model the interactions of mesopredators (baboons), apex predators, and shared prey in the park to analyze how four components affect the proportion …

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How The Bending Kinematics Of Swimming Lampreys Build Negative Pressure Fields For Suction Thrust, Brad J. Gemmell, Stephanie M. Fogerson, John H. Costello, Jennifer R. Morgan, John O. Dabiri, Sean P. Colin Jan 2016

How The Bending Kinematics Of Swimming Lampreys Build Negative Pressure Fields For Suction Thrust, Brad J. Gemmell, Stephanie M. Fogerson, John H. Costello, Jennifer R. Morgan, John O. Dabiri, Sean P. Colin

Integrative Biology Faculty and Staff Publications

Swimming animals commonly bend their bodies to generate thrust. For undulating animals such as eels and lampreys, their bodies bend in the form of waves that travel from head to tail. These kinematics accelerate the flow of adjacent fluids, which alters the pressure field in a manner that generates thrust. We used a comparative approach to evaluate the cause-and-effect relationships in this process by quantifying the hydrodynamic effects of body kinematics at the body-fluid interface of the lamprey, Petromyzon marinus, during steady-state swimming. We compared the kinematics and hydrodynamics of healthy control lampreys to lampreys whose spinal cord had been …

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20-Hydroxyecdysone (20e) Primary Response Gene E93 Modulates 20e Signaling To Promote Bombyx Larval-Pupal Metamorphosis, Xi Liu, Fangyin Dai, Enen Guo, Kang Li, Li Ma, Ling Tian, Yang Cao, Guozheng Zhang, Subba Reddy Palli, Sheng Li Nov 2015

20-Hydroxyecdysone (20e) Primary Response Gene E93 Modulates 20e Signaling To Promote Bombyx Larval-Pupal Metamorphosis, Xi Liu, Fangyin Dai, Enen Guo, Kang Li, Li Ma, Ling Tian, Yang Cao, Guozheng Zhang, Subba Reddy Palli, Sheng Li

Entomology Faculty Publications

As revealed in a previous microarray study to identify genes regulated by 20-hydroxyecdysone (20E) and juvenile hormone (JH) in the silkworm, Bombyx mori, E93 expression in the fat body was markedly low prior to the wandering stage but abundant during larval-pupal metamorphosis. Induced by 20E and suppressed by JH, E93 expression follows this developmental profile in multiple silkworm alleles. The reduction of E93 expression by RNAi disrupted 20E signaling and the 20E-induced autophagy, caspase activity, and cell dissociation in the fat body. Reducing E93 expression also decreased the expression of the 20E-induced pupal-specific cuticle protein genes and prevented growth …

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Sex Allocation And The Emergence Of Helping In Cooperatively Breeding Species., Josh D Dunn, Teodora Vujicic, Geoff Wild Sep 2015

Sex Allocation And The Emergence Of Helping In Cooperatively Breeding Species., Josh D Dunn, Teodora Vujicic, Geoff Wild

Applied Mathematics Publications

In cooperative breeding systems individuals invest in the reproductive success of others. In this paper, we study the emergence of cooperative breeding systems in which reproductively active breeders receive investment from reproductively non-active helpers. Our goal is to understand how the division of an investment between male and female components of breeder fitness (i.e. the helper sex-allocation strategy) influences the emergence of cooperative breeding itself. Using mathematical models, we arrive at expressions for the inclusive-fitness advantage of helpful behaviour that generalize previous work. These expressions assume an ecologically stable environment, and that breeders make evolutionarily stable sex-allocation decisions. We find …

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Bypassing Iron Storage In Endodermal Vacuoles Rescues The Iron Mobilization Defect In The Natural Resistance Associated-Macrophage Protein3natural Resistance Associated-Macrophage Protein4 Double Mutant, Viviane Mary, Magali Schnell Ramos, Cynthia Gillet, Amanda L. Socha, Jerome Giraudat, Astrid Agorio, Sylvain Merlot, Colin Clairet, Sun A. Kim, Tracy Punshon, Mary Lou Guerinot, Sebastien Thomine Sep 2015

Bypassing Iron Storage In Endodermal Vacuoles Rescues The Iron Mobilization Defect In The Natural Resistance Associated-Macrophage Protein3natural Resistance Associated-Macrophage Protein4 Double Mutant, Viviane Mary, Magali Schnell Ramos, Cynthia Gillet, Amanda L. Socha, Jerome Giraudat, Astrid Agorio, Sylvain Merlot, Colin Clairet, Sun A. Kim, Tracy Punshon, Mary Lou Guerinot, Sebastien Thomine

Dartmouth Scholarship

To improve seed iron (Fe) content and bioavailability, it is crucial to decipher the mechanisms that control Fe storage during seed development. In Arabidopsis (Arabidopsis thaliana) seeds, most Fe is concentrated in insoluble precipitates, with phytate in the vacuoles of cells surrounding the vasculature of the embryo. NATURAL RESISTANCE ASSOCIATED-MACROPHAGE PROTEIN3 (AtNRAMP3) and AtNRAMP4 function redundantly in Fe retrieval from vacuoles during germination. When germinated under Fe-deficient conditions, development of the nramp3nramp4 double mutant is arrested as a consequence of impaired Fe mobilization. To identify novel genes involved in seed Fe homeostasis, we screened an …

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Viral Sensing Of The Subcellular Environment Regulates The Assembly Of New Viral Replicase Complexes During The Course Of Infection, Peter D. Nagy May 2015

Viral Sensing Of The Subcellular Environment Regulates The Assembly Of New Viral Replicase Complexes During The Course Of Infection, Peter D. Nagy

Plant Pathology Faculty Publications

Replication of plus-stranded RNA [(+)RNA] viruses depends on the availability of coopted host proteins and lipids. But, how could viruses sense the accessibility of cellular resources? An emerging concept based on tombusviruses, small plant viruses, is that viruses might regulate viral replication at several steps depending on what cellular factors are available at a given time point. I discuss the role of phospholipids, sterols, and cellular WW domain proteins and eukaryotic elongation factor 1A (eEF1A) in control of activation of the viral RNA-dependent RNA polymerase (RdRp) and regulation of the assembly of viral replicase complexes (VRCs). These regulatory mechanisms might …

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An Approach For Determining And Measuring Network Hierarchy Applied To Comparing The Phosphorylome And The Regulome, Chao Cheng, Erik Andrews, Koon-Kiu Yan, Matthew Ung, Daifeng Wang, Mark Gerstein Mar 2015

An Approach For Determining And Measuring Network Hierarchy Applied To Comparing The Phosphorylome And The Regulome, Chao Cheng, Erik Andrews, Koon-Kiu Yan, Matthew Ung, Daifeng Wang, Mark Gerstein

Dartmouth Scholarship

Many biological networks naturally form a hierarchy with a preponderance of downward information flow. In this study, we define a score to quantify the degree of hierarchy in a network and develop a simulated-annealing algorithm to maximize the hierarchical score globally over a network. We apply our algorithm to determine the hierarchical structure of the phosphorylome in detail and investigate the correlation between its hierarchy and kinase properties. We also compare it to the regulatory network, finding that the phosphorylome is more hierarchical than the regulome.

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Methyl Farnesoate Plays A Dual Role In Regulating Drosophila Metamorphosis, Di Wen, Crisalejandra Rivera-Perez, Mohamed Abdou, Qiangqiang Jia, Qianyu He, Xi Liu, Ola Zyaan, Jingjing Xu, William G. Bendena, Stephen S. Tobe, Fernando G. Noriega, Subba R. Palli, Jian Wang, Sheng Li Mar 2015

Methyl Farnesoate Plays A Dual Role In Regulating Drosophila Metamorphosis, Di Wen, Crisalejandra Rivera-Perez, Mohamed Abdou, Qiangqiang Jia, Qianyu He, Xi Liu, Ola Zyaan, Jingjing Xu, William G. Bendena, Stephen S. Tobe, Fernando G. Noriega, Subba R. Palli, Jian Wang, Sheng Li

Entomology Faculty Publications

Corpus allatum (CA) ablation results in juvenile hormone (JH) deficiency and pupal lethality in Drosophila. The fly CA produces and releases three sesquiterpenoid hormones: JH III bisepoxide (JHB3), JH III, and methyl farnesoate (MF). In the whole body extracts, MF is the most abundant sesquiterpenoid, followed by JHB3 and JH III. Knockout of JH acid methyl transferase (jhamt) did not result in lethality; it decreased biosynthesis of JHB3, but MF biosynthesis was not affected. RNAi-mediated reduction of 3-hydroxy-3-methylglutaryl CoA reductase (hmgcr) expression in the CA decreased biosynthesis and titers of the three sesquiterpenoids, resulting in …

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Not Just A Theory--The Utility Of Mathematical Models In Evolutionary Biology, Maria R. Servedio, Yaniv Brandvain, Sumit Dhole, Courtney L. Fitzpatrick, Emma E. Goldberg, Caitlin A. Stern, Jeremy Van Cleve, D. Justin Yeh Dec 2014

Not Just A Theory--The Utility Of Mathematical Models In Evolutionary Biology, Maria R. Servedio, Yaniv Brandvain, Sumit Dhole, Courtney L. Fitzpatrick, Emma E. Goldberg, Caitlin A. Stern, Jeremy Van Cleve, D. Justin Yeh

Biology Faculty Publications

Progress in science often begins with verbal hypotheses meant to explain why certain biological phenomena exist. An important purpose of mathematical models in evolutionary research, as in many other fields, is to act as “proof-of-concept” tests of the logic in verbal explanations, paralleling the way in which empirical data are used to test hypotheses. Because not all subfields of biology use mathematics for this purpose, misunderstandings of the function of proof-of-concept modeling are common. In the hope of facilitating communication, we discuss the role of proof-of-concept modeling in evolutionary biology.

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Hdac8 And Stat3 Repress Bmf Gene Activity In Colon Cancer Cells, Y Kang, Hui Nian, P Rajendran, W Dashwood, John T. Pinto, E Ho, R Dashwood Oct 2014

Hdac8 And Stat3 Repress Bmf Gene Activity In Colon Cancer Cells, Y Kang, Hui Nian, P Rajendran, W Dashwood, John T. Pinto, E Ho, R Dashwood

NYMC Faculty Publications

Histone deacetylase (HDAC) inhibitors are undergoing clinical trials as anticancer agents, but some exhibit resistance mechanisms linked to anti-apoptotic Bcl-2 functions, such as BH3-only protein silencing. HDAC inhibitors that reactivate BH3-only family members might offer an improved therapeutic approach. We show here that a novel seleno-α-keto acid triggers global histone acetylation in human colon cancer cells and activates apoptosis in a p21-independent manner. Profiling of multiple survival factors identified a critical role for the BH3-only member Bcl-2-modifying factor (Bmf). On the corresponding BMF gene promoter, loss of HDAC8 was associated with signal transducer and activator of transcription 3 (STAT3)/specificity protein …

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Collapse Of An Ecological Network In Ancient Egypt, Justin Yeakel, Mathias Pires, Lars Rudolf, Nathaniel Dominy Oct 2014

Collapse Of An Ecological Network In Ancient Egypt, Justin Yeakel, Mathias Pires, Lars Rudolf, Nathaniel Dominy

Dartmouth Scholarship

The dynamics of ecosystem collapse are fundamental to determining how and why biological communities change through time, as well as the potential effects of extinctions on ecosystems. Here, we integrate depictions of mammals from Egyptian antiquity with direct lines of paleontological and archeological evidence to infer local extinctions and community dynamics over a 6,000-y span. The unprecedented temporal resolution of this dataset enables examination of how the tandem effects of human population growth and climate change can disrupt mammalian communities. We show that the extinctions of mammals in Egypt were nonrandom and that destabilizing changes in community composition coincided with …

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Natural Selection On Thermal Performance In A Novel Thermal Environment, Michael L. Logan, Robert M. Cox, Ryan Calsbeek Sep 2014

Natural Selection On Thermal Performance In A Novel Thermal Environment, Michael L. Logan, Robert M. Cox, Ryan Calsbeek

Dartmouth Scholarship

Tropical ectotherms are thought to be especially vulnerable to climate change because they are adapted to relatively stable temperature regimes, such that even small increases in environmental temperature may lead to large decreases in physiological performance. One way in which tropical organisms may mitigate the detrimental effects of warming is through evolutionary change in thermal physiology. The speed and magnitude of this response depend, in part, on the strength of climate-driven selection. However, many ectotherms use behavioral adjustments to maintain preferred body temperatures in the face of environmental variation. These behaviors may shelter individuals from natural selection, preventing evolutionary adaptation …

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Neurospora Wc-1 Recruits Swi/Snf To Remodel Frequency And Initiate A Circadian Cycle, Bin Wang, Arminja N. Kettenbach, Scott A. Gerber, Jennifer J. Loros, Jay C. Dunlap Sep 2014

Neurospora Wc-1 Recruits Swi/Snf To Remodel Frequency And Initiate A Circadian Cycle, Bin Wang, Arminja N. Kettenbach, Scott A. Gerber, Jennifer J. Loros, Jay C. Dunlap

Dartmouth Scholarship

In the negative feedback loop comprising the Neurospora circadian oscillator, the White Collar Complex (WCC) formed from White Collar-1 (WC-1) and White Collar-2 (WC-2) drives transcription of the circadian pacemaker gene frequency (frq). Although FRQ-dependent repression of WCC has been extensively studied, the mechanism by which the WCC initiates a circadian cycle remains elusive. Structure/function analysis of WC-1 eliminated domains previously thought to transactivate frq expression but instead identified amino acids 100–200 as essential for frq circadian expression. A proteomics-based search for coactivators with WCC uncovered the SWI/SNF (SWItch/Sucrose NonFermentable) complex: SWI/SNF interacts with WCC in vivo and …

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Recent Shifts In The Occurrence, Cause, And Magnitude Of Animal Mass Mortality Events, Samuel B. Fey, Adam M. Siepielski, Sébastien Nusslé, Kristina Cervantes-Yoshida, Jason L. Hwan, Eric R. Huber, Maxfield J. Fey, Alessandro Catenazzi, Stephanie M. Carlson Aug 2014

Recent Shifts In The Occurrence, Cause, And Magnitude Of Animal Mass Mortality Events, Samuel B. Fey, Adam M. Siepielski, Sébastien Nusslé, Kristina Cervantes-Yoshida, Jason L. Hwan, Eric R. Huber, Maxfield J. Fey, Alessandro Catenazzi, Stephanie M. Carlson

Dartmouth Scholarship

Mass mortality events (MMEs) are rapidly occurring catastrophic demographic events that punctuate background mortality levels. Individual MMEs are staggering in their observed magnitude: re- moving more than 90% of a population, resulting in the death of more than a billion individuals, or producing 700 million tons of dead biomass in a single event. Despite extensive documentation of individual MMEs, we have no understanding of the major features characterizing the occurrence and magnitude of MMEs, their causes, or trends through time. Thus, no framework exists for contextualizing MMEs in the wake of ongoing global and regional perturbations to natural systems. Here …

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