Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

2016

Chapman University

Discipline
Keyword
Publication

Articles 1 - 30 of 60

Full-Text Articles in Life Sciences

Can Functional Traits Predict Plant Community Response To Global Change?, Sarah Kimball, Jennifer L. Funk, Marko J. Spasojevic, Katharine N. Suding, Scot Parker, Michael K. Goulden Dec 2016

Can Functional Traits Predict Plant Community Response To Global Change?, Sarah Kimball, Jennifer L. Funk, Marko J. Spasojevic, Katharine N. Suding, Scot Parker, Michael K. Goulden

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

One primary goal at the intersection of community ecology and global change biology is to identify functional traits that are useful for predicting plant community response to global change. We used observations of community composition from a long-term field experiment in two adjacent plant communities (grassland and coastal sage shrub) to investigate how nine key plant functional traits were related to altered water and nitrogen availability following fire. We asked whether the functional responses of species found in more than one community type were context dependent and whether community-weighted mean and functional diversity were significantly altered by water and nitrogen …


Can Functional Traits Predict Plant Community Response To Global Change?, Sarah Kimball, Jennifer L. Funk, Marko J. Spasojevic, Katharine N. Suding, Scot Parker, Michael K. Goulden Dec 2016

Can Functional Traits Predict Plant Community Response To Global Change?, Sarah Kimball, Jennifer L. Funk, Marko J. Spasojevic, Katharine N. Suding, Scot Parker, Michael K. Goulden

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

One primary goal at the intersection of community ecology and global change biology is to identify functional traits that are useful for predicting plant community response to global change. We used observations of community composition from a long-term field experiment in two adjacent plant communities (grassland and coastal sage shrub) to investigate how nine key plant functional traits were related to altered water and nitrogen availability following fire. We asked whether the functional responses of species found in more than one community type were context dependent and whether community-weighted mean and functional diversity were significantly altered by water and nitrogen …


Il-15 Activates The Jak3/Stat3 Signaling Pathway To Mediate Glucose Uptake In Skeletal Muscle Cells, James E. Krolopp, Shantaé M. Thornton, Marcia J. Abbott Dec 2016

Il-15 Activates The Jak3/Stat3 Signaling Pathway To Mediate Glucose Uptake In Skeletal Muscle Cells, James E. Krolopp, Shantaé M. Thornton, Marcia J. Abbott

Health Sciences and Kinesiology Faculty Articles

Myokines are specialized cytokines that are secreted from skeletal muscle (SKM) in response to metabolic stimuli, such as exercise. Interleukin-15 (IL-15) is a myokine with potential to reduce obesity and increase lean mass through induction of metabolic processes. It has been previously shown that IL-15 acts to increase glucose uptake in SKM cells. However, the downstream signals orchestrating the link between IL-15 signaling and glucose uptake have not been fully explored. Here we employed the mouse SKM C2C12 cell line to examine potential downstream targets of IL-15-induced alterations in glucose uptake. Following differentiation, C2C12 cells were treated overnight with 100 …


Stability Of Peatland Carbon To Rising Temperatures, R. M. Wilson, A. M. Hopple, M. M. Tfaily, S. D. Sebestyen, C. W. Schadt, L. Pfeifer-Meister, Cassandra Medvedeff, K. J. Mcfarlane, J. E. Kostka, M. Kolton, R. K. Kolka, L. A. Kluber, Jason K. Keller, T. P. Guilderson, N. A. Griffiths, J. P. Chanton, S. D. Brigham, P. J. Hanson Dec 2016

Stability Of Peatland Carbon To Rising Temperatures, R. M. Wilson, A. M. Hopple, M. M. Tfaily, S. D. Sebestyen, C. W. Schadt, L. Pfeifer-Meister, Cassandra Medvedeff, K. J. Mcfarlane, J. E. Kostka, M. Kolton, R. K. Kolka, L. A. Kluber, Jason K. Keller, T. P. Guilderson, N. A. Griffiths, J. P. Chanton, S. D. Brigham, P. J. Hanson

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peatlands contain one-third of soil carbon (C), mostly buried in deep, saturated anoxic zones (catotelm). The response of catotelm C to climate forcing is uncertain, because prior experiments have focused on surface warming. We show that deep peat heating of a 2 m-thick peat column results in an exponential increase in CH4 emissions. However, this response is due solely to surface processes and not degradation of catotelm peat. Incubations show that only the top 20–30 cm of peat from experimental plots have higher CH4 production rates at elevated temperatures. Radiocarbon analyses demonstrate that CH4 and CO2 are produced primarily from …


Synthesis Of Rhamnosylated Arginine Glycopeptides And Determination Of The Glycosidic Linkage In Bacterial Elongation Factor P, Siyao Wang, Leo Corcilius, Phillip B. Sharp, Andrei Rajkovic, Michael Ibba, Benjamin L. Parker, Richard J. Payne Dec 2016

Synthesis Of Rhamnosylated Arginine Glycopeptides And Determination Of The Glycosidic Linkage In Bacterial Elongation Factor P, Siyao Wang, Leo Corcilius, Phillip B. Sharp, Andrei Rajkovic, Michael Ibba, Benjamin L. Parker, Richard J. Payne

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

A new class of N-linked protein glycosylation – arginine rhamnosylation – has recently been discovered as a critical modification for the function of bacterial elongation factor P (EF-P). Herein, we describe the synthesis of suitably protected α- and β-rhamnosylated arginine amino acid “cassettes” that can be directly installed into rhamnosylated peptides. Preparation of a proteolytic fragment of Pseudomonas aeruginosa EF-P bearing both α- and β-rhamnosylated arginine enabled the unequivocal determination of the native glycosidic linkage to be α through 2D NMR and nano-UHPLC-tandem mass spectrometry studies.


Sea Surface Temperature Rises Shift Migration Patterns Due To Ecosystem Changes, Alexia Skrbic, Hesham El-Askary Dec 2016

Sea Surface Temperature Rises Shift Migration Patterns Due To Ecosystem Changes, Alexia Skrbic, Hesham El-Askary

Student Scholar Symposium Abstracts and Posters

The continuing climate change is negatively impacting ecosystems, specifically oceans which are declining and food webs are being altered by the increase of greenhouse gases. The increase of the carbon dioxide and other greenhouse gases is increasing sea surface temperature of the world’s oceans. Certain organisms lower on the food chain like phytoplankton and zooplankton are directly affected by the warming which alters how they process nutrients and their productivity. The limited amount of these primary producers in the oceans and specifically the location they inhabit directly affects all the organisms above them on the food chain. Several marine animals …


Manual And Automated Solid Phase Synthesis Of Peptides For Breast Cancer Cell Targeting, Savannah Carlson Dec 2016

Manual And Automated Solid Phase Synthesis Of Peptides For Breast Cancer Cell Targeting, Savannah Carlson

Student Scholar Symposium Abstracts and Posters

Four peptides were synthesized using solid phase peptide synthesis. The two target peptides synthesized were based off peptide 18-4 and its negative analog. Each were synthesized once manually, and once using an automatic peptide synthesizer. Peptide 18-4 has a high affinity for breast cancer cells, allowing it to be used to detect circulating tumor cells (CTCs) in blood (Kaur et. al, 2015). Manual solid phase peptide synthesis is performed by anchoring the first amino acid to Wang resin and coupling each Fmoc protected amino acid individually until the target sequence is achieved. To synthesize the peptides automatically, the automated Tribute …


Hnrnpa2 Is A Novel Histone Acetyltransferase That Mediates Mitochondrial Stress-Induced Nuclear Gene Expression, Manti Guha, Satish Srinivasan, Kip Guja, Edison Mejia, Miguel Garcia-Diaz, F. Brad Johnson, Gordon Ruthel, Brett A. Kaufman, Eric F. Rappaport, M. Rebecca Glineburg, Ji-Kang Fang, Andres J. Klein-Szanto, Hiroshi Nakagawa, Jeelan Basha, Tapas Kundu, Narayan G. Avadhani Dec 2016

Hnrnpa2 Is A Novel Histone Acetyltransferase That Mediates Mitochondrial Stress-Induced Nuclear Gene Expression, Manti Guha, Satish Srinivasan, Kip Guja, Edison Mejia, Miguel Garcia-Diaz, F. Brad Johnson, Gordon Ruthel, Brett A. Kaufman, Eric F. Rappaport, M. Rebecca Glineburg, Ji-Kang Fang, Andres J. Klein-Szanto, Hiroshi Nakagawa, Jeelan Basha, Tapas Kundu, Narayan G. Avadhani

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Reduced mitochondrial DNA copy number, mitochondrial DNA mutations or disruption of electron transfer chain complexes induce mitochondria-to-nucleus retrograde signaling, which induces global change in nuclear gene expression ultimately contributing to various human pathologies including cancer. Recent studies suggest that these mitochondrial changes cause transcriptional reprogramming of nuclear genes although the mechanism of this cross talk remains unclear. Here, we provide evidence that mitochondria-to-nucleus retrograde signaling regulates chromatin acetylation and alters nuclear gene expression through the heterogeneous ribonucleoprotein A2 (hnRNAP2). These processes are reversed when mitochondrial DNA content is restored to near normal cell levels. We show that the mitochondrial stress-induced …


Partial Amino Acid Sequence Of Lipid Transfer Protein From Fennel (Foeniculum Vulgare) Seeds, Hasan Al-Shiyab, Caroline Aziz Dec 2016

Partial Amino Acid Sequence Of Lipid Transfer Protein From Fennel (Foeniculum Vulgare) Seeds, Hasan Al-Shiyab, Caroline Aziz

Student Scholar Symposium Abstracts and Posters

Fennel (Foeniculum vulgare) is a biennial Egyptian medicinal plant with an aromatic odor that belongs to the family Apiaceae (Umbelliferae). Fennel seeds are commonly used in traditional medicine, as they are known to have anti-inflammatory, anti-fungal and anti-cancerous activities. The major constituents of the fennel plant are sugars, minerals, essential fatty acids, proteins and fibers. Although, there are numerous studies on the medicinal properties of essential oils of the fennel seeds, but there is limited data reported on the proteins and peptides. The aims of this project are to fully characterize the primary structure of proteins and to determine their …


Rapamycin Increases Length And Mechanosensory Function Of Primary Cilia In Renal Eptihelial And Vascular Endothelial Cells, Rinzhin T. Sherpa, Kimberly F. Atkinson, Viviana P. Ferreira, Surya M. Nauli Dec 2016

Rapamycin Increases Length And Mechanosensory Function Of Primary Cilia In Renal Eptihelial And Vascular Endothelial Cells, Rinzhin T. Sherpa, Kimberly F. Atkinson, Viviana P. Ferreira, Surya M. Nauli

Pharmacy Faculty Articles and Research

Primary cilia arebiophysically-sensitive organelles responsible for sensing fluid-flow and transducing this stimulus into intracellular responses. Previous studies have shown that the primary cilia mediate flow-induced calcium influx, and sensitivity of cilia function to flow is correlated to cilia length. Cells with abnormal cilia length or function can lead to a host of diseases that are collectively termed as ciliopathies. Rapamycin, a potent inhibitor of mTOR (mammalian target of rapamycin), has been demonstrated to be a potential pharmacological agent against the aberrant mTOR signaling seen in ciliopathies such as polycystic kidney disease (PKD) and tuberous sclerosis complex (TSC). Here we look …


A Tale Of Two Antennules: The Performance Of Crab Odor-Capture Organs In Air And Water, Lindsay D. Waldrop, Laura A. Miller, Shilpa Khatri Dec 2016

A Tale Of Two Antennules: The Performance Of Crab Odor-Capture Organs In Air And Water, Lindsay D. Waldrop, Laura A. Miller, Shilpa Khatri

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Odour capture is an important part of olfaction, where dissolved chemical cues (odours) are brought into contact with chemosensory structures. Antennule flicking by marine crabs is an example of discrete odour capture (sniffing) where an array of chemosensory hairs is waved through the water to create a flow–no flow pattern based on a narrow range of speeds, diameters of and spacings between hairs. Changing the speed of movement and spacing of hairs at this scale to manipulate flow represents a complicated fluid dynamics problem. In this study, we use numerical simulation of the advection and diffusion of a chemical gradient …


The Complex Evolutionary History Of Aminoacyl-Trna Synthetases, Anargyros Chaliotis, Panayotis Vlastaridis, Dimitris Mossialos, Michael Ibba, Hubert D. Becker, Constantinos Stathopoulos, Grigorios D. Amoutzias Nov 2016

The Complex Evolutionary History Of Aminoacyl-Trna Synthetases, Anargyros Chaliotis, Panayotis Vlastaridis, Dimitris Mossialos, Michael Ibba, Hubert D. Becker, Constantinos Stathopoulos, Grigorios D. Amoutzias

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Aminoacyl-tRNA synthetases (AARSs) are a superfamily of enzymes responsible for the faithful translation of the genetic code and have lately become a prominent target for synthetic biologists. Our large-scale analysis of >2500 prokaryotic genomes reveals the complex evolutionary history of these enzymes and their paralogs, in which horizontal gene transfer played an important role. These results show that a widespread belief in the evolutionary stability of this superfamily is misconceived. Although AlaRS, GlyRS, LeuRS, IleRS, ValRS are the most stable members of the family, GluRS, LysRS and CysRS often have paralogs, whereas AsnRS, GlnRS, PylRS and SepRS are often absent …


Exploring Molecular Mechanisms Of Paradoxical Activation In The Braf Kinase Dimers: Atomistic Simulations Of Conformational Dynamics And Modeling Of Allosteric Communication Networks And Signaling Pathways, Amanda Tse, Gennady M. Verkhivker Nov 2016

Exploring Molecular Mechanisms Of Paradoxical Activation In The Braf Kinase Dimers: Atomistic Simulations Of Conformational Dynamics And Modeling Of Allosteric Communication Networks And Signaling Pathways, Amanda Tse, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

The recent studies have revealed that most BRAF inhibitors can paradoxically induce kinase activation by promoting dimerization and enzyme transactivation. Despite rapidly growing number of structural and functional studies about the BRAF dimer complexes, the molecular basis of paradoxical activation phenomenon is poorly understood and remains largely hypothetical. In this work, we have explored the relationships between inhibitor binding, protein dynamics and allosteric signaling in the BRAF dimers using a network-centric approach. Using this theoretical framework, we have combined molecular dynamics simulations with coevolutionary analysis and modeling of the residue interaction networks to determine molecular determinants of paradoxical activation. We …


Localization And Distribution Of Primary Cilia In The Adult Mouse Heart, Ali Zarban, Hannah C. Saternos, Andrea L. Kalinoski, Lijun Liu, Surya M. Nauli, Wissam A. Aboualaiwi Nov 2016

Localization And Distribution Of Primary Cilia In The Adult Mouse Heart, Ali Zarban, Hannah C. Saternos, Andrea L. Kalinoski, Lijun Liu, Surya M. Nauli, Wissam A. Aboualaiwi

Pharmacy Faculty Articles and Research

Although primary cilia have been shown to play crucial roles in the development of embryonic mouse heart, their presence and function in adult mouse heart remains controversial. In this study, the presence of primary cilia in adult mouse heart was investigated. The presence of primary cilia was initially demonstrated in the surface of cardiac cells of mouse hearts from both young and adult mice by immunostaining with acetylated α-tubulin, a ciliary structural marker. The presence of cardiac primary cilia in 1-, 3-, 6- and 12-month old mice was further confirmed by staining heart tissues with an antibody against pericentrin, a …


The Variation Of Productivity And Its Allocation Along A Tropical Elevation Gradient: A Whole Carbon Budget Perspective, Yadvinder Malhi, Cécile A. J. Girardin, Gregory R. Goldsmith, Christopher E. Doughty, Norma Salinas, Daniel B. Metcalfe, Walter Huaraca Huasco, Javier E. Silva-Espejo, Jhon Del Aguilla-Pasquell, Filio Farfán Amézquita, Luiz E.O.C. Aragão, Rossella Guerrieri, Françoise Yoko Ishida, Nur Bahar, William Farfan-Rios, Oliver L. Phillips, Patrick Meir, Miles Silman Oct 2016

The Variation Of Productivity And Its Allocation Along A Tropical Elevation Gradient: A Whole Carbon Budget Perspective, Yadvinder Malhi, Cécile A. J. Girardin, Gregory R. Goldsmith, Christopher E. Doughty, Norma Salinas, Daniel B. Metcalfe, Walter Huaraca Huasco, Javier E. Silva-Espejo, Jhon Del Aguilla-Pasquell, Filio Farfán Amézquita, Luiz E.O.C. Aragão, Rossella Guerrieri, Françoise Yoko Ishida, Nur Bahar, William Farfan-Rios, Oliver L. Phillips, Patrick Meir, Miles Silman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

  • Why do forest productivity and biomass decline with elevation? To address this question, research to date generally has focused on correlative approaches describing changes in woody growth and biomass with elevation.

  • We present a novel, mechanistic approach to this question by quantifying the autotrophic carbon budget in 16 forest plots along a 3300 m elevation transect in Peru.

  • Low growth rates at high elevations appear primarily driven by low gross primary productivity (GPP), with little shift in either carbon use efficiency (CUE) or allocation of net primary productivity (NPP) between wood, fine roots and canopy. The lack of trend in …


Microfluidic Cantilever Detects Bacteria And Measures Their Susceptibility To Antibiotics In Small Confined Volumes, Hashem Etayash, M. F. Khan, Kamaljit Kaur, Thomas Thundat Oct 2016

Microfluidic Cantilever Detects Bacteria And Measures Their Susceptibility To Antibiotics In Small Confined Volumes, Hashem Etayash, M. F. Khan, Kamaljit Kaur, Thomas Thundat

Pharmacy Faculty Articles and Research

In the fight against drug-resistant bacteria, accurate and high-throughput detection is essential. Here, a bimaterial microcantilever with an embedded microfluidic channel with internal surfaces chemically or physically functionalized with receptors selectively captures the bacteria passing through the channel. Bacterial adsorption inside the cantilever results in changes in the resonance frequency (mass) and cantilever deflection (adsorption stress). The excitation of trapped bacteria using infrared radiation (IR) causes the cantilever to deflect in proportion to the infrared absorption of the bacteria, providing a nanomechanical infrared spectrum for selective identification. We demonstrate the in situ detection and discrimination of Listeria monocytogenes at a …


Covering Ground: A Look At Movement Patterns And Random Walk Behavior In Aquilonastra Sea Stars, Amanda C. Lohmann, Dennis Evangelista, Lindsay D. Waldrop, Christopher L. Mah, Tyson L. Hedrick Oct 2016

Covering Ground: A Look At Movement Patterns And Random Walk Behavior In Aquilonastra Sea Stars, Amanda C. Lohmann, Dennis Evangelista, Lindsay D. Waldrop, Christopher L. Mah, Tyson L. Hedrick

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The paths animals take while moving through their environments affect their likelihood of encountering food and other resources; thus, models of foraging behavior abound. To collect movement data appropriate for comparison with these models, we used time-lapse photography to track movements of a small, hardy, and easy-to-obtain organism, Aquilonastra anomala sea stars. We recorded the sea stars in a tank over many hours, with and without a food cue. With food present, they covered less distance, as predicted by theory; this strategy would allow them to remain near food. We then compared the paths of the sea stars to three …


Selective Anticancer Activity Of Hydroxyapatite/Chitosan-Poly(D,L)-Lactide-Co-Glycolide Particles Loaded With An Androstane-Based Cancer Inhibitor, Nenad Ignjatović, Katarina M. Penov-Gaši, Victoria M. Wu, Jovana J. Ajduković, Vesna V. Kojić, Dana Vasiljević-Radović, Maja Kuzmanović, Vuk Uskoković, Dragab Uskoković Sep 2016

Selective Anticancer Activity Of Hydroxyapatite/Chitosan-Poly(D,L)-Lactide-Co-Glycolide Particles Loaded With An Androstane-Based Cancer Inhibitor, Nenad Ignjatović, Katarina M. Penov-Gaši, Victoria M. Wu, Jovana J. Ajduković, Vesna V. Kojić, Dana Vasiljević-Radović, Maja Kuzmanović, Vuk Uskoković, Dragab Uskoković

Pharmacy Faculty Articles and Research

In an earlier study we demonstrated that hydroxyapatite nanoparticles coated with chitosan-poly(d,l)-lactide-co-glycolide (HAp/Ch-PLGA) target lungs following their intravenous injection into mice. In this study we utilize an emulsification process and freeze drying to load the composite HAp/Ch-PLGA particles with 17β-hydroxy-17α-picolyl-androst-5-en-3β-yl-acetate (A), a chemotherapeutic derivative of androstane and a novel compound with a selective anticancer activity against lung cancer cells. 1H NMR and 13C NMR techniques confirmed the intact structure of the derivative A following its entrapment within HAp/Ch-PLGA particles. The thermogravimetric and differential thermal analyses coupled with mass spectrometry were used to assess the …


Does Persistent Hiv Replication Explain Continued Lymphoma Incidence In The Era Of Effective Antiretroviral Therapy?, Jennifer Totonchy, Ethel Cesarman Sep 2016

Does Persistent Hiv Replication Explain Continued Lymphoma Incidence In The Era Of Effective Antiretroviral Therapy?, Jennifer Totonchy, Ethel Cesarman

Pharmacy Faculty Articles and Research

Non-Hodgkin lymphomas are highly increased in incidence in individuals infected with HIV, and this continues to be the case in spite of highly effective combined antiretroviral therapy (cART). New evidence has demonstrated that while successful virtual recovery of CD4 counts and elimination of HIV from peripheral blood can be achieved with cART, viral replication can still occur in lymphoid tissues. In addition, recent studies have suggested that adipose tissue provides an additional reservoir for HIV-infected macrophages and T lymphocytes even in the context of successful cART therapy. In this review article, we discuss possible mechanisms leading to the development of …


Isoacceptor Specific Characterization Of Trna Aminoacylation And Misacylation In Vivo, Kyle Mohler, Rebecca Mann, Michael Ibba Sep 2016

Isoacceptor Specific Characterization Of Trna Aminoacylation And Misacylation In Vivo, Kyle Mohler, Rebecca Mann, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Amino acid misincorporation during protein synthesis occurs due to misacylation of tRNAs or defects in decoding at the ribosome. While misincorporation of amino acids has been observed in a variety of contexts, less work has been done to directly assess the extent to which specific tRNAs are misacylated in vivo, and the identity of the misacylated amino acid moiety. Here we describe tRNA isoacceptor specific aminoacylation profiling (ISAP), a method to identify and quantify the amino acids attached to a tRNA species in vivo. ISAP allows compilation of aminoacylation profiles for specific isoacceptors tRNAs. To demonstrate the efficacy and …


Maintenance Of Transcription-Translation Coupling By Elongation Factor P, Sara Elgamal, Irina Artsimovitch, Michael Ibba Sep 2016

Maintenance Of Transcription-Translation Coupling By Elongation Factor P, Sara Elgamal, Irina Artsimovitch, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Under conditions of tight coupling between translation and transcription, the ribosome enables synthesis of full-length mRNAs by preventing both formation of intrinsic terminator hairpins and loading of the transcription termination factor Rho. While previous studies have focused on transcription factors, we investigated the role of Escherichia coli elongation factor P (EF-P), an elongation factor required for efficient translation of mRNAs containing consecutive proline codons, in maintaining coupled translation and transcription. In the absence of EF-P, the presence of Rho utilization (rut) sites led to an ~30-fold decrease in translation of polyproline-encoding mRNAs. Coexpression of the Rho inhibitor Psu …


Testing The Trait-Based Community Framework: Do Functional Traits Predict Competitive Outcomes?, Jennifer L. Funk, Amelia Wolf Sep 2016

Testing The Trait-Based Community Framework: Do Functional Traits Predict Competitive Outcomes?, Jennifer L. Funk, Amelia Wolf

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Plant traits can be used to understand a range of ecological processes, including competition from invasive species. The extent to which native and invasive species are competing via limiting similarity or trait hierarchies has important implications for the management of invaded communities. We screened 47 native species that co-occur with Festuca perennis, a dominant invader in California serpentine grassland, for traits pertaining to resource use and acquisition. We then grew F. perennis with ten species spanning a range of functional similarity in pairwise competition trials. Functionally similar species did not have a strong adverse effect on F. perennis performance …


Peroxiredoxin Catalysis At Atomic Resolution, Arden Perkins, Derek Parsonage, Kimberly J. Nelson, O. Maduka Ogba, Paul Ha-Yeon Cheong, Leslie B. Poole, P. Andrew Karplus Sep 2016

Peroxiredoxin Catalysis At Atomic Resolution, Arden Perkins, Derek Parsonage, Kimberly J. Nelson, O. Maduka Ogba, Paul Ha-Yeon Cheong, Leslie B. Poole, P. Andrew Karplus

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peroxiredoxins (Prxs) are ubiquitous cysteine-based peroxidases that guard cells against oxidative damage, are virulence factors for pathogens, and are involved in eukaryotic redox regulatory pathways. We have analyzed catalytically active crystals to capture atomic resolution snapshots of a PrxQ-subfamily enzyme (from Xanthomonas campestris) proceeding through thiolate, sulfenate, and sulfinate species. These analyses provide structures of unprecedented accuracy for seeding theoretical studies, and show novel conformational intermediates giving insight into the reaction pathway. Based on a highly non-standard geometry seen for the sulfenate intermediate, we infer that the sulfenate formation itself can strongly promote local unfolding of the active site to …


A Murine Model Of Inflammation-Induced Cerebral Microbleeds, Rachita K. Sumbria, Mher Mahoney Grigoryan, Vitaly Vasilevko, Tatiana B. Krasieva, Miriam Scadeng, Alexandra K. Dvornikova, Annlia Paganini-Hill, Ronald Kim, David H. Cribbs, Mark J. Fisher Aug 2016

A Murine Model Of Inflammation-Induced Cerebral Microbleeds, Rachita K. Sumbria, Mher Mahoney Grigoryan, Vitaly Vasilevko, Tatiana B. Krasieva, Miriam Scadeng, Alexandra K. Dvornikova, Annlia Paganini-Hill, Ronald Kim, David H. Cribbs, Mark J. Fisher

Pharmacy Faculty Articles and Research

Background: Cerebral microhemorrhages (CMH) are tiny deposits of blood degradation products in the brain and are pathological substrates of cerebral microbleeds. The existing CMH animal models are β-amyloid-, hypoxic brain injury-, or hypertension-induced. Recent evidence shows that CMH develop independently of hypoxic brain injury, hypertension, or amyloid deposition and CMH are associated with normal aging, sepsis, and neurodegenerative conditions. One common factor among the above pathologies is inflammation, and recent clinical studies show a link between systemic inflammation and CMH. Hence, we hypothesize that inflammation induces CMH development and thus, lipopolysaccharide (LPS)-induced CMH may be an appropriate model to …


Decomposing Trends In Adult Body Mass Index, Obesity, And Morbid Obesity, 1971-2012, Ashley Wendell Kranjac, Robert L. Wagmiller Aug 2016

Decomposing Trends In Adult Body Mass Index, Obesity, And Morbid Obesity, 1971-2012, Ashley Wendell Kranjac, Robert L. Wagmiller

Sociology Faculty Articles and Research

Trends in adult obesity have been used to motivate key public health policies in the United States. While these analyses provide important insights into the broad historical contours of the obesity epidemic in the U.S., they shed less light on the proximate mechanisms that have generated these changes and that will ultimately determine the long-term course and pace of change in obesity rates. We used data from the National Health and Nutrition Examination Survey (NHANES), Glenn Firebaugh's linear decomposition technique, and Kitagawa's algebraic decomposition method to decompose change in body mass index (BMI), obesity, and morbid obesity from 1971 through …


Surveillance, Epidemiological, And Virological Detection Of Highly Pathogenic H5n1 Avian Influenza Viruses In Duck And Poultry From Bangladesh, Wahedul Karim Ansari, Md Safiullah Parvej, Mohamed E. El Zowalaty, Sally Jackson, Stephen A. Bustin, Adel K. Ibrahim, Md Tanvir Rahman, Han Zhang, Mohammad Ferdousur Rahman Khan, Md Mostakin Ahamd, Md. Fasiur Rahman, Marzia Rahman, Khm Nazmul H. Nazir, Sultan Ahmed, Md Liakot Hossenn, Md Abdul Kafi, Mat Yamage, Nitish C. Debnath, Graba Ahmed, Hossam Ashour, Md Masoud, Ayman Noreddin, Md B. Rahman Aug 2016

Surveillance, Epidemiological, And Virological Detection Of Highly Pathogenic H5n1 Avian Influenza Viruses In Duck And Poultry From Bangladesh, Wahedul Karim Ansari, Md Safiullah Parvej, Mohamed E. El Zowalaty, Sally Jackson, Stephen A. Bustin, Adel K. Ibrahim, Md Tanvir Rahman, Han Zhang, Mohammad Ferdousur Rahman Khan, Md Mostakin Ahamd, Md. Fasiur Rahman, Marzia Rahman, Khm Nazmul H. Nazir, Sultan Ahmed, Md Liakot Hossenn, Md Abdul Kafi, Mat Yamage, Nitish C. Debnath, Graba Ahmed, Hossam Ashour, Md Masoud, Ayman Noreddin, Md B. Rahman

Pharmacy Faculty Articles and Research

Avian influenza viruses (AIVs) continue to pose a global threat. Waterfowl are the main reservoir and are responsible for the spillover of AIVs to other hosts. This study was conducted as part of routine surveillance activities in Bangladesh and it reports on the serological and molecular detection of H5N1 AIV subtype. A total of 2169 cloacal and 2191 oropharyngeal swabs as well as 1725 sera samples were collected from live birds including duck and chicken in different locations in Bangladesh between the years of 2013 and 2014. Samples were tested using virus isolation, serological tests and molecular methods of RT-PCR. …


Variation In Leaf Wettability Traits Along A Tropical Montane Elevation Gradient, Gregory R. Goldsmith, Lisa Patrick Bentley, Alexander Shenkin, Norma Salinas, Benjamin Blonder, Roberta E. Martin, Rosa Castro-Ccossco, Percy Chambi-Porroa, Sandra Diaz, Brian J. Enquist, Gregory P. Asner, Yadvinder Malhi Jul 2016

Variation In Leaf Wettability Traits Along A Tropical Montane Elevation Gradient, Gregory R. Goldsmith, Lisa Patrick Bentley, Alexander Shenkin, Norma Salinas, Benjamin Blonder, Roberta E. Martin, Rosa Castro-Ccossco, Percy Chambi-Porroa, Sandra Diaz, Brian J. Enquist, Gregory P. Asner, Yadvinder Malhi

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

  • Leaf wetting is often considered to have negative effects on plant function, such that wet environments may select for leaves with certain leaf surface, morphological, and architectural traits that reduce leaf wettability. However, there is growing recognition that leaf wetting can have positive effects.
  • We measured variation in two traits, leaf drip tips and leaf water repellency, in a series of nine tropical forest communities occurring along a 3300-m elevation gradient in southern Peru. To extend this climatic gradient, we also assembled published leaf water repellency values from 17 additional sites. We then tested hypotheses for how these traits should …


Particular Applications Of Food Irradiation Fresh Produce, Anuradha Prakash Jul 2016

Particular Applications Of Food Irradiation Fresh Produce, Anuradha Prakash

Food Science Faculty Articles and Research

On fresh fruits and vegetables, irradiation at low and medium dose levels can effectively reduce microbial counts which can enhance safety, inhibit sprouting to extend shelf-life, and eliminate or sterilize insect pests which can serve to facilitate trade between countries. At the dose levels used for these purposes, the impact on quality is negligible. Despite the fact that regulations in many countries allow the use of irradiation for fresh produce, the technology remains under-utilized, even in the light of an increase in produce related disease outbreaks and the economic benefits of extended shelflife and reduced food waste. Putative concerns about …


Comparison Of Real-Time Pcr And Elisa-Based Methods For The Detection Of Beef And Pork In Processed Meat Products, Adam T. Perestam, Kayleigh K. Fujisaki, Omar Nava, Rosalee S. Hellberg Jul 2016

Comparison Of Real-Time Pcr And Elisa-Based Methods For The Detection Of Beef And Pork In Processed Meat Products, Adam T. Perestam, Kayleigh K. Fujisaki, Omar Nava, Rosalee S. Hellberg

Food Science Faculty Articles and Research

Two commonly used methodologies for species detection within processed meat products are real-time polymerase chain reaction (PCR), a DNA-based method, and enzyme-linked immunosorbent assay (ELISA), a protein-based method. In this study, a real-time PCR assay was compared to a commercial ELISA kit based on sensitivity, specificity, agreement among duplicate samples, cost, time, and ease of use. Fifteen reference samples containing known percentages (0.1–99.9%, w/w) of pork and beef were analyzed in duplicate using both methods. Thirty commercial products, including sausages, pet treats, and canned meats, were also tested in duplicate with each method. Reference sample analysis showed real-time PCR was …


The Explorations Program: Benefits Of Single-Session, Research- Focused Classes For Students And Postdoctoral Instructors, Jeremy L. Hsu, Anna M. Wrona, Sarah E. Brownell, Waheeda Khalfan Jul 2016

The Explorations Program: Benefits Of Single-Session, Research- Focused Classes For Students And Postdoctoral Instructors, Jeremy L. Hsu, Anna M. Wrona, Sarah E. Brownell, Waheeda Khalfan

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We present an update to Explorations, a program at Stanford University that allows undergraduates in an introductory biology course to explore specialized topics in the biological sciences while providing graduate students and postdoctoral scholars the unique opportunity to develop and teach single-session, research-focused classes. We provide an assessment of eight iterations of the program, using program attendance, student and instructor evaluations, senior exit surveys, course grades, and completion of undergraduate honors theses to assess the impact of our program on students and instructors. Students rated their experiences highly, and most reported that the program had a positive impact on their …