Life Sciences Commons^™

Analyzing And Modeling The Dysfunction Of Inhibitory Neurons In Alzheimer’S Disease, Carlos Perez, Jokubas Ziburkus, Ghamim Ullah

Physics Faculty Publications

Alzheimer’s disease (AD) is characterized by the abnormal proteolytic processing of amyloid precursor protein, resulting in increased production of a self-aggregating form of beta amyloid (Aβ). Several lines of work on AD patients and transgenic mice with high Aβ levels exhibit altered rhythmicity, aberrant neuronal network activity and hyperexcitability reflected in clusters of hyperactive neurons, and spontaneous epileptic activity. Recent studies highlight that abnormal accumulation of Aβ changes intrinsic properties of inhibitory neurons, which is one of the main reasons underlying the impaired network activity. However, specific cellular mechanisms leading to interneuronal dysfunction are not completely …

Winner's Curse Correction And Variable Thresholding Improve Performance Of Polygenic Risk Modeling Based On Genome-Wide Association Study Summary-Level Data, Jianxin Shi, Ju-Hyun Park, Jubao Duan, Sonja T. Berndt, Winton Moy, Kai Yu, Lei Song, William Wheeler, Xing Hua, Debra Silverman, Montserrat Garcia-Closas, Chao Agnes Hsiung, Jonine D. Figueroa, Victoria K. Cortessis, Nuria Malats, Margaret R. Karagas

Dartmouth Scholarship

Recent heritability analyses have indicated that genome-wide association studies (GWAS) have the potential to improve genetic risk prediction for complex diseases based on polygenic risk score (PRS), a simple modelling technique that can be implemented using summary-level data from the discovery samples. We herein propose modifications to improve the performance of PRS. We introduce threshold-dependent winner’s-curse adjustments for marginal association coefficients that are used to weight the single-nucleotide polymorphisms (SNPs) in PRS. Further, as a way to incorporate external functional/annotation knowledge that could identify subsets of SNPs highly enriched for associations, we propose variable thresholds for SNPs selection. We applied …

Stability Of Cross-Feeding Polymorphisms In Microbial Communities, Ivana Gudelj, Margie Kinnersley, Peter Rashkov, Karen Schmidt, Frank Rosenzweig

Biological Sciences Faculty Publications

Cross-feeding, a relationship wherein one organism consumes metabolites excreted by another, is a ubiquitous feature of natural and clinically-relevant microbial communities and could be a key factor promoting diversity in extreme and/or nutrient-poor environments. However, it remains unclear how readily cross-feeding interactions form, and therefore our ability to predict their emergence is limited. In this paper we developed a mathematical model parameterized using data from the biochemistry and ecology of an E. coli cross-feeding laboratory system. The model accurately captures short-term dynamics of the two competitors that have been observed empirically and we use it to systematically explore the stability …

Cullin-4 Regulates Wingless And Jnk Signaling-Mediated Cell Death In The Drosophila Eye., Meghana Tare, Ankita Sarkar, Shimpi Bedi, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

In all multicellular organisms, the fundamental processes of cell proliferation and cell death are crucial for growth regulation during organogenesis. Strict regulation of cell death is important to maintain tissue homeostasis by affecting processes like regulation of cell number, and elimination of unwanted/unfit cells. The developing Drosophila eye is a versatile model to study patterning and growth, where complex signaling pathways regulate growth and cell survival. However, the molecular mechanisms underlying regulation of these processes is not fully understood. In a gain-of-function screen, we found that misexpression of cullin-4 (cul-4), an ubiquitin ligase, can rescue reduced eye mutant phenotypes. Previously, …

Expansion Of The Molecular And Morphological Diversity Of Acanthamoebidae (Centramoebida, Amoebozoa) And Identification Of A Novel Life Cycle Type Within The Group, Alexander Tice, Lora Shadwick, Anna Maria Fiore-Donno, Stefen Geisen, Seungho Kang, Gabriel Schuler, Frederick Spiegel, Katherine Wilkinson, Michael Bonkowski, Kenneth Dumack, Daniel Lahr, Eckhard Voelcker, Steffen Claub, Junling Zhang, Matthew Brown

Faculty Publications, Biological Sciences

Background Acanthamoebidae is a “family” level amoebozoan group composed of the genera Acanthamoeba, Protacanthamoeba, and very recently Luapeleamoeba. This clade of amoebozoans has received considerable attention from the broader scientific community as Acanthamoeba spp. represent both model organisms and human pathogens. While the classical composition of the group (Acanthamoeba + Protacanthamoeba) has been well accepted due to the morphological and ultrastructural similarities of its members, the Acanthamoebidae has never been highly statistically supported in single gene phylogenetic reconstructions of Amoebozoa either by maximum likelihood (ML) or Bayesian analyses. Results Here we show using a phylogenomic approach that the Acanthamoebidae is …

Cytochrome C Can Form A Well-Defined Binding Pocket For Hydrocarbons, Levi J. Mcclelland, Harmen B. Steele, Frank G. Whitby, Tung-Chung Mou, David Holley, J B. Ross, Stephen R. Sprang, Bruce E. Bowler

Biological Sciences Faculty Publications

Cytochrome c can acquire peroxidase activity when it binds to cardiolipin in mitochondrial membranes. The resulting oxygenation of cardiolipin by cytochrome c provides an early signal for the onset of apoptosis. The structure of this enzyme-substrate complex is a matter of considerable debate. We present three structures at 1.7-2.0 Å resolution of a domain-swapped dimer of yeast iso-1-cytochrome c with the detergents, CYMAL-5, CYMAL-6, and ω-undecylenyl-β-d-maltopyranoside, bound in a channel that places the hydrocarbon moieties of these detergents next to the heme. The heme is poised for peroxidase activity with water bound in place of Met80, which serves as the …

Recent Diatoms Reported From The Central United States: Register Of Taxa And Synonyms, Mark E. Eberle

Biological Sciences Faculty Publications

This list of diatoms summarizes information for more than 1000 taxa and synonyms reported in published accounts of collections made in the central United States, principally within the states of Kansas, Nebraska, and Oklahoma, but also including adjacent areas in eastern Colorado and western Missouri. The objective was to provide people working on diatom projects in this region with a base reference to help them assess the results of their research. Records from Master’s theses and references focused on fossil diatoms were not incorporated into this list. Specimens were not examined, so taxa presented here are those reported in the …

The Replication Initiator Of The Cholera Pathogen’S Second Chromosome Shows Structural Similarity To Plasmid Initiators, Natalia Orlova, Matthew Gerding, Olha Ivashkiv, Paul Dominic B. Olinares, Brian T. Chait, Matthew K. Waldor, David Jeruzalmi

Publications and Research

The conserved DnaA-oriC system is used to initiate replication of primary chromosomes throughout the bacterial kingdom; however, bacteria with multipartite genomes evolved distinct systems to initiate replication of secondary chromosomes. In the cholera pathogen, Vibrio cholerae, and in related species, secondary chromosome replication requires the RctB initiator protein. Here, we show that RctB consists of four domains. The structure of its central two domains resembles that of several plasmid replication initiators. RctB contains at least three DNA binding winged-helix-turn-helix motifs, and mutations within any of these severely compromise biological activity. In the structure, RctB adopts a headto- head dimeric configuration …

Microbial Phytases And Phytate: Exploring Opportunities For Sustainable Phosphorus Management In Agriculture, Nelly P. Balaban, Aliya D. Suleimanova, Lia R. Valeeva, Inna B. Chastukhina, Natalia L. Rudakova, Margarita R. Sharipova, Eugene V. Shakirov

Biological Sciences Faculty Research

Myo-inositol phosphates (phytates) are important biological molecules produced largely by plants to store phosphorus. Phytate is very abundant in many different soils making up a large portion of all soil phosphorus. This review assesses current phytase science from the perspective of its substrate, phytate, by examining the intricate relationship between the phytate-hydrolyzing enzymes and phytate as their substrate. Specifically, we examine available data on phytate’s structural features, distribution in nature and functional roles. The role of phytases and their localization in soil and plant tissues are evaluated. We provide a summary of the current biotechnological advances in using industrial …

Ric-8a, A G Protein Chaperone With Nucleotide Exchange Activity Induces Long-Range Secondary Structure Changes In Gα, Ravi Kant, Baisen Zeng, Celestine J. Thomas, Brian Bothner, Stephen R. Sprang

Biological Sciences Faculty Publications

Cytosolic Ric-8A has guanine nucleotide exchange factor (GEF) activity and is a chaperone for several classes of heterotrimeric G protein α subunits in vertebrates. Using Hydrogen-Deuterium Exchange-Mass Spectrometry (HDX-MS) we show that Ric-8A disrupts the secondary structure of the Gα Ras-like domain that girds the guanine nucleotide-binding site, and destabilizes the interface between the Gαi1 Ras and helical domains, allowing domain separation and nucleotide release. These changes are largely reversed upon binding GTP and dissociation of Ric-8A. HDX-MS identifies a potential Gα interaction site in Ric-8A. Alanine scanning reveals residues crucial for GEF activity within that sequence. HDX confirms that, …

Bioremoval Of Phenol From Aqueous Solutions Using Native Caribbean Seaweed, Abel E. Navarro, Anibal Hernandez-Vega, Md Emran Masud, Loretta M. Roberson, Liz M. Diaz-Vázquez

Publications and Research

Among several Puerto Rican algae, Sargassum sp. (SG) and Chaetomorpha (CM) showed the highest phenol adsorption capacity from aqueous solutions and were used in optimized adsorption batch experiments at room temperature. The effects of pH, adsorbent dose, phenol concentration, salinity and presence of interfering substances were evaluated. Initial solution pH exhibited a strong effect, mainly on the phenol aqueous chemistry; showing the maximum adsorption at pH 10. Sorption isotherm results were modelled according to the Langmuir, Tempkin and Freundlich equations. Isotherm modelling indicated a maximum adsorption capacity (qmax) of 82.10 and 17.7 mg of phenol per gram of SG and …

Molecular Typing And Virulence Analysis Of Multidrug Resistant Klebsiella Pneumoniae Clinical Isolates Recovered From Egyptian Hospitals, Reham Wasfi, Walid F. Elkhatib, Hossam M. Ashour

Molecular Biosciences Faculty Publications

Klebsiella pneumonia infection rates have increased dramatically. Molecular typing and virulence analysis are powerful tools that can shed light on Klebsiella pneumonia infections. Whereas 77.7% (28/36) of clinical isolates indicated multidrug resistant (MDR) patterns, 50% (18/36) indicated carpabenem resistance. Gene prevalence for the AcrAB efflux pump (82.14%) was more than that of the mdtK efflux pump (32.14%) in the MDR isolates. FimH-1 and mrkD genes were prevalent in wound and blood isolates. FimH-1 gene was prevalent in sputum while mrkD gene was prevalent in urine. Serum resistance associated with outer membrane protein coding gene (traT) was found in all blood …

Sepsis And Hemocyte Loss In Honey Bees (Apis Mellifera) Infected With Serratia Marcescens Strain Sicaria, Nancy L. Burritt, Nicole J. Foss, Eric C. Neeno-Eckwall, James O. Church, Anna M. Hilger, Jacob A. Hildebrand, David M. Warshauer, Nicole T. Perna, James B. Burritt

Biology Faculty Work

Global loss of honey bee colonies is threatening the human food supply. Diverse pathogens reduce honey bee hardiness needed to sustain colonies, especially in winter. We isolated a free-living Gram negative bacillus from hemolymph of worker honey bees (Apis mellifera) found separated from winter clusters. In some hives, greater than 90% of the dying bees detached from the winter cluster were found to contain this bacterium in their hemolymph. Throughout the year, the same organism was rarely found in bees engaged in normal hive activities, but was detected in about half of Varroa destructor mites obtained from colonies that housed …

Vamorolone, A Dissociative Steroidal Compound, Reduces Pro-Inflammatory Cytokine Expression In Glioma Cells And Increases Activity And Survival In A Murine Model Of Cortical Tumor., Elizabeth Wells, Madhuri Kambhampati, Jesse M Damsker, Heather Gordish-Dressman, Sridevi Yadavilli, Oren J Becher, Jamila Gittens, Mojca Stampar, Roger J. Packer, Javad Nazarian

Genomics and Precision Medicine Faculty Publications

Corticosteroids, such as dexamethasone, are routinely used as palliative care in neuro-oncology for their anti-inflammatory benefits, however many patients experience dose limiting side effects caused by glucocorticoid response element (GRE)-mediated transcription. The purpose of this study was to use a murine model to investigate a new steroid alternative, vamorolone, which promises to reduce side effects through dissociating GRE-mediated transcription and NF-κB -mediated anti-inflammatory actions. To compare vamorolone to dexamethasone in reducing pro-inflammatory signals in vitro, murine glioma cells were treated with dexamethasone, vamorolone or vehicle control. Changes in mRNA expression were assessed using the nanostring inflammatory platform. Furthermore, drug …

Comparative Genomic Analysis Of Two Serotype 1/2b Listeria Monocytogenes Isolates From Analogous Environmental Niches Demonstrates The Influence Of Hypervariable Hotspots In Defining Pathogenesis, Aidan Casey, Kieran Jordan, Aidan Coffey, Edward M. Fox, Olivia Mcauliffe

Department of Biological Sciences Publications

The vast majority of clinical human listeriosis cases are caused by serotype 1/2a, 1/2b, 1/2c, and 4b isolates of Listeria monocytogenes. The ability of L. monocytogenes to establish a systemic listeriosis infection within a host organism relies on a combination of genes that are involved in cell recognition, internalization, evasion of host defenses, and in vitro survival and growth. Recently, whole genome sequencing and comparative genomic analysis have proven to be powerful tools for the identification of these virulence-associated genes in L. monocytogenes. In this study, two serotype 1/2b strains of L. monocytogenes with analogous isolation sources, but …

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 …

A Mineralized Alga And Acritarch Dominated Microbiota From The Tully Formation (Givetian) Of Pennsylvania, Usa, John A. Chamberlain Jr., Rebecca B. Chamberlain, James O. Brown

Publications and Research

Sphaeromorphic algal cysts, most probably of the prasinophyte Tasmanites, and acanthomorphic acritarch vesicles, most probably Solisphaeridium, occur in a single 20 cm thick bed of micritic limestone in the lower part of the Middle Devonian (Givetian) Tully Formation near Lock Haven, Pennsylvania. Specimens are composed of authigenic calcite and pyrite crystals about 5–10 µm in length. Some specimens are completely calcitic; some contain both pyrite and calcite; and many are composed totally of pyrite. The microfossils are about 80 to 150 µm in diameter. Many show signs of originally containing a flexible wall composed of at least two layers. Some …

The Vibrio Cholerae Minor Pilin Tcpb Initiates Assembly And Retraction Of The Toxin- Coregulated Pilus, Dixon Ng, Tony Harn, Tuba Altindal, Subramania Kolappan, Jarrad M. Marles, Rajan Lala, Ingrid Spielman, Yang Gao, Caitlyn A. Hauke, Gabriela Kovacikova, Zia Verjee, Ronald K. Taylor, Nicolas Biais, Lisa Craig

Publications and Research

Type IV pilus (T4P) systems are complex molecular machines that polymerize major pilin proteins into thin filaments displayed on bacterial surfaces. Pilus functions require rapid extension and depolymerization of the pilus, powered by the assembly and retraction ATPases, respectively. A set of low abundance minor pilins influences pilus dynamics by unknown mechanisms. The Vibrio cholerae toxin-coregulated pilus (TCP) is among the simplest of the T4P systems, having a single minor pilin TcpB and lacking a retraction ATPase. Here we show that TcpB, like its homolog CofB, initiates pilus assembly. TcpB co-localizes with the pili but at extremely low levels, equivalent …

Stress Physiology And Weapon Integrity Of Intertidal Mantis Shrimp Under Future Ocean Conditions, Maya Devries, Summer Webb, Jenny Tu, Esther Cory, Victoria Morgan, Robert Sah, Dimitri Deheyn, Jennifer Taylor

Faculty Publications, Biological Sciences

Calcified marine organisms typically experience increased oxidative stress and changes in mineralization in response to ocean acidification and warming conditions. These effects could hinder the potency of animal weapons, such as the mantis shrimp’s raptorial appendage. The mechanical properties of this calcified weapon enable extremely powerful punches to be delivered to prey and aggressors. We examined oxidative stress and exoskeleton structure, mineral content, and mechanical properties of the raptorial appendage and the carapace under long-term ocean acidification and warming conditions. The predatory appendage had significantly higher % Mg under ocean acidification conditions, while oxidative stress levels as well as the …

Density Dependence Drives Habitat Production And Survivorship Of Acropora Cervicornis Used For Restoration On A Caribbean Coral Reef, Mark C. Ladd, Andrew A. Shantz, Ken Nedimyer, Deron E. Burkepile

Department of Biological Sciences

Coral restoration is gaining traction as a viable strategy to help restore degraded reefs. While the nascent field of coral restoration has rapidly progressed in the past decade, significant knowledge gaps remain regarding the drivers of restoration success that may impede our ability to effectively restore coral reef communities. Here, we conducted a field experiment to investigate the influence of coral density on the growth, habitat production, and survival of corals outplanted for restoration. We used nursery-raised colonies of Acropora cervicornis to experimentally establish populations of corals with either 3, 6, 12, or 24 corals within 4m² plots, generating …

Effect Of Arginine On Oligomerization And Stability Of N-Acetylglutamate Synthase., N Haskins, A Mumo, P H Brown, Mendel Tuchman, Hiroki Morizono, L Caldovic

Genomics and Precision Medicine Faculty Publications

N-acetylglutamate synthase (NAGS; E.C.2.3.1.1) catalyzes the formation of N-acetylglutamate (NAG) from acetyl coenzyme A and glutamate. In microorganisms and plants, NAG is the first intermediate of the L-arginine biosynthesis; in animals, NAG is an allosteric activator of carbamylphosphate synthetase I and III. In some bacteria bifunctional N-acetylglutamate synthase-kinase (NAGS-K) catalyzes the first two steps of L-arginine biosynthesis. L-arginine inhibits NAGS in bacteria, fungi, and plants and activates NAGS in mammals. L-arginine increased thermal stability of the NAGS-K from Maricaulis maris (MmNAGS-K) while it destabilized the NAGS-K from Xanthomonas campestris (XcNAGS-K). Analytical gel chromatography and ultracentrifugation indicated tetrameric structure of the …

Patchiness Of Ciliate Communities Sampled At Varying Spatial Scales Along The New England Shelf, Jean-David Grattepanche, George B. Mcmanus, Laura A. Katz

Biological Sciences: Faculty Publications

Although protists (microbial eukaryotes) provide an important link between bacteria and Metazoa in food webs, we do not yet have a clear understanding of the spatial scales on which protist diversity varies. Here, we use a combination of DNA fingerprinting (denaturant gradient gel electrophoresis or DGGE) and high-throughput sequencing (HTS) to assess the ciliate community in the class Spirotrichea at varying scales of 1–3 km sampled in three locations separated by at least 25 km—offshore, midshelf and inshore—along the New England shelf. Analyses of both abundant community (DGGE) and the total community (HTS) members reveal that: 1) ciliate communities are …

Recurring Patterns Among Scrambled Genes In The Encrypted Genome Of The Ciliate Oxytricha Trifallax, Jonathan Burns, Denys Kukushkin, Xiao Chen, Laura F Landweber, Masahico Saito, Nataša Jonoska

Mathematics and Statistics Faculty Publications

Some genera of ciliates, such as Oxytricha and Stylonychia, undergo massive genome reorganization during development and provide model organisms to study DNA rearrangement. A common feature of these ciliates is the presence of two types of nuclei: a germline micronucleus and a transcriptionally-active somatic macronucleus containing over 16,000 gene sized "nano-chromosomes". During conjugation the old parental macronucleus disintegrates and a new macronucleus forms from a copy of the zygotic micronucleus. During this process, macronuclear chromosomes assemble through DNA processing events that delete 90-98% of the DNA content of the micronucleus. This includes the deletion of noncoding DNA segments that interrupt …

A Novel Rrm3 Function In Restricting Dna Replication Via An Orc5-Binding Domain Is Genetically Separable From Rrm3 Function As An Atpase/Helicase In Facilitating Fork Progression, Salahuddin Syed, Claus Desler, Lene J Rasmussen, Kristina H Schmidt

Molecular Biosciences Faculty Publications

In response to replication stress cells activate the intra-S checkpoint, induce DNA repair pathways, increase nucleotide levels, and inhibit origin firing. Here, we report that Rrm3 associates with a subset of replication origins and controls DNA synthesis during replication stress. The N-terminal domain required for control of DNA synthesis maps to residues 186-212 that are also critical for binding Orc5 of the origin recognition complex. Deletion of this domain is lethal to cells lacking the replication checkpoint mediator Mrc1 and leads to mutations upon exposure to the replication stressor hydroxyurea. This novel Rrm3 function is independent of its established role …

Chickadees Faced With Unpredictable Food Increase Fat Reserves But Certain Components Of Their Immune Function Decline, Emily A. Cornelius, François Vézina, Lyette Regimbald, Fanny Hallot, Magali Petit, Oliver P. Love

Biological Sciences Publications

In winter, temperate resident birds are often faced with periodic low natural food availability. This reduction or unpredictability in resource availability might then have a negative impact on immune function, given that immune system support is highly resource dependent. We investigated the balance between energetic and immune management in captive black-capped chickadees (Poecile atricapilus) by manipulating the predictability of resources. The control group received food ad lib. every day, while the experimental group received a reduced amount of food on random days and food ad lib. on all other days. We measured two key metrics of energetic management (body and …

Efficient Method For Transfer Of Microinjected Eggs To Mouse Ampulla For Generating Transgenic Mice, Guang Wen, Jin Di, Qian Li, Jianling Chen, Ling Jin, Cheng Wang, Sanqing Xu

Publications and Research

Background: The new method described here is highly efficient in transferring microinjected mouse eggs (MEs) through the bursa membrane of a surrogate mother mouse to the ampulla of the oviduct without damaging the blood vessels on the bursa membrane.

Results: This method causes no loss of blood, and it produces newborn pups/founders from approximately 70% of the transferred MEs, because only a small hole is made on the blood vessel–free area of the bursa membrane and ampulla of the surrogate mother mouse. The infundibulum remains intact. The small hole on the bursa membrane/ ampulla may already heal up before the …

Netrin-3 Peptide (C-19) Is A Chemorepellent And A Growth Inhibitor In Tetrahymena Thermophila, Matthew S. Merical, Kenneth W. Ward, Lois Parks, Heather G. Kuruvilla

Science and Mathematics Faculty Presentations

The netrins are a family of signaling proteins expressed throughout the animal kingdom. Netrins play important roles in developmental processes such as axonal guidance and angiogenesis. Netrin-1, for example, can act as either a chemoattractant or a chemorepellent for axonal growth cones depending upon the concentration of the protein as well as the cell type. Netrin-1 acts as a growth factor in some cell types and is expressed by some tumor cells. Netrin-3 appears to share some signaling apparatus with netrin-1, but is less widely expressed, and its physiological roles are much less understood.

Tetrahymena thermophila are free-living, eukaryotic, ciliated …

Copper Oxide Nanoparticles Impact Several Toxicological Endpoints And Cause Neurodegeneration In Caenorhabditis Elegans, Michael Joseph Mashock, Tyler Zanon, Anthony D. Kappell, Lisa N. Petrella, Erik C. Andersen, Krassimira R. Hristova

Biological Sciences Faculty Research and Publications

Engineered nanoparticles are becoming increasingly incorporated into technology and consumer products. In 2014, over 300 tons of copper oxide nanoparticles were manufactured in the United States. The increased production of nanoparticles raises concerns regarding the potential introduction into the environment or human exposure. Copper oxide nanoparticles commonly release copper ions into solutions, which contribute to their toxicity. We quantified the inhibitory effects of both copper oxide nanoparticles and copper sulfate on C. elegans toxicological endpoints to elucidate their biological effects. Several toxicological endpoints were analyzed in C. elegans, including nematode reproduction, feeding behavior, and average body length. We examined three …

Exploration Of Student Biodiversity Knowledge And Decision-Making For A Wildlife Conservation Socioscientific Issue, Ashley R. Alred

School of Natural Resources: Dissertations, Theses, and Student Research

Global biodiversity, a foundation for ecosystem function, is diminishing at a rate unprecedented in the last 50 years. Biodiversity loss and ecosystem services deterioration is linked to increased food insecurity, reduced water quality and availability, decreased energy security, higher economic losses and human suffering (Millennium Ecosystem Assessment, 2005). Consequently, educators should invest in supporting students in their development of ecological understanding and formal decision-making skills so they are equipped with meaningful tools they can use as scientifically literate citizens. To contribute to that mission, this study seeks to explore student 1) comprehension and explanation of biodiversity concepts and 2) decision-making …

Freeze Tolerance Of Cyphoderris Monstrosa (Orthoptera: Prophalangopsidae), Jantina Toxopeus, Jacqueline Lebenzon, Alexander H. Mckinnon, Brent J. Sinclair

Biology Publications

The great grig, Cyphoderris monstrosa Uhler (Orthoptera: Prophalangopsidae), is a large (20-30 mm, >1 g), nocturnal ensiferan that in habits montane coniferous forests in northwestern North America. C. monstrosa overwinters as a late-instar nymph, but its cold tolerance strategy has not previously been reported. We collected nymphs from near Kamloops, British Columbia, in late spring to determine their cold tolerance strategy. C. monstrosa nymphs were active at low temperatures until they froze at -4.6 ± 0.3 °C. The nymphs survived internal ice formation (i.e. are freeze tolerant), had a lethal temperature between -9 and -12 °C, and could survive for …