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Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Photophysical And Optical Properties Of Semiconducting Polymer Nanoparticles Prepared From Hyaluronic Acid And Polysorbate 80, Adam Langlois, Gage T. Mason, Michael H.L. Nguyen, Mehdi Rezapour, Paul Ludovic Karsenti, Drew Marquardt, Simon Rondeau-Gagné Dec 2019

Photophysical And Optical Properties Of Semiconducting Polymer Nanoparticles Prepared From Hyaluronic Acid And Polysorbate 80, Adam Langlois, Gage T. Mason, Michael H.L. Nguyen, Mehdi Rezapour, Paul Ludovic Karsenti, Drew Marquardt, Simon Rondeau-Gagné

Chemistry and Biochemistry Publications

Copyright © 2019 American Chemical Society. A nanoprecipitation procedure was utilized to prepare novel diketopyrrolopyrrole-based semiconducting polymer nanoparticles (SPNs) with hyaluronic acid (HA) and polysorbate 80. The nanoprecipitation led to the formation of spherical nanoparticles with average diameters ranging from 100 to 200 nm, and a careful control over the structure of the parent conjugated polymers was performed to probe the influence of π-conjugation on the final photophysical and thermal stability of the resulting SPNs. Upon generation of a series of novel SPNs, the optical and photophysical properties of the new nanomaterials were probed in solution using various techniques including …


Insight Into The Molecular Mechanisms For Microcystin Biodegradation In Lake Erie And Lake Taihu, Lauren E. Krausfeldt, Morgan M. Steffen, Robert M. Mckay, George S. Bullerjahn, Gregory L. Boyer, Steven W. Wilhelm Dec 2019

Insight Into The Molecular Mechanisms For Microcystin Biodegradation In Lake Erie And Lake Taihu, Lauren E. Krausfeldt, Morgan M. Steffen, Robert M. Mckay, George S. Bullerjahn, Gregory L. Boyer, Steven W. Wilhelm

Great Lakes Institute for Environmental Research Publications

Microcystins are potent hepatotoxins that are frequently detected in fresh water lakes plagued by toxic cyanobacteria. Microbial biodegradation has been referred to as the most important avenue for removal of microcystin from aquatic environments. The biochemical pathway most commonly associated with the degradation of microcystin is encoded by the mlrABCD (mlr) cassette. The ecological significance of this pathway remains unclear as no studies have examined the expression of these genes in natural environments. Six metatranscriptomes were generated from microcystin-producing Microcystis blooms and analyzed to assess the activity of this pathway in environmental samples. Seventy-eight samples were collected from Lake Erie, …


Comparative Brain Morphology Of The Greenland And Pacific Sleeper Sharks And Its Functional Implications, Kara E. Yopak, Bailey C. Mcmeans, Christopher G. Mull, Kirk W. Feindel, Kit M. Kovacs, Christian Lydersen, Aaron T. Fisk, Shaun P. Collin Dec 2019

Comparative Brain Morphology Of The Greenland And Pacific Sleeper Sharks And Its Functional Implications, Kara E. Yopak, Bailey C. Mcmeans, Christopher G. Mull, Kirk W. Feindel, Kit M. Kovacs, Christian Lydersen, Aaron T. Fisk, Shaun P. Collin

Great Lakes Institute for Environmental Research Publications

In cartilaginous fishes, variability in the size of the brain and its major regions is often associated with primary habitat and/or specific behavior patterns, which may allow for predictions on the relative importance of different sensory modalities. The Greenland (Somniosus microcephalus) and Pacific sleeper (S. pacificus) sharks are the only non-lamnid shark species found in the Arctic and are among the longest living vertebrates ever described. Despite a presumed visual impairment caused by the regular presence of parasitic ocular lesions, coupled with the fact that locomotory muscle power is often depressed at cold temperatures, these sharks remain capable of capturing …


Covalently Functionalized Sawdust For The Remediation Of Phosphate From Agricultural Wastewater, Daniel Meister, David Ure, Angela Awada, Jean-Claude Barrette, Joel Gagnon, Bluent Mutus, John F. Trant Nov 2019

Covalently Functionalized Sawdust For The Remediation Of Phosphate From Agricultural Wastewater, Daniel Meister, David Ure, Angela Awada, Jean-Claude Barrette, Joel Gagnon, Bluent Mutus, John F. Trant

Chemistry and Biochemistry Publications

Phosphate remediation from wastewater is rapidly becoming an ever more attractive process due to a combination of both the economic pressure of increasing phosphate scarcity and the environmental damage caused by untreated agricultural runoff. Ideally, remediated phosphate will be recoverable and would be able to be reused as fertilizer. Many different resins have been investigated, but due to the scale of the challenge, any feasible solution will involve the use of very inexpensive waste products as the solid support. Sawdust, functionalized with iron-binding ligands, is such a potential resin. Sawdust alone binds 0.3 g/kg of phosphate which is insufficient. Iron …


The Influence Of Dynamic Environmental Interactions On Detection Efficiency Of Acoustic Transmitters In A Large, Deep, Freshwater Lake, Natalie V. Klinard, Edmund A. Halfyard, Jordan K. Matley, Aaron T. Fisk, Timothy B. Johnson Sep 2019

The Influence Of Dynamic Environmental Interactions On Detection Efficiency Of Acoustic Transmitters In A Large, Deep, Freshwater Lake, Natalie V. Klinard, Edmund A. Halfyard, Jordan K. Matley, Aaron T. Fisk, Timothy B. Johnson

Great Lakes Institute for Environmental Research Publications

Background: Acoustic telemetry is an increasingly common method used to address ecological questions about the movement, behaviour, and survival of freshwater and marine organisms. The variable performance of acoustic telemetry equipment and ability of receivers to detect signals from transmitters have been well studied in marine and coral reef environments to inform study design and improve data interpretation. Despite the growing use of acoustic telemetry in large, deep, freshwater systems, detection efficiency and range, particularly in relation to environmental variation, are poorly understood. We used an array of 90 69-kHz acoustic receivers and 8 sentinel range transmitters of varying power …


Peptide-Induced Lipid Flip-Flop In Asymmetric Liposomes Measured By Small Angle Neutron Scattering, Michael H.L. Nguyen, Mitchell Dipasquale, Brett W. Rickeard, Milka Doktorova, Frederick A. Heberle, Haden L. Scott, Francisco N. Barrera, Graham Taylor, Charles P. Collier, Christopher B. Stanley, John Katsaras, Drew Marquardt Sep 2019

Peptide-Induced Lipid Flip-Flop In Asymmetric Liposomes Measured By Small Angle Neutron Scattering, Michael H.L. Nguyen, Mitchell Dipasquale, Brett W. Rickeard, Milka Doktorova, Frederick A. Heberle, Haden L. Scott, Francisco N. Barrera, Graham Taylor, Charles P. Collier, Christopher B. Stanley, John Katsaras, Drew Marquardt

Chemistry and Biochemistry Publications

© 2019 American Chemical Society. Despite the prevalence of lipid transbilayer asymmetry in natural plasma membranes, most biomimetic model membranes studied are symmetric. Recent advances have helped to overcome the difficulties in preparing asymmetric liposomes in vitro, allowing for the examination of a larger set of relevant biophysical questions. Here, we investigate the stability of asymmetric bilayers by measuring lipid flip-flop with time-resolved small-angle neutron scattering (SANS). Asymmetric large unilamellar vesicles with inner bilayer leaflets containing predominantly 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and outer leaflets composed mainly of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) displayed slow spontaneous flip-flop at 37 -C (half-time, t1/2 = 140 h). However, …


Metatranscriptomic Analyses Of Diel Metabolic Functions During A Microcystis Bloom In Western Lake Erie (United States), Emily J. Davenport, Michelle J. Neudeck, Paul G. Matson, George S. Bullerjahn, Timothy W. Davis, Steven W. Wilhelm, Maddie K. Denney, Lauren E. Krausfeldt, Joshua M.A. Stough, Kevin A. Meyer, Gregory J. Dick, Thomas H. Johengen, Erika Lindquist, Susannah G. Tringe, Robert Michael L. Mckay Sep 2019

Metatranscriptomic Analyses Of Diel Metabolic Functions During A Microcystis Bloom In Western Lake Erie (United States), Emily J. Davenport, Michelle J. Neudeck, Paul G. Matson, George S. Bullerjahn, Timothy W. Davis, Steven W. Wilhelm, Maddie K. Denney, Lauren E. Krausfeldt, Joshua M.A. Stough, Kevin A. Meyer, Gregory J. Dick, Thomas H. Johengen, Erika Lindquist, Susannah G. Tringe, Robert Michael L. Mckay

Great Lakes Institute for Environmental Research Publications

This study examined diel shifts in metabolic functions of Microcystis spp. during a 48-h Lagrangian survey of a toxin-producing cyanobacterial bloom in western Lake Erie in the aftermath of the 2014 Toledo Water Crisis. Transcripts mapped to the genomes of recently sequenced lower Great Lakes Microcystis isolates showed distinct patterns of gene expression between samples collected across day (10:00 h, 16:00 h) and night (22:00 h, 04:00 h). Daytime transcripts were enriched in functions related to Photosystem II (e.g., psbA), nitrogen and phosphate acquisition, cell division (ftsHZ), heat shock response (dnaK, groEL), and uptake of inorganic carbon (rbc, bicA). Genes …


Tracking Landscape-Scale Movements Of Snow Buntings And Weather-Driven Changes In Flock Composition During The Temperate Winter, Emily A. Mckinnon, Marie Pier Laplante, Oliver P. Love, Kevin C. Fraser, Stuart Mackenzie, François Vézina Sep 2019

Tracking Landscape-Scale Movements Of Snow Buntings And Weather-Driven Changes In Flock Composition During The Temperate Winter, Emily A. Mckinnon, Marie Pier Laplante, Oliver P. Love, Kevin C. Fraser, Stuart Mackenzie, François Vézina

Great Lakes Institute for Environmental Research Publications

Nomadic movements of migratory birds are difficult to study, as the scale is beyond the capabilities of hand-held telemetry (10 s of kms) but too fine-scale for long-range tracking devices like geolocators (50–100 km accuracy). Recent widespread installation of automated telemetry receiving stations allowed us, for the first time, to quantify and test predictions about within-winter movements of a presumed nomadic species, the Snow Bunting (Pletrophenax nivalis). We deployed coded radio-transmitters on 40 individual Snow Buntings during two winters (2015-16 and 2016-17) in southern Ontario, Canada, and tracked movements over a 300 by 300 km area with 69–77 active radio-receiving …


Neuro And Hepatic Toxicological Profile Of (S)-2,4-Diaminobutanoic Acid In Embryonic, Adolescent And Adult Zebrafish, Rosa-Maria Ferraiuolo, Daniel Meister, Dominique Leckie, Jonathan Franke, Lisa A. Porter, John F. Trant Aug 2019

Neuro And Hepatic Toxicological Profile Of (S)-2,4-Diaminobutanoic Acid In Embryonic, Adolescent And Adult Zebrafish, Rosa-Maria Ferraiuolo, Daniel Meister, Dominique Leckie, Jonathan Franke, Lisa A. Porter, John F. Trant

Chemistry and Biochemistry Publications

(S)-2,4-Diaminobutanoic acid (DABA) is a noncanonical amino acid often co-produced by cyanobacteria along with β-N-methylamino-l-alanine (BMAA) in algal blooms. Although BMAA is a well-established neurotoxin, the toxicity of DABA remains unclear. As part of our development of biocompatible materials, we wish to make use of DABA as both a building block and as the end-product of enzymatically-induced depolymerization; however, if it is toxic at very low concentrations, this would not be possible. We examined the toxicity of DABA using both in vivo embryonic and adult zebrafish models. At higher sub-lethal concentrations (700 µM), the fish demonstrated early …


Stable Isotopes Of Carbon Reveal Flexible Pairing Strategies In A Migratory Arctic Bird, Rolanda J. Steenweg, Pierre Legagneux, Glenn T. Crossin, H. Grant Gilchrist, T. Kurt Kyser, Oliver P. Love Jul 2019

Stable Isotopes Of Carbon Reveal Flexible Pairing Strategies In A Migratory Arctic Bird, Rolanda J. Steenweg, Pierre Legagneux, Glenn T. Crossin, H. Grant Gilchrist, T. Kurt Kyser, Oliver P. Love

Great Lakes Institute for Environmental Research Publications

Many birds change their partners every year and pairing may occur before arrival on the breeding grounds. Early pairing strategies can benefit mates by strengthening pair-bonds and increasing the rate of pre-breeding resource acquisition, leading to increased reproductive output and success, especially for migratory species breeding in seasonally-constrained environments like the Arctic. Despite the theorized and documented advantages of early pairing, we know rather little about pairing phenology in many species. Here, we test the use of a stable isotope (carbon δ13C) method to assign geographic origin of paired birds to examine pairing phenology in Arctic-breeding Common Eiders (Somateria mollissima …


Calcium-Ion Batteries: Identifying Ideal Electrolytes For Next-Generation Energy Storage Using Computational Analysis, Mehdi Shakourian-Fard, Ganesh Kamath, S. Maryamdokht Taimoory, John F. Trant Jun 2019

Calcium-Ion Batteries: Identifying Ideal Electrolytes For Next-Generation Energy Storage Using Computational Analysis, Mehdi Shakourian-Fard, Ganesh Kamath, S. Maryamdokht Taimoory, John F. Trant

Chemistry and Biochemistry Publications

Calcium ion batteries show promise as a high-density, next generation replacement for current lithium ion batteries. The precise chemical structure of the carbonate electrolyte solvent has a large impact on calcium battery efficacy. In this computational study, we have investigated the solvation behavior of calcium tetrafluoroborate in both neat carbonates and carbonate mixtures using combined molecular dynamics simulations and quantum mechanical calculations. Our results indicate that both neat ethyl methyl carbonate and a mixture of ethylene carbonate and diethyl carbonate show the highest free-energy of solvation for the Ca2+ ion, making them likely candidates for further focus. The cation’s …


Halogen Bonding And Host–Guest Chemistry Between N-Alkylammonium Resorcinarene Halides, Diiodoperfluorobutane And Neutral Guests, Fangfang Pan, Mohadeseh Dashti, Michael R. Reynolds, Kari Rissanen, John F. Trant, Ngong Kodiah Beyeh Apr 2019

Halogen Bonding And Host–Guest Chemistry Between N-Alkylammonium Resorcinarene Halides, Diiodoperfluorobutane And Neutral Guests, Fangfang Pan, Mohadeseh Dashti, Michael R. Reynolds, Kari Rissanen, John F. Trant, Ngong Kodiah Beyeh

Chemistry and Biochemistry Publications

Single crystal X-ray structures of halogen-bonded assemblies formed between host N-hexylammonium resorcinarene bromide (1) or N-cyclohexylammonium resorcinarene chloride (2), and 1,4-diiodooctafluorobutane and accompanying small solvent guests (meth- anol, acetonitrile and water) are presented. The guests’ inclusion affects the geometry of the cavity of the receptors 1 and 2, while the divalent halogen bond donor 1,4-diiodooctafluorobutane determines the overall nature of the halogen bond assembly. The crystal lattice of 1 contains two structurally different dimeric assemblies A and B, formally resulting in the mixture of a capsular dimer and a dimeric pseudo-capsule. 1H …


Transitions In Microbial Communities Along A 1600 Km Freshwater Trophic Gradient, Mark J. Rozmarynowycz, Benjamin F.N. Beall, George S. Bullerjahn, Gaston E. Small, Robert W. Sterner, Sandra S. Brovold, Nigel A. D'Souza, Susan B. Watson, Robert Michael L. Mckay Apr 2019

Transitions In Microbial Communities Along A 1600 Km Freshwater Trophic Gradient, Mark J. Rozmarynowycz, Benjamin F.N. Beall, George S. Bullerjahn, Gaston E. Small, Robert W. Sterner, Sandra S. Brovold, Nigel A. D'Souza, Susan B. Watson, Robert Michael L. Mckay

Great Lakes Institute for Environmental Research Publications

This study examined vertically-resolved patterns in microbial community structure across a freshwater trophic gradient extending 1600 km from the oligotrophic waters of Lake Superior to the eutrophic waters of Lake Erie, the most anthropogenically influenced of the Laurentian Great Lakes system. Planktonic bacterial communities clustered by Principal Coordinates Analysis (PCoA) on UniFrac distance matrices into four groups representing the epilimnion and hypolimnion of the upper Great Lakes (Lakes Superior and Huron), Lake Superior's northern bays (Nipigon and Black bays), and Lake Erie. The microbes within the upper Great Lakes hypolimnion were the most divergent of these groups with elevated abundance …


Adsorption Of Bovine Serum Albumin (Bsa) By Bare Magnetite Nanoparticles With Surface Oxidative Impurities That Prevent Aggregation, Somayeh Rahdar, Abbas Rahdar, Shahin Ahmadi, John F. Trant Mar 2019

Adsorption Of Bovine Serum Albumin (Bsa) By Bare Magnetite Nanoparticles With Surface Oxidative Impurities That Prevent Aggregation, Somayeh Rahdar, Abbas Rahdar, Shahin Ahmadi, John F. Trant

Chemistry and Biochemistry Publications

Bare, uncoated magnetite nanoparticles, synthesized using an electrochemical surfactant-free synthesis, have highly oxidized surfaces that prevent aggregation. These particles have demonstrated highly intriguing biological activity showing extremely potent antibiotic activity against both gram-positive and gram-negative bacteria with little toxicity to rats. This difference in activity could be ascribed to the nature of the protein corona. In this study the kinetics and thermodynamics of the binding of bovine serum albumin, used as a model serum protein, to these magnetite nanoparticles was analyzed. There is no significant change in particle diameter by dynamic light scattering following adsorption indicating corona formation does not …


Methanol Accelerates Dmpc Flip-Flop And Transfer: A Sans Study On Lipid Dynamics, Michael H.L. Nguyen, Mitchell Dipasquale, Brett W. Rickeard, Christopher B. Stanley, Elizabeth G. Kelley, Drew Marquardt Mar 2019

Methanol Accelerates Dmpc Flip-Flop And Transfer: A Sans Study On Lipid Dynamics, Michael H.L. Nguyen, Mitchell Dipasquale, Brett W. Rickeard, Christopher B. Stanley, Elizabeth G. Kelley, Drew Marquardt

Chemistry and Biochemistry Publications

© 2019 Biophysical Society Methanol is a common solubilizing agent used to study transmembrane proteins/peptides in biological and synthetic membranes. Using small angle neutron scattering and a strategic contrast-matching scheme, we show that methanol has a major impact on lipid dynamics. Under increasing methanol concentrations, isotopically distinct 1,2-dimyristoyl-sn-glycero-3-phosphocholine large unilamellar vesicle populations exhibit increased mixing. Specifically, 1,2-dimyristoyl-sn-glycero-3-phosphocholine transfer and flip-flop kinetics display linear and exponential rate enhancements, respectively. Ultimately, methanol is capable of influencing the structure-function relationship associated with bilayer composition (e.g., lipid asymmetry). The use of methanol as a carrier solvent, despite better simulating some biological conditions (e.g., antimicrobial …


Gramicidin Increases Lipid Flip-Flop In Symmetric And Asymmetric Lipid Vesicles, Milka Doktorova, Frederick A. Heberle, Drew Marquardt, Radda Rusinova, R. Lea Sanford, Thasin A. Peyear, John Katsaras, Gerald W. Feigenson, Harel Weinstein, Olaf S. Andersen Mar 2019

Gramicidin Increases Lipid Flip-Flop In Symmetric And Asymmetric Lipid Vesicles, Milka Doktorova, Frederick A. Heberle, Drew Marquardt, Radda Rusinova, R. Lea Sanford, Thasin A. Peyear, John Katsaras, Gerald W. Feigenson, Harel Weinstein, Olaf S. Andersen

Chemistry and Biochemistry Publications

© 2019 Biophysical Society Unlike most transmembrane proteins, phospholipids can migrate from one leaflet of the membrane to the other. Because this spontaneous lipid translocation (flip-flop) tends to be very slow, cells facilitate the process with enzymes that catalyze the transmembrane movement and thereby regulate the transbilayer lipid distribution. Nonenzymatic membrane-spanning proteins with unrelated primary functions have also been found to accelerate lipid flip-flop in a nonspecific manner and by various hypothesized mechanisms. Using deuterated phospholipids, we examined the acceleration of flip-flop by gramicidin channels, which have well-defined structures and known functions, features that make them ideal candidates for probing …


Abundance And Species Diversity Hotspots Of Tracked Marine Predators Across The North American Arctic, David J. Yurkowski, Marie Auger-Méthé, Mark L. Mallory, Sarah N.P. Wong, Grant Gilchrist, Andrew E. Derocher, Evan Richardson, Nicholas J. Lunn, Nigel E. Hussey, Marianne Marcoux, Ron R. Togunov, Aaron T. Fisk, Lois A. Harwood, Rune Dietz, Aqqalu Rosing-Asvid, Erik W. Born, Anders Mosbech, Jérôme Fort, David Grémillet, Lisa Loseto Mar 2019

Abundance And Species Diversity Hotspots Of Tracked Marine Predators Across The North American Arctic, David J. Yurkowski, Marie Auger-Méthé, Mark L. Mallory, Sarah N.P. Wong, Grant Gilchrist, Andrew E. Derocher, Evan Richardson, Nicholas J. Lunn, Nigel E. Hussey, Marianne Marcoux, Ron R. Togunov, Aaron T. Fisk, Lois A. Harwood, Rune Dietz, Aqqalu Rosing-Asvid, Erik W. Born, Anders Mosbech, Jérôme Fort, David Grémillet, Lisa Loseto

Great Lakes Institute for Environmental Research Publications

Aim: Climate change is altering marine ecosystems worldwide and is most pronounced in the Arctic. Economic development is increasing leading to more disturbances and pressures on Arctic wildlife. Identifying areas that support higher levels of predator abundance and biodiversity is important for the implementation of targeted conservation measures across the Arctic. Location: Primarily Canadian Arctic marine waters but also parts of the United States, Greenland and Russia. Methods: We compiled the largest data set of existing telemetry data for marine predators in the North American Arctic consisting of 1,283 individuals from 21 species. Data were arranged into four species groups: …


A H2ax–Carp-1 Interaction Regulates Apoptosis Signaling Following Dna Damage, Sreeja C. Sekhar, Jaganathan Venkatesh, Vino T. Cheriyan, Magesh Muthu, Edi Levi, Hadeel Assad, Paul Meister, Vishnu V. Undyala, James W. Gauld, Arun K. Rishi Feb 2019

A H2ax–Carp-1 Interaction Regulates Apoptosis Signaling Following Dna Damage, Sreeja C. Sekhar, Jaganathan Venkatesh, Vino T. Cheriyan, Magesh Muthu, Edi Levi, Hadeel Assad, Paul Meister, Vishnu V. Undyala, James W. Gauld, Arun K. Rishi

Chemistry and Biochemistry Publications

Cell Cycle and Apoptosis Regulatory Protein (CARP-1/CCAR1) is a peri-nuclear phosphoprotein that regulates apoptosis via chemotherapeutic Adriamycin (doxorubicin) and a novel class of CARP-1 functional mimetic (CFM) compounds. Although Adriamycin causes DNA damage, data from Comet assays revealed that CFM-4.16 also induced DNA damage. Phosphorylation of histone 2AX (γH2AX) protein is involved in regulating DNA damage repair and apoptosis signaling. Adriamycin or CFM-4.16 treatments inhibited cell growth and caused elevated CARP-1 and γH2AX in human breast (HBC) and cervical cancer (HeLa) cells. In fact, a robust nuclear or peri-nuclear co-localization of CARP-1 and γH2AX occurred in cells undergoing apoptosis. Knock-down …


Plasma Mammalian Leptin Analogue Predicts Reproductive Phenology, But Not Reproductive Output In A Capital-Income Breeding Seaduck, Holly L. Hennin, Pierre Legagneux, H. Grant Gilchrist, Joël Bêty, John P. Mcmurtry, Oliver P. Love Feb 2019

Plasma Mammalian Leptin Analogue Predicts Reproductive Phenology, But Not Reproductive Output In A Capital-Income Breeding Seaduck, Holly L. Hennin, Pierre Legagneux, H. Grant Gilchrist, Joël Bêty, John P. Mcmurtry, Oliver P. Love

Great Lakes Institute for Environmental Research Publications

To invest in energetically demanding life history stages, individuals require a substantial amount of resources. Physiological traits, particularly those related to energetics, can be useful for examining variation in life history decisions and trade-offs because they result from individual responses to environmental variation. Leptin is a protein hormone found in mammals that is proportional to the amount of endogenous fat stores within an individual. Recently, researchers have confirmed that a mammalian leptin analogue (MLA), based on the mammalian sequence of leptin, is present with associated receptors and proteins in avian species, with an inhibitory effect on foraging and body mass …


L-Tryptophan Adsorption Differentially Changes The Optical Behaviour Of Pseudo-Enantiomeric Cysteine-Functionalized Quantum Dots: Towards Chiral Fluorescent Biosensors, Faezeh Askari, Abbas Rahdar, John F. Trant Feb 2019

L-Tryptophan Adsorption Differentially Changes The Optical Behaviour Of Pseudo-Enantiomeric Cysteine-Functionalized Quantum Dots: Towards Chiral Fluorescent Biosensors, Faezeh Askari, Abbas Rahdar, John F. Trant

Chemistry and Biochemistry Publications

Water-soluble chiral graphene quantum dots (GQDs) with a strong blue emission were synthesized by covalently immobilizing l-cysteine or d-cysteine onto the GQDs. Either the amine or the thiol group of cysteine was used to make the bond through amide coupling or thiol-ene click chemistry respectively. The functionalized chiral GQDs were the characterized by FT-IR and UV–vis. The enantiomeric pairs exhibit equal but opposite bands in circular dichroism spectra suggesting that there is no difference in the efficacy of conjugation. The fluorescent response of these chiral GQDs when exposed to l-tryptophan was then studied. The fluorescence of the amide-conjugated GQDs was …


Biogeochemical Characterization Of Metal Behavior From Novel Mussel Shell Bioreactor Sludge Residues, Sara C. Butler, James Pope, Subba Rao Chaganti, Daniel D. Heath, Christopher G. Weisener Jan 2019

Biogeochemical Characterization Of Metal Behavior From Novel Mussel Shell Bioreactor Sludge Residues, Sara C. Butler, James Pope, Subba Rao Chaganti, Daniel D. Heath, Christopher G. Weisener

Great Lakes Institute for Environmental Research Publications

Acid mine drainage (AMD) remediation commonly produces byproducts which must be stored or utilized to reduce the risk of further contamination. A mussel shell bioreactor has been implemented at a coal mine in New Zealand, which is an effective remediation option, although an accumulated sludge layer decreased efficiency which was then removed and requires storage. To understand associated risks related to storage or use of the AMD sludge material, a laboratory mesocosm study investigated the physio-chemical and biological influence in two conditions: anoxic storage (burial deep within a waste rock dump) or exposure to oxic environments (use of sludge on …


Behavioural And Morphological Changes In Fish Exposed To Ecologically Relevant Boat Noises, Megan F. Mickle, Christopher M. Harris, Oliver P. Love, Dennis M. Higgs Jan 2019

Behavioural And Morphological Changes In Fish Exposed To Ecologically Relevant Boat Noises, Megan F. Mickle, Christopher M. Harris, Oliver P. Love, Dennis M. Higgs

Great Lakes Institute for Environmental Research Publications

There is increasing concern about the effect of underwater noise on fish due to rising levels of anthropogenic noise. We performed experiments on the black bullhead (Ameiurus melas), a species with known hearing specializations and located within the Laurentian Great Lakes where there is considerable commercial and recreational boat traffic. We tested and compared physiology (baseline cortisol), behaviour (activity, sheltering), and morphology (ciliary bundles of hair cells) of bullhead to boat noise. At 140 dB re 1 μPa (−54.84 dB re 1 m·s−2), we saw clear behavioural effects in terms of both activity and sheltering levels despite no obvious morphological …


Baseline Corticosterone Does Not Reflect Iridescent Plumage Traits In Female Tree Swallows, Keneth Sarpong, Christine L. Madliger, Christopher M. Harris, Oliver P. Love, Stéphanie M. Doucet, Pierre Paul Bitton Jan 2019

Baseline Corticosterone Does Not Reflect Iridescent Plumage Traits In Female Tree Swallows, Keneth Sarpong, Christine L. Madliger, Christopher M. Harris, Oliver P. Love, Stéphanie M. Doucet, Pierre Paul Bitton

Great Lakes Institute for Environmental Research Publications

The production of high quality secondary sexual traits can be constrained by trade-offs in the allocation of energy and nutrients with other metabolic activities, and is mediated by physiological processes. In birds, the factors influencing male plumage quality have been well studied; however, factors affecting female plumage quality are poorly understood. Furthermore, it remains uncertain which physiological traits mediate the relationship between body condition and ornaments. In this three-year study of after-second-year female tree swallows (Tachycineta bicolor), we investigated (1) the relationship between baseline corticosterone near the end of the brood-rearing period (CORTBR) and feather colour characteristics (hue, saturation, brightness) …


Synthesis, Physical Characterization, Antifungal And Antibacterial Activity Of Oleic Acid-Capped Nanomagnetite And Cobalt-Doped Nanomagnetite, Abbas Rahdar, Hamid Beyzaei, Mohsen Saadat, Xiao Yu, John F. Trant Jan 2019

Synthesis, Physical Characterization, Antifungal And Antibacterial Activity Of Oleic Acid-Capped Nanomagnetite And Cobalt-Doped Nanomagnetite, Abbas Rahdar, Hamid Beyzaei, Mohsen Saadat, Xiao Yu, John F. Trant

Chemistry and Biochemistry Publications

Nanoparticles, 10-14 nm, consisting of either Fe3O4 or Co0.2Fe2.8O4 stabilized with oleic acid, were prepared using solution combustion. Their structural and magnetic properties were examined using X-ray diffractometry, scanning electron microscopy, vibrating sample magnetometry, and Fourier-transform infrared spectroscopy. The properties of both sets of materials are similar except the cobalt-doped particles are considerably less magnetic. The in vitro inhibitory activities of the nanoparticles were assessed against pathogenic bacteria Shigella dysenteriae, Klebsiella pneumoniae, Acinetobacter baumannii, Streptococcus pyogenes, and pathogenic fungi and molds Candida albicans, Fusarium oxysporum and Aspergillus …


Unnatural Amino Acids Improve Affinity And Modulate Immunogenicity: Developing Peptides To Treat Mhc Type Ii Autoimmune Disorders, Daniel Meister, S. Maryamdokht Taimoory, John F. Trant Jan 2019

Unnatural Amino Acids Improve Affinity And Modulate Immunogenicity: Developing Peptides To Treat Mhc Type Ii Autoimmune Disorders, Daniel Meister, S. Maryamdokht Taimoory, John F. Trant

Chemistry and Biochemistry Publications

Many autoimmune diseases, including multiple sclerosis (MS), rheumatoid arthritis (RA), and celiac disease (CD), arise from improper immune system recognition of self or benign peptides as threats. No autoimmune disease currently has a cure. Many treatments suppress the entire immune system to decrease symptom severity. The core molecular interaction underlying these diseases involves specific alleles of the human leukocyte antigen (HLA) receptor hosting the immunodominant peptides associated with the disease (i.e. myelin basic protein, Type II collagen, or α-gliadin) in their binding groove. Once bound, circulating T-cells can recognize the HLA-antigen complex and initiate the complex cascade that forms an …


Chapter 3: The Behaviour Of Vitamin E In Membranes, J. Atkinson, D. Marquardt, T. Harroun Jan 2019

Chapter 3: The Behaviour Of Vitamin E In Membranes, J. Atkinson, D. Marquardt, T. Harroun

Chemistry and Biochemistry Publications

© 2019 The Royal Society of Chemistry. The neutral lipids of the vitamin E family (tocopherols and tocotrienols) are well known antioxidants with -tocopherol (-Toc) being the sole tocopherol retained in mammalian tissues after absorption from the diet. Because of their high hydrophobicity, tocopherols partition easily into biological membranes. The location and dynamic behavior of tocopherols and tocotrienols in phospholipid membranes is essential information for describing the mechanism(s) of action of these molecules. The bilayer orientation and dynamics are central to our comprehension of their action as antioxidants, protecting free radical-induced peroxidation of polyunsaturated phospholipids. Tocopherols and tocotrienols may also …


Vitamin E-Inspired Multi-Scale Imaging Agent, Mikel Ghelfi, Lucas A. Maddalena, Jeffrey A. Stuart, Jeffrey Atkinson, Thad A. Harroun, Drew Marquardt Jan 2019

Vitamin E-Inspired Multi-Scale Imaging Agent, Mikel Ghelfi, Lucas A. Maddalena, Jeffrey A. Stuart, Jeffrey Atkinson, Thad A. Harroun, Drew Marquardt

Chemistry and Biochemistry Publications

© 2018 Elsevier Ltd The production and use of multi-modal imaging agents is on the rise. The vast majority of these imaging agents are limited to a single length scale for the agent (e.g. tissues only), which is typically at the organ or tissue scale. This work explores the synthesis of such an imaging agent and discusses the applications of our vitamin E-inspired multi-modal and multi-length scale imaging agents TB-Toc ((S,E)-5,5-difluoro-7-(2-(5-((6-hydroxy-2,5,7,8-tetramethylchroman-2-yl) methyl) thiophen-2-yl) vinyl)-9-methyl-5H-dipyrrolo-[1,2-c:2’,1’-f][1,3,2]diazaborinin-4-ium-5-uide). We investigate the toxicity of TB-Toc along with the starting materials and lipid based delivery vehicle in mouse myoblasts and fibroblasts. Further we investigate the uptake …


Recent Advances In The Application Of Carbohydrates As Renewable Feedstocks For The Synthesis Of Nitrogen-Containing Compounds, S. Iraj Sadraei, Brent St Onge, John F. Trant Jan 2019

Recent Advances In The Application Of Carbohydrates As Renewable Feedstocks For The Synthesis Of Nitrogen-Containing Compounds, S. Iraj Sadraei, Brent St Onge, John F. Trant

Chemistry and Biochemistry Publications

Carbohydrates, in the form of chitin, chitosan and cellulose, are one of the most available, renewable, and sustainable chemical feedstocks. Their conversion to biofuels, fine chemicals, and industrially-relevant monomers is becoming increasingly viable and promising as innovation decreases the price of this technology, and climate change and the price of fossil fuels increases the social and economic costs of using traditional feedstocks. In recent years, carbohydrates have been increasingly used as sources for nitrogen-containing fine chemicals. This chapter, with 86 references, provides a brief overview of the conversion of carbohydrate biomass to the standard hydrocarbon and oxygen-containing derivatives, and then …


Monarch Butterfly Conservation Through The Social Lens: Eliciting Public Preferences For Management Strategies Across Transboundary Nations, Rodrigo Solis-Sosa, Christina A.D. Semeniuk, Sergio Fernandez-Lozada, Kornelia Dabrowska, Sean Cox, Wolfgang Haider Jan 2019

Monarch Butterfly Conservation Through The Social Lens: Eliciting Public Preferences For Management Strategies Across Transboundary Nations, Rodrigo Solis-Sosa, Christina A.D. Semeniuk, Sergio Fernandez-Lozada, Kornelia Dabrowska, Sean Cox, Wolfgang Haider

Great Lakes Institute for Environmental Research Publications

The monarch butterfly (Danaus plexippus), an iconic species that migrates annually across North America, has steeply declined in numbers over the past decade. Across the species’ range, public, private, and non-profit organizations aim to reverse the monarch decline by engaging in conservation activities such as habitat restoration, larvae monitoring, and butterfly tagging. Urban residents can actively participate in these activities, yet their contribution can also be realized as an electorate body able to influence the design of conservation programs according to their interests. Little is known, however about their preferences toward the objectives and design of international monarch conservation policies. …


Responses Of Phytoplankton Assemblages To Iron Availability And Mixing Water Masses During The Spring Bloom In The Oyashio Region, Nw Pacific, T. Isada, A. Hattori-Saito, H. Saito, Y. Kondo, J. Nishioka, K. Kuma, H. Hattori, R. M.L. Mckay, K. Suzuki Jan 2019

Responses Of Phytoplankton Assemblages To Iron Availability And Mixing Water Masses During The Spring Bloom In The Oyashio Region, Nw Pacific, T. Isada, A. Hattori-Saito, H. Saito, Y. Kondo, J. Nishioka, K. Kuma, H. Hattori, R. M.L. Mckay, K. Suzuki

Great Lakes Institute for Environmental Research Publications

Spring phytoplankton blooms play a major role in the carbon biogeochemical cycle of the Oyashio region, western subarctic Pacific, where the seasonal biological drawdown effect on seawater pCO 2 is one of the greatest among the world's oceans. However, the bloom often terminates before depleting macronutrients, and the initiation and magnitude of the bloom is heterogeneous. We conducted a high resolution taxonomic and physiological assessment of phytoplankton in relation to the different physicochemical water masses of Coastal Oyashio Water (COW), Oyashio water (OYW), and modified Kuroshio water (MKW) in the Oyashio region from April to June 2007. Massive diatom blooms …