Physical Sciences and Mathematics Commons^™

Vitamin E Circular Dichroism Studies: Insights Into Conformational Changes Induced By The Solvent’S Polarity, Drew Marquardt, Brad J. Van Oosten, Mikel Ghelfi, Jeffrey Atkinson, Thad A. Harroun

Chemistry and Biochemistry Publications

We used circular dichroism (CD) to study differences in CD spectra between α-, δ-, and methylated-α-tocopherol in solvents with different polarities. CD spectra of the different tocopherol structures differ from each other in intensity and peak locations, which can be attributed to chromanol substitution and the ability to form hydrogen bonds. In addition, each structure was examined in different polarity solvents using the Reichardt index—a measure of the solvent’s ionizing ability, and a direct measurement of solvent–solute interactions. Differences across solvents indicate that hydrogen bonding is a key contributor to CD spectra at 200 nm. These results are a first …

Use Of Solid N2 Surfaces In Metastable Particle Detection, Wladyslaw Kedzierski, J. W. Mcconkey

Physics Publications

A novel detector is described in which solid nitrogen at 17 K is used as the most significant element. Metastable particles impinge on this element and immediately transfer their internal energy to the solid nitrogen producing photons, via excimer formation or otherwise, whose wavelength depends on the metastable being detected and the energy transfer process. The performance of the instrument for the detection of atomic oxygen and molecular nitrogen metastables is discussed.

Combined Bulk-Rock Hf- And Nd-Isotope Compositions Of Mesoarchaean Metavolcanic Rocks From The Ivisaartoq Supracrustal Belt, Sw Greenland: Deviations From The Mantle Array Caused By Crustal Recycling, Ali Polat

Earth & Environmental Sciences Publications

Bulk-rock Lu-Hf and Sm-Nd isotope compositions, as well as major and trace element data are presented for metavolcanic rocks from the Mesoarchaean (ca. 3075 Ma) Ivisaartoq Supracrustal Belt in the Nuuk region of southern West Greenland. The εHf_t calculated at 3075 Ma range from +0.8 to +3.1 and the corresponding εNd_t values range from +0.7 to +3.6, which forms an array that is displaced off the mantle array for these two isotopic systems. Primitive mantle normalized trace element plots of the metabasalts display negative Nb- and Ti-anomalies in combination with the elevated Th abundances, which is consistent with …

Lithological, Structural, And Geochemical Characteristics Of The Mesoarchean Târtoq Greenstone Belt, South-West Greenland, And The Chugach-Prince William Accretionary Complex, Southern Alaska: Evidence For Uniformitarian Plate-Tectonic Processes, Ali Polat

Earth & Environmental Sciences Publications

The Mesoarchean Târtoq greenstone belt, South-West Greenland, consists of tectonically imbricated slices of metamorphosed basalt, gabbro, peridotite and sedimentary rocks, and is intruded by felsic rocks (now mylonites) with well-preserved duplex structures, representing a relict accretionary prism. The Târtoq greenstone belt is a remnant of a supra-subduction zone ophiolite that originated as back-arc basin oceanic crust. Following the initiation of intra-oceanic subduction, the back-arc oceanic crust accreted to the overriding plate, forming an accretionary prism. The felsic mylonites are compositionally akin to Archean tonalite-trondhjemite-granodiorite suites (TTG). Field observations, along with geochemical and zircon U-Pb age data, indicate that the protoliths …

Two Giants Of Geology: Kevin Charles Anthony Burke And John Frederic Dewey, Ali Polat

Earth & Environmental Sciences Publications

This special issue of the Canadian Journal of the Earth Sciences celebrates the career of two of the greatest geologists of our time, who, during the last three decades of the 20th and the first decade of the 21st century, have put their stamp on the tectonic interpretation of the Earth’s behaviour (Burke also extended his efforts into extra-terrestrial space). How fortunate it is for geology that they are both still active and, by all appearances, are likely to remain so for some time to come. It is an immense honour for us as their students and fellow geologists to …

Morphology-Induced Defects Enhance Lipid Transfer Rates, Yan Xia, Kamil Charubin, Drew Marquardt, Frederick A. Heberle, John Katsaras, Jianhui Tian, Xiaolin Cheng, Ying Liu, Mu Ping Nieh

Chemistry and Biochemistry Publications

Molecular transfer between nanoparticles has been considered to have important implications regarding nanoparticle stability. Recently, the interparticle spontaneous lipid transfer rate constant for discoidal bicelles was found to be very different from spherical, unilamellar vesicles (ULVs). Here, we investigate the mechanism responsible for this discrepancy. Analysis of the data indicates that lipid transfer is entropically favorable, but enthalpically unfavorable with an activation energy that is independent of bicelle size and long- to short-chain lipid molar ratio. Moreover, molecular dynamics simulations reveal a lower lipid dissociation energy cost in the vicinity of interfaces ("defects") induced by the segregation of the long- …

Geochemistry, Nd, Pb And Sr Isotope Systematics, And U-Pb Zircon Ages Of The Neoarchean Bad Vermilion Lake Greenstone Belt And Spatially Associated Granitic Rocks, Western Superior Province, Canada., Ali Polat

Earth & Environmental Sciences Publications

The ca. 2720 Ma Neoarchean Bad Vermilion Lake (BVL) greenstone belt, in the western Superior Province, Canada, is composed of a suite of tholeiitic to calc-alkaline basalts to rhyolites, volcaniclastic rocks, gabbros, and Timiskaming-type siliciclastic sedimentary rocks. The greenstone belt was intruded by Neoarchean granitic rocks, and underwent greenschist facies metamorphism and intense deformation, resulting in mobilization of many elements (e.g., Rb, Ba, Sr, K, U, Pb).

The high-field strength element and rare earth element systematics of the volcanic and volcaniclastic rocks, and gabbros are consistent with subduction zone geochemical signatures, suggesting that the BVL greenstone belt formed in a …

Cholesterol's Location In Lipid Bilayers, Drew Marquardt, Norbert Kučerka, Stephen R. Wassall, Thad A. Harroun, John Katsaras

Chemistry and Biochemistry Publications

It is well known that cholesterol modifies the physical properties of lipid bilayers. For example, the much studied liquid-ordered Lo phase contains rapidly diffusing lipids with their acyl chains in the all trans configuration, similar to gel phase bilayers. Moreover, the Lo phase is commonly associated with cholesterol-enriched lipid rafts, which are thought to serve as platforms for signaling proteins in the plasma membrane. Cholesterol's location in lipid bilayers has been studied extensively, and it has been shown – at least in some bilayers – to align differently from its canonical upright orientation, where its hydroxyl group is in the …

Insights From Molecular Dynamics On Substrate Binding And Effects Of Active Site Mutations In Delta1-Pyrroline-5-Carboxylate Dehydrogenase, Bogdan F. Ion, Mohamed M. Aboelnga, James W. Gauld

Chemistry and Biochemistry Publications

The NAD+-dependent enzyme, 1-pyrroline-5-carboxylate dehydrogenase (P5CDH), has an important role in proline and hydroxyproline catabolism for humans. Specifically, this aldehyde dehydrogenase is responsible for the oxidation of both L-glutamate- -semialdehyde (GSA) and 4-erythro-hydroxy-L-glutamate- -semialdehyde (4-OH-GSA) to their respective L-glutamate product forms. We have performed a detailed molecular dynamics (MD) study of both the reactant and product complex structures of P5CDH to gain insights into ligand binding (i.e., GSA, 4-OH-GSA, NAD+, GLU) in the active site. Moreover, our investigations were further extended to examine the structural impact of S352L, S352A, and E314A mutations on the deficiency in the P5CDH enzymatic activity. …

Elastomers: Reinventing Butyl Rubber For Stretchable Electronics (Adv. Funct. Mater. 29/2016), Akhil Vohra, Heather L. Filiatrault, Stanley D. Amyotte, R. Stephen Carmichael, Natalie D. Suhan, Conrad Siegers, Lorenzo Ferrari, Gregory J.E. Davidson, Tricia Breen Carmichael

Chemistry and Biochemistry Publications

No abstract provided.

Selective Detection Of Singlet Gerade Metastable States Of N-2, Wladyslaw Kedzierski, J. W. Mcconkey

Physics Publications

Metastable N-2 molecules produced by electron impact on N2 are detected using a unique solid nitrogen matrix detector. The time-of-flight system is shown to be selectively sensitive to a(1)Pi(g) and (1)Sigma(+)(g) or (1)Gamma(g) metastable species. The latter species had been identified theoretically previously but was detected experimentally for the first time in the present investigation. Their identification and excitation as a function of electron energy from threshold to 300 eV are presented. Comparison is made with the data obtained by other techniques. Published by AIP Publishing.

Polyisobutylene-Paclitaxel Conjugates With Pendant Carboxylic Acids And Polystyrene Chains: Towards Multifunctional Stent Coatings With Slow Drug Release, John F. Trant, Mahmoud M. Abd Rabo Moustafa, Inderpreet Sran, Elizabeth R. Gillies

Chemistry and Biochemistry Publications

Drug-eluting stents are used in the treatment of atherosclerosis, where the incorporation of anti-proliferative or anti-inflammatory drugs decreases the rate of restenosis, the recurrence of artery narrowing. However, these stents can suffer from limitations such as drug depletion and delamination of the drug-eluting coating from the stent surface. Described here is an approach aimed at addressing these issues. Starting from a maleic anhydride adduct of polyisobutylene (PIB) prepared from butyl rubber, ring opening using paclitaxel (PTX) or a combination of PTX and polystyrene (PS) afforded covalent conjugates of PTX and PIB or PIB-PS graft copolymers bearing pendant carboxylic acids. When …

Geochemistry And Geochronology Of Mylonitic Metasedimentary Rocks Associated With The Proterozoic Miaowan Ophiolite Complex, Yangtze Craton, China: Implications For Geodynamic Events, Ali Polat

Earth & Environmental Sciences Publications

Constraining the timing of tectonothermal events in the Proterozoic Miaowan Ophiolite Complex (MOC) and associated rocks in the southern Huangling dome, Yangtze craton, is critical for understanding late Mesoproterozoic and Neoproterozoic tectonic evolution (ca. 1.2–0.9 Ga) of South China and its relationship with the formation of the Rodinian supercontinent. The MOC consists of metamorphosed dunite and harzburgite, isotropic and layered gabbros, diabasic sheeted dike, basalt, plagiogranite, and calc-silicatebearing siliceous and carbonaceous mylonitic rocks. In this study, we present new field, petrographic, geochemical, geochronological and isotopic data for these metasedimentary rocks and mylonitic metasandstone between the ophiolite and underlying flysch sequence, …

Great Lakes Focus On Water Quality: Vol.4 Iss.3, Uwindsor Administrator

Focus on International Joint Commission Activities

In October and November the Pollution from Land Use Activities Reference Group (PLUARG) will sponsor information meetings throughout the Great Lakes Basin. The purposes of the sessions are to present the PLUARG final report, Environmental Management Strategy for the Great Lakes System, with its conclusions and recomendations (See PLUARG write up, page 6), explain the IJC's hearing process, and encourage people to present their views on the report to the Commission on Public Hearings.

Vuv Study Of Electron Impact Dissociative Excitation Of Thymine, C. J. Tiessen, J. A. Trocchi, J. D. Hein, J. Dech, Wladyslaw Kedzierski, J. W. Mcconkey

Physics Publications

Dissociative excitation of thymine following electron impact was studied in the energy range up to 430 eV. Emissions in the vacuum ultra-violet spectral region below 150 nm were studied and found to be dominated by the hydrogen Lyman series. Emission cross section data reveal that Lyman-α excitation displays a broad maximum at an electron impact energy of 160 eV. The probability of extracting other excited atoms from the parent molecule is found to be insignificant. Possible excitation and dissociation mechanisms in the parent molecule are discussed.

Deliberation, Practical Reasoning And Problem-Solving, Douglas Walton, Alice Toniolo

OSSA Conference Archive

We present a series of realistic examples of deliberation and discuss how they can form the basis for building a typology of deliberation dialogues. The observations from our examples are used to suggest that argumentation researchers and philosophers have been thinking about deliberation in overly simplistic ways. We argue that to include all the kinds of argumentation that make up realistic deliberations, it is necessary to distinguish between different kinds of deliberations. We propose a model including a problem-solving type of deliberation based on practical reasoning, characterised by revisions of the initial issue made necessary by the agents’ increased knowledge …

Exploring Argumentation, Objectivity, And Bias: The Case Of Mathematical Infinity, Ami Mamolo

OSSA Conference Archive

This paper presents an overview of several years of my research into individuals’ reasoning, argumentation, and bias when addressing problems, scenarios, and symbols related to mathematical infinity. There is a long history of debate around what constitutes “objective truth” in the realm of mathematical infinity, dating back to ancient Greece (e.g., Dubinsky et al., 2005). Modes of argumentation, hindrances, and intuitions have been largely consistent over the years and across levels of expertise (e.g., Brown et al., 2010; Fischbein et al., 1979, Tsamir, 1999). This presentation examines the interrelated complexities of notions of objectivity, bias, and argumentation as manifested in …

Argumentation Mining In Parliamentary Discourse, Nona Naderi

OSSA Conference Archive

In parliamentary discourse, politicians expound their beliefs and goals through argumentation, and, to persuade the audience, they communicate their values by highlighting some aspect of an issue, an action which is commonly known as framing. The choices of frames are typically dependent upon the speaker’s ideology.

In this proposed doctoral work, we will computationally analyze framing strategies and present a model for discovering the latent structure of framing of real-world issues in Canadian parliamentary discourse.

Formation Of The Neoarchean Bad Vermilion Lake Anorthosite Complex And Spatially Associated Granitic Rocks At A Convergent Plate Margin, Superior Province, Western Ontario, Canada, Ali Polat, Shuda Zhou, Fred J. Longstaffe, Kunguang Yang, Brian J. Fryer, Chris Weisener

Earth & Environmental Sciences Publications

The Bad Vermilion Lake Anorthosite Complex (henceforth, the BVLA Complex) in western Ontario is one of the well-exposed, anorthosite-bearing, Archean layered intrusions in the Superior Province, Canada. This study presents new whole-rock major and trace element data for the various units of the Complex, oxygen isotope data for the anorthosite, and major and trace element data for the spatially associated granitic rocks intruding the BVLA Complex to constrain their petrogenetic and geodynamic origin. Zircons from granitic rocks have yielded a ²⁰⁷Pb/²⁰⁶Pb age of 2716 ± 18 Ma, constraining the minimum intrusion age of the Complex.

Despite deformation …

Lithospheric Mantle Xenoliths Sampled By Melts From Upwelling Asthenosphere: The Quaternary Tasse Alkaline Basalts Of Southeastern British Columbia, Canada, Ali Polat, Eyal Friedman, Derek J. Thorkelson, Robert Frei

Earth & Environmental Sciences Publications

The Tasse basalts are exposed near the north shore of Quesnel Lake in southeastern British Columbia. They host a variety of mantle xenoliths consisting predominantly of spinel lherzolite with minor dunite and pyroxenite. Mineralogically, the xenoliths are composed of olivine, orthopyroxene, clinopyroxene and spinel characterized by forsterite (Fo_87-93), enstatite (En_90-92), diopside (En_45-50-Wo_40-45-Fs₅), and Cr-spinel (6−11 wt. % Cr), respectively. All of the mantle xenoliths are coarse-grained and show granoblastic textures. Clinopyroxene and spinel display textural evidence for chemical reactions with percolating melts.

The mantle xenoliths are characterized by restricted Mg-numbers …

Focus On International Joint Commission Activities (Issn 0832-6673): Vol.19 Iss.3, Uwindsor Administrator

Focus on International Joint Commission Activities

Enlightened public opinion ultimately set things right in the Reserve Mining case. Following US. District Judge Miles Lord’s order of April 20, 1974 to cease all taconite tailings discharge to Lake Superior, it took much additional effort by the State of Minnesota, intervening environmental groups and the US. Government to stop the 25-year dumping of hundreds of millions of tons of tailings into the world’s fresh- water treasure. It finally happened in the spring of 1980

Focus On International Joint Commission Activities (Issn 0832-6673): Vol.19 Iss.2, Uwindsor Administrator

Focus on International Joint Commission Activities

The glacial history of the Great Lakes basin and the tremendous influence of the lakes themselves create unique conditions. These support a wealth of biological diversity, including many species and communities of global significance. The basin’s sand dunes, coastal marsh- es, rocky shorelines, lakeplain prairies, savannas, forests, fens and other landscapes contain features that are either unique to or are best represented with- in the Great Lakes basin. The remark- able biodiversity of the Great Lakes basin is illustrated by the Indiana Dunes National Lakeshore. This park ranks third among US. National Parks in plant diversity, yet its area is …

Focus On International Joint Commission Activities (Issn 0832-6673): Vol.19 Iss.1, Uwindsor Administrator

Focus on International Joint Commission Activities

In its Seventh Biennial Report on Great Lakes Water Quality (signed in 1993), released this February, the International Joint Commission again concludes that contamination by various persistent toxic substances is ' the biggest problem facing the Great Lakes ecosystem. The Governments of the United States and Canada are committed to restoring and protecting the Great Lakes and the Commission’s reports assist them by identifying progress and further needs.

Focus On International Joint Commission Activities (Issn 0832-6673): Vol.18 Iss.3, Uwindsor Administrator

Focus on International Joint Commission Activities

Drawn by a highly Visible recommendation to sunset industrial uses of chlorine, a record-setting 1,900 participants came to the International Joint Commission’s Biennial Meeting on Great Lakes Water Quality in Windsor, Ontario. Participants at the October 21-24, 1993 event also represented a broader spectrum of society than at previous biennial meetings.

Focus On International Joint Commission Activities (Issn 0832-6673): Vol.18 Iss.2, Uwindsor Administrator

Focus on International Joint Commission Activities

Indianapolis started it all in 1983, when 300 people joined the International Joint Commission for its first Biennial Meeting on Great Lakes Water Quality. Kingston was next in 1985, followed by Toledo in 1987, Hamilton in 1989, and Traverse City in 1991, when more than 1,600 people participated in the meeting. Now, ten years later, Windsor will host the International Joint Commission’s 1993 Biennial Meeting on Great Lakes Water Quality. Why does the Commission hold these meetings, what issues are addressed, and how can attendees participate in this year’s sessions ?

Focus On International Joint Commission Activities (Issn 0832-6673): Vol.18 Iss.1, Uwindsor Administrator

Focus on International Joint Commission Activities

The Virtual Elimination Task Force, appointed by the International Joint Commission in the summer of 1990 to recommend a strategy for virtually eliminating the input of persistent toxic substances to the Great Lakes environment, has released its draft final report for public comment.

Focus On International Joint Commission Activities (Issn 0832-6673): Vol.17 Iss.3, Uwindsor Administrator

Focus on International Joint Commission Activities

When the headaches won't disappear or our child has a languishing cough, we Visit our physician to obtain a cure for our ills. As a society, studies Show that North Americans have a high level of trust in the ability of our doctors to identify possible causes and to prescribe the best solution to our ailments. How likely are our doctors to consider pollutants in our environment as a possible cause of our problems ?

Focus On International Joint Commission Activities (Issn 0832-6673): Vol.17 Iss.2, Uwindsor Administrator

Focus on International Joint Commission Activities

In mid-June, Commissioner Hilary Cleveland and Commission staff visited four communities on the north shore of Lake Superior to meet with the local Remedial Action Plan (RAP) teams, Public Advisory Committee (PAC) members, RAP technical re- viewers, local news media and others interested in the cleanup plans in the four North Shore Areas of Concern: Jackfish Bay, Nipigon Bay, Peninsula Harbour and Thunder Bay.

Focus On International Joint Commission Activities (Issn 0832-6673): Vol.17 Iss.1, Uwindsor Administrator

Focus on International Joint Commission Activities

Thus concludes the International Joint Commission in its Sixth Biennial Report on Great lakes Water Quality, released in mid- April on the 20th anniversary of the signing of the Great Lakes Water Quality Agreement. The Commission’s report focuses on persistent toxic sub- stances, and the steps needed to reach the Great Lakes Water Quality Agreement’s goal of virtual elimination of the inputs of these substances to the Great Lakes system.

Focus On International Joint Commission Activities (Issn 0832-6673): Vol.16 Iss.3, Uwindsor Administrator

Focus on International Joint Commission Activities

Representatives from diverse interests came to discuss their concerns with the International Joint Commission and each other at the 1991 Biennial Meeting on Great Lakes Water Quality in Traverse City, Michigan, September 29 through October 2, 1991. Biennial Meetings are held by the Commission before it prepares recommendations to the Governments of the United States and Canada and the Great Lakes state and provincial governments in accordance with the Great Lakes Water Quality Agreement.