A 9000-Year Old Wapiti (Cervus elaphus) Skeleton from Northern Alberta, and its Implications for the Early Holocene Environment

A complete and fully articulated adult male wapiti (Cervus elaphus) skeleton was recovered from the 50 m terrace of Smoky River, near Watino, Alberta. A collagen-based date on antler gave an age of 9075 ± 305 yr BP (S-2614). The local terrace sequence features three benches, and two previously described fossil sites are placed within it. The importance of the find is that it indicates an environment at 9000 yr BP similar to the present. A brief review of local deglaciation precedes discussion of the paleontology.Un squelette complet et entièrement articulé d'un wapiti adulte a été retiré de la terrasse de 50 m de la rivière Smoky, près de Watino, en Alberta. Le collagène du bois de l'animal a fourni une datation au radiocarbone de 9075 ± 305 BP (S-2614). La série de terrasses locales présente trois niveaux, et deux sites de fossiles déjà décrits auparavant y sont reliés. Les restes de l'animal démontrent que le milieu était, il y a environ 9000 ans, semblable à celui d'aujourd'hui. On présente également un bref compte rendu de la déglaciation locale

An Empirical Analysis of the Equal Credit Opportunity Act

This article will first examine the legislative history of the ECOA to discover (1) the impetus for its enactment; (2) the views of proponents and opponents of the legislation concerning the presence of credit discrimination, its proper cure, and the proposed provisions of the bills introduced to deal with the problem; and (3) the congressional intent as to the use of various credit-granting factors described by the Act. Regulation B will then be similarly examined to find out how the broad mandates of the ECOA have been made concrete for the use of creditors. Finally, the article will focus on a nationwide survey of consumers conducted by the Survey Research Center of the University of Michigan, concentrating on questions which probe credit refusals and the perceived reasons for such refusals. The article will fully describe the survey as well as the model and statistical techniques used to interpret the survey results. Those results will be utilized to suggest changes in the ECOA and Regulation B so that they better reflect the public policy dictated by Congress

Dynamic modeling and monitoring of bridge decks

Abstract available (p. iii

Milena : March and Two Step

https://digitalcommons.library.umaine.edu/mmb-ps/1341/thumbnail.jp

Synthesis and characterisation of star polymers

The objective of this thesis was to investigate the synthesis of well defined star polymers utilising controlled radical polymerisation techniques for potential use as viscosity modifiers in Engine oils. Recent developments in the characterisation of star polymers using multi-detector GPC was investigated by first synthesising a series of star polymers using a core-first technique and ATRP. Core-first initiators were used to initiate the polymerisation of PMMA star polymers which were then analysed using multi-detector GPC. Using Zimm and Stockmayer theory the functionality, f, (number of arms) of the resultant star polymer was estimated over the MWD of the polymer using GPC with in-line viscometry. A variation in functionality with molecular weight was seen, which disagrees with the limited other literature in the field. The GPC technique was then used to determine the functionality of star polymers synthesised using RAFT polymerisation and an arm-first technique to yield star PMMA with a high Mw and PDI. Varying the divinyl species and the ratio of [crosslinker] to [macroRAFT agent] was seen to control the functionality and molecular weight of the star formed. Varying the amount of monomer present at the point of crosslinking was seen to have little contribution to the star polymer formed when the ratio of [MMA] to [macroRAFT agent] was under 10. Switching RAFT agents from 2-cyanoprop-2yl dithiobenzoate (CPDB) to an oil soluble trithiocarbonate, for the RAFT polymerisation of long chain alkyl methacrylate gave hybrid polymerisation kinetics. Through a monomer feed system, controlling the ratio of [monomer] to [RAFT agent] throughout the reaction, polymers of narrow PDI were synthesised and subsequently crosslinked to form oil soluble star polymers. Applying the techniques used for the synthesis of core-crosslinked star polymers using RAFT chemistry to different area of polymer chemistry, glycopolymers; a series of linear mannose and galactose bearing glycopolymers have been synthesised. Trimethylsilyl propargyl methacrylate (TMSPgMA) has been polymerised to varying DP, between 20 and 200, using CPDB as the RAFT agent. Subsequent deprotection of the propargyl groups has yielded a series of alkyne bearing linear polymers. Using a CuAAC reaction to "click" mannose and galactose azide to the polymer scaffolds yielded well defined sugar bearing polymers. A P(TMSPgMA) macroRAFT agent was crosslinked using different crosslinkers to giving a high molecular weight, alkyne bearing, star polymer

A detailed study on understanding glycopolymer library and Con A interactions

Synthetic glycopolymers are important natural oligosaccharides mimics for many biological applications. To develop glycopolymeric drugs and therapeutic agents, factors that control the receptor-ligand interaction need to be investigated. A library of well-defined glycopolymers has been prepared by the combination of copper mediated living radical polymerization and CuAAC click reaction via post-functionalization of alkyne-containing precursor polymers with different sugar azides. Employing Concanavalin A as the model receptor, we explored the influence of the nature and densities of different sugars residues (mannose, galactose, and glucose) on the stoichiometry of the cluster, the rate of the cluster formation, the inhibitory potency of the glycopolymers, and the stability of the turbidity through quantitative precipitation assays, turbidimetry assays, inhibitory potency assays, and reversal aggregation assays. The diversities of binding properties contributed by different clustering parameters will make it possible to define the structures of the multivalent ligands and densities of binding epitopes tailor-made for specific functions in the lectin-ligand interaction. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2588–259

Complex Adaptive Systems, Agent-Based Modeling and Information Assurance

Management of information security issues can be viewed as a complex adaptive system in that hackers are constantly developing new means of trying to penetrate security systems and access information assets. Organizational must adapt too these threats by updating security procedures and systems and by training employees in what must be done to counteract new threats. We present agent-based models that illustrate “phishing” problems, and General Deterrence Theory and Protection Motivation Theory and their application to IA problems. These models are written in Netlogo, an open-source agent-based modeling system, and are freely available for education and training in IA

Understanding corrosion features and alloy microstructural effects on fatigue initiation of corroded AA7050-T7451 using data science

Aluminum alloy 7050-T451 is generally used in aerospace structure due to its high strength-to-weight ratio and high toughness. Local galvanic coupling set up by wicking of electrolyte in between the stainless steel fastener used in the aircrafts and the aluminum substructure promote corrosion of AA7050-T7451. Fatigue crack initiation tend to occur on discontinuities in the aluminum alloy such as the corrosion damage created by the galvanic coupling. Previous study indicate that the individual metrics analyzed for the macro-scale (\u3e250 μm) corrosion features such as pit depth, pit density, pit volume, area of the pit mouth, do not fully correlate to the location of the fatigue crack initiation [1]. The objective of this study is to verify if there is an interaction effect on the metrics analyzed using the macro-scale corrosion damage features using data science techniques. Another objective of this study is to determine if the micro-scale (\u3c250 μm) corrosion features and the alloy microstructure play an important role in the fatigue initiation mechanism of AA7050-T7451. In order to understand the mechanism governing the fatigue crack formation, corrosion damage mimicking the galvanic coupling effect of AA7050-T7451 and SS316 are artificially created on the surface of AA7050-T7451. A small area on the LS surface of the fatigue specimens are exposed to different environmental conditions to create four different corrosion morphologies, namely, shallow and deep discrete pits, fissures and general corrosion with surface recession. These corrosion morphologies are characterized using the optical microscope, white light interferometer, scanning electron microscope and X-ray computed tomography. The specimens are subjected to fatigue loading using a special loading protocol that creates marker bands on the fracture surface. The specimens are cyclically loaded along the L-direction with σmax of 200 MPa, R ratio of 0.5 at a frequency of 20 Hz. The fatigue testing is done at 23°C and a controlled moist environment with \u3e90% relative humidity during the entire test. After fatigue testing, the fractographs of the specimens are obtained using the SEM. The marker bands from these fractographs are analyzed to calculate the crack growth rate and the fatigue initiation life to create a 10 μm crack from the initiation point are estimated. Data science approaches are employed to analyze the interaction effect of the individual metrics reported in the macro-scale corrosion feature analysis. Random forest and logistic regression modeling show that there is minimal significance between the macro-scale corrosion feature predictor variables and the fatigue crack initiation points. Even though data science indicate that these factors have less significance, these factors should not be neglected. The micro-scale corrosion features and the distribution of secondary phase particles as well as the grain character are individually analyzed and correlated to the location of the fatigue crack initiation for all the corrosion damage morphologies. Results show that these individual metrics does not fully dictate the location of the fatigue crack initiation. Future work of this study involves the use of data science techniques to understand the relationship between the micro-scale corrosion features, their possible interaction with the alloy microstructure, and the fatigue crack formation. This study will provide understanding on what governs the fatigue crack initiation and inform current micro-mechanical models to incorporate effects of pertinent parameters in predicting remaining life of corroded specimens. Reference: [1] Co NEC, Burns JT. Effects of macro-scale corrosion damage feature on fatigue crack initiation and fatigue behavior. Int J Fatigue 2017;103:234–47. doi:10.1016/j.ijfatigue.2017.05.028

Characteristics of GaInNAsSb VCSELs operating near 1.55µm

A detailed study of the high-power pulsed operation of C-band optically-pumped GaInNAsSb vertical cavity surface emitting lasers is reported. The devices employ a resonant periodic gain structure grown by molecular beam epitaxy on a GaAs substrate with a 31-pair GaAs/AlAs bottom distributed Bragg reflector and a 4-λ, GaAs-based resonant cavity containing 10 GaInNAsSb quantum wells distributed among the 7 antinodes of the electric field. A dual-pump-band SiO2/TiO2 dielectric top mirror allows efficient optical pumping via low reflectivities at 808nm and 1064nm while providing very high reflectivity at the 1.55μm target emission wavelength. The laser characteristics were evaluated using both a Q-switched Nd:YAG 1064nm pump and a 20W-peak 180ns-pulsed 850nm diode laser. The importance of the gain-cavity detuning was evident from time-dependent spectral measurements of laser material subjected to post-growth annealing at different temperatures between 725 and 775°C. The highest annealing temperature produces the largest blue shift of the gain peak relative to the cavity resonance, resulting in the best power transfer characteristics as well as reduced temperature sensitivity

Automatic Thoughts and Cognitive Restructuring in Cognitive Behavioral Group Therapy for Social Anxiety Disorder

The goal in (Heimberg, R. G. [1991]. A manual for conducting Cognitive Behavior Group Therapy for social phobia (2nd ed.), unpublished manuscript) cognitive behavioral group therapy (CBGT) for social anxiety disorder (social phobia) is to challenge irrational automatic thoughts and create exposures to provide disconfirming evidence for these irrational thoughts as well as habituation to fearful stimuli. Yet little is known about the types of thoughts reported by socially anxious individuals in therapy or which thoughts therapists select for cognitive restructuring in CBGT sessions. The present study analyzed the semantic content of automatic thoughts reported in CBGT and found that the most common thoughts related to poor social performance, negative labels by others, and the anticipation of negative outcomes in feared situations. Principle components analyses indicated the automatic thoughts reflected three underlying themes: Experiencing Anxiety, Negative Self-Evaluation, and Fear of Negative Evaluation. The paper also describes exploratory analyses of which thoughts became the focus of cognitive restructuring exercises and their relationship to treatment outcome. Implications for cognitive therapy are also discussed