1979 Gayle Bonds

1979-1980 Miss Lincoln

A first principles analysis of the effect of hydrogen concentration in hydrogenated amorphous silicon on the formation of strained Si-Si bonds and the optical and mobility gaps

In this paper, we use a model of hydrogenated amorphous silicon generated from molecular dynamics with density functional theory calculations to examine how the atomic geometry and the optical and mobility gaps are influenced by mild hydrogen oversaturation. The optical and mobility gaps show a volcano curve as the hydrogen content varies from undersaturation to mild oversaturation, with largest gaps obtained at the saturation hydrogen concentration. At the same time, mid-gap states associated with dangling bonds and strained Si-Si bonds disappear at saturation but reappear at mild oversaturation, which is consistent with the evolution of optical gap. The distribution of Si-Si bond distances provides the key to the change in electronic properties. In the undersaturation regime, the new electronic states in the gap arise from the presence of dangling bonds and strained Si-Si bonds, which are longer than the equilibrium Si-Si distance. Increasing hydrogen concentration up to saturation reduces the strained bonds and removes dangling bonds. In the case of mild oversaturation, the mid-gap states arise exclusively from an increase in the density of strained Si-Si bonds. Analysis of our structure shows that the extra hydrogen atoms form a bridge between neighbouring silicon atoms, thus increasing the Si-Si distance and increasing disorder in the sample.

Primary Road Bonds, 1950

A brief overview of Iowa's road bonds.

Financial stocks and political bonds: stock market participation and political behavior in the United States and Britain

This dissertation investigates the effect of stock market participation on political behavior. Some observers claim that financial assets—stocks and mutual funds—have a causal effect on political behavior. The “investor class theory” asserts that as people invest in the stock market their partisan attachments shift rightward. The “asset effect theory” claims that financial investments increase political interest and participation. I examine these claims with longitudinal data from the United States and Great Britain covering a twenty-year period from the early 1980s through the mid-2000’s. I also examine the effect of financial asset ownership on political attitudes in the United States during the 2008 stock market crash. I find no evidence to support the argument that stock market participation has any causal effect on partisanship, participation, or political attitudes.

Actualización de los valores corporativos y de los estatutos en la Asociación de Padres Usuarios de Hogares de Bienestar Mis Primeros Amigos en Bogotá

Bogotá (Colombia) : Universidad de La Salle. Facultad de Ciencias Administrativas y Contables. Programa de Administración de Empresas

Articulación de lecciones aprendidas e información de gestión de riesgos para el gerenciamiento de proyectos corporativos del grupo Bancolombia

Las organizaciones adoptan buenas prácticas para el gerenciamiento de proyectos, en donde incorporan procesos para la construcción de lecciones aprendidas y gestión de riesgos, los cuales son vistos como elementos independientes de salida dentro de las diferentes metodologías de proyectos -- Las lecciones aprendidas y el registro de riesgos constituyen una fuente de información que da origen al conocimiento organizacional, y que por lo mismo no pueden considerarse de forma aislada por la estrecha relación que tiene entorno a la generación de conocimiento -- Grandes organizaciones, como el Grupo Bancolombia, carecen de procesos que articulen estas fuentes de conocimiento para que sean considerados realmente como activos organizacionales y no como documentos históricos de los proyectos, y de esta manera generan beneficios para el gerenciamiento de los proyectos

Reverse convertible bonds

I convertible bonds sono degli strumenti finanziari che conferiscono al suo possessore la facoltà di scegliere se, una volta scaduta l'obbligazione, essere rimborsato tramite una somma di denaro (valore nominale) oppure convertire l'obbligazione in un numero predefinito di azioni. Successivamente si è trattato l’argomento della tesi, i reverse convertible bonds. Queste obbligazioni sono simili ai convertible bonds con la differenza che in tal caso il diritto di scegliere se convertire o meno l'obbligazione in azioni è lasciato all'emittente e non al sottoscrittore. I reverse convertible si ottengono dalla combinazione di un coupon bond ordinario (senza l'opzione di conversione) a breve termine e di un'opzione put sulle azioni sottostanti. E' stata analizzata la formula di valutazione dei reverse convertible bonds, data dalla differenza tra il prezzo di un coupon-bond ordinario emesso dalla stessa società e il prezzo di un'opzione put (quest'ultimo moltiplicato per il rapporto di conversione, ossia per il numero di azioni che si ottengono dalla conversione di ciascuna obbligazione convertibile). E’ stata poi fatta un’analisi empirica dei prezzi dei reverse convertible bonds. Sono stati calcolati i prezzi di 7 reverse convertible utilizzando i dati forniti dal database finanziario e macroeconomico, Thomson Reuters Datastream.I prezzi calcolati sono stati poi confrontati con i prezzi di mercato di tali obbligazioni relativamente allo stesso istante temporale, il giorno 6/6/2016.

Young adults’ perceptions of and affective bonds to a rural tourism community

Many rural areas, in Sweden and worldwide, experience population decline where the young leave for education and work in urban areas. Employment has declined in several rural industries, such as agriculture, forestry, and fishing, while growing in other industries are often located in urban areas. Politicians and organizations have put much hope in tourism as a tool of rural development, but can tourism help reverse the rural out-migration trend among young adults? This paper explores how tourism affects young inhabitants’ perceptions of and affective bonds to a rural area in Sweden, the ski resort of Sälen. Students from the 1993–1995 elementary school graduating classes were interviewed about their migration history, childhood, and view of and ties to Sälen. The respondents experience that tourism contributes to a more vital community incorporating influences from elsewhere, but without eliminating the positive aspects of rural life. The regular flow of people – tourists, seasonal workers, and entrepreneurs – passing through Sälen presents opportunities to extend one’s social network that are widely appreciated by respondents. The high in and out mobility constitutes a key part of Sälen’s character. Contributions from tourism – such as employment, entertainment, leisure, and opportunities to forge new social relationships – are available during the adult transition, the life phase when rural areas are often perceived as least attractive. Even though out-migration occurs in Sälen, and some respondents still find Sälen too small, tourism has clearly increased the available opportunities and contributed significantly to making Sälen more attractive to young adults.

Diseño, implementación y seguimiento de estrategias de sensibilización en valores corporativos orientados a la sostenibilidad para el personal administrativo de OMA

Nacional e internacionalmente, la sostenibilidad se ha convertido en el punto clave de las grandes organizaciones, sus actividades y los participantes que se encuentran involucrados. Una empresa es sostenible cuando ha encontrado el equilibrio entre el aspecto económico, social y ambiental, logrando sin lugar a dudas éxito y perdurabilidad en el entorno al que pertenece. Es por esto que el principal objetivo de este proyecto es el diseño e implementación de estrategias de sensibilización en valores corporativos para el personal administrativo de OMA, el cual se enfoca en la creación y desarrollo de actividades que permitan la concientización y cambios en el comportamiento ambiental de los colaboradores de la compañía. A partir de múltiples herramientas como conceptos básicos, normatividad y actividades dinámicas se logró informar y capacitar a los colaboradores de la compañía en temas como la importancia del desarrollo sostenible, política ambiental y prácticas ambientales adecuadas dentro del entorno laboral y sus hogares.

Bidentate N-heterocyclic carbene complex of Manganese as catalyst for hydrosilylation and hydroboration of double and triple bonds

Scopo del presente lavoro di tesi è la sintesi di un complesso di manganese contenente un legante bis N-eterociclico e la sua applicazione come catalizzatore nelle reazioni di idrosililazione e idroborazione di doppi e tripli legami. I composti organici sililati e borilati sono importanti prodotti intermedi in diversi settori della chimica fine grazie alla loro stabilità e alla loro capacità di essere ampiamente funzionalizzati. Idroborazione e idrosililazione, grazie allo sviluppo di catalizzatori appositi, permettono di ottenere questi composti riducendo coprodotti, sottoprodotti e condizioni operative estreme. Generalmente i catalizzatori impiegati industrialmente contengono metalli di transizione costosi, rari e non biocompatibili. Per questo motivo negli ultimi anni la ricerca si è concentrata sullo sviluppo di nuovi catalizzatori a base di metalli della prima serie di transizione tra cui il manganese, noto per essere abbondante sulla crosta terrestre, economico e biocompatibile. I composti N-eterociclici (NHC) sono una classe di leganti tra le più utilizzate poiché oltre a una grossa variabilità di caratteristiche steriche ed elettroniche, consentono di stabilizzare la specie metallica. I complessi N-eterociclici di manganese sono stati scarsamente applicati nelle reazioni di idroborazione e idrosililazione. Per questo motivo, il gruppo dove ho svolto il mio tirocinio si è dedicato a questo tipo di ricerca, sintetizzando e testando un complesso bis-NHC di manganese nell’idrosililazione di carbonili e solfossidi. Il mio lavoro si inserisce all’interno di questo ampio progetto, applicando nuovamente lo stesso complesso su una serie di substrati e reazioni differenti. In particolare, l’idrosililazione è stata applicata su alchini, alcheni e su carbonili (in questo caso attivando il complesso con la luce visibile). Inoltre, si è testata l’attività catalitica del complesso nell’idroborazione di alchini.

Analysis Of The Dna Fourier Transform-infrared Microspectroscopic Signature Using An All-reflecting Objective.

The Fourier transform-infrared (FT-IR) signature of dry samples of DNA and DNA-polypeptide complexes, as studied by IR microspectroscopy using a diamond attenuated total reflection (ATR) objective, has revealed important discriminatory characteristics relative to the PO2(-) vibrational stretchings. However, DNA IR marks that provide information on the sample's richness in hydrogen bonds have not been resolved in the spectral profiles obtained with this objective. Here we investigated the performance of an all reflecting objective (ARO) for analysis of the FT-IR signal of hydrogen bonds in DNA samples differing in base richness types (salmon testis vs calf thymus). The results obtained using the ARO indicate prominent band peaks at the spectral region representative of the vibration of nitrogenous base hydrogen bonds and of NH and NH2 groups. The band areas at this spectral region differ in agreement with the DNA base richness type when using the ARO. A peak assigned to adenine was more evident in the AT-rich salmon DNA using either the ARO or the ATR objective. It is concluded that, for the discrimination of DNA IR hydrogen bond vibrations associated with varying base type proportions, the use of an ARO is recommended.

Thermodynamic Study Of The Micellization Of Zwitterionic Surfactants And Their Interaction With Polymers In Water By Isothermal Titration Calorimetry.

The micellization of a homologous series of zwitterionic surfactants, a group of sulfobetaines, was studied using isothermal titration calorimetry (ITC) in the temperature range from 15 to 65 °C. The increase in both temperature and the alkyl chain length leads to more negative values of ΔGmic(0) , favoring the micellization. The entropic term (ΔSmic(0)) is predominant at lower temperatures, and above ca. 55-65 °C, the enthalpic term (ΔHmic(0)) becomes prevalent, figuring a jointly driven process as the temperature increases. The interaction of these sulfobetaines with different polymers was also studied by ITC. Among the polymers studied, only two induced the formation of micellar aggregates at lower surfactant concentration: poly(acrylic acid), PAA, probably due to the formation of hydrogen bonds between the carboxylic group of the polymer and the sulfonate group of the surfactant, and poly(sodium 4-styrenesulfonate), PSS, probably due to the incorporation of the hydrophobic styrene group into the micelles. The prevalence of the hydrophobic and not the electrostatic contributions to the interaction between sulfobetaine and PSS was confirmed by an increased interaction enthalpy in the presence of electrolytes (NaCl) and by the observation of a significant temperature dependence, the latter consistent with the proposed removal of hydrophobic groups from water.

Membrane Lipid Profile Monitored By Mass Spectrometry Detected Differences Between Fresh And Vitrified In Vitro-produced Bovine Embryos.

Summary This study aimed to evaluate the impact of vitrification on membrane lipid profile obtained by mass spectrometry (MS) of in vitro-produced bovine embryos. Matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) has been used to obtain individual embryo membrane lipid profiles. Due to conditions of analysis, mainly membrane lipids, most favorably phosphatidylcholines (PCs) and sphingomyelins (SMs) have been detected. The following ions described by their mass-to-charge ratio (m/z) and respective attribution presented increased relative abundance (1.2-20×) in the vitrified group: 703.5 [SM (16:0) + H]+; 722.5 [PC (40:3) + Na]+; 758.5 [PC (34:2) + H]+; 762.5 [PC (34:0) + H]+; 790.5 [PC (36:0) + H]+ and 810.5 [PC (38:4) + H]+ and/or [PC (36:1) + Na]+. The ion with a m/z 744.5 [PCp (34:1) and/or PCe (34:2)] was 3.4-fold more abundant in the fresh group. Interestingly, ions with m/z 722.5 or 744.5 indicate the presence of lipid species, which are more resistant to enzymatic degradation as they contain fatty acyl residues linked through ether type bonds (alkyl ether or plasmalogens, indicated by the lowercase 'e' and 'p', respectively) to the glycerol structure. The results indicate that cryopreservation impacts the membrane lipid profile, and that these alterations can be properly monitored by MALDI-MS. Membrane lipids can therefore be evaluated by MALDI-MS to monitor the effect of cryopreservation on membrane lipids, and to investigate changes in lipid profile that may reflect the metabolic response to the cryopreservation stress or changes in the environmental conditions.

Digestive Peptidase Evolution In Holometabolous Insects Led To A Divergent Group Of Enzymes In Lepidoptera.

Trypsins and chymotrypsins are well-studied serine peptidases that cleave peptide bonds at the carboxyl side of basic and hydrophobic l-amino acids, respectively. These enzymes are largely responsible for the digestion of proteins. Three primary processes regulate the activity of these peptidases: secretion, precursor (zymogen) activation and substrate-binding site recognition. Here, we present a detailed phylogenetic analysis of trypsins and chymotrypsins in three orders of holometabolous insects and reveal divergent characteristics of Lepidoptera enzymes in comparison with those of Coleoptera and Diptera. In particular, trypsin subsite S1 was more hydrophilic in Lepidoptera than in Coleoptera and Diptera, whereas subsites S2-S4 were more hydrophobic, suggesting different substrate preferences. Furthermore, Lepidoptera displayed a lineage-specific trypsin group belonging only to the Noctuidae family. Evidence for facilitated trypsin auto-activation events were also observed in all the insect orders studied, with the characteristic zymogen activation motif complementary to the trypsin active site. In contrast, insect chymotrypsins did not seem to have a peculiar evolutionary history with respect to their mammal counterparts. Overall, our findings suggest that the need for fast digestion allowed holometabolous insects to evolve divergent groups of peptidases with high auto-activation rates, and highlight that the evolution of trypsins led to a most diverse group of enzymes in Lepidoptera.

Estudo teórico da interação existente entre a artemisinina e o heme

The purpose of this work is to study theoretically stereoelectronic aspects of the interaction between heme and artemisinin in the transitional heme-artemisinin complex. Through semi-empirical calculations using the PM3 method, the potential energy barrier of artemisinin rotation relative to heme in the heme-artemisinin complex was studied in vacuum and in the partially solvated state. The minimum heat of formation obtained for the complex with and without water molecules is -702.39 and -100.86 kcal mol-1, respectively, which corresponds to the dihedral angle C-Fe-O1-O2 of 43.93º and 51.90º around the iron-oxygen O1 bond, respectively. The water molecules bind to heme via 13 hydrogen bonds and O-H O and 6 C-H O interactions, which accounts for -67.23 kcal mol-1. It is observed that the inclusion of water molecules does not affect significantly the stability of the heme-artemisinin complex.