Objective: To determine the relationship between mineral density and microtensile bond strength of caries-affected dentin (CAD). Methods: Sixty-three extracted human molars with carious lesions and nine extracted sound human molars are collected and flattened to expose the dentin. Caries is removed using Caries Detector (Kuraray Medical, Tokyo, Japan) leaving a firm light pink stained dentin and then bonded with RBC (Z100, shade T, 3M ESPE, Germany) using an etch-and-rinse 3-step adhesive system (Optibond FL,Kerr, Orange, CA, USA). The bonded teeth are stored overnight at 37ºC before vertically sectioned with diamond saw blades (IsoMet 1000, Buehler Ltd., Lake Bluff, IL, USA). The sticks are then trimmed into dumbbell-shaped specimens with a cross-sectional area of 0.5 mm2 and a gauge length of 1 mm. Tensile testing is performed at a crosshead speed of 1 mm/min (Zwick Materials Testing Machine Z2.5/TN1S, Zwick, Ulm, Germany). X-ray microtomography was used to examine the fractured specimens (Micro-CAT II, Siemens Preclinical Solutions, Knoxville, TN) at maximum resolution of 27 microns. The mean mineral densities at the resin-dentin interface of the bonded specimens are calculated using a custom BMD (bone mineral density) analyzer software (Iowa City, IA, USA). Mineral density (image intensity) will be plotted against uTBS (MPa) to determine correlation between these two properties based on Spearman rank correlation test at 0.05 level of statistical significance. Results:There was a statistically significant relationship between µTBS and image intensity (p< 0.0001). However, the correlation coefficient was weak (0.31). Significant effect of the failure mode on the image intensity and the µTBS were observed (p < 0.0001). No significant difference in the mean image intensity was found between the 2 levels (p = 0.6519) and 3 levels of dye staining (p = 0.2531). Intra- and inter-examiner reliability was near perfect (0.99; 0.98) for mineral density measurements. Conclusion: Within the limits imposed in the experimental design, we concluded that the degree of mineralzation of CAD has an influence on its failure mode and µTBS. Positive increasing relationship was also found between CAD's failure mode and its µTBS. Additionally, no significant relationship was found between levels of dye staining and the degree of mineralization.

A single political issue, public financing of a sewage treatment facility for the city of Logan, was studied in an attempt to determine the effect of certain variables on the formation of public policy. The case study method of research was followed, and conclusions were based on data obtained through personal interviews as well as through study of public documents. Among factors which influenced the decisional process was the degree to which technological knowledge was accepted. Policies developed by the state legislature and the federal bureaucracy to deal with environmental pollution also affected the local situation. A conflict which arose over interpretation of certain of these policies was largely resolved in court.

Knowledge of the deeper meanings of attachment to companion animals is limited, particularly in terms of older adults. This study employed a modified grounded theory method, a phenomenological lens and a life course perspective to gather and analyze data garnered from individual interviews and panel discussions in order to investigate the multiple dimensions of older adult men’s relationships with their companion animal dogs. Individual audio-recorded in-depth interviews and repeated panel discussions with a sub-group of the participants, convened as a panel over a three-month period, explored behavioral and emotional manifestations of attachment and the emotional bond to their companion animal dogs and the changing nature of that attachment and bond over their life span. Analysis involved open, axial and selective coding of transcripts to reveal underlying patterns within the data. Outcomes included movement toward a theory of companion animal attachment for older adult men as well as insight into the role of dogs in development of older adult men’s identities. This dissertation offers insight into the deeper understanding of the human-animal bond resulting in enhancing quality of life for both older adult male pet owners and their companion animal dogs.

Having a net dipole moment, water molecules tend to align with an external electric field. The re-orientation of water molecules to align with the field direction can result in structural and dynamic changes in liquid water. Studying these changes can help us to understand the role of an E-field in many biological systems, chemical reactions, and many technological advancements. In short, the application of static electric fields causes molecules to stay aligned with the field, so, fewer hydrogen bonds break, and molecules have slower dynamics. This type of field can be used when the mobility of water molecules needs to be reduced, like in electroporation. Alternating electric fields, on the other hand, cause continuous re-orientation of dipole moments, which results in more H bond breaking, water is less structured, and molecules have faster motion. Water under static and alternating electric fields have several applications in science and technology. Although many of the interesting usages of the application of electric fields to water happen at surfaces, the response of hydrogen bonding of water molecules to an E-field is still not fully understood even in bulk. For instance, the rate of hydrogen bond breaking, the re-orientation of water molecules, and the random walk of water molecules under the restrictions of the static electric field have not been thoroughly assessed. The static electric field limits the re-orientation of water molecules, but the translation reduces at the same time, this is clear evidence of roto-translational coupling, and the static electric field is a great groundwork for studying this coupling which is generated by the hydrogen bonds. For studying the effects of an E-field on H-bonding dynamics in depth, we need a model of hydrogen bonding. There are a few models for dynamics of H-bonding and reorientation of water molecules, including Luzar and Chandler model, published in 1996, and the Laage and Hynes jump model, published in 2006, which are described in the introduction chapter. The two models are related but have different perspectives, so it would be very interesting to look for a more general framework of hydrogen bonding by combining these two models, with the help of the influence of external electric fields. We also explain the relation of the random walk diffusion of water molecules and the hydrogen bonding. Since the external electric field can change the dipole moment of water molecules, for a more realistic picture, we need do the simulations with sophisticated polarizable water models to obtain a better estimate of the behavior of experimental water in an electric field. In this thesis, we introduce our generalized hydrogen bond framework; then we assess this framework, as well as other static and dynamic properties of water under static and alternating electric fields.

L’arrêt de la Cour de cassation du 2 décembre 2005 a énoncé qu’une sûreté réelle consentie pour garantir la dette d’un tiers n’implique aucun engagement personnel à satisfaire à l’obligation d’autrui et n’est dès lors pas un cautionnement,lequel ne se présume pas.La formule de la Cour de cassation,conduit à rejeter toute analogie entre les sûretés réelles pour autrui et le cautionnement personnel.Elle invite également, à ne pas appliquer aux sûretés réelles pour autrui, le régime du cautionnement, car différence de nature, signifie aussi différence de régime. Mais le législateur par sa réforme du droit des procédures collectives a réajusté la solution de la Haute Juridiction. En effet, la jurisprudence postérieure à l’arrêt du 2 décembre 2005, a très souvent manqué de nuance. Les solutions apportées aux différends litiges, résultent le plus souvent d’un raisonnement purement déductif, de la solution tirée de l’arrêt du 2 décembre 2005, de la Haute Juridiction.Les textes qui mentionnent le cautionnement personnel sont systématiquement écartés, au constituant de sûretés réelles pour autrui. Il faudrait maintenant que l’amorce annoncée par le législateur en droit des procédures collectives permette à la jurisprudence d’affiner sa solution. Le droit des procédures collectives de 2008, et de 2014 met en évidence la nécessité de faire apparaître dans la science juridique,la catégorie des sûretés pour autrui, et la catégorie des sûretés pour soi-même. Les sûretés pour autrui, qu’elles soient personnelles ou réelles, devraient obéir à un régime partiellement, puis totalement commun, ce qui signifie finalement qu’il n’y a pas une totale différence de nature entre le cautionnement personnel et les sûretés réelles pour autrui. Les sûretés réelles pour autrui devraient avoir un rôle fondamental dans la vie économique.Pour cela,il faut s’écarter du débat de la nature purement réelle ou mixte des sûretés réelle pour autrui, et s’orienter principalement sur la personne de la caution réelle,qui en l’état actuel de notre droit positif et en tant que tiers à la dette n’est pas protégée.La caution personnelle et la caution réelle sont des sûretés identiques,car elles sont avant tout des garanties de la dette d’autrui, elles sont l’accessoire de la dette du débiteur principal.La seule différence entre ces deux sûretés pour autrui réside dans l’étendue de leur engagement. La caution réelle étant un tiers à la dette et n’étant pas le débiteur, le seul droit des sûretés réelles ne peut répondre que partiellement à la technique de la garantie réelle pour autrui.Car il y a une différence entre celui qui garantit sa propre dette par des sûretés réelles appelé le débiteur,de celui qui garantit la dette d’un tiers par des sûretés réelles appelé la caution réelle. Il serait intéressant pour protéger la caution réelle,d’envisager la création d’une sûreté unique pour garantir réellement la dette d’autrui, en s’inspirant du succès du droit des sûretés Canadien et Américain qui sont des droits souples, réfléchis, modernes et uniformes. La sûreté réelle pour autrui française doit être efficace juridiquement et économiquement pour toutes les parties du contrat. La caution réelle qui engage son unique bien pour garantir la dette d’autrui prend un risque important tout comme la caution personnelle. L’avant-projet de réforme de sûretés de 2017, réintroduit dans un article 2291 le cautionnement réel comme étant une variété de cautionnement. Mais l’avant-projet de réforme de 2006 avait déjà essayé d’introduire le cautionnement réel dans un article 2285, comme étant une variété de cautionnement qui n’avait pas été retenu. Un régime primaire devrait donc être consacré aux garanties pour autrui;puis un droit spécial serait réservé au cautionnement personnel et à la sûreté réelle pour autrui.Cette solution est claire et précise et mettrai enfin un terme à l’amalgame créé par le mécanisme de la garantie réelle pour autrui, par la jurisprudence et la doctrine. / A collateral debt can be garantee personnaly or on sombody else property. The collateral guarantor which commits its only property to guarantee a debt takes a huge risk just like a personal guarantee. The pre reform of securities of 2017, reintroduced in an article 2291 the collateral garantee on property, like in the pre reform of safeties of 2006 in its article 2285, as being a variety of personal garantee. The article 2285 of the 2006 pre reform of securities has not been retained by law. To solve the problem on the protection of the collateral porperty garantor, a primary solution is to establish common rules for both collateral garantees, personal and on properties. And, the special rules of the personal garantee and the collateral garantee on goods. This solution will put an end on the conflict created by the search of the real qualification of the collateral guarantee.

La ciudad de Lima presenta un fuerte rechazo a los derechos de las parejas homosexuales, en la que se han creado movimientos para buscar su aprobación a nivel legislativo, pero continúan existiendo oposiciones. A partir de lo anterior, se pretende analizar tres representaciones sociales del vínculo de pareja homosexual en personas de orientación homosexual. Es una investigación hermenéutica con un análisis temático. Los participantes son 3, cuyas edades se ubican entre los 26 a 29 años, se seleccionaron según la forma en la que afrontaron su homosexualidad. Se optó por entrevistas individuales para analizar cómo es la representación social del vínculo de pareja homosexual. Los resultados revelan que la representación de pareja homosexual que tienen los participantes es en base al modelo tradicional (hombre y mujer), a causa de la estigmatización y los prejuicios que la sociedad presenta, lo cual les provee de dificultades hacia el intento de establecer un vínculo de pareja estable y saludable. Se discuten los resultados considerando las investigaciones empíricas. Este estudio podría dar inicio a nuevas investigaciones. / The city of Lima presents a strong rejection of the rights of homosexual couples, in which movements have been created to seek approval at the legislative level, but there are still oppositions. From the above, it is intended to analyze three social representations of the homosexual couple bond in homosexual persons. It is a hermeneutical investigation with a thematic analysis. The participants are 3, whose ages are between 26 and 29 years, were selected according to the way in which they faced their homosexuality. Individual interviews were chosen to analyze the social representation of the homosexual couple's relationship. The results reveal that the representation of the homosexual couple that the participants have is based on the traditional model (man and woman), because of the stigmatization and prejudices that society presents, which provides them with difficulties towards the attempt to establish a stable and healthy couple bond. The results are discussed considering empirical research. This study could start new research. / Tesis

The work presented in this dissertation has been focused on structure, stability, electronic properties, and chemical bonding of atomic clusters and solid-state compounds. The common thread was development of chemically intuitive models and theoretical methods capable of describing and interpreting bonding and hence, structures of these compounds. Understanding how interactions between atoms in sub-nano clusters and solid-state compounds of certain compositions determine their structures, physical properties, and reactivities is essential for rational design of new materials, catalysts, and molecular devices. A significant part of this work presents joint experimental and theoretical studies of doped boron clusters. Several projects on carbon- and aluminum-substituted boron clusters were aimed at establishing their structures, energetic and electronic properties, and understanding bonding interactions. The dissertation introduces a series of peculiar clusters containing transition metal atoms inside perfectly symmetrical boron rings. These clusters, featuring planar octa-, nona-, and decacoordinated transition metal atoms, were designed based on a simple chemical bonding model governing stabilities of such species. One of the most important parts of this dissertation deals with chemical bonding in the solid state. The Adaptive Natural Density Partitioning method previously developed by the Boldyrev group at Utah State University has proven very efficient for understanding chemical bonding in clusters and complex molecules. In this work, a periodic implementation of this method has been developed, yielding a new theoretical tool capable of interpretation of bonding in solid state in chemically intuitive terms of localized and multi-center bonds.

The discovery that phosphorylation of proteins occurs on nitrogen by particular kinases raises the question of whether a separate class of phosphoramidases also exists, or if known phosphatases carry out the hydrolysis of phosphoramidates. The phosphoramidase activity of a number of phosphatases with different catalytic motifs was studied using the substrates N-phenylphosphoramidate (N-phPAM) and phosphoryl imidazole (PIm). The phosphatases assayed were: the protein tyrosine phosphatase YopH; alkaline phosphatase; the dual-specificity phosphatase VHR; prostatic acid phosphatase, PAcP; PHPT1, the only known phosphohistidine phosphatase; and, the serine/threonine phosphatases Lambda PP and PP1. The catalytic efficiencies, kcat/KM (s-1M-1), were compared for the respective phosphoramidase and phosphatase activities for each enzyme. Ratios of catalytic efficiencies (kcat/KM)/(kcat/KM) of pNPP over PIm are: YopH - 27; AP - 4.1; VHR - 0.22; PAcP - 1.6; AP - 0.51; and PHPT1 - 0.00007. Lambda PP catalyzed hydrolysis of PIm, although kinetic constants could not be obtained. PP1 exhibited no phosphoramidase activity. The results show that most phosphatase catalytic motifs display catalytic promiscuity by cleaving both phosphoesters and phosphoramidates, but with a pronounced preference for one substrate type versus the other.

This in vitro study evaluated the bond and compression strength of cemented leucite reinforced glass ceramics in bovine tooth enamel, comparing three etching times with hydrofluoric acid 10% of the ceramic surface (20, 60 and 90 seconds) and two adhesive treatments (adhesive system + silane and universal adhesive system). For the bond strength test, 120 ceramic cylinders (2mm diameter x 2mm length; n=20) were etched and cemented (80m thick) in enamel with a dual resin cement, varying the adhesive treatment, obtaining the groups: UEXC20s, UEXC60s, UEXC90s, USBU20s, USBU60s, USBU90s. After 24 hours, the shear bond strength test was performed on a universal test machine (0.5mm/min, 50kgf). For the compression test, 30 ceramic plates (5x5mm with 1mm thick, n=5) were etched, received the same adhesive treatments and were cemented (80m) in enamel, obtaining the following groups: CEXC20s, CEXC60s, CEXC90s, CSBU20s, CSBU60s, CSBU90s. After 24 hours of cementation, the compression test (0.5mm/min, 500kgf) was performed. Statistical analysis was performed using two-way ANOVA and Tukey test (=.05). For the shear bond strength test significant differences were found among the adhesives (p<.05). For the etching times there were no differences (p=.059). However, there was a significant interaction between the adhesives and the etching times (p=.021). At 60 seconds, the Silane + ExciTE F DSC Adhesive presented the highest bond strength values (47.53±16.70Mpa). And at 20 seconds, the Universal adhesive presented the lowest bond strength values (27.72±10.76Mpa). For the compression test there were no significant differences between the adhesives (p=.571) and between the times (p=.154). The group that presented the highest values of compression force was the Universal adhesive at 60 seconds (1757.89±200.47N). The lowest values were also the Universal adhesive, but at 90 seconds (1213.30±546.34N). The study concluded that the silane associated with the ExciTE F DSC adhesive showed the highest bond strength values at the etching time of 60 seconds with 10% hydrofluoric acid, without compromising the compressive strength of the leucite reinforced ceramic. / Este estudo in vitro avaliou a resistência de união e compressão da cerâmica reforçada por cimentada em esmalte de dentes bovinos, comparando-se três tempos de condicionamento com ácido fluorídrico 10% da superfície cerâmica (20, 60 e 90 segundos) e dois tratamentos adesivos (sistema adesivo + silano e sistema adesivo universal). Para o teste de resistência de união (U), 120 cilindros cerâmicos (2mm diâmetro x 2mm comprimento; n=20) foram condicionados e cimentados (80 m de espessura) em esmalte, com cimento resinoso dual, variando-se o tratamento adesivo, obtendo-se os grupos: UEXC20s, UEXC60s, UEXC90s, USBU20s, USBU60s, USBU90s. Após 24h, foi realizado o teste de cisalhamento (0,5mm/min, 50kgf). Para o teste de compressão (C), 30 placas cerâmicas (5x5mm com 1mm de espessura; n=5) foram condicionadas, receberam os mesmos tratamentos adesivos e foram cimentadas (80m) em esmalte, obtendo-se os grupos: CEXC20s, CEXC60s, CEXC90s, CSBU20s, CSBU60s, CSBU90s. Após 24h da cimentação, foi realizado o teste de compressão (0,5mm/min, 500kgf). Foi realizada a análise estatística por meio de ANOVA dois critérios e teste de Tukey (P < 0,05). Para o teste de cisalhamento diferenças significativas foram encontradas entre os adesivos (p<0,05). Para os tempos de condicionamento não houve diferenças significativas (p=0,059). No entanto, houve interação significativa entre os adesivos e os tempos de condicionamento (p=0,021). No tempo de 60 segundos, o silano + adesivo ExciTE F DSC apresentou os maiores valores de resistência de união (47,53±16,70Mpa). E no tempo de 20 segundos, o adesivo Universal apresentou os menores valores de resistência de união (27,72±10,76Mpa). Para o teste de compressão não houve diferenças significativas entre os adesivos (p=0,571) e entre os tempos (p=0,154). O grupo que apresentou maiores valores de força de compressão foi o adesivo Universal no tempo de 60 segundos (1757,89±200,47N). Já os menores valores, foi também o adesivo Universal, mas no tempo de 90 segundos (1213,30±546,34N). Pode-se concluir que, o Silano associado ao adesivo ExciTE F DSC, mostrou os maiores valores de resistência de união no tempo de condicionamento de 60 segundos com ácido fluorídrico a 10%, sem comprometer a resistência a compressão da cerâmica reforçada por leucita.

The purpose of this thesis is to investigate the relationship between the annualised volatility and correlation of G7 ten-year bond returns for the period July 1992 to June 1998 and the effects that such a relationship has on portfolio diversification. The stock market crash of 1987 and the growing importance of global equity markets has encouraged a plethora of research into the volatility and correlations between international equity markets. Despite this, very little attention has been paid to the transmission of currency-based bond returns across national boundaries. The findings in this thesis are important because evidence is provided that suggests the benefits of international bond diversification are limited. The evidence provided clearly indicates that because correlations amongst G7 currency-hedged bond returns are high, the relationship between bond volatility and correlation of returns has limited benefits for portfolio managers and traders. As a result, diversification may not significantly reduce portfolio risk. Even during periods of ongoing annualised volatility decreases, the correlation between most markets remains high. Unlike the volatility trends presented in this thesis, there appears to be no trend or consistency amongst the correlation of returns between G7 markets. / Master of Commerce (Hons)