Ligand design in general enables the formation of coordination compounds with multiple functionalities within a single framework. To date, two of the most widely studied ligands are 2,2′:6′,2′′-terpyridine (terpy) and acetylacetone (acac), whose tridentate and bidentate coordination pockets, respectively, enables the formation of metallic complexes with various geometries. The Brusso group had been incorporating imidoyl amidine (ImAm) ligands to build different materials such as organic radicals and fluorescent materials. In particular, the ligands N-2-pyridylimidoyl-2-pyridylamidine (Py2ImAm) and N-2-pyrimidylimidoyl-2-pyrimidylamidine (Pm2ImAm) were recently synthesized and have great appeal to build metallic complexes, as they poses two coordination sites similar to those in terpy and acac. The work presented herein represents the first studies involving the coordination of Py2ImAm and Pm2ImAm as discrete ligands. Our results demonstrate the versatility of these ligand frameworks, in which discrete mononuclear complexes, homometallic and heterometallic polynuclear complexes may be realized. Chapter one serves as a brief introduction to transition metal chemistry and has a comprehensive review of the coordination chemistry of the ImAm ligand framework. In chapter two, the selective coordination of first row transition metals into the bidentate or tridentate sites of Py2ImAm is explored. The formation of these mononuclear complexes is acid-base driven, where a weak acid induces coordination to the tridentate site and a weak base leads to coordination in the bidentate site. Coordination to both sides of Pm2ImAm with manganese or iron is explored in chapter three. The results show the formation of unusual tetranuclear complexes with the metal ions in both low spin and high spin configurations. Chapter four covers the coordination to cobalt, and the formation of polynuclear complexes with different geometries using Pm2ImAm. The magnetochemistry of these cobalt polynuclear complexes is also presented and reveal a single molecule magnet behaviour for one of the complexes. Finally, in chapter five, a one-pot synthesis of copper-manganese heterometallic complexes is presented. Overall, these imidoyl amidine ligands are able to build complexes with different geometries, different electronic configurations (i.e. low or high spin), and different metal ions. These results show a great versatility of ImAm ligands and suggest the future use of these ligands by other research groups.

pK_n values for step-wise dissociation of protons from the protonated ligands (glycine, α-amino isobutyric acid, sarcosine and theonine) were determined potentiometrically with a Beckman Model GS pH meter in aqueous solution at 10, 20, 30 and 40° C. Log K values for step-wise interaction of glycine, α-amino isobutyric acid, sarcosine and threonine with copper(II) ion were also determined potentiometrically with a pH meter at 10, 20, 30 and 40° C. The standard free energy of formation for the step-wise interaction of copper(II) with each of the above ligands was calculated from the values of log K. Enthalpy and entropy changes were calculated for each of the above reactions at 20° C. Measurements of pH were obtained at several ionic strengths for each metal io-ligand system at each temperature. It was assumed that the zwitterion has no charge. The hydrolysis of copper(II) ion and the liquid junction potential were assumed to be negligible. Log K_1 and log K_2 values for the copper(II) chelate of α-amino isobutyric acid are lower than those of glycine at 10 20° C. but higher at 30 and 40° C. This may be related to the positive inductive effect and the steric effect of methyl groups. The large decrease in the log K values of the copper(II) chelate of sarcosine is probably due to two effects, namely, steric and hydration. These two effects counteract the positive inductive effect introduced by the methyl group on the nitrogen and actually decrease its basic strength and thus decrease the bond strength between nitrogen and copper. THe decrease in the log K values of the copper (II) chelate of threonine is explained by the presence of the hydroxyl group which increases the acid strength of the NH_3^+ group and decreases its electron donating power. This is probably due to the hydrogen bonding between the hydrogen of the hydroxyl group and nitrogen of the amino group. Values of log K for the copper(II) chelate of each ligand decrease with the increase in the temperature, indicating that the entropy effect is greater at a lower temperature than at a higher temperature. Calculations of n, [A^-] and log K were carried out on an IBM 650 Computer.

Many Computer-Supported Cooperative Work (CSCW) applications go to great lengths to maximize transparency by making available participants\' actions and respective application states to all others in real-time. Designers might intend to enhance coordination through increased transparency, but what other outcomes might be influenced by these choices? We developed two versions of a CSCW application to support a group idea generation task for collocated groups. One version had diminished transparency in comparison to the other. We studied the effects of this varied transparency on the groups\' generativity and collaboration. We found that in modulating transparency there was a trade-off between generativity and collaboration. Groups with diminished transparency felt that their groupmates built on their ideas more, but groups with increased transparency were more generative. These findings are tentative but suggest that the full story of group vs. solitary, private vs. public manipulations of technology, at least in the area of idea generation, is not yet sufficiently theorized or understood. / Master of Science

L'étendue et les causes des déficits de coordination visuo-manuelle des enfants nés prématurés à bas risque ne sont pas vraiment connus. L'objectif principal de la thèse présentée ici était d'étudier le développement de la coordination visuo-manuelle chez douze prématurés à bas risque, nés après 33-36 semaines de gestation et examinés entre 5 et 23 mois d'âge chronologique. Au cours de la thèse, nous avons mené une série d'études avec des objectifs spécifiques. Dans l'étude 1, nous avons observé le développement de la coordination visuo-manuelle, la prise d'objets, le contrôle de la motricité bimanuelle et la latéralité chez ces enfants prématurés vus entre 6 et 12 mois et comparés à des enfants nés à terme à âge gestationnel équivalent. La perception visuelle des enfants a également été testée à 5 mois et mise en relation avec la coordination visuo-manuelle. Les résultats montrent une perception visuelle globalement normale chez les prématurés qui ne différent des enfants à terme que par une fixation visuelle plus faible. Par contre les enfants prématurés présentent un développement plus lent pour l'intégration visuo-manuelle, la prise d'objet, la coordination bimanuelle et la latéralité. L'hypotonicité et l'âge gestationnel sont les principaux facteurs responsables de ce retard. Aucun retard n'est observé pour le développement postural et locomoteur. Dans l'étude 2 nous avons recherché l'effet de la prématurité sur le développement de la compréhension qu'un objet dont toutes les parties ne sont pas à portée de main peut être saisi par n'importe quelle partie (principe de cohésion). Nous avons présenté aux mêmes enfants prématurés une condition « objet composite » dans laquelle une balle colorée est attachée au bout d'un manche blanc, seul le manche étant à portée de main. Dans une deuxième condition (« déconnection invisible »), la balle paraissait connectée au manche mais ne l'était pas. Les résultats montrent que, en tant que groupe, les bébés prématurés ne présentent pas de retard dans leur prise d'un objet composite. Cependant les enfants prématurés hypotoniques ou nés après 33-34 semaines étaient significativement en retard par rapport aux enfants prématurés hypertoniques. Ces résultats des deux premières études montrent que les nourrissons prématurés, même à bas risque, présentent un retard de développement visuo-manuel dans leur première année de vie et on peut se demander si ce retard se prolonge au-delà de la première année. La réponse à cette question est présentée dans l'étude 3. Nous avons comparé le développement de l'utilisation d'un outil chez les enfants prématurés, âgés alors de 15 à 23 mois, avec celui d'enfants nés à terme d'âge gestationnel équivalent. Comprendre l'affordance d'un outil est une étape importante dans la période sensorimotrice. L'utilisation d'un outil pour prendre un objet hors de portée, par exemple, se développe normalement au cours de la deuxième année. Nous avons présenté aux enfants prématurés un jouet coloré hors de portée et un râteau blanc à portée de main dans cinq conditions de relations spatiales entre le jouet et le râteau. En tant que groupe, les enfants prématurés ont présenté un développement normal de l'utilisation de l'outil. Cependant, ce développement normal n'apparaît pas chez tous les enfants prématurés. Les enfants prématurés hypotoniques ou nés après 33-34 semaines de gestation ont montré un retard significatif dans leur acquisition de l'utilisation de l'outil. Ces résultats montrent que les enfants nés prématurés à faible risque peuvent être retardés dans leur développement de nouvelles compétences manuelles au-delà de la première année. En suivant ces enfants au-delà de deux ans, il devrait être possible de déterminer quels sont les tests les plus prédictifs de déficits neuropsychologiques persistants parmi ceux que nous avons utilisés. Ces résultats devraient néanmoins être confirmés dans une population plus large. / The extent of and reasons for visual-manual coordination deficits in moderate and late low risk preterm born infants are not well known. The aim of the thesis presented here was to investigate the development of visual-manual coordination in twelve low risk preterm infants born after 33-36 weeks of gestation and examined from 5 to 23 months of age. We conducted a series of studies with specific goals. The goal of study 1 was to investigate the development of visual-manual and bimanual coordination as well as handedness in the preterm infants between the postnatal ages of 6 and 12 months, after having evaluated their visual functions at 5 months. Gross motor development was also evaluated every month. Preterm infants were compared to a control group of ten full-term infants according to corrected age. Results show that preterm infants had a visual perception close to normal, with only visual fixation being lower than in full-terms. Preterm infants had delayed development of visual-manual integration, grasping, bimanual coordination and handedness. Tonicity and gestational age at birth were the main variables associated to the delays. There was no delay for gross motor development. The goal of study 2 was to investigate at what age preterm infants integrate the notion of object cohesiveness into their action plan. The same preterm and full-term infants as in first study were presented with a composite object task at 6, 8, and 10 months in two conditions, "composite object" condition, in which a bright ball was attached to the end of a neutral handle, and "invisible disconnection" condition in which the ball seemed to be connected to the handle but was not. Only the handle was within reach. Corrected age comparisons between preterm infants and full-terms showed no significant difference between the two groups. However, the hypotonic preterm infants had a significantly lower performance than the hypertonic infants. Based on the results from studies 1 and 2 it seems that preterm infants, in particular the hypotonic infants, have a delayed development in their first year of life, and one can wonder if this delay remains at later stages. To answer this question, in study 3 we compared the development of tool use in the preterm infants, aged 15 to 23 months, with that of full-terms according to corrected age. Understanding the affordance of a tool is an important milestone in early sensorimotor period. Using a tool to bring within reach an out-of-reach object, for instance, has been shown to develop during the second year in full-term infants. Here we presented preterm infants with an attractive toy out of reach and with a rake-like tool within reach in five conditions of spatial relationships between the toy and the tool. As a group, preterm infants showed a normal development of tool use. However not all preterm infants developped tool use without delay. Hypotonic and moderate preterm infants were significantly delayed in their acquisition of tool use. These results, show that some low risk preterm infants can still be impaired for the development of new manual skills beyond the first year. By following these low risk preterm children, it should be possible to evaluate which of the delays observed in our studies are the best predictors of later neuropsychological deficits in childhood. These results should also be confirmed with a larger sample of preterm infants.

Persons with disabilities tend to be in poorer health compared to those without disabilities, and timely coordination of care is essential for maintaining optimal health and wellness. The problem addressed in the Care Coordination Referral Project was the lack of timely access to health care and preventive care services for clients with disabilities in the organization for which this project was developed. Using the appraisal of guidelines research and evaluation II model, the purpose of this DNP project was to analyze and synthesize the evidence-based literature to support the project and develop an online health care resource manual and protocol. The practice- focused question focused on evidence from literature that supported the development of a resource manual and protocol to provide care coordination to patients with disabilities. The literature indicated that timely access to care was essential to a patient's overall health and well-being. The manual and protocol were approved by an organizational team and included in the patient care plan. Results of a summative evaluation showed that team members agreed that the project objectives were met, the project was appropriate to the setting, and that strong leadership was demonstrated throughout the project. The findings of this project show that providing the resource manual for the nurses might improve the overall health and well- being of patients with disabilities through access to health care and preventive care services access.

The object of the research was to study, by means of ion-exchange chromatography, the product mixture resulting from reaction of trans-[Co(en)₂Cl₂]Cl and SCN¬⁻. Cis-and trans-[Co(en)₂(NCS)Cl]Cl had previously been obtained as products of this reaction. However, the possibility of the presence of other products consistent with the nature of the reactants could not be dismissed. These include the dichlora, dithiocyanato, and aqua complexes. The constituents of the solution resulting from the reaction were separated on a column of Dowex 50W-X8 resin by elution with hydrochloric acid. The eluted fractions were evaporated at room temperature in order to obtain crysta1s to be used for infrared spectral analysis and identification. Three primary fractions were eluted from the column. The first, eluted with 0.5 M HCl, was identified as trans-[Co(en)₂(NCS)Cl]Cl by analysis of the infrared spectrum. Two types of crystals were obtained from the second fraction which was eluted with 1 M HCL. The first crystals to form in this solution were orange in color and were identified by examination of the infrared spectrum as cis-[Co(en)₂(NCS)Cl]Cl. The second crystals obtained from the same fraction were shown to be cis-[Co(en)₂(NCS)Cl]Cl. The crystals isolated from the third fraction, eluted with 3 M¬¬ HCl, were also identified as cis [Co(en)₂(NCS) Cl]Cl. On the basis of observations of the column elution and an analysis of the ultraviolet spectra of’ the eluted fractions, it was concluded that band #2 was cis-[Co(en)₂(NCS)Cl] Cl and band #3 was cis-[Co(en)₂(NCS)(H₂0)]Cl₂. Aquation of cis-[Co(en)₂(NCS)Cl]⁺ was observed to occur on the column as well as in the eluted solution. In addition, rechlorination of the aquated compound was found to occur in the eluted fraction so that after elution the second and third fractions were mixtures of the unaquated and aquated complexes. No crystals of dithiocyanato or dichloro compounds were obtained in the separation so that the reaction was demonstrated to be essentially1:1 between the complex and thiocyanate. Trans-[Co(en)₂(NCS)Cl]Cl was found to comprise forty-nine percent of the typical product mixture. Since other products were present only in very low concentrations, the combined cis-[Co(en)₂(NCS)Cl]Cl and cis-[Co(en)₂(NCS)(H₂0)]Cl₂ contents was estimated at roughly fifty mole percent.

No description available.

This research considers a single-item two-echelon supply chain facing a sequence of stochastic bulky customer demand with random order inter-arrival time and random demand size. The demand process is a general renewal process and the cost functions for both parties involve the renewal function and its integral. The complexity of the general renewal function causes the computational intractability in deciding the optimal order quantities, so approximations for the renewal function and its integral are introduced to address the computational complexity. Asymptotic expansions are commonly used in the literature to approximate the renewal function and its integral when the optimal decisions are relatively large compared to the mean of the inter-renewal time. However, the optimal policies do not necessarily fall in the asymptotic region. So the use of asymptotic expansions to approximate the renewal function and its integral in the cost functions may cause significant errors in decision making. To overcome the inaccuracy of the asymptotic approximation, this research proposes a modified approximation. The proposed approximation provides closed form functions for the renewal function and its integral which could be applied to various optimization problems such as inventory planning, supply chain management, reliability and maintenance. The proposed approximations are tested with commonly used distributions and applied to an application in the literature, yielding good performance. By applying the proposed approximation method to the supply chain cost functions, this research obtains the optimal policies for the decentralized and the centralized cases. The numerical results provide insights into the cost savings realized by the centralization of the supply chain compared to the decentralized case. Furthermore, this research investigates coordination schemes for the decentralized case to improve the utilities of parties. A cost sharing mechanism in which the vendor offers the retailer a contract as a compensation of implementing vendordesired inventory policy is investigated. The sharing could be realized by bearing part of the retailer’s inventory holding cost or fixed cost. The contract is designed to minimize the vendors cost while satisfying the individual rationality of the retailer. Other forms of coordination mechanisms, such as the side payment and delayed payment, are also discussed.

No description available.

No description available.