• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 33
  • 10
  • 7
  • 3
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 61
  • 27
  • 17
  • 14
  • 13
  • 12
  • 11
  • 10
  • 10
  • 10
  • 9
  • 8
  • 8
  • 8
  • 8
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The antimicrobial and antimycobacterial activity of plants used for the treatment of respiratory ailments in Southern Africa and the isolation of anacardic acid from ozoroa paniculosa.

Seaman, Tracy 30 October 2006 (has links)
Masters Research - Fuculty of Health Sciences / Tuberculosis (TB) is one of the leading causes of mortality in the developing world. Mycobacterium tuberculosis, the causative organism, infects approximately a third of the world’s population. With high rates of HIV infection, particularly in sub-Saharan Africa, TB rates are inevitably soaring. Treatment regimens are based on multi-drug therapy taken over a prolo nged period, leading to poor patient compliance, in turn resulting in the development of multi-drug resistant TB (MDR-TB) which is difficult to treat. The need for new anti-TB drugs that can decrease the period of treatment or the number of doses and that will be effective against latent and MDR-TB is desperate. An added advantage would be the ability of a new class of anti-TB drugs to have a novel target to avoid potential crossresistance to existing drugs. Various approaches have been taken to antituberculosis drug development, including the high-throughput screening of plants, which represent an enormous, largely untapped resource of novel compounds. A further parameter to increase the chances of finding promising lead compounds is to focus research on plants that have traditionally been used to treat symptoms associated with TB. Traditional herbalists prescribing plant-based treatments have long played an important role in the provision of primary healthcare, especially in rural areas where most of the population is poor and unable to afford modern drugs. The aim of this study is to research literature resources pertaining to medicinal plants in southern Africa used to treat symptoms associated with TB, collect these plants, prepare methanol and acetone extracts for the antimicrobial and antimycobacterial testing, identify a plant with promising activity, and to isolate the active principle/s. These compounds in turn would be identified structurally and tested for activity against a range of micro-organisms, including mycobacteria, as well as for cytotoxicity. Twenty-three plant parts from nineteen different species were collected and 46 extracts prepared. These extracts were tested against a range of Gram-positive and –negative bacteria and fungi using the disc diffusion and broth micro-dilution methods. The effects of these extracts were also tested against non-pathogenic mycobacteria using the broth microdilution method, and against M. tuberculosis using the radiometric BACTEC 460 ABSTRACT V method. Te n of the nineteen species exhibited activity against two or more of the eleven organisms tested, namely Xerophyta retinervis bark, Helichrysum odoratissimum leaves, Ozoroa paniculosa bark, Eriocephalus africanus leaves, Siphonochilus aethiopicus roots, Conyza scabrida leaves, Syzigium cordatum bark, Tetradenia riparia leaves, Datura stramonium leaves and Dioscorea sylvatica tubers. The acetone extract of O. paniculosa was further pursued for the isolation of its active principles as it exhibited potent activity against Enterococcus faecalis, Pseudomonas aeruginosa, M. tuberculosis and Mycobacterium aurum with MIC’s of less than 1mg/ml. Previous work on related species has indicated anti-cancer, anti-helminthic, anti- malarial and anti-schistosomiasis activities, but no antimicrobial or antimycobacterial properties have been researched. Moronic, anacardic, and ginkgolic acids have previously been isolated from related species. Bio-assay guided fractionation led to the isolation of a known C15:1 anacardic acid (compound 1) and two HPLC fractions (HPLC2 and HPLC3) of which the predominant components of HPLC3 is the saturated analogue of anacardic acid. NMR data of HPLC2 suggest it is also a C15:1 anacardic acid, although the location of its double bond is as yet unkown. These compounds were cytotoxic to CHO cells at 44.9 – 64μg/ml. Compound 1 and HPLC2 were moderately active against M. tuberculosis with MIC’s of 125μg/ml, while HPLC3 had increased activity with an MIC of 31.3μg/ml, work not previously reported. Similarly, HPLC3 had the greatest activity a gainst M. smegmatis with an IC50 value of 22.1μg/ml. M. aurum had higher IC 50 values ranging from 98.4 to 112.5μg/ml for all three compounds. Compound 1 had potent activity against a range of Grampositive bacteria with IC50 values of 1.3, 2.1 and 6.5μg/ml against Bacillus cereus, E. faecalis and Staphylococcus aureus respectively. Furthermore, this compound had good activity against one of two drug-resistant strains of S. aureus tested with IC50’s of 6.9 and 43.2μg/ml. The saturated anacardic acid (HPLC3) in general had poorer activity against Gram-positives than its unsaturated analogues, consistent with reported literature. The anacardic acids had decreased activity against yeast and Gram-negative organisms tested, with IC50 values of around 80μg/ml against Candida albicans, 19 ->250μg/ml for Serratia odorifera, 26 - >250μg/ml for Klebsiella pneumoniae and 17 – 68μg/ml for ABSTRACT VI Pseudomonas aeruginosa, results comparable to those previously reported. The saturated anacardic acid appeared to have better activity than its unsaturated analogues against Gram- negatives and yeast. The current literature suggests that lipophilic compounds have greater activity against M. tuberculosis. Results obtained in this project are in support of these findings, as the saturated anacardic acid, believed to be the major constituent of HPLC3 based on NMR data available, had increased activity against this organism compared to the unsaturated and less hydrophobic compound 1 and HPLC2. It is possible that these findings implicate anacardic acid in the disruption of the mycobacterial cell wall.
2

An Analysis of Acitational Characteristics in the Species of Stokely Carmichael

Bloomquist, Judy Wilson 12 1900 (has links)
In this study, six speeches delivered by Stokely Carmichael, during and immediately following his role as chairman of the Student Nonviolent Coordinating Committee, have been analyzed to determine if, and in what ways, Carmichael used the elements of agitational rhetoric.
3

ANION EFFECTS IN HOMOGENOUS PALLADIUM CATALYSIS AND LUMINESCENT PROPERTIES OF COPPER(I) COMPLEXES BEARING A WEAKLY-COORDINATING ANIONIC N-HETEROCYCLIC CARBENE LIGAND

Sabbers, William Anthony January 2021 (has links)
The general theme of this dissertation concerns how the locality of an anionic moiety, be it a weakly coordinating anion or an anionic ligand, affect the spectroscopic and structural properties of organotransition metal complexes. Probing the columbic interactions between traditional and novel weakly coordinating anions with transition metal complexes, enables synthetic chemists to select anions that can improve catalytic transformations, impart stability of reactive intermediates, or develop new mechanistic insights. Additionally, presented herein is the manifestation of a new class of luminescent copper complexes which bear a weakly coordinating anionic N-heterocyclic carbene ligand.Firstly, a qualitative scale of coordinating ability is prepared by pairing traditional anions and weakly-coordinating anions with [Pd(IPr)(C(O)C9H6N)]+. NMR, IR, Computation, %Vbur, and X-ray crystallographic techniques are used to study the solution and solid-state interactions of these salts. During this study, a novel anion, denoted IMP- is prepared where two B(C6F5) groups are bridged by a phenyl imidazole core. Ultimately, it was found that sterics dictate coordinating ability observed by NMR and %Vbur, while IR and computation show the electronic effects of anion coordination. Continuing our understanding of the interplay between cation and anion, anionic Au(I) complexes are synthesized and paired with the same palladium cation in our first investigation. The framework of these Au(I) anions features a weakly coordinating N-heterocyclic carbene ligand that bears a borate moiety of the NHC backbone. Facile dissociation of a dimethyl sulfide ligand with metal alkoxide/phenoxides/thiophenoxides affords sodium or potassium salts. With these anions in hand, ion pairs are isolated in polar solvents and in the solid state. Au anions reside in the outer sphere of the palladium cation; like that of weakly coordinating anions such as BArF4-. Lastly, Luminescent group 11 organometallic complexes featuring N-heterocyclic carbene (NHC) ligands offer a swath of applications; catalytic transformations in organic chemistry to inorganic material uses in light emitting technologies. Conventional complexes are of the type NHC-M-X, where M is Cu, Ag, or Au and X represents anionic ligands that are often prone to hydrolysis. In this dissertation, Cu(I) complexes featuring this N- heterocyclic carbene ligand bearing a weakly coordinating anionic substituent (WCA-NHC) are prepared. (WCA-NHC)-M-L are air and moisture stable and differ from conventional NHC-M-X in that the metal can be supported by 2 datively-bound ligands. Initial computation reveals a change in dipole of (WCA-NHC)-Cu-PR3 charge transfer compared to that of reported NHC-M-X. By exchanging triphenylphosphine for diphenyl-2-pyridyl phosphine, we can change the emission wavelength by about 200 nm. / Chemistry
4

The Rhetorical Structure of the Student Nonviolent Coordinating Committee

Michaelis, Daniel J. 08 1900 (has links)
The purpose of this study is to analyze the overall rhetorical structure of the Student Nonviolent Coordinating Committee during 1960-1968. The criteria used in this study were adapted from: Joseph R. Gusfield, "Protest, Reform, and Revolt - A Reader in Social Movements;" Dan F. Hahn and Ruth Gonchar, "Studying in Social Movements: A Rhetorical Methodology;" Kurt Lang and Gladys Lang, "Collective Dynamics;" Leland M. Griffin, "The Rhetoric of Historical Movements;" Herbert W. Simons, "Requirements, Problems, and Strategies: A Theory of Persuasion for Social Movements." Gusfield's definition of a movement as "socially shared activities and beliefs directed toward the demand for change in some aspect of the social order" is utilized. To examine the rhetorical structure, it is necessary to divest it from the complex structural aspects of a movement. Simons' theory of the "grand flow" of a movement's persuasion guided this study. The rhetorical requirements of a movement are introduced in Chapter I. The requirements tend to fall into the following sub-categories: the ideology, the strategy, the goals, the membership, and the leadership. Chapter II is devoted to the setting during which the movement was founded. It includes a brief history of social unrest in civil rights struggles in the United States between the years 1950-1960. Chapter III examines the structure of SNCC based upon the philosophy of love and nonviolence, approximately 1960-1964. Chapter IV examines the structure of SNCC based upon a philosophy of hatred and rejection, approximately 1964-1968. The chapter also includes a postscript discussing SNCCts progressive movement away from the philosophy of nonviolence after 1968.
5

A Historical Review of the Coordination of Higher Education in Texas

Waddell, Frederick Jackson 08 1900 (has links)
The problem with which this investigation is concerned is that of providing research on the development of the Coordinating Board, Texas College and University System, and to describe the manner in which it presently functions.
6

Freedom acts a historical analysis of the student non-violent coordination committee and its relationship to theatre of the oppressed /

Gilliam-Smith, Rhonda. January 2008 (has links)
Thesis (Ph. D.)--Miami University, Dept. of Educational Leadership, 2008. / Title from second page of PDF document. Includes bibliographical references (p. 189-199).
7

Virtualization Security Issues in Telemetry Post-Processing Environments

Kalibjian, Jeff 10 1900 (has links)
ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Virtualization technologies have the potential to transform the telemetry post-processing environment. Significant efficiencies can be gained by migrating telemetry post processing activities to virtual computing platforms. However, while facilitating better server utilization, virtualization also presents several challenges; one of the most difficult of those challenges being security. In virtualization, server environments are replicated in software; unfortunately, the security individual servers provide is not replicated in a software stack implementation of a server environment. After reviewing virtualization fundamentals, security issues and their impact on telemetry post processing will be discussed.
8

The Explanatory Power of Reciprocal Behavior for the Inter-Organizational Exchange Context

Pieperhoff, Martina January 2018 (has links) (PDF)
In order to create sustainable competitive advantages, organizations are embedded in dyadic exchange relationships, which depend on the coordination of the behavior of the actors involved. Often, coordinated behavior is explained by trust. Since trust develops in a process of reciprocal responses to presumed trustworthy behavior, it is a reciprocity-based concept. While inter-organizational exchange relationships can appear in different stages (forming, establishing, broken), different reciprocity types (direct, indirect, negative) can be distinguished. The study links reciprocal behavior to different stages of inter-organizational exchange relationships in order to investigate reciprocity as a possible coordination mechanism of behavior and thus explore the basis of coordination of trust-based behavior. Qualitative Comparative Analysis as a set-theoretic approach is applied to analyze the empirical data consisting of 78 qualitative semi-structured interviews with managers of small-, medium- and large-sized companies. The results show that different reciprocity types become effective in different stages of an inter-organizational exchange relationship: For forming inter-organizational exchange relationships indirect reciprocal behavior, besides direct reciprocity, becomes effective while in establishing inter-organizational exchange relationships, direct reciprocal behavior is evident. Negative reciprocal behavior leads to a break up of relationships. Using these results, on the one hand, the concept of trust can be sharpened by deepening the understanding of the trust-building mechanisms and on the other hand, reciprocity can be seen as coordination mechanism in exchange relationships of different stages. In doing so, with this knowledge, relationships can be coordinated towards a long-term orientation in order to create sustainable advantages.
9

Risk pooling via unidirectional inventory transshipments in a decentralized supply chain

Arikan Fichtinger, Emel, Silbermayr, Lena January 2017 (has links) (PDF)
We study risk pooling via unidirectional lateral transshipments between two locations under local decision-making. Unidirectional transshipments can be applicable when cost structures and/or capabilities differ between locations, and it is also a common practice in dual channel supply chains with online and offline sales channels. We show that such a system cannot be coordinated only with varying transshipment prices. The transshipment receiver orders more and the transshipment giver orders less than the respective optimal centralised order quantities. In order to remove this discrepancy, we suggest horizontal coordinationmechanisms by introducing a leftover subsidy for the location providing the transshipments or a shortage subsidy for the location receiving transshipments as well as a combination of shortage and leftover subsidy. Further, we evaluate the impact of network structure by comparing the equilibrium order quantities and profits under the uni- and bidirectional systems as well as a system without transshipments. Since demand correlation is a critical aspect in risk pooling we provide a detailed numerical study to discuss its impact on our findings.
10

O professor coordenador e os desafios na constituição de uma identidade no desenvolvimento profissional: um fazer real e possível

Oliveira, Daniela Claro de 05 October 2016 (has links)
Submitted by Marlene Aparecida de Souza Cardozo (mcardozo@pucsp.br) on 2016-11-08T11:45:51Z No. of bitstreams: 1 Daniela Claro de Oliveira.pdf: 801395 bytes, checksum: 106402cc1c71923c5b4b4470551d4e33 (MD5) / Made available in DSpace on 2016-11-08T11:45:51Z (GMT). No. of bitstreams: 1 Daniela Claro de Oliveira.pdf: 801395 bytes, checksum: 106402cc1c71923c5b4b4470551d4e33 (MD5) Previous issue date: 2016-10-05 / Secretaria da Educação do Estado de São Paulo / This research had for objective, to analyze the process of the coordinating teacher of the cycle of the final years of formation of the Management of North Regional Teaching 1 of the from São Paulo state net, to investigate as the coordinators plans their actions and daily practices starting from the formation that they participate monthly, organized for the section of the Pedagogic Nucleus of this management and to address the importance of a formation proposal to come to provide the coordinating teacher professional development for the construction of former role. In this work we intended to contemplate on her the formative process and their formative needs, under the coordinators' optics. Of the methodological point of view, the present work was developed according to the methodology of the qualitative perspective. It was possible to identify in the group of the analyzed data (rising through interview semistructured) the coordinating teachers' voices in relation to the accomplished formations, a lot of times, it was not in keeping with what was waited in practice as for the professional development as former. It is in this context that is done necessary a formation proposal, that contributes to a professional development and the constitution of an identity in a practice educational former that goes very beyond, demanding an attitude more open epistemological, come back more in the sense from looking and of listening in an action collaborative / Esta pesquisa teve como objetivos analisar o processo de formação do Professor Coordenador do ciclo dos anos finais, da Diretoria de Ensino Regional Norte 1, da Rede Estadual Paulista; investigar como os Coordenadores planejam suas ações e práticas cotidianas a partir da formação que participam mensalmente, organizadas pelo setor do Núcleo Pedagógico desta diretoria; e, direcionar a importância de uma proposta de formação que venha proporcionar o desenvolvimento profissional do Professor Coordenador para a construção do seu papel de formador. Neste trabalho pretendeu-se, ainda, refletir sobre o processo formativo e as suas necessidades formativas, sob a ótica desses coordenadores. Do ponto de vista metodológico, o presente trabalho foi desenvolvido na perspectiva qualitativa, possibilitando identificar, no conjunto dos dados analisados – levantamento por meio de entrevista semiestruturada – as vozes das professoras coordenadoras em relação às formações realizadas quanto ao desenvolvimento profissional como formador. É nesse contexto que se faz necessária uma proposta de formação que contribua para o desenvolvimento profissional e a constituição de uma identidade, numa prática educativa formadora que vai muito além, exigindo uma atitude epistemológica mais aberta, voltada ao olhar e à escuta numa ação colaborativa

Page generated in 0.0797 seconds