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  • 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.
151

Implementation and Evaluation of an Interprofessional Drug Take-Back Event on a University Campus

Ventricelli, Daniel J., Ahmad, Iqra, Sevak, Rajkumar J., Hagemeier, Nicholas E., Gray, Jeffrey A. 01 July 2015 (has links)
Objectives: 1) To describe the interprofessional implementation process and programmatic outcomes of an inaugural drug take-back event on a university campus; 2) To quantify donated medications and summarize donor demographics. Method: East Tennessee State University (ETSU) affiliated colleges, campus organizations, research teams, law enforcement and other community partners collaborated to host the inaugural live drug take-back event on ETSU’s main undergraduate campus. Programmatic outcomes included the number of community stakeholders, ETSU participating colleges, student donors, and donated medication metrics, including controlled substance medications. All donated medications were quantified by drug name and controlled substance schedule. Donor demographic information and perceptions of drug abuse on campus were collected using a brief survey. Results: Fifty pounds of medications were collected for disposal by 42 donors (9 students; 33 non-students). Controlled substances accounted for 8% of donated medications. Nearly 80% of student donors were enrolled in Academic Health Science Center colleges. Aggregate survey results indicated concerns about prescription drug abuse and misuse on campus. Three faculty members, two research fellows, two doctoral students, three graduate assistants and eight professional students from ETSU’s Colleges of Pharmacy and Public Health, as well as additional staff members, represented the contributing community entities and colleges during the live event. Implications: Conduction of drug take-back events on a university campus can promote interprofessional public health interventions and simultaneously reduce opportunities for nonmedical use of prescription drugs in college students. Further research is warranted to establish best practices and maximum impact for college-based take-back events.
152

Prescription Drug Abuse and DEA-Sanctioned Drug Take-Back Events: Characteristics and Outcomes in Rural Appalachia

Gray, Jeffrey A., Hagemeier, Nicholas E. 25 June 2012 (has links)
Proper disposal of controlled substance medications, a legally gray area since the Controlled Substance Act of 1970 was passed, has received renewed attention in recent years because of an increase in deaths related to opioid pain reliever (OPR) overdoses and increased nonmedical use of OPRs.1,2 Prescription drug take-back events have been organized under the purview of the Drug Enforcement Administration (DEA) to properly dispose of controlled substance medications; to decrease prescription medication diversion, abuse, and accidental poisonings; and to decrease environmental hazards resulting from improper medication disposal. The DEA has reported pounds of medications in aggregate donated at take-back events but has not examined the extent to which OPRs are being donated at these events.3 We analyzed the characteristics of donors and medications donated at 11 take-back events in rural Appalachia, an area struggling with disproportionately high rates of OPR nonmedical use and abuse.
153

Mechanisms of biocontrol of Gaeumannomyces graminis var. tritici by Pseudomonas corrugata strain 2140 : genetic and biochemical aspects

Ross, Ian Lindsay. January 1996 (has links) (PDF)
Bibliography: leaves 207-220. Pseudomonas corrigata strain 2140 (Pc2140), isolated from wheat field soil in Australia, antagonises the take-all fungus, Gaeumannomyces graminis var. tritici (Ggt) in vitro and significantly reduces take-all symptoms on wheat in pot trials. This study investigates the mechanisms by which the biocontrol agent reduces the disease symptoms. Biochemical analysis of metabolites of P. corrugata 2140 reveal a number of compounds potentially antagonistic to Ggt and which may play a role in disease control. These include water-soluble antibiotics, siderophores, proteases, peptides and volatiles including hydrogen cyanide.
154

The Relationship among Vocabulary Knowledge, Academic Achievement and the Lexical Richness in Writing in Swedish University Students of English

Lemmouh, Zakaria January 2010 (has links)
The main aims of the thesis are: to explore the development of Swedish university students’ vocabulary knowledge, size and depth and vocabulary use (i.e. lexical richness) in their written output, to examine the relationship between these, their relationship to examination grades, and to investigate how these relationships develop over time. The results showed that over one year of university studies stronger links between the two dimensions of vocabulary knowledge, size and depth are established. No relationship was found between informants’ vocabulary size and lexical richness. However, a modest relationship was found between depth and the lexical richness of student essays. Furthermore, there was a modest relationship between vocabulary knowledge and academic performance. A weaker significant, relationship was found between lexical richness of student essays and academic performance as reflected in the course grade. However, the study did not show evidence of a relationship between lexical richness and essay grade, which seems to indicate that lexical richness, is not an essential criterion in teachers’ assessment of essays. In regard to the development of the informant’s vocabulary knowledge, there was a significant growth in their productive size and depth of vocabulary knowledge after both one and two terms. The informants’ receptive size was found to only develop over two terms of study. Moreover, they produced lexically richer essays in their second term than in their first term of study. The results of the study are discussed in light of the effect of similar learning experience at university and the onset vocabulary ability of the informants. Moreover, the findings are discussed from the perspective of pedagogical implications and vocabulary assessment.
155

Bättre beslut : en studie av socialsekreterarnas handläggning av omhändertagande av barn / Better decisions : a study of social workers when taking children into care

Claezon, Ingrid January 1987 (has links)
This study treats the problems that the social worker (the child welfare worker) is faced with, when deciding to take a child into compulsory care. Empirical data (with particulars of the children and parents involved) covering the public child care at a local authority, was collected from its records and by means of interviews. Data concerning the social workers was obtained through observation, interviews and questionnaires. Out of 166 new child care clients during one year, 77%were teenagers, and nine out of ten children taken into care were adolescents.Taking up a position in child care cases and making decisions about courses of action were mostly difficult or even painful for the social worker. The decision to take a child into care was considered the hardest task in social work.The social worker's dilemma is created by the requirements of the law that any decision to take a child into care should be based on satisfactory predictions of the consequences for the child.The social worker's agony arises out of her attempts to motivate such predictions when in fact she is convinced, through experience,that very few, if any, of the consequences can be safely established.Empirical data showed that motivations of the decisions given in the investigation for the court were often vague and implicit. This may be explained by referring to the emotionally experienced conflict between prediction and subsumption.In other empirical data social workers described their anxiety when handling cases where children are taken into care. This may be analysed as 'the agony of decision-making', caused by their choice between alternative courses of action, and 'the agony of separation' brought about by the social worker's identification either with the child or with its parents.The proposed model for decision-making aims to reduce the social worker's agony, by shifting some of her burden of responsibility over to the society. This is achieved by letting the grounds for a decision to take a child into care rest explicitly on the principia of subsumption. The social worker's task is thereby limited to assessments of the child's present situation. Three criteria of assessment, child abuse, sexual abuse and 'Good-Enough Parenting' are suggested. The study points out the importance of specifying what is counted as 'Good-Enough Parenting'. / digitalisering@umu
156

台灣上市櫃公司資產減損之探討

楊美雪 Unknown Date (has links)
國內35號會計準則公報的實施是會計從歷史成本原則走向公平價值之重要里程碑,在新公報提高財務報表攸關性之同時,卻可能因放棄可靠性而增大企業報導盈餘的空間。是以實施35號公報對企業財務與營運面資訊揭露上之影響,除資產減損認列項目的正確性,認列金額的適足性,相關揭露報導的適當性外,影響資產減損的因素,以及是否具有公司或產業差異性等,均為值得深入探討的議題。 本論文以2004年報及2005年半年報為研究期間,針對資產減損之認列內容是否符合35號公報之規範內容,本研究發現國內上市櫃公司,將原來規範在1號或5號公報、後來納入35號公報受評之資產,在研究期間內認列並報導的資產減損損失合計約為新台幣203億元,分析結果隱喻國內上市櫃公司在適用35號公報時,確有存在不當認列之可能。本研究同時發現在財務報告資訊品質方面存在財務報告附註揭露「會計變動理由及其影響數」以及會計師查核意見書未對適用35號公報予以適當揭露者計有163家;以及母子公司適用35號公報之時點不同者。 至於認列資產減損金額之決定因素,本研究之實證結果發現,企業認列資產減損之大小受獲利能力、經營績效以及資產使用效能等企業營運因素之影響。在企業特性方面,本研究發現負債比例愈高及企業信用風險愈差之企業,其資產減損金額愈大。規模愈大之公司,認列之資產減損愈小;以及資訊電子業者認列顯著較高之資產減損金額。由於企業在適用35號公報上保有彈性判斷之空間,因此本研究發現企業認列資產減損之大小受到企業本身承受能力及洗大澡動機之影響,隱喻35號公報可能是管理當局可以操弄盈餘之工具之ㄧ。 / The implementation of new accounting standard (SFAS No.35) on assets impaired is a milestone of moving from historical cost principle towards fair value principle. As SFAS No. 35 may enhance the relevance of financial information at the cost of reliability, there exists the flexibility of reported earnings through the new communiqué. Based on the importance of the SFAS No.35 on a company’s financial and operational reporting, this thesis investigate the accuracy and adequateness of asset impairment, the appropriateness of reporting and disclosures of asset impairment, the determinants of asset impairment and the characteristics across industry are worth studying into thoroughly. With the topic of the contents of asset impairment in compliance with SFAS No.35, this study finds that the listed companies in Taiwan recognized and reported as asset impairment in the amount of NT $88,094 million for the study period from December, 2004 to June, 2005, of which approximately amounted to NT $20,300 million should be periodically evaluated in accordance with SFAS No.1 or SFAS No.5 before adoption of SFAS No.35. As a result, it metaphors listed company in Taiwan to use SFAS No.35 as an excuse for written off asset value. We explored the accuracy of asset impairment loss and the appropriateness of reporting for asset impairment for listed companies in Taiwan. When analyzing the reporting quality, we found that there were 163 financial reports of listed companies in Taiwan without footnote of “Accounting change and its effect” or explanationary paragraph for accounting change in auditors’ opinion for the study period from December, 2004 to June, 2005. In addition, we also found that four companies within two consolidated group started to adopt SFAS No.35 at the different timing against the rule of consistency on the adoption of accounting principle among consolidated entities. We explored the determinants of asset impairment for the listed companies in Taiwan for the period from December, 2004 to June, 2005. Our empirical results show the following: (1) The size of asset impairment is associated with operational factors such as profitability, operational performance and effectiveness of asset utilization;(2) In the perspective of company characteristic, the size of asset impairment is associated with the debt ratio and worse credit risk ;(3) The bigger company recognized the smaller impairment loss . Compared to other industries ( excluded financial institutions and securities),the huge impairment had been recognized in electronic industry .Since the evaluation of asset value involved a lot of professional judgments , we found that the size of impairment loss was associated with the management reporting motivation and capability to afford such losses . It metaphors that the SFAS No. is one of the vehicle of earning smoothing to be used.
157

Soilborne disease suppressiveness / conduciveness : analysis of microbial community dynamics / by Johannes Hendrikus Habig

Habig, Johannes Hendrikus January 2003 (has links)
Take-all is the name given to the disease caused by a soilborne fungus Gaeumannomyces graminis (Sacc.) von Arx and Olivier var. tritici Walker (Ggt), an ascomycete of the family Magnaportheaceae (Cook, 2003). This fungus is an aggressive soil-borne pathogen causing root rot of wheat (primary host), barley and rye crops (secondary host). The flowering, seedling, and vegetative growth stages can be affected by the infection of the whole plant, leaves, roots, and stems. Infections of roots result in losses in crop yield and quality primarily due to a lowering in nutrient uptake. Take-all is most common in regions where wheat is cultivated without adequate crop rotation. Crop rotation allows time between the planting dates of susceptible crops, which causes a decrease in the inoculum potential of soilborne plant pathogens to levels below an economic threshold by resident antagonistic soil microbial communities. Soilborne disease suppressiveness is an inherent characteristic of the physical, chemical, and/or biological structure of a particular soil which might be induced by agricultural practices and activities such as the cultivation of crops, or the addition of organisms or nutritional amendments, causing a change in the microfloral environment. Disturbances of soil ecosystems that impact on the normal functioning of microbial communities are potentially detrimental to soil formation, energy transfers, nutrient cycling, and long-term stability. In this regard, an overview of soil properties and processes indicated that the use of microbiological and biochemical soil properties, such as microbial biomass, the analysis of microbial functional diversity and microbial structural diversity by the quantification of community level physiological profiles and signature lipid biomarkers are useful as indicators of soil ecological stress or restoration properties because they are more responsive to small changes than physical and chemical characteristics. In this study, the relationship between physico-chemical characteristics, and different biological indicators of soil quality of agricultural soils conducive, suppressive, and neutral with respect to take-all disease of wheat as caused by the soilborne fungus Gaeumannomyces graminis var. tritici (Ggt), were investigated using various techniques. The effect of crop rotation on the functional and structural diversity of soils conducive to take-all disease was also investigated. Through the integration of quantitative and qualitative biological data as well as the physico-chemical characteristics of the various soils, the functional and structural diversity of microbial IV communities in the soils during different stadia of take-all disease of wheat were characterised. All results were evaluated statistically and the predominant physical and chemical characteristics that influenced the microbiological and biochemical properties of the agricultural soils during different stadia of take-all disease of wheat were identified using multivariate analyses. Although no significant difference @ > 0.05) could be observed between the various soils using conventional microbiological enumeration techniques, the incidence of Gliocladium spp. in suppressive soils was increased. Significant differences @ < 0.05) were observed between agricultural soils during different stadia of take-all disease of wheat. Although no clear distinction could be made between soils suppressive and neutral to take-all disease of wheat, soils suppressive and conducive to take-all disease of wheat differed substantially in their community level physiological profiles (CLPPs). Soils suppressive / neutral to take-all disease were characterised by enhanced utilisation of carboxylic acids, amino acids, and carbohydrates, while conducive soils were characterised by enhanced utilisation of carbohydrates. Shifts in the functional diversity of the associated microbial communities were possibly caused by the presence of Ggt and associated antagonistic fungal and bacterial populations in the various soils. It was evident that the relationships amongst the functionality of the microbial communities within the various soils had undergone changes through the different stages of development of take-all disease of wheat, thus implying different substrate utilisation capabilities of present soil microbial communities. Diversity indices were calculated as Shannon's diversity index (H') and substrate equitability (J) and were overall within the higher diversity range of 3.6 and 0.8, respectively, indicating the achievement of very high substrate diversity values in the various soils. A substantial percentage of the carbon sources were utilised, which contributed to the very high Shannon-Weaver substrate utilisation indices. Obtained substrate evenness (equitability) (J) indices indicated an existing high functional diversity. The functional diversity as observed during crop rotation, differed significantly (p < 0.05) from each other, implying different substrate utilisation capabilities of present soil microbial communities, which could possibly be ascribed to the excretion of root exudates by sunflowers and soybeans. Using the Sorenson's index, a clear distinction could be made between the degrees of substrate utilisation between microbial populations in soils conducive, suppressive, and neutral to take-all disease of wheat, as well as during crop rotation. Furthermore, the various soils could also be differentiated on the basis of the microbial community structure as determined by phospholipid fatty acid (PLFA) analysis. Soil suppressive to take-all disease of wheat differed significantly (p < 0.05) from soils conducive, and neutral to take-all disease of wheat, implying a shift in relationships amongst the structural diversity of microbial communities within the various soils. A positive association was observed between the microbial phospholipid fatty acid profiles, and dominant environmental variables of soils conducive, suppressive, and neutral to take-all disease of wheat. Soils conducive and neutral to take-all disease of wheat were characterised by high concentrations of manganese, as well as elevated concentrations of monounsaturated fatty acids, terminally branched saturated fatty acids, and polyunsaturated fatty acids which were indicative of Gram-negative bacteria, Gram-positive bacteria and micro eukaryotes (primarily fungi), respectively. These soils were also characterised by low concentrations of phosphorous, potassium, percentage organic carbon, and percentage organic nitrogen, as well as low soil pH. Soil suppressive to take-all disease of wheat was characterised by the elevated levels of estimated of biomass and elevated concentrations of normal saturated fatty acids, which is ubiquitous to micro-organisms. The concentration of normal saturated fatty acids in suppressive soils is indicative of a low structural diversity. This soil was also characterised by high concentrations of phosphorous, potassium, percentage organic carbon, and percentage organic nitrogen, as well as elevated soil pH. The relationship between PLFAs and agricultural soils was investigated using principal component analysis (PCA), redundancy analysis (RDA) and discriminant analysis (DA). Soil suppressive to take-all disease of wheat differed significantly (p < 0.05) from soils conducive, and neutral to take-all disease of wheat, implying a shift in relationships amongst the structural diversity of microbial communities within the various soils. A positive association was observed between the microbial phospholipid fatty acid profiles, and dominant environmental variables of soils conducive, suppressive, and neutral to take-all disease of wheat. Hierarchical cluster analysis of the major phospholipid fatty acid groups indicated that the structural diversity differed significantly between soils conducive, suppressive, and neutral to take-all disease of wheat caused by Gaeumannomyces graminis var. tritici. The results indicate that the microbial community functionality as well as the microbial community structure was significantly influenced by the presence of take-all disease of wheat caused by Gaeumannomyces graminis var. tritici, and that the characterisation of microbial functional and structural diversity by analysis of community level physiological profiles and phospholipid fatty acid analysis, respectively, could be successfully used as an assessment criteria for the evaluation of agricultural soils conducive, suppressive, and neutral to take-all disease of wheat, as well as in crop rotation systems. This methodology might be of significant value in assisting in the management and evaluation of agricultural soils subject to the prevalence of other soilborne diseases. / Thesis (M.Sc. (Microbiology))--North-West University, Potchefstroom Campus, 2004.
158

La protection des actionnaires minoritaires lors d'opérations de prises de contrôle

Belghith, Kaïs 05 1900 (has links)
Les actionnaires sont au centre du gouvernement des entreprises. Bien qu'une certaine passivité leur soit parfois reprochée, simultanément, des craintes existent qu'une démocratie des actionnaires ne limite excessivement la gestion quotidienne des entreprises. Loin d'être incompatibles, ces deux remarques reflètent la diversité des actionnaires. En pratique, leurs attentes et leur comportement dépendent fortement de deux éléments : la part du capital ou des voix qu'ils détiennent de même que leur identité. Notre recherche porte sur la protection des actionnaires minoritaires dans le cadre d'opérations de prises de contrôle de sociétés publiques. Le sujet soulève une problématique d'une grande actualité dans le contexte canadien, contexte caractérisé par une concentration de l'actionnariat des sociétés publiques. Le sujet fait la conjonction de deux problèmes d'actualité. D'une part, la multiplication des prises de contrôle s'est accrue lors des dernières décennies et ce phénomène semble, plus que jamais, promis à un brillant avenir. D'autre part, le problème de la protection des actionnaires minoritaires se pose de façon toujours plus aiguë, dans le cadre des sociétés par actions de plus en plus importantes où leur rôle tend à s'amenuiser. / Shareholders are at the heart of corporate governance. While some reproach them a certain passivity, others, at the same time, fear that a shareholders' democracy could unduly limit the daily management of corporations. Far from being incompatible, these two statements reveal the wide diversity that surrounds shareholders. In practice, their expectations and their behavior strongly depend on two items: their share in capital or their share of votes, as well as their identity. Our thesis deals with the issue of minority shareholders' protection in the context of takeover operations involving public companies. This topic raises issues of great relevance and is particularly current in the Canadian context that is characterised by a shareholding concentration of public companies. Our topic brings together two current problems. On the one hand, the rise in takeover operations has, in the last decades, been significant and this phenomenon seems, more than ever, to be destined to a very bright future. On the other hand, the issue of minority shareholders' protection also arises, ever so sharply, in the context of growing shareholding companies where shareholders' role seems to be fading.
159

Lietuvos ir pasaulio šuolininkių į tolį moterų paskutiniųjų bėgimo žingsnių ir atsispyrimo biomechaninių parametrų įtaka šuolio į tolį sportiniam rezultatui / Influence of the last running steps and biomechanical parameters of the take off to the performance of Lithuania‘s and world’s female long jumpers

Bernotaitytė, Aistė 10 September 2013 (has links)
Tyrimo objektas. Žingsnių greitis ir ilgis bei išlėkimo greitis ir kampas. Tyrimo tikslas. Ištirti Lietuvos ir Pasaulio šuolininkių į tolį moterų paskutiniųjų bėgimo žingsnių greičio ir ilgio bei išlėkimo greičio ir kampo įtaką sportiniam rezultatui. Tyrimo uždaviniai: 1. Nustatyti ir palyginti Pasaulio ir Lietuvos šuolininkių į tolį paskutiniųjų įsibėgėjimo žingsnių greičio kitimą ir jo įtaką sportiniam rezultatui. 2. Nustatyti ir palyginti Pasaulio ir Lietuvos šuolininkių į tolį paskutiniųjų įsibėgėjimo žingsnių ilgio kitimą ir jo įtaką sportiniam rezultatui 3. Nustatyti ir palyginti Pasaulio ir Lietuvos šuolininkių į tolį išlėkimo greitį ir jo įtaką sportiniam rezultatui. 4. Nustatyti ir palyginti Pasaulio ir Lietuvos šuolininkių į tolį išlėkimo kampą ir jo įtaką sportiniam rezultatui. Tiriamieji. Buvo analizuojamos Pasaulio šuolininkės dalyvavusios 12 Pasaulio lengvosios atletikos čempionate Berlyne (n=8). Lietuvos šuolininkių testavimas atliktas Lietuvos studentų čempionate (2012 m.) Kauno manieže (n=10). Hipotezė. Didelę įtaką šuolio į tolį rezultatui turi bėgimo greitis paskutiniuose metruose prieš atsispyrimą bei išlėkimo greitis ir kampas. Pagrindiniai rezultatai. Pasaulio šuolininkių į tolį greitis paskutiniajame žingsnyje yra 9.33±0,19 m/s, Lietuvos 7.76±0,41 m/s. Pasaulio šuolininkių priešpaskutinis žingsnis yra 2,31±0,17 m, Lietuvos 2,09±0,15 m, paskutinis žingsnis sutrumpėja palyginus su priešpaskutiniuoju 0,24 m, ir 0,06 m atitinkamai. Lietuvos... [toliau žr. visą tekstą] / Research object: Speed and length of the running steps, take off speed and angle. Research goal: To analyze Lithuanian and World female long jumpers –discuss influence of the speed of last running steps as well as takeoff to the performance in the competition. Research tasks: 1. To identify and compare speed ofLithuanian and World long jumpersin the last runningsteps and its influence to the performance in the competition. 2. To identify and compare length of Lithuanian and World long jumpersin the last runningsteps and its influence to the performance in the competition. 3. To identify and compare take off speed of Lithuanian and World long jumpers and its influence to the performance in the competition. 4. To identify and compare take off angle of Lithuanian and World long jumpers and its influence to the performance in thecompetition. Subjects of this research: World’s top female long jumpers who participated at the 12th Athletics Championship in Berlin (n=8). Lithuanian long jumpers who were tested at the Student Athletics Championship in Kaunas in 2012 (n=10). Hypothesis: Significant influence to the result in the long jumps comes from the running speed in the last meters before the take off, also take off speed and angle. Main results: Speed of top World top female long jumpers in the last running step is 9.33±0,19 m/s, meanwhile of Lithuanians 7.76±0,41 m/s. Length of the last step of the World female long jumpers is 2,31±0,17 m, Lithuanians 2,09±0,15 m. The last step... [to full text]
160

Soilborne disease suppressiveness / conduciveness : analysis of microbial community dynamics / by Johannes Hendrikus Habig

Habig, Johannes Hendrikus January 2003 (has links)
Take-all is the name given to the disease caused by a soilborne fungus Gaeumannomyces graminis (Sacc.) von Arx and Olivier var. tritici Walker (Ggt), an ascomycete of the family Magnaportheaceae (Cook, 2003). This fungus is an aggressive soil-borne pathogen causing root rot of wheat (primary host), barley and rye crops (secondary host). The flowering, seedling, and vegetative growth stages can be affected by the infection of the whole plant, leaves, roots, and stems. Infections of roots result in losses in crop yield and quality primarily due to a lowering in nutrient uptake. Take-all is most common in regions where wheat is cultivated without adequate crop rotation. Crop rotation allows time between the planting dates of susceptible crops, which causes a decrease in the inoculum potential of soilborne plant pathogens to levels below an economic threshold by resident antagonistic soil microbial communities. Soilborne disease suppressiveness is an inherent characteristic of the physical, chemical, and/or biological structure of a particular soil which might be induced by agricultural practices and activities such as the cultivation of crops, or the addition of organisms or nutritional amendments, causing a change in the microfloral environment. Disturbances of soil ecosystems that impact on the normal functioning of microbial communities are potentially detrimental to soil formation, energy transfers, nutrient cycling, and long-term stability. In this regard, an overview of soil properties and processes indicated that the use of microbiological and biochemical soil properties, such as microbial biomass, the analysis of microbial functional diversity and microbial structural diversity by the quantification of community level physiological profiles and signature lipid biomarkers are useful as indicators of soil ecological stress or restoration properties because they are more responsive to small changes than physical and chemical characteristics. In this study, the relationship between physico-chemical characteristics, and different biological indicators of soil quality of agricultural soils conducive, suppressive, and neutral with respect to take-all disease of wheat as caused by the soilborne fungus Gaeumannomyces graminis var. tritici (Ggt), were investigated using various techniques. The effect of crop rotation on the functional and structural diversity of soils conducive to take-all disease was also investigated. Through the integration of quantitative and qualitative biological data as well as the physico-chemical characteristics of the various soils, the functional and structural diversity of microbial IV communities in the soils during different stadia of take-all disease of wheat were characterised. All results were evaluated statistically and the predominant physical and chemical characteristics that influenced the microbiological and biochemical properties of the agricultural soils during different stadia of take-all disease of wheat were identified using multivariate analyses. Although no significant difference @ > 0.05) could be observed between the various soils using conventional microbiological enumeration techniques, the incidence of Gliocladium spp. in suppressive soils was increased. Significant differences @ < 0.05) were observed between agricultural soils during different stadia of take-all disease of wheat. Although no clear distinction could be made between soils suppressive and neutral to take-all disease of wheat, soils suppressive and conducive to take-all disease of wheat differed substantially in their community level physiological profiles (CLPPs). Soils suppressive / neutral to take-all disease were characterised by enhanced utilisation of carboxylic acids, amino acids, and carbohydrates, while conducive soils were characterised by enhanced utilisation of carbohydrates. Shifts in the functional diversity of the associated microbial communities were possibly caused by the presence of Ggt and associated antagonistic fungal and bacterial populations in the various soils. It was evident that the relationships amongst the functionality of the microbial communities within the various soils had undergone changes through the different stages of development of take-all disease of wheat, thus implying different substrate utilisation capabilities of present soil microbial communities. Diversity indices were calculated as Shannon's diversity index (H') and substrate equitability (J) and were overall within the higher diversity range of 3.6 and 0.8, respectively, indicating the achievement of very high substrate diversity values in the various soils. A substantial percentage of the carbon sources were utilised, which contributed to the very high Shannon-Weaver substrate utilisation indices. Obtained substrate evenness (equitability) (J) indices indicated an existing high functional diversity. The functional diversity as observed during crop rotation, differed significantly (p < 0.05) from each other, implying different substrate utilisation capabilities of present soil microbial communities, which could possibly be ascribed to the excretion of root exudates by sunflowers and soybeans. Using the Sorenson's index, a clear distinction could be made between the degrees of substrate utilisation between microbial populations in soils conducive, suppressive, and neutral to take-all disease of wheat, as well as during crop rotation. Furthermore, the various soils could also be differentiated on the basis of the microbial community structure as determined by phospholipid fatty acid (PLFA) analysis. Soil suppressive to take-all disease of wheat differed significantly (p < 0.05) from soils conducive, and neutral to take-all disease of wheat, implying a shift in relationships amongst the structural diversity of microbial communities within the various soils. A positive association was observed between the microbial phospholipid fatty acid profiles, and dominant environmental variables of soils conducive, suppressive, and neutral to take-all disease of wheat. Soils conducive and neutral to take-all disease of wheat were characterised by high concentrations of manganese, as well as elevated concentrations of monounsaturated fatty acids, terminally branched saturated fatty acids, and polyunsaturated fatty acids which were indicative of Gram-negative bacteria, Gram-positive bacteria and micro eukaryotes (primarily fungi), respectively. These soils were also characterised by low concentrations of phosphorous, potassium, percentage organic carbon, and percentage organic nitrogen, as well as low soil pH. Soil suppressive to take-all disease of wheat was characterised by the elevated levels of estimated of biomass and elevated concentrations of normal saturated fatty acids, which is ubiquitous to micro-organisms. The concentration of normal saturated fatty acids in suppressive soils is indicative of a low structural diversity. This soil was also characterised by high concentrations of phosphorous, potassium, percentage organic carbon, and percentage organic nitrogen, as well as elevated soil pH. The relationship between PLFAs and agricultural soils was investigated using principal component analysis (PCA), redundancy analysis (RDA) and discriminant analysis (DA). Soil suppressive to take-all disease of wheat differed significantly (p < 0.05) from soils conducive, and neutral to take-all disease of wheat, implying a shift in relationships amongst the structural diversity of microbial communities within the various soils. A positive association was observed between the microbial phospholipid fatty acid profiles, and dominant environmental variables of soils conducive, suppressive, and neutral to take-all disease of wheat. Hierarchical cluster analysis of the major phospholipid fatty acid groups indicated that the structural diversity differed significantly between soils conducive, suppressive, and neutral to take-all disease of wheat caused by Gaeumannomyces graminis var. tritici. The results indicate that the microbial community functionality as well as the microbial community structure was significantly influenced by the presence of take-all disease of wheat caused by Gaeumannomyces graminis var. tritici, and that the characterisation of microbial functional and structural diversity by analysis of community level physiological profiles and phospholipid fatty acid analysis, respectively, could be successfully used as an assessment criteria for the evaluation of agricultural soils conducive, suppressive, and neutral to take-all disease of wheat, as well as in crop rotation systems. This methodology might be of significant value in assisting in the management and evaluation of agricultural soils subject to the prevalence of other soilborne diseases. / Thesis (M.Sc. (Microbiology))--North-West University, Potchefstroom Campus, 2004.

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