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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.
841

The effect of early-life exposure of rats to venlafaxine on behaviour and neurological markers of antidepressant action in adulthood / Renier Kruger

Kruger, Renier January 2014 (has links)
Major depression is a serious mood disorder affecting more than 120 million people worldwide, irrespective of their race or socio-economic status. This psychiatric disorder is predicted to become the second leading cause of disability by the year 2020, second only to heart diseases in the global population, without distinguishing differences in the incidence within defined age groups. Depression is known to affect people across all age groups, including children, adolescents, adults and geriatrics, although older age is associated with an increased susceptibility to major depression and other psychiatric conditions. Until the 1970‘s depression during childhood and adolescence was thought to be uncommon or non-existent. Recent epidemiological studies have demonstrated that there is a persistent escalation in the prevalence of depression in children and adolescents. Accordingly, the number of prescriptions for drugs to treat this disorder in juveniles has escalated significantly. With our current limited understanding of the safety and long-term effects of treatment with antidepressants, the clinician is left making decisions without sound evidence of safety. In addition, psychotropic drugs may affect neurodevelopment during childhood and adolescence and may consequently modulate susceptibility to psychiatric disorders later in life. The objective of the current study was to investigate the effects of early-life (pre-natal and postnatal) chronic treatment with venlafaxine, a dual action serotonin-noradrenalin reuptake inhibitor, during the developmental phase of the serotonin and norepinephrine pathways in stress-sensitive rats on measures of cognition, anxiety-like and depressive-like behaviour later in life. The study also investigated which age shows optimal behavioural changes later in life, following the above mentioned administration of venlafaxine. In addition we also determined the effects that the administration of venlafaxine has on the levels of monoamines l-norepinephrine (l-NE) and serotonin (5-HT) in the prefrontal cortex and the hippocampus. A number of translational animal models of psychiatric disorders have been described and validated, and is suitable for such investigations. For the current study we used stress-sensitive Flinders Sensitive Line (FSL) rats and their controls, Flinders Resistant Line (FRL) rats. Pregnant dams were injected subcutaneously for 14 days with 10 mg/kg venlafaxine or saline from pre-natal day 15 (ND-15) to ND-01. New-born pups were then injected subcutaneously with 3 mg/kg venlafaxine or saline for 14 days from postnatal day 3 (ND+03) to ND+17. These doses were determined from previous studies reported in literature. Four rat treatment groups of both FSL and FRL rats received injections during pre-natal + postnatal ages as follows: saline + saline, venlafaxine + saline, saline + venlafaxine and venlafaxine + venlafaxine. Following the drug treatments, all rat groups were housed under normal conditions until the indicated time to be subjected to a battery of behavioural tests, including the novel object recognition test (nORT), locomotor activity test (Digiscan®), elevated plus maze (EPM) and forced-swim test (FST), scheduled on either ND+35, ND+60 or ND+90. Separate treatment groups were used for each age group. After the behavioural tests animals were decapitated, the brains removed and the prefrontal cortex and hippocampus dissected out. These were analysed at a later stage using an HPLC with electrochemical detection to determine the levels of the monoamines l-NE and 5-HT. All animal procedures were approved by the Ethics Committee of the North-West University (approval number: NWU-00045-10-S5), and are in accordance with the recommendations of the National Institutes of Health guide for the care and use of laboratory animals. The data from the current study suggest that in general FRL rats were not influenced by the early-life treatment with venlafaxine, as observed in the nORT, EPM or FST on ND+35, ND+60 or ND+90. There was minimal changes seen in the immobile behaviour in the FST of FRL rats that received prenatal venlafaxine. As expected, depressive-like behaviour in the FST was significantly enhanced in FSL rats relative to corresponding FRL rat groups as observed at ND+35 and ND+60, but not ND+90. Importantly, depressive-like behaviour was reversed following pre- and postnatal treatment with venlafaxine in FSL rats at ND+60, relative to the corresponding FRL rat groups. Reversal of depressive-like behaviour in FSL rats were not observed at ND+35 or ND+90, suggesting a delayed response that is reversed later in adulthood. The data from the nORT, Digiscan® or EPM did not reveal any significant differences between the various FSL treatment groups, including at ND+60. The current study therefore demonstrated that the treatment regimen employed had a transient effect on depressive-like behaviour later in life and suggested that genetic susceptibility plays an important role in the treatment of depression. This was suggested by the venlafaxine-induced decrease in immobile behaviour exhibited by FSL rats at ND+60 in the FST, and the subsequent increase in immobile behaviour at ND+90. In general, the most significant venlafaxine-induced effects were seen in FSL rats, suggesting genetic susceptibility plays an important role. / MSc (Pharmacology), North-West University, Potchefstroom Campus, 2014
842

Studies on Fusarium poæ, F. sporotrichioides and F. langsethiæ, Responsible for Production of T2/HT2 and Nivalenol in Wheat

NAZARI, LEYLA 21 February 2013 (has links)
La fusariosi della spiga è tra le malattie del grano più distruttive e diffuse al mondo. Alcune specie responsabili di questa malattia sono micotossigene. Ci sono state segnalazioni della presenza di nivalenolo (NIV) e tossine T-2 e HT-2 nel nord Italia, micotossine prodotte da Fusarium poae, F. sporotrichioides e F. langsethiae. I limiti massimi di T-2 e HT-2 ammessi nei cereali non trasformati e nei prodotti a base di cereali non sono ancora stati individuati (Regolamento CE 856/2005). Il programma di dottorato del candidato è inserito in questa linea di ricerca. Sono stati condotti studi in vitro sulla biologia ed ecologia dei funghi produttori di NIV, T-2 e HT-2, considerando quattro isolati di F. poae, due di F. sporotrichioides e due di F. langsethiae. Le prove hanno riguardato la crescita delle colonie, la produzione di spore, la loro germinazione e la produzione di micotossine. La gravità dell'infezione, l'invasione (quantità di DNA nelle spighe), la resa in granella e la produzione di tossine sono state misurate a diversi tempi, temperature (in planta) e stadi fenologici (in campo) dopo l'inoculazione artificiale. Al fine di verificare l'attendibilità dei dati, tutti gli esperimenti in planta e in campo sono stati ripetuti per due anni. / The Fusarium head blight is one of the most destructive diseases of wheat in different parts of the world. Some of the species responsible for Fusarium head blight are potentially mycotoxigenic. There are reports of nivalenol (NIV), T-2 toxin and HT-2 in northern Italy. These are metabolites produced by F. poae, F. sporotrichioides, and F. langsethiae. The maximum limits of T-2 and HT-2 permitted in unprocessed cereals and cereal-based products, included in EC Regulation 856/2005 has not been identified. The PhD program of the candidate is placed in this line of the research. In vitro studies conducted on the biological and ecological of pathogenic fungi producer NIV, T-2 and HT-2 including four isolates of F. poae, two of F. sporotrichioides and two isolate of F. langsethiae. Tests were carried out to investigate the conidia germination, colony growth, spore production and mycotoxins production. The infection severity, invasion (amount of DNA in spikes), grain yield and toxin production were measured at different temperatures, different time (in planta) and different growth stages (in field) after artificial inoculation.
843

Serotonin 5-HT Receptor Currents in the Healthy Rodent Prefrontal Cortex and in a Model of Affective Disorders

Goodfellow, Nathalie M. 07 August 2013 (has links)
Affective disorders represent one of the greatest global burdens of disease. Work in patients with affective disorders demonstrates that serotonin (5-HT) signaling within the prefrontal cortex, particularly at the level of the 5-HT receptors, plays an integral role in both the pathology and treatment of these diseases. Surprisingly, the characterization of the prefrontal 5-HT receptors under both healthy and pathological conditions remains incomplete. The technique of whole cell electrophysiological recording provides an unparalleled tool for investigating the functional effects of these 5-HT receptors on neurons in acute prefrontal cortical slices. The objectives of my thesis were to delve deeper into the 5-HT receptor subtypes that modulate the prefrontal cortex in the healthy control rodents and to examine how this modulation was disrupted in a rodent model of affective disorders. In work from healthy control rodents, I examined two prefrontal 5-HT receptor-mediated currents. I show for the first time the presence of the 5-HT1A receptor during the early postnatal period, a critical developmental window during which this receptor programs adult anxiety behaviors. In adulthood, I characterized an inhibitory current mediated by the 5-ht5A receptor; findings that will permit the classification of this receptor within the 5-HT receptor family. Collectively, this investigation of functional early 5-HT1A receptors and adult 5-ht5A receptors offers a novel conceptual framework for understanding 5-HT receptor modulation of the healthy prefrontal cortex. To model vulnerability to affective disorder in the rodent, I used the early stress of maternal separation. In early stress rodents, I observed a marked increase in 5-HT1A receptor currents during the early postnatal period, the critical time window for the programming of anxiety. By comparison, in adulthood I found that rodents exposed to early stress displayed increased 5-HT2A receptor currents. These findings provide novel insight into the developmental and long-lasting pathology underlying early stress, indicating that the early prefrontal 5-HT1A receptor and adult prefrontal 5-HT2A receptors as a potential therapeutic target in treatment of affective disorders At a fundamental level, the findings provided herein offer critical insight into the cellular mechanisms underlying affective disorders, one of the most debilitating and costly diseases worldwide.
844

Gated Communities As A New Upper-middle Class Utopia In Turkey: The Case Of Angora Houses

Ertuna, Ayberk Can 01 December 2003 (has links) (PDF)
The aim of this thesis is to analyse the effects of gated communities in the increasing fragmentation of urban space and in the increasing polarisation among different classes in the Turkish context, more specifically in the capital, Ankara. Since the case study is based on an upper-middle class suburban gated community, first, suburbanisation &ldquo / as a wave of urbanisation&rdquo / is analysed. Then, the debates about the middle class and the transformation that this social stratum has undergone are discussed. Later, the formation of gated communities around the world and in Turkey are analysed within the general framework of the transformation of the urban sphere. Finally, the theoretical arguments are scrutinised by incorporating the findings of the case study carried out in Angora Houses. In this study Angora Houses is concluded to be a gated community which is &ldquo / fortified&rdquo / for the preservation of an upper-middle class lifestyle rather than for security concerns and which reproduces socio-spatial inequalities among Ankaraites rather than standing as only the expression of them.
845

The Role Of Local Capabilities In The Exporting Smes And Their Role In The Regional Economic Grtowth: The Case Study Of Ankara

Celebi, Deniz 01 December 2003 (has links) (PDF)
In the literature there is a great emphasis on the theories of regional growth and development. In many theories, the role of small and medium sized enterprises (SMEs) in the economic growth and development of different regions has been widely discussed. Therefore, there is an emphasis upon the importance of the SMEs in the growth and development of the regional and national economies. The aim of this study is to clarify the role of local capabilities in the exporting SMEs and consequently define their role in regional growth and shed some light on the situation of the local capabilities in Ankara province. Therefore, in this study, firstly the theoretical framework of regional growth theories and the role of exporting SMEs in the regional economic growth are constructed. Secondly, the increasing role of different types of SMEs in the regional growth and their defining characteristics are discussed. Thirdly, brief remarks on SMEs in the Turkish economy and Ankara have been provided. Afterwards, the main hypothesis of this study tested through the results iv iv obtained from the survey that was done with SMEs in Ankara province and success factors of SMEs are drawn from the in-depth interviews. Finally, by making a general evaluation some policy implications have been drawn.
846

Design Problems Of Aoc As A Public Property

Yildirim, Derya 01 March 2004 (has links) (PDF)
In this thesis, the loss of land totality and loss of sight of establishment purposes of a unique application AO&Ccedil / which is a very vital open green area for Ankara is discussed since it was established. The importance of AO&Ccedil / for the city of Ankara, loosing its land totality and diverging from its establishment purposes was of interest to public opinion for long years. This study aims to analyze the location of AO&Ccedil / in the city, the role of AO&Ccedil / within Ankara Metropolitan area, its qualities and the future objectives of the State Farm which were deviated from its establishment purposes by means of inefficient planning regulations. It is obvious that as a public property, the establishment purposes and the ideology behind AO&Ccedil / must be reevaluated considering the opportunities of the State Farm as a huge open green area for the city. Moreover, some future principles for the fragmented farmlands must be determined according to the development area of the city. v With this aim, the location of AO&Ccedil / in the city and the roles given to AO&Ccedil / by the Ankara city plans is analyzed since its establishment and the reevaluation of establishment purposes and the basic objectives necessary for the future development of AO&Ccedil / and design principles necessary to preserve the totality of AO&Ccedil / and open farmlands back to public use is argued in this thesis.
847

Urban Compactness: A Study Of Ankara Urban Form

Caliskan, Olgu 01 September 2004 (has links) (PDF)
Sustainable urban development is mentioned together with the concept of urban form in contemporary planning literature. The main reason behind this is a need for determining an ideal physical development scheme and its main principles of urban future in a broad term. Besides, the operational side of urban planning requires a concrete set of design codes in order to transform urban space in both macro and mezzo scale. At this point, the concept of urban compactness and the idea of Compact City have come into the agenda of planning. In the last decade, the model of compact city has become a prototype of sustainable urban form in developed countries. It is also argued whether compact urbanity is a nostalgic metaphor or an engineering solution. It has emerged as a reaction to the negative consequences of urban sprawl and suburbanization as the anti-urbanist urban phenomena in Western geographies. Hence, the relevance of urban compactness should be examined for developing and underdeveloped countries and their settlement structures. The basic motivation of the thesis is to examine the relevance and validity of urban compactness in the case of Turkey as a developing Eurasian country. For this end, the evolution of urban compactness as a fact and an idea in the historical context of developed countries and it&rsquo / s meaning for the developing world / Ankara is examined as a case study by re-reading its planning history and the transformation of its urban form from the point of view of compactness.
848

A Design Problem Of Under-utilized Spaces: The Case Of Ankara-old Industrial District

Cirik, Umut 01 March 2005 (has links) (PDF)
The problem of under-utilized spaces has become an important problem of cities during the last decades. In rapidly urbanizing cities, especially in the city centers where the early city settlement or old town was situated, many urban and industrial functions have moved out leaving behind abandoned or under-utilized. These spaces, due to political, economical, cultural and spatial reasons, could neither undergo healthy urban transformation process nor be reused. Such spaces pose problems to contemporary urban planning and architecture. This thesis takes up the problem of under-utilized space exemplified in the inner city of Ankara, where a large stock of land is public property. The thesis defines the problem of under-utilized space and analyzes the causes for their emergence. The aim of the study is to understand the urban character of under-utilized part of the old industrial district, which is one of the most important districts in the city center of Ankara, and develop urban transformation approaches in particular for the old industrial district as well as for similar urban areas. The thesis focuses on the urban design dimension of transformation process. Urban design as a public policy makes important contributions in solving urban problems. The thesis develops some urban design principles in accordance with some spatial, functional and social concerns in order to redevelop the old industrial district. With this contribution the study emphasizes the importance of urban design as a tool which can be utilized in the urban transformation process by urban planners and architects.
849

Urban Projects&#039 / Implementations Towards A European City: A Case Analysis Of Eskisehir Greater Municipality

Babadogan, Hale 01 June 2005 (has links) (PDF)
This thesis analyzes the projects&rsquo / implementations of EskiSehir Greater Municipality in European City context. In this thesis, Regional and Urban Policies of European Union and their historical bases are discussed, moreover / projects of EskiSehir Greater Municipality are examined in accordance with these theoretic parts and with principles of a European City. The thesis also seeks to answer the questions such as why Turkish cities have an aim to be a European City and what should be accomplished to satisfy the conditions of European City.
850

Social Stratification And Consumption Profiles Of Ankara: A Case Study In Ankara Residential Areas

Akpinar, Figen 01 January 2005 (has links) (PDF)
SOCIAL STRATIFICATION AND CONSUMPTION PROFILES OF ANKARA: A CASE STUDY IN ANKARA RESIDENTIAL AREAS This dissertation attempts to develop a social stratification model considering its spatial dimension for the households in the city of Ankara. The spatiality of social class has rarely been in the agenda of scholars and has not been explored empirically. For this reason, the study aims to test the hypothesis that social segregation in Turkish cities is empirically measurable and manifests itself in the common patterns of behaviours and similar conditioning of existence in the urban space. The focus of attention of the thesis is based on the relationship between the material inequalities of different social strata within its territorial context. If a class becomes a social reality, this must be shown in the formation of common patterns of behaviour and attitude, and manifests itself in urban space. In short the scope of the study is a twofold: Thesis questions are: (1) how and upon what basis social groups and strata can be located in the economic and socio-cultural structure of the society. This part of the study deals with the objective &amp / #8216 / &amp / #8217 / set&amp / #8217 / &amp / #8217 / of criteria / thesis question (2) whether the same coherency can be coincided in the space. This part deals with the analysis of the spatial dimension of social &amp / #8216 / &amp / #8217 / class&amp / #8217 / &amp / #8217 / which means segregation. Thesis findings provide sufficient evidence that the differences stemmed from the material possessions and consumption patterns of the urban households cannot be understood by employing the conventional instruments as such rural/urban, traditional/modern as the division of axes. New conceptualisation urgently is needed and consumption studies offer prospective and highly potential issue.

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