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Herbicide tolerance in amenity grassesFisher, R. January 1975 (has links)
No description available.
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Investigation of methods for determination of Wireless Node's Cluster ConnectivityWang, Xu January 2015 (has links)
Recent advancement in wireless communications and electronics has enabled the development of sensor networks. With development in technology, wireless sensor network is used more and more in our daily life, because the technology is more flexible and cheaper than the wired sensor network. The objective of this study has been to solve the problem that how closely a group of mobile wireless nodes are clustered. Matlab is used to simulate the various situations of nodes. There are two major parts in this software design. One is the function of detecting the movement of the mouse. Another is the function of estimating the connectivity of the nodes. Some methods will be proposed and evaluated through some realistic scenarios.
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Nosocomial pathogens within biofilmsJones, Steven Michael January 2001 (has links)
No description available.
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Degradation of human vault RNA1 by RNA interference and multidrug resistance in GLC4/REV, a small-cell lung cancer cell lineArdehali, M. Behfar M. January 2003 (has links)
There is no abstract available for this thesis. / Department of Biology
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The main currents of modern anarchist political thoughtMorrison, Douglas Kent January 1971 (has links)
This thesis has investigated the four main branches of modern anarchist political thought. It has emphasized the relationships between the individual and the society in which he lives.Each of the main currents of anarchism – anarcho-communism, anarcho-syndicalism, anarchist individualism, and religious anarchism -- were described in their three essential components: 1) the critique of the existing order; 2) the concept of revolution; 3) the vision of the future anarchist order.The thesis attempted to point out each theory's philosophical contradictiors as well as its theoretical strengths.
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The effects of aging, exercise and food restriction on the development of insulin resistance in adipocytes of young ratsKastello, Gary M. January 1987 (has links)
Male Sprague-Dawley rats were used to determine whether insulin resistance develops between 1.5-4.0 months of age and whether it is related to aging or the development of obesity. Animals were randomly placed into a single 1.5 months old group (1.5 CN) or raised in one of three 4.0 month old groups; exercise trained (ET), pairfed (PF), or sedentary control (4.0 CN). The ET group was fed ad Iibitum and had free access to a spontaneous exercise wheel, while the PF group was fed to maintain equal body weight with the ET group. The young group was sacrificed with nembutal injection (45 mg/kg body weight) at 1.5 months while the other three groups were sacrificed at 4.0 months of age. Epididymal fat pads were removed, digested with collagenase (5 mg/ml) and the isolated cells sized and assayed for 2-deoxyglucose transport over a range of insulin concentrations (0-1000 µU/ml). Body composition (percent fat, bone and muscle) was performed on the carcasses of these animals at a later date. The 2-deoxyglucose transport of the 1.5 CN group was significantly greater than the 4.0 CN group at insulin concentrations of 50, 250 and 1000 uU/ml and significantly greater than all 4.0 months groups at 1000 11U/ml- The adipocyte size was significantly smaller in the 1.5 CN group followed in ascending order by the ET, PF and 4.0 CN group. The body compositions demonstrated the expected trends as the 1.5 CN group had the highest percent bone and muscle while demonstrating the lowest percent fat. The ET group was most able to maintain the body composition of the 1.5 CN group, while the PF and 4.0 CN groups were least able to maintain this composition respectively.The results indicate that: 1) Adipocyte insulin resistance develops in the rat between 1.5 and 4.0 months of age. 2) This development of insulin resistance is related to obesity and not to aging. 3) Exercise may prevent the development of insulin resistance by preventing adipocyte hypertrophy. 4) Exercise helps maintain optimal body composition. These results should be of interest to type II diabetics as an exercise program may decrease their adipocyte size, enhance body composition and decrease insulin resistance.
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A metabolomics approach for characterising tuberculosis / Ilse OlivierOlivier, Ilse January 2012 (has links)
In 2001, the WHO declared tuberculosis (TB) a global emergency, as one third of the world‟s
population suffered from latent M. tuberculosis infection. Today, a decade later, millions of
people still die worldwide as a result of this disease. This growing TB incidence may be
ascribed to a variety of reasons, including, amongst others, the inadequacies associated with
the currently available diagnostic methods and TB treatment regimes, especially when
considering the growing MDR-TB and HIV epidemics.
This study investigated the potential of metabolomics as a tool for characterising TB and various
TB-causing bacteria, allowing for a better understanding of TB disease mechanisms, which may
ultimately lead to improved diagnostic and treatment regimens.
Firstly, we investigated the potential of a fatty acid, metabolomics approach to characterise
various cultured Mycobacterium species. For this exploration, three fatty acid extraction
procedures, prior to GC-MS analyses, were compared based on their respective repeatability
and extraction capacities. Using the data obtained from the analyses done with the most
optimal extraction approach (the modified Bligh-Dyer method), multivariate statistical analyses
were able to differentiate between the various Mycobacterium species at a detection limit of 1 x
103 bacterial mL-1, in 16 hours. Subsequently, the compounds best describing the variation
between the sample groups were identified as potential metabolite markers and were discussed
in the light of previous studies.
The most optimal GC-MS, fatty acid metabolomics approach, mentioned above, was then
applied to analyse and characterise a wild-type M. tuberculosis parent strain and two rifampicinresistant
conferring rpoB mutants (S522L and S531L). Due to the variation in their fatty acid
profiles, a clear differentiation was achieved between these M. tuberculosis sample groups, and
those metabolites contributing most to this variation were identified as metabolite markers
characteristic for rifampicin-resistance. The altered metabolite markers detected in the rpoB
mutants propose a decreased synthesis of various 10-methyl branched-chain fatty acids and
cell wall lipids, and an increased use of the shorter-chain fatty acids and alkanes as alternative
carbon sources. Furthermore, the rpoB S531L mutant, previously reported to occur in well over
50% of all clinical rifampicin-resistant M. tuberculosis strains, showed a better capacity for using
these alternative energy sources, in comparison to the less frequently detected rpoB S522L
mutant.
The developed fatty acid GC-MS metabolomics approach was then successfully adapted in
order to improve its speed, cost and complexity. This improved fatty acid extraction method was furthermore compared to another, similar approach (total metabolome extraction method),
developed for the extraction of a much wider variety of compounds, prior to GC-MS and
statistical data analyses. Although both these methods show promise for bacterial
characterisation using matabolomics, the total metabolome extraction method proved the better
of the two methods because it is comparatively simpler, faster (taking less than 4 hours), more
repeatable, better differentiates between sample groups due to less within group variation, has
a lower detection limit, and isolates a wider variety of biologically relevant metabolites (as
opposed to fatty acids alone). We, furthermore, identified and described the occurrence of
those compounds, extracted by both methods, which contribute most to the variation between
the bacterial groups, in order to validate these methods for metabolomic applications and the
isolation of compounds with biological relevance.
In order to evaluate the potential of this developed metabolomics approach for application to
biological samples other than bacteriological cultures, it was adapted for the direct analyses of
complex sputum samples. For this application, four sputum pre-extraction preparation methods,
including three standard Mycobacterium cell isolation procedures (Sputolysin, NALC-NaOH,
and NaOH) and a fourth, applying only a simple ethanol homogenisation step, prior to direct
sputum extraction, were compared. Of these methods, the ethanol homogenisation method
proved to have the best comparative extraction efficiency, repeatability and differentiation
capacity, when used in combination with the previously developed metabolomics methods.
Subsequently, when applying this approach to patient collected sputum samples, a set of
metabolite markers, differentiating the TB-positive from the TB-negative samples, were
identified. These markers could directly be linked to: 1) the physical presence of the M.
tuberculosis in these samples; 2) changes in the bacterial metabolome due to in vivo growth
conditions and; 3) changes in the human metabolome due to pulmonary M. tuberculosis
infection.
In addition to the proposal of a number of new hypotheses, explaining various mechanisms of
TB and drug-resistant TB, the mapping of the newly identified metabolite markers to known
metabolic pathways led to the confirmation of various previously suggested metabolic pathways
and alterations thereof due to an assortment of perturbations. Therefore, this study significantly
contributes to the characterisation of various TB causing bacteria, rifampicin-resistant M.
tuberculosis strains and the TB disease state, which may in future lead to the development of
innovative TB vaccination, diagnostic and treatment protocols. / Thesis (PhD (Biochemistry))--North-West University, Potchefstroom Campus, 2012
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The assessment of multiple antibiotic resistant enterococci in communal and commercial cattle faecal samples and their water sources in Mafikeng, North-West Province, RSA / Lerato Lisbeth Njaki RamatlhapeRamatlhape, Lerato Lisbeth Njaki January 2006 (has links)
Enterococcus species are found in faeces of mammals, birds, insects, reptiles, but also soil, plants and water. These bacteria can also be isolated from animal products such as milk, cheese and meat.
This study was aimed at isolating Enterococcus species from communal and commercial cattle faecal and water samples. A further objective was to determine the antibiotic resistance profiles of the isolates as well as some of the potential factors and mechanisms that could be responsible for their resistance to antibiotics.
A total of 79 cattle faecal and water samples were collected from the communal and commercial farms. Sixty-five faecal samples were collected from commercial (33 healthy and 16 diarrhoeal cattle) and communal (16 healthy cattle) farms. Twelve water samples were collected from the commercial farms and 2 from the communal farm.
From all the samples collected, 129 Enterococcus isolates were identified. Isolates, which included Enterococcus faecium (E. faecium), Enterococcus avium (E. avium), Enterococcus durans (E. durans) and Streptococcus bovis I (Sc. bovis !), were isolated from bovine faeces and water samples, while E. avium was only isolated from water at the communal farm. Furthermore, isolates from the healthy and diarrhoeal commercial cattle included E. faecium, E. avium, E. durans and Sc. bovis I. E. faecium and E. avium species were also isolated from the commercial farm cattle water sources. However, E. faecium was the predominant species in communal cattle faecal and water samples. On the other hand, E. avium was dominant in. commercial cattle faecal and water samples.
Multiple antibiotic resistance (MAR) was observed in enterococci from all samples at both farm types. The predominant MAR phenotype that was prevalent in all enterococci species was GENSMX- NAL-NIT-KAN-STR All isolates showed an MAR index above 0.2 (water; 0.58 to 0.68 and faeces; 0.6 to l. 7). Cluster analysis based on antibiotic inhibition zone diameter data, resulted in dendrograms that showed a similar relationship of Enterococcus isolates from the two farms. Between 13% and 50% of Enterococcus isolates from cattle faeces and water samples from communal and commercial farms were resistant to vancomycin and oxytetracycline. In general, 11% of all the Enterococcus isolates from the cattle faeces was resistant to vancomycin. Thirty one per cent of the isolates from cattle water sources were resistant to both drugs. Vancomycin Resistant Enterococcus (VRE) genes conveying the vanC phenotype were obtained from E. durans and E. avium. This was an unexpected result. The tet A, tet Band tet C genes were not obtained from any of the Enterococcus species.
Further studies on antibiotic resistance should be undertaken especially in rural areas, where farmers could be using over-the-counter medicines such as tetracycline even when it is not necessary. It was speculated in this study that there could be a development of potential reservoirs of antibiotic resistance in farmlands. In order to prevent the distribution of MAR organisms or their transferable resistance genes, a sensible use of antibiotics is necessary in veterinary medicine, animal husbandry and human medicine. / MSc. (Agriculture) North-West University, Mafikeng Campus, 2006
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A metabolomics approach for characterising tuberculosis / Ilse OlivierOlivier, Ilse January 2012 (has links)
In 2001, the WHO declared tuberculosis (TB) a global emergency, as one third of the world‟s
population suffered from latent M. tuberculosis infection. Today, a decade later, millions of
people still die worldwide as a result of this disease. This growing TB incidence may be
ascribed to a variety of reasons, including, amongst others, the inadequacies associated with
the currently available diagnostic methods and TB treatment regimes, especially when
considering the growing MDR-TB and HIV epidemics.
This study investigated the potential of metabolomics as a tool for characterising TB and various
TB-causing bacteria, allowing for a better understanding of TB disease mechanisms, which may
ultimately lead to improved diagnostic and treatment regimens.
Firstly, we investigated the potential of a fatty acid, metabolomics approach to characterise
various cultured Mycobacterium species. For this exploration, three fatty acid extraction
procedures, prior to GC-MS analyses, were compared based on their respective repeatability
and extraction capacities. Using the data obtained from the analyses done with the most
optimal extraction approach (the modified Bligh-Dyer method), multivariate statistical analyses
were able to differentiate between the various Mycobacterium species at a detection limit of 1 x
103 bacterial mL-1, in 16 hours. Subsequently, the compounds best describing the variation
between the sample groups were identified as potential metabolite markers and were discussed
in the light of previous studies.
The most optimal GC-MS, fatty acid metabolomics approach, mentioned above, was then
applied to analyse and characterise a wild-type M. tuberculosis parent strain and two rifampicinresistant
conferring rpoB mutants (S522L and S531L). Due to the variation in their fatty acid
profiles, a clear differentiation was achieved between these M. tuberculosis sample groups, and
those metabolites contributing most to this variation were identified as metabolite markers
characteristic for rifampicin-resistance. The altered metabolite markers detected in the rpoB
mutants propose a decreased synthesis of various 10-methyl branched-chain fatty acids and
cell wall lipids, and an increased use of the shorter-chain fatty acids and alkanes as alternative
carbon sources. Furthermore, the rpoB S531L mutant, previously reported to occur in well over
50% of all clinical rifampicin-resistant M. tuberculosis strains, showed a better capacity for using
these alternative energy sources, in comparison to the less frequently detected rpoB S522L
mutant.
The developed fatty acid GC-MS metabolomics approach was then successfully adapted in
order to improve its speed, cost and complexity. This improved fatty acid extraction method was furthermore compared to another, similar approach (total metabolome extraction method),
developed for the extraction of a much wider variety of compounds, prior to GC-MS and
statistical data analyses. Although both these methods show promise for bacterial
characterisation using matabolomics, the total metabolome extraction method proved the better
of the two methods because it is comparatively simpler, faster (taking less than 4 hours), more
repeatable, better differentiates between sample groups due to less within group variation, has
a lower detection limit, and isolates a wider variety of biologically relevant metabolites (as
opposed to fatty acids alone). We, furthermore, identified and described the occurrence of
those compounds, extracted by both methods, which contribute most to the variation between
the bacterial groups, in order to validate these methods for metabolomic applications and the
isolation of compounds with biological relevance.
In order to evaluate the potential of this developed metabolomics approach for application to
biological samples other than bacteriological cultures, it was adapted for the direct analyses of
complex sputum samples. For this application, four sputum pre-extraction preparation methods,
including three standard Mycobacterium cell isolation procedures (Sputolysin, NALC-NaOH,
and NaOH) and a fourth, applying only a simple ethanol homogenisation step, prior to direct
sputum extraction, were compared. Of these methods, the ethanol homogenisation method
proved to have the best comparative extraction efficiency, repeatability and differentiation
capacity, when used in combination with the previously developed metabolomics methods.
Subsequently, when applying this approach to patient collected sputum samples, a set of
metabolite markers, differentiating the TB-positive from the TB-negative samples, were
identified. These markers could directly be linked to: 1) the physical presence of the M.
tuberculosis in these samples; 2) changes in the bacterial metabolome due to in vivo growth
conditions and; 3) changes in the human metabolome due to pulmonary M. tuberculosis
infection.
In addition to the proposal of a number of new hypotheses, explaining various mechanisms of
TB and drug-resistant TB, the mapping of the newly identified metabolite markers to known
metabolic pathways led to the confirmation of various previously suggested metabolic pathways
and alterations thereof due to an assortment of perturbations. Therefore, this study significantly
contributes to the characterisation of various TB causing bacteria, rifampicin-resistant M.
tuberculosis strains and the TB disease state, which may in future lead to the development of
innovative TB vaccination, diagnostic and treatment protocols. / Thesis (PhD (Biochemistry))--North-West University, Potchefstroom Campus, 2012
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The discipline of freedom: Foucault, neo-liberal governmentality and resistanceFleming, Andrew 13 January 2014 (has links)
Michel Foucault is often is taken to represent human beings as products of insidious structures of power that lie beyond control and perception. This is an unfair characterisation since a deeper reading into his work reveals reflections and even insistences on creativity, resistance and freedom as fundamental components of human experience. My aim is to unify these two aspects of Foucault's thought so as to provide a positive account of political resistance to power relations in contemporary neo-liberal society.
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