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No description available.

The study of architectural surface to the end of developing `Deep Surface and the implementation of the deep surface to aid in the development of a new research facility for the University of Pretoria. / Dissertation (MArch(Prof))--University of Pretoria, 2009. / Architecture / unrestricted

In this study a standardized 46 week chronic drinking water toxicity protocol was used to elucidate the toxic potential of Sutherlandia frutescens (S. frutescens) using histopathologic, morphometric and transmission electron microscopic analysis. The histopathologic changes in the duodenum, heart, kidney, liver, lung, pancreas and spleen of male Wistar rats were evaluated. Fifty-four rats were randomly divided into four groups: Group 1 – Normal diet control (ND control), n=7, Group 2 – Normal diet + plant extract (ND + p), n=9, Group 3 – High fat diet control (HFD control), n=19Group 4 – High fat diet + p (HFD + p), n=19In the high fat group male Wistar rats were fed ±55 g/day of a specialised high fat diet over a 46 week period to induce obesity and an insulin resistant state. The treatment groups (groups 2 and 4) received a dose concentration of a tea extract of the S. frutescens plant in their drinking water daily. This study showed that the consumption of S. frutescens significantly reduces weight gain in male Wistar rats on a chronic high fat diet (p≤0.001 vs. HFD control group). S. frutescens appears to propagate periportal and centrilobular glycogen storage in rat hepatocytes in the experimental groups as exemplified by a significantly (p≤0.0001 vs. control groups) increased incidences of Periodic Acid Schiff (PAS) positive staining S. frutescens also reduced intracellular lipid accumulation as made evident by the significantly lower incidence of epicardial adipose tissue (EAT), hepatic steatosis and pancreatic interstitial fat. Obesity was associated with increased fibrotic lesions such as myocardial perivascular fibrosis, centrilobular hepatic fibrosis and pancreatic periductal fibrosis. Obesity associated hypertension contributed to the widespread and significant increase in the average lesion severity of arterial congestion in all organs in the HFD control group. Pulmonary infection was equally prevalent in all rats. Despite the complex histopathology in all groups, differences in the control groups, such as, the presence of a conservative polymorphonuclear leukocyte (PMNL) infiltration, substantial intra-alveolar oedema and focal arterial wall hypertrophy in the control groups was highly suggestive of Sendai viral infection. However histopathologic evidence, in the treatment groups, suggested chronic recurrent viral infection with superimposed Mycoplasma pulmonis (M. pulmonis) bacterial infection. The impact of advanced suppurative pulmonary infection was widespread and exemplified by increased lesion incidences of spontaneous murine progressive cardiomyopathy (MCP) and spontaneous chronic progressive nephropathy (CPN) among others. In conclusion S. frutescens administered for 46 weeks to male Wistar rats significantly lowered intracellular lipid accumulation and obesity associated myocardial, renal, hepatobiliary, pulmonary and pancreatic histopathology. Moreover, duodenal, cardiovascular, hepatobiliary, pulmonary, renal, pancreatic and splenic tissue did not show histopathologic evidence of direct plant extract associated toxicity or carcinogenicity.

Flow chemistry and continuous processing techniques are now frequently used in synthetic laboratories, taking advantage of the ability to contain reactive or hazardous intermediates and to perform moderate scale-up processes for important compounds. However, only a limited number of methods and tools for connecting flow synthesis steps into a single protocol have been described, and as a result manual interventions are frequently required between consecutive stages. There are two main challenges to overcome. Work-up operations such as solvent extractions and filtrations are invariably needed to ensure high purity of the intermediates. Solutions for achieving this are well established within industrial facilities for continuous production, but adapting such machinery for laboratory use is rarely straightforward. Secondly, the combination of multiple steps tends to result in a more elaborate reactor configuration. The control procedures required to achieve optimum performance may then be beyond the capabilities of a single researcher. Computer control and remote monitoring can help to make such experiments more practical; but commercially-available systems are often highly specialised, and purpose-built at high cost for a particular system, and so are not suitable for laboratory scientists to use routinely. This work describes the development of software tools to enable rapid prototyping of control systems that can integrate multiple instruments and devices (in Chapter 2). These are applied to three multi-step synthesis projects, which also make use of enabling technologies such as heterogeneous reagents and in-line work-up techniques so that material can be passed directly from one stage to the next: In Chapter 1, a series of analogues of a precursor to imatinib, a tyrosine kinase inhibitor used for the treatment of chronic myeloid leukaemia, are prepared. A “catch-react-release” technique for solid-phase synthesis is used, with computer-controlled operation of the reactors. In Chapter 3, a two-step procedure for the synthesis of piperazine-2-carboxamide, a valuable 3D building block, is developed. A computer control system enabled extended running and the integration of several machines to perform optimisation experiments. In Chapter 4, improvements to the continuous synthesis of 2-aminoadamantane-2-carboxylic acid are discussed. This includes an integrated sequence of three reactions and three workup operations. The final chapter describes a project to evaluate the application of control techniques to a medicinal chemistry project. New ligands for BRD9 and CECR2, proteins involved in the recognition of acetylated histone proteins, are produced. A number of triazolopyridazine compounds were synthesised and tested using a number of assay techniques, including a frontal-affinity chromatography system under development within our group. Pleasingly, the qualitative FAC data showed a good correlation with biological assessments made using established assay techniques. Further work using the FAC method is ongoing.

Fundamental to the understanding of how rivers transform and shape our environment is the role of turbulence and complex, three-dimensional flow, such as vorticity, in sediment transport and erosion. However, classical sediment transport models (or formulae) are based, for the most part, on boundary shear stress and do not incorporate these natural phenomena. This is understandable given that the relationship between turbulence generation, intensity and form; the influence of turbulence on mobile sediment; and the magnitude and patterns of deposition and erosion are complex and difficult to quantify. Nevertheless, the failure to incorporate turbulence and complex, three-dimensional flow into existing models means that our understanding of sediment transport remains incomplete. The central hypothesis of this thesis is that vortical motion is the main factor in the development of local scour. To examine this, a comprehensive experimental approach was taken. This approach involved detailed measurements of the unique three-dimensional patterns of velocity, turbulence and bed morphology associated with flow in an open channel with and without the presence of submerged groyne-like structures (stream barbs and wing dikes) at both the laboratory and field scales. Using densely spaced velocity data and new techniques for processing and analyzing these data, it was possible to identify complex features of the flow field at both scales, such as the presence of vortex cores, and correlate these with changes in bed levels. These data provide a unique perspective of the spatial variability of velocity, turbulence and bed morphology in open channels (and in particular in channel bends, where flow is highly three-dimensional). In particular, it was found that, of the flow parameters analyzed, turbulent stresses were most correlated to scour in channel bends without the presence of structures. In contrast, vorticity was found to be the dominant factor in local scour hole development in the vicinity of submerged structures at both the laboratory and field scale. Such data are rare (if non-existent) in existing experimental research, particularly at the scale of a large natural river. This research also examines stream barb design and performance. Stream barbs (also known as submerged groynes or spur dikes) are a relatively novel approach to stream bank protection and are not common in Canada. The design and installation of stream barbs in a creek in Ottawa (Sawmill Creek) was undertaken to serve as a demonstration project for the use of these structures in a semi-alluvial channel, for which no such case studies exist. Three years of monitoring the site and the performance of these structures to reduce bank erosion and improve aquatic habitat have been carried out. Laboratory testing of stream barb performance was also undertaken and showed that with improper design, the outer bank in a channel bend may be more susceptible to erosion due to excessive local scour downstream of the barb. In particular, to avoid bank erosion downstream of the barb, barbs should be small, such that they create minimum flow obstruction, and include a bank key that is wider than the barb itself and extends in the downstream direction.

No description available.

Background: Two commonly used strength training exercises are the chin-up- and the lat-pulldown exercise. Both exercises are performed by using similar movement patterns and by using the same primary muscles. Previous research has shown that each exercise can exhibit unique training stimulus and should not be considered interchangeably. However, there is limited research regarding comparison of muscle activation between the exercises. Knowing the amount of muscle activation when performing the exercises, can help strength training participants to choose exercise and relative workload according to the specific muscles they want to target. Purpose: This study sought to compare muscle activation (measured as average) in m. latissimus dorsi (LD), m. biceps brachii (BB), middle m. trapezius (TR) and m. rectus abdominis (RA) between performing the chin-up at 100% of participants’ individual bodyweight (BW) with lat-pulldown at 50%-, 65%- and 75% BW. Methods: Twenty strength trained male participants (25.0 ± 3.3 yr; 181.0 ± 5.8 cm; 82.0 ± 7.8 kg) were examined during the study. Surface electromyography (SEMG) was collected from LD, BB, TR & RA during the exercises. Average muscle activation was expressed as percentage of maximum voluntary isometric contraction (%MVIC). Exercise execution was as identical as possible for both exercises and was performed using pronated handgrip and a grip width equal to 1.5 times the participants individual biacromial distance. Results: Statistically significant (p<0.05) increases in average muscle activation were found in LD, BB and RA during chin-up 100% BW compared to lat-pulldown at 50%-, 65% and 75% BW. However, for TR no significant difference (p=0.145) was found between chin-up 100% BW and lat-pulldown when performed at 75% BW. Conclusion: These results indicate that performing the lat-pulldown using workload somewhere between 75-100% BW can exhibit the same muscle activation as performing the chin-up at 100% BW. Keywords: Strength training, Surface electromyography, Muscle activation, Chin-up exercise, Latpulldown exercise, Different workloads, Randomisation, Cross-over, Observational

Total lungkapacitet (TLC) är den totala volymen gas i lungorna efter en maximal inspiration. Den kan beräknas med kroppspletysmograf utifrån tryckförändringar och Boyles lag respektive utifrån gasspädning med metan alternativt helium som spädningsgas. Vanligen används kroppspletysmografi och för att kunna använda metangasspädning som substitut är överensstämmelsen mellan metoderna av intresse. Studiens syfte var att jämföra TLC från single-breath metangasspädning med TLC från kroppspletysmografi. Data gällande patienter som genomgått båda undersökningarna vid samma tillfälle enligt standardförfarande samlades in. Studien var en retrospektiv tvärsnittsstudie och populationen á 48 patienter innehöll lika många män som kvinnor, åldrar från 10 till 87 år samt med och utan angivna respiratoriska sjukdomar. TLC från kroppspletysmografin sträckte sig från 2,6 till 8,4 liter och TLC från metangasspädningen sträckte sig från 2,5 till 7,7 liter. TLC från gasspädningen var i genomsnitt 0,59 liter mindre än TLC från kroppspletysmografin. Metangasspädningen underskattade TLC med 11,3%. Skillnaden mellan kroppspletysmografins TLC och metangasspädningens TLC var signifikant vilket fastställdes med t-test för parvisa observationer. På grund av studiepopulationens natur finns behov av ytterligare studier med större populationer. TLC från metangasspädningen uppgick till 88,7% av TLC från kroppspletysmografin och gasspädning kan inte utan ökad risk för underskattning av TLC användas som substitut för kroppspletysmografi. / Total lung capacity (TLC) is the gas volume in the lungs after maximal inspiration. It can be calculated using whole-body plethysmography, pressure changes and Boyle’s law, or using gas dilution with methane or helium as inert gas. Agreement between the methods is of interest to make substitution of the more commonly used whole-body plethysmography with methane dilution possible. This retrospective cross-sectional study aimed to compare TLC from single-breath methane dilution with TLC from whole-body plethysmography. Data concerning patients who underwent these two standard procedure examinations in one visit was collected. The population of 48 had an even gender distribution, included ages 10 to 87 and patients with or without known respiratory diseases. TLC from whole-body plethysmography ranged between 2,6 and 8,4 liters. TLC from methane dilution ranged between 2,5 and 7,7 liters. TLC from gas dilution averaged 0,59 liters less than TLC from whole-body plethysmography and underestimated TLC by 11,3%. Paired samples t-test determined the difference between methods to be significant. Due to the nature of this population, further studies of larger populations are needed. Methane dilution TLC amounted to 88,7% of TLC from whole-body plethysmography which therefore cannot be substituted with methane dilution without increased risk of underestimating TLC.