201 |
An assessment of constraints to accurate reporting of cattle mortality in Odi district, North West ProvinceMakgatho, Cathrine Nnditsheni 08 March 2005 (has links)
The aim of the study was to assess the constraints to accurate reporting of cattle mortality in Odi district, North West Province. The method that was followed in this study was based on participatory action research. The cattle owning community of Odi district participated at every phase. They were the ones who first spoke to veterinary services about ways to decrease the diseases and mortalities of their cattle. Out of this came a questionnaire so that the actual facts could be determined. A total number of 60 farmers were randomly selected from 12 villages. One farmer pulled out and we were left with 59 farmers. Since the area of study was communal, most farmers were men (n=55) and only four of them were female. It was suspected that there was a communication problem and this was proven, as 23 farmers were not even aware that mortalities have to be reported by law. The real problem was that causes of death were not being diagnosed because farmers were not aware that a necropsy could give information on the causes of death. Farmers were keen to receive training in necropsy techniques so as to be able to discuss the cause of death of cattle with the state veterinarian. A skills training course was done with the farmers at the Department of Veterinary Pathology of the Faculty of Veterinary Science, University of Pretoria. Farmers were taught to recognise the names and characteristics of normal organs and how to cut open a carcass correctly. A necropsy was demonstrated and thereafter farmers were given cattle organs from the abattoir to cut open themselves using gloves and protective clothing. Diagnostic skills were not taught as diagnosis of diseases is the province of a registered veterinarian. Farmers were given a checklist of organs and encouraged to contact the state veterinarian to describe what the carcass and organs looked like as soon after death as possible. The state veterinarian could give a tentative diagnosis over the telephone. A CD-Rom was developed as a training aid for skills training of small-scale farmers and animal health technicians (AHT’s), in elementary necropsy techniques. Farmers were thereafter visited monthly for 12 months by the state veterinarian and the AHT`s to record cattle mortalities and possible causes of death. As a result of the skills training, the number of animals reported dead did not change, but the number of unknown causes of death dropped significantly, as owners were able to correctly describe necropsy lesions in the carcasses and organs of the cattle that had died. It was concluded that the skills training technique used was an effective method of extension for recognizing causes of death in cattle and it is suggested that the CD-Rom that was developed, be used for training purposes by the state veterinary services of North West Province. / Dissertation (MSc (Veterinary Sciences))--University of Pretoria, 2004. / Paraclinical Sciences / unrestricted
|
202 |
The effect of haemolysis on antithrombin concentration as determined by a chromogenic methodVan der Merwe, Liesel Laura 27 February 2006 (has links)
The presence of free haemoglobin in serum or plasma can markedly affect the outcome of laboratory tests. Normal concentrations of plasma haemoglobin in carefully obtained specimens are less than 0.025g/l. The presence of free haemoglobin in a sample increases the spectrophotometric absorbance of tests run at wavelengths within the absorbance range of haemoglobin (400 – 440nm). Little is known about the effects of haemolysis on the determination of antithrombin levels in canine plasma samples. Two plasma pools, designated AT 100 and AT 70 were prepared. The AT 70 pool was prepared by diluting pooled plasma with 0.9% saline in a ratio of 7:3. A unit of whole blood was collected from a healthy donor animal. The erythrocytes were lysed by freezing and thawing. The solution was centrifuged, the supernatant collected and filtered using 1.2 um and 0.22 um filters sequentially to remove residual red cell stroma. The haemoglobin concentration of the solution was determined using a modification of the automated Drabkin method. Intermediate haemoglobin solutions of decreasing known concentrations were prepared by the addition of saline. The intermediate solutions were added to the plasma pools in a 1+9 manner and a series of samples were prepared with final calculated and measured haemoglobin concentrations of 0.0; 0.5; 1.5; 2.5; 3.5; 4.5 and 5.5 g/l. The AT determinations were performed using a functional chromogenic assay and the spectrophotometric absorbances were read using a 405 nm filter, as specified. Increasing concentrations of haemoglobin resulted in a decrease in the AT value measured. A simple linear regression analysis was performed on both AT70 and AT100 using a two-step regression analysis. The slopes up to [Hb] 1.5g/l were not significant whereas the slopes at between [Hb] 1.5 – 5.5 g/l were significant ( p< 0.001). The slope equation for AT 100 was y= -5.742X+ 115.24 with R 2 = 0.794 and for AT 70 was y = - 4.2037X + 66.821, with R 2 = 0.936. A conversion table was created by interpolation of data between these two lines. These results show that it is possible, using a conversion equation, to perform the AT assay in haemoglobinaenic serum, thus opening the way to further evaluation of the coagulation status in patients with haemolytic disease processes. / Dissertation (MMedVet (Med))--University of Pretoria, 2005. / Companion Animal Clinical Studies / unrestricted
|
203 |
Effect of early enteral nutrition on intestinal permeability, protein-losing enteropathy and outcome in canine parvoviral enteritisMohr, Albertus Jacobus 29 March 2005 (has links)
Canine parvovirus (CPV) infection is characterized by a disruption of gut barrier function, which allows the systemic entry of bacteria and endotoxin, and the development of the systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). Despite the lack of prospective data, conventional wisdom has dictated that “gut rest” with initial nil per os (NPO) remains the nutritional treatment of choice for CPV enteritis. However, early enteral nutrition (EEN) has been shown to be superior to starvation in human critical illnesses associated with gut barrier dysfunction. Documented benefits of EEN include improved intestinal permeability, reduced incidences of bacteremia, endotoxemia, SIRS and MODS, decreased catabolism, and improved clinical outcome. A prospective, randomized, controlled clinical trial was conducted to evaluate the effect of EEN on intestinal permeability, protein-losing enteropathy, and clinical outcome in naturally occurring severe CPV enteritis in 30 puppies. Parvoviral infection was confirmed by fecal electron microscopy, and dogs were hospitalized for 6 days. Dogs were randomly assigned to 2 groups. Fifteen dogs received nil per os until vomiting had ceased for 12 hours, after which a low fat diet was fed (initial NPO group; control). Fifteen dogs were fed immediately (Pedigree® Canine Concentration Instant Diet) by nasoesophageal tube (EEN group). All other treatments were identical. Disease severity was semi-quantified by a clinical scoring system. Intestinal permeability was assessed using urinary lactulose and rhamnose recoveries (%L and %R) and L/R ratios. Fecal <FONT FACE=”SYMBOL”>a</FONT>1-proteinase inhibitor concentrations (<FONT FACE=”SYMBOL”>a</FONT>1-PI) quantified protein-losing enteropathy. Enteral tube feeding was not associated with any significant complications. The median time taken to normalization of habitus and appetite, and the resolution of vomiting and diarrhea, was consistently 1 day shorter for the EEN group for each parameter. Body weight remained stable in the NPO group, while EEN was associated with significant weight gain (8.4% by day 6). This supports reduced catabolism with EEN. Compared with reference values, urinary %Ls were elevated, %Rs reduced, and L/R ratios increased throughout the study for both groups. %L behaved significantly differently between groups (p=0.035), with a progressive decrease in the EEN group vs. a progressive increase in NPO. This may indicate earlier repair of intestinal epithelial necrosis, or improved tight junction structure and/or function due to EEN. Such an improvement in gut barrier function might potentially limit endotoxin and/or bacterial translocation. The decreased %R in both groups is consistent with villus atrophy. There were no significant differences in %R or L/R ratios between the two groups over time. Fecal <FONT FACE=”SYMBOL”>a</FONT>1-PI concentrations were increased throughout the study in both groups. There were no significant differences between the declines over time for fecal <FONT FACE=”SYMBOL”>a</FONT>1-PI concentrations between groups. Thirteen of 15 NPO dogs (87%) and all of the EEN dogs (100%) survived (non-significant; p = 0.48). This study demonstrates that EEN may be effectively instituted in CPV enteritis, and supports the use of EEN in gut barrier dysfunction. / Dissertation (MMedVet (Med))--University of Pretoria, 2002. / Companion Animal Clinical Studies / unrestricted
|
204 |
Hypoglycaemia in virulent canine babesiosis: Prevalence and risk factorsKeller, Ninette 08 March 2005 (has links)
A study was conducted to determine the prevalence of and potential risk factors for hypoglycaemia in canine babesiosis due to Babesia canis rossi. Plasma glucose concentration was measured at presentation in 250 dogs with babesiosis, of which 111 were admitted to hospital. The overall prevalence of hypoglycaemia (< 3.3 mmol/l) was 9% (23/250). Twenty-two hypoglycaemic dogs required admission, making the prevalence of hypoglycaemia in admitted cases 19.8%. Sixteen dogs had severe hypoglycaemia (¡Ü 2.2 mmol/l) of which 5 had a blood glucose < 1 mmol/l. Hyperglycaemia (> 5.6 mmol/l) was present in 38 (38/250; 5.2%) dogs of which 21 (21/250; 8.4%) were admitted and severe hyperglycaemia (> 15 mmol/l) did not occur. Risk factors for hypoglycaemia identified by univariable analysis were: Collapsed state (P < 0.00001), severe anaemia (P = 0.0002), icterus (P = 0.003), age below 6 months (P = 0.02) and vomition (P = 0.03). After logistic regression analysis, collapsed state (OR = 17.8, 95% CI: 1.9 to 171, P = 0.01) and young age (OR = 2.8, 95% CI: 0.8 to 9.7, P = 0.1) remained significantly associated with hypoglycaemia. Toy breeds and pregnant bitches were not at higher risk for hypoglycaemia than other dogs. Hypoglycaemia was only associated with overt neurological signs in two dogs. Blood glucose concentration should ideally be measured in all dogs requiring treatment for babesiosis, but is mandatory in collapsed dogs, puppies and dogs with severe anaemia, vomition or icterus. Many cases have probably been misdiagnosed, as cerebral babesiosis in the past and hypoglycaemia should be suspected in any case with coma or other neurological signs; however, this should in no circumstances be the only reason to suspect hypoglycaemia. / Dissertation (MMedVet (Med))--University of Pretoria, 2004. / Companion Animal Clinical Studies / unrestricted
|
205 |
The pharmacokinetics of diminazene aceturate after intramuscular and intravenous administration in the healthy dogMiller, David B 23 March 2005 (has links)
Diminazene is the therapy of choice for canine babesiosis in South Africa. Differences in the dosage described for diminazene usage and the occurrence of mortality at doses equal to or close to the recommended treatment dose for the treatment of canine babesiosis have been described. This has necessitated the need to more fully understand the absorption and disposition of diminazene in dogs. An intravenous (i.v.) as well as an intramuscular (i.m.) pharmacokinetic study was conducted to determine the pharmacokinetics of diminazine in healthy dogs as well as to describe the binding characteristics of diminazine (in the blood) in vivo and in vitro. Diminazene pharmacokinetics showed a large inter-individual variation after i.m. administration at 4.2 mg/kg (% CV 37 – 163) with a rapid absorption (K01-Hl - 6.6 + 10.8 min resulting in a Cmax of 1849 + 268.7 ng/ml at Tmax of 20 min. There was a rapid distribution phase (T½a 21.6 + 11.4 min) with the distribution into the peripheral compartment being more rapid than the distribution back in to the central compartment. A mean elimination half-life (T½<FONT FACE="SYMBOL">b</FONT> 5.31 + 3.89 h) was derived. At 1 h after i.m. injection, 75 % of the diminazene in whole blood was in the plasma fraction. Compartmental analysis of the i.v. data after diminazene administration at 2 mg/kg revealed a Cmax of 3725 + 1672.8 ng/ml with a rapid distribution phase (T½a 7.0 + 6.2 min) with a long elimination half-life (T½<FONT FACE="SYMBOL">b</FONT> - 32.0 ± 28.8 h). The distribution into the peripheral compartment was more rapid than the distribution back into the central compartment as measured by K12 and K21 (K12 - 8.78 + 8.71; K21 0.32 + 0.25). The i.v. pharmacokinetic results were very variable between the dogs with a % CV of 55.5 – 137.2. We hypothesize that the rapid distribution phase is a result of diminazene being sequestered into the liver, followed by a slow terminal phase were diminazene is both redistributed to the peripheral tissues and renally excreted. The T½<FONT FACE="SYMBOL">b</FONT> of 32.0 ± 28.8 h in the i.v. study is considerably longer than the elimination half-life (T½<FONT FACE="SYMBOL">b</FONT> - 5.31 + 3.89 h) found in the i.m. study. This is most likely due the 25 ng/ml limit of detection of the HPLC, detecting the i.v. tail but not the i.m. tail. This is not surprising as the Cmax levels following i.v administration were more than 2 times higher than after i.m. administration. Further pharmacokinetic studies with diminazene in dogs should take account of the rapid absorption of diminazene after i.m. administration and the low levels of diminazene in the terminal phases. The initial sequestration of diminazene in the liver and distribution to the peripheral compartment needs further clarification. With the knowledge gained of the pharmacokinetics of diminazene in healthy dogs, a population pharmacokinetic study in dogs with babesiosis is recommended. This will allow us to more fully appreciate alterations in the pharmacokinetics of diminazene in diseased populations and the potential covariants exerting an effect. It is our current recommendation that diminazene given i.m. at 4.2 mg/kg not be repeated within a 21 day period. / Dissertation (MMedVet (Med))--University of Pretoria, 2003. / Companion Animal Clinical Studies / unrestricted
|
206 |
The prevalence of subclinical gastroduodenal ulceration in dachshunds with intervertebral disc prolapseDowdle, Sara-Anne Margaret 30 March 2005 (has links)
The primary objective of this study was to determine the prevalence of subclinical gastroduodenal ulceration (GDU) in a population of Dachshunds undergoing decompressive surgery for acute intervertebral disc prolapse (IVDP). Secondary objectives included determining the extent to which treatment with ulcerogenic drugs, prior to admission, and the severity of spinal injury, would influence the prevalence of GDU. It aimed to further establish patient risk profile components (for example: age, weight, sex or concurrent disease conditions) that might influence the prevalence of GDU and make suggestions as to whether all dogs presenting with acute IVDP should be treated with anti-ulcerogenic drugs on admission for decompressive surgery. Thirty Dachshunds were admitted into the study after a diagnosis of acute IVDP was confirmed based on clinical signs and lumbar myelography. Full histories were obtained from both the owners and the referring veterinarians. Information obtained included any previous history of spinal disease, duration of clinical signs, rate of deterioration of clinical signs and drugs administered prior to admission. A full clinical and neurological examination was performed on each patient at admission. Blood and serum chemistry samples were taken to rule out any concurrent diseases that may have contributed to the development of GDU. Three regions in the stomach (cardia, corpus and pyloris) as well as the proximal duodenum were visualised using gastroduodenoscopy. The following criteria were assessed: colour and appearance of mucosa, presence and distribution of erosion, ulceration and/or submucosal haemorrhages. These results were combined with those obtained from histopathology of pinch biopsy samples, taken from the same four regions, in order to obtain the overall prevalence. Criteria used to assess histopathology of the regions included: disruption of the epithelial lining, haemorrhage into the submucosa and infiltration of neutrophils or macrophages into the submucosa. All dogs were scoped and biopsy samples taken on the first day of admission and three to four days post-surgery. Seventy six percent of Dachshunds that presented with IVDP had visual and/or histopathologic evidence of GDU. The highest overall prevalence of GDU was shown to occur in the pyloric region of the stomach both pre- and post-surgery. No significant correlation was found between the prevalence of GDU and the administration ulcerogenic drugs prior to admission. Similarly, no correlation was found between GDU and the severity of neurological signs, the duration of clinical signs prior to admission, the length of the procedure (general anaesthesia or surgery), age weight or sex. No significant statistical difference was found between the pre- and post-surgery results. Veterinarians should be aware of this potentially serious complication when dealing with Dachshunds with acute IVDP. The judicious use of ulcerogenic drugs and early use of prophylactic anti-ulcer medication is recommended in all patients presenting with this condition. / Dissertation (MMedVet (Surg))--University of Pretoria, 2003. / Companion Animal Clinical Studies / unrestricted
|
207 |
A preliminary study to investigate the serum urea: creatinine ratio in canine babesiosis in South AfricaDe Scally, Martin Patrick 26 July 2005 (has links)
In order to investigate the increased serum urea: creatinine ratio encountered in canine babesiosis in South Africa, packed cell volume (PCV), serum haemoglobin, serum total bilirubin, plasma ammonia, serum urea, serum creatinine, calculated serum urea: creatinine ratio, serum cystatin-C, total serum protein (TSP) and urine analysis were performed in this study. The model consisted of 28 canine babesiosis patients, 25 in group 1, the anaemic group with PCV < 20%, and 3 in group 3, the haemoconcentrated group with PCV > 50%. 13 canine babesiosis negative dogs made up group 2, the control group. Unpublished human malaria data from 363 patients was also analysed and the urea: creatinine ratio was calculated in order to determine whether elevated serum urea: creatinine ratios also occur in this disease. The serum urea: creatinine ratio was > 20 in 23/25 anaemic patients, 3/13 control patients and 2/3 haemoconcentrated patients. The mean and median serum urea: creatinine ratio for the anaemic babesia group was 46.32 and 41.36, for the haemoconcentrated babesia group 25.10 and 20.85, for the malaria patients 20.64 and 18.75, and for the control group 15.91 and 15.36 respectively. Mean and median serum urea: creatinine ratio was significantly elevated and the distribution varied significantly between the anaemic babesiosis group compared with the control group (p=0.000003). Serum urea: creatinine ratio was elevated in canine babesiosis patients, especially when they are anaemic. The serum urea: creatinine ratio was also found to be elevated in the human malaria patients. Serum urea was found to be elevated in 17/25 anaemic patients, 0/13 control patients and 3/3 haemoconcentrated patients. Mean and median values for serum urea were 12.83 mmol/l and 11.8 mmol/l and 5.09 mmol/l and 4.3 mmol/l for the anaemic group and the control group respectively. Mean and median serum urea was significantly elevated and the distribution varied significantly between the anaemic group compared with the control group (p=0.00003). Serum creatinine was elevated in 0/25 anaemic patients 0/13 control patients and 2/3 haemoconcentrated patients. Mean and median values for serum creatinine were 72.08 <font face="symbol">m</font>mol/l and 67 <font face="symbol">m</font>mol/l, and 78.69 <font face="symbol">m</font>mol/l and 75 <font face="symbol">m</font>mol/l for the anaemic group and the control group respectively. Mean, median and distribution of serum creatinine did not vary significantly between the control group and the anaemic babesia group (p=0.274488). Serum cystatin-C was elevated in 0/25 anaemic patients, 0/13 control patients and 2/3 haemoconcentrated patients. The two haemoconcentrated patients with elevated serum urea and serum creatinine also had elevated serum cystatin-C. One of these two patients was available for post mortem and had significant renal lesions on histopathology. These two patients also had a urine specific gravity (SG) < 1.030 (1.020 for both cases). Mean and median values for serum cystatin-C were 0.71 mg/l and 0.7 mg/l, and 0.67 mg/l and 0.7 mg/l for the anaemic group and the control group respectively. Mean, median and distribution of serum cystatin-C did not vary significantly between the control group and the anaemic babesia group, (p=0.450172). Using the Spearman-rank test for correlation coefficients serum creatinine but not serum urea had a significant positive correlation with serum cystatin-C; and serum urea had a significant positive correlation with the serum urea: creatinine ratio. Log serum creatinine was significantly correlated to log serum cystatin-C, (r2=0.52, p<0.001). Log serum urea was also significantly correlated to log serum cystatin-C, (r2=0.14, p=0.024), however, this correlation was relatively poor compared to that of serum creatinine with serum cystatin-C. Log serum urea: creatinine ratio was not significantly correlated with log serum cystatin-C, (r2=0.014, p=0.485). Given its resistance to interference from the elevated plasma and serum pigments found in canine babesiosis, an elevated serum cystatin-C was taken to indicate significant renal disease. Therefore we can deduce that the increased serum urea: creatinine ratio encountered in canine babesiosis is a result of disproportionately elevated serum urea concentrations, which is of non-renal origin. A similar event appears to be present in human falciparum malaria patients. The cause of this phenomenon in either disease is unknown; but various forms of prerenal azotaemia, hyperureagenesis and laboratory perturbations may play a role. Serum creatinine was a better measure of significant renal disease than serum urea in this study. There also appeared to be no added benefit of measuring serum cystatin-C. Mean and median values for PCV were 11.64% and 11%, and 46.08% and 48% for the anaemic group and the control group respectively. As expected the mean and median PCV was significantly lower and the distribution varied significantly between the control group and the anaemic babesia group (p=0.000001). The mean and median values for PCV in the haemoconcentrated group were 54.33% and 54% respectively. Serum haemoglobin was > 1.6 g/l in 8/25 anaemic patients, 0/13 control patients and 3/3 haemoconcentrated patients. Mean and median values for serum haemoglobin were 1.72 g/l and 1.3 g/l, and 0.88 g/l and 0.8 g/l for the anaemic group and the control group respectively. Mean and median serum haemoglobin was significantly elevated and distribution of serum haemoglobin varied significantly between the control group and the anaemic babesia group (p=0.002364). Serum total bilirubin was > 15 <font face="symbol">m</font>mol/l in 11/25 anaemic patients, 0/3 haemoconcentrated patients and 0/13 control patients. Mean and median values for serum total bilirubin were 22.42 <font face="symbol">m</font>mol/l and 10.6 <font face="symbol">m</font>mol/l, and 10.63 <font face="symbol">m</font>mol/l and 11.0 <font face="symbol">m</font>mol/l for the anaemic group and the control group respectively. The median and the distribution of serum total bilirubin did not vary significantly between the control group and the anaemic babesia group (p=0.355888). TSP was elevated in 5/25 anaemic patients, was below the normal laboratory reference range in 5/25 anaemic patients, was elevated in 1/13 control patients, and was normal in all the haemoconcentrated cases. Mean and median values for TSP were 58.60 g/l and 54 g/l, and 60.92 g/l and 60.0 g/l for the anaemic group and the control group respectively. The mean, median and distribution of TSP did not vary significantly between the control group and the anaemic babesia group (p=0.130661).Plasma ammonia was elevated in 16/25 anaemic patients, 0/13 control patients and 2/3 haemoconcentrated patients. Mean and median values for plasma ammonia were 78.77 <font face="symbol">m</font>mol/l and 53.8 mol/l, and 23.18 <font face="symbol">m</font>mol/l and 21.5 <font face="symbol">m</font>mol/l for the anaemic group and the control group respectively. Mean and median plasma ammonia was significantly elevated and the distribution of plasma ammonia varied significantly between the control group and the anaemic babesia group (p=0.009562). Using the Spearman-rank test for correlation coefficients PCV had a significant negative correlation with plasma ammonia, serum urea and serum urea: creatinine ratio. Serum haemoglobin and serum bilirubin had a significant positive correlation with plasma ammonia, serum urea and serum urea: creatinine ratio. Plasma ammonia also had a significant positive correlation with serum urea and serum urea: creatinine ratio. These correlations may be explained by substrate loading as a result of haemolysis. I speculate that various protein by-products of haemolysis may cause the hyperammonaemia encountered via deamination of these proteins. This in turn may lead to ureagenesis, the physiological process of ammonia clearance. This ureagenesis may be excessive and therefore may account for the elevated serum urea encountered in patients with normal serum creatinine and serum cystatin-C concentrations. Alternatively the presence of an elevated serum haemoglobin concentration with its high intrinsic absorptive capacity in the 300 nm to 500 nm wave length range, may positively bias the measurement of serum urea and plasma ammonia concentrations. Serum urea is measured at 340 nm and plasma ammonia is measured at 365 nm. Thus a non-physiological process could also explain the above correlations. Urine analysis of the canine babesiosis patients showed mild evidence of renal disease as portrayed by proteinuria, renal tubular epithelium (RTE) celluria and granular casts. However, these findings, as well as the presence of an elevated serum urea, haemoglobinaemia and haemoglobinuria, bilirubinaemia and bilirubinuria, were present in both patients with mild renal disease and patients with overt renal disease. Therefore the benefit of single serum urea concentrations and random urine sediment analysis in canine babesiosis is questioned. Serial urine analysis monitoring was not investigated. This study concluded that serum urea is often elevated due to non-renal factors in canine babesiosis patients. This causes an elevated serum urea: creatinine ratio in this disease, with a similar event appearing to occur in human malaria patients. The cause of these elevated ratios remains undetermined, but is likely to be as a result of hyperureagenesis or laboratory error. The measurement of serum creatinine, urine SG and hourly urine production is advocated to detect significant renal disease in these patients. There appeared to be no added benefit derived from the measurement of serum cystatin-C concentrations in canine babesiosis patients in this preliminary study. / Dissertation (MMedVet (Medicine))--University of Pretoria, 2005. / Companion Animal Clinical Studies / unrestricted
|
208 |
Gender-based issues in aviation, attitudes towards female pilots : a cross-cultural analysisWilson, Janice 30 March 2005 (has links)
Aviation is a global industry. Many professional pilots follow a career path that takes them into employment crossing national and international boundaries. They take with them their training, qualifications and experiences, and then build on these in diverse organisational and national cultural environments. They also carry with them their personal and professional attitudes, which then influence their behaviour. Professional pilots still often display a historically masculine attitude, which affects the relationship on the flight deck, particularly when one of the pilots is female. Because perceptions based on gender differences (real or alleged) have a pervasive and powerful influence on behaviour, it is important to manage gender diversity properly to meet the demands of a two-gender workplace. This has important implications for flight crew effectiveness and aviation safety. The study started with an overview of the literature, historical data on female aviators, selected relevant legislation and current world trends in aviation. A survey was then designed as the basis for a cross-cultural study of attitudes towards female pilots. The primary objective of this study was to develop a instrument to assess female and male aviators' perceptions regarding gender-related pilot behaviour across cultures and to determine the main and interaction effects of biographical variables on the perceptions held by professional pilots. The research group consisted of two non-probability samples: 183 pilots from the United States of America and 530 pilots from South Africa. An Aviation Gender Attitude Questionnaire (AGAQ) was devised to provide valid and reliable measurements of attitudes with regard to female pilots' Flying Proficiency and Safety Orientation. To determine the similarity or difference in the response patterns of the two samples, factor analysis, Tucker's coefficient of agreement and analysis of item bias were used. Univariate and multivariate analysis of variance were applied to uncover any possible main and interaction effects of the biographical characteristics on the respondents¡¯ perceptions of gender-related pilot behaviour. The results of the Principal Axis Factor Analysis performed on the AGAQ indicated little difference in the factor structures for the United States and South African groups. Tucker's phi-coefficient of congruence indicated factoral agreement (Tucker's phi ¡Ý 0.95) between the United States and South African respondents with regard to both factors of the AGAQ. The items of the two factors showed no uniform or non-uniform bias for pilots from the different culture groups. The results of the n-way ANOVAs and MANOVAs indicated that gender is the primary independent variable that has a significant effect (p< 0.001) on pilots' perceptions and attitudes towards female pilots. The mean scores for the female pilots were significantly higher than their male counterparts for both Flying Proficiency and Safety Orientation. The research findings are of particular interest in the field of Crew Resources Management (CRM) and ¡®Hazardous Attitudes¡¯ training. Topics such as gender issues and diversity management should be addressed to improve and advance gender-sensitive CRM training. Managing gender issues is critical to sustain and improve aviation safety and effective performance in mixed gender multi-crew environments. / Thesis (PhD (Human Resources Management))--University of Pretoria, 2004. / Human Resource Management / unrestricted
|
209 |
Generiese riglyne vir die implementering van gelyke geleenthede by ‘n groep nie-aangewese werknemers (Afrikaans)Strauss, Eltrone 16 March 2005 (has links)
Employment equity initiatives often fail in organisations because of the negative perceptions and lack of support from members of the non-designated group towards the process of implementation of employment equity. The purpose of the study was to identify non-designated-friendly generic guidelines for the implementation of employment equity in an organisation. Phase one of the study comprised of qualitative research where a literature study was conducted on the methods used to introduce affirmative action, training of affirmative action candidates, and managing of diversity in the work place. During the second phase of the study a quantitative, survey-approach was followed to determine the perceptions and preferences of the non-designated sample (n-100) with regard to the implementation of employment equity. From the results of the survey a number of generic guidelines, which are acceptable for employees from the non-designated group, were identified. These guidelines can be utilised to minimise resistance when implementing employment equity measures in the workplace. / Dissertation (MCom (Human Resources Management))--University of Pretoria, 2004. / Human Resource Management / unrestricted
|
210 |
Microbiological quality of goat milk obtained under different production systemsKyozaire, Joan Kitiibwa 23 March 2005 (has links)
Reliability of quality of milk produced by smallholder farmers was assessed by means of a comparative analysis of the microbiological quality and somatic cell counts (SCC) of the raw milk obtained from dairy goats. Information regarding dairy goat farming and goat milk production in and around Pretoria was initially determined by means of a questionnaire. With this information, dairy goat herds were selected for the study, based on the fact that these farms produced milk for both domestic and commercial consumption. The study was conducted on three commercial dairy goat farms each under a different production system, the extensive, semi-intensive and intensive production systems. The method of milking varied with the type of production system; hand milking, bucket system and pipeline milking respectively. Udder health under the respective production systems was assessed by means of bacterial analysis of udder half milk samples. Bacteriology of bulk milk samples was also determined in order to assess the level of hygiene in the milking environment. In addition, water samples from the different farms were analysed for their microbial quality. Results of these parameters were compared between the different production systems using the analysis of variance. Capability of safe raw milk production by smallholder dairy goat farmers was then evaluated from the results obtained. Reliability of the SCC as a reflection of goat udder health was also evaluated. Further assessment was carried out to determine the relationship between udder conformation and presence of intra-mammary infection and SCC of the raw milk. Bacteria potentially capable of producing either food poisoning or enhanced spoilage of raw milk were cultured from the goat milk samples. These included pathogens such as Staphylococcus aureus, Bacillus cereus and Enterococcus faecalis, found associated with use of milking machines as was the case in the intensive and semi-intensive production systems compared to the extensive production system. The prevalence of intramammary infection was 33.3%. Coagulase negative staphylococci were the most common cause of intramammary infection with a prevalence of 86.6% of the infected udder halves. They includedStaphylococcus epidermidis, Staphylococcus simulans and Staphylococcus intermedius. The remaining 13.4% of the infection was due to Staphylococcus aureus. Somatic Cell Counts were not a reflection of udder health status, hence, not reliable in the prediction of goat udder health (p = 0.2 Fisher’s exact test of association). No significant relationship was proved to exist between the udder conformation and presence of intra-mammary infection or SCC of the milk produced. Raw milk obtained by the bucket system milking machine had the lowest total bacterial count (TBC) (16 450 Colony Forming Units per millilitre [CFU/ml]) as compared to that by pipeline milking machine (36 300 CFU/ml) or hand milking (48 000 CFU/ml). In comparison to the other two production systems, it was shown that dairy goat farming under the extensive production system, where hand milking was practised, was adequate for production of safe raw goat milk. Coliforms were found to be the most predominantly isolated organisms from the raw milk obtained under the extensive production system. However, these can be eliminated by pasteurisation of the milk. The extensive production system, therefore, could be a means to promote dairy farming in developing communities through smallholder farmers. This could be facilitated by extension services aimed at monitoring management on the farms. This would, consequently, help alleviate the problem of food security and low income in these communities. / Dissertation (MMedVet (Hyg))--University of Pretoria, 2003. / Paraclinical Sciences / unrestricted
|
Page generated in 0.04 seconds