373 research outputs found
The role of calcium in the regulation of NADH oxidation in Jerusalem artichoke tubers
Imperial Users onl
Identification and drug sensitivities of Acanthamoeba species causing keratitis : a thesis presented in partial fulfillment of the requirements for the degree of Master of Science in Microbiology at Massey University, Palmerston North, New Zealand
Acanthamoebic keratitis is a distinct, vision-threatening ophthalmological condition, the incidence of which is increasing with increased usage of contact lenses. Diagnosis can be difficult and chemotherapeutic treatment is prolonged and often ineffective. It is therefore desirable to discover a quick and accurate means of diagnosing acanthamoebic keratitis, and to gain knowledge regarding which chemotherapeutic agents are most effective against acanthamoebic keratitis. The first goal of this thesis was to examine ten DNA extraction procedures and determine their effectiveness in extracting DNA from Acanthamoeba cells. Of these ten methods, four (2, 7, 8, 10) could be performed in less than one day and showed consistent results in PCR reactions. The second goal of this thesis involved the application of arbitrarily primed polymerase chain reaction (AP-PCR) in an attempt to type and group strains of Acanthamoeba species. Examination of 16 isolates with primers AP0l, AP02, AM1, AM2, P1 and P2, showed each of the banding patterns, resulting from AP-PCR analysis, were unique to the isolate tested. Further, there were few bands which occurred in more than one isolate, with insufficient similarities to form groupings of isolates. Two chemotherapeutic agents were selected for a preliminary study into drug sensitivities in Acanthamoeba species and strains. The first of these was Baquacil (20% polyhexamethylene biguanide (PHMB)), and the second was Brolene (0.1% propamidine isethionate). Within 48 hours 97% of all isolates tested reached zero viability at a concentration of 0.05% PHMB, and 100% of isolates tested reached zero viability at 0.1% PHMB. The results of this study would suggest that the concentration of PHMB be at least 0.05% when used to treat acanthamoebic keratitis. Within 48 hours of exposure to 0.1% propamidine isethionate (Brolene), only 30% of all isolates tested reached zero viability. However, 60% of isolates tested showed at least 80% reduction in viability within 48 hours of exposure to 0.1% propamidine isethionate. The ultimate goal of this thesis was to form groups of isolates using PCR and drug sensitivities and to discover any correlation between these groups. The results of AP- PCR analysis however suggests a high genetic heterogeneity within the Acanthamoeba genus, thus preventing any correlation with drug sensitivity tests
Advising the Student-Athlete
The purpose of this essay is to review recent institutional studies which describe the academic preparation and subsequent performance of student-athletes and to discuss their implication for the advising process. This was a reprint from a NACADA Journal article
DNA extraction from formalin-fixed tissue: new light from the Deep-Sea
DNA samples were extracted from ethanol and formalin-fixed decapod crustacean tissue using a new method based on Tetramethylsilane (TMS)-Chelex. It is shown that neither an indigestible matrix of cross-linked protein nor soluble PCR inhibitors impede PCR success when dealing with formalin-fixed material. Instead, amplification success from formalin-fixed tissue appears to depend on the presence of unmodified DNA in the extracted sample. A staining method that facilitates the targeting of samples with a high content of unmodified DNA is provided
Investigating primary preservice teachers’ ultraviolet radiation awareness and perceived ability to teach sun safety
Issue addressed
Sun protection practices in Australian primary schools remain inconsistent. Therefore, this study investigates primary PSTs sun protective sun behaviours, ultraviolet (UV) radiation awareness and perceived ability to teach sun safety. Methods
A convenience sample of undergraduate PSTs (N = 275; mean age = 23.13 years) enrolled at one Western Australian university completed an online survey. Descriptive analyses provided features of the data. Factors associated with sun protection behaviours and perceived knowledge and skill to teach sun safety were explored using multivariable logistic regression models. Results
Lesser than 10% of participants reported using sun protective measures daily (midday shade use: 6.5%; sunscreen: 7.6%; hat: 4.4%). Only 56.3% reported they understand the UV index, with 68.0% rarely/never using it to aid sun protection. Under half the participants reported they felt they had the knowledge (38.5%) or skills (40%) to effectively teach sun safety in primary schools. Regression analysis revealed gender, undergraduate, year and skin sensitivity were not predictors of UV index use (P \u3e .05) or perceived knowledge of sun safety (P \u3e .05). Skin sensitivity was the strongest predictor for shade usage (P = .02), hat usage (P = .05) and perceived skill to teach sun safety (P = .02). Conclusions
Survey data indicate UV radiation is inconsistently understood by PSTs. Many felt that they did not have the required knowledge or skill to teach sun safety effectively. So what?
Improving PSTs UV radiation knowledge while at university is a potential opportunity to improve sun safety delivery in primary schools. A targeted intervention for PSTs is warrante
A novel skin cancer prevention strategy: Preservice teachers\u27 perceptions of a sun safety intervention and experiences in schools
Issue addressed: Teachers play a vital role in developing children\u27s sun protection routines however upskilling preservice teachers (PSTs) while at university has not yet been trialled as a targeted skin cancer prevention strategy. Hence, this study investigated PSTs perceptions and experiences of sun safety following a brief pilot intervention and placement in primary schools in Western Australia. Methods: This study used a triangulation mixed methods design. Participants (n = 161) completed a post intervention survey which was analysed quantitatively. A random sub-sample was invited to participate in focus groups (three groups, n = 21) and one-on-one interviews (n = 4). This data was transcribed and uploaded in NVIVO software for thematic analysis. Results: Participants felt the intervention increased their awareness of the dangers of overexposure to ultraviolet radiation (UVR) with many feeling more knowledgeable, skilled and confident to teach sun safety in school settings. Most reported clear sun safety messages in their placement schools. However, only 34.4 % reported they had been briefed on the school\u27s sun safety procedures. There was consensus among PSTs that sun protection in primary schools needs to be improved to maximise the protection of children from harmful UVR overexposure. Participants supported a need for consistent sun protection messaging across primary schools with greater emphasis on education rather than compliance management to sun protection. Conclusion: Enhancing existing teacher education programs to include more rigorous curriculum content and pedagogical approaches to sun protection education is a novel skin cancer prevention strategy and could feasibly support PSTs self-efficacy to effectively deliver sun safety curriculum in Australian schools
Genome evolution in the genus Sorghum (Poaceae)
BACKGROUND AND AIMS: The roles of variation in DNA content in plant evolution and adaptation remain a major biological enigma. Chromosome number and 2C DNA content were determined for 21 of the 25 species of the genus Sorghum and analysed from a phylogenetic perspective. METHODS: DNA content was determined by flow cytometry. A Sorghum phylogeny was constructed based on combined nuclear ITS and chloroplast ndhF DNA sequences. KEY RESULTS: Chromosome counts (2n = 10, 20, 30, 40) were, with few exceptions, concordant with published numbers. New chromosome numbers were obtained for S. amplum (2n = 30) and S. leiocladum (2n = 10). 2C DNA content varies 8.1-fold (1.27-10.30 pg) among the 21 Sorghum species. 2C DNA content varies 3.6-fold from 1.27 pg to 4.60 pg among the 2n = 10 species and 5.8-fold (1.52-8.79 pg) among the 2n = 20 species. The x = 5 genome size varies over an 8.8-fold range from 0.26 pg to 2.30 pg. The mean 2C DNA content of perennial species (6.20 pg) is significantly greater than the mean (2.92 pg) of the annuals. Among the 21 species studied, the mean x = 5 genome size of annuals (1.15 pg) and of perennials (1.29 pg) is not significantly different. Statistical analysis of Australian species showed: (a) mean 2C DNA content of annual (2.89 pg) and perennial (7.73 pg) species is significantly different; (b) mean x = 5 genome size of perennials (1.66 pg) is significantly greater than that of the annuals (1.09 pg); (c) the mean maximum latitude at which perennial species grow (-25.4 degrees) is significantly greater than the mean maximum latitude (-17.6) at which annual species grow. CONCLUSIONS: The DNA sequence phylogeny splits Sorghum into two lineages, one comprising the 2n = 10 species with large genomes and their polyploid relatives, and the other with the 2n = 20, 40 species with relatively small genomes. An apparent phylogenetic reduction in genome size has occurred in the 2n = 10 lineage. Genome size evolution in the genus Sorghum apparently did not involve a 'one way ticket to genomic obesity' as has been proposed for the grasses
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