Thesis ((DMed)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: We have developed an innovative multimedia e-learning resource, the Electrolyte Workshop, to provide students and clinicians with instruction and the opportunity for simulated practice in managing electrolyte and acid-base disorders. Our teaching approach is built around relevant physiology and makes use of real cases and storytelling to engage the learner. We have documented the challenges encountered during the development process and have made recommendations for the managing of similar projects. While there are many factors that must be in place to ensure successful e-learning, this dissertation focuses on an important but under-appreciated factor, namely the usability of the computer interface. Usability describes how easy technology interfaces are to use and is routinely evaluated and optimized in the software development industry. This is not yet the case with e-learning, especially in the area of medical education. Poor usability limits the potential benefit of educational resources, as this means that learners will struggle with the interface as well as with the challenges of the content presented. A comprehensive usability evaluation of our Electrolyte Workshop was completed. This included testing with typical end-users, where data were collected via standardized questionnaires and by observing and analysing their interactions with our application. We employed heuristic evaluation as an additional approach and assembled a panel of experts to evaluate our application against a set of heuristics, or principles of good interface design. Many serious usability problems were identified, thus severely limiting the potential educational impact of our Electrolyte Workshop. There was a striking disconnect between the objective measures of usability and self-reported questionnaire data. Our user-testing data make a useful contribution to the debate on how many users are required to find most of the usability problems in an interface. Heuristic evaluation proved to be a very efficient approach. However, both user testing and heuristic evaluation detected serious problems which were missed with the other method. These evaluations informed a comprehensive revision of our application and we could then compare the original with an optimized version in a randomized trial. We found large improvements in objective usability measures, which are likely to increase the satisfaction and motivation of learners. There were similar scores on measures of learning. This was not surprising as our participants were all relatively high-knowledge learners and not novices as regards the subject matter. Our study clearly indicates that the usability evaluation of e-learning resources is critical, and provides an example of how clinician-teachers can improve the usability of the resources they develop. Usability should be evaluated as a routine part of the development and implementation of e-learning materials, modules and programmes. This should start with the earliest versions of the resource, when making changes is easier and less costly. We have demonstrated that a combination of methods should be employed and have highlighted the utility of heuristic evaluation. An iterative approach should be followed, with several cycles of testing and re-design. User testing should always include the study of objective usability measures and not rely only on self-reported measures of user satisfaction. / AFRIKAANSE OPSOMMING: Ons het ’n innoverende multimediahulpbron vir e-leer, die Electrolyte Workshop, ontwikkel om studente en klinici van ’n onderrighulpmiddel sowel as die geleentheid vir gesimuleerde oefening in die hantering van elektroliet en suur-basis stoornisse te voorsien. Ons onderrigbenadering is gegrond op relevante fisiologie en maak gebruik van werklike gevalle en vertelkuns om die leerder te betrek en te boei. Ons het die uitdagings gedurende die ontwikkelingsproses opgeteken en aanbevelings oor die bestuur van soortgelyke projekte gedoen. Hoewel suksesvolle e-leer van etlike faktore afhang, konsentreer hierdie verhandeling op ’n belangrike dog onderskatte faktor, naamlik die bruikbaarheid van die rekenaarkoppelvlak. Bruikbaarheid verwys na die gemak waarmee tegnologiekoppelvlakke gebruik kan word, en word gereeld in die sagtewareontwikkelingsbedryf beoordeel en verbeter. Tog is dit nog nie die geval met e-leer nie, veral op die gebied van mediese onderrig. Swak bruikbaarheid beperk die moontlike voordeel van opvoedkundige hulpbronne, aangesien leerders voor die dubbele uitdaging van ’n ingewikkelde koppelvlak én die voorgeskrewe inhoud te staan kom. ’n Omvattende bruikbaarheidsbeoordeling is van die Electrolyte Workshop onderneem. Dit het toetsing met tipiese eindgebruikers ingesluit, waarvoor data met behulp van gestandaardiseerde vraelyste ingesamel en gebruikers se interaksie met die toepassing waargeneem en ontleed is. Ons het heuristiese evaluering as bykomende benadering gebruik en ’n kennerspaneel saamgestel om ons toepassing aan die hand van ’n stel heuristiek, oftewel beginsels van goeie koppelvlakontwerp, te beoordeel. ’n Hele aantal ernstige bruikbaarheidsprobleme is uitgewys, wat die moontlike opvoedkundige impak van die Electrolyte Workshop erg beperk. Daar was merkbare teenstrydigheid tussen die objektiewe bruikbaarheidsmaatstawwe en die selfaangemelde vraelysdata. Ons gebruikerstoetsdata lewer ’n waardevolle bydrae tot die debat oor hoeveel gebruikers nodig is om die meeste van die bruikbaarheidsprobleme met ’n koppelvlak te ontdek. Heuristiese evaluering was ʼn baie doeltreffende benadering. Tog het gebruikerstoetsing op sekere ernstige probleme afgekom wat heuristiese evaluering misgekyk het, en andersom. Hierdie beoordelings het as grondslag gedien vir ’n omvattende hersiening van die toepassing, waarna ons die oorspronklike weergawe in ’n verewekansigde proef met ’n verbeterde weergawe kon vergelyk. Die objektiewe bruikbaarheidsmaatstawwe het groot verbeterings getoon, wat waarskynlik leerders se tevredenheid en motivering sal verhoog. Leermaatstawwe het soortgelyke tellings opgelewer. Dít was egter te wagte gewees, aangesien die deelnemers almal betreklik ingelig was oor die vakmateriaal, eerder as nuwelinge. Ons studie het bevestig dat die bruikbaarheidsbeoordeling van e-leerhulpbronne noodsaaklik is, en bied ’n voorbeeld van hoe klinici-opvoeders bruikbaarder hulpbronne kan ontwikkel. Bruikbaarheid behoort as ’n roetinedeel van die ontwikkeling en inwerkingstelling van e-leermateriaal, -modules en -programme beoordeel te word. Dit behoort reeds by die vroegste weergawes van die hulpbron te begin, wanneer dit makliker en goedkoper is om veranderinge aan te bring. Ons het ook getoon dat ’n kombinasie van metodes gebruik behoort te word, en het die nut van heuristiese evaluering beklemtoon. ’n Herhalende benadering moet gevolg word, met etlike siklusse van toetsing en herontwerp. Gebruikerstoetsing behoort altyd die beoordeling van objektiewe bruikbaarheidsmaatstawwe in te sluit, en moenie slegs op selfaangemelde maatstawwe van gebruikerstevredenheid staatmaak nie.

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Experiments were conducted to investigate the effects of formulating rations using different ingredients and of manipulating the cation-anion balance of the rations on production, acid-base status, metabolism of macrominerals and renal function of dairy cows. The effects of dietary cation-anion balance were studied during early, mid and late lactation as well as during the dry period. Feeding an alfalfa-haylage based diet vs a corn silage based diet, both having the same cation-anion balance did not affect the voluntary consumption, milk yield or milk composition of cows in early lactation. The acid-base status of the animals was not affected by dietary treatment. The lower urinary bicarbonate concentration observed with the alfalfa haylage-based diet was not associated with a lower total urinary bicarbonate excretion since urine volume was significantly higher than when cows were fed the corn silage-based diet. Manipulating dietary cation-anion balance, however, resulted in changes in acid-base status at all stages of lactation studied. Urinary bicarbonate concentration and total daily excretion were increased by a higher dietary cation-anion balance at all stages of lactation. Similar effects of dietary cation-anion balance on urinary bicarbonate did not, however, translate into similar changes in production or intake by cows at differing stages of lactation. Cows in early and mid lactation seemed to have benefited more from a highly positive dietary cation-anion balance than cows in late lactation or dry period.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Bibliography: leaves 150-158. / by Ramesh Shrikrishna Patil. / Ph.D.

O objetivo deste estudo foi avaliar o comportamento eletroquímico e do distúrbio ácido-básico em atletas de alto rendimento durante o campeonato mundial de Karatê realizado pela WKO (World Karate Organization) em 2014. A amostra foi composta por 19 atletas do gênero masculino, com idade média de 34 ± 8 anos. Todos eles eram faixas pretas, e tinham mais de 5 anos de prática na modalidade. Foram realizadas coletas de sangue capilar da polpa digital dos dedos da mão em três momentos: repouso, 5 minutos após o combate e 10 minutos após combate (kumite). A amostra foi analisada utilizando o aparelho de gasometria GEM Premier 3000, utilizando os parâmetros pH, Na+, K+, Ca2+, lactato e HCO3−. Os valores relacionados ao distúrbio ácido-básico apresentaram diferenças estatísticas (p<0,05) na maioria dos momentos coletados. Os valores de lactato encontrados foram de 2,77 ± 0,97 mmol/L no repouso, 6,57 ± 2,1 para 5 minutos após e de 4,06 ± 1,55 para 10 minutos após o combate. Os dados coletados relativos aos marcadores eletrolíticos não apresentaram diferenças estatísticas em seus valores (p<0,05). Através dos dados levantados, conjecturamos que a modalidade pode ser caracterizada como exercício de alta intensidade e com predominância do sistema glicolítico. A análise do distúrbio ácido-básico é uma medida eficiente para auxiliar no controle das cargas de treinamento. / The objective of this study was to analyze the electrochemical and acid-base disorders in high performance athletes during the World Karate Championship hosted by the WKO (World Karate Organization) in 2014. In this study 19 male athletes were analyzed (age 34 ± 8), black belts and with over 5 years of experience in the sport. Capillary blood samples from the digital pulp of the finger were collected in three stages: rest, 5 minutes after and 10 minutes after fighting (kumite). The sample was analyzed using blood gas analyzer GEM Premier 3000, using the parameters pH, Na+, K+, Ca2+, lactate e HCO3−. The values related to acid-base disturbance presented statistical differences (p <0.05) in most of the collected moments. The lactate levels found were 2.77 ± 0.97mmol / L in rest, 6.57 ± 2.1 for 5 minutes after and 4.06 ± 1.55 for 10 minutes after combat. The samples collected for the electrolytic markers showed no statistical differences in their values (p <0.05). Through the data collected, we conjecture that the sport can be characterized as a high-intensity exercise and with a predominance of the glycolytic system. The analysis of acid-base disturbance is an efficient method to assist in the control of training loads.

O objetivo deste estudo foi avaliar o comportamento eletroquímico e do distúrbio ácido-básico em atletas de alto rendimento durante o campeonato mundial de Karatê realizado pela WKO (World Karate Organization) em 2014. A amostra foi composta por 19 atletas do gênero masculino, com idade média de 34 ± 8 anos. Todos eles eram faixas pretas, e tinham mais de 5 anos de prática na modalidade. Foram realizadas coletas de sangue capilar da polpa digital dos dedos da mão em três momentos: repouso, 5 minutos após o combate e 10 minutos após combate (kumite). A amostra foi analisada utilizando o aparelho de gasometria GEM Premier 3000, utilizando os parâmetros pH, Na+, K+, Ca2+, lactato e HCO3−. Os valores relacionados ao distúrbio ácido-básico apresentaram diferenças estatísticas (p<0,05) na maioria dos momentos coletados. Os valores de lactato encontrados foram de 2,77 ± 0,97 mmol/L no repouso, 6,57 ± 2,1 para 5 minutos após e de 4,06 ± 1,55 para 10 minutos após o combate. Os dados coletados relativos aos marcadores eletrolíticos não apresentaram diferenças estatísticas em seus valores (p<0,05). Através dos dados levantados, conjecturamos que a modalidade pode ser caracterizada como exercício de alta intensidade e com predominância do sistema glicolítico. A análise do distúrbio ácido-básico é uma medida eficiente para auxiliar no controle das cargas de treinamento. / The objective of this study was to analyze the electrochemical and acid-base disorders in high performance athletes during the World Karate Championship hosted by the WKO (World Karate Organization) in 2014. In this study 19 male athletes were analyzed (age 34 ± 8), black belts and with over 5 years of experience in the sport. Capillary blood samples from the digital pulp of the finger were collected in three stages: rest, 5 minutes after and 10 minutes after fighting (kumite). The sample was analyzed using blood gas analyzer GEM Premier 3000, using the parameters pH, Na+, K+, Ca2+, lactate e HCO3−. The values related to acid-base disturbance presented statistical differences (p <0.05) in most of the collected moments. The lactate levels found were 2.77 ± 0.97mmol / L in rest, 6.57 ± 2.1 for 5 minutes after and 4.06 ± 1.55 for 10 minutes after combat. The samples collected for the electrolytic markers showed no statistical differences in their values (p <0.05). Through the data collected, we conjecture that the sport can be characterized as a high-intensity exercise and with a predominance of the glycolytic system. The analysis of acid-base disturbance is an efficient method to assist in the control of training loads.