Dissertation presented in partial compliance with the requirements for a Masters Degree in Technology: Chiropractic, Technikon Natal, 1998. / Very few studies of medial tibial stress syndrome type II address the treatment of the condition. There is a need to find a method of hastening the recovery of the condition. Therefore the objective of this study was to determine whether application of ultrasound therapy to medial tibial stress syndrome type Il would influence the recovcrv of this condition. / M

O resultado clínico a longo prazo das osteotomias valgizantes da tíbia depende da obtenção do adequado alinhamento do eixo mecânico pelo procedimento cirúrgico. Essa correção do eixo mecânico é obtida pela adição ou subtração de cunhas ósseas. O tamanho das cunhas pode ser planejado pré-operatoriamente ou determinado durante a cirurgia utilizando controle intraoperatório do alinhamento do membro. Modernamente, o controle intraoperatório pode ser realizado com auxílio de equipamentos de navegação cirúrgica computadorizados. Neste estudo, comparamos os valores dos eixos mecânicos e dos tamanhos das cunhas obtidos pelo método de planejamento pré-operatório das osteotomias com cálculo trigonométrico e pelas cirurgias auxiliadas por sistema de navegação intraoperatória. A medida dos eixos mecânicos em imagens radiográficas panorâmicas dos membros inferiores foi realizada por catorze cirurgiões de joelho em treze pacientes. A cirurgia de osteotomia valgizante auxilada por navegação cirúrgica foi realizada pelo mesmo cirurgião nos mesmos treze pacientes, documentando-se o tamanho da cunha de adição medial e os eixos mecânicos do membro inferior. Após as cirurgias, planejamos os tamanhos das cunhas de adição medial, por cálculo trigonométrico, utilizando os dados dos eixos mecânicos medidos nas radiografias. Nós realizamos comparação entre os valores dos eixos mecânicos obtidos nas cirurgias e os valores medidos nas imagens radiográficas e entre os tamanhos das cunhas de adição medial medidos intraoperatoriamente e planejadas nos cálculos trigonométricos. A análise dos dados foi realizada por análise descritiva dos resultados e por gráficos de Bland e Altman. Como resultados, observamos alta correlação entre os valores dos eixos mecânicos medidos nos exames radiográficos e pelo navegador cirúrgico e observamos que os valores planejados para as cunhas de adição são diferentes dos valores medidos durante as cirurgias / The long-term clinical outcome of tibial osteotomy depends on achieving the proper mechanical axis alignment for the surgery. Adding or subtracting bone wedges obtains the mechanical axis correction. The correction size may be planned preoperatively or defined during surgery under limb alignment control. Nowadays, the limb alignment control may be accomplished with the aid of computerized surgical navigation equipment. In this study, we compared the values of the mechanical axes and the wedges sizes obtained by the osteotomies preoperative planning method with trigonometric calculation and those values measured on navigated surgeries. Fourteen knee surgeons performed the measurement of the mechanical axes in panoramic radiographs of the lower limbs of thirteen patients. The same surgeon performed all thirteen surgeries. The wedges sizes and the mechanical axes of the lower limb were measured during surgeries. After surgery, the sizes of the planned addition of medial wedges, for trigonometric calculation, using data from the mechanical axis measured on the radiographs. We carry out comparison between the values of the mechanical axes obtained in the surgeries and the values measured in the radiographs and between the sizes of the wedges and wedge sizes planned in trigonometric calculations. We performed data analyses by descriptive analysis and Bland and Altman. We have observed a high correlation between the values of the mechanical axes measured on radiographs and in navigated surgeries and noticed that the planned values for wedges are different from values measured during surgery

La mosca minadora Liriomyza huidobrensis es una plaga agrícola de importancia mundial, ampliamente distribuida y representa la plaga más dañina en el cultivo de papa en el Perú. El control biológico, que incluye el uso de parasitoides, representa la mejor estrategia para el control de esta plaga. La utilización exitosa de los parasitoides dependerá de nuestro conocimiento de dichos factores, incluyendo las interacciones tritróficas entre plantas hospederas, insectos y parasitoides. Nuestro estudio se realizó sobre el parasitoide Chrysocharis flacilla con el objetivo de evaluar el efecto de las interacciones tróficas en determinados parámetros biológicos como longevidad, supervivencia, producción de progenie, proporción sexual y longitud de la tibia posterior. Se desarrollaron tres sistemas de procedencia del parasitoide: Papa - L. huidobrensis, Haba - L. huidobrensis y Maíz -L. graminivora, cuyos adultos interactuaron con tres asociaciones de prueba idénticas a los sistemas de procedencia mencionados. Todas las evaluaciones se realizaron mediante pruebas Elección y No Elección. C. flacilla presentó una variación intraespecifica en todos los parámetros evaluados. Se encontraron diferencias significativas en su longevidad, supervivencia, proporción sexual y longitud de la tibia posterior luego de interactuar con las distintas asociaciones planta – minador de prueba; asimismo, en su producción de progenie entre las tres procedencias estudiadas. Se menciona la implicancia que puede tener la planta hospedera, así como, el minador hospedero sobre dicha variación en C. flacilla. Finalmente, el parasitoide no presenta preferencia por alguno de sus sistemas de procedencia y las asociaciones tróficas Haba - L. huidobrensis y Maíz -L. graminivora pueden funcionar adecuadamente como hospederos alternos del parasitoide. / ---The leaf miner Liriomyza huidobrensis is an agricultural pest of global importance, widely distributed, representing the most damaging pest in Peru for potato crop. Biological control, including the use of parasitoids, represents the best strategy for controlling this pest. The successful uses of parasitoids will depend on our knowledge of many factors, including tritrophic interactions between host plants, insects and parasitoids. Our study was performed on parasitoid Chrysocharis flacilla in order to assess the effect of trophic interactions in biological parameters such as longevity, survival, production of progeny, sex ratio and posterior tibia length. Three parasitoid origin systems were developed: Potato - L. huidobrensis, Faba bean - L. huidobrensis and Maize -L. graminivora, whose adults interacted with three associations identical to origin systems mentioned. Assessments were made in both No Choice and Choice Tests. We found that C. flacilla has an intraspecific variation in all biological parameters assessed. We found significant differences on longevity, survival, sex ratio and posterior tibia length after interactions with the three different crop – leaf miner associations assessed; moreover, offspring production showed significant differences among the three origin systems studied. We discuss host plant and host leaf miner implications on such intraspecific variation in parasitoid. Finally, C. flacilla does not have any preference for its origin systems; and the trophic associations Faba bean - L. huidobrensis and Maize -L. graminivora can function adequately as alternate hosts of the parasitoid. Keywords: longevity, survival, sex ratio, posterior tibia length, offspring, No choice test, Choice test, plant-leafminer-parasitoid association. / Tesis

The effects of diet type, amino acid (AA), and apparent metabolizable energy (AME) levels in male broiler diets from d 8 to 21 on blood, small intestine, bone, and growth performance were investigated. Eight experimental diets with 2 protein sources [high inclusion of distiller's dried grains with solubles diet (hDDGS) or high inclusion of meat and bone meal diet (hMBM)], 2 AA densities (moderate or high), and 2 AME densities (2,998kcal/kg or 3,100kcal/kg), were fed to the broiler chicks from 8 to 21 days of age (d). High AME diets may lower feed cost by lowering feed intake. Intestinal morphology changes responded to dietary treatments, which may facilitate nutrients digestion and absorption in high MBM diets as well as in high DDGS diets. In addition, high AA or AME diets from 8 to 20 d improved feed conversion during experimental phase and influenced meat yields at 55 d.

No description available.

The tibia is a frequent site of injury in frontal automotive collisions. The bulk of experimental cadaveric studies on injury tolerance assume load is applied in line with the leg’s long axis, leaving non-standard postures largely uninvestigated. The purpose of this work was to study the effects of non-standard postures on the tibia’s injury tolerance. A pneumatic system was designed to facilitate impact testing. This system allows the user to fire a projectile of variable mass towards a specimen at a range of velocities by varying the supplied air pressure. Impact tests were performed using pairs of isolated cadaveric tibias. Within each pair of specimens, two postures were compared by varying the angle of the bone’s long axis relative to the direction of impact, representing knee extension and corresponding plantarflexion. It was found that the specimens held further from the axial posture sustained injury at lower forces. Two commonly-used Anthropomorphic Test Device legforms were impacted in these non-standard postures. New load limits were proposed for the use of these devices in off-axis impact testing. In order to compare directly with the loads measured by the legforms, it was necessary to measure forces and moments internal to the bone’s long axis. A non-invasive load estimation method was developed and tested using strain measured from the surface of four specimens. The method performed poorly under impact conditions, but may be refined in the future. Quantifying the effect of posture on injury risk in the tibia allows for the refinement of existing injury criteria. Ultimately, this can be used to enhance the design of protective devices to reduce the incidence of tibia fractures in automotive collisions. / Thesis / Master of Applied Science (MASc) / Fractures of the tibia (the shin bone) are common in automotive collisions, and often lead to long-term impairment. Experimental studies on these kinds of injuries are usually performed with the lower leg aligned with the direction of impact, which does not reflect the range of postures an occupant may assume during a crash. Cadaveric tibias were subjected to impact loading in two different postures. It was found that the specimens held further from an axial posture sustained fractures at lower forces. Two commonly-used crash test dummy legs were also impacted in these non-standard postures to test their performance. Suggestions were made for new load limits to be used with these devices in non-standard postures. The finding that leg posture has an effect on injury risk in the tibia can be used in the future to design and evaluate better protective devices and ultimately reduce the incidence of these injuries.

No description available.

The purpose of this study was to assess the validity, as well as to test novel approaches to improving the reliability, of mechanical response tissue analysis (MRTA). Twenty composite tibiae underwent MRTA testing on three separate days to determine intra- and inter-day reliability of bending stiffness. The bones were then subjected to three-point bending tests to directly determine elastic modulus. Within- and between-day reliability of tibial bending stiffness with MRTA was moderate (CV = 24%) and poor (CV = 74%), respectively. No relationship was observed between the two testing methods due to the wide variation in tibial bending stiffness values with MRTA. The second part of the study sought to determine within- and between-day reliability of MRTA in young women with the current testing protocol and compare the results with those from newly-designed protocols. Twelve women (23 ± 2 yr, 162 ± 7 cm, 57 ± 7kg, 19 ± 4 % fat) were tested for tibial bending stiffness with MRTA over 5 days. The current protocol was compared to protocols where day-to-day subject positioning was quantified, subjects were tested in a supine position, and various bending stiffness prediction models were used. Within- (CV = 20%) and between-day (CV = 19%) reliability of tibial bending stiffness with MRTA was moderate using the original methodology. Modifications to this protocol either resulted in similar or worse reliability. / Ph. D.

Mechanical response tissue analysis (MRTA) provides a noninvasive means of estimating the cross-sectional bending stiffness (EI) of long bones, and thus can serve as a predictor of bone strength. Estimates of bone bending stiffness are derived from the point impedance response of a long bone to low frequency (70-500Hz) stimulation according to beam vibration theory. MRTA has demonstrated the ability to reliably estimate human ulnar bending stiffness with between-test coefficients of variation of 5%, and in vivo measurements of monkey tibiae have been validated with ex vivo 3-point mechanical bending tests. Human tibial MRTA measurement has achieved between-trial coefficients of variation of only 12%, so a new physical MRTA configuration and improved computer algorithms have been developed in an attempt to improve upon this level of reliability. The new configuration removes the rigid proximal and distal tibial restraints and models the tissue behavior with a 12-parameter algorithm that accounts for free vibration at the ankle and knee joints. Initial testing with only the hardware changes and application of the 7-parameter model of tissue behavior used in earlier systems yielded unacceptable variation. Subsequent reliability testing with application of 6-, 9-, and 12-parameter models demonstrated modest improvements, prompting the development of the more robust 12-parameter model used in the present study. Evaluation of 110 college-age females (age 20.2±1.8 yr, height 163.3±5.9 cm, weight 60.7±9.3 kg, BMI 22.8±3.1 kg·m⁻²) with the current MRTA system has demonstrated an improvement in within-trial reliability for unsupported tibial EI measurement with a coefficient of variation of 11.2%. These results demonstrate the ability of the system to measure tibial response characteristics when both proximal and distal ends are free of rigid support. Long-term measurement reliability is still problematic with a coefficient of variation of 36.5% for a set of 4 measurements spanning 21 months. / Ph. D.

No description available.