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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Pressure distribution and myoelectric activity as a function of seating parameters

Treaster, Delia E. January 1986 (has links)
No description available.
12

Characterization of the Ionic Currents In Cultured Small Intensely Fluorescent Cells from Superior Cervical Ganglia of Neonatal Rats

Alexander, Stephen A. January 1999 (has links)
The superior cervical ganglion (SCG) is the largest of the sympathetic chain ganglia which control a number of autonomic cardiovascular reflexes via neural activity in the postganglionic nerve trunk. In addition to the large principal neurons, these ganglia contain a minority population of smaller cells, the small intensely fluorescent or SIF cells, so named because of their intense fluorescence following treatments which reveal the presence of endogenous catecholamines (mainly dopamine in the rat). The physiological functions of the SIF cells are largely unknown and various roles have been proposed including (i) dopaminergic interneuron, which modulates ganglionic transmission, (ii) endocrine function, since many of them have a close association with the vasculature and (iii) chemosensory function, similar to that of the arterial chemoreceptors which sense blood gases and pH. Understanding the physiological role of SIF cells has been hampered by their small size, sparse distribution and relative inaccessibility, all of which render microelectrode electrophysiological studies difficult. In this thesis these limitations were overcome by use of (i) dissociated cell cultures of the rat SCG, in which growth conditions favoured SIF cell survival but not that of the principal neurons, and (ii) the novel high resolution patch clamp/whole cell recording technique which is ideal for the study of the electrophysiology of small cells. The ionic currents, which underlie many basic electrophysiological processes, were characterized in 5-16 day old cultures of SIF cells obtained from the SCG of neonatal rats. The main methodology consisted of whole cell recording under voltage clamp conditions, which permit the study of membrane ionic currents. Five main ionic currents were identified in all of the SIF cells ( > 100) studied: (i) a fast transient inward Na+ current, sensitive to the well-known blocker of voltage-gated Na+ channels i.e. tetrodotoxin or TTX; (ii) the delayed rectifier outward K+ current that is found in a variety of cell types; (iii) a Ca2+- activated outward K+ current, sensitive to Ca2+ channel blockers; (iv) a transient inward Ca2+ current which appears to be carried by N-type Ca2+ channels and (v) a slower, sustained inward Ca2+ current which appears to be carried by L-type Ca2+ channels. In addition a third type of outward K+ current, the fast transient K+ current or lA, was found in SIF cells obtained from 3-7 day old rats, but not from 1 day old rats. It therefore appears that this lA current, which is known to modulate firing frequency in neurons develops rapidly in vivo during the first postnatal week. This broad repertoire of ion channels in SIF cells suggests several possible sites for modulation by various agents including neurotransmitters, neuromodulators, or other chemosensitive agents. Since SIF cells were recently proposed to have arterial chemoreceptor function similar to glomus cells, the effect of one such stimulus, i.e. an acidic (intracellular) pH, was tested. It has recently been suggested that a decrease in intracellular pH is part of the pathway responding to extracellular stimuli in the glomus cell (Stea, Alexander and Nurse, in press). Acidification of the SIF cell's cytoplasm with the K+/H+ ionophore nigericin resulted in a suppression of both the fast inward Na+ current as well as the outward K+ current. However, these effects do not appear to beunique to SIF cells and therefore the possibility of a chemoreceptor role m the cardiovascular system requires further study. In summary, the characterization of the various ionic currents in SIF cells resulting from this thesis provides the necessary background which should eventually resolve not only the question of the physiological role of SIF cells in autonomic ganglia, but also help to understand the underlying mechanisms responsible for SIF cell function. / Thesis / Master of Science (MS)
13

The effects of sagittal plane postures on trunk rotation range of motion

Montgomery, Trevor January 2008 (has links)
Axial rotation is regarded as an essential movement of the trunk that allows many individuals to participate in vocations, sports and activities of daily living. Unfortunately when the destabilising nature of rotation is combined with that of spinal flexion, the risk of injuring the spine can increase significantly. Few studies have investigated the potential benefits that maximizing trunk rotation has in certain vocation and sport-related arenas and none have looked at whether adopting certain spinal postures in the sagittal plane can maximise trunk rotation more than others. The aim of the study was to determine the effects of alterations of trunk inclination, spinal posture, pelvic fixation and turning direction on the active range of motion (ROM) of trunk rotation. Twenty healthy individuals participated in the main study. Retro-reflective markers were placed on key anatomical locations and used to track the movement of the thorax and pelvis during a series of repeated maximal trunk rotations in ten different spinal positions within the sagittal plane. Trunk kinematics and kinetics were recorded simultaneously using an optoelectronic motion analysis and force platform measuring system. A repeated-measures multiple analysis of variance (MANOVA) was used to test for the main effects of trunk inclination, spinal posture, fixation of pelvis and direction of turn on maximum active ROM of trunk rotation, maximum pelvic rotation and the anterior-posterior and lateral displacement of the centre of pressure (COP). To investigate test-retest reliability, ten participants were tested on two separate days. Repeatability for each outcome measure was investigated using interclass correlation coefficients (ICC) and Bland Altman graphs. The majority of subjects showed reasonable test-retest reliability for trunk rotation measures in each of the test positions, with ICC’s ranging between 0.562 – 0.731. Overall, trunk inclination (0°, 22.5°, 45°) forward in the sagittal plane had a significant effect on trunk and pelvic rotation (p<0.001) and lateral displacement of the COP (p<0.005) during trunk rotation. As trunk inclination increased from 0° to 45° there was an average increase in trunk rotation ROM of approximately 10 % (approximately 3.4°). Furthermore, increasing trunk inclination led to an increase in lateral displacement of the COP and a decrease in pelvic rotation. Spinal posture (neutral, flexed, extended) at a forward inclination of 45° had a significant effect on trunk rotation (p<0.01) and pelvic rotation (p<0.05), with a neutral spine averaging approximately 3 % (approximately 1.1°) more trunk rotation than a flexed or extended posture. The position and posture of the spine in the sagittal plane appears to have a significant influence on ranges of trunk rotation. The study suggests that rotating the trunk when adopting a neutral spine inclined to 45° will maximise range of trunk rotation and encourage a natural stabilisation of the lower body. This posture meets the unique set of biomechanical requirements for the sport of golf and may help to reduce the risk of injury in manual material handling tasks. Conversely, rotating the trunk whilst the thoracolumbar spine is flexed leads to a reduction in trunk rotation ROM, encourages greater pelvic and lower body rotation, reduces torque production of the trunk and may increase the risk of lower back injury. These findings have important implications in relation to the teaching of spinal position during vocations, sports and activities of daily living that seek to maximise trunk rotation.
14

BODY ARMOR INDUCED CHANGES IN THE TRUNK MECHANCIAL AND NEUROMUSCULAR BEHAVIOR

Tromp, Rebecca Leigh 01 January 2015 (has links)
While military body armor is used among warfighters for protection on and off the battlefield, it has been suggested to impede performance and act as a risk factor for the development of musculoskeletal disorders, especially low back pain. Apart from personal suffering, low back pain in soldiers is a great economic burden on the US economy. The objective of this study was to quantify the changes in trunk mechanical and neuromuscular behavior following prolonged exposure to body armor compared to exposure without. A crossover study design was used where 12 sex-balanced participants completed a series of tests before and after 45 minutes of treadmill walking with and without body armor. The tests included range of motion, isometric trunk tests, sudden perturbations, and stress relaxation. As a whole, exposure duration considered in this study resulted in no significant differences in performance between armor and no armor conditions. However, comparing the effects of body armor among the sex-differentiated groups showed a body armor -induced increase in range of trunk motion in the sagittal plane among females (p = 0.0018) and a decrease in pelvic range of motion in the transverse plane among both males (p=0.025) and females (p=0.004).
15

The effects of sagittal plane postures on trunk rotation range of motion

Montgomery, Trevor January 2008 (has links)
Axial rotation is regarded as an essential movement of the trunk that allows many individuals to participate in vocations, sports and activities of daily living. Unfortunately when the destabilising nature of rotation is combined with that of spinal flexion, the risk of injuring the spine can increase significantly. Few studies have investigated the potential benefits that maximizing trunk rotation has in certain vocation and sport-related arenas and none have looked at whether adopting certain spinal postures in the sagittal plane can maximise trunk rotation more than others. The aim of the study was to determine the effects of alterations of trunk inclination, spinal posture, pelvic fixation and turning direction on the active range of motion (ROM) of trunk rotation. Twenty healthy individuals participated in the main study. Retro-reflective markers were placed on key anatomical locations and used to track the movement of the thorax and pelvis during a series of repeated maximal trunk rotations in ten different spinal positions within the sagittal plane. Trunk kinematics and kinetics were recorded simultaneously using an optoelectronic motion analysis and force platform measuring system. A repeated-measures multiple analysis of variance (MANOVA) was used to test for the main effects of trunk inclination, spinal posture, fixation of pelvis and direction of turn on maximum active ROM of trunk rotation, maximum pelvic rotation and the anterior-posterior and lateral displacement of the centre of pressure (COP). To investigate test-retest reliability, ten participants were tested on two separate days. Repeatability for each outcome measure was investigated using interclass correlation coefficients (ICC) and Bland Altman graphs. The majority of subjects showed reasonable test-retest reliability for trunk rotation measures in each of the test positions, with ICC’s ranging between 0.562 – 0.731. Overall, trunk inclination (0°, 22.5°, 45°) forward in the sagittal plane had a significant effect on trunk and pelvic rotation (p<0.001) and lateral displacement of the COP (p<0.005) during trunk rotation. As trunk inclination increased from 0° to 45° there was an average increase in trunk rotation ROM of approximately 10 % (approximately 3.4°). Furthermore, increasing trunk inclination led to an increase in lateral displacement of the COP and a decrease in pelvic rotation. Spinal posture (neutral, flexed, extended) at a forward inclination of 45° had a significant effect on trunk rotation (p<0.01) and pelvic rotation (p<0.05), with a neutral spine averaging approximately 3 % (approximately 1.1°) more trunk rotation than a flexed or extended posture. The position and posture of the spine in the sagittal plane appears to have a significant influence on ranges of trunk rotation. The study suggests that rotating the trunk when adopting a neutral spine inclined to 45° will maximise range of trunk rotation and encourage a natural stabilisation of the lower body. This posture meets the unique set of biomechanical requirements for the sport of golf and may help to reduce the risk of injury in manual material handling tasks. Conversely, rotating the trunk whilst the thoracolumbar spine is flexed leads to a reduction in trunk rotation ROM, encourages greater pelvic and lower body rotation, reduces torque production of the trunk and may increase the risk of lower back injury. These findings have important implications in relation to the teaching of spinal position during vocations, sports and activities of daily living that seek to maximise trunk rotation.
16

Control of Goal-Directed Reaches in Older Adults

Khanafer, Sajida 22 December 2022 (has links)
Healthy individuals can adjust their movements when changes arise to the body or the environment. Advanced age is associated with central and peripheral changes that may negatively impact one’s ability to adapt motor performance, such us upper-limb (UL) reaching movements. In this thesis, we conducted four studies to address the impact of aging on coordination and adaptation of goal-directed reaches. In the first experiment, we examined compensatory arm–trunk coordination in older adults during trunk-assisted reaching, using two motor tasks : 1) the Stationary Hand Task (SHT) in which older and young participants were asked to maintain a fixed hand position while flexing forward at the trunk, and 2) the Reaching Hand Task (RHT) in which participants were instructed to reach to a within-arm’s reach target while simultaneously flexing forward at the trunk (Raptis et al., 2007; Sibindi et al., 2013). We found that in SHT, young and older participants were able to maintain a stable hand position and compensate for trunk movement by appropriate angular rotations at the elbow and shoulder joints. As well, in the RHT, both groups made similar small overshoot errors. However, older participants performance was significantly more variable compared to young adults. These results suggest that older adult preserve their ability to coordinate arm and trunk movements efficiently during reaching but are not as consistent as young adults. In the second experiment, we sought to determine the ability of older adults to adjust shoulder and elbow coordination in response to changing task demands. Thus, we asked young and older adults to perform the RHT of Raptis et al. (2007) from the first experiment. A detailed comparison of UL kinematics during reaches in the presence and absence of trunk motion (i.e., free- vs. blocked-trunk trials) was performed and compared between young and older adults. We found that participants in both age group were able to coordinate motion at the elbow and shoulder joints in accordance with motion at the trunk. However, the extent of changes at the UL joints was smaller and more variable in older adults compared to young ones, especially when trunk motion was involved. These results imply that older adults can coordinate their UL movements based on task requirements, but with less consistent performance compared to young adults. In the third experiment, we investigated the preservation of intermanual transfer and retention of implicit visuomotor adaptation in older adults. We had young and older participants train to reach with visual feedback rotated 30° counter-clockwise relative to their actual hand motion. Furthermore, we examined whether providing augmented somatosensory feedback regarding movement endpoint would enhance visuomotor adaptation. We found that older adults demonstrated a comparable magnitude of implicit adaptation, transfer, and retention of visuomotor adaptation as observed in young adults, regardless of the presence of augmented somatosensory feedback. These results indicate that intermanual transfer and retention do not differ significantly between young and older adults when adaptation is driven implicitly, regardless the availability of augmented somatosensory feedback. In the fourth experiment, we looked to determine age-related differences in the engagement of offline and online control processes during implicit visuomotor adaptation. A detailed analysis of reaching performance was conducted and between young and older adults, during and after visuomotor adaptation. We found that when rotation was introduced, participants in both age took longer time to complete their movements, reached with a lower peak velocity and spent more time homing in on the target compared to reaches with aligned cursor feedback. Additionally, older adults had more curved paths with rotated cursor feedback compared to their reaches with aligned cursor feedback. Moreover, these changes in reaching performance continued following adaptation for both groups. These results suggest that young and older adults engage more in online control processes during implicit visuomotor adaptation. Together, these studies show that older adults: 1) maintain the ability to use compensatory arm-trunk coordination to maintain reaching accuracy, 2) preserve the ability to adjust the coordination between UL joints to meet task demands, 3) maintain the ability to adjust reaches to meet changes in the reaching environment, as well as transfer and retain the newly acquired movement, and 4) preserve the ability to modify the control processes underlying these adapted movements to meet the demands of the reaching environment. In conclusion, the flexibility to coordinate and adapt upper limb reaching performance to meet changes in task demands is maintained across lifespan.
17

Improving pruning wound protection against grapevine trunk disease pathogens

Mutawila, Cheusi 03 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Grapevine trunk diseases are a cause of decline and loss of productivity in grapevines at all stages of growth. These diseases are caused by a complex of wood-inhabiting fungi that infect mainly through pruning wounds. The management of these diseases relies on wound protection to prevent infection since there are no eradicative control measures to cure infected vines. There are few or no fungicides registered for grapevine pruning wound protection in most countries, while Trichoderma biocontrol agents are often available. This study aimed at improving grapevine wound protection by Trichoderma (T.) spp. and to gain a better understanding of the factors and mechanisms involved in biocontrol. The effect of pruning time (early or late) and five timings of application of the biocontrol agent after pruning on pruning wound colonisation by T. atroviride and T. harzianum were determined. Chenin blanc and Cabernet Sauvignon vineyards were pruned in July (early) and August (late) of 2011 and 2012, and pruning wounds were treated with suspensions of the Trichoderma spp. at various times (0, 6, 24, 48 and 96 hours) after pruning. Wound colonisation was depended on the physiological state of the vine at pruning for both cultivars. However, for the 2012 season in Chenin blanc, wound colonisation was similarly high for both pruning times, which was attributed to high rainfall and humidity. Application of the biocontrol agents 6 hours after pruning consistently resulted in high wound colonisation by the Trichoderma spp. in both cultivars and pruning times. In both cultivars, pruning wound infection due to natural inoculum was higher in wounds made in late winter than those made earlier. The effect of conidial formulation in nutritional (glucose, yeast extract and urea) and bio-enhancing (chitin and cell free culture filtrates) additives, on pruning wound colonisation by T. atroviride was also investigated. Nutritional additives increased the extent of pruning wound colonisation by T. atroviride compared to the un-amended conidial suspensions in a glass house study. The additives as well as Garrison, a fungicide containing pruning wound paint, and Eco77®, a registered T. harzianum biocontrol product, were tested in field trials for wound protection from infection by Phaeomoniella (Pa.) chlamydospora. In 2011, the pathogen was inoculated a day after pruning and all the Trichoderma spp. treatments similarly reduced Pa. chlamydospora infection by 75% to 90% in Thompson Seedless, while control was less in Chenin blanc and ranged from 40% to 74%. In 2012, the trial was carried out on Chenin blanc only and the pathogen was inoculated at intervals of 1, 3 and 7 days after pruning. Wound protection by the Trichoderma treatments was highest when wounds were inoculated with Pa. chlamydospora seven days after pruning. Two conidial formulations, a culture filtrate made from a chitin based medium and a combination of yeast extract, urea and glucose, consistently enhanced biocontrol efficacy. These formulations reduced Pa. chlamydospora infection to levels similar to those of Garrison. The integration of chemical and biological wound protection could provide both immediate and long term wound protection, but is limited by the sensitivity of the biocontrol agent to fungicides. Benzimidazole resistant Trichoderma strains were generated by gamma irradiation from the wild type isolates of T. atroviride (UST1 and UST2) and T. harzianum (T77). Mutants from UST1 and UST2 were of similar biological fitness as the wild type isolates and retained their in vitro antagonistic activity against grapevine trunk pathogens, while the mutant from T77 had reduced fitness and was not antagonistic to the pathogens. The wild type, UST1, and its mutant were tested alone and in combination with thiophanate methyl and carbendazim, respectively, for their ability to prevent pruning wound infection by Pa. chlamydospora. The combination of the UST1 mutant and carbendazim was the most effective treatment and gave the highest reduction in Pa. chlamydospora infection (70% to 93% control). Grapevine cell cultures were used to compare the response of grapevines to T. atroviride and Eutypa (E.) lata as a first step to determining the importance of Trichoderma-grapevine interactions in pruning wound bio-protection. The expression of genes coding for enzymes of the phenylpropanoid pathway and pathogenesis related (PR) proteins was profiled over a 48-hour period using quantitative reverse transcriptase PCR. The cell cultures responded to fungal elicitors in a hypersensitive-like response that lead to a decrease in cell viability. Fungal elicitors from both fungi triggered the same genes and caused up-regulation of phenylalanine ammonia-lyase (PAL), 4 coumaroyl Co-A ligase (CCo-A), stilbene synthase (STS), chitinase class IV (CHIT IV), PR 3 and PR 4, and a down regulation of chalcone synthase (CHS) genes. Higher expression of PAL and CHIT IV in cell cultures treated with the T. atroviride elicitor led to a significantly higher (P < 0.05) total phenolic content and chitinolytic enzyme activity of the cell cultures compared to cell cultures treated with the E. lata elicitor. The response of the cell cultures to the T. atroviride elicitor signifies that the induction of grapevine resistance may be involved in wound bio-protection. The role of secondary metabolites produced by Trichoderma spp. used in pruning wound protection was also investigated. A volatile antimicrobial compound, 6-pentyl α-pyrone (6PP), was isolated and found to be the major secondary metabolite from the T. atroviride (UST1 and UST2) and T. harzianum (T77) isolates. This metabolite was found to inhibit mycelial growth, spore and conidia germination of E. lata, Neofussicocum (N.) australe, N. parvum and Pa. chlamydospora. The production of 6PP was induced when the T. atroviride isolates were grown in a grapevine wood extract medium while for UST1, the 6PP concentration was further doubled when it was co-cultured with N. parvum. Results therefore, indicate that 6PP is involved in the Trichoderma-pathogen interactions on pruning wounds. The results of this study have provided new information in regards to the application of Trichoderma-based pruning wound products. The best time of application proved to be 6 hours post pruning. The formulation of conidial suspensions of Trichoderma spp. with nutritional additives and in protein extracts of the biocontrol agent showed potential in reducing variability of wound bio-protection. However, further research would be necessary to develop commercial products. The application of a fungicide together with Trichoderma spp. in the field holds promise to improve control, but would require further trials for possible commercialisation. This study is the first to report on grapevine host defence genes that are activated by the Trichoderma spp. used in pruning wound protection. Together with the characterisation of the major secondary metabolite produced by these Trichoderma spp., this information aids in understanding the mechanisms involved in the complex interaction between the biocontrol agent, the host and the pathogen. / AFRIKAANSE OPSOMMING: Wingerdstamsiektes veroorsaak terugsterwing en verlies aan produktiwiteit in wingerdstokke gedurende alle groeifases. Hierdie siektes word veroorsaak deur „n verskeidenheid van hout-koloniserende swamme wat die wingerdstok meestal deur snoeiwonde infekteer. Die bestuur van hierdie siektes is afhanklik van wondbeskerming om infeksie te verhoed, omdat daar geen uitwissende beheermetodes na infeksie bestaan nie. In meeste lande is daar min of geen swamdoders geregistreer vir snoeiwond beskerming, terwyl Trichoderma biobeheer agente gereëld beskikbaar is. Hierdie studie poog om wingerd wondbeskerming deur Trichoderma (T.) spp. te verbeter en „n meer volledige begrip van die faktore en meganismes betrokke by biologiese beheer te ontwikkel. Die effek van die tydsberekening van snoei (vroeg of laat) en vyf behandelingstye van die biobeheer agent na snoei op die kolonisering van snoeiwonde deur T. atroviride en T. harzianum is bepaal. Chenin blanc en Cabernet Sauvignon wingerde is gesnoei gedurende Julie (vroeg) en Augustus (laat) in 2011 en 2012, en snoeiwonde is behandel met Trichoderma spp. suspensies op verskillende tydspunte (0, 6, 24, 48 en 96 ure) na snoei. Wond-kolonisering was afhanklik van die fisiologiese toestand van die wingerdstok gedurende snoei vir albei kultivars. Gedurende die 2012 seisoen was wond-kolonisering ewe hoog vir albei snoeitye op Chenin blanc. Dit is verklaar deur hoë reënval en humiditeit gedurende daardie seisoen. Die aanwending van biobeheer agente 6 ure na snoei het konsekwent hoë kolonisering deur Trichoderma spp. tot gevolg gehad op albei kultivars en albei snoeitye. In albei kultivars is wondinfeksie as gevolg van natuurlike inokulum hoër gewees in wonde gemaak gedurende laat winter as in wonde wat vroeër in die seisoen gemaak is. Die effek van konidia formulasie in voeding (glukose, gisekstrak en urea) en bioverbetering (chitien en sel-vrye kultuurfiltraat) toevoegings op snoeiwond-kolonisering deur T. atroviride is ook ondersoek. Voeding toevoegings het die omvangs van snoeiwond-kolonisering deur T. atroviride vergroot in vergelyking met ongewysigde konidia suspensies gedurende „n glashuis studie. Die toevoegings, sowel as Garrison, „n snoeiwond verf wat „n swamdoder bevat, en Eco77®, „n geregistreerde T. harzianum biobeheer produk, is getoets in veldproewe vir wondbeskerming teen infeksie deur Phaeomoniella (Pa.) chlamydospora. In 2011 is die patogeen geïnokuleer „n dag na snoei en al die Trichoderma spp. behandelings het infeksie verminder met 75% tot 90% op Thompson Seedless. Beheer was minder suksesvol op Chenin blanc, waar slegs 40% tot 74% beheer behaal is. In 2012 is die proef uitgevoer slegs op Chenin blanc en die patogeen is geïnokuleer teen intervalle van 1, 3 en 7 dae na snoei. Wondbeskerming by die Trichoderma behandelinge was die hoogste wanneer wonde sewe dae na snoei geïnokuleer is met Pa. chlamydospora. Twee konidia formulasies, „n kultuurfiltraat wat bestaan het uit „n chitien-gebaseerde medium en „n kombinasie van gisekstrak, urea en glukose het deurlopend die effektiwiteit van biobeheer verbeter. Hierdie formulasies het Pa. chlamydospora infeksie verminder tot soortgelyke vlakke behaal deur Garrison. Die integrasie van chemiese- en biobeheer in wondbeskerming kan onmiddelike en langtermyn wondbeskerming bied, maar is beperk deur die sensitiwiteit van die biobeheer agent teen swamdoders. Benzimidazole-weerstandbiedende Trichoderma isolate is ontwikkel deur gamma-bestraling van die wilde-tipe isolate van T. atroviride (UST1 en UST2) en T. harzianum (T77). Mutante van UST1 en UST2 het soortgelyke biologiese fiksheid getoon as die wilde-tipe en het hul in vitro antagonistiese aktiwiteit teen wingerd stampatogene behou, terwyl die mutant van T77 verminderde fiksheid getoon het en nie meer antagonisties teen patogene was nie. Die wilde-tipe, UST1, en sy mutant is apart en in kombinasie met thiofanaatmetiel en carbendazim, respektiewelik, getoets vir die vermoë om snoeiwonde te beskerm teen Pa. chlamydospora. Die kombinasie van die UST1 mutant met carbendazim was die mees effektiewe behandeling en het die hoogste vermindering in Pa. chlamydospora infeksie gelewer (70 tot 93% beheer). As „n beginpunt om die belang van Trichoderma-wingerd interaksies in snoiewondbeheer te bepaal, is die invloed van T. atroviride en Eutypa (E.) lata op somatiese selkulture van wingerd vergelyk. Die effek van dié behandelings op ensieme in die fenielpropanoïedweg en patogenese-verwante (PR) proteïene is bepaal deur intydse PKR (real time PCR) van die korresponderende gene oor „n 48 uur tydperk. Die swam-afkomstige ontlokkers het „n hipersensitiewe-tipe reaksie in die selkulture ontlok, wat tot „n afname in sellewensvatbaarheid gelei het. Ontlokkers afkomstig van beide swamme het dieselfde gene aangeskakel en het induksie van fenielalanien ammoniak-liase (PAL), 4 kumaroïel Ko-A ligase (CCo-A), stilbeen sintase (STS), chitienase klas IV (CHIT IV), PR 3 en PR 4 veroorsaak en „n onderdrukking in chalkoon sintase (CHS) gene tot gevolg gehad. Hoër uitdrukking van PAL en CHIT IV in selkulture behandel met die T. atroviride ontlokker het gelei tot „n beduidende hoër (P < 0.05) totale fenoolinhoud en chitienolitiese aktiwiteit in selkulture in vergelyking met selkulture wat behandel is met die E. lata ontlokker. Die reaksie van die selkulture op die T. atroviride ontlokker dui daarop dat die induksie van wingerd weerstandbiedenheid betrokke mag wees in wond biobeheer. Die rol van sekondêre metaboliete geproduseer deur Trichoderma spp. wat gebruik word in snoeiwond beheer is ook ondersoek. „n Vlugtige antimikrobiese verbinding, 6-pentiel α-pyroon (6PP) is geïsoleer en bepaal om die hoof sekondêre metaboliet afkomstig vanuit die T. atroviride (UST1 en UST2) en T. harzianum (T77) isolate te wees. Hierdie metaboliet is betrokke by inhibisie van miselium groei, spoor en konidium ontkieming van E. lata, Neofusicoccum (N.) australe, N. parvum en Pa. chlamydospora. Die produksie van 6PP is geïnduseer deur die T. atroviride in wingerd hout ekstrak te kweek. In die geval van UST1, is die 6PP konsenstrasie verdubbel deur die isolaat met saam met N. parvum te kweek. Hierdie resultaat is „n aanduiding dat 6PP betrokke is in die Trichoderma-patogeen interaksie op snoeiwonde. Die resultate van hierdie studie het nuwe inligting met betrekking tot die aanwending van Trichoderma-gebaseerde snoeiwond produkte verskaf. Die beste tyd vir aanwending van sulke produkte was 6 ure na snoei. Die formulasie van konidia suspensies van Trichoderma spp. met voeding toevoegings en in proteïen ekstrakte van die biobeheer agent het potensiaal getoon in die vermindering van variasie in wondbeskerming deur biobeheer agente. Verdere navorsing sal nodig wees om kommersiële produkte te ontwikkel. Die aanwending van „n swamdoder saam met Trichoderma spp. in die wingerd is belowend om beheer te verbeter, maar het meer proewe nodig voor kommersialisering. Hierdie studie is die eerste om wingerd beskerming gene wat deur Trichoderma spp. geaktiveer word aan te meld. Laasgenoemde, saam met die beskrywing van die hoof sekondêre metaboliete wat deur hierdie Trichoderma spp. geproduseer word, dra by tot „n meer volledige begrip van die meganismes betrokke by die komplekse interaksie tussen die biobeheer agent, die gasheer en die patogeen.
18

Relation mellan bål- och axelrörlighet hos elitspelande tennisjuniorer / The relationship between trunk and shoulder range of motion in elite junior tennis players

Petersen, Nadja January 2016 (has links)
Abstrakt Bakgrund: Upprepade rörelser och hållning i dagliga aktiviteter, arbete eller idrott kan påverka det neuromuskuloskeletala systemet. Upprepade förändringar av hållning och rörelser kan ge upphov till lokaliserad stress på vävnaden. Inom tennis är axelleden väl studerad. I litteraturen ses adaptiva förändringar av axelrörlighet hos tennisspelare och andra kastidrottare. Bålens rörlighet och förhållandet mellan bål- och axelrörlighet är ej studerad. Syfte: Syftet med studien var att undersöka bålrotation, glenohumeralledsrotation och korrelation mellan bålrotation och glenohumeralledsrotation hos elitspelande tennisjuniorer 16-19 år samt att identifiera eventuella idrottsspecifika adaptationer avseende bålrotation och glenohumeralledsrotation. Metod: Passiv rotationsrörlighet i glenohumeralleden mättes med en clinometer på en smartphone samt aktiv bålrotation i sittande med en goniometer placerad vid T2. Deltagarna var 32 tennisjuniorer och kontrollgruppen bestod av 30 fotbollsjuniorer i ålder 16-19 år. Deskriptiv statistik för inåt- utåtrotation och bålrotation presenterades. Skillnader mellan tennis och kontrollgrupp analyserades. Korrelation mellan bålrotation och  inåt- samt utåtrotation analyserades. Resultat: Bålrotation mot icke dominant sida var lägre hos tennisspelarna jämfört med fotbollsspelarna. Ingen tydlig korrelation kunde ses mellan rotationsrörlighet i axeln och bålrotation. Tennisspelarna hade sämre inåtrotation och total rotationsrörlighet (TROM) i glenohumeralleden i dominant arm jämfört med fotbollsspelarna, dessutom minskar deras inåtrotation och TROM med stigande ålder. Konklusion: Det föreligger antydningar till adaptiva förändringar hos tennisspelare med minskad bålrotation åt icke dominant sida samt nedsatt inåtrotation på dominant axel. / Abstract Background: Repeated movements and sustained postures in daily activity, work and in sports can influence the neuromusculoskeletal system. Repeated changes in posture and movement might cause local stress in the tissue. Adaptive effects in the mobility of the shoulder in tennis players and other overhead athletes are well documented in the literature. Research of trunk mobility and its effect on the shoulder is limited. Aim: The aim of this study was to investigate trunk rotation, glenohumeral rotation and the correlation between trunk rotation and glenohumeral rotation in elite junior tennis players 16-19 years old. Secondly, to identify athletic adaptations in trunk rotation and glenohumeral rotation in elite junior tennis players. Methods: Range of motion in the glenohumeral joint for internal and external rotation was measured with a clinometer on a smartphone. Range of motion for trunk rotation was measured with seated rotation test with a goniometer placed at T2. The participants were 32 elite junior tennis players and the control group was 30 elite junior soccer players aged 16-19 years old. Descriptive statistics for range of motion in shoulder and trunk rotation was presented. Differences between tennis players and control group were analyzed. Correlation between trunk rotation and internal and external rotation was analyzed. Results: Trunk rotation to the non dominant side had lower scores in tennis players than in soccer players. No obvious correlation was detected between shoulder rotation and trunk rotation. Tennis players had less internal rotation and total rotation range of motion (TROM) in their dominant arm compared to the control group.  This reduction in internal rotation and TROM increased with age. Conclusion: There are some indications for adaptive changes in tennis players with reduced trunk rotation to the non dominant side and reduced internal rotation in the dominant shoulder.
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Avaliação da estabilidade no exercício long stretch front do pilates

Santos, Artur Bonezi dos January 2018 (has links)
A estabilidade do tronco é geralmente desafiada nas sessões do método Pilates. A compreensão da estabilidade/instabilidade, desafiada pela alteração de molas e dependente do nível de treinamento dos executantes, possui grande impacto no controle do tronco. Após uma revisão sistemática foi possível verificar que a principal técnica biomecânica empregada para compreender a estabilidade do tronco é a modelagem. Sendo assim, o objetivo deste estudo foi desenvolver e avaliar um modelo biomecânico para quantificar e comparar a estabilidade do tronco em dois diferentes níveis de praticantes de Pilates e em dois diferentes níveis de intensidade do exercício long stretch front do Pilates. O exercício long stretch front, criado para utilizar o powerhouse e desafiar a estabilidade do tronco, é executado no aparelho reformer na posição de prancha e consiste na extensão de ombros. O movimento foi modelado como um sistema massa-mola sendo a rigidez (K) o parâmetro de estabilidade do tronco. Como dados de entrada foram utilizadas informações cinemáticas, de câmeras infra-vermelho, cinéticas, de células de carga acopladas ao equipamento reformer, e informações antropométricas extraídas da literatura. Foram avaliados 15 praticantes avançados de Pilates e 15 iniciantes. Os indivíduos mais experientes foram mais estáveis durante o exercício do que iniciantes, F(1,28)=7,965; η2=0,22; p=0,009. A execução dos exercícios com duas molas apresentou menor rigidez do que com uma única mola, F(1,28)=67,891; η2=0,71; p<0,001. Não houve interação entre os fatores, F(1,28)=0,587; η2=0,02; p=0,450. Quando os grupos foram comparados separadamente para cada um dos níveis de dificuldade, os mais experientes (K = 272 ± 27 Nm/rad) apresentaram maior rigidez que os iniciantes (K = 171 ± 42 Nm/rad) com uma única mola, e também com o uso de duas molas, com K = 196 ± 17 Nm/rad para os executantes experientes e K = 108 ± 21 Nm/rad para os executantes iniciantes. Conclui-se que o modelo proposto, utilizando o coeficiente de rigidez, foi capaz de quantificar a estabilidade durante o exercício longh stretch front do Pilates. O modelo também identificou as diferenças entre indivíduos mais ou menos experientes, bem como quando o exercício é executado com uma ou com duas molas. / Trunk stability is usually challenged during Pilates method ’sessions. The stability/instability, generated by altering springs or by the practitioner’s experience level during a Pilates exercise, has great impact in trunk control. Following a systematic review, it was observed that modelling is the main biomechanical technique applied for understanding trunk stability. Hence, this study aimed to develop and evaluate a biomechanical model for quantifying and compare trunk stability in two different Pilates practitioners levels and two different intensities of the exercise during Pilates’ long stretch front exercise. The long stretch front exercise, created for using the powerhouse and challenging trunk stability, is performed in the reformer apparatus, keeping the trunk in the plunk position while shoulder extension is performed. The movement was modelled as a spring-mass system using stiffness (K) as the parameter to express trunk stability. Model input consisted of kinematics data, obtained from infrared cameras images, kinetic data, from load cells attached to the reformer equipment, and anthropometric data, obtained from literature. Fifteen experienced and 15 beginner Pilates practitioners, who performed ten repetitions of the exercise in two difficulty levels, with one and two springs, were evaluated. Experienced subjects were more stable during the exercise when compared to beginners F(1.28)=7.965; η2=0.22; p=0.009. The exercise performed using two springs presented a lower rigidity level when compared to one spring F(1.28)=67.891; η2=0.71; p<0.001. There was no interaction between the factors , F(1.28)=0.587; η2=0.02; p=0.450. When groups were compared separately for each difficulty level, experienced (K=272 ± 27 Nm.rad-1) presented higher rigidity than beginners (K=171 ± 42 Nm.rad-1) using one spring, and also using two springs with K=196 ± 17 Nm.rad-1 for experienced performers and K=108 ± 21 Nm.rad-1 for beginners. Concludes that the proposed model is capable of quantifying stability during the Pilates long stretch front exercise using rigidity coefficient. In addition model identifies differences between more or less experienced subjects, as well as when the exercise is performed using one or two springs.
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Role of an Aquatic and Non Aquatic Environment on Trunk Muscle Activation

VandenBerg, Jeanne P. 01 May 2011 (has links)
Low back pain (LBP) is a widespread problem affecting a number of people. Traditionally treated by nonoperative approaches the recent development of water currents and treadmills imbedded into pools has spurred physical therapists and athletic trainers to incorporate the use of aquatic therapy into their rehabilitation programs. OBJECTIVE: Determine if select trunk muscle activity levels are different in water-based exercises compared to land-based exercises. METHODS: 11 healthy male participants age 25.9 ± 5.53 years, whom did not have a history of and were not currently experiencing LBP or injury. Muscle activity was monitored via electromyography (EMG) at the rectus abdominis (RA), external oblique (EO), lower abdominals (LA), erector spinae (ES), and lumbar multifidis (MT). Each subject performed (1) maximum voluntary contractions (MVC’s), (2) land-based exercises, and (3) water-based exercises. A paired samples t test was used to compare abdominal bracing (ABbrace), abdominal hallowing (ABhol), Anterior/Posterior pelvic tilts (APTilts), and lateral pelvic tilts (LatTilts) between comparable land and water conditions; general linear model-repeated measures was run to compare the 11 different water exercises; ABbrace, ABhol, APTilts, LatTilts, physioball push down (PBPushDown), PB lateral flexion, PB transverse rotations, stationary marching, leg abduction, and wall sits with sagittal and transverse plane arm movements. Follow-up multiple comparisons (LSD) were performed between water exercises using a Holm’s corrected alpha level set at 0.05. RESULTS: Land-based exercises elicited greater EMG activity compared to water-based activities for all muscles (%MVC land vs. %MVC water): RA %MVC (8.3-19.3 vs. 2.1-9.7, P = .003-.029); LA %MVC (27-105 vs. 5.2-25, P = .001-.016); EO %MVC (13-59 vs. 4.8-24.5, P = .001-.303); ES %MVC (19.1-37.6 vs. 7.75-22.1, P = .001-.039) and MT %MVC (16-25.4 vs. 5.9-8.8, P = .00-.005). For water comparison ABbrace and PB exercises produced the most muscle activity while WallSitSag/Trans consistently produced the least muscle activity. CONCLUSION: Even with reduced muscle activity in the water, the calculated % mean MVCs were high enough (at or below 25% MVC) to provide muscle endurance and stability gains. With the information provided from the analysis of water exercise comparison, practitioners can effectively progress patients through a rehabilitation program.

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