99 resultados para Organ masses.
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This action research project investigated the use of a collaborative learning approach for addressing issues associated with teaching urban design to large, diverse cohorts. As a case study, I observed two semesters of an urban design unit that I revised between 2011 and 2012 to incorporate collaborative learning activities. Data include instructional materials, participant observations, peer-reviews of collaborative learning activities, feedback from students and instructors and student projects. Themes that emerged through qualitative analysis include the challenge of removing inequalities inherent in the diverse cohort, the challenge of unifying project guidance and marking criteria, and the challenge of providing project guidance for a very large cohort. Most notably, the study revealed a need to clarify learning objectives relating to design principles in order to fully transition to and benefit from a collaborative learning model.
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Introduction. Calculating segmental (vertebral level-by-level) torso masses in Adolescent Idiopathic Scoliosis (AIS) patients allows the gravitational loading on the scoliotic spine during relaxed standing to be determined. This study used CT scans of AIS patients to measure segmental torso masses and explores how joint moments in the coronal plane are affected by changes in the position of the intervertebral joint’s axis of rotation; particularly at the apex of a scoliotic major curve. Methods. Existing low dose CT data from the Paediatric Spine Research Group was used to calculate vertebral level-by-level torso masses and joint torques occurring in the spine for a group of 20 female AIS patients (mean age 15.0 ± 2.7 years, mean Cobb angle 53 ± 7.1°). Image processing software, ImageJ (v1.45 NIH USA) was used to threshold the T1 to L5 CT images and calculate the segmental torso volume and mass corresponding to each vertebral level. Body segment masses for the head, neck and arms were taken from published anthropometric data. Intervertebral (IV) joint torques at each vertebral level were found using principles of static equilibrium together with the segmental body mass data. Summing the torque contributions for each level above the required joint, allowed the cumulative joint torque at a particular level to be found. Since there is some uncertainty in the position of the coronal plane Instantaneous Axis of Rotation (IAR) for scoliosis patients, it was assumed the IAR was located in the centre of the IV disc. A sensitivity analysis was performed to see what effect the IAR had on the joint torques by moving it laterally 10mm in both directions. Results. The magnitude of the torso masses from T1-L5 increased inferiorly, with a 150% increase in mean segmental torso mass from 0.6kg at T1 to 1.5kg at L5. The magnitudes of the calculated coronal plane joint torques during relaxed standing were typically 5-7 Nm at the apex of the curve, with the highest apex joint torque of 7Nm being found in patient 13. Shifting the assumed IAR by 10mm towards the convexity of the spine, increased the joint torque at that level by a mean 9.0%, showing that calculated joint torques were moderately sensitive to the assumed IAR location. When the IAR midline position was moved 10mm away from the convexity of the spine, the joint torque reduced by a mean 8.9%. Conclusion. Coronal plane joint torques as high as 7Nm can occur during relaxed standing in scoliosis patients, which may help to explain the mechanics of AIS progression. This study provides new anthropometric reference data on vertebral level-by-level torso mass in AIS patients which will be useful for biomechanical models of scoliosis progression and treatment. However, the CT scans were performed in supine (no gravitational load on spine) and curve magnitudes are known to be smaller than those measured in standing.
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Introduction: Calculating segmental (vertebral level-by-level) torso masses in Adolescent Idiopathic Scoliosis (AIS) patients allows the gravitational loading on the scoliotic spine during relaxed standing to be estimated. This study used supine CT scans of AIS patients to measure segmental torso masses and explored the joint moments in the coronal plane, particularly at the apex of a scoliotic major curve. Methods: Existing low dose CT data from the Paediatric Spine Research Group was used to calculate vertebral level-by-level torso masses and joint moments occurring in the spine for a group of 20 female AIS patients with right sided thoracic curves. The mean age was 15.0 ± 2.7 years and all curves were classified Lenke Type 1 with a mean Cobb angle 52 ± 5.9°. Image processing software, ImageJ (v1.45 NIH USA) was used to create reformatted coronal plane images, reconstruct vertebral level-by-level torso segments and subsequently measure the torso volume corresponding to each vertebral level. Segment mass was then determined by assuming a tissue density of 1.04x103 kg/m3. Body segment masses for the head, neck and arms were taken from published anthropometric data (Winter 2009). Intervertebral joint moments in the coronal plane at each vertebral level were found from the position of the centroid of the segment masses relative to the joint centres with the segmental body mass data. Results and Discussion: The magnitude of the torso masses from T1-L5 increased inferiorly, with a 150% increase in mean segmental torso mass from 0.6kg at T1 to 1.5kg at L5. The magnitudes of the calculated coronal plane joint moments during relaxed standing were typically 5-7 Nm at the apex of the curve, with the highest apex joint torque of 7Nm. The CT scans were performed in the supine position and curve magnitudes are known to be 7-10° smaller than those measured in standing, due to the absence of gravity acting on the spine. Hence, it can be expected that the moments produced by gravity in the standing individual will be greater than those calculated here.
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People's decision to join an organ donor registry and have a discussion with family about their organ donation preference increases the likelihood that their family will consent to donation of their organs. This study explores the effectiveness of three interventions compared to a control condition to increase individual consent (registering and discussing donation wishes) for organ donation. Australian residents who had not previously communicated their consent (N = 177) were randomly allocated to complete an online survey representing either an extended theory of planned behaviour motivational intervention (strengthening intention via attitudes, subjective norms, control, moral norms and identity), a volitional intervention using constructs from the health action process approach (strengthening the translation of intentions into action using action plans and coping plans), a combined motivational and volitional intervention, or a control condition. Registering, but not discussing, intentions increased in the motivational compared to non-motivational conditions. For joining the organ donor registry, the combination of strengthening intentions (motivational) as well as forming specific action (when, where, how, and with whom for discussing) and coping (listing potential obstacles and how these may be overcome) plans (volitional) resulted in significantly higher rates of self-reported behaviour. There was no evidence for this effect on discussion.
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Organ motion as a result of respiration is an important field of research for medical physics. Knowledge of magnitude and direction of this motion is necessary to allow for more accurate radiotherapy treatment planning. This will result in higher doses to the tumour whilst sparing healthy tissue. This project involved human trials, where the radiation therapy patient's kidneys were CT scanned under three different conditions; whilst free breathing (FB), breath-hold at normal tidal inspiration (BHIN), and breath-hold at normal tidal expiration (BHEX). The magnitude of motion was measured by recording the outline of the kidney from a Beam's Eye View (BEV). The centre of mass of this 2D shape was calculated for each set using "ImageJ" software and the magnitude of movement determined from the change in the centroid's coordinates between the BHIN and BHEX scans. The movement ranged from, for the left and right kidneys, 4-46mm and 2-44mm in the superior/inferior (axial) plane, 1-21mm and 2- 16mm in the anterior/posterior (coronal) plane, and 0-6mm and 0-8mm in the lateral/medial (sagittal) plane. From exhale to inhale, the kidneys tended to move inferiorly, anteriorly and laterally. A standard radiotherapy plan, designed to treat the para-aortics with opposed lateral fields was performed on the free breathing (planning) CT set. The field size and arrangement was set up using the same parameters for each subject. The prescription was to deliver 45 Gray in 25 fractions. This field arrangement and prescription was then copied over to the breath hold CT sets, and the dosimetric differences were compared using Dose Volume Histograms (DVH). The point of comparison for the three sets was recorded as the percentage volume of kidney receiving less than or equal to 10 Gray. The QUASAR respiratory motion phantom was used with the range of motion determined from the human study. The phantom was imaged, planned and treated with a linear accelerator with dose determined by film. The effect of the motion was measured by the change in the penumbra of the film and compared to the penumbra from the treatment planning system.
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Introduction Calculating segmental torso masses in Adolescent Idiopathic Scoliosis (AIS) patients allows the gravitational loading on the scoliotic spine during relaxed standing to be estimated. Methods Low dose CT data was used to calculate vertebral level-by-level torso masses and spinal joint torques for 20 female AIS patients (mean age 15.0 ± 2.7 years, mean Cobb angle 53 ± 7.1°). ImageJ software (v1.45 NIH USA) was used to threshold the T1 to L5 CT images and calculate the segmental torso volume and mass for each vertebral level. Masses for the head, neck and arms were taken from published data.1 Intervertebral joint torques in the coronal and sagittal planes at each vertebral level were found from the position of the centroid of the segment masses relative to the joint centres (assumed to be at the centre of the intervertebral disc). The joint torque at each level was found by summing torque contributions for all segments above that joint. Results Segmental torso mass increased from 0.6kg at T1 to 1.5kg at L5. The coronal plane joint torques due to gravity were 5-7Nm at the apex of the curve; sagittal torques were 3-5.4Nm. Conclusion CT scans were in the supine position and curve magnitudes are known to be smaller than those in standing.2 Hence, this study has shown that gravity produces joint torques potentially of higher than 7Nm in the coronal plane and 5Nm in the sagittal plane during relaxed standing in scoliosis patients. The magnitude of these torques may help to explain the mechanics of AIS progression and the mechanics of bracing. This new data on torso segmental mass in AIS patients will assist biomechanical models of scoliosis.
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Understanding people's organ donation decisions may narrow the gap between organ supply and demand. In two studies, participants who had not recorded their posthumous organ donation decision (Study 1, N = 210; Study 2, N = 307) completed items assessing prototype/willingness model (PWM; attitude, subjective norm, donor prototype favorability and similarity, willingness) constructs. Attitude, subjective norm, and prototype similarity predicted willingness to donate. Prototype favorability and a Prototype Favorability × Similarity interaction predicted willingness (Study 2). These findings provide support for the PWM in altruistic health contexts, highlighting the importance of people's perceptions about organ donors in their donation decisions.
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Background Adolescent Idiopathic Scoliosis is the most common type of spinal deformity whose aetiology remains unclear. Studies suggest that gravitational forces in the standing position play an important role in scoliosis progression, therefore anthropometric data are required to develop biomechanical models of the deformity. Few studies have analysed the trunk by vertebral level and none have performed investigations of the scoliotic trunk. The aim of this study was to determine the centroid, thickness, volume and estimated mass, for sections of the trunk in Adolescent Idiopathic Scoliosis patients. Methods Existing low-dose Computed Tomography scans were used to estimate vertebral level-by-level torso masses for 20 female Adolescent Idiopathic Scoliosis patients. ImageJ processing software was used to analyse the Computed Tomography images and enable estimation of the segmental torso mass corresponding to each vertebral level. Findings The patients’ mean age was 15.0 (SD 2.7) years with mean major Cobb Angle of 52° (SD 5.9) and mean patient weight of 58.2 (SD 11.6) kg. The magnitude of torso segment mass corresponding to each vertebral level increased by 150% from 0.6kg at T1 to 1.5kg at L5. Similarly, the segmental thickness corresponding to each vertebral level from T1-L5 increased inferiorly from a mean 18.5 (SD 2.2) mm at T1 to 32.8 (SD 3.4) mm at L5. The mean total trunk mass, as a percentage of total body mass, was 27.8 (SD 0.5) % which was close to values reported in previous literature. Interpretation This study provides new anthropometric reference data on segmental (vertebral level-by-level) torso mass in Adolescent Idiopathic Scoliosis patients, useful for biomechanical models of scoliosis progression and treatment.
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Introduction Calculating segmental torso masses in Adolescent Idiopathic Scoliosis (AIS) patients allows the gravitational loading on the scoliotic spine during relaxed standing to be estimated. Methods Low dose CT data was used to calculate vertebral level-by-level torso masses and spinal joint torques for 20 female AIS patients (mean age 15.0 ± 2.7 years, mean Cobb angle 53 ± 7.1°). ImageJ software (v1.45 NIH USA) was used to threshold the T1 to L5 CT images and calculate the segmental torso volume and mass for each vertebral level. Masses for the head, neck and arms were taken from published data. Intervertebral joint torques in the coronal and sagittal planes at each vertebral level were found from the position of the centroid of the segment masses relative to the joint centres (assumed to be at the centre of the intervertebral disc. The joint torque at each level was found by summing torque contributions for all segments above that joint. Results Segmental torso mass increased from 0.6kg at T1 to 1.5kg at L5. The coronal plane joint torques due to gravity were 5-7Nm at the apex of the curve; sagittal torques were 3-5.4Nm. Conclusion CT scans were in the supine position and curve magnitudes are known to be smaller than those in standing. Hence, this study has shown that gravity produces joint torques potentially of higher than 7Nm in the coronal plane and 5Nm in the sagittal plane during relaxed standing in scoliosis patients. The magnitude of these torques may help to explain the mechanics of AIS progression and the mechanics of bracing. This new data on torso segmental mass in AIS patients will assist biomechanical models of scoliosis.
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Weta possess typical Ensifera ears. Each ear comprises three functional parts: two equally sized tympanal membranes, an underlying system of modified tracheal chambers, and the auditory sensory organ, the crista acustica. This organ sits within an enclosed fluid-filled channel-previously presumed to be hemolymph. The role this channel plays in insect hearing is unknown. We discovered that the fluid within the channel is not actually hemolymph, but a medium composed principally of lipid from a new class. Three-dimensional imaging of this lipid channel revealed a previously undescribed tissue structure within the channel, which we refer to as the olivarius organ. Investigations into the function of the olivarius reveal de novo lipid synthesis indicating that it is producing these lipids in situ from acetate. The auditory role of this lipid channel was investigated using Laser Doppler vibrometry of the tympanal membrane, which shows that the displacement of the membrane is significantly increased when the lipid is removed from the auditory system. Neural sensitivity of the system, however, decreased upon removal of the lipid-a surprising result considering that in a typical auditory system both the mechanical and auditory sensitivity are positively correlated. These two results coupled with 3D modelling of the auditory system lead us to hypothesize a model for weta audition, relying strongly on the presence of the lipid channel. This is the first instance of lipids being associated with an auditory system outside of the Odentocete cetaceans, demonstrating convergence for the use of lipids in hearing.
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The aim of this thesis was to establish an individualized, patient-specific diagnostic and therapeutic preclinical disease model for bone metastasis research. Tissue engineering of humanized bone within mice allowed the development of a humanized immune system in the host animal. This novel platform makes it possible to analyze the growth of human cancer cells in human bone in the presence of human immune cells.
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Ediea homevalensis H. Nishida, Kudo, Pigg & Rigby gen. et sp. nov. is proposed for permineralized pollen-bearing structures from the Late Permian Homevale Station locality of the Bowen Basin, Queensland, Australia. The taxon represents unisexual fertile shoots bearing helically arranged leaves on a central axis. The more apical leaves are fertile microsporophylls bearing a pair of multi-branched stalks on their adaxial surfaces that each supports a cluster of terminally borne pollen sacs. Proximal to the fertile leaves there are several rows of sterile scale-like leaves. The pollen sacs (microsporangia) have thickened and dark, striate walls that are typical of the Arberiella type found in most pollen organs presumed to be of glossopterid affinity. An examination of pollen organs at several developmental stages, including those containing in situ pollen of the Protohaploxypinus type, provides the basis for a detailed analysis of these types of structures, which bear similarities to both compression/impression Eretmonia-type glossopterid microsporangiate organs and permineralized Eretmonia macloughlinii from Antarctica. These fossils demonstrate that at least some Late Permian pollen organs were simple microsporophyll-bearing shoot systems and not borne directly on Glossopteris leaves.
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This article examines a social media assignment used to teach and practice statistical literacy with over 400 students each semester in large-lecture traditional, fully online, and flipped sections of an introductory-level statistics course. Following the social media assignment, students completed a survey on how they approached the assignment. Drawing from the authors’ experiences with the project and the survey results, this article offers recommendations for developing social media assignments in large courses that focus on the interplay between the social media tool and the implications of assignment prompts.