Magnetic resonance spectroscopy and neurocognitive dysfunction in obstructive sleep apnea before and after CPAP treatment

STUDY OBJECTIVES: To determine whether cerebral metabolite changes may underlie abnormalities of neurocognitive function and respiratory control in OSA. DESIGN: Observational, before and after CPAP treatment. SETTING: Two tertiary hospital research institutes. PARTICIPANTS: 30 untreated severe OSA patients, and 25 age-matched healthy controls, all males free of comorbidities, and all having had detailed structural brain analysis using voxel-based morphometry (VBM). MEASUREMENTS AND RESULTS: Single voxel bilateral hippocampal and brainstem, and multivoxel frontal metabolite concentrations were measured using magnetic resonance spectroscopy (MRS) in a high resolution (3T) scanner. Subjects also completed a battery of neurocognitive tests. Patients had repeat testing after 6 months of CPAP. There were significant differences at baseline in frontal N-acetylaspartate/choline (NAA/Cho) ratios (patients [mean (SD)] 4.56 [0.41], controls 4.92 [0.44], P = 0.001), and in hippocampal choline/creatine (Cho/Cr) ratios (0.38 [0.04] vs 0.41 [0.04], P = 0.006), (both ANCOVA, with age and premorbid IQ as covariates). No longitudinal changes were seen with treatment (n = 27, paired t tests), however the hippocampal differences were no longer significant at 6 months, and frontal NAA/Cr ratios were now also significantly different (patients 1.55 [0.13] vs control 1.65 [0.18] P = 0.01). No significant correlations were found between spectroscopy results and neurocognitive test results, but significant negative correlations were seen between arousal index and frontal NAA/Cho (r = -0.39, corrected P = 0.033) and between % total sleep time at SpO(2) < 90% and hippocampal Cho/Cr (r = -0.40, corrected P = 0.01). CONCLUSIONS: OSA patients have brain metabolite changes detected by MRS, suggestive of decreased frontal lobe neuronal viability and integrity, and decreased hippocampal membrane turnover. These regions have previously been shown to have no gross structural lesions using VBM. Little change was seen with treatment with CPAP for 6 months. No correlation of metabolite concentrations was seen with results on neurocognitive tests, but there were significant negative correlations with OSA severity as measured by severity of nocturnal hypoxemia. CITATION: O'Donoghue FJ; Wellard RM; Rochford PD; Dawson A; Barnes M; Ruehland WR; Jackson ML; Howard ME; Pierce RJ; Jackson GD. Magnetic resonance spectroscopy and neurocognitive dysfunction in obstructive sleep apnea before and after CPAP treatment.

Investigating higher education and secondary school web-based learning environments using the WEBLEI

Classroom learning environments are rapidly changing as new digital technologies become more education-friendly. What are students’ perceptions of their technology-rich learning environments? This question is critical as it may have an impact on the effectiveness of the new technologies in classrooms. There are numerous reliable and valid learning environment instruments which have been used to ascertain students’ perceptions of their learning environments. This chapter focuses on one of these instruments, the Web-based Learning Environment Instrument (WEBLEI) (Chang & Fisher, 2003). Since its initial development, this instrument has been used to study a range of learning environments and this chapter presents the findings of two example case-studies that involve such environments.

Cultural challenges to secondary prevention: Implications for Saudi women

Like other highly developed countries, cardiovascular disease (CVD) and coronary heart disease (CHD) are major health problems in Saudi Arabia. The aetiology of cardiovascular disease (CVD) burden within the Saudi population is similar to Western countries with atherosclerosis, hypertension, ischemic heart disease and diabetes highly prevalent with the main risk factors being smoking, obesity and inactivity. There are differences between Saudi men and women in epidemiology, risk factors and health service provision for CHD. These sex and gender based factors are important in considering the health and well-being of Saudi women. Currently, there is limited focus on the cardiovascular health of Saudi women. The aim of this paper is to examine culturally specific issues for Saudi women and the implications for secondary prevention.

3D reconstruction of long bones utilising magnetic resonance imaging (MRI)

The design of pre-contoured fracture fixation implants (plates and nails) that correctly fit the anatomy of a patient utilises 3D models of long bones with accurate geometric representation. 3D data is usually available from computed tomography (CT) scans of human cadavers that generally represent the above 60 year old age group. Thus, despite the fact that half of the seriously injured population comes from the 30 year age group and below, virtually no data exists from these younger age groups to inform the design of implants that optimally fit patients from these groups. Hence, relevant bone data from these age groups is required. The current gold standard for acquiring such data–CT–involves ionising radiation and cannot be used to scan healthy human volunteers. Magnetic resonance imaging (MRI) has been shown to be a potential alternative in the previous studies conducted using small bones (tarsal bones) and parts of the long bones. However, in order to use MRI effectively for 3D reconstruction of human long bones, further validations using long bones and appropriate reference standards are required. Accurate reconstruction of 3D models from CT or MRI data sets requires an accurate image segmentation method. Currently available sophisticated segmentation methods involve complex programming and mathematics that researchers are not trained to perform. Therefore, an accurate but relatively simple segmentation method is required for segmentation of CT and MRI data. Furthermore, some of the limitations of 1.5T MRI such as very long scanning times and poor contrast in articular regions can potentially be reduced by using higher field 3T MRI imaging. However, a quantification of the signal to noise ratio (SNR) gain at the bone - soft tissue interface should be performed; this is not reported in the literature. As MRI scanning of long bones has very long scanning times, the acquired images are more prone to motion artefacts due to random movements of the subject‟s limbs. One of the artefacts observed is the step artefact that is believed to occur from the random movements of the volunteer during a scan. This needs to be corrected before the models can be used for implant design. As the first aim, this study investigated two segmentation methods: intensity thresholding and Canny edge detection as accurate but simple segmentation methods for segmentation of MRI and CT data. The second aim was to investigate the usability of MRI as a radiation free imaging alternative to CT for reconstruction of 3D models of long bones. The third aim was to use 3T MRI to improve the poor contrast in articular regions and long scanning times of current MRI. The fourth and final aim was to minimise the step artefact using 3D modelling techniques. The segmentation methods were investigated using CT scans of five ovine femora. The single level thresholding was performed using a visually selected threshold level to segment the complete femur. For multilevel thresholding, multiple threshold levels calculated from the threshold selection method were used for the proximal, diaphyseal and distal regions of the femur. Canny edge detection was used by delineating the outer and inner contour of 2D images and then combining them to generate the 3D model. Models generated from these methods were compared to the reference standard generated using the mechanical contact scans of the denuded bone. The second aim was achieved using CT and MRI scans of five ovine femora and segmenting them using the multilevel threshold method. A surface geometric comparison was conducted between CT based, MRI based and reference models. To quantitatively compare the 1.5T images to the 3T MRI images, the right lower limbs of five healthy volunteers were scanned using scanners from the same manufacturer. The images obtained using the identical protocols were compared by means of SNR and contrast to noise ratio (CNR) of muscle, bone marrow and bone. In order to correct the step artefact in the final 3D models, the step was simulated in five ovine femora scanned with a 3T MRI scanner. The step was corrected using the iterative closest point (ICP) algorithm based aligning method. The present study demonstrated that the multi-threshold approach in combination with the threshold selection method can generate 3D models from long bones with an average deviation of 0.18 mm. The same was 0.24 mm of the single threshold method. There was a significant statistical difference between the accuracy of models generated by the two methods. In comparison, the Canny edge detection method generated average deviation of 0.20 mm. MRI based models exhibited 0.23 mm average deviation in comparison to the 0.18 mm average deviation of CT based models. The differences were not statistically significant. 3T MRI improved the contrast in the bone–muscle interfaces of most anatomical regions of femora and tibiae, potentially improving the inaccuracies conferred by poor contrast of the articular regions. Using the robust ICP algorithm to align the 3D surfaces, the step artefact that occurred by the volunteer moving the leg was corrected, generating errors of 0.32 ± 0.02 mm when compared with the reference standard. The study concludes that magnetic resonance imaging, together with simple multilevel thresholding segmentation, is able to produce 3D models of long bones with accurate geometric representations. The method is, therefore, a potential alternative to the current gold standard CT imaging.

Charity law review and civil society : paving the way from alienation to social inclusion in Northern Ireland ; the resonance with experience in Australia

This paper considers the opportunity, presented by the forthcoming charity law review in Northern Ireland, for adjusting the charity law framework so as to focus charitable activity on the circumstances typical of societies in conflict or experiencing transition. This opportunity is one for broadening the definition of 'charitable purpose' to include activities directed towards forestalling alienation and facilitating social inclusion. It would include rehabilitating the victims of social confrontation and developing related services of advocacy, mediation and reconciliation. It argues that a creative response to this opportunity could address the current social inclusion agenda and thereby contribute to the consolidation of civil society in this jurisdiction. It suggests that the experience in Northern Ireland, as an exemplar of a society in transition, has a resonance with the experience in Australia. It further suggests that it could also have a relevance for approaching the management of tensions within or between nations where people may otherwise come to perceive themselves as alienated...

In vitro estimation of foetal liver volume using ultrasound, x-ray computed tomography and magnetic resonance imaging

Sixteen formalin-fixed foetal livers were scanned in vitro using a new system for estimating volume from a sequence of multiplanar 2D ultrasound images. Three different scan techniques were used (radial, parallel and slanted) and four volume estimation algorithms (ellipsoid, planimetry, tetrahedral and ray tracing). Actual liver volumes were measured by water displacement. Twelve of the sixteen livers also received x-ray computed tomography (CT) and magnetic resonance (MR) scans and the volumes were calculated using voxel counting and planimetry. The percentage accuracy (mean ± SD) was 5.3 ± 4.7%, −3.1 ± 9.6% and −0.03 ± 9.7% for ultrasound (radial scans, ray volumes), MR and CT (voxel counting) respectively. The new system may be useful for accurately estimating foetal liver volume in utero.

Exploring antecedent factors in (Queensland) secondary school teachers’ early retirement intentions

Mature-age secondary teachers offer teaching a wealth of knowledge and skills that can contribute greatly to the quality of education. However, as with the greater workforce, there is an increasing trend for mature-age teachers to elect to retire early or to move into other work. Despite studies suggesting that teachers may be negatively affected by stress, there has been no research into the attitudes of mature-age teachers relating to early retirement and whether these or other factors are instrumental in their decision to retire from teaching. There is, however, a broad range of studies, commentary and analyses on ageing and work that can be utilised to develop a powerful analytical framework to identify the factors that can potentially influence the decision to take early retirement. This study examined the antecedent factors which influenced the early retirement decisions in 16 Queensland secondary school teachers. This study examined factors relating to the teachers decision to retire early and explored school and other factors relating to their decision. In addition, differences between urban and rural secondary school teachers were examined. Given the potentially complex nature of teachers. retirement decisions, the study utilised a qualitative approach. The study found that retired secondary teachers are confronted by ageing realities that are not responded to adequately by the education system, and participants expressed a general dissatisfaction with aspects of school management, especially as it related to bullying and non-inclusion in teaching-related decision making. This study also identified organisational issues within Education Queensland which contributed to system failures that affected mature-age teachers that need to be addressed. This study is one of the first studies to explore the factors influencing early retirement decisions in teachers. The implications of these factors on policy for Education Queensland and for workplace policies in general are discussed.

How people construct their experience of living with secondary lymphoedema in the context of their everyday lives in Australia

Purpose The purpose of this work was to explore how men and women construct their experiences living with lymphoedema following treatment for any cancer in the context of everyday life. Methods The design and conduct of this qualitative study was guided by Charmaz’ social constructivist grounded theory. To collect data, focus groups and telephone interviews were conducted. Audiotapes were transcribed verbatim and imported into NVivo8 to organise data and codes. Data were analysed using key grounded theory principles of constant comparison, data saturation and initial, focused and theoretical coding. Results Participants were 3 men and 26 women who had developed upper- or lower-limb lymphoedema following cancer treatment. Three conceptual categories were developed during data analysis and were labelled ‘accidental journey’, ‘altered normalcy’ and ‘ebb and flow of control’. ‘Altered normalcy’ reflects the physical and psychosocial consequences of lymphoedema and its relationship to everyday life. ‘Accidental journey’ explains the participants’ experiences with the health care system, including the prevention, treatment and management of their lymphoedema. ‘Ebb and flow of control’ draws upon a range of individual and social elements that influenced the participants’ perceived control over lymphoedema. These conceptual categories were inter-related and contributed to the core category of ‘sense of self’, which describes their perceptions of their identity and roles. Conclusions Results highlight the need for greater clinical and public awareness of lymphoedema as a chronic condition requiring prevention and treatment, and one that has far-reaching effects on physical and psychosocial well-being as well as overall quality of life.

Microstructural magnetic resonance imaging of articular cartilage

The focus of this Editorial is recent developments in magnetic resonance imaging (MRI) modalities for evaluation of the microstructure and macromolecular organisation of articular cartilage. We place a specific emphasis on three types of measurements: (1) MRI transverse spin-relaxation mapping (T2 mapping); (2) diffusion-tensor imaging; and (3) compression micro-MRI (uMRI) measurements of articular cartilage in vitro. Such studies have a significant role to play in improving the understanding of the fundamental biomechanics of articular cartilage and in the development of in vitro models of early osteoarthritis. We discuss how the supramolecular organisation of the cartilage extracellular matrix and its behaviour under mechanical compression can be inferred from diffusion-tensor and T2 maps with in-plane resolution ~100 um. The emphasis is on in vitro studies performed under controlled physiological conditions but in vivo applications of T2 mapping and DTI are also briefly discussed.

Prevalence and prognostic significance of secondary lymphedema following breast cancer

Background The adverse consequences of lymphedema following breast cancer in relation to physical function and quality of life are clear; however, its potential relationship with survival has not been investigated. Our purpose was to determine the prevalence of lymphedema and associated upper-body symptoms at 6 years following breast cancer and to examine the prognostic significance of lymphedema with respect to overall 6-year survival (OS). Methods and Results A population-based sample of Australian women (n=287) diagnosed with invasive, unilateral breast cancer was followed for a median of 6.6 years and prospectively assessed for lymphedema (using bioimpedance spectroscopy [BIS], sum of arm circumferences [SOAC], and self-reported arm swelling), a range of upper-body symptoms, and vital status. OS was measured from date of diagnosis to date of death or last follow-up. Kaplan-Meier methods were used to calculate OS and Cox proportional hazards models quantified the risk associated with lymphedema. Approximately 45% of women had reported at least one moderate to extreme symptom at 6.6 years postdiagnosis, while 34% had shown clinical evidence of lymphedema, and 48% reported arm swelling at least once since baseline assessment. A total of 27 (9.4%) women died during the follow-up period, and lymphedema, diagnosed by BIS or SOAC between 6–18 months postdiagnosis, predicted mortality (BIS: HR=2.5; 95% CI: 0.9, 6.8, p=0.08; SOAC: 3.0; 95% CI: 1.1, 8.7, p=0.04). There was no association (HR=1.2; 95% CI: 0.5, 2.6, p=0.68) between self-reported arm swelling and OS. Conclusions These findings suggest that lymphedema may influence survival following breast cancer treatment and warrant further investigation in other cancer cohorts and explication of a potential underlying biology.

Front page schools, back page schools : a case study of factors perceived to affect academic performance in five Papua New Guinea secondary schools

Papua New Guinea has reformed its colonial established education system and made huge investments with the help of donors to achieve equal access and quality education for all its citizens. Despite this national aspiration and these policy reforms and investments, secondary schools that enrol grade 9 students who are relatively equal in education ability show huge disparities in their grade 10 academic performances. This study examined perceptions of students, teachers and principals regarding factors affecting the disparity in academic performance in the context of a developing country. The central question for the study is: What are the perceptions of students and teachers of the factors that affect disparities in secondary schools' academic performance? This qualitative case study involved two high and three low academic performing secondary schools in Western Highlands Province of Papua New Guinea. Primary data were collected through focus groups and semi-structured interviews involving 112 participants. Students and teachers are key participants in this study, as it intends to find out the realities of schools, yet they are an under-researched group. A postcolonial and sense of community conceptual framework was developed for the analysis of the participants. perceptions. In addition, scholarship on school effectiveness and equity in education informed the interpretation of the findings. Three themes were evident in participants. views. First, participants expressed their view that differences in academic performance were related to the adequacy and equitability of resources. The inequities in resource inputs led some of them to coin the metaphor of .back page and front page. schools. Second, many expressed the view that deficiencies in implementing bilingual education, given the difficulty of catering for 800 vernacular languages, contribute to poor English proficiency and subsequent poor academic performance. Finally, participants believed that, in order to have a positive school culture, it is necessary for educators to recognise and respect contemporary students. identities, communal/tribal membership and needs. This study has implications for national education policy on resource allocation to address equality and equity, bilingual education and teacher education. Moreover, as the study found that high academic performance in this context is also influenced by intra-school social relationships, these relationships need to be nurtured. When appropriately nurtured, they become an important factor in sustaining quality education for all secondary school students. This thesis has laid the foundations for further research and invites further investigations into policy and implementation of school reforms aimed at improving academic achievement.

Secondary curve behavior in Lenke Type 1C adolescent idiopathic scoliosis after thoracoscopic selective anterior thoracic fusion

Study Design. Analysis of a case series of 24 Lenke 1C adolescent idiopathic scoliosis (AIS) patients receiving selective thoracoscopic anterior scoliosis correction. Objective. To report the behaviour of the compensatory lumbar curve in a group of Lenke IC AIS patients following thoracoscopic anterior scoliosis correction, and to compare the results of this study with previously published data. Summary of Background Data. Several prior studies have reported spontaneous lumbar curve correction for both anterior and posterior selective fusion in Lenke 1C/King-Moe II patients; however to our knowledge no previous studies have reported outcomes of thoracoscopic anterior correction for this curve type. Methods. All AIS patients with a curve classification of Lenke 1C and a minimum of 24 months follow-up were retrieved from a consecutive series of 190 AIS patients who underwent thoracoscopic anterior instrumented fusion. Cobb angles of the major curve, instrumented levels, compensatory lumbar curve, and T5-T12 kyphosis were recorded, as well as coronal spinal balance, T1 tilt angle and shoulder balance. All radiographic parameters were measured before surgery and at 2, 6, 12 and 24 months after surgery. Results. Twenty-four female patients with right thoracic curves had a mean thoracic Cobb angle of 53.0° before surgery, decreasing to 24.9° two years after surgery. The mean lumbar compensatory Cobb angle was 43.5° before surgery, spontaneously correcting to 25.4° two years after surgery, indicating balance between the thoracic and lumbar scoliotic curves. The lumbar correction achieved (41.8%) compares favourably to previous studies. Conclusions. Selective thoracoscopic anterior fusion allows spontaneous lumbar curve correction and achieves coronal balance of main thoracic and compensatory lumbar curves, good cosmesis and patient satisfaction. Correction and balance are maintained 24 months after surgery.

Combined VEGF and PDGF treatment reduces secondary degeneration after spinal cord injury

Trauma to the spinal cord creates an initial physical injury damaging neurons, glia, and blood vessels, which then induces a prolonged inflammatory response, leading to secondary degeneration of spinal cord tissue, and further loss of neurons and glia surrounding the initial site of injury. Angiogenesis is a critical step in tissue repair, but in the injured spinal cord angiogenesis fails; blood vessels formed initially later regress. Stabilizing the angiogenic response is therefore a potential target to improve recovery after spinal cord injury (SCI). Vascular endothelial growth factor (VEGF) can initiate angiogenesis, but cannot sustain blood vessel maturation. Platelet-derived growth factor (PDGF) can promote blood vessel stability and maturation. We therefore investigated a combined application of VEGF and PDGF as treatment for traumatic spinal cord injury, with the aim to reduce secondary degeneration by promotion of angiogenesis. Immediately after hemisection of the spinal cord in the rat we delivered VEGF and PDGF and to the injury site. One and 3 months later the size of the lesion was significantly smaller in the treated group compared to controls, and there was significantly reduced gliosis surrounding the lesion. There was no significant effect of the treatment on blood vessel density, although there was a significant reduction in the numbers of macrophages/microglia surrounding the lesion, and a shift in the distribution of morphological and immunological phenotypes of these inflammatory cells. VEGF and PDGF delivered singly exacerbated secondary degeneration, increasing the size of the lesion cavity. These results demonstrate a novel therapeutic intervention for SCI, and reveal an unanticipated synergy for these growth factors whereby they modulated inflammatory processes and created a microenvironment conducive to axon preservation/sprouting.

Leadership practices of Kuwaiti Secondary School Principals for embedding ICT

Globalisation and the emergence of knowledge-based economies have forced many countries to reform their education system. The enhancement of human capital to meet modern day demands of a knowledge economy, and equip the new generation with the capacity to meet the challenges of the 21st Century has become a priority. This change is particularly necessary in economies typical of countries, such as Kuwait, which have been dependent on the exploitation of non-renewable natural resources. Transiting from a resource-based economy to an economy based on knowledge and intellectual skills poses a key challenge for an education system. Significant in the development of this new economy has been the expansion of Information Communication Technology (ICT). In education, in particular, ICT is a tool for transforming the education setting. However, transformation is only successful where there are effective change management strategies and appropriate leadership. At the school level, rapid changes have affected the role that principals take particularly in relation to leading the change process. Therefore, this study investigated the leadership practices of school principals for embedding ICT into schools. The case study assessed two Kuwaiti secondary schools; both schools had well established ICT programs. The mode of data collection used a mixed-methods design, to address the purpose of the study, namely, to examine the leadership practices of school principals when managing the change processes associated with embedding ICT in the context of Kuwait. A theoretical model of principal leadership, developed, from the literature, documented and analysed the practices of the respective school principals. The study used the following five data sources: (a) face to face interviews (with each school principal), and two focus group interviews (with five teachers and five students, from each school); (b) school documents (related to the implementation and embedding of ICT); (c) one survey (of all teachers in each school); (d) an open-ended questionnaire (of participating principals and teachers); and (e) the observation of ICT activities (PD ICT activities and instruction meetings). The study revealed a range of strategies used by the principals and aligned with the theoretical perspective. However, these strategies needed to be refined and selectively used to fit the Kuwait context, both culturally and organisationally. The principals of Schools A and B employed three key strategies to maximise the impact on the teaching staff incorporating ICT into their teaching and learning practices. These strategies were: (a) encouragement for teaching staff to implement ICT in their teaching; (b) support to meet the material and human needs of teaching staff using ICT; and (c) provision of instructions and guidance for teaching staff in how and why such behaviours and practices should be performed. The strategies provided the basic leadership practices required to construct a successful ICT embedded implementation process. Hence, a revised model of leadership that has applicability in the adoption of ICT in Kuwait was developed. The findings provide a better understanding of how a school principal’s leadership practices impact upon the ICT embedding process. Hence, the outcome of this study informs emerging countries, which are also undergoing major change related to ICT, for example, other members of the Cooperation Council for the Arab States of the Gulf. From an educational perspective, this knowledge has the potential to support ICT-based learning environments that will help educational practitioners to effectively integrate ICT into teaching and learning that will facilitate students’ ICT engagement, and prepare them for the ICT development challenges that are associated with the new economy; this is achieved by increasing students’ knowledge and performance. Further, the study offers practical strategies that have been shown to work for school principals leading ICT implementation in Kuwait. These strategies include how to deal with the shortage in schools’ budgets, and the promotion of the ICT vision, as well as developing approaches to build collaborative culture in the schools.