Does strabismus surgery improve quality and mood, and what factors influence this?

Aims To establish the impact of adult strabismus surgery on clinical and psychosocial well-being and determine who experiences the greatest benefit from surgery and how one could intervene to improve quality of life post-surgery. Methods A longitudinal study, with measurements taken pre-surgery and at 3 and 6 months post-surgery. All participants completed the AS-20 a disease specific quality of life scale, along with measures of mood, strabismus and appearance-related beliefs and cognitions and perceived social support. Participants also underwent a full orthoptic assessment at their preoperative visit and again 3 months postoperatively. Clinical outcomes of surgery were classified as success, partial success or failure, using the largest angle of deviation, diplopia and requirement for further therapy. Results 210 participants took part in the study. Strabismus surgery led to statistically significant improvements in psychosocial and functional quality of life. Those whose surgery was deemed a partial success did however experience a deterioration in quality of life. A combination of clinical variables, high expectations, and negative beliefs about the illness and appearance pre-surgery were significant predictors of change in quality of life from pre- to post-surgery. Conclusions Strabismus surgery leads to significant improvements in quality of life up to 6 months postoperatively. There are however a group of patients who do not experience these benefits. A series of clinical and psychosocial factors have now been identified, which will enable clinicians to identify patients who may be vulnerable to poorer outcomes post-surgery and allow for the development of interventions to improve quality of life after surgery

Comparative investigations on digestion in grazing (Ceratotherium simum) and browsing (Diceros bicornis) rhinoceroses

Rhinoceroses represent the largest extant herbivores with extensive dietary specialization for plant groups like browse (black rhino Diceros bicornis) or grass (white rhino Ceratotherium simum). However, it is not clear to what extent such diet selection patterns are reflected in adaptations of digestive physiology of the respective feeding types. In this study, feeding trials with four black and five white rhinos were conducted in four zoos. The animals had ad libitum access to the same batch of grass hay (second cut; neutral detergent fiber (NDF) 63% dry matter (DM), crude protein 10.2% DM). Total intake, fecal N content, in vitro digestibility of NDF residues of feces, fecal particle size and mean retention time (MRT) of particles (Cr-mordanted fiber; 1–2 mm) and fluid (Co-EDTA) were quantified. The average daily DM intake was 70±12 g/kg BW0.75 for white and 73±10 g/kg BW0.75 for black rhinos. In the in vitro fermentation test fecal NDF residues of black rhinos resulted in higher gas productions at fermentation times of 12 to 24 h, indicating that white rhinos have a superior capacity to digest NDF. Average MRT for fluids and particles was 28±4 h and 43±5 h in white and 34±4 h and 39±4 h in black rhinos. The selectivity factor (SF=MRTparticle /MRTfluid) was higher for white (1.5±0.2) than for black rhinos (1.2±0.1) (p=0.016). In a comparison of 12 ruminant and 3 rhino species, SF was correlated to percentage of grass in diet (R=0.75). Mean fecal particle size was higher in white (9.1±1.94 mm) than in black rhinos (6.1±0.79 mm) (p=0.016). The results demonstrate differences between white and black rhinos in terms of retention times and fiber digestibility. The more selective retention of particles by the white rhino corresponds with the higher digestion of fiber measured indirectly. Furthermore there is indication for a general pattern of high SF in grazing ruminants and rhinos. The difference in fecal particle size between both rhino species might be due to the considerable difference in body weight

Simplifying asteroseismic analysis of solar-like oscillators: An application of principal component analysis for dimensionality reduction

The asteroseismic analysis of stellar power density spectra is often computationally expensive. The models used in the analysis may use several dozen parameters to accurately describe features in the spectra caused by oscillation modes and surface granulation. Many parameters are often highly correlated, making the parameter space difficult to quickly and accurately sample. They are, however, all dependent on a smaller set of parameters, namely the fundamental stellar properties. We aim to leverage this to simplify the process of sampling the model parameter space for the asteroseismic analysis of solar-like oscillators, with an emphasis on mode identification. Using a large set of previous observations, we applied principal component analysis to the sample covariance matrix to select a new basis on which to sample the model parameters. Selecting the subset of basis vectors that explains the majority of the sample variance, we redefine the model parameter prior probability density distributions in terms of a smaller set of latent parameters. We are able to reduce the dimensionality of the sampled parameter space by a factor of two to three. The number of latent parameters needed to accurately model the stellar oscillation spectra cannot be determined exactly but is likely only between four and six. Using two latent parameters, the method is able to describe the bulk features of the oscillation spectrum, while including more latent parameters allows for a frequency precision better than $\approx10\%$ of the small frequency separation for a given target. We find that sampling a lower-rank latent parameter space still allows for accurate mode identification and parameter estimation on solar-like oscillators over a wide range of evolutionary stages. This allows for the potential to increase the complexity of spectrum models without a corresponding increase in computational expense.Comment: Accepted for publication in Astronomy & Astrophysics. 11 pages. 10 figure

Phase transition close to room temperature in BiFeO3 thin films

BiFeO3 (BFO) multiferroic oxide has a complex phase diagram that can be mapped by appropriately substrate-induced strain in epitaxial films. By using Raman spectroscopy, we conclusively show that films of the so-called supertetragonal T-BFO phase, stabilized under compressive strain, displays a reversible temperature-induced phase transition at about 100\circ, thus close to room temperature.Comment: accepted in J. Phys.: Condens. Matter (Fast Track Communication

Nondestructive analysis of urinary calculi using micro computed tomography

BACKGROUND: Micro computed tomography (micro CT) has been shown to provide exceptionally high quality imaging of the fine structural detail within urinary calculi. We tested the idea that micro CT might also be used to identify the mineral composition of urinary stones non-destructively. METHODS: Micro CT x-ray attenuation values were measured for mineral that was positively identified by infrared microspectroscopy (FT-IR). To do this, human urinary stones were sectioned with a diamond wire saw. The cut surface was explored by FT-IR and regions of pure mineral were evaluated by micro CT to correlate x-ray attenuation values with mineral content. Additionally, intact stones were imaged with micro CT to visualize internal morphology and map the distribution of specific mineral components in 3-D. RESULTS: Micro CT images taken just beneath the cut surface of urinary stones showed excellent resolution of structural detail that could be correlated with structure visible in the optical image mode of FT-IR. Regions of pure mineral were not difficult to find by FT-IR for most stones and such regions could be localized on micro CT images of the cut surface. This was not true, however, for two brushite stones tested; in these, brushite was closely intermixed with calcium oxalate. Micro CT x-ray attenuation values were collected for six minerals that could be found in regions that appeared to be pure, including uric acid (3515 – 4995 micro CT attenuation units, AU), struvite (7242 – 7969 AU), cystine (8619 – 9921 AU), calcium oxalate dihydrate (13815 – 15797 AU), calcium oxalate monohydrate (16297 – 18449 AU), and hydroxyapatite (21144 – 23121 AU). These AU values did not overlap. Analysis of intact stones showed excellent resolution of structural detail and could discriminate multiple mineral types within heterogeneous stones. CONCLUSIONS: Micro CT gives excellent structural detail of urinary stones, and these results demonstrate the feasibility of identifying and localizing most of the common mineral types found in urinary calculi using laboratory CT

Comparative methods for PET image segmentation in pharyngolaryngeal squamous cell carcinoma

Several methods have been proposed for the segmentation of ¹⁸F-FDG uptake in PET. In this study, we assessed the performance of four categories of ¹⁸F-FDG PET image segmentation techniques in pharyngolaryngeal squamous cell carcinoma using clinical studies where the surgical specimen served as the benchmark

Construct validation of the Amblyopia and Strabismus Questionnaire (A&SQ) by factor analysis

Background: The Amblyopia and Strabismus Questionnaire (A&SQ) was previously developed to assess quality of life (QoL) in amblyopia and/or strabismus patients. Here, factor analysis with Varimax rotation was employed to confirm that the questions of the A&SQ correlated to dimensions of quality of life (QoL) in such patients. Methods: Responses on the A&SQ from three groups were analyzed: healthy adults (controls) (n = 53), amblyopia and/or strabismus patients (n = 72), and a historic cohort of amblyopes born between 1962-1972 and occluded between 1968-1974 (n = 173). The correlations among the responses to the 26 A&SQ items were factor-analysed by Principal Component Analysis (PCA). As the development of the A&SQ was intuitive-deductive, it was expected that the pattern of correlation could be explained by the five a priori hypothesized dimensions: fear of losing the better eye, distance estimation, visual disorientation, diplopia, and social contact and cosmetic problems. Distribution of questions along the factors derived by PCA was examined by orthogonal Varimax rotation. Results: Data from 296 respondents were analyzed. PCA provided that six factors (cutoff point eigenvalue >1.0) accumulatively explained 70.5% of the variance. All A&SQ dimensions but one matched with four factors found by Varimax rotation (factor loadings >0.50), while two factors pertained to the fifth dimension. The six factors explained 33.7% (social contact and cosmetic problems); 10.3% (near distance estimation); 8.7% (diplopia); 7.2% (visual disorientation); 6.3% (fear of losing the better eye); and 4.3% (far distance estimation), together 70.48% of the item variance. Conclusion: The highly explained variance in the A&SQ scores by the factors found by the PCA confirmed the a priori hypothesized dimensions of this QoL instrument

Using targeted vouchers and health equity funds to improve access to skilled birth attendants for poor women: a case study in three rural health districts in Cambodia

<p>Abstract</p> <p>Background</p> <p>In many developing countries, the maternal mortality ratio remains high with huge poor-rich inequalities. Programmes aimed at improving maternal health and preventing maternal mortality often fail to reach poor women. Vouchers in health and Health Equity Funds (HEFs) constitute a financial mechanism to improve access to priority health services for the poor. We assess their effectiveness in improving access to skilled birth attendants for poor women in three rural health districts in Cambodia and draw lessons for further improvement and scaling-up.</p> <p>Methods</p> <p>Data on utilisation of voucher and HEF schemes and on deliveries in public health facilities between 2006 and 2008 were extracted from the available database, reports and the routine health information system. Qualitative data were collected through focus group discussions and key informant interviews. We examined the trend of facility deliveries between 2006 and 2008 in the three health districts and compared this with the situation in other rural districts without voucher and HEF schemes. An operational analysis of the voucher scheme was carried out to assess its effectiveness at different stages of operation.</p> <p>Results</p> <p>Facility deliveries increased sharply from 16.3% of the expected number of births in 2006 to 44.9% in 2008 after the introduction of voucher and HEF schemes, not only for voucher and HEF beneficiaries, but also for self-paid deliveries. The increase was much more substantial than in comparable districts lacking voucher and HEF schemes. In 2008, voucher and HEF beneficiaries accounted for 40.6% of the expected number of births among the poor. We also outline several limitations of the voucher scheme.</p> <p>Conclusions</p> <p>Vouchers plus HEFs, if carefully designed and implemented, have a strong potential for reducing financial barriers and hence improving access to skilled birth attendants for poor women. To achieve their full potential, vouchers and HEFs require other interventions to ensure the supply of sufficient quality maternity services and to address other non-financial barriers to demand. If these conditions are met, voucher and HEF schemes can be further scaled up under close monitoring and evaluation.</p