389 research outputs found
The Royal College of Ophthalmologists' National Ophthalmology Database study of cataract surgery: report 1, visual outcomes and complications.
Aim
To describe the outcomes of cataract surgery in the United Kingdom.
Methods
Anonymised data on 180 114 eyes from 127 685 patients undergoing cataract surgery between August 2006 and November 2010 were collected prospectively from 28 sites. Outcome measures included intraoperative and postoperative complication rates, and preoperative and postoperative visual acuities.
Results
Median age at first eye surgery was 77.1 years, 36.9% cases had ocular co-pathology and 41.0% patients underwent cataract surgery on both eyes. Preoperative visual acuity was 0.30 logMAR or better in 32.0% first eyes and 47.7% second eyes. Postoperative best-measured visual acuity was 0.00 and 0.30 logMAR or better in 50.8 and 94.6% eyes without ocular co-pathology, and 32.5 and 79.9% in eyes with co-pathology. For eyes without co-pathology, postoperative uncorrected distance visual acuity was 0.00 and 0.30 logMAR or better in 27.3 and 80.9% eyes. Posterior capsule rupture or vitreous loss or both occurred in 1.95% cases, and was associated with a 42 times higher risk of retinal detachment surgery within 3 months and an eight times higher risk of endophthalmitis.
Conclusion
These results provide updated data for the benchmarking of cataract surgery. Visual outcomes, and the rate of posterior capsule rupture or vitreous loss or both appear stable over the past decade
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Bioavailability in soils
The consumption of locally-produced vegetables by humans may be an important exposure pathway for soil contaminants in many urban settings and for agricultural land use. Hence, prediction of metal and metalloid uptake by vegetables from contaminated soils is an important part of the Human Health Risk Assessment procedure. The behaviour of metals (cadmium, chromium, cobalt, copper, mercury, molybdenum, nickel, lead and zinc) and metalloids (arsenic, boron and selenium) in contaminated soils depends to a large extent on the intrinsic charge, valence and speciation of the contaminant ion, and soil properties such as pH, redox status and contents of clay and/or organic matter. However, chemistry and behaviour of the contaminant in soil alone cannot predict soil-to-plant transfer. Root uptake, root selectivity, ion interactions, rhizosphere processes, leaf uptake from the atmosphere, and plant partitioning are important processes that ultimately govern the accumulation ofmetals and metalloids in edible vegetable tissues. Mechanistic models to accurately describe all these processes have not yet been developed, let alone validated under field conditions. Hence, to estimate risks by vegetable consumption, empirical models have been used to correlate concentrations of metals and metalloids in contaminated soils, soil physico-chemical characteristics, and concentrations of elements in vegetable tissues. These models should only be used within the bounds of their calibration, and often need to be re-calibrated or validated using local soil and environmental conditions on a regional or site-specific basis.Mike J. McLaughlin, Erik Smolders, Fien Degryse, and Rene Rietr
A Method of Drusen Measurement Based on the Geometry of Fundus Reflectance
BACKGROUND: The hallmarks of age-related macular degeneration, the leading cause of blindness in the developed world, are the subretinal deposits known as drusen. Drusen identification and measurement play a key role in clinical studies of this disease. Current manual methods of drusen measurement are laborious and subjective. Our purpose was to expedite clinical research with an accurate, reliable digital method. METHODS: An interactive semi-automated procedure was developed to level the macular background reflectance for the purpose of morphometric analysis of drusen. 12 color fundus photographs of patients with age-related macular degeneration and drusen were analyzed. After digitizing the photographs, the underlying background pattern in the green channel was leveled by an algorithm based on the elliptically concentric geometry of the reflectance in the normal macula: the gray scale values of all structures within defined elliptical boundaries were raised sequentially until a uniform background was obtained. Segmentation of drusen and area measurements in the central and middle subfields (1000 μm and 3000 μm diameters) were performed by uniform thresholds. Two observers using this interactive semi-automated software measured each image digitally. The mean digital measurements were compared to independent stereo fundus gradings by two expert graders (stereo Grader 1 estimated the drusen percentage in each of the 24 regions as falling into one of four standard broad ranges; stereo Grader 2 estimated drusen percentages in 1% to 5% intervals). RESULTS: The mean digital area measurements had a median standard deviation of 1.9%. The mean digital area measurements agreed with stereo Grader 1 in 22/24 cases. The 95% limits of agreement between the mean digital area measurements and the more precise stereo gradings of Grader 2 were -6.4 % to +6.8 % in the central subfield and -6.0 % to +4.5 % in the middle subfield. The mean absolute differences between the digital and stereo gradings 2 were 2.8 +/- 3.4% in the central subfield and 2.2 +/- 2.7% in the middle subfield. CONCLUSIONS: Semi-automated, supervised drusen measurements may be done reproducibly and accurately with adaptations of commercial software. This technique for macular image analysis has potential for use in clinical research
The effects of equine-assisted activities on the social functioning in children and adolescents with autism spectrum disorder
Equine-assisted activities and therapies are increasing in popularity for treatment of ASD symptoms. This research evaluated effects of a 5-week programme of therapeutic riding on social functioning of children/adolescents (N = 15) with ASD. The effectiveness of the programme was evaluated using the autism spectrum quotient, the Vineland Adaptive Behaviour Scale and the empathising and systemising quotient. Results established that the TR intervention increased empathising and reduced maladaptive behaviours. The findings also indicated that specific adaptive behaviours like socialization and communication were not affected by the intervention. Thus, a complex picture of the effects of this intervention emerges: while TR does not change all of the child’s behaviour, it can improve specific aspects of social functioning and also reduce maladaptive ASD traits
National and firm-level drivers of the devolution of HRM decision making to line managers
Multinational companies must understand the influences on responsibility for managing people so that they can manage talent consistently thus ensuring that it is transferable across locations. We examine the impact of firm and national level characteristics on the devolution of HRM decision making to line managers. Our analysis draws on data from 2335 indigenous organizations in 21 countries. At the firm level, we found that where the HR function has higher power, devolution is less likely. At the national level, devolution of decision making to line management is more likely in societies with more stringent employment laws and lower power distance
Eculizumab treatment: stochastic occurrence of C3 binding to individual PNH erythrocytes
C5 blockade by eculizumab prevents complement-mediated intravascular hemolysis in paroxysmal nocturnal hemoglobinuria (PNH). However, C3-bound PNH red blood cells (RBCs), arising in almost all treated patients, may undergo extravascular hemolysis reducing clinical benefits. Despite the uniform deficiency of CD55 and of CD59, there are always two distinct populations of PNH RBCs, with (C3+) and without (C3-) C3 binding
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Rapid and objective assessment of neural function in autism spectrum disorder using transient visual evoked potentials
OBJECTIVE:
There is a critical need to identify biomarkers and objective outcome measures that can be used to understand underlying neural mechanisms in autism spectrum disorder (ASD). Visual evoked potentials (VEPs) offer a noninvasive technique to evaluate the functional integrity of neural mechanisms, specifically visual pathways, while probing for disease pathophysiology.
METHODS:
Transient VEPs (tVEPs) were obtained from 96 unmedicated children, including 37 children with ASD, 36 typically developing (TD) children, and 23 unaffected siblings (SIBS). A conventional contrast-reversing checkerboard condition was compared to a novel short-duration condition, which was developed to enable objective data collection from severely affected populations who are often excluded from electroencephalographic (EEG) studies.
RESULTS:
Children with ASD showed significantly smaller amplitudes compared to TD children at two of the earliest critical VEP components, P60-N75 and N75-P100. SIBS showed intermediate responses relative to ASD and TD groups. There were no group differences in response latency. Frequency band analyses indicated significantly weaker responses for the ASD group in bands encompassing gamma-wave activity. Ninety-two percent of children with ASD were able to complete the short-duration condition compared to 68% for the standard condition.
CONCLUSIONS:
The current study establishes the utility of a short-duration tVEP test for use in children at varying levels of functioning and describes neural abnormalities in children with idiopathic ASD. Implications for excitatory/inhibitory balance as well as the potential application of VEP for use in clinical trials are discussed
The Cognitive Ecology of the Internet
In this chapter, we analyze the relationships between the Internet
and its users in terms of situated cognition theory. We first argue that the Internet is a new kind of cognitive ecology, providing almost constant access to a vast amount of digital information that is increasingly more integrated into our cognitive routines. We then briefly introduce situated cognition theory
and its species of embedded, embodied, extended, distributed and collective
cognition. Having thus set the stage, we begin by taking an embedded
cognition view and analyze how the Internet aids certain cognitive tasks. After
that, we conceptualize how the Internet enables new kinds of embodied
interaction, extends certain aspects of our embodiment, and examine how
wearable technologies that monitor physiological, behavioral and contextual
states transform the embodied self. On the basis of the degree of cognitive
integration between a user and Internet resource, we then look at how and
when the Internet extends our cognitive processes. We end this chapter with
a discussion of distributed and collective cognition as facilitated by the Internet
Mediating boundaries between knowledge and knowing
This article reflects critically on the use of a wiki as a data repository for knowledge transfer and as a mediating technical platform for social learning in the context of a multi-country programme of agricultural research for development. The wiki was designed to foster sustainable social learning and an emergent community of practice among biophysical and social researchers acting for the first time as co-researchers. Over time, the technologically mediated element of the learning system was judged to have failed. The article is based on an inquiry that asked ‘How can learning system design cultivate learning opportunities and respond to learning challenges in an online environment to support research for development practice?’ The article also considers the wider context and institutional setting in which the knowledge work took place. </jats:p
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