431 research outputs found
Does air gas aesthesiometry generate a true mechanical stimulus for corneal sensitivity measurement?
Background: Belmonte Ocular Pain Meter (OPM) air jet aesthesiometry overcomes some
of the limitations of the Cochet-Bonnet aesthesiometer. However, for true mechanical
corneal sensitivity measurement, the airflow stimulus temperature of the aesthesiometer
must equal ocular surface temperature (OST), to avoid additional response from
temperature-sensitive nerves. The aim of this study was to determine: (A) the stimulus
temperature inducing no or least change in OST; and (B) to evaluate if OST remains
unchanged with different stimulus durations and airflow rates.
Methods: A total of 14 subjects (mean age 25.14 2.18 years; seven women) participated
in this clinical cohort study: (A) OST was recorded using an infrared camera (FLIR A310)
during the presentation of airflow stimuli, at five temperatures, ambient temperature
(AT) +5C, +10C, +15C, +20C and +30C, using the OPM aesthesiometer (duration
three seconds; over a four millimetre distance; airflow rate 60 ml/min); and (B) OST
measurements were repeated with two stimulus temperatures (AT +10C and +15C)
while varying stimulus durations (three seconds and five seconds) and airflow rates
(30, 60, 80 and 100 ml/min). Inclusion criteria were age <40 years, no contact lens wear,
absence of ocular disease including dry eye, and no use of artificial tears. Repeated measures
(analysis of variance) and appropriate post-hoc t-tests were applied.
Results: (A) Stimulus temperatures of AT +10C and +15C induced the least changes in
OST (−0.20 0.13C and 0.08 0.05C). (B) OST changes were statistically significant
with both stimulus temperatures and increased with increasing airflow rates (p < 0.001),
and were more marked with stimulus temperature AT +10C.
Conclusion: A true mechanical threshold for corneal sensitivity cannot be established with
the air stimulus of the Belmonte OPM because its air jet stimulus with mechanical setting
is likely to have a thermal component. Appropriate stimulus selection for an air jet aesthesiometer
must incorporate stimulus temperature control that can vary with stimulus duration
and airflow rate
Early predictors of separation anxiety disorder : early stranger anxiety, parental pathology and prenatal factors
<i>Objective:</i> The present study seeks to extend research on the etiology of separation anxiety disorder (SAD) in a German-speaking sample by examining differences between children with SAD and healthy comparisons, using a retrospective-reporting paradigm. <i>Method:</i> The sample included 106 children with SAD and 44 healthy children between the ages of 4 and 14 years. Parents completed questionnaires and structured clinical interviews to assess parental pathology, pregnancy variables and strong early stranger anxiety. <i>Results:</i> Children with SAD were more likely than healthy children to have had a phase of stronger stranger anxiety in infancy. Further, early stranger anxiety remained a significant predictor of SAD after controlling for maternal depression. Meaningful effects were not found for the influence of parental age at birth or other pregnancy factors. <i>Conclusion:</i> This study provides beginning evidence of the potential predictive value of strong stranger anxiety in distinguishing children with SAD from those with no disorder, above and beyond the influence of parental pathology.</jats:p
Layer-by-layer assembly of multi-layered droplet interface bilayers (multi-DIBs)
Droplet interface bilayers (DIBs) have tremendous promise as platforms for fundamental biomembrane studies and in biotechnology. Being composed of a single bilayer however limits their biomimetic potential, as many cell membrane motifs are composed of multiple aligned bilayers. We describe a technology to manufacture cell-sized multi-layered DIBs (multi-DIBs) by coating giant unilamellar vesicles with a further monolayer, and allowing such structures to make contact with themselves or a monolayer coated droplet. This easily customisable strategy will pave the way for an expanded repertoire of DIB functionality, for example by facilitating the incorporation of multiple-bilayer spanning protein complexes
Combining Slaughterhouse Surveillance Data with Cattle Tracing Scheme and Environmental Data to Quantify Environmental Risk Factors for Liver Fluke in Cattle.
Liver fluke infection causes serious disease (fasciolosis) in cattle and sheep in many regions of the world, resulting in production losses and additional economic consequences due to condemnation of the liver at slaughter. Liver fluke depends on mud snails as an intermediate host and infect livestock when ingested through grazing. Therefore, environmental factors play important roles in infection risk and climate change is likely to modify this. Here, we demonstrate how slaughterhouse data can be integrated with other data, including animal movement and climate variables to identify environmental risk factors for liver fluke in cattle in Scotland. We fitted a generalized linear mixed model to the data, with exposure-weighted random and fixed effects, an approach which takes into account the amount of time cattle spent at different locations, exposed to different levels of risk. This enabled us to identify an increased risk of liver fluke with increased animal age, rainfall, and temperature and for farms located further to the West, in excess of the risk associated with a warmer, wetter climate. This model explained 45% of the variability in liver fluke between farms, suggesting that the unexplained 55% was due to factors not included in the model, such as differences in on-farm management and presence of wet habitats. This approach demonstrates the value of statistically integrating routinely recorded slaughterhouse data with other pre-existing data, creating a powerful approach to quantify disease risks in production animals. Furthermore, this approach can be used to better quantify the impact of projected climate change on liver fluke risk for future studies
Emerging dietary patterns: impact on child health
What we eat today and how we decide to produce sufficient food to meet both demand and nutritional requirements will determine the availability, diversity and quality of diets for future generations.
Acceptability and normalisation of new dietary patterns must be prioritised to the same extent as education on environmental sustainability and health, because these are important social levers. They can help to reduce the psychosocial barriers and anxieties often connected to the behaviour changes that are needed to transition away from the traditional Western eating habits that are now increasingly subject to critical scrutiny.
Without understanding the motivations and facilitators to change eating habits (and then designing and amplifying solutions which make those changes attractive and compelling in the modern world) positive changes to young people’s health and their environment through better food will not come quickly enough to halt potentially catastrophic consequences for people and planet.
Changing consumption is seen by experts as the most powerful lever compared to food waste reduction or more efficient food production methods and technological solutions. There is simply not enough on Earth to sustain the increase of intensification required to continue feeding a global population on its current trajectory with a diet so rich in animal produce.
However, radical behaviour modification is challenging and therefore cross-sector, bold and perhaps unorthodox leadership is necessary to inspire alteration in the food system, which will have a knock-on effect in terms of changing food environments and therefore food perceptions, narratives and behaviours.
There are no ‘quick fix’ solutions, but what is undeniable is that populations can only make effective shifts in dietary patterns if government and the food industry help them to make those changes. This requires budgetary investment in public health information and the implementation of policies that promote ways to eat healthily that are also affordable and environmentally sustainable. The aim is to offer food that tastes as good as it can be made to look so that uptake is maximised and the benefits are cumulative.
The inevitable upheaval incurred by making any alteration to entrenched patterns of consumption that have been centuries in the making should not be underestimated, but carrying on as before is no longer credible nor desirable. The aim is to offer ‘nutritious’ food.
‘If we don’t take action, the collapse of our civilisations and the extinction of much of the natural world is on the horizon’ Sir David Attenborough.
This Report is our initial contribution to a conversation that has only just begun.It is unlikely to be the last
Quantitative analysis of three-dimensional fibrillar collagen microstructure within the normal, aged and glaucomatous human optic nerve head
The aim of this study was to quantify connective tissue fibre orientation and alignment in young, old and glaucomatous human optic nerve heads (ONH) to understand ONH microstructure and predisposition to glaucomatous optic neuropathy. Transverse (seven healthy, three glaucomatous) and longitudinal (14 healthy) human ONH cryosections were imaged by both second harmonic generation microscopy and small angle light scattering (SALS) in order to quantify preferred fibre orientation (PFO) and degree of fibre alignment (DOFA). DOFA was highest within the peripapillary sclera (ppsclera), with relatively low values in the lamina cribrosa (LC). Elderly ppsclera DOFA was higher than that in young ppsclera (p < 0.00007), and generally higher than in glaucoma ppsclera. In all LCs, a majority of fibres had preferential orientation horizontally across the nasal–temporal axis. In all glaucomatous LCs, PFO was significantly different from controls in a minimum of seven out of 12 LC regions (p < 0.05). Additionally, higher fibre alignment was observed in the glaucomatous inferior–temporal LC (p < 0.017). The differences between young and elderly ONH fibre alignment within regions suggest that age-related microstructural changes occur within the structure. The additional differences in fibre alignment observed within the glaucomatous LC may reflect an inherent susceptibility to glaucomatous optic neuropathy, or may be a consequence of ONH remodelling and/or collapse
START adolescents: study protocol of a randomised controlled trial to investigate the efficacy of a low-threshold group treatment programme in traumatised adolescent refugees
Introduction No evaluated therapeutic approaches, that can efficiently be established in routine mental healthcare, are currently available for traumatised adolescent refugees in Germany. This study evaluates the efficacy of the Stress-Traumasymptoms-Arousal-Regulation-Treatment (START) programme to reduce trauma-related symptoms and psychological distress in traumatised adolescent refugees based in Germany.
Methods and analysis This randomised, waiting-list-controlled, multicentre trial with a 12-week follow-up will include 174 refugee minors with partial or full post-traumatic stress disorder who are fluent in either Arabic, Dari, English, German or Somali. Eligible refugee minors will be randomised to the START or waiting-list control groups. The manualised 8-week START programme is based on techniques of dialectical behaviour therapy (DBT), fosters adaptive coping with emotional distress and traumatic symptoms and comprises eight therapy modules and a booster session. Study assessments are planned at baseline, post-treatment (ie, after programme participation or waiting time), booster session at week 12 or 12-week waiting time, and at the 12-week follow-up. Primary and coprimary outcomes are changes in psychological distress and traumatic symptoms at post-treatment and will be analysed as response variables in linear mixed regression models. Secondary outcomes are changes in further trauma-related and other psychopathological symptoms, emotion regulation and intermediate effects of the programme at follow-up. We will also assess effects of the programme with ecological momentary assessments and on neuroendocrine stress parameters using hair cortisol.
Ethics and dissemination This study has been approved by the lead ethics committee of Rhineland-Palatinate and the ethics committees of participating sites. The study results will be disseminated through peer-reviewed publications and scientific conferences
Measuring the refractive index of bovine corneal stromal cells using quantitative phase imaging
The cornea is the primary refractive lens in the eye and transmits >90% of incident visible light. It has been suggested that the development of postoperative corneal haze could be due to an increase in light scattering from activated corneal stromal cells. Quiescent keratocytes are thought to produce crystallins that match the refractive index of their cytoplasm to the surrounding extracellular material, reducing the amount of light scattering. To test this, we measured the refractive index (RI) of bovine corneal stromal cells, using quantitative phase imaging of live cells in vitro, together with confocal microscopy. The RI of quiescent keratocytes (RI = 1.381 ± 0.004) matched the surrounding matrix, thus supporting the hypothesis that keratocyte cytoplasm does not scatter light in the normal cornea. We also observed that the RI drops after keratocyte activation (RI = 1.365 ± 0.003), leading to a mismatch with the surrounding intercellular matrix. Theoretical scattering models showed that this mismatch would reduce light transmission in the cornea. We conclude that corneal transparency depends on the matching of refractive indices between quiescent keratocytes and the surrounding tissue, and that after surgery or wounding, the resulting RI mismatch between the activated cells and their surrounds significantly contributes to light scattering
A comparison of the effects of the colour and size of coloured overlays on young children’s reading
This study compared the effects of the colour and size of overlays on reading time, reading errors and on the clarity of text with young primary school children. The sample comprised a non-clinical, typical, sample from an East London primary school. One hundred and six children aged between four and seven years were asked to read 11 short passages of text (60 words) either with full page overlays or smaller reading rulers (53 in each group). This sample included younger children than has often been tested before. The 11 short passages allowed an assessment of baseline reading performance (no reading aid) and performance while reading with each of a set of ten coloured reading aids. Two different, yet beneficial, colours were determined: the most effective and the clearest/most comfortable. Both of these measures are not usually recorded. All but four children had reduced reading times with one of the reading aids and all but one reported their aid improved the perceived visual clarity of the text: the size of the reading aid did not affect reading time or visual clarity significantly. The numbers of skipped words and errors/mis-read words also decreased when reading with the most effective and most comfortable reading aid. Near visual acuity was assessed with and without each child’s most effective coloured aid. The most effective aid improved acuity in over a third of the children. Acuity has not been assessed in previous studies. As reported previously, different colours helped different children. In conclusion, coloured reading overlays reduced reading times on the reading test employed here and the size of the reading aid was not crucial to facilitate performance. The largest reductions occurred for the youngest readers, suggesting these aids may be particularly effective for early readers
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