66 research outputs found
Report on the chemical qualities and analysis of a combustible mineral substance from the Mersey River, Tasmania, forwarded by Mr. A. McNaughtan, of Hobart Town
A report written by Professor Penny, Professor of Chemisty at the Andersonian University, Glasgow and read 13th of September 1854 before the Royal Society of Tasmania. The report states, this mineral consists essentially of a mixture of silicious
sand and clay, with a combustible fossil substance, resembling
resin. It also contains small quantities of water
and iron pyrites, (sulphuret of iron). Under the microscope the leading ingredients may be
easily recognized and distinguished. When heated in the open fire it readily kindles, and
burns with a bright voluminous flame
Breakfast glycaemic index and exercise: combined effects on adolescents' cognition
The aim of the present study was to examine the combined effects of breakfast glycaemic index (GI) and a mid-morning bout of exercise on adolescents’ cognitive function. Participants were randomly allocated to a high or low GI breakfast group in a mixed research design, where each participant completed two experimental trials (exercise and resting). Forty-two adolescents (12.4±0.5 years old), undertook a bout of exercise (ten repeats of level one of the multi-stage fitness test; exercise trial) or continued to rest (resting trial) following consumption of either a high or low GI breakfast. A battery of cognitive function tests (visual search test, Stroop test and Sternberg paradigm) was completed 30 min before and 45 min following the exercise. Average heart rate during exercise was 170±15 beats.min-1. On the complex level of the Stroop test, response times improved across the morning following the low GI breakfast on both the exercise and resting trials, though the improvement was greatest on the exercise trial. However, response times only improved on the resting trial following the high GI breakfast (p = 0.012). On the 5 letter level of the Sternberg paradigm, response times improved across the morning following the low GI breakfast (regardless of exercise) and only on the exercise trial following the high GI breakfast (p = 0.019). The findings of the present study suggest that the combined effects of breakfast GI and exercise in adolescents depend upon the component of cognitive function examined. A low GI breakfast and mid-morning bout of exercise were individually beneficial for response times on the Sternberg paradigm, whereas they conferred additional benefits for response times on the Stroop test
Hyperglycemia and Diabetes Downregulate the Functional Expression of TRPV4 Channels in Retinal Microvascular Endothelium
Retinal endothelial cell dysfunction is believed to play a key role in the etiology and pathogenesis of diabetic retinopathy. Numerous studies have shown that TRPV4 channels are critically involved in maintaining normal endothelial cell function. In the current paper, we demonstrate that TRPV4 is functionally expressed in the endothelium of the retinal microcirculation and that both channel expression and activity is downregulated by hyperglycaemia. Quantitative PCR and immunostaining demonstrated molecular expression of TRPV4 in cultured bovine retinal microvascular endothelial cells (RMECs). Functional TRPV4 activity was assessed in cultured RMECs from endothelial Ca2+-responses recorded using fura-2 microfluorimetry and electrophysiological recordings of membrane currents. The TRPV4 agonist 4α-phorbol 12,13-didecanoate (4-αPDD) increased [Ca2+]i in RMECs and this response was largely abolished using siRNA targeted against TRPV4. These Ca2+-signals were completely inhibited by removal of extracellular Ca2+, confirming their dependence on influx of extracellular Ca2+. The 4-αPDD Ca2+-response recorded in the presence of cyclopiazonic acid (CPA), which depletes the intracellular stores preventing any signal amplification through store release, was used as a measure of Ca2+-influx across the cell membrane. This response was blocked by HC067047, a TRPV4 antagonist. Under voltage clamp conditions, the TRPV4 agonist GSK1016790A stimulated a membrane current, which was again inhibited by HC067047. Following incubation with 25 mM D-glucose TRPV4 expression was reduced in comparison with RMECs cultured under control conditions, as were 4αPDD-induced Ca2+-responses in the presence of CPA and ion currents evoked by GSK1016790A. Molecular expression of TRPV4 in the retinal vascular endothelium of 3 months' streptozotocin-induced diabetic rats was also reduced in comparison with that in age-matched controls. We conclude that hyperglycaemia and diabetes reduce the molecular and functional expression of TRPV4 channels in retinal microvascular endothelial cells. These changes may contribute to diabetes induced endothelial dysfunction and retinopathy
So much to say, so little time: A longitudinal study to determine if Lord Melvyn Bragg clutters.
Lord Melvyn Bragg is a radio and television broadcaster and presenter who currently hosts the
BBC Radio 4 discussion show 'In Our Time'. During this show he is required to question guests
and keep conversations on topic. His speech can sound very fast and irregular with many errors
and reformulations, which perceptually could be considered as cluttering. This study aimed to
determine the extent to which Melvyn Bragg could be considered to clutter.
Twelve mp3 podcasts of the radio broadcasts, available from the BBC Radio 4 website, were
used for analysis. The sound files were edited and annotated in PRAAT. They were analysed for
repair type and frequency (repetitions, deletions, substitutions, insertions and other), pause type
and frequency (silent pauses, filled pauses, breath pauses, prolongations and other) and an
orthographic transcription was produced. Articulation rate was also calculated. These results
were compared to the results from 64 typical speakers in the Human Communication Research
Centre Map Task Corpus (HCRC MTC) (Anderson et al., 1991).The Cluttering Severity
Instrument (CSI) was used on one sample to determine the severity of any clutter-like
behaviours.
The results found that Melvyn Bragg used an articulation rate that fell within normal limits set
by the HCRC MTC data. The only disfluency type that was significantly more frequent in
Melvyn Bragg's speech than in the HCRC MTC data was repetitions. The results for all other
repair and pause types were within the normal limits, as set by the HCRC MTC data. The results
of the CSI showed that Melvyn Bragg presents with a similar language profile to 3 known
people who clutter, however he has a much lower severity rating than them. Overall the results
suggest that Melvyn Bragg cannot be considered as a person who clutters.
Whilst the results of this study ought to be viewed with caution due to the small volume of data,
they provide clinical implications and reinforcement of the need for further research and
development of a definition of cluttering, and a provision of normative and standardised data for
diagnosis of cluttering.bsc_Speunpub1686_ethesesunpu
Calibration of confidence and assessed clinical skills competence in undergraduate paediatric OSCE scenarios: a mixed methods study
Abstract Background The relationship between confidence and competence in clinical skills development is complex but important. This study aims to determine undergraduate paediatric student confidence in performing three common paediatric clinical skills framed as Objective Structured Clinical Examination (OSCE) scenarios and to compare this with subsequent assessed performance. The study also aims to explore possible barriers to successful paediatric skills completion. Methods A mixed-methods study was conducted on medical students. Cross-sectional questionnaire data relating to confidence in performing a number of paediatric skills were compared with assessed paediatric skills competency. Focus groups were carried out to identify themes in paediatric skills completion to triangulate this data. Results Eighty-five medical students participated in the study. Students had high levels of pre-test confidence in their ability to perform paediatrics skills. However agreement between pre-test confidence and subsequent task performance was poor and students had significantly greater belief in their skills ability than was subsequently demonstrated. Focus groups identified paediatric skills complexity, conflicting teaching and having limited supervised skills opportunities and as being possible contributory factors to this discrepancy. Conclusions Student paediatric skills confidence is not matched by performance. The reasons for this are diverse but mostly modifiable. A major factor is the lack of supervised skills experience with appropriate feedback to support students in learning to calibrate their confidence against their competence. A number of recommendations are made including the introduction of formative assessment opportunities
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