60 resultados para quantitative study
Resumo:
The Gutmann Acceptor Number (AN), which is a quantitative measure of Lewis acidity, has been estimated using the P-31 NMR chemical shift of a probe molecule, triethylphosphine oxide, for a range of chlorometallate(III) ionic liquids, based on Group 13 metals (aluminium(III), gallium(III) and indium(III)) and the 1-octyl-3-methylimidazolium cation, at different compositions. The results were interpreted in terms of extant speciation studies of chlorometallate(III) ionic liquids, and compared with a range of standard molecular solvents and acids. The value of these data were illustrated in terms of the selection of appropriate ionic liquids for specific applications.
Resumo:
A quantitative study of refractive whole beam defocusing and small scale breakup induced by optical ionization of subpicosecond and picosecond, 0.25 and 1 mu m, laser pulses in gas-jet targets at densities above 1 x 10(19) cm(-3) has been carried out. A significant reduction of the incident laser intensity was observed due to refraction from ionization-induced density gradients. The level of refraction measured with optical probing correlated well with the fraction of energy transmitted through the plasma. The numerical and analytical models were found to agree well with experimental observations.
Resumo:
Purpose: To identify the specific characteristics making glasses designs, particularly those compatible with adjustable glasses, more or less appealing to Chinese children and their parents. Patients and Methods: Primary and secondary school children from urban and rural China with < = -1.00 diopters of bilateral myopia and their parents ranked four conventional-style frames identified by local optical shops as popular versus four child-specific frames compatible with adjustable spectacles. Scores based on the proportion of maximum possible ranking were computed for each style. Selected children and their parents also participated in Focus Groups (FGs) discussing spectacle design preference. Recordings were transcribed and coded by two independents reviewers using NVivo software. Results: Among 136 urban primary school children (age range 9-11 years), 290 rural secondary school children (11-17 years) and 16 parents, all adjustable-style frames (scores on 0-100 scale 25.7-62.4) were ranked behind all conventional frames (63.0-87.5). For eight FGs including 12 primary children, 26 secondary children and 16 parents, average kappa values for NVivo coding were 0.81 (students) and 0.70 (parents). All groups agreed that the key changes to make adjustable designs more attractive were altering the round lenses to rectangular or oval shapes and adding curved earpieces for more stable wear. The thick frames of the adjustable designs were considered stylish, and children indicated they would wear them if the lens shape were modified. Conclusions: Current adjustable lens designs are unattractive to Chinese children and their parents, though this study identified specific modifications which would make them more appealing.
Resumo:
Following on from a quantitative study, this research used a qualitative methodology to investigate the lived experience of 3 men with chronic posttraumatic stress disorder associated with the conflict in Northern Ireland who reported auditory hallucinations. Data analysis used the Framework method. Results showed that beliefs about voices, dissociation of identity and body, and interpersonal impact were central superordinate themes associated with auditory hallucinations in posttraumatic stress disorder. Central subordinate themes included feeling a lack of controllability over voices, experiencing them as ego-dystonic, and feeling an increased sense of isolation and shame because of their presence. Results provide an in-depth analysis of participants' lived experiences and enhance understanding of previous quantitative findings.
Resumo:
Title Evaluation of Video Presentation to Deliver Surgical Anatomy Teaching
Authors Walsh I.K., Boohan M., Dorman A.
Objectives To evaluate the efficacy of newly introduced video presentation to deliver Surgical Anatomy teaching to undergraduate medical students.
Design and Setting Qualitative and quantitative study using questionnaires and focus groups, employing students undertaking the perioperative medicine module of the phase 4 undergraduate medical curriculum at Queen’s University Belfast.
Outcome Measures To determine:
(1) if video presentation is effective in delivering surgical anatomy teaching,
(2) student’s learning preferences regarding this teaching method.
Results The questionnaire response rate was 89% (216 of 244 students; female: male ratio 1.25) and 42 students participated in 6 focus groups. Mean questionnaire responses indicated a favourable opinion on quality assurance items, with a mixed response to video presentation as a learning method. 71% of students preferred to receive a lecture in person, rather than via video presentation. There were no statistically significant differences between genders regarding learning preferences in general and regarding video versus live presentation in particular. Exploratory factor analysis demonstrated that favourable responses to video presentation were strongly associated with perceived audiovisual quality and learning preferences (Cronbach’s alpha coefficient 0.77), with 72% of students considering video presentation worthwhile. Positive perception of overall quality was strongly associated with learning preferences as well as more generic quality assurance issues (80% students; alpha coefficient 0.83).
The results were supported by triangulation of the above quantitative data with qualitative data generated by the focus groups. Students further articulated the view that video presentation may be more appropriate and effective in a mixed method setting.
Reference Basu Roy R, McMahon GT. Video-based cases disrupt deep critical thinking in problem-based learning. Med Educ 2012 Apr;46(4):426-435.
Resumo:
Title Evaluation of Multidisciplinary Delivery of Surgical Anatomy Teaching
Authors Walsh I.K., Taylor S.J., Dorman A, Boohan M.
Objectives To evaluate the efficacy of newly introduced multidisciplinary methods to deliver Surgical Anatomy teaching to undergraduate medical students.
Design and Setting Qualitative and quantitative study using questionnaires and focus groups, employing students of the perioperative and emergency medicine (POEM) module of the phase 4 undergraduate medical curriculum at Queen’s University Belfast.
Outcome Measures To determine:
(1) if multidisciplinary teaching is effective in delivering surgical anatomy teaching,
(2) student’s learning preferences regarding this teaching method.
Results The questionnaire response rate was 89% (216 of 244 students; female: male ratio 1.25) and 42 students participated in 6 focus groups. Mean questionnaire responses indicated a favourable opinion on quality assurance items and multidisciplinary teaching. 81% of students agreed that multidisciplinary teaching enhanced learning and 86% felt that this did not adversely affect interaction. A positive contribution towards POEM learning was reported for Radiology (95% of students), Anatomy (93%) and Surgery (78%). The benefits of multidisciplinary teaching were congruent for Anatomy, Radiology and Surgery with 78% of students indicating a perceived favourable association with learning. Multidisciplinary teaching was not associated with diluted interaction, with 62% of students describing interaction as sufficient. 88% of students positively ranked tutor characteristics of enthusiasm and encouragement as being strongly associated with teacher quality. Positive perception of overall quality was strongly associated with learning preferences as well as more generic quality assurance issues (80% students; alpha coefficient 0.83).
The results were supported by triangulation of the above quantitative data with qualitative data generated by the focus groups. Whilst students frequently misunderstood the meaning of “multidisciplinary teaching”, there was an appreciation of the method’s worth; students recognised and valued the relevance of Anatomy, Radiology and Surgery teaching to POEM learning. The importance of vertically integrating Anatomy into all stages of the undergraduate curriculum was especially recognised.
Reference Aarnio M, Nieminen J, Pyorala E, Lindbolm-Ylanne S. Motivating medical students to learn. 2010 Med Teach;32(4):199-204.
Resumo:
The education system in Northern Ireland is characterized by division, with
around 95% of the pupil population attending predominantly co-religionist
schools. In a society that is transitioning from a thirty year conflict that has been
framed by hostilities between the main Catholic and Protestant communities, reconciliation
interventions in education have sought to promote the value of intergroup
contact between pupils attending separate schools. Some qualitative research
suggests that such initiatives are more likely to have positive outcomes for
pupils from more middle class backgrounds than those from more disadvantaged
communitiesand areas that experienced high levels of conflict related incidents and deaths during the pre-ceasefire years. Drawing on contact theory and empirical evidence from a large scale quantitative study, we seek to examine this theory. Using free school meals as a proxy for social class, our findings are consistent in finding that there is a differential impact of contact for those from less affluent backgrounds, and we conclude by arguing that this should be reflected in policy responses.
Resumo:
PURPOSE: This systematic review aimed to report and explore the survival of dental veneers constructed from non-feldspathic porcelain over 5 and 10 years.
MATERIALS AND METHODS: A total of 4,294 articles were identified through a systematic search involving all databases in the Cochrane Library, MEDLINE (OVID), EMBASE, Web of Knowledge, specific journals (hand-search), conference proceedings, clinical trials registers, and collegiate contacts. Articles, abstracts, and gray literature were sought by two independent researchers. There were no language limitations. One hundred sixteen studies were identified for full-text assessment, with 10 included in the analysis (5 qualitative, 5 quantitative). Study characteristics and survival (Kaplan-Meier estimated cumulative survival and 95% confidence interval [CI]) were extracted or recalculated. A failed veneer was one which required an intervention that disrupted the original marginal integrity, had been partially or completely lost, or had lost retention more than twice. A meta-analysis and sensitivity analysis of Empress veneers was completed, with an assessment of statistical heterogeneity and publication bias. Clinical heterogeneity was explored for results of all veneering materials from included studies.
RESULTS: Within the 10 studies, veneers were fabricated with IPS Empress, IPS Empress 2, Cerinate, and Cerec computer-aided design/computer-assisted manufacture (CAD/CAM) materials VITA Mark I, VITA Mark II, Ivoclar ProCad. The meta-analysis showed the pooled estimate for Empress veneers to be 92.4% (95% CI: 89.8% to 95.0%) for 5-year survival and 66% to 94% (95% CI: 55% to 99%) for 10 years. Data regarding other non-feldspathic porcelain materials were lacking, with only a single study each reporting outcomes for Empress 2, Cerinate, and various Cerec porcelains over 5 years. The sensitivity analysis showed data from one study had an influencing and stabilizing effect on the 5-year pooled estimate.
CONCLUSION: The long-term outcome (> 5 years) of non-feldspathic porcelain veneers is sparsely reported in the literature. This systematic review indicates that the 5-year cumulative estimated survival for etchable non-feldspathic porcelain veneers is over 90%. Outcomes may prove clinically acceptable with time, but evidence remains lacking and the use of these materials for veneers remains experimental.
Resumo:
There is a dearth of evidence focusing on student preferences for computer-based testing versus
testing via student response systems for summative assessment in undergraduate education.
This quantitative study compared the preference and acceptability of computer-based testing
and a student response system for completing multiple choice questions in undergraduate
nursing education. After using both computer-based testing and a student response system to
complete multiple choice questions, 192 first year undergraduate nursing students rated their
preferences and attitudes towards using computer-based testing and a student response system.
Results indicated that seventy four percent felt the student response system was easy to use.
Fifty six percent felt the student response system took more time than the computer-based testing
to become familiar with. Sixty Percent felt computer-based testing was more users friendly.
Seventy Percent of students would prefer to take a multiple choice question summative exam
via computer-based testing, although Fifty percent would be happy to take using student response
system. Results are useful for undergraduate educators in relation to student’s preference
for using computer-based testing or student response system to undertake a summative
multiple choice question exam
Resumo:
Reliable detection of JAK2-V617F is critical for accurate diagnosis of myeloproliferative neoplasms (MPNs); in addition, sensitive mutation-specific assays can be applied to monitor disease response. However, there has been no consistent approach to JAK2-V617F detection, with assays varying markedly in performance, affecting clinical utility. Therefore, we established a network of 12 laboratories from seven countries to systematically evaluate nine different DNA-based quantitative PCR (qPCR) assays, including those in widespread clinical use. Seven quality control rounds involving over 21,500 qPCR reactions were undertaken using centrally distributed cell line dilutions and plasmid controls. The two best-performing assays were tested on normal blood samples (n=100) to evaluate assay specificity, followed by analysis of serial samples from 28 patients transplanted for JAK2-V617F-positive disease. The most sensitive assay, which performed consistently across a range of qPCR platforms, predicted outcome following transplant, with the mutant allele detected a median of 22 weeks (range 6-85 weeks) before relapse. Four of seven patients achieved molecular remission following donor lymphocyte infusion, indicative of a graft vs MPN effect. This study has established a robust, reliable assay for sensitive JAK2-V617F detection, suitable for assessing response in clinical trials, predicting outcome and guiding management of patients undergoing allogeneic transplant.
Resumo:
PURPOSE To characterise subtypes of fundus autofluorescence (AF), the progression of retinal atrophy and correlate these findings with genotype in Stargardt Disease. METHODS Full clinical examination and AF imaging was undertaken in 68 patients with Stargardt Disease. The baseline data were compared with those at follow-up. Patients were classified into three AF subtypes: type 1 had a localised low signal at the fovea surrounded by a homogeneous background; type 2 had a localised low signal at the macula surrounded by a heterogeneous background with numerous foci of abnormal signal; type 3 had multiple low signal areas at the posterior pole with a heterogeneous background. At baseline, there were 19 patients with type 1, 41 with type 2, and 8 with type 3. The areas of reduced AF signal were measured and rate of atrophy enlargement (RAE) was calculated as the difference of the atrophy size over time (mm2) divided by the follow-up interval (yrs). Molecular screening of ABCA4 was undertaken. RESULTS The mean follow-up interval was 9.1 years. 42% of type 1 progressed to type 2, and 12% of type 2 progressed to type 3. RAE (mm2/yr) based upon baseline AF subtypes was significantly different; 0.06 in type 1, 0.67 in type 2, and 4.37 in type 3. ABCA4 variants were identified in 57 patients. There was a significant association between AF subtype and genotype. CONCLUSIONS The AF pattern at baseline influences the enlargement of atrophy over time and has genetic correlates. These data are likely to assist in the provision of counselling on prognosis in Stargardt Disease and be valuable for future clinical trials.