Retinal drusen detection using the Nidek F-10 SLO in retro-mode

Presentaton Purpose:We conducted a small study to assess the novel, retro - mode imaging technique of the NIDEK F-10 scanning laser ophthalmoscope, for detecting and quantifying retinal drusen. Methods:Fundus photographs of 4 eyes of 2 patients taken in retro-mode on the Nidek F-10 SLO were graded independently by 6,experienced, masked fundus graders for the presence of retinal drusen , and compared to stereo colour fundus photographs taken with a Topcon TRC-50DX camera. Results:The mean number of retinal drusen detected in retro mode was 142.96+/- 60.8, range 63-265, and on colour fundus photography mean of 66.6+/-32.6, range 26-177. All observers independently detected approximately twice as many drusen on retro-mode than colour fundus photography (p<0.0001, Student’s paired t-test) . The statistical significance of interobserver variation in drusen detection was p=0.07 on colour fundus photography , and p=0.02 on retro mode ( ANOVA) . Conclusions:The retro-mode of the F-10 camera uses infrared laser and an aperture with a modified central stop, with the aperture deviated laterally from the confocal light path. This forms a pseudo -3D image which is a new means of detecting abnomalites in the deeper retinal layers. Retro-mode imaging of retinal drusen using the F-10 Nidek SLO is a highly sensitive technique for detecting and quantifying retinal drusen , and detected twice as many drusen than colour fundus photography. This small pilot study suggests that this novel type of imaging may have a role in the future detection and analysis of retinal drusen, a field that is likely to become increasingly important in future AMD prevention studies.

Statnote 33:the intra-class correlation coefficient

The intra-class correlation coefficient (ICC or ri) is a method of measuring correlation when the data are paired and therefore, should be used when experimental units are organised into groups. A useful analogy is with the unpaired or paired ‘t’ test to compare the differences between the means of two groups. In studies of reproducibility, there may actually be little difference between the ICC and Pearson’s ‘r’ for ‘true’ repeated measurements. If, however, there is a systematic change in the measurements made on the first compared with the second occasion, then the ICC will be significantly less than ‘r’, and less confidence would be placed in the reproducibility of the results.

Neuromuscular response to whole body vibration treatment during static and dynamic squat exercises

The impact of whole body vibrations (vibration stimulus mechanically transferred to the body) on muscular activity and neuromuscular response has been widely studied but without standard protocol and by using different kinds of exercises and parameters. In this study, we investigated how whole body vibration treatments affect electromyographic signal of rectus femoris during static and dynamic squat exercises. The aim was the identification of squat exercise characteristics useful to maximize neuromuscular activation and hence progress in training efficacy. Fourteen healthy volunteers performed both static and dynamic squat exercises without and with vibration treatments. Surface electromyographic signals of rectus femoris were recorded during the whole exercise and processed to reduce artifacts and to extract root mean square values. Paired t-test results demonstrated an increase of the root mean square values (p<0.05) in both static and dynamic squat exercises with vibrations respectively of 63% and 108%. For each exercise, subjects gave a rating of the perceived exertion according to the Borg's scale but there were no significant changes in the perceived exertion rate between exercises with and without vibration. Finally, results from analysis of electromyographic signals identified the static squat with WBV treatment as the exercise with higher neuromuscular system response. © 2012 IEEE.

Monocyte subpopulation counts and TNF alpha associations with clinical outcome post ST elevation myocardial infarction

Background Monocytes are implicated in the initiation and progression of the atherosclerotic plaque contributing to its instability and rupture. Although peripheral monocytosis has been related to poor clinical outcome post ST elevation myocardial infarction (STEMI), only scarce information is available of mechanisms of this association. Tumour necrosis factor alpha (TNFα) is a key cytokine in the acute phase inflammatory response, and it is predominantly produced by inflammatory macrophages. Little is known about TNFα association with circulating monocyte subpopulations post STEMI. Method A total of 142 STEMI patients (mean age 62±13 years; 72% male) treated with percutaneous revascularization were recruited with blood samples obtained within first 24 hours from the onset and on day 10-14. Peripheral blood monocyte subpopulations were enumerated and characterized using flow cytometry after staining for CD14, CD16 and CCR2 and were defined as: CD14++CD16-CCR2+ (Mon1), CD14++CD16+CCR+ (Mon2) and CD14+CD16++CCR2- (Mon3) cells. Plasma levels of TNFα were measured by enzyme-linked immunosorbent assay (ELISA, Peprotec system, UK). Major adverse cardiac events (MACE), defined as recurrent STEMI, new diagnosis of heart failure and death were recorded at follow up, mean of 164±134 days. Results TNFα levels were significantly higher 24 hours post STEMI, compared to day 14 (paired t-test, p <0.001) with day 1 levels weakly correlated with total monocyte count as well as Mon1 (Spearman’s correlation, r=0.19, p=0.02 and r=0.22, p=0.01, respectively). There was no correlation between TNFα and Mon2 or Mon3 subpopulations. TNFα levels were significantly higher in patients with a recorded MACE (n=28, Mann-Whitney test, p<0.001) (figure 1).⇓

Utilising fiction to promote english language acquisition

Towards the end of the university stage, students residing in the United Arab Emirates and specialising in subjects other than English are expected- amongst other university requirements- to have acquired adequate communicative competence as well as a repertoire of critical thinking skills. Despite the efforts made within the field of teaching English to EFL university students in the country, the output gained in terms of acquired skills and competencies is still below expectations. The main concerns of the current thesis are, therefore, a) to investigate the factors which inhibit EFL university students’ progress in the areas of acquiring adequate communicative competence as well as critical thinking skills, and b) to propose a course book and pedagogic methods to improve students’ progress in the areas of acquiring adequate communicative competence as well as critical thinking skills. Believing in the essential role literature plays in enhancing critical thinking and promoting communicative competence on the part of EFL learners, the current study introduces a course, designed and implemented by the researcher: LEARN AND GAIN. The proposed course is fiction-based language teaching, adopting the view that literature is a resource rather than an object, thus advocating the use of literature as one of the main resources in foreign/second language acquisition. Investigating whether or not the proposed course was effective in promoting EFL university students’ communicative competence as well as enhancing their critical thinking skills, a study sample taken from the study population was selected. Adopting an experimental design, the research project involved two groups: experimental and control. The experimental group students were exposed to the proposed course whilst the control group students were exposed to a general English language course. To examine treatment effectiveness, the researcher set and administered a pre-post test. Divided into two main parts, communicative critical reading competence and communicative critical writing competence, the pre-post test measured subjects’ communicative critical reading competence and subjects’ communicative critical writing competence. In addition, a pre-post questionnaire was administered and a semi-structured interview was conducted involving the experimental group students, to gain an awareness of students’ attitudes towards learning literary texts in general, and the proposed course in particular. To examine issues of interest and relevance, gender differences: male vs. female, and university major: science vs. non-science, were also examined for enrichment purposes. For the purpose of gathering sufficient data about subjects’ achievements on the pre-post, the following statistical tests were conducted: Mann-Whitney test, and paired data t-test. Based on the statistical findings, the experimental group students’ performance on the communicative critical reading competence pre-post test and the communicative critical writing competence pre-post test was significantly better than their counterparts of the control group students. Speaking of gender differences in relation to language performance on the communicative critical reading competence pre-post test and the communicative critical writing competence pre-post test, no significant differences were cited. Neither did the researcher cite any significant performance differences between science/non-science students on the communicative critical reading competence pre-post test and the communicative critical writing competence pre-post test. As far as the questionnaire’s findings are concerned, the experimental group students’ responses to the post-questionnaire’s items were more positive than those of their responses to the pre-questionnaire’s, thus indicating some positive attitudes towards literature, which students possibly gained throughout the course of implementation. Relating the discussion to the interview’s results, students conveyed their satisfaction with the proposed course, emphasising that promoting English language skills through the use of literary texts was rewarding. In the light of findings and conclusions, a number of recommendations as well as implications have been proposed. The current study aimed to arrive at some appropriate suggestions to a number of enquiries, yet concluding with some areas of enquiry to be explored for further research.

StatNote 38 : The sign test

The sign test is a simple non-parametric test which can be used on paired data, i.e., two related samples, matched samples, or repeated measurements on the same sample. It was developed by Wilcoxon before the more powerful and familiar ‘Wilcoxon signed-rank test’ described in a previous statnote . This statnote describes the use of the sign test with reference to two scenarios: (1) to compare the cleanliness of two hospital wards as assessed by a sample of observers and (2) to compare bacterial contamination on cloths and sponges from a domestic kitchen.