SyTroN: a virtual classroom for collaborative and distant e-learning systemby teleoperating real devices

Distant E-learning is a main issue nowadays, and it is strongly motivated by social and economical considerations. The increased people mobility and the reduction of educational costs push to develop ad hoc solutions enabling to access to knowledge regardless to geographical situation and economical capabilities. These parameters should not be limits for good training: learning material's pertinence and efficiency have to remain the core of educational activities. In this paper we address the problem through SyTroN: a tele-learning system. This system combines virtual reality and teleoperation techniques to offer an open platform with two main objectives. The first one is to propose intuitive virtual classrooms/desks, including a real teacher supervision and supporting collaborative and individual distant learning. The second goal is to place learners in real conditions with remote connections to real devices allowing distant experimentations. Both goals participate to increase learning impacts and to reduce costs, that is, sharing costly real devices from anywhere at any time. After 5 years of development, our work has been validated by an extensive use at a high engineering school. In situ tests and learning impact studies have been done. They show some advantages and some drawbacks of our global solution

The analysis of road traffic accident data in the implementation of road safety remedial programmes

Thesis (M.Ing.)--Stellenbosch University, 2001.ENGLISH ABSTRACT: A road safety remedial programme has as an objective the improvement of road transportation safety by applying road safety engineering remedial measures to hazardous road network elements in a manner that will be economically efficient. Since accident data is the primary manifestation of poor safety levels it must be analysed in manner that will support the overall objective of economic efficiency. Three steps in the process of implementing a road safety remedial programme, that rely on the systematic analysis of accident data, are the identification of hazardous locations, the ranking of hazardous locations and the evaluation of remedial measure effectiveness. The efficiency of a road safety remedial programme can be enhanced by using appropriate methodologies to measure safety, identify and rank hazardous locations and to determine the effectiveness of road safety remedial measures. There are a number of methodologies available to perform these tasks, although some perform much better than other. Methodologies based on the Empirical Bayesian approach generally provide better results than the Conventional methods. Bayesian methodologies are not often used in South Africa. To do so would require the additional training of students and engineering professionals as well as more research by tertiary and other research institutions. The efficiency of a road safety remedial programme can be compromised by using poor quality accident data. In South Africa the quality of accident data is generally poor and should more attention be given to the proper management and control of accident data. This thesis will report on, investigate and evaluate Bayesian and Conventional accident data analysis methodologies.AFRIKAANSE OPSOMMING: Die doel van 'n padveiligheidsverbeteringsprogram is om op die mees koste effektiewe manier die veiligheid van onveilige padnetwerkelemente te verbeter deur die toepassing van ingenieursmaatreëls. Aangesien padveiligheid direk verband hou met verkeersongelukke vereis die koste effektiewe implementering van 'n padveiligheidsverbeteringsprogram die doelgerigte en korrekte ontleding van ongeluksdata. Om 'n padveiligheidsverbeteringsprogram te implementeer word die ontleding van ongeluksdata verlang vir die identifisering en priortisering van gevaarkolle, sowel as om die effektiwiteit van verbeteringsmaatreëls te bepaal. Die koste effektiwiteit van 'n padveiligheidsverbeteringsprogram kan verbeter word deur die regte metodes te kies om padveiligheid te meet, gevaarkolle te identifiseer en te prioritiseer en om die effektiwiteit van verbeteringsmaatreëls te bepaal. Daar is verskeie metodes om hierdie ontledings te doen, alhoewel sommige van die metodes beter is as ander. Die 'Bayesian' metodes lewer oor die algemeen beter resultate as die gewone konvensionele metodes. 'Bayesian' metodes word nie. in Suid Afrika toegepas nie. Om dit te doen sal addisionele opleiding van studente en ingenieurs vereis, sowel as addisionele navorsing deur universiteite en ander navorsing instansies. Die gebruik van swak kwaliteit ongeluksdata kan die integriteit van 'n padveiligheidsverbeteringsprogram benadeel. Die kwaliteit van ongeluksdata in Suid Afrika is oor die algemeen swak en behoort meer aandag gegee te word aan die bestuur en kontrole van ongeluksdata. Die doel van hierdie tesis is om verslag te doen oor 'Bayesian' en konvensionele metodes wat gebruik kan word om ongeluksdata te ontleed, dit te ondersoek en te evalueer.Maste

Factors Associated with the Incidence of Anemia in Female Students at SMA Negeri I Jayapura in 2018

Background: Anemia is a condition in which the amount of red blood cells or hemoglobin in the body is lower than usual. Adolescent girls are more likely to develop anemia as a result of their dietary habits, nutritional status, nutrient consumption, viral infections, and menstrual patterns. In 2007, the frequency of anemia among adolescent girls in Jayapura city was 16.7%. Objectives: The goal of this study was to learn about the factors that contributed to anemia among female students at SMA Negeri I Jayapura in 2018. Methods: Analytic descriptive research with a cross sectional method is the sort of investigation. There were 83 students in grades XI and XII that participated in the study.  Data were analyzed using the Pearson Correlation test. Result: The results of the analysis showed that there was a relationship between iron intake (p = 0.001), energy intake (p = 0.000), and protein intake (p = 0.002) with the incidence of anemia. Whereas there was no significant correlation between vitamin C intake (p = 0.702), nutritional status (p = 0.711), and pocket money (p = 0.340) with the incidence of  anemia among female students in SMA Negeri I Jayapura in 2018

Monolithes de silice et de carbone à porosité hiérarchisée obtenus par frittage SPS

La silice SBA-15 et le carbone CMK-3 possèdent une grande surface spécifique et un volume important de mésopores ordonnés dans une symétrie hexagonale (groupe d’espace p6 mm). Il est nécessaire de préserver leurs caractéristiques lors de la mise en forme de ces matériaux, pour un grand nombre d’applications. Le frittage SPS (Spark Plasma Sintering) des poudres a été effectué sans charge ou avec une charge uniaxiale de 25 MPa et à des températures de 600 à 800 ◦C pour la silice et 1100 à 1300 ◦C pour le carbone, pendant 5 minutes. Les isothermes d’adsorption/désorption d’azote montrent que les monolithes obtenus conservent une surface spécifique élevée (300 à 500 m2/g) et un volume mésoporeux de l’ordre de 0,7 cm3/g. La coexistence de la mésoporosité et d’une macroporosité interconnectée de volume voisin est observée par MEB (Microscopie Électronique à Balayage) et MET (Microscopie Électronique en Transmission). En outre, l’organisation de la mésoporosité est partiellement maintenue comme le mettent en évidence la DRX (Diffraction des Rayons X) et la MET

Cell sorting in a Petri dish controlled by computer vision.

Fluorescence-activated cell sorting (FACS) applying flow cytometry to separate cells on a molecular basis is a widespread method. We demonstrate that both fluorescent and unlabeled live cells in a Petri dish observed with a microscope can be automatically recognized by computer vision and picked up by a computer-controlled micropipette. This method can be routinely applied as a FACS down to the single cell level with a very high selectivity. Sorting resolution, i.e., the minimum distance between two cells from which one could be selectively removed was 50-70 micrometers. Survival rate with a low number of 3T3 mouse fibroblasts and NE-4C neuroectodermal mouse stem cells was 66 +/- 12% and 88 +/- 16%, respectively. Purity of sorted cultures and rate of survival using NE-4C/NE-GFP-4C co-cultures were 95 +/- 2% and 62 +/- 7%, respectively. Hydrodynamic simulations confirmed the experimental sorting efficiency and a cell damage risk similar to that of normal FACS

Diagnostic accuracy of computed tomography coronary angiography in patients with a zero calcium score

To evaluate the diagnostic accuracy of 64-slice CT coronary angiography (CT-CA) for the detection of significant coronary artery stenosis in patients with zero on the Agatston Calcium Score (CACS). We enrolled 279 consecutive patients (96 male, mean age 48±12 years) with suspected coronary artery disease. Patients were symptomatic (n=208) or asymptomatic (n=71), and underwent conventional coronary angiography (CAG). For CT-CA we administered an IV bolus of 100 ml of iodinated contrast material. CT-CA was compared to CAG using a threshold for significant stenosis of ≤50%. The prevalence of disease demonstrated at CAG was 15% (1.4% in asymptomatic). The population at CAG showed no or non-significant disease in 85% (238/279), single vessel disease in 9% (25/279), and multi-vessel disease in 6% (16/279). Sensitivity, specificity, and positive and negative predictive values of CT-CA vs. CAG on the patient level were 100%, 95%, 76%, and 100% in the overall population and 100%, 100%, 100%, and 100% in asymptomatic patients, respectively. CT-CA proves high diagnostic performance in patients with or without symptoms and with zero CACS. The prevalence of significant disease detected by CT-CA was not negligible in asymptomatic patients. The role of CT-CA in asymptomatic patients remains uncertain

PIWI-interacting RNAs as novel regulators of pancreatic beta cell function.

P-element induced Wimpy testis (PIWI)-interacting RNAs (piRNAs) are small non-coding RNAs that interact with PIWI proteins and guide them to silence transposable elements. They are abundantly expressed in germline cells and play key roles in spermatogenesis. There is mounting evidence that piRNAs are also present in somatic cells, where they may accomplish additional regulatory tasks. The aim of this study was to identify the piRNAs expressed in pancreatic islets and to determine whether they are involved in the control of beta cell activities. piRNA profiling of rat pancreatic islets was performed by microarray analysis. The functions of piRNAs were investigated by silencing the two main Piwi genes or by modulating the level of selected piRNAs in islet cells. We detected about 18,000 piRNAs in rat pancreatic islets, many of which were differentially expressed throughout islet postnatal development. Moreover, we identified changes in the level of several piRNAs in the islets of Goto-Kakizaki rats, a well-established animal model of type 2 diabetes. Silencing of Piwil2 or Piwil4 genes in adult rat islets caused a reduction in the level of several piRNAs and resulted in defective insulin secretion and increased resistance of the cells to cytokine-induced cell death. Furthermore, overexpression in the islets of control animals of two piRNAs that are upregulated in diabetic rats led to a selective defect in glucose-induced insulin release. Our results provide evidence for a role of PIWI proteins and their associated piRNAs in the control of beta cell functions, and suggest a possible involvement in the development of type 2 diabetes. Data have been deposited in Gene Expression Omnibus repository under the accession number GSE93792. Data can be accessed via the following link: https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?token=ojklueugdzehpkv&acc=GSE93792

Diagnostic accuracy of 64-slice computed tomography coronary angiography for the detection of in-stent restenosis: A meta-analysis

Background: We sought to evaluate the diagnostic accuracy of 64-slice multi-detector row computed tomography (MDCT) compared with invasive coronary angiography for in-stent restenosis (ISR) detection. Methods: MEDLINE, Cochrane library, and BioMed Central database searches were performed until April 2009 for original articles. Inclusion criteria were (1) 64-MDCT was used as a diagnostic test for ISR, with >50% diameter stenosis selected as the cut-off criterion for significant ISR, using invasive coronary angiography and quantitative coronary angiography as the standard of reference; (2) absolute numbers of true positive, false positive, true negative, and false negative results could be derived. Standard meta-analytic methods were applied. Results: Nine studies with a total of 598 patients with 978 stents included were considered eligible. On average, 9% of stents were unassessable (range 0-42%). Accuracy tests with 95% confidence intervals (CIs) comparing 64-MDCT vs invasive coronary angiography showed that pooled sensitivity, specificity, positive and negative likelihood ratio (random effect model) values were: 86% (95% CI 80-91%), 93% (95% CI 91-95%), 12.32 (95% CI 7.26-20.92), 0.18 (95% CI 0.12-0.28) for binary ISR detection. The symmetric area under the curve value was 0.94, indicating good agreement between 64-MDCT and invasive coronary angiography. Conclusions: 64-MDCT has a good diagnostic accuracy for ISR detection with a particularly high negative predictive value. However, still a relatively large proportion of stents remains uninterpretable. Accordingly, only in selected patients, 64-MDCT may serve as a potential alternative noninvasive method to rule out ISR

Local host response following an intramammary challenge with Staphylococcus fleurettii and different strains of Staphylococcus chromogenes in dairy heifers

Coagulase-negative staphylococci (CNS) are a common cause of subclinical mastitis in dairy cattle. The CNS inhabit various ecological habitats, ranging between the environment and the host. In order to obtain a better insight into the host response, an experimental infection was carried out in eight healthy heifers in mid-lactation with three different CNS strains: a Staphylococcus fleurettii strain originating from sawdust bedding, an intramammary Staphylococcus chromogenes strain originating from a persistent intramammary infection (S. chromogenes IM) and a S. chromogenes strain isolated from a heifer's teat apex (S. chromogenes TA). Each heifer was inoculated in the mammary gland with 1.0 x 10(6) colony forming units of each bacterial strain (one strain per udder quarter), whereas the remaining quarter was infused with phosphate-buffered saline. Overall, the CNS evoked a mild local host response. The somatic cell count increased in all S. fleurettii-inoculated quarters, although the strain was eliminated within 12 h. The two S. chromogenes strains were shed in larger numbers for a longer period. Bacterial and somatic cell counts, as well as neutrophil responses, were higher after inoculation with S. chromogenes IM than with S. chromogenes TA. In conclusion, these results suggest that S. chromogenes might be better adapted to the mammary gland than S. fleurettii. Furthermore, not all S. chromogenes strains induce the same local host response