Pseudoexfoliation and Opacification of Intraocular Lenses

Purpose: To report two cases of spoke-like intraocular lens (IOL) opacification that resembles pseudoexfoliation of the crystalline lens. Methods: Case series presentation. Results: Patient 1 developed a circle of spoke-like opacification on the anterior IOL surface7 years after phacoemulsification. Patient 2 had paracentral anterior surface IOL opacification 18 months after cataract extraction and clinical pseudoexfoliation in the fellow eye. Conclusion: Spoke-like anterior IOL opacification should raise the suspicion of pseudoexfoliation syndrome

Estimates of cycle times in stochastic Petri nets

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Sensitivity analysis for stationary and ergodic queues

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On the cut-off phenomenon in some queueing systems

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The Impact of Bacteriospermia on Semen Parameters: A Meta-Analysis

Objective: To evaluate the impact of bacteriospermia on semen parameters. Materials and methods: We used the Medline (1966-2017), Scopus (2004-2017), Clinicaltrials.gov (2008-2017), EMBASE, (1980-2017), LILACS (1985-2017) and Cochrane Central Register of Controlled Trials CENTRAL (1999-2017) databases in our primary search along with the reference lists of electronically retrieved full-text papers. Meta-analysis was performed with the RevMan 5.3 software. Results: Eighteen studies were finally included. Men were stratified in two groups, healthy controls (5,797 men) and those suffering from bacteriospermia (3,986 men). Total sperm volume was not affected by the presence of bacteriospermia when all pathogens were analyzed together (MD 0.02 95%CI -0.13,0.17). Both sperm concentration (MD -27.06, 95% CI -36.03, -18.08) and total sperm count (MD -15.12, 95% CI -21.08, -9.16) were significantly affected by bacteriospermia. Decreased rates of normal sperm morphology were also found (MD -5.43%, 95% CI -6.42, -4.44). The percentage of alive sperm was significantly affected by bacteriospermia (MD -4.39 %, 95% CI -8.25, -0.53).  Total motility was also affected by bacteriospermia (MD -3.64, 95% CI -6.45, -0.84). In addition to this, progressive motility was significantly affected (MD -12.81, 95% CI -18.09, -7.53). Last but not least, pH was importantly affected (MD 0.03, 95% Cl 0.01, 0.04). Conclusion: Bacteriospermia significantly affects semen parameters and should be taken in mind even when asymptomatic. Further studies should evaluate the impact of antibiotic treatment on semen parameters and provide evidence on fertility outcome

Correlation between mesenteric fat thickness and serum apolipoproteins in patients with peripheral arterial occlusive disease

BACKGROUND: Visceral fat possesses the most detrimental potential for cardiovascular morbidity through the release of adipokines, as well as metabolic and proinflammatory mediators, which adversely affect metabolic and vascular homeostasis. Among the different types of visceral adipose tissue, mesenteric fat is considered particularly detrimental, due to its close proximity to the portal circulation, affecting directly the liver, which is the main regulator of body metabolic homeostasis. Mesenteric fat can be reliably estimated using abdominal ultrasonography, the only available imaging method able to depict individual mesenteric leaves. Aim of the present study was to investigate the correlation of mesenteric fat thickness (MFT) with serum apolipoprotein levels in patients undergoing digital subtraction angiography in a single center. METHODS: 35 male patients with peripheral arterial disease were examined. After careful examination of the periumbilical area, the mesenteric leaves were identified. The maximal distance between each pair of sequential leaves was measured, and the mean value of the three thickest leaves was determined as the mesenteric fat thickness. Six apolipoprotein fasting serum concentrations were measured using a Luminex proteomics platform (xMAP Multiplex immunoassay): apolipoprotein A-I (apoAI), apolipoprotein A-II (apoAII), apolipoprotein B (apoB), apolipoprotein C-II (apoCII), apolipoprotein C-III (apoCIII) and apolipoprotein E (apoE). RESULTS: MFT correlated with apoAII and apoB serum concentrations. The correlations with apoAII and apoB remained significant following correction for BMI. No correlations were noted between MFT and serum apoAI, apoCII, apoCIII or apoE levels before or after adjustment for BMI. CONCLUSIONS: Our study indicates that MFT is significantly correlated with the concentration of atherogenic low density lipoproteins particles, as well as with apoAII, a determinant of free fatty acids levels. No correlation was observed between mesenteric fat thickness and very low density lipoprotein or chylomicron particles concentration

Investigating drivers' visual search strategies : towards an efficient training intervention

Road crashes are the main cause of death of young people in the developed world. The factors that cause traffic crashes are numerous; however, most researchers agree that a lack of driving experience is a major contributing factor. Another reason that has been reported for the increased crashes is that novice drivers have not developed the optimum visual search strategies of their more experienced counterparts. Although several training interventions have tried to improve scanning of novice drivers, they have limited success. The aims of this Thesis are to identify some parameters that influence visual search and to develop an efficient training intervention that will improve drivers’ visual skills. In Experiment 1 an image-based questionnaire was used to assess driving instructors’ and novice drivers’ priority ratings to different areas of the driving scene. Results showed that for both groups the opinions regarding visual field prioritisation were highly consistent when compared to chance. Despite the rating consistencies, group differences were found, across all scenarios with “Rear View Mirrors” being the visual field with the most frequent observed group differences. Certain categories (“Road Ahead” and “Mirrors”) were highly ranked across all scenarios, while other categories were more scenario specific. In Experiments 2 ;3 a novel experimental paradigm was used to investigate the interaction bottom-up and top-down influences upon drivers’ visual attention. Analysis showed that participants’ fixation locations had a stronger relationship with where participants clicked (top down) than with saliency peaks (bottom up). In Experiments 4 ;5 the difference in eye movements between driving instructors and learner drivers was examined during simulated driving. Results showed that driving instructors had an increased sampling rate, shorter processing time and broader scanning of the road than learner drivers. Scenario-specific analysis showed that instructors fixated more than learners on side mirrors while learners showed higher visual allocation to the rear view mirror. It was also found that poor visibility conditions and especially rain decrease the effectiveness of drivers’ visual search. Finally in Experiments 6, 7 ;8 we asked how we can improve learner drivers’ visual skills. Results from Experiments 6 ;7 demonstrated that the ability to distinguish between the eye movements of learner drivers and driving instructors improved as the number of objective differences between the two groups increased across specific scenarios. In Experiment 8 a pilot study showed that a scenario specific training intervention can improve certain aspects of learner drivers’ visual skills. The findings of this Thesis have both theoretical and practical implications regarding drivers’ visual search.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Investigating drivers’ visual search strategies: towards an efficient training intervention

Road crashes are the main cause of death of young people in the developed world. The factors that cause traffic crashes are numerous; however, most researchers agree that a lack of driving experience is a major contributing factor. Another reason that has been reported for the increased crashes is that novice drivers have not developed the optimum visual search strategies of their more experienced counterparts. Although several training interventions have tried to improve scanning of novice drivers, they have limited success. The aims of this Thesis are to identify some parameters that influence visual search and to develop an efficient training intervention that will improve drivers’ visual skills. In Experiment 1 an image-based questionnaire was used to assess driving instructors’ and novice drivers’ priority ratings to different areas of the driving scene. Results showed that for both groups the opinions regarding visual field prioritisation were highly consistent when compared to chance. Despite the rating consistencies, group differences were found, across all scenarios with “Rear View Mirrors” being the visual field with the most frequent observed group differences. Certain categories (“Road Ahead” and “Mirrors”) were highly ranked across all scenarios, while other categories were more scenario specific. In Experiments 2 & 3 a novel experimental paradigm was used to investigate the interaction bottom-up and top-down influences upon drivers’ visual attention. Analysis showed that participants’ fixation locations had a stronger relationship with where participants clicked (top down) than with saliency peaks (bottom up). In Experiments 4 & 5 the difference in eye movements between driving instructors and learner drivers was examined during simulated driving. Results showed that driving instructors had an increased sampling rate, shorter processing time and broader scanning of the road than learner drivers. Scenario-specific analysis showed that instructors fixated more than learners on side mirrors while learners showed higher visual allocation to the rear view mirror. It was also found that poor visibility conditions and especially rain decrease the effectiveness of drivers’ visual search. Finally in Experiments 6, 7 & 8 we asked how we can improve learner drivers’ visual skills. Results from Experiments 6 & 7 demonstrated that the ability to distinguish between the eye movements of learner drivers and driving instructors improved as the number of objective differences between the two groups increased across specific scenarios. In Experiment 8 a pilot study showed that a scenario specific training intervention can improve certain aspects of learner drivers’ visual skills. The findings of this Thesis have both theoretical and practical implications regarding drivers’ visual search