Fusion of Knowledge-Based and Data-Driven Approaches to Grammar Induction

Georgiladakis S, Unger C, Iosif E, et al. Fusion of Knowledge-Based and Data-Driven Approaches to Grammar Induction. In: Fifteenth Annual Conference of the International Speech Communication Association. 2014.Using different sources of information for grammar induction results in grammars that vary in coverage and precision. Fusing such grammars with a strategy that exploits their strengths while minimizing their weaknesses is expected to produce grammars with superior performance. We focus on the fusion of grammars produced using a knowledge-based approach using lexicalized ontologies and a data-driven approach using semantic similarity clustering. We propose various algorithms for finding the map- ping between the (non-terminal) rules generated by each gram- mar induction algorithm, followed by rule fusion. Three fusion approaches are investigated: early, mid and late fusion. Results show that late fusion provides the best relative F-measure per- formance improvement by 20%

Factors associated with disease evolution in Greek patients with inflammatory bowel disease

BACKGROUND: The majority of Crohn's disease patients with B1 phenotype at diagnosis (i.e. non-stricturing non-penetrating disease) will develop over time a stricturing or a penetrating pattern. Conflicting data exist on the rate of proximal disease extension in ulcerative colitis patients with proctitis or left-sided colitis at diagnosis. We aimed to study disease evolution in Crohn's disease B1 patients and ulcerative colitis patients with proctitis and left-sided colitis at diagnosis. METHODS: 116 Crohn's disease and 256 ulcerative colitis patients were followed-up for at least 5 years after diagnosis. Crohn's disease patients were classified according to the Vienna criteria. Data were analysed actuarially. RESULTS: B1 phenotype accounted for 68.9% of Crohn's disease patients at diagnosis. The cumulative probability of change in disease behaviour in B1 patients was 43.6% at 10 years after diagnosis. Active smoking (Hazard Ratio: 3.01) and non-colonic disease (non-L2) (Hazard Ratio: 3.01) were associated with behavioural change in B1 patients. Proctitis and left-sided colitis accounted for 24.2%, and 48.4% of ulcerative colitis patients at diagnosis. The 10 year cumulative probability of proximal disease extension in patients with proctitis and left-sided colitis was 36.8%, and 17.1%, respectively (p: 0.003). Among proctitis patients, proximal extension was more common in non-smokers (Hazard Ratio: 4.39). CONCLUSION: Classification of Crohn's disease patients in B1 phenotype should be considered as temporary. Smoking and non-colonic disease are risk factors for behavioural change in B1 Crohn's disease patients. Proximal extension is more common in ulcerative colitis patients with proctitis than in those with left-sided colitis. Among proctitis patients, proximal extension is more common in non-smokers

Optimisation of Radiation Exposure to Gastroenterologists and Patients during Therapeutic ERCP

This study intended to optimize the radiation doses for gastroenterologists and patients during therapeutic endoscopic retrograde cholangiopancreatography (ERCP) and to compare the doses based on available data obtained by other researchers. A total of 153 patients were studied in two Gastroenterology Departments, (group A, 111; group B, 42). Thermoluminescent dosimeters (TLD) were used to measure the staff and patients entrance surface air kerma (ESAK) at different body sites. The mean ESAK and effective doses per procedure were estimated to be 68.75 mGy and 2.74 mSv, respectively. Staff was exposed to a heterogonous doses. The third examiner (trainee) was exposed to a high dose compared with other examiners because no shield was located to protect him from stray radiation. Patients and examiners doses were lower compared to the lowest values found in previous studies taking into consideration the heterogeneity of patients and equipment. Staff doses during ERCP are within the safety limit in the light of the current practice

Reduction of Radiation Doses to Patients and Staff During Endoscopic Retrograde Cholangiopancreatography

Background/Aim: Endoscopic retrograde cholangiopancreatography (ERCP) is associated with a considerable radiation exposure for patients and staff. While optimization of the radiation dose is recommended, few studies have been published. The purpose of this study has been to measure patient and staff radiation dose, to estimate the effective dose and radiation risk using digital fluoroscopic images. Entrance skin dose (ESD), organ and effective doses were estimated for patients and staff. Materials and Methods: Fifty-seven patients were studied using digital X-ray machine and thermoluminescent dosimeters (TLD) to measure ESD at different body sites. Organ and surface dose to specific radiosensitive organs was carried out. The mean, median, minimum, third quartile and the maximum values are presented due to the asymmetry in data distribution. Results: The mean ESD, exit and thyroid surface dose were estimated to be 75.6 mGy, 3.22 mGy and 0.80 mGy, respectively. The mean effective dose for both gastroenterologist and assistant is 0.01 mSv. The mean patient effective dose was 4.16 mSv, and the cancer risk per procedure was estimated to be 2 × 10 -5 . Conclusion: ERCP with fluoroscopic technique demonstrate improved dose reduction, compared to the conventional radiographic based technique, reducing the surface dose by a factor of 2, without compromising the diagnostic findings. The radiation absorbed doses to the different organs and effective doses are relatively low