8 resultados para Collective subject discourse technique

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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The various meanings of discourse connectives like while and however are difficult to identify and annotate, even for trained human annotators. This problem is all the more important that connectives are salient textual markers of cohesion and need to be correctly interpreted for many NLP applications. In this paper, we suggest an alternative route to reach a reliable annotation of connectives, by making use of the information provided by their translation in large parallel corpora. This method thus replaces the difficult explicit reasoning involved in traditional sense annotation by an empirical clustering of the senses emerging from the translations. We argue that this method has the advantage of providing more reliable reference data than traditional sense annotation. In addition, its simplicity allows for the rapid constitution of large annotated datasets.

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OBJECT: Patients with complex craniocerebral pathophysiologies such as giant cerebral aneurysms, skull base tumors, and/or carotid artery occlusive disease are candidates for a revascularization procedure to augment or preserve cerebral blood flow. However, the brain is susceptible to ischemia, and therefore the excimer laser-assisted nonocclusive anastomosis (ELANA) technique has been developed to overcome temporary occlusion. Harvesting autologous vessels of reasonable quality, which is necessary for this technique, may at times be problematic or impossible due to the underlying systemic vascular disease. The use of artificial vessels is therefore an alternative graft for revascularization. Note, however, that it is unknown to what degree these grafts are subject to occlusion using the ELANA anastomosis technique. Therefore, the authors studied the ELANA technique in combination with an expanded polytetrafluoroethylene (ePTFE) graft. METHODS: The experimental surgeries involved bypassing the abdominal aorta in the rabbit. Ten rabbits were subjected to operations representing 20 ePTFE graft-ELANA end-to-side anastomoses. Intraoperative blood flow, followup angiograms, and long-term histological characteristics were assessed 75, 125, and 180 days postoperatively. Angiography results proved long-term patency of ePTFE grafts in all animals at all time points studied. Data from the histological analysis showed minimal intimal reaction at the anastomosis site up to 180 days postoperatively. Endothelialization of the ePTFE graft was progressive over time. CONCLUSIONS: The ELANA technique in combination with the ePTFE graft seems to have favorable attributes for end-to-side anastomoses and may be suitable for bypass procedures.

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OBJECTIVES: The objectives of this systematic review were to assess the survival rate of implants placed in sites with transalveolar sinus floor elevation. MATERIAL AND METHODS: An electronic search was conducted to identify prospective and retrospective cohort studies on transalveolar sinus floor elevation, with a mean follow-up time of at least 1 year after functional loading. Failure and complication rates were analyzed using random-effects Poisson regression models to obtain summary estimates/ year proportions. RESULTS: The search provided 849 titles. Full-text analysis was performed for 176 articles, resulting in 19 studies that met the inclusion criteria. Meta-analysis of these studies indicated an estimated annual failure rate of 2.48% (95% confidence interval (95% CI): 1.37-4.49%) translating to an estimated survival rate of 92.8% (95% CI): 87.4-96.0%) for implants placed in transalveolarly augmented sinuses, after 3 years in function. Furthermore, subject-based analysis revealed an estimated annual failure of 3.71% (95% CI: 1.21-11.38%), translating to 10.5% (95% CI: 3.6-28.9%) of the subjects experiencing implant loss over 3 years. CONCLUSION: Survival rates of implants placed in transalveolar sinus floor augmentation sites are comparable to those in non-augmented sites. This technique is predictable with a low incidence of complications during and post-operatively.

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In the last century, studies established the origin of pulmonary fat embolism (PFE) and identified mechanical trauma as main source for PFE. This prospective study focused on determining a possible influence of cardiopulmonary resuscitation (CPR), in the context of an aging population, on the occurrence of PFE. Lung tissue samples from 256 bodies were examined using the twin-edged knife technique without preliminary fixation but after staining with Sudan III. PFE grading was determined according to Falzi and performed at a 10× magnification. For statistical analysis, bodies were grouped by age, gender, and putrefaction and categorized following whether they had experienced trauma, CPR, the combination of both, or no mechanical impact. There was a significant correlation of trauma, CPR, and the combination of both to PFE but no noticeable influence of gender or putrefaction. An age over 70 years promotes a PFE due to resuscitation.

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Self-administered online surveys provide a higher level of privacy protection to respondents than surveys administered by an interviewer. Yet, studies show that asking sensitive questions is problematic also in self-administered mode. Because respondents might not be willing to reveal the truth and provide answers that are subject to social desirability bias, the validity of prevalence estimates of sensitive behaviors gained via online surveys can be challenged. A well-known method to combat these problems is the Randomized Response Technique (RRT). However, convincing evidence that the RRT provides more valid estimates than direct questioning in online mode is still lacking. Moreover, an alternative approach called the Crosswise Model (CM) has recently been suggested to overcome some of the deficiencies of the RRT. In the context of an online survey on plagiarism and cheating on exams among students of two Swiss universities (N = 6,494), we tested different implementations of the RRT and the CM and compared them to direct questioning using a randomized experimental design. Results reveal a poor performance of the RRT, which failed to elicit higher prevalence estimates than direct questioning. Using the CM however, significantly higher prevalence estimates were obtained making it a promising new alternative to the conventional RRT.

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Self-administered online surveys provide a higher level of privacy protection to respondents than surveys administered by an interviewer. Yet, studies indicate that asking sensitive questions is problematic also in self-administered surveys. Because respondents might not be willing to reveal the truth and provide answers that are subject to social desirability bias, the validity of prevalence estimates of sensitive behaviors from online surveys can be challenged. A well-known method to overcome these problems is the Randomized Response Technique (RRT). However, convincing evidence that the RRT provides more valid estimates than direct questioning in online surveys is still lacking. A new variant of the RRT called the Crosswise Model has recently been proposed to overcome some of the deficiencies of existing RRT designs. We therefore conducted an experimental study in which different implementations of the RRT, including two implementations of the crosswise model, were tested and compared to direct questioning. Our study is a large-scale online survey (N = 6,037) on sensitive behaviors by students such as cheating in exams and plagiarism. Results indicate that the crosswise-model RRT---unlike the other variants of RRT we evaluated---yields higher prevalence estimates of sensitive behaviors than direct questioning. Whether higher estimates are a sufficient condition for more valid results, however, remains questionable.

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Social desirability and the fear of sanctions can deter survey respondents from responding truthfully to sensitive questions. Self-reports on norm breaking behavior such as shoplifting, non-voting, or tax evasion may therefore be subject to considerable misreporting. To mitigate such misreporting, various indirect techniques for asking sensitive questions, such as the randomized response technique (RRT), have been proposed in the literature. In our study, we evaluate the viability of several variants of the RRT, including the recently proposed crosswise-model RRT, by comparing respondents’ self-reports on cheating in dice games to actual cheating behavior, thereby distinguishing between false negatives (underreporting) and false positives (overreporting). The study has been implemented as an online survey on Amazon Mechanical Turk (N = 6,505). Our results indicate that the forced-response RRT and the unrelated-question RRT, as implemented in our survey, fail to reduce the level of misreporting compared to conventional direct questioning. For the crosswise-model RRT, we do observe a reduction of false negatives (that is, an increase in the proportion of cheaters who admit having cheated). At the same time, however, there is an increase in false positives (that is, an increase in non-cheaters who falsely admit having cheated). Overall, our findings suggest that none of the implemented sensitive questions techniques substantially outperforms direct questioning. Furthermore, our study demonstrates the importance of distinguishing false negatives and false positives when evaluating the validity of sensitive question techniques.