To resolve the ontology understanding problem, the structural features and the potential important terms of a large-scale ontology are investigated from the perspective of complex networks analysis. Through the empiri...To resolve the ontology understanding problem, the structural features and the potential important terms of a large-scale ontology are investigated from the perspective of complex networks analysis. Through the empirical studies of the gene ontology with various perspectives, this paper shows that the whole gene ontology displays the same topological features as complex networks including "small world" and "scale-free",while some sub-ontologies have the "scale-free" property but no "small world" effect.The potential important terms in an ontology are discovered by some famous complex network centralization methods.An evaluation method based on information retrieval in MEDLINE is designed to measure the effectiveness of the discovered important terms.According to the relevant literature of the gene ontology terms,the suitability of these centralization methods for ontology important concepts discovering is quantitatively evaluated.The experimental results indicate that the betweenness centrality is the most appropriate method among all the evaluated centralization measures.展开更多
Background: Direct ZN (Ziehl-Neelsen) sputum smear microscopy for diagnosis of TB (tuberculosis) has low sensitivity, especially in TB/HIV co-infected patients. Sputum concentration by bleach (NaOCI) with sedim...Background: Direct ZN (Ziehl-Neelsen) sputum smear microscopy for diagnosis of TB (tuberculosis) has low sensitivity, especially in TB/HIV co-infected patients. Sputum concentration by bleach (NaOCI) with sedimentation has been used to increase the sensitivity of sputum smear microscopy in many settings but with varying results. Objective: To determine whether bleach plus centrifugation significantly improves the detection of AFB (acid-fast bacilli) in ZN smear-negative sputum specimens. Methods: Three hundred and seventy sputum specimens were collected from new TB suspects attending a Nairobi referral district hospital and processed for direct microscopy using ZN technique and culture on Lowenstein Jensen Media. All smear-negative specimens were treated with 3.5% bleach and left to stand for 30 min before centrifugation. The bleach treated smears were processed and examined using ZN technique. Results: Of the 370 specimens, 200 (54%) were positive culture. The number of sputum samples that were smear-positive by direct ZN was 138 (37.2%), with a sensitivity of 66%. After treatment of direct ZN smear-negative specimens with 3.5% bleach and centrifugation, the total number of AFB smear-positive samples increased to 171 with an increase in sensitivity of 66% to 81.1% (15.1%). Conclusion: In this study, bleach with centrifugation significantly increased the yield of sputum smear microscopy. Further evaluation of these techniques in routine programmes is required especially in settings where the burden of TB/HIV is high.展开更多
Axial age theory suggests that a major transformation of thought occurred across several civilisations, including ancient Greece, in the period 800-200 BCE. This paper questions whether any such transformation can be ...Axial age theory suggests that a major transformation of thought occurred across several civilisations, including ancient Greece, in the period 800-200 BCE. This paper questions whether any such transformation can be identified in ancient Greece. It focuses on texts associated with "mystery religions" and the works of Presocratic philosophers as potential evidence for transformation. It demonstrates that there was a continuity of thought throughout the period, and that "rationality" was never seen to be in conflict with "traditional religious ideas".展开更多
基金The National Basic Research Program of China (973Program) (No.2005CB321802)Program for New Century Excellent Talents in University (No.NCET-06-0926)the National Natural Science Foundation of China (No.60873097,90612009)
文摘To resolve the ontology understanding problem, the structural features and the potential important terms of a large-scale ontology are investigated from the perspective of complex networks analysis. Through the empirical studies of the gene ontology with various perspectives, this paper shows that the whole gene ontology displays the same topological features as complex networks including "small world" and "scale-free",while some sub-ontologies have the "scale-free" property but no "small world" effect.The potential important terms in an ontology are discovered by some famous complex network centralization methods.An evaluation method based on information retrieval in MEDLINE is designed to measure the effectiveness of the discovered important terms.According to the relevant literature of the gene ontology terms,the suitability of these centralization methods for ontology important concepts discovering is quantitatively evaluated.The experimental results indicate that the betweenness centrality is the most appropriate method among all the evaluated centralization measures.
文摘Background: Direct ZN (Ziehl-Neelsen) sputum smear microscopy for diagnosis of TB (tuberculosis) has low sensitivity, especially in TB/HIV co-infected patients. Sputum concentration by bleach (NaOCI) with sedimentation has been used to increase the sensitivity of sputum smear microscopy in many settings but with varying results. Objective: To determine whether bleach plus centrifugation significantly improves the detection of AFB (acid-fast bacilli) in ZN smear-negative sputum specimens. Methods: Three hundred and seventy sputum specimens were collected from new TB suspects attending a Nairobi referral district hospital and processed for direct microscopy using ZN technique and culture on Lowenstein Jensen Media. All smear-negative specimens were treated with 3.5% bleach and left to stand for 30 min before centrifugation. The bleach treated smears were processed and examined using ZN technique. Results: Of the 370 specimens, 200 (54%) were positive culture. The number of sputum samples that were smear-positive by direct ZN was 138 (37.2%), with a sensitivity of 66%. After treatment of direct ZN smear-negative specimens with 3.5% bleach and centrifugation, the total number of AFB smear-positive samples increased to 171 with an increase in sensitivity of 66% to 81.1% (15.1%). Conclusion: In this study, bleach with centrifugation significantly increased the yield of sputum smear microscopy. Further evaluation of these techniques in routine programmes is required especially in settings where the burden of TB/HIV is high.
文摘Axial age theory suggests that a major transformation of thought occurred across several civilisations, including ancient Greece, in the period 800-200 BCE. This paper questions whether any such transformation can be identified in ancient Greece. It focuses on texts associated with "mystery religions" and the works of Presocratic philosophers as potential evidence for transformation. It demonstrates that there was a continuity of thought throughout the period, and that "rationality" was never seen to be in conflict with "traditional religious ideas".