1,603 research outputs found
A mouse model of lamellar intrastromal femtosecond laser keratotomy: ultra-structural, inflammatory, and wound healing responses
Molecular Vision173005-3012MVEP
Paraoxonase 1 activity as a predictor of cardiovascular disease in type 2 diabetes
The role of paraoxonase 1 in cardiovascular disease complications in type 2 diabetes mellitus is not fully understood. We studied paraoxonase activity towards paraoxon in 188 non-diabetic and 140 diabetic subjects using general linear models and univariate analysis. Adjusting for age revealed a reduction in activity towards paraoxon was associated with a significant increase in risk (p=0.023) for cardiovascular disease complications in diabetic patients. Multivariate analysis of two plasma measures of paraoxonase activity using paraoxon and diazoxon also showed reduced paraoxonase activity towards paraoxon was associated with a significant increase in risk (p=0.045) for cardiovascular disease complications in diabetic patients. These analyses showed that a reduced paraoxonase activity towards paraoxon was associated with ethnicity. Based on multivariate analysis, subjects of Malay ethnic origin have significantly higher than expected activity (p=0.008, compared to Indians), towards paraoxon than subjects of Chinese origin who in turn had higher than expected paraoxonase activity (p=0.028, compared to Indians) Indian subjects
Impedimetric measurement of DNA–DNA hybridisation using microelectrodes with different radii for detection of methicillin resistant Staphylococcus aureus (MRSA)
Due to their electroanalytical advantages, microelectrodes are a very attractive technology for sensing and monitoring applications. One highly important application is measurement of DNA hybridisation to detect a wide range of clinically important phenomena, including single nucleotide polymorphisms (SNPs), mutations and drug resistance genes. The use of electrochemical impedance spectroscopy (EIS) for measurement of DNA hybridisation is well established for large electrodes but as yet remains relatively unexplored for microelectrodes due to difficulties associated with electrode functionalisation and impedimetric response interpretation. To shed light on this, microelectrodes were initially fabricated using photolithography and characterised electrochemically to ensure their responses matched established theory. Electrodes with different radii (50, 25, 15 and 5 µm) were then functionalised with a mixed film of 6-mercapto-1-hexanol and a thiolated single stranded ssDNA capture probe for a specific gene from the antibiotic resistant bacterium MRSA. The complementary oligonucleotide target from the mecA MRSA gene was hybridised with the surface tethered ssDNA probe. The EIS response was evaluated as a function of electrode radius and it was found that charge-transfer (RCT) was more significantly affected by hybridisation of the mecA gene than the non-linear resistance (RNL) which is associated with the steady state current. The discrimination of mecA hybridisation improved as electrode radius reduced with the RCT component of the response becoming increasingly dominant for smaller radii. It was possible to utilise these findings to produce a real time measurement of oligonucleotide binding where changes in RCT were evident one minute after nanomolar target addition. These data provide a systematic account of the effect of microelectrode radius on the measurement of hybridisation, providing insight into critical aspects of sensor design and implementation for the measurement of clinically important DNA sequences. The findings open up the possibility of developing rapid, sensitive DNA based measurements using microelectrodes
Barriers to colorectal cancer screening in Asia: A systematic review
Purpose: Colorectal cancer (CRC) is among the top five cancers afflicting both men and women globally. Once predominantly a Western disease, it has begun to rise in Asian countries as well. This systematic review aims to compile and analyze the various barriers towards colorectal cancer screening in Asia, and to determine if the barriers are consistent throughout the continent.Methods: Article Inclusion criteria for based on year of publication from year 2008 till 2015, has been conducted in Asia, and written in English language. A total of 23 studies were included in this review, chosen via primary search of journal websites and databases, and a secondary search through the reference lists of eligible articles.Results: It was found that major barriers of colorectal cancer screening are; poor education/knowledge, negative perceptions towards screening, aversion to test results, financial constraints, time constraints, lack of physicians’ recommendation, limited/difficult access to screening locations, fatalistic beliefs, low perceived risks, language barriers, confidence in traditional medicine/distrust in Western medicine,ignorance and old age.Conclusion: Lack of knowledge/education is the most critical barrier that is linked to a majority of other barriers that can hinder a person from undergoing CRC screening for early prevention, detection and treatment. Majority of these barriers encountered regarding the poor rates of CRC screening are similar across countries in Asia.Keywords: Colorectal cancer screening, Barrier, Knowledge, Criteria for eligibilit
Flux ropes in the Hermean magnetotail: Distribution, properties, and formation
An automated method was applied to identify magnetotail flux rope encounters in MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) magnetometer data. The method identified significant deflections of the northâ south component of the magnetic field coincident with enhancements in the total field or dawnâ dusk component. Two hundred fortyâ eight flux ropes are identified that possess wellâ defined minimum variance analysis (MVA) coordinate systems, with clear rotations of the field. Approximately 30% can be well approximated by the cylindrically symmetric, linearly forceâ free model. Flux ropes are most common moving planetward, in the postmidnight sector. Observations are intermittent, with the majority (61%) of plasma sheet passages yielding no flux ropes; however, the peak rate of flux ropes during a reconnection episode is â ¼5Â minâ 1. Overall, the peak postmidnight rate is â ¼0.25Â minâ 1. Only 25% of flux ropes are observed in isolation. The radius of flux ropes is comparable to the ion inertial length within Mercury’s magnetotail plasma sheet. No clear statistical separation is observed between tailward and planetward moving flux ropes, suggesting the nearâ Mercury neutral line (NMNL) is highly variable. Flux ropes are more likely to be observed if the preceding lobe field is enhanced over background levels. A very weak correlation is observed between the flux rope core field and the preceding lobe field orientation; a stronger relationship is found with the orientation of the field within the plasma sheet. The core field strength measured is â ¼6 times stronger than the local dawnâ dusk plasma sheet magnetic field.Key PointsTwo hundred fortyâ eight flux ropes identified in Mercury’s magnetotail (74 cylindrical and linearly forceâ free)Flux ropes most commonly observed by MESSENGER postmidnight, moving planetwardFlux ropes observed intermittently, but most often when the preceding lobe field is enhancedPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138858/1/jgra53697_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138858/2/jgra53697.pd
Colorectal cancer screening
Estudo referente a duas noticias veiculadas na imprensa virtual, analisada com base em conceitos da Teoria da Comunicação e correlacionadas a alguns casos de infração ética aplicada pelo Conselho Regional de Enfermagem do Rio de Janeiro. As considerações finais apontaram para quatro eixos que visam colaborar com o aumento do cuidado seguro prestado à clientela
Key Success Factors and Guidance for International Collaborative Design Projects
In the built environment (BE) sector, the co-creation process of design demands understanding of requirements (as viewed by parties involved), mobilisation of tacit knowledge, negotiation, and complex exchange of information. The need to collaborate over distance has further exacerbated the complexity of the process, and, in itself, represents a significant challenge for BE professionals who are increasingly expected to undertake this process within globally distributed virtual teams. The research aims to identify key success factors and develop guidance for international collaborative design projects, via the implementation of collaborative design courses in UK and Canadian universities over three academic years. Questionnaire surveys, focus groups, observation of online meetings, personal reflections provided data for the analysis. The findings reveal the significance of the perceived risk of collaboration and a difference in preferred communication mode between architects and civil/structural engineers. These findings suggest the impact of training in the subject discipline, and that the opportunity for co-located working has helped the development of trust. The guidance is aimed at BE educators who wish to implement this activity in their courses
Incidental detection of an occult oral malignancy with autofluorescence imaging: a case report
BACKGROUND: Autofluorescence imaging is used widely for diagnostic evaluation of various epithelial malignancies. Cancerous lesions display loss of autofluorescence due to malignant changes in epithelium and subepithelial stroma. Carcinoma of unknown primary site presents with lymph node or distant metastasis, for which the site of primary tumour is not detectable. We describe here the use of autofluorescence imaging for detecting a clinically innocuous appearing occult malignancy of the palate which upon pathological examination was consistent with a metastatic squamous cell carcinoma.
CASE DESCRIPTION: A submucosal nodule was noted on the right posterior hard palate of a 59-year-old white female during clinical examination. Examination of this lesion using a multispectral oral cancer screening device revealed loss of autofluorescence at 405 nm illumination. An excisional biopsy of this nodule, confirmed the presence of a metastatic squamous cell carcinoma. Four years ago, this patient was diagnosed with metastatic squamous cell carcinoma of the right mid-jugular lymph node of unknown primary. She was treated with external beam irradiation and remained disease free until current presentation.
CONCLUSION: This case illustrates the important role played by autofluorescence tissue imaging in diagnosing a metastatic palatal tumour that appeared clinically innocuous and otherwise would not have been biopsied
Score Fusion by Maximizing the Area under the ROC Curve
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-02172-5_61Information fusion is currently a very active research topic
aimed at improving the performance of biometric systems. This paper
proposes a novel method for optimizing the parameters of a score fusion
model based on maximizing an index related to the Area Under the ROC
Curve. This approach has the convenience that the fusion parameters are
learned without having to specify the client and impostor priors or the
costs for the different errors. Empirical results on several datasets show
the effectiveness of the proposed approach.Work supported by the Spanish projects DPI2006-15542-C04 and TIN2008-04571 and the Generalitat Valenciana - Consellería d’Educació under an FPI scholarship.Villegas Santamaría, M.; Paredes Palacios, R. (2009). Score Fusion by Maximizing the Area under the ROC Curve. En Pattern Recognition and Image Analysis: 4th Iberian Conference, IbPRIA 2009 Póvoa de Varzim, Portugal, June 10-12, 2009 Proceedings. Springer Verlag (Germany). 473-480. https://doi.org/10.1007/978-3-642-02172-5_61S473480Toh, K.A., Kim, J., Lee, S.: Biometric scores fusion based on total error rate minimization. Pattern Recognition 41(3), 1066–1082 (2008)Jain, A., Nandakumar, K., Ross, A.: Score normalization in multimodal biometric systems. Pattern Recognition 38(12), 2270–2285 (2005)Gutschoven, B., Verlinde, P.: Multi-modal identity verification using support vector machines (svm). In: Proceedings of the Third International Conference on Information Fusion. FUSION 2000, vol. 2, pp. THB3/3–THB3/8 (July 2000)Ma, Y., Cukic, B., Singh, H.: A classification approach to multi-biometric score fusion. In: Kanade, T., Jain, A., Ratha, N.K. (eds.) AVBPA 2005. LNCS, vol. 3546, pp. 484–493. Springer, Heidelberg (2005)Maurer, D.E., Baker, J.P.: Fusing multimodal biometrics with quality estimates via a bayesian belief network. Pattern Recogn. 41(3), 821–832 (2008)Ling, C.X., Huang, J., Zhang, H.: Auc: a statistically consistent and more discriminating measure than accuracy. In: Proc. of IJCAI 2003, pp. 519–524 (2003)Yan, L., Dodier, R.H., Mozer, M., Wolniewicz, R.H.: Optimizing classifier performance via an approximation to the wilcoxon-mann-whitney statistic. In: Machine Learning, Proceedings of the Twentieth International Conference (ICML 2003), Washington, DC, USA, pp. 848–855. AAAI Press, Menlo Park (2003)Marrocco, C., Molinara, M., Tortorella, F.: Exploiting auc for optimal linear combinations of dichotomizers. Pattern Recogn. Lett. 27(8), 900–907 (2006)Marrocco, C., Duin, R.P.W., Tortorella, F.: Maximizing the area under the roc curve by pairwise feature combination. Pattern Recogn. 41(6), 1961–1974 (2008)Paredes, R., Vidal, E.: Learning prototypes and distances: a prototype reduction technique based on nearest neighbor error minimization. Pattern Recognition 39(2), 180–188 (2006)Villegas, M., Paredes, R.: Simultaneous learning of a discriminative projection and prototypes for nearest-neighbor classification. In: IEEE Conference on Computer Vision and Pattern Recognition. CVPR 2008, pp. 1–8 (2008)Nandakumar, K., Chen, Y., Dass, S.C., Jain, A.: Likelihood ratio-based biometric score fusion. IEEE Transactions on Pattern Analysis and Machine Intelligence 30(2), 342–347 (2008)Poh, N., Bengio, S.: A score-level fusion benchmark database for biometric authentication. In: Kanade, T., Jain, A., Ratha, N.K. (eds.) AVBPA 2005. LNCS, vol. 3546, pp. 1059–1070. Springer, Heidelberg (2005)National Institute of Standards and Technology: NIST Biometric Scores Set - Release 1 (BSSR1) (2004), http://www.itl.nist.gov/iad/894.03/biometricscores/Bengio, S., Mariéthoz, J., Keller, M.: The expected performance curve. In: Proceedings of the Second Workshop on ROC Analysis in ML, pp. 9–16 (2005
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