Comparative study on the detection of early dental caries using thermo-photonic lock-in imaging and optical coherence tomography

Early detection of dental caries is known to be the key to the effectiveness of therapeutic and preventive approaches in dentistry. However, existing clinical detection techniques, such as radiographs, are not sufficiently sensitive to detect and monitor the progression of caries at early stages. As such, in recent years, several optics-based imaging modalities have been proposed for the early detection of caries. The majority of these techniques rely on the enhancement of light scattering in early carious lesions, while a few of them are based on the enhancement of light absorption at early caries sites. In this paper, we report on a systemic comparative study on the detection performances of optical coherence tomography (OCT) and thermophotonic lock-in imaging (TPLI) as representative early caries detection modalities based on light scattering and absorption, respectively. Through controlled demineralization studies on extracted human teeth and µCT validation experiments, several detection performance parameters of the two modalities such as detection threshold, sensitivity and specificity have been qualitatively analyzed and discussed. Our experiment results suggests that both modalities have sufficient sensitivity for the detection of well-developed early caries on occlusal and smooth surfaces; however, TPLI provides better sensitivity and detection threshold for detecting very early stages of caries formation, which is deemed to be critical for the effectiveness of therapeutic and preventive approaches in dentistry. Moreover, due to the more specific nature of the light absorption contrast mechanism over light scattering, TPLI exhibits better detection specificity, which results in less false positive readings and thus allows for the proper differentiation of early caries regions from the surrounding intact areas. The major shortcoming of TPLI is its inherent depth-integrated nature, prohibiting the production of depth-resolved/B-mode like images. The outcomes of this research justify the need for a light-absorption based imaging modality with the ability to produce tomographic and depth-resolved images, combining the key advantages of OCT and TPLI.York University Librarie

A generalized approach for compliant mechanism design using the synthesis with compliance method, with experimental validation

Compliant mechanisms offer numerous advantages over their rigid-body counterparts. The synthesis with compliance technique synthesizes compliant mechanisms for conventional rigid-body synthesis tasks with energy/torque specifications at precision positions. In spite of its usefulness, the method suffers from some limitations/problems. The purpose of this work is to investigate these sensitivities with the synthesis with compliance technique and improve upon existing method. A new, simple but efficient, method for synthesis with compliance using an optimization approach is proposed, and its usefulness and simplicity demonstrated over the existing method. The strongly and weakly coupled system of kinematic and energy/torque equations in the existing method has been studied, and the new method is made simple by removing the strong coupling between these sets of equations. All synthesis cases are solved by treating them as though they are governed by weakly coupled systems of equations. Representative examples of different synthesis tasks are presented. The results are verified with finite element analysis software ABAQUS® and ANSYS® by means of coupler curve/precision position comparisons, and stored energy comparisons. An experimental setup has been devised to perform experiments on compliant mechanisms for validation purposes. The results obtained using the Pseudo-Rigid-Body Model (PRBM) for compliant mechanism synthesis match closely with experimental and finite element analysis (FEA) results, and hence reinforce the utility of the synthesis with compliance method using the PRBM in compliant mechanism synthesis --Abstract, page iii

A Study on Coporate Governance and the Financial Performance of Selected Indian Companies

Good governance is the expectations of every stakeholder, specially, shareholder. Governance is related with the controlling of the activity and controlling of the corporate sector can be termed as corporate governance. But the implementation of ‘Corporate Governance’ is not that much simple as its meaning. Corporate Governance is recently emerged concept and has taken the attention of each and every country, investors and corporate professionals. Corporate governance is the practice, which requires transparency, accountability and good performance from the corporate executives. It has, its strong base from the internal management of company, to the shareholders’ value as well as corporate social responsibility. Reasons for selecting corporate level units which are functioning in India is to find out whether corporate governance is actually being practiced by the corporate level executives or not

A Cross Sectional Survey Study to find out the role of Avarana as a diagnostic tool in General Practice with special reference to Madhumeha

Srotas and Avarana are essential factors of Samprapti of almost all the Nija roga. Avarana is an underestimated and neglected aspect of Roga Samprapti. Therefore a survey study was conducted to gather data about understanding of Avarana w.s.r. to Madhumeha (Diabetes Mellitus). A dully prepared questionnaire pro forma on Avarana have been proposed and send it to 83 Ayurvedic doctors from NIA & across India to collect data. Questionnaire included choices of different samprapti ghataka like Agni, Dosha, Dushya, Srotasa, Ama, Avarana, Nidana and response against question “Is Avarana an important samprapti ghataka in day to day practice?On a small study of NIA it was found that 39.76% consultants included Avarana, 66.27% included dosha vighatana, 56.63% included dushya, 54.22% included Agni 53.01% included Ama, 48.19% included srotasa and 36.15% included nidana as a samprapti ghataka for diagnosing the disease in day to day practice. Response against question Is Avarana an important samprapti ghataka in day to day practice 62 (74.70%) consultants answered Yes, but Avarana the records show that only 28 (33.74%) were using Avarana as an important samprapti ghataka, 11 (13.25%) were seeing daily >10 patients in their OPD/IPD and 18 (21.69%) were unable to explain why Avarana should be an important samprapti ghataka. Out of rest 21 (25.30%) answered No, 14 (16.87%) were unable to explain their response & 7 (8.43%) cited difficulty in understanding Avarana in diagnosis in day to day practice.On an average it was found that 33.41% patients were consulted in OPD and 2.43% in IPD. Most of the consultants use only 7 samprapti ghataka for diagnosis of diseases. 62 (74.70%) consultants answered ‘Yes’ in response to question (Is Avarana an important samprapti ghataka in day to day practice?), but no satisfactory explanation was given

Metaplastic Carcinoma of the Left Breast with Extensive Chondroid Differentiation

Metaplastic breast carcinoma is very rare neoplasm which contains mixture of carcinomatous (epithelial) and sarcomatous (mesenchymal) elements in variable proportion. Metaplastic carcinoma with chondroid differentiation is even rarer. We report a case of metaplastic carcinoma with extensive chondroid differentiation as there is paucity of information regarding pathological features and clinical outcomes for these rare tumors. Tumor had characteristic definite areas of classic infiltrating duct carcinoma with abundant chondromyxoid matrix, focal areas of chondrosarcoma and cartilagenous metaplasia. Tumour cells were immunoreactive for S-100, ER, and PR. When pathologist encounter breast tumor with chondroid differentiation, careful gross sampling, histopathology and immunoreactivity for mesenchymal and epithelial component are most useful to differentiate metaplastic carcinoma from malignant phylloides tumors and malignant adenomyoepithelioma

Development of a Hub and Spoke Model for Bus Transit Route Network Design

AbstractFor a large city bus transit service, a point to point route network, attempting to connect each node to every other node results in large number of routes in the network which makes it practically very complex to understand and operate the services. To overcome these limitations a different transit network design approach is required. A combination of traditional destination oriented routes along with direction oriented routes, which is called as Hub and Spoke network could be better for operating bus transit in large network. Previous research works done using hub-and-spoke model mainly concentrates on airline network, where the influencing factors and variables for network design could be substantially different than transit network. This paper presents an approach to develop hub and spoke route network for bus transit services. Whole process consists of obtaining potential hubs, finding optimum location of hubs and allocation of non-hub nodes to hub nodes, generating inter hub and intra-hub routes and the frequencies for running buses. The model developed in this study is tested on the Mandl's Swiss network of fifteen nodes. The Mandl's network is most widely used by many researchers to analyze their models developed for point to point bus transit route network. The results suggest noticeable savings in operator cost along with slight increase in user cost