Immunodiagnosis of tuberculosis: An update

Tuberculosis is still a major health problem in most developing countries and its incidence is rising in many developed countries. This resurgence has been attributed to the HIV epidemic and TB has been declared as a global health emergency by WHO in 1993. The diagnosis of tuberculosis mainly depends upon initial clinical suspicion and radiographic findings with subsequent bacteriological confirmation by sputum smear examination and culture. Lack of sensitivity in smear examination, non specificity of radiological findings, extended tum around time ofMycobacterium tuberculosis culture and difficulties in diagnosing paucibacillary, childhood and extrapulmonary tuberculosis has necessitated to explore the utility of immunodiagnosis of tuberculosis as a convenient and cost effective test to supplement clinical information for definite diagnosis. Many commercial tests are available in the market for diagnosis of TB. Most of these tests are based on the detection of IgG, IgA and IgM antibodies to specific mycobacterial antigen or mixture of antigens. Indigenous immunoassay systems have explored excretory-secretory ES-31 mycobacterial antigen for immunodiagnosis of TB. Many a time there is lack of consistent elevation in all the three Ig classes in active infection thus making it more important to determine the ideal antibody isotype assay for reliable diagnosis of tuberculosis and to save the costs of the patient for unnecessary investigations.     

Review of the Semiconductor Industry and Technology Roadmap

The semiconductor industry operates in a constant state of deflation. It is vital to our survival and progress in this knowledge era. The industry is extremely competitive and requires ongoing technological advances to improve performance while reducing costs to remain competitive. Gaining an understanding of important facets of this industry is essential. Besides knowing about semiconductor history, other aspects of interest include types of semiconductor products in the marketplace and their uses, typical semiconductor-chip making process, overall industry review and trends. One critical tool used by the industry to direct product and technology development is a technology roadmap. Review of the initial and current semiconductor technology roadmap would further enhance our understanding of semiconductor industry.     

Postgraduate conception of research methodology: implications for learning and teaching

This qualitative inquiry investigates postgraduate students’ conceptions of research methodology and how it contributes to their learning. It explores factors likely to motivate student choice of research methodology and challenges in understanding research methods. The research was carried out at research-intensive universities in New Zealand and in Malaysia with similar postgraduate programmes. Participants were enrolled in Masters and Ph.D. programmes. Findings revealed that participants share a recognition that research methodology is a significant body of knowledge in postgraduate education. However, there were noticeable differences in perspectives regarding what constitutes research methodology and whether or not it should be conceived as a discipline. To some participants, learning research methodology is less of a discipline but rather an acquisition of a set of isolated facts and skills without necessarily acquiring a deeper understanding of research. Furthermore, postgraduate students choose research methodology based on a number of factors such as familiarity with a method, methodological orientation of the primary supervisor, the domain of study, and the nature of research problems pursued. Participants reported that the key challenges they face in understanding research methodology include framing research questions, understanding the theory or literature and its role in shaping research outcomes, and difficulties in performing data analysis.     

Classical angular momentum of light: A paradox and its resolution

Angular momentum carried by a classical circularly polarized electromagnetic plane wave (light) appears to be identically zero inasmuch as its linear field-momentum density is directed along wave propagation, and, therefore, the angular momentum, being the integrated moment of the linear momentum density about an axis parallel to the direction of propagation, necessarily vanishes — in detail. This, however, contradicts the established fact that circularly polarized light does carry angular momentum that remains classically non-zero. The paradox is resolved in a physically transparent manner by treating this problem as that of a transversely bounded, and hence necessarily non-trans verse, electromagnetic wave propagating along a circular waveguide, in the limit as its radius tends to infinity. We get a non-zero angular momentum that bears the correct ratio to wave energy. This angular momentum derives essentially and exactly from the boundary conditions for the geometry considered. This is an interesting example of surface terms giving a volume (bulk) contribution, much as in the entirely different context of orbital diamagnetism, which was regarded as a surprise of theoretical physics by Rudolf Peierls.[1]     

On a Problem of Alaoglu and Erdős

Starting with an elementary problem that appeared in the Putnam mathematics competition, we proceed to discuss some techniques of transcendental number theory and prove the following result. If p, q, r are distinct primes and if c is a real number with the property that p^c, q^c, r^c are integers, then c must be a non-negative integer. The tools used are some linear algebra and complex analysis. The zero-density estimate method discussed here was used by Alan Baker to prove his celebrated theorem on linear forms in logarithms. The question as to whether we can replace three primes by two primes is an open question.     

Vulcanization of rubber

The chemical modifications that occur during vulcanization of rubber and methods for controlling the process are discussed.     

Beyond the Flipped Classroom: A Highly Interactive Cloud-Classroom (HIC) Embedded into Basic Materials Science Courses

The present study compares the highly interactive cloud-classroom (HIC) system with traditional methods of teaching materials science that utilize crystal structure picture or real crystal structure model, in order to examine its learning effectiveness across three dimensions: knowledge, comprehension and application. The aim of this study was to evaluate the (HIC) system, which incorporates augmented reality, virtual reality and cloud-classroom to teach basic materials science courses. The study followed a pretest–posttest quasi-experimental research design. A total of 92 students (aged 19–20 years), in a second-year undergraduate program, participated in this 18-week-long experiment. The students were divided into an experimental group and a control group. The experimental group (36 males and 10 females) was instructed utilizing the HIC system, while the control group (34 males and 12 females) was led through traditional teaching methods. Pretest, posttest, and delayed posttest scores were evaluated by multivariate analysis of covariance. The results indicated that participants in the experimental group who used the HIC system outperformed the control group, in the both posttest and delayed posttest, across three learning dimensions. Based on these results, the HIC system is recommended to be incorporated in formal materials science learning settings.     

Assessment of cortical bone microdamage following insertion of microimplants using optical coherence tomography: a preliminary study

Objectives

The study was done to evaluate the efficacy of optical coherence tomography (OCT), to detect and analyze the microdamage occurring around the microimplant immediately following its placement, and to compare the findings with micro-computed tomography (μCT) images of the samples to validate the result of the present study.

Methods

Microimplants were inserted into bovine bone samples. Images of the samples were obtained using OCT and μCT. Visual comparisons of the images were made to evaluate whether anatomical details and microdamage induced by microimplant insertion were accurately revealed by OCT.

Results

The surface of the cortical bone with its anatomical variations is visualized on the OCT images. Microdamage occurring on the surface of the cortical bone around the microimplant can be appreciated in OCT images. The resulting OCT images were compared with the μCT images. A high correlation regarding the visualization of individual microcracks was observed. The depth penetration of OCT is limited when compared to μCT.

Conclusions

OCT in the present study was able to generate high-resolution images of the microdamage occurring around the microimplant. Image quality at the surface of the cortical bone is above par when compared with μCT imaging, because of the inherent high contrast and high-resolution quality of OCT systems. Improvements in the imaging depth and development of intraoral sensors are vital for developing a real-time imaging system and integrating the system into orthodontic practice.