Direct senstivity test for isoniazid.

IT is well known that the results of isoniazid sensitivity tests by the indirect method have prognostic significance in the treatment of tuberculosis with regimens containing isoniazid (Tuberculosis Chemotherapy Centre, Madras, 1960 ; Devadatta et al., 1961) ; the indirect method is, however, complex and time-consuming, and therefore not feasible in institutions with limited facilities. Direct sensitivity tests are attractive because they involve only one stage of handling (i.e. cultures need not be set up), are simpler and less expensive, and consume less time. Although the direct sensitivity test introduced by Middlebrook and co-workers (Middlebrook and Cohn, 1958 ; Russell and Middlebrook, 1961) using 7H10 agar medium yielded satisfactory results, it has certain disadvantages. Thus, the medium employed is expensive, the in are not readily available in this country and, in our experience at Madras, losses due to contamination can be considerable. This paper describes a direct sensitivity test for isoniaid using Lowenstein- Jensen medium, and compares the findings obtained by this method with those obtained by the indirect method

Effect of storage for three months at different temperatures on the sensitivity to streptomycin and isoniazid of cultures of tubercle bacilli

MAINTENANCE of bacterial strains by repeated subcultivation is both expensive, laborious and time-consuming ; moreover, there is always the possibility of contamination or of differential selection of sub-strains with specific properties. In consequence, several methods, such as freeze-drying or storage at low temperatures, have been introduced by which bacterial cultures can be kept alive for long periods with their reproductive and metabolic activity at an extremely low level. However, information is rather sparse on such methods for the storage of tubercle bacilli. For instance, Corper and Gauss (1923) found that tubercle bacilli remained viable in Petroff's egg medium or glycerol agar after storage in the incubator or refrigerator for 4 to 8 months. Later workers (Heckly, 1950 ; Stern and Tompsett, 1951 ; Jones, 1957 ; Tsukamura, 1965) suggested preservation of cultures by freezing them in various diluents. More recently, Tarshis (1961) compared storage of cultures in various diluents at –20°C. and concluded that, with minor exceptions, most types of mycobacteria (including tubercle bacilli) can be stored for at least 3 years without any major change in their viability or drug resistance. However, these procedures are time-consuming, expensive and require special equipment and are? therefore, not very practicable in developing countries with limited resources

GRB000301C with peculiar afterglow emission

The CCD magnitudes in Johnson V and Cousins R and I photometric passbands are determined for GRB 000301C afterglow starting ~ 1.5 day after the gamma-ray burst. In fact we provide the earliest optical observations for this burst. Light curves of the afterglow emissions in U, B, V, R, I, J and K' passbands are obtained by combining the present measurements with the published data. Flux decay shows a very uncommon variation relative to other well observed GRBs. Overall, there is a steepening of the optical and near-infrared flux decay caused by a geometric and sideways expanding jet. This is superimposed by a short term variability especially during early time (Delta t < 8 days). The cause of variability is not well understood, though it has occurred simultaneously with similar amplitude in all the filters. We derive the early and late time flux decay constants using jet model. The late time flux decay is the steepest amongst the GRB OTs observed so far with alpha ~ 3. Steepening in the flux decay seems to have started simultaneously around Delta t ~ 7.6 day in all passbands. The value of spectral index in the optical-near IR region is ~ -1.0. Redshift determination with z=2.0335 indicates cosmological origin of the GRB having a luminosity distance of 16.6 Gpc. Thus it becomes the second farthest amongst the GRBs with known distances. An indirect estimate of the fluence > 20 keV indicates, if isotropic,> =10^53 ergs of release of energy. The enormous amount of released energy will be reduced, if the radiation is beamed which is the case for this event. Using a jet break time of 7.6 days, we infer a jet opening angle of ~ 0.15 radian. This means the energy released is reduced by a factor of ~ 90 relative to the isotropic value.Comment: LaTeX file, 11 pages including 4 figures, uses psfig.sty, Bull. Astron. Society of India(accepted, Sept, 2000 issue

Challenges in Diabetes Care in India : Sheer Numbers, Lack of Awareness and Inadequate Control

Abstract With an estimated 40 million people suffering from the condition, the largest in any country in the world, diabetes has become a major health care problem in India. Recent epidemiological studies from India point to the great burden due to diabetes and its micro and macrovascular complications. This is primarily because the status of diabetes control in India is far from ideal. Based on the available data, the mean glycated hemoglobin levels are around 9% which is at least 2% higher than the goal currently suggested by international bodies. The IMPROVE study has helped identify the barriers to good control of diabetes both among patients as well as physicians in today’s practice. However the recent ACCORD study points to the dangers of overaggressive treatment, especially in high risk in elderly patients. A balanced approach to improve awareness about diabetes and its control both among patients and the medical fraternity is urgent need of the hour in India. The associated risks of tight control in high risk groups should also be kept in mind

Quantum non-demolition measurements of single donor spins in semiconductors

We propose a technique for measuring the state of a single donor electron spin using a field-effect transistor induced two-dimensional electron gas and electrically detected magnetic resonance techniques. The scheme is facilitated by hyperfine coupling to the donor nucleus. We analyze the potential sensitivity and outline experimental requirements. Our measurement provides a single-shot, projective, and quantum non-demolition measurement of an electron-encoded qubit state.Comment: 8+ pages. 4 figures. Published versio

Adaptive homodyne phase discrimination and qubit measurement

Fast and accurate measurement is a highly desirable, if not vital, feature of quantum computing architectures. In this work we investigate the usefulness of adaptive measurements in improving the speed and accuracy of qubit measurement. We examine a particular class of quantum computing architectures, ones based on qubits coupled to well controlled harmonic oscillator modes (reminiscent of cavity-QED), where adaptive schemes for measurement are particularly appropriate. In such architectures, qubit measurement is equivalent to phase discrimination for a mode of the electromagnetic field, and we examine adaptive techniques for doing this. In the final section we present a concrete example of applying adaptive measurement to the particularly well-developed circuit-QED architecture.Comment: 9 pages, 8 figures. Published versio

Large sized moustached Thryssa, Thryssa mystax (Bloch & Schneider, 1801) recorded from Cochin coast in Kerala

Two large sized specimens of Thryssa mystax (Family: Engraulidae) were caught in Chooda valai and landed at Chellanam fish landing centre on 20th July 2013. The specimens measured 24.8 cm (Fig. 1) and 24 cm in total length and weighed 100 g and 80 g respectively. These sizes of this species are recorded for the first time in the world