Molecular beacons: nucleic acid hybridization and emerging applications

Molecular beacons (MBs) are a novel class of nucleic acid probes that become fluorescent when bound to a complementary sequence. Because of this characteristic, coupled with the sequence specificity of nucleic acid hybridization and the sensitivity of fluorescence techniques, MBs are very useful probes for a variety of applications requiring the detection of DNA or RNA. We survey various applications of MBs, including the monitoring of DNA triplex formation, and describe recent developments in MB design that enhance their sensitivity

A Newton-like method and its application

AbstractIn this paper we prove an existence and uniqueness theorem for solving the operator equation F(x)+G(x)=0, where F is a Gateaux differentiable continuous operator while the operator G satisfies a Lipschitz-condition on an open convex subset of a Banach space. As corollaries, a theorem of Tapia on a weak Newton's method and the classical convergence theorem for modified Newton-iterates are deduced. An existence theorem for a generalized Euler–Lagrange equation in the setting of Sobolev space is obtained as a consequence of the main theorem. We also obtain a class of Gateaux differentiable operators which are nowhere Frechet differentiable. Illustrative examples are also provided

Evaluation of Natural Radioactivity Levels and Exhalation rate of 222Rn and 220Rn in the Soil Samples from the Kuthiran Hills, Kerala, India

Background: Exposure to radon and its decay products is one of the important contributors of radiation doses to human population. Radon exhalation study is important for understanding the contribution of the soil towards the total radioactivity concentration found inside the dwellings. Purpose: The aim of the present study is to investigate the radioactivity levels and radium and radon exhalation rates in soil samples collected from Kuthiran hills and nearby places in Thrissur district, Kerala state, India. On the basis of this data, radiological health hazard parameters are also evaluated. Methods: About 18 soil samples were collected from the study location. The radium, thorium and potassium activity concentrations were analyzed by HPGe gamma ray spectrometer. The “can technique” using LR-115 type II plastic track detectors have been used for the measurement of radon exhalation rate in soil samples. Results: The mean values of activity concentrations of 226Ra, 232Th and 40K were 64.60 Bqkg-1, 109.03 Bqkg-1and 972.67 Bqkg-1 respectively. The mean value of radon mass exhalation rate is 9.19 mBqkg-1h-1 and thoron surface exhalation rate is and 237.9 mBqm-2s-1. The radium equivalent activity concentration of all the soil samples was below the level of 370 Bqkg-1, recommended for building materials, by OECD 1979 (Organization for Economic Cooperation and Development). Conclusions: The results show that the study area is safe, as far as the health hazard effects of radium and radon exhalation rate are concerned. This data will be helpful in establishing new regulations and safety limits, related to the radiation dose and radon activity in Kuthiran hills

Numerical wave optics and the lensing of gravitational waves by globular clusters

We consider the possible effects of gravitational lensing by globular clusters on gravitational waves from asymmetric neutron stars in our galaxy. In the lensing of gravitational waves, the long wavelength, compared with the usual case of optical lensing, can lead to the geometrical optics approximation being invalid, in which case a wave optical solution is necessary. In general, wave optical solutions can only be obtained numerically. We describe a computational method that is particularly well suited to numerical wave optics. This method enables us to compare the properties of several lens models for globular clusters without ever calling upon the geometrical optics approximation, though that approximation would sometimes have been valid. Finally, we estimate the probability that lensing by a globular cluster will significantly affect the detection, by ground-based laser interferometer detectors such as LIGO, of gravitational waves from an asymmetric neutron star in our galaxy, finding that the probability is insignificantly small.Comment: To appear in: Proceedings of the Eleventh Marcel Grossmann Meetin