Discussion on a possible neutrino detector located in India

We have identified some important and worthwhile physics opportunities with a possible neutrino detector located in India. Particular emphasis is placed on the geographical advantage with a stress on the complimentary aspects with respect to other neutrino detectors already in operation.     

Asymmetrical hippocampal connectivity in mesial temporal lobe epilepsy: evidence from resting state fMRI

Background

Recent studies have shown that the human right-hemispheric auditory cortex is particularly sensitive to reduction in sound quality, with an increase in distortion resulting in an amplification of the auditory N1m response measured in the magnetoencephalography (MEG). Here, we examined whether this sensitivity is specific to the processing of acoustic properties of speech or whether it can be observed also in the processing of sounds with a simple spectral structure. We degraded speech stimuli (vowel /a/), complex non-speech stimuli (a composite of five sinusoidals), and sinusoidal tones by decreasing the amplitude resolution of the signal waveform. The amplitude resolution was impoverished by reducing the number of bits to represent the signal samples. Auditory evoked magnetic fields (AEFs) were measured in the left and right hemisphere of sixteen healthy subjects.

Results

We found that the AEF amplitudes increased significantly with stimulus distortion for all stimulus types, which indicates that the right-hemispheric N1m sensitivity is not related exclusively to degradation of acoustic properties of speech. In addition, the P1m and P2m responses were amplified with increasing distortion similarly in both hemispheres. The AEF latencies were not systematically affected by the distortion.

Conclusions

We propose that the increased activity of AEFs reflects cortical processing of acoustic properties common to both speech and non-speech stimuli. More specifically, the enhancement is most likely caused by spectral changes brought about by the decrease of amplitude resolution, in particular the introduction of periodic, signal-dependent distortion to the original sound. Converging evidence suggests that the observed AEF amplification could reflect cortical sensitivity to periodic sounds.     

Poly(acrylonitrile) ultrafiltration membranes. I. Polymer‐salt‐solvent interactions

Fourier transform infrared spectroscopy was used to study the interactions among LiCl, ZnCl₂, and AlCl₃ with N,N‐dimethylformamide (DMF) and poly(acrylonitrile) (PAN). It was observed that all three salts complex with DMF as well as PAN. The strength of the cation interaction with the >C?O oxygen of DMF was found to be higher than that with the ? CN group of PAN. The >C?O stretching frequency of DMF with ZnCl₂ was red shifted, indicating stronger complex formation compared with other two cations. With the addition of salt, the salt–DMF pseudo solvent was found to become a θ solvent for PAN compared with neat DMF. This change in PAN solvation power was primarily the result of DMF–salt complexation. As a result of the complexation, Mark‐Houwink constant a, was found to reduce from 0.75 (for pure DMF) to ～0.6 for DMF–salt solvents, indicating decreased PAN chain expansion. Comparison of intrinsic viscosity [η] values indicated that addition of salts to PAN–DMF solutions resulted in: (i) decrease in the DMF solvation power, which causes less expanded polymer coils, and (ii) increased interpolymer chain entanglements via salt‐promoted chain association. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2061–2073, 2005     

Distinction between normal and leukemic bone marrow by water protons nuclear magnetic resonance relaxation times

Pulsed nuclear magnetic resonance studies have been carried out on bone marrow of normal human subjects and patients with leukemia: chronic myeloid leukemia (CML) and acute myeloid leukemia (AML). It was observed that the proton spin-lattice relaxation time (T₁) value was discriminatory in the normal and leukemic cases with a statistical significance of (p < 0.01). Ouabain treatment of cells did not show any perceptible change of T₁ value when compared with the nontreated cells, indicating that the concomitant cation effluxes do not affect spin-lattice relaxation time. The water contents of normal, leukemic, and ouabain treated cells were in the range 60%–80%. Higher Fe levels were encountered in the normal than the leukemic samples, while levels of Zn, Cu, Mn, Co, and Ni were elevated in the leukemic samples compared with the normals. Despite the T₁ differences observed, the multiparameter studies do not uniquely pinpoint factors responsible for the elevation of T₁ in the malignant state.     

Biomolecular electronics in the twenty-first century

A relentless decrease in the size of silicon-based microelectronics devices is posing problems. The most important among these are limitations imposed by quantum-size effects and instabilities introduced by the effects of thermal fluctuations. These inherent envisaged problems of present-day systems have prompted scientists to look for alternative options. Advancement in the understanding of natural systems such as photosynthetic apparatuses and genetic engineering has enabled attention to be focused on the use of biomolecules. Biomolecules have the advantages of functionality and specificity. The invention of scanning tunneling microscopy and atomic force microscopy has opened up the possibility of addressing and manipulating individual atoms and molecules. Realization of the power of self-assembly principles has opened a novel approach for designing and assembling molecular structures with desired intricate architecture. The utility of molecules such as DNA as a three-dimensional, high-density memory element and its capability for molecular computing have been fully recognized but not yet realized. More time and effort are necessary before devices that can transcend existing ones will become easily available. An overview of the current trends that are envisaged to give rich dividends in the next millen-nium are discussed.     

Simultaneous LC Estimation of Glimepiride and Metformin in Glimepiride Immediate Release and Metformin Sustained Release Tablets

In the present study, a simple, rapid and precise liquid chromatographic method was developed and validated for the simultaneous determination of glimepiride and metformin in sustained release formulation. The separation was achieved on a Nucleosil 100-5SA column, 250 × 4.6 mm i.d., 5 μm using a mobile phase composed of 1.7 % ammonium dihydrogen phosphate buffer pH 3.0: acetonitrile (70:30 v/v).The instrumental settings were a flow rate of 1.0 ml min^?1 and a detector wavelength of 230 nm. The retention time of glimepiride and metformin were 5.1 and 11.3, respectively. The developed method was validated in terms of specificity, sensitivity, linearity, range, accuracy, precision and ruggedness. The proposed method was successfully applied to the sustained release pharmaceutical dosage form for the simultaneous determination of glimepiride and metformin without any interference by excipients.