Frequency and time profiles of metric wave isolated Type I solar noise storm bursts at high spectral and temporal resolution

Type I noise storms constitute a sizeable faction of the active-Sun radio emission component. Observations of isolated instances of such bursts, in the swept-frequency-mode at metric wavelengths, have remained sparse, with several unfilled regions in the frequency coverage. Dynamic spectra of the burst radiation, in the 30 - 130 MHz band, obtained from the recently commissioned digital High Resolution Spectrograph (HRS) at the Gauribidanur Radio Observatory, on account of the superior frequency and time resolution, have unravelled in explicit detail the temporal and spectral profiles of isolated bursts. Apart from presenting details on their fundamental emission features, the time and frequency profile symmetry, with reference to custom-specific Gaussian distributions, has been chosen as the nodal criterion to statistically explain the state of the source regions in the vicinity of magnetic reconnections, the latent excitation agent that contributes to plasma wave energetics, and the quenching phenomenon that causes damping of the burst emission.Comment: 9 pages 7 black and white / grey-scale figures (inclusive of 3 composite). MNRAS - accepte

Quantized Orbits and Resonant Transport

A tight binding representation of the kicked Harper model is used to obtain an integrable semiclassical Hamiltonian consisting of degenerate "quantized" orbits. New orbits appear when renormalized Harper parameters cross integer multiples of $\pi/2$. Commensurability relations between the orbit frequencies are shown to correlate with the emergence of accelerator modes in the classical phase space of the original kicked problem. The signature of this resonant transport is seen in both classical and quantum behavior. An important feature of our analysis is the emergence of a natural scaling relating classical and quantum couplings which is necessary for establishing correspondence.Comment: REVTEX document - 8 pages + 3 postscript figures. Submitted to Phys.Rev.Let

The Fabrication Of Metal-Oxide Semiconductor Transistors Using Cerium Dioxide As A Gate Oxide Material

Cerium dioxide was employed as a gate insulator for an enhancement-type n-channel metal-oxide-semiconductor (MOS) transistor. Cerium was evaporated in a tungsten boat and immediately oxidized for oxide uniformity. The use of CeO2 as a gate oxide in MOS transistor yielded a low positive threshold voltage with negligible interface charge effects. This resulted in the transistor performing as an enhancement type device

Surface effects on nanowire transport: numerical investigation using the Boltzmann equation

A direct numerical solution of the steady-state Boltzmann equation in a cylindrical geometry is reported. Finite-size effects are investigated in large semiconducting nanowires using the relaxation-time approximation. A nanowire is modelled as a combination of an interior with local transport parameters identical to those in the bulk, and a finite surface region across whose width the carrier density decays radially to zero. The roughness of the surface is incorporated by using lower relaxation-times there than in the interior. An argument supported by our numerical results challenges a commonly used zero-width parametrization of the surface layer. In the non-degenerate limit, appropriate for moderately doped semiconductors, a finite surface width model does produce a positive longitudinal magneto-conductance, in agreement with existing theory. However, the effect is seen to be quite small (a few per cent) for realistic values of the wire parameters even at the highest practical magnetic fields. Physical insights emerging from the results are discussed.Comment: 15 pages, 7 figure

Review article: the effects of antitumour necrosis factor-α on bone metabolism in inflammatory bowel disease.

BACKGROUND: Patients with inflammatory bowel disease (IBD) are at increased risk of osteoporosis. A number of studies have emerged in recent years indicating that tumour necrosis factor (TNF) blockade appears to have a beneficial effect on bone mineral density (BMD) in IBD patients. AIMS: To provide a review of the available data regarding the effect of the currently licensed anti-TNF-α therapies on bone metabolism and BMD in IBD patients. METHODS: A Medline search was performed using the search terms \u27infliximab\u27, \u27bone metabolism\u27, \u27IBD\u27, \u27BMD\u27, \u27bone markers\u27, \u27adalimumab\u27, \u27bone disease\u27, \u27Crohn\u27s disease\u27 and \u27ulcerative colitis\u27. RESULTS: Infliximab has a beneficial effect on bone turnover markers in Crohn\u27s disease (CD) patients in the short term. The longest study to date comprising 24 CD patients showed an overall improvement in two bone formation markers - b-alkaline phosphatase (P = 0.022) and osteocalcin (P = 0.008) at 4 months post-treatment. Moreover, the largest study to date comprising 71 CD patients showed significant improvement in sCTx, a bone resorption marker (P = 0.04) at week-8 post-treatment. There is little data looking at the effect of anti-TNF-α therapy on bone metabolism in ulcerative colitis. Moreover, the long-term effects of anti-TNF-α therapy on bone structure and fracture risk in IBD patients are currently not known. The effect of cessation of anti-TNF-α therapy on bone metabolism is also unknown. CONCLUSION: Properly controlled long-term trials are needed to fully evaluate the impact of TNF blockade on bone mineral density

EFFECT OF LYCOPENE ON CHRONIC MILD STRESS-INDUCED HYPERLIPIDEMIA IN WISTAR ALBINO RATS

Objective: Chronic mild stress is the most valid model in inducing depression in rodents. In this method, rats were subjected to CMS for 6 weeks of stress. Methods: In this method, rodents were subjected to a series of mild stressors for CMS for six weeks in an unpredictable manner. Results: Biochemical and pathological changes were observed. Lycopene treatment at 10 mg/kg and 20 mg/kg could revert these biochemical changes. Histopathological studies showed there is a neuronal loss in CMS and CMS+Vehicle groups. Lycopene treatment reverted this condition. Conclusion: Lycopene treatment might revert this biochemical change by inhibiting a rate-limiting enzyme, HMG-CoA reductase. Histopathology of the brain revealed that rats subjected to chronic mild stress showed a decreased neuronal loss in the hippocampus. Lycopene treatment showed a neuroprotective effect against CMS-induced neuronal loss

Global Superdiffusion of Weak Chaos

A class of kicked rotors is introduced, exhibiting accelerator-mode islands (AIs) and {\em global} superdiffusion for {\em arbitrarily weak} chaos. The corresponding standard maps are shown to be exactly related to generalized web maps taken modulo an ``oblique cylinder''. Then, in a case that the web-map orbit structure is periodic in the phase plane, the AIs are essentially {\em normal} web islands folded back into the cylinder. As a consequence, chaotic orbits sticking around the AI boundary are accelerated {\em only} when they traverse tiny {\em ``acceleration spots''}. This leads to chaotic flights having a quasiregular {\em steplike} structure. The global weak-chaos superdiffusion is thus basically different in nature from the strong-chaos one in the usual standard and web maps.Comment: REVTEX, 4 Figures: fig1.jpg, fig2.ps, fig3.ps, fig4.p

Induction of rifampicin metabolism during treatment of tuberculous patients with daily and fully intermittent regimens containing the drug

Self-induction of rifampicin metabolism during daily and intermittent chemotherapy was studied by monitoring the changes in the serum half-life of the drug over a 4-week period in patients with pulmonary tuberculosis. Rifampicin 450 mg was administered to 8 patients who received treatment daily, 7 on thrice-weekly and 7 others on twice-weekly treatment. Serum half-life was computed from concentrations of the drug determined at 3, 4½ and 6 hours after drug administration, on admission and at 1, 2 and 4 weeks after start of treatment. In the daily series, the mean serum half-life decreased from 4.9 hours on admission to 3.6 hours at 1 week (P = 0.02), and treatment beyond this had no further effect. In the thrice-weekly series, maximal induction was observed at the 2nd week, the mean values on admission and at 2 weeks being 5.8 and 3.7 hours, respectively (P < 0.01). In the twiceweekly series, maximal induction was observed only at the 4th week, the mean values on admission and at 4 weeks being 4.9 and 3.7 hours, respectively (P < 0.01). Serum activity of gamma glutamyl transferase was not found to be a suitable in vivo marker to monitor induction of the hepatic microsomal enzymes as no significant changes were observed in the activity of this enzyme in any of the 3 series during the 4-week period

Semiclassical description of multiphoton processes

We analyze strong field atomic dynamics semiclassically, based on a full time-dependent description with the Hermann-Kluk propagator. From the properties of the exact classical trajectories, in particular the accumulation of action in time, the prominent features of above threshold ionization (ATI) and higher harmonic generation (HHG) are proven to be interference phenomena. They are reproduced quantitatively in the semiclassical approximation. Moreover, the behavior of the action of the classical trajectories supports the so called strong field approximation which has been devised and postulated for strong field dynamics.Comment: 10 pages, 11 figure