Exact Expressions for Minor Hysteresis Loops in the Random Field Ising Model on a Bethe Lattice at Zero Temperature

We obtain exact expressions for the minor hysteresis loops in the ferromagnetic random field Ising model on a Bethe lattice at zero temperature in the case when the driving field is cycled infinitely slowly.Comment: Replaced with the published versio

Dynamics of bootstrap percolation

Bootstrap percolation transition may be first order or second order, or it may have a mixed character where a first order drop in the order parameter is preceded by critical fluctuations. Recent studies have indicated that the mixed transition is characterized by power law avalanches, while the continuous transition is characterized by truncated avalanches in a related sequential bootstrap process. We explain this behavior on the basis of a through analytical and numerical study of the avalanche distributions on a Bethe lattice.Comment: Proceedings of the International Workshop and Conference on Statistical Physics Approaches to Multidisciplinary Problems, IIT Guwahati, India, 7-13 January 200

Analysis of wasp-waisted hysteresis loops in magnetic rocks

The random-field Ising model of hysteresis is generalized to dilute magnets and solved on a Bethe lattice. Exact expressions for the major and minor hysteresis loops are obtained. In the strongly dilute limit the model provides a simple and useful understanding of the shapes of hysteresis loops in magnetic rock samples.Comment: 11 pages, 4 figure

Critical Hysteresis in Random Field XY and Heisenberg Models

We study zero-temperature hysteresis in random-field XY and Heisenberg models in the zero-frequency limit of a cyclic driving field. We consider three distributions of the random field and present exact solutions in the mean field limit. The results show a strong effect of the form of disorder on critical hysteresis as well as the shape of hysteresis loops. A discrepancy with an earlier study based on the renormalization group is resolved.Comment: 10 pages, 6 figures; this is published version (added some text and references

Hysteresis in Random Field XY and Heisenberg Models: Mean Field Theory and Simulations at Zero Temperature

We examine zero temperature hysteresis in random field XY and Heisenberg models in the zero frequency limit of a cyclic driving field. Exact expressions for hysteresis loops are obtained in the mean field approximation. These show rather unusual features. We also perform simulations of the two models on a simple cubic lattice and compare them with the predictions of the mean field theory.Comment: replaced by the published versio

Emerging strategies of targeting lipoprotein lipase for metabolic and cardiovascular diseases

Although statins and other pharmacological approaches have improved the management of lipid abnormalities, there exists a need for newer treatment modalities especially for the management of hypertriglyceridemia. Lipoprotein lipase (LPL), by promoting hydrolytic cleavage of the triglyceride core of lipoproteins, is a crucial node in the management of plasma lipid levels. Although LPL expression and activity modulation is observed as a pleiotropic action of some the commonly used lipid lowering drugs, the deliberate development of drugs targeting LPL has not occurred yet. In this review, we present the biology of LPL, highlight the LPL modulation property of currently used drugs and review the novel emerging approaches to target LPL

Voter Dynamics on an Ising Ladder: Coarsening and Persistence

Coarsening and persistence of Ising spins on a ladder is examined under voter dynamics. The density of domain walls decreases algebraically with time as $t^-{1/2}$ for sequential as well as parallel dynamics. The persistence probability decreases as $t^{-\theta_{s}}$ under sequential dynamics, and as $t^{-\theta_{p}}$ under parallel dynamics where $\theta_{p} = 2 \theta_{s} \approx .88$. Numerical values of the exponents are explained. The results are compared with the voter model on one and two dimensional lattices, as well as Ising model on a ladder under zero-temperature Glauber dynamics.Comment: replaced with published version (text somewhat expanded): 11 pages, 2 figure

Biological Activities and Volatile Constituents of Aegle marmelos (L.) Corrêa from Nepal

Aegle marmelos, a deciduous fruit tree that grows in Nepal, has numerous uses in traditional medicine, being used as an anti-inflammatory, antidiarrheal, heart disease treatment, and in birth control. In this study, leaves were collected to obtain, analyze, and examine the bioactivity of the essential oil of A. marmelos, which is often referred to as bael tree in Nepal. The essential oil from leaves was obtained by hydrodistillation. The chemical composition, determined by GC-MS, revealed 82 compounds, with 81 components being identified. The major component was limonene (64.1%), with the other two abundant components being (E)-β-ocimene (9.7%) and germacrene B (4.7%). Bioassay screening of the essential oil indicated marginal toxicity against MCF-7 human breast adenocarcinoma cells (LC50 = 98.2 µg mL-1), but good larvicidal activity against mosquitoes (Culex pipiens) (LC50 = 2.15 µg mL-1), nematocidal activity against Caenorhabditis elegans, (LC50 = 113 µg mL-) and insecticidal activity against termites (Reticulitermes virginicus), fruit flies (Drosophila melanogaster), and fire ants (Solenopsis invica × richteri). The essential oil of A. marmelos showed remarkable brine shrimp lethality. Antimicrobial and antifungal activity of the leaf oil was negligible. Most of the observed biological activity was apparently due to the relatively high level of limonene (64.1%) in the essential of the leaf essential oil from A. marmelos

Structure-activity and in vivo evaluation of a novel lipoprotein lipase (LPL) activator

Elevated triglycerides (TG) contribute towards increased risk for cardiovascular disease. Lipoprotein lipase (LPL) is an enzyme that is responsible for the metabolism of core triglycerides of very-low density lipoproteins (VLDL) and chylomicrons in the vasculature. In this study, we explored the structure-activity relationships of our lead compound (C10d) that we have previously identified as an LPL agonist. We found that the cyclopropyl moiety of C10d is not absolutely necessary for LPL activity. Several substitutions were found to result in loss of LPL activity. The compound C10d was also tested in vivo for its lipid lowering activity. Mice were fed a high-fat diet (HFD) for four months, and treated for one week at 10 mg/kg. At this dose, C10d exhibited in vivo biological activity as indicated by lower TG and cholesterol levels as well as reduced body fat content as determined by ECHO-MRI. Furthermore, C10d also reduced the HFD induced fat accumulation in the liver. Our study has provided insights into the structural and functional characteristics of this novel LPL activator