The Oslo model, hyperuniformity, and the quenched Edwards-Wilkinson model

We present simulations of the 1-dimensional Oslo rice pile model in which the critical height at each site is randomly reset after each toppling. We use the fact that the stationary state of this sandpile model is hyperuniform to reach system of sizes $> 10^7$. Most previous simulations were seriously flawed by important finite size corrections. We find that all critical exponents have values consistent with simple rationals: $\nu=4/3$ for the correlation length exponent, $D =9/4$ for the fractal dimension of avalanche clusters, and $z=10/7$ for the dynamical exponent. In addition we relate the hyperuniformity exponent to the correlation length exponent $\nu$. Finally we discuss the relationship with the quenched Edwards-Wilkinson (qEW) model, where we find in particular that the local roughness exponent is $\alpha_{\rm loc} = 1$.Comment: 20 pages, 26 figure

Critical Behavior of Sandpile Models with Sticky Grains

We revisit the question whether the critical behavior of sandpile models with sticky grains is in the directed percolation universality class. Our earlier theoretical arguments in favor, supported by evidence from numerical simulations [ Phys. Rev. Lett., {\bf 89} (2002) 104303], have been disputed by Bonachela et al. [Phys. Rev. E {\bf 74} (2004) 050102] for sandpiles with no preferred direction. We discuss possible reasons for the discrepancy. Our new results of longer simulations of the one-dimensional undirected model fully support our earlier conclusions.Comment: 8 pages, 3 eps figures, accepted in Physica A, elsart.cls attache

Many universality classes in an interface model restricted to non-negative heights

We present a simple 1-d stochastic model with two control parameters and a surprisingly rich zoo of phase transitions. At each (discrete) site $x$ and time $t$, there is an integer $n(x,t)$ that satisfies a linear interface equation with added random noise. Depending on the control parameters, this noise may or may not satisfy the detailed balance condition, so that the model is -- for suitable initial conditions -- in the Edwards-Wilkinson (EW) or in the Kardar-Parisi-Zhang (KPZ) universality class. In addition, there is also a constraint $n(x,t) \geq 0$. Points $x$ where $n>0$ on one side and $n=0$ on the other are called ``fronts". These fronts can be ``pushed" or ``pulled", depending on the control parameters. For pulled fronts, the lateral spreading is in the directed percolation (DP) universality class, while it is of a novel type for pushed fronts, with yet another novel behavior in between. In the DP case, the activity at each active site can in general be arbitrarily large, in contrast to previous realizations of DP. Finally, we find two different types of transitions when the interface detaches from the line $n=0$ (with $\langle n(x,t)\rangle \to const$ on one side, and $\to \infty$ on the other), again with new universality classes. We also discuss a mapping of this model to the avalanche propagation in a directed Oslo rice pile model in specially prepared backgrounds.Comment: 14 pages, 17 figures ( use pdf latex

REPRODUCTIVE CYCLE OF FEMALE COMMON INDIAN ROCK LIZARD, PSAMMOPHILUS BLANFORDANUS: SEASONAL OVARY AND OVIDUCT HISTOLOGY

The lizard Psammophilus (Reptilia: Diapsida: Agamidae) is commonly called as rock lizard. It has only been reported that female P. blanfordanus is a seasonal breeder otherwise research on its reproduction is limited. Therefore, to investigate the relationship between environmental and reproductive behaviour, studies on gonadosomatic index (GSI), histology and histometry of ovary and oviduct were undertaken. The GSI, relative weight of ovaries (ROW) and oviducts (ROiW) are highest during the breeding season. The ROW and ROiW are positively correlated with temperature, rainfall and relative humidity (RH). The histology and histometry of ovary and oviducts show that the breeding season in this animal is from April to June/July and sometimes extends to early August. During this period the diameter of oocyte, oviduct and oviduct glandular layer is increased. The thicknessof oviduct glandular is also increased but thickness of oviduct muscle layer is decreased. The reproductive cycle of this animal is associate type. The study will be helpful in understanding its evolutionary adaptability to different seasons

Steady State and Relaxation Spectrum of the Oslo Rice-pile

We show that the one-dimensional Oslo rice-pile model is a special case of the abelian distributed processors model. The exact steady state of the model is determined. We show that the time evolution operator W for the system satisfies the equation W^{n+1} = W^n where n = L(L+1)/2 for a pile with L sites. This is used to prove that W has only one eigenvalue 1 corresponding to the steady state, and all other eigenvalues are exactly zero. Also, all connected time-dependent correlation functions in the steady state of the pile are exactly zero for time difference greater that n. Generalization to other abelian critical height models where the critical thresholds are randomly reset after each toppling is briefly discussed.Comment: 11 pages, latex, no figure

The pattern of distant metastasis and clinicopathological factors associated with de-novo metastatic cervical cancer: a retrospective analysis

Background: Metastatic cervical cancer carries poor prognosis. The factors associated with distant metastasis in newly diagnosed cervical cancer patients are not clear.Methods: A retrospective analytical study was performed to study the pattern of distant metastasis, and to evaluate the factors associated with de-novo metastatic cervical cancer. Univariate and multivariate analysis (by MANOVA) were used to evaluate the association. P≤0.05 was considered significant.Results: Out of 1321 newly diagnosed cervical cancer patients, 54 (4.1%) had de-novo metastatic disease and most of which (81%) were found at single site. Common sites of distant metastasis were non-regional nodes, followed by liver, lung, peritoneum and bone. Univariate analysis showed the factors associated with de-novo metastasis were non squamous subtype, high grade histology, bulky primary tumor (>4 cm), pelvic/para-aortic lymphadenopathy, and hydroureteronephrosis. Multivariate analysis revealed the factors associated with de-novo metastasis were bulky primary tumor (>4 cm), high grade histology, pelvic/para aortic lymphadenopathy, hydroureteronephrosis.Conclusions: Newly diagnosed cervical cancer patients with bulky primary tumor, high grade histology, pelvic or para aortic lymphadenopathy, hydroureteronephrosis are associated with higher risk of de-novo distant metastasis