Analytical detection of stationary and dynamic patterns in a prey-predator model with reproductive Allee effect in prey growth.

Allee effect in population dynamics has a major impact in suppressing the paradox of enrichment through global bifurcation, and it can generate highly complex dynamics. The influence of the reproductive Allee effect, incorporated in the prey's growth rate of a prey-predator model with Beddington-DeAngelis functional response, is investigated here. Preliminary local and global bifurcations are identified of the temporal model. Existence and non-existence of heterogeneous steady-state solutions of the spatio-temporal system are established for suitable ranges of parameter values. The spatio-temporal model satisfies Turing instability conditions, but numerical investigation reveals that the heterogeneous patterns corresponding to unstable Turing eigenmodes act as a transitory pattern. Inclusion of the reproductive Allee effect in the prey population has a destabilising effect on the coexistence equilibrium. For a range of parameter values, various branches of stationary solutions including mode-dependent Turing solutions and localized pattern solutions are identified using numerical bifurcation technique. The model is also capable to produce some complex dynamic patterns such as travelling wave, moving pulse solution, and spatio-temporal chaos for certain range of parameters and diffusivity along with appropriate choice of initial conditions. Judicious choices of parametrization for the Beddington-DeAngelis functional response help us to infer about the resulting patterns for similar prey-predator models with Holling type-II functional response and ratio-dependent functional response.

Analysis of a Prey-Predator Model with Non-local Interaction in the Prey Population.

Non-local reaction-diffusion equation is an important area to study the dynamics of the individuals which compete for resources. In this paper, we describe a prey-dependent predator-prey model with Holling type II functional response with a generalist predator. In particular, we want to see the behavior of the system in the presence of non-local interaction. Introduction of non-local intraspecific competition in prey population leads to some new characteristics in comparison with the local model. Comparisons have been made between the local and non-local interactions of the system. The range of non-local interaction enlarges the parametric domain on which stationary patterns exist. The periodic oscillation for the local model in the Hopf domain can be stabilized by suitable limit of strong non-local interaction. An increase in the range of non-local interaction increases the Turing domain up to a certain level, and then, it decreases. Also, increasing the range of non-local interaction results in the overlap of nearby foraging areas and hence alters the size of the localized patches and formation of multiple stationary patches. Numerical simulations have been carried out to validate the analytical findings and to establish the existence of multiple stationary patterns, oscillatory solution, two-periodic solution and other spatiotemporal dynamics.

Wavelength Selection in Gyrotactic Bioconvection.

We investigate pattern formation by swimming micro-organisms (bioconvection), when their orientation is determined by balance between gravitational and viscous torques (gyrotaxis), due to being bottom heavy. The governing equations, which consist of the Navier-Stokes equations for an incompressible fluid coupled with a micro-organism conservation equation, are solved numerically in a large cross section chamber with periodic boundary conditions in the horizontal directions. The influence of key parameters on wavelength selection in bioconvection patterns is investigated numerically. For realistic ranges of parameter values, the computed wavelengths are in good agreement with the experimental observations provided that the diffusion due to randomness in cell swimming behaviour is small, refuting a recently published claim that the mathematical model becomes inaccurate at long times. We also provide the first computational evidence of "bottom-standing" plumes in a three-dimensional simulation.

Non-adenomatous non-epithelial carcinoma (hemangiopericytoma) of prostate treated with conservative surgery followed by adjuvant chemoradiation.

Hemangiopericytoma is a malignant vascular tumour of soft tissue. Microscopically, the tumour shows tightly packed cellular areas surrounding thin-walled branching blood vessels. Traditionally these tumours are treated using wide surgical excision. Only a very few cases of hemangiopericytoma of the prostate have been described worldwide. The feasibility of managing such a case with a combination of conservative surgery and adjuvant anti-malignancy treatment is unexplored. Here, we report a case of hemangiopericytoma of the prostate treated with local excision, with preservation of prostate, followed by adjuvant radiotherapy (40 Gy in 20 fractions to pelvis followed by 24 Gy in 12 fractions as boost to prostate) and chemotherapy (doxorubicin and iphosphamide). Post-treatment computed tomography scan after 4 weeks showed regression of pelvic lymph nodes and a normal-appearing prostate. Levels of serum prostate-specific and carcinogenic embryonic antigen were normal throughout the period of treatment. To date, followup has been uneventful, except for occasional bouts of diarrhea.We conclude that conservative surgery followed by adjuvant radiation and chemotherapy, with subsequent close follow-up, may adequately control localized disease in selected cases of hemangiopericytoma of the prostate. The role of conservative surgery in tumours located at other sites has yet to be defined.

Effect of kernels on spatio-temporal patterns of a non-local prey-predator model.

Non-local interaction describes the effects of mobility of a population species in their spatial locations. Non-local interaction is incorporated into a prey-predator model by introducing an integral term with appropriate kernel function. The kernel function determines the nature and range of the accessibility of the resources. We consider a nonlocal spatio-temporal prey-predator model with additive weak Allee effect in prey growth and density-dependent predator mortality. The dynamics of the model is examined in presence of a parabolic and a triangular kernel functions. Comparisons are made between the resulting dynamics of the nonlocal model with these kernels for the same range of nonlocal interaction. A linear stability analysis is performed for both the kernels to derive Turing and spatial-Hopf bifurcation conditions. In general, Turing bifurcation curves are different for the two kernels and the same is true for spatial-Hopf bifurcation curves. This results in different dynamics for the two kernels for some parameter values. However, for a fixed range of nonlocal interaction, the dynamics of the model with these two kernels are almost similar for most of the parameter values explored. Increase in the range of nonlocal interaction up to a certain value stabilizes the system dynamics, and then, it destabilizes. Extensive numerical simulations are performed to illustrate the system dynamics.

Nuclear matrix protein SMAR1 control regulatory T-cell fate during inflammatory bowel disease (IBD).

Regulatory T (Treg) cells are essential for self-tolerance and immune homeostasis. Transcription factor Foxp3, a positive regulator of Treg cell differentiation, has been studied to some extent. Signal transducer and activator of transcription factor 3 (STAT3) is known to negatively regulate Foxp3. It is not clear how STAT3 is regulated during Treg differentiation. We show that SMAR1, a known transcription factor and tumor suppressor, is directly involved in maintaining Treg cell fate decision. T-cell-specific conditional knockdown of SMAR1 exhibits increased susceptibility towards inflammatory disorders, such as colitis. The suppressive function of Treg cells is compromised in the absence of SMAR1 leading to increased T helper type 17 (Th17) differentiation and inflammation. Compared with wild-type, the SMAR1(-/-) Treg cells showed increased susceptibility of inflammatory bowel disease in Rag1(-/ -) mice, indicating the role of SMAR1 in compromising Treg cell differentiation resulting in severe colitis. We show that SMAR1 negatively regulate STAT3 expression favoring Foxp3 expression and Treg cell differentiation. SMAR1 binds to the MAR element of STAT3 promoter, present adjacent to interleukin-6 response elements. Thus Foxp3, a major driver of Treg cell differentiation, is regulated by SMAR1 via STAT3 and a fine-tune balance between Treg and Th17 phenotype is maintained.

Epithelial mesenchymal transition in lung cancer cells: A quantitative analysis.

Cellular auto-fluorescence along with morphological and cytoskeletal features were assessed in lung cancer cells undergoing induced epithelial mesenchymal transition (EMT). During EMT progression, significant increase was observed in cellular aspect ratio (AR), filamentous (F)-actin and green auto-fluorescence intensities while blue intensity decreased. These features were provided to a kernel classification framework. The classification accuracy were impressive, thus these features along with the classification technique can be considered as suitable tools for automated grading of lung cancer cells undergoing EMT progression.

Spinal cord compression in HbE-thalassaemia.

Two cases of spinal cord compression due to extramedullary haemopoiesis in haemoglobine E thalassaemia are described. Possible mechanisms and treatment modes are discussed.

Acute intracerebral haematoma--an unusual presentation of herpes simplex encephalitis.

A young man presented with acute headache, behavioral abnormality and CT scan evidence of intracerebral hematoma. Detailed investigation established its infective origin due to herpes simplex virus type-I. The patient made an excellent recovery following a course of acyclovir. Frank intracerebral haematoma in the form of well defined mass on CT scan in patient with herpes simplex encephalitis is extremely rare.

Flocculation properties of polyacrylamide grafted carboxymethyl guar gum (CMG-g-PAM) synthesised by conventional and microwave assisted method.

A novel polymeric flocculant based on polyacrylamide grafted carboxymethyl guar gum (CMG-g-PAM) has been synthesised by grafting polyacrylamide chains onto CMG backbone using conventional redox grafting and microwave assisted grafting methods. Under optimum grafting conditions, 82% and 96% grafting efficiencies have been observed in case of conventional and microwave assisted methods respectively. The optimum sample has been characterized using viscometry, spectroscopic analysis, elemental analysis, molecular weight and radius of gyration determination. The flocculation characteristics of grafted and ungrafted polysaccharides have been evaluated in kaolin suspension, municipal sewage wastewater and decolourization efficiency of a dye solution (methylene blue). It is evident from results that CMG-g-PAM synthesised by microwave assisted grafting method is showing best flocculation characteristics.

Contralateral trigeminal neuropathy in a case of convexity cerebellar meningioma.

Cerebellar convexity meningioma is a rare entity and associated contralateral trigeminal neuropathy is even rarer presentation. We here a case of left sided convexity cerebellar meningioma associated with right trigeminal neuropathy in a 63-year-old lady is presented. Suboccipital craniectomy (left) and near total removal was done. The hypoaesthesia of right hemiface disappeared totally at the time of discharge.

Wavelengths of gyrotactic plumes in bioconvection.

Bioconvection occurs as the result of the collective behaviour of many micro-organisms swimming in a fluid and is realized as patterns similar to those of thermal convection which occur when a layer of fluid is heated from below. We consider the phenomenon of pattern formation due to gyrotaxis, an orientation mechanism which results from the balance of gravitational and viscous torques acting on bottom-heavy micro-organisms. The continuum model of Pedley et al. (1988, J. Fluid. Mech. 195, 223-237) is used to describe the suspension. The system is governed by the Navier-Stokes equations for an incompressible fluid coupled with a micro-organism conservation equation. These equations are solved numerically using a conservative finite-difference scheme. To examine the dependence of the horizontal pattern wavelengths on the parameters, we consider two-dimensional solutions in a wide chamber using rigid side walls. The wavelengths of the numerical computations are in good agreement with the experimental observations and we provide the first computational examples of the commonly seen 'bottom-standing' plumes.

Axisymmetric bioconvection in a cylinder.

In three-dimensional bioconvection, the regions of rising and sinking fluid are dissimilar. This geometrical effect is studied for axisymmetric bioconvection in a cylindrical cell with stress-free (i.e. normal velocity and tangential stress vanish) lateral and top boundaries, and rigid bottom boundary. Using the continuum model of Pedley et al. (1988, J. Fluid Mech.195, 223-237) for bioconvection in a suspension of swimming, gyrotactic microorganisms, the structure and stability of an axisymmetric plume in a deep chamber are investigated. The system is governed by the Navier-Stokes equations for an incompressible fluid coupled with a microorganism conservation equation. These equations are solved numerically using a conservative finite-difference scheme. Comparisons are made with two-dimensional bioconvection.

1,4-Methano-11a-methyl-4,4a,11,11a-tetrahydro-1H-benzo[b]fluoren-11-one.

The title compound, C(19)H(16)O, crystallizes with two molecules of opposite chirality in the asymmetric unit. In both molecules, the naphthalene and cyclopentanone moieties are individually planar. The two cyclopentane rings adopt envelope conformations, while the cyclohexane ring adopts a boat conformation.