Dynamics of a prey-predator model involving a prey refuge and disease in the predator

In this paper, a mathematical model consisting of a prey-predator involving a prey refuge and infectious disease in the predator has been proposed and analyzed. Two types of functional responses are used to describe the feeding of the predator on the available prey. The existence, uniqueness and boundedness of the solution of the system are discussed. The dynamical behavior of the system has been investigated locally as well as globally using suitable Lyapunov function. The persistence conditions of the system are established. Local bifurcation near the equilibrium points has been investigated. The Hopf bifurcation conditions around the positive equilibrium point are derived. Finally, numerical simulations are carried out to specify the control parameters and confirm the obtained results Keywords: Prey-Predator, Disease, Refuge, Stability, Bifurcation

Exhibition of Bleaching Resistance Via Adaptive Bleaching Pattern by Coral Reefs of the Gulf of Mannar during Massive Bleaching Event 2019

Coral reefs in the Gulf of Mannar (GoM) and Palk Bay regions are facing potential threats from climate change, sedimentation and anthropogenic activities. Considerably, coral reefs in these two regions are highly damaged due to frequent bleaching events caused by increased sea surface temperature (SST) recorded over the past two decades. Recently, during February to May 2019, mass bleaching event of corals was documented again in GoM and Palk Bay regions due to increased sea surface temperatures ranged between 32°C to 36°C. Despite of completely bleached corals, some coral colonies of the same bleached coral species have displayed adaptive bleaching pattern (ABP) for survival. This incidence is displayed by the symbiotic zooxanthellae to protect coral polyps from environmental stress such as elevated temperatures. These observations infer that coral colonies with preferential bleaching pattern ability would serve as environmental stress resisting coral colonies which can be used for restoration activities and cryopreservation. Further studies are needed to explain the potential mechanisms or specific environmental drivers responsible for ABP.   

Data Preparation and Analysis for Andhra Pradesh Clusters

Local clusters are highly preferable in all domains due to complex and large Database applications are available. Clustering techniques are applied to local clusters as per needs of local clusters. We can apply divide and conquer rule for local clusters. Local clusters are always constructed as per needs of local bodies. In future we can combine or integrate these local clusters with big clusters or centralized clusters. The number of local cluster formation is completely depend upon requirements of local bodies. But in some contexts they must work along with central systems when they are integrated or combine with central systems

Pseudogap phase of high-Tc compounds described within the LDA+DMFT+Sigma approach

LDA+DMFT+Sigma_k approach was applied to describe pseudogap phase of several prototype high-Tc compounds e.g. hole doped Bi2212 and LSCO systems and electron doped NCCO and PCCO, demonstrating qualitative difference of the Fermi surfaces (FS) for these systems. Namely for Bi2212 and LSCO the so called "hot-spots" (intersection of a bare FS and AFM Brillouin zone (BZ) boundary), where scattering on pseudogap fluctuations is most intensive were not observed. Instead here we have Fermi arcs with smeared FS close to the BZ boundary. However for NCCO and PCCO "hot-spots" are clearly visible. This qualitative difference is shown to have material specific origin. Good agreement with known ARPES data was demon strated not only for FS maps but also for spectral function maps (quasiparticle bands in cluding lifetime and interaction broadening).Comment: 4 pages, 4 figures, 1 table, SNS2010 proceedings (24-28 May 2010, Shanghai, China

Bioinvasive Seaweed Genus, Turbinaria in Coral Reefs of Gulf of Mannar

Coral reefs are the important marine biodiversity hotspots, providing livelihood for coastal population around the world. In recent times, coral reef ecosystems are facing natural and anthropogenic threats. Coral reefs in the Gulf of Mannar Marine Biosphere Reserve, southeast coast of Tamil Nadu, India are one of the peculiar ecosystems less studied. Thus, to unveil the potential threats in the coral reefs of Gulf of Mannar region, the present study has made several coral reef monitoring by Line Intercept Transect method in the Gulf of Mannar group of Islands. Surveys revealed the canopy-forming indigenous and invasive macroalgal species, Turbinaria ornata, T. decurrens and T. conoides overgrowing dead reef areas. Although these macroalgae are not an alien species in these islands, but have become increasingly abundant and competing against coral colonies for space. Underwater visual censuses have indicated Turbinaria species as opportunistic invaders. These species are taking the advantage of dead corals for substrata and thereby restricting the settlement of coral polyps. Dense growths of these species have formed patches with several 100s of thalli per m-2 and as continuous canopies in some dead reef areas. Further studies on spatial and temporal distribution of these invasive species are yet to be undertaken for developing better management strategies

In Situ Observation on the Mass Aggregation of Edible Sea Urchin Stomopneustes variolaris in Shingle Island, Gulf of Mannar

This study report significant observation on the mass aggregation of sea urchin species Stomopneustes variolaris from Shingle Island. S. variolaris is well known edible sea urchin species to coastal population. Intensive underwater surveys were conducted during the period of January and February, 2019 at different sites of Mandapam group of Islands in Gulf of Mannar. S .variolaris were found underneath and periphery of the dead reef, on the algal bed and on the exposed substratum. The density of the species 6-9 individuals / m2 was observed during the survey. Adult and young S. variolaris were recorded during the survey but juvenile was not observed as they usually hide within the dead rocks. The mass aggregation appears to be due to seasonal occurrence that exploit intensive grazing on macroalgae during the post monsoon in Gulf of Mannar. This study also discussed the commercial importance of this edible sea urchin species which could be an important food sources for the coastal population of Gulf of Mannar

MHD Unsteady Memory Convective Flow through Porous Medium with Variable Suction

A free convective unsteady visco-elastic flow through porous medium of variable permeability bounded by an infinite vertical porous plate with variable suction, constant heat flux under the influence of transverse uniform magnetic field has been investigated in the present study. The permeability of porous medium fluctuates with time about the constant mean. Approximate solutions for mean velocity, transient velocity, mean temperature and transient temperature of non-Newtonian flow and skin friction are obtained. The effects of various parameters such as Pr (Prandtl number), Gr (Grashof number), M (Hartmann number), ω (frequency parameter) and k0 (mean permeability parameter) on the above are depicted, skin friction, amplitude and phase are shown graphically and discussed. Expressions for fluctuating parts of velocity ‘Mr’ and ‘Mi’ are found and plotted graphically, effects of different parameters on them are discussed

Dynamic conformational changes of a tardigrade group-3 late embryogenesis abundant protein modulate membrane biophysical properties

A number of intrinsically disordered proteins (IDPs) encoded in stress-tolerant organisms, such as tardigrade, can confer fitness advantage and abiotic stress tolerance when heterologously expressed. Tardigrade-specific disordered proteins including the cytosolic-abundant heat-soluble proteins are proposed to confer stress tolerance through vitrification or gelation, whereas evolutionarily conserved IDPs in tardigrades may contribute to stress tolerance through other biophysical mechanisms. In this study, we characterized the mechanism of action of an evolutionarily conserved, tardigrade IDP, HeLEA1, which belongs to the group-3 late embryogenesis abundant (LEA) protein family. HeLEA1 homologs are found across different kingdoms of life. HeLEA1 is intrinsically disordered in solution but shows a propensity for helical structure across its entire sequence. HeLEA1 interacts with negatively charged membranes via dynamic disorder-to-helical transition, mainly driven by electrostatic interactions. Membrane interaction of HeLEA1 is shown to ameliorate excess surface tension and lipid packing defects. HeLEA1 localizes to the mitochondrial matrix when expressed in yeast and interacts with model membranes mimicking inner mitochondrial membrane. Yeast expressing HeLEA1 shows enhanced tolerance to hyperosmotic stress under nonfermentative growth and increased mitochondrial membrane potential. Evolutionary analysis suggests that although HeLEA1 homologs have diverged their sequences to localize to different subcellular organelles, all homologs maintain a weak hydrophobic moment that is characteristic of weak and reversible membrane interaction. We suggest that such dynamic and weak protein-membrane interaction buffering alterations in lipid packing could be a conserved strategy for regulating membrane properties and represent a general biophysical solution for stress tolerance across the domains of life.</p

Dynamic conformational changes of a tardigrade group-3 late embryogenesis abundant protein modulate membrane biophysical properties

A number of intrinsically disordered proteins (IDPs) encoded in stress-tolerant organisms, such as tardigrade, can confer fitness advantage and abiotic stress tolerance when heterologously expressed. Tardigrade-specific disordered proteins including the cytosolic-abundant heat-soluble proteins are proposed to confer stress tolerance through vitrification or gelation, whereas evolutionarily conserved IDPs in tardigrades may contribute to stress tolerance through other biophysical mechanisms. In this study, we characterized the mechanism of action of an evolutionarily conserved, tardigrade IDP, HeLEA1, which belongs to the group-3 late embryogenesis abundant (LEA) protein family. HeLEA1 homologs are found across different kingdoms of life. HeLEA1 is intrinsically disordered in solution but shows a propensity for helical structure across its entire sequence. HeLEA1 interacts with negatively charged membranes via dynamic disorder-to-helical transition, mainly driven by electrostatic interactions. Membrane interaction of HeLEA1 is shown to ameliorate excess surface tension and lipid packing defects. HeLEA1 localizes to the mitochondrial matrix when expressed in yeast and interacts with model membranes mimicking inner mitochondrial membrane. Yeast expressing HeLEA1 shows enhanced tolerance to hyperosmotic stress under nonfermentative growth and increased mitochondrial membrane potential. Evolutionary analysis suggests that although HeLEA1 homologs have diverged their sequences to localize to different subcellular organelles, all homologs maintain a weak hydrophobic moment that is characteristic of weak and reversible membrane interaction. We suggest that such dynamic and weak protein-membrane interaction buffering alterations in lipid packing could be a conserved strategy for regulating membrane properties and represent a general biophysical solution for stress tolerance across the domains of life.</p

A Solvable Regime of Disorder and Interactions in Ballistic Nanostructures, Part I: Consequences for Coulomb Blockade

We provide a framework for analyzing the problem of interacting electrons in a ballistic quantum dot with chaotic boundary conditions within an energy $E_T$ (the Thouless energy) of the Fermi energy. Within this window we show that the interactions can be characterized by Landau Fermi liquid parameters. When $g$, the dimensionless conductance of the dot, is large, we find that the disordered interacting problem can be solved in a saddle-point approximation which becomes exact as $g\to\infty$ (as in a large-N theory). The infinite $g$ theory shows a transition to a strong-coupling phase characterized by the same order parameter as in the Pomeranchuk transition in clean systems (a spontaneous interaction-induced Fermi surface distortion), but smeared and pinned by disorder. At finite $g$, the two phases and critical point evolve into three regimes in the $u_m-1/g$ plane -- weak- and strong-coupling regimes separated by crossover lines from a quantum-critical regime controlled by the quantum critical point. In the strong-coupling and quantum-critical regions, the quasiparticle acquires a width of the same order as the level spacing $\Delta$ within a few $\Delta$'s of the Fermi energy due to coupling to collective excitations. In the strong coupling regime if $m$ is odd, the dot will (if isolated) cross over from the orthogonal to unitary ensemble for an exponentially small external flux, or will (if strongly coupled to leads) break time-reversal symmetry spontaneously.Comment: 33 pages, 14 figures. Very minor changes. We have clarified that we are treating charge-channel instabilities in spinful systems, leaving spin-channel instabilities for future work. No substantive results are change