The magnetization-driven random field Ising model at T=0

We study the hysteretic evolution of the random field Ising model (RFIM) at T=0 when the magnetization M is controlled externally and the magnetic field H becomes the output variable. The dynamics is a simple modification of the single-spin-flip dynamics used in the H-driven situation and consists in flipping successively the spins with the largest local field. This allows to perform a detailed comparison between the microscopic trajectories followed by the system with the two protocols. Simulations are performed on random graphs with connectivity z=4 (Bethe lattice) and on the 3-D cubic lattice. The same internal energy U(M)is found with the two protocols when there is no macroscopic avalanche and it does not depend on whether the microscopic states are stable or not. On the Bethe lattice, the energy inside the macroscopic avalanche also coincides with the one that is computed analytically with the H-driven algorithm along the unstable branch of the hysteresis loop. The output field, defined here as dU/dM, exhibits very large fluctuations with the magnetization and is not self-averaging. Relation to the experimental situation is discussed.Comment: 11 pages, 13 figure

Indigenous Knowledge’s for Healthy Habits and Life

Health and habits are interrelated. Our older generations viewed nature and all living beings as the beads of the same manacle. From rising up early in the morning till the moment of sleep enraptures us at night we are entangled in various activities that goes hand in hand with nature. Our ancestors realized much earlier that the pros and cones of these deeds will reflect through our health

Influence of the driving mechanism on the response of systems with athermal dynamics: the example of the random-field Ising model

We investigate the influence of the driving mechanism on the hysteretic response of systems with athermal dynamics. In the framework of local-mean field theory at finite temperature (but neglecting thermallly activated processes), we compare the rate-independent hysteresis loops obtained in the random field Ising model (RFIM) when controlling either the external magnetic field $H$ or the extensive magnetization $M$. Two distinct behaviors are observed, depending on disorder strength. At large disorder, the $H$-driven and $M$-driven protocols yield identical hysteresis loops in the thermodynamic limit. At low disorder, when the $H$-driven magnetization curve is discontinuous (due to the presence of a macroscopic avalanche), the $M$-driven loop is re-entrant while the induced field exhibits strong intermittent fluctuations and is only weakly self-averaging. The relevance of these results to the experimental observations in ferromagnetic materials, shape memory alloys, and other disordered systems is discussed.Comment: 11 pages, 11 figure

Influence of Thermal Effluents on the Growth Characteristics of Phytoplankton in the Waters of Tuticorin Bay

The paper reports the results of investigations conducted in 1990, on the physico-chemical aspects of Tuticorin Bay waters in relation to the abundance of phytoplankton. Selected species of phytoplankton were experimental1y cultured to study the influence of thermal effluents. For this purpose cultures ,vere raised in media collected from 4 stations. showing different extents of pollution. Four species of nannoplankton, namely. l sochrysis galbana (Haptophyceae), Dicrateria inornata (chrysophyceae), Tetraselmis gracilis (Chloro-phyceae) and Chaetoceros calcitrans (Bacillariophyceae) were grown in the water samples collected from selected stations. The experiments showed stimulatory trend of growth for the first 7-8 days and gradual inhibitory effect on the multiplication in subsequent days. Among them, the phytoflagellates (Jsochrysis, Dicrateria and Tetraselmis)showed good growth in the samples of media collected from locations near to the pollution source. The rate of production of both Tetraselmis and Dicrateria, which are known to exist in the polluted waters, indicated enhanced growth in the Bay waters. The growth of the diatom, Chaetoceros has been found to be uniform except in the sample collected from the point nearest to the source of pollution. Though the long-term effects of these samples have not been studied, the experiments revealed the possible effects of.thermal effiuents on the phytoplankton population in the waters of Tuticorin Bay

Cyclic feeding of low and high protein diets reduces production cost of Labeo rohita (Hamilton, 1822)

Eighty four days feeding trial (3 feeding cycle ; each cycle of 28 days comprising 21 days with low protein and 7 days with normal or high protein diets) was conducted with Labeo rohita fingerlings to investigate the growth performance. Four diets; D1 (10% CP); D2 (30% CP); D3 (35% CP) and D4 (40% CP) were prepared. A total of 225 fingerlings were distributed randomly into five treatments in triplicates. T1 and T2 groups were fed with D1 and D2 diets respectively throughout the experimental period. The feeding cycle of 28 days consisted of 21 days feeding with D1 and 7 days with D2 (T3); D3 (T4) or D4 (T5). Higher growth rate in terms of specific growth rate, feed conversion ratio and apparent net protein utilisation were found in T2 and T3 group compared to T4 and T5. However, protein efficiency ratio of T3 group was significantly higher than the T2 group (p<0.05). Highest and lowest content of protein and lipid was observed in T2 group, whereas, the ash content was highest in T1 group. Feeding cost was considerably reduced with T3 group of low protein intake (43.63%) registering 20.17% saving in production cost. The results indicate that fish fed with cyclic feeding schedule of 21 days with D1 (10% CP) followed by 7 days with a normal diet, D2 (30% CP) could reduce the production cost with considerable savings in feed cost

Processing The Interspecies Quorum-Sensing Signal Autoinducer-2 (AI-2) Characterization Of Phospho-(S)-4,5-Dihydroxy-2,3-Pentanedione Isomerization By LsrG Protein

The molecule (S)-4,5-dihydroxy-2,3-pentanedione (DPD) is produced by many different species of bacteria and is the precursor of the signal molecule autoinducer-2 (AI-2). AI-2 mediates interspecies communication and facilitates regulation of bacterial behaviors such as biofilm formation and virulence. A variety of bacterial species have the ability to sequester and process the AI-2 present in their environment, thereby interfering with the cell-cell communication of other bacteria. This process involves the AI-2-regulated lsr operon, comprised of the Lsr transport system that facilitates uptake of the signal, a kinase that phosphorylates the signal to phospho-DPD (P-DPD), and enzymes (like LsrG) that are responsible for processing the phosphorylated signal. Because P-DPD is the intracellular inducer of the lsr operon, enzymes involved in P-DPD processing impact the levels of Lsr expression. Here we show that LsrG catalyzes isomerization of P-DPD into 3,4,4-trihydroxy-2-pentanone-5-phosphate. We present the crystal structure of LsrG, identify potential catalytic residues, and determine which of these residues affects P-DPD processing in vivo and in vitro. We also show that an lsrG deletion mutant accumulates at least 10 times more P-DPD than wild type cells. Consistent with this result, we find that the lsrG mutant has increased expression of the lsr operon and an altered profile of AI-2 accumulation and removal. Understanding of the biochemical mechanisms employed by bacteria to quench signaling of other species can be of great utility in the development of therapies to control bacterial behavior

Discovery and partial genomic characterisation of a novel nidovirus associated with respiratory disease in wild shingleback lizards (Tiliqua rugosa)

A respiratory disease syndrome has been observed in large numbers of wild shingleback lizards (Tiliqua rugosa) admitted to wildlife care facilities in the Perth metropolitan region of Western Australia. Mortality rates are reportedly high without supportive treatment and care. Here we used next generation sequencing techniques to screen affected and unaffected individuals admitted to Kanyana Wildlife Rehabilitation Centre in Perth between April and December 2015, with the resultant discovery of a novel nidovirus significantly associated with cases of respiratory disease according to a case definition based on clinical signs. Interestingly this virus was also found in 12% of apparently healthy individuals, which may reflect testing during the incubation period or a carrier status, or it may be that this agent is not causative in the disease process. This is the first report of a nidovirus in lizards globally. In addition to detection of this virus, characterisation of a 23,832 nt segment of the viral genome revealed the presence of characteristic nidoviral genomic elements providing phylogenetic support for the inclusion of this virus in a novel genus alongside Ball Python nidovirus, within the Torovirinae sub-family of the Coronaviridae. This study highlights the importance of next generation sequencing technologies to detect and describe emerging infectious diseases in wildlife species, as well as the importance of rehabilitation centres to enhance early detection mechanisms through passive and targeted health surveillance. Further development of diagnostic tools from these findings will aid in detection and control of this agent across Australia, and potentially in wild lizard populations globally

Particle growing mechanisms in Ag-ZrO2 and Au-ZrO2 granular films obtained by pulsed laser deposition

Thin films consisting of Ag and Au nanoparticles embedded in amorphous ZrO2 matrix were grown by pulsed laser deposition in a wide range of metal volume concentrations in the dielectric regime (0.08<x(Ag)<0.28 and 0.08<x(Au)<0.52). High resolution transmission electron microscopy (TEM) showed regular distribution of spherical Au and Ag nanoparticles having very sharp interfaces with the amorphous matrix. Mean particle size determined from X-ray diffraction agreed with direct TEM observation. The silver mean diameter increases more abruptly with metal volume content than that corresponding to gold particles prepared under the same conditions. Two mechanisms of particle growing are observed: nucleation and particle coalescence, their relative significance being different in both granular systems, which yields very different values of the percolation threshold (xc(Ag)~0.28 and xc(Au)~0.52).Comment: 6 figure

Versatility of field theory motivated nuclear effective Lagrangian approach

We analyze the results for infinite nuclear and neutron matter using the standard relativistic mean field model and its recent effective field theory motivated generalization. For the first time, we show quantitatively that the inclusion in the effective theory of vector meson self-interactions and scalar-vector cross-interactions explains naturally the recent experimental observations of the softness of the nuclear equation of state, without losing the advantages of the standard relativistic model for finite nuclei

Tropical Fourier-Motzkin elimination, with an application to real-time verification

We introduce a generalization of tropical polyhedra able to express both strict and non-strict inequalities. Such inequalities are handled by means of a semiring of germs (encoding infinitesimal perturbations). We develop a tropical analogue of Fourier-Motzkin elimination from which we derive geometrical properties of these polyhedra. In particular, we show that they coincide with the tropically convex union of (non-necessarily closed) cells that are convex both classically and tropically. We also prove that the redundant inequalities produced when performing successive elimination steps can be dynamically deleted by reduction to mean payoff game problems. As a complement, we provide a coarser (polynomial time) deletion procedure which is enough to arrive at a simply exponential bound for the total execution time. These algorithms are illustrated by an application to real-time systems (reachability analysis of timed automata).Comment: 29 pages, 8 figure