Toxicity and Behaviour of Clarias Gariepinus (Burchell, 1822) Fingerlings subjected to Piscicidal Plant Extract of Aidon Tetrapleura Tetraptera

The study was carried out to investigate the toxicity of water extract of Tetrapleura tetraptera fruits on catfish (Clarias gariepinus) fingerlings. The experiment was carried out under laboratory conditions for 96 hours with 30 fingerlings treated with each of the six graded concentrations (0g/300ml, 15g/300ml, 30g/300ml 45g/300ml, 60g/300ml and 75g/300ml) of dried fruits of Tetrapleura tetraptera. The study showed that the higher the concentration of the extract the higher the mortality of fingerlings while the toxicity of the extract reduced with time. Fifty percent mortality of the fingerlings was recorded at 24, 20 and 16 hours for 45g/300ml, 60g/300ml and 75g/300ml concentrations of extracts respectively. The result also showed that there were significant differences (P 0.05) in relation to mean mortality of fingerlings. The treated fingerlings were observed to showerratic swimming and loss of balance at high concentrations of extract. It is recommended that more studies be carried out on other parts of Tetrapleura tetraptera and their effect on different fish species

Optimal stochastic modelling with unitary quantum dynamics

Identifying and extracting the past information relevant to the future behaviour of stochastic processes is a central task in the quantitative sciences. Quantum models offer a promising approach to this, allowing for accurate simulation of future trajectories whilst using less past information than any classical counterpart. Here we introduce a class of phase-enhanced quantum models, representing the most general means of causal simulation with a unitary quantum circuit. We show that the resulting constructions can display advantages over previous state-of-art methods - both in the amount of information they need to store about the past, and in the minimal memory dimension they require to store this information. Moreover, we find that these two features are generally competing factors in optimisation - leading to an ambiguity in what constitutes the optimal model - a phenomenon that does not manifest classically. Our results thus simultaneously offer new quantum advantages for stochastic simulation, and illustrate further qualitative differences in behaviour between classical and quantum notions of complexity.Comment: 9 pages, 5 figure

Vertical Structure of Neutrino-Dominated Accretion Disk and Applications to Gamma-Ray Bursts

We revisit the vertical structure of neutrino-dominated accretion flows in spherical coordinates. We stress that the flow should be geometrically thick when advection becomes dominant. In our calculation, the luminosity of neutrino annihilation is enhanced by one or two orders of magnitude. The empty funnel along the rotation axis can naturally explain the neutrino annihilable ejection.Comment: 13 pages, 3 figures, accepted for publication in Ap

Interfering trajectories in experimental quantum-enhanced stochastic simulation

Simulations of stochastic processes play an important role in the quantitative sciences, enabling the characterisation of complex systems. Recent work has established a quantum advantage in stochastic simulation, leading to quantum devices that execute a simulation using less memory than possible by classical means. To realise this advantage it is essential that the memory register remains coherent, and coherently interacts with the processor, allowing the simulator to operate over many time steps. Here we report a multi-time-step experimental simulation of a stochastic process using less memory than the classical limit. A key feature of the photonic quantum information processor is that it creates a quantum superposition of all possible future trajectories that the system can evolve into. This superposition allows us to introduce, and demonstrate, the idea of comparing statistical futures of two classical processes via quantum interference. We demonstrate interference of two 16-dimensional quantum states, representing statistical futures of our process, with a visibility of 0.96 $\pm$ 0.02.Comment: 9 pages, 5 figure

Entanglement evolution in a cascaded system with losses

The dynamics of a cascaded system that consists of two atom-cavity subsystems is studied by using the quantum trajectory method. Unwanted losses are included, such as photon absorption and scattering by the cavity mirrors and spontaneous emission of the atoms. Considering an initially excited two-level atom in the source subsystem, analytical solutions are obtained. The entanglement evolution is studied for the two atoms and for the two intracavity fields.Comment: 6 pages, 4 figure

Magnetic ordering and structural phase transitions in strained ultrathin SrRuO3_{3}/SrTiO3_{3} superlattice

Ruthenium-based perovskite systems are attractive because their Structural, electronic and magnetic properties can be systematically engineered. SrRuO$_3$/SrTiO$_3$ superlattice, with its period consisting of one unit cell each, is very sensitive to strain change. Our first-principles simulations reveal that in the high tensile strain region, it transits from a ferromagnetic (FM) metal to an antiferromagnetic (AFM) insulator with clear tilted octahedra, while in the low strain region, it is a ferromagnetic metal without octahedra tilting. Detailed analyses of three spin-down Ru-t$_{2g}$ orbitals just below the Fermi level reveal that the splitting of these orbitals underlies these dramatic phase transitions, with the rotational force constant of RuO$_6$ octahedron high up to 16 meV/Deg$^2$, 4 times larger than that of TiO$_6$. Differently from nearly all the previous studies, these transitions can be probed optically through the diagonal and off-diagonal dielectric tensor elements. For one percent change in strain, our experimental spin moment change is -0.14$\pm$0.06 $\mu_B$, quantitatively consistent with our theoretical value of -0.1 $\mu_B$.Comment: 3 figures, 1 supplementary material, accepted by Phys. Rev. Let