Ecological thresholds and large carnivores conservation: Implications for the Amur tiger and leopard in China

The ecological threshold concept describes how changes in one or more factors at thresholds can result in a large shift in the state of an ecosystem. This concept focuses attention on limiting factors that affect the tolerance of systems or organisms and changes in them. Accumulating empirical evidence for the existence of ecological thresholds has created favorable conditions for practical application to wildlife conservation. Applying the concept has the potential to enhance conservation of two large carnivores, Amur tiger and leopard, and the knowledge gained could guide the construction of a proposed national park. In this review, ecological thresholds that result from considering a paradigm of bottom-up control were evaluated for their potential to contribute to the conservation of Amur tiger and leopard. Our review highlights that large carnivores, as top predators, are potentially affected by ecological thresholds arising from changes in climate (or weather), habitat, vegetation, prey, competitors, and anthropogenic disturbances. What's more, interactions between factors and context dependence need to be considered in threshold research and conservation practice, because they may amplify the response of ecosystems or organisms to changes in specific drivers. Application of the threshold concept leads to a more thorough evaluation of conservation needs, and could be used to guide future Amur tiger and leopard research and conservation in China. Such application may inform the conservation of other large carnivores worldwide

Non-damping oscillations at flaring loops

Context. QPPs are usually detected as spatial displacements of coronal loops in imaging observations or as periodic shifts of line properties in spectroscopic observations. They are often applied for remote diagnostics of magnetic fields and plasma properties on the Sun. Aims. We combine imaging and spectroscopic measurements of available space missions, and investigate the properties of non-damping oscillations at flaring loops. Methods. We used the IRIS to measure the spectrum over a narrow slit. The double-component Gaussian fitting method was used to extract the line profile of Fe XXI 1354.08 A at "O I" window. The quasi-periodicity of loop oscillations were identified in the Fourier and wavelet spectra. Results. A periodicity at about 40 s is detected in the line properties of Fe XXI, HXR emissions in GOES 1-8 A derivative, and Fermi 26-50 keV. The Doppler velocity and line width oscillate in phase, while a phase shift of about Pi/2 is detected between the Doppler velocity and peak intensity. The amplitudes of Doppler velocity and line width oscillation are about 2.2 km/s and 1.9 km/s, respectively, while peak intensity oscillate with amplitude at about 3.6% of the background emission. Meanwhile, a quasi-period of about 155 s is identified in the Doppler velocity and peak intensity of Fe XXI, and AIA 131 A intensity. Conclusions. The oscillations at about 40 s are not damped significantly during the observation, it might be linked to the global kink modes of flaring loops. The periodicity at about 155 s is most likely a signature of recurring downflows after chromospheric evaporation along flaring loops. The magnetic field strengths of the flaring loops are estimated to be about 120-170 G using the MHD seismology diagnostics, which are consistent with the magnetic field modeling results using the flux rope insertion method.Comment: 9 pages, 9 figures, 1 table, accepted by A&

Anisotropic Behavior of Knight Shift in Superconducting State of Na_xCoO_2yH_2O

The Co Knight shift was measured in an aligned powder sample of Na_xCoO_2yH_2O, which shows superconductivity at T_c \sim 4.6 K. The Knight-shift components parallel (K_c) and perpendicular to the c-axis (along the ab plane K_{ab}) were measured in both the normal and superconducting (SC) states. The temperature dependences of K_{ab} and K_c are scaled with the bulk susceptibility, which shows that the microscopic susceptibility deduced from the Knight shift is related to Co-3d spins. In the SC state, the Knight shift shows an anisotropic temperature dependence: K_{ab} decreases below 5 K, whereas K_c does not decrease within experimental accuracy. This result raises the possibility that spin-triplet superconductivity with the spin component of the pairs directed along the c-axis is realized in Na_xCoO_2yH_2O.Comment: 5 pages, 5 figures, to be published in Journal of Physical Society of Japan vol. 75, No.

Signals in Single-Event Pion Interferometry for Granular Sources of Quark-Gluon Plasma Droplets

We investigate two-pion Bose-Einstein correlations of quark-gluon plasma droplet sources in single-event measurements. We find that the distribution of the fluctuation between correlation functions of the single- and mixed-events provide useful signals to detect the granular structure of the source.Comment: 6 pages, 6 figures, in LaTe

Finite Size Scaling of Domain Chaos

Numerical studies of the domain chaos state in a model of rotating Rayleigh-Benard convection suggest that finite size effects may account for the discrepancy between experimentally measured values of the correlation length and the predicted divergence near onset

Pair Distribution Function of One-dimensional "Hard Sphere" Fermi and Bose Systems

The pair distributions of one-dimensional "hard sphere" fermion and boson systems are exactly evaluated by introducing gap variables.Comment: 4 page

Possible superconductivity above 25 K in single crystalline Co-doped BaFe2_{2}As2_{2}

We present superconducting properties of single crystalline Ba(Fe$_{0.9}$Co$_{0.1}$)$_{2}$As$_{2}$ by measuring magnetization, resistivity, upper critical field, Hall coefficient, and magneto-optical images. The magnetization measurements reveal fish-tail hysteresis loop at high temperatures and relatively high critical current density above $J_{c}=10^{5}$ A/cm$^{2}$ at low temperatures. Upper critical field determined by resistive transition is anisotropic with anisotropic parameter $\sim$ 3.5. Hall effect measurements indicate that Ba(Fe$_{0.9}$Co$_{0.1}$)$_{2}$As$_{2}$ is a multiband system and the mobility of electron is dominant. The magneto-optical imaging reveals prominent Bean-like penetration of vortices although there is a slight inhomogeneity in a sample. Moreover, we find a distinct superconductivity above 25 K, which leads us to speculate that higher transition temperature can be realized by fine tuning Co-doping level.Comment: 4 pages, 5 figure

High Sensitivity Hot-wire based Wind Velocity Sensor using Co-doped Fiber and Fiber Bragg Grating for use in mining applications

In this paper, a mathematical model of the temperature distribution in a fiber-optic version of the familiar 'hot-wire' wind velocity sensor has been established and a practical sensor device realized and investigated for use in coal mining applications. The relationship between the dynamic measurement range, the sensitivity, the sensor probe surface heat transfer coefficient and the wind speed (in the region where the sensor probe is located) has been investigated. The veracity of the predicted performance of the fiber-optic hot-wire mathematical model has then been verified by experiment. The sensitivity of the sensor probe to wind velocity was measured across several wind velocity ranges to be ∼1500pm per unit m/s wind velocity (in the range of 0 - 0.5 m/s), ∼330pm per unit m/s in the range 0.5 - 2 m/s and ∼50pm per unit m/s in the range of 2.0 - 4.5 m/s