Acclimation responses of gill ionocytes of red tilapia (Oreochromis mossambicus × O. niloticus) to water salinity and alkalinity

To understand the acclimation strategies of red tilapia to different environments, this study aimed to evaluate different responses of red tilapia (O. mossambicus × O. niloticus) to salinity (10-30‰), alkalinity (1-3 gL^-1 NaHCO3) and salinity and alkalinity (10/1-30/3 ‰/gL^-1 NaHCO3) environments. Localization, type, size, and numeration of gill ionocytes were investigated on the same specimens by scanning electron microscopy (SEM) and immunohistochemistry (IHC) with antibodies of Na+/K+-ATPase (NKA), Na+/K+/2Cl-contransporter (NKCC), cystic fibrosis transmembrane conductance regulator (CFTR) and carbonic anhydrase (CA). Ionocytes were only located on filaments conducted by SEM. Four types of ionocytes namely pit, convex, concave and transitory types were determined morphologically by their apical openings of which concave and transitory type were not present in freshwater (FW) and saltwater (SW) fish (10). Both ionocytes size and number increased with elevated stress levels. In comparison to FW, density of ionotypes increased to about 4.75, 3.00 and 3.44 fold in SW (30), AW (3) and S&AW (30/3) respectively. Immunoreactive cells on gill filaments confirmed branchial distribution of ionocytes. Immunoreaction of NKA, NKCC and CA appeared in FW except for CFTR while they all appeared in SW (30), AW (3) and S&AW (30/3)

Measurement of the Atmospheric Muon Spectrum from 20 to 3000 GeV

The absolute muon flux between 20 GeV and 3000 GeV is measured with the L3 magnetic muon spectrometer for zenith angles ranging from 0 degree to 58 degree. Due to the large exposure of about 150 m2 sr d, and the excellent momentum resolution of the L3 muon chambers, a precision of 2.3 % at 150 GeV in the vertical direction is achieved. The ratio of positive to negative muons is studied between 20 GeV and 500 GeV, and the average vertical muon charge ratio is found to be 1.285 +- 0.003 (stat.) +- 0.019 (syst.).Comment: Total 32 pages, 9Figure

Response of SDOF nonlinear oscillators with lightly fractional derivative damping under real noise excitations

This paper deals with the response of single-degree-of-freedom (SDOF) strongly nonlinear oscillator with lightly fractional derivative damping to external and (or) parametric real noise excitations. First, the state vector of the displacement and the velocity is approximated by one-dimensional time-homogeneous diffusive Markov process of amplitude through using the stochastic averaging method. Then, the stationary probability density of amplitude is obtained by solving the Fokker-Planck-Kolmogorov (FPK) equation associated with the averaged Itô equation of amplitude, in which the Fourier series expansions are used to obtain the explicit expressions of the drift and diffusion coefficients. Finally, the response of a Duffing oscillator with lightly fractional derivative damping under external and parametric real noise excitations is evaluated by using the proposed procedure and compared with that from the Monte Carlo simulation of original system