Influences of dietary lipid and phosphorus levels on retention and excretion of phosphorus and nitrogen in fingerlings red sea bream, Pagrus major

A laboratory based 2x3 factorial experiment was conducted for 12 weeks to investigate the influences of dietary lipid and phosphorus (P) levels on retention and excretion of phosphorus and nitrogen (N) in fingerling red sea bream. Two levels of lipid (210 and 260 g/kg) and three levels of phosphorus (17, 14 and 12 g/kgˉ¹) in the dry diets were tested. Duplicate groups of 25 red sea bream (average weight 3.74±0.07 g) per 60L glass tank were fed experimental diets three times a day near to satiation level at 22 to 28°C water temperature. A reduction in dietary fish meal from 500 to 300 g/kg dry diet, corresponding to a supplementation in both dietary lipid and P resulted in significant increase in both P and N retention which resulted in the reduction of their excretion by red sea bream. The overall results of the present study demonstrated that both lipid and phosphorus supplementation are necessary for developing less-polluting feed which in turn, reduce fish meal level in the diet of fingerling red sea bream. Further studies in this regard with different size and age groups of red sea bream are warranted

Dynamical Casimir effect for magnons in a spinor Bose-Einstein condensate

Magnon excitation in a spinor Bose-Einstein condensate by a driven magnetic field is shown to have a close analogy with the dynamical Casimir effect. A time-dependent external magnetic field amplifies quantum fluctuations in the magnetic ground state of the condensate, leading to magnetization of the system. The magnetization occurs in a direction perpendicular to the magnetic field breaking the rotation symmetry. This phenomenon is numerically demonstrated and the excited quantum field is shown to be squeezed.Comment: 8 pages, 3 figure

Spin-Charge Separation and Kinetic Energy in the t-J Model

I show that spin-charge separation in 2-D t-J model leads to an increase of kinetic energy. Using a sum rule, I derive an exact expression for the lowest possible KE (E_{bound}) for any state without doubly occupied sites. KE of relevant slave-boson and Schwinger-boson mean-field states -- which exhibit complete spin-charge separation -- are found to be much larger than E_{bound}. Examination of n(k) shows that the large increse in KE is due to excessive depletion of electrons from the bottom of the band (Schwinger boson) and of holes from the top (slave boson). To see whether the excess KE is simply due to poor treatment of the constraints, I solve the constraint problem analytically for the Schwinger boson case in the J = 0 limit. This restores gauge invariance, incorrectly violated in MF theories. The result is a generalized Hartree-Fock state of the Hubbard model, but one that includes spin waves. Even after constraints are imposed correctly, the KE remains much larger than E_{bound}. These results support the notion, advanced earlier [PRB 61, 8663 (2000)] that spin-charge separation in the MF state costs excessive KE, and makes the state unstable toward recombination processes which lead to superconductivity in d = 2 and a Fermi liquid state in higher dimensions.Comment: 13 pages, LateX plus three figures. To appear in Phys Rev B Typos correcte

Schwinger-Boson Mean-Field Theory of Mixed-Spin Antiferromagnet L2BaNiO5L_2BaNiO_5

The Schwinger-boson mean-field theory is used to study the three-dimensional antiferromagnetic ordering and excitations in compounds $L_2BaNiO_5$, a large family of quasi-one-dimensional mixed-spin antiferromagnet. To investigate magnetic properties of these compounds, we introduce a three-dimensional mixed-spin antiferromagnetic Heisenberg model based on experimental results for the crystal structure of $L_2BaNiO_5$. This model can explain the experimental discovery of coexistence of Haldane gap and antiferromagnetic long-range order below N\'{e}el temperature. Properties such as the low-lying excitations, magnetizations of $Ni$ and rare-earth ions, N\'{e}el temperatures of different compounds, and the behavior of Haldane gap below the N\'{e}el temperature are investigated within this model, and the results are in good agreement with neutron scattering experiments.Comment: 12 pages, 6 figure

Hydrogen absorption properties of amorphous (Ni0.6Nb0.4−yTay)100−xZrx membranes

Ni based amorphous materials have great potential as hydrogen purification membranes. In the present work the melt spun (Ni0.6Nb0.4−yTay)100−xZrx with y=0, 0.1 and x=20, 30 was studied. The result of X-ray diffraction spectra of the ribbons showed an amorphous nature of the alloys. Heating these ribbons below T < 400 °C, even in a hydrogen atmosphere (1−10 bar), the amorphous structure was retained. The crystallization process was characterized by differential thermal analysis and the activation energy of such process was obtained. The hydrogen absorption properties of the samples in their amorphous state were studied by the volumetric method, and the results showed that the addition of Ta did not significantly influence the absorption properties, a clear change of the hydrogen solubility was observed with the variation of the Zr content. The values of the hydrogenation enthalpy changed from ~37 kJ/mol for x=30 to ~9 kJ/mol for x=20. The analysis of the volumetric data provides the indications about the hydrogen occupation sites during hydrogenation, suggesting that at the beginning of the absorption process the deepest energy levels are occupied, while only shallower energy levels are available at higher hydrogen content, with the available interstitial sites forming a continuum of energy levels

Effects of dietary phosphorus and zinc levels on growth artd bone mineralization in fingerlings of rainbow trout, Oncorhynchus mykiss

A laboratory based 2 x 2 factorial experiment was conducted to investigate the influences of dietary phosphorus and zinc levels on growth and bone mineralization in fingerlings of rainbow trout for 21 weeks. Two levels of phosphorus (19 and 30 mg/g) and two levels of zinc (55 and 103 Ag/g) in the dry diets were tested. Duplicate tanks of 30 rainbow trout (average weight 1.56 ± 0.24 g) per 60L glass tank were fed experimental diets three times a day to apparent satiation level at 15 to 24°C water temperature. The results of the present study demonstrated that dietary phosphorus supplementation influenced the growth and bone mineralization whereas zinc levels significantly (p<0.05) influenced bone mineralization in rainbow trout. Further investigations in this area with different size and age groups of this fish are broadly needed

Smaller sample sizes for phase II trials based on exact tests with actual error rates by trading-off their nominal levels of significance and power

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Comment on 'Anti-tumour activity of abiraterone and diethylstilboestrol when administered sequentially to men with castration-resistant prostate cancer'

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A strong-coupling expansion for the Hubbard model

We reconsider the strong-coupling expansion for the Hubbard model recently introduced by Sarker and Pairault {\it et al.} By introducing slave particles that act as projection operators onto the empty, singly occupied and doubly occupied atomic states, the perturbation theory around the atomic limit distinguishes between processes that do conserve or do not conserve the total number of doubly occupied sites. This allows for a systematic $t/U$ expansion that does not break down at low temperature ($t$ being the intersite hopping amplitude and $U$ the local Coulomb repulsion). The fermionic field becomes a two-component field, which reflects the presence of the two Hubbard bands. The single-particle propagator is naturally expressed as a function of a $2 \times 2$ matrix self-energy. Furthermore, by introducing a time- and space-fluctuating spin-quantization axis in the functional integral, we can expand around a ``non-degenerate'' ground-state where each singly occupied site has a well defined spin direction (which may fluctuate in time). This formalism is used to derive the effective action of charge carriers in the lower Hubbard band to first order in $t/U$. We recover the action of the t-J model in the spin-hole coherent-state path integral. We also compare our results with those previously obtained by studying fluctuations around the large-$U$ Hartree-Fock saddle point.Comment: 20 pages RevTex, 3 figure

Study on Sedation with Local Analgesia in Calves

. The effect of sedatives and analgesics on heart rate, respiration rate and rectal temperature were observed. Heart rate and respiration rate significantly decreased during sedation with xylazine hydrochloride plus 2% lignocaine hydrochloride or 0.5% bupivacaine hydrochloride. A significantly decreased heart rate and respiration rate also found during sedation with diazepam plus 2% lignocaine hydrochloride or 0.5% bupivacaine hydrochloride. Two percent lignocaine hydrochloride showed short onset, rapid spreading and no side effect. Duration of analgesia was longer with 0.5 % bupivacaine hydrochloride (55.88±1.58 min in Group B and 48±11.25 min in Group D) compared to 2% lignocaine hydrochloride (39.60±5.77 min in Group A and 43.6±5.81 min in Group C). Xylazine hydrochloride showed short onset and long duration of sedation compared to diazepam. So for herniorraphy, xylazine hydrochloride can be used as a better sedative while 0.5 % bupivacaine hydrochloride can be used as a local analgesic for longer duration of action