Effect of temperature and salinity on the hatching of eggs and larval development of sugpo, Penaeus monodon

Abstract only.Incubation of Penaeus monodon eggs and rearing of different larval stages were undertaken at nine temperature-salinity combinations. The eggs, nauplii, zoea and mysis from one spawner kept as stock culture at ambient temperatures of 26-30°C and salinity of 32-33 ppt were exposed to temperature levels of 23, 28 and 33°C and salinity levels of 23, 28 and 33 ppt. Eggs and nauplii survived the sudden change of temperature and salinity (from ambient to experimental) but the zoea and mysis did not. However, salinities of 23 and 28 ppt in combination with any of the temperature levels produced weak larvae. Highest mean hatching rate was obtained at the temperature-salinity combination of 23°C-33 ppt, followed by 28°C-33 ppt and 33°C-33 ppt. Incubation periods for these treatments were 22, 16 and 14 hr, respectively. Survival rate of nauplius (taken from stock cultures) to first zoeal stage was highest at 28°C-33 ppt, followed by 33°C-33 ppt and 23°C-33 ppt with molting time of 50, 45 and 75 hr, respectively. The nauplii exposed to 33°C-33 ppt molted to zoea stage within 38 to 40 hr but later died. Those exposed to 23°C-33 ppt and 28°C-33 ppt reached zoea stage within 57 to 60 hr and 48 to 50 hr, respectively. Similarly, the nauplii taken from the stock cultures and reared until postlarval stage (P1) under experimental conditions completed the zoea and mysis stages in 9 to 11 days at 28°C C-33 ppt, 7 to 9 days at 33°C-33 ppt, and 13 to 15 days at 23°C-33 ppt. Statistical analysis showed that salinity had highly significant effect on rates of hatching of eggs and survival from nauplius to first zoeal stage but not temperature although the latter had an apparent effect. However, both factors affected time of hatching of eggs and time of molting from nauplius to zoea. Interaction effect was significant only on rate and time of hatching. Different sources (spawners) of eggs and nauplii did not have significant effect on time of hatching and molting from nauplius to zoea, but significantly affected the hatching rate of eggs and survival rate of nauplii to zoea stage

On the failure of subadditivity of the Wigner-Yanase entropy

It was recently shown by Hansen that the Wigner-Yanase entropy is, for general states of quantum systems, not subadditive with respect to decomposition into two subsystems, although this property is known to hold for pure states. We investigate the question whether the weaker property of subadditivity for pure states with respect to decomposition into more than two subsystems holds. This property would have interesting applications in quantum chemistry. We show, however, that it does not hold in general, and provide a counterexample.Comment: LaTeX2e, 4 page

"Missing" boundary conditions? Discretize first, substitute next, and combine later

A simple approach exists to prevent the need for constructing boundary conditions in situations where they are not explicitly supplied by the original analytical formulation of the problem. An example is the Poisson equation for the pressure in calculations of incompressible flow. Other examples are the streamfunction-vorticity formulation where no condition for the vorticity is present, and ADI methods where boundary conditions for the intermediate timesteps must be provided. In short, this approach can be described as follows: first discretize the equations of motion, next substitute the original boundary conditions (for the velocity), and finally combine the discrete equations (e.g., to a modified Poisson equation).

Solid transformations as a variant of three-dimention nanotechnology

The given article discusses a variant of natural nanotechnology in a volume material under solid-phase transformation. The article provides results on acoustic splitting in ammonium oxide NH4ClO4 in the low-temperature region. Ammonium oxide NH4ClO4 is structurally complex and chemically unstable. It has been stated that splitting of an acoustic wave in ammonium perchlorate under acoustical spectroscopy clearly detects coexistence of centrosymmetrical and noncentrosymmetrical phases. So, by example of ammonium perchlorate we consider possible use of acoustic splitting as a method of onset registration and growth control of a new phase within the parent one. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2068

Quasiparticle Relaxation Rates in a spatially inhomogeneous superconductor

Effective quasi-particle relaxation rates in reduced gap regions of a dirty superconductor (S) at low temperatures are calculated from microscopic theory

The structure, regulation, and performance of pension funds in nine industrial countries

The author offers an overview of issues relating to the development of funded pension schemes in industrial countries. The analysis applies the economic theory of pension regulation to experience with the structure, regulation, and performance of funds in nine countries - Canada, Denmark, Germany, Japan, Netherlands, Sweden, Switzerland, the United Kingdom, and the United States - seeking to shed light on the finance of old age security in developing countries and the reform of pension funds in industrial countries. The main points of the analysis follow. Pension funds are either defined benefit or defined contribution. The individual bears more risk with defined contribution plans because the pension benefit depends on asset returns. Conceptually, defined benefit funds offer better employee retirement insurance. Private defined benefit pensions are generally available only through companies and typically include some restriction of labor mobility. Because of some shortcomings of fully or largely funded plans, especially for income redistribution, governments have chosen to maintain at least basic levels of pay-as-you-go social security. The scope of such unfunded social security schemes is the key determinant of the scale of private retirement savings. The extent to which pension funds are used as a vehicle for retirement saving depends on the regulatory regime. Tax advantages are the most important incentive, but a wide range of other regulatory choices also make pension funds more or less attractive to firms and employees. And some regulations, such as those affecting the portability of pensions, may have important consequences for economic efficiency. Though countries differ widely in their regulation of pension funds, some suggestions for good practice can still be made. Whether pension funds are a cost effective way of providing pensions depends on the real asset returns that can be attained, in relation to the growth of real wages. Ideally, there should be a gap of 2 to 3 percent between them. Portfolio distributions and fund management are the key determinants of returns to pension funds, subject to the returns available in the market. Prudent diversification in domestic and foreign markets and indexation of much of pension funds'portfolios both appear to be important. Pension funds affect capital markets in many ways. They influence market structure and demand for securities; stimulate innovation, allocative efficiency, and market development; and have a positive effect on overall saving. They may also have some deleterious effects, such as increases in volatility, short termism, and weakening of the control exerted by investors and creditors over firms. Prospects for pension funds in industrial countries vary with the maturity of existing funds and the generosity of social security benefits. In countries such as France, Germany, and Italy, growth in coming decades could be sizable. The key recommendations for countries that are just starting pension funds are for a mix of social security and private funds; for separate funding rather than book reserves; for defined benefit plans, subject to appropriate regulation; and for company-based pension funds.Pensions&Retirement Systems,Insurance&Risk Mitigation,Environmental Economics&Policies,Insurance Law,Banks&Banking Reform

The local magnetic moments and hyperfine magnetic fields in disordered metal-metalloid alloys

The local magnetic moments and hyperfine magnetic fields (HFF) in the ordered alloys Fe_{15}Sn and Fe_{15}Si are calculated with the first-principles full-potential linear augmented plane wave (FP LAPW) method. The results are compared with the experimental data on Fe-M (M=Si, Sn) disordered alloys at small metalloid concentration. The relaxation of the lattice around the impurity and its influence on the quantities under consideration are studied. The mechanism of the local magnetic moment formation is described. It is proved that the main distinction between these alloys is connected with the different lattice parameters. Three contributions to the HFF are discussed: the contributions of the core and valence electron polarization to the Fermi-contact part, and the contibution from the orbital magnetic moment.Comment: 3 pages, 3 figures, submitted to Phys. Rev.

Multilevel iterative solvers for the edge finite element solution of the 3D Maxwell equation

In the edge vector finite element solution of the frequency domain Maxwell equations, the presence of a large kernel of the discrete rotor operator is known to ruin convergence of standard iterative solvers. We extend the approach of [1] and, using domain decomposition ideas, construct a multilevel iterative solver where the projection with respect to the kernel is combined with the use of a hierarchical representation of the vector finite elements. The new iterative scheme appears to be an efficient solver for the edge finite element solution of the frequency domain Maxwell equations. The solver can be seen as a variable preconditioner and, thus, accelerated by Krylov subspace techniques (e.g. GCR or FGMRES). We demonstrate the efficiency of our approach on a test problem with strong jumps in the conductivity. [1] R. Hiptmair. Multigrid method for Maxwell's equations. SIAM J. Numer. Anal., 36(1):204-225, 1999

Hard X-ray spectra and positions of solar flares observed by RHESSI: photospheric albedo, directivity and electron spectra

<p><b>Aims</b>: We investigate the signature of the photospheric albedo contribution in solar flare hard X-ray spectra, the effect of low energy cutoffs in electron spectra, and the directivity of hard X-ray emission.</p> <p><b>Methods</b>: Using Ramaty High Energy Solar Spectroscopic Imager (RHESSI) flare data we perform a statistical analysis of spatially integrated spectra and positions of solar flares.</p> <p><b>Results</b>: We demonstrate clear centre-to-limb variation of photon spectral indices in the 15-20 keV energy range and a weaker dependency in the 20-50 keV range which is consistent with photospheric albedo as the cause. The results also suggest that low-energy cutoffs sometimes inferred in mean electron spectra are an artefact of albedo. We also derive the anisotropy (ratio of downward/observer directed photons) of hard X-ray emission in the 15-20 keV range for various heliocentric angles.</p&gt

Virtual Analysis and Reduction of Side-Channel Vulnerabilities of Smartcards

This paper focuses on the usability of the PINPAS tool. The PINPAS tool is an instruction-level interpreter for smartcard assembler languages, augmented with facilities to study side-channel vulnerabilities. The tool can simulate side-channel leakage and has a suite of utilities to analyze this. The usage of the tool, for the analysis of a cryptographic algorithm is illustrated using the standard AES and RSA. Vulnerabilities of the implementations are identified and protective measures added. It is argued, that the tool can be instrumental for the design and realization of secure smartcard implementations in a systematic wa