Aerosol scattering of ultraviolet sunlight in the tropical maritime atmosphere

The effects of atmospheric aerosol scattering on the vertical profile of solar ultraviolet radiation are investigated. Measurements of diffuse and total ultraviolet radiation were made using a rocketborne optical sonde in the marine atmosphere of Antigua. During observations, the sun was at zenith. Vertical profiles of directly transmitted solar radiation were calculated by subtraction of the diffuse component from the total radiance. Using these values of direct downward solar UV-flux, the optical thickness of the atmosphere was derived as a function of altitude. Absorption by ozone was also considered. In the troposphere the values of observed optical thickness were in general equal to or lower than those expected theoretically from Rayleigh scattering alone. The measured radiation profiles were compared with those computed for a multiple scattering model atmosphere. Some computations regarding the interaction of UV-sunlight with maritime aerosols are presented

Serum antibody against Vibrio anguillarum in cultured rainbow trout (Oncorhynchus mykiss)

In order to determine the concentration of the antibodies against the pathogenic Vibrio anguillarum, three hundred blood samples were taken from 9-12 month old cultured rainbow trout (Oncorhynchus mykiss) in 4 farms in the north and west region of Fars Province, which had been exposed to this bacteria. An indirect ELISA was employed to examine the serum. Using soluble antigen (SA) indicated that 54% of the examined blood samples contained antibodies against Vibrio anguillarum, while by using whole cell antigen (WCB) only 53% of samples were found to be seriopositive. The highest seriopositivity rate (83%) was observed in farm #2, where clinical signs of vibriosis also occurred. This study revealed that Rainbow trouts fed on raw marine fish meal powder are more exposed to V. anguillarum. Vibriosis in cultured Rainbow trout in Iranian inland freshwater farms is also discussed in this paper

Dynamic evolving neural fuzzy inference system equalization scheme in mode division multiplexer for optical fiber transmission

The performance of optical mode division multiplexer (MDM) is affected by inter-symbol interference (ISI), which arises from higher-order mode coupling and modal dispersion in multimode fiber (MMF). Existing equalization algorithms in MDM can mitigate linear channel impairments, but cannot tackle nonlinear channel impairments accurately. Therefore, mitigating the noise in the received signal of MDM in the presence of ISI to recover the transmitted signal is important issue. This paper aims at controlling the broadening of the signal from MDM and minimizing the undesirable noise among channels. A dynamic evolving neural fuzzy inference system (DENFIS) equalization scheme has been used to achieve this objective. Results illustrate that nonlinear DENFIS equalization scheme can improve the received distorted signal from an MDM with better accuracy than previous linear equalization schemes such as recursive‐least‐square (RLS) algorithm. Desirably, this effect allows faster data transmission rate in MDM. Additionally, the successful offline implementation of DENFIS equalization in MDM encourages future online implementation of DENFIS equalization in embedded optical systems

Transaction Management in Distributed Database Systems: The Case of Oracle’s Two-Phase Commit

Distributed database systems (DDBS) pose different problems when accessing distributed and replicated databases. Particularly, access control and transaction management in DDBS require different mechanism to monitor data retrieval and update to databases. Current trends in multi-tier client/server networks make DDBS an appropriated solution to provide access to and control over localized databases. Oracle, as a leading Database Management System (DBMS) vendor employs the two-phase commit technique to maintain consistent state for the database. The objective of this paper is to explain transaction management in DDBS and how Oracle implements this technique. An example is given to demonstrate the step involved in executing the two-phase commit. By using this feature of Oracle, organizations will benefit from the use of DDBS to successfully manage the enterprise data resource

The Cholesterol Lowering Effects of Eurycoma Longifolia Jack (Tongkat Ali) Root Extract in Male Rats

Background: To investigate the effect of Eurycoma longifolia Jack root extract on serum lipids in rats. Methods: Twenty-six mature male albino Wistar rats were used in this study. A group of 18 rats were fed a high fat and high cholesterol diet for 4 weeks, after which their lipid profile was compared to the control group, who were kept on a normal diet. The rats were then further divided into three groups, the Cf group that continued to feed on a high fat and cholesterol diet only, and group A and group B who continued on a high fat diet with the addition of 5 mg/kg and 10 mg/kg of Eurycoma longifolia Jack root extract respectively for 4 weeks. After the 4 week period, the rat's lipid profiles were analysed again. Results: Group A and B showed significant total cholesterol reduction when compared to the Cf group, 140 ± 7.23, 139.63 ± 7.95, 192.14 ± 8.96 mg/dL respectively (p < 0.001). The total cholesterol/HDL ratio in group A was 5 however there was a sharp increase in group B to a high-risk level of 9.2 indicating a significant drop in HDL levels. The LDL level increased significantly in both group A and B compared to the Cf group. Conclusions: Eurycoma longifolia Jack root extract is effective in lowering total cholesterol, however the dose needs to be adjusted to prevent an excessive decrease in HDL levels

Quantum measures and integrals

We show that quantum measures and integrals appear naturally in any $L_2$-Hilbert space $H$. We begin by defining a decoherence operator $D(A,B)$ and it's associated $q$-measure operator $\mu (A)=D(A,A)$ on $H$. We show that these operators have certain positivity, additivity and continuity properties. If $\rho$ is a state on $H$, then D_\rho (A,B)=\rmtr\sqbrac{\rho D(A,B)} and $\mu_\rho (A)=D_\rho (A,A)$ have the usual properties of a decoherence functional and $q$-measure, respectively. The quantization of a random variable $f$ is defined to be a certain self-adjoint operator \fhat on $H$. Continuity and additivity properties of the map f\mapsto\fhat are discussed. It is shown that if $f$ is nonnegative, then \fhat is a positive operator. A quantum integral is defined by \int fd\mu_\rho =\rmtr (\rho\fhat\,). A tail-sum formula is proved for the quantum integral. The paper closes with an example that illustrates some of the theory.Comment: 16 page

Hydrodynamics of single-deadrise hulls and their catamaran configurations

AbstractAsymmetric planing hulls are often used on high-speed catamarans. In this study, a linearized potential-flow method is applied for modeling steady hydrodynamics of single asymmetric hulls and their catamaran setups. Numerical results are validated with available experimental data and empirical correlations. Parametric calculation results are presented for the lift coefficient and the center of pressure for variable hull geometry, spacings, and speed regimes. The lift coefficient is found to increase at smaller hull spacings and decrease at higher Froude numbers and higher deadrise angles