Effects of gamma radiation on codling moth, Cydia pomonella (L.), eggs

The radiosensitivity of codling moth, Cydia pomonella (L.), eggs in different stages of development was studied. Eggs ranging in age from 1–24 to 97–120 h were exposed, at 24 h intervals, to gamma radiation doses ranging from 10 to 350 Gy. The effects of gamma radiation on egg hatch, pupation and adult emergence was examined. Results showed that the radiosensitivity of codling moth eggs decreased with increasing age. Egg hatch in 1–24 h old eggs was significantly affected at 20 Gy dose and at 60 Gy dose, egg hatch decreased to about 1%. At the age of 25–48 h, however, egg hatch at 60 Gy dose was about 10%, and egg sensitivity to gamma irradiation decreased significantly in the 49–72 h age group; 60 Gy dose had no significant effect on egg hatch. Eggs irradiated few hours before hatch (at the blackhead stage), were the most resistant ones; 100 Gy had no significant effect on egg hatch and at 350 Gy dose over 56% of the eggs hatched. When adult emergence was used as a criterion for measuring effectiveness, however, the effect of gamma radiation was very sever. A dose of 60 Gy completely prevented adult emergence and at 100 Gy dose all resulted larvae died before pupation.     

Multi-elemental analysis of solidified mineral melt samples by Laser-Induced Breakdown Spectroscopy coupled with a linear multivariate calibration

Laser-Induced Breakdown Spectroscopy (LIBS) has been successfully applied for multi-elemental analysis of solidified mineral melt samples containing several oxides present in various concentrations. The plasma was generated using a Nd:YAG laser and the spectra were acquired using an Echelle spectrometer, coupled to an ICCD detector, which covers a spectral range from 200 to 780 nm. Using a set of 19 calibration samples, we first established univariate calibration curves for the major elements (Al, Fe, Mg, Ca, Ti and Si). We found out that the presence of matrix effects makes such a model, traditionally used in LIBS, not satisfying for quantitative analysis of such samples. Indeed, no sufficiently linear trends can be extracted from the calibration curves for the elements of interest considering all the samples. Instead, a much more robust calibration approach was obtained by considering a multivariate model. The matrix effects are then taken into account by correcting the spectroscopic signals emitted by a given species due the presence of the others ones. More specifically, we established here a calibration model using a 2nd order polynomial linear multivariate inverse regression. The capability of this approach was then checked using a 2nd set of samples with an unknown composition. A good agreement was observed between the analysis provided by X-ray fluorescence (XRF) and the LIBS measurements coupled to the multivariate model for the unknown samples.     

Optical linear response function with linear and diagonal quadratic electron-vibration coupling in mixed quantum-classical systems

Optical linear response function of linearly and quadratically coupled mixed quantum-classical condensed phase systems is derived. The linear response function is derived using Kapral's formalism of statistical mechanics in mixed quantum-classical systems. Our mixed quantum-classical linear dipole moment correlation function J(t) is compared with the full quantum J(t) [Y. J. Yan and S. Mukamel, J. Chem. Phys. 85, 5908 (1986)] in the high temperature limit. Model calculations and discussion of our results are presented. Various formulas of Franck-Condon factors for both linear and quadratic coupling are discussed.     

Analysis of DNA polymorphisms on the human Y-chromosome by microchip electrophoresis

Validation of microchip electrophoresis in DNA analysis has been carried out using an Agilent 2100 Bioanalyzer. With a DNA 500 Assay Kit, the reproducibility and accuracy of fragment sizing of a 10 bp DNA ladder have been shown to be satisfactory with the relative standard deviation and the relative error mostly below 1.0 and 5.0% (n = 12), respectively. Both intraday and interday validations of fragment sizing and quantitation have also been performed with a 7500 Assay Kit (n = 48). Although the results of quantitation are not as good as that of sizing, due to the manual introduction of samples and markers into the chip wells, they are still sufficient to carry out further analyses of practical samples. Based on such reliable results, fast analysis of DNA polymorphisms on the human Y-chromosome has been realized with microchip electrophoresis. The total analysis times of three genomic polymorphisms on the Y-chromosome, Y Alu polymorphism, 47z/StuI, and 12f2, are all within 100 s, and the relative standard deviation and relative error of fragment sizes are below 3.5 and 3.7%, respectively. In addition, a mixture of nine DNA markers on the human Y-chromosome related to examine the cause of spermatogenic failure have been separated successfully with the smallest fragment size difference of 7 bp. Our results demonstrate the potential of microchip electrophoresis in polymorphism analysis with the advantages of high speed, good reproducibility, high precision, and high resolution.     

Regio- and diastereoselective boron-mediated aldol reactions of chiral α,β,γ,δ-unsaturated N-acyloxazolidinones

Chiral N-acyloxazolidinones derived from conjugated dienoic acids undergo boron-mediated aldol condensation in good yield and with high regio- and diastereoselectivity to provide a convenient method for introducing a 1,3-diene subunit. The condensation of a homologous triene derivative is also described.     

Simple photometric determination of free cyanide ion in aqueous solution with 2,6-dichlorophenolindophenol

In this work, a simple photometric method with high accuracy and precision for measuring trace amounts of free cyanide ion in aqueous solution is demonstrated. Under the evaluated conditions, we could determine CN⁻ concentration in the range of 5–70 ppm easily. The work is based upon the photometric titration of CN⁻ with Co(II) in the presence of 2,6-dichlorophenolindophenol (DCPIP) at λ_max = 602 nm in aqueous solution. The optimal conditions, such as pH, ionic strength, and concentration of chromopher were evaluated. The interence effect of many other cations and anions studied and the results are given here. The optimized titration was successfully used to determine the concentration of free cyanide ion in aqueous solutions.     

Comparison of Artificial Neural Networks with Partial Least Squares Regression for Simultaneous Determinations by ICP-AES

Simultaneous determination of several elements （U, Ta, Mn, Zr and W） with inductively coupled plasma atomic emission spectrometry （ICP-AES） in the presence of spectral interference was performed using chemometrics methods. True comparison between artificial neural network （ANN） and partial least squares regression （PLS） for simultaneous determination in different degrees of overlap was investigated. The emission spectra were recorded at uranium analytical line （263.553 nm） with a 0.06 nm spectral window by ICP-AES. Principal component analysis was applied to data and scores on 5 dominant principal components were subjected to ANN. A 5-5-5 （input, hidden and output neurons） network was used with linear transfer function after both hidden and output layers. The PI,S model was trained with five latent variables and 20 samples in calibration set. The relative errors of predictions （REP） in test set were 3.75% and 3.56% for ANN and PLS respectively.     

Exponential periodic attractor of discrete-time BAM neural networks with transmission delays

In this paper, we investigate discrete-time bidirectional associative memory (BAM) neural networks with periodic coefficients and transmission delays. By using matrix measure, spectral theory, and contraction theory, some sufficient conditions are attained for the existence of a unique exponential periodic attractor. Finally, computer simulations illustrate the dynamic behavior of the unique exponential periodic attractor. Moreover, the unique exponential periodic attractor is also given precisely. The numerical simulation is performed to show our results.     

Worker deployment in dual resource constrained systems with a task-type factor

This paper investigates worker learning and forgetting phenomenon in a dual resource constrained system (DRC) setting. Worker learning and forgetting in two and three stage DRC systems are modeled according to the dual-phase learning and forgetting model (DPLFM), which is based on the theory that a task has separate cognitive and motor requirements. Results show that the task-type (with respect to its learning rate and proportion of cognitive and motor requirements) affects the performance of training and deployment policies in DRC systems, and as such it should be included in future DRC research.     

Electro-spray of high viscous liquids for producing mono-sized spherical alginate beads

Alginate beads, often used for controlled release of enzymes and drugs, are usually produced by spraying sodium alginate liquid into a gelling agent using mechanical vibration nozzle or air jet. In this work an alternative method of electro-spray was employed to form droplets with desired size from a highly viscous sodium alginate solution using constant DC voltage. The droplets were then cured in a calcium chloride solution. The main objective was to produce mono-sized beads from such a highly viscous and non-Newtonian liquid (1000-5000 mPa s). The effects of nozzle diameter, flow rate and concentration of liquid on the size of the beads were investigated. Among the parameters studied, voltage had a pronounced effect on the size of beads as compared to flow rate zzle diameter and concentration of alginate liquid. The size of beads was reduced to a minimum value with increasing the voltage in the range of 0-10 kV. At the early stages of voltage increase (I.e. Up to about 4 kV), the rate of size reduction was relatively low, while the dripping mode dominated. However, in the middle part of the range of applied voltage, where the rate of size reduction was high (I.e. About 4-7 kV), an unstable transition occurred between dripping and jetting. At the end part of the range (I.e. 7-10 kV) jet mode of spray was observed. Increasing the height of fall of the droplets was found to improve the sphericity of the beads, because of the increased time of flight for the droplets. This was especially identifiable at higher concentrations of the alginate liquid (I.e. 3 w/v%)