Some concepts on design of surfactant gels and vesicles

It is conjectured that anionic-cationic surfactant combination can be regarded as equivalent to a double chain surfactant and using molecular packing considerations it is shown that vesicles, viscoelastic solutions and liquid crystals can be designed by the proper choice of chain lengths of the pair. Using these concepts new systems are designed, from mixtures of cetyltrimethyl ammonium bromide and sodium alkyl sulfonates, to produce both viscoelastic gels and vesicles.     

Algorithm for converting a forest of quadtrees to a binary array

An algorithm for reconstructing a binary array of size N sx N from its forest of quadtree representation is presented. The algorithm traverses each tree of the forest in preorder and maps each ‘black’ node into the spatial domain. The time complexity in mapping is O(log N × B_n + B_p), where B_n is the number of black nodes in the forest and B_p is the number of black pixels in the N × N array. The algorithm has been implemented on an Apple II.     

L-NAME does not affect exercise-induced pulmonary hypertension in thoroughbred horses

The present study was carried out to examine the effects of nitric oxide synthase inhibition with Nomega-nitro-L-arginine methyl ester (L-NAME) on the right atrial as well as on the pulmonary arterial, capillary, and venous blood pressures of horses during rest and exercise performed at maximal heart rate (HRmax). Experiments were carried out on seven healthy, sound, exercise-trained Thoroughbred horses. Using catheter-tip manometers, with signals referenced at the point of the shoulder, we determined phasic and mean right atrial and pulmonary vascular pressures in two sets of experiments [control (no medications) and L-NAME (20 mg/kg iv given 10 min before exercise studies)]. The studies were carried out in random order 7 days apart. Measurements were made at rest and during treadmill exercise performed on a 5% uphill grade at 6, 8, and 14.2 m/s. Exercise on a 5% uphill grade at 14.2 m/s elicited HRmax and could not be sustained for >90 s. In quietly standing horses, L-NAME administration caused a significant rise in right atrial, as well as pulmonary arterial, capillary, and venous pressures. This indicates that nitric oxide synthase inhibition modifies the basal pulmonary vasomotor tone. In both treatments, exercise caused progressive significant increments in right atrial and pulmonary vascular pressures, but the values recorded in the L-NAME study were not different from those in the control study. The extent of exercise-induced tachycardia was significantly decreased in the L-NAME study at 6 and 8 m/s but not at 14.2 m/s. Thus, L-NAME administration may not modify the equine pulmonary vascular tone during exercise at HRmax. However, as indicated by a significant reduction in heart rate, L-NAME seems to modify the sympathoneurohumoral response to submaximal exercise.     

Identification of pole-like structures from mobile lidar data of complex road environment

Pole-like structures (PLSs) located in road environment are important roadway assets. They play a vital role in road safety inspection and road planning. The use of light detection and ranging (lidar) based mobile mapping technology for mapping of PLSs is an important area of research as it holds the potential for automation. Point cloud data of rural, peri-urban, and urban road environment are used in this study, which pose special challenge in view of the complexity of terrain, unlike well-planned roads, which have been the subject of interest in existing literature for identification of PLSs. A new five-step method is proposed in this article. The first two steps, i.e. ground filtering and voxelization of filtered non-ground points, are used for data size reduction. Next three steps are used to extract PLSs from reduced data. The proposed method was tested on point cloud data of three test sites having different levels of complexities. PLSs including partially occluded pole, tilted pole, pole situated very close to other objects, and vertical pole attached to tilted pole were accurately identified. Average correctness and completeness, respectively of 92.6% and 94.9%, were achieved in three different complex test sites, i.e. urban, peri-urban, and rural sites, respectively. Computation complexity shows that our proposed method delivers fast and computationally efficient solution for identifying the PLSs from volumetric mobile lidar point cloud. Impact of PLSs on road safety and road planning is also addressed for these selected test sites.     

Learning Sparse Feature Representations Using Probabilistic Quadtrees and Deep Belief Nets

Learning sparse feature representations is a useful instrument for solving an unsupervised learning problem. In this paper, we present three labeled handwritten digit datasets, collectively called n-MNIST by adding noise to the MNIST dataset, and three labeled datasets formed by adding noise to the offline Bangla numeral database. Then we propose a novel framework for the classification of handwritten digits that learns sparse representations using probabilistic quadtrees and Deep Belief Nets. On the MNIST, n-MNIST and noisy Bangla datasets, our framework shows promising results and outperforms traditional Deep Belief Networks.     

FEEDBACK CONTROL,DEVELOPMENT STRATEGY,AND MACROECONOMIC PLANNING

The amplitude of a postsynaptic potential attenuates as it spreads from the synapse to the trigger zone, where spike generation is initiated. Thus, especially in neurons with a large dendritic structure, great variability in synaptically evoked changes of the membrane potential at the trigger zone can be expected. Therefore the randomly distributed magnitudes of jumps caused by input processes were assumed in Stein's neuronal model with reversal potentials. Two distributions, normal and exponential, were applied for this purpose. The normal distribution has no influence on statistical characteristics of the interspike interval (1SI). For the exponential distribution the mean ISI, as well as the coefficient of variation, increases nonlinearly with the parameter of the distribution. The coefficient of variation is limited by the value 1. The estimation of the mean ISI by the method of Smith and Smith (1984) is not applicable for the investigated model.     

Microwave drying of mango ginger (Curcuma amada Roxb): prediction of drying kinetics by mathematical modelling and artificial neural network

Curcuma amada (Mango ginger) was dried at four different power levels ranging 315–800 W to determine the effect of microwave power on moisture content, moisture ratio, drying rate, drying time and effective diffusivity. Among the fifteen thin layer drying models considered for evaluating the drying behaviour, the semi‐empirical Midilli et al., model described the drying kinetics very well with R² > 0.999. Drying rate and effective diffusivity increased as the microwave power output increased. Activation energy was estimated by a modified Arrhenius type equation and found to be 21.6 kW kg^?1. A feed‐forward artificial neural network using back‐propagation algorithm was also employed to predict the moisture content during MW drying and found adequate to predict the drying kinetics with R² of 0.985.     

Captopril and its synthesis from chiral intermediates

Captopril is an antihypertensive agent that inhibits the angiotensin‐converting enzyme of the renin–angiotensin system. Chiral intermediates are used in the synthesis of the drug. These intermediates are obtained by resolution of racemic compounds or by chemical, biocatalytic methods and or by asymmetric synthesis by biocatalytic process. This article reviews the various chemical and biochemical processes involved in the synthesis of the chiral drug, including the pharmacological action of captopril. © 2001 Society of Chemical Industry     

Inhibition of Rhizomucor miehei and Candida rugosa lipases by D-glucose in esterification between L-alanine and D-glucose

A detailed kinetic study of the esterification of D-glucose with L-alanine catalyzed by lipases from Rhizomucor miehei (RML) and Candida rugosa (CRL) showed that both lipases follow the Ping-Pong Bi-Bi mechanism, in which L-alanine and D-glucose bind in subsequent steps releasing water and L-alanyl-D-glucose, with competitive substrate inhibition by D-glucose at higher concentrations leading to the formation of dead-end lipase.D-glucose complexes. An attempt to obtain the best fit of this kinetic model through curve fitting yielded good approximates of the apparent values of four important kinetic parameters: for RML-k(cat)=0.29+/-0.028x10(-3) M h(-1) mg(-1), K(m L-alanine)= 4.9+/-0.51x10(-3) M, K(m D-glucose)=0.21+/-0.018x10(-3) M, and K(i D-glucose)=1.76+/-0.19x10(-3) M; for CRL-k(cat)= 0.75+/-0.08x10(-3) M h(-1) mg(-1), K(m L-alanine)=56.2+/-5.7x10(-3) M, K(m D-glucose)=16.2+/-1.8x10(-3) M, and K(i D-glucose) =21.0+/-1.9x10(-3) M.     

Rapid detection of Salmonella in pet food: design and evaluation of integrated methods based on real-time PCR detection

Reducing the risk of Salmonella contamination in pet food is critical for both companion animals and humans, and its importance is reflected by the substantial increase in the demand for pathogen testing. Accurate and rapid detection of foodborne pathogens improves food safety, protects the public health, and benefits food producers by assuring product quality while facilitating product release in a timely manner. Traditional culture-based methods for Salmonella screening are laborious and can take 5 to 7 days to obtain definitive results. In this study, we developed two methods for the detection of low levels of Salmonella in pet food using real-time PCR: (i) detection of Salmonella in 25 g of dried pet food in less than 14 h with an automated magnetic bead-based nucleic acid extraction method and (ii) detection of Salmonella in 375 g of composite dry pet food matrix in less than 24 h with a manual centrifugation-based nucleic acid preparation method. Both methods included a preclarification step using a novel protocol that removes food matrix-associated debris and PCR inhibitors and improves the sensitivity of detection. Validation studies revealed no significant differences between the two real-time PCR methods and the standard U.S. Food and Drug Administration Bacteriological Analytical Manual (chapter 5) culture confirmation method.