Ant algorithms for image feature extraction

This paper extends on previous work in applying an ant algorithm to image feature extraction, focusing on edge pattern extraction, as well as the broader study of self-organisation mechanisms in digital image environments. A novel method of distributed adaptive thresholding is introduced to the ant algorithm, which enables automated distributed adaptive thresholding across the swarm. This technique is shown to increase performance of the algorithm, and furthermore, eliminates the requirement for a user set threshold, allowing the algorithm to autonomously adapt an appropriate threshold for a given image, or data set. Additionally this approach is extended to allow for simultaneous multiple-swarm multiple-feature extraction, as well as dynamic adaptation to changing imagery.     

Electrodeposits as Bases for Paints

Two proprietary bright nickel solutions were operated under simulated production conditions, properties of the deposits and of the solutions being measured periodically. No particular difficulty was experienced in operating each bath for about 1200 Ah/gal, after which the solutions began to produce unacceptable deposits.

Important properties affected by ageing of the solution were brightness, internal stress and ductility. Stress tended to increase and ductility to decrease. The brightness range of one solution contracted with time, and the solution was deemed to require purifying when it became impossible to maintain brightness all over the plated articles. Purification of the other solution was considered to be necessary when the deposit became excessively brittle. Drag-out and other solution losses were small; had they been larger, the solutions would probably have produced satisfactory plate for a longer period, for reasons discussed in the paper.

Many properties were unaffected by ageing, e.g. throwing power, microhardness, adhesion. It was also found that the accuracy of two methods of determining nickel thickness—B.N.F. jet test and thermoelectric method—was unrelated to the length of service of the plating bath.

The changes in properties appear to be due to organic impurities in the solution, arising more probably from decomposition of addition agents than from external sources. Consideration of the factors determining the concentration of impurities suggests that it would be more economical in practice to maintain a tolerated level of impurity than to remove all the impurity periodically.     

Proximate factors mediating "contact" calls in adult female baboons (Papio cynocephalus ursinus) and their infants.

"Contact" calls are widespread in social mammals and birds, but the proximate factors that motivate call production and mediate their contact function remain poorly specified. Field study of chacma baboons (Papio cynocephalus ursinus) revealed that contact barks in adult females were motivated by separation both from the group at large and from their dependent infants. A variety of social and ecological factors affect the probability of separation from either one or both. Results of simultaneous observations and a playback experiment indicate that the contact function of calling between mothers and infants was mediated by occasional maternal retrieval rather than coordinated call exchange. Mothers recognized the contact barks of their own infants and often were strongly motivated to locate them. However, mothers did not produce contact barks in reply unless they themselves were at risk of becoming separated from the group. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of Pigeon Pea and Plantain Starches on the Compressional,Mechanical, and Disintegration Properties of Paracetamol Tablets

ABSTRACT

A study has been made of the effects of pigeon pea starch obtained from the plant Cajanus cajan (L) Millisp. (family Fabaceae) and plantain starch obtained from the unripe fruit of Musa paradisiaca L. (family Musaceae) on the compressional, mechanical, and disintegration properties of paracetamol tablets in comparison with official corn starch BP. Analysis of compressional properties was done by using density measurements, and the Heckel and Kawakita equations, whereas the mechanical properties of the tablets were evaluated by using tensile strength (T-a measure of bond strength) and brittle fracture index (BFI-a measure of lamination tendency). The ranking for the mean yield pressure, P_y, for the formulations containing the different starches was generally corn < pigeon pea < plantain starch while the ranking for P_k, an inverse measure of the amount of plasticity, was pigeon pea < plantain < corn starch, which indicated that formulations containing corn starch generally exhibited the fastest onset of plastic deformation, whereas those formulations containing pigeon pea starch exhibited the highest amount of plastic deformation during tableting. The tensile strength of the tablets increased with increase in concentration of the starches while the Brittle Fracture Index decreased. The ranking for T was pigeon pea > plantain > corn starch while the ranking for BFI was corn > plantain > pigeon pea starch. The bonding capacity of the formulations was in general agreement with the tensile strength results. The disintegration time (DT) of the formulation increased with concentration of plantain and corn starches but decreased with concentration of pigeon pea starch. The general ranking of DT values was plantain < pigeon pea < corn starch. Notably, formulations containing pigeon pea starch exhibited the highest bond strength and lowest brittleness, suggesting the usefulness of pigeon pea starch in producing strong tablets with minimal lamination tendency. Plantain starch, on the other hand, would be more useful where faster disintegration of tablet is desired. The results show that the starches could be useful in various formulations depending on the intended use of the tablets with the implication that the experimental starches can be developed for commercial purposes.     

Comparison of bactericidal activity of six lysozymes at atmospheric pressure and under high hydrostatic pressure

The antibacterial working range of six lysozymes was tested under ambient and high pressure, on a panel of five gram-positive (Enterococcus faecalis, Bacillus subtilis, Listeria innocua, Staphylococcus aureus and Micrococcus lysodeikticus) and five gram-negative bacteria (Yersinia enterocolitica, Shigella flexneri, Escherichia coli O157:H7, Pseudomonas aeruginosa and Salmonella typhimurium). The lysozymes included two that are commercially available (hen egg white lysozyme or HEWL, and mutanolysin from Streptomyces globisporus or M1L), and four that were chromatographically purified (bacteriophage lambda lysozyme or LaL, bacteriophage T4 lysozyme or T4L, goose egg white lysozyme or GEWL, and cauliflower lysozyme or CFL). T4L, LaL and GEWL were highly pure as evaluated by silver staining of SDS-PAGE gels and zymogram analysis while CFL was only partially pure. At ambient pressure each gram-positive test organism displayed a specific pattern of sensitivity to the six lysozymes, but none of the gram-negative bacteria was sensitive to any of the lysozymes. High pressure treatment (130-300 MPa, 25 degrees C, 15 min) sensitised several gram-positive and gram-negative bacteria for one or more lysozymes. M. lysodeikticus and P. aeruginosa became sensitive to all lysozymes under high pressure, S. typhimurium remained completely insensitive to all lysozymes, and the other bacteria showed sensitisation to some of the lysozymes. The possible applications of the different lysozymes as biopreservatives, and the possible reasons for the observed differences in bactericidal specificity are discussed.