Meat production using four terminal pig lines

The influence of terminal sire (Duroc (D1 and D2), Large White/Pietrain (LW/P) and Large White (LW)) on several meat production and meat quality traits was investigated in 452 male and female offspring of Landrace/Large White dams. Age at slaughter, carcass length, carcass weight and dressing yield were similar for all lines, as was the production of shoulders, chops, and ribs with bacon. D2‐sired pigs produced more noble pieces as a percentage of their carcass weight than the other three lines. LW/P‐ and LW‐sired pigs were generally leaner than Duroc‐sired pigs. LW/P and LW pigs had the highest percentage of cuts (longissimus dorsi and semimembranosus muscle) classified as pale, soft and exudative (PSE) meat. There were no large differences between the lines in the occurrence of dark, firm and dry (DFD) cuts. Copyright © 2003 Society of Chemical Industry     

Structural transformations during chloromethylation of flexible polystyrene networks

Strong morphologic variations were noted in the chloromethylation of styrene copolymers incorporating TAT or DVB as crosslinking agents. In the first case control over the chloromethylation conditoins (solvent, temperature, time) can be applied in order to mold the final porous structure of the chloromethylated polymer. In the case of XE-305 containing higher concentration of crosslinking agent, the chloromethylation conditions have a less, but still significant, effect on the structure and functional group distribution of the product. Under conditions of low ratios of chloromethylating agent (CME) or catalyst (SnCl₄), the chlorine incorporation figures are medium, but chlorine distribution through the cross section of the bead is more or less homogeneous. Increase in the above ratios results in increased chlorine concentrations, but also in higher degree of secondary crosslinking and uneven chlorine distribution profiles. Preselection of the experimental conditions enables calculated introduction of functional groups. In the case of TAT–styrene copolymers, controlled experimental conditions are used to form a porous structure with low and high chlorine distribution. Such a porous polymer can then be functionalized by other reactions. Under certain chloromethylation conditions, the chloromethylated TAT–styrene copolymer is aminated to produce anion exchange resins, without further morphological changes.     

Mode of action of lactocin 705, a two-component bacteriocin from Lactobacillus casei CRL705

Lactocin 705 is a bacteriocin whose activity depends on the complementary action of two peptides (705alpha and 705beta) of 33-amino-acid residues each and is produced by Lactobacillus casei CRL705. Biologically active, synthetic lactocin 705 was used to study the mode of action on sensitive cells of Lactobacillus plantarum CRL691. The addition of 90 nmol l(-1) of lactocin 705 to cells of L. plantarum dissipated both, the membrane potential (DeltaPsi) and the pH gradient (DeltapH). Energized membrane, obtained after the addition of glucose, were more susceptible to lactocin 705 action leading to the immediate release of intracellular K(+) and inorganic phosphate. When the role of various ions on sensitive cells were analyzed, only Ca(2+) ion exhibited a protective effect against lactocin 705. These data suggest that the presence of a proton motive force (PMF) promotes the interaction of the bacteriocin with the cytoplasmic membrane of energized cells, leading to pore formation which allows for the efflux of ions, thereby ensuring efficient killing of target bacteria.     

Development of computer-aided design systems for metal-forming processes

Computer-aided forging die design system FACT and roll pass design system DIAGNO have been developed for immediate use in small- and medium-size metal-forming industries. Some illustrative graphics and printouts of these systems appropriate for process evaluation are presented to describe their capability.     

Lightpath arrangement in survivable rings to minimize the switchingcost

This paper studies the design of low-cost survivable wavelength-division-multiplexing (WDM) networks. To achieve survivability, lightpaths are arranged as a set of rings. Arrangement in rings is also necessary to support SONET/SDH protection schemes such as 4FBLSR above the optical layer. This is expected to be the most common architecture in regional (metro) networks. We assume that we are given a set of lightpaths in an arbitrary network topology and aim at finding a partition of the lightpaths to rings adding a minimum number of lightpaths to the original set. The cost measure that we consider (number of lightpaths) reflects the switching cost of the entire network. In the case of a SONET/SDH higher layer, the number of lightpaths is equal to the number of add-drop multiplexers (ADMs) (since two subsequent lightpaths in a ring can share an ADM at the common node). We prove some negative results on the tractability and approximability of the problem and provide an approximation algorithm with a worst case approximation ratio of 8/5. We study some special cases in which the performance of the algorithm is improved. A similar problem was introduced, motivated, and studied by Liu, Li, Wan and Frieder (see Proc. INFOCOM 2000, p.1020-1025, 2000) Gerstel, Lin and Sasaki, (see Proc. IEEE INFOCOM '98, p. 94-101, 1998)(where it was termed minimum ADM problem). However, these two works focused on a ring topology while we generalize the problem to an arbitrary network topology