Reclamation of Marine Chitinous Materials for Chitosanase Production via Microbial Conversion by Paenibacillus macerans

[[abstract]]: Chitinous materials from marine byproducts elicit great interest among biotechnologists for their potential biomedical or agricultural applications. In this study, four kinds of marine chitinous materials (squid pens, shrimp heads, demineralized shrimp shells, and demineralized crab shells) were used to screen the best source for producing chitosanase by Paenibacillus macerans TKU029. Among them, the chitosanase activity was found to be highest in the culture using the medium containing squid pens as the sole carbon/nitrogen (C/N) source. A chitosanase which showed molecular weights at 63 kDa was isolated from P. macerans cultured on a squid pens medium. The purified TKU029 chitosanase exhibited optimum activity at 60 ◦C and pH 7, and was stable at temperatures under 50 ◦C and pH 3-8. An analysis by MALDI-TOF MS revealed that the chitosan oligosaccharides (COS) obtained from the hydrolysis of water-soluble chitosan by TKU029 crude enzyme showed various degrees of polymerization (DP), varying from 3–6. The obtained COS enhanced the growth of four lactic acid bacteria strains but exhibited no effect on the growth of E. coli. By specialized growth enhancing effects, the COS produced from hydrolyzing water soluble chitosan with TKU029 chitinolytic enzymes could have potential for use in medicine or nutraceuticals.[[sponsorship]]MOST[[notice]]補正完

Neighborhood search for solving personal scheduling problem in available time windows with split-min and deadline constraints

The scheduling of individual jobs with certain constraints so that efficiency is a matter of concern. Jobs have deadlines to complete, can be broken down but not too small, and will be scheduled into some available time windows. The goal of the problem is to find a solution so that all jobs are completed as soon as possible. This problem is proved to be a strongly $NP$-hard problem. The implementation of the proposed MILP model using a CPLEX solver was also conducted to determine the optimal solution for the small-size dataset. For large-size dataset, heuristic algorithms are recommended such as First Come First Served (FCFS), Earliest Deadline (EDL), and neighborhood search including  Stochastic Hill Climbing (SHC), Random Restart Hill Climbing (RRHC), Simulated Annealing (SA) to determine a good solution in an acceptable time. Experimental results will present in detail the performance among the groups of exact, heuristic, and neighborhood search methods

Minimizing makespan of Personal Scheduling problem in available time-windows with split-min and setup-time constraints

This paper deals with personal scheduling problem in available time-windows with split-min and setup-time constraints. The jobs are splitable into sub-jobs and a common lower bound on the size of each sub-job is imposed. The objective function aims to find a feasible schedule that minimizes the maximum completion time of all jobs. The proposed scheduling problem was proved to be strongly NP-hard by a reduction to 3-SAT problem in the preliminary results. We propose in this paper an exact method based on MILP model to find optimal solution, some heuristics to find feasible solution and a meta-heuristic based on tabu search algorithm to find good solution. The computational results show the performance of proposed exact method, some heuristics and tabu search algorithm

L'envoi d'argent et de biens par les immigrants originaires de l'Amérique latine à Montréal : l'intimité économique au coeur des pratiques transnationales

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Vision et dialogue : les objectifs de la Suisse dans le système global de la propriété intellectuelle

1. Introduction 1987-1997 : dix ans se sont écoulés depuis le jour où les négociateurs ont commencé le Cycle d’Uruguay. Encore un exercice voué à l’échec, pensaient les esprits chagrins en 1987. Ils en voulaient pour preuve les travaux des organisations internationales qui ont voulu soit relever le niveau de la protection (comme l’Organisation mondiale de la propriété intellectuelle – OMPI) – soit empoigner le domaine de la propriété intellectuelle d’une autre manière (comme la CNUCED). Aujou..

Vision und Dialog : die Zielsetzungen der Schweiz im globalen System des geistigen Eigentums

1.Einführung 1987 – 1997 : Zehn Jahre sind seit dem Beginn der Uruguay-Runde verstrichen. Pessimisten sahen damals in dieser Verhandlungsrunde lediglich ein weiteres Unterfangen, das von vornherein zum Scheitern verurteilt war : Die Bestrebungen der internationalen Organisationen, die entweder eine Verstärkung des patentrechtlichen Schutzes erreichen (wie die Weltorganisation für geistiges Eigentum, WIPO) oder den Bereich des geistigen Eigentums auf andere Weise an sich reissen wollten (wie d..

Vision und Dialog : die Zielsetzungen der Schweiz im globalen System des geistigen Eigentums

1.Einführung 1987 – 1997 : Zehn Jahre sind seit dem Beginn der Uruguay-Runde verstrichen. Pessimisten sahen damals in dieser Verhandlungsrunde lediglich ein weiteres Unterfangen, das von vornherein zum Scheitern verurteilt war : Die Bestrebungen der internationalen Organisationen, die entweder eine Verstärkung des patentrechtlichen Schutzes erreichen (wie die Weltorganisation für geistiges Eigentum, WIPO) oder den Bereich des geistigen Eigentums auf andere Weise an sich reissen wollten (wie d..

Toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the developing male Wistar(Han) rat II: chronic dosing causes developmental delay

We have investigated whether fetal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes defects in the male reproductive system of the rat, using chronically exposed rats to ensure continuous exposure of the fetus. 5-6 week old rats were exposed to control diet, or diet containing TCDD, to attain an average dose of 2.4, 8 and 46 ng TCDD kg-1 day-1 for twelve weeks, whereupon the rats were mated, and allowed to litter; rats were switched to control diet after parturition. Male offspring were allowed to develop until kills on PND70 (25 per group), or PND120 (all remaining animals). Offspring from the high dose group showed an increase in total litter loss, and the number of animals alive on post-natal day (PND) 4 in the high dose group was ~26% less than control. The high and medium dose offspring showed decreased weights at various ages. Balano-preputial separation was significantly delayed in all three dose groups, compared to control. There were no significant effects of maternal treatment when the offspring were subjected to a functional observational battery, or learning tests, with the exception that the high dose group showed a deficit in motor activity. 20 rats per group were mated to females, and there were no significant effects of maternal treatment on the fertility of these rats, nor on the F1 or F2 sex ratio. Sperm parameters at PND70 and 120 showed no significant effect of maternal treatment, with the exception that there was an increase in the proportion of abnormal sperm in the high dose group at PND70; this is associated with the developmental delay in puberty in this dose group. There were no remarkable findings of maternal treatment on organ weights, with the exception that testis weights were reduced by ~10% at PND70 (but not PND120), and although the experiment was sufficiently powered to detect small changes, ventral prostate weight was not reduced. There were no significant effects of maternal treatment upon histopathological comparison of high dose and control group organs. These data confirm that developmental exposure to TCDD shows no potent effect on adult sperm parameters or accessory sexual organs, but show that delay in BPS occurs after exposure to low doses of TCDD, and this is dependent upon whether TCDD is administered acutely or chronically

Growth Kinetics, Carbon Isotope Fractionation, and Gene Expression in the Hyperthermophile Methanocaldococcus jannaschii during Hydrogen-Limited Growth and Interspecies Hydrogen Transfer

Hyperthermophilic methanogens are often H2 limited in hot subseafloor environments, and their survival may be due in part to physiological adaptations to low H2 conditions and interspecies H2 transfer. The hyperthermophilic methanogen Methanocaldococcus jannaschii was grown in monoculture at high (80 to 83 μM) and low (15 to 27 μM) aqueous H2 concentrations and in coculture with the hyperthermophilic H2 producer Thermococcus paralvinellae. The purpose was to measure changes in growth and CH4 production kinetics, CH4 fractionation, and gene expression in M. jannaschii with changes in H2 flux. Growth and cell-specific CH4 production rates of M. jannaschii decreased with decreasing H2 availability and decreased further in coculture. However, cell yield (cells produced per mole of CH4 produced) increased 6-fold when M. jannaschii was grown in coculture rather than monoculture. Relative to high H2 concentrations, isotopic fractionation of CO2 to CH4(εCO2-CH4) was 16‰ larger for cultures grown at low H2 concentrations and 45‰ and 56‰ larger for M. jannaschii growth in coculture on maltose and formate, respectively. Gene expression analyses showed H2-dependent methylene-tetrahydromethanopterin (H4MPT) dehydrogenase expression decreased and coenzyme F420-dependent methylene-H4MPT dehydrogenase expression increased with decreasing H2 availability and in coculture growth. In coculture, gene expression decreased for membrane-bound ATP synthase and hydrogenase. The results suggest that H2 availability significantly affects the CH4 and biomass production and CH4 fractionation by hyperthermophilic methanogens in their native habitats

Two approximation methods of spatial derivatives on unstructured triangular meshes and their application in computing two dimensional flows

Two approximation methods (the Green's theorem technique and the directional derivative technique) of spatial derivatives have been proposed for finite differences on unstructured triangular meshes. Both methods have the first order accuracy. A semi-implicit time matching methods beside the third order Adams-Bashforth method are used in integrating the water shallow equations written in both non-conservative and conservative forms. To remove spurious waves, a smooth procedure has been used. The model is tested on rectangular grids triangulari2jed after the 8-neighbours strategy. In the context of the semi-implicit time matching methods, the directional Derivative technique is more accurate than Green's theorem technique. The results from the third order Adams-Bashforth scheme are the most accurate, especially for discontinuous problems. In this case, there is a minor difference between two approximation techniques of spatial derivatives