Transglutaminase-catalyzed preparation of chitosan-ovalbumin films

Microbial transglutaminase was employed as catalyst for preparing chitosan–ovalbumin films. The films showed low solubility at a wide range of pH and underwent to a good enzymatic hydrolysis with trypsin. The degree of swelling was reduced and the mechanical resistance of the chitosan–ovalbumin films increased from 24 to 35MPa after enzymatic treatment with transglutaminase. The barrier efficiency toward water vapour was slightly improved for the films prepared by transglutaminase-mediated cross-linking

One year OSIRHYS IV project synthesis: mechanical behaviour of 700 bar type iv high pressure vessel code qualification.

International audienceIn this paper we present results of the OSIRHYS IV French project which aims to develop andvalidate models and methods for composite high pressure design and optimization withbehavior uncertainties knowledge. Models of the five partners of this project are presentedand burst simulation results are compared for three test temperatures (-40°C, 15°C and85°C)

Putrescine-polysaccharide conjugate as transglutaminase substrates and their possible use in producing crosslinked films

Putrescine (1,4-diaminobutane) was covalently linked to alginate and low-methoxyl pectin to synthesize new aminated polysaccharides. Both putrescine-pectin and -alginate conjugates, although the latter at higher concentrations, were found to be able to act as effective acyl acceptor transglutaminase substrates in vitro using both dimethylated casein and soy flour proteins as acyl donors. Monodansylcadaverine, a well known acyl acceptor transglutaminase substrate, dose-dependently counteracted the covalent binding of the aminated polysaccharides to the proteins. Putrescine-pectin conjugate was also tested to prepare, in combination with soy flour proteins, edible films in the presence of purified microbial transglutaminase. Characterization of the enzymatically crosslinked films showed a significant decreased water vapor permeability, with respect to the ones obtained with non-aminated pectin in the presence of transglutaminase, as well as improved mechanical properties, such as high extensibility. Possible biotechnological applications of hydrocolloid films containing putrescine-polysaccharide derivatives enzymatically crosslinked to proteins were suggested

Chitosan-whey protein edible films produced in the absence or presence of transglutaminase: Analysis of their mechanical and barrier properties

Chitosan-whey protein edible films with different protein concentrations were prepared in the absence or presence of microbial transglutaminase as cross-linking agent. The films prepared in the presence of the enzyme showed low solubility at a wide range of pH, a lower degree of swelling, and good biodegradability following protease treatments. The presence of transglutaminase induced also an enhancement in film mechanical resistance and a reduction in their deformability. Finally, the barrier efficiency toward oxygen and carbon dioxide was found to be markedly improved in the cross-linked films which showed also a lower permeability to water vapor. Some potential practical applications of transglutaminase-treated chitosan-whey protein films are suggested

Thirty Years After Michael E. Porter: What Do We Know About Business Exit?

Although a business exit is an important corporate change initiative, the buyer’s side seems to be more appealing to management researchers than the seller’s because acquisitions imply growth, i.e., success. Yet from an optimistic viewpoint, business exit can effectively create value for the selling company. In this paper we attempt to bring the relevance of the seller’s side back into our consciousness by asking: What do we know about business exit? We start our exploration with Porter (1976), focusing on literature that investigates the antecedents of, barriers to, and outcomes of business exit. We also include studies from related fields such as finance and economics.1 Through this research we determine three clusters of findings: factors promoting business exit, exit barriers, and exit outcomes. Overall, it is the intention of this paper to highlight the importance of business exit for research and practice. Knowing what we know about business exits and their high financial value we should bear in mind that exit need not mean failure but a new beginning for a corporation

Multiple agency perspective, family control, and private information abuse in an emerging economy

Using a comprehensive sample of listed companies in Hong Kong this paper investigates how family control affects private information abuses and firm performance in emerging economies. We combine research on stock market microstructure with more recent studies of multiple agency perspectives and argue that family ownership and control over the board increases the risk of private information abuse. This, in turn, has a negative impact on stock market performance. Family control is associated with an incentive to distort information disclosure to minority shareholders and obtain private benefits of control. However, the multiple agency roles of controlling families may have different governance properties in terms of investors’ perceptions of private information abuse. These findings contribute to our understanding of the conflicting evidence on the governance role of family control within a multiple agency perspectiv

Effective quantum volume, fidelity and computational cost of noisy quantum processing experiments

Today's experimental noisy quantum processors can compete with and surpass all known algorithms on state-of-the-art supercomputers for the computational benchmark task of Random Circuit Sampling [1-5]. Additionally, a circuit-based quantum simulation of quantum information scrambling [6], which measures a local observable, has already outperformed standard full wave function simulation algorithms, e.g., exact Schrodinger evolution and Matrix Product States (MPS). However, this experiment has not yet surpassed tensor network contraction for computing the value of the observable. Based on those studies, we provide a unified framework that utilizes the underlying effective circuit volume to explain the tradeoff between the experimentally achievable signal-to-noise ratio for a specific observable, and the corresponding computational cost. We apply this framework to recent quantum processor experiments of Random Circuit Sampling [5], quantum information scrambling [6], and a Floquet circuit unitary [7]. This allows us to reproduce the results of Ref. [7] in less than one second per data point using one GPU.Comment: 14 pages, 13 figure

Disposable electrochemical biosensors for Brettanomyces bruxellensis and total yeast content in wine based on core-shell magnetic nanoparticles

Two different disposable amperometric biosensors for the rapid detection and quantification of Brettanomyces bruxellensis (Brett) and total yeast content in wine were constructed. The biosensing approach implied the use of magnetic capturing elements based on core-shell Fe3O4@SiO2 superparamagnetic nanoparticles (NanoCaptors) functionalized with specific bioreceptors: Concanavalin A (Con A) for total yeast analysis, and anti-Brett polyclonal antibodies for Brett. A Con A-peroxidase conjugate and carbon screen printed electrodes were used as signaling element and sensing interfaces, respectively. The biosensor based on antibody-modified magnetic nanoparticles allowed the amperometric detection of B. bruxellensis in buffer solution and red wine samples in the range of 10 - 106 CFU/mL, with low detection limits of 6 CFU/mL and 8 CFU/mL, respectively. In addition, the use of Con A-linked magnetic nanoparticles as capturing elements allowed determination of total yeast content in buffer solution and red wine in the range of 10 - 106 CFU/mL, with detection limit of 5 CFU/mL. These electrochemical biosensors also exhibited high reproducibility, selectivity and storage stability

Worldscope meets Compustat: A Comparison of Financial Databases

With this study we are the first to systematically compare today's two major counterparts as a source of accounting and financial data for researchers: Compustat North America by Standard & Poor's and Worldscope by Thomson Financial. This investigation is conducted for U.S. and partly Canadian data over an extensive period from 1985 to 2003. We examine more than 650 data items available in both databases and address the question of whether or not the decision for one or the other source may have an impact on the outcome of research projects. It is probably commonly assumed that this impact is minor, but it also leaves room to question certain results. We show that the use of both databases should lead to comparable results, but also find that if, e.g. a size bias, is not treated with care the quality of results may differ considerable. Furthermore after 1998 the number of firms covered by Worldscope exceeds the one covered by Compustat by about one fourth

Shotgun nanoLC-MS/MS proteogenomics to document MALDI-TOF biomarkers for screening new members of the Ruegeria genus

The identification of bacteria by means of matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry directly using whole cells has become a standard method in clinical diagnosis due to its rapidity and simplicity. Nevertheless, the analysis of environmental samples with this approach still represents a challenge due to the enormous microbial diversity existing on earth and the lack of a comprehensive database. Most of the environmentally relevant species comprise only one unique strain, while pathogens such as Escherichia coli, with 667 described strains, are well documented. In such case, identification of the proteins responsible for the peak signals within MALDI-TOF spectra can give crucial information for species discrimination. To give higher confidence in MALDI-TOF biomarker description we exploited information from proteins identified by shotgun nanoLC-MS/MS, consisting of the identification and quantification of low-molecular-weight proteins after SDS-PAGE, in-gel trypsin proteolysis and analysis of tryptic peptides. We also proposed the standardization of the inclusion of internal calibrants in the bacterial sample to improve the accuracy of the MALDI-TOF measurements. In this way, nine candidate biomarkers were tentatively proposed for Ruegeria lacuscaerulensis ITI-1157. The conserved biomarkers were theoretically deduced for all other Ruegeria strains whose genomes have been sequenced and their corresponding m/z MALDI-TOF signals were estimated. Among these, DNA-binding protein, HU, and ribosomal proteins, L29, L30, L32 and S17, were shown experimentally to be also the most prominent and conserved signals in the other strain tested, Ruegeria pomeroyi DSS-3. Thus, we suggested that these five biomarkers, which give rise to 10 m/z peak signals derived from the mono- and doubly protonated proteins, are the best candidates for identifying bacteria belonging to the Ruegeria genus, and quickly assessed their phylogenetic proximity to described species. As an application of these biomarkers, we quickly screened 30 seawater bacterial isolates by MALDI-TOF and found one belonging to the Ruegeria genus, as further confirmed by 16S RNA sequencing. Due to its simplicity and effectiveness, this technique could be of immense value in monitoring bacteria in the environment in the near future