Effects of Added Phosphates on Lipid Stability During Salt Curing and Rehydration of Cod (Gadus morhua)

Effects of added phosphates on retardation of lipid oxidation of salted cod during processing, storage and after rehydration were investigated. Lipid hydrolysis progress and development of color, primary and secondary lipid oxidation products and fluorescence intensities were determined. Added phosphates significantly retarded lipid hydrolysis and lipid oxidation progress, resulting in lower free fatty acid , lipid hydroperoxides (PV), thiobarbituric acid-reactive substances (TBARS) as well as fluorescence intensities (δF _or and δF _aq). Significant correlation between the lipid oxidation products (PV, TBARS, δF _or and δF _aq) and yellow/brownish discoloration (b* value) of salted cod was observed. Principal component analysis showed that TBARS, b* value and δF _or were the strongest indicators of lipid oxidation during salting and storage.     

Strategies for Water Quality Assessment: A Multiparametric Analysis of Microbiological Changes in River Waters

River waters are classified worldwide in relation to their chemical quality status, which is assessed by the presence of inorganic and organic pollutants. Meanwhile, microbiological quality evaluations are based mainly on the occurrence of pathogens and faecal contaminants, which are indirectly retrieved by standard cultivation methods. In this study, the structural dynamics of a riverine bacterioplankton community were investigated through a quantitative single‐cell approach with the use of flow cytometry for the quantification of total, viable and active cells. Furthermore, catalyzed reporter deposition (CARD)‐FISH was used for the evaluation of Proteobacteria and Cytophaga–Flavobacteria bacterial classes. The aim was to identify the major cytometric and phylogenetic cell groups that most representatively reflect the physical and chemical changes occurring in an upland‐to‐lowland transect along a human‐impacted river (the Foglia River, Italy). The use of CARD‐FISH to obtain cell abundance measurements of specific taxonomic clusters enabled different microbial propagation dynamics along the river transects to be identified. Furthermore, our results highlighted that the multiparametric approach with flow cytometry produces basic microbiological parameters in a reasonable time span that is consistent with the requirements for an early warning monitoring strategy with respect to integrated riverine water quality assessments. Copyright © 2015 John Wiley & Sons, Ltd.     

Determination of viability of Aeromonas hydrophila in increasing concentrations of sodium chloride at different temperatures by flow cytometry and plate count technique

Aeromonads in waters and foods can represent a risk to human health. Factors such as sodium chloride concentration and temperature can affect growth and viability of several food and water-borne pathogens. The behaviour of an Aeromonas hydrophila strain in the presence of 1.7%, 3.4% and 6% NaCl concentrations at 24 degrees C and 4 degrees C was studied over a 188 day period. Viability and membrane potential were assessed by flow cytometry; growth was evaluated by plate count technique. Flow cytometry evidenced that A. hydrophila retained viability over the period although varying according to temperature and salt concentrations. Colony Forming Units were generally lower in number than viable cells especially in the presence of 6% NaCl, indicating the occurrence of stressed cells which maintain metabolic activity yet are not able to grow on agar plates. In conclusion, A. hydrophila showed a long-term halotolerance even at elevated (6%) NaCl concentrations and a lesser sensitivity to salt at low temperature; therefore, low temperature and salt, which are two important factors limiting bacterial growth, do not assure safety in the case of high initial contamination. Finally, cytometry appears a valid tool for the rapid detection of the viability of pathogenic bacteria in food and environmental matrices to control and prevent health risks.     

Elastomer‐modified epoxy/amine systems in a resin transfer moulding process

The effect of the elastomer structure on toughening highly crosslinked epoxy systems in a resin transfer moulding process (RTM) was investigated. Two kinds of elastomers containing carboxyl functionalized groups were used: (1) a reactive liquid elastomer based on carboxyl‐terminated butadiene‐acrylonitrile copolymer (CTBN), (2) a preformed core‐shell rubber (CSR). The introduction of CTBN rubber caused the modification in the glass transition temperature due to the miscibility in the epoxy matrix, whereas CSR particles did not. During cure, these elastomers affected the morphological, rheological and dielectric behaviour of epoxy/amine systems. A blend of 5% CTBN and 5% CSR exhibited a bimodal distribution of rubber particle sizes (analyzed by transmission electron microscopy) whereas scanning electron microscopy showed the glass fibre‐matrix cohesion in fracture surfaces. A semi‐empirical model was used (developed by Castro‐Macosko for describing chemorheological behaviour of epoxy/amine systems for the RTM process). The increase in viscosity and the reduction in ion conductivity were the two key parameters to monitor the cure process. The presence of rubber affected the rheological behaviour involving initial viscosity and gel point. The investigation of temperatures, pressures and ionic conductivities in various glass fibre layers was conducted to control the front flow filling and the cure reaction. The introduction of rubber modified the inflexion area of the cured rubber–epoxy blends by changing the cure rate. Copyright © 2004 Society of Chemical Industry     

Antifungal activity of water‐soluble chitosan against Colletotrichum capsici in postharvest chili pepper

Experimental results proved that the development of Colletotrichum capsici B4 is extremely sensitive to water‐soluble chitosan (WSC) and inhibitory effects increase with increasing concentrations of WSC. In the in vitro test, the results showed that the entire prevention of conidial germination and mycelial diameter development are recognized in a potato dextrose agar medium containing 0.4% and 0.8% WSC, respectively. WSC was more efficient in a potato dextrose broth where it absolutely prevented the mycelial development of C. capsici B4 at a concentration of 0.32%. WSC treatments considerably decreased disease prevalence and the lesion diameter of anthracnose disease on chilli pepper fruits in the in vivo experiments. Experiments in biochemistry indicated that the activities of the key defense‐related enzymes in peel, consisting of chitinase, β‐1,3‐glucanase and total phenolic content, were increased by both C. capsici B4 infection and C. capsici B4 treatment, and was further treated with a 0.5% WSC concentration.

Practical applications

From the present studies we conclude that water‐soluble chitosan (WSC) can directly inhibit the development of C. capsici B4 isolated from infected chili pepper fruits showing typical symptoms of anthracnose in in vitro and effectively control anthracnose in chili pepper fruit in in vivo with concentration‐dependent antifungal effects. These findings suggest that WSC may be recognized as a feasible effective alternative to artificial fungicides for postharvest disease control of chili pepper fruits.     

Use of sky brightness measurements from ground for remote sensing of particulate polydispersions

The software code SKYEAD.pack for retrieval of aerosol size distribution and optical thickness from data of direct and diffuse solar radiation is described; measurements are carried out with sky radiometers in the wavelength range 0.369-1.048 μm. The treatment of the radiative transfer problem concerning the optical quantities is mainly based on the IMS (improved multiple and single scattering) method, which uses the delta-M approximation for the truncation of the aerosol phase function and corrects the solution for the first- and second-order scattering. Both linear and nonlinear inversion methods can be used for retrieving the size distribution. Improved calibration methods for both direct and diffuse radiation, the data-analysis procedure, the results from the proposed code, and several connected problems are discussed. The results can be summarized as follows: (a) the SKYRAD.pack code can retrieve the columnar aerosol features with accuracy and efficiency in several environmental situations, provided the input parameters are correctly given; (b) when data of both direct and diffuse solar radiation are used, the detectable radius interval for aerosol particles is approximately from 0.03 to 10 μm; (c) besides the retrieval of the aerosol features, the data-analysis procedure also permits the determination of average values for three input parameters (real and imaginary aerosol refractive index, ground albedo) from the optical data; (d) absolute calibrations for the sky radiometer are not needed, and calibrations for direct and diffuse radiation can be carried out with field data; (e) the nonlinear inversion gives satisfactory results in a larger radius interval, without the unrealistic humps that occur with the linear inversion, but the results strongly depend on the first-guess spectrum; (f) aerosol features retrieved from simulated data showed a better agreement with the given data for the linear inversion than for the nonlinear inversion.     

Rainfall estimation from infrared data using an improved version of the Auto-Estimator Technique

In order to apply a suitable procedure for now-casting application in the case of heavy precipitation events, we discuss possible improvements to the Auto-Estimator Technique (AET). The AET rain estimation technique identifies precipitating clouds by comparing two successive infrared satellite images. If the pixel in the second image is colder, then upward motion is assumed and the convective system is considered to be a precipitating cloud. If the pixel in the second image is warmer, then the convective system is likely to be in a weakening phase and no precipitation is assigned. In the case of horizontal movement of the convective system, for instance approaching and weakening, the pixel in the second image can be colder without any upward motion or rain. We propose an improvement of AET (IAET) that determines the cloud top temperature variation and the corresponding rain rate estimation, taking into account the effect of horizontal motion of clouds, obtained by optical flow techniques. Precipitation events over Sardinia during November 1999, May 2000 and June 2000 were analysed. Three-hour cumulated precipitation on one pixel size area were determined by infrared Meteosat data, using both AET and IAET. A comparison between satellite estimation and 49 corresponding ground data stations was made. Contingency tables and relative statistical indices (Bias, False Alarm Ratio, Probability of Detection, Hit Rate, Critical Success Index), and errors on 3 h precipitation (mean absolute error (MAE) and Bias) were computed. When no horizontal motion of the convective system is present, AET and IAET have the same performances. In the events of May 2000, with fast movement of the precipitation system, AET significantly overestimates the rain rate while IAET gives much better performances.     

SmartClients: Constraint Satisfaction as a Paradigm for Scaleable Intelligent Information Systems

Many information systems are used in a problem solving context. Examples are travel planning systems, catalogs in electronic commerce, or agenda planning systems. They can be made more useful by integrating problem-solving capabilities into the information systems. This poses the challenge of scaleability: when hundreds of users access a server at the same time, it is important to avoid excessive computational load.We present the concept of SmartClients: lightweight problem-solving agents based on constraint satisfaction which can carry out the computation- and communication-intensive tasks on the user's computer. We present an example of an air travel planning system based on this technology.     

A Multiagent System for the Reliable Execution of Automatically Composed Ad-hoc Processes

This article presents an architecture to automatically create ad-hoc processes for complex value-added services and to execute them in a reliable way. The uniqueness of ad-hoc processes is to support users not only in standardized situations like traditional workflows do, but also in unique non-recurring situations. Based on user requirements, a service composition engine generates such ad-hoc processes, which integrate individual services in order to provide the desired functionality. Our infrastructure executes ad-hoc processes by transactional agents in a peer-to-peer style. The process execution is thereby performed under transactional guarantees. Moreover, the service composition engine is used to re-plan in the case of execution failures. The work presented in this article was supported by the Swiss National Science Foundation as part of the project MAGIC (FNRS-68155), as well as by the Swiss National Funding Agency OFES as part of the European projects KnowledgeWeb (FP6-507482) and DIP (FP6-507483). Authors in alphabetic order