E-redesigning of society: towards experiential connectivity of generations in Lithuania

The paper reflects on the unique experience of social and technological development in Lithuania since the regaining of independence as a newly reshaped society constructing a distinctive competitive IST-based model at global level. This has presented Lithuanian pattern of how to integrate different experiences and relations between generations in implementing complex information society approaches. The resulting programme in general is linked to the Lisbon objectives of the European Union. The experience of transitional countries in Europe, each different but facing some common problems, may be useful to developing countries in Africa.

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Fabrication of polystyrene microfluidic devices using a pulsed CO<Subscript>2</Subscript> laser system

In this article, we described a simple and rapid method for fabrication of droplet microfluidic devices on polystyrene substrate using a CO₂ laser system. The effects of the laser power and the cutting speed on the depth, width and aspect ratio of the microchannels fabricated on polystyrene were investigated. The polystyrene microfluidic channels were encapsulated using a hot press bonding technique. The experimental results showed that both discrete droplets and laminar flows could be obtained in the device.     

Joint tracking coefficients and the time delay of a nonstationary linear system,preceded by a static nonlinearity

The paper considers a block-oriented nonlinear Hammerstein system that consists of a linear block with real-valued time-varying unknown coefficients and a pure time delay, preceded by the static nonlinearity. The joint tracking of linear block coefficients and the time delay while processing observation samples is under consideration. The difficulty of the tracking process consists in the initial nonconvexity of the objective function to be minimized, in respect of the time delay. To obtain current estimates of the true coefficients and the time delay it is necessary to overcome the multiextremality of the objective function. A global optimization problem could be solved by changing a form of the nonconvex objective function into a convex one. The optimization problem has been subdivided into two problems that are analyzed in this article, as well. The first one consists of removal of the objective function multiextremality in respect of the time delay, while hunting for the global extremum. Therefore, the well-known approach based on the method of corrective operators, which is used to transform the multiextremal criterion into a unimodal function for the nonstationary Wiener system, is developed here for the Hammerstein one. The other problem consists of the applicability of unified adaptive algorithms, used for Wiener systems in the case of Hammerstein systems. The recursive parametric identification technique, based on the adaptive algorithm procedures, is developed here for the nonstationary block-oriented Hammerstein systems, too. The applicability of algorithms is supported by various simulation tests solved by computer for distinct inputs and for two static nonlinearities.     

Effect of raspberry pomace extracts isolated by high pressure extraction on the quality and shelf‐life of beef burgers

Raspberry pomace extracts isolated with supercritical carbon dioxide (SCE) and pressurised ethanol/water (ETE) were tested in beef burgers. Only ETE additives effectively inhibited lipid oxidation and the growth of microorganisms, as it was observed by measuring the changes of thiobarbituric acid reactive substances, bacterial counts and the content of O₂ and CO₂ during storage in the modified atmosphere package. ETE additives also demonstrated some meat colour preservation effects, which were assessed by the intensity of hamburger colour and metmyoglobin concentration. However, ETE additives did not alter burger's taste at the applied concentrations (up to 1%). It may be concluded that the most effective extracts possessing strong antioxidant and antimicrobial activity may be isolated from raspberry pomace by the pressurised liquid extraction with a hydroethanolic solvent; such extracts may be considered as promising additives in meat products for improving their stability and enriching with beneficial to health phytochemicals.     

Comparative study of indices used in toxicity evaluation of effluents

Several toxicological indices currently proposed (inter)nationally to aid decision-making tasks in effluent control were compared. To evaluate effluent ranking differences between the indices an inversion distance as a similarity measure was proposed. The major factor influencing effluent ranking were found to be a composition of test-battery. Differences in mathematical operator of the indices such as, e.g. arithmetic mean (used in averaging indices) or maximum one (used in an approach of the most sensitive test in a battery), affect the ranking similarity noticeably lesser than the modification of the percentage effect level of the measurement endpoints. Effluent and/or river flow parameters incorporated into the indices substantially modify ranking results of the effluent set. For the analysis, the toxicological information on 23 effluents from municipal wastewater treatment plants operating in cities and small towns of Lithuania as well as test-battery data on industrial effluents published elsewhere were used. It seems that the general statements achieved in the current study can be applied to any set of effluents.     

Nearest and reverse nearest neighbor queries for moving objects

With the continued proliferation of wireless communications and advances in positioning technologies, algorithms for efficiently answering queries about large populations of moving objects are gaining interest. This paper proposes algorithms for k nearest and reverse k nearest neighbor queries on the current and anticipated future positions of points moving continuously in the plane. The former type of query returns k objects nearest to a query object for each time point during a time interval, while the latter returns the objects that have a specified query object as one of their k closest neighbors, again for each time point during a time interval. In addition, algorithms for so-called persistent and continuous variants of these queries are provided. The algorithms are based on the indexing of object positions represented as linear functions of time. The results of empirical performance experiments are reported.     

Antioxidant properties of garden strawberry leaf extract and its effect on fish oil oxidation

The present study characterises garden strawberry leaf extract and reports its effect on shelf life and quality characteristics of fish oil. Radical scavenging capacity of the extract in DPPH^? and ABTS^?+ assays was equivalent to 1207 and 1579 μmol g^?1 of trolox equivalents, respectively, total phenolic content was 257 mg g^?1 of gallic acid equivalents. Phenolic and volatile constituents were analysed by liquid chromatography/mass spectrometry (LC/MS) and gas chromatography/mass spectrometry (GC/MS). The extract was added to fish oil and its oxidation was followed during 42 days: peroxide, p‐anisidine values and hexanal concentration were lower in the samples with extract, particularly at the end of storage. The effect of extract on fatty acid composition was not significant, however the changes in the percentages of some individual acids were observed. Fish oil containing 5% of extract had lower levels of lipid oxidation in comparison to other samples. The results indicate that strawberry leaves could be a potential source of natural antioxidants.