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  • Author: B. van Vlies x
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Abstract

This paper reports on an experimental study investigating alternative communication modes to English as a Lingua Franca. The purpose was to examine the effectiveness of different modes of communication and to gain insight in communication strategies used by interlocutors to solve referential conflicts. Findings show that ELF may not necessarily be the most effective mode of communication for speakers who do not share a native language. In the context of multinational corporations, RM may be regarded as a viable alternative to English for negotiating mutual understanding, particularly for speakers with (linguistically) closely related mother tongues.

Results of a numerical analysis of a set of one-dimensional reaction -diffusion equations are presented. The basis of these equations is a model scheme of chemical reactions, involving auto-and cross-catalytic steps (“Brusselator”). The steady state problem is solved numerically, fully exploiting the properties of recently developed continuation codes. Bifurcation diagrams are constructed for zero flux boundary conditions. For a relatively large diffusivity of initial species the Brusselator displays a huge number of dissipative steady state structures. At low system lengths a mechanism of perturbed bifurcation may be percieved. Bifurcations coincide with turning points of asymmetric solution branches. Completely isolated solutions prove to exist as well. For the problem without limited diffusion of the initial species, a careful bifurcation analysis show s the existence of a number of higher order bifurcations. At some of these points asymmetric profiles emanate from other asymmetric structures. Bifurcation points and limit points do not necessarily coincide. Stability analysis shows that relatively few steady states are stable. Especially symmetric solutions are found to be stable.

Abstract

Analysis of the tropical marine sponge Axinella carteri afforded six unusual alkaloids, including the new brominated guanidine derivative 3-bromo-hymenialdisine. The structure elucidation of the new alkaloid is described. The alkaloid patterns of sponges collected in Indonesia or in the Philippines were shown to be qualitatively identical suggesting de novo synthesis by the sponge or by endosymbiontic microorganisms rather than uptake by filterfeeding. All alkaloids were screened for insecticidal activity as well as for cytotoxicity. The guanidine alkaloids hymenialdisine and debromohymenialdisine exhibited insecticidal activity towards neonate larvae of the polyphagous pest insect Spodoptera littoralis (LD50s of 88 and 125 ppm, respectively), when incorporated into artificial diet and offered to the larvae in a chronic feeding bioassay. The remaining alkaloids, including the new compound, were inactive in this bioassay. Cytotoxicity was studied in vitro using L5178y mouse lymphoma cells. Debromohymenialdisine was again the most active compound (ED50 1.8 μg/ml) followed by hymenialdisine and 3-bromohymenialdisine, which were essentially equitoxic and exhibited ED50s of 3.9 μg/ml in both cases. The remaining alkaloids were inactive against this cell line

Abstract

Commercials regularly feature foreign accents. This paper aims to investigate whether the use of foreign accents in radio commercials is more effective for congruent than incongruent products, and whether foreign-accented commercials are evaluated differently than non-accented commercials. In an experiment, a group of 228 Dutch participants rated non-accented and accented commercials for four different products in a between-subject design. The products were either congruent or incongruent with the foreign accent in the commercial (e.g. a German-accented commercial for sausage vs. olive oil). Foreign-accented commercials for congruent products were assessed more positively on a number of variables than foreign-accented commercials for incongruent products. Foreign-accented commercials were rated more negatively than commercials without a foreign accent.

Abstract

Privacy is becoming a urgent issue in information systems nowadays because of the stringent requirements imposed by data protection regulations. Traditional security approaches based on access control and authorization are not adequate to address these requirements. The underlying fundamental problem is that those approaches are preventive and thus they are not able to deal with exceptions. In this paper, we present a practical privacy framework that shifts the problem of preventing infringements into a problem of detecting infringements. The framework is based on systematic log auditing, use of patterns and privacy metrics to detect and quantify infringements.

Abstract

Background

Correct handling and storage of blood samples for coagulation tests are important to assure correct diagnosis and monitoring. The aim of this study was to assess the pre-analytical practices for routine coagulation testing in European laboratories.

Methods

In 2013–2014, European laboratories were invited to fill in a questionnaire addressing pre-analytical requirements regarding tube fill volume, citrate concentration, sample stability, centrifugation and storage conditions for routine coagulation testing (activated partial thromboplastin time [APTT], prothrombin time in seconds [PT-sec] and as international normalised ratio [PT-INR] and fibrinogen).

Results

A total of 662 laboratories from 28 different countries responded. The recommended 3.2% (105–109 mmol/L) citrate tubes are used by 74% of the laboratories. Tube fill volumes ≥90% were required by 73%–76% of the laboratories, depending upon the coagulation test and tube size. The variation in centrifugation force and duration was large (median 2500 g [10- and 90-percentiles 1500 and 4000] and 10 min [5 and 15], respectively). Large variations were also seen in the accepted storage time for different tests and sample materials, for example, for citrated blood at room temperature the accepted storage time ranged from 0.5–72 h and 0.5–189 h for PT-INR and fibrinogen, respectively. If the storage time or the tube fill requirements are not fulfilled, 72% and 84% of the respondents, respectively, would reject the samples.

Conclusions

There was a large variation in pre-analytical practices for routine coagulation testing in European laboratories, especially for centrifugation conditions and storage time requirements.