An integrating view on the viewing abstraction: Contexts and perspectives in software development,AI, and databases

Viewing entities from different situations and representing and processing them in different contexts constitutes a fundamental concern in various disciplines of computer science. Not surprisingly, the viewing abstraction is supported by many languages and techniques employed either for programming or world modelling. This paper presents an overview on various manifestations of viewing mechanisms in formal notations including software development techniques, knowledge representation languages, and data models. The concepts of context and perspective are introduced in form of a language-independent framework in order to capture and systematically discuss features that characterize viewing mechanisms, such as the relationship between the two, the relation between different perspectives on the same conceptual entity, or operations supporting effective construction of contexts. In addition, it is argued that the full power of viewing can be exploited by supporting both notions: contexts as well as perspectives. In order to achieve this support, any formal notation has to fulfill a number of general requirements which are stated as a result of the investigation and the survey.     

Zur Position von Mathematik und Mathematiker/innen in der Industrieforschung vor 1945

The paper considers the status of mathematics and mathematicians in German industrial labs from the 1920s. As an example, we take the use of statistical methods in the electrical engineering company Osram in Berlin. In the United States, the former employee and member of a special mathematical research department of the Bell Telephone Laboratories, Walter Andrew Shewhart (1891–1967), is regarded as the father of statistical quality control. Although the first textbook on applications of mathematical statistics to problems of mass production was published in Germany in 1927, Germany was nevertheless generally considered as conservative in using statistical methods until 1945. In the past we have known little about whether and how these methods were actually applied in German industry before 1945. The present analysis is based on laboratory reports and other sources. It shows that in this field of research there was a close cooperation between industry and university, which was cut off in the mid 1930s due to the Nazi regime. Furthermore, we discovered that female researchers – such as Iris Runge (1888–1966) in the Osram company – could as individuals play a decisive role as mathematical consultants. The position of Runge will be described and compared with the position of mathematical researchers in other industrial labs.

am Beispiel früher Anwendung von mathematischer Statistik in der Osram G.m.b.H. Hans Wu?ing zum 80. Geburtstag gewidmet

     

Bioaccumulation of cyanuric acid in edible tissues of shrimp following experimental feeding

Due to concerns that cyanuric acid (CYA)-contaminated feed had been used in aquaculture and could enter the human food chain, a method to quantify CYA residues in the edible tissues of fish and shrimp was previously developed and validated. This paper provides further data on the deliberate feeding of CYA to shrimp to determine the extent of residue accumulation in edible tissue. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed for the analysis of CYA in shrimp tissue. Edible tissue of shrimp fed 1666 or 3333 mg kg?1 CYA in their diet (approximately 55 and 124 mg kg?1 body weight) contained 0.767 and 0.406 mg kg?1 CYA, respectively. The residue levels are below the World Health Organization (WHO) tolerable daily intake level for CYA and are generally considered unlikely to pose a human health risk.     

Probing conserved amino acids in phospholipase D (Brassica oleracea var. capitata) for their importance in hydrolysis and transphosphatidylation activity

In addition to hydrolysis of glycerophospholipids, phospholipases D (PLDs) catalyze the head group exchange. The molecular basis of this transphosphatidylation potential, which strongly varies for PLDs from different sources, is unknown hitherto. Recently, the genes of two PLD isoenzymes from white cabbage have been sequenced and expressed in Escherchia coli, yielding the basis for mutational studies. In the present paper, three sequence characteristics of the isoenzyme (PLD2) that corresponds to the often used enzyme isolated from cabbage leaves have been probed for their importance in hydrolysis as well as transphosphatidylation activities: (i) the two HKD motifs, (ii) the C terminus and (iii) the eight cysteine residues. All these regions or amino acids are highly conserved in alpha-type plant PLDs. Based on multiple alignments, predictions of secondary structure and comparisons of hydrophobicity profiles, 35 enzyme variants were created and assayed. All positions tested proved to be very sensitive towards amino acid exchanges with respect to hydrolytic activity in the absence of glycerol as well as to the ratio of hydrolytic and transphosphatidylation activities in the presence of glycerol. A significant increase of total activity and transphosphatidylation activity could be obtained by the substitutions C310S and C625S.     

NTM gedenkt—Dirk Jan Struik 30. September 1894–21. Oktober 2000

Ohne Zusammenfassung     

Effect of Br gassing after Ar plasma treatment of polyolefins

For simulation and acceleration of artificial polymer ageing, polyolefin foils were exposed to low-pressure Ar plasma. Plasma particle bombardment and irradiation induce C–C and C–H bond scissions by σ?→?σ ^? excitations on the surface and in near-surface layers. Consequently, radicals are generated. They react by recombination, cross-linking, metastable trapping of the radical site or formation of olefinic double bonds. The long-living and metastable trapped C-radicals as well as double bonds in polyolefins were immediately exposed to bromine vapour without breaking the vacuum after switching-off the plasma. These reactive sites rapidly react with the molecular bromine under formation of C–Br bonds. For 5?min of argon plasma exposure, the elemental concentration of bromine was 13% for polyethylene and 22% Br/C for polypropylene as analysed by X-ray photoelectron spectroscopy. Nevertheless, not all C radical sites have reacted with bromine. Later on, when the polyolefins brought in contact with ambient air, an additional post-plasma reaction of the remaining trapped radicals with oxygen was observed. The oxygen concentrations were lower after bromine gassing, thus repressing partially the post-plasma oxidation in the analysed layer (ca. 6?nm) by radical quenching. Such bromination took place either at the surface or in near-surface layers because the Attenuated Total Reflectance (ATR)-FTIR spectra (sampling depth ca. 2500?nm) did not show significant changes for argon plasma-treated PE foils with and without bromine vapour exposure. Further addition of bromine may also occur on C=C double bonds.     

Person-centered technology enhanced learning: Dimensions of added value

Extensive research has shown that person-centered learning aiming at students’ development on the levels of intellect, skills, and attitudes is effective in face-to-face education. More recently, advances in web-technology let us ask: Is humanistic, person-centered learning also effective along the application of modern technology? In this contribution we reflect 10 years of research at the University of Vienna, Austria. Essentially, we found that, given learners perceive the teacher’s or facilitator’s person-centered attitudes and courses employ a thoughtful blend of face-to-face and online elements, courses tend to be perceived by students as carrying value far beyond just cognitive gains: for example, students indicate that – more than with traditional instruction – they are motivated to engage in active, self-initiated learning. In particular, they improve their team skills, interpersonal relationships, and become better listeners. They learn significantly from the multiple perspectives they perceive.