Teaching information systems to small business management

The availability of cheaper, more efficient small computers opened up the possibility for medium-sized firms to install their own EDP system. Nevertheless these firms do not make sufficient use of EDP. One major reason for this is the lack of management knowledge about good computer applications. The paper describes a way to close this gap.On the basis of pilot and empirical studies, a combination of introductory lectures, autodidacts studies, and concluding lectures is proposed.To support the small business management, a manual was first designed. This deals with the practical problems and decisions of small and medium sized firms. In order to achieve better training seminars were designed that combined information materials with other systems of learning. The methods and the contents of these seminars including various case studies is described.     

1H-NMR of the amidation of syndiotactic poly(methacrylic acid) with carbodiimide

Summary The reaction of syndiotactic poly(methacrylic acid) with dicyclohexylcarbodiimide in the presence of benzylamine yields syndiotactic methacrylic acid-methacryloyl-N-benzylamide copolymers. A limiting conversion to amide of about 62% and a tendency of alternation for the monomer units is observed by¹H-NMR. The amidation is accompanied by the formation of a smaller amount of cyclic imide as a side reaction. The imide portion can also be transformed into amide by a consecutive hydrolysis step.     

Vinyl chloride,identification and solution of a problem

More than 8 years have passed after the identification of vinyl chloride (VC) as having a carcinogenic potential. It appears to be useful to recapitulate the development of the VC disease and of the measures in the PVC producing plants, taken until now, in the Federal Republic of Germany. It can be shown how this problem has been solved by cooperation of all persons involved, the chemical companies, the organizations responsible for occupational safety, the trade-unions representatives, the physicians and other experts. As a result of the manifold technical, medical, and other precautions, the operating conditions could be improved essentially. Currently, concentration levels of VCM in the workplace amount to 1 ppm or below in nearly all plants.     

Persistence of vector replacement systems is decidable

Summary In a persistent vector replacement system (VRS) or Petri net, an enabled transition can become disabled only by firing itself. Here, an algorithm is presented which allows to decide whether an arbitrary VRS is persistent or not, and if so, to construct a semilinear representation of the set of states reachable in the system.     

Identification of the Sex Pheromone of the Currant Shoot Borer Lampronia capitella

Under an artificial light:dark cycle, females of Lampronia capitella were observed calling, with extended terminal abdominal segments, during the first 2 hr of the photoperiod. Extracts of terminal abdominal segments from females elicited large electroantennographic responses from male antennae. Gas chromatography with electroantennographic detection revealed three active peaks. Based on comparison of retention times and mass spectra of synthetic standards, these compounds were identified as (Z,Z)-9,11-tetradecadienol and the corresponding acetate and aldehyde. The electroantennographic activity of the four geometric isomers of all three compounds was investigated, and the respective (Z,Z)-isomer was found to be the most active in all cases. Aldehydes generally elicited larger antennal responses than alcohols, whereas acetates were the least active compounds. A subtractive trapping assay in the field, based on a 13:26:100 micrograms mixture of (Z,Z)-9,11-tetradecadienal, (Z,Z)-9,11-tetradecadienyl acetate, and (Z,Z)-9,11-tetradecadienol confirmed that all three compounds are pheromone components. Subtraction of (Z,Z)-9,11-tetradecadienol from the blend completely eliminated its attractiveness, whereas the other two-component blends showed reduced activity. This is the first pheromone identification from the monotrysian superfamily Incurvarioidea, confirming that the common pheromones among ditrysian moths (long-chain fatty acid derivatives comprising alcohols, acetates, and aldehydes with one or more double bonds) is not an autapomorphy of Ditrysia, but a synapomorphy of the more advanced heteroneuran lineages.     

Acquired and Partially De Novo Synthesized Pyrrolizidine Alkaloids in Two Polyphagous Arctiids and the Alkaloid Profiles of Their Larval Food-Plants

The profiles of pyrrolizidine alkaloids (PAs) in the two highly polyphagous arctiids Estigmene acrea and Grammia geneura and their potential PA sources in southeastern Arizona were compiled. One of four species of Boraginaceae, Plagiobothrys arizonicus, contained PAs; this is the first PA record for this plant species. The principle PA sources are Senecio longilobus (Asteraceae) and Crotalaria pumila (Fabaceae). The known PA pattern of S. longilobus was extended; the species was found to contain six closely related PAs of the senecionine type. Three novel PAs of the monocrotaline type, named pumilines A-C, were isolated and characterized from C. pumila, a species not studied before. The pumilines are the major PAs in the seeds, while in the vegetative organs they are accompanied by the simple necine derivatives supinidine and as the dominant compound subulacine (1beta,2beta-epoxytrachelanthamidine). In both plant species, the PAs are stored as N-oxides, except C. pumila seeds, which accumulate the free bases. Great variation in PA composition was observed between local populations of C. pumila. The PA profiles were established for larvae and adults of E. acrea that as larvae had fed on an artificial diet supplemented with crotalaria-powder and of G. geneura fed with S. longilobus. In both experiments, the larvae had a free choice between the respective PA source and diet or food plants free of PAs. The profiles compiled for the two species reflect the alkaloid profiles of their PA sources with one exception, subulacine could never be detected in E. acrea. Besides acquired PAs, insect PAs synthesized from acquired necine bases and necic acids of insect origin were detected in the two arctiid species. These insect PAs that do not occur in the larval food sources accounted for some 40-70% (E. acrea) and 17-37% (G. geneura) of total PAs extracted from the insects. A number of novel insect PAs were identified. Plant-acquired and insect PAs were found to accumulate as N-oxides. The results are discussed in relation to specific biochemical, electrophysiological, and behavioral mechanisms involved in PA sequestration by arctiids.     

Improving generalization capabilities of dynamic neural networks

This work addresses the problem of improving the generalization capabilities of continuous recurrent neural networks. The learning task is transformed into an optimal control framework in which the weights and the initial network state are treated as unknown controls. A new learning algorithm based on a variational formulation of Pontrayagin's maximum principle is proposed. Under reasonable assumptions, its convergence is discussed. Numerical examples are given that demonstrate an essential improvement of generalization capabilities after the learning process of a dynamic network.