RDBM—A relational data base machine

After a short introduction to the field of data base machines the design of the RDBM (Relational Data Base Machine) is presented, which provides all the functions required of a relational data base system. Frequently used and time-consuming functions are supported by appropriate hardware components. A transaction-oriented multi-user system was designed which exploits the inherent parallelism of user tasks and data base functions.The RDBM consists of a quasi-associative mass store together with a system of special function processors with common access to a large main memory, and a general purpose mini-computer exercising overall control over all hardware components.     

Fundoplication for the treatment of gastroesophageal reflux in hiatal hernia

Blood pressure (BP) levels were recorded in 2223 male and 2205 female children and adolescents ranging in age from 7 to 18 years. In addition, 521 male adults (soldiers) ranging in age from 21 to 25 years were included in the study. Children and adolescents who participated in the survey were selected at random the Elementary and High Schools. The results of the study showed that a gradual increase occurred in the systolic, as well as in the diastolic component of blood pressure from 7 to 18 years of age. By contrast, there was no increase with age in the systolic and diastolic blood pressure in the young male adult subjects, who had BP measurements comparable to those observed in children. A child was characterized as hypertensive according to the criteria outlined by Master et al. Children with BP between the 90th and the 95th percentile were considered as suspect hypertensive, whereas those with BP exceeding the 95th percentile were considered definitely hypertensive. The overall incidence of hypertension in children in this survey was 3.1%.     

IV. Referate

Ohne Zusammenfassung     

Kinetics of the hydrogenation of rapeseed oil: II. Rate equations of chemical reactions

The kinetics of rapeseed oil hydrogenation was studied at 140–220 C and at 0.3–10 atm hydrogen pressure in a laboratory reactor in the presence of 0.05% nickel catalyst. A mathematical model was fitted to the experimental data, and temperature and pressure dependence of the different reaction steps was discussed on the basis of the model. The adequacy of the model was tested by means of a residual analysis.     

Fate of aflatoxins and fumonisins during the processing of maize into food products in Benin

The fate of aflatoxins and fumonisins, two mycotoxins that cooccur in maize, was studied through the traditional processing of naturally contaminated maize in mawe, makume, ogi, akassa, and owo, maize-based foods common in Benin, West Africa. Levels of total aflatoxin and fumonisin were measured at the main unit operations of processing, and the unit operations that induce significant reduction of mycotoxin level were identified. Overall reduction of mycotoxin level was more significant during the preparation of makume (93% reduction of aflatoxins, 87% reduction of fumonisins) and akassa (92% reduction of aflatoxins, 50% reduction of fumonisins) than that of owo (40% reduction of aflatoxins, 48% reduction of fumonisins). Sorting, winnowing, washing, crushing combined with dehulling of maize grains were the unit operations that appeared very effective in achieving significant mycotoxin removal. Aflatoxins and fumonisins were significantly recovered in discarded mouldy and damaged grains and in washing water. Fermentation and cooking showed little effect. During the preparation of ogi and akassa, reduction of fumonisin levels measured in food matrix was lower (50%) compared to mawe and makume, probably due to significant fumonisin release in ogi supernatant. Consequently, the use of ogi supernatant for preparing beverages or traditional herbal medicines could be harmful as it is likely to be contaminated with mycotoxin from the raw maize.     

Wavefronts in the focus of a light microscope

We report the visualization of the wavefronts of light in the focal region of an objective lens. The focused wavefronts are measured for the highest available numerical aperture, i.e, 1·4 oil immersion. The measurement is accomplished by scanning a scattering probe through the focal region of a lens illuminated by plane waves. The scattered light is coherently added to an external reference beam and focused into a point-like detector. The registered signal allows the determination of the three-dimensional shape of the wavefronts in the focal region and their evolution in time.     

Reversible photoswitching enables single-molecule fluorescence fluctuation spectroscopy at high molecular concentration

We demonstrate that photoswitchable markers enable fluorescence fluctuation spectroscopy at high molecular concentration. Reversible photoswitching allows precise control of the density of fluorescing entities, because the equilibrium between the fluorescent ON- and the dark OFF-state can be shifted through optical irradiation at a specific wavelength. Depending on the irradiation intensity, the concentration of the ON-state markers can be up to 1,000 times lower than the actual concentration of the labeled molecular entity. Photoswitching expands the range of single-molecule detection based experiments such as fluorescence fluctuation spectroscopy to large entity concentrations in the micromolar range.     

Dual-color 4Pi-confocal microscopy with 3D-resolution in the 100 nm range

We report the development of simultaneous two-color channel recording in 4Pi-confocal microscopy. A marked increase of spatial resolution over confocal microscopy becomes manifested in 4Pi-confocal three-dimensional (3D) data stacks of dual-labeled objects. The fundamentally improved resolution is verified both with densely labeled fluorescence beads as well as with membrane labeled fixed Escherichia coli. The synergistic combination of dual-color 4Pi-confocal recording with image restoration results in dual-color imaging with a 3D resolution in the 100 nm range.