Attachment of Salmonella typhimurium to Poultry Skin as Related to Cell Viability

³H-labeled S. typhimurium cells inactivated by gamma-radiation (⁶⁰Co) and by formaldehyde (5%) were used to determine if cell viability affected attachment to poultry skin. Both gamma-irradiated and formal-dehyde-treated cells attached like live cells. There was no difference in attachment between cells grown in a chemically defined medium (SCDM) or in brain heart infusion broth (BHI). Live and gamma-irradiated cells and BHI-grown and SCDM-grown cells had similar surface hydrophobicity. Live and gamma-irradiated cells had similar cell surface charges, whereas BHI and SCDM-grown cells had different surface charges. Differences in cell surface charge did not affect attachment rate.     

Aspects of surface and environment protection in German mining areas

Hard coal mining in the German Ruhr district has a tradition of more than 200 years. Starting in the south near the river Ruhr with mining of seams near to the surface, mining wandered to the north with coal seams deeper and deeper. In the same way all environmental effects of mining wandered from south to north, as there are abandoned mining sites, contaminated areas, burning mining dumps, subsided areas and gas accesses at day ground. This all happened in a very high populated area with more than four million inhabitants. Therefore Germany has a long tradition in solving environmental problems of mining activities. The very good interaction of mine authority, mining companies and the mine workers' union is the main reason why the problems of decreasing mining activities in Germany were solved without economic, environmental or social hazards.     

A City Metaphor to Support Navigation in Complex Information Spaces

A major problem in modern information systems is to locate information and to re-find information one has seen before. Systems like the World Wide Web are heavily interlinked, but do not show structures that help users to navigate the information it contains. The use of appropriate navigation metaphors can help to make the structure of modern information systems easier to understand and therefore easier to use.We propose a conceptual user interface metaphor based on the structure of a city. Cities are very complex spatial environments and people know how to get information, how to reach certain locations in a city, and how to make use of the available infrastructure, etc. Cities provide a rich set of navigational infrastructure that lends itself to creating sub-metaphors for navigational tools. A city metaphor makes this existing knowledge about a structured environment available to the user of a computerized information system.We first focus on several properties necessary for future user interfaces (or user interface metaphors) that will distinguish them from current systems, like the richness of information or the use of visualizations to show the structure of information spaces. We also describe the strengths and problems of spatial user-interface metaphors. Then we present the structure of the information city metaphor, its structuring and navigation metaphors and what we see as its main advantages and problems. We further outline a few scenarios of how an Information City might work. Finally, we compare implementing this metaphor using either a textual or a graphical virtual environment or a combination.     

Observation of the loss of the hydroxyapatite sixfold symmetry in a human fetal tooth enamel crystal

A deviation from the hydroxyapatite hexagonal symmetry of a human tooth enamel crystal observed by high-resolution electron microscopy is reported. This symmetry deviation is characterized by: (1) ‘preferential’ planes that can be indexed as (100) with an intensity that differs from the (300) and the other {100} hexagonal equivalent planes; and (2) streaking of higher order reflections in the optical diffractogram of the image of the crystal. Computer simulations show that similar ‘preferential’ planes can also be observed at specific crystal tilt angles (and/or beam tilt and/or objective aperture misalignment) and at crystal thickness/microscope defocus values in images of hydroxyapatite crystals observed along the [0001] or [] zone axes. The streaking of higher order reflections in the optical diffractogram is related to a deformation of the crystal itself and does indeed show a symmetry deviation of the crystal under observation.     

Calibration of a wide-field frequency-domain fluorescence lifetime microscopy system using light emitting diodes as light sources

High brightness light emitting diodes are an inexpensive and versatile light source for wide‐field frequency‐domain fluorescence lifetime imaging microscopy. In this paper a full calibration of an LED based fluorescence lifetime imaging microscopy system is presented for the first time. A radio‐frequency generator was used for simultaneous modulation of light emitting diode (LED) intensity and the gain of an intensified charge coupled device (CCD) camera. A homodyne detection scheme was employed to measure the demodulation and phase shift of the emitted fluorescence, from which phase and modulation lifetimes were determined at each image pixel. The system was characterized both in terms of its sensitivity to measure short lifetimes (500 ps to 4 ns), and its capability to distinguish image features with small lifetime differences. Calibration measurements were performed in quenched solutions containing Rhodamine 6G dye and the results compared to several independent measurements performed with other measurement methodologies, including time correlated single photon counting, time gated detection, and acousto optical modulator (AOM) based modulation of excitation sources. Results are presented from measurements and simulations. The effects of limited signal‐to‐noise ratios, baseline drifts and calibration errors are discussed in detail. The implications of limited modulation bandwidth of high brightness, large area LED devices (～40 MHz for devices used here) are presented. The results show that phase lifetime measurements are robust down to sub ns levels, whereas modulation lifetimes are prone to errors even at large signal‐to‐noise ratios. Strategies for optimizing measurement fidelity are discussed. Application of the fluorescence lifetime imaging microscopy system is illustrated with examples from studies of molecular mixing in microfluidic devices and targeted drug delivery research.     

Sensitivity analysis of pulse-frequency-modulated control using a linearized model†

The paper discusses the sensitivity of pulse-frequency modulated (PFM) control systems with respect to changes in the plant and controller parameters. The investigations of the sensitivity behaviour of non-linear PFM control systems are carried out using a linearized approach for the PFM controller, as proposed by Frank and Dillmann. The goal of this paper is to study the effectiveness of this method as applied to the investigation of an unstable plant. The sensitivity functions of the PFM system and the corresponding continuous equivalent systems are evaluated by considering parameter changes in the actual plant. The limitations of this method are pointed out.     

EFFECT OF PARTICLE SIZE AND SAMPLE SIZE ON LIPID STABILITY OF MILLED FLAXSEED (Linum usitatissimum L.)

Experiments were conducted to determine the effect of sample size and particle size on lipid oxidation of milled flaxseed. An initial experiment showed that most of the lipid oxidation detected in milled flaxseed samples occurred on the surface that was exposed to the air during storage. In a subsequent experiment, milled flaxseed at 100, 200 and 300 g were stored in the dark in rectangular pans for 8, 24 and 48 days at 50C. Lipid oxidation, as determined by surface lipid content, peroxide value and α-linolenic acid content, was lower in the 300 g samples than in the 100 g samples of milled flaxseed. Large versus small samples had less apparent lipid oxidation because of their inherently lower surface to volume ratio. In a third experiment, oxidation was lower in lipid extracted from coarse ( > 600 µm) than fine particles ( < 600 µm), after 48 days of storage.

PRACTICAL APPLICATIONS

This research has practical applications to the flaxseed milling and food industries. These results show that assessment of lipid oxidation in milled flaxseed needs to consider sample size (collection). Milled flaxseed oxidized predominantly at the sample surface where a polymerized layer of flaxseed particles formed over time. Relatively little oxidation occurred in the interior of the sample. Thus, sampling from the surface or interior of a milled flaxseed sample will end in different results and conclusions. Similarly, results will vary with surface : interior ratio of milled flaxseed. Food manufacturers may want to discard the top layer of milled flaxseed that has been exposed to air. Lipid oxidation was less with coarse than fine particles. Thus it would be prudent not to use milled flaxseed with a finer particle size than is necessary for acceptable end-use quality.     

NaF-KF-K2NbF7 Fused Salt Temperature-Solubility Diagram

Freezing and eutectic temperatures were determined for the NaF-KF-K₂NbF₇ ternary system and the NaF-K₂NbF₇, KFK₂NbF₇, and NaF-KF binary systems. The compound KF-K₂NbF₇ freezes congruently at 770°C; eutectics occur at 708° and 724°C for high- and low-K₂NbF₇ mixtures, respectively. The NaF-K₂NbF₇ eutectic freezes at 658°C. The ternary system has two eutectics, a high-KF mixture and a high-K₂NbF₇ mixture, which occur at 663° and 652°C, respectively.     

GERMAN PSYCHOLOGY AND ITS JOURNALS.

GERMAN PSYCHOLOGY JOURNALS ARE DESCRIBED AND COMPARED TO SIMILAR AMERICAN JOURNALS. CONTENT AREAS, PUBLICATION DATA, AND AUTHORS' AFFILIATIONS ARE ENUMERATED. ON THE AVERAGE, GERMAN JOURNALS HAVE A 20% REJECTION RATE, A 6-MO PUBLICATION LAG, 25% NON-GERMAN AUTHORS, AND ARTICLES TWICE AS LONG AS THEIR AMERICAN COUNTERPARTS. GERMAN SELECTION CRITERIA AND ARTICLE QUALITY ARE EVALUATED, AND HISTORICAL FACTORS FOR PRESENT PUBLICATION PROCEDURES ARE DISCUSSED. INTEREST AREAS AND PUBLICATION QUANTITY ARE SHOWN FOR VARIOUS PSYCHOLOGICAL INSTITUTES IN GERMANY. (PsycINFO Database Record (c) 2010 APA, all rights reserved)