The proposed robot software interfaces SRL and IRDATA

This paper discusses the research activities on robotics at the Institut für Informatik III of the Universität Karlsruhe, Karlsruhe, Federal Republic of Germany. The projects are directed towards the design of user-oriented programming systems and intelligent sensors and controls for industrial robots. The work includes: Development of a high order programming language for assembly robots, simulation of assembly systems, design of a polyprocessor controller for robots, conception of design rules for the integration of robots into CIM systems, development of vision devices and design of multisensor systems for manipulators.     

Molecular cDNA cloning and tissue distribution of mRNA encoding a novel ATP-binding cassette (ABC) half-transporter

After feeding a commercial rodent chow for 8 weeks, tissues from male and female rats were collected and examined for selenium content, glutathione peroxidase (GPX) activities and selenoprotein W (Se-W) levels. There were no differences (P > 0.05) between plasma selenium content, plasma GPX activity, whole blood selenium content, or whole blood GPX activity between male and female rats. There was also no gender effect on selenium concentration in muscle, brain, spleen, and skin, but selenium concentration in liver was higher (P < 0.05) in female than in male rats. Western blots indicated that the tissue distribution of Se-W was similar in male and female rats. Se-W protein level was high in testes of male rats but very low in ovaries of female rats. Muscle and skin from female rats had significantly higher (P < 0.05) Se-W levels than from male rats. Consistent with Se-W content, the Se-W mRNA levels from female skins were significantly higher (P < 0.05) than from male rats. The expression of Se-W was different in various tissues and gender influenced this regulation in some tissues.     

Biostatical and biomathematical evaluation of morphometric data--illustrated on the example of the relationship between axon diameter and thickness of the myelin sheat. I. 1st data evaluation step: empiric regression

Application of the biostatistical procedure of empirical regression on a first data processing stage is demonstrated by examples from morphometrical research concerning the connection between axon caliber and thickness of myelin sheat of nerve fibers. This mathematical kind of describing connections between continuous random variables offers advantages which are discussed under the aspects of information compressing, of automatic data processing, and of providing objective basis for the process of data handling and decision making of further evaluations.     

An interface crack between an orthotropic thin film and substrate

This work is concerned with a semi-infinite interface crack between a thin film and a substrate. The two materials are assumed to be linearly elastic and orthotropic. A solution is presented for the stress field due to an edge dislocation on the interface which is valid for any combinations of material parameters. It is found that the behavior of such a bi-material system is governed by 6 independent material parameters. The stress intensity factor is computed for general edge loadings by solving integral equations numerically, and the size of the K-dominant zone is also studied for a residually stressed thin film. The situations in which the K-field zone of dominance is very small are identified and discussed.     

Molecular dynamics and conformation in the gel and liquid-crystalline phases of phosphatidylethanolamine bilayers

Solid-state deuterium and carbon-13 nuclear magnetic resonance (NMR) spectra have been used to study the molecular dynamics and conformation of dipalmitoylphosphatidylethanolamine (DPPE) in both the gel (L beta) and liquid-crystalline (L alpha) phases. For this purpose DPPE was labeled with 13C in the carbonyl group of the sn-2 chain and with 2H at three different positions--4, 8, and 12--of the sn-2 chain, at the 2 position of the glycerol backbone, and at the 1 position of the ethanolamine head group. The 13C carbonyl and 2H chain spectra indicate that in the gel phase the DPPE molecules are diffusing about their long axes at rates of 10(5)-10(6) s-1 and the acyl chains are in an approximately all-trans conformation. The glycerol backbone spectra suggest that the backbone is in a gauche conformation in the gel state, rather than a trans conformation such as found in single crystals. The head group spectra in the gel phase are broad, featureless lines of about 20-kHz width. At the L beta leads to L alpha phase transition several changes take place. As is well-known, the chains disorder, and fast long-axis rotational diffusion begins, which results in the sharp, axially symmetric L alpha phase 2H spectra, which are a factor of 2 narrower than those observed in the L beta phase. The head group spectra also sharpen substantially at the transition, although their total width remains approximately constant. The invariance of the spectral width suggests that the average head group conformation is similar in both phases. However, the sharper spectra seen in the L alpha phase indicate that the rates of the head group motions in this phase are at least 3 orders of magnitude faster than those in the L beta phase. Thirdly, the 2H spectra of the glycerol backbone labeled DPPE narrow by a factor of about 4, and we believe this is due to a conformational change in this region of the molecule. Consistent with this interpretation is the fact that the powder pattern exhibited by the sn-2 13C = O in the L beta phase collapses to an isotropic-like line at the phase transition.     

"Periodic" seizures

PURPOSE: To describe regularly recurring ictal phenomena as recorded in a single patient whose seizure disorder related to a left temporal cavernous angioma. METHODS: Seizures were recorded by left temporal subdural strip electrodes which were bilaterally placed because of ambiguous seizure origin and right temporal memory dysfunction at Wada testing. Seizure length, interseizure intervals, and interseizure onset intervals were visually assessed. The coefficient of variation was used as an estimate of variability in seizure periodicity. RESULTS: Mean seizure durations varied from 68 to 95 s; coefficients of variation varied from 0.08 to 0.18, values similar to other periodic biological phenomena. Mean daily seizure intervals varied from 96 to 152 s with coefficients of variation ranging from 0.12 to 0.35. Interseizure onset intervals had smaller coefficients of variation (0.03-0.20). Manifestations of these simple partial seizures included a rising epigastric sensation and nausea. CONCLUSIONS: Previously described periodic EEG phenomena are interictal events or appear with peripheral events of similar cadence. Therefore, we remain unaware of any documentation of periodic ictal electrographic events. The restricted propagation and duration of these recorded seizures may have simplified their pathophysiology allowing a stereotyped involvement of excitatory and inhibitory mechanisms producing the periodicity.     

Mesenchymal Stromal Cell Therapy in Novel Porcine Model of Diffuse Liver Damage Induced by Repeated Biliary Obstruction

In liver surgery, biliary obstruction can lead to secondary biliary cirrhosis, a life-threatening disease with liver transplantation as the only curative treatment option. Mesenchymal stromal cells (MSC) have been shown to improve liver function in both acute and chronic liver disease models. This study evaluated the effect of allogenic MSC transplantation in a large animal model of repeated biliary obstruction followed by partial hepatectomy. MSC transplantation supported the growth of regenerated liver tissue after 14 days (MSC group, n = 10: from 1087 ± 108 (0 h) to 1243 ± 92 mL (14 days); control group, n = 11: from 1080 ± 95 (0 h) to 1100 ± 105 mL (14 days), p = 0.016), with a lower volume fraction of hepatocytes in regenerated liver tissue compared to resected liver tissue (59.5 ± 10.2% vs. 70.2 ± 5.6%, p < 0.05). Volume fraction of connective tissue, blood vessels and bile vessels in regenerated liver tissue, serum levels of liver enzymes (AST, ALT, ALP and GGT) and liver metabolites (albumin, bilirubin, urea and creatinine), as well as plasma levels of IL-6, IL-8, TNF-α and TGF-β, were not affected by MSC transplantation. In our novel, large animal (pig) model of repeated biliary obstruction followed by partial hepatectomy, MSC transplantation promoted growth of liver tissue without any effect on liver function. This study underscores the importance of translating results between small and large animal models as well as the careful translation of results from animal model into human medicine.     

Development of vibration damping materials based on butyl rubber: A study of the phase equilibrium,rheological, and dynamic properties of compositions

A detailed study of butyl rubber-based vibration damping formulations linking their composition, morphology, phase structure, viscosity, mechanical loss factor, and other characteristics is presented for the first time. High performance of the compositions including aromatic petroleum oil is explained by limited solubility of the plasticizer that leads to the formation of a highly-viscous emulsion (η_20°C ≈ 1000 Pa·s) consisting of a swollen butyl rubber matrix and dispersed oil droplets in the broad composition range. Chalk is found to be the best inorganic filler as its spherical particles provide strong adhesion to the reinforcing layer of aluminum foil. Aiming to eliminate ecologically unfriendly aromatic compounds, a new low-cost binding agent formulation based on butyl rubber mixed with polyisobutylene and highly refined mineral oil is suggested. Being environmentally safe, it possesses high viscosity of 1000–3000 Pa·s, cohesion strength of 3.5–5.0 N/cm, penetration of 4.5–6.0 mm, and mechanical loss factor up to 0.34 at room temperature, which are as good as, or even better than, the properties of currently produced vibration damping materials containing aromatic compounds. New materials can be used in car and aircraft parts for effective vibration isolation.