Wolfgang Ehlers

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Conservation tillage may concentrate organic matter and carbon in the soil, thus improving soil quality and counteracting CO2-increase in the atmosphere. In parts of Germany however, continuous conservation tillage can cause problems in soil and crop management, resulting in a need to shift to short-term conventional tillage, such as mouldboard ploughing.(More)
Based on the Theory of Porous Media (mixture theories extended by the concept of volume fractions), a model describing the mechanical behavior of hydrated soft tissues such as articular cartilage is presented. As usual, the tissue will be modeled as a materially incompressible binary medium of one linear viscoelastic porous solid skeleton saturated by a(More)
Finite element models for hydrated soft biological tissue are numerous but often exhibit certain essential deficiencies concerning the reproduction of relevant mechanical and electro-chemical responses. As a matter of fact, singlephasic models can never predict the interstitial fluid flow or related effects like osmosis. Quite a few models have more than(More)
The distribution of a crop rooting system can be defined by root length density (RD), root length (RL) per soil layer of depth Δz, sum of root length (SRL) in the soil profile (total root length) or rooting depth (z r . The combined influence of these root system parameters on water uptake is not well understood. In the present study, field data are(More)
A model for the operationalization of empirical research of defense mechanisms is presented. Measures for operationalized defense diagnoses are discussed against the background of a cognitive model of different coding of information channels (linguistic and perceptual coding). Studies for the operationalized diagnoses in the clinical assessment of defense(More)
A potassium loss of 3–11% (6.0±2.7%) of total body potassium, was produced in 6 normal subjects during the course of a metabolic balance study of 13–16 days duration using a supplemented formula diet. This resulted in the development of a marked hypokaliaemic alkalosis. There were no significant changes of blood sugar, free fatty acid and plasma insulin(More)
Four new cases with congenital homozygous factor VII deficiency are described. Factor VII levels were reduced to less than 1%, 3%, 8% and 10%, respectively. The incidence and severity of bleeding symptoms were well correlated with the measured factor VII activity. In the severe case of factor VII deficiency (less than 1%) a home treatment program was(More)
METHODS AND RESULTS By differential display we isolated a new cDNA-fragment, named C13, that is downregulated in malignant prostate tissues. Northern hybridization revealed the fragment to be part of 3.0 and 4.4 kb mRNAs. Fluorescence in situ hybridization, Southern blotting and radiation hybrid mapping demonstrated a chromosomal localization of C13 on(More)