ALBERT

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  • 1
    Electronic Resource
    Electronic Resource
    Effect of the insecticide methidathion on agricultural soil microflora (1992)
    Springer
    Biology and fertility of soils 13 (1992), S. 173-175 
    Details
    ISSN: 1432-0789
    Keywords: Methidathion ; Soil microflora ; Enumeration of functional bacterial groups ; Acetylene reduction assay ; ARA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary We studied the effects of the organophosphorus insecticide methidathion, at concentrations of 10, 50, 100, 200 and 300 μg g-1 in an agricultural soil, on fungi, total bacterial populations, aerobic N2-fixing bacteria, denitrifying bacteria, nitrifying bacteria (phases I and II), and nitrogenase activity (acetylene reduction assay). The presence of 10–300 μg g-1 of methidathion significantly increased fungal populations (colony-forming units). Denitrifying bacteria, aerobic N2-fixing bacteria and N2 fixation were significantly increased at concentrations of 50–300 μg g-1. The total number of bacteria increased significantly at concentrations of 100–300 μg g-1. Nitrifying bacteria decreased initially at concentrations of 300 μg g-1, but recovered rapidly to levels similar to those in the control soil without the insecticide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336275
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Geochemical aspects of aluminium in forest soils in Galicia (N.W. Spain) (1992)
    Springer
    Biogeochemistry 16 (1992), S. 167-180 
    Details
    ISSN: 1573-515X
    Keywords: Al speciation ; soil solution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The aqueous speciation of Al was studied in acid forest soils in N.W. Spain. Aluminum concentrations were 10–70 μmol L−1, with variable proportions oflabile, nonlabile, andacid-soluble Al. Almost all thelabile Al was found complexed with F−, Al3+ concentrations being low. The importance of organic matter was seen in the formation of Al-organic complexes in the solid soil fraction and the presence of aqueous alumino-organic complexes in superficial horizons (umbric epipedons) rich in organic matter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00002817
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  • 3
    Electronic Resource
    Electronic Resource
    A boundary integral method for steady flow in unsaturated porous media (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    International Journal for Numerical and Analytical Methods in Geomechanics 16 (1992), S. 581-601 
    Details
    ISSN: 0363-9061
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Geosciences
    Notes: The governing equation for steady flow in a homogeneous, partially saturated, porous medium can be written in a linear form if one adopts a hydraulic conductivity function which varies exponentially with capillary-pressure head. The resulting linear field equation is a steady Fokker-Planck equation and is well-suited to numerical solution by the boundary integral equation method (BIEM). The exponential conductivity function is often used in soil physics and is known to be a reasonable approximation over limited ranges of pressure head. A computer code based on the BIEM for obtaining numerical solutions is described and tested. The BIEM is found to exhibit quadratic convergence with element size reduction on smooth solutions and on singular problems, if mesh grading is used. Agreement between results from the BIEM code and a finite element code that solves the fully non-linear problem is excellent, and is achieved at a substantial advantage in computer processing time. As an illustrative example, the code is applied to determine the distribution of moisture in the vicinity of a tunnel.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nag.1610160804
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  • 4
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    Coupling between distant biofilms and emergence of nutrient time-sharing (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-05-12
    Description: Bacteria within communities can interact to organize their behavior. It has been unclear whether such interactions can extend beyond a single community to coordinate the behavior of distant populations. We discovered that two Bacillus subtilis biofilm communities undergoing metabolic oscillations can become coupled through electrical signaling and synchronize their growth dynamics. Coupling increases competition by also synchronizing demand for limited nutrients. As predicted by mathematical modeling, we confirm that biofilms resolve this conflict by switching from in-phase to antiphase oscillations. This results in time-sharing behavior, where each community takes turns consuming nutrients. Time-sharing enables biofilms to counterintuitively increase growth under reduced nutrient supply. Distant biofilms can thus coordinate their behavior to resolve nutrient competition through time-sharing, a strategy used in engineered systems to allocate limited resources.
    Keywords: Engineering
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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