ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • synchronous fluorescence spectroscopy  (2)
  • 14CO2-excretion  (1)
  • Springer  (3)
Collection
Keywords
Publisher
  • Springer  (3)
Years
  • 1
    Electronic Resource
    Electronic Resource
    Spectroscopic properties of dissolved humic substances - a reflection of land use history in a fen area (1999)
    Springer
    Biogeochemistry 47 (1999), S. 219-238 
    Details
    ISSN: 1573-515X
    Keywords: dissolved humic substances ; FTIR spectroscopy ; land use history ; peat ; synchronous fluorescence spectroscopy ; UV/VIS spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The elemental composition and spectroscopic properties of dissolved fulvic acids isolated from different sampling media (topsoil, ground and surface water) of a natural fen area (high portion of organic soils) were examined to reveal the effects of land use history. These effects need to be known if dissolved humic substances are to be a major factor in identifying the impact of present and future changes in land use. Dissolved fulvic acids (topsoil, groundwater) from highly degraded peatlands (due to a long-term agricultural use) exhibit lower C/N ratios, higher absorption in the UV spectra, and higher absorption at 1,620 cm−1 in the FTIR spectra compared with fulvic acids from relatively intact peatlands. These properties illustrate that long-term agricultural use with high inputs results in increased aromatic structures and a further humification of dissolved fulvic acids due to very strong peat decomposition compared with relatively intact peatlands. Synchronous fluorescence spectra also indicate the higher level of aromatic structures within fulvic acids isolated from sites with long-term agricultural use (high peat decomposition) compared with a land use history resulting in a lower peat decomposition. The different sources of fulvic acids in surface water (precipitation, runoff, interflow, groundwater) are the main reason for these effects not being detected in fulvic acids isolated from surface water. Short-term changes in land use characterized by a transition from crop farming to an unimproved grassland were found not to affect the spectroscopic properties of dissolved fulvic acids. A humification index deduced from the synchronous fluorescence spectra is proposed. We have strong evidence that dissolved humic substances indicate changes in the environmental conditions (both anthropogenic and natural) of wetlands with a high proportion of organic soils.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006134214244
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Spectroscopic properties of dissolved humic substances — a reflection of land use history in a fen area (1999)
    Springer
    Biogeochemistry 47 (1999), S. 219-238 
    Details
    ISSN: 1573-515X
    Keywords: dissolved humic substances ; FTIR spectroscopy ; land use history ; peat ; synchronous fluorescence spectroscopy ; UV/VIS spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The elemental composition and spectroscopic properties of dissolved fulvic acids isolated from different sampling media (topsoil, ground and surface water) of a natural fen area (high portion of organic soils) were examined to reveal the effects of land use history. These effects need to be known if dissolved humic substances are to be a major factor in identifying the impact of present and future changes in land use. Dissolved fulvic acids (topsoil, groundwater) from highly degraded peatlands (due to a long-term agricultural use) exhibit lower C/N ratios, higher absorption in the UV spectra, and higher absorption at 1,620 cm−1 in the FTIR spectra compared with fulvic acids from relatively intact peatlands. These properties illustrate that long-term agricultural use with high inputs results in increased aromatic structures and a further humification of dissolved fulvic acids due to very strong peat decomposition compared with relatively intact peatlands. Synchronous fluorescence spectra also indicate the higher level of aromatic structures within fulvic acids isolated from sites with long-term agricultural use (high peat decomposition) compared with a land use history resulting in a lower peat decomposition. The different sources of fulvic acids in surface water (precipitation, runoff, interflow, groundwater) are the main reason for these effects not being detected in fulvic acids isolated from surface water. Short-term changes in land use characterized by a transition from crop farming to an unimproved grassland were found not to affect the spectroscopic properties of dissolved fulvic acids. A humification index deduced from the synchronous fluorescence spectra is proposed. We have strong evidence that dissolved humic substances indicate changes in the environmental conditions (both anthropogenic and natural) of wetlands with a high proportion of organic soils.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00994924
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Studies on the ascorbic acid metabolism of callitrichid monkeys by14C isotope excretion technique (1990)
    Springer
    European journal of nutrition 29 (1990), S. 192-196 
    Details
    ISSN: 1436-6215
    Keywords: Ascorbic acid metabolism ; Callitrichidae ; stress ; 14CO2-excretion ; Ascorbinsäurestoffwechsel ; Krallenaffen ; Streß ; 14CO2-Ausscheidung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Bei den beiden Affenarten Callithrix jacchus und Saguinus fuscicollis, die der gleichen Neuweltaffenfamilie der Krallenaffen angehören, wurden extrem unterschiedliche Serumascorbatspiegel gefunden, obwohl die Tiere unter identischen Bedingungen in derselben Kolonie gehalten wurden. Die14C-Ausscheidung von oral verabreichter 1-14C-AA wurde unter marginaler wie auch reichlicher Vitamin-C-Versorgung sowie unter Streßbedingungen untersucht. Zwischen niedriger und hoher Vitamin-C-Versorgung traten große Unterschiede im14C-Ausscheidungsmodus auf. Der Speziesunterschied war dabei geringer als der Unterschied zwischen individuellen Streß-/Nichtstreß-Bedingungen, aber in beiden Fällen war er gleichartig. In vergleichbaren Versuchen reagierte S. fuscicollis derart, daß ein höherer Streßzustand bei dieser Spezies angenommen werden kann.
    Notes: Summary Recently it has been found that the two monkey species Callithrix jacchus and Saguinus fuscicollis, both belonging to the same New World monkey family Callitrichidae and held in the same colony under identical conditions, had extremely different serum ascorbate levels. To examine the ascorbic acid metabolism the14C-excretion of orally given 1-14C-ascorbic acid was studied under conditions of marginal and abundant vitamin C supply and under intentional stress. There were large differences in the mode of14C excretion between low and high ascorbate supply. The differences were smaller between stress/no stress conditions intraindividually than between the two species, but they were in the same manner. In comparable trials S. fuscicollis reacted such that a higher status of stress can be supposed in this species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02021558
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...