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  • 1
    ISSN: 1432-1939
    Keywords: Submerged macrophytes ; Annuals ; Seed size ; Seed bank ; Temporary Mediterranean marsh
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The abundance and composition of the submerged macrophyte seed bank in the Doñana marsh (southwestern Spain) was evaluated to assess its relationship with the overlying vegetation. The results obtained demonstrate the existence of a dense seed-bank, both in terms of the number of seeds and their biomass, which represented about 10% (5% for angiosperms and 〉20% for Charophyta) of the total plant biomass, which ensures the maintenance of the annual submerged macrophyte populations of the seasonally inundated Donñana marsh. Seed bank and established vegetation were coupled, as reflected in the existence of significant correlations between their structure and abundance. This coupling was lacking for Charophyta, whose oospores are widespread and abundant across the marsh, even at locations where they are absent, or rare, in the established vegetation. These differences between the seed bank of annual angiosperms and Charophyta appear to reflect, in part, structural differences between angiosperm seeds and Charophyta oospores, with important ecological consequences. An important aspect of these differences is the allocation of Charophyta reproductive effort to many small propagules lacking embryo storage, compared to those of angiosperms, which ensures their efficient dispersal and numerical abundance in the seed bank.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Annals of hematology 45 (1982), S. 1-11 
    ISSN: 1432-0584
    Keywords: Bence Jones proteinuria ; Glomerular filtration rate ; Myelomatosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Forty-two consecutive patients with untreated myelomatosis (MM) formed the basis of settling the validity of measuring the renal plasma clearance (RPC), either indirectly using the serum creatinine or directly using the glomerular filtration rate (GFR) when studying anaemia, calcium metabolism, proteins in serum and urine, and prognosis. Patients without light chain excretion in the urine had a higher GFR (P〈0.01) than patients with light chain excretion. The haemoglobin concentration (Hb) was strongly correlated (P〈0.001) to both, serum creatinine and GFR. Patients with normal serum concentrations of the physiological immunoglobulins had higher Hb (P〈0.01) than patients with reduced serum immunoglobulins. Patients with serum calcium 〉3.00 mmol/l had additional reduced GFR compared with the other myeloma patients. The serum parathyroid hormone was decreased (P〈0.01) and inversely correlated to the GFR. Patients with increased serum creatinine, reduced GFR or with osteolytic bone lesions had a decreased survival rate. The study shows that the major factor in prediction of Hb and prognosis in patients with MM is the RPC expressed either as the serum creatinine or the GFR. In addition, the significant correlations between the GFR and the other variables in MM assessed the RPC to be a useful and valuable marker in studies of anaemia, protein and calcium metabolism and prognosis in MM.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1572-977X
    Keywords: Avicennia alba ; growth ; internodal sequences ; mangrove age determination ; Rhizophora apiculata ; Sonneratia caseolaris ; Thailand
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The occurrence of periodic changes in the length of the internodes of the seedlings of SE Asian mangrove species (Rhizophora apiculata, Avicennia alba, and Sonneratia caseolaris) growing in the Pak Phanang estuary (Nakhon Si Thammarat, SE Thailand) was confirmed. The annual nature of these periodic changes was verified through comparisons with the observed average number of internodes produced by plants tagged for one year. The cycles in the sequence of internodal length of the seedlings had an average (± SE) period of 16.0 ± 0.78 internodes for Avicennia alba, 25.0 ± 1.2 internodes for Sonneratia caseolaris, and 8.29 ± 0.40 internodes for Rhizophora apiculata. These values are remarkably close to, and not significantly different (t‐test, P 〉 0.05) from the average (± SE) annual number of internodes of 17.6 ± 0.8 for Avicennia alba, 28.8 ± 2.1 for Sonneratia caseolaris, and 8.03 ± 0.36 for Rhizophora apiculata produced in a year by tagged plants. In addition, the average (± SE) growth of the tagged plants was 0.39 ± 0.018 cm day-1 for Avicennia alba, 0.24 ± 0.015 cm day-1 for Sonneratia caseolaris, and 0.091 ± 0.0036 cm day-1 for Rhizophora apiculata. These estimates were very close to those (0.45 ± 0.06 cm day-1 for Avicennia alba, 0.32 ± 0.01 cm day-1 for Sonneratia caseolaris, and 0.13 ± 0.005 cm day-1 for Rhizophora apiculata) derived as the product of the mean number of internodes produced per day, calculated from the inferred number of internodes produced per year, and the mean length of the internodes of the plants. These findings indicate that the use of regular, annual changes in the length of the internodes of mangrove seedlings can be used reliably to determine their age and to estimate their growth rate.
    Type of Medium: Electronic Resource
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