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  • nitrogen  (3)
  • oxygen uptake  (3)
  • Agenesis  (2)
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Nutrient cycling in agroecosystems 46 (1996), S. 179-187 
    ISSN: 1573-0867
    Schlagwort(e): electrical conductivity ; leaching ; nitrogen ; pH ; phosphorus ; potassium ; release pattern ; slow-release fertilizers ; temperature
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract We studied the effect of temperature on the release of N, P, and K from slow-release fertilizers (SRF). The study was conducted in micro-lysimeters filled with moist peat medium. Increasing the temperature from 4 to 12°C slightly increased N release from three different slow-release N (SRN) carriers with different particle sizes and coating thicknesses. At 21°C the rate of release was significantly different than the other two temperatures. Urea formaldehyde (UF), sulphur coated urea (SCU) and coated calcium nitrate (CCN), incubated in sphagnum moss peat, released between 3 and 20% of the applied N in six weeks. For eight synthetic and organic NPK carriers, the release pattern was similar to UF and SCU. However, the leaching losses of N from the NPK fertilizers were up to twenty times more than for the SRN products. Except for Osmocote® and Duna, which released 30–40% of the applied N as mineral-N within six weeks, all other slow-release and slowly mineralized NPK carriers acted like readily water-soluble compound NPK. Temperature did not affect the nutrient release from NPK fertilizers.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 1572-9680
    Schlagwort(e): alley cropping ; maize ; nitrogen ; organic matter ; soil fertility ; Leucaena leucocephala ; Flemingia congesta
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract A detailed study of the soil chemical and physical properties in seven-year-old alley cropping trial containingLeucaena leucocephala andFlemingia congesta in Northern Zambia is described. There was a strong correlation between the maize yield and the total amount of nitrogen applied, both from prunings and fertiliser, suggesting that a major reason for the observed benefit from alley cropping, particularly withLeucaena, was due to an improvement in nitrogen supply.Leucaena produced significantly more biomass, and its leaves had higher concentrations of nitrogen, phosphorous and potassium and lower C/N and C/P ratios than did those ofFlemingia. There was also evidence that the trees had a beneficial effect on other soil chemical properties; under the hedgerows, particularly those ofLeucaena, there were higher levels of organic carbon, Mg, K and ECEC, and pH values were also highest. It is suggested that higher levels of organic carbon in the alley crop treatments were responsible for the improvements observed in soil physical properties. Lower bulk density, lower penetration resistance, and a higher infiltration rate and pore volume fraction were measured in the alley crops, although there was no significant change in the soil water release parameters. A deteriorating effect of constant applications of nitrogen fertiliser on soil fertility was observed; as the level of urea application increased, there were significant decreases in Mg, K and pH, increases in Al and soil acidity, and higher penetrometer resistance. These results highlight the urgent need for further research on biological methods of maintaining soil fertility.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Surgical and radiologic anatomy 21 (1999), S. 221-224 
    ISSN: 1279-8517
    Schlagwort(e): Gall bladder ; Agenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé L'absence congénitale de la vésicule biliaire est une malformation dont l'incidence est évaluée de 0,013 à 0,075 %. Nous rapportons deux observations d'agénésie de la vésicule biliaire, représentant les premiers cas de l'Afrique du Sud, nous les confronterons au 413 cas de la littérature. Pour confirmer le diagnostic d'agénésie de la vésicule biliaire, il est nécessaire d'exclure les localisations vésiculaires anormales, soit intra-hépatiques, soit rétro-hépatiques, soit dans le foie gauche, soit à l'intérieur de l'omentum ou du ligament falciforme, voire même rétro-péritonéales. Les patients porteurs d'agénésie de la vésicule biliaire sont classés en trois catégories : 1) Sujets porteurs de multiples anomalies foetales (12,9 %) 2) Sujets asymptômatiques (33,6 %) 3) Sujets avec manifestations cliniques (55,6 %). Néanmoins, les modalités diagnostiques habituelles peuvent, dans de rares conditions, se présenter dans le cadre d'une urgence chirurgicale abdominale. L'agénésie de la vésicule biliaire est une malformation bien connue, mais reste une anomalie rare. Avec l'avènement des abords chirurgicaux à minima, la laparotomie peut être évitée à condition que dans les cas suspectés, on réalise une exploration par endoscopie rétrograde des voies biliaires et pancréatiques (ERCP) et un scanner abdominal.
    Notizen: Summary Congenital absence of the gall bladder is an extremely rare embryological aberration with a reported incidence ranging between 0.013 and 0.075%. This report, the first from South Africa, discusses 2 cases of gall bladder agenesis, bringing to 413 the number of cases reported in the literature. In confirming the diagnosis of an agenesis of the gall bladder, it is necessary to exclude the abnormal locations which are intrahepatic, retrohepatic, on the left side, or within the lesser omentum or falciform ligament and retroperitoneal. Patients with gall bladder agenesis are classified into 3 categories: i) Multiple foetal anomaly (12.9%), ii) Asymptomatic (31.6%) and iii) Symptomatic (55.6%). Notwithstanding current diagnostic modalities, this rare condition may still present a dilemma to the abdominal surgeon. Agenesis of the gall bladder is a well-recognised but uncommon congenital abnormality. With the advent of minimal access surgery laparotomy may be avoided as the condition, when suspected, may be confirmed by ERCP and CT scan.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Surgical and radiologic anatomy 21 (1999), S. 221-224 
    ISSN: 1279-8517
    Schlagwort(e): Gall bladder ; Agenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Congenital absence of the gall bladder is an extremely rare embryological aberration with a reported incidence ranging between 0.013 and 0.075%. This report, the first from South Africa, discusses 2 cases of gall bladder agenesis, bringing to 413 the number of cases reported in the literature. In confirming the diagnosis of an agenesis of the gall bladder, it is necessary to exclude the abnormal locations which are intrahepatic, retrohepatic, on the left side, or within the lesser omentum or falciform ligament and retroperitoneal. Patients with gall bladder agenesis are classified into 3 categories: i) Multiple foetal anomaly (12.9%), ii) Asymptomatic (31.6%) and iii) Symptomatic (55.6%). Notwithstanding current diagnostic modalities, this rare condition may still present a dilemma to the abdominal surgeon. Agenesis of the gall bladder is a well-recognised but uncommon congenital abnormality. With the advent of minimal access surgery laparotomy may be avoided as the condition, when suspected, may be confirmed by ERCP and CT scan.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Plant and soil 127 (1990), S. 213-218 
    ISSN: 1573-5036
    Schlagwort(e): dry matter yield ; nickel ; nitrogen ; nutrient concentration ; wheat roots ; wheat tops
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract A glasshouse experiment was conducted to study the effect of Ni on the growth and nutrients concentration in wheat (Triticum aestivum Cv. WH 291) in the presence and absence of applied N as urea. Responses to N application were observed up to 120 μg N g−1 soil. No response to Ni was observed in the dry matter yield of wheat tops (leaves + stem) in the absence of applied N while in the presence of applied N, significant yield increases were obtained at 12.5μg Ni g−1 soil. Nickel was not toxic to wheat up to 50μg Ni g−1 soil in the presence of 120μg N g−1 soil. Nitrogen and Ni concentration in wheat tops and roots increased with increasing levels of applied N and Ni, respectively. Applied Ni had an antagonistic effect on N concentration. Similarly, N reduced the Ni concentration in the wheat tissues. Positive growth responses to Ni were associated with 22 and 15μg Ni g−1 in wheat tops, in the presence of applied N at 60 and 120μg N g−1 soil, while Ni toxicity was associated with 63, 92.5 and 112.5μg Ni g−1 in wheat tops, in the absence and presence of applied N at 60 and 120μg N g−1 soil, respectively.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Hydrobiologia 78 (1981), S. 81-86 
    ISSN: 1573-5117
    Schlagwort(e): metabolism ; oxygen uptake ; respiration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The O2 uptake through water has been measured in case of Heteropneustes fossilis during development and growth and its relationship to body size established. A higher rate of O2 uptake during the early phase of ontogenesis is related to intense growth of the respiratory surface area and increasing metabolic demand of the fish. The logarithmic plot of data for O2 uptake in relation to body size shows a statistically significant two-component curve; one related to the fish when it is a fully aquatic breather and the other when it changes to bimodal gas exchange. The onset of the air breathing habit brings about a 40% drop in O2 uptake through water, which is made good through the newly developed air breathing organ.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Hydrobiologia 66 (1979), S. 129-133 
    ISSN: 1573-5117
    Schlagwort(e): Metabolism ; oxygen uptake ; Respiration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The O2 consumption (mg/hr) through water in case of Anabas testudineus during development and growth has been measured and its relationship to body weight or length studied. The logarithmic plot of 02 uptake through water either against body weight or length suggested a statistically significant (P 〉 3.53) two-component curve, the point of intersection being at 11 mg body weight and 1.78 cm body length. These are the theoretical values of weight or length at which the responsibility of supplementing nearly 40% of the total O2 demand through the newly developed air breathing organ falls in the early life of the fish. One of the impelling causes forcing developing fry of Anabas to adopt a bimodal gas exchange machinery seems to be 4 fold increase in the diffusion distance at the gills.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    ISSN: 1573-5117
    Schlagwort(e): respiration ; oxygen uptake ; metabolism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Oxygen uptake in relation to body size during the early life of the fish Channa punctatus shows a significant two-component curve: one related to the fully aquatic phase and the other to the bimodal phase of respiration. The onset of the air-breathing habit around the 18–20th day after hatching brings about a 45% drop in O2 uptake through the gill/skin in water.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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