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  • 1
    ISSN: 1432-0789
    Keywords: Microbial biomass ; No-till agrosystem ; Maize ; Fumigation ; Extraction method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The soil microbial biomass contains important labile pools of C, N, P, and S, and fluctuations in its size and activity can significantly influence crop productivity. In cropping systems where fertilizer use is reduced or eliminated and green-manure legumes are used, nutrient availability is more directly linked to C-cycle dynamics. We observed the fluctuations in microbial biomass C and P, and in microbial biomass activity over three cropping seasons in continuous maize and 2-year maize-wheat-soybean rotation agroecosystems under no-till and reduced-chemical-input management. We estimated the concentrations of microbial C and P using fumigation-incubation and fumigation-extraction techniques for the surface 20 cm of Cecil and Appling series soils (clayey, kaolinitic, thermic, Typic Kanhapludults). There were significant seasonal fluctuations in microbial C and P under all cropping systems. Generally, the magnitude of fluxes and the quantity of microbial C and P tended to be higher in reduced-chemical-input systems due to tillage and incorporation of crop, weed, and legume residues. Over 3 years, the means for microbial C were 435 under reduced-input maize; 289 under no-till maize; 374 und the reduced-input crop rotation; and 288 mg kg-1 soil under the no-till rotation. The means for microbial P were 5.2 under reduced-input maize; 3.5 under no-till maize; 5.0 under the reduced-input rotation; and 3.5 mg kg-1 soil under the no-till rotation. Estimates of microbial activity, derived from CO2−C evolution and specific respiratory activity (mg CO2−C per mg biomass C), suggest that reduced-chemical-input management may cause a larger fraction of the biomass to be relatively “inactive” but may also increase the activity of the remaining fraction over that in no-till. Thus in these specific systems, the turnover of C and P through the microbial biomass with a reduced chemical input to the soil may be higher than under a no-till system.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European radiology 9 (1999), S. 1556-1569 
    ISSN: 1432-1084
    Keywords: Key words: HIV ; Computed tomography ; Thorax ; Chest radiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. A wide variety of thoracic disorders can arise in patients infected with the human immunodeficiency virus (HIV), although recent developments in the therapeutic management of AIDS patients has resulted in a changing pattern of chest disease. The use of CT in the diagnosis and management of these thoracic manifestations is discussed along with the CT appearances of the various infectious and non-infectious complications of the acquired immune deficiency syndrome (AIDS) which are commonly encountered in clinical practice.
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  • 3
    ISSN: 1432-1084
    Keywords: Key words: Lung neoplasms – Lymphoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. The aim of this study was to describe the imaging features of pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma. The chest radiographs (n = 18) and CT scans (n = 17) of 24 patients (18 men and 6 women) aged 27–78 years (mean = 56 years), with a known diagnosis of pulmonary MALT lymphoma, were retrospectively reviewed by two radiologists and the imaging findings are described. Six of the 24 patients had a history of an autoimmune disorder and 1 patient had acquired immune deficiency syndrome. Multiple pulmonary lesions were identified in 19 of 24 patients (79 %) and solitary lesions in 4 of 24 patients (17 %). Diffuse pulmonary infiltration was present in 1 patient. Lesions included masses or mass-like areas of consolidation (n = 21) and pulmonary nodules (n = 18). Associated findings were air bronchograms, airway dilatation, a positive angiogram sign and a halo of ground-glass shadowing at lesion margins. Peribronchovascular thickening was also observed, as were hilar or mediastinal lymph node enlargement and pleural effusions or thickening. Although rare, the diagnosis of pulmonary MALT lymphoma should be considered in patients with the imaging features described, particularly when in association with an indolent clinical course or a history of autoimmune disease.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    World journal of urology 14 (1996), S. 384-387 
    ISSN: 1433-8726
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cloacal exstrophy patients are often difficult to reconstruct. Urinary continence is usually achievable only with a catheterizable stoma of some type. Since cloacal exstrophy is usually associated with omphalocele or gastroschisis, one-stage closure of the abdominal wall defect is frequently impossible. We prefer to incorporate the exstrophic large bowel, which separates the hemibladders, into the closed bladder as a sort of “natural” augmentation to maximize its volume for use as a continent reservoir. If a silastic “silo” or synthetic mesh is required to close the abdominal wall, excessive scarring occurs and later creation of a continent stoma is usually difficult and time-consuming. In all but those with the smallest abdominal wall defects we recommend that the omphalocele and upper abdominal wall be repaired first, replacing the evicted gut into the peritoneal cavity. During nutritional stabilization a tissue expander is placed under the superficial musculature of the chest wall. The flap is enlarged by gradual inflation of the tissue expander until it fills the abdominal wall defect left by subsequent closure of the cloacal exstrophy. The flap is then rotated inferiorly with blood supply intact at the time of bladder closure to make good the remaining abdominal wall defect. This flap improves the appearance of the abdominal wall and reduces scarring. Thus, this approach has the possibility of making subsequent operations to provide continence shorter, simpler, and more successful in most infants with cloacal exstrophy.
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  • 5
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Kepone and its metabolites ; Chlordecone ; Kepone metabolites ; Pesticide analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary High-performance liquid chromatography (HPLC) was used to separate chlordecone (Kepone), and two of its metabolites, hydrochlordecone and dihydrochlordecone. Elution of the three peaks occured after the solvent concentration reached 100% methanol and was maintained at 100% for approximately five minutes. The method was linear for chlordecone in the concentration range of 10 to 100 μg.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of systems integration 6 (1996), S. 159-179 
    ISSN: 1573-8787
    Keywords: Computer Integrated Systems ; objects ; nets ; algebras ; layers ; compute controllers ; CIM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract In recent years computers have been incorporated into large scale systems such as nuclear plant, flight control, and manufacturing systems. Such Computer Integrated Systems (CIS) normally consist of heterogeneous subsystems. The integration of heterogeneous subsystems requires that the subsystems be portable, inter-operable, and integrable at both software and hardware levels so that the integrated system should function properly. Objects and nets are proposed as the atomic elements of CIS's. An object is defined as a computational model of an arbitrary entity. Then three representation schemes of an object are introduced: algebraic, modular, and graphical. Two operations on objects,Composition andUnion, are introduced as means of combining two objects into a larger one. As an application of this approach, a Computer Integrated Manufacturing (CIM) system is represented as a network of objects.
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  • 8
    ISSN: 1432-1998
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Thirty-three neonatal renal masses were evaluated during a 2-year interval. The final diagnoses in these 33 patients were hydronephrosis [14], multicystic dysplastic kidney [10], renal vein thrombosis [3], obstructed upper pole duplication [2], polycystic kidney disease [2], nephroblastomatosis [1], and mesoblastic nephroma [1]. We recommend an integrated imaging approach that utilizes sonography to clarify anatomy and renal scintigraphy or excretory urography to determine renal function.
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  • 9
    ISSN: 1573-4919
    Keywords: glycolysis ; glycogenolysis ; high energy phosphate stores ; glycolytic flux ; cardiomyocytes ; myocardial ischemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Experimentally, enhanced glycolytic flux has been shown to confer many benefits to the ischernic heart, including maintenance of membrane activity, inhibition of contracture, reduced arrhythmias, and improved functional recovery. While at moderate low coronary flows, the benefits of glycolysis appear extensive, the controversy arises at very low flow rates, in the absence of flow; or when glycolytic substrate may be present in excess, such that high glucose concentrations with or without insulin overload the cell with deleterious metabolises. Under conditions of total global ischemia' glycogen is the only substrate for glycolytic flux. Glycogenolysis may only be protective until the accumulation of metabolises (lactate, H+, NADH, sugar phosphates and Pi ) outweighs the benefit of the ATP produced. The possible deleterious effects associated with increased glycolysis cannot be ignored, and may explain some of the controversial findings reported in the literature. However, an optimal balance between the rate of ATP production and rate of accumulation of metabolises (determined by the glycolytic flux rate and the rate of coronary washout), may ensure optimal recovery. In addition, the effects of glucose utilisation must be distinguished from those of glycogen, differences which may be explained by functional compartmentation within the cell.
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  • 10
    ISSN: 1573-1561
    Keywords: Morning-glory ; Ipomoea hederacea ; growth inhibition ; p-coumaric acid ; allelopathic interactions ; leucine ; methionine ; glucose ; nitrate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Studies of allelopathy have emphasized primarily the identification and quantification of phytotoxins in soils, with only limited attention directed toward how organic (carbon) and inorganic constituents (nutrients) in the soil may modify the action of such phytotoxins. In the present study, increasing carbon (C) levels (up to 108μg C/g soil) supplied as glucose, phenylalanine, orp-hydroxybenzoic acid did not alter morning-glory biomass, but similar C levels supplied as leucine, methionine, orp-coumaric acid were inversely related to morning-glory biomass. Similar joint action and multiplicative analyses were used to describe morning-glory biomass response to various C sources and to generate dose isolines for combinations ofp-coumaric acid and methionine at two NO3-N levels and for combinations ofp-coumaric acid and glucose at one NO3-N level. Methionine, glucose, and NO3-N treatments influenced the inhibitory action ofp-coumaric acid on biomass production of morning-glory seedlings. For example, results from the multiplicative analysis indicated that a 10% inhibition of morning-glory biomass required 7.5μgp-coumaric acid/g soil, while the presence of 3.68μg methionine/g soil thep-coumaric acid concentration required for 10% inhibition was only 3.75μg/ g soil. Similar response trends were obtained forp-coumaric acid and glucose. The higher NO3-N (14 vs. 3.5μg/g) treatments lowered the methionine and increased thep-coumaric acid concentrations required for 10% inhibition of morning-glory biomass. These results suggested that allelopathic interactions in soil environments can be a function of interacting neutral substances (e.g., glucose), promoters (e.g., NO3-N), and/or inhibitors (e.g., methionine andp-coumaric acid) of plant growth.
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