ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • thermogenesis  (3)
  • Phosphorus  (2)
  • flowing polymer solution  (2)
  • Springer  (7)
  • Nature Publishing Group
  • American Meteorological Society (AMS)
Sammlung
Schlagwörter
Verlag/Herausgeber
  • Springer  (7)
  • Nature Publishing Group
  • American Meteorological Society (AMS)
Erscheinungszeitraum
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Oecologia 91 (1992), S. 281-287 
    ISSN: 1432-1939
    Schlagwort(e): Vesicular-arbuscular mycorrhizas ; Densitydependence ; Plant population dynamics ; Resource depletion ; Phosphorus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The interaction of density and mycorrhizal effects on the growth, mineral nutrition and size distribution of seedlings of two perennial members of the Fabaceae was investigated in pot culture. Seedlings of Otholobium hirtum and Aspalathus linearis were grown at densities of 1, 4, 8 and 16 plants per 13-cm pot with or without vesicular-arbuscular (VA) mycorrhizal inoculum for 120 days. Plant mass, relative growth rates, height and leaf number all decreased with increasing plant density. This was ascribed to the decreasing availability of phosphorus per plant as density increased. O. hirtum was highly dependent on mycorrhizas for P uptake but both mycorrhizal and non-mycorrhizal A. linearis seedlings were able to extract soil P with equal ease. Plant size distribution as measured by the coefficient of variation (CV) of shoot mass was greater at higher densities. CVs of mycorrhizal O. hirtum plants were higher than those of non-mycorrhizal plants. CVs of the facultatively mycorrhizal A. linearis were similar for both mycorrhizal and non-mycorrhizal plants. Higher CVs are attributed to resource preemption by larger individuals. Individuals in populations with high CVs will probably survive stress which would result in the extinction of populations with low CVs. Mass of mycorrhizal plants of both species decreased more rapidly with increasing density than did non-mycorrhizal plant mass. It is concluded that the cost of being mycorrhizal increases as plant density increases, while the benefit decreases. The results suggest that mycorrhizas will influence density-dependent population processes of faculative and obligate mycorrhizal species.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 44 (1988), S. 40-42 
    ISSN: 1420-9071
    Schlagwort(e): TRH ; TRH analogues ; thermogenesis ; brown adipose tissue
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Acute or chronic injection of RX 77368 (a TRH analogue; 1 mg/kg s.c.) stimulated oxygen consumption (VO2) and brown adipose tissue activity in the rat, and decreased weight gain Other TRH analogues (CG 3509, RGH 2202) and TRH itself also stimulated VO2. These thermogenic actions are probably mediated centrally by stimulation of sympathetic outflow to brown fat.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    ISSN: 1435-1536
    Schlagwort(e): Light-scattering ; flowing polymer solution ; dilute polymer solution ; orientation and deformation of macromolecules ; polystyrene
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau
    Notizen: Abstract We describe the behavior of dilute polymer solutions by means of light-scattering under shear flow. Solution properties of polystyrene in benzene over a wide range of molecular weight has been studied to determine the coefficientsa andK of the Mark-Houwink relationship and to estimate the rheological conditions with regard to light-scattering experiments of flowing polymer solutions. The investigations were carried out to measure the shear-rate dependence of macromolecules in solution, e.g., to observe an orientation and changing of the mean-square radius of gyration.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Rheologica acta 31 (1992), S. 274-282 
    ISSN: 1435-1528
    Schlagwort(e): Light-scattering ; flowing polymer solution ; dilute polystyrene solution ; Taylor-vortex ; solvent power
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: Abstract Rheological measurements and light-scattering experiments were performed on dilute solutions of high molecular polystyrene. We are able to describe the orientation behavior of chain molecules under shear flow by means of light-scattering. Beyond that these investigations of light-scattering of flowing polymer solutions are an useful and suitable tool for detection and characterization of Taylor vortex formation. We can estimate the appearance of these hydrodynamic instabilities, which overlay the laminar main flow and we can observe a typical influence of the solvent power on it.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Bioscience reports 7 (1987), S. 791-799 
    ISSN: 1573-4935
    Schlagwort(e): tumour necrosing factor ; brown fat ; thermogenesis ; GDP-binding ; food intake ; body weight ; rats
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract A single intravenous injection of recombinant human tumour necrosis factor (TNF) resulted in significant, but transient (24–48 hr) reductions in food intake and body weight, and increases in rectal temperature, resting oxygen consumption (VO2) and brown adipose tissue (BAT) thermogenic activity (mitochondrial GDP-binding). The increased VO2 was inhibited by β-adrenergic blockade (propranolol), and activation of BAT was prevented by denervation of the tissue. In adult (4-month old) animals, TNF induced greater reductions in food intake and body weight, caused general malaise and some fatalities, but did not significantly alter VO2 or BAT activity. However, the reduction in VO2 following β-adrenergic blockade was greater in TNF-treated rats and BAT activity was enhanced when compared to pair-fed controls. Injection of adult rats with gamma-interferon induced small changes in body weight and temperature which were slightly potentiated when injected with a low dose of TNF. The results indicate that TNF stimulates sympathetic outflow to BAT. This effect may be partly responsible for the increases in body temperature and metabolic rate associated with TNF treatment and with cancer cachexia.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Bioscience reports 6 (1986), S. 3-18 
    ISSN: 1573-4935
    Schlagwort(e): brown adipose tissue ; thermogenesis ; cold ; diet ; neural control ; hormonal control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Plant ecology 130 (1997), S. 143-153 
    ISSN: 1573-5052
    Schlagwort(e): Community boundaries ; Fynbos ; Nitrogen ; Phosphorus ; Soils
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The relationship between changes in soil nutrient characteristics and fynbos community boundaries was investigated near Cape Agulhas, South Africa. Soil characteristics relating to total nutrient content (pH, total N and total P, organic carbon, and various cations) were assessed at sites along three transects crossing the boundaries between five plant communities. Dynamics of available N and P in soils of three communities were studied in the field over one year, using ion-exchange resins. There was a wide range in the degree of change in soil nutrient content across different community boundaries. The characteristics that varied most were pH, total N, Ca and total P. Differences in available nutrients among soils indicated that the communities in this landscape were associated with a mosaic of N and P availability. It is proposed that spatial variation in soil nutrient availability rather than total soil nutrient contents may be important in explaining landscape-level species distributions and community composition in nutrient-poor mediterranean-climate ecosystems.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...