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  • 1
    ISSN: 1432-136X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Lingual salt glands, secreting hyperosmotic Na/K solutions in response to methacholine, are present inCrocodylus acutus andC. johnstoni but apparently absent from the alligatorids,Alligator mississipiensis andCaiman crocodilus. 2. Both secretory rates (6–20 μmol/100 g·h) and concentrations (450–600 mM Na) of glandular secretions are essentially identical in the marine/estuarineC. acutus andC. porosus and significantly higher than in the freshwaterC. johnstoni (1–2 μmol/100 g·h; 320–420 mM Na). 3. Lingual glands inAlligator secrete isosmotic Na/K at low rates (1–2 μmol/100 g·h) while those ofCaiman show no response to methacholine. 4. The physiological contrast between alligatorids and crocodylids is reflected in distinct differences in the superficial appearance of the tongue and lingual pores. 5. It is postulated that the alligatorid condition of low secretory capacity and isosmotic secretion reflects the primitive salivary function of lingual glands from which the salt-secreting capability in crocodylids was derived.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 157 (1987), S. 227-235 
    ISSN: 1432-136X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Resting metabolic rates (RMR) of 34 species from 18 genera of boas and pythons (Serpentes: Boidae), with body masses ranging from 2 to 67,800 g, were determined as oxygen consumption ( $$\dot V_{O_2 }$$ ) and carbon dioxide production ( $$\dot V_{CO_2 }$$ ) at three ambient temperatures (T a). The temperature coefficient of metabolism (Q10) averaged 2.61 betweenT a of 20–30°C and 2.65 between 30 and 34°C. The respiratory exchange ratio RE (= $$\dot V_{CO_2 }$$ / $$\dot V_{O_2 }$$ ) increased slightly with increasingT a (0.795 at 20°C, 0.819 at 30°C, and 0.834 at 34°C). Interspecific differences in Q10 and RE were slight or insignificant. A multiple regression relating metabolism ( $$\dot V_{O_2 }$$ ) to mass andT a explained 97% of the variance in the pooled interspecific data. The mass exponent was 0.806, which is approximately the same as reported for squamates and for all reptilian taxa combined. The mean within-species slope (0.732) was significantly less than the slope for pooled data, but did not differ significantly from 0.75. In 40 of 42 cases (14 species at 3T a), within-species slopes did not differ from each other. Values of the adjusted mean Y, from covariance analysis, were significantly and positively correlated with mass, indicating that the mass coefficient increases with increasing mass. Considerable variation in metabolic rate is apparent both within and between ecological and taxonomic categories.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 157 (1987), S. 393-402 
    ISSN: 1432-136X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Thermogenic incubation has been documented in two large species of pythons, but the phenomenon has not been studied in small species with concomitantly large heat transfer coefficients. We describe behavior, metabolic rates, mass changes, and temperature relations for adult ball pythons (Python regius), the smallest member of the genus, during the reproductive cycle. Egg and hatchling metabolism and hatchling growth rates were also examined. Rates of oxygen consumption ( $$\dot V_{O_2 } $$ ) of both gravid and non-gravid snakes showed typical ectothermic responses to changing ambient temperature (T a). TheQ 10 forT a's of 20–35°C was 2.2–2.3. The $$\dot V_{O_2 } $$ of gravid females was significantly greater than that of non-gravid snakes at allT a. Maximum oxygen consumption ( $$\dot V_{O_2 } $$ max) during forced exercise was about 12 times resting $$\dot V_{O_2 } $$ atT a=30°C. Eggs (5–6 per female) were laid in April. Total clutch mass was approximately 32% of the females' pre-oviposition mass. After oviposition, mother snakes coiled tightly around their clutches and remained in close attendance until the eggs hatched in June. Sudden decreases inT a elicited abrupt but transient 2- to 4-fold increases in the $$\dot V_{O_2 } $$ of incubating females. Similar responses were not observed in non-incubating snakes. The steady-state $$\dot V_{O_2 } $$ of incubating females was independent ofT a. In no case was body temperature (T b) elevated more than a few tenths of a degree aboveT a in steady-state conditions. The $$\dot V_{O_2 } $$ of developing eggs increased sigmoidally through the 58–70 day incubation period. Total oxygen consumption during incubation atT a=29.2°C was about 3.61 per egg. Young snakes quadrupled their mass during their first year of growth. Compared to larger python species which are endothermic during incubation, ball pythons have similar aerobic scopes and higher mass-specific $$\dot V_{O_2 } $$ max. However, effective endothermy in ball pythons is precluded by high thermal conductance and limited energy stores.
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 19 (1981), S. 2451-2455 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Adsorption of iodide-125, a γ emitter, was used as a quantitative methodology for polymer adsorption surface coverage analysis. Adsorption of I-125 on clean platinum produced surface elemental ratios of I:Pt of 1:4. The technique was applied to the adsorption of polyethylene glycol terephthalate from trifluoroacetic acid on platinum flags with a 2-cm2 surface area. This polymer adsorption is approximated by a logarithmic relationship similar to the Temkin isotherm. Polymer coverage attained up to 99.6% of the surface.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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