Incubation

About: Incubation is a research topic. Over the lifetime, 5748 publications have been published within this topic receiving 126541 citations.

Microbial biomass in relation to c and n mineralization during laboratory incubations

Abstract: Net carbon and nitrogen mineralization rates were determined for an arable soil during 12 weeks at 37†C using an aerobic incubation-leaching technique. The amounts of mineralized C and N were compared to changes in the contents of C and N in microbial biomass (as determined by the chloroform fumigation incubation method; CFIM) during the incubation and to amounts of organic C and N in the leachates. Microorganisms were also followed by direct counting of bacteria, measurements of total hyphal lengths and fluorescein diacetate (FDA)-active hyphae, and by most probable number determinations of protozoa (naked amoebae and flagellates). Numbers of naked amoebae increased nearly 10-fold initially and then decreased between weeks 6 and 12. Bacterial numbers and FDA-active hyphae decreased during the incubation, and the relative composition changed slightly in favour of bacteria. Total hyphal lengths remained almost constant. A total of 105 μg N g' − soil dry wt and 1179 μg C g − soil dry wt was mineralized during the incubation, while the microbial N pool decreased by 42 γm − soil dry wt and the microbial C pool decreased by 225μ g − soil dry wt. Soluble organic matter in the leachates amounted to 16 and 31% of mineralized C and N, respectively. The possibility of measuring C mineralization with less frequent teachings and determinations of N mineralization offers an easy method for assessing changes in labile soil organic matter over time or for comparisons between soils. Through the use of appropriate C-to-N ratios, the N-content in the labile pool can be calculated.

Acclimation to hypothermic incubation in developing chicken embryos (Gallus domesticus): I. Developmental effects and chronic and acute metabolic adjustments.

Abstract: Chronic exposure to a low incubation temperature clearly slows the development of poikilothemic chicken embryos (or any other poikilotherms), but little is known about the more subtle developmental effects of temperature, especially on physiological regulatory systems. Consequently, two populations of chicken embryos were incubated at 38 degrees C and 35 degrees C. When compared at the same development stage, incubation temperature had no significant impact on embryonic survival or growth. Moreover, the relative timing of major developmental landmarks (e.g. internal pipping), expressed as a percentage of development, was unaffected by temperature. The ability to maintain the rate of oxygen consumption ((O(2))) during an acute drop in ambient temperature (T(a)) improved from Hamburger-Hamilton (HH) stages 39-40 to 43-44 in the 38 degrees C but not the 35 degrees C populations. Late stage (HH43-44) embryos incubated at 38 degrees C could maintain (O(2)) (approximately 27-33 micro l g(-1) min(-1)) during an acute drop in T(a) to approximately 30 degrees C. However, at the same stage 35 degrees C embryos acutely measured at 38 degrees C were unable to similarly maintain their (O(2)), which fell as soon as T(a) reached 36 degrees C. Thus, while hypothermic incubation does not affect gross development (other than would be predicted from a simple effect of Q(10)), there is a significant delay in the relative timing of the onset of thermoregulatory ability induced by hypothermic incubation.

Nest temperature and respiratory gases during natural incubation in the broad-shelled river turtle, Chelodina expansa (Testudinata : Chelidae)

Abstract: Temperature was monitored in three natural nests, and oxygen and carbon dioxide partial pressure monitored in one natural nest of the broad-shelled river turtle, Chelodina expansa, throughout incubation. Nest temperature decreased after nest construction in autumn, remained low during winter and gradually increased in spring to a maximum in summer. In a nest where temperature was recorded every hour, temperature typically fluctuated through a 2 degrees C cycle on a daily basis throughout the entire incubation period, and the nest always heated faster than it cooled. Oxygen and carbon dioxide partial pressures in this nest were similar to soil oxygen and carbon dioxide partial pressures for the first 5 months of incubation, but nest respiratory gas tensions deviated from the surrounding soil over the last three months of incubation. Nest respiratory gas tensions were not greatly different from those in the atmosphere above the ground except after periods of rain. After heavy rain during the last 3 months of incubation the nest became moderately hypoxic (P-O2 similar to 100 Torr) and hypercapnic (P-CO2 similar to 50 Torr) for several successive days. These short periods of hypoxia and hypercapnia were not lethal.

Incubation times for eggs of the turtle chelydra serpentina (testudines: chelydridae) at various

Abstract: Eggs of the common snapping turtle, Chelydra serpentina, were incubated at constant temperatures of 20-35?C. Incubation was successful at temperatures of 22-30?C. Duration of incubation was inversely related to temperature. The rate of development during the final weeks of incubation appeared to be independent of temperature.