Effect of temperature and hydric conditions on blood pH in embryonic snapping turtles (Chelydra serpentina)

1990 ◽  
Vol 68 (1) ◽  
pp. 190-193 ◽  
Author(s):  
Geoffrey F. Birchard ◽  
Mary J. Packard ◽  
Gary C. Packard
Keyword(s):  
Partial Pressure ◽  
Water Potential ◽  
Pure Water ◽  
Effect Of Temperature ◽  
Chelydra Serpentina ◽  
Blood Samples ◽  
Ph Changes ◽  
Blood Ph ◽  
Snapping Turtles ◽  
Increasing Temperature

The effect of temperature on blood pH in embryonic snapping turtles (Chelydra serpentina) was examined to determine whether the blood pH changes in the same manner as the neutral pH of pure water. Eggs were incubated on moistened vermiculite (water potential of −150 or −950 kPa) at 26 or 27 °C. On day 59 of incubation, eggs were placed in individual containers and assigned to incubators set at temperatures between 18.5 and 30 °C. Blood samples were taken on day 60 of incubation. Blood pH of the embryos varied in a manner similar to that observed in adults of this species: blood pH declined with increasing temperature, with a slope of −0.021 pH/°C. The decrease of blood pH with increasing temperature may be accomplished passively, with blood CO2 partial pressure increasing as a result of greater metabolic production of CO2 while the diffusive excretion of this gas remains relatively constant. No effect of substrate water potential on blood pH was observed.

Modification of the hydric environment by eggs of snapping turtles (Chelydra serpentina)

1984 ◽  
Vol 62 (12) ◽  
pp. 2401-2403
Author(s):  
William H. N. Gutzke
Keyword(s):  
Water Potential ◽  
Chelydra Serpentina ◽  
Snapping Turtles

Flexible-shelled eggs of snapping turtles (Chelydra serpentina) incubated on a dry substrate in the laboratory lost sufficient water to cause the water potential of their environment to increase significantly. This modification of the hydric environment prevented eggs from becoming desiccated and demonstrated the capacity of reptilian eggs to modify their environment in such a manner as to enhance their likelihood of completing development.

scholarly journals The behaviour of crystals and lenses of fats on the surface of water.—Part II. The effect of temperature on the equilibrium pressure

1925 ◽  
Vol 109 (750) ◽  
pp. 318-330 ◽  
Keyword(s):  
Surface Tension ◽  
Pure Water ◽  
Hydrocarbon Chain ◽  
Effect Of Temperature ◽  
Two Dimensional ◽  
Equilibrium Pressure ◽  
Equilibrium Surface Tension ◽  
Rate Of Spread ◽  
Definite Interval ◽  
Increasing Temperature

In Part I a study was made of the rate of spread and unimolecular nature of films of fatty substances, containing a long hydrocarbon chain and a polar “head,” over a surface of pure water or of N/100 HC1. It was shown that after a definite interval of time, the surface became saturated with a unimolecular film in equilibrium with either a crystal or a lens of the substance in question, and that the time taken to attain equilibrium as well as the equilibrium surface tension was a function of the temperature. In the present paper the effect of increasing temperature on the two-dimensional equilibrium pressure is considered in detail.

scholarly journals Modified-atmosphere Packaging of Blueberry Fruit: Effect of Temperature on Package O2 and CO2

1992 ◽  
Vol 117 (3) ◽  
pp. 436-441 ◽  
Author(s):  
Randolph M. Beaudry ◽  
Arthur C. Cameron ◽  
Ahmad Shirazi ◽  
Diana L. Dostal-Lange
Keyword(s):  
Steady State ◽  
Partial Pressure ◽  
Modified Atmosphere Packaging ◽  
Vaccinium Corymbosum ◽  
Effect Of Temperature ◽  
Modified Atmosphere ◽  
Highbush Blueberry ◽  
Partial Pressures ◽  
Effects Of Temperature ◽  
Increasing Temperature

Highbush blueberry (Vaccinium corymbosum L. `Bluecrop') fruit sealed in low-density polyethylene packages were incubated at 0, 5, 10, 15, 20, or 25C until O2 and CO2 levels in the package reached a steady state. A range of steady-state O2 partial pressures (1 to 18 kPa) was created by placing a range of fruit weights within packages having a constant surface area and film thickness. The steady-state O2 partial pressure in packages containing the same weight of fruit decreased as temperature increased, indicating the respiratory rate rose more rapidly (i.e., had a greater sensitivity to temperature) than O2 transmission through the film. Steady-state O2 and CO2 partial pressures were used to calculate rates of O2 uptake. CO2 Production. and the respiratory quotient (RO). The effects of temperature and 02 partial pressure on O2 uptake and CO2 production and the RQ were characte∼zed. The steady-state O, partial pressure at which the fruit began to exhibit anaerobic CO2 production (the RQ breakpoint) increased with increasing temperature, which implies that blueberry fruit can be stored at lower O2 partial pressures when stored at lower temperatures.

Daily and seasonal variation in hydric conditions and temperature inside nests of common snapping turtles (Chelydra serpentina)

1985 ◽  
Vol 63 (10) ◽  
pp. 2422-2429 ◽  
Author(s):  
Gary C. Packard ◽  
Gary L. Paukstis ◽  
Thomas J. Boardman ◽  
William H. N. Gutzke
Keyword(s):  
Seasonal Variation ◽  
Water Potential ◽  
Water Relations ◽  
Chelydra Serpentina ◽  
Fair Weather ◽  
Diel Cycles ◽  
Water Potentials ◽  
Snapping Turtles ◽  
Warm Weather ◽  
Heavy Rainfalls

Water potential and temperature are interrelated variables that must be studied simultaneously to gain insight concerning the water relations of reptilian eggs incubating in subterranean nests. We measured these variables inside nests of common snapping turtles (Chelydra serpentina) using thermocouple psychrometry. Water potentials in nests were high after heavy rainfalls, but declined during periods of fair weather. Likewise, temperatures in nests increased progressively during intervals of warm weather, but declined abruptly during cool periods accompanied by overcast and precipitation. On clear days, diel cycles in temperature occurred at the top, in the middle, and at the bottom of nests, but the cycles were slightly out of phase and their amplitudes decreased with increasing depth. These cycles in temperature drove cycles in evaporation–condensation of water that led in turn to complex cycles in diffusion of vapour. Net movement of vapour was into nests on some occasions, but out of them on others. Transport of liquid occurred also in the vicinity of nests, but probably was less important than transport of vapour as a means for translocating water. The eggs themselves influenced water potentials and vapour pressures in the vicinity of their nests and thereby elicited different movements of water in their immediate surroundings than occurred in the soil at large.

scholarly journals Theoretical Effect of Temperature on Threshold in the Hodgkin-Huxley Nerve Model

1966 ◽  
Vol 49 (5) ◽  
pp. 989-1005 ◽  
Author(s):  
Richard Fitzhugh
Keyword(s):  
Relaxation Time ◽  
Relaxation Times ◽  
Giant Axon ◽  
Temperature Curve ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Ionic Conductances ◽  
And Shifts ◽  
The Right ◽  
Increasing Temperature

In the squid giant axon, Sjodin and Mullins (1958), using 1 msec duration pulses, found a decrease of threshold with increasing temperature, while Guttman (1962), using 100 msec pulses, found an increase. Both results are qualitatively predicted by the Hodgkin-Huxley model. The threshold vs. temperature curve varies so much with the assumptions made regarding the temperature-dependence of the membrane ionic conductances that quantitative comparison between theory and experiment is not yet possible. For very short pulses, increasing temperature has two effects. (1) At lower temperatures the decrease of relaxation time of Na activation (m) relative to the electrical (RC) relaxation time favors excitation and decreases threshold. (2) For higher temperatures, effect (1) saturates, but the decreasing relaxation times of Na inactivation (h) and K activation (n) factor accommodation and increased threshold. The result is a U-shaped threshold temperature curve. R. Guttman has obtained such U-shaped curves for 50 µsec pulses. Assuming higher ionic conductances decreases the electrical relaxation time and shifts the curve to the right along the temperature axis. Making the conductances increase with temperature flattens the curve. Using very long pulses favors effect (2) over (1) and makes threshold increase monotonically with temperature.

scholarly journals Evaluation of the BDNF, NGF, NT3 and NT4 Genes Expressions in the Brains of Neonatal Mice with Hypothyroidism

2017 ◽  
Vol 7 (1) ◽  
pp. 171
Author(s):  
Hamid Reza Adeli Bhroz ◽  
Kazem Parivar ◽  
Iraj Amiri ◽  
Nasim Hayati Roodbari
Keyword(s):  
Dose Group ◽  
Low Dose ◽  
Pure Water ◽  
Intervention Group ◽  
Control Group ◽  
High Dose ◽  
Endocrine Glands ◽  
Blood Samples ◽  
High Doses ◽  
The Brain

Background and Aim: Thyroid is one of the endocrine glands, (T3 and T4) play a significant role in the development of prenatal brain and the following stages. The study aimed to evaluate the effect of hypothyroidism on the amount of expression of NT4, NT3, nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in brain of one-day rat neonates with hypothyroidism.Materials and Methods: In total, 25 mature mice of Albino NMRI race were selected after mating, divided into three group, control, as well as low-dose and high-dose intervention groups. Samples of the control group received pure water during pregnancy, whereas subjects of the intervention group with low and high doses of the medication were administered with 20 mg and 100 mg methimazole powder (dissolved in 100 cc water), respectively. After child delivery, blood samples were obtained from mother mice to determine the level of T3 and T4 in blood serum. Following that, the brain of one-day mice were removed by surgery and assessed to determine the amount of expression of NT4, NT3, NGF and BDNF using the complete kit of RT-PCR.Results: Levels of T4 and T3 in the control group were 28 ug/dl and 1.59 ug/dl, respectively. In the low-dose intervention group, the amounts of the mentioned hormones were 8 ug/dl and 0.85 ug/dl, significantly, indicating a significant reduction in the expression of NT4, NT3, NGF and BDNF genes, compared to the control group. Moreover, T4 and T3 were 6 ug/dl and 0.79 ug/dl in the high-dose group, respectively, conveying a significant decrease in the expression of NT4, NT3, NGF and BDNF genes, compared to the control group (P<0.05).

The Adaptive Strategy for Overwintering by Hatchling Snapping Turtles (Chelydra serpentina)

2001 ◽  
Vol 35 (3) ◽  
pp. 514 ◽  
Author(s):  
Paul A. Sims ◽  
Gary C. Packard ◽  
Philip L. Chapman
Keyword(s):  
Adaptive Strategy ◽  
Chelydra Serpentina ◽  
Snapping Turtles

Mercury concentrations in snapping turtles (Chelydra serpentina) correlate with environmental and landscape characteristics

Ecotoxicology ◽  
2011 ◽  
Vol 20 (7) ◽  
pp. 1599-1608 ◽  
Author(s):  
Madeline A. Turnquist ◽  
Charles T. Driscoll ◽  
Kimberly L. Schulz ◽  
Martin A. Schlaepfer
Keyword(s):  
Chelydra Serpentina ◽  
Landscape Characteristics ◽  
Snapping Turtles
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