Seasonal synchronization of emergence in Dolania americana (Ephemeroptera: Behningiidae)

1987 ◽  
Vol 65 (12) ◽  
pp. 3177-3185 ◽  
Author(s):  
Janice G. Peters ◽  
William L. Peters ◽  
Thomas J. Fink
Keyword(s):  
Water Temperature ◽  
Temperature Dependent ◽  
Blackwater River ◽  
Temperature Regimes ◽  
Different Populations ◽  
Seasonal Synchronization

This paper summarizes factors regulating seasonal emergence of Dolania americana in the Blackwater River, Florida, U.S.A. Emergence is temperature-dependent, and emergence on a given day can be predicted from the period of nymphal maturation and the pattern of temperatures on previous mornings. Development of the last two nymphal instars follows a pattern that can be interpreted linearly or by day-degree summations. Increases in water temperature at time of emergence (dawn) on the previous day provide the best correlation with emergence. Different responses to temperature events that cue emergence probably result from the effects of different temperature regimes in which the different populations develop. In experiments, males emerged equally 1 and 2 days after increases in the daily low water temperature, while females emerged more frequently after 2 days of increasing temperatures.

An Alternative Approach to Analyzing the Interstitial Decay from the End of Range Damage During Millisecond Annealing

2008 ◽  
Vol 1070 ◽  
Author(s):  
Renata Camillo-Castillo ◽  
Mark E Law ◽  
Kevin S Jones
Keyword(s):  
Annealing Time ◽  
Dwell Time ◽  
Extended Defects ◽  
Temperature Dependent ◽  
Temperature Regimes ◽  
Alternative Approach ◽  
Small Times ◽  
Conventional Annealing ◽  
Kinetics Of ◽  
Anneal Temperature

ABSTRACTFlash-assist Rapid Thermal Processing (RTP) presents an opportunity to investigate annealing time and temperature regimes which were previously not accessible with conventional annealing techniques such as Rapid Thermal Annealing. This provides a unique opportunity to explore the early stages of the End of Range (EOR) damage evolution and also to examine how the damage evolves during the high temperature portion of the temperature profile. However, the nature of the Flash-assist RTP makes it is extremely difficult to reasonably compare it to alternative annealing techniques, largely because the annealing time at a given temperature is dictated by the FWHM of the radiation pulse. The FWHM for current flash tools vary between 0.85 and 1.38 milliseconds, which is three orders of magnitude smaller to that required for a RTA to achieve similar temperatures. Traditionally, the kinetics of the extended defects has been studied by time dependent studies utilizing isothermal anneals; in which specific defect structures could be isolated. The characteristics of Flash-assist RTP do not allow for such investigations in which the EOR defect evolution could be closely tracked with time. Since the annealing time at the target temperature for the Flash-assist RTP is essentially fixed to very small times on the order of milliseconds, isochronal anneals are a logical experimental approach to temperature dependent studies. This fact presents a challenge in the data analysis and comparison. Another feature of Flash-assist RTP which makes the analysis complex is the ramp time relative to the dwell time spent at the peak fRTP temperature. As the flash anneal temperature is increased the total ramp time can exceed the dwell time at the peak temperature, which may play a significantly larger role in dictating the final material properties. The inherent characteristics of Flash-assist RTP have consequently required the development of another approach to analyzing the attainable experimental data, such that a meaningful comparison could be made to past studies. The adopted analysis entails the selection of a reference anneal, from which the decay in the trapped interstitial density can be tracked with the flash anneal temperature, allowing for the kinetics of the interstitial decay to be extracted.

The effects of age, temperature, light quantity and wavelength on the swimming behaviour of the cercariae of Cryptocotyle lingua (Digenea: Heterophyidae)

Parasitology ◽  
1992 ◽  
Vol 105 (1) ◽  
pp. 131-137 ◽  
Author(s):  
J. G. Rea ◽  
S. W. B. Irwin
Keyword(s):  
Life Span ◽  
Water Temperature ◽  
Light Source ◽  
Laboratory Experiments ◽  
Temperature Dependent ◽  
Release Point ◽  
Successful Transmission ◽  
Active Life ◽  
Light Quantity ◽  
Precipitous Decline

Laboratory experiments indicated that the active life-span of the cercariae of Cryptocotyle lingua was temperature-dependent. An increase in water temperature and population age both correlated with a tendency for the organisms to become decaudate. The larvae were strongly photoresponsive to lateral light but with time, horizontal swimming rates (HSRs) from release point to light source progressively declined. When measured over a range of light quantities, HSRs peaked at 30 μM/m2/s. HSRs were also influenced by water temperature. A rapid increase occurred up to 15 °C after which there was a precipitous decline. HSRs to coloured light were negatively correlated with increasing wavelength. When offered a choice between colours, cercariae favoured the shorter wavelengths. The implications of these responses for successful transmission are discussed.

Lipids: Alkenones, Polar Lipids, and Ether Lipids

2011 ◽  
Author(s):  
Thomas S. Bianchi ◽  
Elizabeth A. Canuel
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Water Temperature ◽  
Wide Temperature Range ◽  
Polar Lipids ◽  
Ambient Water ◽  
Unsaturated Lipids ◽  
Temperature Regimes ◽  
Temperature Proxy ◽  
Long Chain

This chapter focuses on several classes of polar lipids, including alkenones, which are di-, tri-, and tetra-unsaturated long-chain ketones. These compounds are produced by a restricted number of species of prymnesiophyte algae (coccolithophorid alga Emiliania huxleyi), living over a wide temperature range. Prymnesiophytes are able to live under different temperature regimes because they are able to regulate the degree of unsaturation of these compounds; as ambient water temperature decreases, unsaturation increases. Long-chain ketones are more stable than most unsaturated lipids and can survive diagenesis. Because of these properties, alkenones have been used widely as paleothermometers. Paleoclimate studies of continental environments have been hampered by the lack of a useful temperature proxy. Glycerol dialkyl glycerol tetraethers (GDGTs) occur ubiquitously, including sites where alkenones are not produced due to the absence/low abundance of alkenone-producing algae. The TEX86 index, based on the number of cyclopentane rings in the GDGTs, provides a useful paleotemperature index for lakes and other sites where alkenones are not produced. The analysis of intact polar molecules is also becoming more widespread with the advent of liquid chromatography mass spectrometry techniques.

Dormancy and Germination of Seed of Eight Populations of Themeda australis

1982 ◽  
Vol 30 (4) ◽  
pp. 373 ◽  
Author(s):  
RH Groves ◽  
MW Hagon ◽  
PS Ramakrishnan
Keyword(s):  
Population Stratification ◽  
Physiological Adaptation ◽  
Dormant Seed ◽  
Seed Formation ◽  
Fresh Seed ◽  
Temperature Regimes ◽  
Germination Characteristics ◽  
Moisture Regimes ◽  
Different Populations ◽  
Climatic Characteristics

Seed of eight populations of Themeda australis (R.Br.) Stapf from sites nith the widest range of climates in Australia and Papua New Guinea (P.N.G.) was tested for its dormancy status and germination responses to different temperature and moisture regimes. The populations were from Lae. P.N.G.. Katherine. N.T.. Mundubbera. Qld. Alice Springs. N.T.. Tantangara. N.S.W.. Adelaide Hills. S.A.. Bunbury, W.A. and Hobart. Tas. Dormancy of fresh seed was negligible in Lae and Mundubbera populations. considerable in the Alice Springs population and intermediate in populations from Katherine and all temperate sites. Addition of gibberellic acid hastened the release from dormancy of seed from Katherine and Bunbury. Exposure of plants to three different temperature regimes during seed formation had an effect on dormancy of the Katherine population. Stratification at 4°C and high alternating daily temperatures (45 20°C) hastened the loss of dormancy of fresh seeds of some populations. Germination of non-dormant seed of the different populations was relatively unaffected b) temperatures between 20 and 40°C. Germination of the Alice Springs population was the most sensitive to increasing water stress and that from Lae the least sensitive. Radicle elongation of seedlings from Alice Springs was significantly greater than that of most other populations at a water potential of - I .0 MPa. The differences reported for seed dormancy and germination characteristics of T. australis populations do not reflect a strong physiological adaptation to the climatic characteristics of the sites from which they were collected.

Temperature-dependent reproduction and survival of Gyrodactylus salaris Malmberg, 1957 (Platyhelminthes: Monogenea) on Atlantic salmon (Salmo salar L.)

Parasitology ◽  
1991 ◽  
Vol 102 (1) ◽  
pp. 105-112 ◽  
Author(s):  
P. A. Jansen ◽  
T. A. Bakke
Keyword(s):  
Atlantic Salmon ◽  
Water Temperature ◽  
Salmo Salar ◽  
Temperature Dependent ◽  
Survival And Reproduction ◽  
Two Temperatures ◽  
The Mean ◽  
Relationship Of ◽  
The Relationship ◽  
Capacity For Increase

SUMMARYThe relationship of survival and reproduction of Gyrodactylus salaris Malmberg on the Atlantic salmon (Salmo salar) to water temperature (2·5–19·0 °C), was studied on the basis of temporal sequence of births and age at death of individual parasites on isolated salmon, and of infrapopulation growth on isolated and grouped salmon. Mean life-span of the parasite was negatively correlated with water temperature: 33·7 days at 2·5 °C and 4·5 days at 19·0 °C. The average number of offspring per parasite peaked between 6·5 and 13·0 °C, and was approximately 2·4 at these two temperatures. Both the period between the successive births of the offspring (max 4) and the estimated generation time were negatively correlated with temperature. The innate capacity for increase (rm) was positively correlated with temperature: from 0·02 (/parasite/day) at 2·5 °C to 0·22 (/parasite/day) at 19·0 °C. Growth of the infrapopulations was positively correlated with water temperature and was higher on isolated fish than on grouped fish, though less than the potential parasite population growth estimated from rm. In the infrapopulations the mean intensity of parasites continued to increase throughout all the experiments on both isolated fish and on grouped fish.

SIMULATION OF TEMPERATURE-DEPENDENT DEVELOPMENT IN POPULATION DYNAMICS MODELS

1975 ◽  
Vol 107 (11) ◽  
pp. 1167-1174 ◽  
Author(s):  
R. E. Stinner ◽  
G. D. Butler ◽  
J. S. Bacheler ◽  
C. Tuttle
Keyword(s):  
Population Dynamics ◽  
Trichoplusia Ni ◽  
Variable Temperature ◽  
Heliothis Zea ◽  
Anthonomus Grandis ◽  
Temperature Dependent ◽  
Dependent Development ◽  
Temperature Regimes ◽  
Population Dynamics Models ◽  
Dynamics Models

AbstractThe simulation of variability in temperature-dependent development is discussed. An algorithm for simulation of this variability is developed and validated under constant and variable temperature regimes for Anthonomus grandis, Trichoplusia ni, and Heliothis zea.

Variability in temperature-dependent germination in eastern black nightshade (Solanum ptycanthum)

1991 ◽  
Vol 69 (7) ◽  
pp. 1463-1470 ◽  
Author(s):  
L. A. Hermanutz ◽  
S. E. Weaver
Keyword(s):  
Genetic Variability ◽  
Cultural Practices ◽  
Germination Rate ◽  
Base Temperature ◽  
Range Limit ◽  
Temperature Dependent ◽  
Marginal Populations ◽  
Solanum Ptycanthum ◽  
Temperature Regimes ◽  
Response To Temperature

The colonization potential of the northwardly migrating weed Solanum ptycanthum was evaluated by comparing germination profiles of southern agrestal populations with northern marginal populations sampled from both ruderal and agrestal habitats. Under laboratory conditions, the seed from five maternal families from each population was subjected to six light:dark temperature regimes from 18:8 to 40:30 °C and germination rate (time to 50% germination) and final percent germination were monitored. The base temperature and thermal time (degree-days) required for 50% germination were calculated. Seeds from southern agrestal populations germinated over a broader temperature range than northern agrestal populations but had similar rates of germination, base temperatures, and thermal times. At the northern range limit, ruderal populations germinated faster and had smaller thermal times than agrestal populations but had similar base temperatures. Delayed emergence in agrestal habitats may be a response to cultural practices. Seeds from northern populations were heavier than southern populations. Plasticity of germination response to temperature did not differ between populations. The observed levels of genetic variability in all germination parameters suggest that future range expansion would be possible. Key words: temperature-dependent germination, agrestal, ruderal, marginal populations, genetic variability, plasticity.

Sign in / Sign up

Export Citation Format

Share Document