Effect of temperature on the ovipositional biology and egg viability of the cattle tickBoophilus annulatus (Acari: Ixodidae)

1988 ◽  
Vol 5 (1-2) ◽  
pp. 1-14 ◽  
Author(s):  
R. B. Davey
2004 ◽  
Vol 32 (4) ◽  
pp. 367-369 ◽  
Author(s):  
G. Salpiggidis ◽  
E. Navrozidis ◽  
M. J. Copland

1987 ◽  
Vol 65 (7) ◽  
pp. 1733-1740 ◽  
Author(s):  
Dennis A. Lee ◽  
John R. Spence

Males and females of Ostrinia nubilalis (Hübner) from Alberta were held at constant and variable temperatures within a 17–32 °C range to determine the effect of temperature on longevity, daily oviposition, egg viability, total fecundity, reproductive period, and oviposition rate. The lower developmental thresholds and thermal summations for each stage were calculated from linear regressions. Moths from the South Saskatchewan River valley laid significantly more eggs over a longer period than those from the surrounding plains. The upper threshold for oviposition was higher (27 °C) for valley than for plains borers (25 °C). Optimum temperatures for egg viability were also higher for valley (25–27 °C) than for plains borers (22 °C). Fluctuating temperatures increased survival of both sexes compared with equivalent constant temperatures. Differences in male and female longevity likely arose in response to selection for different reproductive strategies in each sex. Long-lived individuals achieved high fecundity by reproducing at a low rate over many age-classes, while short-lived individuals reproduced at a high rate over few age-classes, with less total fecundity. Fecundity and reproductive period in the corn borer are plastic phenotypes that can change rapidly under differing environments.


1994 ◽  
Vol 84 (4) ◽  
pp. 515-520 ◽  
Author(s):  
Simon R. Leather

AbstractOver the temperature range 5° to 25°C, fecundity of Panolis flammea (Denis & Schiffermüller) showed a non-linear response, the optimal temperature for fecundity being 15°C. At 6°C females laid 17 eggs each whilst at 15°C they laid 166 eggs. Pre-oviposition period showed a significantly negative response, being shortest at 25°C (2.5 days). Adult longevity was significantly affected by temperature, being 20 days at 8°C and 6.8 days at 25°C. Egg hatch and development in the laboratory was linearly and positively related to temperature over the range of 2° to 20°C, ranging from 39.9 days at 5°C to 6 days at 25°C. The lethal limit for egg viability was 25°C. The theoretical threshold for egg development was calculated to be 2.79°C. Storage of eggs at temperatures of 2°C for periods in excess of 10 days had a significant effect on the percentage of eggs hatching. The significance of these findings in implementing control operations is discussed.


Author(s):  
P. R. Swann ◽  
W. R. Duff ◽  
R. M. Fisher

Recently we have investigated the phase equilibria and antiphase domain structures of Fe-Al alloys containing from 18 to 50 at.% Al by transmission electron microscopy and Mössbauer techniques. This study has revealed that none of the published phase diagrams are correct, although the one proposed by Rimlinger agrees most closely with our results to be published separately. In this paper observations by transmission electron microscopy relating to the nucleation of disorder in Fe-24% Al will be described. Figure 1 shows the structure after heating this alloy to 776.6°C and quenching. The white areas are B2 micro-domains corresponding to regions of disorder which form at the annealing temperature and re-order during the quench. By examining specimens heated in a temperature gradient of 2°C/cm it is possible to determine the effect of temperature on the disordering reaction very precisely. It was found that disorder begins at existing antiphase domain boundaries but that at a slightly higher temperature (1°C) it also occurs by homogeneous nucleation within the domains. A small (∼ .01°C) further increase in temperature caused these micro-domains to completely fill the specimen.


Author(s):  
T. Geipel ◽  
W. Mader ◽  
P. Pirouz

Temperature affects both elastic and inelastic scattering of electrons in a crystal. The Debye-Waller factor, B, describes the influence of temperature on the elastic scattering of electrons, whereas the imaginary part of the (complex) atomic form factor, fc = fr + ifi, describes the influence of temperature on the inelastic scattering of electrons (i.e. absorption). In HRTEM simulations, two possible ways to include absorption are: (i) an approximate method in which absorption is described by a phenomenological constant, μ, i.e. fi; - μfr, with the real part of the atomic form factor, fr, obtained from Hartree-Fock calculations, (ii) a more accurate method in which the absorptive components, fi of the atomic form factor are explicitly calculated. In this contribution, the inclusion of both the Debye-Waller factor and absorption on HRTEM images of a (Oll)-oriented GaAs crystal are presented (using the EMS software.Fig. 1 shows the the amplitudes and phases of the dominant 111 beams as a function of the specimen thickness, t, for the cases when μ = 0 (i.e. no absorption, solid line) and μ = 0.1 (with absorption, dashed line).


1990 ◽  
Vol 80 (3) ◽  
pp. 431-436 ◽  
Author(s):  
Isabelle Delvallee ◽  
Annie Paffen ◽  
Geert-Jan De Klerk

1973 ◽  
Vol 29 (01) ◽  
pp. 183-189
Author(s):  
C. A Praga ◽  
E. M Pogliani

SummaryTemperature represents a very important variable in ADP-induced platelet aggregation.When low doses of ADP ( < 1 (μM) are used to induce platelet aggregation, the length of the incubation period of PRP in the cuvette holder of the aggregometer, thermostatted at 37° C, is very critical. Samples of the same PRP previously kept at room temperature, were incubated for increasing periods of time in the cuvette of the aggregometer before adding ADP, and a significant decrease of aggregation, proportional to the length of incubation, was observed. Stirring of the PRP during the incubation period made these changes more evident.To measure the exact temperature of the PRP during incubation in the aggre- gometer, a thermocouple device was used. While the temperature of the cuvette holder was stable at 37° C, the PRP temperature itself increased exponentially, taking about ten minutes from the beginning of the incubation to reach the value of 37° C. The above results have a practical significance in the reproducibility of the platelet aggregation test in vitro and acquire particular value when the effect of inhibitors of ADP induced platelet aggregation is studied.Experiments carried out with three anti-aggregating agents (acetyl salicyclic acid, dipyridamole and metergoline) have shown that the incubation conditions which influence both the effect of the drugs on platelets and the ADP breakdown in plasma must be strictly controlled.


1967 ◽  
Vol 17 (01/02) ◽  
pp. 112-119 ◽  
Author(s):  
L Dintenfass ◽  
M. C Rozenberg

SummaryA study of blood coagulation was carried out by observing changes in the blood viscosity of blood coagulating in the cone-in-cone viscometer. The clots were investigated by microscopic techniques.Immediately after blood is obtained by venepuncture, viscosity of blood remains constant for a certain “latent” period. The duration of this period depends not only on the intrinsic properties of the blood sample, but also on temperature and rate of shear used during blood storage. An increase of temperature decreases the clotting time ; also, an increase in the rate of shear decreases the clotting time.It is confirmed that morphological changes take place in blood coagula as a function of the velocity gradient at which such coagulation takes place. There is a progressive change from the red clot to white thrombus as the rates of shear increase. Aggregation of platelets increases as the rate of shear increases.This pattern is maintained with changes of temperature, although aggregation of platelets appears to be increased at elevated temperatures.Intravenously added heparin affects the clotting time and the aggregation of platelets in in vitro coagulation.


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