Development, Longevity and Fecundity of the False Wireworms Pterohelaeus-Darlingensis and Pterohelaeus-Alternatus (Coleoptera, Tenebrionidae) .4. Models for Larval and Pupal Development Under Fluctuating Temperatures

1986 ◽  
Vol 34 (6) ◽  
pp. 815 ◽  
Author(s):  
PG Allsopp
Keyword(s):  
Stochastic Model ◽  
Low Temperatures ◽  
Considerable Variability ◽  
Ambient Conditions ◽  
Pupal Development ◽  
Long Period ◽  
New Models ◽  
The Difference ◽  
Fluctuating Temperatures ◽  
Coleoptera Tenebrionidae

The usefulness of models derived from constant-temperature rearing in predicting development of larvae and pupae of Pterohelaeus darlingensis Carter and P, alternatus Pascoe under fluctuating temperature was determined. In general, these models underestimated development. The magnitude of the difference was proportional to the length of the development period and, by inference, negatively related to the temperatures experienced. New models were developed with data from individuals reared under fluctuating temperatures. The linear model gave better predictions of development under ambient conditions than did the curvilinear Stinner model for pupae of P. darlingensis, but both models gave similar predictions for larvae of both species. Development of P. alternatus pupae was still underestimated by both models. Substantial discrepancies between observed and expected development of individuals reared under a regimen incorporating a long period at low temperatures indicate that such a regimen is deleterious. Given the considerable variability in development rates between individuals, a stochastic model may predict development more accurately.

Estimation of the Number of Injected Interstitial Atoms during Nitrous Oxidation of Silicon

1999 ◽  
Vol 568 ◽  
Author(s):  
D. Skarlatos ◽  
L.F. Giles ◽  
C. Tsamis ◽  
A. Claverie ◽  
D. Tsoukalas
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperatures ◽  
Dislocation Loops ◽  
Ambient Conditions ◽  
Transmission Electron ◽  
Dry Oxidation ◽  
Interstitial Atoms ◽  
The Difference

ABSTRACTIn this work we use dislocation loops to monitor the interstitial injection during the oxynitridation (oxidation in 100% N2O ambient) of silicon at low temperatures (850–950 °C). The interstitials captured by the loops are measured using Transmission Electron Microscopy. The number of Si atoms released after oxynitridation was calculated from the difference in the total amount of atoms stored in the loops between oxidizing and inert ambient. We obtained that this number is larger compared with the respective under the same dry oxidation (in 100% O2 ambient) conditions.

A semi-hybrid model for malaria with limited superinfection

1998 ◽  
Vol 30 (04) ◽  
pp. 1027-1057 ◽  
Author(s):  
Philippe Picard
Keyword(s):  
Stochastic Model ◽  
Population Size ◽  
Hybrid Model ◽  
Human Population ◽  
Threshold Level ◽  
The Other ◽  
The Difference ◽  
The One

Modelling malaria with consistency necessitates the introduction of at least two families of interconnected processes. Even in a Markovian context the simplest fully stochastic model is intractable and is usually transformed into a hybrid model, by supposing that these two families are stochastically independent and linked only through two deterministic connections. A model closer to the fully stochastic model is presented here, where one of the two families is subordinated to the other and just a unique deterministic connection is required. For this model a threshold theorem can be proved but the threshold level is not the one obtained in a hybrid model. The difference disappears only when the human population size approaches infinity.

scholarly journals Behavior and Energy Losses of Cows during the Period of Low Temperatures

2021 ◽  
Vol 24 (5) ◽  
pp. 46-53
Author(s):  
Oleksandr O. Borshch ◽  
Oleksandr V. Borshch ◽  
Yurii Mashkin ◽  
Vasyl Malina ◽  
Maxim Fedorchenko
Keyword(s):  
Low Temperatures ◽  
Heat Insulation ◽  
Energy Losses ◽  
Strong Wind ◽  
The Past ◽  
Air Temperatures ◽  
The Difference ◽  
And Behavior ◽  
Positive Effect ◽  
Moderate Climate

Over the past 20 years, dairy farms in Ukraine have been actively introducing the keeping of cows in easy-to-assemble premises. However, in a moderate climate (with four distinct year seasons), the issues of microclimate, energy losses of animals and their behavior during the cold period of the year for keeping in such premises have not been fully studied. The purpose of this work was to study the influence of the heat insulation elements use of side curtains in easy-to-assemble premises during the period of low temperatures on microclimate, energy outgoings for thermoregulation and behavior of cows. The research conducted in the central part of Ukraine (Kyiv region). The research was conducted during January-February (29-43 days of the year) 2021. This period characterized by low average daily temperatures of -12.2– -18.7°С, strong wind gusts and daily precipitation in the form of snow. Two easy-toassemble premises for 400 heads were used for research. Parameters of placements (LxWxH): 150х32х10.5 m. The first one was without the use of curtains heat insulation elements, and the second one was with these elements of heat insulation. It was found that the use of polycarbonate wall heat insulation elements had a positive effect on the microclimate in the placement during the period of low temperatures. Indicators of average daily air temperatures in the placement were 3.2 and 8.8°C higher compared to the temperature in the same premise without the use of heat insulation elements and the environment. The wind speed also differed by 0.18 and 11.04 m/s, respectively. In addition, the heat insulation of the walls affected the temperature under the lying cow (+1.8°C), energy outgoings for thermoregulation (-1.93 MJ) and the number of cows that lay in the period of the lowest temperatures (+3.23-9.83%) compared to the placement without heat insulation elements. The difference in temperature of rubber carpet in the compared premises was significant: +3.3°C in the premises with heat insulation elements compared to the premises without heat insulation

scholarly journals The principal magnetic susceptibilities of neodymium sulphate octahydrate at low temperatures

1939 ◽  
Vol 170 (941) ◽  
pp. 266-271 ◽  
Keyword(s):  
Low Temperatures ◽  
Room Temperature ◽  
Energy Levels ◽  
Constant Factor ◽  
The Other ◽  
Crystalline Field ◽  
Cubic Symmetry ◽  
The Subject ◽  
The Difference ◽  
The One

The magnetic and other related properties of neodymium sulphate have been the subject of numerous investigations in recent years, but there is still a remarkable conflict of evidence on all the essential points. The two available determinations of the susceptibility of the powdered salt at low temperatures, those of Gorter and de Haas (1931) from 290 to 14° K and of Selwood (1933) from 343 to 83° K both fit the expression X ( T + 45) = constant over the range of temperature common to both, but the constants are not the same and the susceptibilities at room temperature differ by 11%. The fact that the two sets of results can be converted the one into the other by multiplying throughout by a constant factor suggested that the difference in the observed susceptibilities was due to some error of calibration. It could, however, also be due to the different purity of the samples examined though the explanation of the occurrence of the constant factor is then by no means obvious. From their analysis of the absorption spectrum of crystals of neodymium sulphate octahydrate Spedding and others (1937) conclude that the crystalline field around the Nd+++ ion is predominantly cubic in character since they find three energy levels at 0, 77 and 260 cm. -1 .* Calculations of the susceptibility from these levels reproduce Selwood’s value at room temperature but give no agreement with the observations-at other temperatures. On the other hand, Penney and Schlapp (1932) have shown that Gorter and de Haas’s results fit well on the curve calculated for a crystalline field of cubic symmetry and such a strength that the resultant three levels lie at 0, 238 and 834 cm. -1 , an overall spacing almost three times as great as Spedding’s.

On an inequality of long period in the motions of the Earth and Venus

1837 ◽  
Vol 3 ◽  
pp. 77-78
Keyword(s):  
Principal Term ◽  
The Sun ◽  
Method Of Calculation ◽  
The Third ◽  
Long Period ◽  
Mean Motion ◽  
The Earth ◽  
The Mean ◽  
The Difference

The author had pointed out, in a paper published in the Philosophical Transactions for 1828, on the corrections of the elements of Delambre’s Solar Tables, that the comparison of the corrections of the epochs of the sun and the sun’s perigee, given by the late observations, with the corrections given by the observations of the last century, appears to indicate the existence of some inequality not included in the arguments of those tables. As it was necessary, therefore, to seek for some inequality of long period, he commenced an examination of the mean motions of the planets, with the view of discovering one whose ratio to the mean motion of the earth could be expressed very nearly by a proportion of which the terms are small. The appearances of Venus are found to recur in very nearly the same order every eight years; some multiple, therefore, of the periodic time of Venus is nearly equal to eight years. It is easily seen that this multiple must be thirteen; and consequently eight times the mean motion of Venus is nearly equal to thirteen times the mean motion of the earth. The difference is about one 240th of the mean annual motion of the earth; and it implies the existence of an inequality of which the period is about 240 years. No term has yet been calculated whose period is so long with respect to the periodic time of the planets disturbed. The value of the principal term, calculated from the theory, was given by the author in a postscript to the paper above referred to. In the present memoir he gives an account of the method of calculation, and includes also other terms which are necessarily connected with the principal inequality. The first part treats of the perturbation of the earth’s longitude and radius victor; the second of the perturbation of the earth in latitude; and the third of the perturbations of Venus depending upon the same arguments.

The influence of temperature on development, longevity, and fecundity in the Rutherglen bug, Nysius vinitor (Hemiptera : Lygaeidae)

1972 ◽  
Vol 20 (1) ◽  
pp. 67 ◽  
Author(s):  
M Kehat ◽  
M Wyndham
Keyword(s):  
Egg Laying ◽  
Population Increase ◽  
Threshold Temperature ◽  
Nymphal Development ◽  
Influence Of Temperature On ◽  
Males And Females ◽  
The Mean ◽  
The Difference ◽  
Fluctuating Temperatures ◽  
Significant Mortality

The mean duration of the egg stage of N. vinitor at constant temperatures ranged from 36.8 days at 15C to 3.8 days at 32C and that of the nymphs from 45 days at 20C to 12.0 days at 32C. Within the range 20-35C egg and nymphal mortalities were low; temperatures of 12 or 40C were lethal to both eggs and nymphs. Mean nymphal development times for males and females were similar. The threshold temperature for egg development was 14.5C and that for nymphs 15C; 70 and 225 day-degrees were required for completing egg and nymphal development respectively. The immature stages developed more rapidly at fluctuating temperatures out of doors than they did indoors at constant temperatures equal to the mean of the fluctuating temperatures. Within the range of screen temperatures 21.5-23.0C the difference between mean development in shade and in sun was 9-10 days. Age-specific fecundity and mortality schedules were determined for N. vinitor at constant temperatures. Temperature and longevity were inversely related and males survived longer than females. Thus at 22OC mean longevity of males was 115 days and of females 90 days, as compared with 31 and 18 days respectively at 30�C. After a maturation period that was longer at lower temperatures, daily egg-laying per female decreased with age from a maximum that occurred before there was significant mortality of females. The rates of the cumulative egg-laying increased with temperature from 22 to 35C. Mean total number of eggs per female was significantly higher at 25 and 30�C than at 22 or 35�C. However, life-table calculations revealed that a temperature of 35�C yielded the maximum rate of population increase. Within the range 22-35C, temperatures and rc values were linearly related. Unmated females laid significantly fewer eggs than those that had mated, but survived longer.

Influence of Temperature on Performance in Guinea Pigs

1957 ◽  
Vol 190 (3) ◽  
pp. 457-458 ◽  
Author(s):  
Charles G. Wilber
Keyword(s):  
Low Temperatures ◽  
Guinea Pigs ◽  
Peak Performance ◽  
Albino Rats ◽  
Small Animals ◽  
Influence Of Temperature ◽  
Influence Of Temperature On ◽  
Endocrine Factors ◽  
The Difference ◽  
Large Animals

Guinea pigs were forced to swim to total exhaustion in water at various temperatures. Small animals (400 gm) showed peak performance at about 40°C, large ones (1000 gm) at about 35°C. Large animals swam longer at low temperatures but shorter at high temperatures than did small ones. At 35°C all guinea pigs swam for an average of about 150 minutes. In general this species shows much less capacity for swimming than do albino rats. The difference may be related to diet or to endocrine factors.

A stochastic model for investments in different technologies for electricity production in the long period

2013 ◽  
Vol 22 (2) ◽  
pp. 407-426 ◽  
Author(s):  
Maria Teresa Vespucci ◽  
Marida Bertocchi ◽  
Mario Innorta ◽  
Stefano Zigrino
Keyword(s):  
Stochastic Model ◽  
Electricity Production ◽  
Long Period
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