scholarly journals The Effects of Temperature and of Egg-Laying on the Longevity of Drosophila subobscura

2002 ◽  
Vol 2002 (37) ◽  
Author(s):  
J. Maynard Smith
Keyword(s):  
Animal Species ◽  
Initial Period ◽  
Egg Laying ◽  
Drosophila Subobscura ◽  
Force Of Mortality ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Favourable Environment ◽  
Rate Of Ageing ◽  
Increasing Temperature

If an outbred population of adult Drosophila is kept from the time of emergence in a uniform and favourable environment there is a fairly protracted initial period during which very few individuals die, followed by a period during which the force of mortality rises rapidly until all individuals are dead. Similar life tables can be obtained for most animal species, provided that the environment is favourable and the population is neither genetically very diverse nor excessively inbred. Such results show that progressive changes take place in individuals, starting at the time of emergence, and that these changes ultimately result in death or render individuals increasingly susceptible to various extrinsic causes of death. As would be expected, in poikilotherms such changes proceed more rapidly at higher temperatures, as is shown by the decrease in the expectation of life with increasing temperature. It was the purpose of the present investigation to discover how far the processes responsible for death in D. subobscura are the same at different temperatures, differing only in the rate at which they proceed, and how far different processes are concerned at different temperatures. The results obtained strongly suggest that different processes are responsible for ageing at different temperatures; they also indicate a connexion between the rate of egg-laying and the rate of ageing, and this possibility has been confirmed by a study of ageing in virgin females and in females lacking ovaries. Reproduced by permission. J. Maynard Smith, The Effects of Temperature and of Egg-Laying on the Longevity of Drosophila subobscura. J. Exp. Biol. 35 , 832-842 (1958).

scholarly journals Effects of Temperature on Wear Properties and Mechanisms of HVOF Sprayed CoCrAlYTa-10%Al2O3 Coatings and H13 Steel

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1224
Author(s):  
Zheng Wei ◽  
Yuping Wu ◽  
Sheng Hong ◽  
Weihua Yang ◽  
Wei Shi
Keyword(s):  
Wear Rate ◽  
Wear Properties ◽  
H13 Steel ◽  
Hvof Spraying ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Increasing Temperature ◽  
Worn Surface ◽  
Oxygen Fuel ◽  
Better Than

In this study, the CoCrAlYTa-10%Al2O3 coatings were prepared by the high-velocity oxygen-fuel (HVOF) spraying. A series of ball-on-disk sliding wear tests were conducted to evaluate the tribological properties of the coatings at different temperatures (25 °C, 200 °C, 400 °C, and 600 °C). The results showed that the average coefficients of friction (COFs) of the CoCrAlYTa-10%Al2O3 coatings were lower than that of H13 steel at different temperatures. The average COFs of the CoCrAlYTa-10%Al2O3 coatings and H13 steel both decreased with increasing temperature. The wear rate of the CoCrAlYTa-10%Al2O3 coatings increased first and then decreased. The microhardness of worn surface of the CoCrAlYTa-10%Al2O3 coatings increased with increasing temperature, while the microhardness of worn surface of H13 steel at 25 °C and 200°C was higher than that at 400 °C and 600 °C. The wear mechanism of the two materials was mainly abrasive wear. The tribofilms were formed on the worn surface of the CoCrAlYTa-10%Al2O3 coatings, which had a good protective effect. Due to thermal softening and low binding strength of debris, it was difficult for H13 steel to form the tribofilms. The wear rate of H13 steel was much higher than that of the CoCrAlYTa-10%Al2O3 coatings at 400 °C and 600 °C, indicating that the high temperature wear resistance of the coatings was much better than that of H13 steel.

Thermal Stability of Moniliformin at Varying Temperature, pH, and Time in an Aqueous Environment†

2000 ◽  
Vol 63 (11) ◽  
pp. 1598-1601 ◽  
Author(s):  
GRACIELA PINEDA-VALDES ◽  
LLOYD B. BULLERMAN
Keyword(s):  
Animal Species ◽  
Keshan Disease ◽  
Aqueous Environment ◽  
Buffer Solutions ◽  
Processing Times ◽  
Effects Of Temperature ◽  
The Stability ◽  
Increasing Temperature ◽  
Major Reduction ◽  
Thermal Stability Of

Moniliformin (MON) is a widely occurring mycotoxin, produced mainly by Fusarium proliferatum and Fusarium subglutinans in corn, that has been shown to be acutely toxic for various animal species and is a suspected cause of Keshan disease in China. The effects of temperature (100, 125, and 150°C) and pH (4, 7, and 9) on the stability of MON were determined in aqueous buffer solutions at processing times ranging from 10 to 60 min. The percentage of MON reduction was positively related to increasing temperature and pH. MON was most stable at pH 4. After 60 min at pH 4 and 150°C, MON was reduced by only 5%. Heating at pH 10 caused major reduction of MON. After 60 min at pH 10 and 100, 125, and 150°C, MON was reduced by 56, 72, and 83%, respectively. One trial done at 175°C and pH 10 showed that less than 1% MON remained after 60 min of processing.

scholarly journals The Effects of Temperature and of Egg-Laying on the Longevity of Drosophila Subobscura

1958 ◽  
Vol 35 (4) ◽  
pp. 832-842 ◽  
Author(s):  
J. MAYNARD SMITH
Keyword(s):  
Young Adult ◽  
Survival Time ◽  
Sharp Increase ◽  
Adult Life ◽  
Egg Laying ◽  
Drosophila Subobscura ◽  
Partial Regression ◽  
Adult Life Span ◽  
Prolongation Of Life ◽  
Effects Of Temperature

1. The adult life span of Drosophila subobscura has been measured at temperatures varying from 20° to 33° C. A sharp increase in the slope of the curve of log survival time against temperature occurs at temperatures above 31° C. 2. Changes which occur in individuals at 33° C. or above are reversible, at least in part, at 20° C.; but changes occurring at 30·5° C. are irreversible in the sense that the total survival time at 30·5° C. is not increased by intervening periods at 20° C. 3. Exposure of young adult flies to 30·5° C. for a period of about half their expectation of life at that temperature significantly increases the further expectation of life of females at 20° C. but does not alter the expectation of life of males. Such exposure causes a partial regression of the ovaries of females, a permanent change in their behaviour and a reduction in their rate of egg-laying; exposure does not alter the behaviour or seriously reduce the fertility of males. 4. ‘Ovariless’ females and virgin females live for significantly longer than do normal mated females. The expectation of life of ‘ovariless’ females at 20° C. is not altered by exposure to 30·5° C. It is concluded that egg-laying accelerates the ageing of females at 20° C., and that the prolongation of life of females exposed to 30·5° C. is due to the reduction in the rate at which such females subsequently lay eggs.

Effect of Temperature and Water Immersion on the Mechanical Properties of Coated Fabrics

2010 ◽  
Vol 129-131 ◽  
pp. 230-234
Author(s):  
Ying Ying Zhang ◽  
Qi Lin Zhang ◽  
Chuan Zhi Zhou ◽  
Ying Zhou
Keyword(s):  
Mechanical Properties ◽  
Water Immersion ◽  
Effect Of Temperature ◽  
C 23 ◽  
Different Temperatures ◽  
Temperature Induction ◽  
Effects Of Temperature ◽  
C 50 ◽  
Coated Fabrics ◽  
Increasing Temperature

As composite, the mechanical properties of coated fabrics are sensitive to environment. This paper presented mechanical properties under different environments. A list of uniaxial tests are carried out under different temperatures including -20°C, 0°C, 23°C, 50°C, and 70°C. First, the tensile behaviors at room temperature and the failure behaviors are studied. Then, the effects of temperature on mechanical properties are determined. Finally, the effects of water immersion on mechanical properties are discussed. Results show PTFE coated fabrics remained unchanged in varying temperature and humidity. The temperature has effects on the mechanical properties of PVC coated fabrics. With increasing temperature, the strength decrease and the strain at break increase. The temperature induction factors are proposed for the design and analysis. The water immersion has little effect on the mechanical properties because of the impervious coating.

scholarly journals Effects of temperature on tissue–diet isotopic spacing of nitrogen and carbon in otolith organic matter

2019 ◽  
Vol 70 (12) ◽  
pp. 1757 ◽  
Author(s):  
Jane A. Godiksen ◽  
Ming-Tsung Chung ◽  
Arild Folkvord ◽  
Peter Grønkjær
Keyword(s):  
Stable Isotopes ◽  
Organic Matter ◽  
Ambient Temperature ◽  
Trophic Position ◽  
Effect Of Temperature ◽  
Δ13c Values ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Increasing Temperature ◽  
Rearing Experiment

Reconstruction of the trophic position of a fish can be performed by analysing stable nitrogen and carbon isotopes in otolith protein. However, ambient temperature may affect the tissue–diet isotopic spacing of stable isotopes from diet to predator tissue and bias estimates of trophic position. To test this, otolith protein, heart and muscle tissue from a rearing experiment with juvenile cod held at different temperatures (4, 7, 10 and 14°C) were analysed. There was no significant effect of temperature on otolith δ15N, whereas muscle and heart exhibited a slight decrease in δ15N values with increasing temperature corresponding to maximum of 0.6‰ over the 10°C range. By contrast, the otolith protein δ13C values at 4 and 7°C were significantly higher than for 10 and 14°C, suggesting an approximate 1‰ increased tissue–diet enrichment at the lower temperatures. Temperature had no significant effect on muscle and heart δ13C values. Considering the annual mean variation in ocean temperatures, our results indicate that the trophic signals recorded in the otoliths will reflect changes in diet isotope values with little bias from the ambient temperature experienced by the fish.

scholarly journals Drosophilaembryogenesis scales uniformly across temperature and developmentally diverse species

2013 ◽  
Author(s):  
Steven Gregory Kuntz ◽  
Michael B Eisen
Keyword(s):  
Thermal Environment ◽  
Time Lapse ◽  
Egg Laying ◽  
Tropical Species ◽  
Relative Timing ◽  
Animal Development ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Time Lapse Imaging ◽  
The Impact

Temperature affects both the timing and outcome of animal development, but the detailed effects of temperature on the progress of early development have been poorly characterized. To determine the impact of temperature on the order and timing of events duringDrosophila melanogasterembryogenesis, we used time-lapse imaging to track the progress of embryos from shortly after egg laying through hatching at seven precisely maintained temperatures between 17.5°C and 32.5°C. We employed a combination of automated and manual annotation to determine when 36 milestones occurred in each embryo.D. melanogasterembryogenesis takes 33 hours at 17.5°C, and accelerates with increasing temperature to a low of 16 hours at 27.5°C, above which embryogenesis slows slightly. Remarkably, while the total time of embryogenesis varies over two fold, the relative timing of events from cellularization through hatching is constant across temperatures. To further explore the relationship between temperature and embryogenesis, we expanded our analysis to cover ten additionalDrosophilaspecies of varying climatic origins. Six of these species, likeD. melanogaster, are of tropical origin, and embryogenesis time at different temperatures was similar for them all.D. mojavensis, a sub-tropical fly, develops slower than the tropical species at lower temperatures, whileD. virilis, a temperate fly, exhibits slower development at all temperatures. The alpine sister speciesD. persimilisandD. pseudoobscuradevelop as rapidly as tropical flies at cooler temperatures, but exhibit diminished acceleration above 22.5°C and have drastically slowed development by 30°C. Despite ranging from 13 hours forD. erectaat 30°C to 46 hours forD. virilisat 17.5°C, the relative timing of events from cellularization through hatching is constant across all of the species and temperatures examined here, suggesting the existence of a previously unrecognized timer controlling the progress of embryogenesis that has been tuned by natural selection in response to the thermal environment in which each species lives.

Effects of temperature gradient on the granite’s mechanical properties

2021 ◽  
pp. 1-10
Author(s):  
Jinyong Pei ◽  
Huagang He ◽  
Dongtao Hu ◽  
Shanke Lv ◽  
Jing Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Gradient ◽  
Strain Curve ◽  
Peak Stress ◽  
Tangent Modulus ◽  
Peak Strain ◽  
Compression Tests ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Increasing Temperature

Temperature gradient significantly affects the production of surrounding rock stress in mining engineering. The mechanics and deformation characteristics of the rock will change under the temperature gradient, thereby increasing the probability of accidents in the roadway. This paper conducts uniaxial compression tests on granite at different temperatures from room temperature to 250∘C, and analyzes in detail the changes in the stress-strain curve, peak stress, peak strain and tangent modulus of granite under high temperature and different temperature gradient conditions. The results of this study are as follows: (1) Under high temperature conditions, the granite’s peak stress and tangent elastic modulus increased with temperature from 17 to 100∘C, then decreased from 100∘C to 250∘C, whereas the granite’s peak strain increased steadily with increasing temperature; (2) under temperature gradient, the granite’s peak stress and tangent modulus first decreased and then increased with increasing temperature gradient, while the granite’s peak strain first decreased and then increased at 100∘C, but first increased and then decreased from 150∘C to 250∘C.

scholarly journals A Comparative Electrochemical and Morphological Investigation on the Behavior of NiCr and CoCr Dental Alloys at Various Temperatures

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 256
Author(s):  
Florentina Golgovici ◽  
Mariana Prodana ◽  
Florentina Gina Ionascu ◽  
Ioana Demetrescu
Keyword(s):  
Low Temperatures ◽  
Artificial Saliva ◽  
Electrochemical Stability ◽  
Morphological Investigation ◽  
Dental Alloys ◽  
Ion Release ◽  
Icp Ms ◽  
Different Temperatures ◽  
Good Concordance ◽  
Increasing Temperature

The purpose of our study is to compare the behavior of two reprocessed dental alloys (NiCr and CoCr) at different temperatures considering the idea that food and drinks in the oral cavity create various compositions at different pH levels; the novelty is the investigation of temperature effect on corrosion parameters and ion release of dental alloys. Electrochemical stability was studied together with morphology, elemental composition and ions release determination. The results obtained are in good concordance: electrochemistry studies reveal that the corrosion rate is increasing by increasing the temperature. From SEM coupled with EDS, the oxide film formed on the surface of the alloys is stable at low temperatures and a trend to break after 310K. ICP-MS results evidence that in accordance with increasing temperature, the quantities of ions released from the alloys immersed in artificial saliva also increase, though they still remain small, less than 20 ppm.

scholarly journals Simulation of FDSOI-ISFET with Tunable Sensitivity by Temperature and Dual-Gate Structure

Electronics ◽  
2021 ◽  
Vol 10 (13) ◽  
pp. 1585
Author(s):  
Hanbin Wang ◽  
Jinshun Bi ◽  
Mengxin Liu ◽  
Tingting Han
Keyword(s):  
Gate Voltage ◽  
Computer Aided Design ◽  
Silicon On Insulator ◽  
Fully Depleted ◽  
Gate Structure ◽  
Different Temperatures ◽  
Dual Gate ◽  
Sensitivity Changes ◽  
Increasing Temperature ◽  
Aided Design

This work investigates the different sensitivities of an ion-sensitive field-effect transistor (ISFET) based on fully depleted silicon-on-insulator (FDSOI). Using computer-aided design (TCAD) tools, the sensitivity of a single-gate FDSOI based ISFET (FDSOI-ISFET) at different temperatures and the effects of the planar dual-gate structure on the sensitivity are determined. It is found that the sensitivity increases linearly with increasing temperature, reaching 890 mV/pH at 75 °C. By using a dual-gate structure and adjusting the control gate voltage, the sensitivity can be reduced from 750 mV/pH at 0 V control gate voltage to 540 mV/pH at 1 V control gate voltage. The above sensitivity changes are produced because the Nernst limit changes with temperature or the electric field generated by different control gate voltages causes changes in the carrier movement. It is proved that a single FDSOI-ISFET can have adjustable sensitivity by adjusting the operating temperature or the control gate voltage of the dual-gate device.

scholarly journals Correlation and prediction of solubility of hydrogen in alkenes and its dissolution properties

2021 ◽  
Author(s):  
Mohammad Jamali ◽  
Amir Abbas Izadpanah ◽  
Masoud Mofarahi
Keyword(s):  
Equation Of State ◽  
Binary Interaction ◽  
Absolute Deviation ◽  
Dissolution Properties ◽  
Different Temperatures ◽  
Binary Interaction Parameters ◽  
Delta G ◽  
Hoff Equation ◽  
Increasing Temperature ◽  
Total Average

AbstractIn this work, solubility of hydrogen in some alkenes was investigated at different temperatures and pressures. Solubility values were calculated using the Peng–Robinson equation of state. Binary interaction parameters were calculated using fitting the equation of state on experimental data, Group contribution method and Moysan correlations and total average absolute deviation for these methods was 3.90, 17.60 and 13.62, respectively. Because hydrogen solubility in Alkenes is low, Henry’s law for these solutions were investigated, too. Results of calculation showed with increasing temperature, Henry’s constant was decreased. The temperature dependency of Henry’s constants of hydrogen in ethylene and propylene was higher than to other alkenes. In addition, using Van’t Hoff equation, the thermodynamic parameters for dissolution of hydrogen in various alkenes were calculated. Results indicated that the dissolution of hydrogen was spontaneous and endothermic. The total average of dissolution enthalpy ($${\Delta H}^{^\circ }$$ Δ H ∘ ) and Gibbs free energy ($${\Delta G}^{^\circ }$$ Δ G ∘ ) for these systems was 3.867 kJ/mol and 6.361 kJ/mol, respectively. But dissolution of hydrogen in almost of alkenes was not an entropy-driven process.

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