The effects of temperature and photoperiod on diapause development in the eggs of four species of Lestes (Odonata: Zygoptera)

1973 ◽  
Vol 51 (12) ◽  
pp. 1257-1265 ◽  
Author(s):  
W. W. Sawchyn ◽  
N. S. Church
Keyword(s):  
Subsequent Development ◽  
Second Phase ◽  
Inhibitory Effects ◽  
Temperature Controlled ◽  
Effects Of Temperature ◽  
Diapause Development

Lestes disjunctus, L. unguiculatus, and L. dryas diapause late in embryogenese when the embryo is almost fully formed. Lestes congener enters diapause just before blastokinesis. Lestes disjunctus, L. unguiculatus, and L. congener undergo a primarily temperature-controlled phase of diapause development, which proceeds most rapidly at 10 °C. In the field it is completed in most eggs by the end of October in L. disjunctus and L. unguiculatus, and by the end of November in L. congener. Subsequent development in L. disjuncius and L. unguiculatus is inhibited by photoperiods shorter than 12 to 14 h. There apparently is some overlap between the temperature- and photoperiod-controlled phases. The inhibitory effects of short photoperiods gradually disappear during the winter. In L. congener there is no significant photoperiod-controlled second phase of diapause. Diapause development in L. dryas probably is similar to that in L. disjunctus and L. unguiculatus.

Diapause and overwintering of the carrot fly, Psila rosae (F.) (Diptera: Psilidae)

1981 ◽  
Vol 71 (4) ◽  
pp. 583-590 ◽  
Author(s):  
A. J. Burn ◽  
T. H. Coaker
Keyword(s):  
Adult Emergence ◽  
Early Spring ◽  
Pupal Weight ◽  
Prepupal Stage ◽  
Psila Rosae ◽  
Carrot Fly ◽  
Soil Temperatures ◽  
Similar Temperature ◽  
Effects Of Temperature ◽  
Diapause Development

AbstractPsila rosae (F.) overwinters in Britain in both the larval and pupal stages. Overwintering pupae formed in October and November at soil temperatures of between 10 and 16°C entered diapause. A period of similar temperature in the laboratory during the prepupal stage also caused pupae to enter diapause. Overwintering larvae continued to feed and gain weight; they pupated in early spring at soil temperatures of 2–8°C but did not enter diapause. The sensitivity to diapause-inducing conditions decreased between November and March, associated with changes in developmental temperatures and pupal weight. The differential effects of temperature on larval, pupal and diapause development together serve to synchronise adult emergence from the overwintering population. The mechanisms which allow overwintering by a variable proportion of larvae and pupae also provide the opportunity for the development of a third generation of adult flies in October and November.

The Hypothalamo–Pituitary–Adrenocortical Axis—An Overview of the Role of Glucocorticoids in the Pathophysiology of Endocrine Disorders and Perspectives for the Future

2011 ◽  
Vol 07 (01) ◽  
pp. 65
Author(s):  
Christopher D John ◽  
Julia C Buckingham ◽  
◽  
Keyword(s):  
Acute Stress ◽  
Subsequent Development ◽  
Endocrine Disorders ◽  
Adaptive Responses ◽  
Inhibitory Effects ◽  
Cellular Processes ◽  
Physiological Processes ◽  
Wear And Tear ◽  
Adaptive Processes

Glucocorticoids (GCs) are the end products of the hypothalamo–pituitary–adrenocortical axis (HPA) and, via activation of the ubiquitously expressed GC receptor, influence numerous physiological processes. GCs are also involved in the regulation of basal homeostasis as well as mediating adaptive responses to stress that act to restore homeostasis. This article discusses the various factors that are important in regulating plasma and intracellular GC concentrations and describes the genomic and non-genomic mechanisms used by GCs to influence cellular processes. We describe the concept of allostatic overload associated with chronic HPA activation and the subsequent development of tissue dysfunction and disease. While allostasis is associated with acute stress and a restoration of homeostasis, chronic stress is likely to induce allostatic overload owing to the sustained activation of adaptive processes. Increased wear and tear in GC-sensitive tissues can eventually lead to tissue dysfunction and disease. Chronic elevations in GCs can also induce dysfunction or disease associated with decreased tissue function owing to the prolonged inhibitory effects of GCs or the redistribution of metabolic resource away from physiological systems not involved in restoring homeostasis. Numerous endocrine-related disorders are associated with aberrant GC levels and in terms of pathophysiology may be linked with chronic tissue-specific alterations in GC actions.

Diapause in parasitic nematodes: a review

2002 ◽  
Vol 80 (11) ◽  
pp. 1817-1840 ◽  
Author(s):  
R I Sommerville ◽  
K G Davey
Keyword(s):  
Parasite Burden ◽  
Parasitic Nematodes ◽  
Second Phase ◽  
Fourth Stage ◽  
Environmental Signals ◽  
The Third ◽  
Developmental Arrest ◽  
Third Stage ◽  
Animal Hosts ◽  
Diapause Development

This review considers in a selective way the literature on diapause in parasitic nematodes, concentrating on four species of animal parasites and three species of plant parasites. We define diapause as a developmental arrest which is temporarily irreversible, so development will not resume, even under favourable conditions, until some intrinsic changes have been completed. Our analysis recognises four stages in diapause. The first is induction, typically brought about by environmental signals (although diapause may be genetically programmed independently of the environment). These environmental signals typically do not have an immediate effect on development, but we recognise a second phase, which we call the diapause pathway, in which worms have been induced to enter diapause at a later developmental stage. Surprisingly, entry into the diapause pathway may under some circumstances be reversible. The third stage is diapause development, a period during which development is suspended, but some ill-understood process must be completed prior to the fourth stage, emergence from diapause. Although diapause development is complete, resumption of development may be further delayed because of conditions in the host or in the environment: the worm is once more capable of development, but development is prevented by unfavourable conditions extrinsic to the worm. These may include the immune state of the host or the total parasite burden in animal hosts.

The influence of temperature on the post-diapausal development and survival in the aestivating eggs of Halotydeus destructor (Acari : Eupodidae)

1970 ◽  
Vol 18 (3) ◽  
pp. 315 ◽  
Author(s):  
MMH Wallace
Keyword(s):  
Temperature Response ◽  
Subsequent Development ◽  
Temperature Tolerance ◽  
Effect Of Temperature ◽  
Halotydeus Destructor ◽  
Rate Of Development ◽  
High Temperature Tolerance ◽  
Influence Of Temperature On ◽  
Higher Temperature ◽  
Diapause Development

After diapause development is complete, moistened aestivating eggs of H. destructor develop successfully within the temperature range 5-20.5C. The rate of development up to the deutovum stage increases with temperature up to about 20C and then rapidly decreases. Eggs will tolerate temperatures between 25 and 31.5C for up to 53 days without undergoing morphogenesis, but this treatment retards subsequent development at 16C. Exposure to alternating temperatures accelerates the rate of development but, if the higher temperature exceeds 20.5C, development is retarded. The effect of temperature on the rate of development within the deutovum stage is similar to that on non-diapause winter eggs throughout their morphogenesis. Air-dry eggs will tolerate temperatures up to 75C but moist eggs are killed by exposure for 1 day to 45C. This high temperature tolerance, together with the limitations on development imposed by temperature, ensures that the aestivating eggs do not hatch before early autumn, even in the event of unseasonal summer rain. The temperature response curve and its ecological significance are discussed briefly.

scholarly journals Further Evidence of the Involvement of Thrombin in Platelet Release by ADP and Other Agents

1977 ◽  
Author(s):  
N. G. Ardlie ◽  
Huzoor- Akbar
Keyword(s):  
Calcium Concentration ◽  
Chelating Agent ◽  
Coagulation Factors ◽  
Free Calcium ◽  
Second Phase ◽  
Inhibitory Effects ◽  
Buffer Solution ◽  
Release Reaction ◽  
Free Calcium Concentration ◽  
Platelet Release

There is evidence of the involvement of coagulation factors in platelet aggregation and the release reaction caused by ADP and collagen but this has been challenged. This report concerns further experiments which can explain the apparently conflicting observations of various laboratories and which provide additional evidence of the involvement of coagulation factors and thrombin in the platelet release reaction caused by ADP and other agents.Washed platelets suspended in a buffer solution responded poorly to ADP with no second phase aggregation or release of [3H]5HT. In contrast, washed platelets suspended in dialysed plasma underwent second phase aggregation and released radioactivity. This response depended on calcium. Dialysed plasma deficient in factors XI or X did not restore second phase aggregation or the release reaction. Hirudin and heparin inhibited second phase aggregation and release by ADP and epinephrine. However, the inhibitory effects of heparin and hirudin on ADP,epinephrine and collagen were not observed when citrate was present. To explore the possibility that a reduction of the free calcium concentration accounts for the inhibition of action of these antithrombin agents by citrate experiments with EGTA were carried out. This alternative chelating agent also prevented the inhibitory actions of heparin and hirudin.These observations support the view that platelets and clotting function cooperatively in platelet reactions involved in haemostasis. We suggest that small amounts of thrombin formed prior to fibrin clotting mediate platelet reactions in haemostasis initiated by collagen and ADP and that secondary aggregation does not represent a citrate artifact.

Effects of Temperature on Optical Absorbance Spectra of Oxy-, Carboxy-, and Deoxyhemoglobin

1992 ◽  
Vol 38 (7) ◽  
pp. 1360-1364 ◽  
Author(s):  
J M Steinke ◽  
A P Shepherd
Keyword(s):  
Linear Function ◽  
Major Effect ◽  
Optical Absorbance ◽  
Absorbance Change ◽  
Temperature Controlled ◽  
Effects Of Temperature ◽  
Absorbance Spectra

Abstract The optical absorbance spectra of oxy-, carboxy-, and deoxyhemoglobin were recorded at wavelengths from 479 to 651 nm and at temperatures of 20, 30, and 40 degrees C. As noted in earlier reports, a major effect of lowering the temperature was an increase in the absorptivities at or near the absorbance maxima. However, at other wavelengths, reducing the temperature increased, decreased, or caused no change in absorbance. At wavelengths where temperature-induced shifts did occur, the absorbance change appeared to be a linear function of temperature. Unlike previous reports, the data presented here are quantitative and thus can be used to predict temperature-induced errors in spectrophotometric measurements of the relative concentrations of these hemoglobin species. Examples are given of the error that would occur in a widely used CO-Oximeter, the IL482, if it were not temperature controlled. Thus, the data presented here should be particularly useful to the operators and designers of spectrophotometric instruments such as oximeters, CO-Oximeters, and hemoglobinometers.

TIME REDUCTION DURING RESTORATION OF THE EXTERIOR OF A HISTORICAL BUILDING

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Renato Lagana
Keyword(s):  
Execution Time ◽  
Subsequent Development ◽  
Second Phase ◽  
Building Structures ◽  
Construction Site ◽  
Urban Centers ◽  
Historical Building ◽  
Protection Measures ◽  
Long Time

Emergency management due to partial collapse of facade elements is a great interest topic. The collapse often occurs in unexpected damage to building structures of architectural value within the historic urban centers. The actions often require a long time to implement. After an initial delimitation and isolation of the damaged surfaces are initiated, discovery and design of the restoration are started. The economic coverage, no less important, is often done over the years. We undertake a case study, developed in the intervention performed in front of the Cathedral of Reggio Calabria. The study covered aspects related to the organization of the first measures after the collapse of some decorative elements and the subsequent development of the site. The first phase involved the organization and implementation of protection measures to achieve tight deadlines to allow the use of space for an important and non-deferrable event. Authorization procedures for this first phase were expedited and operating procedure for the management of safety for temporary installations was established. The second phase, managed in a day, involved the intervention to ensure the practicability and ensure the safety of users. The preparation of the construction site optimized the execution time of the procedures. The design of the temporary works optimized the work of the teams involved in work sequencing, which resulted in reduced downtime and possible interference. The result of the design choices and operational programming optimized the execution time.

Assessing the effects of temperature on the population of Aedes aegypti, the vector of dengue

2009 ◽  
Vol 137 (8) ◽  
pp. 1188-1202 ◽  
Author(s):  
H. M. YANG ◽  
M. L. G. MACORIS ◽  
K. C. GALVANI ◽  
M. T. M. ANDRIGHETTI ◽  
D. M. V. WANDERLEY
Keyword(s):  
Life Cycle ◽  
Aedes Aegypti ◽  
Controlled Experiments ◽  
Dengue Disease ◽  
Offspring Number ◽  
Vector Population ◽  
Different Temperatures ◽  
Vector Borne ◽  
Temperature Controlled ◽  
Effects Of Temperature

SUMMARYDengue is a vector-borne disease transmitted by the mosquito Aedes aegypti. The incidence of dengue disease shows a clear dependence on seasonal variation. How does the temperature affect the incidence? We addressed this question indirectly by estimating the size of the A. aegypti population for different temperatures applying population dynamics theory. In order to achieve this objective we designed temperature-controlled experiments to assess the entomological parameters regarding the mosquito's life-cycle at different temperatures. By obtaining the mortality, transition and oviposition rates for different stages of the life-cycle of the mosquito we were able to calculate the basic offspring number Q0, which is the capacity of vector reproduction and ultimately gives the size of the vector population.

scholarly journals Biphasic regulation of development of the high-affinity saxitoxin receptor by innervation in rat skeletal muscle.

1982 ◽  
Vol 80 (5) ◽  
pp. 753-768 ◽  
Author(s):  
S J Sherman ◽  
W A Catterall
Keyword(s):  
Skeletal Muscle ◽  
Subsequent Development ◽  
Receptor Site ◽  
Triceps Surae ◽  
Second Phase ◽  
Adult Density ◽  
Rat Skeletal Muscle ◽  
High Affinity ◽  
Site Density ◽  
Receptor Sites

Specific binding of 3H-saxitoxin (STX) was used to quantitate the density of voltage-sensitive sodium channels in developing rat skeletal muscle. In adult triceps surae, a single class of sites with a KD = 2.9 nM and a density of 21 fmol/mg wet wt was detected. The density of these high-affinity sites increased from 2.0 fmol/mg wet wt to the adult value in linear fashion during days 2-25 after birth. Denervation of the triceps surae at day 11 or 17 reduced final saxitoxin receptor site density to 10.4 or 9.2 fmol/mg wet wt, respectively, without changing KD. Denervation of the triceps surae at day 5 did not alter the subsequent development of saxitoxin receptor sites during days 5-9 and accelerated the increase of saxitoxin receptor sites during days 9-13. After day 13, saxitoxin receptor development abruptly ceased and the density of saxitoxin receptor sites declined to 11 fmol/wg wet wt. These results show that the regulation of high-affinity saxitoxin receptor site density by innervation is biphasic. During the first phase, which is independent of continuing innervation, the saxitoxin receptor density increases to 47-57% of the adult level. After day 11, the second phase of development, which is dependent on continuing innervation, gives rise to the adult density of saxitoxin receptors.

Sign in / Sign up

Export Citation Format

Share Document