Somitogenesis in amphibian embryos

Development ◽  
1980 ◽  
Vol 58 (1) ◽  
pp. 107-118
Author(s):  
Jonathan Cooke ◽  
Tom Elsdale

Temperature shocks of a few minutes duration at 37 °C to tail-bud embryos of Rana induce zones of abnormal segmentation along the somite files subsequently produced. The immediate result of a temperature shock is a temporary arrest of development as a whole, following which the schedule of somite determination and formation is resumed at the normal rate. It is during the period immediately following this that the zone of abnormal somite pattern is determined. Thus the length of the abnormal zone reflects the total time taken by the morphogenetic system to recover from the disturbance, and might depend upon variables affecting both the duration of the initial arrest and the duration of the recovery period itself. Observations are presented demonstrating how the lengths of abnormal zones, caused by a temperature shock of any particular severity, are affected by three variables: (1) the ambient temperature to which the embryos were adapted before shock, (2) the ambient temperature of post-shock development, (3) the stage in somitogenesis, i.e. the number of somites already formed at the time of shock. The data (in this and previous papers of the series) support models postulating that the spatial periodicity in cell behaviour, that is somite morphogenesis, reflects a normal interaction between two hidden aspects of development, one a wavefront of cellular activation passing down the body axis, and the other having the character of a temporal periodicity throughout the tissue. Temperature shock, as well as halting the wavefront (i.e. stopping development) temporarily, leads to a subsequent period during which there is only gradual recovery of normal co-ordination between the periodicity within cells of the tissue and the wavefront progress. It is the relative rate of this recovery, alone, that is responsible for variation in the length of the abnormal zone.

Author(s):  
E. K. Krasavina ◽  
I. V. Yatsyna

Professional allergodermatoses are accompanied by cytochemical and immunochemical changes in the body of patients. The use of ozone therapy techniques in this category of patients can accelerate the recovery period and normalize the above indicators.


Hydrobiologia ◽  
2021 ◽  
Author(s):  
Rungtip Wonglersak ◽  
Phillip B. Fenberg ◽  
Peter G. Langdon ◽  
Stephen J. Brooks ◽  
Benjamin W. Price

AbstractChironomids are a useful group for investigating body size responses to warming due to their high local abundance and sensitivity to environmental change. We collected specimens of six species of chironomids every 2 weeks over a 2-year period (2017–2018) from mesocosm experiments using five ponds at ambient temperature and five ponds at 4°C higher than ambient temperature. We investigated (1) wing length responses to temperature within species and between sexes using a regression analysis, (2) interspecific body size responses to test whether the body size of species influences sensitivity to warming, and (3) the correlation between emergence date and wing length. We found a significantly shorter wing length with increasing temperature in both sexes of Procladius crassinervis and Tanytarsus nemorosus, in males of Polypedilum sordens, but no significant relationship in the other three species studied. The average body size of a species affects the magnitude of the temperature-size responses in both sexes, with larger species shrinking disproportionately more with increasing temperature. There was a significant decline in wing length with emergence date across most species studied (excluding Polypedilum nubeculosum and P. sordens), indicating that individuals emerging later in the season tend to be smaller.


2014 ◽  
Vol 54 (9) ◽  
pp. 1476 ◽  
Author(s):  
N. Y. Kim ◽  
S. J. Kim ◽  
J. H. Park ◽  
M. R. Oh ◽  
S. Y. Jang ◽  
...  

The present study aimed to gather basic information on measuring body surface temperature (BST) of cattle by using infrared thermography (IRT) and find out whether BST measurement is a useful method to detect thermal balance of livestock. Twenty-seven Hanwoo steers were examined in a field trial. The BST of five body regions (eye, nose, horn, ear, rear) was measured five times daily, with three replicates, during 3 days each season. Body surface temperature of cattle is directly affected by ambient temperature and humidity, and showed different ranges for each region. The BSTs of nose, horns and ears were significantly (P < 0.05) lower than those of eyes and rear area. Rear-area BST was significantly lower than eye-area BST when the ambient temperature was low (P < 0.05). Eye BST (EBST) was highest (P < 0.05) and the least variable of all BSTs measured. Therefore, the eye area of cattle was the most thermostable part of the body. There were significant (P < 0.05) differences among seasonal EBSTs of steers. The EBST range was highest in the summer (37.9–42.2°C), followed by autumn (34.3–37.4°C), spring (33.8–36.5°C) and winter (29.8–32.6°C). During extreme cold, EBST showed a large standard deviation. During conditions of extreme heat, EBST was above the average body temperature of cattle. The results of the present study indicated that BST well reflects the thermal circumstances surrounding animals and may be used as one of the effective tools for precision cattle farming.


2021 ◽  
Vol 8 (32) ◽  
pp. 3039-3042
Author(s):  
Lekshmi Raj Jalaja ◽  
Stuti Lohia ◽  
Priyadarsini Bentur ◽  
Ravi Ramgiri

‘Obesity’ is defined as a condition with excess body fat to the extent that health and well-being are adversely affected and uses a class system based on the body mass index (BMI), by the world health organization (WHO). Anaesthetic management of morbidly obese is challenging, as there is an increased risk of perioperative respiratory insufficiency and supplemental oxygen must be given throughout recovery period. The incidence of morbid obesity continues to grow and anaesthesiologists are exposed to obese patients presenting for various procedures. The prevalence of obesity is on the upward trend worldwide. Obesity is a multisystem disorder, involving the respiratory and cardiovascular systems, and therefore, undergoing a surgical procedure under anaesthesia may entail a considerable risk. Thus, a multidisciplinary approach is required in treating such patients. Quantification of the extent of obesity is done using the body mass index. BMI is defined as the relationship between weight and height (weight [kg] / height2 [m2 ]).


1957 ◽  
Vol 188 (3) ◽  
pp. 435-438 ◽  
Author(s):  
M. J. Fregly ◽  
N. B. Marshall ◽  
J. Mayer

Goldthioglucose-obese mice cannot adjust their food intake to meet the increased energy requirements due to cold. At all ambient temperatures above 15°C the spontaneous running activity of these animals is less than that observed for nonobese controls. Activity of obese mice is maximal at 19°C and minimal at 15°C or lower. Body weights decrease during exposure to cold. In contrast to that of obese mice, running activity of nonobese controls is maximal at an ambient temperature of 25°C but nearly ceases at 15°C or lower. The food intake of these animals increases in the cold and remains elevated even at temperatures at which activity decreases. The body weight of nonobese controls is either maintained constant or increases during exposure to cold air.


1987 ◽  
Vol 115 (4) ◽  
pp. 478-482 ◽  
Author(s):  
J. Roffi ◽  
F. Chami ◽  
P. Corbier ◽  
D. A. Edwards

Abstract. In the neonatal male rat, a rapid and transient increase in serum testosterone occurs about 2 h after birth. This post-partum testosterone surge (PPTS) has been implicated in the masculinization and defeminization of the central nervous system. The present study shows that environmental temperature can have a profound influence on the PPTS. Male rats were delivered from their mothers by caesarean section on day 22 of gestation. Immediately thereafter, neonatal males were placed at an ambient temperature of either 18, 21, 24 or 30°C. With 2 h of exposure, the body temperature was in close correspondence with the ambient temperature. The PPTS was clearly abolished in the pups exposed for 2 h at either 18 or 21°C. The effect of temperature was reversible: by placing pups at either 18 or 21°C for 2 h after delivery, and then rewarming by placing them with a foster mother, the PPTS was delayed until 4 h after birth, i.e. 2 h after the beginning of rewarming. Thus, environmental cooling appears to retard the development of neural and/or endocrine systems mediating the PPTS. Aberrant maternal care which would produce substantial cooling of the male pups would be expected to affect the PPTS, which in turn might affect the sexuality of male progeny.


1991 ◽  
Vol 156 (1) ◽  
pp. 21-39 ◽  
Author(s):  
H. O. PÖRTNER ◽  
N. A. ANDERSEN ◽  
N. HEISLER

Proton-equivalent ion transfer processes between animals and ambient water were determined under normoxic control conditions during anaerobiosis and the subsequent recovery period in the marine worm Sipunculus nudus L. During anaerobiosis and recovery, transepithelial H+-equivalent ion transfer was generally correlated with changes in extracellular pH, with some disparities in ‘spring’ animals. The typical initial alkalosis induced by phosphagen cleavage during early anaerobiosis was reflected by a loss of basic equivalents. The acidosis, which developed later, reflecting production of acidic metabolic intermediates, resulted in a relatively small net extrusion of protons into the water. The coelomic acidosis during recovery was greatly exaggerated by the release of protons during phosphagen repletion and by the considerable elevation of Pco2 after normoxia had been reattained. The acidosis stimulated the net release of H+ to the water at a rate several times higher than that during anaerobiosis. The efficient transfer of protons from the body fluids to the environmental water during recovery facilitated normalization of coelomic pH, long before protons dissociated from the large amounts of organic acids produced as anaerobic intermediates could be removed from the body fluids by metabolism. Although the transfer of net H+ equivalents to the water coincided with coelomic acidosis, the rates of transfer during different periods of the experiment were primarily correlated with overall metabolic rate. Low net proton transfer rates associated with anaerobiosis were not sufficient to maintain acid-base parameters typical for normoxia, whereas re-establishment of aerobic conditions facilitated a greatly increased transepithelial H+ transfer rate. These data suggest that the transfer capacity of the energy-consuming translocation mechanism may primarily be determined by the rate of metabolic turnover and, accordingly, by theamount of available energy.


2020 ◽  
Author(s):  
Martín Altuna ◽  
Paul V. Hickner ◽  
Gustavo Castro ◽  
Santiago Mirazo ◽  
Adalberto A. Pérez de León ◽  
...  

Abstract BackgroundFeral swine (Sus scrofa) are highly invasive and threaten animal and public health in the Americas. New World screwworm (Cochliomyia hominivorax) is listed by the World Organization for Animal Health as a notifiable infestation because myasis cases affect livestock, wildlife, and humans in endemic areas, and outbreaks can be of high socioeconomic consequence in regions where screwworm was eradicated. However, a knowledge gap exists on screwworm infestation of feral swine in South America where C. hominivorax is endemic. Here, we report infestation with C. hominivorax in feral swine harvested in the Department of Artigas where the Republic of Uruguay shares borders with Brazil and Argentina. MethodsMyiasis caused by the larvae of C. hominivorax were identified in feral swine with the support and collaboration of a local feral swine hunting club over a three-year period in the Artigas Department of Uruguay. Harvested feral swine were examined for the presence of lesions where maggots causing the myiasis could be sampled and processed for taxonomic identification. The sites of myiasis on the body of infested feral swine and geospatial data for each case were recorded. Feral swine sex and relative size were registered along with ambient temperature and precipitation.ResultsMyiases caused by screwworms were recorded in 27 of 618 feral swine harvested. Cases detected in males over 40 kg were associated with wounds that, because of their location, were likely caused by aggressive dominance behavior between adult males. The overall prevalence of screwworm infestation in feral swine was associated with ambient temperature, but not precipitation. Case numbers peaked in the warmer spring and summer months. ConclusionThis is the first report for South America of myasis caused by C. hominivorax in feral swine. In contrast to myasis in cattle that can reach deep into host tissues, screwworms in feral swine tended to cause superficial infestation. Feral swine present challenges to control screwworms in endemic areas. Screwworm populations maintained by feral swine may contribute to human cases in rural areas of Uruguay, which highlights the One Health importance of this invasive species-ectoparasite interaction.


Global warming has become a problem of world wide, because it endangers living things. The consequences of global warming include the increase of the earth temperature and climate change. The increase of temperature (heating) in a city which is referred to urban heat island (UHI) is also the same problem in architecture. This research aimed to analyze the ambienttemperature of the UHI due to the motor vehicleactivities. Samples were taken from several locations: (1) Bahu Mall Parking area; (2) Manado Town Square 2 parking area; (3) along the Wolter Monginsidi street in front of Bahu Mall and (4) along the Piere Tendean street in front of Manado Town Square. This research used a quantitative method with a field survey. This research found that the ambient temperature increased when motor vehicles were stationary with engine on or moved. The temperature increased due to the heat from the engine and the reflection of the sun’s heat from the body of the vehicles. The heat level obtained from the survey was 34,8 0C to 39,4 0C. For this reason, a specific material for vehicle’s body is needed to prevent the increase of ambient temperature.


1969 ◽  
Vol 72 (3) ◽  
pp. 371-378 ◽  
Author(s):  
R. G. Gunn

SUMMARYA subclinical calcium or phosphorus dietary deficiency on many hill pastures and a relationship between this and the premature loss of permanent incisor teeth are postulated. The effects of small individual supplements of calcium (12 g calcium carbonate suspended in water) or phosphorus (13 g monosodium phosphate in solution) supplied three times a week between mid-February and the end of May to Scottish Blackface ewes which grazed reseeded pasture in April and May were compared with those of no mineral supplement and with those of no mineral supplementon hill pastures throughout.Neither supplement had any significant effect on the number or weights of lambs born or reared on reseeded pastures. Both resulted in significantly greater ewe live-weight gain during the treatment period, in a significant improvement in the firmness and permanence of the incisor teeth, and in significantly higher serum Ca levels during lactation. All effects increased with advancing age.The use of hill pastures during late pregnancy and early lactation without any mineral supplement could result in significantly poorer ewe live-weight gain during the treatment period depending on season. This was also associated with significantly lighter single lambs at 6 weeks and with slower deterioration of the incisor teeth.It is suggested that minerals lost from the body during lactation on reseeded pastures are not replaced during the autumn recovery period on hill pastures and that a gradual depletion occurs throughout life, leading possibly to demineralization of the alveolar bone and premature loss of the incisor teeth. It is suggested that this is indicative of a higher mineral requirement for maintenance of the permanent dentition than is necessary for normal acceptable growth andreproductive performance. Mineral content of hill herbage may therefore be too low to supply requirements at the levels of OM intake normal on hill pastures.


Sign in / Sign up

Export Citation Format

Share Document