Food-deprivation affects seawater acclimation in tilapia: hormonal and metabolic changes

1996 ◽  
Vol 199 (11) ◽  
pp. 2467-2475 ◽  
Author(s):  
M Vijayan ◽  
J Morgan ◽  
T Sakamoto ◽  
E Grau ◽  
G Iwama

We tested the hypothesis that nutritional state affects seawater acclimation by transferring either fed or food-deprived (2 weeks) male tilapia (Oreochromis mossambicus) from fresh water to full-strength sea water. Food-deprivation resulted in a significant increase in plasma concentrations of Na+, Cl-, cortisol, glucose, total amino acid, glutamate, serine and alanine, and in hepatic pyruvate kinase (PK) and lactate dehydrogenase (LDH) activities, whereas the prolactin-188 to prolactin-177 ratio (tPRL188:tPRL177) and plasma prolactin-188 (tPRL188), lactate, arginine and hepatic glycogen content and hepatic alanine aminotransferase (AlaAT) and 3-hydroxyacyl-Coenzyme A dehydrogenase (HOAD) activities were lower than in the fed group. Seawater transfer significantly increased the tPRL188:tPRL177 ratio and plasma concentrations of Na+, Cl-, K+, growth hormone (GH), glucose, aspartate, tyrosine, alanine, methionine, phenylalanine, leucine, isoleucine and valine levels as well as gill Na+/K+-ATPase activity and hepatic PK and LDH activities, whereas plasma tPRL177, tPRL188, glycine and lysine concentrations were significantly lower than in fish retained in fresh water. There was a significant interaction between nutritional state and salinity that affected the tPRL188:tPRL177 ratio and plasma concentrations of Cl-, GH, glucose, aspartate, tyrosine, serine, alanine, glycine, arginine and hepatic PK, LDH, AlaAT, aspartate aminotransferase, glutamate dehydrogenase and HOAD activities. These results, taken together, indicate that food-deprived fish did not regulate their plasma Cl- levels, despite an enhancement of plasma hormonal and metabolic responses in sea water. Our study also suggests the possibility that plasma prolactin and essential amino acids may be playing an important role in the seawater acclimation process in tilapia.

1968 ◽  
Vol 49 (2) ◽  
pp. 325-339 ◽  
Author(s):  
G. L. FLETCHER ◽  
W. N. HOLMES

1. Intake of food, water and electrolyte by ducks maintained on fresh water and on hypertonic saline were measured over periods up to several months. 2. Transfer to saline approximately equivalent to 60% sea water was followed during the first 24 hr. by a sharp rise and fall in the plasma concentrations of sodium and chloride, which thereafter remained similar to the concentrations found in the freshwater-maintained birds. 3. Transfer to saline equivalent to 100% sea water resulted in a rise in these concentrations during the first 10 hr., which continued for a period up to 14 days, after which the birds either died or became unhealthy. 4. Upon transfer to saline drinking water (284 mM/l. Na+, 6.0 mM/l. K+) there was a gradual loss of body weight accompanied by a reduction in the food and water intake. Body weights tended to become stable after about 3 weeks, but some individuals continued to lose weight while others regained what they had lost. 5. When the concentration of sodium chloride in the drinking water exceeded 143 mM/l. the amount of sodium chloride ingested remained constant. Thus there was progressive decline in the volume of water drunk as the concentration increased. It would appear therefore that the saline-adapted duck possessed some mechanism whereby the daily intake of sodium chloride was regulated. 6. The cloacal output from saline-adapted ducks over a 24 hr. period showed that only 10% of the ingested sodium was excreted via this pathway as compared with over 70% of the ingested potassium. Most of the sodium appeared to be excreted via the nasal glands. 7. The possible interactions between the renal and extra-renal excretory pathways in the maintenance of homeostasis during adaptation to diets including hypertonic saline or seawater are discussed.


Author(s):  
Olga Mashukova ◽  
Olga Mashukova ◽  
Yuriy Tokarev ◽  
Yuriy Tokarev ◽  
Nadejda Kopytina ◽  
...  

We studied for the first time luminescence characteristics of the some micromycetes, isolated from the bottom sediments of the Black sea from the 27 m depth. Luminescence parameters were registered at laboratory complex “Svet” using mechanical and chemical stimulations. Fungi cultures of genera Acremonium, Aspergillus, Penicillium were isolated on ChDA medium which served as control. Culture of Penicillium commune gave no light emission with any kind of stimulation. Culture of Acremonium sp. has shown luminescence in the blue – green field of spectrum. Using chemical stimulation by fresh water we registered signals with luminescence energy (to 3.24 ± 0.11)•108 quantum•cm2 and duration up to 4.42 s, which 3 times exceeded analogous magnitudes in a group, stimulated by sea water (p < 0.05). Under chemical stimulation by ethyl alcohol fungi culture luminescence was not observed. Culture of Aspergillus fumigatus possessed the most expressed properties of luminescence. Stimulation by fresh water culture emission with energy of (3.35 ± 0.11)•108 quantum•cm2 and duration up to 4.96 s. Action of ethyl alcohol to culture also stimulated signals, but intensity of light emission was 3–4 times lower than under mechanical stimulation. For sure the given studies will permit not only to evaluate contribution of marine fungi into general bioluminescence of the sea, but as well to determine places of accumulation of opportunistic species in the sea.


2018 ◽  
Vol 3 (2) ◽  
pp. 38-47
Author(s):  
Muhammad Abdul Azis ◽  
Nuryake Fajaryati

This research aims to create a Reosquido desalination tool for evaporation methods using a microcontroller. This tool can control the temperature to speed up the evaporation process in producing fresh water. The method applied to Reosquido desalination uses Evaporation. The first process before evaporation is the detection of temperature in sea water that will be heated using an element heater. The second process of temperature measurement is to turn off and turn on the Arduino Uno controlled heater, when the temperature is less than 80 ° then the heater is on. The third process is evaporation during temperatures between 80 ° to 100 °, evaporation water sticks to the glass roof which is designed by pyramid. Evaporated water that flows into the reservoir is detected by its solubility TDS value. The fourth process is heater off when the temperature is more than 100 °. Based on the results of the testing, the desalination process using a microcontroller controlled heater can speed up the time up to 55% of the previous desalination process tool, namely manual desalination prsoes without using the heater element controlled by the temperature and controlled by a microcontroller which takes 9 hours. Produces fresh water as much as 30ml from 3000ml of sea water, so that it can be compared to 1: 100.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sonia Yun Liu ◽  
Shemil P. Macelline ◽  
Peter V. Chrystal ◽  
Peter H. Selle

AbstractThe prime purpose of this review is to explore the pathways whereby progress towards reduced-crude protein (CP) diets and sustainable chicken-meat production may be best achieved. Reduced-CP broiler diets have the potential to attenuate environmental pollution from nitrogen and ammonia emissions; moreover, they have the capacity to diminish the global chicken-meat industry’s dependence on soybean meal to tangible extents. The variable impacts of reduced-CP broiler diets on apparent amino acid digestibility coefficients are addressed. The more accurate identification of amino acid requirements for broiler chickens offered reduced-CP diets is essential as this would diminish amino acid imbalances and the deamination of surplus amino acids. Deamination of amino acids increases the synthesis and excretion of uric acid for which there is a requirement for glycine, this emphasises the value of so-called “non-essential” amino acids. Starch digestive dynamics and their possible impact of glucose on pancreatic secretions of insulin are discussed, although the functions of insulin in avian species require clarification. Maize is probably a superior feed grain to wheat as the basis of reduced-CP diets; if so, the identification of the underlying reasons for this difference should be instructive. Moderating increases in starch concentrations and condensing dietary starch:protein ratios in reduced-CP diets may prove to be advantageous as expanding ratios appear to be aligned to inferior broiler performance. Threonine is specifically examined because elevated free threonine plasma concentrations in birds offered reduced-CP diets may be indicative of compromised performance. If progress in these directions can be realised, then the prospects of reduced-CP diets contributing to sustainable chicken-meat production are promising.


1975 ◽  
Vol 97 (3) ◽  
pp. 266-275
Author(s):  
R. N. Bergman ◽  
M. El Refai

The survival of mammals is dependent upon a relatively constant, adequate supply of glucose to the central nervous system, despite large fluctuations in the amount of food available. When food is abundant, the liver stores ingested carbohydrate as glycogen, and during fasts, the stored glycogen is released at a precisely regulated rate to maintain the blood glucose level. The rates of storage and release of carbohydrate by the liver are determined by the plasma concentrations of several bloodborne signals; most important are the concentrations of glucose, and the hormones insulin and glucagon. To understand the complex control relationships of these three signals as they affect the liver, their individual dynamic influences have been determined experimentally, and they have been integrated by means of a computer simulation of the pathways of hepatic glycogen metabolism. The simulation studies have led to specific hypotheses about the biochemical effects of glucose and insulin on the liver. The simulation studies have also led to the conclusion that glucose exerts a rapid moment-to-moment influence of glucose on the rate of uptake of glucose by the liver. Insulin, however, by exerting a slower influence on the sensitivity of the liver to glucose, is very effective in “optimizing” the amount of glycogen which the liver stores food during food intake. Thus, integrated experimental and simulation studies can lead to a view of a physiological regulating system which does not emerge from either approach used alone.


1986 ◽  
Vol 66 (3) ◽  
pp. 643-651 ◽  
Author(s):  
J. A. FITZGERALD ◽  
G. A. EVERETT ◽  
J. APGAR

The effect of low dietary Zn intake upon several plasma endocrine and metabolic profiles was examined during late gestation in the ewe. Thirty adult, primiparous Finncross ewes were fed a low Zn diet with (+Zn, n = 14) or without (0Zn, n = 16) supplemental Zn in the drinking water starting day 1 of pregnancy. Although the mean prepartum progesterone and prolactin concentrations were lower (P < 0.05 and P < 0.01, respectively) in 0Zn than in +Zn ewes, the peak prolactin concentrations in 0Zn ewes at lambing were similar to +Zn ewes. Both basal and thyrotropin-releasing-hormone (TRH)-induced prolactin release were less (P < 0.01) in 0Zn ewes 2 d postpartum. Plasma concentrations of 13, 14-dihydro-15-keto prostaglandin F2α (PGFM) of ewes sampled within 45 min post-lambing were lower (P < 0.05) in 0Zn ewes. There was no difference in cortisol concentrations within 45 min after lambing between 0Zn and + Zn ewes. Plasma protein concentrations in 0Zn ewes were higher (P < 0.01) than those in +Zn ewes during pregnancy. In summary, these data show that low Zn intake in the pregnant ewe affected several endocrine and metabolic plasma parameters associated with normal pregnancy and parturition. Key words: Zinc, parturition, dystocia, feed intake, ovine


2014 ◽  
Vol 592-594 ◽  
pp. 2409-2415 ◽  
Author(s):  
S. Naga Sarada ◽  
Banoth Hima Bindu ◽  
Sri Rama R. Devi ◽  
Ravi Gugulothu

In recent years with the exacerbation of energy shortage, water crisis increases around the world. With the continuous increase in the level of greenhouse gas emissions, the use of various sources of renewable energy is increasingly becoming important for sustainable development. Due to the rising oil price and environmental regulations, the demand of utilizing alternative power sources increased dramatically. Alternative energy and its applications have been heavily studied for the last decade. Energy and water are essential for mankind that influences the socioeconomic development of any nation. Pure water resources become more and more scarce every day as rivers, lakes wells and even seawater pollution rapidly increases. Solar energy is one promising solution to secure power and potable water to future generation. The process of distillation can be used to obtain fresh water from salty, brackish or contaminated water. Water is available in different forms such as sea water, underground water, surface water and atmospheric water. Clean water is essential for good health. The search for sustainable energy resources has emerged as one of the most significant and universal concerns in the 21st century. Solar energy conversion offers a cost effective alternative to our traditional usages. Solar energy is a promising candidate in many applications. Among the alternative energy sources used for electricity production, wind and solar energy systems have become more attractive in recent years. For areas where electricity was not available, stand alone wind and solar systems have been increasingly used. The shortage of drinking water in many countries throughout the world is a serious problem. Humankind has depended for ages on river, sea water and underground water reservoirs for its fresh water needs. But these sources do not always prove to be useful due to the presence of excessive salinity in the water. To resolve this crisis, different methods of solar desalination have been used in many countries. Distillation is a well known thermal process for water purification, most importantly, water desalination. Most of the conventional water distillation processes are highly energy consuming and require fossil fuels as well as electric power for their operation. Single basin solar still is a popular solar device used for converting available brackish or waste water into potable water. Because of its lower productivity, it is not popularly used. Numbers of works are under taken to improve the productivity and efficiency of the solar still. There are large numbers of PCMs that melt and solidify at wide range of temperatures, making them attractive in a number of applications. PCMs have been widely used in latent heat thermal storage systems for heat pumps, solar engineering and spacecraft thermal control applications. The use of PCMs for heating and cooling applications for buildings has been investigated within the past decade. The experimental results computed in the field of water distillation process using solar energy in the presence of energy storage materials sodium sulphate and sodium acetate are discussed in this paper. Keywords: solar energy, saline water, distillation, phase change material.


1981 ◽  
Vol 90 (2) ◽  
pp. 179-191 ◽  
Author(s):  
S. HENDRICKS ◽  
C. A. BLAKE

The effects of varying amounts of copulatory stimulation on patterns of plasma concentrations of prolactin and progesterone were evaluated in 3- and 12-month-old female rats. The 12-month-old group included rats which still exhibited oestrous cycles and rats in persistent vaginal oestrus (PVO). The extent of copulatory stimulation was defined by the number of intromissions received during mating: ≤5,15 or > 50. Blood samples were drawn over the 8 days after mating through a cannula inserted into the right external jugular vein. Plasma from the samples was assayed for prolactin and progesterone. In aged but still cyclic rats, pregnancy rates were positively correlated with the number of intromissions received during mating. Only one rat in PVO became pregnant. All animals which became pregnant and rats in PVO which, after mating, exhibited a disruption of the pattern of PVO, showed the nocturnal surge of plasma prolactin characteristic of pregnant and pseudopregnant rats. While these surges persisted until day 8 after mating in pregnant animals, they were absent by this time in the rats in PVO. Prolactin surges were present in some but not all of the aged rats which did not become pregnant. Progesterone concentrations were raised in all pregnant animals except the one pregnant rat in PVO and, while not related to the number of intromissions, concentrations were higher 8 days after mating in young compared with those in aged pregnant rats. Plasma progesterone was low in rats in PVO regardless of disruption of the pattern of PVO. We have concluded that the failure of limited copulatory stimulation to induce pregnancy in older rats results, at least in part, from its failure to initiate nocturnal prolactin surges. Nevertheless, our data suggest that matings which are not experimentally limited should provide ample stimulation to establish such surges. Although reduced plasma concentrations of prolactin and progesterone at pro-oestrus and reduced plasma progesterone through part of gestation may contribute to decreasing fertility in aged rats, other unidentified factors appear to be involved in mediating the capacity of extensive copulatory stimulation to induce pregnancy in these animals.


Author(s):  
OO Sinitsyna ◽  
VV Turbinsky ◽  
TM Ryashentseva ◽  
EP Lavrik

Background. Uneven distribution of fresh water sources on the land surface encourages a search for effective techniques of potable water preparation by desalination of seawater. Hygienic issues of such desalination methods as distillation, reverse osmosis, electrodialysis, and ion exchange have been investigated by now and appropriate limitations, requirements, and additional measures to ensure safety of desalinated drinking water have been established. Objective. To summarize and systematize the results of studying characteristics of various methods of seawater desalination for its further use for drinking and household purposes. Materials and methods. We conducted a systematic review of studies published in Russian and in English, found in the PubMed and Web of Science databases, and selected 40 literary sources containing an empirical assessment of effectiveness of seawater desalination and preparation of drinking water. We also scrutinized regulatory documents and guidelines of domestic sanitary legislation. The research results were systematized by the main desalination methods. Results and discussion. We established that the use of seawater for the preparation of fresh water for drinking and household purposes is becoming increasingly widespread around the world. Drinking water obtained from seawater, in all cases, requires additional treatment and measures to optimize its mineral composition and protect against microorganisms. Conclusion. The main challenges of ensuring sanitary and epidemiological wellbeing of the population when using desalinated seawater for drinking and household purposes include selection of a source, arrangement of sites of water intake properly protected from natural and man-made pollution, substantiation of techniques and modes of preliminary preparation of source seawater adequate to its composition, basic desalination, ensuring safety of products of destruction and migration of toxic substances from reagents and materials of desalination plants, additional conditioning with the necessary elements and disinfection of the prepared water, as well as environmental protection from desalination waste.


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