Decrease In Environmental Temperature Research Articles

Modeling and Optimization Control for an Engine Electrified Cooling System to Minimize Fuel Consumption

The engine friction and actuator power are the main factors of the cooling system affecting the fuel economy of a spark ignition (SI) engine. An electrified cooling system containing an electric fan, pump, and thermostat provides an opportunity to reduce fuel consumption. The coolant temperature is always kept at a high fixed value within the safe temperature range to avoid friction losses caused by overcooling; however, the actuator power is not typically considered. Recent publications have attempted to minimize the actuator power and the coolant temperature is maintained in a range. Nevertheless, neither method quantitatively considers both factors. In this paper, the integrated consideration of engine friction and actuator power is presented to minimize engine fuel consumption. The accuracy of a control-oriented model of a cooling system is improved first in an attempt to exert the full potential of the model. Then, the proposed strategy for minimum fuel consumption is constructed as an optimization problem and the improvement of fuel economy obtained by the proposed strategy is evaluated using a causal suboptimal controller and dynamic programming (DP)-based global optimal controller. Compared with a causal coolant temperature tracking controller, the causal suboptimal controller and the global optimal controller based on the proposed strategy both achieve significant improvements. Compared with a global optimal controller for minimum actuator power, the global optimal controller based on the proposed strategy achieves a certain improvement and this effect can increase as the environmental temperature decreases. Finally, a real-time implementation of the proposed strategy on a hardware platform using model predictive control (MPC) with a limited horizon is presented, which shows the feasibility of the proposed strategy.

Critical temperature in feedback-controlled electromigration of gold nanostructures

This paper presents several experiments demonstrating the need for a more nuanced picture of electromigration (EM) than that of a fixed critical junction temperature at which EM onset occurs. Our data suggests that even for a fixed cross-sectional geometry the critical junction temperature for EM, Tc, varies with environmental temperature, thermal resistance of adjacent regions, and even the direction of the current flow in asymmetric structures. We have performed feedback-controlled EM on nanowires at environmental temperatures between 75 and 260 K and fit the EM onset points with a constant junction power model. We find that average fit critical power is monotonically increasing with decreasing temperature, but is decidedly nonlinear at lower temperatures. We extract and compare the corresponding Tc values using several different thermal models which utilize measured values of nanowire thermal conductivity for our devices: these models all agree on a moderately increasing Tc with decreasing environmental temperature. This is tentatively explained by enhanced current-driven annealing on the voltage ramp prior to EM onset which decreases structural scattering, thereby increasing the critical temperature at which wind-force-driven hopping events will achieve a critical atomic flux. We also obtain fit critical power for a series of bowtie structures of identical constriction but varying adjacent thermal resistance (Rth), and estimate that Tc in the constriction varies with Rth for higher resistance structures. Critical power measurements on a second series of asymmetric bowties further suggests that Tc also depends on the alignment of the electron flow with the temperature gradient at the constriction.

Response of antioxidant enzymes and digestive enzymes to temperature stress in Lates calcarifer larvae

Acute temperature stress in 15-day post-hatch (DPH) Lates calcarifer larvae was studied using the semi-static bioassay method to understand the physical response of fish larvae to low temperature. In this study, 20oC, 22oC, 24oC, and 26oC were tested and 28oC was the control. Antioxidant enzyme activity including superoxide dismutase (SOD), peroxidase (POD), catalase, acid phosphatase (ACP), glutathione peroxidase (GSH-Px) and digestive enzymes including lipase, amylase, trypsin, pepsin were used as the physical indicators. SOD activities were elevated to scavenge excess reactive oxygen species (ROS) after exposure to lower temperatures, and their activities increased dramatically in relation to the increasing residue time. POD enzyme activity maintained a low level in the early stage of cold exposure and increased to a high level in relation to exposure time. Catalase, GSH-Px, and ACP activities were elevated in fish after exposure to lower temperatures compared to those in fish maintained at 28oC. Lipase activity decreased after exposure to lower temperatures and modestly elevated over time. The highest amylase activity was observed in the control group. However, trypsin and pepsin activity was elevated with the decrease of environmental temperature. Our results indicate that lower temperature significantly affects activity of antioxidant enzymes and digestive enzymes in barramundi larvae. Barramundi larvae exhibited a certain tolerance of low temperature for a short period. Results from the present study will improve our understanding of the physical response of warm water fish to low temperatures and can therefore guide hatchery practices for Lates calcarifer.

Improving Motivation of Treadmill Exercise for Reducing the Body Weight by Decreasing the Environmental Temperature in a Hamster Model (A Hypothesis)

Aims. The current issue is how to increase the motivation of treadmill exercise in reducing the body weight for those who are less motivated. Method. A hamster model was put into a 0.5 meter diameter treadmill apparatus and motivated with the decreasing environmental temperature by 5 degrees (30-25 C). Result and conclusion. A temperature drop of 4 degrees Celsius in 73 minutes from 30 degrees Celsius (at 08:57 am) to 26 degrees Celsius (at 10:10 am) has motivated the subject to run at a speed of 73 minutes per 1699 meters or 23.28 meters per minute. A temperature drop of 1 degree Celsius in 102 minutes from 26 degrees Celsius (at 10:10 am) to 25 degrees Celsius (at 11:52 am) has motivated the subject to run at 102 minutes per 3320 meters or 32.55 meters per minute. This means that lower environmental temperatures better motivate the subject to activity than higher temperatures.

Mass mortality of eastern box turtles with upper respiratory disease following atypical cold weather.

Emerging infectious diseases cause population declines in many ectotherms, with outbreaks frequently punctuated by periods of mass mortality. It remains unclear, however, whether thermoregulation by ectotherms and variation in environmental temperature is associated with mortality risk and disease progression, especially in wild populations. Here, we examined environmental and body temperatures of free-ranging eastern box turtles Terrapene carolina during a mass die-off coincident with upper respiratory disease. We recorded deaths of 17 turtles that showed clinical signs of upper respiratory disease among 76 adult turtles encountered in Berea, Kentucky (USA), in 2014. Of the 17 mortalities, 11 occurred approximately 14 d after mean environmental temperature dropped 2.5 SD below the 3 mo mean. Partial genomic sequencing of the major capsid protein from 1 sick turtle identified a ranavirus isolate similar to frog virus 3. Turtles that lacked clinical signs of disease had significantly higher body temperatures (23°C) than sick turtles (21°C) during the mass mortality, but sick turtles that survived and recovered eventually warmed (measured by temperature loggers). Finally, there was a significant negative effect of daily environmental temperature deviation from the 3 mo mean on survival, suggesting that rapid decreases in environmental temperature were correlated with mortality. Our results point to a potential role for environmental temperature variation and body temperature in disease progression and mortality risk of eastern box turtles affected by upper respiratory disease. Given our findings, it is possible that colder or more variable environmental temperatures and an inability to effectively thermoregulate are associated with poorer disease outcomes in eastern box turtles.

Metabolic Response of Visceral White Adipose Tissue of Obese Mice Exposed for 5 Days to Human Room Temperature Compared to Mouse Thermoneutrality.

Housing of laboratory mice at room temperature (22°C) might be considered a constant cold stress, which induces a thermogenic program in brown adipose tissue (BAT). However, the early adaptive response of white adipose tissue (WAT), the fat storage organ of the body, to a change from thermoneutrality to room temperature is not known. This was investigated here for various WAT depots, focusing on epididymal WAT (eWAT), widely used as reference depot. Male adult diet-induced obese (DIO) C57BL/6JOlaHsd mice housed at thermoneutrality (29°C), were for 5 days either switched to room temperature (22°C) or remained at thermoneutrality. Energy metabolism was continuously measured using indirect calorimetry. At the end of the study, serum metabolomics and WAT transcriptomics were performed. We confirmed activation of the thermogenic program in 22°C housed mice. Body weight and total fat mass were reduced. Whole body energy expenditure (EE) was increased, with a higher fatty acid to carbohydrate oxidation ratio and increased serum acylcarnitine levels, while energy intake was not significantly different between the two groups. Transcriptome analysis of eWAT identified tissue remodeling and inflammation as the most affected processes. Expression of pro-inflammatory M1 macrophage-related genes, and M1 over M2 macrophage ratio were decreased, which might be linked to an increased insulin sensitivity. Markers of thermogenesis were not altered in eWAT. Decreased expression of tryptophan hydroxylase 2 (Tph2) and cholecystokinin (Cck) might represent altered neuroendocrine signaling. eWAT itself does not show increased fatty acid oxidation. The three measured WATs, epididymal, mesenteric, and retroperitoneal, showed mainly similar responses; reduced inflammation (s100a8), decreased carbohydrate oxidation, and no or small differences in fatty acid oxidation. However, Ucp1 was only expressed and increased in rWAT in 22°C housed mice. Cck expression was decreased in the three WATs, significantly in eWAT and rWAT, in contrast to Tph2, which was decreased in eWAT while not expressed in mWAT and rWAT. Our data show that tissue remodeling, inflammation and neuroendocrine signaling are early responses in WAT to a moderate decrease in environmental temperature.

Bulk soybean grain mass temperature in warehouses with isolated vents and vent-exhaust combined systems

ABSTRACT: This study aimed to compare the temperatures in the mass of bulk soybeans ( Glycine max ) in warehouses with isolated vents and vent-combined exhaustion. A completely randomized design was used, with two treatments and ten repetitions. Treatments consisted of warehouse with curved vents and warehouse with curved + static exhaust vents. Each repetition contained the average of all readings in three days in all cables of the warehouse part under study, totaling 10 repetitions per month. The variable analyzed was the temperature in the grain mass in the lower, middle and upper parts of the warehouse from January to May 2012. The environment temperature and humidity were also registered. Static hoods, along with curved vents on the roof of the warehouse showed a tendency to reduce the temperature of the soybean mass with decrease in environmental temperature and increase in relative environmental humidity.

Influence of environmental temperature on exergetic parameters of a combined cycle power plant

Ambient conditions have significant effect on combined cycle power plants (CCPPs). Parameters-like efficiencies, fuel consumption, power production and even operation cost differ according to the ambient conditions that depend on the climate that cannot be changed. Therefore, deciding the location of the plant wisely would bring more efficient and profitable. In this paper, exergy analysis based on the second law of thermodynamics, considering environmental temperature variations, are performed for a cogeneration power plant. Mathematical model of analyse is introduced. Magnitudes of the variation of irreversibility, reversible power, power production and specific fuel consumption (SFC) are evaluated for the combined cycle. The results indicated that, decrease of environmental temperature augments the energy performance of the combined cycle form about 53% to 56% and improves the exergetic performance from about 51% to 56%. However, the augmentation via temperature decrease is not continuous. It is shown that the environmental temperature decrease causes a reduction about 5% in the SFC.

INFLUENCE OF ENVIRONMENTAL TEMPERATURE ON EXERGETIC PARAMETERS OF A COMBINED CYCLE POWER PLANT

Ambient conditions have significant effect on combined cycle power plants (CCPPs). Parameters-like efficiencies, fuel consumption, power production and even operation cost differ according to the ambient conditions that depend on the climate that cannot be changed. Therefore, deciding the location of the plant wisely would bring more efficient and profitable. In this paper, exergy analysis based on the second law of thermodynamics, considering environmental temperature variations, are performed for a cogeneration power plant. Mathematical model of analyse is introduced. Magnitudes of the variation of irreversibility, reversible power, power production and specific fuel consumption (SFC) are evaluated for the combined cycle. The results indicated that, decrease of environmental temperature augments the energy performance of the combined cycle form about 53% to 56% and improves the exergetic performance from about 51% to 56%. However, the augmentation via temperature decrease is not continuous. It is shown that the environmental temperature decrease causes a reduction about 5% in the SFC.

Updraft Buoyancy within and Moistening by Cumulonimbi prior to MJO Convective Onset in a Regional Model

Abstract Processes responsible for widespread development of moderately deep cumulonimbi during a transition period before onset of two large-scale convective events associated with the Madden–Julian oscillation in late 2011 are investigated. A regional model (WRF) is capable of rapidly producing an approximately 3-day-long transition period prior to MJO convective onset similar to observed transition periods, during which moderately deep cumulonimbi were prevalent. During transition periods, evaporation in precipitating elements and horizontal advection of moisture away from the clouds in the nearby clear-air environment contributed to humidification below 400 hPa. Nonprecipitating clouds were present in the model mostly between 900 and 950 hPa and had no major impact on tropospheric moistening. Whether nonprecipitating cumuli grew into moderately deep cumulonimbi largely depended on the buoyancy of updrafts that extended into the 700–850-hPa layer. As mean environmental temperatures decreased, the mean cumulus updraft buoyancy in this layer became less negative. The start of two simulated transition periods were marked by rapid decreases in environmental temperature caused by reduction in environmental subsidence and/or increased cooling by advection or radiation. Small, widespread changes in the difference between 700- and 850-hPa environmental and updraft temperatures—on the order of 0.1 K and less than 0.4 K—had important ramifications for whether shallow clouds grew vertically into moderately deep clouds that moistened the troposphere and made it conducive to MJO convective onset.

The effect of temperature on the evolution of per offspring investment in a globally distributed family of marine invertebrates (Crustacea: Decapoda: Lithodidae).

Within the marine environment, per offspring investment (POI) is associated with modes in larval development; an increase in POI has often been described with a decrease in temperature, as evidenced along latitudinal clines. However, the environmental drivers of POI remain largely hypothetical and have not yet been tested within an evolutionary context. Here, we test the hypothesis that developmental temperature is linked to POI within a globally distributed and diverse family of benthic crustaceans, the Lithodidae, also known as stone or king crab. To do this, we examine variations in egg diameter—a proven corollary of POI—within the Lithodidae. Based on a rare case of well-construed phylogeny, we test the relationship between egg diameter and two aspects of the maternal physical environment: water depth and temperature. We observe a significant relationship between decreasing environmental temperature and an increase in POI within genera of lithodid crabs, and independent of depth. There is a clear correlation of high levels in POI with a decrease in temperature in lithodid crab genera currently inhabiting the deep sea, all of which follow a food-independent (lecithotrophic) mode of larval development. In contrast, lithodid genera thriving in the warmer waters of shallow (continental shelf) seas follow a feeding (planktotrophic) mode in larval development. We conclude that temperature is an important factor governing POI, and discuss its importance in the evolution of larval lecithotrophy in marine invertebrates.Electronic supplementary materialThe online version of this article (doi:10.1007/s00227-015-2776-8) contains supplementary material, which is available to authorized users.

Effect of cold stress on immunity in rats.

An increase in the morbidity of upper respiratory tract infections and the attack and exacerbation of autoimmune diseases has been observed to occur in the few days following sudden environmental temperature decreases, but the mechanisms for these phenomena are not well understood. To determine the effect of a sudden ambient temperature drop on the levels of stress hormones and T-lymphocyte cytokines in the plasma, the Toll-like receptor 4 (TLR4) expression of immunocompetent cells in rat spleens and the levels of regulatory T (Treg) cells in the peripheral blood, Sprague Dawley rats were divided into three groups of different ambient temperatures (20, 4 and −12°C). In each group, there were four observation time-points (1, 12, 24 and 48 h). Each ambient temperature group was subdivided into non-stimulation, lipopolysaccharide-stimulation and concanavalin A-stimulation groups. The levels of adrenocorticotropin (ACTH), epinephrine (EPI), angiotensin-II (ANG-II), interleukin-2 (IL-2), interferon-γ (IFN-γ), IL-4 and IL-10 in the plasma were determined using ELISA. The cellular expression levels of TLR4 and the presence of cluster of differentiation (CD)4+CD25+ and CD4+CD25+Forkhead box P3 (Foxp3)+ cells were determined using flow cytometry. The experiments demonstrated that the ACTH, EPI, ANG-II and IL-10 levels in the plasma were significantly increased at 4 and −12°C compared with those at 20°C, while the plasma levels of IFN-γ, IL-2 and IL-4, the TLR4 expression rates of immunocompetent cells in the rat spleen and the percentage of CD4+CD25+Foxp3+ Treg cells among the CD4+CD25+ Treg cells in the peripheral blood were decreased at 4 and −12°C compared with those at 20°C. These data indicate that cold stress affects the stress hormones and the innate and adaptive immunity functions in rats.

Adherence to Bergmann’s rule by lizards may depend on thermoregulatory mode: support from a nocturnal gecko

Bergmann's rule predicts an increase in body size with decreasing environmental temperature; however, the converse pattern has been found in the majority of lizards studied to date. For these ectotherms, small body size may provide thermal benefits (rapid heat uptake when basking), which would be highly advantageous in cold environments. Yet such an advantage may not exist in nocturnal lizards (which do not avidly bask), in which Bergmann's rule has not been closely studied. We have examined whether the body size of a primarily nocturnal gecko, Woodworthia "Otago/Southland" changed with elevation and operative temperature (determined using physical copper models). In a laboratory study, we investigated whether thermoregulatory mode (heliothermy or thigmothermy) alters the effect of body size on heating and cooling rates. This gecko followed Bergmann's rule, thereby showing the opposite of the dominant pattern in diurnal lizards. Size at maturity, maximum size of adults and size at birth were larger at higher elevations and at lower operative temperatures. Using physical models, we found that large body size can confer thermal benefits for nocturnal lizards that remain within diurnal retreats. Bergmann's rule should not be dismissed for all lizards. Our results clearly support Bergmann's rule for at least one thigmothermic species, for which large body size may provide thermal benefits. Future studies on Bergmann's rule in lizards should consider thermoregulatory mode. We advocate that this ecogeographic rule be examined in relation to operative temperature measured at field sites. Finally, we predict that climate warming may weaken the relationship between body size and elevation in this gecko.

Temperature sensing by membranes.

Bacteria remodel the fluidity of their membrane bilayer precisely via the incorporation of proportionally more unsaturated fatty acids (or fatty acids with analogous properties) as growth temperature decreases. This process, termed homoviscous adaptation, is suited to disrupt the order of the lipid bilayer and optimizes the performance of a large array of cellular physiological processes at the new temperature. As such, microbes have developed molecular strategies to sense changes in membrane fluidity, provoked by a decrease in environmental temperature, and initiate cellular responses that upregulate the biosynthesis of unsaturated fatty acids. This review focuses on the architecture of a membrane fluidity communication network; how thermal information is integrated, processed, and transduced to control gene expression; how membrane-mediated structural changes of a cold sensor are accomplished; and the intriguing possibility that temperature-induced deformations of the cell membrane act as allosteric regulators of protein function.

Effects of low temperature stress on photosynthesis in potato leaves

The effects of low temperature stress on photosynthesis in leaves of seven regular potato cultivars and two Hunan endemic potato species have been studied.The results showed that the photosynthetic rate(Pn) was significantly reduced with decreasing environmental temperature for all the species,however,every species exhibited different declining rate.For example,the maximum net photosynthetic rates(Pnmax) between 10 ℃ and 20 ℃ treatments of Jinshanshu,Zhongzaihuangpi,Zhongshu3,Zhongshu5,Xiangshu1,Favorita were reduced by 51.0%,33.4%,44.5%,42.6%,14% and 17% respectively,where the Pnmax variations in these two groups of treatments reach significant level(P0.05).On the other hand,the decreasing rates of Pnmax of Kexin series(1,3,4) were within 4.5%,and insignificant variations were found between 10 ℃ and 20 ℃ treatments(P﹥0.05).The apparent quantum yield(AQY),the light saturation points(LSP),the light compensation points(LCP),stomatal conductance(Gs) and transpiration rate(Tr) were significantly decreased under 10 ℃ temperature stress(P0.05).The Pnmax values of Favorita,Zhongshu3 and Xiangshu1 under 5 ℃ temperature stress were 9.85,7.54,5.13 μmol/(m2.s) respectively,while Pn values of the other materials were essentially zero.Increased intercellular CO2concentration(Ci) were observed after an obvious declination when the environmental temperature decreased from 10 ℃ to 5 ℃.The above results indicate that the photosynthetic rateunder 5 ℃ low temperature stress can be served as a promising index in for evaluation of seedling cold tolerance.

Australian Snakes Do Not Follow Bergmann’s Rule

Bergmann’s Rule (i.e., the tendency of body size to increase with decreasing environmental temperature) was originally explained by a mechanism that is unique to endotherms. Nevertheless, geographic variation of body size of ectotherms, including snakes, is increasingly studied, and some claim that the rule should apply to ectotherms, or to thermoregulating ectotherms. Such studies usually focus on assemblages or on species in a region, but mostly ignore species’ ecological and biological traits when seeking biogeographic patterns. We examined the relationship between environmental temperatures and body size of 146 Australian snake species. We examined this relationship while considering the effects of ecological traits (activity time and habitat use), climatic variables which are thought to influence snake body size, and shared ancestry. Our finding suggest that Bergmann’s Rule is not a valid generalization across species of Australian snakes. Furthermore, ecological traits greatly influence the relationship between snake body size and environmental temperature. Body size of fossorial species decreases with environmental temperature, whereas body size of nocturnal, surface active species increases. Body size of diurnal, surface active species is not related to environmental temperature. Our results indicate that lumping all species in a clade together is misleading, and that ecological traits profoundly affect the geographic variation of snake body size. Though environmental temperature generally does not exert a strong selective force on snake body size, this relationship differs for taxa exhibiting different ecological traits.

Influence of freezing on physicochemical forms of natural and technogenic radionuclides in Chernozem soil

AbstractSharp variations of different climatic parameters influence the transport, transfer, and deposition of contaminants in nature. Investigations of the impact of environmental temperature on the fractionation of radionuclides in soil are necessary for adequate assessment of their distribution and bioavailability in case of a nuclear accident. The impact of a sharp decrease of environmental temperature shortly after radioactive contamination on the physicochemical fractionation of natural and technogenic radionuclides in Chernozem soil and its influence on their potential migration ability and bioavailability in case of subsequent warming were evaluated. The soil was contaminated in a laboratory with 241Am, 60Co, 137Cs, 228Ra, 234Th, and U and two temperature regimes were used for storage. Changes of the radionuclides association with various soil phases in the first weeks after contamination were studied. Physicochemical forms of 241Am, 60Co, 228Ra, 234Th, and U were determined using two sequential extraction procedures. The ion-exchangeable forms of 137Cs were evaluated by single extraction with 1 M NH4NO3. The data showed that the freezing, following the radioisotope contamination of the soil, causes an increase of the amount of potentially mobile forms of radiocobalt, radiocesium, radium, and thorium and has an insignificant impact on the fractionation of americium and uranium.

An Intercontinental Analysis of Climate-Driven Body Size Clines in Reptiles: No Support for Patterns, No Signals of Processes

Climatic gradients impose clinal selection on animal ecological and physiological performance, often promoting geographic body size clines. Bergmann’s rule predicts that body size increases with decreasing environmental temperatures given the need to retain body-heat through adjustments of body-mass-to-surface-area ratio. This prediction generally holds for endotherms, but remains controversial for ectotherms. An alternative interpretation, the ‘resource rule’, suggests that food abundance, primary productivity and precipitation (which, unlike temperature, do not necessarily correlate with geography), drive body size clines. We investigate geographic variation in body size within 65 species of lizards and snakes (squamates) based on an intercontinental dataset (6,500+ specimens belonging to 56 Israeli species, and multiple populations of nine Liolaemus species from Argentina and Chile). Bergmann’s rule is only rarely supported by our data (in four species, 6 %), whereas six species (9 %) follow its converse (hence, it is unsupported in 94 % of cases). Similarly, size increases with resource abundance in only 12 species (18 %). Therefore, although neither of the rules is supported, factors suggested by the resource rule are better predictors of body size than temperature. Surprisingly, we show that some measures of the extent of a species’ climatic envelope do not affect the likelihood of it showing a size-climate relationship. We conclude that negative size-temperature associations are an exception rather than a generality among squamates.

Thermal stability of retained austenite in Cr–Ni weld metals at low temperatures

As environmental temperature decreases, the amount of retained austenite is more likely to greatly reduce due to the thermal austenite–martensite transformation caused by the decreased thermal stability of retained austenite, probably making its amount lower than the required content. In the present study, the thermal stability of retained austenite in Cr–Ni weld metals was investigated to see whether sufficient retained austenite can be maintained at low temperatures. The specific experimental procedure is as follows: briefly, the samples were cooled in turn from room temperature to 0, −20, −40, −60, −80, −100 and −196°C; the amount of retained austenite at the above temperatures was measured using X-ray diffraction. Through investigating the dependence of the content of retained austenite on temperature, it was revealed that when the content of retained austenite is <20%, retained austenite can be maintained until −196°C.

Phosphoethanolamine in brain of the euritherm lake fish Perccottus glehni (Eleotridae, Perciformes, Dyb. 1877) as a phenomenon depending on temperature factor

Effects of a seasonal decrease of environmental temperature and cold shock on pools of free amino acids (FAA) was studied in brain of the eurythermal pond fish P. glehni. It is for the first time that in the brain of eurythermal animals the nonprotein amino acid phosphoethanolamine (PEA) was revealed. It was found there in a large amount only under conditions of near-zero temperatures. It was shown that in the P. glehni brain, as a result of the seasonal decrease of temperature, the PEA pool rose intensively from 0.3 % at the summer period to 33.6 % in winter. On the contrary, the brain taurine pool that in the summer was the highest as compared with other FAA (29.0% of the total pool) decreased to 8.9% by the beginning of the winter period. The same negative correlation of the taurine and PEA amounts was found under action of acute cold shock (+1 degree C): throughout 4 days the taurine level also decreased from 32.2 to 14.5% of the total pool, whereas the PEA level rose swiftly (from 2.1 to 15.3%). Both kinds of the low temperature action led, apart from PEA, to an intensive increase of the serine pool and accumulation of phosphoserine. Role of PEA in biochemical evolution and adaptation of brain to low temperatures is discussed. It is suggested that accumulation of PEA, phosphoserine, and serine is associated with a change of the status of phospholipids of membrane at low temperatures.