Rise In Environmental Temperature Research Articles

Temperature-dependent 2-dimensional porous FG plates free vibration analysis using finite element approach

This work aims to address the free vibration analysis of two-dimensional porous 2-D FG plates with temperature-dependent properties that are subjected to thermomechanical loading. The revised element finite element model has seven degrees of freedom and has been developed based on higher-order shear deformation theory. The material constitutions in two directions along the length and thickness are varied according to the revised index law of power. The current proposed numerical approach has been evaluated with existing literature results to find good amiability between them. With all side-supported boundary conditions, the effect of thermomechanical loads and porosity allocation on free vibration analysis of temperature-dependent material FG plates is explored. Also, the consequence of consistent and erratic porous portions of free vibration characteristics on 2D FG plates is studied. 2D properties are disbanded, which affects the natural frequency of the FG plate. In this case, the rise in environmental temperature and index values reduces the frequencies of the porous FG plates. Changeable porous distribution on FG plates obtained exemplary frequency characteristics compared with the consistent porous distribution.

Insights into the Mechanisms of Heat Priming and Thermotolerance in Tobacco Pollen.

Global warming leads to a progressive rise in environmental temperature. Plants, as sessile organisms, are threatened by these changes; the male gametophyte is extremely sensitive to high temperature and its ability to preserve its physiological status under heat stress is known as acquired thermotolerance. This latter can be achieved by exposing plant to a sub-lethal temperature (priming) or to a progressive increase in temperature. The present research aims to investigate the effects of heat priming on the functioning of tobacco pollen grains. In addition to evaluating basic physiological parameters (e.g., pollen viability, germination and pollen tube length), several aspects related to a correct pollen functioning were considered. Calcium (Ca2+) level, reactive oxygen species (ROS) and related antioxidant systems were investigated, also to the organization of actin filaments and cytoskeletal protein such as tubulin (including tyrosinated and acetylated isoforms) and actin. We also focused on sucrose synthase (Sus), a key metabolic enzyme and on the content of main soluble sugars, including UDP-glucose. Results here obtained showed that a pre-exposure to sub-lethal temperatures can positively enhance pollen performance by altering its metabolism. This can have a considerable impact, especially from the point of view of breeding strategies aimed at improving crop species.

Heat stress on microbiota composition, barrier integrity, and nutrient transport in gut, production performance, and its amelioration in farm animals.

Livestock species experience several stresses, particularly weaning, transportation, overproduction, crowding, temperature, and diseases in their life. Heat stress (HS) is one of the most stressors, which is encountered in livestock production systems throughout the world, especially in the tropical regions and is likely to be intensified due to global rise in environmental temperature. The gut has emerged as one of the major target organs affected by HS. The alpha- and beta-diversity of gut microbiota composition are altered due to heat exposure to animals with greater colonization of pathogenic microbiota groups. HS also induces several changes in the gut including damages of microstructures of the mucosal epithelia, increased oxidative insults, reduced immunity, and increased permeability of the gut to toxins and pathogens. Vulnerability of the intestinal barrier integrity leads to invasion of pathogenic microbes and translocation of antigens to the blood circulations, which ultimately may cause systematic inflammations and immune responses. Moreover, digestion of nutrients in the guts may be impaired due to reduced enzymatic activity in the digesta, reduced surface areas for absorption and injury to the mucosal structure and altered expressions of the nutrient transport proteins and genes. The systematic hormonal changes due to HS along with alterations in immune and inflammatory responses often cause reduced feed intake and production performance in livestock and poultry. The altered microbiome likely orchestrates to the hosts for various relevant biological phenomena occurring in the body, but the exact mechanisms how functional communications occur between the microbiota and HS responses are yet to be elucidated. This review aims to discuss the effects of HS on microbiota composition, mucosal structure, oxidant-antioxidant balance mechanism, immunity, and barrier integrity in the gut, and production performance of farm animals along with the dietary ameliorations of HS. Also, this review attempts to explain the mechanisms how these biological responses are affected by HS.

The utilization of paving blocks as environmental heat reduction materials

Global warming increases the overall temperature of the earth's surface and leads to climate change. Therefore, it plays an important impact on human life, especially in the architecture field. This study aims to identify the rise in environmental temperature due to parked cars with running engines and the use of paving blocks as heat-reducing material. This is a quantitative research with data collected and measured directly in the field, before being processed and explored of natural and waste materials in the laboratory. The results showed: (1) an increase in environmental temperature of ± 34.80C - 39.40C, or 50C to 100C due to parked cars with running engines, (2) the use of rectangular and hexagon paving blocks as heat-reducing material. Therefore, the increase in environmental temperature is reduced by the use of paving blocks, which comprises of basic (cement, sand, and water), natural (grass and fibers), and recycled materials (sawdust and styrofoam).

A preliminary study on urban malaria during the minor transmission season: The case of Adama City, Oromia, Ethiopia

The distribution of malaria shows considerable spatial heterogeneity globally, regionally and locally. For the design of effective malaria control and elimination, and for its implementation in Ethiopia, urban malaria should be given due attention. Therefore, the present study was aimed to examine the status of urban malaria during the minor transmission season in Adama city. A total of 2590 febrile patients were screened using the gold standard microscopy-based blood test for malaria diagnosis from seven purposively selected health facilities found in Adama City from April to July 2018. Socio-demographic data were collected from malaria positive patients to correlate predisposing factors; like previous malaria history, settlement, travel history, age, and other associated risk factors with malaria incidence. Climatological data, such as temperature and relative humidity, recorded during the study period were also collected from the data base of Adama meteorology center for analysis. The microscopic data indicated that from a total of 2590 febrile patients screened for malaria during the study period 3.7% (97/2590) of them were confirmed malaria positive. Adolescents and adults (≥15 years of age) were found to be most affected by Plasmodium vivax (66%) and Plasmodium falciparum (20.5%), and mixed (6%). Analysis of the climatological data revealed a rise in environmental temperature and relative humidity during the study that coincides with the increase of malaria cases, since it creates favorable mosquito breeding for malaria transmission in the city. P. vivax was found as a predominant species in causing malaria burden indicating its public health problem in Adama city affecting the productive age group of the community, adolescents and adults, during the minor transmission season of malaria. In addition to its public health importance by causing morbidity and mortality such kind of scenario may also exacerbates poverty.

Risk factors for cutaneous myiasis (blowfly strike) in pet rabbits in Great Britain based on text-mining veterinary electronic health records

Blowfly strike is a devastating and often rapidly fatal disease in rabbits. In Great Britain (GB), Lucilia sericata is the primary causative species. Despite its severity, there has been minimal investigatory work into the disease in rabbits. Here we used text mining to screen electronic health records (EHRs) from a large sentinel network of 389 veterinary practices in GB between March 2014 and April 2017 for confirmed cases of blowfly strike in rabbits.Blowfly strike was identified in 243 of 42,226 rabbit consultations (0.6%), affecting 205 individual rabbits. The anatomical site of recorded blowfly strike lesions was overwhelmingly the perineal area (n = 109, 52.4%). Less commonly lesions were observed affecting other areas of the body (n = 9, 4.3%) and head (n = 8, 3.8%); in 83 consultations (39.9%), the affected area was not specified. Of the rabbits presenting with blowfly strike, 44.7% were recorded as being euthanized or died.A case control study was used to identify risk factors for blowfly strike in this population. Whilst sex and neuter status in isolation were not significantly associated with blowfly strike, entire female rabbits showed a 3.3 times greater odds of being a case than neutered female rabbits. Rabbits five years of age and over were more than 3.8 times likely to present for blowfly strike. For every 1 °C rise in environmental temperature between 4.67 °C and 17.68 °C, there was a 33% increase risk of blowfly strike, with cases peaking in July or August. Overall blowfly strike cases started earlier and peaked higher in the south of Great Britain. The most northerly latitude studied was at lower risk of blowfly strike than the most southerly (OR = 0.50, p < 0.001). There appeared to be no significant relationship between blowfly strike in rabbits and either the sheep density or rural and urban land coverage types.The results presented here can be used for targeted health messaging to reduce the impact of this deadly disease for rabbits. We propose that real-time temporal and spatial surveillance of the rabbit disease may also help inform sheep control, where the seasonal profile is very similar, and where routine surveillance data is also not available. Our results highlight the value of sentinel databases based on EHRs for research and surveillance.

Effect of Heat Stress on Physiological Parameters of Layers: A Review

Layer flocks are reared for egg production. In the present scenario, climate change is having important effect on agriculture and farm animal production. Rise in environmental temperature is of major concern since it leads to heat stress. Increase in demand for chicken product’s protein supply also, puts challenge to the environment. Technologies are being developed for the intensification of poultry production. We have to still develop new technologies which will be viable and suit according to the climate change and become resilient to heat stress. Beyond the thermoneutral zone or at high ambient temperatures the egg production of layer decreases necessitating to manage heat stress properly. The decrease in egg productivity is dependent on different variables. In the present review, various physiological parameters in layers have been discussed which are being affected by heat stress, either naturally or under artificial conditions. Based on the physiological variables mentioned, other variables have to be explored, which if managed, may result in better egg production.

Thermodynamic performance of pre-pressurization in a cryogenic tank

To supply more actual initial physical field for launch of cryogenic propellant tank, it is necessary to investigate the thermodynamic performance of propellant tank before launch. As cryogenic propellant tank will experience the ground open parking and ground pre-pressurization phase, the present study is particularly to investigate the pressurization performance and temperature distribution in a cryogenic liquid oxygen (LOX) tank for the above parts. One CFD model is established with both the vapor-liquid interface phase change and external forced convection heat exchange considered. The results show that during the ground parking part, the intense nucleate boiling appears in cryogenic tank firstly, then the boiling intensity becomes weak, finally, it tends to be stable. With the high temperature gas oxygen (GOX) injecting into tank, tank pressure fluctuates among the setting pressure limits. The ullage is condensed during the whole pre-pressurization part. Influenced by heat transferring from the ullage and the external heat leakage, the thermal stratified layer becomes thick with time continuing. With the environmental temperature varying from 253.0K to 313.0K, its effect on tank pressure and liquid temperature distribution is not so obvious in this study. The unique large change is that the ullage center line temperature increases with the rise of environmental temperature, while the other parameters have slight changes.

Effects of climate change on yak production at high altitude

Yak is considered the life-line of highland pastoral nomads who raise them on high altitude ranges under transhumance. Yak production at high-altitude alpine ranges may be affected due to the gradual increase of environmental temperature as a result of impending climate change. The mean environmental temperature of yak habitat at 3,000 m above mean sea level in Northeastern Indian Himalaya, varying from 1.2 to 11.1°C and 7.9 to 19.7°C during winter and summer seasons, respectively, evidencing the heat stress to the yaks in summer with THI more than 52. When environmental temperature exceeds 13°C, adaptive mechanisms of body accelerate respiration rate and heart rate to cope with heat stress in yaks. It was reported that the climate change is already witnessed at high altitude with average rise of environmental temperature 0.01 to 0.04°C/year and the expected increase of 2– 3°C have potentially catastrophic for high-altitude animals and ecosystem. The alpine pasture decreased in vegetative above ground biomass and composition which results in starvation or loss of body condition appeared to be manifested as reduced fertility in yak with low milk yield. Further, climate change may result in increase of pests and diseases at the lower permanent settlements of sub-alpine region thereby making these areas incompatible for yaks. Mitigation of heat stress in yak possibly can be done through three means by physical modification of the environment, improved nutritional management and genetic development of strains that would be less sensitive to heat stress.

Cloning and stress expression analysis of glucose regulated protein 78 ku(GRP78)in mud crab(Scylla paramamosain)

Glucose regulated protein 78 ku(GRP78) was one member of heat shock protein 70(HSP70) family. As a molecular chaperone,GRP78 plays important roles in regulating the protein folding and maintaining the stability of endoplasmic reticulum. In this study,we firs cloned the full-length cDNA sequence of GRP78 from mud crab,Scylla paramamosain using RT-PCR and RACE. The full-lengty of GRP78 cDNA is 2 284 bp with 1 962 bp open reading frame encoding 653 amino acids. The homologous analysis indicated that the deduced amino acids contained the signature sequences of HSP70 and the endoplasmic reticulum retention sequence in the C-terminal domain. The deduced amino acid sequence shared high identity with previously reported GRP78s. RT-PCR indicated that GRP78 was expressed in various tissues. When S. paramamosain juveniles exposed to different temperatures and salinities after 12 hours,the expression of GRP78 gene increased with the rise of environmental temperature and a high expression of GRP78 was detected in high salinity(30). So we infer that GRP78 in S. paramamosain might participate in protein folding and the response to environmental stress.

Design and fabrication of a micro thermal actuator for cellular grasping

The development of a novel polymer-based micro robotic gripper that can be actuated in a fluidic medium is presented in this paper. Our current work is to explore new materials and designs for thermal actuators to achieve micromanipulation of live biological cells. We used parylene C to encapsulate a metal heater, resulting in effectively a tri-layered thermal actuator. Parylene C is a bio-compatible dielectric polymer that can serve as a barrier to various gases and chemicals. Therefore, it is suitable to serve as a thermal/electrical/chemical isolation material for protecting the metal heater from exposing to an aqueous environment. We have demonstrated parylene actuators (2 mm×100 μm×0.5 μm) to operate in an aqueous environment using 10 to 80 mW input power. The temperature of these actuators at full deflection was estimated to be ∼60°C, which is much lower than the typical requirement of >100°C to actuate other conventional MEMS actuators.Danio rerio follicles in fluidic medium were captured successfully using these actuators. Moreover, these actuators were found to be responsive to moderate rise in environmental temperature, and hence, we could vary the fluidic medium temperature to actuate trimorphs on a chip without any input of electrical energy, i.e., raising the fluidic temperature from 23°C to 60°C could actuate the trimorphs to grasp follicles of ∼1 mm size in diameter. At 60°C, the embryos inside the follicles were observed to be alive, i.e., they were still moving in the biological fluid isolated by the follicle membrane. The smallest follicles grasped were ∼500 μm in diameter using 800 μm×130 μm×0.6 μm actuators. The fabrication process, modeling, and optimization of the trimorph actuators are presented. Based on the successful operation of these polymer-based actuators, we are currently developing multifinger thermal microgrippers for cellular grasping and manipulation, which can potentially be hybridly integrated with circuits for computer control.

The relation of changes in the individual levels of heat resistance of muscle tissue to their initial values during heat acclimation of Asellus aquaticus

1. 1.|In hog slater, Asellus aquaticus, five extremities were consecutively isolated in the course of heat acclimation to study the pattern of changes in the level of the heat resistance of muscle tissue of each single specimen. 2. 2.|The initial response of the population, during acclimation, is for the muscle resistance of different individuals to become less varied. Then a simultaneous increase in tissue resistance occurs in all ammals, which is complete by the 6th day of acclimation. Afterwards the heat resistance of muscles in the majority of animals shows little change and then, in spite of maintenance of acclimation, it starts to return to its initial level. 3. 3.|Thermal acclimation causes a temporary decrease in the variability of the heat resistance of the muscle tissue and also a temporary stabilization of this physiological characteristic to a new level. This phenomenon is a phenotypical masking of genotypic differences in a physiological characteristic in the population studied during changes in environmental temperature. 4. 4.|At all the stages of acclimation the relation of individual increases in cellular heat resistance to their initial levels follows a hyperbolic exponential equation. This implies that to a rise in environmental temperature a population responds as an integral functional system.

Temperature Independence of the Annual Cycle of Standard Metabolism in the Pumpkinseed

Abstract Standard metabolic rate of the pumpkinseed Lepomis gibbosus was estimated from measurements of routine oxygen consumption and random activity at acclimation temperatures of 8–32 C and within each season of the year. Routine and standard metabolic rates increased from winter (January-March) minima to spring (April-June) maxima, independently of acclimation temperature. For example, standard metabolic rate of a 100-g fish increased from 1.8, 3.0, and 4.8 mg O2˙hour−1 at 8, 16, and 24 C, respectively, during winter, to 3.5, 5.6, and 9.2 mg O2˙hour−1 at the same temperatures, respectively, during spring. The annual energy requirement for standard metabolism, derived from seasonal rate-temperature curves and a simulated annual temperature cycle at 44°N latitude, is 5.01 × 105 joules. The annual cycle is anticipatory in that the increase in metabolic rate during spring begins independently of the vernal rise in environmental temperature. Depression of standard metabolism during fall and winter suggests...

Influence of environmental temperature on flow rate of foodstuffs through the gastrointestinal tract of rainbow trout

Experiments were carried out with rainbow trout ( Salmo gairdneri) to determine the rate of passage of foodstuffs through the digestive tract, before and after a rise in environmental temperature from 9–10°C to 18°C in 1 day. Transit rate was analyzed from the rate of fecal excretion of a marker (Cr 2O 3) incorporated in the diet. In a first experiment on trout weighing about 80 g, mean retention time (MRT) (Castle, 1956) and mean transit time (MTT) (Zierlier, 1958) of the marker, starting from the 9°C acclimated values (34 h for MRT and MTT), decreased as early as the first day after the temperature change (24 and 26 h respectively) and reached the 18°C acclimated values (19 and 21 h respectively) in 4–7 days. In a second experiment on trout weighing about 140 g the pattern of response of MRT and MTT to the temperature increase was similar to that observed in the first experiment: they were 27 and 29 h at 10°C, 16 and 19 h on the second day after the temperature change, and 13 h and 15 h after acclimation at 18°C, respectively. These changes related to environmental temperature were independent of any increase in food consumption. The differences in transit rate of marker between the two experiments could be attributed to the higher body weight and food consumption in the second experiment. Excretion of Cr 2O 3 in the feces was analyzed in the second experiment through a four-compartment model involving the stomach, anterior and posterior intestine, and feces. Fractional evacuation rate of marker in each digestive tract compartment was calculated according to the model. All compartments were affected by the temperature increase. There was a transitory acceleration of transit rate, observed principally in the stomach. These alterations were achieved by the eighth day after the temperature change and it was concluded that acclimation to the new temperature was accomplished in 1 week.

Observations on excystment in vitro ofCotylurus variegatus metacercariae (Trematoda: Strigeidae)

Excystment in vitro ofCotylurus variegatus metacercariae requires a trypsin-bile salt medium for digesting the cyst wall, and events are triggered by a rise in environmental temperature of up to 41°C. Pepsin pretreatment, while effective in removing extraneous host tissues, is not a prerequisite for excystment in vitro. The metacercaria plays an active role in its release, contractile movements being stimulated by bile salts over a temperature range of 30–41° C. Synthetic sodium taurocholate was only one third effective in excystment compared with sodium taurocholate from ox bile. Excystment was maximal at pH 7.5, but conditions of osmolarity, redox potential or gas phase were not of apparent importance.

Relationship between pulse rate and energy expenditure during graded work at different temperatures.

Abstract Pulse rate and energy expenditure were measured on fifteen male subjects who had been given ergometer cycling of ‘O’ and 32·6 W to 97·8 W in three temperatures of 22°C, 30°C, and 37°C. The variation in pulse rate of each graded work period was compared with the variation in energy expenditure for each environmental temperature. The pulse rate was significantly increased with the rise of environmental temperature (p << 0·01) whereas the energy expenditure (kJ min−1) was consistently or effectively decreased with higher graded work. However, a correlation was obtained between the pulse rate and energy expenditure during graded work up to a limit of 150 beats min−1, 160 beats min−1, and 170 beats min−1 in temperatures of 22°C, 30°C, and 37°C respectively. The results were analysed by computing the analysis of variance and regression equation evaluated for each temperature, indicating that independent regression lines having two components, one above 95 and other below 95 beats min−1 were required in each set of temperature. The percentage error between observed and predicted values (pooled) or energy expenditure for the two ranges of pulse rates varied from 0·3 to 11·5 and from 0·5 to 9·5 respectively in the three temperatures.

The Minimum Metabolizable Energy Requirement of Laying Hens

SummaryPrevious estimates of the maintenance ME requirements of laying hens have included an energy contribution to egg production. In the present article the maintenance ME requirements of mature, ovariectomized hens of each of an egg and broiler strain have been used as a basis for determining the minimum ME requirements for different bodyweights, temperatures and rates of egg production. A mean compound percentage reduction in the maintenance ME requirement of 2.7% per 1°C rise in environmental temperature determined for cockerels which have no active ovary, an efficiency of utilization of dietary ME of 75% and an egg energy of 6.5 kJ/g egg were used in the calculations. The minimum ME requirements of laying hens may be derived from the following equations: (i) Egg-producing strain: MEmin = 388W3/4 l 0.027 (22-t) + 8.67 E(ii) Meat-producing strain: MEmin = 450W3/4 l 0.027 (22-t) + 8.67 Ewhere MEmin = minimum ME requirement, kJ/d; W = bodyweight, kg;E = egg product, g/d and t = environmental temperature, °C.

Breed Differences of Feed and Water Consumption and Some Physiological Traits of Chickens reared under Different Environmental Temperatures

For a physiological characterization of an apparent breed difference observed in survival time without feed and/or water, feed intake, water intake, body temperature, skin temperature and the plasma levels of glucose and protein on ad libitum feeding under different environmental temperatures were compared in White Leghorn males of two strains, dwarf (dwarf-WL) and non-dwarf (normal-WL), Fayoumi and Silky males at 32 weeks of age.Birds were kept at the room temperature of 16, 23 and 30°C.Normal-WL that survived the shortest periods of time without feed and/or water than other breeds in our previous work3) consumed the most feed and water in four breeds utilized in this investigation at 30°C. On the other hand, dwarf-WL that survived the longest periods of time without feed and/or water consumed the least feed and water in four breeds at 30°C.It was observed in normal-WL, dwarf-WL and Fayoumi that feed consumption was decreased with the rise of environmental temperature, and water consumtion was increased. However, in Silky breed, feed consumption was increased with the rise of environmental temperature.Dwarf-WL consumed the least amount of water per unit of body weight among these breeds in each environmental temperature.Plasma total protein, plasma glucose levels and skin temperature changed with the rise of environmental temperature. Changing pattern in Silky breed were differed from other breeds.

Sweating--physiology and pathophysiology.

Summary Sweating is a function of the sweat glands which are present in the skin and widely distributed over the general body surface. Sweat is produced as a thermoregulatory response to heat, either from a rise in environmental temperature or endogenously from a rise in body temperature, e.g. during exercise. Evaporation of sweat from the skin causes cooling as long as the environmental humidity is not excessive. Thermoregulatory sweating occurs over the general body surface, while that which is associated with emotional states is seen mainly on the face, palms and feet. However, considerable differences in the sweating pattern, in response to various stimuli, are found between individuals. Sweating is abnormal when either too much (hyperhidrosis) or too little, or none (hypohidrosis or anhidrosis) is produced either generally or in particular regions of the body. Methods for measuring sweat production and the application of these techniques to studying the pathophysiology of the response are also discussed.

Radiation-induced life span shortening of Artemia under different temperature conditions

Adult life span of Artemia by sexual difference was investigated. The mean life span of male-female mixed populations was longer than that of segregated male or female populations. When freshly matured Artemia was irradiated with the acute doses of γ-rays, significant reductions in life span resulted after doses of 10 krads and above. When non-irradiated and irradiated Artemia were kept at various temperatures, the length of life span in both groups decreased with rise in environmental temperature. Survival time at 15°C was prolonged by three times in non-irradiated control group, and by four times in irradiated groups as compared with survival at 32°C. From the present data, radiation induced life span shortening was detected.