Exposure of cattle to controlled subzero temperature: growth hormone, glucose, and free fatty acid concentrations in plasma.
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Acclimatization↗
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Results for “Temperature environment”
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Chemoreceptor reflexes in the newborn infant: effect of CO2 on the ventilatory response to hypoxia.
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Carbon Dioxide↗
Dietary, caging and temperature factors in the ageing of collagen fibres in rat tail tendon.
The effect of dietary fat, carbohydrate and protein on tail tendon collagen ageing was studied in male Wistar rats. When rats were fed low-calorie diets there was no evidence that the content of carbohydrate, fat or protein affected the ageing of collagen. However, on high-calorie diets there was evidence that high-fat diets (21%) either saturated or unsaturated aged collagen fibres at a faster than low-fat diets (7%). Isolated housing of rats, which is necessary to control food intake, was found to slow the rate of collagen ageing. This effect was associated with reduced tail tendon temperatures.
Aging↗
Environmental and management factors affecting the welfare of chickens on commercial farms in the United Kingdom and Denmark stocked at five densities.
Data from a large commercial-scale experiment in which 10 major broiler producer companies stocked whole houses of birds at 30, 34, 38, 42, and 46 kg/m2 were analyzed to identify 1) temperature and humidity profiles achieved throughout the growth cycle, 2) management practices and equipment that contributed to observed variation in environmental conditions, and 3) the extent to which environmental variables affected bird welfare. The study involved a total of 2.7 million birds in 114 houses on commercial farms with measurement of a wide range of environmental and bird variables. Much of the variation in broiler health and welfare was associated with the percentage of time a company could maintain house temperature and RH within limits recommended by the breeder company. RH in the first week of life was particularly important to later health, suggesting that better control of humidity might lead to improved welfare. Key management factors affecting bird welfare were those relating to good ventilation and air control such as the type of ventilation, type of drinker, numbers of stockmen, and litter type. Controlling the environment, particularly temperature, humidity, and air and litter quality, is crucial to broiler chicken welfare. This does not mean that stocking density is unimportant, but lowering stocking density on its own, without regard to the environment the birds experience, is not sufficient. Genuine improvements in bird welfare will come from setting standards that combine stocking density, safeguards on the environment, and the genetic makeup of the birds.
Animal Husbandry↗
Simulated and experimental temperature responses in man during exercise in varying environments.
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Adult↗
Oocyte growth.
The main elements of reproduction are exposed with emphasis on its preparation during the larval stage. The system oocyte-nurse cells-follicular cells is described and the principal features of egg morphogenesis are indicated. Two types of problems are concentrated on : 1) sequential determination of growth and evolution of the follicle in the ovarian tube, 2) morphological and biochemical aspects of chorion formation. Variation in the functioning of the oocyte's morphogenetic system is explored with discussion of the role of larval alimentation, temperature, hormonal environment and genetic factors.
Animal Feed↗
Hand skin temperature variations for work in moderately cold environments and the effectiveness of periodic rewarming.
An investigation of skin surface temperature variations under actual work conditions for four locations on the hand studied the utility of hot water immersion sinks for restoring heat to the hands during exposure to moderately cold temperatures in a food processing plant. Hand skin temperature was recorded for 15 subjects in 2 jobs with an ambient temperature of 13.3 degrees C (56 degrees F) and 1 job with an ambient temperature of 23.9 degrees C (75 degrees F). Averaged over all jobs, the mean temperature for the dorsal and palmar third finger was 17.7 degrees C (63.9 degrees F), which was significantly (p < 0.01) cooler than the mean dorsal and palmar hand temperature of 28.9 degrees C (84.0 degrees F). There was no significant difference between dorsal and palmar temperatures for either the finger or the hand (p > 0.05). In the warm environment there were no significant differences in skin temperature for any of the four hand locations (p > 0.05). An exponential model of digital warming and cooling was empirically derived using 12 subjects for predicting finger skin temperature when periodically rewarming the hands using a hot water immersion sink. The dorsal and palmar finger had a mean time constant of 151 sec for warming during immersion, 640 sec for initial cooling after a 15- to 30-min rest break at room temperature, and 198 sec for cooling after rewarming in the hot sink. The sink did not appreciably raise minimum finger skin temperature after subjects rewarmed the hands for as long as 2 min and then worked for more than 10 min without a rewarming session.
Adult↗
The susceptibility of different gastropod species to the infection with Varestrongylus sagittatus (Mueller, 1890) Dougherty, 1945.
The susceptibility of 11 species of terrestrial gastropods to the infection with Varestrongylus sagittatus has been studied under laboratory conditions. The gastropods Zenobiella umbrosa, Monachoides incarnata. Deroceras reticulatum, Cepaea nemoralis, Cepaea hortensis, Arion rufus, and Trichia hispida are new potential intermediate hosts of V. sagittatus. The highest susceptibility and the shortest period of development of the V. sagittatus larvae occurred in Succinea putris. The development of V. sagittatus larvae inside S. putris did not proceed at the temperature of 5 degrees C, but at 10 degrees C, 15 degrees C, 20 degrees C, and 25 degrees C, the period of development became shorter with increasing temperature of environment. The length of V. sagittatus larvae reached the following values: 0.302-0.327 mm in first-stage larvae, 0.385-0.550 mm in second-stage larvae, and 0.484-0.590 mm in third-stage larvae. At the temperature of 25 degrees C, the larvae of V. sagittatus did not reach the third stage if the course of the experiment only in Helicigona arbustorum.
Animals↗
Effect of temperature and different sex ratios on physical activity and life span in the adult housefly, Musca domestica.
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Animals↗
The low-Ca2+ response virulence regulon of human-pathogenic Yersiniae.
The Lcr is thought to function when the yersiniae infect their mammalian host (see Fig. 2). At present, all evidence points to roles of the Lcr in protecting the bacteria in extracellular niches. We can speculate that early in infection, the yersiniae experience a 37 degrees C extracellular, Ca(2+)-containing environment. Temperature-induction and down-modulation by Ca2+ would occur for Lcr genes, resulting in a cytotoxic and weakly anti-phagocytic surface on the bacteria. Yersiniae that are taken up into macrophages may find a low-Ca2+, inductive environment for expression and release of Yops and V antigen. Upon release from macrophages, the accumulated Yops may render the bacteria sufficiently anti-phagocytic to resist ingestion by neutrophils, and Lcr virulence proteins such as YopM, and perhaps V antigen and other Yops might act to dampen the inflammatory response and prevent secondary influxes of phagocytes. The abundant nucleotides from necrotic host cells undergoing nucleic acid breakdown might then promote extracellular growth. Even though Lcr virulence genes would be expressed at an intermediate level under these conditions, this may be sufficient for the continued undermining of the host natural defenses. It also is possible that there are additional environmental signals, not yet identified, that modulate Lcr virulence gene expression and permit strong expression in extracellular microenvironments that arise as a result of the host-yersiniae interactions.
Calcium↗
Cold-induced ascites in broiler chickens and its improvement by temperature-controlled rearing.
Pulmonary hypertension syndrome (PHS), also known as ascites, in broiler chickens prevailed in the local area of Ibaraki prefecture, Japan, and was investigated epidemiologically, serologically, and pathologically. PHS developed in chickens older than 35 days of age when rapid increase of body weight started. Approximately 90% of affected birds were males, in which weight increase was greater than in females. Serologic test revealed that PHS broilers had an increase of hematocrit value. Pathologic studies indicated that the heart of affected birds had an obese-induced pressure and cold exposure triggered congestion in the right ventricle/cava and an increase in peritoneal fluid. These changes were consistent with the previous reports of PHS, so we designed the experiment of effects on cold-induced PHS birds in a temperature-controlled house. After the 10 PHS birds at 55 days were reared for 14 days in a temperature-controlled house at 20 +/- 5 C, ascites disappeared in eight birds and hematocrit values decreased to normal range in nine birds. Our finding indicated that temperature-controlled environment may be one solution to reduce mortality in PHS birds.
Animals↗
Structure of d(TGCGCA)2 at 293 K: comparison of the effects of sequence and temperature.
The crystal structure of a hexameric DNA fragment with the sequence d(TGCGCA)(2) has been solved and refined at 293 K at a resolution of 1.64 A. The molecule adopts a left-handed Z-type helical conformation which is common in alternating pyrimidine-purine sequences. The presence of A.T base pairs at the two terminals does not perturb the structure to any great degree. However, several sequence-specific microstructural changes are noticeable. The structure of the identical sequence determined at 120 K involving somewhat different crystallization conditions has been reported previously [Harper et al. (1998), Acta Cryst. D54, 1273-1284]. A comparison of the present structure with that at low temperature and with that of d(CGCGCG)(2) shows that the effect of the change in sequence is greater than the combined effect of changes in temperature and environment.
Base Pairing↗
Chemical composition of Corallina mediterranea Areschoug and Corallina granifera Ell. et Soland.
The composition of sterols, volatiles and some polar compounds from three Corallina samples (C. granifera and C. mediterranea from the Black Sea and C. mediterranea from the Mediterranean Sea) was established. The sterol composition of the Black Sea samples was similar but it differs from that of the Mediterranean sample. The composition of the volatiles was very complex. The main groups of constituent were hydrocarbons, alcohols, carbonyl compounds, acids and their esters, terpenes. The composition of the polar components, soluble in n-butanol, was also established. There were some differences in the chemical composition of the two Black Sea species, which may be due to the biodiversity between them, while the differences in the composition of the two C. mediterranea samples could be due to the differences in the environment (salinity, temperature, pollution, etc.).
1-Butanol↗
Ambient-temperature beverages are consumed at a rate similar to chilled water in heat-exposed workers.
Palatability of beverages has been shown to influence drinking patterns and hydration. Cool beverages are known to enhance palatability; however, situations exist in which cooling is not possible. The purpose of this study was to determine the palatability of a variety of flavors of ambient temperature beverages. Ten healthy males performed two work trials in a temperature-controlled environment (WBGT = 30 degrees C; wet = 25 degrees C, dry = 40 degrees C, globe = 41 degrees C). In one trial, the subjects had only chilled water to drink. In the second trial the subjects drank their choice (any or all) of five ambient temperature beverages (water, fruit punch, lemon-lime, orange, and cola). Repeated measures ANOVA showed no difference in absolute or relative fluid consumption between the two trials (chilled = 1730 +/- 316 mL and 21 +/- 5 mL/kg; ambient [all five beverages combined] = 1510 +/- 219 mL and 19 +/- 4 mL/kg). There was no difference in the rate of fluid consumption between the two trials (608 +/- 88 mL/30 min and 674 +/- 82 mL/30 min, p > 0.05). Additionally, when combining all ambient-temperature, flavored beverages, consumption was significantly greater than that of ambient temperature water (1245 +/- 206 vs. 255 +/- 86 mL, p < 0.05). These findings demonstrate that providing ambient temperature beverages in a hot condition results in fluid consumption values similar to chilled water. These findings are relevant to industry in that there may be times when workers are at risk for heat-related illness due to dehydration and chilled beverages are not available. By providing flavored beverages, fluid consumption may be maintained and degree of heat-illness may be lessened.
Adult↗
Influence of a high ambient temperature and administration of clenbuterol on body composition in rats.
This study was conducted to determine the effects of the oral administration of the beta agonist clenbuterol on body composition in growing rats reared under a high ambient temperature. Forty-three male Wistar-strain rats of 5 weeks of age were divided into 6 groups: 2 levels of ambient temperature (26 and 33 degrees C) and 3 dose levels of clenbuterol (0, 50, and 100 micrograms/kg diet) under each ambient temperature. All rats were raised for 7 weeks. From the 3rd week, rats in the clenbuterol-treated groups were fed a diet containing clenbuterol. Both the lipid and cholesterol content in the rat liver, and the epididymal adipose tissue weight were significantly higher in the hot environment than in the temperature environment. Body fat component was significantly higher in rats in the 33 degrees C groups in comparison with that in rats in the 26 degrees C groups. On the other hand, body protein component was significantly lower in the 33 degrees C groups than in the 26 degrees C groups. Although the administration of clenbuterol significantly decreased fat and increased protein in the 26 degrees C groups, no particular influence of clenbuterol administration on body composition was observed in the 33 degrees C groups.
Administration, Oral↗
New procedures to estimate water temperatures and water depths for application in climate-dengue modeling.
Two new approaches have been developed to estimate water temperatures and water depths in containers that commonly are used as breeding sites for mosquitoes, the primary vectors of dengue viruses. These estimates are incorporated in recently developed stochastic simulation models used to describe the daily dynamics of dengue virus transmission in the urban environment. Water temperature estimates are provided through a regression model that includes meteorological variables not previously used; results show that they are significantly better than those used in previous dengue transmission models. Water depth models use a climatic water budget approach which estimates moisture storage within containers. The water depth models are less precise than those developed for water temperature; however, results are superior to those used in previous models. These new approaches should improve estimates of the impact of water conditions on dengue vectors.
Aedes↗
Magnesium-DNA interactions from interpretation of 25Mg-nmr relaxation rates: field and coion dependence.
We have used 25Mg-nmr to investigate the binding of magnesium ions to double-stranded DNA. We have measured line shapes for 25Mg in the presence of monodisperse calf thymus DNA (160 base pairs; b.p.) (magnesium: phosphate = 2.0) at two different field strengths, 11.75 T and 7.05 T, and used the isotropic model of two-site exchange developed by Westlund and Wennerstrom to simultaneously fit the line shapes at both field strengths. This model does not reproduce the observed field dependence. This is in contrast to a previous study [E. Berggren, L. Nordenskiold, and W.H. Braunlin (1992), Biopolymers, Vol. 32, pp. 1339-1350] in which a similar model of isotropic two-site exchange qualitatively reproduced the temperature dependence of the line widths. Relaxation rates were also measured as a function of magnesium: phosphate ratio and coion type. These measurements were used to assess the sensitivity of magnesium relaxation measurements to small changes in DNA structure induced by changes in the solvent environment. The temperature dependence of the line shape varies with the type of coion (chloride or sulfate) present. This coion dependence of the line shape is consistent with the coion dependence of the aggregation midpoint temperature reported by Bloomfield and co-workers [O.A. Knoll, M.G. Fried, and V.A. Bloomfield (1988) in Structure and Expression, Vol. 2, R.H. Sarma and M. H. Sarma, Eds., Adenine Press, New York] and attributed to a lyotropic effect. These results suggest that even at low magnesium: phosphate ratios, relaxation parameters are specific to each magnesium-coion-DNA system.
Animals↗
[Spectrum analysis of erythrocyte intracellular hemoglobin with a novel fast multi-channel micro-spectrophotometry].
With the application of a novel fast multi-channel micro-spectrophotometry (MMSP), the absorption spectrum of intracellular hemoglobin molecule in a human single living red blood cell was monitored under the altered physiological environments (pH, temperature, partial pressure of oxygen, and osmotic pressure). It was found that on the absorption spectrum curve of hemoglobin the spike, the height and the position of the characteristic absorption peaks at 540 and 575 nm were altered obviously with the changes in physiological conditions, indicating that the concentration, structure and function of the hemoglobin in the red blood cell may be closely associated with the physiological environments.
Algorithms↗