Effects of body composition and body dimension on body temperature regulation during exercise in hot and cool environments.
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Adult↗
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The development of Plasmodium falciparum in experimentally infected Anopheles gambiae (Diptera: Culicidae) under ambient microhabitat temperature in western Kenya.
The effect of microhabitat temperature variation on the early development of Plasmodium falciparum in experimentally infected Anopheles gambiae s.s. (Diptera: Culicidae) was studied. Batches of mosquitoes were fed artificially on gametocyteamic blood obtained from human volunteers and then held in five environmental conditions described as: (1) incubator maintained at constant temperature of 28 +/- 1 degrees C as control; (2) temperature unregulated laboratory environment; (3) screen house; (4) grass thatched mud house and (5) corrugated iron roofed mud house. Both the grass and iron roofed mud houses were real houses found in the village communities around the ICIPE Research Centre in Mbita Point, Suba District south-western Kenya. The temperature and relative humidity of these holding environments were recorded over the study period. Mosquitoes were dissected after 24 h and 7 days to enumerate ookinetes and oocysts stages, respectively in their midguts. The mean temperature observed in the temperature-unregulated laboratory (28 degrees C) was significantly higher than the temperature of the screen house (24 degrees C) while the mean temperature observed in the iron roof mud house (27 degrees C) was comparable with that in the grass-thatched mud house (27 degrees C) although the iron roof house experienced more variation (coefficient of variation, C.V., = 9.6%) and higher peaking temperatures than the grass-thatch house. The mean relative humidity for the laboratory and screen house were 23% and 32.5%, respectively, much lower than relative humidity in the incubator (73%). Relative humidity of the grass thatch hut (42%) and Iron roof hut (51%) were also lower than those of the incubator. The ookinete intensities for mosquitoes in the screen house (10.11 +/- 1.79 ookinetes/midgut) were not statistically different (P = 0.41) from those held in the laboratory (7.50 +/- 1.19 ookinetes/midgut) or in the incubator (9.89 +/- 1.47 ookinetes/midgut). The holding environments influenced the oocyst infection rates (P = 0.04) that increased from 8.4% in the screen house to 10.2% in the laboratory. The highest infection rate (12.5%) was observed in mosquitoes held in the incubator. However, the mean oocyst intensities in mosquitoes did not differ under these environments (P = 0.58). In the 'real village house' environments, the mean ookinete intensities were not statistically different between groups of mosquitoes compared to the incubator (P = 0.86). The oocyst infection rates observed in the highly fluctuating iron roof house were 9.4% as compared to 9.0% and 6.9% in the more stable and constant habitats of grass thatch house and incubator, respectively. Results show that the natural microhabitats did not influence the infections rates in mosquitoes (P = 0.62). These findings indicate that the variation in temperatures prevailing in western Kenya particularly inside the village houses do not impede the development of malaria parasites in A. gambiae mosquitoes.
Animals↗
Physico-chemical studies of micelle formation on sepia cartilage collagen solutions in acetate buffer and its interaction with ionic and nonionic micelles. Hydrodynamic and thermodynamic studies.
Sepia cartilage collagen (pepsin-extracted) in acetate buffer (pH = 2.98) forms micelles at a particular concentration below which they do not normally form. The critical micelle concentration (cmc) of the collagen was determined in buffer as well as in SDS, cetyltrimethylammonium bromide (CTAB) and Tween-80 micellar environments at different temperatures. Mutual interaction of collagen micelles with the ionic and nonionic micelles through the formation of the mixed micelle concept has also been found. The cmc of collagen decreased in the presence of SDS and Tween-80 micelles whereas it increased in the presence of CTAB micelles. This clearly suggests that the micelle formation of collagen is facilitated by the presence of SDS and Tween-80 and hindered by CTAB micelles. The various thermodynamic parameters were estimated from viscosity measurements and the transfer of collagen into the micelles of various surfactants and the reverse phenomenon was analyzed. This analysis has also been modelled conceptually as a different phase and the results have supported the above phenomenon. Our thermodynamic results are also able to predict the exact denaturation temperature as well as the structural order of water in the collagen in various environments. The hydrated volumes, Vh, of collagen in the above environments and intrinsic viscosity were also calculated. The low intrinsic viscosity, [eta], of collagen in an SDS environment compared to buffer and other surfactant environments suggested more workable systems in cosmetic and dermatological skin care preparations. The one and two-hydrogen-bonded models of this collagen in various environments have been analyzed. The calculated thermodynamic parameters varied with the concentration of collagen. The change of thermodynamic parameters from coil-coil to random-coil conformation upon denaturation of collagen were calculated from the amount of proline and hydroxyproline residues and compared with viscometric results. Thermodynamic results suggest that the stability of the collagen in the additive environments is in the following order: SDS greater than Tween-80 greater than buffer greater than CTAB.
Acetates↗
Numerically dominant denitrifying bacteria from world soils.
Nineteen soils, three freshwater lake sediments, and oxidized poultry manure were examined to determine the dominant denitrifier populations. The samples, most shown or expected to support active denitrification, were from eight countries and included rice paddy, temperate agricultural, rain forest, organic, and waste-treated soils. Over 1,500 organisms that could grow anaerobically on nitrate agar were isolated. After purification, 146 denitrifiers were obtained, as verified by production of N(2) from NO(3) (-). These isolates were characterized by 52 properties appropriate for the Pseudomonas-Alcaligenes group. Numerical taxonomic procedures were used to group the isolates and compare them with nine known denitrifier species. The major group isolated was representative of Pseudonomas fluorescens biotype II. The second most prevalent group was representative of Alcaligenes. Other Pseudomonas species as well as members of the genus Flavobacterium, the latter previously not known to denitrify, also were identified. One-third of the isolates could not utilize glucose or other carbohydrates as sole carbon sources. Significantly, none of the numerically dominant denitrifiers we isolated resembled the most studied species: Pseudomonas denitrificans, Pseudomonas perfectomarinus, and Paracoccus denitrificans. Denitrification appears to be a property of a very diverse group of gram-negative, motile bacteria, as shown by the large number (22.6%) of ungrouped organisms. The diversity of denitrifiers from a given sample was usually high, with at least two groups present. Denitrifiers, nitrite accumulators, and organisms capable of anaerobic growth were present in the ratio of 0.20+/-0.23:0.81+/-0.23:1. There were few correlations between their numbers and the sample characteristics measured. However, the temperatures at which isolates could grow were significantly related to the temperatures of the environments from which they were isolated. Regression analysis revealed few relationships between physical parameters and bacterial types, save for the anaerobe numbers, in which 94% of the variance could be accounted for.
Anaerobiosis↗
Effect of cutaneous denervation of face and trunk on thermoregulatory responses to cold in rats.
The effect of eliminating afferent input from cutaneous thermoreceptors of the face and trunk on the ability of rats to regulate body temperature in cool environments was studied. Thermoregulatory ability in a cool environment was assessed first in a 25 degrees C environment and then during slow (20 min) and rapid (5 min) reductions of ambient temperature (Ta) to 15 degrees C by monitoring rate of heat production, rectal temperature, and skin temperature on the back, ear, and tail. These measurements were made in four rats while they were intact and during the 2 wk after cutaneous denervation. Rats were found to regulate body temperature well even after the cutaneous nerves of the trunk and face were sectioned. In eight rats the metabolic curve was determined before and 7-10 days after cutaneous denervation. Although the minimal resting metabolic rates did not differ in the two conditions, the lower critical temperature was significantly elevated from 26.8 to 28.9 degrees C and the rate of rise in metabolic rate per degrees celsius decrease in Ta was also significantly higher after cutaneous denervation. It appears that the higher rate of heat production is in compensation for an increase in the rate of heat loss in denervated rats.
Animals↗
[Central temperature during chronic exposure to a warm climate].
Rectal temperature was determined at rest in 603 healthy melanoderm african men, in their natural environment. The ambient temperatures were noted between 20 and 38 degrees C on the morning and 23 to 46 degrees C on the afternoon, according to the season and place. On the morning results a significant positive correlation was found between rectal and ambient temperatures. On the afternoon results the situation was more complex: there was a positive correlation only with comfortable and warm ambient temperatures (23-35 degrees C), but not with higher temperatures (36-46 degrees C). Furthermore 28 young sportmen performed a submaximal 30 min exercise test on a cycloergometer at 2 ambient temperatures (comfortable and hot) and the difference in rectal temperature was appreciated between the beginning and the end of each activity. Results showed the same increase in the body temperature during the 2 tests. These results suggest that human thermoregulation remains effective in the subtropical area but can be adapted to the climatic conditions in permanent residents. Then the internal temperature is modified by the increasing ambient temperature, but there is a superior limit of this deep body temperature: when it is overpassed, a strong corrective mechanism is applied.
Adaptation, Physiological↗
Effect of diet and population density on male turkeys under various environmental conditions. 2. Body composition and meat yield.
Large White Nicholas male turkeys were reared at two stocking densities (.21 or .46 m2 per bird) and fed one of four diets: 1) control corn and soybean (mash) with 1% fat (CSM); 2) as Diet 1, pelleted (CSP); 3) as Diet 1 with supplemental fat increasing from 1 through 8% with age (CSF); and 4) as Diet 1 with barley at 0, 20, 35, 50, and 65% during successive 4-wk periods (CSB). The turkeys were reared in four environments: (A) intermittent light schedule [4(2 h light (L):4 h dark D))] with temperature at 7 or 21 C during light and dark photoperiod, respectively; (B) and (D) with intermittent light (2L:4D) with a constant 21 and 7 C temperatures, respectively; (C) continuous light cycle (18L:6D) with temperatures as in Environment A. At 20 wk of age, two turkeys per replicate pen, were killed for determination of body composition and meat yield. Compared with turkeys fed CSM diet, those on CSF and CSP diet had increased percentage carcass fat. Meat yield per bird and percentage carcass fat were greater for turkeys reared at .46 m2 per bird compared with rearing at .21 m2 per bird. Pelleting and fat supplementation resulted in significantly increased amounts of breast meat and leg compared with CSM. Breast meat yield (percentage) and amount were greater at 7 C (Environment D) than at 21 C (Environment B) and the cycling regimen (Environment A). Percentage abdominal fat was greatest at 7 C. Interactions of environment and diet were detected for breast meat yield percentage (P less than .023) and weight (P less than .036). Diet type had no effect on percentage breast meat or weight in Environment C. An increased amount of breast meat was obtained by feeding CSP in Environments A, B, and D, and dietary fat supplementation increased breast meat yield in Environments A and D over CSM treatment.
Adipose Tissue↗
Interaction between drought and chronic high temperature during kernel filling in wheat in a controlled environment.
Wheat plants (Triticum aestivum L. 'Lyallpur'), limited to a single culm, were grown at day/night temperatures of either 18/13 degrees C (moderate temperature), or 27/22 degrees C (chronic high temperature) from the time of anthesis. Plants were either non-droughted or subjected to two post-anthesis water stresses by withholding water from plants grown in different volumes of potting mix. In selected plants the demand for assimilates by the ear was reduced by removal of all but the five central spikelets. In non-droughted plants, it was confirmed that shading following anthesis (source limitation) reduced kernel dry weight at maturity, with a compensating increase in the dry weight of the remaining kernels when the total number of kernels was reduced (small sink). Reducing kernel number did not alter the effect of high temperature following anthesis on the dry weight of the remaining kernels at maturity, but reducing the number of kernels did result in a greater dry weight of the remaining kernels of droughted plants. However, the relationship between the response to drought and kernel number was confounded by a reduction in the extent of water stress associated with kernel removal. Data on the effect of water stress on kernel dry weight at maturity of plants with either the full complement or reduced numbers of kernels, and subjected to low and high temperatures following anthesis, indicate that the effect of drought on kernel dry weight may be reduced, in both absolute and relative terms, rather than enhanced, at high temperature. It is suggested that where high temperature and drought occur concurrently after anthesis there may be a degree of drought escape associated with chronic high temperature due to the reduction in the duration of kernel filling, even though the rate of water use may be enhanced by high temperature.
Acclimatization↗
[Effect of temperature conditioning and of humidity of the environment on energy metabolism in athrepsia in infants].
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Energy Metabolism↗
Fatty Acid accumulation in maturing flaxseeds as influenced by environment.
The effects of temperature and light on boll and shoot maturity and on the accumulation of fatty acids in developing seeds of flax (Linum usitatissimum L.) were determined in controlled environments. Palmitic and linoleic acids decreased but linolenic increased in percent as seed formation progressed. In the same period, oleic acid increased in percent in 1 variety and decreased in another. Increased temperatures hastened these changes and resulted in decreased iodine value of the oil at maturity.Calculated on a weight basis (mg per 1000 seeds), all 5 major fatty acids increased during seed formation. Increased temperatures initially accelerated the accumulation of all fatty acids, but the period of net fatty acid synthesis was eventually shortened in comparison with cooler temperatures. At 15 degrees and 20 degrees , linolenic acid accumulation closely paralleled the rate of boll maturation, measured by boll moisture content; at 30 degrees linolenic accumulation ceased before maturation could be detected.A photoperiod of 20 hours accelerated plant maturity resulting in decreased seed weight in comparison with a photoperiod of 16 hours. Eight hour photoperiod favored late blossoming and depressed seed weight, oil content, and fatty acid content. Weights of linoleic and linolenic acids were high in both the 16 and 20 hour photoperiods.Linolenic acid was reduced in percent and weight per 1000 seeds at light intensities of 1200 ft-c as compared with 2700 ft-c.
Journal Article↗
[Isolation and biological characteristics of rhizobia strains from Abrus cantoniensis].
OBJECTIVE: The research aimed at studying the biological characteristics of rhizobia isolated from Abrus cantoniensis. METHOD: The rhizobia strains, isolated from different environments in Guangxi, were studied for their growing characters and the generation time. They were also compared for survival capabilities under stresses caused by NaCl, pH, temperature, and different kinds and concentration of antibiotics. RESULT: The strains obtained from A. cantoniensis in subtropical zone produced alkali in YMA medium, the average generation time was 14.8 hours, and thus they belong to slow-growing rhizobia. Rhizobia strains differed greatly in respect to tolerance of high temperature, adaptability of acidic environment and sensitivity to four antibiotics, but they had the same abilities of using different carbon and nitrogen sources. After 70 days from inoculated strains, the seedling formed nodules on the root (85.0%), and the dry matter of vine was increased by 51.1%. CONCLUSION: The rhizobia strains isolated from different ecological environments are good germplasm resources of tolerances to high temperature and acidic environment. The research will greatly help utilize the rhizobia resources and enhance the quality of crude drugs of medicinal leguminosae.
Abrus↗
Technical report # 39: cold chain guidance for medicinal products: maintaining the quality of temperature-sensitive medicinal products through the transportation environment. Parenteral Drug Association.
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Drug Packaging↗
Quantifying energy and mass transfer in crop canopies: sensors for measurement of temperature and air velocity.
Here we report on the in situ performance of inexpensive, miniature sensors that have increased our ability to measure mass and energy fluxes from plant canopies in controlled environments: 1. Surface temperature. Canopy temperature measurements indicate changes in stomatal aperture and thus latent and sensible heat fluxes. Infrared transducers from two manufacturers (Exergen Corporation, Newton, MA; and Everest Interscience, Tucson, AZ, USA) have recently become available. Transducer accuracy matched that of a more expensive hand-held infrared thermometer. 2. Air velocity varies above and within plant canopies and is an important component in mass and energy transfer models. We tested commercially-available needle, heat-transfer anemometers (1 x 50 mm cylinder) that consist of a fine-wire thermocouple and a heater inside a hypodermic needle. The needle is heated and wind speed determined from the temperature rise above ambient. These sensors are particularly useful in measuring the low wind speeds found within plant canopies. 3. Accurate measurements of air temperature adjacent to plant leaves facilitates transport phenomena modeling. We quantified the effect of radiation and air velocity on temperature rise in thermocouples from 10 to 500 micrometers. At high radiation loads and low wind speeds, temperature errors were as large as 7 degrees C above air temperature.
Air Conditioning↗
Characterisation of the fluorescence from freshwater, planktonic bacteria.
Amino acid-like fluorescence has been used as an indicator of biological activity in wastewater effluent and in natural waters, and can be detected using fluorescence spectroscopy. Little or no work has been able to state conclusively that these so called 'amino acid-like' fluorophores are associated with proteins present as a result of bacterial activity. This work aims to ascertain whether bacteria are one possible cause of these 'amino acid-like' peaks observed in natural waters. In addition, fluorescence derived solely from one bacterial source was determined as a function of the growth time and temperature. The bacterium Pseudomonas aeruginosa was isolated from the urban River Tame, Birmingham, UK, and planktonic bacteria were grown in sterile, sealed glass jars, in 100 ml growth media. Bacteria were grown at 11, 25 and 37 degrees C, over a maximum of 10 days. A 3D Excitation-Emission Matrix (EEM) plot was generated from fluorescence analysis of the samples. Both tryptophan and tyrosine-like fluorescence, resembling that observed in natural and waste waters, was observed in these samples, indicating that observed fluorescence signals from aquatic systems in the literature were of biotic origin. Significant differences in fluorescence signals were obtained from planktonic cells grown at different temperatures. At 25 and 37 degrees C, cells were found to produce predominantly tryptophan-like fluorescence, with some tyrosine-like fluorescence also detected. A further unknown fluorophore was also detected (emission wavelength of approximately 460 nm, with three excitation centres at 225, 260 and 390 nm), likely to be a bacterially produced metabolite. At 11 degrees C, a more environmentally realistic temperature in temperate environments, quantitative and qualitative differences were observed in fluorescence signals when compared with the higher temperatures, indicating that laboratory observations conducted at higher temperatures may not be easily used to interpret environmental processes.
Bacterial Proteins↗
Prone position may increase temperature around the head of the infant.
Recommendations to adopt the supine position were followed by a dramatic decrease of SIDS. But no explanation has been given for the association between SIDS and the prone position nor for its decrease in the supine position. We report data on an infant and a mannequin demonstrating an increase in temperature around the head in the prone position. A 4-month-old boy presented an acute life-threatening event related to temperature after febrile otitis despite treatment: 40.5 degrees C, heart rate 280 bpm with circulatory failure and cardiorespiratory arrest requiring resuscitation. There were no seizures. Blood and CSF cultures were negative. The course under antibiotics was favourable. On d 3, we measured temperature at several sites on and around the heat. Temperatures were higher in the prone than in the supine position in pericephalic areas: +1 degrees C (supracephalic), +2.5 degrees C (peritemporal), and +3.5 degrees C (submandibular). In a thermoregulated room, we used a mechanically ventilated mannequin of an infant. The prone position was also associated with an increase in temperature around the head: +3.3 degrees C (supracephalic), +1.8 degrees C (peritemporal), and +1.1 degrees C (submandibular). Changing from the supine to prone position thus increased temperature around the head (infant and mannequin). To our knowledge, this has not been reported before. SIDS is related to factors modifying temperature status and environment. Furthermore, evacuation of heat is mandatory for an infant. We think the increase in temperature around the head in the prone position is due to the absence of convective fluxes, and speculate it could impair thermolysis.
Body Temperature↗
[Temperature measurement in breath alcohol analysis].
Breath-alcohol concentration determined in expired alveolar air depends even at equal blood concentration on the temperature of the breath while leaving the subject's mouth. By using a two-stage simulator it is possible to simulate the physiological reality and to examine the measuring conditions of the temperature. The results show the essential influence of the mouthpieces and the environmental temperature on the measured values. Deviations especially appear at low environmental temperature. To reduce systematic deviations an electrically heated support of the temperature probe was developed which diminishes the influence of the mouthpieces to -0.3 degree centigrade. This device almost eliminates the influence of temperature of the environment.
Alcoholic Intoxication↗
[Regulation of the biosynthesis of secondary metabolites in Streptomyces galbus].
The effect of inhibiting and stimulating agents on the biosynthesis of secondary metabolites (actinomycin X and melanoid pigments) was studied in Streptomyces galbus as a function of the growth temperature. D-Valine was shown to inhibit actinomycin synthesis and to stimulate production of melanoid pigments. Tryptophan stimulated the synthesis of both actinomycin and melanoid pigments. The temperature of growth was found to regulate the biosynthesis of secondary metabolites by the culture. The organism synthesized actinomycin at 28 degrees C, but it switched to the production of melanoid pigments at 42 degrees C. This may be considered as a protective reaction of the organism to an increase in the temperature of the environment and in UV radiation which is possible under natural conditions as a consequence of temperature elevation. The paper presents a hypothetical scheme for the regulation of biosynthesis of actinomycin and melanoid pigments by temperature. According to the scheme, the culture synthesizes secondary metabolites from tryptophan to hydroxykynurenine via a general pathway which is then bifurcated: at 28 degrees C--through methylhydroxyanthranilic acid to actinocin to actinomycin; at 42 degrees C--through hydroxyanthranilic acid, o-aminophenol, pyrocatechol, and possibly, o-benzoquinone, to melanin.
Antibiosis↗
Influence of thermal and nutritional acclimatization on body temperatures and metabolic rate.
1. An investigation of the influence of previous thermal and nutritional experience on body temperatures and metabolic rate has been carried out with growing piglets. Littermates were kept, from shortly after birth, at either 10 or 35 degrees C and fed either a high (H) or a low (L) energy intake. At 8 weeks of age the animals were exposed to a series of environmental temperatures of 10, 20, 27 and 35 degrees C for 1.5 hr and their rates of oxygen consumption were determined over the last 45 min. At the end of the session body temperatures were measured. 2. Rectal temperatures measured 24 hr after the start of the last meal were higher at each test temperature in piglets which had been living at 35 degrees C than in those at 10 degrees C. Also, rectal temperatures were higher in those on the H intake for animals which had been living in either the hot or the cold environment. 3. Skin temperature on the back was similar in all groups at any given test temperature although there was a tendency for those on an H intake to have the higher temperatures. Skin temperatures of the legs and ears were higher in the 10H and 10L groups than in the 35H or 35L groups at all the test environmental temperatures; energy intake had little effect. 4. Metabolic rate was greater for the animals on the H than the L intake, for those which had been living at either 10 or 35 degrees C at all the test environmental temperatures. The analysis did not reveal any significant difference related to the overall effect of living temperature, which was independent of energy intake. 5. At thermal neutrality (27 degrees C) there was a significant interaction, between energy intake and normal living temperature, on metabolic rate. Living temperature was found to modify the effect of intake: the difference between the two intakes was greater in those from the cold environment than from the hot.
Acclimatization↗