Differential effects of ambient temperature and humidity on allogrooming, self-grooming, and scratching in wild Japanese macaques

This study presents data on the effects of variations in ambient temperature and humidity on behaviors related to the care of the pelage (allogrooming, self-grooming, and scratching) in wild Japanese macaques (Macaca fuscata yakui). The amount of time monkeys spent allogrooming was essentially unaffected by variations in ambient temperature and relative humidity. Frequency of scratching and, to a lesser extent, time spent self-grooming significantly increased when ambient temperature and/or relative humidity increased. These results are interpreted in relation to the differences in ultimate function that exist between allogrooming (with both hygienic and social functions) and self-grooming and scratching (with a solely hygienic function).     

Temperatures of expired air under varying climatic conditions

Measurements of expiration temperatures were carried out under different climatic conditions. In one series of experiments the ambient air temperature was varied, in another the relative humidity of the ambient air. The temperatures of the ambient air ranged between –5°C and 30°C and the relative humidity between 10% and 90%. The results reveal a high variability of the expiration temperatures, when the ambient air temperature is changed, and almost constant expiration temperatures, when the relative humidity is altered but the ambient air temperature is kept constant. Nasal expiration temperatures are more sensitive to changes of the meteorological parameters than oral expiration temperatures.     

The mechanical properties of stratum corneum. I. The effect of water and ambient temperature on the tensile properties of newborn rat stratum corneum.

The tensile properties of the outermost layer of skin of neonatal rats, the stratum corneum, were investigated at a constant strain rate as a function of moisture content and ambient test temperature. The results show that the mechnical behavior of this membrane, whose primary constituent is the fibrous protein keratin, can be significantly altered by variations in both the sorbed water content and ambient temperature. In particular, a brittle to ductile transition was observed at 25 degrees C once the hydration level exceeded 70% relative humidity. Similarly, an identical phenomenon was detected at temperatures beyond 40 degrees C for specimens whose equilibrium moisture concentrations were maintained at 10 g H2 O/100 g dry protein. Differential scanning calrimetry measurements showed the presence of a molecular relaxation process which migrated from 42 degrees C at 40% relative humidity to --18 degrees C at 95% relative humidity. It is postulated that this relaxation process, possibly corresponding to the glass transition of the fibrous protein component of stratum corneum, is primarily responsible for the observed behavior.     

Ethanol modulates the VR-1 variant amiloride-insensitive salt taste receptor. II. Effect on chorda tympani salt responses

The effect of ethanol on the amiloride- and benzamil (Bz)-insensitive salt taste receptor was investigated by direct measurement of intracellular Na(+) activity ([Na(+)](i)) using fluorescence imaging in polarized fungiform taste receptor cells (TRCs) and by chorda tympani (CT) taste nerve recordings. CT responses to KCl and NaCl were recorded in Sprague-Dawley rats, and in wild-type (WT) and vanilloid receptor-1 (VR-1) knockout mice (KO). CT responses were monitored in the presence of Bz, a specific blocker of the epithelial Na(+) channel (ENaC). CT responses were also recorded in the presence of agonists (resiniferatoxin and elevated temperature) and antagonists (capsazepine and SB-366791) of VR-1 that similarly modulate the Bz-insensitive VR-1 variant salt taste receptor. In the absence of mineral salts, ethanol induced a transient decrease in TRC volume and elicited only transient phasic CT responses. In the presence of mineral salts, ethanol increased the apical cation flux in TRCs without a change in volume, increased transepithelial electrical resistance across the tongue, and elicited CT responses that were similar to salt responses, consisting of both a phasic component and a sustained tonic component. At concentrations <50%, ethanol enhanced responses to KCl and NaCl, while at ethanol concentrations >50%, those CT responses were inhibited. Resiniferatoxin and elevated temperature increased the sensitivity of the CT response to ethanol in salt-containing media, and SB-366791 inhibited the effect of ethanol, resiniferatoxin, and elevated temperature on the CT responses to mineral salts. VR-1 KO mice demonstrated no Bz-insensitive CT response to NaCl and no sensitivity to ethanol. We conclude that ethanol increases salt taste sensitivity by its direct action on the Bz-insensitive VR-1 variant salt taste receptor.     

Anti-adhesive Property of Maize Leaf Surface Related with Temperature and Humidity

The anti-adhesive surfaces have always aroused great interest of worldwide scientists and engineers.But in practical applications,it often faces the threat and impact of temperature and humidity.In this work,the excellent anti-adhesive performance of maize leaf under high temperature and humidity were investigated in detail.Firstly,the adhesion forces of the maize leaf surface under different temperature and humidity were measured by using Atomic Force Microscopy (AFM).The temperature of the substrate was varied between 23 ℃ to 100 ℃,and the ambient relative humidity is from 18％ to 100％.It was found that the adhesion force of maize leaf decreased with the increase of temperature and humidity.The mechanism of its excellent anti-adhesive performance of maize leaf under high temperature and relative humidity was revealed.The transverse and longitudinal ridges on maize leaf surface interlace with each other,forming small air pockets,which reduces the actual contact area between the object and the maize leaf.With the increase of humidity,the liquid film will be formed in the air pockets gradually and so much water vapor is produced with increase of temperature.Then the air flow rate increases though the wavy top of transverse ridges,inducing the dramatic decrease of adhesion force.Inspired by this mechanism,four samples with this bionic structure were made.This functional "biomimetic structure" would have potential value in the wide medical equipments such as high frequency electric knife with anti-adhesion surface under high temperature and high humidity.     

不同形状城市湿地对周边环境温湿度的影响

2015年春、夏、秋季选择大庆市区5种不同形状特征的城市湿地及周边环境作为研究对象,利用小尺度定量测定的方法,分析城市湿地形状特征对周边环境温、湿效益的影响.结果表明: 不同形状特征的城市湿地均具有增湿降温效应.其中,夏季的增湿降温效应最强,春季其次,秋节最差.形状特征对湿地的降温增湿能力具有显著影响,不规则形状湿地>规则形状湿地(近圆形湿地、近矩形湿地)>长条形状湿地;增湿降温日变化受环境温度影响较大,即早晚弱、中午强,春、秋季增湿降温幅度最大的时段为12:00—14:00,夏季增湿降温幅度最大的时段为14:00—16:00.     

Stimulation of the salt receptor of the blowfly. III. The alkali halides

Application of solutions of each of the alkali halides to the tip of a labellar sensillum of the blowfly elicited a repetitive neural discharge from the salt receptor. The records were qualitatively similar to those for NaCl. For each of the alkali chlorides and sodium halides, the shapes of the curves of the response of the salt receptor as a function of concentration were similar to that for NaCl. The alkali halides exhibited a regular pattern of relative stimulating effectiveness for the salt receptor. The effectiveness of the anions increased monotonically with atomic number. The effectiveness of the cations was greatest for potassium and declined as the atomic number was increased or decreased. This hierarchy for stimulating effectiveness was maintained at all tested molarities. The response to a mixture of two salts appeared to be an average of those to the single salts at concentrations equal to the total concentration of the mixture. Cross-adaptation was observed between the alkali halides. The results indicate that an explanation of stimulation of the salt receptor must apply to all the salts tested and that both the anion and the cation affect a salt's stimulating effectiveness.     

Direct transesterification of gases by "dry" immobilized lipase

Several different reactor configurations, including single pass, continuous recycle, and batch reactor modes, were used to investigate the effects of temperature and water activity, or relative humidity, on lipase-catalyzed, gas-phase transesterifications. Temperature and relative humidity were controlled both inside reactors and throughout the course of the reaction to account for and optimize their effects. Results indicated that, at low relative humidity, reaction rates increased with temperature up to 60 degrees C. However, when relative humidity was increased, a similar increase in temperature resulted in the loss of nearly all enzyme activity. These results are consistent with the idea that enzymes without free water are more thermally stable. Furthermore, at constant ambient temperatures, production increased dramatically with an increase in relative humidity, confirming the idea that an increase in water activity increases catalytic activity. A mass balance performed on reactors at higher relative humidity revealed that hydrolysis (rather than transesterification) of the ester substrate could significantly decrease product yields.     

Flowering and Growth Response of Peanut Plants (Arachis hypogaea L. var. Starr) at Two Levels of Relative Humidity

Peanut plants (Arachis hypogaea L. var. Starr) grown under two different relative humidities were used in all experiments. All plants were germinated and grown to flowering in the greenhouse. At this time, one group was moved to a growth room under 95% relative humidity. After 50 days the humidity of the growth room was lowered to 50%. The second group was moved into a growth room at 50% relative humidity and after 50 days the humidity was raised to 95%.     

Effect of environmental characteristics on Pythium and Mesocriconema spp. in golf course greens in Alabama

The role the environment has on populations of Pythium and Mesocriconema spp. was investigated at 5 golf course locations in east central Alabama. Every 4 to 5 weeks soil samples were collected from 3 golf greens on each of the 5 golf courses. Environmental data, including air and soil temperature, pH and relative humidity, were also collected. Dilution plating and a combined sieving and sugar flotation procedure were conducted to determine the populations of Pythium and Mesocriconema spp. for each month. Isolates of Pythium from 4 months were also identified. Pythium spp. populations increased as soil temperature and ambient air temperature prior to sampling decreased (P < 0.05). Pythium spp. populations were highest in the winter and lowest in the spring. At some locations, populations of Mesocriconema spp. increased as soil acidity and populations of Pythium spp. decreased (P < 0.05) and as ambient air temperature prior to sampling increased (P < 0.05). Eight species of Pythium were isolated from 4 months, with Pythium rostratum being the most commonly isolated. Results suggest that Pythium and Mesocriconema spp. prefer different soil environments.     

Development of rabbit embryos during a 96-h period of in vitro culture after superovulatory treatment under conditions of elevated ambient temperature.

The effects of elevated ambient temperature on the response to exogenous gonadotropins were evaluated in female New Zealand White rabbits exposed to 33+/-1 degrees C (mean +/- SE) and 10-30% relative humidity (8 h/day) during a 5-day period. Does were treated with pFSH (0.3 mg/0.3 ml Standard Armour) twice daily during three consecutive days with a minimum interval of 8 h between injections. Six hours after the last FSH injection all does were removed from the experimental chamber, given hCG (25 IU/kg) and paired overnight. Nineteen hours after pairing, embryos were flushed from the reproductive tracts, evaluated, and subjected to in vitro culture during a 96-h period. The ovulatory responses to exogenous gonadotropins and fertilization rates did not differ significantly under conditions of elevated ambient temperature, whereas fewer blastocysts and increased number of degenerate embryos were observed after culture. We conclude that although hyperthermia was induced during exposure to elevated ambient temperature, it did not alter the ovulatory responses to gonadotropin treatment and plasma concentrations of FSH and LH compared with does in a thermoneutral environment. Exposure of donor rabbits to elevated ambient temperature before mating, however, increased embryonic degeneration.     

Environmental conditions and their impact on immunocompetence and pathogen susceptibility of the Caribbean termite Nasutitermes acajutlae

1. Little is known about interactions between environmental conditions surrounding insects and their immune responses. 2. The environment in and around termite colonies, including temperature, relative humidity, soil pH, and light was analysed using principal components analysis (PCA). 3. The relationship between these abiotic parameters and two aspects of termite immunity (phenoloxidase activity and lipid content) was examined in field‐caught workers of Nasutitermes acajutlae Holmgren. Finally, termites from warm/dry and cool/moist habitats were exposed to Metarhizium anisopliae to determine their susceptibility to mycosis. 4. PCA indicated that environmental components external to the nest [ambient temperature, ambient relative humidity (RH), soil temperature and light] comprised the majority (PC1 = 37.5%) of variation. Internal variables (nest temperature and RH) and nest volume accounted for 19.6% (PC2) of the variation with pH comprising 12.9% (PC3). 5. AIC and regression models suggested that ambient temperature was most strongly and positively associated with immune variables and that relative humidity may also play a role. Termites from warm/dry colonies were less susceptible to M. anisopliae than termites from cool/moist colonies. 6. Thus, termites nesting in warmer habitats may exhibit increased immune‐related measures and reduced susceptibility to mycosis compared with termites from cooler habitats.     

Evaporative heat loss from group-housed growing pigs at high ambient temperatures

The effects of relative humidity and ambient temperature on evaporative heat loss were studied in 12 trials each with a group of 10 gilts with an initial BW of 61.7 kg (58.0–65.5 kg). The ambient temperature inside a respiration chamber was increased by 2 °C d⁻¹ starting at 16 °C and ending at 32 °C. Relative humidity was set at 50%, 65% or 80% and remained constant within each trial. The animals had free access to feed and water. Skin temperature (SkinT), total heat production (HP), evaporative heat loss (EvapH), respiration rate (RR), and wallowing of the animals were recorded. SkinT was lowest at 80% relative humidity (P<0.05). For each degree Celsius rise in SkinT, wallowing increased by 0.19% (P<0.05). For each degree Celsius rise in ambient temperature, total HP decreased by 115 kJ pig⁻¹ d⁻¹ and EvapH increased by 290 kJ pig⁻¹ d⁻¹ (P<0.05). It was concluded that under constant high ambient temperature and relative humidity, the pigs clearly employ respiratory evaporation to lose heat. Wallowing showed the importance of skin EvapH with higher temperatures, especially at high relative humidity. This study shows the importance of evaporative cooling from the skin. The implication is that pigs at high ambient temperatures, especially in combination with a high relative humidity, should be able to wet themselves. For animal welfare and environmental reasons, it is important that they are able to wet their skin.     

The mechanical properties of stratum corneum: I. The effect of water and ambient temperature on the tensile properties of newborn rat stratum corneum

The tensile properties of the outermost layer of skin of neonatal rats, the stratum corneum, were investigated at a constant strain rate as a function of moisture content and ambient test temperature. The results show that the mechanical behavior of this membrane, whose primary constituent is the fibrous protein keratin, can be significantly altered by variations in both the sorbed water content and ambient temperature. In particular, a brittle to ductile transition was observed at 25°C once the hydration level exceeded 70% relative humidity. Similarly, an identical phenomenon moisture concentrations were maintained at 10 g H₂O/100 g dry protein. Differential scanning calorimetry measurements showed the presence of a molecular relaxation process which migrated from 42°C at 40% relative humidity to −18°C at 95% relative humidity. It is postulated that this relaxation process, possibly corresponding to the glass transition of the fibrous protein component of stratum corneum, is primarily respnsible for the observed behavior.     

Stomatal responses to humidity in Opuntia inermis in relation to control of CO2 and H2O exchange patterns

Summary At constant cladode temperature the stomatal resistance of O. inermis increased when the cladode-air vapor pressure difference was increased and stomatal resistance decreased when the cladode-air vapor pressure difference was lowered. Net CO₂ fixation in the dark was very responsive to these humidity dependent changes in stomatal resistance. Net CO₂ fixation and stomatal resistance in the light did not respond to changes in cladode-air vapor pressure differences in the light under the conditions tested. When temperature response functions for dark CO₂ fixation were examined at constant ambient humidity, the reduction in dark CO₂ fixation at higher temperatures was largely due to stomatal closure in response to the increased vapor pressure difference. The water requirement for net CO₂ fixation in the dark at typical nocturnal vapor pressure differences was about 10 times lower than that of net CO₂ fixation in the light at vapor pressure differences typical of the late afternoon. The role of the stomatal responses to humidity in determining the patterns and rates of net CO₂ exchange in the light or dark, and its possible ecological significance is discussed.     

Effect of Temperature on Survival of Airborne Mycoplasma pneumoniae

Aerosols of Mycoplasma pneumoniae were prepared at each of eight relative humidities between 0 and 85% and at five separate temperatures between 10 and 43 C. Survival of these organisms was found to be a function of both relative humidity and temperature. However, the temperature response was mediated by humidity in that the effects of temperature could be observed only if some water vapor was present. At all temperatures, survival of M. pneumoniae in aerosols was found to be best at the extremes of relative humidity. The effects of temperature were such that irrespective of relative humidity an increase in temperature resulted in a decreased airborne survival time.     

Influence of temperature on the hygropreference of the Collembolan, Cryptopygus antarcticus, and the mite, Alaskozetes antarcticus from the maritime Antarctic

The hygropreference of adult Cryptopygus antarcticus and Alaskozetes antarcticus was investigated over 2 h at 5, 10 and 20 degrees C, along humidity gradients (9-98% RH) established by means of different salt solutions. Two chamber arrangements were employed, linear and grid, to determine any influence of thigmotactic behaviour on distribution within the RH gradient. The humidity preference of both species varied with temperature. At 5 and 10 degrees C, C. antarcticus distributed homogeneously showing no clear RH preference. At 20 degrees C, this species preferred the highest humidity (98% RH). A. antarcticus demonstrated a preference for the lowest humidity (9% RH) at 5 degrees C, but at 10 degrees C its distribution differed between the two arena types. At 20 degrees C, A. antarcticus showed no clear humidity preference. Assays to control for experimental asymmetries along the gradient; thigmotactic behaviour; and aggregative behaviour exclude these factors as explanations for the observed results. The mean initial water content of samples did not differ significantly between temperature regimes (C. antarcticus: 68.6, 71.1 and 74.3%; A. antarcticus: 68.1, 70.1 and 68.6% at 5, 10 and 20 degrees C respectively), but the level of water loss increased significantly with temperature. The influence of desiccation tolerance and the ecological significance of the observed humidity preferences are discussed.     

The Evaporative Function of Cockroach Hygroreceptors

Insect hygroreceptors associate as antagonistic pairs of a moist cell and a dry cell together with a cold cell in small cuticular sensilla on the antennae. The mechanisms by which the atmospheric humidity stimulates the hygroreceptive cells remain elusive. Three models for humidity transduction have been proposed in which hygroreceptors operate either as mechanical hygrometers, evaporation detectors or psychrometers. Mechanical hygrometers are assumed to respond to the relative humidity, evaporation detectors to the saturation deficit and psychrometers to the temperature depression (the difference between wet-bulb and dry-bulb temperatures). The models refer to different ways of expressing humidity. This also means, however, that at different temperatures these different types of hygroreceptors indicate very different humidity conditions. The present study tested the adequacy of the three models on the cockroach’s moist and dry cells by determining whether the specific predictions about the temperature-dependence of the humidity responses are indeed observed. While in previous studies stimulation consisted of rapid step-like humidity changes, here we changed humidity slowly and continuously up and down in a sinusoidal fashion. The low rates of change made it possible to measure instantaneous humidity values based on UV-absorption and to assign these values to the hygroreceptive sensillum. The moist cell fitted neither the mechanical hygrometer nor the evaporation detector model: the temperature dependence of its humidity responses could not be attributed to relative humidity or to saturation deficit, respectively. The psychrometer model, however, was verified by the close relationships of the moist cell’s response with the wet-bulb temperature and the dry cell’s response with the dry-bulb temperature. Thus, the hygroreceptors respond to evaporation and the resulting cooling due to the wetness or dryness of the air. The drier the ambient air (absolutely) and the higher the temperature, the greater the evaporative temperature depression and the power to desiccate.     

Evidence that humidity influences snake activity patterns: a field study of the Malayan pit viper Calloselasma rhodostoma

Multivariate statistical methods were used to elucidate which environmental factors influence the activity patterns of free-living Malayan pit vipers, Calloselasma rhodostoma. Fourteen adult snakes were implanted with miniature radiotransmitters and located a total of 887 times in 5 months. The pit vipers usually remained coiled on the ground for several consecutive days before moving at night to a new site. Partial correlation tests revealed that the frequency and distance of movements to new sites by tagged snakes were highly positively correlated with ambient relative humidity, but not with rainfall, ambient temperature or the lunar cycle. This finding was corroborated by the frequency with which active non-tagged C. rhodostoma were encountered at night, In each site, the proportion of the snakes' bodies exposed to view was positively correlated with ambient humidity, and the snakes retreated to areas with deeper undergrowth when ambient humidity was low. Overt thermoregulatory behaviour was not observed, and implanted thermosensitive transmitters revealed that the snakes were passive thermoconformers.
These findings seem lo contradict much of the current literature which shows temperature to be the dominant abiotic factor affecting reptilian activity, but most herpetologists have considered only temperate forms. Ambient temperature in our tropical study site was warm and relatively constant throughout the year (mean daily range = 24- 33°C), so the pit vipers could passively maintain body temperature within a fairly narrow range, with a daytime mean of 29.4°C. Ambient relative humidity, on the other hand, was very variable, and confining exposure and activity to periods of high ambient humidity may be necessary to avoid dehydration     

城市河道绿带宽度对空气温湿度的影响

以北京市北五环清河旁侧8段不同宽度的绿带为研究对象, 分别对样地和对照样地的气温和相对湿度进行同步测定, 每2 h测定一次, 每个季节连续测定7天。结果显示: 绿带在春、夏、秋季具有增湿降温效应, 并且此效应随着绿带宽度的增加而不断增强, 夏季的增湿降温效应最强, 春、秋季节的增湿降温效应差别不大; 绿带在冬季具有保温增湿效应, 随着绿带宽度的增加, 保温效应不断增强, 增湿效应不断减弱。四季中, 绿带温湿度变化受环境温度的影响较大, 在一天中的14:00-16:00时段, 春、夏、秋季增湿降温效应最强; 在此时段冬季的保温效应最弱, 增湿效应最强。