温、湿度对美洲斑潜蝇发育、存活及食量的影响

以花斑芸豆Phaseolus vulgaris为食料植物,在不同温、湿度组合下,观测了美洲斑潜蝇Liriomyza sativae的发育、存活及取食特征。结果表明,卵、幼虫和蛹期的发育速率与温度的关系均呈S型曲线。发育起点温度为：卵,8.9℃;幼虫, 10.1℃;蛹,9.6℃;整个未成熟期,9.5℃。有效积温为：卵,57.7日·度;幼虫,53.9日·度;蛹,151.9日·度;整个未成熟期,264.2日·度。湿度对发育速率的影响不明显。温度对存活的影响较大,当温度>34℃或<19℃时,各虫态的存活率都显著降低。湿度对存活率的影响主要发生在蛹期,当湿度低于50%时,蛹的羽化率显著降低。在高温、低湿的条件下,蛹不能羽化。在相对低温下的累计取食面积大于高温时的相应值,在25℃时达到1.6 cm²,而在28℃及以上温度时取食面积只有0.9 cm²左右。     

Synergistic interactions within disturbed habitats between temperature, relative humidity and UVB radiation on egg survival in a diadromous fish

Anthropogenic impacts, including urbanization, deforestation, farming, and livestock grazing have altered riparian margins worldwide. One effect of changes to riparian vegetation is that the ground-level light, temperature, and humidity environment has also been altered. Galaxias maculatus, one of the most widely distributed fishes of the southern hemisphere, lays eggs almost exclusively beneath riparian vegetation in tidally influenced reaches of rivers. We hypothesized that the survival of these eggs is greatly affected by the micro-environment afforded by vegetation, particularly relating to temperature, humidity and UVB radiation. We experimentally reduced riparian vegetation height and altered shading characteristics, tracked egg survival, and used small ground-level temperature, humidity and UVB sensors to relate survival to ground-level effects around egg masses. The ground-level physical environment was markedly different from the surrounding ambient conditions. Tall dense riparian vegetation modified ambient conditions to produce a buffered temperature regime with constant high relative humidity, generally above 90%, and negligible UVB radiation at ground-level. Where vegetation height was reduced, frequent high temperatures, low humidity, and high UVB irradiances reduced egg survival by up to 95%. Temperature effects on egg survival were probably indirect, through reduced humidity, because developing eggs are known to survive in a wide range of temperatures. In this study, it was remarkable how such small variations in relatively small sites could have such a large effect on egg survival. It appears that modifications to riparian vegetation and the associated changes in the physical conditions of egg laying sites are major mechanisms affecting egg survival. The impacts associated with vegetational changes through human-induced disturbances are complex yet potentially devastating. These effects are particularly important because they affect a very small portion of habitat that is required to complete the life history of a species, despite the wide distribution of adults and juveniles across aquatic and marine environments.     

Influence of temperature and relative humidity on the development ofAmblyseius alstoniae (Acari: Phytoseiidae)

Reproduction and development ofAmblyseius alstoniae Gupta is significantly affected by temperature and relative humidity (rh), optimum being a temperature of 25°C andrh of 70%. At this combination, the viability of eggs, fecundity and daily egg production were higher, oviposition period and longevity were of longer duration, and mortality was minimal. Increase or decrease in these temperature andrh levels leads to a drop in fecundity, longevity and oviposition period and an increase in mortality. Longevity of females is always greater than that of males, irrespective of temperature andrh. Female: male ratio decreases with increase in temperature, irrespective ofrh.     

环境因子对真水狼蛛胚胎发育的影响

研究了温度、相对湿度和光照时间对真水狼蛛（Pirata piraticus）胚胎发育的影响。结果表明,温度不仅影响真水狼蛛胚胎发育的全过程,也对胚胎发育的各阶段有影响,在20℃-35℃范围内,随着温度的升高,胚胎发育加快,卵的发育起点温度为11.9℃,低温下,卵的孵化整齐度高温下要高,28℃时,孵化率最高。为探讨真水狼蛛胚胎发育的影响因子和合适条件,考虑温度、相对湿度和光照时间3个因子的综合作用,按照二次正交旋转组合设计的要求安排实验,得出了影响胚胎发育历期、胚胎成形率和孵化率的二次回归模型,并分析了其影响因子,利用孵化率的回归模型,得到了真水狼蛛卵孵化的最优条件为温度为27℃-28.5℃,相对湿度为94％－97％,光照时间为14－17h。     

Influenza virus transmission is dependent on relative humidity and temperature

Using the guinea pig as a model host, we show that aerosol spread of influenza virus is dependent upon both ambient relative humidity and temperature. Twenty experiments performed at relative humidities from 20% to 80% and 5 degrees C, 20 degrees C, or 30 degrees C indicated that both cold and dry conditions favor transmission. The relationship between transmission via aerosols and relative humidity at 20 degrees C is similar to that previously reported for the stability of influenza viruses (except at high relative humidity, 80%), implying that the effects of humidity act largely at the level of the virus particle. For infected guinea pigs housed at 5 degrees C, the duration of peak shedding was approximately 40 h longer than that of animals housed at 20 degrees C; this increased shedding likely accounts for the enhanced transmission seen at 5 degrees C. To investigate the mechanism permitting prolonged viral growth, expression levels in the upper respiratory tract of several innate immune mediators were determined. Innate responses proved to be comparable between animals housed at 5 degrees C and 20 degrees C, suggesting that cold temperature (5 degrees C) does not impair the innate immune response in this system. Although the seasonal epidemiology of influenza is well characterized, the underlying reasons for predominant wintertime spread are not clear. We provide direct, experimental evidence to support the role of weather conditions in the dynamics of influenza and thereby address a long-standing question fundamental to the understanding of influenza epidemiology and evolution.     

Effects of temperature and relative humidity on the stability of paper-immobilized antibodies

The stability of a paper-immobilized antibody was investigated over a range of temperatures (40-140 °C) and relative humidities (RH, 30-90%) using both unmodified filter paper and the same paper impregnated with polyamide-epichlorohydrin (PAE) as supports. Antibody stability decreased with increasing temperature, as expected, but also decreased with increasing RH. At 40 °C, the half-life was more than 10 days, with little dependence on RH. However, at 80 °C, the half-life varied from ~3 days at low RH to less than half an hour at 90% RH, demonstrating that hydration of the antibody promotes unfolding. Antibody stability was not influenced by the PAE paper surface treatment. This work shows that antibodies are good candidates for development of bioactive paper as they have sufficient stability at high temperature to withstand printing and other roll-to-roll processing steps, and sufficient low temperature stability to allow long-term storage of bioactive paper materials.     

Predicting the effect of relative humidity on skin temperature and skin wettedness

The purpose of this research is to investigate the relative humidity effects on skin temperature and skin wettedness for different operative temperatures. For this aim, thermal interactions between human body and environment are simulated. In this simulation, Gagge 2-node model is used but includes some significant modifications. The simulation is to apply the Gagge 2-node model to individual segments rather than to whole body. Also, the results of the simulation are compared with present measurements, and available experimental data and simulated results in the literature in order to present reliability of the 16 segments-Gagge 2-node model. It is determined that the simulation results are in good agreement with measured results obtained from present experiments, and simulated results and experimental data in the literature.     

Effect of changes in relative humidity and temperature on ultrathin chitosan films

We have prepared uniform films of chitosan with thicknesses 20 nm < h < 200 nm by spincoating solutions of chitosan dissolved in dilute acetic acid onto silicon substrates while controlling the spin speed and the relative humidity inside the spincoater. After neutralizing the films, they readily absorbed water in the presence of high humidity. Heating of the films to elevated temperatures caused a large irreversible decrease in the film thickness, a small increase in the index of refraction, and a reduction in water absorption, as measured using ellipsometry. Comparisons of infrared absorption measurements of chitosan films collected before and after heating indicate an increase in the degree of acetylation with heating. Collectively, these observations are consistent with the release of bound water and a chemical change similar to acetylation at elevated temperatures.     

Effects of temperature and relative humidity on biological indicators used for ethylene oxide sterilization.

A study was made to determine the effects of temperature and moisture on the D-value of a common biological indicator. Relative humidity (RH) was varied between 10 and 70% in increments of 10%, and temperature was varied between 30 and 70 degrees C in increments of 10 degrees C. Temperature was found to have a pronounced effect on the D-value. At 60% RH, the D-value varied from 15.0 min at 30 degrees C to 1.1 min at 70 degrees C. When RH was plotted against the average D-value at the various temperatures, the temperature curves at or above 50 degrees C were more erratic and the RH had a significant effect. The study showed that temperature and RH must be controlled if biological indicators are to be properly calibrated for use in ethylene oxide sterilization.     

Influence of relative gas humidity on the inactivation efficiency of a low temperature gas plasma

Aims:  To investigate the effect of relative gas humidity on the inactivation efficiency of a cascaded dielectric barrier discharge (CDBD) in air against Aspergillus niger and Bacillus subtilis spores on PET foils.
Methods and Results:  The inactivation kinetics as a function of treatment time were determined using synthetic air with different relative humidity as the process gas. Spores of A. niger and B. subtilis respectively were evenly sprayed on PET foils for use as bioindicators. In the case of A. niger, increased spore mortality was found at a high relative gas humidity of 70% (approx. 2 log₁₀). This effect was more evident at prolonged treatment times. In contrast, B. subtilis showed slightly poorer inactivation at high gas humidity.
Conclusions:  Water molecules in the process gas significantly affect the inactivation efficiency of CDBD in air.
Significance and Impact of the Study:  Modifying simple process parameters such as the relative gas humidity can be used to optimize plasma treatment to improve inactivation of resistant micro-organisms such as conidiospores of A. niger .     

Effects of temperature and relative humidity on mating and survival of sterile Drosophila suzukii

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is a widely distributed pest species of soft-skinned fruits. Recent studies suggest the use of sterile insect technique (SIT) as a control method for this species; however, many factors can impact effectiveness of a SIT programme, including the environmental conditions. Environmental condition is critical at the time of the release and in the days afterwards, since it may impact sterile insects’ survival and ability to mate. Thus, we verified the influence of temperature and relative humidity on mating and survival of fertile and sterile D. suzukii, when insects were food provided or deprived. Highest mating rates occurred when sterile or fertile flies provided with food were exposed to 25ºC or 81%–100% relative humidity, while temperatures of 10 and 35ºC and humidity below 60% impaired mating. Overall, mating rate among food-deprived flies was low in all temperatures and humidity levels tested, but fertile insects were more prone to mate when compared to sterile flies. Survival was negatively influenced by high temperatures, low relative humidity and food deprivation. The information present in this study is useful to be considered for release of sterile D. suzukii.     

温湿度对黄刺蛾越冬代成虫羽化的影响

研究温度、相对湿度等主要环境因子对黄刺蛾Cnidocampa flavescens(Walker)越冬代成虫羽化的影响。结果表明,20~30℃是成虫羽化的最适宜温度范围,其羽化率分别可达82.7%~87.3%,15℃和35℃下羽化率显著较低。高相对湿度对成虫羽化有利,RH80%和90%下羽化率分别为84.0%、81.0%,羽化率比RH70%以下显著提高。不同温度对黄刺蛾羽化进度有一定影响,在15,20,25,30,35℃下,其羽化高峰期分别出现在第5周、第4周、第2周、第2周和第3周;分别用直线回归和Logisitic回归模拟天数与累计羽化进度的关系,2种模型均极显著。用直线回归模型计算,越冬成虫在25℃下的理论羽化截止日期最早,时间为6月3日。     

The effect of relative humidity on the behaviour and development of Triatoma brasiliensis

Abstract The preference for relative humidity (RH) and suitability of different levels of this environmental parameter were investigated in the haematophagous bug Triatoma brasiliensis Neiva, 1911 (Hemiptera, Reduviidae). The hygropreference of T. brasiliensis was studied using a RH gradient and the effect of different RHs on the egg hatching, nymph mortality and moulting success was also analysed. The results show that egg hatching in first-instar nymphs of T. brasiliensis was lower at extreme RHs and, particularly, it was lowest at 9.3% RH. The survival of starved nymphs was not affected by RH, but the percentage of engorged nymphs and the ecdysis success of these nymphs once fed was diminished strongly by high humidity. Fourth-instar nymphs preferred to stay at the lowest RH during the first 5 days after feeding and during ecdysis. This preference changed markedly during starvation. Fifteen days after ecdysis, the bugs moved towards intermediate humidities, and 30 days after ecdysis they even preferred the most humid sectors of the gradient. Females preferred to lay eggs in dry environments, suggesting that they may not have a particular hygropreference for oviposition, but that they simply lay their eggs at the RHs where they prefer to stay.     

Effects of temperature, relative humidity, absolute humidity, and evaporation potential on survival of airborne Gumboro vaccine virus

Survival of airborne virus influences the extent of disease transmission via air. How environmental factors affect viral survival is not fully understood. We investigated the survival of a vaccine strain of Gumboro virus which was aerosolized at three temperatures (10°C, 20°C, and 30°C) and two relative humidities (RHs) (40% and 70%). The response of viral survival to four metrics (temperature, RH, absolute humidity [AH], and evaporation potential [EP]) was examined. The results show a biphasic viral survival at 10°C and 20°C, i.e., a rapid initial inactivation in a short period (2.3 min) during and after aerosolization, followed by a slow secondary inactivation during a 20-min period after aerosolization. The initial decays of aerosolized virus at 10°C (1.68 to 3.03 ln % min(-1)) and 20°C (3.05 to 3.62 ln % min(-1)) were significantly lower than those at 30°C (5.67 to 5.96 ln % min(-1)). The secondary decays at 10°C (0.03 to 0.09 ln % min(-1)) tended to be higher than those at 20°C (-0.01 to 0.01 ln % min(-1)). The initial viral survival responded to temperature and RH and potentially to EP; the secondary viral survival responded to temperature and potentially to RH. In both phases, survival of the virus was not significantly affected by AH. These findings suggest that long-distance transmission of airborne virus is more likely to occur at 20°C than at 10°C or 30°C and that current Gumboro vaccination by wet aerosolization in poultry industry is not very effective due to the fast initial decay.     

The effect of temperature, relative humidity and rainfall on airborne ragweed pollen concentrations

Major weather parameters have long been known to alter airborne pollen and spore concentrations. The following study was conducted to study the effect of three of these parameters on airborne ragweed pollen concentrations.During the ragweed (RW) season for the years 1997 and 1998, 10 minute pollen collections were taken at least every 4 hours using an Allergenco MK-3 spore trap. Slides were fixed, and counted microscopically at 400X. During this same period, weather parameters were monitored by an Automated Weather Systems recording station located within a few meters of the collector.The ragweed season for this region begins in mid August and ends by mid October. Temperature patterns for the period demonstrated usual daily fluctuations with highs 13 to 35 °C and lows 8 to 24 °C. Relative humidity readings for the period varied between 25 and 100%. Highest RW values were seen after seasonal cooling in September. Daily rainfall for the period varied between 0 and 100 mm. Airborne RW always declined sharply after strong rainfall events (> 10 mm/day). Peak airborne RW concentrations were often associated with the passing of frontal boundaries and the change in wind direction and velocity that accompanies that passing.Factors influencing airborne RW concentrations are multiple and complex, but atmospheric forces have great influence. The passing of major weather fronts and the associated temperature drops, wind disturbances and rainfall are the major factors.     

Bacterial pleomorphism and competition in a relative humidity gradient

The response of different bacterial species to reduced water availability was studied using a simple relative humidity gradient technique. Interestingly, distinct differences in morphology and growth patterns were observed between populations of the same species growing at different relative humidity. Gram-positive cocci increased in cell size as they approached humidity growth limits and staphylococcal species started growing in tetrad/cubical formations instead of their normal grape-like structures. Gram-negative rods displayed wave-like patterns, forming larger waves as they became increasingly filamentous at low humidity. In contrast, cells of the Gram-positive bacterium Bacillus subtilis became shorter, curved, and eventually almost coccoid. Moreover, B. subtilis started to sporulate at low humidity. The altered morphology and/or growth patterns of bacteria growing at low humidity might be more ecologically relevant than their textbook appearance at high humidity since their natural habitats are often dry. Transmission electron microscopic analyses revealed that staphylococci grown at low humidity have significantly thickened cell walls, which may explain why these cells displayed increased resistance to vancomycin. We conclude that our relative humidity gradient technique is widely applicable for investigating effects of relative humidity on microbial survival, growth and competitive success at solid–air interfaces, making it a versatile tool in microbial ecology.     

Effect of temperature and relative humidity on the development and fecundity of Chilo partellus (Swinhoe) (Lepidoptera: Crambidae)

The spotted stemborer, Chilo partellus (Swinhoe) (Lepidoptera: Crambidae), is one of the most important insect pests attacking maize and sorghum in Ethiopia. Recent studies have indicated that the pest is spreading to new locations where it was not reported before. In the current study, laboratory investigations were carried out to determine the combined effect of different levels of relative humidity and temperature regimes on the development and fecundity of C. partellus, as these physical factors are known to play an important role in the life cycle of insects and adaptability to local climate. Developmental time, longevity, potential fecundity and realized fecundity of C. partellus were measured under controlled conditions. Three temperature regimes (22°C, 26°C and 30°C) and three relative humidity levels (40%, 60% and 80%) were tested. It was found that temperature, relative humidity (RH) and their interaction significantly affected the developmental time, adult longevity, potential fecundity and realized fecundity of the pest. Developmental time was inversely related to temperature. Mean duration of C. partellus life cycle was 70.2 days at 22°C and 80% RH, whereas it took only 26.5 days to complete its life cycle at 30°C and 40% RH. Male and female longevity were similar in most cases. The adult life span ranged between 6.9-11.1 days at 22°C and 3.1-7.2 days at 30°C for different levels of relative humidity. The most suitable conditions for C. partellus development and fecundity were 26-30°C temperatures regimes and 60-80% RH levels.