Microclimatic adaptation and differences in food consumption and assimilation efficiency of different shell colour morphs of the land snail Arianta arbustorum

Food consumption and assimilation efficiency of different shell colour morphs adapted to various microclimatic conditions were determined. Five-factor analysis of variance (adaptation temperature, relative humidity, phenotypic shell colour, age class and time of acclimatization) was used. There are differences between different levels of adaptation temperature and relative humidity in the effect on food consumption in the two morphs. The interaction of these two factors is also significant. There is no effect of the phenotypic shell colour on the food consumption, but there is a relation between shell colour and adaptation temperature. Food consumption is greater in the juveniles. The interactions between age class and adaptation temperature or relative humidity are relevant. Acclimatization to these conditions shows a highly significant effect on the food consumption. The brown and yellow morphs of Arianta arbustorum consumed different amounts of food in relation to the adaptation temperature.
Assimilation efficiency is independent of temperature but declines at high relative humidity. There is a relation between adaptation temperature and relative humidity, but not between the phenotypic shell colour and age class factors. The yellow morphs show higher assimilation efficiencies than the brown morphs during cold adaptation to 5 °C and at the highest level of relative humidity (98%).     

Dampness,mites and respiratory allergy

Summary This paper reviews the relationships between humidity, house-dust mites and respiratory allergy. In vitro relationship between relative humidity and house-dust mite growth are quite clear cut. In real conditions also, there is a significant association between relative humidity and the presence of live mites. The relevance of house-dust mites for respiratory allergy lies on clinical, physiopathological and mostly on epidemiological data. The latter demonstrate a correlation between exposure to mites and risk of sensitization and development of overt allergic diseases. Lastly, humidity of dwellings is linked to respiratory allergy. These results should lead to building safer dwellings for allergic subjects, or modifying existing dwellings. In this respect, emphasis should be put on a proper ventilation rate and also a proper behaviour of inhabitants in order to minimize humidity production.     

Stomatal Response to Environment with Sesamum indicum. L

Leaf resistance of Sesamum indicum L. increased when the humidity gradient between leaf and air was increased, at moderate temperatures, even though calculated carbon dioxide concentrations within the leaf decreased slightly. Mesophyll resistance remained relatively constant when humidity gradients were changed, indicating that the increases in leaf resistance were mainly caused by reductions in stomatal aperture and that nonstomatal aspects of photosynthesis and respiration were not affected. Low carbon dioxide concentrations inside the leaf decreased but did not eliminate resistance response to the humidity gradient. Internal carbon dioxide concentrations had little effect on resistance in humid air but had moderate effects on resistance with large humidity gradients between leaf and air. Stomatal response to humidity was not present at high leaf temperatures. Effects of humidity gradients on photosynthetic and stomatal responses to temperature suggested that large humidity gradients may contribute to mid-day closure of stomata and depressions in photosynthesis.     

The Interaction Effects of Temperature and Humidity on Emergency Room Visits for Respiratory Diseases in Beijing,China

Few epidemiological studies have been reported as to whether there was any interactive effect between temperature and humidity on respiratory morbidity, especially in Asian countries. The present study used time-series analysis to explore the modification effects of humidity on the association between temperature and emergency room (ER) visits for respiratory, upper respiratory tract infection (URI), pneumonia, and bronchitis in Beijing between 2009 and 2011. Results showed that an obvious joint effect of temperature and humidity was revealed on ER visits for respiratory, URI, pneumonia, and bronchitis. Below temperature threshold, the temperature effect was stronger in low humidity level and presented a trend fall with humidity level increase. The effect estimates per 1 °C increase in temperature in low humidity level were ?2.88 % (95 % confidence interval (CI) ?3.08, ?2.67) for all respiratory, ?3.24 % (?3.59, ?2.88) for URI, ?1.48 % (?1.93, ?1.03) for pneumonia, and ?3.79 % (?4.37, ?3.21) for bronchitis ER visits, respectively. However, above temperature threshold, temperature effect was greater in high humidity level and trending upward with humidity level increasing. In high humidity level, a 1 °C increase in temperature, the effect estimates were 1.84 % (1.55, 2.13) for all respiratory, 1.76 % (1.41, 2.11) for URI, and 7.48 % (4.41, 10.65) for bronchitis ER visits. But, there was no statistically significant for pneumonia. This suggests that the modifying effects of the humidity should be considered when analyzing health impacts of temperature.     

Water potential, turgor and cell wall properties in elongating tissues of the hydrotropically bending roots of pea (Pisum sativum L.)

The hydrotropic bending of roots of an ageotropic pea mutant, ageotropum, was studied in humid air in a chamber with a steady humidity gradient. We examined the effects of atmospheric humidity around the root on the water status of root tissues, as well as the wall growth and the hydraulic properties of the elongating tissues. Atmospheric humidity at the surface of the root was clearly lower on the side orientated towards the air with lower humidity than on the side orientated towards the air with higher humidity. However, there were no differences in water potential and osmotic potential between the tissues that faced air with higher and lower humidities in the elongating and mature regions. Plastic extensibility was higher in the tissues that faced the air with lower humidity than in the tissues that faced the air with higher humidity. No differences in turgor pressure and yield threshold were observed between the tissues that faced air with higher and lower humidities. Therefore, the extensibility of the cell wall appeared to be responsible for the different growth rates of tissues in root hydrotropism. A further probable cause of the hydrotropical bending of roots is changes in the hydraulic conductance in the elongating tissues. Since the hydrotropic bending of roots occurred only when a root tip was exposed to a humidity gradient, hydrotropism might occur after perception of a difference in humidity by the root tip, with accompanying changes in cell wall extensibility and hydraulic conductance.     

Leaf hydraulic conductivity and stomatal responses to humidity in amphistomatous leaves

The response of stomata to changes in humidity for a single surface of an amphistomatous leaf was investigated in Xanthium strumarium and Vicia faba using gas exchange and direct observation of stomatal apertures. The stomatal response to humidity for a given surface was found to be the same whether or not the humidity for the opposite surface was changed concurrently. Stomata on the surface for which humidity was constant showed no response to changes in humidity for the opposite surface. Despite large changes in epidermal turgor on the surface for which humidity was changed, there was no change in epidermal turgor for the surface with constant humidity. Measurements of transpiration and epidermal turgor as functions of the mole fraction gradient of water between leaf and air were used to calculate a value for leaf hydraulic resistance. The results suggest that in these species, the mechanism for the stomatal response to humidity resides in the epidermis or the mesophyll very close to the epidermis, and that most of the hydraulic resistance of the leaf occurs between the xylem and the evaporating sites.     

KIRA指标的拓展及其在中国植被与气候关系研究中的应用

根据Kira以月平均气温5℃为界的热量指数和干湿度指数概念,提出了以月平均气温10℃为界的生物热量指数,包括生物温暖指数(BWI)和生物寒冷指数(BCI),并修正其干湿度指数为生物干湿度指数(BK).利用中国689个标准气象台站的资料,分析我国主要植被类型分布与热量因子和干湿度因子的关系,得出两者之间较好的相关性,生物温暖指数、寒冷指数和干湿度指数的散点图较好地表现了中国各植被类型与气候指标的关系和格局.以10℃为界的生物温暖指数不仅对我国森林植被的地理分布和温度气候带的划分具有较好的指示作用,而且对西南部高山、亚高山地区的植被与气候关系指示性较强;生物寒冷指数则对亚热带和热带的指示性很好,能够较好区分亚热带南部及热带地区;由热量指数和降水量综合得出的生物干湿度指数,对中国西北部干旱、半干旱区以至全国的植被分布与水分、热量因子的关系分析有较好的应用价值.     

Effects of temperature and humidity on emergence dynamics of Plutella xylostella (Lepidoptera: Plutellidae)

The effects of temperature and humidity on the emergence patterns of diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), were studied at four temperatures (20, 25, 28, and 33 degrees C),three relative humidities (50, 70, and 90%) and a photoperiod of 14:10 (L:D) h. Both sexes emerged primarily in the late afternoon to early morning, and the peaks of emergence varied depending on temperature and humidity. Females emerged significantly earlier than males. Incubation at 33 degrees C and 90% RH had a significant effect on the emergence rate, but no significant interaction was found between temperature and humidity. Emergence duration was 25.3 h for both sexes at 90% RH, with emergence duration at 33 degrees C lower than the other treatments. The sex ratios of diamondback moth under different temperature and humidity treatments were approximately 1:1, and there were no significant effects of temperature and humidity or interactions between these two factors.     

Low rates of change enhance effect of humidity on the activity of insect hygroreceptors

The inability to measure humidity during stimulation has so far prevented us from understanding the contribution of moist cells and dry cells to orientation in a gradient of humidity. The problem was solved in the present study by means of a UV-absorption hygrometer that made it possible to monitor humidity at a rate of 100 Hz. The antennal moist and dry cells of the cockroach were exposed to humidities alternatively falling or rising at low rates between -1% RH s(-1) and +1% RH s(-1) (relative humidity). Impulse frequency of both types of cells depended simultaneously on instantaneous humidity and its rate of change. High frequencies of the moist cells signal high humidity. But at a given humidity, the response frequency is higher still when humidity is also rising. Conversely, high frequencies of the dry cell signal low humidity, and frequency is higher still at a given humidity when humidity is also falling. These responses ensure that the cockroach spent a minimum time in environments where desiccation or hydration occur and may thus protect the animal from emerging accidentally from under cover into moving air. In the constant-humidity retreat of the cockroach, fluctuating or even drifting discharge frequencies could serve as an early warning: return!     

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。     

Experimental penetration of Trichophyton mentagrophytes into human stratum corneum

We present confirmation of the experimental penetration of Trichophyton mentagrophytes into human stratum corneum under designated conditions of temperature and humidity. When stratum corneum, obtained from healthy human heel region, was incubated at 100% humidity, mycelium was observed in the corneum layer on day 2 at 35 °C and 27 °C, and on day 4 at 15 °C. At 90% humidity, the hyphae penetrated into the stratum corneum on day 4 at 35 °C, and on day 6 at 27 °C. Whereas, at 80% humidity, no fungal elements were observed in the stratum corneum at both 27 °C and 35 °C for up to 7 day. These data suggested that humidity was a more important environmental factor for penetration than temperature, and that at least 90% humidity is necessary for dermatophytes to penetrate into the stratum corneum within a few days. Mean humidity in the interdigital space between the fourth and fifth toes was found to be approximately 98%. This revised version was published online in June 2006 with corrections to the Cover Date.     

实验兔脚皮炎与相对湿度的相关性及对热原筛选实验的影响分析

目的分析实验兔脚皮炎发病率与相对湿度的相关性及脚皮炎实验兔对热原筛选实验合格率的影响。方法将2006、2007年实验室相对湿度记录、实验兔脚皮炎记录及热原筛选实验记录进行汇总统计,并对数据进行生物学分析。结果实验室相对湿度超过70％时,可导致实验兔脚皮炎发病率的升高,二者存在显著相关性（P〈0．01）;有脚皮炎的实验兔可降低筛选实验的合格率,二者存在显著相关性（P〈0．01）;实验兔基础体温的高低,对筛选合格率有显著影响（P〈0．0001）。结论实验兔的脚皮炎发病率与环境相对湿度有显著的正相关性,当实验室相对湿度超过实验兔适宜湿度范围时,可导致其脚皮炎的发病率上升;有脚皮炎的实验兔与无脚皮炎的实验免相比,可显著降低热原筛选实验的合格率。     

红松阔叶混交林林隙光量子通量密度、气温和空气相对湿度的时空分布格局

以小兴安岭原始红松阔叶混交林林隙为研究对象,通过对林隙内光量子通量密度(PPFD)、气温和空气相对湿度进行连续观测,比较其间的时空分布格局.结果表明：晴天和阴天阔叶红松林林隙的PPFD日最大值均出现在11:00—13:00,晴天林隙内各个时段最大值出现位置不同,日最大值出现在林隙北侧林冠边缘处;而阴天各个时段最大值均处于林隙的中心.林隙内月平均PPFD 为6月最高、9月最低,极差7月最大.林隙内晴天气温的峰值出现在9:00—15:00,而阴天气温峰值在15：00—19：00,均位于林隙中心南8 m.5:00—9:00林隙各点阴天的气温都高于晴天,9:00—19:00则相反.月平均气温为6月最高、9月最低.晴天和阴天空气相对湿度的峰值均出现在5:00—9:00,日最大值在林隙西侧林冠边缘处,且阴天的相对湿度始终大于晴天.月平均相对湿度为7月最高、6月最低.晴天PPFD的异质性大于阴天,而气温和相对湿度的异质性则不明显.生长季内不同月份PPFD、气温和空气相对湿度的最大值所处位置不同.PPFD和气温的月均值在林隙中心及附近变化梯度较大,而相对湿度的月均值则在林隙边缘变化梯度较大.     

水份含量对紫膜薄层某些光学性质的影响

本文研究在乾燥紫膜薄层中不同水合程度对光循环中间体M衰减速率,对园二色谱(CD)和蛋白紫外荧光光谱的影响.在相对湿度小于70%时,M衰减速率相对稳定,不随湿度改变而变化;但当湿度大于70%时,则衰减速率急剧上升.从可见区的CD光谱中,也发现了在相对湿度大于70%后,旋转强度急剧上升.蛋白紫外荧光光谱随湿度增加未发现有明显变化.实验结果说明一定水份的含量对紫膜完成质子泵功能是必不可少的,它能改变色素团的微环境,从而改变色素团和蛋白间的相互作用.     

稻麦轮作生态系统中土壤湿度对N2O产生与排放的影响

通过对太湖地区稻麦轮作生态系统的N₂O排放及土壤湿度进行系统观测和开展一系列模拟实验,研究了降雨和土壤湿度对N₂O排放和产生过程的影响.结果表明,春季和秋季麦田N₂O排放与降雨量呈明显正相关,但水稻田和冬季麦田的N₂O排放不受降雨影响.稻麦轮作周期内的N₂O排放较强烈地受土壤湿度制约,土壤湿度为田间持水量的97～100%或84～86%WFPS(土壤体积含水量与总孔隙度的百分比)时,N₂O排放最强,低于此湿度范围时,N₂O排放通量与土壤湿度呈正相关,反之,则呈负相关.田间N₂O排放随土壤湿度的变化形式与模拟条件下培养土壤样品的N₂O产生率变化非常相似,但前者的最佳湿度范围比后者窄,而且偏小.     

Measurement of gas exchange rates in plant tissue culture vessels

The aerial microenvironment in culture vessels has a significant effect on the growth and development of plantlets in vitro. Since the gas exchange between outside air and inner air can influence the microenvironment of culture vessel, it is necessary to measure the air exchange rate for various vessels. In this study, water vapor was used as the tracer gas, and the change of absolute humidity inside the vessel was calculated continuously by the measured values of a relative humidity sensing element. The outside environment was maintained at constant humidity level by a saturated salt solution. The RH data were transformed into absolute humidity and the specific humidity ratio. The air exchange rates of several tissue culture vessels were then calculated. The exchange rate was between 0.0145 h^–1 to 0.0376 h^–1. This technique provides an inexpensive, rapid and simple way to determine the air exchange rate of a culture vessel within a short period. The effects of the air current velocities on the exchange rates of vessels were also determined.     

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.     

Humidity affects genetic architecture of heat resistance in Drosophila melanogaster

Laboratory experiments on Drosophila have often demonstrated increased heritability for morphological and life‐history traits under environmental stress. We used parent–offspring comparisons to examine the impact of humidity levels on the heritability of a physiological trait, resistance to heat, measured as knockdown time at constant temperature. Drosophila melanogaster were reared under standard nonstressful conditions and heat‐shocked as adults at extreme high or low humidity. Mean knockdown time was decreased in the stressful dry environment, but there was a significant sex‐by‐treatment interaction: at low humidity, females were more heat resistant than males, whereas at high humidity, the situation was reversed. Phenotypic variability of knockdown time was also lower in the dry environment. The magnitude of genetic correlation between the sexes at high humidity indicated genetic variation for sexual dimorphism in heat resistance. Heritability estimates based on one‐parent–offspring regressions tended to be higher under desiccation stress, and this could be explained by decreased environmental variance of heat resistance at low humidity. There was no indication that the additive genetic variance and evolvability of heat resistance differed between the environments. The pattern of heritability estimates suggests that populations of D. melanogaster may have a greater potential for evolving higher thermal tolerance under arid conditions.     

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.