Mean Vapor Pressure Research Articles

Input selection and performance optimization of ANN-based streamflow forecasts in the drought-prone Murray Darling Basin region using IIS and MODWT algorithm

Forecasting streamflow is vital for strategically planning, utilizing and redistributing water resources. In this paper, a wavelet-hybrid artificial neural network (ANN) model integrated with iterative input selection (IIS) algorithm (IIS-W-ANN) is evaluated for its statistical preciseness in forecasting monthly streamflow, and it is then benchmarked against M5 Tree model. To develop hybrid IIS-W-ANN model, a global predictor matrix is constructed for three local hydrological sites (Richmond, Gwydir, and Darling River) in Australia's agricultural (Murray-Darling) Basin. Model inputs comprised of statistically significant lagged combination of streamflow water level, are supplemented by meteorological data (i.e., precipitation, maximum and minimum temperature, mean solar radiation, vapor pressure and evaporation) as the potential model inputs. To establish robust forecasting models, iterative input selection (IIS) algorithm is applied to screen the best data from the predictor matrix and is integrated with the non-decimated maximum overlap discrete wavelet transform (MODWT) applied on the IIS-selected variables. This resolved the frequencies contained in predictor data while constructing a wavelet-hybrid (i.e., IIS-W-ANN and IIS-W-M5 Tree) model. Forecasting ability of IIS-W-ANN is evaluated via correlation coefficient (r), Willmott's Index (WI), Nash–Sutcliffe Efficiency (ENS), root-mean-square-error (RMSE), and mean absolute error (MAE), including the percentage RMSE and MAE. While ANN models are seen to outperform M5 Tree executed for all hydrological sites, the IIS variable selector was efficient in determining the appropriate predictors, as stipulated by the better performance of the IIS coupled (ANN and M5 Tree) models relative to the models without IIS. When IIS-coupled models are integrated with MODWT, the wavelet-hybrid IIS-W-ANN and IIS-W-M5 Tree are seen to attain significantly accurate performance relative to their standalone counterparts. Importantly, IIS-W-ANN model accuracy outweighs IIS-ANN, as evidenced by a larger r and WI (by 7.5% and 3.8%, respectively) and a lower RMSE (by 21.3%). In comparison to the IIS-W-M5 Tree model, IIS-W-ANN model yielded larger values of WI=0.936–0.979 and ENS=0.770–0.920. Correspondingly, the errors (RMSE and MAE) ranged from 0.162–0.487m and 0.139–0.390m, respectively, with relative errors, RRMSE=(15.65–21.00) % and MAPE=(14.79–20.78) %. Distinct geographic signature is evident where the most and least accurately forecasted streamflow data is attained for the Gwydir and Darling River, respectively. Conclusively, this study advocates the efficacy of iterative input selection, allowing the proper screening of model predictors, and subsequently, its integration with MODWT resulting in enhanced performance of the models applied in streamflow forecasting.

Modified physiologically equivalent temperature—basics and applications for western European climate

A new thermal index, the modified physiologically equivalent temperature (mPET) has been developed for universal application in different climate zones. The mPET has been improved against the weaknesses of the original physiologically equivalent temperature (PET) by enhancing evaluation of the humidity and clothing variability. The principles of mPET and differences between original PET and mPET are introduced and discussed in this study. Furthermore, this study has also evidenced the usability of mPET with climatic data in Freiburg, which is located in Western Europe. Comparisons of PET, mPET, and Universal Thermal Climate Index (UTCI) have shown that mPET gives a more realistic estimation of human thermal sensation than the other two thermal indices (PET, UTCI) for the thermal conditions in Freiburg. Additionally, a comparison of physiological parameters between mPET model and PET model (Munich Energy Balance Model for Individual, namely MEMI) is proposed. The core temperatures and skin temperatures of PET model vary more violently to a low temperature during cold stress than the mPET model. It can be regarded as that the mPET model gives a more realistic core temperature and mean skin temperature than the PET model. Statistical regression analysis of mPET based on the air temperature, mean radiant temperature, vapor pressure, and wind speed has been carried out. The R square (0.995) has shown a well co-relationship between human biometeorological factors and mPET. The regression coefficient of each factor represents the influence of the each factor on changing mPET (i.e., ±1 °C of T a = ± 0.54 °C of mPET). The first-order regression has been considered predicting a more realistic estimation of mPET at Freiburg during 2003 than the other higher order regression model, because the predicted mPET from the first-order regression has less difference from mPET calculated from measurement data. Statistic tests recognize that mPET can effectively evaluate the influences of all human biometeorological factors on thermal environments. Moreover, a first-order regression function can also predict the thermal evaluations of the mPET by using human biometeorological factors in Freiburg.

The Afforestation Effect on Regional Climate: Take Xuzhou Region as an Example

Forest coverage has been increasing in the Xuzhou region, Jiangsu Province, China, since the 1960s, increasing from about 1–31.8% in 2013, or expanding by more than 30 times in the past 50 years. Normalized Differential Vegetation Index data which represents ‘the degree of green’ in 1998–2008 also showed an obvious increasing trend in the Xuzhou region. Even though the climate is affected by a population increase and urbanization, the effects of forest vegetation on the regional climate are still very significant in the Xuzhou area. Using statistical analysis, remote sensing and numerical simulation, the main effects of climate on vegetation are as follows. (1) Reduced range of annual temperatures and increased warming rate. Based on meteorological observation data, the mean high temperature showed a declining trend over the 50 year study period, while the mean lowest temperature did increase, and the annual mean temperature range declined from 24.3 °C in the 1960s to 22.0 °C in the 2000s. For the four seasons, the minimum winter temperature increased moderately and the maximum temperature decreased significantly. Simulation results from Regional Climate Model, version 3 (RegCM3) also suggested that with the increase of forest coverage the warming rate decreased over this entire region. (2) Increasing humidity. Based on single point meteorological observations, the mean water vapor pressure rose from 13.4 hPa in the 1960s to 14.2 hPa in the 2000s; the rising trend in winter was the most significant. In addition, results from the RegCM3 model showed coincident conclusions. In the entire Xuzhou region, the water vapor mixing ratio rose from 9.75 kg/kg in the 1960s to 10.35 kg/kg in the 1990s. Furthermore, the relative humidity was 80.5% in the 1980s, and 81.3% in the 1990s, suggesting an increasing trend for atmospheric humidity exists under the warming conditions. (3) Significantly reduced wind speed at and near the earth’s surface. Based on observations, wind speed decreased from 10.99 m/s in the 1960s to 7.59 m/s in the 2000s; in addition, wintertime wind speeds decreased significantly. Data from the RegCM3 model clearly show wind speed at the surface fell from 4.72 m/s in the 1960s to 1.4 m/s in the 1980s, to 1.2 m/s in the 1990s, then to 0.6 m/s in the 2000s in the entire Xuzhou region. (4) Reduced duration of surface sunshine. Weather station data showed that the monthly mean sunshine hours were 198.4 h in the 1960s, but only 165.5 h in the 2000s.

Differences in seasonality and temperature dependency of stand transpiration and canopy conductance between Japanese cypress (Hinoki) and Japanese cedar (Sugi) in a plantation

AbstractIn this paper, we present an investigation of interspecies differences in transpiration of the 2 most common plantation forest tree species in Japan, both in the family Cupressaceae with different northern limits of native distribution, Japanese cypress (Hinoki; Chamaecyparis obtusa Sieb. et Zucc.) and Japanese cedar (Sugi; Cryptomeria japonica D. Don). The stem sap flow rate was measured in 2 nearby stands of similar leaf area index in a 42‐year‐old plantation. Single‐tree and stand‐scale transpiration rates (Etre and Esta, respectively) were observed during an ideal autumn environment. At the stand scale, mean sap flux density of Hinoki was greater than that of Sugi, whereas total sapwood area per ground area was smaller in Hinoki than Sugi. Because the 2 variables had counterbalancing effects on transpiration, Esta of Hinoki was similar to (94% of) that of Sugi. This offset was also found between the mean Etre of the 2 species. Esta was similar between the stands from May to October, whereas Esta of Sugi was notably greater than that of Hinoki from February to April. During these 3 months, the difference in cumulative Esta was 21.7 mm, which accounted for 79% of the difference in annual Esta between Hinoki and Sugi (192 and 219 mm/year, respectively). We found that canopy conductance (Gc) and its sensitivity to the mean vapour pressure deficit during daylight hours in Sugi were particularly high in early spring, whereas those in Hinoki shifted gradually throughout the growing season. This difference was related to the optimal temperature of Gc in Sugi, which was approximately 10 °C lower than that in Hinoki. Our results suggest that plantations of water‐conserving species such as Hinoki produce timber slowly but yield water resources generously. Moreover, for plantations of trees sensitive to high temperature, such as Sugi, managers should be concerned about possible future decline caused by anticipated global warming.

Light use efficiency of a warm-temperate mixed plantation in north China.

Light use efficiency (LUE) is one of the important parameters on calculating terrestrial gross primary productivity (GPP) and net primary productivity (NPP). Based on 5-year (2006-2010) carbon flux and climatic variable data of a mixed plantation in north China, the seasonal and interannual variation of LUE was investigated and the biophysical controls were examined. Our results show that LUE had a distinct seasonal course, and peaked in the vigorous growing season with a value of 0.92-1.27g CMJ-1. During the period of 2006-2010, annual mean LUE ranged between 0.54 and 0.62g CMJ-1, and it was linearly correlated with annual GPP. In the growing season, LUE was significantly linked with the water availability variables (including monthly mean vapor pressure deficit (VPD), precipitation, evaporative fraction (EF), and the ratio of precipitation to evapotranspiration (P/ET)) and canopy conductance (g c). However, EF was a better estimator of LUE compared with other biophysical variables. LUE decreased with an increase of the clearness index (CI), indicating that LUE was higher under cloudy sky conditions than that under sunny sky conditions in the mixed plantation.

Manipulating plant geometry to improve microclimate, grain yield, and harvest index in grain sorghum.

Cultivar selection, planting geometry, and plant population are the key factors determining grain sorghum yields in water deficit areas. The objective of this study was to investigate whether clump geometry (three plants clustered) improves microclimate within crop canopy when plants are grown under varying water levels. In a 2-yr sorghum (Sorghum bicolor L. Moench) greenhouse study, plants were grown at two geometries (clump and conventional evenly spaced planting, ESP), two water levels (high and low, representing well-watered and water-limited condition, respectively), and three soil surface treatments (lid covered, straw-mulched, and bare). Air temperature and relative humidity (RH) within the plant canopy were measured every five minutes at different growth stages. Mean vapor pressure deficits (VPDs) within the clumps were consistently lower than those for ESPs, indicating that clumps improved the microclimate. Clumps had significantly higher harvest index (HI) compared to ESPs (0.48 vs. 0.43), which was largely due to clumps having an average of 0.4 tillers per plant compared to 1.2 tillers per plant for ESPs. Grain yield in the current study was similar between clumps and ESPs. However, our results suggest that improved microclimate was likely a reason for clumps producing significantly higher grain yields compared to ESPs in previous studies.

Assessing the social and environmental determinants of pertussis epidemics in Queensland, Australia: a Bayesian spatio-temporal analysis.

Pertussis epidemics have displayed substantial spatial heterogeneity in countries with high socioeconomic conditions and high vaccine coverage. This study aims to investigate the relationship between pertussis risk and socio-environmental factors on the spatio-temporal variation underlying pertussis infection. We obtained daily case numbers of pertussis notifications from Queensland Health, Australia by postal area, for the period January 2006 to December 2012. A Bayesian spatio-temporal model was used to quantify the relationship between monthly pertussis incidence and socio-environmental factors. The socio-environmental factors included monthly mean minimum temperature (MIT), monthly mean vapour pressure (VAP), Queensland school calendar pattern (SCP), and socioeconomic index for area (SEIFA). An increase in pertussis incidence was observed from 2006 to 2010 and a slight decrease from 2011 to 2012. Spatial analyses showed pertussis incidence across Queensland postal area to be low and more spatially homogeneous during 2006-2008; incidence was higher and more spatially heterogeneous after 2009. The results also showed that the average decrease in monthly pertussis incidence was 3·1% [95% credible interval (CrI) 1·3-4·8] for each 1 °C increase in monthly MIT, while average increase in monthly pertussis incidences were 6·2% (95% CrI 0·4-12·4) and 2% (95% CrI 1-3) for SCP periods and for each 10-unit increase in SEIFA, respectively. This study demonstrated that pertussis transmission is significantly associated with MIT, SEIFA, and SCP. Mapping derived from this work highlights the potential for future investigation and areas for focusing future control strategies.

Determination of a suitable indicator of tomato water content based on stem diameter variation

This paper describes a study on stem diameter variations (SDV) of tomatoes planted in a greenhouse on the North China Plain in autumn. The results indicated that comparing full irrigation (T0) and water stress (T1) treatments, the indexes of MDS (maximum daily shrinkage), predawn leaf water potential and midday stem water potential were all able to diagnose tomato water stress in a timely manner, but the MDS had the advantages of sensitivity and signal intensity that the others lacked. The critical soil water baseline was 75%FC, below which the water stress inner tomato stem was able to be precisely diagnosed by MDS. Statistical analyses of the MDS under T0 and T1 treatments as well as the main meteorological factors showed that the treatments were correlated according to linear correlations and quadratic polynomials respectively, and the key meteorological factors influencing tomato SDV in a greenhouse were the daily mean vapor pressure deficit (VPDm) and daily maximum radiation (Rmax). The prediction equation for MDS consisted of VPDm and Rmax,was able to predict the values of MDS under full irrigation exactly, which could be used as the baseline of the tomato water content diagnosing and irrigation planning.

Diurnal response of effective quantum yield of PSII photochemistry to irradiance as an indicator of photosynthetic acclimation to stressed environments revealed in a xerophytic species

Monitoring responses of plants to stresses in situ using the chlorophyll-fluorescence (ChlF) technique has been of growing interest, but challenged by lack of stable daytime indicators, limiting the method’s application. Seasonal changes in diurnal responses of effective quantum yield of photosystem II (PSII) photochemistry (ΦPSII) to photosynthetically active radiation (PAR) have been assumed to reflect changes in physiological status of plants in changing environments. We examined the responses of diurnal ΦPSII to PAR in relation to environmental factors through continuous season-long monitoring of ChlF of PSII in a desert shrub species, Artemisia ordosica. Response data were analysed with a modification of the diurnal regression method by Durako (2012). Diurnal variation in ΦPSII for A. ordosica was largely controlled by PAR, decreasing with increasing PAR. The rates of the response of diurnal ФPSII to PAR (slopes) were down-regulated by seasonal changes in environmental factors, in particular, high values for daily mean air temperature (Ta) and vapor pressure deficit (VPD), and up-regulated with increases in soil water content (SWC). The y-intercepts of diurnal ФPSII-PAR regressions were linearly related to maximal quantum yield of PSII photochemistry (Fv/Fm) during the growing season, increasing with increasing SWC. Our results confirm the suggestion by Durako (2012) that the y-intercept of diurnal ФPSII-PAR relationship serves as a good proxy for Fv/Fm in non-invasive monitoring of the physiological status of plants with the ChlF technique.

Stem water storage dynamics of Vochysia divergens in a seasonally flooded environment

Stem radius measurements can vary over the short and medium-term in relation to changes in certain environmental parameters, providing useful information about the impacts of climate variation on tree physiology and growth processes. Here, use a variety of approaches to identify the main environmental variables that influence annual stem water dynamics in the tree Vochysia divergens in a seasonally flooded forest in Northwest Pantanal, Brazil. The circadian stem cycle and diel phases of stem radius (contraction, recovery and increment) was quantified over two growth seasons (2013–2015) using high resolution dendrometer measurements. Our results demonstrate that stem radial variation is strongly linked to water availability which, in turn, is significantly associated with soil water content (SWC) and actual vapor pressure (ea). Our data suggest that the duration of contraction and recovery phases are related to SWC, whereas the increment phase is more influenced by the phenological cycle of the tree. The contraction phase has a limiting association with high vapor pressure deficit (VPD) (decoupled from SWC), indicating stomatal regulation. The circadian stem cycle was characterized by monthly fluctuations reflecting atmospheric water demand status. Monthly mean actual vapor pressure (eamean) was strongly associated with annual variation in the amplitude of the circadian stem cycle.

Interrelationships among dry season leaf fall, leaf flush and transpiration: insights from sap flux measurements in a tropical dry deciduous forest

AbstractWe measured the sap flux densities of 12 deciduous trees in a tropical dry deciduous forest with high seasonality of available water located in Cambodia and evaluated the seasonal trends in transpiration and leaf phenology. For all trees, the minimum transpiration was recorded in the middle of the dry season, and almost all trees restarted transpiration before the first monsoon rain. The occurrence of the ‘paradox’ of leaf phenology was confirmed. During the dry season, transpiration was controlled by leaf phenology and decreased with an increase in the duration of the leafless period. In contrast, during the wet season, daily changes in transpiration were determined by changes in evaporative demand. Transpiration during the dry season accounted for more than 30% of the annual total among trees, and at the stand scale, the dry season contribution was 38%. The dry season transpiration was not negligible for the water balance in this ecosystem. The soil water condition in the shallow layer, where the main root system is located, was not the source of transpiration during the dry season. This implied that the root probably extended to a deep layer and absorbed water. The relationships between the mean canopy stomatal conductance and vapour pressure deficit revealed that most trees were isohydric. Isohydric behaviour controlling stomatal openness to avoid xylem hydraulic failure was also confirmed at the stand scale and was advantageous for these trees, allowing them to continue transpiring under the high evaporative demand during the dry season. Copyright © 2015 John Wiley & Sons, Ltd.

Thermal indices in Western part of Turkey

In this study are used heat index, effective temperature, wet bulb globe temperature, and apparent temperature indices. Air vapor pressure, temperature, relative humidity, and wind speed data are very effective meteorological parameters over the sensitive temperature. Daily mean temperature (°C), relative humidity (%), wind speed (m/s), and vapor pressure (hPa) data are used in this study. Using the thermal indices is calculated to long-term data from 49 stations distributed over the western part of Turkey. The Mann-Kendall test is applied to identify statistically significant trends at each series of thermal indices. The results of this study have shown that there are marked spatiotemporal variations in the thermal indices in the western part of Turkey. Increasing trends are stronger in summer compare with other season. Analysis are displayed that the increasing trends have shown warm-hot and discomfort days, especially during the summer season. High values of these indices are mainly connected to Azor high-pressure system and Monsoonal circulation and weakly etesian winds in summer.

Environmental drivers of the spatiotemporal dynamics of respiratory syncytial virus in the United States.

Epidemics of respiratory syncytial virus (RSV) are known to occur in wintertime in temperate countries including the United States, but there is a limited understanding of the importance of climatic drivers in determining the seasonality of RSV. In the United States, RSV activity is highly spatially structured, with seasonal peaks beginning in Florida in November through December and ending in the upper Midwest in February-March, and prolonged disease activity in the southeastern US. Using data on both age-specific hospitalizations and laboratory reports of RSV in the US, and employing a combination of statistical and mechanistic epidemic modeling, we examined the association between environmental variables and state-specific measures of RSV seasonality. Temperature, vapor pressure, precipitation, and potential evapotranspiration (PET) were significantly associated with the timing of RSV activity across states in univariate exploratory analyses. The amplitude and timing of seasonality in the transmission rate was significantly correlated with seasonal fluctuations in PET, and negatively correlated with mean vapor pressure, minimum temperature, and precipitation. States with low mean vapor pressure and the largest seasonal variation in PET tended to experience biennial patterns of RSV activity, with alternating years of “early-big” and “late-small” epidemics. Our model for the transmission dynamics of RSV was able to replicate these biennial transitions at higher amplitudes of seasonality in the transmission rate. This successfully connects environmental drivers to the epidemic dynamics of RSV; however, it does not fully explain why RSV activity begins in Florida, one of the warmest states, when RSV is a winter-seasonal pathogen. Understanding and predicting the seasonality of RSV is essential in determining the optimal timing of immunoprophylaxis.

Changes in the distribution of mechanically dependent plants along a gradient of past hurricane impact

The severity of the effects that large disturbance events such as hurricanes can have on the forest canopy and the associated mechanically dependent plant community (epiphytes, climbers, etc.) is dependent on the frequency and intensity of the disturbance events. Here we investigate the effects of different structural and environmental properties of the host trees and previously modelled past hurricanes on dependent plants in Cusuco National Park, Honduras. Tree-climbing methods were employed to sample different dependent life-forms in ten 150 × 150 m plots. We identified 7094 individuals of dependent plants from 214 different species. For holo- and hemi-epiphytes, we found that diversity was significantly negatively related to past hurricane impact. The abundance of dependent plants was greatly influenced by their position in tree canopy and hurricane disturbance regimes. The relationship between abundance and mean branch height shifts across a gradient of hurricane impact (from negative to positive), which might result from a combination of changes in abundance of individual species and composition of the dependent flora across sites. Mechanically dependent plants also responded to different structural and environmental conditions along individual branches. The variables that explained much of the community differences of life-forms and families among branches were branch surface area and bryophyte cover. The factors that explained most variation at a plot level were mean vapour pressure deficit and elevation. At the level of the individual tree, the most important factors were canopy openness and past hurricane impact. We believe that more emphasis needs to be placed on the effects that past disturbance events have on mechanically dependent plant communities, particularly in areas that are prone to catastrophic perturbations.

Thermodynamic modeling of KCl + H2O and KCl + NaCl + H2O systems using electrolyte NRTL model

A comprehensive thermodynamic model based on electrolyte NRTL activity coefficient model is developed for KCl+H2O binary and KCl+NaCl+H2O ternary systems. To model KCl+H2O binary systems, we identify required binary interaction parameters for (K+Cl−):H2O pair by regressing experimental thermodynamic data including mean ionic activity coefficient, osmotic coefficient, vapor pressure, enthalpy, and heat capacity. To model KCl+NaCl+H2O ternary systems, we obtain required binary interaction parameters for (Na+Cl−):H2O pair from the literature and (K+Cl−):(Na+Cl−) pair by regressing available thermodynamic data including osmotic coefficient, vapor pressure, and solubility for KCl+NaCl+H2O ternary systems. The model accurately represents all thermodynamic properties with temperature from 273.15 to 473.15K and electrolyte concentration up to saturation. This model should be useful for process modeling and simulation of aqueous electrolyte solutions involving KCl.

Qualitative and quantitative assessment of unresolved complex mixture in PM2.5 of Bakersfield, CA

The 2010 CalNex (California Nexus) field experiment offered an opportunity for detailed characterization of atmospheric particulate carbon composition and sources in Bakersfield, CA. In the current study, the authors describe and employ a new protocol for reporting unresolved complex mixture (UCM) in over 30 daily samples. The Bakersfield, CA site has significant contribution from UCM, 2.9 ± 2.2% of the daily OC, which makes it an ideal first application. The new protocol reports two UCM peaks for Bakersfield with unique mean vapor pressure, retention time, mass spectra and daily ambient concentration trends. The first UCM peak, UCM-A, was comprised of semi-volatile compounds including alkanes, alkenes, and alkynes, with a mean vapor pressure of 2E-04 Torr and medium to heavy-duty diesel exhaust as a likely source. The second UCM peak, UCM-B, was comprised of linear, branched, and cyclic alkanes, with a mean vapor pressure of 1E-08 Torr. UCM-B had strong similarities to UCM in the NIST Standard Reference Material 1649b (urban dust) and to previously reported, detailed UCM for a representative Bakersfield sample, with possible sources including: motor vehicle exhaust, agricultural activities, and construction activities.

Childhood intermittent and persistent rhinitis prevalence and climate and vegetation: a global ecologic analysis

BackgroundThe effect of climate change and its effects on vegetation growth, and consequently on rhinitis, are uncertain. ObjectiveTo examine between- and within-country associations of climate measures and the normalized difference vegetation index with intermittent and persistent rhinitis symptoms in a global context. MethodsQuestionnaire data from 6- to 7-year-olds and 13- to 14-year-olds were collected in phase 3 of the International Study of Asthma and Allergies in Childhood. Associations of intermittent (>1 symptom report but not for 2 consecutive months) and persistent (symptoms for ≥2 consecutive months) rhinitis symptom prevalences with temperature, precipitation, vapor pressure, and the normalized difference vegetation index were assessed in linear mixed-effects regression models adjusted for gross national income and population density. The mean difference in prevalence per 100 children (with 95% confidence intervals [CIs]) per interquartile range increase of exposure is reported. ResultsThe country-level intermittent symptom prevalence was associated with several country-level climatic measures, including the country-level mean monthly temperature (6.09°C; 95% CI, 2.06–10.11°C per 10.4°C), precipitation (3.10 mm; 95% CI, 0.46–5.73 mm; per 67.0 mm), and vapor pressure (6.21 hPa; 95% CI, 2.17–10.24 hPa; per 10.4 hPa) among 13- to 14-year-olds (222 center in 94 countries). The center-level persistent symptom prevalence was positively associated with several center-level climatic measures. Associations with climate were also found for the 6- to 7-year-olds (132 center in 57 countries). ConclusionSeveral between- and within-country spatial associations between climatic factors and intermittent and persistent rhinitis symptom prevalences were observed. These results provide suggestive evidence that climate (and future changes in climate) may influence rhinitis symptom prevalence.

Analyses of Transpiration and Growth of Paprika (Capsicum annuum L.) as Affected by Moisture Content of Growing Medium in Rockwool Culture

Since the moisture content (MC) of growing medium closely related with the crop transpiration, the MC should be included to the environmental factors to be considered for irrigation control in soilless culture. The objective of this study was to analyze the transpiration of paprika plants using daily mean solar radiation (RAD) and vapor pressure deficit (VPD) as well as the growth of the plants at different MCs of rockwool growing media. The starting points of irrigation were controlled by a moisture sensor with minimum set points of 40%, 50%, and 60% of MCs. The canopy transpirations were measured for 80 to 120 days after transplanting and analyzed. The transpirations were well regressed with a combination of both RAD and VPD rather than daily mean RAD only under the controlled MCs. The transpiration at 60% MC was higher than those at 50% and 40% MCs. Leaf area, leaf fresh and dry weights at 60% MC were higher than those at 50% and 40% MCs while the number of leaves had no significant difference among the MCs. There were no significant differences in number of fruits and fruit size among all the MCs, while fruit weight was significantly lower at 40% MC than other treatments. Fresh and dry fruit yields were the highest at 60% MC. Therefore it was concluded that the transpiration was affected by the MC of rockwool growing medium and the minimum set point of 50-60% MC of rockwool growing medium gave better effects on the growth of the paprika plants.

Stem water storage in five coexisting temperate broad-leaved tree species: significance, temporal dynamics and dependence on tree functional traits

The functional role of internal water storage is increasingly well understood in tropical trees and conifers, while temperate broad-leaved trees have only rarely been studied. We examined the magnitude and dynamics of the use of stem water reserves for transpiration in five coexisting temperate broad-leaved trees with largely different morphology and physiology (genera Fagus, Fraxinus, Tilia, Carpinus and Acer). We expected that differences in water storage patterns would mostly reflect species differences in wood anatomy (ring vs. diffuse-porous) and wood density. Sap flux density was recorded synchronously at five positions along the root-to-branch flow path of mature trees (roots, three stem positions and branches) with high temporal resolution (2 min) and related to stem radius changes recorded with electronic point dendrometers. The daily amount of stored stem water withdrawn for transpiration was estimated by comparing the integrated flow at stem base and stem top. The temporal coincidence of flows at different positions and apparent time lags were examined by cross-correlation analysis. Our results confirm that internal water stores play an important role in the four diffuse-porous species with estimated 5-12 kg day(-1) being withdrawn on average in 25-28 m tall trees representing 10-22% of daily transpiration; in contrast, only 0.5-2.0 kg day(-1) was withdrawn in ring-porous Fraxinus. Wood density had a large influence on storage; sapwood area (diffuse- vs. ring-porous) may be another influential factor but its effect was not significant. Across the five species, the length of the time lag in flow at stem top and stem base was positively related to the size of stem storage. The stem stores were mostly exhausted when the soil matrix potential dropped below -0.1 MPa and daily mean vapor pressure deficit exceeded 3-5 hPa. We conclude that stem storage is an important factor improving the water balance of diffuse-porous temperate broad-leaved trees in moist periods, while it may be of low relevance in dry periods and in ring-porous species.

Modeling of Strong Electrolytes with ePPC-SAFT up to High Temperatures

An extension of the PPC-SAFT equation of state to treat strong electrolyte aqueous solutions is presented. It is capable of describing the behavior of such systems up to 473 K with a good precision and without requiring temperature-dependent model parameters. Long-range Coulombic interactions are taken into account using the mean spherical approximation (MSA) for a primitive model of the electrolyte solution, and the effect of solvation is described using short-range ion–water interactions mediated through association sites. Pairing between anions and cations is also treated through site–site interactions. A Born term is added to describe the change of dielectric constant resulting from solvation. A single ion-specific, temperature-independent model parameters are used, for 20 alkali-halide aqueous solutions. The Pauling ionic diameters are used for all terms (hard sphere, MSA, and Born). The dispersion energy of the ions is considered negligible. In the resulting ePPC-SAFT model, only the water–ion association energy is considered as an adjustable parameter. The results show coherent energy density behavior with respect to ionic size. The approach allows the calculation of the mean ionic activity coefficient, density, or vapor pressure of the aqueous solutions over a wide range of temperatures and molalities (298–573 K and 0–6 m). Moreover, salting out of carbon dioxide and methane in saline water can also be predicted accurately. A discussion of the changes in ion hydration at different salinity is also presented taking advantage of the model proposed that explicitly includes ion–water site–site interactions.