Effect of temperature and relative humidity on some biological traits of two <i>Trichogramma cacoeciae</i> (Marchal) (Hymenoptera: Trichogrammatidae) strains

Previous studies have found relationships between DNA methylation and various environmental contaminant exposures. Associations with weather have not been examined. Because temperature and humidity are related to mortality even on non-extreme days, we hypothesized that temperature and relative humidity may affect methylation. We repeatedly measured methylation on long interspersed nuclear elements (LINE-1), Alu, and 9 candidate genes in blood samples from 777 elderly men participating in the Normative Aging Study (1999-2009). We assessed whether ambient temperature and relative humidity are related to methylation on LINE-1 and Alu, as well as on genes controlling coagulation, inflammation, cortisol, DNA repair, and metabolic pathway. We examined intermediate-term associations of temperature, relative humidity, and their interaction with methylation, using distributed lag models. Temperature or relative humidity levels were associated with methylation on tissue factor (F3), intercellular adhesion molecule 1 (ICAM-1), toll-like receptor 2 (TRL-2), carnitine O-acetyltransferase (CRAT), interferon gamma (IFN-γ), inducible nitric oxide synthase (iNOS), and glucocorticoid receptor, LINE-1, and Alu. For instance, a 5°C increase in 3-week average temperature in ICAM-1 methylation was associated with a 9% increase (95% confidence interval: 3% to 15%), whereas a 10% increase in 3-week average relative humidity was associated with a 5% decrease (-8% to -1%). The relative humidity association with ICAM-1 methylation was stronger on hot days than mild days. DNA methylation in blood cells may reflect biological effects of temperature and relative humidity. Temperature and relative humidity may also interact to produce stronger effects.

Study’s Excerpt:• The research aimed to determine the effects of temperature and humidity on Powdery mildew Pathogens of Watermelon.• Sphaerotheca fulginea subjected to different temperature and humidity levels.• Temperature of 30°C was found optimum for fuliginea conidial germination and Invivo infection.• High Humidity of >70% triggered the fuliginea infection on Watermelon.Full Abstract:Powdery mildew (PM) caused by (Sphaerothe cafuliginea fungus) is a major foliar disease affecting greenhouse and field-grown watermelon throughout the world. Infection at early stage of watermelon plant by S. fuliginea reduces seedling and vigor, causes premature desiccation of leaves. This research aims to investigate the effects of temperature and relative humidity on the conidial germination, and in vivo infection of Sphaerotheca fuliginea on healthy watermelon plant. The experiment was laid out on Completely Randomized Design (CRD) in the laboratory with (5) replications in each case. Conidia of Sphaerotheca fuliginea was subjected to different temperature and relative humidity of (30, 35, 40, 45 °C and 52%,63%,86% , 94% respectively) for conidial germination, mycelium length, width and in vivo infection. Results showed that lower temperature ranges (30°C-35°C) and higher relative humidity (>70%) often to enhances the conidial germination of Sphaerotheca fuliginea and in vivo infection, research revealed how Powdery Mildew be triggered by lower temperature of 30°C and high relative humidity of ~94% in watermelon (Citrullus lanatus) in Shagari Local Government Area of Sokoto State. Based on the result obtained it can be recommended that the best time for Watermelon cultivation around Shagari Local Government Area should be from February to May in which temperature and relative humidity level are not favourable for the development of Powdery Mildew.

The effects of temperature and relative humidity on phenol-formaldehyde resin bonding were evaluated. Two flakes in a lap-shear configuration were bonded under an environment of controlled temperature (110 °C, 120 °C, 130 °C, 140 °C) and relative humidity (41%, 75%, 90%) for a series of time periods (0.25 to 16 min). The lap-shear specimens were then shear-tested on a mechanical testing machine and the results were used to establish a family of bond strength development curves at each temperature and level of relative humidity. At 110°C, the higher relative humidity appeared to retard resin bonding. The effects of relative humidity diminished as temperature increased to 140 °C. Bond strength development was chemical ratecontrolled. The rate of bond strength development at each relative humidity follows a first order reaction mechanism. The activation energy of resin-wood bonding, determined by bonding kinetics, was higher than that of resin alone, determined by differential scanning calorimetry. This comparison indicates that to form a strong resin-wood bond, a higher energy level might be required.

The respiration rate of fruits is influenced by the temperature and relative humidity (RH) of the surrounding air. This research aims to determine the effect of storage air temperature and RH on the respiration rate of the coated banana. In this work, the bananas were coated with a combination of sago starch and cellulose nanofiber then was measured the respiration rate. The respiration rate was investigated using a closed system at three different temperatures namely 10°C, 17.5°, and 27°C, and three levels of RH that are about 70%, 80%, and 90% during 10 days of storage. Changes in oxygen and carbon dioxide concentrations were measured daily. The respiration rates of the coated banana (O2 consumption (RO2) and CO2 production (RCO2)) and the RQ value was influenced by storage time, storage temperature, and the interaction of those two factors. RH was found to have no significant effect on these three parameters. The Arrhenius equation was found to be suitable for the RO2 and RCO2 model and can be used to predict RO2 or RCO2 of the coated banana under real conditions for RH ranging from 70% to 90% and storage temperature ranging from 10°C to 27°C.

In this study, the effects of temperature and relative humidity on the resonant frequency of a micro-electro-mechanical system (MEMS) cantilever resonator under atmospheric pressure (p=101325 Pa) are discussed. The squeeze film damping (SFD) problem of MEMS cantilever resonators is modeled by solving the modified molecular gas lubrication (MMGL) equation, the equation of motion of micro-cantilever, and their appropriate boundary conditions, simultaneously in the eigen-value problem. The effective viscosity (µeff(RH, T)) of moist air is utilized to modify the MMGL equation to consider the effects of temperature and relative humidity under atmospheric pressure. Thus, the effects of temperature (T) and relative humidity (RH) on the resonant frequency of MEMS cantilever resonators over a wide range of gap thicknesses and under atmospheric pressure are discussed. The results showed that the frequency shift increases as the relative humidity and temperature increase. The influence of relative humidity on the resonant frequency becomes more significant under conditions of higher temperature and smaller gap thickness.

The joint and interaction effect of high temperature and humidity on mortality in China

The effect of relative humidity (RH) of air on the mechanical properties of roasted turkey breast was studied using a rheological model. The raw turkey breast with a moisture content of ca. 75%, protein content of ca. 24% and fat content of ca. 1% was roasted in a convection steam oven at 180C and five RH levels (0, 20, 50, 70 and 90%). The elastic modulus decreased, whereas the flow consistency index and the flow limit increased with an increase in RH from 0 to 70%. Significant differences were observed in elastic modulus between RH levels of 0 and 20% versus 50, 70 and 90%. As regard the flow consistency index and the flow limit, significant differences were observed between 0 versus 50 and 70% RH levels. No significant differences in those values were reported at RH exceeding 50%. The flow consistency index was independent of RH of air level.Practical ApplicationsThe proposed method can be used to determine the effect of treatment parameters on the rheological properties of the analyzed product, and to assess its final quality. The presented mathematical model allows to evaluate the rheological properties of turkey breast meat roasted in a convection steam oven independently of the type of mechanical tests used to determine those values. The obtained results support the selection of roasting parameters (relative humidity) aimed at yielding a product with the desired rheological properties.

SummaryTo investigate the effect of temperature and relative humidity (RH) on the absorption kinetics of self‐activated and moisture‐activated O2 scavengers for packaged food, kinetic parameters of each O2 scavenger were evaluated at 43%, 75% or 100% RH and at 10, 25 and 40 °C respectively. Absorption kinetics was well described by a first‐order reaction with an Arrhenius type behaviour. For moisture‐activated O2 scavengers, a proper high RH was needed to ensure a high O2 absorption capacity, as average O2 absorption capacity was 3.82 mL at 43% RH and 43.40 mL at 75% RH. When the temperature increased, O2 absorption rate constant ascended from 10 °C to 40 °C on an average of 0.153 and 0.306 h−1 in moisture‐activated and self‐activated O2 scavengers respectively. We could take the effect of temperature and RH into account when we chose different types of iron‐based O2 scavengers for packaged food.

To understand the relationships of daily average temperature and relative humidity with outpatient visit frequency of patients with chronic obstructive pulmonary disease, and whether temperature and relative humidity have a lag effect. The effects of daily average temperature, relative humidity, and their interaction in Lanzhou between January 2013 and December 2017 on the outpatient visit frequency of chronic obstructive pulmonary disease patients were analyzed using Poisson generalized linear regression model combined with distributed lag non-linear model. There was a non-linear relationship between the daily average temperature and the outpatient visit frequency of chronic obstructive pulmonary disease patients. Between -12 °C and -8 °C, the outpatient visit frequency increased gradually with the decrease of the daily average temperature, and the outpatient visit frequency of chronic obstructive pulmonary disease patients increased by 11.60% per 1 °C of temperature drop. The daily average relative humidity also presented a non-linear effect on the outpatient visit frequency chronic obstructive pulmonary disease patients. When the daily average relative humidity was in the range of 15%-28%, the outpatient visit frequency increased gradually with the decrease of relative humidity, and the outpatient visit frequency of COPD patients increased by 37.05% for every 1% decrease of relative humidity. A synergistic effect was found between air temperature and relative humidity on chronic obstructive pulmonary disease, that is, under different relative humidity, the effect of air temperature was different. When the daily average relative humidity ≤ 50% and the daily average temperature≤11 °C, the effect of air temperature was the most obvious. For every 1 °C drop in temperature, the daily out-patient visit frequency of the whole population increased by 12.68% (5.62% in males and 7.56% in females; 5.24% in population < 65 years and 14.74% in population ≥ 65 years). When the daily average relative humidity > 50% and the daily average temperature ≤ 11 °C, the daily outpatient visit frequency of the whole population increased by 9.00% for every 1 °C drop in temperature (< 65 years, 7.11%; ≥65 years, 10.93%). When the daily average temperature > 11 °C, the temperature had no effect on the daily outpatient visit frequency of chronic obstructive pulmonary disease patients under different relative humidity. The presence of a certain extent of interaction is observed between daily average temperature and relative humidity. Low-temperature and dry environment (relative humidity ≤50%, temperature ≤11 °C) as well as low-temperature and high-humidity environment (relative humidity > 50%, temperature ≤11 °C) can both increase the risk of outpatient visit in chronic obstructive pulmonary disease patients.

Active food package incorporating an ethanol vapour-controlled release sachet has been known for its efficacies to delay microbial proliferation in fresh fruit and vegetable. High humidity inside the package could be utilized as a stimulus for conditional releases as a means to stabilize the sachet prior to being used. The present research was undertaken to investigate the effects of relative humidity on ethanol vapour release from the hydrophilic film-based sachet. The prototype 4-side sealed sachets were made of either ethylene vinyl acetate (EVA) or laminated film comprising EVA and Nylon/PE (designated as ENP). A gas chromatogram equipped with a flame-ionized detector (FID-GC) was employed to analyze ethanol vapour concentration levels released from both sachet types and accumulated in headspaces of sealed glass beakers having different relative humidity (RH) levels. For a given RH level, the concentrations in the headspaces containing the ENPbased sachets were lower than those containing the EVA-based sachets. Delays of ethanol vapour release up to 24 h were observed in the ENP-based sachet system, whilst these did not occur among EVA-based sachets. Both sachets could release ethanol vapour with faster rates and subsequently higher concentrations accumulated at the very high relative humidity level (90-99% RH), compared to lower RH levels (60-89% RH). However, the release rates and concentration levels accumulated in 60-75% RH were not different from those in 80-89% RH. Extents of water vapour uptake by films were relatively small when the films were kept at the lower RH levels, but these became exponentially increased when the RH levels were ≥90%RH. Experimental data on water vapour uptakes were well predicted by an exponential model (R2 0.92-0.99; and root mean square of errors (RMSE) 0.004-0.054). Overall, experiment findings indicate that the ENP film caused delayed ethanol vapour releases from the sachet. The relative humidity levels had significant effects on the releases from hydrophilic film-based sachets

Effect of temperature and relative humidity on ultraviolet (UV254) inactivation of airborne porcine respiratory and reproductive syndrome virus

Objectives: This study was performed to examine bioaerosols in indoor air in public restrooms, as well as to assess the effects of air temperature and relative humidity on bioaerosol levels. Methods: A cross-sectional survey was performed in ten male and ten female restrooms. An air sampler (Anderson type) was used for sampling total suspended bacteria (TSB), Gram-negative bacteria (GNB), Gram-positive bacteria (GPB), opportunistic bacteria (OP), Staphylococcus spp., and total suspended fungi (TSF). Results: The levels of TSB were <TEX>$10-10^2CFU/m^3$</TEX> and TSF <TEX>$10-10^2CFU/m^3$</TEX>, respectively. The GNB level was <TEX>$0-10CFU/m^3$</TEX>, and GPB and OP levels were <TEX>$10-10^2CFU/m^3$</TEX>. Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) were detected in 90% of the restrooms. The GPB level was higher in the female restrooms than in the male restrooms (p < 0.05). TSB, GNB, and TSF showed higher levels in restrooms in buildings over 30 years old (p < 0.01). The main effect of air temperature or relative humidity and interaction effect of the two factors on the TSB level were significant (p < 0.05), while the effect of relative humidity on the TSF level was significant (p < 0.001). Conclusions: These results indicate that there is a wide variation in the bioaerosol levels among different restrooms. The observed differences in bioaerosol levels reflect different building histories. The effects of air temperature and/or relative humidity reveal that bioaerosol levels may vary according to season or time of day. Future research is needed to further characterize the relation between the bioaerosol levels and surface contamination in restrooms.

With increasing walnut production in California, walnuts are stored for longer times. It is increasingly important to optimize storage conditions, wherever possible, to reduce quality degradation. We examined the effects of temperature (5, 15, and 25 °C) and relative humidity (20%, 40%, and 60% in year 1 and 40%, 60%, and 80% in year 2) on the rate of quality degradation of four walnut varieties. The relationship between water activity and moisture content was investigated for each variety. In addition, the effects of harvest timing (early vs. late) and storage as shelled or in-shell product were investigated. Later harvested walnuts had darker kernel color (P &lt; 0.001), and walnuts stored as kernels (shelled) had higher rates of peroxide formation and free fatty acid development than walnuts stored in-shell. Temperature had a significant effect on quality with faster degradation at higher temperatures. There was a significant interaction between temperature and relative humidity effects on quality. The effects of relative humidity were often not significant at storage temperatures of 5 °C but were apparent at 15 °C and at 25 °C. Managing relative humidity during walnut storage is difficult under typical commercial storage conditions; however, when low temperature storage is used, quality is preserved even when relative humidity is not controlled, although storage at 80% relative humidity should be avoided. To reduce the rate of color darkening and rancidity development during commercial storage, operators should emphasize storage at lower temperatures, at least below 15 °C.

Theoretically, free space optical communication has been proved to be viable and capable of providing high data rates, secured and license-free transmission but it is seriously susceptible to atmospheric conditions/turbulence majorly fog and other primary weather parameters. In this work, the effects of temperature and relative humidity on ultra-high frequency (UHF) optical communication during fog have been investigated using an optical instrumentation system capable of measuring signal strengths and concurrently measured the temperature and relative humidity at two unlicensed frequencies (900 and 1800 MHz). Temperature shows high level negative correlation with signal attenuation between -0.6060 and -0.8599 while relative humidity shows positive correlation coefficient with signal attenuation between 0.5737 and 0.7551 for the frequencies 900 and 1800 MHz respectively. This implies that the relationship between the optical signal attenuation, temperature and relative humidity are higher, stronger and statistically significant. In addition, empirical models for predicting the variations of temperature and relative humidity on UHF optical signal attenuation during fog were developed.

Modeling the effect of temperature and relative humidity on the ethylene oxide fumigation of Salmonella and Enterococcus faecium in whole black peppercorn