Preconceptional and prenatal exposure to diurnal temperature variation increases the risk of childhood pneumonia

Background Pneumonia is the leading cause of death and hospitalization among young children worldwide, but its risk factors remain unclear. Objective To evaluate the effect of maternal exposure to diurnal temperature variation (DTV) during preconceptional and prenatal periods on childhood pneumonia. Methods A retrospective cohort study by case-control design was conducted for pneumonia (N = 699) and normal (N = 811) children under age of 14 who were enrolled in XiangYa Hospital, Changsha, China from May 2017 to April 2019. Demographic data including gender, age, birth season, gestational age, parity, mode of delivery, and parental atopy were collected from the electronic medical records in the hospital system. We obtained the data of daily DTV in Changsha during 2003–2019 from China Meteorological Administration. Maternal exposure to DTV during preconceptional and prenatal periods was respectively calculated by the average of daily DTV during one year and three months before conception and entire pregnancy as well as the three trimesters. The association between maternal exposure to outdoor DTV and childhood pneumonia was analyzed by multiple logic regression model. Results We found that childhood pneumonia was significantly associated with exposure to an increase in DTV during one year before conception and entire pregnancy, with ORs (95 % CI) = 2.53 (1.56–4.10) and 1.85 (1.24–2.76). We further identified a significant risk of pneumonia of DTV exposure during the first and second trimester of pregnancy. Sensitivity analysis showed that boys were more susceptible to the effect of prenatal exposure to outdoor DTV during pregnancy particularly in the first two trimesters compared to girls. Conclusions Preconceptional and prenatal exposure to DTV plays an important role in development of childhood pneumonia, especially during the first and second trimesters of pregnancy.

Effects of microtopography, root exudates analogues and temperature variation on CO2 and CH4 production from fire-degraded tropical peat

<p>Despite being an important terrestrial carbon (C) reserve, tropical peatlands (TP) have been heavily degraded through extensive drainage and fire, to an extent where degraded TP occupies one-tenth of the total peatland area in Southeast Asia (as in 2015). Consequently, repeated fires along with frequent flooding can alter the microtopography, vegetation composition as well as higher diurnal temperature variation due to open canopy, where each is known to influence C dynamics. However, assessing the importance of all these variables on-site can be challenging due to difficult site conditions; hence an incubation experiment approach may provide more useful insights in disentangling the complex interplay of these important variables in regulating GHG (CO<sub>2</sub> and CH<sub>4</sub>) production and emissions from fire-degraded tropical peatland areas. Therefore, we conducted an incubation study to investigate the interactions of microtopography (creating water-saturation conditions: mesic, flooded oxic, and anoxic), labile C inputs (in form of root exudate secretion from ferns and sedges), as well as on-site diurnal temperature variation in regulating CO<sub>2</sub> and CH<sub>4</sub> production from fire-degraded tropical peat.</p><p>            We found that CO<sub>2</sub> and CH<sub>4</sub> production significantly varied among treatments and were strongly regulated by microtopography, labile C inputs, and temperature variation. Mesic (oxic) treatments acted as a strong source of CO<sub>2</sub> (230.4 ± 29 µgCO<sub>2 </sub>g<sup>-1 </sup>hr<sup>-1</sup>) and mild sink for CH<sub>4</sub> (-5.6 ± 0.2 ngCH<sub>4 </sub>g<sup>-1 </sup>hr<sup>-1</sup>) compared to anoxic treatments acting as a mild source of CO<sub>2</sub> (61.3 ± 6.2 µgCO<sub>2 </sub>g<sup>-1 </sup>hr<sup>-1</sup>) and strong source of CH<sub>4 </sub>(591.9 ± 112.1 ngCH<sub>4 </sub>g<sup>-1 </sup>hr<sup>-1</sup>). The addition of labile C enhanced both the CO<sub>2</sub> and CH<sub>4</sub> production irrespective of the treatment conditions, whereas the effect of diurnal temperature variation was clearly pronounced in mesic (for CO<sub>2</sub>) and anoxic (for CH<sub>4</sub>) conditions. Q<sub>10</sub> values for both CO<sub>2</sub> and CH<sub>4</sub> production varied significantly with higher values for CO<sub>2</sub> in mesic treatments (1.21 ± 0.28) and higher for CH<sub>4</sub> in anoxic treatments (1.56 ± 0.35). We also observed a gradient across conditions, where flooded oxic treatments showed in-between values both for CO<sub>2</sub> and CH<sub>4</sub> production and temperature sensitivity, further reflecting the importance of on-site peat water-saturation in regulating the GHG production and emission from the fire degraded tropical peatland areas.</p><p>            Overall, these findings highlight how the water-saturation conditions due to microtopographic variation in peat surface, quality, and quantity of labile C secreted from plant communities and temperature variation during a day can influence the GHGs production rates from the fire degraded tropical peat. More importantly, given the current state and extent of degraded tropical peatland areas and future climate and land-use changes as well as frequent fire episodes in the region, our results demonstrate the increasing trend in GHG production from the fire-degraded tropical peatlands in Southeast Asia.</p>

Preconceptional and prenatal exposure to diurnal temperature variation increases the risk of childhood pneumonia

Background: Pneumonia is the leading cause of death and hospitalization among young children worldwide, but its risk factors remain unclear. Objective: To evaluate the effect of maternal exposure to diurnal temperature variation (DTV) during preconceptional and prenatal periods on childhood pneumonia.Methods: A retrospective cohort study by case-control design was conducted for pneumonia (N=699) and normal (N=811) children under age of 14 who were enrolled in XiangYa Hospital, Changsha, China from May 2017 to April 2019. Demographic data including gender, age, birth season, gestational age, parity, mode of delivery, and parental atopy were collected from the electronic medical records in the hospital system. We obtained the data of daily DTV in Changsha during 2003-2019 from China Meteorological Administration. Maternal exposure to DTV during preconceptional and prenatal periods was respectively calculated by the average of daily DTV during one year and three months before conception and entire pregnancy as well as the three trimesters. The association between maternal exposure to outdoor DTV and childhood pneumonia was analyzed by multiple logic regression model. Results: We found that childhood pneumonia was significantly associated with exposure to an increase in DTV during one year before conception and entire pregnancy, with ORs (95% CI) = 2.53 (1.56-4.10) and 1.85 (1.24-2.76). We further identified a significant risk of pneumonia of DTV exposure during the first and second trimester of pregnancy. Sensitivity analysis showed that boys were more susceptible to the effect of prenatal exposure to outdoor DTV during pregnancy particularly in the first two trimesters compared to girls.Conclusions: Preconceptional and prenatal exposure to DTV plays an important role in development of childhood pneumonia, especially during the first and second trimesters of pregnancy.

Pyroelectric nanoplates for reduction of CO2 to methanol driven by temperature-variation

Carbon dioxide (CO2) is a problematic greenhouse gas, although its conversion to alternative fuels represents a promising approach to limit its long-term effects. Here, pyroelectric nanostructured materials are shown to utilize temperature-variations and to reduce CO2 for methanol. Layered perovskite bismuth tungstate nanoplates harvest heat energy from temperature-variation, driving pyroelectric catalytic CO2 reduction for methanol at temperatures between 15 °C and 70 °C. The methanol yield can be as high as 55.0 μmol⋅g−1 after experiencing 20 cycles of temperature-variation. This efficient, cost-effective, and environmental-friendly pyroelectric catalytic CO2 reduction route provides an avenue towards utilizing natural diurnal temperature-variation for future methanol economy.

Preconceptional and prenatal exposure to diurnal temperature variation increases the risk of childhood pneumonia

Background: Pneumonia is the leading cause of death and hospitalization among young children worldwide, but its risk factors remain unclear. Objective: To evaluate the effect of maternal exposure to diurnal temperature variation (DTV) during preconceptional and prenatal periods on childhood pneumonia. Methods: A retrospective cohort study by case-control design was conducted for pneumonia (N=699) and normal (N=811) children under age of 14 who were enrolled in XiangYa Hospital, Changsha, China from May 2017 to April 2019. Demographic data including gender, age, birth season, gestational age, parity, mode of delivery, and parental atopy were collected from the electronic medical records in the hospital system. We obtained the data of daily DTV in Changsha during 2003-2019 from China Meteorological Administration. Maternal exposure to DTV during preconceptional and prenatal periods was respectively calculated by the average of daily DTV during one year and three months before conception and entire pregnancy as well as the three trimesters. The association between maternal exposure to outdoor DTV and childhood pneumonia was analyzed by multiple logic regression model. Results: We found that childhood pneumonia was significantly associated with exposure to an increase in DTV during one year before conception and entire pregnancy, with ORs (95% CI) = 2.53 (1.56-4.10) and 1.85 (1.24-2.76). We further identified a significant risk of pneumonia due to DTV exposure during the first and second trimester of pregnancy. Sensitivity analysis showed that boys were more susceptible to the effect of prenatal exposure to outdoor DTV during pregnancy particularly in the first two trimesters compared to girls. Conclusions: Preconceptional and prenatal exposure to DTV plays an important role in development of childhood pneumonia, especially during the first and second trimesters of pregnancy.

Diurnal Temperature Variation and Using Fever to Screen for Infectious Diseases

Fevers have been used as marker of disease state for hundreds of years and are frequently used to screen for infectious diseases during outbreaks. However, body temperature and fevers have been shown to vary over the course of a day and across individuals by age, sex and other characteristics. The objective of this paper is to describe the individual variation in diurnal temperature patterns during episodes of febrile activity using a database of millions of recorded temperatures across the United States. We then model the probability of recording a fever during a single reading at given time for individuals who are experiencing a febrile episode. We find a wide variation in body temperatures over the course of a day and across individual characteristics. Similarly, the likelihood of recording a fever may vary widely by the time of day when the reading is taken and by an individual's age or sex. These results suggest diurnal temperature variation and demographics should be considered when using body temperature to screen for disease, especially for diseases that are contagious.