Social distancing to combat the COVID-19 pandemic has led to widespread reductions in air pollutant emissions. Quantifying these changes requires a business-as-usual counterfactual that accounts for ...the synoptic and seasonal variability of air pollutants. We use a machine learning algorithm driven by information from the NASA GEOS-CF model to assess changes in nitrogen dioxide (NO.sub.2) and ozone (O.sub.3) at 5756 observation sites in 46 countries from January through June 2020. Reductions in NO.sub.2 coincide with the timing and intensity of COVID-19 restrictions, ranging from 60 % in severely affected cities (e.g., Wuhan, Milan) to little change (e.g., Rio de Janeiro, Taipei). On average, NO.sub.2 concentrations were 18 (13-23) % lower than business as usual from February 2020 onward. China experienced the earliest and steepest decline, but concentrations since April have mostly recovered and remained within 5 % of the business-as-usual estimate. NO.sub.2 reductions in Europe and the US have been more gradual, with a halting recovery starting in late March. We estimate that the global NO.sub.x (NO + NO.sub.2) emission reduction during the first 6 months of 2020 amounted to 3.1 (2.6-3.6) TgN, equivalent to 5.5 (4.7-6.4) % of the annual anthropogenic total. The response of surface O.sub.3 is complicated by competing influences of nonlinear atmospheric chemistry. While surface O.sub.3 increased by up to 50 % in some locations, we find the overall net impact on daily average O.sub.3 between February-June 2020 to be small. However, our analysis indicates a flattening of the O.sub.3 diurnal cycle with an increase in nighttime ozone due to reduced titration and a decrease in daytime ozone, reflecting a reduction in photochemical production.
Social-distancing to combat the COVID-19 pandemic has led to widespread reductions in air pollutant emissions. Quantifying these changes requires a business-as-usual counterfactual that accounts for ...the synoptic and seasonal variability of air pollutants. We use a machine learning algorithm driven by information from the NASA GEOS-CF model to assess changes in nitrogen dioxide (NO2) and ozone (O3) at 5,756 observation sites in countries from January through June 2020. Reductions in NO2 coincide with timing and intensity of COVID-19 restrictions, ranging from 60% in severely affected cities (e.g., Wuhan, Milan) to little change (e.g., Rio de Janeiro, Taipei). On average, NO2 concentrations were (13-23) % lower than business as usual from February 2020 onward. China experienced the earliest and steepest decline, but concentrations since April have mostly recovered and remained within 5% to the business-as-usual estimate. NO2 reductions in Europe and the US have been more gradual with a halting recovery starting in late March. We estimate that the global NOx (NO+NO2) emission reduction during the first 6 months of 2020 amounted to 3.1 (2.6-3.6) TgN, equivalent to 5.5(4.7-6.4) % of the annual anthropogenic total. The response of surface O3 is complicated by competing influences of non-linear atmospheric chemistry. While surface O3 increased by up to 50% in some locations, we find the overall net impact on daily average O3 between February -June 2020 to be small. However, our analysis indicates a flattening of the O3 diurnal cycle with an increase in nighttime ozone due to reduced titration and a decrease in daytime ozone, reflecting a reduction in photochemical production.
Elevated levels of reactive oxygen species and intracellular Ca
play a key role in endothelial barrier dysfunction in acute lung injury. We previously showed that H
O
-induced increases in ...intracellular calcium concentrations (Ca
) in lung microvascular endothelial cells (LMVECs) involve the membrane Ca
channel, transient receptor potential vanilloid-4 (TRPV4) and that inhibiting this channel attenuated H
O
-induced barrier disruption in vitro. We also showed that phosphorylation of TRPV4 by the Src family kinase, Fyn, contributes to H
O
-induced Ca
influx in LMVEC. In endothelial cells, Fyn is tethered to the cell membrane by CD36, a fatty acid transporter. In this study, we assessed the effect of genetic loss or pharmacological inhibition of CD36 on Ca
responses to H
O
H
O
-induced Ca
influx was attenuated in LMVEC isolated from mice lacking CD36 (CD36
). TRPV4 expression and function was unchanged in LMVEC isolated from wild-type (WT) and CD36
mice, as well as mice with deficiency for Fyn (Fyn
). TRPV4 immunoprecipitated with Fyn, but this interaction was decreased in CD36
LMVEC. The amount of phosphorylated TRPV4 was decreased in LMVEC from CD36
mice compared with WT controls. Loss of CD36 altered subcellular localization of Fyn, while inhibition of CD36 fatty acid transport with succinimidyl oleate did not attenuate H
O
-induced Ca
influx. Lastly, we found that CD36
mice were protected from ischemia-reperfusion injury in vivo. In conclusion, our data suggest that CD36 plays an important role in H
O
-mediated lung injury and that the mechanism may involve CD36-dependent scaffolding of Fyn to the cell membrane to facilitate TRPV4 phosphorylation.
Elevated levels of reactive oxygen species and intracellular Ca
2+
play a key role in endothelial barrier dysfunction in acute lung injury. We previously showed that H
2
O
2
-induced increases in ...intracellular calcium concentrations (Ca
2+
i
) in lung microvascular endothelial cells (LMVECs) involve the membrane Ca
2+
channel, transient receptor potential vanilloid-4 (TRPV4) and that inhibiting this channel attenuated H
2
O
2
-induced barrier disruption in vitro. We also showed that phosphorylation of TRPV4 by the Src family kinase, Fyn, contributes to H
2
O
2
-induced Ca
2+
influx in LMVEC. In endothelial cells, Fyn is tethered to the cell membrane by CD36, a fatty acid transporter. In this study, we assessed the effect of genetic loss or pharmacological inhibition of CD36 on Ca
2+
responses to H
2
O
2
. H
2
O
2
-induced Ca
2+
influx was attenuated in LMVEC isolated from mice lacking CD36 ( CD36
−/−
). TRPV4 expression and function was unchanged in LMVEC isolated from wild-type (WT) and CD36
−/−
mice, as well as mice with deficiency for Fyn ( Fyn
−/−
). TRPV4 immunoprecipitated with Fyn, but this interaction was decreased in CD36
−/−
LMVEC. The amount of phosphorylated TRPV4 was decreased in LMVEC from CD36
−/−
mice compared with WT controls. Loss of CD36 altered subcellular localization of Fyn, while inhibition of CD36 fatty acid transport with succinimidyl oleate did not attenuate H
2
O
2
-induced Ca
2+
influx. Lastly, we found that CD36
−/−
mice were protected from ischemia-reperfusion injury in vivo. In conclusion, our data suggest that CD36 plays an important role in H
2
O
2
-mediated lung injury and that the mechanism may involve CD36-dependent scaffolding of Fyn to the cell membrane to facilitate TRPV4 phosphorylation.
Girl’s Leadership Camp for Computing and Robotics AbstractThe C-STEM Center hosted its first annual one-week C-STEM/NCWIT Girl's Leadership Campfor Computing and Robotics for middle school girls on ...July 22-26, 2013. The goal of this camp isto motivate girls in middle school to learn science, technology, engineering, and math (STEM)concepts through a fun and exciting robotics-based curriculum. We want them to be leadersamong their peers and inspire other young girls to gain interest in science and technology. Thecamp was led by three college female students as coaches and assisted by five high schoolfemale students as assistant coaches. The camp was attended by 15 middle school girls fromthe greater Sacramento region. Girls at the camp had learned the basics of robotics, theprinciples of engineering, and C/C++ programming. In addition, they had learned important lifeskills including teamwork, presentation skills, leadership skills, building confidence, andbreaking gender stereotypes The girls also had heard from and discussed with experts invarious science and technology fields to gain exposure to the variety of options they haveavailable to them. At the end of the camp, they had created multi-media video presentationswith robotics, similar to the RoboPlay Video Competition, and presented them to parents andpeers. The girls who participated in the camp were given modular robotics kits to take back totheir middle schools so they can start computing and robotics clubs of their own. Coaches andassistant coaches mentor girls over the academic school year to facilitate the development ofthese clubs and their participation in RoboPlay Competition. In this paper, the curriculum andlesions learned through this first camp will be presented. 1
Social-distancing to combat the COVID-19 pandemic has led to widespread reductions in air pollutant emissions. Quantifying these changes requires a business as usual counterfactual that accounts for ...the synoptic and seasonal variability of air pollutants. We use a machine learning algorithm driven by information from the NASA GEOS-CF model to assess changes in nitrogen dioxide (NO\(_{2}\)) and ozone (O\(_{3}\)) at 5,756 observation sites in 46 countries from January through June 2020. Reductions in NO\(_{2}\) correlate with timing and intensity of COVID-19 restrictions, ranging from 60% in severely affected cities (e.g., Wuhan, Milan) to little change (e.g., Rio de Janeiro, Taipei). On average, NO\(_{2}\) concentrations were 18% lower than business as usual from February 2020 onward. China experienced the earliest and steepest decline, but concentrations since April have mostly recovered and remained within 5% to the business as usual estimate. NO\(_{2}\) reductions in Europe and the US have been more gradual with a halting recovery starting in late March. We estimate that the global NO\(_{x}\) (NO+NO\(_{2}\)) emission reduction during the first 6 months of 2020 amounted to 2.9 TgN, equivalent to 5.1% of the annual anthropogenic total. The response of surface O\(_{3}\) is complicated by competing influences of non-linear atmospheric chemistry. While surface O\(_{3}\) increased by up to 50% in some locations, we find the overall net impact on daily average O\(_{3}\) between February - June 2020 to be small. However, our analysis indicates a flattening of the O\(_{3}\) diurnal cycle with an increase in night time ozone due to reduced titration and a decrease in daytime ozone, reflecting a reduction in photochemical production. The O\(_{3}\) response is dependent on season, time scale, and environment, with declines in surface O\(_{3}\) forecasted if NO\(_{x}\) emission reductions continue.
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