Assessment of the Performance of TROPOMI NO2 and SO2 Data Products in the North China Plain: Comparison, Correction and Application

The TROPOspheric Monitoring Instrument (TROPOMI) aboard the Sentinel-5 Precursor satellite has been used to detect the atmospheric environment since 2017, and it is of great significance to investigate the accuracy of its products. In this work, we present comparisons between TROPOMI tropospheric NO2 and total SO2 products against ground-based MAX-DOAS at a single site (Xianghe) and OMI products over a seriously polluted region (North China Plain, NCP) in China. The results show that both NO2 and SO2 data from three datasets exhibit a similar tendency and seasonality. In addition, TROPOMI tropospheric NO2 columns are generally underestimated compared with collocated MAX-DOAS and OMI data by about 30–60%. In contrast to NO2, the monthly average SO2 retrieved from TROPOMI is larger than MAX-DOAS and OMI, with a mean bias of 2.41 (153.8%) and 2.17 × 1016 molec cm−2 (120.7%), respectively. All the results demonstrated that the TROPOMI NO2 as well as the SO2 algorithms need to be further improved. Thus, to ensure reliable analysis in NCP area, a correction method has been proposed and applied to TROPOMI Level 3 data. The revised datasets agree reasonably well with OMI observations (R > 0.95 for NO2, and R > 0.85 for SO2) over the NCP region and have smaller mean biases with MAX-DOAS. In the application during COVID-19 pandemic, it showed that the NO2 column in January-April 2020 decreased by almost 25–45% compared to the same period in 2019 due to the lockdown for COVID-19, and there was an apparent rebound of nearly 15–50% during 2021. In contrast, a marginal change of the corresponding SO2 is revealed in the NCP region. It signifies that short-term control measures are expected to have more effects on NO2 reduction than SO2; conversely, we need to recognize that although the COVID-19 lockdown measures improved air quality in the short term, the pollution status will rebound to its previous level once industrial and human activities return to normal.

NogoA-expressing astrocytes limit peripheral macrophage infiltration after ischemic brain injury in primates

Astrocytes play critical roles after brain injury, but their precise function is poorly defined. Utilizing single-nuclei transcriptomics to characterize astrocytes after ischemic stroke in the visual cortex of the marmoset monkey, we observed nearly complete segregation between stroke and control astrocyte clusters. Screening for the top 30 differentially expressed genes that might limit stroke recovery, we discovered that a majority of astrocytes expressed RTN4A/ NogoA, a neurite-outgrowth inhibitory protein previously only associated with oligodendrocytes. NogoA upregulation on reactive astrocytes post-stroke was significant in both the marmoset and human brain, whereas only a marginal change was observed in mice. We determined that NogoA mediated an anti-inflammatory response which likely contributes to limiting the infiltration of peripheral macrophages into the surviving parenchyma.

Ethnography of Health and Illness Behaviour in Nigeria

The ineffective initiatives to tackle Nigeria's various health issues have contributed to the marginal change in health outcomes. Besides ignoring the value of tackling public health problems, it will make the situation even worse for vulnerable Nigerians that frequently remain at the wrong end. This work followed a conceptual measure to explain the targets and purpose of the work comprehensively. The study was information was sourced from the Nigerian Ministry of Health through their web search engines, rational analysis and necessary documentation. The main challenges that public health is facing in Nigeria seem to be communicable diseases, vector control on some diseases, maternal deaths, child mortality rates, improper sanitation, hygiene, disease control, non - contagious diseases, and the issue of injuries from some diseases road accidents and many more. At the moment, Nigeria is struggling to accomplish strategic development goals. However, given coordinated action by the Nigerian Government, funding organisations, including NGOs, provide healthcare efficiently and effectively in Nigeria.

Instrumental Variable Estimation in Demographic Studies: The LATE interpretation of the IV estimator with heterogenous effects

Heterogeneous effects of treatment on an outcome is a plausible assumption to make about the vast majority of causal relationships studied in the social sciences. In these circumstances the IV estimator is often interpreted as yielding an estimate of a Local Average Treatment Effect (LATE): a marginal change in the outcome for those whose treatment is changed by the variation of the particular instrument in the study. Our aim is to explain the relationship between the LATE parameter and its IV estimator by using a simple model which is easily accessible to applied researchers, and by relating the model to examples from the demographic literature. A focus of the paper is how additional heterogeneity in the instrument – treatment relationship affects the properties and interpretation of the IV estimator. We show that if the two kinds of heterogeneity are correlated, then the LATE parameter combines both the underlying treatment effects and the parameters from the instrument – treatment relationship. It is then a more complicated concept than many researchers realise.

Performance Modelling and Analysis of IoT based Edge computing policies

In today’s era, the acceptance of IoT-based edge devices is growing exponentially, which creates challenges of data acquisition, processing, and communication. In the edge computing paradigm, intelligence is shifted from the center to the edge by performing specific processing and prediction locally. A strategy based on reducing communication resources between sensors and edge devices is the prime focus of this investigation. It uses a predictive model-based policy at edge devices for the reconstruction of not delivered context vector. A new hybrid Averaged Exponential Smoothening (AES) policy proposed is based on the current context vectors as well as a smoothing vector to reduce reconstruction error and improve the percentage of communication. It is observed that if we send data only when there is a marginal change in data then we can reduce communication overhead as well as keep reconstruction error low. This policy would be suitable for IoT-based edge computing applications for the smart city such as Smart Home, Healthcare, and Intelligent traffic to delivers the power of AI.

Impacts of COVID-19 lockdown restrictions on urban NO2 and O3 level in Germany with consideration of meteorological impacts and seasonal variation

<p>In 2020, the entire world population has witnessed an unprecedented virus outbreak in terms of COVID-19, which led to restrictions in human activities across the world. Strict measures in Germany started on March-21, 2020 and ended on April-30, 2020, while more relaxed measures continued until July 2020. Vehicle traffic volume and industrial activities were drastically reduced, and, as a result, pollutant emission rates were expected to be reduced. Changes in atmospheric pollutant concentrations are an indicator for changes in emission rates although they are not directly proportional as concentrations are heavily influenced by meteorological conditions and as atmospheric photochemical reactions can be non-linear. Without accounting for the influence of meteorology and atmospheric photochemical reactions, a simple comparison of the lockdown period pollutant concentration values with pre-lockdown only to estimate emissions could be misleading. To normalize the effects of meteorological conditions and atmospheric chemical transformation and reactions, we adopted a method of comparing the predicted Business As Usual (BAU) NO<sub>2</sub> and O<sub>3</sub> concentrations, i.e., the expected value of NO<sub>2</sub> and O<sub>3</sub> concentration for 2020 meteorological conditions without lockdown restrictions, with the observed NO<sub>2</sub> and O<sub>3</sub> concentrations. BAU NO<sub>2</sub> and O<sub>3</sub> concentrations corresponding to 2020 meteorological conditions were predicted based on wind speed and sunshine duration (and season of the day) using the previous year NO<sub>2</sub> and O<sub>3</sub> concentrations as the references. Compared to BAU levels, big metropolitan cities in Germany show a decline in observed NO<sub>2</sub> level (-24.5 to -37.7 %) in the strict lockdown period and rebound to the BAU level at the end of July 2020. In contrast, there is a marginal change in O<sub>3</sub> level (+9.6 to -7.4 %). We anticipate that the imbalanced changes in precursors emission (decrease in NO<sub>X</sub> and increase in volatile organic compounds (VOCs) emission) are attributed to the marginal changes in observed O<sub>3</sub> level compared to BAU level; decreased NO<sub>X</sub> would decrease the O<sub>3</sub> concentration due to NO<sub>X</sub>-limited conditions, and increased VOCs would increase the O<sub>3 </sub>concentration. These results imply that the balanced emission control between the VOCs and NO<sub>X</sub> are required to limit the secondary pollutant (O<sub>3</sub>) formation.</p>

The distribution of the tax burden and the income distribution: theory and empirical evidence

We compare the tax burden distribution across incomes and the income share distribution, based on a stochastic dominance approach. We find conditions to assess the progressivity of different sources of taxes, given knowledge of the income share elasticities, which measure the relative marginal change in the income share accruing to each class of income, associated to a marginal increase in income. We first consider a simple setting with only indirect taxes and then extend it to savings and direct taxation. The progressivity of a given set of taxes depends on the correlation between the relative incidence of the different sources of taxation and the income elasticity of household net expenditure. We use this approach to test empirically for the progressivity of the fiscal system.

At what level of corruption does economic growth decrease?

Purpose The purpose of this study is to examine the impact of corruption on economic growth by testing the hypothesis that the relationship between these two variables is nonlinear and by assessing the veracity of the assumption that corruption is always detrimental to economic growth. Several cross-country studies have treated this question but the findings are not universally robust. Design/methodology/approach In this paper, a panel data analysis has been used to examine 88 countries over the 1984-2011 period. A cross-sectional framework is used in which growth rate and the International Country Risk Guide (ICRG) index are observed only once for each country. Findings The findings indicate that beyond an optimal threshold, both high and low corruption levels can decrease economic growth. Under this optimal threshold, a moderate level of corruption, defined by the point of reversal of the curve of the marginal corruption effect on growth, could have advantages for economic growth. Originality/value This paper shows that the threshold would be a corruption level between 2.5 and 3, which represents the “acceptable corruption level”. This result is conforming to one of the ten principles of economics: “Rational people think at the marginal change”. This threshold represents the point where the marginal benefits of corruption are equal to marginal costs incurred by corruption. Conversely, lack of corruption may be a mechanism that slows down growth.

An Extension to Late Rentierism, using a Comparative Compound Diversification Index, to Show the Movement Towards Mixed Mode Economic Diversification and Development, in the GCC States

This study draws together several strands of research, including late rentierism, economic diversification in the GCC states of the UAE, Qatar, Kuwait, Oman, Kingdom of Saudi Arabia, and Bahrain, in an attempt to measure the direction of the trend towards a mixed mode economy. A comparative compound diversification index (CCDI) is developed to measure the movement along the late rentier continuum of development. The research is based on data from various Global Innovation Index (GII) reports and databases, which provide the attributes used to measure the overall trends. It creates a foundation for the ongoing measurement of this trend over the coming decade, and provides a correlation with the oil price fluctuations, thereby measuring how much the GCC states dependence may be changing, however incrementally, and however marginally that may be. The study does confirm a move towards a mixed mode economy, with knowledge-based, technology and innovation led activities at the heart of that incremental and marginal change.

What Happens When We have Winter Heating of Our Rooms?

The illustrious question by German Astrophysicist R. Emden, “Why do we have winter heating?” has been re-examined for air following both the ideal and imperfect gas laws; the internal energy of the air in the room remains unaffected in the former case whereas it increases marginally for the latter one. The findings corresponding to ideal gas law were correlated by Emden with the mass of a person which does not change even though food is constantly consumed. This example corresponds to adulthood when the mass of a person remains more or less constant. But the marginal change of internal energy in the case of van der Waals gas is consistent with three stages of a person — initially a person grows during childhood followed by adulthood when he has more or less constant weight and finally in old age, it deteriorates.