Research on the Growth Mechanism of PM2.5 in Central and Eastern China during Autumn and Winter from 2013–2020

Haze is a majorly disastrous type of weather in China, especially central and eastern of China. The development of haze is mainly caused by highly concentrated fine particles (PM2.5) on a regional scale. Here, we present the results from an autumn and winter study conducted from 2013 to 2020 in seven highly polluted areas (27 representative stations) in central and eastern China to analyze the growth mechanism of PM2.5. At the same time, taking Beijing Station as an example, the characteristics of aerosol composition and particle size in the growth phase are analyzed. Taking into account the regional and inter-annual differences of fine particles (PM2.5) distribution, the local average PM2.5 growth value of the year is used as the boundary value for dividing slow, rapid, and explosive growth (only focuses on the hourly growth rate greater than 0). The average value of PM2.5 in the autumn and winter of each regional representative station shows a decreasing trend as a whole, especially after 2017, whereby the decreasing trend was significant. The distribution value of +ΔPM2.5 (PM2.5 hourly growth rate) in the north of the Huai River is lower than that in the south of the Huai River, and both of the +ΔPM2.5 after 2017 showed a significant decreasing trend. The average PM2.5 threshold before the explosive growth is 70.8 µg m−3, and the threshold that is extremely prone to explosive growth is 156 µg m−3 to 277 µg m−3 in north of the Huai River. For the area south of the Huai River, the threshold for PM2.5 explosive growth is relatively low, as a more stringent threshold also puts forward stricter requirements on atmospheric environmental governance. For example, in Beijing, the peak diameters gradually shift to larger sizes when the growth rate increases. The number concentration increasing mainly distributed in Aitken mode (AIM) and Accumulation mode (ACM) during explosive growth. Among the various components of submicron particulate matter (PM1), organic aerosol (OA), especially primary OA (POA), have become one of the most critical components for the PM2.5 explosive growth in Beijing. During the growth period, the contribution of secondary particulate matter (SPM) to the accumulated pollutants is significantly higher than that of primary particulate matter (PPM). However, the proportion of SPM gradually decreases when the growth rate increases. The contribution of the PPM can reach 48% in explosive growth. Compared to slow and rapid growth, explosive growth mainly occurs in the stable atmosphere of higher humidity, lower pressure, lower temperature, small winds, and low mixed layers.

Advancing Endodormancy Release in Temperate Fruit Trees Using Agrochemical Treatments

Endodormancy in temperate fruit trees like Prunus is a protector state that allows the trees to survive in the adverse conditions of autumn and winter. During this process, plants accumulate chill hours. Flower buds require a certain number of chill hours to release from endodormancy, known as chilling requirements. This step is crucial for proper flowering and fruit set, since incomplete fulfillment of the chilling requirements produces asynchronous flowering, resulting in low quality flowers, and fruits. In recent decades, global warming has endangered this chill accumulation. Because of this fact, many agrochemicals have been used to promote endodormancy release. One of the first and most efficient agrochemicals used for this purpose was hydrogen cyanamide. The application of this agrochemical has been found to advance endodormancy release and synchronize flowering time, compressing the flowering period and increasing production in many species, including apple, grapevine, kiwi, and peach. However, some studies have pointed to the toxicity of this agrochemical. Therefore, other non-toxic agrochemicals have been used in recent years. Among them, Erger® + Activ Erger® and Syncron® + NitroActive® have been the most popular alternatives. These two treatments have been shown to efficiently advance endodormancy release in most of the species in which they have been applied. In addition, other less popular agrochemicals have also been applied, but their efficiency is still unclear. In recent years, several studies have focused on the biochemical and genetic variation produced by these treatments, and significant variations have been observed in reactive oxygen species, abscisic acid (ABA), and gibberellin (GA) levels and in the genes responsible for their biosynthesis. Given the importance of this topic, future studies should focus on the discovery and development of new environmentally friendly agrochemicals for improving the modulation of endodormancy release and look more deeply into the effects of these treatments in plants.

Long-Term Change Analysis of PM2.5 and Ozone Pollution in China’s Most Polluted Region during 2015–2020

In this study, a time change analysis of fine particulate (PM2.5) emission in multi-resolution emission inventory in China (MEIC) from 2013 to 2016 was conducted. It was found that PM2.5 emissions showed a decreasing trend year by year, and that the annual total emission of PM2.5 decreased by 28.5% in 2016 compared with that of 2013. When comparing the observation data of PM2.5 and ozone (O3), it was found that both PM2.5 and O3 show obvious seasonal changes. The emission of PM2.5 in autumn and winter is higher than that in summer, while that of O3 is not. Our study showed that in the 2015–2020 period, annual mean concentrations of PM2.5 and O3 in Beijing varied from 80.87 to 38.31 μg m-3 and 110.75 to 106.18 μg m-3, respectively. Since 2015, the observed value of PM2.5 has shown an obvious downward trend. Compared with 2015, the average annual PM2.5 concentrations in Beijing, Shanghai, Xuzhou, Zhengzhou, and Hefei in 2020 had decreased by 52.62%, 40.35%, 22.2%, 46.84%, and 45.11%, respectively, while O3 showed an upward trend. Compared with the annual averages of 2015 and 2020, Beijing and Shanghai saw a decrease of 4.13% and 8.46%, respectively, while Xuzhou, Zhengzhou, and Hefei saw an increase of 7.08%, 19.46%, and 41.57%, respectively. The comparison shows that PM2.5 is becoming less threatening in China and that ozone is becoming more difficult to control. Air pollution is a modifiable risk factor. Appropriate sustainable control policies are recommended to protect public health.

Surveillance, Epidemiology and Impact of EV-A71 Vaccination on Hand, Foot, and Mouth Disease in Nanchang, China, 2010–2019

After the first national-scale outbreak of Hand, foot, and mouth disease (HFMD) in China, a national surveillance network was established. Here we described the epidemiology and pathogenic profile of HFMD and the impact of EV-A71 vaccination on pathogen spectrum of enteroviruses in the southeastern Chinese city of Nanchang during 2010–2019. A total of 7,951 HFMD cases from sentinel hospitals were included, of which 4,800 EV-positive cases (60.4%) were identified by real-time RT-PCR. During 2010–2012, enterovirus 71 (EV-A71) was the main causative agent of HFMD, causing 63.1% of cases, followed by 19.3% cases associated with coxsackievirus A16 (CV-A16). Since 2013, the proportion of other enteroviruses has increased dramatically, with the sub genotype D3 strain of Coxsackievirus A6 (CV-A6) replacing the dominance of EV-A71. These genetically diverse native strains of CV-A6 have co-transmitted and co-evolved in Nanchang. Unlike EV-A71 and CV-A16, most CV-A6 infections were concentrated in autumn and winter. The incidence of EV-A71 infection negatively correlated with EV-A71 vaccination (r = −0.990, p = 0.01). And severe cases sharply declined as the promotion of EV-A71 vaccines. After 2-year implementation of EV-A71 vaccination, EV-A71 is no longer detected from the reported HFMD cases in Nanchang. In conclusion, EV-A71 vaccination changed the pattern of HFMD epidemic, and CV-A6 replaced the dominance of EV-A71 over time.

Markov chains to determine the probability of climate change for planting selection in the city of Caxias do Sul

ABSTRACT: The Markov stochastic chain model and the analytical hierarchy process (AHP) were used as tools to support decision-making for the best crop-planting choice in the city of Caxias do Sul, Brazil. Temperature and precipitation information were collected from the Meteorological Database for Teaching and Research of the National Institute of Meteorology of Brazil for the period 1997-2017. The stochastic model was applied to obtain the probability of transition between a range of variations for temperature and precipitation. In the second phase of the study, an algebraic model was developed, making it possible to link the probability of the Markov chain transition matrix to the AHP judgment matrix. In the third phase, the AHP was applied as a tool to determine the most beneficial crop that could be planted for the studied city, considering the evaluated criteria: temperature, precipitation, and soil pH. The alternatives for crop planting were carrots, tomatoes, apples, and grapes. These were chosen because they are the most-planted crops in the city of Caxias do Sul. The ranking of the benefit-force results of applying the model for spring was carrots (0.297), apples (0.259), grapes (0.228), and tomatoes (0.215); for summer: grapes (0.261), tomatoes (0.261), apples (0.238), and carrots (0.230); for autumn: carrots (0.316), grapes (0.243), tomatoes (0.228), and apples (0.213); and for winter: carrots (0.327), tomatoes (0.235), apples (0.222), and grapes (0.216). Thus, it was concluded that farmers would have a better chance of success if they planted carrots during the spring, autumn, and winter, and grapes during the summer.

Seasonal mite population distribution on Caryocar brasiliense trees in the Cerrado domain

Caryocar brasiliense Camb. (Malpighiales: Caryocaraceae) trees have a wide distribution in the Cerrado, and it is protected by federal laws. The need to monitor and understand pest damage to crops and forests is a major motivation for the study of population distribution. The mites (Acari) population distributions on C. brasiliense are unknown. We studied seasonal mite population distribution and their ecological indices on C. brasiliense trees in Cerrado areas during three years. Greatest number of Agistemus sp. (Stigmaeidae), Histiostoma sp. (Histiostomidae), Proctolaelaps sp. (Ascidae), and diversity and species richness on leaves of C. brasiliense occurred in the autumn; Tetranychus sp.1 (Tetranychidae) on leaves in the autumn and winter; Histiostoma sp., and Proctolaelaps sp. in fruits in the summer. No significant effect of season was observed in the abundance of Eutetranychus sp., Tetranychus sp.2 (Tetranychidae) and Acaridae. The populations of Acaridae, Eutetranychus sp., Proctolaelaps sp. and Tetranychus sp.1 negatively correlated with temperature. Proctolaelaps sp. and Tetranychus sp.1 correlated negatively with rainfall and Eutetranychus sp. and Proctolaelaps sp. positively with sunlight. The period with low rainfall and relative humidity increases the phytophagous mites and their predators, especially Agistemus sp.. The Tetranychus sp. and Histiostoma sp. species may become pests in C. brasiliense in the Cerrado domain.

Anatomopathological findings of Testudines necropsied in the Distrito Federal, Brazil

ABSTRACT: In order to determine the main anatomopathological findings of Testudines necropsied in the Distrito Federal, all necropsy records performed at the “Laboratório de Patologia Veterinária” of the “Universidade de Brasília” (LPV-UnB) on Testudines during the period from January 2008 to July 2020 were reviewed. The 72 cases reviewed were grouped and classified according to species, sex, origin, season of occurrence, and diagnosis. In 69.44% of the cases the species was informed in the necropsy protocols, which included Phrynops geoffroanus (38%), Trachemys dorbigni (36%), Chelonoidis carbonaria (14%), Chelonoidis denticulata (10%) and Podocnemis expansa (2%). In 30.55% of the cases this parameter was not informed and were classified only as Testudines. In 41.66% of the cases the sex was informed, being female 22.22%, male 19.44%, and 58.33% were not informed. Of these animals 79.16% were from environmental agencies and 20.84% from zoos and/or guardians. In 70.83% of the animals analyzed they were directly related to the autumn and winter seasons, with June being the most frequent month (29.17%). The conclusive diagnosis was possible in 68.05% of the cases. The category of disorders caused by injurious agents (48.97%) was the most prevalent, followed by inflammatory disorders (32.65%) and nutritional and metabolic disorders (28.57%). The main diagnoses were carapace and/or plastron fracture with 30.61%, hepatic steatosis (20.40%) and pneumonia (10.22%). Most cases of carapace or plastron fracture and hepatic steatosis occurred in animals from environmental agencies.

A Study of PM 10, PM 2.5 Concentrations in the Atmospheric Air in Kraków, Poland

The air in Kraków is one of the most polluted in Europe. Polish standards for notification and alert levels for PM10 particulate matterare one of the the highest in Europe and exceed the recommendations of the World Health Organization (WHO) for safe daily concentrations by several times. The article presents the results of airborne dust measurements in three districts of Kraków. The study hasshown that the concentration of PM2.5 and PM10 particulate matter exceeded the annual average permissible levels. Empirical measurements of PM2.5 show significantly higher air pollution values than the data notified by stationary monitoring stations installed intwo locations. The high value of Pearson linear correlation coefficient confirms that weather conditions have a significant impact on airquality in Kraków. Wind speed in the autumn and winter seasons has by far the greatest influence on air quality in al. Krasińskiego,in the Ruczaj and Kurdwanów districts. A strong negative correlation was displayed. Manual measurements should be used to verifydata obtained from air monitoring stations. It is to be expected that, in Kraków, air purity will improve due to the implementation ofan anti-smog resolution and subsidies for the replacement of obsolete heating systems with more environmentally friendly solutions.

Vpliv sezone na in vitro razgradljivost in fermentabilnost krmil v vampovem soku navadnega jelena (Cervus elaphus L.)

Transition from summer to winter changes red deer digestive tract physiology and digestive processes. The objective of the trial was to determine the effects of season on in vitro apparent (<em>iv</em>ADMD) and true dry matter (<em>iv</em>TDMD) digestibility, in vitro gas production parameters and short-chain fatty acid synthesis (SCFA) in red deer hinds of eleven substrates naturally occurring in Slovenia (chestnut fruits, acorns of common and sessile oak, two fresh grasses) and those frequently used in supplemental red deer feeding (two grass hays and two grass silages, apple pomace and sugar beet roots). There were no differences in <em>iv</em>ADMD, <em>iv</em>TDMD, determined by incubation of feeds in buffered rumen fluid, as there were no differences in majority of gas production parameters between autumn and winter season. Only the parameter “C” (specific gas production rate) was frequently higher (<em>p</em> &lt; 0.05) in winter season than in autumn season. The amounts of SCFA were similar between two seasons. However, the proportion of acetic acid tended to be higher in winter, while the proportions of propionic and butyric acid tended to be higher in autumn than in winter especially in high fibre feeds. On contrary, in high starch feeds such as oak acorns and chestnut fruits, the proportion of propionic acid was higher (<em>p</em> &lt; 0.05) in winter, while of butyric acid in autumn (<em>p</em> &lt; 0.05). Despite the fact that the number of used substrates (n = 11) and animal rumen fluid donors (n = 6) were small, these results indicate a shift in rumen microbial metabolism between autumn and winter season.

Assessment of Fire Effects on Surface Runoff Erosion Susceptibility: The Case of the Summer 2021 Forest Fires in Greece

The wildfires of summer 2021 in Greece were among the most severe forest fire events that have occurred in the country over the past decade. The conflagration period lasted for 20 days (i.e., from 27 July to 16 August 2021) and resulted in the devastation of an area of more than 3600 Km2. Forest fire events of similar severity also struck other Mediterranean countries during this period. Apart from their direct impacts, forest fires also render an area more susceptible to runoff erosion by massively removing its vegetation, among other factors. It is clear that immediately after a forest fire, most areas are much more susceptible to erosion. In this paper, we evaluate the erosion hazard of Attica, Northern Euboea, and the Peloponnese that were devastated by forest fires during the summer of 2021 in Greece, in comparison with their geological and geomorphological structures, as well as land cover and management. Given that a very significant part of these areas were burnt during the major conflagrations of this summer, erosion risk, as well as flood risk, are expected to be very high, especially for the coming autumn and winter. For the evaluation of erosion risk, the burnt areas were mapped, and the final erosion-risk maps were constructed through GIS software. The final maps suggest that most of the burnt areas are highly susceptible to future surface runoff erosion events.