scholarly journals Developing a novel hybrid model for the estimation of surface 8-h ozone (O<sub>3</sub>) across the remote Tibetan Plateau during 2005–2018

2020 ◽  
Author(s):  
Rui Li ◽  
Yilong Zhao ◽  
Ya Meng ◽  
Wenhui Zhou ◽  
Ziyu Zhang ◽  
...  

Abstract. We developed a two-stage model named random forest-generalized additive model (RF-GAM) based on satellite data, meteorological factors, and other geographical covariates to predict the surface 8-h O3 concentration across the remote Tibetan Plateau. The 10-fold cross-validation result suggested that RF-GAM showed the excellent performance with the highest R2 value (0.76) and lowest root mean square error (RMSE) (14.41 μg/m3) compared with other seven machine learning models. The predictive performance of RF-GAM model showed significantly seasonal discrepency with the highest R2 value observed in summer (0.74), followed by winter (0.69) and autumn (0.67), and the lowest one in spring (0.64). Additionally, the unlearning ground-observed O3 data collected from open websites were applied to test the transferring ability of the novel model, and confirmed that the model was robust to predict the surface 8-h O3 concentration during other periods (R2 = 0.67, RMSE = 25.68 μg/m3). RF-GAM was then used to predict the daily 8-h O3 level over Tibetan Plateau during 2005–2018 for the first time. It was found that the estimated O3 concentration displayed a slow increase from 64.74 ± 8.30 μg/m3 to 66.45 ± 8.67 μg/m3 2005 through 2015, whereas it decreased from the peak to 65.87 ± 8.52 μg/m3 during 2015–2018. Besides, the estimated 8-h O3 concentrations exhibited notably spatial variation with the highest values in some cities of North Tibetan Plateau such as Huangnan (73.48 ± 4.53 μg/m3) and Hainan (72.24 ± 5.34 μg/m3), followed by the cities in the central region including Lhasa (65.99 ± 7.24 μg/m3) and Shigatse (65.15 ± 6.14 μg/m3), and the lowest one in some cities of Southeast Tibetan Plateau such as Aba (55.17 ± 12.77 μg/m3). Based on the 8-h O3 critical value (100 μg/m3) scheduled by World Health Organization (WHO), we further estimated the annually mean nonattainment days over Tibetan Plateau this period. It should be noted that most of the cities in Tibetan Plateau shared with the excellent air quality, while several cities (e.g., Huangnan, Haidong, and Guoluo) still suffered from more than 40 nonattainment days each year, which should be paid more attention to alleviate local O3 pollution. The result shown herein confirms the novel hybrid model improves the prediction accuracy and can be applied to assess the potential health risk, particularly in the remote regions with sparse monitoring sites.

2020 ◽  
Vol 20 (10) ◽  
pp. 6159-6175 ◽  
Author(s):  
Rui Li ◽  
Yilong Zhao ◽  
Wenhui Zhou ◽  
Ya Meng ◽  
Ziyu Zhang ◽  
...  

Abstract. We developed a two-stage model called the random-forest–generalised additive model (RF–GAM), based on satellite data, meteorological factors, and other geographical covariates, to predict the surface 8 h O3 concentrations across the remote Tibetan Plateau. The 10-fold cross-validation result suggested that RF–GAM showed excellent performance, with the highest R2 value (0.76) and lowest root-mean-square error (RMSE) (14.41 µg m−3), compared with other seven machine-learning models. The predictive performance of RF–GAM showed significant seasonal discrepancy, with the highest R2 value observed in summer (0.74), followed by winter (0.69) and autumn (0.67), and the lowest one in spring (0.64). Additionally, the unlearning ground-observed O3 data collected from open-access websites were applied to test the transferring ability of the novel model and confirmed that the model was robust in predicting the surface 8 h O3 concentration during other periods (R2=0.67, RMSE = 25.68 µg m−3). RF–GAM was then used to predict the daily 8 h O3 level over the Tibetan Plateau during 2005–2018 for the first time. It was found that the estimated O3 concentration displayed a slow increase, from 64.74±8.30 µg m−3 to 66.45±8.67 µg m−3 from 2005 to 2015, whereas it decreased from the peak to 65.87±8.52 µg m−3 during 2015–2018. Besides this, the estimated 8 h O3 concentrations exhibited notable spatial variation, with the highest values in some cities of the northern Tibetan Plateau, such as Huangnan (73.48±4.53 µg m−3) and Hainan (72.24±5.34 µg m−3), followed by the cities in the central region, including Lhasa (65.99±7.24 µg m−3) and Shigatse (65.15±6.14 µg m−3), and the lowest O3 concentration occurred in a city of the southeastern Tibetan Plateau called Aba (55.17±12.77 µg m−3). Based on the 8 h O3 critical value (100 µg m−3) provided by the World Health Organization (WHO), we further estimated the annual mean nonattainment days over the Tibetan Plateau. It should be noted that most of the cities on the Tibetan Plateau had excellent air quality, while several cities (e.g. Huangnan, Haidong, and Guoluo) still suffered from more than 40 nonattainment days each year, which should be given more attention in order to alleviate local O3 pollution. The results shown herein confirm that the novel hybrid model improves the prediction accuracy and can be applied to assess the potential health risk, particularly in remote regions with few monitoring sites.


Author(s):  
Amir Khodavirdipour ◽  
Motahareh Piri ◽  
Sarvin Jabbari ◽  
Mohammad Khalaj-kondori

AbstractThe novel coronavirus disease 2019 (COVID-19) belongs to coronaviridae families, like sarbecovirus (SARS), and causes pyrexia, pertussis, and acute respiratory distress syndrome (ARDS) in major. Started from Wuhan, China now forced the World Health Organization (WHO) to call it a pandemic. These dreadful figures elevate the need for rapid action for a rapid diagnostic tool, an efficacious therapy, or vaccine for such widespread disease. Here we reviewed all the latest research and trials including conventional antiviral medicines that have a narrow and finite effect on COVID-19. Recently, some advances have been made by a nucleotide/nucleoside analogues (NUC) inhibitor (remdesivir), ivermectin (antiparasitic drug), and convalescent plasma, the later one has more recently been approved by the Food and Drug Administration (FDA). In addition, a clinical-grade soluble human angiotensin-converting enzyme (ACE2), named hrsACE2, was able to inhibit the infection of human blood vessel organoids, as well as the human kidney organoids, by the virus. As of now, innovative therapeutics based on the CRISPR/Cas13d might overcome the challenge of COVID-19 either as a treatment option or precise and rapid diagnostic tool due to its rapid and precise nature. In this updated comprehensive rapid review, we try to cover all recent findings in terms of genomics, diagnosis, prevention, and treatment.


2020 ◽  
Vol 58 (12) ◽  
pp. 2025-2035
Author(s):  
María Sol Ruiz ◽  
María Belén Sánchez ◽  
Yuly Masiel Vera Contreras ◽  
Evangelina Agrielo ◽  
Marta Alonso ◽  
...  

AbstractObjectivesThe quantitation of BCR-ABL1 mRNA is mandatory for chronic myeloid leukemia (CML) patients, and RT-qPCR is the most extensively used method in testing laboratories worldwide. Nevertheless, substantial variation in RT-qPCR results makes inter-laboratory comparability hard. To facilitate inter-laboratory comparative assessment, an international scale (IS) for BCR-ABL1 was proposed.MethodsThe laboratory-specific conversion factor (CF) to the IS can be derived from the World Health Organization (WHO) genetic reference panel; however, this material is limited to the manufacturers to produce and calibrate secondary reference reagents. Therefore, we developed secondary reference calibrators, as lyophilized cellular material, aligned to the IS. Our purpose was both to re-evaluate the CF in 18 previously harmonized laboratories and to propagate the IS to new laboratories.ResultsOur field trial including 30 laboratories across Latin America showed that, after correction of raw BCR-ABL1/ABL1 ratios using CF, the relative mean bias was significantly reduced. We also performed a follow-up of participating laboratories by annually revalidating the process; our results support the need for continuous revalidation of CFs. All participating laboratories also received a calibrator to determine the limit of quantification (LOQ); 90% of them could reproducibly detect BCR-ABL1, indicating that these laboratories can report a consistent deep molecular response. In addition, aiming to investigate the variability of BCR-ABL1 measurements across different RNA inputs, we calculated PCR efficiency for each individual assay by using different amounts of RNA.ConclusionsIn conclusion, for the first time in Latin America, we have successfully organized a harmonization platform for BCR-ABL1 measurement that could be of immediate clinical benefit for monitoring the molecular response of patients in low-resource regions.


2020 ◽  
Vol 14 (4) ◽  
pp. 193-197
Author(s):  
Alan Glasper

In light of the emergence in China of COVID-19, the novel corona virus, emeritus professor Alan Glasper, from the University of Southampton discusses the role of the World Health Organization and other public health institutions in responding to potential new global pandemics and deliberates on the role of NHS staff in coping with infectious disease in clinical environments.


2003 ◽  
Vol 104 (4) ◽  
pp. 415-420 ◽  
Author(s):  
Juan M. BUSTAMANTE ◽  
Héctor W. RIVAROLA ◽  
Alicia R. FERNÁNDEZ ◽  
Julio E. ENDERS ◽  
Ricardo FRETES ◽  
...  

Chagas' disease is caused by Trypanosoma cruzi, which is transmitted by reduviid bugs. The World Health Organization has estimated that about 16–18 million people in the Americas are infected, and that more than 100 million are at risk. In the present study we have used a murine model to analyse if particular T. cruzi strains (Tulahuen strain and SGO-Z12 isolate from a chronic patient) and/or re-infection may determine, during the indeterminate phase of experimental Chagas' disease, changes that could explain the different evolution of cardiac lesions. Re-infected mice reached higher parasitaemias than those infected for the first time. The survival in the indeterminate phase of mice infected with Tulahuen strain was 50.0%, while the SGO-Z12-infected group presented a significantly higher survival rate (77.1%; P<0.01). The SGO-Z12-re-infected group showed a survival rate (70.9%) significantly higher than that of the Tulahuen-re-infected group (37.0%; P<0.01). Electrocardiographic abnormalities were found in 66% of Tulahuen-infected mice, while in SGO-Z12-infected group such abnormalities were found in only 36% of animals (P<0.01). The two groups exhibited similar percentages of electrocardiographic dysfunction on re-infection, although intraventricular blocks were more frequent in Tulahuen-re-infected mice (P<0.01). Hearts from infected or re-infected mice with either parasite showed mononuclear infiltrates. The SGO-Z12-re-infected and Tulahuen-re-infected groups exhibited a significantly diminished affinity (P<0.05) and a significantly increased density (P<0.05) of cardiac β-adrenergic receptors compared with the infected and non-infected groups. The indeterminate phase of Chagas' disease is defined as a prolonged period that is clinically silent, but the present findings show that different T. cruzi strains and re-infection are able to alter the host–parasite equilibrium, and these factors may be responsible for inducing progressive cardiopathy.


2021 ◽  
Vol 18 (1) ◽  
pp. 1-6
Author(s):  
Roselyn Naidu ◽  
Lionel Joseph ◽  
Syed Sauban Ghani

The current study investigated drinking water quality of samples taken from Arolevu village, a locality situated in Nadi, Fiji. The groundwater samples were collected and subjected to a comprehensive physicochemical and biological analysis. The analysis for the drinking water sample was conducted seasonally, six times a year, that is, three for the dry season and three for the wet season. The results retrieved from the analysis were compared to its maximum contamination levels (MCLs) based on the health-based guidelines provided by the World Health Organization (WHO). The WHO standards were used as an attribute to determine the sources of contaminants likely to be present at the study site. A degradation trend in drinking water quality in the context of climate change may lead to potential health impacts. Hence, it is important to understand seasonal variations in drinking water quality. A proper understanding of the drinking water quality through seasonal water analysis for nitrate, nitrite, potassium, calcium, magnesium and chlorine content as well as its microbiological presence to reduce preventable risks such as using calculated amounts of fertilisers and upgrading the sewerage system to alleviate drinking water contamination is devised through this study.


2017 ◽  
Vol 7 (3) ◽  
pp. 378-386 ◽  
Author(s):  
Xiaoqin Zhou ◽  
Yajie Li ◽  
Zifu Li ◽  
Yue Xi ◽  
Sayed Mohammad Nazim Uddin ◽  
...  

The World Health Organization suggests storing human urine for at least 6 months at 20 °C prior to application as fertilizer to reduce the potential health risks from pathogenic organisms. Such a storage condition for human urine, however, not only requires a long period of time and large space but also ignores the risk of nitrogen losses. In this study, human urine underwent thermal treatment during storage to improve disinfection and to inhibit urea hydrolysis. Microbial indicators such as Escherichia coli and fecal coliforms and the concentration of ammonia/ammonium were investigated in urine samples that were stored at 60 °C and 70 °C. Both the inactivation of indicators and decomposition of urea improved under storage temperatures of 60 °C and 70 °C compared with storage under ambient temperature. Therefore, human urine is recommended to be stored at 70 °C for 7 days for hygienic and stabilization purposes. Under this storage condition, pH is maintained below 8.0 and ammonia/ammonium content is maintained at approximately 800 mg/L.


Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1496
Author(s):  
Eun-Hee Lee ◽  
Yunsoo Chang ◽  
Seung-Woo Lee

The coronavirus disease 2019 (COVID-19) pandemic is a general health crisis and has irreversible impacts on human societies. Globally, all people are at risk of being exposed to the novel coronavirus through transmission of airborne bioaerosols. Public health actions, such as wearing a mask, are highly recommended to reduce the transmission of infectious diseases. The appropriate use of masks is necessary for effectively preventing the transmission of airborne bioaerosols. The World Health Organization (WHO) suggests washing fabric masks or throwing away disposable masks after they are used. However, people often use masks more than once without washing or disposing them. The prolonged use of a single mask might—as a result of the user habitually touching the mask—promote the spread of pathogens from airborne bioaerosols that have accumulated on the mask. Therefore, it is necessary to evaluate how long the living components of bioaerosols can be viable on the masks. Here, we evaluated the viability of airborne Bacillus subtilis (B. subtilis) in bioaerosols filtered on woven and anti-droplet (non-woven) face masks. As a simulation of being simultaneously exposed to sand dust and bioaerosols, the viability rates of bioaerosols that had accumulated on masks were also tested against fine dust and airborne droplets containing bacteria. The bioaerosols survived on the masks immediately after the masks were used to filter the bioaerosols, and the bacteria significantly proliferated after one day of storage. Thereafter, the number of viable cells in the filtered bioaerosols gradually decreased over time, and the viability of B. subtilis in bioaerosols on the masks varied, depending on the mask material used (woven or non-woven). Despite the reduction in viability, bioaerosols containing living components were still found in both woven and anti-droplet masks even after six days of storage and it took nine days not to have found them on masks. The number of viable cells in bioaerosols on masks significantly decreased upon exposure of the masks to fine dust. The results of this study should provide useful information on how to appropriately use masks to increase their duration of effectiveness against bioaerosols.


2021 ◽  
Vol 16 (1) ◽  
pp. 128-135
Author(s):  
Anita Y. N. Lim

Abstract I wrote this journal in March 2020 prior to the World Health Organization declaring the COVID-19 infection as a worldwide pandemic on March 11. The situation in Singapore was unfolding even as public healthcare institutions were tasked to lead the charge to contain the novel coronavirus as it was then called. This journal describes my experiences and impressions during my work in an isolation ward at the National University Hospital during this early period. I was to be catapulted into Pandemic Team 3 in the second and third weeks of February 2020. The urgency of hospital measures to respond to the novel coronavirus meant that the general medicine consultant roster which I was on was hijacked to support the pandemic wards. I thought wryly to myself that it was a stroke of genius to commandeer the ready-made roster of senior physicians; it would have been difficult for the roster monster to solicit senior physicians to volunteer when there were still so many unknowns about this virus. Graphic images of the dire situation in Wuhan, China, were circulating widely on social media. It was heart-wrenching to read of Dr. Li Wen Liang’s death. He had highlighted the mysterious pneumonia-causing virus. The video clip of him singing at a karaoke session that went viral underscored the tragedy of a young life cut short. Questions raced in my mind. “Are we helpless to prevent the spread of this virus?” “Is the situation in China to be replicated here in Singapore?” This seemed incredulous, yet, might it be possible? The immediate responses that jumped up within me was “yes, it’s possible, but let’s pray not. Whatever has to be done, must be done.”


2020 ◽  
Vol 3 (3) ◽  
pp. 01-02
Author(s):  
Khadiga Ismail

COVID-19 has high transmissibility and infectivity among human. On January 30, 2020, the World Health Organization (WHO) in an effort to slow down the global spread of the virus declared the outbreak, “A global public health emergency of international concern". The skin manifestations of the novel coronavirus COVID-19 were not recognized at the early stages of the pandemic but have received much recent attention in scientific journals. Reported manifestations range from pseudo-chilblains to a morbilliform (measles-like) exanthem, urticaria, vesicular eruptions, a dengue-like petechial rash and ovate scaling macules, and plaques mimicking pityriasis rosea.


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