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1.
Jiaotong Yunshu Xitong Gongcheng Yu Xinxi/Journal of Transportation Systems Engineering and Information Technology ; 22(3):15-24, 2022.
Article in Chinese | Scopus | ID: covidwho-1924762

ABSTRACT

In order to explore the choice behavior of residents' travel mode in the post-COVID-19 era, a choice behavior experiment was conducted. A mixed Logit model and a latent class conditional Logit model of travel mode choice were constructed based on the data obtained from questionnaire surveys. Stata software was used to calibrate the model parameters, and the main factors influencing residents' travel mode choices were obtained. The results show that both models reflect the heterogeneity of individual travel mode choices. Compared with the mixed Logit model, the latent class conditional Logit model has an improvement of 13% in the goodness of fit and an increase of 3.03% in the prediction accuracy, which provides an effective tool for analyzing individual heterogeneity of travel behavior under public health emergencies. The latent class conditional Logit model divides residents into four and five groups according to the two scenarios of low and medium risk areas. From the perspective of travel mode attributes, the waiting time and the traveling time have become the most important influencing factors for residents to choose the travel modes. From the perspective of personal socio-economic attributes, women with higher incomes are more inclined to choose private cars to travel. The older are more sensitive to travel costs, and men are more willing to choose bus and subway travel. Copyright © 2022 by Science Press.

2.
Chinese Journal of Biologicals ; 34(6):699-703, 2021.
Article in Chinese | EMBASE | ID: covidwho-1894085

ABSTRACT

Objective To explore the application and safety of apheresis technology in collection of Coronavirus Disease 2019 (COVID-19) convalescent plasma (CP), and to analyze the quality characteristics of the plasma. Methods The general data of COVID-19 convalescent plasma (CP) donors, including gender, age, date of discharge or release from medical isolation, were collected based on informed consent. After physical examination, the CP was collected by apheresis technology with plasma separator, inactivated with methylene blue, and determined for severe acute respiratory symptom Coronavirus 2 (SARS-CoV-2) nucleic acid and specific antibody (RBD-IgG) against SARS-CoV-2. Results The collection process went well, and no serious adverse events related to plasma collection were reported during or after the collection. The average age of COVID-19 CP donors was 38 years (n = 933). The distributions of blood groups A, B, AB and 0 in RhD (+) COVID-19 CP were 33. 4%, 29. 2%, 10% and 27. 2% respectively. The plasma donation date was 18 d from the discharge date in average. All the test results of SARS-CoV-2 nucleic acid in CP were negative, while the proportion of plasma samples at SARS-CoV-2 antibody titer of more than 1: 160 was 92. 60%. Conclusion Apheresis technology was safe and reliable. The COVID-19 CP contained high titer antibody. Large-scale collection and preparation of inactivated plasma against SARS-CoV-2 played an important role in the treatment of COVID-19.

3.
PubMed; 2020.
Preprint in English | PubMed | ID: ppcovidwho-333497

ABSTRACT

BACKGROUND: The 2019 novel coronavirus (2019-nCoV or SARS-CoV-2) has spread more rapidly than any other betacoronavirus including SARS-CoV and MERS-CoV. However, the mechanisms responsible for infection and molecular evolution of this virus remained unclear. METHODS: We collected and analyzed 120 genomic sequences of 2019-nCoV including 11 novel genomes from patients in China. Through comprehensive analysis of the available genome sequences of 2019-nCoV strains, we have tracked multiple inheritable SNPs and determined the evolution of 2019-nCoV relative to other coronaviruses. RESULTS: Systematic analysis of 120 genomic sequences of 2019-nCoV revealed co-circulation of two genetic subgroups with distinct SNPs markers, which can be used to trace the 2019-nCoV spreading pathways to different regions and countries. Although 2019-nCoV, human and bat SARS-CoV share high homologous in overall genome structures, they evolved into two distinct groups with different receptor entry specificities through potential recombination in the receptor binding regions. In addition, 2019-nCoV has a unique four amino acid insertion between S1 and S2 domains of the spike protein, which created a potential furin or TMPRSS2 cleavage site. CONCLUSIONS: Our studies provided comprehensive insights into the evolution and spread of the 2019-nCoV. Our results provided evidence suggesting that 2019-nCoV may increase its infectivity through the receptor binding domain recombination and a cleavage site insertion. ONE SENTENCE SUMMARY: Novel 2019-nCoV sequences revealed the evolution and specificity of betacoronavirus with possible mechanisms of enhanced infectivity.

4.
Embase; 2021.
Preprint in English | EMBASE | ID: ppcovidwho-331185

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic of novel corona virus disease (COVID-19). The neutralizing monoclonal antibodies (mAbs) targeting the receptor binding domain (RBD) of SARS-CoV-2 are among the most promising strategies to prevent and treat COVID-19. However, SARS-CoV-2 variants of concern (VOCs) profoundly reduced the efficacies of most of mAbs and vaccines approved for clinical use. Herein, we demonstrated mAb 35B5 efficiently neutralizes both wild-type (WT) SARS-CoV-2 and VOCs, including B.1.617.2 (delta) variant, in vitro and in vivo. Cryo-electron microscopy (cryo-EM) revealed that 35B5 neutralizes SARS-CoV-2 by targeting a unique epitope that avoids the prevailing mutation sites on RBD identified in circulating VOCs, providing the molecular basis for its pan-neutralizing efficacy. The 35B5-binding epitope could also be exploited for the rational design of a universal SARS-CoV-2 vaccine.

5.
46th International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz 2021 ; 2021-August, 2021.
Article in English | Scopus | ID: covidwho-1731017

ABSTRACT

Spectral properties of S and S1 spike proteins were studied using vibration spectroscopy methods. Also, vibration signatures of amino acids that make up the RGD, the part of S1 protein responsible for adhesion, were studied by Terahertz (THz) time-domain, Infrared (IR) and Raman spectroscopies in the low-frequency and in the fingerprint. THz metamaterials have been developed that increase the sensitivity of THz spectroscopy to the presence of both proteins. We have studied the spectra of amino acids, which play a role in the adhesion of proteins, on the metal surfaces of metamaterials, aluminum, and gold. Spectral differences were found between S and S1 proteins of SARS-CoV-2. The spectral differences between amino acids prepared in the form of thin films and in the form of bulk sample are discussed. © 2021 IEEE

6.
MEDLINE;
Preprint in English | MEDLINE | ID: ppcovidwho-326575

ABSTRACT

COVID-19 is an ongoing global crisis in which the development of effective vaccines and therapeutics will depend critically on understanding the natural immunity to the virus, including the role of SARS-CoV-2-specific T cells. We have conducted a study of 42 patients following recovery from COVID-19, including 28 mild and 14 severe cases, comparing their T cell responses to those of 16 control donors. We assessed the immune memory of T cell responses using IFNgamma based assays with overlapping peptides spanning SARS-CoV-2 apart from ORF1. We found the breadth, magnitude and frequency of memory T cell responses from COVID-19 were significantly higher in severe compared to mild COVID-19 cases, and this effect was most marked in response to spike, membrane, and ORF3a proteins. Total and spike-specific T cell responses correlated with the anti-Spike, anti-Receptor Binding Domain (RBD) as well as anti-Nucleoprotein (NP) endpoint antibody titre (p<0.001, <0.001 and =0.002). We identified 39 separate peptides containing CD4 + and/or CD8 + epitopes, which strikingly included six immunodominant epitope clusters targeted by T cells in many donors, including 3 clusters in spike (recognised by 29%, 24%, 18% donors), two in the membrane protein (M, 32%, 47%) and one in the nucleoprotein (Np, 35%). CD8+ responses were further defined for their HLA restriction, including B*4001-restricted T cells showing central memory and effector memory phenotype. In mild cases, higher frequencies of multi-cytokine producing M- and NP-specific CD8 + T cells than spike-specific CD8 + T cells were observed. They furthermore showed a higher ratio of SARS-CoV-2-specific CD8 + to CD4 + T cell responses. Immunodominant epitope clusters and peptides containing T cell epitopes identified in this study will provide critical tools to study the role of virus-specific T cells in control and resolution of SARS-CoV-2 infections. The identification of T cell specificity and functionality associated with milder disease, highlights the potential importance of including non-spike proteins within future COVID-19 vaccine design.

7.
Frontiers in Built Environment ; 7:11, 2022.
Article in English | Web of Science | ID: covidwho-1674316

ABSTRACT

The built environment closely relates to the development of COVID-19 and post-disaster recovery. Nevertheless, few studies examine its impacts on the recovery stage and corresponding urban development strategies. This study examines the built environment's role in Wuhan's recovery at the city block level through a natural experiment. We first aggregated eight built environmental characteristics (BECs) of 192 city blocks from the perspectives of density, infrastructure supply, and socioeconomic environment;then, the BECs were associated with the recovery rates at the same city blocks, based on the public "COVID-19-free" reports of about 7,100 communities over the recovery stages. The results showed that three BECs, i.e., "number of nearby designated hospitals," "green ratio," and "housing price" had significant associations with Wuhan's recovery when the strict control measures were implemented. At the first time of reporting, more significant associations were also found with "average building age," "neighborhood facility development level," and "facility management level." In contrast, no associations were found for "controlled residential land-use intensity" and "plot ratio" throughout the stages. The findings from Wuhan's recovery pinpointing evidence with implications in future smart and resilient urban development are as follows: the accessibility of hospitals should be comprehensive in general;and the average housing price of a city block can reflect its post-disaster recoverability compared to that of the other blocks.

8.
Chinese General Practice ; 24(34):4349-4355, 2021.
Article in Chinese | Scopus | ID: covidwho-1600044

ABSTRACT

Background: In the context of public health emergencies, for example, the COVID-19 pandemic, community hospitals may face challenges to provide diagnosis and treatment services and to reduce the disease burden for patients with mental problems. However, general practitioners(GPs)' capabilities in diagnosing and treating mental disorders are unsatisfactory. Objective: To develop a system for identifying community-dwelling outpatients with mental disorders needing emergency management amid a public health emergency by GPs, to promote GPs' capabilities in diagnosing and treating mental disorders, and the health of such patients. Methods: From May to June 2020, based on a literature review and an investigation of work requirements for GPs, we formed a framework for identifying community-dwelling outpatients with mental disorders needing emergency management amid a public health emergency by GPs with indicators initially determined. Then we screened and revised the indicators according to the results of a two-round Delphi survey with 15 experts(in the field of general practice or mental health medicine), and finally determined the indicators(with a mean value of weighted importance>3.5, coefficient of variation <25%, and rate of getting full marks >20%) for the formal system identifying community-dwelling outpatients with mental disorders needing emergency management amid a public health emergency by GPs. Results: Information of the experts surveyed: 13 of them had a graduate degree, and 10 had a senior professional title. Positive coefficients of the experts: All the experts(100%) actively responded to the two rounds of survey. Authority coefficients of the experts: the authority coefficient of the six domains were >0.70. The degree of agreement between the experts: the Kendall's W in the second round of survey was 0.278(χ2=100.197, P<0.001), which was higher than 0.245(χ2=73.597, P<0.001)in the first round of survey. The final indicators: 24 indicators in six domains involving mental symptoms, diagnosis of mental illness, severity of mental illness, personality, physical status, family and social background. Conclusion: Our system may help GPs to high-efficiently identify community-dwelling outpatients with severe mental disorders needing emergency treatment or referrals. However, the accuracy of the system needs to be verified further. Copyright © 2021 by the Chinese General Practice.

9.
Ieee Transactions on Automation Science and Engineering ; : 17, 2021.
Article in English | Web of Science | ID: covidwho-1583778

ABSTRACT

The ongoing coronavirus disease 2019 (COVID-19) is a pandemic causing millions of deaths, devastating social and economic disruptions. Testing individuals for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the pathogen of COVID-19, is critical for mitigating and containing COVID-19. Many countries are implementing group testing strategies against COVID-19 to improve testing capacity and efficiency while saving required workloads and consumables. A group of individuals' nasopharyngeal/oropharyngeal (NP/OP) swab samples is mixed to conduct one test. However, existing group testing methods neglect the fact that mixing samples usually leads to substantial dilution of viral ribonucleic acid (RNA) of SARS-CoV-2, which seriously impacts the sensitivity of tests. In this paper, we aim to screen individuals infected with COVID-19 with as few tests as possible, under the premise that the sensitivity of tests is high enough. To achieve this goal, we propose an Adaptive Group Testing (AdaGT) method. By collecting information on the number of positive and negative samples that have been identified during the screening process, the AdaGT method can estimate the ratio of positive samples in real-time. Based on this ratio, the AdaGT algorithm adjusts its testing strategy adaptively between an individual testing strategy and a group testing strategy. The group size of the group testing strategy is carefully selected to guarantee that the sensitivity of each test is higher than a predetermined threshold and that this group contains at most one positive sample on average. Theoretical performance analysis on the AdaGT algorithm is provided and then validated in experiments. Experimental results also show that the AdaGT algorithm outperforms existing methods in terms of efficiency and sensitivity.

10.
Aerosol and Air Quality Research ; 21(12):13, 2021.
Article in English | Web of Science | ID: covidwho-1580177

ABSTRACT

Airborne transmission of infectious diseases attracts great attention since the COVID-19 pandemic. Yet, there has been an intense dispute about aerosol transmission of the disease, which is largely due to lack of qualified instruments for studying the subject. Air sampling plays a critical role in all air pollution related study, and particularly critical for airborne pathogen detection. Here, we designed and evaluated a portable and high volume (400 L min-1) cyclone sampler named as Yao-CSpler using aerosolized Polystyrene (PS) uniform microspheres, Bacillus subtilis var. niger, Pseudomonas fluorescens, and both indoor and outdoor air particles. The experimental cutoff size of the Yao-CSpler was demonstrated to be 0.58 m (while the calculated theoretical value is 1.84 m), and the sampler has shown stable microbial collection performances for bacteria, fungi, and even viruses. The sampler had a physical collection efficiency of close 100% for particles of larger than 1 m. Jet-to-liquid distance and sampling duration were shown to substantially influence the sampler performance. Given the same sampling duration, the performances of the Yao-CSpler were significantly higher than those of the traditional BioSampler (SKC Inc.) in terms of samples' bacterial diversity. The developed sampler coupled with a robot has been successfully applied to sampling airborne SARS-CoV-2 in both Wuhan and Beijing during the COVID-19 outbreaks. With a high sampling flow, the Yao-CSpler was shown to be able to collect the SARS-CoV-2 with a detectable concentration level down to 9-219 viruses m-3 in clinical settings housing COVID-19 patients. Further more efficient bioaerosol sampler, which is able to rapidly capture low level pathogenic agents, is urgently required to better understand and confront airborne transmission of infectious diseases.

11.
Studies in Systems, Decision and Control ; 366:673-730, 2022.
Article in English | Scopus | ID: covidwho-1516831

ABSTRACT

In this chapter, we analyzed the impacts of the COVID-19 outbreak in Brazil, one of the most severely affected countries by the pandemic in the world. We discussed the overall characteristics of the pathogen (SARS-CoV-2) and its diffusion in Brazil over time and its main differences compared to other common infectious diseases in Brazil, such as Dengue and Zika. We then performed quantitative experiments to forecast the trend of confirmed cases and deaths from COVID-19 using a machine learning method for both country and state levels. We also estimated the instantaneous reproducing number over time for each Brazilian state and grouped them into clusters, aiming at identifying the heterogeneity between the Brazilian States. We also analyzed the magnitude of underreporting of COVID-19 cases in Brazil’s most affected states during the early stages of the pandemic. Moreover, we summarized the impacts of the pandemic on Brazil’s economic activities and social life, analyzing the dynamics of macroeconomic indicators, the effectiveness of the emergency financial assistance granted by the Brazilian government, and the relative level of adherence to social distancing in the Brazilian states since the beginning of lockdown measures. Finally, we presented the main challenges for Brazil after the pandemic fades away, focusing on the economic recovery and future public policies. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

12.
Journal of the American Society of Nephrology ; 32:80-81, 2021.
Article in English | EMBASE | ID: covidwho-1490265

ABSTRACT

Background: How the COVID-19 pandemic altered aspects of dialysis initiation, such as eGFR at initiation, selection of peritoneal dialysis (PD), and, in patients initiating hemodialysis (HD), use of a central venous catheter (CVC), is not fully understood. Methods: We analyzed the most recently updated quarterly USRDS data available. Using Poisson and logistic regression, we studied weekly changes in eGFR at dialysis initiation, use of PD (versus HD), and use of incident CVCs, overall and by strata of race, during the first half of 2020 compared to a forecast of 2020, had 2017-2019 historical trends continued. Results: Mean eGFR at dialysis initiation decreased by 0.33 mL/min/1.73 m2 in weeks 19-22, compared with historical trends;non-Hispanic Black patients exhibited the largest decrease, at 0.61 mL/min/1.73 m2. The odds of initiating dialysis with eGFR <10 ml/min/ 1.73m2 were highest during weeks 19-22 (May;OR 1.14, 1.05-1.17), corresponding to an absolute increase of 2.9%. Although initiation of both HD and PD fell, PD fell less, such that the odds of initiating PD (versus HD) were 24% higher (OR 1.24, 1.14-1.34) in weeks 11-14. Odds of initiating HD with a CVC increased by 30% (OR 1.30, 1.20-1.41) in weeks 15-18, representing an absolute increase of 3.3%. Conclusions: In the first half of 2020, eGFR at dialysis initiation fell, most prominently in non-Hispanic Blacks. During the initial wave of the pandemic, odds of utilizing PD, compared with HD, increased by nearly 25%, and odds of using a CVC at HD initiation increased by 30%.

13.
Journal of the American Society of Nephrology ; 32:79, 2021.
Article in English | EMBASE | ID: covidwho-1490264

ABSTRACT

Background: How the COVID-19 pandemic altered ESKD incidence, dialysis initiation, and preemptive kidney transplantation is unknown. Methods: Using Centers for Medicare & Medicaid Services data, we investigated the incidence of ESKD, dialysis initiation, and preemptive kidney transplantation by week during the first half of 2020. Using Poisson regression, we compared findings in 2020 to a forecast of 2020, had 2017-2019 historical trends continued, overall and by strata of age and race. Results: Mean weekly counts of patients with new ESKD are shown in the Figure. Incidence of ESKD dropped dramatically in 2020 compared with the expected incidence, particularly during epidemiologic weeks 15-18 (April;incidence rate ratio [IRR] 0.75, 95% CI 0.73-0.78), before approaching pre-pandemic levels in weeks 23-26 (June;IRR 0.93, 0.90-0.95). Across age groups, the decrease was most pronounced during weeks 15-18 among individuals aged ≥75 years (IRR 0.69, 0.66-0.73, compared with individuals aged 45-64 years, IRR 0.80, 0.77-0.84). In terms of race, the decrease was least notable among non-Hispanic Blacks (IRR 0.85, 0.81-0.89) and was most pronounced in non-Hispanic Whites (IRR 0.72, 0.69-0.74) and Hispanics (IRR 0.73, 0.69-0.78). Dialysis initiation reached a nadir during weeks 15-18 (IRR 0.76, 0.74-0.78), and preemptive kidney transplantation decreased even more strikingly during this period (IRR 0.56, 0.46-0.67). Conclusions: During the first wave of the COVID-19 pandemic in 2020, the number of patients starting treatment for ESKD fell to a level not observed since 2011. Changes in ESKD incidence and utilization of treatment modalities may reflect differential access to care.

14.
Journal of the American Society of Nephrology ; 32:70, 2021.
Article in English | EMBASE | ID: covidwho-1489733

ABSTRACT

Background: Patients with ESKD are at high risk of mortality from COVID-19. The extent to which increased mortality in the ESKD population in 2020 was related to COVID-19 vs other causes in the setting of disruption of healthcare delivery is not clear. Methods: We used the Death Notification Form (CMS-2746) to examine excess allcause and COVID-related mortality in Jan through Aug of 2020 among the whole ESKD population and by race/ethnicity adjusting for age and comorbidity. We further examined causes of non-COVID-related mortality in 2020 compared with 2017-2019. Results: All-cause mortality increased by 13.1% during Jan-Aug 2020 compared with mortality during the same period in 2017-2019. Peak overall and excess mortality occurred during Apr (Figure), when 14.7% of all deaths were attributed to COVID-19. COVID-related deaths declined to a nadir of 6.2% of all deaths in June and then increased again in Jul and Aug. Excess mortality was approximately twice as high among Black and Hispanic patients as among whites. Between Feb and Apr, there was substantial excess non-COVID mortality in addition to COVID mortality, whereas most excess mortality during May to Aug was related to COVID-19. There were 4310 excess deaths during Feb-Apr 2020. 1576 (37%) were due to COVID-19, and 517 (12%) were attributed to pneumonia. Thus, approximately half of the excess mortality was not due to COVID-19, including 1635 excess deaths due to cardiac arrest, cause unknown. Conclusions: Patients with ESKD experienced substantial excess mortality in 2020 relative to prior years that affected Black and Hispanic patients disproportionately. Approximately half of the excess mortality was likely caused by COVID-19. There was also excess mortality in the early phase of the pandemic that was not attributed to COVID-19.

15.
Chinese Journal of New Drugs ; 30(19):1775-1782, 2021.
Article in Chinese | EMBASE | ID: covidwho-1473137

ABSTRACT

Objective: To compare the correlation between the results of SARS-CoV-2 neutralizing antibody colloidal gold test cards prepared by two different principles and the SARS-CoV-2 pseudovirus neutralization experiment, and to evaluate the feasibility of the neutralizing antibody colloidal gold test card for the SARS-CoV-2 neutralizing antibody detection in different populations. Methods: Two kinds of SARS-CoV-2 neutralizing antibody colloidal gold test cards using double antigen sandwich method (manufacturer A) and competitive blocking method (manufacturers B) were used to detect the samples with SARS-CoV-2 neutralizing antibody titers. Detection sensitivity and the correlation between the two methods and the neutralization experiment were compared. The intravenous human immunoglobulin and specific immunoglobulin prepared before the outbreak of COVID-19 epidemic were detected to investigate the specificity of the eligible test card. In order to determine whether there is a hook effect, individual immunized plasma samples of high ELISA titers were tested with series of dilutions and original dilution. Single post-immunized plasma samples were detected with different ELISA titers, the positive rates were determined and the color changes were observed. Single post-immunized plasma samples were screened in the low-dilution area of ELISA according to chromaticity of 120NT50 and 300NT50 on the colorimetric card to prepare pooled plasma. The results were compared with the currently used indirect ELISA method. Results: The detection limits of manufacturers A and B for the first-generation NIBSC international standard 20/136 (anti-SARS-CoV-2 human immunoglobulin international standard) were 0.612 5 and 5 IU•mL-1, respectively. The results of different titers of pooled plasma (both of post-immunization with SARS-CoV-2 vaccine and COVID-19 convalescence plasma) have a good correlation with the neutralizing antibody titer. The post-immunization plasma with high ELISA dilutions (above 10 000) did not show hook effect. The positive rate of individual plasma of different ELISA dilution levels reached 100% when the dilution was above 160, and the uniformity of the chromaticity was higher when the dilution level was above 640. The overall chromaticity became darker as the ELISA dilution increased. The chromaticities of Ppool 120NT50 and Ppool 300NT50 screened according to the colorimetric chart were close to the neutralizing antibody titers. Conclusion: The correlation between the results of the manufacturer A neutralizing antibody test card using the dual antigen sandwich method to detect SARS-CoV-2 neutralizing antibody in convalescent plasma and post-immunization plasma and the titer of the pseudovirus neutralization experiment is better than that of the manufacturer B product using the competitive inhibition method and indirect ELISA. And the color brightness of the detection line is positively correlated with the level of neutralizing antibody, which can be used for preliminary screening of neutralizing antibody in different populations.

17.
American Journal of Respiratory and Critical Care Medicine ; 203(9):1, 2021.
Article in English | Web of Science | ID: covidwho-1407553
18.
Chinese Education and Society ; 54(1-2):68-89, 2021.
Article in English | Scopus | ID: covidwho-1402206

ABSTRACT

Abstract: An online survey of 1577 private kindergarten teachers was conducted during the pandemic, and their career situation and its influencing factors were described and analyzed. The results indicate that, although the private kindergarten teachers tended to cope positively with the impact of the COVID-19 pandemic, their concern for future development exhibited significant correlation with work fatigue and avoidance of learning, reflecting the negative occupational ecology for private kindergarten teachers during the pandemic. The COVID-19 pandemic resulted in a substantial reduction in income for the private kindergarten teachers, with a decline of 50% or more in income for more than 76% of teachers;the higher the reduction in income for the private kindergarten teachers, the more strongly their work fatigue, concern for future development, and avoidance of learning were expressed, accompanied by a significant decline in the frequency of online teaching activities. To address the current state of career situation among private kindergarten teachers produced by the pandemic, support mechanisms should be strengthened, to prevent the erosion of teachers;measures to combat the pandemic in the industry should be furthered, to build occupational confidence;educational equity should be promoted, to achieve balanced development;and online educational resources should be enriched, to standardize online educational activities. © 2021 Taylor & Francis Group, LLC.

19.
6th International Conference on Advances in Energy Resources and Environment Engineering (ICAESEE) ; 647, 2020.
Article in English | Web of Science | ID: covidwho-1396593

ABSTRACT

Affected by Coronavirus and low oil price, global oil and gas M&A has been in a downturn in 2020. Countries with oil and gas resource intended to revise fiscal terms, enhancing the economics of producing assets and new developments. Many oil companies have faced severe challenges with impact on Coronavirus and oil price crash. According to IHS expectation, the same tightness will continue into 2021. Learned from international oil companies experience, Chinese oil companies should pay more attention to cost reduction, seize opportunities of the M&A market to get high quality projects , and focus more on energy transition.

20.
Sustainability (Switzerland) ; 13(11), 2021.
Article in English | Scopus | ID: covidwho-1282584

ABSTRACT

Given the impact of COVID‐19 and the desert locust plague, the Ethiopian food security issue has once again received widespread attention. Its food crisis requires comprehensive and systematic research to achieve the United Nations Sustainable Development Goal of zero hunger. This review discusses the current situation and the causes of food security in Ethiopia. We focus on the challenges in the food security assessment field. The article lists seven typical causes of food insecurity and three roots of food security in Ethiopia. Long‐term food security assessment and a comprehensive understanding and manageability for food security causes are considered as the main existing research challenges. Climate‐resilient management, water management, and long‐term ecosystem network monitoring and data mining are suggested as potential roadmap for future re-search. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

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