Using meta-learning to recommend an appropriate time-series forecasting model.

BACKGROUND: There are various forecasting algorithms available for univariate time series, ranging from simple to sophisticated and computational. In practice, selecting the most appropriate algorithm can be difficult, because there are too many algorithms. Although expert knowledge is required to make an informed decision, sometimes it is not feasible due to the lack of such resources as time, money, and manpower. METHODS: In this study, we used coronavirus disease 2019 (COVID-19) data, including the absolute numbers of confirmed, death and recovered cases per day in 187 countries from February 20, 2020, to May 25, 2021. Two popular forecasting models, including Auto-Regressive Integrated Moving Average (ARIMA) and exponential smoothing state-space model with Trigonometric seasonality, Box-Cox transformation, ARMA errors, Trend, and Seasonal components (TBATS) were used to forecast the data. Moreover, the data were evaluated by the root mean squared error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE), and symmetric mean absolute percentage error (SMAPE) criteria to label time series. The various characteristics of each time series based on the univariate time series structure were extracted as meta-features. After that, three machine-learning classification algorithms, including support vector machine (SVM), decision tree (DT), random forest (RF), and artificial neural network (ANN) were used as meta-learners to recommend an appropriate forecasting model. RESULTS: The finding of the study showed that the DT model had a better performance in the classification of time series. The accuracy of DT in the training and testing phases was 87.50% and 82.50%, respectively. The sensitivity of the DT algorithm in the training phase was 86.58% and its specificity was 88.46%. Moreover, the sensitivity and specificity of the DT algorithm in the testing phase were 73.33% and 88%, respectively. CONCLUSION: In general, the meta-learning approach was able to predict the appropriate forecasting model (ARIMA and TBATS) based on some time series features. Considering some characteristics of the desired COVID-19 time series, the ARIMA or TBATS forecasting model might be recommended to forecast the death, confirmed, and recovered trend cases of COVID-19 by the DT model.

Modeling and forecasting number of confirmed and death caused COVID-19 in IRAN: A comparison of time series forecasting methods.

BACKGROUND: The COVID-19 pandemic conditions are still prevalent in Iran and other countries and the monitoring system is gradually discovering new cases every day. Therefore, it is a cause for concern around the world, and forecasting the number of future patients and death cases, although not entirely accurate, helps the governments and health-policy makers to make the necessary decisions and impose restrictions to reduce prevalence. METHODS: In this study, we aimed to find the best model for forecasting the number of confirmed and death cases in Iran. For this purpose, we applied nine models including NNETAR, ARIMA, Hybrid, Holt-Winter, BSTS, TBATS, Prophet, MLP, and ELM network models. The quality of forecasting models is evaluated by three performance metrics, RMSE, MAE, and MAPE. The best model is selected by the lowest value of performance metrics. Then, the number of confirmed and the death cases forecasted for the 30 next days. The used data in this study is the absolute number of confirmed, death cases from February 20 to August 15, 2020. RESULTS: Our findings suggested that based on existing data in Iran, the suitable model with the lowest performance metrics for confirmed cases data obtained MLP network and the Holt-Winter model is the suitable model for forecasting death cases in the future. These models forecasted on September 14, 2020, we will have 2484 new confirmed and 114 new death cases of COVID-19. CONCLUSION: According to the results of this study and the existing data, we concluded that the MLP and Holt-Winter models had the lowest error in forecasting in comparison to other methods. Some models had fitted poorly in the test phase and this is because many other factors that are either not available or have been ignored in this study and can affect the accuracy of forecast results. Based on the trend of data and forecast results, the number of confirmed cases and death cases are almost constant and decreasing, respectively. However, due to disease progression and ignoring the recommendations and protocols of the Ministry of health, there is a possibility of re-emerging this disease more seriously in Iran and this requires more preventive care.

Antibacterial and Synergistic Effects of Herbal Extracts in Combination with Amikacin and Imipenem Against Multidrug-Resistant Isolates of Acinetobacter.

Acinetobacter species are defined as multidrug-resistant pathogens and the development of resistance against antimicrobials is a major problem in the treatment of infections caused by them. This study aimed to evaluate the antibacterial activity of aqueous and methanol extracts of Salvia chorassanica and Artemisia khorassanica on multidrug-resistant Acinetobacter isolates and also examining the interaction of the methanol extract of the plants with the combination of amikacin and imipenem. First, the presence of adeI and adeB genes in bacterial isolates was investigated. The aqueous and methanol extracts of the leaves of the plants were prepared by Maceration method. Minimum Inhibition Concentration (MIC) values were determined to evaluate the antibacterial activities of plant extracts and antibiotics. Combined effects of the antibiotics with plant extracts were performed using the checkerboard method. The accumulation assay was used to examine the inhibitory effects of plant extracts on the bacterial efflux pump. MIC results indicated that the methanol extracts were effective against Acinetobacter species. FICI values indicated that the combination of antibiotics with methanol plant extracts improves bacterial sensitivity to antibiotics. The extracts also exhibited efflux pump inhibitory activities. Consequently, combination of the plant extracts with antibiotics could enhance the antibiotic susceptibility of resistant pathogens.