Enhanced Photocatalytic Degradation of the Imidazolinone Herbicide Imazapyr upon UV/Vis Irradiation in the Presence of CaxMnOy-TiO2 Hetero-Nanostructures: Degradation Pathways and Reaction Intermediates

[Abstract] The determination of reaction pathways and identification of products of pollutants degradation is central to photocatalytic environmental remediation. This work focuses on the photocatalytic degradation of the herbicide Imazapyr (2-(4-methyl-5-oxo-4-propan-2-yl-1H-imidazol-2-yl) pyridine-3-carboxylic acid) under UV-Vis and visible-only irradiation of aqueous suspensions of CaᵪMnOᵧ-TiO₂, and on the identification of the corresponding degradation pathways and reaction intermediates. CaᵪMnOᵧ-TiO₂ was formed by mixing CaᵪMnOᵧ and TiO₂ by mechanical grinding followed by annealing at 500 °C. A complete structural characterization of CaᵪMnOᵧ-TiO₂ was carried out. The photocatalytic activity of the hetero-nanostructures was determined using phenol and Imazapyr herbicide as model pollutants in a stirred tank reactor under UV-Vis and visible-only irradiation. Using equivalent loadings, CaᵪMnOᵧ-TiO₂ showed a higher rate (10.6 μM·h⁻¹) as compared to unmodified TiO₂ (7.4 μM·h⁻¹) for Imazapyr degradation under UV-Vis irradiation. The mineralization rate was 4.07 μM·h⁻¹ for CaᵪMnOᵧ-TiO₂ and 1.21 μM·h⁻¹ for TiO₂. In the CaᵪMnOᵧ-TiO₂ system, the concentration of intermediate products reached a maximum at 180 min of irradiation that then decreased to a half in 120 min. For unmodified TiO₂, the intermediates continuously increased with irradiation time with no decrease observed in their concentration. The enhanced efficiency of the CaᵪMnOᵧ-TiO₂ for the complete degradation of the Imazapyr and intermediates is attributed to an increased adsorption of polar species on the surface of CaᵪMnOᵧ. Based on LC-MS, photocatalytic degradation pathways for Imazapyr under UV-Vis irradiation have been proposed. Some photocatalytic degradation was obtained under visible-only irradiation for CaᵪMnOᵧ-TiO₂. Hydroxyl radicals were found to be main reactive oxygen species responsible for the photocatalytic degradation through radical scavenger investigations.This research received external funding from the British Council under the STREAM-MENA Institutional Links Scheme Grant number 278072873. This is a collaboration between Ulster University (UK), Technion Institute (Israel) and Rabat University (Morocco). MC acknowledges support from Ministerio de Economía y Competitividad (Spain) through project CTQ2015-71238-R (MINECO/FEDER). AS would like to acknowledge the financial support received from Ulster University (UK) through the VCRS scholarship. PS would like to acknowledge funding from Invest Northern Ireland for the BioDevices projectBritish Council; 27807287

The Impact of the COVID-19 Pandemic on Healthy Lifestyle Behaviors and Perceived Mental and Physical Health of People Living with Non-Communicable Diseases: An International Cross-Sectional Survey

The huge burden and vulnerability imposed by non-communicable diseases (NCDs) during the COVID-19 pandemic highlighted how healthy lifestyle behaviors and the well-being of people living with NCDs need to be prioritized. The aim of our study is to better understand the impact of the COVID-19 pandemic on healthy lifestyle behaviors and perceived mental and physical health among adults living with NCDs, as compared to people without NCDs. We conducted a cross-sectional study using a global online survey through Qualtrics. Over four months, 3550 participants from 65 countries worldwide responded to the survey. The study included 3079 surveys with no missing data (complete survey responses) that were used for analysis. People with NCDs were more likely to report statistically significant worsening physical health (p = 0.001) and statistically insignificant worsening mental health (p = 0.354) when compared to pre-pandemic levels. They reported lower rates of smoking during the pandemic than those without NCDs, and a statistically significant (p < 0.001) relationship was found between weight gain and NCDs. Therefore, the perceived physical and mental health, including changes in body weight and tobacco consumption, of people with NCDs were significantly impacted during the pandemic. In conclusion, this study indicates that the pandemic had a significant impact on perceived physical and mental health, changes in body weight, and tobacco consumption among people with NCDs

Factors Influencing Imazapyr Herbicide Removal from Wastewater Using Photocatalytic Ozonation

This study investigates the degradation of imazapyr herbicide from wastewater by photocatalytic ozonation using TiO2 as a semiconductor. Effects of operational parameters on imazapyr removal efficiency including TiO2 dosing, initial herbicide concentration and pH were also studied. Obtained results showed that more than 90% of removal efficiency representing the disappearance of imazapyr was maintained until 7 mu M in the presence of 200 mgL(-1) of UV100-TiO2. Otherwise, the degradation of imazapyr followed the first-order kinetics with a photocatalytic rate constant of 0.247 min(-1), and complete degradation was achieved within 20 min using photocatalytic ozonation for 5 mu M of Imazapyr at pH 7

A Neural Network-Based System to Predict Early MOOC Dropout

In recent years, MOOC (Massively Open Online Courses) revolu-tion has transformed the landscape of distance learning. Based on the distribution of educational content, this type of education is expected to undergo the same revolution as all of the traditional sectors of content and service sales, such as music, video, and commerce, due to the emergence of new technologies. How-ever, the completion rate remains a key metric of MOOC success as the number of students registering for a MOOC usually decreases during the course. This rate can reach 2 to 10% at the end of the course. Therefore, predicting dropouts is an excellent way to identify students at risk and make timely decisions. In this study, a prediction model is developed using one of the most widely used methods, the recurrent neural network (RNN). As a result, our model can be considered as an optimal option in terms of accuracy and fit for predicting dropouts in MOOCs

Towards an Adaptive Learning Model using Optimal Learning Paths to Prevent MOOC Dropout

Currently, massive open online courses (MOOCs) are experiencing major developments and are becoming increasingly popular in distance learning programs. The goal is to break down inequalities and disseminate knowledge to everyone by creating a space for exchange and interaction. Despite the improvements to this educational model, MOOCs still have low retention rates, which can be attributed to a variety of factors, including learners’ heterogeneity. The paper aims to address the issue of low retention rates in MOOCs by introducing an innovative prediction model that provides the best (optimal) learning path for at-risk learners. For this purpose, learners at risk of dropping out are identified, and their courses are adapted to meet their needs and skills. A case study is presented to validate the effectiveness of our approach using classification algorithms for prediction and the ant colony optimization (ACO) algorithm to optimize learners’ paths

Clinical features of the initial cases of 2009 pandemic influenza A (H1N1) virus infection in an university hospital of Morocco

<p>Abstract</p> <p>Background</p> <p>The first case of 2009 pandemic influenza A (H1N1) virus infection in our center was documented on June 15. Subsequently, persons with suspected cases of infection and contacts of those with suspected infection were tested. Persons in whom infection was confirmed were hospitalized and quarantined, and some of them were closely observed for the purpose of investigating the nature and duration of the disease. The aim of the present study was to describe baseline characteristics, treatment, outcomes, hospital length of stay and mortality of the first 186 cases of influenza A (H1N1) virus infection, with special interest in those developing severe respiratory failure with intensive care unit (ICU) care requirement.</p> <p>Methods</p> <p>observational study of 186 consecutive cases of influenza A (H1N1) virus infection admitted in 3 departments that were reference centers for the care of patients with influenza A and 4 ICU in Ibn Sina university hospital (Rabat, Morocco) between June and December 2009. Real time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) testing was used to confirm infection. Demographic data, symptoms, comorbid conditions, illness progression, laboratory and chest radiologic findings, treatments, clinical outcomes and ICU care requirement were closely monitored.</p> <p>Results</p> <p>The mean age of the 186 patients was 17.6 ± 14.8 years, 47.8% had less than 14 years and 57% were male. The median duration of symptoms before hospital admission was 3 days (interquartile range (IQR): 2-5). The most common symptoms were fever (in 91.5% of the patients), cough in 92.5%, and nasal congestion in 62.4%. Twenty four percent of patients had comorbid respiratory disorders and 7.5% were pregnant. Abnormalities in chest radiography were detected in 26.3% of 186 patients on admission or after hospitalization. Twenty patients have required ICU care and 10 have required mechanical ventilation. The hospital length of stay was 5 days (IQR: 4-5). The following were risk factors of ICU admission: older age (p = 0.03), long duration of symptoms (p = 0.07), asthma (p = 0.01), obesity (P < 0.001), abnormalities of chest radiography (P < 0.001), leukocytosis (p = 0.005), and higher C-reactive protein (CRP) (P < 0.001). The ICU length of stay was 4 days (IQR: 3-6.7). The mortality rate was 3.5% among all patients and 30% among ICU patients.</p> <p>Conclusions</p> <p>Close observation of patients infected with the 2009 pandemic influenza A (H1N1) virus infection provided us with several information. The influenza A (H1N1) virus infection affected young people particularly, with comorbid respiratory disorders. Risk factors of ICU admission were older age, long duration of symptoms, asthma, obesity, abnormalities of chest radiography, leukocytosis and higher CRP. Clinicians should be aware of complications of influenza A (H1N1) virus infection, particulary in patients with risk factors.</p