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To better understand the chemical controls of sub- and super-saturated aerosol water uptake, we designed and conducted a series of chamber experiments to investigate the evolution of secondary organic aerosol (SOA) particle physicochemical properties during photo-oxidation of single and mixed biogenic (α-pinene, isoprene) and anthropogenic (o-cresol) volatile organic compounds (VOCs) in the presence of ammonium sulfate seeds. During the 6 h experiments, the cloud condensation nuclei (CCN) activity at super-saturation of water (0.1 %–0.5 %), hygroscopic growth factor at 90 % relative humidity (RH), and non-refractory PM1 chemical composition were recorded concurrently. Attempts to use the hygroscopicity parameter κ to reconcile water uptake ability below and above water saturation from various VOC precursor systems were made, aiming to predict the CCN activity from the sub-saturated hygroscopicity. The thermodynamic model AIOMFAC (aerosol inorganic-organic mixtures functional groups activity coefficients) was used to simulate κ values of model compound mixtures to compare with the observation and to isolate the controlling factors of water uptake at different RHs. The sub- and super-saturated water uptake (in terms of both κHTDMA and κCCN) were mainly controlled by the SOA mass fraction, which depended on the SOA production rate of the precursors, and the SOA composition played a second-order role. For the reconciliation of κHTDMA and κCCN, the KHTDMA/KCCN ratio increased with the SOA mass fraction and this was observed in all investigated single and mixed VOC systems, independent of initial VOC concentrations and sources. For all VOC systems, the mean κHTDMA of aerosol particles was ∼25 % lower than the κCCN at the beginning of the experiments with inorganic seeds. With the increase of condensed SOA on inorganic seed particles throughout the experiments, the discrepancy of κHTDMA and κCCN became weaker (down to ∼0 %) and finally the mean κHTDMA was ∼60 % higher than κCCN on average when the SOA mass fraction approached ∼0.8. As indicated by AIOMFAC model simulations, non-ideality alone cannot fully explain the κ discrepancy at high SOA mass fraction (0.8). A good agreement in κCCN between model and observation was achieved by doubling the molecular weight of the model compounds or by reducing the dry particle size in the CCN counter. This indicates that the evaporation of semi-volatile organics in the CCN counter together with non-ideality could have led to the observed κ discrepancy. As a result, the predicted CCN number concentrations from the κHTDMA and particle number size distribution were ∼10 % lower than CCN counter measurement on average at the beginning, and further even turned to an overestimation of ∼20 % on average when the SOA mass fraction was ∼0.8. This chemical composition-dependent performances of the κ-Köhler approach on CCN prediction can introduce a variable uncertainty in predicting cloud droplet numbers from the sub-saturated water uptake, the influence of which on models still needs to be investigated., Atmospheric Chemistry and Physics, 22 (6), ISSN:1680-7375, ISSN:1680-7367

A comprehensive chamber investigation of photochemical secondary organic aerosol (SOA) formation and transformation in mixtures of anthropogenic (o-cresol) and biogenic (alpha-pinene and isoprene) volatile organic compound (VOC) precursors in the presence of NOx and inorganic seed particles was conducted. To enable direct comparison across systems, the initial concentration (hence reactivity) of the systems towards the dominant OH oxidant was adjusted. Comparing experiments conducted in single-precursor systems at various initial reactivity levels (referenced to a nominal base case VOC concentration, e.g. halving the initial concentration for a 1/2 initial reactivity experiment) as well as their binary and ternary mixtures, we show that the molecular interactions from the mixing of the precursors can be investigated and discuss challenges in their interpretation. The observed average SOA particle mass yields (the organic particle mass produced for a mass of VOC consumed) in descending order were found for the following systems: alpha-pinene (32 +/- 7 %), alpha-pinene-o-cresol (28 +/- 9 %), alpha-pinene at 1/2 initial reactivity (21 +/- 5 %), alpha-pinene-isoprene (16 +/- 1 %), alpha-pinene at 1/3 initial reactivity (15 +/- 4 %), o-cresol (13 +/- 3 %), alpha-pinene-o-cresol-isoprene (11 +/- 4 %), o-cresol at 1/2 initial reactivity (11 +/- 3 %), o-cresol-isoprene (6 +/- 2 %), and isoprene (0 +/- 0 %). We find a clear suppression of the SOA mass yield from alpha-pinene when it is mixed with isoprene, whilst no suppression or enhancement of SOA particle yield from o-cresol was found when it was similarly mixed with isoprene. The alpha-pinene-o-cresol system yield appeared to be increased compared to that calculated based on the additivity, whilst in the alpha-pinene-o-cresol-isoprene system the measured and predicted yields were comparable. However, in mixtures in which more than one precursor contributes to the SOA particle mass it is unclear whether changes in the SOA formation potential are attributable to physical or chemical interactions, since the reference basis for the comparison is complex. Online and offline chemical composition as well as SOA particle volatility, water uptake, and "phase" behaviour measurements that were used to interpret the SOA formation and behaviour are introduced and detailed elsewhere., Atmospheric Chemistry and Physics, 22 (21), ISSN:1680-7375, ISSN:1680-7367

BackgroundAs the SARS-CoV2 Omicron variant spreads in several countries, healthcare workers’ (HCWs) perceptions and worries regarding vaccine effectiveness and boosters warrant reassessment.MethodsAn online questionnaire among HCWs in Saudi Arabia (KSA) was distributed from Dec 1st to 6th 2021 to assess their perceptions, vaccine advocacy to the Omicron variant, and their perception of the effectivness of infection prevention measures and vaccination to prevent its spread, their Omicron variant related worries in comparison to the other variants, and their agreement with mandatory vaccination in general for adults.ResultsAmong the 1285 HCW participants, two-thirds were female, 49.8 % were nurses, 46.4% were physicians, and 50.0% worked in tertiary care hospitals. 66.9% considered vaccination to be the most effective way to prevent the spread of the Omicron variant and future variants. The respondents however perceived social distancing (78.0%), universal masking (77.8%), and avoiding unnecessary travel (71.4%) as slightly superior to vaccination to prevent the spread of SARS-CoV-2 variants. HCWs aging 55 or older agreed singficanlty with vaccine ineffictivness to control Omicron spread, while those who believed in non-pharmacolgical infection prevention measures agreed signifcantly with vaccination for that purpose. Male HCWs had a significant agreement with mandatory vaccination of all eligible adult populations. On the other hand, unwilling HCWs to receive the vaccine had strong disagreements with mandatory vaccination.ConclusionsThe current study in the first week of Omicron showed that only two-thirds of HCWs felt that vaccination was the best option to prevent the spread of the Omicron variant, indicating the need for further motivation campaigns for vaccination and booster dose. HCWs had a strong belief in infection prevention measures to contain the spread of SARS-CoV-2 variants that should be encouraged and augmented.

BackgroundAs the COVID-19 Omicron variant emerged and spread globally at an alarming speed, healthcare workers’ (HCWs) uncertainties, worries, resilience, and coping strategies warrant assessment. The COVID-19 pandemic had a severe psychological impact on HCWs, including the development of Post-Traumatic Stress symptoms. Specific subgroups of HCWs, such as front-line and female workers, were more prone to poor mental health outcomes and difficulties facing stress.MethodsThe responses to an online questionnaire among HCWs in Saudi Arabia (KSA) were collected December 1-5, 2021, aiming to assess their Omicron variant’s uncertainties, worries, resilience, and coping strategies. Three validated instruments were used to achieve the study’s goals: the Brief Resilient Coping Scale, the Standard Stress Scale (SSS), and the Intolerance of Uncertainty Scale (IUS) - Short Form.ResultsThe online survey was completed by 1285 HCWs. Females made up the majority (64%). The BRCS score of resilient coping was negatively and substantially linked with the SSS score of stress (r=-0.313, p = 0.010). Furthermore, the IUS had a positive and significant relationship with stress (r=0.326, p= 0.010). Increased stress levels were linked to a considerable drop in resilient coping scores. Furthermore, being a Saudi HCW or a nurse was linked to a significant reduction in resilient coping ratings. Coping by following healthcare authorities’ preventative instructions and using the WHO website as a source of information was linked to a considerable rise in resilient coping.ConclusionsFollowing the emergence of the Omicron variant of SARS-CoV-2 in late 2021, a rapid investigation into the correlates of stress and resilient coping among the HCWs in KSA was conducted. The negative association between resilient coping and stress was clearly shown, as well as how underlying intolerance of uncertainty is linked to higher stress among HCWs quickly following the development of a new infectious threat. The study provides early insights to develop and promote coping strategies for emerging SARS-CoV-2 variants.

A combination of online and offline mass spectrometric techniques was used to characterize the chemical composition of secondary organic aerosol (SOA) generated from the photooxidation of α-pinene in an atmospheric simulation chamber. The filter inlet for gases and aerosols (FIGAERO) coupled with a high-resolution time-of-flight iodide chemical ionization mass spectrometer (I–ToF-CIMS) was employed to track the evolution of gaseous and particulate components. Extracts of aerosol particles sampled onto a filter at the end of each experiment were analyzed using ultra-performance liquid chromatography ultra-high-resolution tandem mass spectrometry (LC-Orbitrap MS). Each technique was used to investigate the major SOA elemental group contributions in each system. The online CIMS particle-phase measurements show that organic species containing exclusively carbon, hydrogen and oxygen (CHO group) dominate the contribution to the ion signals from the SOA products, broadly consistent with the LC-Orbitrap MS negative mode analysis which was better able to identify the sulphur-containing fraction. An increased abundance of high carbon number (nC ≥ 16) compounds additionally containing nitrogen (CHON group) was detected in the LC-Orbitrap MS positive ionisation mode, indicating a fraction missed by the negative mode and CIMS measurements. Time series of gas-phase and particle-phase oxidation products provided by online measurements allowed investigation of the gas-phase chemistry of those products by hierarchical clustering analysis to assess the phase partitioning of individual molecular compositions. The particle-phase clustering was used to inform the selection of components for targeted structural analysis of the offline samples. Saturation concentrations derived from near-simultaneous gaseous and particulate measurements of the same ions by FIGAERO-CIMS were compared with those estimated from the molecular structure based on the LC-Orbitrap MS measurements to interpret the component partitioning behaviour. This paper explores the insight brought to the interpretation of SOA chemical composition by the combined application of online FIGAERO-CIMS and offline LC-Orbitrap MS analytical techniques.

Symptomatische Lymphozelen (SLZ) gehören zu den häufigsten Komplikationen bei einer radikalen Prostatektomie (RP) mit pelviner Lymphadenektomie (RP+PLAE). Studien konnten in den letzten Jahren insbesondere eine Verbesserung der Frühkontinenz nach subtrigonaler -Retzius-sparend- (RS-RARP) zeigen. Ziel dieser Dissertation war die Beschreibung und Validierung einer Nahttechnik zur Prävention von postoperativen LZ nach RS-RP mit PLAE. Eingeschlossen wurden 236 konsekutive Patienten mit subtrigonaler RARP und pelviner Lymphadenektomie eines Operateurs in der Zeit von Juni 2015 bis Ende Mai 2019. Retrospektiv wurden klinische, pathologische und perioperative Daten erhoben. Bei 91 Patienten erfolgte am Ende der Operation eine spezielle Naht zum Offenhalten beider Lymphadenektomiegebiete. Hierzu wurde mittels Vicryl 3-0 Naht jeweils der mediale Rand des Peritoneums parietal iliakal beidseits mit der Inzision im Spatium vesico-rectale vernäht. Verglichen wurden die symptomatischen und asymptomatischen LZ in der Gruppe mit und ohne Naht. Außerdem wurden perioperative und pathologische Risikofaktoren für die Entstehung der LZ und SLZ untersucht und mit den publizierten Daten verglichen. Es bestand kein signifikanter Unterschied der Patientendaten zwischen den Gruppen mit und ohne Naht bezüglich der prä- und postoperativen Parameter mit Ausnahme der ASA-Klassifikation sowie der Leukozytenzahl prä- und dem ersten postoperativen Tag. Bezüglich der symptomatischen Lymphozelen im postoperativen Verlauf zeigte sich eine signifikante Reduktion der SLZ-Rate mit der neuen Naht auf 3 % (3/91) p-Wert: 0,047 im Vergleich zu 10 % (15/145) ohne Naht. Eine nummerische Reduktion der gesamten Lymphozelen kann in dieser Arbeit beschrieben werden (40% ohne Naht vs. 27% mit Naht) p:0,07. Es zeigten sich keine signifikanten Unterschiede in der Komplikationsrate nach der Clavien Dindo Klassifikation, was für die Sicherheit der Nahttechnik spricht. In der Interventionsgruppe konnte kein Fall mit Ileus-Symptomatik festgestellt werden. Sollten sich die beschriebenen Ergebnisse in prospektiv randomisierten Studien bestätigen, kann diese OP-Technik zur Reduktion einer der häufigsten postoperativen Komplikationen der subtrigonalen RARP beitragen.

Urban residents are frequently exposed to high levels of traffic-derived air pollution for short time periods, often (but not exclusively) during commuting. Although chronic air pollution exposure and health effects, including neurological effects on children and older adults, are known to be correlated, causal effects of acute pollution exposure on brain function in healthy young adults remain sparsely investigated. Neuroinflammatory accounts suggest effects could be delayed by several hours and could affect attention, especially in social contexts. Using a controlled atmosphere chamber, we exposed 81 healthy young adults to either diluted diesel exhaust (equivalent to polluted roadside environments) or clean air for one hour. Half of each group immediately completed a selective attention task to assess cognitive control; remaining participants completed the task after a 4-hour delay. Cognitive control was significantly poorer after diesel versus clean air exposure for those in the delay but not immediate test condition, suggesting an inflammatory basis for this acute negative effect of air pollution on cognition. These findings provide the first experimental evidence that acute diesel exposure, comparable to polluted city streets, causes a negative effect on cognitive control several hours later. These findings may explain commuter mental fatigue and support clean-air initiatives.

Radiofrequency neurotomy (RFN) of facet or sacroiliac joints is widely used for the treatment of chronic axial pain and can provide long-term pain relief in well-selected patients. The most common side effect is transient neuropathic pain at the paravertebral level of interest. Pain physicians commonly administer corticosteroid post-neurotomy to reduce the risk of post-neurotomy neuropathic pain, yet it remains unclear if this provides a true reduction in incidence.To determine the efficacy of corticosteroid administration post-lesion in preventing the development of post-neurotomy neuropathic pain after cervical, thoracic, lumbar, and sacroiliac joint radiofrequency denervation.Randomized, placebo-controlled, double-blind prospective study.Ambulatory Surgical Center within a Tertiary Hospital System.This trial is registered on ClinicalTrials.gov (NCT03247413). Permission to conduct human research was obtained from the Institutional Review Board. Eligible patients included those with cervical, thoracic, or lumbar facet or sacroiliac joint pain who had positive concordant medial branch blocks (thus scheduled for bilateral RFN), at least 18 years of age, and English-speaking. Patients received dexamethasone vs saline (control) at each lesion site, serving as their own control (with laterality). Follow-ups were completed at 4- and 8-weeks post-intervention to evaluate the incidence of post-procedure pain (questionnaire) and function using the Oswestry Disability Index (ODI) or the Neck Disability Index (NDI).At the time of data analysis, 35/63 patients completed the study protocol. There was a statistically significant reduction in the incidence of post-neurotomy pain in the steroid group vs the control group (20/35 control group vs 3/35 steroid group, P0.001). ODI/NDI scores changed differently over time depending on the spinal level of neurotomy, showing statistically significant improvement in ODI/NDI in the cervical subgroup and lumbar subgroup at 4-week (P = 0.05) and 8-week time points (P0.01), respectively. There was no improvement of ODI scores in the sacral subgroup. The incidence of post-neurotomy neuropathic pain was not significantly different among patients with different spinal levels of neurotomy. Patients who developed post-neurotomy neuropathic pain did not differ in ODI/NDI scores at any time point.This study has several limitations, most notably the number of patients lost to follow-up, the use of a single corticosteroid, and the use of laterality for incidence reporting. Additionally, all procedures were performed by a single interventionalist using one neurotomy system.A statistically significant reduction in post-neurotomy pain was observed in the steroid group. This protocol can be feasibly conducted in an effective and resource-efficient manner. Additional research is needed to increase the power of the study.

There is a growing demand for integrating an assessment tool to select wastewater treatment alternatives based on sustainability in the Jordanian wastewater sector. The sector in Jordan has a unique and critical situation that has raised concerns among stakeholders, including donors, and international and national organizations, to carefully select a sustainable treatment system for each case. The Jordanian government set a tool to distinguish between treatment systems, and this tool is mainly focused on financial criteria. However, the sector needs to integrate assessment tools with a wider consideration of other sustainability criteria. Usually, stakeholders are not equipped with a clear methodology to perform sustainability assessments. Therefore, this study proposes and develops a Multi-Criteria Analysis (MCA) tool to evaluate wastewater treatment alternatives from a sustainability perspective for a case study in Jordan—Al Azraq town. Firstly, the study explored the decision and organizational context of the wastewater sector through several interviews. Secondly, assessment criteria and indicators were proposed to compare three proposed treatment alternatives. Finally, the Analytical Hierarchy Process (AHP) was applied with composite scores to evaluate wastewater treatment alternatives. Finally, The results of the composite scores indicated that French Constructed Wetland (FCW) was the best option for this case study, with a score of 3.13, followed by Stabilization Pond (SP) as the second sustainable option, with a score of 2.67, and lastly, Activated Sludge (AS), with a score of 2.07. Several conclusions have been highlighted during the process development, such as the importance of selecting sustainability indicators carefully, and engaging stakeholders during the design and implementation of the assessment.

Deep learning models are prone to being fooled by imperceptible perturbations known as adversarial attacks. In this work, we study how equipping models with Test-time Transformation Ensembling (TTE) can work as a reliable defense against such attacks. While transforming the input data, both at train and test times, is known to enhance model performance, its effects on adversarial robustness have not been studied. Here, we present a comprehensive empirical study of the impact of TTE, in the form of widely-used image transforms, on adversarial robustness. We show that TTE consistently improves model robustness against a variety of powerful attacks without any need for re-training, and that this improvement comes at virtually no trade-off with accuracy on clean samples. Finally, we show that the benefits of TTE transfer even to the certified robustness domain, in which TTE provides sizable and consistent improvements.

Truncus arteriosus (TA) is a rare congenital heart anomaly presenting with mild cyanosis and congestive heart failure. It occurs when the blood vessels coming out of the heart in the developing baby fail to separate completely during development, leaving a common trunk responsible for the pulmonary and systemic perfusion. There are several variants of TA, depending on the specific anatomy and arterial connection. We report a case of a full-term newborn who developed cyanosis and desaturation during the first day of life. Investigations and echocardiography were consistent with TA type IV. Prostaglandin infusion was immediately started, and then, a successful palliative right modified Blalock Taussig shunt was performed.

This article explores the ways in which two international water agreements on the Yarmouk tributary to the Jordan River induce or impede transformation to equitable transboundary water arrangements. The agreements in question were reached between Jordan and Syria in 1987, and between Jordan and Israel in 1994. Following a brief review of theory and a summary of the body of knowledge on 'model' agreements, the article combines official river-gauging data with interviews and textual analysis to query the text and role of the agreements, particularly in relation to key dams and other infrastructure. Both agreements are found to i) lack important clauses that could govern groundwater abstraction, environmental concerns, water quality, and the ability to adapt to changing water quality, availability and need; and ii) include both ambiguous and rigid clauses that result in generally inequitable allocation of water and thus of the benefits derived from its use. Due to their omissions and to their reflection of the asymmetries in power between the states, both agreements are found to be 'blind' to existing use, to be incapable of dealing with urgent governance needs, and to impede more equitable arrangements.

Renewable energy sources are the best solution to reduce dependence on conventional and nonrenewable sources that also cause environmental pollution. With the increase in the prices of conventional fuels globally, the increase of gas emissions resulting from its use, and the impact on the environment and the global climate; various renewable energy sources have emerged as an alternative to traditional sources of energy. Ssolar energy is one of the most important renewable energy sources used globally; The technology used is relatively simple and uncomplicated, compared to the technology used in other renewable energy sources. Solar energy is the ideal alternative to conventional energy in the Gaza Strip in Palestine, due to the relatively high solar radiation in the region, which makes its application more practical and economical compared to other parts of the world. Palestine has higher rates of total solar absorption, ranging from 4-8 kWh / m2 per day, which is high compared to other countries. This paper offers a solution to the Gaza Strip, which has suffered from a severe power shortage due to the Israeli blockade, by using solar PV as a backup system and a good alternative to diesel generators. Photovoltaic cells convert the sunlight into DC electric power. Where the major problem of the PV is that with the changing of atmospheric conditions, the voltage is changing, and so the maximum power is changing. We know that PV systems are still very expensive; therefore, the Artificial Neural Network controller is designed for the converter to secure the maximum power to the system to increase the efficiency of it. ANN controller is designed to bring out the maximum power from the solar panel. This paper uses a controller that utilizes MPPT technique to increase the efficiency of converting solar energy into electrical energy by modifying the duty cycle of Puls Width Modulation (PWM) for the boost converter to obtain the MPP energy from solar cells at all times. A solar panel applied and their components are individually modeled in the MATLAB / SIMULINK program to simulate a real PV system behavior, then an MPPT technique, including DC/DC boost converter was designed. Then an ANN controller is designed and then trained to get the maximum power 65 point from the solar panel at different atmospheric conditions. Also, this controller is compared with the direct connected method without an MPPT controller. The system performance is measured by changing solar radiation and temperature of the PV module. The findings indicate that MPPT ANN has a fast response to the variability and is more efficient, which means more power transfer to the system. The outcome shows that the photovoltaic module directly associated without MPPT technique has less efficiency because of the mismatch between the photovoltaic module and the load.

About eighty percent of wastewater is discharged into the environment untreated. Many challenges are decelerating solving the global sanitation problem, such as the financial limitations and lack of technical capacities. Parallel to this, many countries are facing a growing demand on their limited water resources. Higher water demand and limited availability leads to over-abstraction and deterioration in the availability and quality water resources. In this situation, wastewater can be a new water source. Therefore, there is a growing interest in finding low-cost, easy-to-operate and sustainable sanitation solutions. Constructed wetlands (CWs) in recent years have proved their capability in the sanitation sector as an appropriate sanitation system in different contexts, CWs have proved their ability to treat several types of wastewaters for several decades. Several benefits and facts, such as the low construction and operational costs of CWs, low-energy, and less operational requirements, have raised the interests in CWs as a treatment technology. Several studies have investigated CWs suitability based on different sustainability indices (technical, social, environmental, etc.). In this paper, a comprehensive review covers the definition, types, treatment processes, sustainability criteria, limitations, and challenges of CWs. The paper also focuses on climate change resilience and circular economic approach under the technical and financial criteria, respectively.

To better understand the chemical controls of sub- and super-saturated aerosol water uptake, we designed and conducted a series of chamber experiments to investigate the evolution of aerosol physicochemical properties during SOA formation from the photochemistry of single or mixed biogenic (α-pinene, isoprene) and anthropogenic (o-cresol) volatile organic compounds (VOCs) in the presence of ammonium sulphate seeds. During the six-hour experiments, the cloud condensation nuclei (CCN) activity at super-saturation of water (0.1 ~ 0.5 %), hygroscopic growth factor at 90 % RH, and non-refractory PM1 chemical composition were recorded concurrently. The hygroscopicity parameter κ was used to represent water uptake ability below and above water saturation, and the κ-Kӧhler approach was implemented to predict the CCN activity from the sub-saturated hygroscopicity. The sub- and super-saturated water uptake (in terms of κHTDMA and κCCN) were mainly controlled by the SOA mass fraction which depended on the SOA production rate of the precursors, and the SOA composition played a second-order role. For the reconciliation of κHTDMA and κCCN, the κHTDMA / κCCN ratio increased with the SOA mass fraction and this was observed in all investigated single and mixed VOC systems, independent of initial VOC concentrations and sources. For all VOC systems, the mean κHTDMA of aerosol particles was ~ 25 % lower than the κCCN at the beginning of the experiments with inorganic seeds. With the increase of condensed SOA on seed particles throughout the experiments, the discrepancy of κHTDMA and κCCN became weaker (down to ~ 0 %) and finally the mean κHTDMA was ~ 60 % higher than κCCN on average when the SOA mass fraction approached ~ 0.8. This is possibly attributable to the non-ideality of solutes at different RH or the different co-condensation of condensable organic vapours within the two instruments. As a result, the predicted CCN number concentrations from the κHTDMA and particle number size distribution were ~ 10 % lower than CCN counter measurement on average at the beginning, and further even turned to an overestimation of ~ 20 % on average when the SOA mass fraction was ~ 0.8. This chemical composition-dependent performances of κ-Kӧhler approach on CCN prediction can introduce a variable uncertainty in predicting cloud droplet numbers from the sub-saturated water uptake.

Background WHO defines an attack on health care as “any act of verbal or physical violence or obstruction or threat of violence that interferes with the availability, access and delivery of curative and/or preventive health services during emergencies.” Gaza's Great March of Return (GMR) began on Mar 30, 2018, with 322 Palestinians killed and 33 141 injured by December, 2019, and first-response health-care teams exposed to high levels of violence. The aims of this study were threefold: to explore the vulnerabilities of health workers to attacks during the GMR; to understand the effectiveness and comprehensiveness of systems for monitoring health attacks; and to identify potential strategies and interventions to improve protection. Methods WHO's Surveillance System for Attacks on Healthcare (SSA) verifies and records health attacks. We analysed SSA data for the Gaza Strip from Mar 30, 2018, to Dec 31, 2019, examining the number and type of attacks, the mechanisms of injury, and the distribution of attacks by gender, time, and location. We analysed the correlation of health worker injuries and deaths with total injuries and deaths of Palestinians during the GMR. We held interviews and focus groups with individuals working for organizations defined as partners contributing to the SSA in the Gaza Strip, to understand data comprehensiveness, the nature and impact of violence, and protection gaps and strategies. Findings During the study period, there were 567 confirmed incidents, in which three health workers were killed, 845 health workers were injured, and 129 ambulances and vehicles and 7 health facilities were damaged, including one hospital and three medical field stations. Of the total health personnel killed and injured, 166 of 848 (20%) were in the Gaza governorate, 274 (32%) were in the Khan Yunis governorate, 119 (14%) were in the middle governorate, 192 (22%) were in North governorate, and 96 (11%) were in the Rafah governorate. Of 845 injuries, 743 (88%) were in men, 45 (5%) were live ammunition injuries, 62 (7%) were rubber bullet injuries, 151 (18%) were gas canister injuries, 41 (5%) were shrapnel injuries, and 533 (64%) were gas inhalation injuries. Injuries and deaths among health workers correlated moderately (R2=0·54) with and accounted for 2% of the total. Qualitative findings highlighted the incidental and structural nature of violence, normalisation and under-reporting of attacks, the need for improved coordination of protection for health care, and gaps in the availability of protective equipment. Interpretation Health-care workers function at great personal risk. The correlation of attacks against health care with total injuries and deaths points to the need for alignment of efforts to protect health care with strategies to safeguard civilian populations, including protection of populations living under occupation and those engaged in civil demonstrations. Health-care workers identified the need for systemic measures to improve protection through training, monitoring, and coordination, and through linking of monitoring and documentation of health attacks with stronger accountability measures for prevention. Funding In 2017 and 2018, WHO's Right to Health Advocacy programme received funding from the Swiss Development Cooperation and the oPt Humanitarian Fund.

This paper forecasts the digital economy trends during a COVID-19 pandemic in the world. Considered the USA one of the world's largest economies and has recently been shifting almost completely to digital economies. Therefore, this paper used the auto-regressive integrated moving average (ARIMA) model and the gross domestic product (GDP) for the USA over the period 1960-2019. As we arrive at the peak of the COVID-19 pandemic, one of the most squeezing questions confronting us is: what is the likely effect of the ongoing emergency on the digital economy development rate? The results have been shown first that the GDP growth for both years 2020 and 2021 is approximately 6% for the USA. Second, we conclude that the COVID-19 pandemic cannot influence the countries that depend on technology and the digital economy. Thus, technology is playing a very significant role in our daily life and nations’ economies.

With the spread of the COVID19 pandemic, blended learning has become one of the most used methods in educational organizations such as universities, community colleges, and schools. In blended learning, the students’ practical activities are done in more than one way, including simulation software and the place of study. For chemical experiment programs, the classification of handwritten chemical formulas plays an important role in determining the simulation software’s efficiency. Accordingly, in this study, we propose a model for handwritten chemical formula classification. First, this paper describes a handwritten chemical formulas dataset that contains eight classes (HCFD8). Second, convolutional neural networks (CNNs) with pre-trained weights are used as a deep feature extractor to extract features from the images. Third, due to limited training images per class, the proposed model uses data augmentation techniques to expand the training images. Then, an enhanced multilayer perceptron (EMLP) strategy is used to classify the image. Finally, we provide a performance analysis of typical deep learning approaches on HCFD8, which shows that the proposed model performs good accuracy results.

The phase behaviour of aerosol particles plays a profound role in atmospheric physicochemical processes, influencing their physical and optical properties and further impacting climate and air quality. However, understanding of aerosol phase behaviour is still incomplete, especially that of multicomponent particles which contain inorganic compounds and secondary organic aerosol (SOA) from mixed volatile organic compound (VOC) precursors. We report measurements conducted in the Manchester Aerosol Chamber (MAC) to investigate the aerosol rebounding tendency, measured as bounce fraction, as a surrogate of particle phase behaviour during SOA formation from photo-oxidation of biogenic (α-pinene, isoprene) and anthropogenic (o-cresol) VOCs and their binary mixtures on deliquescent ammonium sulphate seed. Aerosol phase behaviour is RH and chemical composition dependent. Liquid (bounce fraction, BF  80 % and non-liquid behaviour (BF > 0.8) at RH BF = 0.2, 0.5, 0.8) increased towards a maximum with increasing organic-inorganic-mass ratio (MRorg/inorg) during SOA formation evolution in all investigated VOC systems. With the use of comparable initial ammonium sulphate seed concentration, the SOA production rate of the VOC systems determines the MRorg/inorg, and consequently the change of the phase behaviour. Although less important than RH and MRorg/inorg, the SOA composition plays a second-order role, with differences in liquid-to-nonliquid transition at moderate MRorg/inorg of ~1 observed between biogenic and anthropogenic-containing VOC systems. The real atmospheric consequences of our results are that any processes changing ambient RH or MRorg/inorg will influence their particle phase behaviour. Where abundant anthropogenic VOCs contribute to SOA, compositional changes of SOA may influence phase behaviour at moderate organic mass fraction (~50 %) compared with purely biogenic SOA. Further studies are needed on more complex and realistic atmospheric mixtures.

The physical and chemical properties of black carbon (BC) and organic aerosols are important for predicting their radiative forcing in the atmosphere. During the Soot Aerodynamic Size Selection for Optical properties (SASSO) project and a EUROCHAMP-2020 transnational access project, different types of light absorbing carbon were studied, including BC from catalytically stripped diesel exhaust, a flame burner, a colloidal graphite standard (Aquadag), and from controlled flaming wood combustion. Brown carbon (BrC) was also investigated in the form of organic aerosol emissions from wood burning (pyrolysis and smouldering) and from the nitration of secondary organic aerosol (SOA) proxies produced in a photochemical reaction chamber. Here we present insights into the physical and chemical properties of the aerosols, with optical properties being presented in subsequent publications. The dynamic shape factor (χ) of BC particles and material density (ρm) of organic aerosols were investigated by coupling a charging-free Aerodynamic Aerosol Classifier (AAC) with a Centrifugal Particle Mass Analyzer (CPMA) and Scanning Mobility Particle Sizer (SMPS). The morphology of BC particles was captured by transmission electron microscopy (TEM). For BC particles from the diesel engine and flame burner emissions, the primary spherule sizes were similar, around 20 nm. With increasing particle size, BC particles adopted more collapsed/compacted morphologies for the former source but tended to show more aggregated morphologies for the latter source. For particles emitted from the combustion of dry wood samples, the χ of BC particles and the ρm of organic aerosols were observed in the ranges 1.8–2.17 and 1.22–1.32 g/cm3, respectively. Similarly, for wet wood samples, the χ and ρm ranges were 1.2–1.85 and 1.44–1.60 g/cm3, respectively. Aerosol mass spectrometry measurements show no clear difference in mass spectra of the organic aerosols in individual burn phases (pyrolysis or smouldering phase) with the moisture content of the wood samples. This implies that the effect moisture has on the organic chemical profile of wood burning emissions is through changing the durations of the different phases of the burn cycle, not through the chemical modification of the individual phases. In this study, the incandescence signal of a Single Particle Soot Photometer (SP2) was calibrated with three different types of BC particles and compared with that from an Aquadag standard that is commonly used to calibrate SP2 incandescence to a BC mass. A correction factor is defined as the ratio of the incandescence signal from an alternative BC source to that from the Aquadag standard, and took values of 0.82 (or 0.79), 0.88 and 0.84–0.91 for the BC particles emitted from the diesel engine running under hot (or cold idle) conditions, the flame burner and wood combustion, respectively. These correction factors account for differences in instrument response to BC from different sources compared to the standardised Aquadag calibration and are more appropriate than the common value of 0.75 recommended by Laborde et al. (2012b) when deriving the mass concentration of BC emitted from diesel engines. Quantifying the correction factor for many types of BC particles found commonly in the atmosphere may enable better constraints to be placed on this factor depending on the BC source being sampled, and thus improve the accuracy of future SP2 measurements of BC mass concentrations.