Data Analytics for COVID-19 Pandemic

Since the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, the pandemic situation has begun to undergo positive changes with the joint efforts of various countries and world organizations. However, pressures such as the COVID-19 mutations and the sharp rise in confirmed cases have brought uncertainties to the prevention and control of the pandemic. The overall situation is still severe and complex. Based on the multi-dimensional spatial-temporal COVID-19 data collected by the open-source NetEase News (NEN) website and a real-time dynamic website, it is to explore the characteristics of the pandemic data, visualize the development trend, and analyze the spread of the pandemic in this paper. Moreover, it is to provide a rule basis for the prevention and control of the COVID-19 pandemic by constructing the decision tree model. From the results, some suggestions are provided for decision-makers.

Influence of Graphite Powder on the Mechanical and Acoustic Emission Characteristics of Concrete

In this paper, uniaxial compressive strength (UCS) test and three-point bending (TPB) test, together with an acoustic emission (AE) system, were performed to investigate the mechanical properties and AE characteristic changes of concrete with different graphite powder (GP) content. The results show that: (1) Poor adhesion and low interlocking of graphite with cement stone increase the initial defects of concrete, reducing its elastic modulus and the cyclo-hoop effect, and thus weakening the compressive strength. (2) For concrete with a low graphite content, the second sharp rise in ringing counts or energy released during the compressive process can be regarded as a failure alarm. However, as GP content increases, the second sharp rise fades away, while the first sharp rise becomes more visible. At high GP content, the first sharp rise is better for predicting failure. (3) The initial defects caused by GP significantly lower the initial fracture toughness, but its bridging effect greatly increases the critical crack mouth opening displacement and thus significantly enhances the unstable fracture toughness of concrete, by up to 9.9% at 9% GP content. (4) In contrast to compressive process, the sharp increase in AE signals preceding failure during the fracture process cannot be used to predict failure because it occurs too close to the ultimate load. However, as GP can significantly increase the AE signals and damage value in the stable period, such failure precursor information can provide a safety warning for damage development.

Immunity acquired by a minority active fraction of the population could explain COVID-19 spread in Greater Buenos Aires (June-November 2020)

The COVID-19 pandemic had an uneven development in different countries. In Argentina, the pandemic began in march 2020 and, during the first 3 months, the vast majority of cases were concentrated in a densely populated region that includes the city of Buenos Aires (country capital) and the Greater Buenos Aires area that surrounds it. This work focuses on the spread of COVID-19 between June and November 2020 in Greater Buenos Aires. Within this period of time there was no vaccine, basically only the early wild strain of SARS-CoV-2 was present, and the official restriction and distancing measures in this region remained more or less constant. Under these particular conditions, the incidences show a sharp rise from June 2020 and begin to decrease towards the end of August until the end of November 2020. In this work we study, through mathematical modelling and available epidemiological information, the spread of COVID-19 in this region and period of time. We show that a coherent explanation of the evolution of incidences can be obtained assuming that only a minority fraction of the population got involved in the spread process, so that the incidences decreased as this group of people was becoming immune. The observed evolution of the incidences could then be a consequence at the population level of lasting immunity conferred by SARS-CoV-2.

Tracheotomy Outcomes in 71 COVID-19 Patients: A Multi-Centric Study in Saudi Arabia

Since its outbreak in late 2019, the COVID-19 pandemic has seen a sharp rise in the demand for oxygen and ventilation facilities due to the associated extensive damage that it causes to the lungs. This study is considered the first and largest study in Saudi Arabia to evaluate the outcomes of tracheostomy in intubated COVID-19 patients. This is a retrospective, observational cohort study that was conducted at King Abdulaziz Medical City (KAMC) in Jeddah, Western Region, Saudi Arabia and King Fahad Armed Forces Hospital, Jeddah, Saudi Arabia. The findings of the study revealed that seventy-one patients with COVID-19 underwent tracheotomy between 1 March 2020 and 31 October 2020. The average period between intubation and tracheostomy was 9.97 days. Hypertension, diabetes, lung disease and obesity (BMI > 30) were significant risk factors of mortality. The overall 30-day mortality rate was 38.4%.

Surge in SARS-CoV-2 transmission in school-aged children and household contacts, England, August to October 2021

Easing of COVID-19 restrictions in England in the summer of 2021 was followed by a sharp rise in cases among school-aged children. Weekly rates of SARS-CoV-2 infection in primary and secondary school children reached 733.3 and 1,664.7/100,000 population, respectively, by week 39 2021. A surge in household clusters with school-aged index cases was noted at the start of the school term, with secondary cases predominantly in children aged 5–15 years and adults aged 30–49 years.

Gas-Phase Nucleation of Diamond Clusters upon a Sharp Rise in Temperature under Conditions of CVD Synthesis

It is shown that the predominant nucleation of diamond nuclei (instead of graphite ones) in plasma or hot-filament assisted CVD technology is due to a sharp increase in the temperature of the region of the initial gas mixture’s motion. The nucleation of diamond nuclei then occurs immediately in the gas phase. The reason for such predominant nucleation is high oversaturation by small hydrocarbon fragments in the gas mixture, due to a rapid change in temperature and substantial differences between the desorption of such fragments from the surfaces of nuclei and the oxidation of nuclei. A way is described of synthesizing massive diamonds without the use of high pressures and CVD technology in its traditional form.

China's Energy Security: Going Beyond the Traditional Approach

<p>China's rapidly growing economy has seen a sharp rise in energy consumption and correspondingly a new focus on energy security. Over the last decade, China has adopted an energy security approach emphasizing its external energy supply, especially oil supply, which is quite similar to the approach established in industrialized Western countries (IWCs) since the 1970s' energy crises. However, China‟s energy situation is profoundly different from the West with over 90 percent of its energy being produced domestically and nearly 70 percent being coal-based. To explain why the approach in China is similar to that of major IWCs, I demonstrate that while the IWCs constructed their energy security concept and subsequent policy responses on their energy situation, China's approach has largely been influenced by a domestic ideational factor and Western energy security concept. By providing a detailed examination of China's energy situation, highlighting the unique energy security vulnerabilities and threats it faces, I argue current mainstream energy security thinking in China does not match its comprehensive energy situation. It is therefore not adequate to address its energy security challenges. The thesis concludes that, a 'broader' energy security approach, going beyond the traditional thinking, should be developed to incorporate more energy sectors and domestic energy issues in China.</p>

China's Energy Security: Going Beyond the Traditional Approach

<p>China's rapidly growing economy has seen a sharp rise in energy consumption and correspondingly a new focus on energy security. Over the last decade, China has adopted an energy security approach emphasizing its external energy supply, especially oil supply, which is quite similar to the approach established in industrialized Western countries (IWCs) since the 1970s' energy crises. However, China‟s energy situation is profoundly different from the West with over 90 percent of its energy being produced domestically and nearly 70 percent being coal-based. To explain why the approach in China is similar to that of major IWCs, I demonstrate that while the IWCs constructed their energy security concept and subsequent policy responses on their energy situation, China's approach has largely been influenced by a domestic ideational factor and Western energy security concept. By providing a detailed examination of China's energy situation, highlighting the unique energy security vulnerabilities and threats it faces, I argue current mainstream energy security thinking in China does not match its comprehensive energy situation. It is therefore not adequate to address its energy security challenges. The thesis concludes that, a 'broader' energy security approach, going beyond the traditional thinking, should be developed to incorporate more energy sectors and domestic energy issues in China.</p>

OpenSAFELY: impact of national guidance on switching anticoagulant therapy during COVID-19 pandemic

BackgroundEarly in the COVID-19 pandemic, the National Health Service (NHS) recommended that appropriate patients anticoagulated with warfarin should be switched to direct-acting oral anticoagulants (DOACs), requiring less frequent blood testing. Subsequently, a national safety alert was issued regarding patients being inappropriately coprescribed two anticoagulants following a medication change and associated monitoring.ObjectiveTo describe which people were switched from warfarin to DOACs; identify potentially unsafe coprescribing of anticoagulants; and assess whether abnormal clotting results have become more frequent during the pandemic.MethodsWith the approval of NHS England, we conducted a cohort study using routine clinical data from 24 million NHS patients in England.Results20 000 of 164 000 warfarin patients (12.2%) switched to DOACs between March and May 2020, most commonly to edoxaban and apixaban. Factors associated with switching included: older age, recent renal function test, higher number of recent INR tests recorded, atrial fibrillation diagnosis and care home residency. There was a sharp rise in coprescribing of warfarin and DOACs from typically 50–100 per month to 246 in April 2020, 0.06% of all people receiving a DOAC or warfarin. International normalised ratio (INR) testing fell by 14% to 506.8 patients tested per 1000 warfarin patients each month. We observed a very small increase in elevated INRs (n=470) during April compared with January (n=420).ConclusionsIncreased switching of anticoagulants from warfarin to DOACs was observed at the outset of the COVID-19 pandemic in England following national guidance. There was a small but substantial number of people coprescribed warfarin and DOACs during this period. Despite a national safety alert on the issue, a widespread rise in elevated INR test results was not found. Primary care has responded rapidly to changes in patient care during the COVID-19 pandemic.

Gravitational waves from GRB core spindown

We investigate long Gamma-Ray Bursts (GRB) which manifest a sharp linear rise followed by an exponential decay in their γ-ray prompt emission observed with the BAT instrument on board the Swift satellite. We offer a simple electrodynamic model that may account for these particular characteristics. We associate the sharp rise with the winding of the magnetic field by the fast rotating core that formed in the interior of the stellar precursor. We also associate the subsequent exponential decay with the electromagnetic spindown of the core following the release of the electromagnetic jet from the stellar interior. Any non-axisymmetric distortion in the rotating core will generate gravitational waves with exponentially decreasing frequency, a so-called ‘down-chirp’. We obtain a detailed estimate of the gravitational wave profile if the distortion of spacetime is due to the winding of a non-axisymmetric component of the magnetic field during that particular phase of the burst. We offer 7 particular time intervals during which one may look into LIGO archival data for the presence of our particular predicted waveforms in order to test our interpretation.