scholarly journals Spatiotemporal evolution of COVID-19 infection and detection within night light networks: comparative analysis of USA and China

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Christopher Small ◽  
Daniel Sousa
Keyword(s):  
Spatial Distribution ◽  
Network Structure ◽  
Population Distribution ◽  
Spatial Network ◽  
Size Distributions ◽  
Spatial Networks ◽  
Spatiotemporal Evolution ◽  
Low Luminance ◽  
Wide Range ◽  
The Usa

AbstractThe spatial distribution of population affects disease transmission, especially when shelter in place orders restrict mobility for a large fraction of the population. The spatial network structure of settlements therefore imposes a fundamental constraint on the spatial distribution of the population through which a communicable disease can spread. In this analysis we use the spatial network structure of lighted development as a proxy for the distribution of ambient population to compare the spatiotemporal evolution of COVID-19 confirmed cases in the USA and China. The Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band sensor on the NASA/NOAA Suomi satellite has been imaging night light at ~ 700 m resolution globally since 2012. Comparisons with sub-kilometer resolution census observations in different countries across different levels of development indicate that night light luminance scales with population density over ~ 3 orders of magnitude. However, VIIRS’ constant ~ 700 m resolution can provide a more detailed representation of population distribution in peri-urban and rural areas where aggregated census blocks lack comparable spatial detail. By varying the low luminance threshold of VIIRS-derived night light, we depict spatial networks of lighted development of varying degrees of connectivity within which populations are distributed. The resulting size distributions of spatial network components (connected clusters of nodes) vary with degree of connectivity, but maintain consistent scaling over a wide range (5 × to 10 × in area & number) of network sizes. At continental scales, spatial network rank-size distributions obtained from VIIRS night light brightness are well-described by power laws with exponents near −2 (slopes near −1) for a wide range of low luminance thresholds. The largest components (104 to 105 km2) represent spatially contiguous agglomerations of urban, suburban and periurban development, while the smallest components represent isolated rural settlements. Projecting county and city-level numbers of confirmed cases of COVID-19 for the USA and China (respectively) onto the corresponding spatial networks of lighted development allows the spatiotemporal evolution of the epidemic (infection and detection) to be quantified as propagation within networks of varying connectivity. Results for China show rapid nucleation and diffusion in January 2020 followed by rapid decreases in new cases in February. While most of the largest cities in China showed new confirmed cases approaching zero before the end of February, most of these cities also showed distinct second waves of cases in March or April. Whereas new cases in Wuhan did not approach zero until mid-March, as of December 2020 it has not yet experienced a second wave of cases. In contrast, the results for the USA show a wide range of trajectories, with an abrupt transition from slow increases in confirmed cases in a small number of network components in January and February, to rapid geographic dispersion to a larger number of components shortly before mobility reductions occurred in March. Results indicate that while most of the upper tail of the network had been exposed by the end of March, the lower tail of the component size distribution has only shown steep increases since mid-June.

scholarly journals Study on the Relationship between Mechanical Properties and Mesostructure of Microbial Cemented Sand Bodies

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Yue Yan ◽  
Yang Tang ◽  
Guobin Xu ◽  
Jijian Lian ◽  
Dengfeng Fu
Keyword(s):  
Compressive Strength ◽  
Spatial Distribution ◽  
Network Structure ◽  
Ground Improvement ◽  
Influential Factors ◽  
Spatial Network ◽  
Cemented Sand ◽  
Multiple Parameters ◽  
Improvement Method ◽  
The Relationship

Microbial-induced calcite precipitation (MICP) is a novel ground improvement method to effectively increase the strength of sandy soil. However, the relationship between the compressive strength of cemented sand and mesostructure of the cemented structure has not been addressed adequately. In this paper, a suite of microbial cementing experiments were conducted, considering multiple parameters controllable in testing. Twenty-two cementing columns were examined by uniaxial compressive strength (UCS) tests to explore the response of variations in compressive strength. The correlation of compressive strength with mesostructure of cemented samples was investigated using the X-ray computed tomography (XCT) method. Three main influential factors—the uniform spatial distribution, increasing contents, and increasing size of the crystals—were found to contribute positively to the strength behavior. Under relatively uniform spatial distribution, increasing the contents of crystals facilitated the initial construction of “spatial network” structure, and further stacks of calcium carbonate crystals promote the complete construction of the “spatial network” structure, and thus helped to increase compressive strength. The spatial distribution curves of crystals are in good agreement with the destructive characteristic curves of structures.

Network Organizational Structure (a Scientific and Practical Review)

2020 ◽  
Vol 26 (6) ◽  
pp. 613-618
Author(s):  
A. V. Altukhov ◽  
S. A. Tishchenko
Keyword(s):  
Organizational Structure ◽  
Network Structure ◽  
Business Models ◽  
Scientific Development ◽  
Network Structures ◽  
Scientific Publications ◽  
Wide Range ◽  
Modern Business ◽  
History Of ◽  
Business Structures

The presented study reviews practically relevant research papers in the field of network structures, modern network business models and platforms.Aim. The study aims to elaborate and explain the concept of network structure and platform and to show the reasons for the progressiveness and potential of network organizational structure at the current stage of socio-economic and scientific development.Tasks. The authors highlight the main scientific ideas about network structures in business, including significant studies in this area; provide and explain the main terms and definitions and examine the key characteristics of network business structures; characterize “platforms” as an important concept for modern business and show the relationship between platforms and network structures.Methods. This study uses analysis of information and subsequent synthesis of new knowledge in the form of the authors’ conclusions and a wide range of relevant scientific publications of Russian and foreign authors, including original publications in English and French.Results. The history of network structures is briefly provided. Definitions and characteristics of such concepts as “network structure” and “platform” in relation to business are provided and explained by the authors.

scholarly journals Geospatial Analysis of COVID-19: A Scoping Review

2021 ◽  
Vol 18 (5) ◽  
pp. 2336
Author(s):  
Munazza Fatima ◽  
Kara J. O’Keefe ◽  
Wenjia Wei ◽  
Sana Arshad ◽  
Oliver Gruebner
Keyword(s):  
Disease Mapping ◽  
Geospatial Analysis ◽  
Hotspot Analysis ◽  
Spatial Studies ◽  
Epidemiological Modeling ◽  
Wide Range ◽  
Scoping Reviews ◽  
Disease Pattern ◽  
The Usa ◽  
Meta Analyses

The outbreak of SARS-CoV-2 in Wuhan, China in late December 2019 became the harbinger of the COVID-19 pandemic. During the pandemic, geospatial techniques, such as modeling and mapping, have helped in disease pattern detection. Here we provide a synthesis of the techniques and associated findings in relation to COVID-19 and its geographic, environmental, and socio-demographic characteristics, following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) methodology for scoping reviews. We searched PubMed for relevant articles and discussed the results separately for three categories: disease mapping, exposure mapping, and spatial epidemiological modeling. The majority of studies were ecological in nature and primarily carried out in China, Brazil, and the USA. The most common spatial methods used were clustering, hotspot analysis, space-time scan statistic, and regression modeling. Researchers used a wide range of spatial and statistical software to apply spatial analysis for the purpose of disease mapping, exposure mapping, and epidemiological modeling. Factors limiting the use of these spatial techniques were the unavailability and bias of COVID-19 data—along with scarcity of fine-scaled demographic, environmental, and socio-economic data—which restrained most of the researchers from exploring causal relationships of potential influencing factors of COVID-19. Our review identified geospatial analysis in COVID-19 research and highlighted current trends and research gaps. Since most of the studies found centered on Asia and the Americas, there is a need for more comparable spatial studies using geographically fine-scaled data in other areas of the world.

scholarly journals Modeling Spatiotemporal Population Changes by Integrating DMSP-OLS and NPP-VIIRS Nighttime Light Data in Chongqing, China

2021 ◽  
Vol 13 (2) ◽  
pp. 284
Author(s):  
Dan Lu ◽  
Yahui Wang ◽  
Qingyuan Yang ◽  
Kangchuan Su ◽  
Haozhe Zhang ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Relative Error ◽  
Urban Areas ◽  
Large Scale ◽  
Population Distribution ◽  
Spatial Optimization ◽  
Distribution Data ◽  
Mountainous Areas ◽  
Mean Relative Error ◽  
Nighttime Light

The sustained growth of non-farm wages has led to large-scale migration of rural population to cities in China, especially in mountainous areas. It is of great significance to study the spatial and temporal pattern of population migration mentioned above for guiding population spatial optimization and the effective supply of public services in the mountainous areas. Here, we determined the spatiotemporal evolution of population in the Chongqing municipality of China from 2000–2018 by employing multi-period spatial distribution data, including nighttime light (NTL) data from the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP-OLS) and the Suomi National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite (NPP-VIIRS). There was a power function relationship between the two datasets at the pixel scale, with a mean relative error of NTL integration of 8.19%, 4.78% less than achieved by a previous study at the provincial scale. The spatial simulations of population distribution achieved a mean relative error of 26.98%, improved the simulation accuracy for mountainous population by nearly 20% and confirmed the feasibility of this method in Chongqing. During the study period, the spatial distribution of Chongqing’s population has increased in the west and decreased in the east, while also increased in low-altitude areas and decreased in medium-high altitude areas. Population agglomeration was common in all of districts and counties and the population density of central urban areas and its surrounding areas significantly increased, while that of non-urban areas such as northeast Chongqing significantly decreased.

scholarly journals Regional Disparity and Patients Mobility: Benefits and Spillover Effects of the Spatial Network Structure of the Health Services in China

2021 ◽  
Vol 18 (3) ◽  
pp. 1096
Author(s):  
Liping Fu ◽  
Kaibo Xu ◽  
Feng Liu ◽  
Lu Liang ◽  
Zhengmin Wang
Keyword(s):  
Health Economic ◽  
Health Services ◽  
Network Structure ◽  
Spillover Effect ◽  
Spillover Effects ◽  
Health Economy ◽  
Spatial Network ◽  
Spatial Effects ◽  
Medical Resource ◽  
Medical Resources

Background: The distribution of medical resources in China is seriously imbalanced due to imbalanced economic development in the country; unbalanced distribution of medical resources makes patients try to seek better health services. Against this backdrop, this study aims to analyze the spatial network characteristics and spatial effects of China’s health economy, and then find evidence that affects patient mobility. Methods: Data for this study were drawn from the China Health Statistical Yearbooks and China Statistical Books. The gravitational value of China’s health spatial network was calculated to establish a network of gravitational relationships. The social network analysis method was used for centrality analysis and spillover effect analysis. Results: A gravity correlation matrix was constructed among provinces by calculating the gravitational value, indicating the spatial relationships of different provinces in the health economic network. Economically developed provinces, such as Shanghai and Jiangsu, are at the center of the health economic network (centrality degree = 93.333). These provinces also play a strong intermediary role in the network and have connections with other provinces. In the CONCOR analysis, 31 provinces are divided into four blocks. The spillover effect of the blocks indicates provinces with medical resource centers have beneficial effects, while provinces with insufficient resources have obvious spillover effects. Conclusion: There is a significant gap in the geographical distribution of medical resources, and the health economic spatial network structure needs to be improved. Most medical resources are concentrated in economically developed provinces, and these provinces’ positions in the health economic spatial network are becoming more centralized. By contrast, economically underdeveloped regions are at the edge of the network, causing patients to move to provinces with medical resource centers. There are health risks of the increasing pressure to seek medical treatment in developed provinces with abundant medical resources.

scholarly journals Bioinsecticides based on plant essential oils: a short overview

2020 ◽  
Vol 75 (7-8) ◽  
pp. 179-182
Author(s):  
Murray B. Isman
Keyword(s):  
Essential Oils ◽  
Crop Protection ◽  
Large Body ◽  
Regulatory Agencies ◽  
The European Union ◽  
Plant Essential Oils ◽  
The Past ◽  
Wide Range ◽  
The Usa ◽  
Regulatory Challenges

AbstractInterest in the discovery and development of plant essential oils for use as bioinsecticides has grown enormously in the past 20 years. However, successful commercialization and utilization of crop protection products based on essential oils has thus far lagged far behind their promise based on this large body of research, most notably because with the exceptions of the USA and Australia, such products receive no special status from regulatory agencies that approve new pesticides for use. Essential oil-based insecticides have now been used in the USA for well over a decade, and more recently have seen use in the European Union (EU), Korea, and about a dozen other countries, with demonstrated efficacy against a wide range of pests and in numerous crop systems. For the most part these products are based on commodity essential oils developed as flavor and fragrance agents for the food and cosmetic industries, as there are formidable logistic, economic, and regulatory challenges to the use of many other essential oils that otherwise possess potentially useful bioactivity against pests. In spite of these limitations, the overall prospects for biopesticides, including those based on essential oils, are encouraging as the demand for sustainably-produced and/or organic food continues to increase worldwide.

scholarly journals 3 per cent-accurate predictions for the clustering of dark matter, haloes, and subhaloes, over a wide range of cosmologies and scales

2020 ◽  
Vol 499 (4) ◽  
pp. 4905-4917
Author(s):  
S Contreras ◽  
R E Angulo ◽  
M Zennaro ◽  
G Aricò ◽  
M Pellejero-Ibañez
Keyword(s):  
Dark Matter ◽  
Spatial Distribution ◽  
Cosmological Parameters ◽  
Galaxy Surveys ◽  
Circular Velocity ◽  
Initial Application ◽  
Wide Range ◽  
Massive Neutrinos ◽  
Dynamical Dark Energy ◽  
Better Than

ABSTRACT Predicting the spatial distribution of objects as a function of cosmology is an essential ingredient for the exploitation of future galaxy surveys. In this paper, we show that a specially designed suite of gravity-only simulations together with cosmology-rescaling algorithms can provide the clustering of dark matter, haloes, and subhaloes with high precision. Specifically, with only three N-body simulations, we obtain the power spectrum of dark matter at z = 0 and 1 to better than 3 per cent precision for essentially all currently viable values of eight cosmological parameters, including massive neutrinos and dynamical dark energy, and over the whole range of scales explored, 0.03 < $k/{h}^{-1}\, {\rm Mpc}^{-1}$ < 5. This precision holds at the same level for mass-selected haloes and for subhaloes selected according to their peak maximum circular velocity. As an initial application of these predictions, we successfully constrain Ωm, σ8, and the scatter in subhalo-abundance-matching employing the projected correlation function of mock SDSS galaxies.

Events in Northern Africa and Middle East: Causes and Consequences

2011 ◽  
pp. 11-25
Author(s):  
I. Labinskaya
Keyword(s):  
Middle East ◽  
North Africa ◽  
Large Scale ◽  
Arab Countries ◽  
Northern Africa ◽  
External Factors ◽  
Wide Range ◽  
The Usa ◽  
Oriental Studies

Political developments in North Africa and the Middle East that have begun in January 2011 are gaining strength and involve an increasing number of Arab countries. The participants of the Roundtable – experts from IMEMO, Institute of Oriental Studies (RAS), Institute of the USA and Canada (RAS) and Mrs. E. Suponina from “Moscow News” newspaper analyzed a wide range of issues associated with these events. Among them are: 1) the reasons for such a large-scale explosion, 2) the nature of the discussed developments (revolutions, riots?) and who are the subjects of the current “Arab drama”, 3) the role of Islam and political Islamism, 4) the role of external factors.

A New World Economic order formation

2021 ◽  
pp. 932-950
Author(s):  
Vladislav Vyacheslavovich Emelyanov
Keyword(s):  
Oil And Gas ◽  
World Order ◽  
The United States ◽  
New Order ◽  
The West ◽  
Wide Range ◽  
The World ◽  
The Usa ◽  
World Economic Order ◽  
The Impact

Every few decades, the world order changes due to various geopolitical, economic and other circumstances. For example, as a result of globalization, the world order has undergone significant changes in the last forty years. Globalization has led to the destruction of the postwar world order, as well as to world leadership by the United States and the West. However, in recent decades, as a result of globalization, the U.S. and the West began to cede their leadership to developing countries, so there is now a change in the economic structure of relations in the world system. Today the center of economic growth is in the East, namely in Asia. There are no new superpowers in the world at the moment, but the unipolar world will cease to exist due to the weakening of the U. S. leadership, which will lead to a change in the world order. A new leader, which may replace the U. S., will not have as wide range of advantages as the USA has. Most likely, the essence of the new order will be to unite the largest countries and alliances into blocks, for example, the USA together with the Trans-Pacific Partnership, the EU, etc. The article outlines forecasts of GDP growth rates as well as the global energy outlook; analyzes the LNG market as well as the impact of the pandemic on the global oil and gas market; and lists the characteristics of U. S. geopolitics.

scholarly journals Characteristics of registered clinical trials assessing treatments for COVID-19: a cross-sectional analysis

BMJ Open ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. e039978 ◽  
Author(s):  
Hemalkumar B Mehta ◽  
Stephan Ehrhardt ◽  
Thomas J Moore ◽  
Jodi B Segal ◽  
G Caleb Alexander
Keyword(s):  
Clinical Trials ◽  
Clinical Investigation ◽  
Scientific Progress ◽  
Cross Sectional ◽  
Design Elements ◽  
Cross Sectional Analysis ◽  
Therapeutic Benefits ◽  
Wide Range ◽  
The Usa ◽  
Sectional Analysis

ObjectivesThe coronavirus disease 2019 (COVID-19) pandemic has prompted many initiatives to identify safe and efficacious treatments, yet little is known regarding where early efforts have focused. We aimed to characterise registered clinical trials assessing drugs or plasma treatments for COVID-19.Design, setting and participantsCross-sectional analysis of clinical trials for the treatment of COVID-19 that were registered in the USA or in countries contributing to the WHO’s International Clinical Trials Registry Platform. Relevant trial entries of drugs or plasma were downloaded on 26 March 2020, deduplicated, verified with reviews of major medical journals and WHO websites and independently analysed by two reviewers.Main outcome(s)Trial intervention, sponsorship, critical design elements and specified outcomesResultsOverall, 201 clinical trials were registered for testing the therapeutic benefits of 92 drugs or plasma, including 64 in monotherapy and 28 different combinations. Only eight (8.7%) products or combinations involved new molecular entities. The other test therapies had a wide range of prior medical uses, including as antivirals, antimalarials, immunosuppressants and oncology treatments. In 152 trials (75.7%), patients were randomised to treatment or comparator, including 55 trials with some form of blinding and 97 open-label studies. The 49 (24.4%) of trials without a randomised design included 29 single armed studies and 20 trials with some comparison group. Most trial designs featured multiple endpoints. Clinical endpoints were identified in 134 (66.7%) of trials and included COVID-19 symptoms, death, recovery, required intensive care and hospital discharge. Clinical scales were being used in 33 (16.4%) trials, most often measures of oxygenation and critical illness. Surrogate endpoints or biomarkers were studied in 88 (42.3%) of trials, primarily assays of viral load. Although the trials were initiated in more than 17 countries or regions, 100 (49.8%) were registered in China and 78 (37.8%) in the USA. Registered trials increased rapidly, with the number of registered trials doubling from 1 March to 26 March 2020.ConclusionsWhile accelerating morbidity and mortality from the COVID-19 pandemic has been paralleled by early and rapid clinical investigation, many trials lack features to optimise their scientific value. Global coordination and increased funding of high-quality research may help to maximise scientific progress in rapidly discovering safe and effective treatments.

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