scholarly journals Topological and Thermodynamic Entropy Measures for COVID-19 Pandemic through Graph Theory

Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1992
Author(s):  
G. Kirithiga Nandini ◽  
R. Sundara Rajan ◽  
A. Arul Shantrinal ◽  
T. M. Rajalaxmi ◽  
Indra Rajasingh ◽  
...  
Keyword(s):  
Biological Evolution ◽  
Genetic Network ◽  
Topological Indices ◽  
Mitigation Strategies ◽  
Contact Tracing ◽  
Topological Characterization ◽  
Christmas Trees ◽  
Global Pandemic ◽  
Mathematical Techniques ◽  
Underlying Mechanisms

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the global pandemic, coronavirus disease-2019 (COVID-19) which has resulted in 60.4 million infections and 1.42 million deaths worldwide. Mathematical models as an integral part of artificial intelligence are designed for contact tracing, genetic network analysis for uncovering the biological evolution of the virus, understanding the underlying mechanisms of the observed disease dynamics, evaluating mitigation strategies, and predicting the COVID-19 pandemic dynamics. This paper describes mathematical techniques to exploit and understand the progression of the pandemic through a topological characterization of underlying graphs. We have obtained several topological indices for various graphs of biological interest such as pandemic trees, Cayley trees, Christmas trees, and the corona product of Christmas trees and paths. We have also obtained an analytical expression for the thermodynamic entropies of pandemic trees as a function of R0, the reproduction number, and the level of spread, using the nested wreath product groups. Our plots of entropy and logarithms of topological indices of pandemic trees accentuate the underlying severity of COVID-19 over the 1918 Spanish flu pandemic.

scholarly journals Neurological Complications of COVID-19: Underlying Mechanisms and Management

2021 ◽  
Vol 22 (8) ◽  
pp. 4081
Author(s):  
Ghaydaa A. Shehata ◽  
Kevin C. Lord ◽  
Michaela C. Grudzinski ◽  
Mohamed Elsayed ◽  
Ramy Abdelnaby ◽  
...  
Keyword(s):  
Neuromuscular Junctions ◽  
Neurological Complications ◽  
Cerebrovascular Diseases ◽  
World Health ◽  
Neurological Sequelae ◽  
Global Pandemic ◽  
Underlying Mechanisms ◽  
Health Organization ◽  
Demyelinating Disorders ◽  
Taste And Smell

COVID-19 is a severe respiratory disease caused by the newly identified human coronavirus (HCoV) Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). The virus was discovered in December 2019, and in March 2020, the disease was declared a global pandemic by the World Health Organization (WHO) due to a high number of cases. Although SARS-CoV-2 primarily affects the respiratory system, several studies have reported neurological complications in COVID-19 patients. Headache, dizziness, loss of taste and smell, encephalitis, encephalopathy, and cerebrovascular diseases are the most common neurological complications that are associated with COVID-19. In addition, seizures, neuromuscular junctions’ disorders, and Guillain–Barré syndrome were reported as complications of COVID-19, as well as neurodegenerative and demyelinating disorders. However, the management of these conditions remains a challenge. In this review, we discuss the prevalence, pathogenesis, and mechanisms of these neurological sequelae that are secondary to SARS-CoV-2 infection. We aim to update neurologists and healthcare workers on the possible neurological complications associated with COVID-19 and the management of these disease conditions.

scholarly journals Rapid implementation of virtual neurology in response to the COVID-19 pandemic

Neurology ◽  
2020 ◽  
Vol 94 (24) ◽  
pp. 1077-1087 ◽  
Author(s):  
Scott N. Grossman ◽  
Steve C. Han ◽  
Laura J. Balcer ◽  
Arielle Kurzweil ◽  
Harold Weinberg ◽  
...  
Keyword(s):  
Care Delivery ◽  
Mitigation Strategies ◽  
Urgent Care ◽  
Technology Infrastructure ◽  
Information Technology Infrastructure ◽  
Care Services ◽  
Global Pandemic ◽  
Specific Practice ◽  
Government Rules ◽  
Rapid Deployment

The COVID-19 pandemic is causing world-wide social dislocation, operational and economic dysfunction, and high rates of morbidity and mortality. Medical practices are responding by developing, disseminating, and implementing unprecedented changes in health care delivery. Telemedicine has rapidly moved to the frontline of clinical practice due to the need for prevention and mitigation strategies; these have been encouraged, facilitated, and enabled by changes in government rules and regulations and payer-driven reimbursement policies. We describe our neurology department's situational transformation from in-person outpatient visits to a largely virtual neurology practice in response to the COVID-19 pandemic. Two key factors enabled our rapid deployment of virtual encounters in neurology and its subspecialties. The first was a well-established robust information technology infrastructure supporting virtual urgent care services at our institution; this connected physicians directly to patients using both the physician's and the patient's own mobile devices. The second is the concept of one patient, one chart, facilitated by a suite of interconnected electronic medical record (EMR) applications on several different device types. We present our experience with conducting general teleneurology encounters using secure synchronous audio and video connections integrated with an EMR. This report also details how we perform virtual neurologic examinations that are clinically meaningful and how we document, code, and bill for these virtual services. Many of these processes can be used by other neurology providers, regardless of their specific practice model. We then discuss potential roles for teleneurology after the COVID-19 global pandemic has been contained.

Topological characterization of dendrimer, benzenoid, and nanocone

2018 ◽  
Vol 74 (1-2) ◽  
pp. 35-43
Author(s):  
Wei Gao ◽  
Muhammad Kamran Siddiqui ◽  
Najma Abdul Rehman ◽  
Mehwish Hussain Muhammad
Keyword(s):  
Chemical Properties ◽  
Chemical Compounds ◽  
Topological Indices ◽  
Zagreb Index ◽  
Topological Characterization ◽  
Complex Molecules ◽  
Chemical Structures ◽  
Physico Chemical ◽  
Quantitative Structure Activity Relationships

Abstract Dendrimers are large and complex molecules with very well defined chemical structures. More importantly, dendrimers are highly branched organic macromolecules with successive layers or generations of branch units surrounding a central core. Topological indices are numbers associated with molecular graphs for the purpose of allowing quantitative structure-activity relationships. These topological indices correlate certain physico-chemical properties such as the boiling point, stability, strain energy, and others, of chemical compounds. In this article, we determine hyper-Zagreb index, first multiple Zagreb index, second multiple Zagreb index, and Zagreb polynomials for hetrofunctional dendrimers, triangular benzenoids, and nanocones.

Modeling Social Learning and Culture

2013 ◽  
Author(s):  
William Hoppitt ◽  
Kevin N. Laland
Keyword(s):  
Social Learning ◽  
Cultural Evolution ◽  
Cultural Transmission ◽  
Model Building ◽  
Biological Evolution ◽  
Reaction Diffusion ◽  
Agent Based ◽  
Mathematical Expressions ◽  
Mathematical Techniques ◽  
Neutral Models

This chapter describes a variety of approaches to modeling social learning, cultural evolution, and gene-culture coevolution. The model-building exercise typically starts with a set of assumptions about the key processes to be explored, along with the nature of their relations. These assumptions are then translated into the mathematical expressions that constitute the model. The operation of the model is then investigated, normally using a combination of analytical mathematical techniques and simulation, to determine relevant outcomes, such as the equilibrium states or patterns of change over time. The chapter presents examples of the modeling of cultural transmission and considers parallels between cultural and biological evolution. It then discusses theoretical approaches to social learning and cultural evolution, including population-genetic style models of cultural evolution and gene-culture coevolution, neutral models and random copying, social foraging theory, spatially explicit models, reaction-diffusion models, agent-based models, and phylogenetic models.

scholarly journals Mass screening of asymptomatic persons for SARS-CoV-2 using saliva

2020 ◽  
Author(s):  
Isao Yokota ◽  
Peter Y Shane ◽  
Kazufumi Okada ◽  
Yoko Unoki ◽  
Yichi Yang ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Mass Screening ◽  
Disease Outbreaks ◽  
High Sensitivity ◽  
Nucleic Acid Amplification ◽  
Contact Tracing ◽  
Global Pandemic ◽  
Screening Study ◽  
Highly Correlated ◽  
Few Data

Abstract Background COVID-19 has rapidly evolved to become a global pandemic due largely to the transmission of its causative virus through asymptomatic carriers. Detection of SARS-CoV-2 in asymptomatic people is an urgent priority for the prevention and containment of disease outbreaks in communities. However, few data are available in asymptomatic persons regarding the accuracy of PCR testing. Additionally, although self-collected saliva has significant logistical advantages in mass screening, its utility as an alternative specimen in asymptomatic persons is yet to be determined. Methods We conducted a mass-screening study to compare the utility of nucleic acid amplification, such as reverse transcriptase polymerase chain reaction (RT-PCR) testing, using nasopharyngeal swabs (NPS) and saliva samples from each individual in two cohorts of asymptomatic persons: the contact tracing cohort and the airport quarantine cohort. Results In this mass-screening study including 1,924 individuals, the sensitivity of nucleic acid amplification testing with nasopharyngeal and saliva specimens were 86% (90%CI:77-93%) and 92% (90%CI:83-97%), respectively, with specificities greater than 99.9%. The true concordance probability between the nasopharyngeal and saliva tests was estimated at 0.998 (90%CI:0.996-0.999) on the estimated airport prevalence at 0.3%. In positive individuals, viral load was highly correlated between NPS and saliva. Conclusion Both nasopharyngeal and saliva specimens had high sensitivity and specificity. Self-collected saliva is a valuable specimen to detect SARS-CoV-2 in mass screening of asymptomatic persons.

scholarly journals “Scuola Sicura”: a school screening program to prevent the spread of COVID-19 among students in Piedmont, Italy

2021 ◽  
Author(s):  
Elena Farina ◽  
Ilenia Eboli ◽  
Teresa Spadea ◽  
Carlo Saugo ◽  
Lorenzo Richiardi ◽  
...  
Keyword(s):  
Secondary Schools ◽  
Large Scale ◽  
Screening Program ◽  
Transmission Rate ◽  
Outcome Evaluation ◽  
Mitigation Strategies ◽  
Contact Tracing ◽  
Local Health ◽  
Regional Government ◽  
School Screening

Abstract ObjectivesThe regional government of Piedmont approved an experimental screening testing program entitled “Scuola Sicura” with the aim to: rapidly contain thes spread of COVID-19 in the school population together with general mitigation strategies such as contact tracing, and case isolation, and to monitor the transmission rate in this population. In this paper we report the initial process and outcome evaluation results and the criticalities encountered during program rollout.DesignDescriptive study of the trend in the period Janaury-March 2021.The evaluation of the preventive capacity of the program is limited to the period of in-class learning. The data sources used are the COVID-19 platform Piedmont, the archives of the local health Departments and the CedAP-SDO archive. Setting and participantsThe screening program targeted second and third grade students in first level secondary schools throughout Piedmont. Each class was subdivided into four groups; one group each week underwent screening, yielding one test per student per month.Main outcome measuresThe following indices were calculated with a 95% confidence interval: 1. number of positive cases detected vs. total number of students tested in the “Scuola Sicura” program;2. number of positive cases detected outside the “Scuola Sicura” program vs total number of students enrolled in the 2nd and 3rd grades of first-level secondary schools in Piedmont.To evaluate the preventive capacity, quarantines were detected. In order to investigate the spread of COVID-19 in households, the mother-child pair was tracked and cases of positivity among mothers were identified. Results69% of schools in Piedmont participated in the program; the actual participation was 19.5% of the total number of students enrolled in second and third grades of first-level secondary schools. SS detected 114 positives cases for SARS-CoV-2, yielding a prevalence of 0.52% (95%CI 0.42-0.61) when calculated for the total number of students tested by the program. Starting from 08.03.2021, the target classes have started distance learning: 69 of the 114 positive students were identified before that date, leading to the activation of 67 quarantine measures. For 61 of the 69 cases (88%) identified by SS before 8 March, the mother-child couple was reconstruncted through record linkage between the CedAP and SDO archives. Forty-six mothers perfomed a swab test after that of the child with a positive result in 24% of cases (n=11). Asymptomatic cases identified at screening accounted for 26.5% of the total number of cases occurred in the participating classes.ConclusionsThis is one of the few studies (and the first in Italy) to describe the functioning and predictive capacity of school screening testing for COVID-19 in a real-world situation. Our findings provide data-driven suggestions for government agencies when planning large-scale school screening testing programs. When well organized and implemented jointly with other transmission prevention measures and contact tracing, school screening may be a viable strategy to keep schools open when high levels of the virus are circulating in the community.

scholarly journals A model of COVID-19 propagation based on a gamma subordinated negative binomial branching process

2020 ◽  
Author(s):  
Jérôme Levesque ◽  
David W. Maybury ◽  
R. H. A. David Shaw
Keyword(s):  
Branching Process ◽  
Negative Binomial ◽  
Mitigation Strategies ◽  
Contact Tracing ◽  
Bayesian Hierarchical ◽  
Disease Propagation ◽  
Work Spaces ◽  
Trade Offs ◽  
Case Count ◽  
Office Environments

AbstractWe build a parsimonious Crump-Mode-Jagers continuous time branching process of COVID-19 propagation based on a negative binomial process subordinated by a gamma subordinator. By focusing on the stochastic nature of the process in small populations, our model provides decision making insight into mitigation strategies as an outbreak begins. Our model accommodates contact tracing and isolation, allowing for comparisons between different types of intervention. We emphasize a physical interpretation of the disease propagation throughout which affords analytical results for comparison to simulations. Our model provides a basis for decision makers to understand the likely trade-offs and consequences between alternative outbreak mitigation strategies particularly in office environments and confined work-spaces. Combining the asymptotic limit of our model with Bayesian hierarchical techniques, we provide US county level inferences for the reproduction number from cumulative case count data over July and August of this year.

scholarly journals Social network heterogeneity is essential for contact tracing

2020 ◽  
Author(s):  
Bjarke Frost Nielsen ◽  
Kim Sneppen ◽  
Lone Simonsen ◽  
Joachim Mathiesen
Keyword(s):  
Social Network ◽  
Social Structure ◽  
Mitigation Strategy ◽  
Mitigation Strategies ◽  
Contact Tracing ◽  
Activity Levels ◽  
Proximity Data ◽  
Personal Mobility ◽  
Network Heterogeneity ◽  
The Social

Contact tracing is suggested as an effective strategy for controlling an epidemic without severely limiting personal mobility. Here, we explore how social structure affects contact tracing of COVID-19. Using smartphone proximity data, we simulate the spread of COVID-19 and find that heterogeneity in the social network and activity levels of individuals decreases the severity of an epidemic and improves the effectiveness of contact tracing. As a mitigation strategy, contact tracing depends strongly on social structure and can be remarkably effective, even if only frequent contacts are traced. In perspective, this highlights the necessity of incorporating social heterogeneity into models of mitigation strategies.

scholarly journals Counter-intuitive COVID-19 Trajectories - Explanations, Early Warning Indicator and Mitigation Strategies

2021 ◽  
Author(s):  
B Shayak ◽  
Mohit Manoj Sharma
Keyword(s):  
Social Interactions ◽  
Early Warning ◽  
Critical Mass ◽  
Mass Effect ◽  
Mitigation Strategies ◽  
Contact Tracing ◽  
Epidemiological Models ◽  
Early Warning Indicator ◽  
Small Change ◽  
Parameter Values

The COVID-19 trajectories worldwide have shown several surprising features which are outside the purview of classical epidemiological models. These include (a) almost constant and low daily case rates over extended periods of time, (b) sudden waves emerging from the above solution despite no or minimal change in the level of non-pharmaceutical interventions (NPI), and (c) reduction or flattening of case counts following relaxation of NPI. To explain these phenomena, we add contact tracing to our recently developed cluster seeding and transmission (CST) model. We find no fewer than four effects which make prediction of epidemic trajectories uncertain. These are (a) cryptogenic instability, where a small increase in population-averaged contact rate causes a large increase in cases, (b) critical mass effect, where a wave manifests after weeks of quiescence with no change in parameter values, (c) knife-edge effect, where a small change in parameter across a critical value causes a huge change in the response of the system, and (d) hysteresis effect, where the timing and not just the strength of a particular NPI determines the subsequent behaviour. Despite these effects however, some non-obvious conclusions regarding NPI appear to be robust. In particular, (a) narrowing the circle of one's social interactions can be as effective a measure as reducing interactions altogether, and (b) a good contact tracing program can effectively substitute for much more invasive measures. Finally, we propose the contact tracing capacity ratio - a metric of the load to which the tracers are subject - as a reliable early warning indicator of an imminent epidemic wave.

scholarly journals Edible and Herbal Plants for the Prevention and Management of COVID-19

2021 ◽  
Vol 12 ◽  
Author(s):  
Sha Li ◽  
Chien-Shan Cheng ◽  
Cheng Zhang ◽  
Guo-Yi Tang ◽  
Hor-Yue Tan ◽  
...  
Keyword(s):  
Medicinal Plants ◽  
Dietary Supplements ◽  
Functional Foods ◽  
The Novel ◽  
Organ Protection ◽  
Global Pandemic ◽  
Potential Benefits ◽  
Herbal Plants ◽  
Dietary Components ◽  
Underlying Mechanisms

Background: The outbreak of the pandemic coronavirus disease 2019 (COVID-19) has now become a global pandemic spreading throughout the world. Unfortunately, due to the high infectiousness of the novel β-coronavirus, it is very likely to become an ordinary epidemic. The development of dietary supplements and functional foods might provide a strategy for the prevention and management of COVID-19.Scope and Approach: A great diversity of potential edible and medicinal plants and/or natural compounds showed potential benefits in managing SARS, which may also combat COVID-19. Moreover, many plants and compounds have currently been proposed to be protective against COVID-19. This information is based on data-driven approaches and computational chemical biology techniques. In this study, we review promising candidates of edible and medicinal plants for the prevention and management of COVID-19. We primarily focus on analyzing their underlying mechanisms. We aim to identify dietary supplements and functional foods that assist in managing this epidemic.Key findings and Conclusion: We infer that acetoside, glyasperin, isorhamnetin, and several flavonoid compounds may prevent and/or be effective in managing COVID-19 by targeting the viral infection, reducing the host cytokine storm, regulating the immune response, and providing organ protection. These bioactive dietary components (used either alone or in combination) might assist in the development of dietary supplements or functional foods for managing COVID-19.

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