scholarly journals On Linear Growth in COVID-19 Cases

2020 ◽  
Vol 8 (1) ◽  
pp. 211-215
Author(s):  
Michael Grinfeld ◽  
Paul A. Mulheran

AbstractWe present an elementary model of COVID-19 propagation that makes explicit the connection between testing strategies and rates of transmission and the linear growth in new cases observed in many parts of the world.

Author(s):  
Michael Grinfeld ◽  
Paul A. Mulheran

We present an elementary model of COVID-19 propagation that makes explicit the connection between testing strategies and rates of transmission and the linear growth in new cases observed in many parts of the world. An essential feature of the model is that it captures the population-level response to the infection statistics information provided by governments and other organisations. The conclusions from this model have important implications regarding benefits of wide-spread testing for the presence of the virus, something that deserves greater attention.


2020 ◽  
Author(s):  
Victoria Oladoyin ◽  
Oluyemi Okunlola ◽  
Oluwaseyi Israel ◽  
Demilade Ibirongbe ◽  
Joy Osifo ◽  
...  

AbstractBackgroundAn understanding of willingness of people to disclose coronavirus disease 2019 (COVID-19) symptoms and take the COVID-19 test will help provide important insight for motivators towards the self-surveillance and testing strategies recommended by the World Health Organization to curtail and halt the transmission of COVID-19.ObjectivesThis study assessed willingness to disclose symptoms suggestive of COVID-19 and willingness to take COVID-19 test as well as their predictors.MethodsA cross-sectional online survey of 524 Nigerian adults, aged ≥ 18 years, residing in Nigeria and who had not taken the COVID-19 test was conducted. Information on willingness to disclose COVID-19 symptoms, take COVID-19 test and possible predictors were collected. Data were analysed using descriptive and inferential statistics evaluated at 5% significance level.ResultsMean age of respondents was 35.8 ± 10.7 years and 57.0% were males. Majority (85.8% and 86.2% respectively) were willing to disclose COVID-19 symptoms and take COVID-19 test. Self-risk perception of contracting COVID-19 predicted both willingness to disclose COVID-19 symptoms (aOR=3.236; 95%CI=1.836-5.704) and take COVID-19 test (aOR=3.174; 95%CI=1.570-6.419). Willingness to disclose COVID-19 symptoms (aOR=13.060; 95%CI= 6.253-27.276), knowledge of someone who had taken the test (aOR= 4.106; 95%CI= 1.179-14.299) and thought that it was important for people to know their COVID-19 status (aOR=3.123; 95%CI= 1.516-6.434) also predicted willingness to take COVID-19 test.ConclusionNigerians are willing to disclose symptoms suggestive of COVID-19 and take the COVID-19 test. Investment in interventions developed based on the predicting factors will help speed up the finding and testing of suspected COVID-19 cases.


Author(s):  
Ivans Kulesovs

<p class="R-AbstractKeywords"><span lang="EN-US">Mobile applications conquer the world, but iOS devices hold the major share of tablets market among the corporate workers. This study aims to identify the aspects (i.e. features and/ or limitations) that influence the testing of the native iOS applications. The aspects related to general mobile applications testing are identified through the systematic literature review of academic sources. iOS applications testing aspects are identified through the review of non-academic (multivocal) literature sources. The identified aspects are merged and discussed in detail using the reviewed sources and based on the author’s professional experience in iOS applications testing. The references to the credible sources are provided in order to support the professional experience findings. The study eliminates the gap that exists in the academic world in regards to iOS applications testing. The practitioners are also encouraged to fulfill their iOS applications testing strategies with the identified aspects.</span></p>


2021 ◽  
Author(s):  
Yashaswini Mandayam Rangayyan ◽  
Sriram Kidambi ◽  
Mohan Raghavan

Background: With countries across the world facing repeated epidemic waves, it becomes critical to monitor, mitigate and prevent subsequent waves. Common indicators like active case numbers can flatter to deceive in the presence of systemic inefficiencies like insufficient testing or contact tracing. Test positivity rates are sensitive to testing strategies and cannot estimate the extent of undetected cases. Reproductive numbers estimated from logarithms of new incidences are inaccurate in dynamic scenarios and not sensitive enough to capture changes in efficiencies. Systemic fatigue results in lower testing, inefficient tracing and quarantining thereby precipitating the onset of the epidemic wave. Methods: We propose a novel indicator for detecting the slippage of test-trace efficiency based on the numbers of deaths/hospitalizations resulting from known and hitherto unknown infections. This can also be used to forecast an epidemic wave that is advanced or exacerbated due to drop in efficiency. Results: Using a modified SEIRD epidemic simulator we show that (i) Ratio of deaths/hospitalizations from an undetected infection to total deaths converges to a measure of systemic test-trace inefficiency. (ii) This index forecasts the slippage in efficiency earlier than other known metrics. (iii) Mitigation triggered by this index helps reduce peak active caseload and eventual deaths. Conclusions: Deaths/hospitalizations accurately track the systemic inefficiencies and detect latent cases. Based on these results we make a strong case that administrations use this metric in the ensemble of indicators. Further hospitals may need to be mandated to distinctly register deaths/hospitalizations due to previously undetected infections. Keywords: Covid19 Epidemic Epidemiology Mathematical model Death rates


2021 ◽  
Vol 6 ◽  
pp. 179
Author(s):  
Luiza Madia Lourenco ◽  
Celina Monteiro Abreu ◽  
Larissa Deadame de Figueiredo Nicolete ◽  
Viviana Mabombo ◽  
Tacilta Nhampossa ◽  
...  

During the coronavirus disease 2019 (COVID-19) pandemic, uncoordinated national responses have been observed around the world which have contributed to the difficulties in controlling the spread of the virus. This lack of dialogue between nations reflects several key determinants including the lack of platforms for non-English speaking researchers and healthcare professionals to engage with critical matters in their native languages. Here, we demonstrate how setting up a dedicated forum for Portuguese-speaking professionals from Brazil, Mozambique and Portugal facilitated the comparison of testing strategies undertaken by those countries during 2020. This working group was established in response to an open workshop conducted in Portuguese in March 2020, in which renowned scientists from lusophone countries were invited to share the COVID-19 responses in their respective countries. To date, the group has convened to address actions, in turn identifying the opportunity to publish the different established approaches to testing strategies undertaken by their countries. This effort highlighted that the governments of those three countries took very different approaches, from case definition to type of test most commonly deployed. This piece emphasizes the need for international bodies to acknowledge the importance of creating forums which are more inclusive to non-speaking English professionals who are at the frontline of healthcare response in challenging settings such as low- and middle-income countries. Finally, fostering approaches like this could represent an efficient strategy to facilitate dialogue, building the necessary steps for a more coordinated response to future global threats.


2020 ◽  
Author(s):  
R.A. Betensky ◽  
Y. Feng

AbstractAs the COVID-19 pandemic spreads across the world, it is important to understand its features and responses to public health interventions in real-time. The field of infectious diseases epidemiology has highly advanced modeling strategies that yield relevant estimates. These include the doubling time of the epidemic and various other representations of the numbers of cases identified over time. Crude estimates of these quantities suffer from dependence on the underlying testing strategies within communities. We clarify the functional relationship between testing and the epidemic parameters, and thereby derive sensitivity analyses that explore the range of possible truths under various testing dynamics. We derive the required adjustment to the estimates of interest for New York City. We demonstrate that crude estimates that assume stable testing or complete testing can be biased.


2018 ◽  
Vol 41 ◽  
Author(s):  
Ana Gantman ◽  
Robin Gomila ◽  
Joel E. Martinez ◽  
J. Nathan Matias ◽  
Elizabeth Levy Paluck ◽  
...  

AbstractA pragmatist philosophy of psychological science offers to the direct replication debate concrete recommendations and novel benefits that are not discussed in Zwaan et al. This philosophy guides our work as field experimentalists interested in behavioral measurement. Furthermore, all psychologists can relate to its ultimate aim set out by William James: to study mental processes that provide explanations for why people behave as they do in the world.


2020 ◽  
Vol 43 ◽  
Author(s):  
Michael Lifshitz ◽  
T. M. Luhrmann

Abstract Culture shapes our basic sensory experience of the world. This is particularly striking in the study of religion and psychosis, where we and others have shown that cultural context determines both the structure and content of hallucination-like events. The cultural shaping of hallucinations may provide a rich case-study for linking cultural learning with emerging prediction-based models of perception.


2019 ◽  
Vol 42 ◽  
Author(s):  
Nazim Keven

Abstract Hoerl & McCormack argue that animals cannot represent past situations and subsume animals’ memory-like representations within a model of the world. I suggest calling these memory-like representations as what they are without beating around the bush. I refer to them as event memories and explain how they are different from episodic memory and how they can guide action in animal cognition.


1994 ◽  
Vol 144 ◽  
pp. 139-141 ◽  
Author(s):  
J. Rybák ◽  
V. Rušin ◽  
M. Rybanský

AbstractFe XIV 530.3 nm coronal emission line observations have been used for the estimation of the green solar corona rotation. A homogeneous data set, created from measurements of the world-wide coronagraphic network, has been examined with a help of correlation analysis to reveal the averaged synodic rotation period as a function of latitude and time over the epoch from 1947 to 1991.The values of the synodic rotation period obtained for this epoch for the whole range of latitudes and a latitude band ±30° are 27.52±0.12 days and 26.95±0.21 days, resp. A differential rotation of green solar corona, with local period maxima around ±60° and minimum of the rotation period at the equator, was confirmed. No clear cyclic variation of the rotation has been found for examinated epoch but some monotonic trends for some time intervals are presented.A detailed investigation of the original data and their correlation functions has shown that an existence of sufficiently reliable tracers is not evident for the whole set of examinated data. This should be taken into account in future more precise estimations of the green corona rotation period.


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