scholarly journals Effects of Latency on Estimates of the COVID-19 Replication Number

2020 ◽  
Vol 82 (9) ◽  
Author(s):  
Lorenzo Sadun
Keyword(s):  
Replication Number

Flag-transitive 2-designs with the prime square replication number

2021 ◽  
Vol 344 (2) ◽  
pp. 112225
Author(s):  
Jiaxin Shen ◽  
Shenglin Zhou
Keyword(s):  
Replication Number

scholarly journals Heterogeneity index of zucchini yield on a protected environment and experimental planning

2008 ◽  
Vol 26 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Sandra Feijó ◽  
Lindolfo Storck ◽  
Alessandro Dal'Col Lúcio ◽  
Sidinei José Lopes ◽  
Danton C Garcia ◽  
...  
Keyword(s):  
Total Yield ◽  
Fruit Weight ◽  
Fruit Yield ◽  
Heterogeneity Index ◽  
Experimental Planning ◽  
Plot Size ◽  
Harvest Frequency ◽  
Significant Difference ◽  
Replication Number ◽  
The Mean

The objectives of this work were to assess zucchini heterogeneity index and fruit weight at different harvest frequencies for plants grown on a protected environment; to estimate the optimum plot size; and to determine the least significant difference among treatments, varying plot size and replication number. Plants of cultivar Caserta were grown in a plastic greenhouse, using spaces of 0.80 x 1.00 among plants and lines, respectively. The following harvest frequencies were studied: fruits harvested daily, (1) at 10:00, (2) at 10:00 and 18:00, (3) at 8:00, 10:00, 12:00, 14:00, 16:00 and 18:00 h and; (4) fruits harvested every other day, at 18:00 h. Twenty-seven harvests were carried out, collecting fruits larger than 0.15 m. Plots were planned with 1, 2, 3, and 6 plants per row. Heterogeneity index was estimated according to Smith's method and, the optimum plot size, according to modified maximum curvature method. Fruit yield per plant gradually increased reaching a maximum at the 15th harvest. Total yield was of 3214, 3124, 3928 and 3248 g plant¹, respectively, at the harvest frequencies 1, 2, 3 and 4, with no significant differences among them. The heterogeneity index in the plastic greenhouse was nearly zero. The use of smaller plots combined with a larger number of replications increased the experimental accuracy. Although optimum plot size to assess total fruit yield varied between one and seven plants, depending on the harvest frequency, plots with three plants per row plots, with six replications, were the most appropriate design, allowing detecting a least significant difference among treatments equal to 76% of the mean.

scholarly journals Viral Infection Spreading and Mutation in Cell Culture

Mathematics ◽  
2022 ◽  
Vol 10 (2) ◽  
pp. 256
Author(s):  
Latifa Ait Mahiout ◽  
Bogdan Kazmierczak ◽  
Vitaly Volpert
Keyword(s):  
Viral Load ◽  
Viral Infection ◽  
Competitive Exclusion ◽  
Reaction Diffusion ◽  
System Of Equations ◽  
Virus Variant ◽  
Replication Number ◽  
Infected Cells ◽  
Analytical Formulas ◽  
Speed Of Propagation

A new model of viral infection spreading in cell cultures is proposed taking into account virus mutation. This model represents a reaction-diffusion system of equations with time delay for the concentrations of uninfected cells, infected cells and viral load. Infection progression is characterized by the virus replication number Rv, which determines the total viral load. Analytical formulas for the speed of propagation and for the viral load are obtained and confirmed by numerical simulations. It is shown that virus mutation leads to the emergence of a new virus variant. Conditions of the coexistence of the two variants or competitive exclusion of one of them are found, and different stages of infection progression are identified.

scholarly journals Effects of latency on estimates of the COVID-19 replication number

2020 ◽  
Author(s):  
Lorenzo Sadun
Keyword(s):  
Public Policy ◽  
Latency Period ◽  
Data Sets ◽  
Replication Number

It is not currently known how long it takes a person infected by the COVID-19 virus to become infectious. Models of the spread of COVID-19 use very different lengths for this latency period, leading to very different estimates of the replication number R, even when models work from the same underlying data sets. In this paper we quantify how much varying the length of the latency period affects estimates of R, and thus the fraction of the population that is predicted to be infected in the first wave of the pandemic. This variation underscores the uncertainty in our understanding of R and raises the possibility that R may be considerably greater than has been assumed by those shaping public policy.

scholarly journals A packet replication algorithm for delay tolerant networks based on multi-metric

2021 ◽  
Vol 2093 (1) ◽  
pp. 012023
Author(s):  
Yongguang Liu
Keyword(s):  
Utility Function ◽  
Entropy Weight ◽  
Average Delay ◽  
Original Algorithm ◽  
Performance Metric ◽  
Replication Number ◽  
Encounter Time ◽  
Delay Tolerant ◽  
Utility Metrics ◽  
The Impact

Abstract Utility function of packet is often used to decide how to replicate packet in DTN networks. But this method has more uncertainty and relies on a single performance metric. For this problem, in order to reduce the impact of a single metric uncertainty, multiple utility metrics are introduced in the new algorithm. A packet replication probability calculation method based on entropy weight is designed. By calculating the entropy weight of each metric, the algorithm obtains the replication probability of each packet and takes the probability as the priority of packet replication. Because of considering the two metrics of packet expected transmission delay and node encounter possibility, the algorithm effectively reduces the influence of encounter time distribution problem and direction prediction problem in the original algorithm, and reduces the uncertainty of utility function. Simulation results show that the algorithm reduces the packet replication number and the average delay, improves the successful packet delivery rate. The overall performance of the network is further improved.

scholarly journals Time And Mode Of Epidemic Hcv-2 Subtypes Dispersal In Europe: Phylodynamics Of Hcv-2c In Italy And Albania

2021 ◽  
Author(s):  
Erika Ebranati ◽  
Alessandro Mancon ◽  
Martina Airoldi ◽  
Silvia Renica ◽  
Renata Shkjezi ◽  
...  
Keyword(s):  
Bayesian Approach ◽  
Temporal Scale ◽  
Effective Number ◽  
Guinea Bissau ◽  
Exponential Increase ◽  
Replication Number ◽  
Prevalent Subtype ◽  
Spatio Temporal ◽  
Phylodynamic Analysis ◽  
The Bayesian Approach

Newly characterising 245 Italian and Albanian HCV-2 NS5B sequences collected between 2001 and 2016 was used to reconstruct the origin and dispersion pathways of HCV-2c. The tree of a subset of these sequences aligned with 247 publicly available sequences was reconstructed in spatio-temporal scale using the Bayesian approach, and the effective replication number (Re) was estimated using the birth-death model. Our findings show that HCV-2c was the most prevalent subtype in Italy and Albania, and that GT2 originated in Guinea Bissau in the XVI century and spread to Europe in the XX century. The HCV-2c subtype had two internal nodes respectively dating back to the 1930s and 1950s having as most probable locations Ghana and Italy, respectively. Phylodynamic analysis revealed an exponential increase in the effective number of infections and Re in both Italy between the 1950s and 1980s, and Albania between the 1990s and the early 2000s. It seems very likely that HCV-2c reached Italy from Africa at the time of the second Italian colonisation (1936-1941), but did not reach Albania until the period of dramatic migration to Italy in the 1990s.

scholarly journals Efficient and Privacy for Data Integrity and Data Replication in Cloud Computing

2019 ◽  
Vol 8 (12) ◽  
pp. 333-336
Keyword(s):  
Cloud Computing ◽  
Distributed Computing ◽  
Execution Time ◽  
Data Replication ◽  
Data Integrity ◽  
Replication Factor ◽  
Neighborhood Information ◽  
Replication Number ◽  
Replication Procedure ◽  
Provably Secure

Distributed computing and capacity administrations enable customers to move their server farm and applications to unified huge server farms and in this manner keep away from the weight of neighborhood information stockpiling and upkeep. In any case, this stances new moves identified with making secure and solid information stockpiling over temperamental specialist organizations. In this examination, we address the issues of guaranteeing the uprightness of information stockpiling and information replication in distributed computing. To begin with, specifically, we consider strategies for decreasing the weight of producing a steady measure of metadata at the customer side. what's more, Second we proposed and set forth the aftereffects of a framework which will execute a capacity technique that uses the Division and Replication procedure for putting away the information. In this framework, the record will be divided and these parts will be duplicated by the replication factor before putting away it upon the cloud. Replication of a prevalent document and putting away its imitation in the areas closer to the customers who are settling on solicitations is the best decision to lessen the execution time. Despite the fact that replication helps in expanding accessibility, the topic of how to choose an ideal replication number and right areas to put the copies are open difficulties. By abusing some great characteristics of the bilinear gathering, we can devise a basic and effective review administration for open confirmation of untrusted and reappropriated capacity, which can be significant for accomplishing broad organization of distributed computing. While numerous earlier examinations on guaranteeing remote information uprightness did not consider the weight of creating check metadata at the customer side, the target of this investigation is to determine this issue. In addition, our plan likewise underpins information elements and open obviousness. Broad security and execution investigation demonstrates that the proposed plan is profoundly effective and provably secure.

Replication occurs at discrete foci spaced throughout nuclei replicating in vitro

1989 ◽  
Vol 94 (3) ◽  
pp. 471-477 ◽  
Author(s):  
A.D. Mills ◽  
J.J. Blow ◽  
J.G. White ◽  
W.B. Amos ◽  
D. Wilcock ◽  
...  
Keyword(s):  
Dna Replication ◽  
High Speed ◽  
Microscopic Analysis ◽  
Pulse Labelling ◽  
Replication Forks ◽  
Culture Cells ◽  
Replication Number ◽  
Replication Foci ◽  
Sperm Nuclei

Demembranated Xenopus sperm nuclei were induced to replicate synchronously in a low-speed supernatant (LSS) of Xenopus eggs by preincubation in a high-speed supernatant (HSS). DNA replication was observed by incorporation of [alpha-32P]dATP, BrdUTP or biotin-dUTP. Biotin-dUTP incorporation, visualised with fluorescent streptavidin, reveals a striking pattern of replication foci throughout replicating nuclei. We show that this represents a precursor to the bright uniform fluorescence seen later. Confocal microscopic analysis of nuclei fixed early in replication reveals that these foci of DNA replication number about 100–300 for each nucleus and probably represent the replicon clusters already described for tissue culture cells. Foci are evenly distributed throughout the nuclei and are not concentrated at or near the nuclear envelope. Complete replication of each nucleus occurs in an average time of only one hour in this system. Hence we calculate that there must be at least 300–1000 replication forks together in each cluster. Furthermore, pulse labelling at later times in the period of replication reveals a similar pattern of foci indicating that replication forks remain tightly clustered in groups of at least 300 throughout the period of DNA replication.

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