scholarly journals Average and Standard Deviation of the Error Function for Random Genetic Codes with Standard Stop Codons

2021 ◽  
Vol 70 (1) ◽  
Author(s):  
Dino G. Salinas
2021 ◽  
Author(s):  
Adair L Borges ◽  
Yue Clare Lou ◽  
Rohan Sachdeva ◽  
Basem Al-Shayeb ◽  
Alexander L. Jaffe ◽  
...  

The genetic code is a highly conserved feature of life. However, some alternative genetic codes use reassigned stop codons to code for amino acids. Here, we survey stop codon recoding across bacteriophages (phages) in human and animal gut microbiomes. We find that stop codon recoding has evolved in diverse clades of phages predicted to infect hosts that use the standard code. We provide evidence for an evolutionary path towards recoding involving reduction in the frequency of TGA and TAG stop codons due to low GC content, followed by acquisition of suppressor tRNAs and the emergence of recoded stop codons in structural and lysis genes. In analyses of two distinct lineages of recoded virulent phages, we find that lysis-related genes are uniquely biased towards use of recoded stop codons. This convergence supports the inference that stop codon recoding is a strategy to regulate the expression of late stage genes and control lysis timing. Interestingly, we identified prophages with recoded stop codons integrated into genomes of bacteria that use standard code, and hypothesize that recoding may control the lytic-lysogenic switch. Alternative coding has evolved many times, often in closely related lineages, indicating that genetic code is plastic in bacteriophages and adaptive recoding can occur over very short evolutionary timescales.


2020 ◽  
Author(s):  
B. L .ARORA

Abstract In this paper, we analyse the COVID-19 data of the number of confirmed positive infectious COVID-19 cases (I) in Maharashtra, the second most populous state of India, having a population of nearly 123 million – more than the population of most of the European countries. For this analysis, we use COVID-19 data for the period from April 1, 2020 to August 24, 2020 to find the flex in the I - t curve, where the second derivative of the curve becomes negative. i.e. the date from which the rate of growth of the number of infections starts decreasing – or a peak occurs in the daily new COVID – 19 positive cases. Here I is the total number of cumulative COVID-19 positive cases and t is the time (in days). The observed data are fitted by employing the Gauss error function formulaa + b erf(cx - d),(with four adjustable arbitrary parameters a, b, c, and d) following the prescriptions adopted by Ciufolini and Paolozzi [1] for the analysis of the COVID-19 data from Italy and China. The date of flex is found using data from April 1 to August 11, then the data from April 1 to August 12, and so on, till the data from April 1 to August 24. There is a variation in the dates of flex for these 14 sets of data; however, the date of flex converges to a definite date towards the later sets. We also calculate the standard deviation of these values to calculate the uncertainty in the expected date of flex. Using these parameter values, we also calculate the expected values of COVID–19 positive cases for future. From this data, we estimate the date(s) at which there is sufficient reduction in the number of new daily positive cases and the number of such cases are likely to increase by say, 1000.The data for the number of fatalities in the city is also fitted to a Gauss error function with four parameters of the above type and we estimate in this case also, the date of flex as well as the dates at which the number of fatalities reduces in proportion to sufficient reduction in the number of new COVID-19 cases, which in this case is approximately 34 (for 1000 new infections). The data for the above analysis has been taken from the website covid19India.org and Aarogya Setu App [2] of the Government of India.


Author(s):  
Dénes Száz ◽  
Alexandra Farkas ◽  
András Barta ◽  
Balázs Kretzer ◽  
Ádám Egri ◽  
...  

The theory of sky-polarimetric Viking navigation has been widely accepted for decades without any information about the accuracy of this method. Previously, we have measured the accuracy of the first and second steps of this navigation method in psychophysical laboratory and planetarium experiments. Now, we have tested the accuracy of the third step in a planetarium experiment, assuming that the first and second steps are errorless. Using the fists of their outstretched arms, 10 test persons had to estimate the elevation angles (measured in numbers of fists and fingers) of black dots (representing the position of the occluded Sun) projected onto the planetarium dome. The test persons performed 2400 elevation estimations, 48% of which were more accurate than ±1°. We selected three test persons with the (i) largest and (ii) smallest elevation errors and (iii) highest standard deviation of the elevation error. From the errors of these three persons, we calculated their error function, from which the North errors (the angles with which they deviated from the geographical North) were determined for summer solstice and spring equinox, two specific dates of the Viking sailing period. The range of possible North errors Δ ω N was the lowest and highest at low and high solar elevations, respectively. At high elevations, the maximal Δ ω N was 35.6° and 73.7° at summer solstice and 23.8° and 43.9° at spring equinox for the best and worst test person (navigator), respectively. Thus, the best navigator was twice as good as the worst one. At solstice and equinox, high elevations occur the most frequently during the day, thus high North errors could occur more frequently than expected before. According to our findings, the ideal periods for sky-polarimetric Viking navigation are immediately after sunrise and before sunset, because the North errors are the lowest at low solar elevations.


2021 ◽  
Vol 5 (1) ◽  
pp. 11-19
Author(s):  
I. R. Ilaboya ◽  
J. S. Okpoko

The focus of this research is to apply the selected error function equation to establish the equilibrium isotherm model that best describes the adsorption of Pb2+ and Mn2+ onto acid-activated shale.  Data collected from the batch experiment were analyzed using selected isotherm models (Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Sips and Redlich-Peterson). To compute the isotherm parameters used in choosing the best-fit isotherm model, selected non-linear error functions, namely, error sum of the square, normalized standard deviation, hybrid error function, root mean square error and Marquardt’s percent standard deviation were employed. From the scanning electron microscope results, it was observed that the surface characteristics of the shale change considerably with calcination and acid treatment but the acid-treated shale shows better uneven porous surface characteristics. Error function computation shows that the Dubinin-Radushkevich isotherm model had the least sum of normalized error of 0.3623 for Pb2+ adsorption and 0.5465 for Mn2+ adsorption; hence, it was selected as the best isotherm model for explaining the sorption of Pb(II) and Mn(II) ions unto acid-activated shale.


Author(s):  
Dimitrij Lang

The success of the protein monolayer technique for electron microscopy of individual DNA molecules is based on the prevention of aggregation and orientation of the molecules during drying on specimen grids. DNA adsorbs first to a surface-denatured, insoluble cytochrome c monolayer which is then transferred to grids, without major distortion, by touching. Fig. 1 shows three basic procedures which, modified or not, permit the study of various important properties of nucleic acids, either in concert with other methods or exclusively:1) Molecular weights relative to DNA standards as well as number distributions of molecular weights can be obtained from contour length measurements with a sample standard deviation between 1 and 4%.


2020 ◽  
Vol 29 (3) ◽  
pp. 429-435
Author(s):  
Patricia C. Mancini ◽  
Richard S. Tyler ◽  
Hyung Jin Jun ◽  
Tang-Chuan Wang ◽  
Helena Ji ◽  
...  

Purpose The minimum masking level (MML) is the minimum intensity of a stimulus required to just totally mask the tinnitus. Treatments aimed at reducing the tinnitus itself should attempt to measure the magnitude of the tinnitus. The objective of this study was to evaluate the reliability of the MML. Method Sample consisted of 59 tinnitus patients who reported stable tinnitus. We obtained MML measures on two visits, separated by about 2–3 weeks. We used two noise types: speech-shaped noise and high-frequency emphasis noise. We also investigated the relationship between the MML and tinnitus loudness estimates and the Tinnitus Handicap Questionnaire (THQ). Results There were differences across the different noise types. The within-session standard deviation averaged across subjects varied between 1.3 and 1.8 dB. Across the two sessions, the Pearson correlation coefficients, range was r = .84. There was a weak relationship between the dB SL MML and loudness, and between the MML and the THQ. A moderate correlation ( r = .44) was found between the THQ and loudness estimates. Conclusions We conclude that the dB SL MML can be a reliable estimate of tinnitus magnitude, with expected standard deviations in trained subjects of about 1.5 dB. It appears that the dB SL MML and loudness estimates are not closely related.


Author(s):  
Wilfried Pott ◽  
Georg Fröhlich ◽  
Özgür Albayrak ◽  
Johannes Hebebrand ◽  
Ursula Pauli-Pott

Fragestellung: Es wurde der Frage nachgegangen, ob sich erfolgreiche Teilnehmer eines ambulanten familienzentrierten Gewichtskontrollprogramms durch spezifische familiäre und psychologische Charakteristiken auszeichnen. Einbezogen wurden die psychosoziale Risikobelastung der Familie, Depressivität und Bindungsstil der Hauptbezugsperson, der Body mass index (BMI) und der BMI-Standardabweichungswert («Standard deviation score», SDS) des teilnehmenden Kindes und der Familienmitglieder sowie die individuelle psychische Belastung des teilnehmenden Kindes. Methodik: Die Daten wurden per Interview und Fragebogen vor dem Behandlungsbeginn erhoben. Von 136 in das Programm aufgenommenen übergewichtigen und adipösen Kindern zwischen 7 und 15 Jahren beendeten 116 das 12-monatige Interventionsprogramm. Von diesen zeigten 100 (85,3 %) eine Reduktion des BMI-SDS und 79 (68.1 %) eine mehr als 5 %ige Reduktion des BMI-SDS. Diese «erfolgreichen» Kinder wurden mit 56 «nicht erfolgreichen» (Abbrecher und Kinder mit einer 5 %igen oder geringeren Reduktion des BMI-SDS) verglichen. Ergebnisse: Nicht erfolgreiche Kinder unterschieden sich von den erfolgreichen durch ein höheres Alter, eine höhere psychosoziale Risikobelastung, Depressivität und einen vermeidenden Bindungsstil der Mutter sowie durch das Vorhandensein adipöser Geschwister. In einer logistischen Regressionsanalyse zeigten sich mütterliche Depressivität und das Vorhandensein adipöser Geschwister als beste und voneinander unabhängige Prädiktoren. Schlussfolgerungen: Um die spezifischen Bedürfnisse der Familien zu erfüllen und einen Misserfolg zu verhindern, sollten zusätzliche Programmbausteine zur spezifischen Unterstützung von Jugendlichen mit adipösen Geschwistern und Müttern mit Depressionen und vermeidenden Bindungsstil entwickelt werden. Die Wirksamkeit dieser Module muss dann in weiteren Studien überprüft werden.


1969 ◽  
Vol 14 (9) ◽  
pp. 470-471
Author(s):  
M. DAVID MERRILL
Keyword(s):  

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