scholarly journals Modeling Agrobacterium-Mediated Gene Transformation of Tobacco (Nicotiana tabacum)—A Model Plant for Gene Transformation Studies

2021 ◽  
Vol 12 ◽  
Author(s):  
Gniewko Niedbała ◽  
Mohsen Niazian ◽  
Paolo Sabbatini
Keyword(s):  
Transgenic Plants ◽  
Multiple Regression ◽  
Transformation Efficiency ◽  
Approximation Error ◽  
Gene Transformation ◽  
Critical Parameters ◽  
Stepwise Multiple Regression ◽  
Ex Post ◽  
Ann Models ◽  
The Mean

The multilayer perceptron (MLP) topology of an artificial neural network (ANN) was applied to create two predictor models in Agrobacterium-mediated gene transformation of tobacco. Agrobacterium-mediated transformation parameters, including Agrobacterium strain, Agrobacterium cell density, acetosyringone concentration, and inoculation duration, were assigned as inputs for ANN–MLP, and their effects on the percentage of putative and PCR-verified transgenic plants were investigated. The best ANN models for predicting the percentage of putative and PCR-verified transgenic plants were selected based on basic network quality statistics. Ex-post error calculations of the relative approximation error (RAE), the mean absolute error (MAE), the root mean square error (RMS), and the mean absolute percentage error (MAPE) demonstrated the prediction quality of the developed models when compared to stepwise multiple regression. Moreover, significant correlations between the ANN-predicted and the actual values of the percentage of putative transgenes (R2 = 0.956) and the percentage of PCR-verified transgenic plants (R2 = 0.671) indicate the superiority of the established ANN models over the classical stepwise multiple regression in predicting the percentage of putative (R2 = 0.313) and PCR-verified (R2= 0.213) transgenic plants. The best combination of the multiple inputs analyzed in this investigation, to achieve maximum actual and predicted transgenic plants, was at OD600 = 0.8 for the LB4404 strain of Agrobacterium × 300 μmol/L acetosyringone × 20 min immersion time. According to the sensitivity analysis of ANN models, the Agrobacterium strain was the most important influential parameter in Agrobacterium-mediated transformation of tobacco. The prediction efficiency of the developed model was confirmed by the data series of Agrobacterium-mediated transformation of an important medicinal plant with low transformation efficiency. The results of this study are pivotal to model and predict the transformation of other important Agrobacterium-recalcitrant plant genotypes and to increase the transformation efficiency by identifying critical parameters. This approach can substantially reduce the time and cost required to optimize multi-factorial Agrobacterium-mediated transformation strategies.

scholarly journals Predictive formula of cervical lordosis in asymptomatic young population

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Yuchen Zhu ◽  
Zhongcheng An ◽  
Yingjian Zhang ◽  
Hao Wei ◽  
Liqiang Dong
Keyword(s):  
Multiple Regression ◽  
Pearson Correlation ◽  
Reference Value ◽  
Vertical Axis ◽  
Stepwise Multiple Regression ◽  
Cervical Lordosis ◽  
Sagittal Vertical Axis ◽  
Thoracic Inlet ◽  
Sagittal Parameters ◽  
The Mean

Abstract Background Not a large number of previous studies have reported the normal sagittal balance of the cervical spine and physiological cervical lordosis (CL) has not been clearly defined yet. Methods This was a prospective radiological analysis of asymptomatic subjects. The following cervical sagittal parameters were measured: CL, thoracic inlet angle (TIA), T1 slope (T1S), neck tilt (NT), and C2–7 sagittal vertical axis (C2–7 SVA). The Pearson correlation test was calculated, and the stepwise multiple regression analysis was conducted by using the CL (dependent variable) and the other cervical sagittal parameters (independent variables) to determine the best sets of predictors. A paired sample t test was conducted between the predicted and measured values. Results The mean age of 307 participants was 24.54 + 3.07. The mean CL, TIA, T1S, NT, and C2–C7 SVA was 17.11° ± 6.31°, 67.87° ± 7.78°, 25.84° ± 5.36°, 42.53° ± 6.68°, and 14.60 ± 8.20 mm, respectively. The formula was established as follows: CL = 0.762 × T1S − 0.392 × C2–C7 SVA + 0.25 × TIA − 13.795 (R = 0.812, R2 = 0.660) (stepwise multiple regression) and CL = 0.417 × TIA − 11.193 (R = 0.514, R2 = 0.264) (simple linear regression). There was no statistical difference between the predicted CL and the measured CL (t = 0.034, P = 0.973). Conclusions There was a significant correlation between CL and other cervical sagittal parameters, including TIA, T1S, NT, and C2–C7 SVA in asymptomatic Chinese population. The results of this study may serve as a normal reference value for the study of asymptomatic population.

scholarly journals Dynamic modeling of nutrient use and individual requirements of lactating sows1

2019 ◽  
Vol 97 (7) ◽  
pp. 2822-2836 ◽  
Author(s):  
Raphaël Gauthier ◽  
Christine Largouët ◽  
Charlotte Gaillard ◽  
Laetitia Cloutier ◽  
Frédéric Guay ◽  
...  
Keyword(s):  
Feed Intake ◽  
Average Daily Gain ◽  
Individual Performance ◽  
Maintenance Cost ◽  
Nutrient Requirements ◽  
Modeling Approach ◽  
Ex Post ◽  
Nutrient Use ◽  
The Mean ◽  
On Farm

AbstractNutrient requirements of sows during lactation are related mainly to their milk yield and feed intake, and vary greatly among individuals. In practice, nutrient requirements are generally determined at the population level based on average performance. The objective of the present modeling approach was to explore the variability in nutrient requirements among sows by combining current knowledge about nutrient use with on-farm data available on sows at farrowing [parity, BW, backfat thickness (BT)] and their individual performance (litter size, litter average daily gain, daily sow feed intake) to estimate nutrient requirements. The approach was tested on a database of 1,450 lactations from 2 farms. The effects of farm (A, B), week of lactation (W1: week 1, W2: week 2, W3+: week 3 and beyond), and parity (P1: 1, P2: 2, P3+: 3 and beyond) on sow performance and their nutrient requirements were evaluated. The mean daily ME requirement was strongly correlated with litter growth (R2 = 0.95; P < 0.001) and varied slightly according to sow BW, which influenced the maintenance cost. The mean daily standardized ileal digestible (SID) lysine requirement was influenced by farm, week of lactation, and parity. Variability in SID lysine requirement per kg feed was related mainly to feed intake (R2 = 0.51; P < 0.001) and, to a smaller extent, litter growth (R2 = 0.27; P < 0.001). It was lowest in W1 (7.0 g/kg), greatest in W2 (7.9 g/kg), and intermediate in W3+ (7.5 g/kg; P < 0.001) because milk production increased faster than feed intake capacity did. It was lower for P3+ (6.7 g/kg) and P2 sows (7.3 g/kg) than P1 sows (8.3 g/kg) due to the greater feed intake of multiparous sows. The SID lysine requirement per kg of feed was met for 80% of sows when supplies were 112 and 120% of the mean population requirement on farm A and B, respectively, indicating higher variability in requirements on farm B. Other amino acid and mineral requirements were influenced in the same way as SID lysine. The present modeling approach allows to capture individual variability in the performance of sows and litters according to farm, stage of lactation, and parity. It is an initial step in the development of new types of models able to process historical farm data (e.g., for ex post assessment of nutrient requirements) and real-time data (e.g., to control precision feeding).

Studies on the storage of potatoes. III. The composition of the atmosphere in a potato clamp

1950 ◽  
Vol 40 (3) ◽  
pp. 227-232 ◽  
Author(s):  
E. M. Crook ◽  
D. J. Watson
Keyword(s):  
Multiple Regression ◽  
Wind Velocity ◽  
Practical Importance ◽  
Oxygen Depletion ◽  
Unsaturated Compounds ◽  
The Face ◽  
Flow Through ◽  
The Mean ◽  
Oxygen Concentrations

The CO2 concentration in the atmosphere of a potato clamp varied between 0·06 and 0·86%. The sum of CO2 and oxygen concentrations remained approximately constant at 21%. The CO2 concentration increased with time from December to April. This was attributed to increase in the rate of respiration of the potatoes caused by rise of temperature. Wind blowing in the direction normal to the face of the clamp reduced the COa concentration, presumably by causing external air to flow through the clamp coverings. A multiple regression of CO2 concentration on temperature of the potatoes at the time of sampling, and on the mean component of wind velocity normal to the clamp face estimated over a period of 3 hr. before the time of sampling, accounted for 64% of the variance between sampling occasions.Unsaturated compounds were detected in the clamp atmosphere by absorption in bromine; the concentration of these, expressed as ethylene, varied between 0·004 and 0·025%.The magnitude of CO2 accumulation and oxygen depletion in the clamp atmosphere was too small to produce effects of practical importance on the storage behaviour of the potatoes. If the unsaturated compounds were ethylene, the concentration present was sufficient to cause appreciable retardation of sprouting.

scholarly journals Comparison of corneal irregular astigmatism by the type of corneal regular astigmatism

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuta Ueno ◽  
Risa Nomura ◽  
Takahiro Hiraoka ◽  
Katsuhito Kinoshita ◽  
Mutsuko Ohara ◽  
...  
Keyword(s):  
Higher Order ◽  
Stepwise Multiple Regression ◽  
Group Differences ◽  
Corneal Surface ◽  
Fourier Harmonic ◽  
Normal Human ◽  
The Mean ◽  
Human Eyes ◽  
Topography Data ◽  
Irregular Astigmatism

AbstractWe investigated the relation between corneal regular and irregular astigmatism in normal human eyes. In 951 eyes of 951 patients, corneal irregular astigmatism, such as asymmetry and higher-order irregularity components, was calculated using the Fourier harmonic analysis of corneal topography data within the central 3-mm zone of the anterior corneal surface. The eyes were classified by the type of corneal regular astigmatism into four groups; minimum (< 0.75 diopters), with-the-rule (WTR), against-the-rule (ATR), and oblique astigmatism. The mean age was significantly different among the four groups (P < 0.001); patients with WTR astigmatism were the youngest, followed by those with minimum, oblique, and ATR astigmatism. Significant inter-group differences were found among the four groups in asymmetry (P = 0.005) and higher-order irregularity components (P < 0.001); the largest was in eyes with oblique astigmatism, followed by ATR, WTR, and minimum astigmatism. The stepwise multiple regression analysis revealed that corneal regular astigmatism pattern significantly influenced the amount of corneal irregular astigmatism after controlling for confounding factors (P < 0.001). Corneal irregular astigmatism, such as asymmetry and higher order irregularity components, was the largest in eyes with oblique astigmatism, followed by those with ATR, WTR, and minimum astigmatism, even after adjustment for age of subjects.

Service quality of property managers of shopping complexes in Ibadan, Nigeria

2019 ◽  
Vol 37 (3) ◽  
pp. 310-326 ◽  
Author(s):  
Samson Oluseun Ojekalu ◽  
Olatoye Ojo ◽  
Timothy Tunde Oladokun ◽  
Sumoila Aremu Olabisi ◽  
Sunday Samuel Omoniyi
Keyword(s):  
Service Quality ◽  
Multiple Regression ◽  
Management Practice ◽  
Sampling Technique ◽  
Primary Data ◽  
Stepwise Multiple Regression ◽  
Systematic Sampling ◽  
Content Type ◽  
Five Axes

PurposeThe purpose of this paper is to assess the service quality (SQ) of property managers of shopping complexes in Ibadan with a view to improving management practice.Design/methodology/approachPrimary data were used for the study through questionnaire administration. Ibadan was stratified into five axes using existing major roads where shopping complexes were highly concentrated. From each axis, 33, 65, 48, 64 and 66 shopping complexes were identified (Oyo State Ministry of Land, Housing and Survey, 2017), and the systematic sampling technique (20 percent) was adopted to select 57 out of 276 shopping complexes and 192 (10 percent) out of 1919 occupiers of the shopping complexes in the study area. In total, 157 occupiers responded to the questionnaire, and the data were analyzed using mean ranking and stepwise multiple regression.FindingsThis study found that professionalism, tangible, assurance and empathy dimensions of SQ were rated fair, whereas reliability and responsiveness dimensions were rated poor. Also, stepwise multiple regression analysis predicted 78.5 percent overall SQ of property managers, and assurance, professionalism and empathy dimensions contributed significantly to the overall SQ. Hence, reliability and responsiveness dimensions of SQ need to be improved. It is expected that the findings of this study will help property managers to understand the role of various dimensions of SQ for enhanced property management practice.Originality/valueThe study is one of the few studies that assessed the SQ of property managers of shopping complex with a view to improving its management practice.

Predicting Adolescent Blood Pressure: Implications for Health Education Practice

1988 ◽  
Vol 9 (3) ◽  
pp. 187-208
Author(s):  
Matthew Adeyanju
Keyword(s):  
Blood Pressure ◽  
Socioeconomic Status ◽  
Health Education ◽  
Multiple Regression ◽  
Alcohol Intake ◽  
Ideal Body Weight ◽  
Skinfold Thickness ◽  
Stepwise Multiple Regression ◽  
Baseline Survey ◽  
Education Practice

The study was set up to potentially determine if a stepwise multiple regression model composed of such factors as sociodemographics, attitudes, and behaviors in combination with selected biomedical measures can be used to predict adolescent at risk health conditions such as hypertension and to examine the implications for health education practice. The study population consisted of 650 ninth grade (14–16-year-old) students in the baseline survey (1981) and 606 twelfth grade students in the final survey of 1985. Data collected included clinical measures of height, weight, triceps skinfold thickness, blood pressure, body mass index (BMI), resting pulse, and percent ideal body weight (PIBW). Self-reported health behaviors, attitudes, and sociodemographic variables were also assessed. Principal factor analysis with varimax rotation was employed to determine the grouping of the behavioral/attitudinal test items. Stepwise multiple regression analysis was used to determine the variables' potentials as predictors of blood pressure in adolescents. Significant potential predictors of male diastolic blood pressure included smoking, alcohol intake habits, obesity, pulse, race, age and parents' socioeconomic status; while predictors for the females focused on smoking, alcohol intake habits, stress, obesity, pulse and race. Potential indicators for male systolic blood pressure were smoking, alcohol habits, weight, height, race, parent's socioeconomic status; while smoking, alcohol habits, stress, obesity, pulse and race for the females. Community health promotion, prevention and educational programs directed at these potential predictors need to be implemented to encourage healthful lifestyles in the younger generation.

scholarly journals Do regulators overestimate the costs of regulation?

2014 ◽  
Vol 5 (2) ◽  
pp. 315-332 ◽  
Author(s):  
R. David Simpson
Keyword(s):  
Regulatory Compliance ◽  
Summary Statistics ◽  
Compliance Cost ◽  
Strong Argument ◽  
Cost Estimates ◽  
Compliance Costs ◽  
Average Ratio ◽  
Ex Post ◽  
Ex Ante ◽  
The Mean

Abstract:It has occasionally been asserted that regulators typically overestimate the costs of the regulations they impose. A number of arguments have been proposed for why this might be the case. The most widely credited is that regulators fail sufficiently to appreciate the effects of innovation in reducing regulatory compliance costs. Most existing studies have found that regulators are more likely to over- than to underestimate costs. While it is difficult to develop summary statistics to aggregate the results of different studies of disparate industries, one such measure is the average of the ratio of ex ante estimates of compliance costs to ex post estimates of the same costs. This ratio is generally greater than one. In this paper I argue that neither the greater frequency of overestimates nor the fact that the average ratio of ex ante to ex post cost estimates is greater than one necessarily demonstrates that ex ante estimates are biased. There are several reasons to suppose that the distribution of compliance costs could be skewed, so that the median of the distribution would lie below the mean. It is not surprising, then, that most estimates would prove to be too high. Moreover, Jensen’s inequality implies that the expected ratio of ex ante to ex post compliance costs would be greater than one. I propose a regression-based test of the bias of ex ante compliance cost estimates, and cannot reject the hypothesis that estimates are unbiased. Failure to reject a hypothesis with limited and noisy data should not, of course, be interpreted as a strong argument to accept the hypothesis. Rather, this paper argues for the generation of more and better information. Despite the existence of a number of papers reporting ex ante and ex post compliance cost estimates, it is surprisingly difficult to get a large sample with which to make such comparisons.

scholarly journals Determination of the Firing Pin Critical Velocity and the Critical Power in the Percussive Initiation of Primer Caps

2016 ◽  
Vol 7 (4) ◽  
pp. 33-66
Author(s):  
Andrzej FARYŃSKI ◽  
Andrzej DŁUGOŁĘCKI ◽  
Jarosław DĘBIŃSKI ◽  
Łukasz SŁONKIEWICZ
Keyword(s):  
Experimental Data ◽  
Critical Velocity ◽  
Hot Spot ◽  
Pulse Power ◽  
Critical Parameters ◽  
Simplified Model ◽  
Initiation Mechanism ◽  
The Mean ◽  
Institute Of Technology ◽  
Explosive Reaction

This work involved testing of the probability of initiating a KWM-3 type of primer cap as a function of the firing pin velocity upon impact. The tested firing pin was accelerated to the required velocity by a falling mass. The measurements under this work were made with a measurement system and methodologies developed at Air Force Institute of Technology (AFIT) in Warsaw (Poland). The percussive pulse velocity and power was altered by modifying the percussive mass to keep the initiating pulse energy constant at two levels: Ewe = 272 mJ and 343 mJ. The firing pin velocity values estimated by experimental data to bring a 50% probability of percussive primer cap initiation were within the interval vi50% = 0.34÷0.51 m/s. It was found that the mean primer cap ignition delay rose from approx. 0.7 ms at a percussion velocity of 1.5 m/s to 6 ms at 0.17 m/s. The experimental data suggest the values of Ewe x vi50% = 0.136. A simplified model was proposed for the deformation of the primer cap base and compressed pyrotechnical mixture shape. The model served to determine the approximate time trend for the penetration of the primer cap by the firing pin, including velocity, power and emitted energy, by assuming a complete energy transfer from the percussive mass to the primer cap. The mean initiating pulse power calculated from the model at the vi50% interval was Pavg = 120÷180 W, whereas the maximum initiating pulse power was Pmax = 170÷250 W. The calculated time values for firing pin penetration were very close to the aforementioned primer cap ignition delays at the respective velocity and percussive mass values. This indirectly indicates nearly complete energy transmission from the percussive masses to the primer caps. A location was identified within the compressed pyrotechnical mixture shape volume which could form the hot spot for initiation of the explosive reaction. Based on the calculation results using the simplified model, and assuming that the energy and diffusive heat flux output to and from the explosive reaction initiation hot spot were equivalent, the expression of Ewe x vi50% derived from the result was approx. 0.18. This means that the two critical parameters of primer cap initiation: (i) velocity, which can be identified with vi50% (and the respective power) and (ii) Ewe50%, i.e. the energy threshold below which the probability of primer cap initiation is less than 0.5, are interrelated. Aside from the initiation mechanism proposed and applied to calculate the firing pin critical velocity, this work discusses several other initiation mechanisms, all of which were ruled out during the testing process.

scholarly journals ОПТИМІЗАЦІЯ ВИМІРЮВАЛЬНИХ ЗАСОБІВ НАПРУЖЕНО-ДЕФОРМОВАНОГО СТАНУ ЗА ДОПОМОГОЮ ТЕНЗОДАТЧИКІВ

2019 ◽  
pp. 50-56
Author(s):  
Людмила Володимирівна Кузьмич ◽  
Дмитро Петрович Орнатський ◽  
Володимир Павлович Квасніков
Keyword(s):  
Strain Gauge ◽  
Strain State ◽  
Approximation Error ◽  
Strain Gauges ◽  
Mean Square ◽  
Stress Strain ◽  
Stress Strain State ◽  
Destabilizing Factors ◽  
Mechanical Factors ◽  
The Mean

In the article, the principles of construction, design and mathematical modeling of deformation and stresses of complex technical constructions are developed with the help of strain gauges and strain gauges taking into account destabilizing factors, which allows to significantly reduce the level of errors in relation to existing measurement methods and known analogs.The method of digital compensation provides a more significant reduction in the errors of measuring transducers compared with the method of analog compensation. Features and technical indicators of this method are considered on an example of measuring pressure transducer with foil strain gauges.This method is universal, allows us to adjust not only the errors of the measurement channel nonlinearity and additional errors but also the errors associated with the effect of interferences of the general type due to ground resistance, which induces the connection between the measuring channels of the main and destabilizing factor.The disadvantages of this method include a significant amount of computations, which sharply increases with increasing order of approximating polynomials.The purpose is to develop a method and means of measuring stress-strain state using strain gauge, free from the above - mentioned shortcomings.The main destabilizing factors that limit the measurement accuracy using strain gauge are:- random processes (noises, obstacles, etc.);- changes in parameters of measuring transducers due to aging and physical degradation;- effects of external climatic and mechanical factors (temperature, humidity, etc.).The influence of the main destabilizing factors limiting the accuracy of the measurement of the stress-strain state of complex technical constructions with the help of strain gauges was analyzed, among which the influences of external climatic and mechanical factors are one of the most important ones. Regarding the systematic components, the most important in statistical measurements are the errors of nonlinearity and the temperature component of the error.For the study, two main alloys were taken, which today has the widest use as a material for strain gauges - it is constantan and karma. For these materials, the influence of the range of temperature changes, the spread of the values of temperature error on the mean-square value of the error of approximation by power polynomials was investigated.Using the NUMERY package, the dependence of the approximation error on the order of the approximating polyphony was determined. It is established that the mean square error value in the wide temperature range for both constantan and karma has a weak correlation with the order of a polynomial.

scholarly journals Incidencia de las características personales e inherentes al empleo sobre la satisfacción de los trabajadores en España

2020 ◽  
Vol 32 (1) ◽  
pp. 311
Author(s):  
María Carmen Sánchez Sellero ◽  
Pedro Sánchez Sellero
Keyword(s):  
Labour Market ◽  
Multiple Regression ◽  
Linear Models ◽  
Stepwise Multiple Regression ◽  
Deep Recession

This paper tries to determine the main features of the labour satisfaction. We applied the mentioned analysis to the current Spanish labour market, which is affected by a deep recession and instability. We want to get differences between personal and job-related features in order to find which better explain the labour satisfaction. Data come from the Quality of Labour Life Survey corresponding to the year 2010 by Ministry of Labour and Immigration of Spain. By means of linear models (ANOVA) we find that job-related variables explain better labour satisfaction, also, all the coefficients are positive. Finally, we propose a stepwise multiple regression which let us to put in order the effect of job-related variables on labour satisfaction. The variable with higher influence on labour satisfaction is motivation.

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