scholarly journals Prevalences of Pospiviroid Contamination in Large Seed Lots of Tomato and Capsicum, and Related Seed Testing Considerations

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1034 ◽  
Author(s):  
David Dall ◽  
Lindsay Penrose ◽  
Andrew Daly ◽  
Fiona Constable ◽  
Mark Gibbs
Keyword(s):  
Sample Sizes ◽  
Tomato Seed ◽  
Seed Testing ◽  
Large Seed ◽  
Binomial Distributions ◽  
Commercial Seed ◽  
Larger Sample ◽  
Worthwhile Investment

Analyses of pospiviroids in commercial seed lots of tomato and capsicum, determined by testing of 12,000 to 40,000 seeds per lot, have enabled the development of empirically-derived distribution curves for the observed prevalences of viroids in those commodities. Those distribution curves can be considered in conjunction with statistically-based estimates of detection that would be achieved using other sample sizes. Statistical calculations using binomial distributions show that sample sizes of 3000 and 9400 seeds allow detection of viroid prevalences as low as 0.1% and 0.032%, respectively, with 95% confidence. Applying those calculations to observed viroid prevalences in contaminated tomato seed lots, it is estimated that the use of sample sizes of 3000 and 9400 seeds would detect 15% and 42%, respectively, of the contaminated seed lots identified using the larger sample sizes of approximately 20,000 seeds reported in this study. It is concluded that the higher costs associated with testing of larger sample sizes represent a worthwhile investment in agricultural biosecurity.

How Strong Is the Evidence for the Effectiveness of Working Memory Training?

2019 ◽  
pp. 58-76
Author(s):  
Claudia C. von Bastian ◽  
Sabrina Guye ◽  
Carla De Simoni
Keyword(s):  
Working Memory ◽  
Cognitive Abilities ◽  
Small Sample ◽  
Sound Studies ◽  
Working Memory Training ◽  
Memory Training ◽  
Sample Sizes ◽  
Small Sample Sizes ◽  
Transfer Tasks ◽  
Larger Sample

This chapter argues that the question of whether working memory training can induce cognitive plasticity in terms of transfer effects cannot be conclusively answered yet due to persisting methodological issues across the literature. The shortcomings discussed include the lack of theoretically motivated selection of training and transfer tasks, the lack of active control groups, and small sample sizes. These problems call into question the strength of the existing evidence. Indeed, reevaluating published findings with Bayesian inference indicated that only a subset of published studies contributed interpretable evidence. The chapter concludes that the current body of literature cannot conclusively support claims that WM training does or does not improve cognitive abilities and stresses the need for theory-driven, methodologically sound studies with larger sample sizes.

A Longitudinal Field Investigation of Auditor Risk Assessments and Sample Size Decisions

2003 ◽  
Vol 78 (4) ◽  
pp. 983-1002 ◽  
Author(s):  
Randal J. Elder ◽  
Robert D. Allen
Keyword(s):  
Sample Size ◽  
Field Investigation ◽  
Risk Assessments ◽  
Sample Sizes ◽  
Accounting Firms ◽  
Inherent Risk ◽  
Changes In Risk ◽  
Larger Sample ◽  
Average Sample ◽  
Do So

This study examines changes in auditor risk assessments and sample size decisions based on information gathered from three large accounting firms for audits during 1994 and 1999. The five-year interval between data collection periods allows us to measure changes in risk assessments and sample sizes between the two periods. Auditors relied on controls and assessed inherent risk below the maximum on most audits, and were more likely to do so in the later period, consistent with a trend of lower risk assessment levels. Average sample sizes declined between 1994 and 1999 for the firms that had larger sample sizes in the earlier period. Overall, we find a significant relationship between inherent risk assessments and sample sizes, but this relationship is stronger in the earlier period and is not significant for all firms, especially in the later period. We find limited evidence of a relationship between control risk and sample sizes.

scholarly journals The Impact of Improved Microarray Coverage and Larger Sample Sizes on Future Genome-Wide Association Studies

2013 ◽  
Vol 37 (4) ◽  
pp. 383-392 ◽  
Author(s):  
Karla J. Lindquist ◽  
Eric Jorgenson ◽  
Thomas J. Hoffmann ◽  
John S. Witte
Keyword(s):  
Association Studies ◽  
Genome Wide Association ◽  
Genome Wide Association Studies ◽  
Sample Sizes ◽  
Genome Wide ◽  
The Impact ◽  
Larger Sample

scholarly journals A correction to the exact test based on the Ewens sampling distribution

1996 ◽  
Vol 68 (3) ◽  
pp. 259-260 ◽  
Author(s):  
Montgomery Slatkin
Keyword(s):  
Small Sample ◽  
Sampling Distribution ◽  
Sample Sizes ◽  
Exact Test ◽  
Small Sample Sizes ◽  
Larger Sample

SummaryThe exact test for neutrality based on the Ewens sampling distribution described previously (Slatkin, 1994) is not correct. The problem is that the test as described is based on the probability of the ordered configuration of numbers of alleles, while it should be based on the probability of the unordered configuration. The correctly implemented exact test leads to results that are similar to those from the homozygosity test proposed by Watterson (1977) for relatively small sample sizes but can still differ substantially for larger sample sizes. Programs to perform the exact test are available from the author.

scholarly journals Sample Size to Estimate the Mean and Median of Traits in Canola

2018 ◽  
Vol 10 (11) ◽  
pp. 123
Author(s):  
Alberto Cargnelutti Filho ◽  
Cleiton Antonio Wartha ◽  
Jéssica Andiara Kleinpaul ◽  
Ismael Mario Marcio Neu ◽  
Daniela Lixinski Silveira
Keyword(s):  
Sample Size ◽  
Aerial Part ◽  
Dry Matter ◽  
Central Tendency ◽  
Sample Sizes ◽  
Brassica Napus L ◽  
Fresh Matter ◽  
The Mean ◽  
Productive Traits ◽  
Larger Sample

The aim of this study was to determine the sample size (i.e., number of plants) required to estimate the mean and median of canola (Brassica napus L.) traits of the Hyola 61, Hyola 76, and Hyola 433 hybrids with precision levels. At 124 days after sowing, 225 plants of each hybrid were randomly collected. In each plant, morphological (plant height) and productive traits (number of siliques, fresh matter of siliques, fresh matter of aerial part without siliques, fresh matter of aerial part, dry matter of siliques, dry matter of aerial part without siliques, and dry matter of aerial part) were measured. For each trait, measures of central tendency, variability, skewness, and kurtosis were calculated. Sample size was determined by resampling with replacement of 10,000 resamples. The sample size required for the estimation of measures of central tendency (mean and median) varies between traits and hybrids. Productive traits required larger sample sizes in relation to the morphological traits. Larger sample sizes are required for the hybrids Hyola 433, Hyola 61, and Hyola 76, in this sequence. In order to estimate the mean of canola traits of the Hyola 61, Hyola 76 e Hyola 433 hybrids with the amplitude of the confidence interval of 95% equal to 30% of the estimated mean, 208 plants are required. Whereas 661 plants are necessary to estimate the median with the same precision.

scholarly journals High-Low Level Support Vector Regression Prediction Approach (HL-SVR) for Data Modeling with Input Parameters of Unequal Sample Sizes

2021 ◽  
pp. 2150029
Author(s):  
Maolin Shi ◽  
Liye Lv ◽  
Zhenggang Guo ◽  
Wei Sun ◽  
Xueguan Song ◽  
...  
Keyword(s):  
Support Vector Regression ◽  
Data Modeling ◽  
Support Vector ◽  
Sample Sizes ◽  
Low Level ◽  
Input Parameters ◽  
High Level ◽  
Prediction Approach ◽  
Larger Sample ◽  
Unequal Sample Sizes

Support vector regression (SVR) has been widely used to reduce the high computational cost of computer simulation. SVR assumes the input parameters have equal sample sizes, but unequal sample sizes are often encountered in engineering practices. To solve this issue, a new prediction approach based on SVR, namely as high-low level SVR approach (HL-SVR) is proposed for data modeling of input parameters of unequal sample sizes in this paper. The proposed approach consists of low-level SVR models for the input parameters of larger sample sizes and high-level SVR model for the input parameters of smaller sample sizes. For each training point of the input parameters of smaller sample sizes, one low-level SVR model is built based on its corresponding input parameters of larger sample sizes and their responses of interest. The high-level SVR model is built based on the obtained responses from the low-level SVR models and the input parameters of smaller sample sizes. A number of numerical examples are used to validate the performance of HL-SVR. The experimental results indicate that HL-SVR can produce more accurate prediction results than SVR. The proposed approach is applied to the stress analysis of dental implant, in which the structural parameters have massive samples but the material of implant can only be selected from Ti and its alloys. The obtained prediction results of the HL-SVR approach are much better than SVR. The proposed approach can be used for the design, optimization, and analysis of engineering systems with input parameters of unequal sample sizes.

scholarly journals Clinical Efficacy Analysis of Two Different Surgical Approaches to Laparoscopic Radical Cystectomy with Urinary Diversion for Invasive Bladder Cancer

2020 ◽  
pp. 1-5
Author(s):  
Li-feng Zhang ◽  
Bowen Tang ◽  
Shenglin Gao ◽  
Jiasheng Chen ◽  
Chao Lu ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Radical Cystectomy ◽  
Clinical Efficacy ◽  
Invasive Bladder Cancer ◽  
Intestinal Function ◽  
Sample Sizes ◽  
Advantages And Disadvantages ◽  
Function Recovery ◽  
Larger Sample

Objective: The present study aimed to compare the efficacy, and advantages and disadvantages of laparoscopic radical cystectomy + extraperitoneal bilateral ureterocutaneostomy versus laparoscopic radical cystectomy + ileal cystoplasty (Bricker procedure) in the treatment of invasive bladder cancer. Method: Forty-five patients (retrospectively registered) with grade II–III bladder invasive urothelial carcinoma were divided into two groups to compare clinical efficacy, operative duration and blood loss, postoperative intestinal function recovery, length of hospitalization, and complications. Those in the ureterocutaneostomy group (n=25) were treated using laparoscopic radical cystectomy + extraperitoneal bilateral ureterocutaneostomy, while those in the ileal cystoplasty group (n=20) were treated using laparoscopic radical cystectomy + ileal cystoplasty. Results: Laparoscopic radical cystectomy + extraperitoneal bilateral ureterocutaneostomy shortened the operation, improved patient tolerance, and decreased postoperative intestinal function recovery time. However, its long-term clinical efficacy needs further study using larger sample sizes to confirm these results. Conclusion: Results of this study demonstrated that extraperitoneal bilateral ureterocutaneostomy after cystectomy had advantages of less trauma, a shorter learning curve, less surgical bleeding, and quicker postoperative recovery. Although early and mid-term follow-up revealed a slightly higher incidence of hydronephrosis, the severity of complications was not high in most patients. Nevertheless, the long-term clinical efficacy of this procedure needs further study using larger sample sizes.

Improved Graphs for Calculating Sample Sizes When Comparing Two Independent Binomial Distributions

Biometrics ◽  
1979 ◽  
Vol 35 (4) ◽  
pp. 875 ◽  
Author(s):  
John Aleong ◽  
Diantha E. Bartlett
Keyword(s):  
Sample Sizes ◽  
Binomial Distributions
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