scholarly journals Distribution of psychological types in urban adolescents (on the example of Kharkiv District)

2020 ◽  
Keyword(s):  
General Education ◽  
Statistical Power ◽  
Small Sample Size ◽  
Personal Characteristics ◽  
Small Sample ◽  
Eysenck Personality Questionnaire ◽  
Test Analysis ◽  
Psychological Types ◽  
Anonymous Testing ◽  
Depth Study

The materials of anonymous testing of 530 students in grades 9‒11 of six Kharkiv secondary schools, including general education, sports, gymnasiums, and a school with in-depth study of a foreign language, have been analyzed. In total, 252 boys and 278 girls aged 14‒17 years were examined. Eysenck personality questionnaire (EPQ) was used to determine the temperament type taking into account introversion and/or extraversion of the personality, as well as emotional stability. A proportion of various temperament types (sanguine, phlegmatic, choleric, and melancholic) and the indices of introversion, extraversion and ambiversion were calculated. The material was analyzed separately for each school, as well as for the Kharkiv population as a whole. The results are presented as percentages with 95 % confidence intervals. The girls showed a greater interest in the study, 43 % of them agreed to participate in the questionnaire, while only 38 % of the boys agreed to take the test. Analysis of the personal characteristics distribution within the different schools revealed a wide variation range. The proportion of psychological types of boys in various schools changed as follows: sanguine persons from 14.7 to 53.8 %, phlegmatic persons from 10.2 to 25.3 %, choleric persons from 7.7 to 38.3 %, melancholic persons from 9.5 to 23.5 %, introverts from 14.7 to 36.0 %, extroverts from 8.8 to 55.1 %, and ambiverts from 28.6 to 76.5 %. The psychotype proportion among girls was also variable. The small sample size did not allow us to draw a conclusion about the significance of differences between schools in any psychological characteristics, thus, we could not associate them with the school specialization. To increase statistical power, the data were pooled and the results were presented as population indices. The distribution of personal characteristics in boys and girls was as follows: sanguine persons 31.0 and 19.8 %, phlegmatic persons 21.0 and 19.4 %, choleric persons 27.0 and 44.2 %, melancholic persons 21.0 and 16.6 %, introverts 23.8 and 19.8 %, extroverts 32.1 and 36.0 %, ambiverts 44.1 and 44.2 %. Statistically significant gender differences were found for choleric and sanguine temperaments.

Statistical Power Analysis can Improve Fisheries Research and Management

1990 ◽  
Vol 47 (1) ◽  
pp. 2-15 ◽  
Author(s):  
Randall M. Peterman
Keyword(s):  
Sample Size ◽  
Power Analysis ◽  
Statistical Power ◽  
Small Sample Size ◽  
Industrial Effluent ◽  
Small Sample ◽  
Detectable Effect ◽  
Type Ii ◽  
Sampling Variability ◽  
Statistical Power Analysis

Ninety-eight percent of recently surveyed papers in fisheries and aquatic sciences that did not reject some null hypothesis (H0) failed to report β, the probability of making a type II error (not rejecting H0 when it should have been), or statistical power (1 – β). However, 52% of those papers drew conclusions as if H0 were true. A false H0 could have been missed because of a low-power experiment, caused by small sample size or large sampling variability. Costs of type II errors can be large (for example, for cases that fail to detect harmful effects of some industrial effluent or a significant effect of fishing on stock depletion). Past statistical power analyses show that abundance estimation techniques usually have high β and that only large effects are detectable. I review relationships among β, power, detectable effect size, sample size, and sampling variability. I show how statistical power analysis can help interpret past results and improve designs of future experiments, impact assessments, and management regulations. I make recommendations for researchers and decision makers, including routine application of power analysis, more cautious management, and reversal of the burden of proof to put it on industry, not management agencies.

Nipple Confusion

PEDIATRICS ◽  
1993 ◽  
Vol 92 (2) ◽  
pp. 300-301
Author(s):  
DOREN FREDRICKSON
Keyword(s):  
Breast Feeding ◽  
Statistical Power ◽  
White Women ◽  
Small Sample Size ◽  
False Negative ◽  
Small Sample ◽  
Bottle Feeding ◽  
Feeding Duration ◽  
Breast Feed ◽  
The Impact

To the Editor.— I wish to comment on the study reported by Cronenwett et al,1 which was a fascinating prospective study among married white women who planned to breast-feed. Women were randomly selected to perform either exdusive breast-feeding or partial breast-feeding with bottled human milk supplements to determine the impact of infant temperament and limited bottle-feeding on breast-feeding duration. The authors admit that small sample size and lack of statistical power make a false-negative possible.

scholarly journals Comparison of statistical methods for analysis of small sample sizes for detecting the differences in efficacy between treatments for knee osteoarthritis

2020 ◽  
Author(s):  
Chia-Lung Shih ◽  
Te-Yu Hung
Keyword(s):  
Knee Osteoarthritis ◽  
Sample Size ◽  
Statistical Methods ◽  
Statistical Power ◽  
Permutation Test ◽  
Small Sample Size ◽  
Small Sample ◽  
T Test ◽  
Sample Sizes ◽  
Knee Oa

Abstract Background A small sample size (n < 30 for each treatment group) is usually enrolled to investigate the differences in efficacy between treatments for knee osteoarthritis (OA). The objective of this study was to use simulation for comparing the power of four statistical methods for analysis of small sample size for detecting the differences in efficacy between two treatments for knee OA. Methods A total of 10,000 replicates of 5 sample sizes (n=10, 15, 20, 25, and 30 for each group) were generated based on the previous reported measures of treatment efficacy. Four statistical methods were used to compare the differences in efficacy between treatments, including the two-sample t-test (t-test), the Mann-Whitney U-test (M-W test), the Kolmogorov-Smirnov test (K-S test), and the permutation test (perm-test). Results The bias of simulated parameter means showed a decreased trend with sample size but the CV% of simulated parameter means varied with sample sizes for all parameters. For the largest sample size (n=30), the CV% could achieve a small level (<20%) for almost all parameters but the bias could not. Among the non-parametric tests for analysis of small sample size, the perm-test had the highest statistical power, and its false positive rate was not affected by sample size. However, the power of the perm-test could not achieve a high value (80%) even using the largest sample size (n=30). Conclusion The perm-test is suggested for analysis of small sample size to compare the differences in efficacy between two treatments for knee OA.

Three-year results of phase I retinal gene therapy trial for CNGA3-mutated achromatopsia: results of a non randomised controlled trial

2021 ◽  
pp. bjophthalmol-2021-319067
Author(s):  
Felix Friedrich Reichel ◽  
Stylianos Michalakis ◽  
Barbara Wilhelm ◽  
Ditta Zobor ◽  
Regine Muehlfriedel ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Primary Endpoint ◽  
Statistical Power ◽  
Small Sample Size ◽  
Controlled Trial ◽  
Statistical Significance ◽  
Small Sample ◽  
Functional Improvement ◽  
Limiting Factor ◽  
Serious Adverse Events

AimsTo determine long-term safety and efficacy outcomes of a subretinal gene therapy for CNGA3-associated achromatopsia. We present data from an open-label, nonrandomised controlled trial (NCT02610582).MethodsDetails of the study design have been previously described. Briefly, nine patients were treated in three escalating dose groups with subretinal AAV8.CNGA3 gene therapy between November 2015 and October 2016. After the first year, patients were seen on a yearly basis. Safety assessment constituted the primary endpoint. On a secondary level, multiple functional tests were carried out to determine efficacy of the therapy.ResultsNo adverse or serious adverse events deemed related to the study drug occurred after year 1. Safety of the therapy, as the primary endpoint of this trial, can, therefore, be confirmed. The functional benefits that were noted in the treated eye at year 1 were persistent throughout the following visits at years 2 and 3. While functional improvement in the treated eye reached statistical significance for some secondary endpoints, for most endpoints, this was not the case when the treated eye was compared with the untreated fellow eye.ConclusionThe results demonstrate a very good safety profile of the therapy even at the highest dose administered. The small sample size limits the statistical power of efficacy analyses. However, trial results inform on the most promising design and endpoints for future clinical trials. Such trials have to determine whether treatment of younger patients results in greater functional gains by avoiding amblyopia as a potential limiting factor.

scholarly journals Randomized Controlled Trial of Strain-Specific Probiotic Formulation (Renadyl) in Dialysis Patients

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ranganathan Natarajan ◽  
Bohdan Pechenyak ◽  
Usha Vyas ◽  
Pari Ranganathan ◽  
Alan Weinberg ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Statistical Power ◽  
Small Sample Size ◽  
Controlled Trial ◽  
Statistical Significance ◽  
Venous Blood ◽  
Small Sample ◽  
Uremic Toxin ◽  
Double Blind

Background. Primary goal of this randomized, double-blind, placebo-controlled crossover study of Renadyl in end-stage renal disease patients was to assess the safety and efficacy of Renadyl measured through improvement in quality of life or reduction in levels of known uremic toxins. Secondary goal was to investigate the effects on several biomarkers of inflammation and oxidative stress.Methods. Two 2-month treatment periods separated by 2-month washout and crossover, with physical examinations, venous blood testing, and quality of life questionnaires completed at each visit. Data were analyzed with SAS V9.2.Results. 22 subjects (79%) completed the study. Observed trends were as follows (none reaching statistical significance): decline in WBC count(-0.51×109/L,P=0.057)and reductions in levels of C-reactive protein(-8.61 mg/L,P=0.071)and total indoxyl glucuronide(-0.11 mg%,P=0.058). No statistically significant changes were observed in other uremic toxin levels or measures of QOL.Conclusions. Renadyl appeared to be safe to administer to ESRD patients on hemodialysis. Stability in QOL assessment is an encouraging result for a patient cohort in such advanced stage of kidney disease. Efficacy could not be confirmed definitively, primarily due to small sample size and low statistical power—further studies are warranted.

scholarly journals A laminar augmented cascading flexible neural forest model for classification of cancer subtypes based on gene expression data

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Lianxin Zhong ◽  
Qingfang Meng ◽  
Yuehui Chen ◽  
Lei Du ◽  
Peng Wu
Keyword(s):  
Gene Expression ◽  
Gene Expression Data ◽  
Small Sample Size ◽  
Small Sample ◽  
Expression Data ◽  
Cancer Subtypes ◽  
Cancer Pathogenesis ◽  
Depth Study ◽  
And Function

Abstract Background Correctly classifying the subtypes of cancer is of great significance for the in-depth study of cancer pathogenesis and the realization of personalized treatment for cancer patients. In recent years, classification of cancer subtypes using deep neural networks and gene expression data has gradually become a research hotspot. However, most classifiers may face overfitting and low classification accuracy when dealing with small sample size and high-dimensional biology data. Results In this paper, a laminar augmented cascading flexible neural forest (LACFNForest) model was proposed to complete the classification of cancer subtypes. This model is a cascading flexible neural forest using deep flexible neural forest (DFNForest) as the base classifier. A hierarchical broadening ensemble method was proposed, which ensures the robustness of classification results and avoids the waste of model structure and function as much as possible. We also introduced an output judgment mechanism to each layer of the forest to reduce the computational complexity of the model. The deep neural forest was extended to the densely connected deep neural forest to improve the prediction results. The experiments on RNA-seq gene expression data showed that LACFNForest has better performance in the classification of cancer subtypes compared to the conventional methods. Conclusion The LACFNForest model effectively improves the accuracy of cancer subtype classification with good robustness. It provides a new approach for the ensemble learning of classifiers in terms of structural design.

scholarly journals Rare variants regulate expression of nearby individual genes in multiple tissues

PLoS Genetics ◽  
2021 ◽  
Vol 17 (6) ◽  
pp. e1009596
Author(s):  
Jiajin Li ◽  
Nahyun Kong ◽  
Buhm Han ◽  
Jae Hoon Sul
Keyword(s):  
Gene Expression ◽  
Complex Traits ◽  
Statistical Power ◽  
Rare Variants ◽  
Small Sample Size ◽  
Tissue Expression ◽  
Small Sample ◽  
Ratio Test ◽  
Common Variants ◽  
Regulatory Effects

The rapid decrease in sequencing cost has enabled genetic studies to discover rare variants associated with complex diseases and traits. Once this association is identified, the next step is to understand the genetic mechanism of rare variants on how the variants influence diseases. Similar to the hypothesis of common variants, rare variants may affect diseases by regulating gene expression, and recently, several studies have identified the effects of rare variants on gene expression using heritability and expression outlier analyses. However, identifying individual genes whose expression is regulated by rare variants has been challenging due to the relatively small sample size of expression quantitative trait loci studies and statistical approaches not optimized to detect the effects of rare variants. In this study, we analyze whole-genome sequencing and RNA-seq data of 681 European individuals collected for the Genotype-Tissue Expression (GTEx) project (v8) to identify individual genes in 49 human tissues whose expression is regulated by rare variants. To improve statistical power, we develop an approach based on a likelihood ratio test that combines effects of multiple rare variants in a nonlinear manner and has higher power than previous approaches. Using GTEx data, we identify many genes regulated by rare variants, and some of them are only regulated by rare variants and not by common variants. We also find that genes regulated by rare variants are enriched for expression outliers and disease-causing genes. These results suggest the regulatory effects of rare variants, which would be important in interpreting associations of rare variants with complex traits.

scholarly journals MISSING VALUE IMPUTATION VIA GRAPH COMPLETION IN QUESTIONNAIRE SCORES FROM PERSONS WITH DEMENTIA

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S972-S972
Author(s):  
Chen Kan ◽  
Won Hwa Kim ◽  
Ling Xu ◽  
Noelle L Fields
Keyword(s):  
Missing Data ◽  
Statistical Power ◽  
Missing Values ◽  
Small Sample Size ◽  
Small Sample ◽  
Small Scale ◽  
Assessment And Treatment ◽  
Using Data ◽  
Small Sample Sizes ◽  
Clinical Conditions

Abstract Background: Questionnaires are widely used to evaluate cognitive functions, depression, and loneliness of persons with dementia (PWDs). Successful assessment and treatment of dementia hinge on effective analysis of PWDs’ answers. However, many studies, especially pilot ones, are with small sample sizes. Further, most of them contain missing data as PWDs skip some study sessions due to their clinical conditions. Conventional imputation strategies are not well-suited as bias will be introduced because of insufficient samples. Method: A novel machine learning framework was developed based on harmonic analysis on graphs to robustly handle missing values. Participants were first embedded as nodes in the graph with edges derived by their similarities based on demographic information, activities of daily living, etc. Then, questionnaire scores with missing values were regarded as a function on the nodes, and they were estimated based on spectral analysis of the graph with a smoothness constraint. The proposed approach was evaluated using data from our pilot study of dementia subjects (N=15) with 15% data missing. Result: A few complete variables (binary or ordinal) were available for all participants. For each variable, we randomly removed 5 scores to mimic missing values. With our approach, we could recover all missing values with 90% accuracy on average. We were also able to impute the actual missing values in the dataset within reasonable ranges. Conclusion: Our proposed approach imputes missing values with high accuracy despite the small sample size. The proposed approach will significantly boost statistical power of various small-scale studies with missing data.

Identification of phenotype-relevant differentially expressed genes in breast cancer demonstrates enhanced quantile discretization protocol’s utility in multi-platform microarray data integration

2016 ◽  
Vol 14 (05) ◽  
pp. 1650022 ◽  
Author(s):  
Darlington S. Mapiye ◽  
Alan G. Christoffels ◽  
Junaid Gamieldien
Keyword(s):  
Breast Cancer ◽  
Translational Control ◽  
Statistical Power ◽  
Numerical Range ◽  
Small Sample Size ◽  
Small Sample ◽  
Differentially Expressed ◽  
Data Repositories ◽  
The Individual ◽  
Selection Of

Microarray for transcriptomics experiments often suffer from limited statistical power due to small sample size. Quantile discretization (QD) maps expression values for a sample into a series of equivalently sized ‘bins’ that represent a discrete numerical range, e.g. [Formula: see text]4 to [Formula: see text]4, which enables normalized data from multiple experiments and/or expression platforms to be combined for re-analysis. We found, however, that informal selection of bin numbers often resulted in loss of the underlying correlation structure in the data through assigning of the same numerical value to genes that are in reality expressed at significantly different levels within a sample. Here we report a procedure for determining an optimal bin number for dataset. Applying this to integrated public breast cancer datasets enabled statistical identification of several differentially expressed tumorigenesis-related genes that were not found when analyzing the individual datasets, and also several cancer biomarkers not previously indicated as having utility in the disease. Notably, differential modulation of translational control and protein synthesis via multiple pathways were found to potentially have central roles in breast cancer development and progression. These findings suggest that our protocol has significant utility in making meaningful novel biomedical discoveries by leveraging the large public expression data repositories.

scholarly journals One-to-one tutoring and mathematics students’ achievement in the United Arab Emirates

2019 ◽  
Vol 16 (1) ◽  
pp. 27-44
Author(s):  
Barry J. Fraser ◽  
Abeer A. Hasan
Keyword(s):  
College Students ◽  
Secondary School ◽  
Learning Environment ◽  
General Education ◽  
United Arab Emirates ◽  
Small Sample Size ◽  
Small Sample ◽  
Structured Interviews ◽  
One To One ◽  
And Mathematics

In this study in the United Arab Emirates (UAE), we investigated college students’ perceptions of their past experience of receiving one-to-one tutoring support in mathematics when they were in secondary school. In addition, we also explored students’ reasons for taking one-to-one tutoring in mathematics, the perceived impact of one-to-one tutoring in overcoming shortcomings of school mathematics teaching and on their mathematics achievement, and whether the learning environment at school influenced decisions about having one-to-one tutoring. Eight case-study students were involved in recalling how beneficial one-to-one tutoring was through semi-structured interviews. Because of the small sample size, the research involved only qualitative data based on the recollections of college students who were attending a one-year course in the General Education department of Abu Dhabi Men’s College. The research provided valuable insights into how some students considered having a one-to-one tutor beneficial for their achievement when they were in secondary school. Educators must consider students’ learning environment as being one of the main reasons for deciding whether or not to undertake one-to-one tutoring to raise their achievement in mathematics. ﻓﻲ ھذه اﻟد را ﺳﺔ ﻓﻲ دوﻟ ﺔ ا ﻹﻣﺎ را ت اﻟ ﻌرﺑﯾﺔ اﻟ ﻣﺗ ﺣدة، د رﺳﻧﺎ ﺗ ﺻورا ت طﻼب اﻟ ﺟﺎ ﻣﻌﺎ ت ﻋن ﺗ ﺟرﺑﺗﮭم اﻟ ﺳﺎﺑﻘﺔ ﻓﻲ ﺗﻘدﯾم د ﻋم ﺗﻌﻠﯾﻣ ﻲ ﻓ رد ي ﻓﻲ اﻟ رﯾﺎ ﺿﯾﺎ ت ﻋﻧدﻣﺎ ﻛﺎﻧ وا ﻓﻲ اﻟ ﻣد رﺳﺔ اﻟﺛﺎﻧ وﯾﺔ. ﺑﺎ ﻹ ﺿﺎﻓﺔ إ ﻟ ﻰ ذ ﻟ ك ، ا ﺳ ﺗ ﻛ ﺷ ﻔ ﻧ ﺎ أ ﯾ ﺿً ﺎ أ ﺳ ﺑ ﺎ ب ا ﻟ ط ﻼ ب ﻹ ﺟ ر ا ء د ر و س ﻓ ر د ﯾ ﺔ ﻓ ﻲ اﻟر ﯾﺎ ﺿ ﯾﺎ ت ، وا ﻟﺗﺄﺛﯾ ر اﻟ ﻣﻠ ﺣو ظ ﻟﻠ د رو س اﻟﻔ ردﯾ ﺔ ﻋﻠ ﻰ ﺗ ﺣ ﺻ ﯾﻠ ﮭم ﻓ ﻲ اﻟر ﯾﺎ ﺿ ﯾﺎ ت ، وﻣ ﺎ إذا ﻛﺎﻧ ت ﺑﯾﺋﺔ اﻟﺗ ﻌﻠم ﻓ ﻲ اﻟ ﻣد رﺳﺔ ﻗد أﺛ ر ت ﻋﻠ ﻰ اﻟﻘ را را ت اﻟ ﻣﺗ ﻌﻠﻘﺔ ﺑﺎ ﻟ ﺣ ﺻ ول ﻋ ﻠ ﻰ ﺗد ر ﯾ ب ﻓ ر د ي . د ر س وا ﺣ د. ﺷ ﺎ ر ك ﺛ ﻣﺎﻧ ﯾ ﺔ ﻣ ن ط ﻼ ب د ر ا ﺳ ﺔ اﻟﺣ ﺎﻟ ﺔ ﻓ ﻲ اﻟﺗذﻛﯾ ر ﺑ ﻣد ى ﻓﺎﺋدة اﻟﺗد رﯾ س اﻟﻔ رد ي ﻣ ن ﺧﻼل ﻣ ﻘ ﺎ ﺑ ﻼ ت ﺷ ﺑ ﮫ ﻣ ﻧ ظ ﻣ ﺔ . ﻧ ظ رً ا ﻟ ﺻ ﻐ ر ﺣ ﺟ م ا ﻟ ﻌ ﯾ ﻧ ﺔ ، ﺗ ﺿ ﻣ ن ا ﻟ ﺑ ﺣ ث ﻓ ﻘ ط ﺑ ﯾ ﺎ ﻧ ﺎ ت ﻧ و ﻋ ﯾ ﺔ ا ﺳ ﺗ ﻧ ﺎ دًا إ ﻟ ﻰ ذ ﻛ ر ﯾ ﺎ ت ط ﻼ ب ا ﻟ ﺟ ﺎ ﻣ ﻌ ﺎ ت ا ﻟ ذ ﯾ ن ﺣ ﺿ ر و ا دو رة ﻣدﺗ ﮭﺎ ﻋﺎم وا ﺣد ﻓ ﻲ ﻗ ﺳم اﻟﺗ ﻌﻠﯾم اﻟ ﻌﺎم ﻓ ﻲ ﻛﻠﯾﺔ أﺑو ظ ﺑ ﻲ ﻟ ﻠ ط ﻼ ب . ﻗ د م ا ﻟ ﺑ ﺣ ث ر ؤ ى ﻗ ﯾّﻣ ﺔ ﺣ و ل ﻛﯾ ﻔﯾ ﺔ ﻧ ظر ﺑ ﻌ ض اﻟ طﻼب ﻓ ﻲ وﺟود ﻣد ر س وا ﺣد ﻣﻔﯾد ﻟﺗ ﺣﻘﯾﻘ ﮭم ﻋﻧدﻣ ﺎ ﻛﺎﻧ وا ﻓ ﻲ اﻟ ﻣد رﺳﺔ اﻟﺛﺎﻧ وﯾ ﺔ. ﯾ ﺟ ب ﻋﻠ ﻰ اﻟ ﻣﻌﻠ ﻣﯾ ن ا ﻋﺗﺑﺎ ر ﺑﯾﺋ ﺔ ﺗ ﻌﻠم اﻟ طﻼب وا ﺣدة ﻣ ن ا ﻷﺳﺑﺎ ب اﻟ رﺋﯾ ﺳﯾ ﺔ ﻟﺗ ﻘ ر ﯾ ر ﻣﺎ إ ذا ﻛﺎ ن ﯾ ﺟ ب ﻋ ﻠﯾﮭم إ ﺟ ر ا ء د ر و س ﻓ ر دﯾ ﺔ أ م ﻻ ﻟ ر ﻓ ﻊ ﻣ ﺳ ﺗ و ى ﺗ ﺣ ﺻ ﯾﻠﮭم ﻓ ﻲ اﻟ ر ﯾﺎ ﺿ ﯾﺎ ت .

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