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Cochran’s Q-Test on Soil Helminth Prevalence 土壤蠕虫流行率的Cochran q检验
Biometrical Letters Pub Date : 2021-12-01 DOI: 10.2478/bile-2021-0013
I. J. David, M. Adehi, P. O. Ikwuoche
{"title":"Cochran’s Q-Test on Soil Helminth Prevalence","authors":"I. J. David, M. Adehi, P. O. Ikwuoche","doi":"10.2478/bile-2021-0013","DOIUrl":"https://doi.org/10.2478/bile-2021-0013","url":null,"abstract":"Summary A study was made of the prevalence of nine geohelminth egg types in 184 soil samples from 16 recreational parks in Abuja metropolis, Nigeria. Cochran’s Q-test was applied to determine whether the difference in the proportions of the egg types found in the soil samples was significant. At a 5% significance level, it was found that the prevalence of the egg types was significantly different in the 184 soil samples from 16 parks. To identify which of the geohelminth eggs had a significantly larger mean proportional prevalence, a minimum required difference mean comparison technique was applied. The mean comparison test showed that Taenia and Coccocidia eggs were highly prevalent, with significantly larger mean proportions than the other analyzed geohelminth eggs in the 184 examined soil samples.","PeriodicalId":8933,"journal":{"name":"Biometrical Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78770224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Influence of different sowing density in two varieties of maize. Part II. Relation to agricultural morphological features 不同播种密度对两个玉米品种产量的影响。第二部分。与农业形态特征的关系
Biometrical Letters Pub Date : 2021-12-01 DOI: 10.2478/bile-2021-0016
P. Szulc, K. Ambroży-Deręgowska
{"title":"Influence of different sowing density in two varieties of maize. Part II. Relation to agricultural morphological features","authors":"P. Szulc, K. Ambroży-Deręgowska","doi":"10.2478/bile-2021-0016","DOIUrl":"https://doi.org/10.2478/bile-2021-0016","url":null,"abstract":"Summary In this paper, we investigate the effect of seeding density on several morphological features such as plant height, height of the production ears, ear length, ear diameter, leaf area, and LAI (leaf area index). Inference is based on a series of three-year two-factor experiments with two hybrid maize varieties – SY Cooky and Drim “stay-green” type – and 5 sowing densities: 6, 7, 8, 9 and 10 plants per m2. The “stay-green” maize variety had production cobs significantly higher on the plant, and had a thicker cob and a larger leaf assimilation area than the conventional variety. Increasing maize sowing density from 6 to 10 plants m−2 resulted in a linear decrease in cob length and diameter, while it increased the LAI. Significantly higher chlorophyll content, expressed in SPAD units, was found in the “stay-green” hybrid at the BBCH 67 stage in a wet (2012) and drier year (2014), compared with the traditional variety. This may indicate that such a variety is more tolerant to stress conditions.","PeriodicalId":8933,"journal":{"name":"Biometrical Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85646799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
On sample size calculation in testing treatment efficacy in clinical trials 临床试验中检验疗效的样本量计算
Biometrical Letters Pub Date : 2021-12-01 DOI: 10.2478/bile-2021-0010
Rownak Jahan Tamanna, M. Alam, A. Hossain, M. H. R. Khan
{"title":"On sample size calculation in testing treatment efficacy in clinical trials","authors":"Rownak Jahan Tamanna, M. Alam, A. Hossain, M. H. R. Khan","doi":"10.2478/bile-2021-0010","DOIUrl":"https://doi.org/10.2478/bile-2021-0010","url":null,"abstract":"Summary Sample size calculation is an integral part of any clinical trial design, and determining the optimal sample size for a study ensures adequate power to detect statistical significance. It is a critical step in designing a planned research protocol, since using too many participants in a study is expensive, exposing more subjects to the procedure. If a study is underpowered, it will be statistically inconclusive and may cause the whole protocol to fail. Amidst the attempt to maximize power and the underlying effort to minimize the budget, the optimization of both has become a significant issue in the determination of sample size for clinical trials in recent decades. Although it is hard to generalize a single method for sample size calculation, this study is an attempt to offer something that might be a basis for finding a permanent answer to the contradictions of sample size determination, by the use of simulation studies under simple random and cluster sampling schemes, with different sizes of power and type I error. The effective sample size is much higher when the design effect of the sampling method is smaller, particularly less than 1. Sample size increases for cluster sampling when the number of clusters increases.","PeriodicalId":8933,"journal":{"name":"Biometrical Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85657052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Influence of different sowing density in two varieties of maize. Part I. Relation to yielding 不同播种密度对两个玉米品种产量的影响。第一部分与屈服的关系
Biometrical Letters Pub Date : 2021-12-01 DOI: 10.2478/bile-2021-0015
K. Ambroży-Deręgowska, P. Szulc
{"title":"Influence of different sowing density in two varieties of maize. Part I. Relation to yielding","authors":"K. Ambroży-Deręgowska, P. Szulc","doi":"10.2478/bile-2021-0015","DOIUrl":"https://doi.org/10.2478/bile-2021-0015","url":null,"abstract":"Summary A study was carried out to determine the effect of sowing density on the yield of maize of two different varieties. The field experiment was carried out in 2012–2014 at the Department of Agronomy of Poznań University of Life Sciences. The first-order factor was the variety: SY Cooky and Drim “stay-green”; the second-order factor was sowing density: 6, 7, 8, 9, 10 plants per m2. Weather conditions during the maize growing seasons significantly influenced the values of the studied traits. Significantly the lowest green mass yield of maize was obtained at the sowing density of 6 plants m−2, and the highest for 10 plants m−2. The “stay-green” variety significantly responded to an increase in sowing density with reduced fresh weight of leaf blades of a single plant compared with the conventional variety. This indicated highly effective photosynthesis with a lower plant density per unit area, which is also the basis for effective absorption of solar radiation for these maize varieties.","PeriodicalId":8933,"journal":{"name":"Biometrical Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83401708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Asymmetry models based on ordered score and separations of symmetry model for square contingency tables 基于有序分值的非对称模型和方形列联表对称模型的分离
Biometrical Letters Pub Date : 2021-06-01 DOI: 10.2478/bile-2021-0002
S. Ando
{"title":"Asymmetry models based on ordered score and separations of symmetry model for square contingency tables","authors":"S. Ando","doi":"10.2478/bile-2021-0002","DOIUrl":"https://doi.org/10.2478/bile-2021-0002","url":null,"abstract":"Summary This study proposes two original asymmetry models based on ordered scores for square contingency tables with the same row and column ordinal classifications. The proposed models can be applied to cases in which the scores of all categories are known or unknown. In the proposed models, the log odds for an observation falling in the (i, j)th cell instead of the (j, i)th cell are inversely proportional to the difference of the ordered scores corresponding to categories i and j. The asymmetry parameter of the proposed model can be useful for inferring whether the row variable is stochastically greater than the column variable or vice versa. The proposed models constantly hold when the symmetry model holds, but the converse is not necessarily true. This study also examines what is necessary for a model, in addition to the proposed models, to satisfy the symmetry model, and gives separations of the symmetry model using the proposed and marginal mean equality models. We apply real data to show the utility of the proposed models. The proposed models provide a better fit than that of the existing models.","PeriodicalId":8933,"journal":{"name":"Biometrical Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83980157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Stability Analysis of a Mathematical Model for the Use of Wolbachia to Stop the Spread of Zika Virus Disease 利用沃尔巴克氏体阻止寨卡病毒传播的数学模型的稳定性分析
Biometrical Letters Pub Date : 2021-06-01 DOI: 10.2478/bile-2021-0003
M. Anyanwu, G. Mbah
{"title":"Stability Analysis of a Mathematical Model for the Use of Wolbachia to Stop the Spread of Zika Virus Disease","authors":"M. Anyanwu, G. Mbah","doi":"10.2478/bile-2021-0003","DOIUrl":"https://doi.org/10.2478/bile-2021-0003","url":null,"abstract":"Summary The use of wolbachia-infected mosquitoes to stop the spread of zika virus disease is modeled and analyzed. The model consists of a system of 10 ordinary differential equations which describes the dynamics of the disease in the human population, a wolbachia-free Aedes aegypti population, and a wolbachia-infected Aedes aegypti population used for disease control. A stability analysis of the disease-free equilibrium is conducted, which shows that it is both locally and globally asymptotically stable when the reproduction number is less than one. The result of the stability analysis shows that the spread of zika virus disease can be stopped, irrespective of the initial sizes of the infected human and mosquito populations, when wolbachia-infected Aedes aegypti are introduced in the area where the disease is endemic.","PeriodicalId":8933,"journal":{"name":"Biometrical Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81301785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
An anti-sum-symmetry model and its orthogonal decomposition for ordinal square contingency tables with an application to grip strength test data 序方列联表的反和对称模型及其正交分解及其在握力试验数据中的应用
Biometrical Letters Pub Date : 2021-06-01 DOI: 10.2478/bile-2021-0004
S. Ando
{"title":"An anti-sum-symmetry model and its orthogonal decomposition for ordinal square contingency tables with an application to grip strength test data","authors":"S. Ando","doi":"10.2478/bile-2021-0004","DOIUrl":"https://doi.org/10.2478/bile-2021-0004","url":null,"abstract":"Summary For the analysis of R × R square contingency tables, we need to estimate an unknown probability distribution with high confidence from obtained observations. For that purpose, we need to perform the analysis using a statistical model that fits the data well and has a simple interpretation. This study proposes two original models that have symmetric and asymmetric structures between the probability with which the sum of row and column variables is t, for t = 2, . . ., R, and the probability with which the sum of row and column variables is 2(R + 1) − t. The study also reveals that it is necessary to satisfy the anti-global symmetry model, in addition to the proposed asymmetry model, in order to satisfy the proposed symmetry model. This decomposition theorem is useful to explain why the proposed symmetry model does not hold. Moreover, we show that the value of the likelihood ratio chi-squared statistic of the proposed symmetry model is equal to the sum of those of the decomposed models. We evaluate the utility of the proposed models by applying them to real-world grip strength data.","PeriodicalId":8933,"journal":{"name":"Biometrical Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84083702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Properties of an MLE algorithm for the multivariate linear model with a separable covariance matrix structure 具有可分离协方差矩阵结构的多元线性模型的最大似然算法的性质
Biometrical Letters Pub Date : 2021-06-01 DOI: 10.2478/bile-2021-0005
A. Szczepańska-Álvarez, B. Zawieja, Adolfo Álvarez
{"title":"Properties of an MLE algorithm for the multivariate linear model with a separable covariance matrix structure","authors":"A. Szczepańska-Álvarez, B. Zawieja, Adolfo Álvarez","doi":"10.2478/bile-2021-0005","DOIUrl":"https://doi.org/10.2478/bile-2021-0005","url":null,"abstract":"Summary In this paper we present properties of an algorithm to determine the maximum likelihood estimators of the covariance matrix when two processes jointly affect the observations. Additionally, one process is partially modeled by a compound symmetry structure. We perform a simulation study of the properties of an iteratively determined estimator of the covariance matrix.","PeriodicalId":8933,"journal":{"name":"Biometrical Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73652348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Measure of departure from average marginal homogeneity for the analysis of collapsed ordinal square contingency tables 倒序方列联表分析中偏离平均边际均匀性的测度
Biometrical Letters Pub Date : 2021-06-01 DOI: 10.2478/bile-2021-0006
Manabu Aizawa, K. Yamamoto, S. Tomizawa
{"title":"Measure of departure from average marginal homogeneity for the analysis of collapsed ordinal square contingency tables","authors":"Manabu Aizawa, K. Yamamoto, S. Tomizawa","doi":"10.2478/bile-2021-0006","DOIUrl":"https://doi.org/10.2478/bile-2021-0006","url":null,"abstract":"Summary In clinical research, collected data are often classified into ordered categories using a set threshold to evaluate efficacy and safety of treatment. Data can be summarized as a shift table, which displays the change in the frequency of subjects across specified categories from the baseline to post-baseline. Although ordered categories are sometimes recombined into three categories, the combined patterns vary. To consider various collapsed patterns comprehensively, this paper proposes a new measure that represents the degree of departure from average marginal homogeneity, and can distinguish between two kinds of marginal inhomogeneity. Additionally, applications of the proposed measure to clinical data are discussed.","PeriodicalId":8933,"journal":{"name":"Biometrical Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85128274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Defining the effective deformation of the vertebral column 确定脊柱的有效变形
Biometrical Letters Pub Date : 2020-12-01 DOI: 10.2478/bile-2020-0010
A. Daghighi, H. Tropp
{"title":"Defining the effective deformation of the vertebral column","authors":"A. Daghighi, H. Tropp","doi":"10.2478/bile-2020-0010","DOIUrl":"https://doi.org/10.2478/bile-2020-0010","url":null,"abstract":"Summary The Cobb angle is calculated in the coronal plane, irrespective of vertebral rotation, lordokyphosis and local wedge properties of individual verte-brae other than the end plates used for the measurement. Rigorous three-dimensional generalizations of the Cobb angle are complicated for at least two reasons. Firstly, the vertebral column is segmented, not continuous, making the choice of rigorous model ambiguous. Secondly, there exists an inherent curvature (in terms of thoracic kyphosis and lumbar lordosis) that may be considered physiologically healthy or ’normal’. When attempting to find a three-dimensional deviation measure, such normal sagittal curvature must be compensated for. In this paper we introduce a three-dimensional local deformation parameter (which we call the local effective deformation) motivated by both biomechanics and the basic theory of spatial curves, and simultaneously introduce a technical procedure to estimate the parameter from CT scans using MPR (multi-phase reconstruction) in PACS (IDS-7). A detailed description of the proposed modelling of vertebral column deformation is given, together with a stepwise procedure to estimate the three-dimensional deformation (in terms of local effective deformation). As a deformation measure it requires knowledge about the natural healthy kypholordosis. A method is described by which such knowledge may be incorporated in future work.","PeriodicalId":8933,"journal":{"name":"Biometrical Letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82429063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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