scholarly journals ANALYSES OF GENE FREQUENCIES

Genetics ◽  
1973 ◽  
Vol 74 (4) ◽  
pp. 679-700
Author(s):  
C Clark Cockerham
Keyword(s):  
Variance Components ◽  
Small Sample ◽  
Gene Frequencies ◽  
F Test ◽  
Estimable Functions ◽  
Intraclass Correlations ◽  
Different Types ◽  
Informational System ◽  
Tests Of Hypotheses

ABSTRACT Models of variance components and their intraclass correlational equivalences are developed for genes falling into various categories of subdivisions within a population. Estimable functions are elaborated demonstrating that intraclass correlations can be estimated only relative to that for the least related genes in the informational system. The effects of different types of subdivisions-and of ignoring them-on the parameters are demonstrated. Small sample estimators are formulated for all of the parameters by three different methods, including both a weighted and an unweighted method of analysis of the variation among subpopulations. How estimators change with assumptions about the parameters is illustrated. Various tests of hypotheses are outlined in X2 and F-test terminology. Discussed are factors which may affect the correlations and the manner in which their effects are manifest, hopefully in clarification of some of the misconceptions that have arisen in this connection.

Immunological Determined Plasminogen Groups And Its Possible Biological Relevance

1981 ◽  
Author(s):  
V Sachs ◽  
R Dörner ◽  
E Szirmai
Keyword(s):  
Human Plasma ◽  
Type I ◽  
Type Ii ◽  
Precipitation Line ◽  
Gene Frequencies ◽  
Type Iii ◽  
Different Types ◽  
Human Plasminogen ◽  
Gel Diffusion ◽  
Good Agreement

Anti human plasminogen sera of the rabbit precipitate human plasma in the agar gel diffusion test by means of intra-basin absorption with plasminogenfree human plasma with three different types: type I is represented by one strong precipitation line, type II by two lines, a big one and a small one, and type III by three slight but distinct lines. The following frequencies of the different types have been observed in a sample of 516 human plasmas: type I 65%, type II 33% and type III 2%. Suppose the types are phenotypical groups of a diallelic system where the types I and III represent the homozygous genotypes and the type II the heterozygous the estimated gene frequencies are in good agreement with the expected values. There is also a good agreement of the distribution of plasminogen groups determined by electrofocussing from RAUM et al. and HOBART. The plasminogen groups possibly may have also a biological meaning because the plasmas of type III always have a lesser fibrinolytic activity than the plasmas of the other types.

scholarly journals Null expectation of spatial correlograms under a stochastic process of genetic divergence with small sample sizes

2000 ◽  
Vol 23 (4) ◽  
pp. 739-743 ◽  
Author(s):  
Mariana Pires de Campos Telles ◽  
José Alexandre Felizola Diniz-Filho
Keyword(s):  
Stochastic Process ◽  
Genetic Divergence ◽  
Isolation By Distance ◽  
Genetic Distances ◽  
Small Sample ◽  
Group Method ◽  
Gene Frequencies ◽  
Exponential Relationship ◽  
Local Populations ◽  
Pair Group

An Ornstein-Uhlenbeck process was used to simulate the exponential relationship between genetic divergence and geographic distances, as predicted by stochastic processes of population differentiation, such as isolation-by-distance, stepping-stone or coalescence models. These simulations were based only on the spatial coordinates of the local populations that defined a spatial unweighted pair-group method using arithmetic averages (UPGMA) link among them. The simulated gene frequency surfaces were then analyzed using spatial autocorrelation procedures and Nei's genetic distances, constructed with different numbers of variables (gene frequencies). Stochastic divergence in space produced strong spatial patterns at univariate and mutivariate levels. Using a relatively small number of local populations, the correlogram profiles varied considerably, with Manhattan distances greater than those defined by other simulation studies. This method allows one to establish a range of correlogram profiles under the same stochastic process of spatial divergence, thereby avoiding the use of unnecessary explanations of genetic divergence based on other microevolutionary processes.

scholarly journals Prevalence of Blood Groups in Eastern UP Population

2020 ◽  
Author(s):  
Pradeep Kumar ◽  
Vandana Rai
Keyword(s):  
Small Sample Size ◽  
Uttar Pradesh ◽  
Allelic Frequency ◽  
Blood Groups ◽  
Small Sample ◽  
Blood Type ◽  
Allele Frequency Distribution ◽  
Abo Blood Groups ◽  
Male And Female ◽  
Different Types

Approximately 300 different types of blood groups are identified so far, the ABO and Rh antigens are still the clinically most significant and genetically most polymorphic of all human blood group systems to date. A total of 200 unrelated individuals from Uttar Pradesh were studied for the phenotype and allele frequency distribution of ABO and Rh (D) blood groups. In total 200 samples analyzed, phenotype B blood type has the highest frequency 36.5% (n=73), followed by O (34.5%; n=69), A (20.5%; n=41) and AB (8.5%; n=17). The O, A and B frequencies were 0.5849, 0.1571 and 0.2580 respectively. The overall phenotypic frequencies of ABO blood groups were B>O>A>AB. The variation in phenotypic frequencies between male and female might be due to small sample size of male sample. The allelic frequency of Rh-negative was 0.2.

Selective inspection planning with ageing forecast for sewer types

2002 ◽  
Vol 46 (6-7) ◽  
pp. 389-396 ◽  
Author(s):  
R. Baur ◽  
R. Herz
Keyword(s):  
Environmental Risks ◽  
Small Sample ◽  
Storm Water ◽  
Actual Condition ◽  
Inspection Planning ◽  
Transition Functions ◽  
Sewer Network ◽  
Different Types ◽  
Sewer Rehabilitation ◽  
Water Profile

Investments in sewer rehabilitation must be based on inspection and evaluation of sewer conditions with respect to the severity of sewer damage and to environmental risks. This paper deals with the problems of forecasting the condition of sewers in a network from a small sample of inspected sewers. Transition functions from one into the next poorer condition class, which were empirically derived from this sample, are used to forecast the condition of sewers. By the same procedure, transition functions were subsequently calibrated for sub-samples of different types of sewers. With these transition functions, the most probable date of entering a critical condition class can be forecast from sewer characteristics, such as material, period of construction, location, use for waste and/or storm water, profile, diameter and gradient. Results are shown for the estimates about the actual condition of the Dresden sewer network and its deterioration in case of doing nothing about it. A procedure is proposed for scheduling the inspection dates for sewers which have not yet been inspected and for those which have been inspected before.

scholarly journals Narratives of cooperation, resilience and resistance: workers’ self-recovery in times of crisis

2019 ◽  
Vol 39 (9/10) ◽  
pp. 851-864 ◽  
Author(s):  
Luca Antonazzo
Keyword(s):  
Small Sample ◽  
Workplace Democracy ◽  
Cross Sectional ◽  
International Debate ◽  
Content Type ◽  
The Great Recession ◽  
Different Types ◽  
Multi Level ◽  
Sectional Analysis ◽  
Opening Up

Purpose Worker-recuperated enterprises have appeared in Europe with increasing frequency since 2008, following the Great Recession that hit the western economies. The purpose of this paper is to depict the phenomenon of worker-recuperated enterprises in Italy, focusing on two different types of business recovery, that of workers buyouts and that of recovered social spaces. The paper compares these on the basis of four analytical dimensions: resilience/resistance, relationship with the market, relationship with the territory and workplace democracy. Design/methodology/approach The corpus of the research is based on the cross-sectional analysis of workers’ narratives. These were collected, within a small sample of theoretically relevant cases, in order to retrace and analyse the path from the crisis of the former companies to establishment of the workers’ cooperatives and their social and economic features. Findings The collected narratives allowed for a multi-level comparison between different types of worker-recuperated enterprises, providing some insights on their emergence, their features in terms of resilience and resistance, their relationship with the market economy and their outcomes in terms of workplace democracy and support to employment. Originality/value Worker buyouts are gaining ground in Europe as an effective mechanism to oppose the fall of the employment rate in consequence of economic crises. This research intends to offer some data and arguments to the current international debate on the effectiveness of these mechanisms in coping with economic shocks and opening up to a sustainable and cooperative work-driven economy.

scholarly journals The Impact of Improved Thermistor Calibration on the Expendable Bathythermograph Profile Data

2017 ◽  
Vol 34 (9) ◽  
pp. 1947-1961 ◽  
Author(s):  
Marlos Goes ◽  
Elizabeth Babcock ◽  
Francis Bringas ◽  
Peter Ortner ◽  
Gustavo Goni
Keyword(s):  
Small Sample Size ◽  
Heat Content ◽  
Small Sample ◽  
Profile Data ◽  
Expendable Bathythermograph ◽  
Different Types ◽  
Long Term Trends ◽  
The Mean ◽  
The Impact

AbstractExpendable bathythermograph (XBT) data provide one of the longest available records of upper-ocean temperature. However, temperature and depth biases in XBT data adversely affect estimates of long-term trends of ocean heat content and, to a lesser extent, estimates of volume and heat transport in the ocean. Several corrections have been proposed to overcome historical biases in XBT data, which rely on constantly monitoring these biases. This paper provides an analysis of data collected during three recent hydrographic cruises that utilized different types of probes, and examines methods to reduce temperature and depth biases by improving the thermistor calibration and reducing the mass variability of the XBT probes.The results obtained show that the use of individual thermistor calibration in XBT probes is the most effective calibration to decrease the thermal bias, improving the mean thermal bias to less than 0.02°C and its tolerance from 0.1° to 0.03°C. The temperature variance of probes with screened thermistors is significantly reduced by approximately 60% in comparison to standard probes. On the other hand, probes with a tighter weight tolerance did not show statistically significant reductions in the spread of depth biases, possibly because of the small sample size or the sensitivity of the depth accuracy to other causes affecting the analysis.

Sample Size and Accuracy of Estimates in Multilevel Models

Methodology ◽  
2011 ◽  
Vol 7 (3) ◽  
pp. 111-120 ◽  
Author(s):  
Omar Paccagnella
Keyword(s):  
Variance Components ◽  
Multilevel Models ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Estimation Procedure ◽  
Small Sample ◽  
Standard Errors ◽  
Sample Sizes ◽  
Monte Carlo Simulation Study ◽  
Small Sample Sizes

In a multilevel framework several researches have investigated the behavior of estimates in finite samples, particularly for continuous dependent variables. Some findings show poor precise estimates for the variance components. On the other hand, discrete response multilevel models have been investigated less widely. In this paper we analyze the influence of different factors on the accuracy of estimates and standard errors of estimates in a binary response 2-level model, through a Monte Carlo simulation study. We investigate the hypothesis of: (a) small sample sizes; (b) different intraclass correlation coefficients; (c) different numbers of quadrature points in the estimation procedure. Standard errors of estimates are studied through a noncoverage indicator. In all instances we have considered, the point estimates are unbiased (even with very small sample sizes), while the variance components are underestimated. The accuracy of the standard errors of variance estimates needs a very large number of groups.

GENOTYPE-ENVIRONMENT INTERACTIONS IN YIELD OF WHEAT

1969 ◽  
Vol 49 (6) ◽  
pp. 743-751 ◽  
Author(s):  
R. J. Baker
Keyword(s):  
Detailed Analysis ◽  
Spring Wheat ◽  
Variance Components ◽  
Wheat Yield ◽  
Yield Stability ◽  
Western Canada ◽  
Environment Interaction ◽  
Hard Red Spring Wheat ◽  
Genotype Environment Interaction ◽  
Different Types

A detailed analysis of genotype-environment interactions was carried out among yields of six cultivars of hard red spring wheat grown at each of nine locations in five different years. Subdividing the sum of squares for genotype-environment interactions into components due to each cultivar indicated that the Finlay-Wilkinson method of measuring yield stability is of little value for wheat yield in western Canada. Conventional estimates of variance components due to the different types of genotype-environment interaction indicated that all except the genotype-year interaction were significant and important.

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