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Testing Correlation in a Three-Level Model
AbstractIn this paper, we present a statistical approach to evaluate the relationship between variables observed in a two-factors experiment. We consider a three-level model with covariance structure $${\varvec{\Sigma }} \otimes {\varvec{\Psi }}_1 \otimes {\varvec{\Psi }}_2$$ Σ ⊗ Ψ 1 ⊗ Ψ 2 , where $${\varvec{\Sigma }}$$ Σ is an arbitrary positive definite covariance matrix, and $${\varvec{\Psi }}_1$$ Ψ 1 and $${\varvec{\Psi }}_2$$ Ψ 2 are both correlation matrices with a compound symmetric structure corresponding to two different factors. The Rao’s score test is used to test the hypotheses that observations grouped by one or two factors are uncorrelated. We analyze a fermentation process to illustrate the results. Supplementary materials accompanying this paper appear online.
Biochemical Properties of Bioactive Compounds in the Oil from Polish Varieties of Camelina sativa Cultivated in 2019–2022
AbstractCold‐pressed Camelina oil is a traditional oil registered as a traditional food in Poland. Camelina oil has health‐promoting properties and high oxidative stability. This may be due to the presence of various bioactive antioxidant compounds such as carotenoids, sterols and polyphenols. Bioactive compounds content in Camelina oil depends mainly on the varieties and on the conditions under which the crop was grown therefore the aim of the research was to analyse antioxidant bioactive compounds in oil from different cultivars of Camelina sativa seeds and to determine their relationship with oil parameters.
D-optimal strain sensor placement for mechanical load estimation in the presence of nuisance loads and thermal strain
Iron Deficiency Anemia in Infants—Diagnostic Challenge and Assessment of Dietary Impact on Its Prevalence
Background/Objectives: Iron deficiency affects 2% of infants under six months of age and 4–18% of infants aged 6–12 months and may lead to anemia. Given the consequences of iron deficiency in infancy and the importance of adequate nutrition, this study aimed to assess indicators of iron metabolism in infants whose parents participated in nutritional education. Methods: The study included 104 infants, divided into a study group (SG, n = 52) receiving a nutritional education intervention and a control group (CG, n = 52). Peripheral blood morphology parameters and biochemical markers, e.g., iron status (serum iron, transferrin, ferritin, and hepcidin), were evaluated at 3 and 12 months of age. Additionally, at study end, parents completed a three-day dietary diary to assess their infant’s iron intake. Results: After nearly one year of intervention, no cases of anemia based on hemoglobin concentration were identified in either group. However, infants in the SG were less likely to present iron and ferritin concentrations below reference ranges compared to the CG. In the CG, low ferritin levels occurred more frequently at 12 months than at baseline. This finding may be related to higher dietary iron intake in the SG, as insufficient iron intake was more common among the CG. Heatmap analysis revealed strong positive correlations among erythrocyte indices, confirming their internal consistency. No single parameter emerged as a superior marker of iron deficiency, emphasizing the need for a combined assessment of iron status. Conclusions: Parental nutritional education may improve iron status and reduce the risk of iron metabolism disorders in infants.
Environmental impact on downy mildew infection for different pea varieties
Summary In general, varieties of any cultivated species can differ in many aspects. One of the desirable traits in breeding new varieties is high yield, which can be significantly reduced by plant diseases. This study is an extension of previous research about the resistance of seed pea lines to downy mildew, and provides an extended analysis of this type of experiment. The probability of a degree of infection is determined based on a logistic model with a multinomial distribution. In the analysis the impact of a fixed effect of variety and random environmental effects is considered. It is shown that the environmental effects (combinations of years and location – macro-environments) significantly influence the resistance to diseases, and the differences among environments are larger than the variability of differences among genotypes over all environments. For two types of soils (light and rich) the most resistant varieties, which are significantly different from the control variety, are indicated.
Notes on parametric functions in the linear model
Summary Starting from a simple Gauss–Markov model, this paper presents notes about criteria for the estimability of parametric functions of the vector of interest in linear models. The results obtained for the transformed models are compared with known results from the literature.