Unlabelled: Mixtures of multivariate leptokurtic-normal distributions have been recently introduced in the clustering literature based on mixtures of elliptical heavy-tailed distributions. They have the advantage of having parameters directly related to the moments of practical interest. We derive two estimation procedures for these mixtures. The first one is based on the majorization-minimization algorithm, while the second is based on a fixed point approximation. Moreover, we introduce parsimonious forms of the considered mixtures and we use the illustrated estimation procedures to fit them. We use simulated and real data sets to investigate various aspects of the proposed models and algorithms.
Supplementary Information: The online version contains supplementary material available at 10.1007/s11634-023-00558-2.
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http://dx.doi.org/10.1007/s11634-023-00558-2 | DOI Listing |
Environ Toxicol Chem
January 2025
Centro di Referenza Nazionale per l'Analisi e Studio di Correlazione tra Ambiente, Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici, Italy.
A statistical procedure has been developed to derive a screening value from an observational study related to the developmental toxicity observed in loggerhead turtle (Caretta caretta) eggs exposed to long chain per- and polyfluoroalkyl substances (PFAS). A dataset of 41 nests in which the hatching rate was inversely correlated with the increase in the PFAS concentration in unhatched eggs was processed via a categorical regression approach. After outliers identification and removal, categorical regression analysis tested the relationships of the outcomes with the following parameters: perfluoro-nonanoic (PFNA), decanoic (PFDA), undecanoic (PFUdA), and dodecanoic (PFDoA) acids; perfluoroctansulfonate (PFOS); polychlorobiphenyls (PCBs) 28, 52, 101, 138, 153, 180; lead (Pb), total mercury (Hgtot), and cadmium (Cd); and other factors, such as "nest site," "clutch size," "incubation duration," and "nest minimum depth," as confounders/modifiers of the hatching rate.
View Article and Find Full Text PDFBMC Public Health
January 2025
The First Hospital of Jilin University, No.1 Xinmin Street, Changchun, 130012, China.
Background: Phthalate exposure has been hypothesized to influence cholesterol metabolism and gallstone pathogenesis, but previous studies are limited. We aimed to examine the associations between urinary phthalate metabolites and prevalence of gallstone disease in a nationally representative sample.
Methods: We analyzed data on 1,696 adults aged ≥ 30 years from the National Health and Nutrition Examination Survey (NHANES) 2017-2018.
Environ Pollut
January 2025
Department of Environmental Health Sciences, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA. Electronic address:
Background: Previous epidemiological studies on the associations between hazardous air pollutants (HAPs) and breast cancer (BC) have largely neglected rural, medically underserved areas in the United States, which differ in exposures and disparities compared to urban areas.
Objectives: We aimed to examine the associations between carcinogenic HAPs and BC risk in a rural population.
Methods: Using a nested case-control design, 574 cases and 2,295 incidence density-sampled controls matched 1:4 on index age and race were included from the Arkansas Rural Community Health study.
J Biophotonics
January 2025
Department of Electronic Engineering, Maynooth University, Kildare, Ireland.
Broadband CARS is a coherent Raman scattering technique that provides access to the full biological vibrational spectrum within milliseconds, facilitating the recording of widefield hyperspectral Raman images. In this work, BCARS hyperspectral images of unstained cells from two different cell lines of immune lineage (T cell [Jurkat] and pDCs [CAL-1]) were recorded and analyzed using multivariate statistical algorithms in order to determine the spectral differences between the cells. A classifier was trained which could distinguish the known cells with a 97% out-of-bag accuracy.
View Article and Find Full Text PDFBMC Chem
January 2025
Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
Lidocaine poses challenges when it comes to direct spectrophotometric measurement due to the lack of sharp peak within its spectra in zero-order. This lack of a distinct peak makes it difficult to accurately quantify lidocaine using traditional direct spectrophotometric methods. In our study, different univariate and multivariate spectrophotometric techniques have been established and their validity has been assessed for the determination of the mixture of Lidocaine HCl (LD), Oxytetracycline HCl (OTC) together with LD carcinogenic impurity [2,6- dimethylaniline] DMA.
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