Bimodal data sets are very common in different areas of knowledge. The crude birth rates data, fish length data, egg diameter data, the eruption and interruption times of the Old Faithful geyser, are examples of this type of data. In this paper, a new class of symmetric density functions for modeling bimodal data as described above are presented. From density functions with support on , the symmetry is getting by reflecting the density function in the negative semi-axis with their respective normalization. In this way, if the primitive density function is unimodal, then the resulting density will be bimodal. We introduce asymmetry parameters and study their behavior, in particular the values of their modes and some other statistical values of interest. The cases for densities generated by Gamma, Weibull, Log-normal, and Birnbaum-Saunders densities, among others are studied. Statistical inference is performed from a classical perspective. A small simulation study to evaluate the benefits and limitations of the new proposal. In addition, an application to a data set related to the fetal weight in grams obtained through ultrasound in a sample of 500 units is also presented; the results show the great usefulness of the model in practical situations.
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http://dx.doi.org/10.1080/02664763.2021.1959527 | DOI Listing |
Natl Sci Rev
February 2025
SinoProbe Laboratory, Key Laboratory of Continental Dynamics of Ministry of Natural Resources, Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China.
The onset age and depth of the central Tibet strike-slip faults are two still unresolved fundamental issues with regard to the Cenozoic tectonic evolution of central Tibet. Here we present a comprehensive dataset of geochronological, geochemical and structural data on recently discovered en-echelon dykes representing the incipient development of strike-slip faulting from the Lunpola basin in central Tibet. Our results provide evidence for mantle-derived, bimodal magmatism linked to lithospheric-scale strike-slip faulting at 35-32 Ma, and demonstrate that the central Tibet strike-slip faults are at least 20 Ma older than previously estimated (15-8 Ma).
View Article and Find Full Text PDFSex Reprod Healthc
January 2025
Department of Obstetrics and Gynecology, University of Washington, Seattle, WA, USA.
Objective: To examine abortion care in the largest academic medical center in Washington, a state protective of abortion rights, before and after the Supreme Court Dobbs decision.
Methods: This retrospective cohort study evaluated abortion provision at the University of Washington between January 1, 2022 and October 31, 2023. Data on patient sociodemographic and clinical characteristics were extracted from electronic medical records.
Audiol Res
December 2024
Department of Audiology and Speech Language Pathology, Kasturba Medical College Mangalore, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India.
Hearing loss in children can have a detrimental impact on their development, thus lowering the psychological well-being of parents. This study examined the amount of parental stress, learned helplessness, and perceived social support in mothers of children with hearing loss (MCHL) and mothers of typically developing children (MTDC), as well as the relationship between various possible contributing factors to parental stress such as learned helplessness and perceived social support. Three questionnaires measured parental stress (Parental Stress Scale; PSS), learned helplessness (Learned Helplessness Scale; LHS), and perceived social support (Perceived Social Support-Friends PSS-Fr and Perceived Social Support-Family PSS-Fa Scale) in 100 MCHL and 90 MTDC.
View Article and Find Full Text PDFPediatr Transplant
February 2025
Division of Critical Care Medicine, National Center for Child Health and Development, Tokyo, Japan.
Background: Liver transplantation has improved survival rates in pediatric patients with end-stage liver failure. However, post-liver transplant infection remains a threat to patient recovery. This study reported the frequency and patterns of infections after liver transplantation and identified factors related to the accuracy of fever source investigation.
View Article and Find Full Text PDFJ Am Soc Mass Spectrom
January 2025
Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, United States.
An inherent strength of hydrogen/deuterium exchange coupled to mass spectrometry (HDX-MS) is its ability to detect the presence of multiple conformational states of a protein, which often manifest as multimodal isotopic envelopes. However, the statistical considerations for accurate analysis of multimodal spectra have yet to be established. Here we outline an unrestrained binomial distribution fitting approach with the corresponding statistical tests to accurately detect and, when possible, deconvolute isotopic distributions that contain multiple subpopulations.
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