Background: Snakes exhibit sexual dimorphism in both head size and shape. Such differences are often attributed to different reproductive roles and feeding habits. We aim to investigate how sexual dimorphism is displayed in the highly specialised fish-egg-eating snake, , by analysing two complementary features: body size and skull morphology.
Methods: We used data on body length, weight, and skull shape from 27 measurements of 116 males and females of . We investigated both sexual dimorphism and allometric (multivariate and bi-variate) properties of skull growth in the analysed data set.
Results: We found that although there was female-biased sexual size dimorphism in body length, females were not heavier than males, contrary to what is commonly observed pattern among snakes. Moreover, females tend to possess relatively smaller heads than males. However, we only found very subtle differences in skull shape reflected in nasal width, mandibular fossa, quadrate crest and quadrate length.
Discussion: We suggest that the feeding specialisation in does not allow for an increase in body thickness and the size of the head above a certain threshold. Our results may be interpreted as support for prey-size divergence as a factor driving skull dimorphism since such species in which the sexes do not differ in prey size also shows very subtle or no differences in skull morphology.
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http://dx.doi.org/10.7717/peerj.11311 | DOI Listing |
Nat Med
January 2025
Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot, Israel.
Sleep tests commonly diagnose sleep disorders, but the diverse sleep-related biomarkers recorded by such tests can also provide broader health insights. In this study, we leveraged the uniquely comprehensive data from the Human Phenotype Project cohort, which includes 448 sleep characteristics collected from 16,812 nights of home sleep apnea test monitoring in 6,366 adults (3,043 male and 3,323 female participants), to study associations between sleep traits and body characteristics across 16 body systems. In this analysis, which identified thousands of significant associations, visceral adipose tissue (VAT) was the body characteristic that was most strongly correlated with the peripheral apnea-hypopnea index, as adjusted by sex, age and body mass index (BMI).
View Article and Find Full Text PDFJ Arthroplasty
January 2025
Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA; Department of Orthopaedic Surgery, Newton-Wellesley Hospital, Newton, MA, USA. Electronic address:
Background: Despite the growing utilization of robotic-assisted total hip arthroplasty (rTHA), major debate remains regarding its comparative effectiveness in achieving optimal patient outcomes compared to manual total hip arthroplasty (mTHA). This study aimed to compare both the rate and time to achieve minimal clinically important difference (MCID) between rTHA and mTHA.
Methods: We conducted a retrospective analysis comparing 341 rTHAs with a 1:3 propensity score-matched cohort of 1,023 mTHAs performed from 2016 to 2022.
Med Image Anal
January 2025
Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA. Electronic address:
The relationship between brain connections and non-imaging phenotypes is increasingly studied using deep neural networks. However, the local and global properties of the brain's white matter networks are often overlooked in convolutional network design. We introduce TractGraphFormer, a hybrid Graph CNN-Transformer deep learning framework tailored for diffusion MRI tractography.
View Article and Find Full Text PDFJCO Precis Oncol
January 2025
Department of Medicine, Massachusetts General Hospital, Boston, MA.
Purpose: Immune checkpoint inhibitors (ICIs) are now first-line therapy for most patients with recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC), and cetuximab is most often used as subsequent therapy. However, data describing cetuximab efficacy in the post-ICI setting are limited.
Methods: We performed a single-institution retrospective analysis of patients with R/M HNSCC treated with cetuximab, either as monotherapy or in combination with chemotherapy, after receiving an ICI.
Stroke
February 2025
Division of Interventional Neuroradiology, Department of Radiology (H.C., S.M., D.G.), University of Maryland Medical Center, Baltimore.
Background: Sex-specific differences in stroke risk factors, clinical presentation, and outcomes are well documented. However, little is known about real-world differences in transient ischemic attack (TIA) hospitalizations and outcomes between men and women.
Methods: This was a retrospective cohort study of the 2016 to 2021 Nationwide Readmissions Database in the United States.
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