title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=15 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Cross-cultural adaptation and validation of a Resistance Training Skill Battery for use in Chinese-speaking adolescents link: https://peerj.com/articles/20387 last-modified: 2025-12-15 description: PurposeAlthough the Resistance Training Skills Battery (RTSB) is a well-established instrument for assessing resistance training (RT) skill competency in Western populations, its applicability to Chinese adolescents remains unvalidated. This study aimed to translate, cross-culturally adapted, and validated the RTSB for Mandarin-speaking Chinese adolescents.MethodsEmploying established guidelines for cross-cultural adaptation, our study involved translating the RTSB into Chinese (RTSB-C), followed by back-translation, adaptation, and validation. The study quantified test-retest reliability, intra- and inter-rater reliability, and construct validity. Adolescents aged 12–16 years (n = 64) underwent two RTSB-C assessments, two weeks apart. Muscular fitness was evaluated using muscle fitness tests (handgrip strength, timed push-up, and countermovement jumps) to establish criterion validity.ResultsThe RTSB-C demonstrated fair to excellent test-retest reliability across the two timepoints, the intra-class coefficient (ICC) for the RTSB-C was notably high at 0.94 (95% CI [0.90–0.95]); The intra-rater reliability was 0.94 (p < 0.001), and inter-rater reliability was 0.41–0.93 (p < 0.05). Construct validity was confirmed through linear regression analysis, with the model accounting for 46.8% of the variance in muscle fitness scores (MFS), and with gender (r = 0.47, p < 0.001) and RTSB-C scores (r = 0.45, p < 0.001) emerging as significant predictors.ConclusionsWe successfully translated and cross-culturally adapted the RTSB from English to Chinese, affirming its reliability and validity in assessing the RT skills of Chinese-speaking adolescents. The RTSB-C is recommended for accurate evaluation of RT competence in this demographic. creator: Xiaolu Zha creator: David Lubans creator: Jordan Smith creator: Ran Wang uri: https://doi.org/10.7717/peerj.20387 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Zha et al. title: gllvm 2.0: fast fitting of advanced ordination methods and joint species distribution models link: https://peerj.com/articles/20338 last-modified: 2025-12-12 description: BackgroundOver the past decade, joint species distribution models (JSDMs) and model-based ordination have emerged as powerful tools for the analysis of community ecology data. Generalized linear latent variable models (GLLVMs) offer a flexible framework for multivariate analysis of a wide range of data types, based on including a small number of latent variables to perform dimension reduction while accounting for residual correlation between species.Fast estimation methodsThe R package gllvm implements a wide range of GLLVMs, with estimation performed via fast approximate likelihood-based techniques; including the recently proposed extended variational approximation, which is applicable to almost any combination of response type and link function. Since its original development and accompanying software paper, the gllvm package has undergone a significant overhaul, consolidating its place as a general framework for joint modeling of community ecology datasets.Expanded functionalitiesSome of the key new features of gllvm include model-based constrained and concurrent ordination methods, capacity to account for nested/hierarchical sampling designs, and (phylogenetic) random effects. On top of this, other notable improvements include a great expansion of the response types that it can handle, enhanced capabilities of GLLVM inference, selection and prediction, and an easier-to-use interface for model fitting. creator: Pekka Korhonen creator: Francis K.C. Hui creator: Jenni Niku creator: Sara Taskinen creator: Bert van der Veen uri: https://doi.org/10.7717/peerj.20338 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Korhonen et al. title: Revisiting the Poison Dart Frog Ameerega ingeri (Anura: Dendrobatidae): external morphology, tadpoles, natural history, distribution, advertisement call, phylogenetic position and conservation link: https://peerj.com/articles/20078 last-modified: 2025-12-12 description: Many amphibian species have been described based solely on preserved specimens, leaving significant gaps in our understanding of their behavior, natural history, population status, and phylogenetic relationships—factors essential for effective conservation. Ameerega ingeri, a dark poison frog originally believed to be endemic to Colombia, exemplifies this challenge. Described from only four specimens, its coloration in life, ecological traits, and distribution remained poorly understood for decades, leading to taxonomic confusion with closely related species. In this study, we revisit A. ingeri by providing new distribution records that extend its known range, along with detailed morphological and acoustic descriptions, dietary analysis, and population data. By integrating molecular and acoustic data with ecological and natural history observations, we clarify its taxonomic identity and distinguish it from congeners. Furthermore, we assess its conservation status based on updated occurrence and population data, and propose its inclusion in a threat category according to IUCN criteria. Our findings enhance the understanding of dendrobatid diversity and highlight the importance of field-based research on poorly known and potentially threatened species to support informed conservation strategies. creator: Juan C. Diaz-Ricaurte creator: Alejandro Navarro-Morales creator: César Malambo creator: Junner F. González-Ibarra creator: Yulfreiler Garavito-David creator: Felipe Silva de Andrade creator: Mario A. Madrid-Ordoñez creator: Maykoll J. Parra-Olarte creator: Diego Huseth Ruiz-Valderrama creator: Betselene Murcia-Ordoñez creator: Amanda Varago creator: Diego J. Santana uri: https://doi.org/10.7717/peerj.20078 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Diaz-Ricaurte et al. title: Retrospective on decadal progress of the NOAA/NPS ocean noise reference station network link: https://peerj.com/articles/20382 last-modified: 2025-12-11 description: The National Oceanic and Atmospheric Administration (NOAA), in partnership with the U.S. National Park Service (NPS), established the Ocean Noise Reference Station Network (NRS) in 2014 as a foundational component of NOAA’s Ocean Noise Strategy. This long-term effort aims to characterize baseline ocean ambient sound conditions across diverse marine environments and to inform management of noise impacts on protected species and habitats within U.S. waters. The NRS is now composed of 13 autonomous passive acoustic monitoring stations strategically positioned across the U.S. Exclusive Economic Zone (EEZ), extending from Arctic regions to tropical waters in depths ranging from 33 to 4,790 m. These locations include several National Marine Sanctuaries and National Parks, such as the recently designated Chumash Heritage National Marine Sanctuary off the coast of California. Each station is equipped to continuously sample low-frequency underwater sound at five kHz, enabling the detection of anthropogenic, geophysical, and biological acoustic signals. To date the network has sampled over 72 years of calibrated acoustic data. The spatial breadth and consistent methodology of the NRS allow for comparative acoustic assessments across diverse marine ecosystems. In addition to applied research functions, the NRS has served as a platform for education and training, offering opportunities for students to develop skills for marine science and data analysis. Looking forward, the NRS project team is focused on network expansion, improved data delivery, and broader integration with collaborative scientific initiatives. NRS recordings are being archived in partnership with NOAA’s National Centers for Environmental Information to enhance accessibility and long-term utility. Efforts are underway to develop standardized metadata and summary products to accompany raw audio files, making the data more usable for a wide range of stakeholders in the ocean science community. The NRS is evolving into a fully integrated national framework for ocean sound monitoring that supports scientific inquiry, management decision-making, national security interests, and public engagement with ocean acoustic environments. creator: Samara M. Haver creator: Robert P. Dziak creator: Leila T. Hatch creator: Joseph Haxel creator: Christopher Kavanagh creator: Haru Matsumoto creator: Megan F. McKenna creator: Lauren Roche creator: Sofie M. Van Parijs creator: Carrie C. Wall creator: Jason Gedamke uri: https://doi.org/10.7717/peerj.20382 license: https://creativecommons.org/publicdomain/zero/1.0/ rights: ©2025 Haver et al. title: Alleviation of cold stress impacts on grapes by the chitosan-salicylic acid nanocomposite (CS-SA NCs) application link: https://peerj.com/articles/20368 last-modified: 2025-12-11 description: Low temperature is a major abiotic stressor that limits the distribution of various fruit tree species worldwide. In this study, the effects of chitosan-salicylic acid nanocomposite (CS-SA NCs) treatment were evaluated on antioxidant enzyme activity, the antioxidant pool, and membrane stability indices in the grapevine cultivar ‘Flame seedless’ under cold stress conditions. Prolonged exposure to cold, compared to the control, led to a reduction in maximum fluorescence (Fm), variable fluorescence (Fv), the ratio of photochemical to non-photochemical use of light energy in photosystem II (Fv/F0), and the ratio of variable fluorescence to maximum fluorescence (Fv/Fm). Levels of chlorophylls, carotenoids, total soluble protein content, antioxidant enzyme activity, ascorbate, and glutathione activity significantly decreased with increasing cold stress duration. Electrolyte leakage, malondialdehyde, and hydrogen peroxide content increased by 75%, 60%, and 80%, respectively, after 16 hours of cold stress compared to the control. Nanocomposite treatment significantly enhanced antioxidant activity and stabilized membranes under cold stress by reducing electrolyte leakage and malondialdehyde release. Overall, CS-SA NCs act as a biological stimulant and can be effectively used to improve the physiological and biochemical responses of grapevines under cold stress. Further research is needed to gain a comparative understanding of various physiological responses, which will help guide the application of this nanocomposite in extension services and field production systems. creator: Mohammad Ali Aazami creator: Lamia Vojodi Mehrabani creator: Mohammad Bagher Hassanpouraghdam creator: Farzad Rasouli creator: Gholam Reza Mahdavinia creator: Sona Skrovankova creator: Sezai Ercisli creator: Jiri Mlcek uri: https://doi.org/10.7717/peerj.20368 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Aazami et al. title: Human-mediated dispersal of Geniotrigona thoracica (Apidae: Meliponini) colonies promotes high genetic diversity and reduces population structuring in managed populations link: https://peerj.com/articles/20460 last-modified: 2025-12-10 description: The stingless bee Geniotrigona thoracica is a key managed pollinator in Southeast Asia, valued for its honey, propolis, and colony trade. In Thailand, frequent human-mediated movement of colonies raises concerns about its effects on genetic diversity and population structure. We analysed variation in mitochondrial (COI and 16S rRNA) and nuclear (five microsatellite loci) markers from 70 colonies sampled across 17 meliponaries in seven southern provinces. Microsatellite data revealed high genetic diversity and low nuclear differentiation (K = 1; Fst = 0.0024–0.1219; all P > 0.05), with extensive gene flow (Nm = 3.60–207.83) among provinces. In contrast, mitochondrial markers indicated moderate-to-high differentiation (Fst = 0.619), consistent with mito-nuclear discordance arising from sex-biased. Managed colonies exhibited elevated heterozygosity and allelic richness, likely reflecting admixture from colony exchange, while unique haplotypes in certain provinces suggest introductions from external sources. Significant inbreeding was detected only in Yala, possibly linked to habitat loss and reduced effective population size. Our findings indicate that current meliponicultural practices maintain high genetic diversity in G. thoracica despite mitochondrial structuring, but increasing colony movement between genetically distinct populations may risk erosion of local adaptations, underscoring the need for genetic screening prior to translocation. creator: Orawan Duangphakdee creator: Ekgachai Jeratthitikul creator: Pisit Poolprasert creator: Rujira Pongkitsittiporn creator: Chama Inson creator: Atsalek Rattanawannee uri: https://doi.org/10.7717/peerj.20460 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Duangphakdee et al. title: High abundance of Early Miocene sea cows from Qatar shows repeated evolution of seagrass ecosystem engineers in Eastern Tethys link: https://peerj.com/articles/20030 last-modified: 2025-12-10 description: Coastal ecosystems that include seagrasses are potential carbon sinks that require strategic conservation of top trophic consumers, such as dugongs, to maintain their function. It is unclear, however, how long seagrass ecosystems have persisted in geologic time because their fossil record is poor, although the record of their associated vertebrate consumers offers useful proxies. Here we describe an area of dense Early Miocene dugongid remains from Qatar. We documented over 172 sites in <1 km2 from one stratigraphic level, including material representing a new species of fossil dugongine dugongid. This taxon is unrelated to coeval Early Miocene dugongids from India and the Eastern Tethys and it is distantly related to extant dugongs, which occupy seagrass habitats of the Persian or Arabian Gulf (hereafter ‘Gulf’) today. The monodominant assemblage in this area likely reflects a single fossil dugongid taxon and matches the ecological diversity and geospatial distribution of modern-day live-dead assemblages in the Gulf. This fossil site from Qatar shows that the Gulf has repeatedly evolved sea cow communities with different taxa over the past 20 million years and coincides with an Early Miocene marine biodiversity hotspot in Arabia, prior to its eastward shift to the Indo-Australian Archipelago where dugongs continue to thrive today. creator: Nicholas D. Pyenson creator: Ferhan Sakal creator: Jacques LeBlanc creator: Jon Blundell creator: Katherine D. Klim creator: Christopher D. Marshall creator: Jorge Velez-Juarbe creator: Katherine Wolfe creator: Faisal Al-Naimi uri: https://doi.org/10.7717/peerj.20030 license: https://creativecommons.org/publicdomain/zero/1.0/ rights: ©2025 Pyenson et al. title: Differential effects of physical activity on cognitive and motor performance in obese young adults link: https://peerj.com/articles/20481 last-modified: 2025-12-09 description: The rising prevalence of obesity among young adults presents significant health challenges, particularly due to its adverse effects on cognitive function and physical mobility. This cross-sectional study examined the effects of physical activity on cognitive performance and gait speed in obese individuals aged 18 to 25 years. Seventy-six participants were categorized as either physically active or sedentary based on the Global Physical Activity Questionnaire. All enrolled participants completed the study, and no data were missing. Anthropometric data, including body mass, height, waist circumference, and hip circumference, were collected using standardized procedures. Cognitive assessments included the Trail Making Test, Stroop Color and Word Test, Hand Reaction Time Test, and Logical Memory Test. Gait speed was evaluated using the 10-meter walk test. The physically active group showed significantly better results in logical memory, executive function, and all Stroop test conditions (p < 0.05). No group differences were found in reaction time, Stroop interference score, or gait speed (p > 0.05). These findings suggest that higher physical activity levels are linked to better cognitive performance, highlighting the value of promoting physical activity in young adults with obesity. The lack of observed differences in gait speed and reaction time may indicate that these functions are less sensitive to early changes or require longer periods of inactivity to decline in this population. creator: Piangkwan Sa-nguanmoo creator: Busaba Chuatrakoon creator: Puntarik Keawtep creator: Savitree Thummasorn creator: Tanawat Thongsukdee creator: Patimakorn Homjan creator: Phumiphat Phetcharat uri: https://doi.org/10.7717/peerj.20481 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Sa-nguanmoo et al. title: Effects of core stability exercises on balance among Chinese children and youth with intellectual disabilities link: https://peerj.com/articles/20454 last-modified: 2025-12-09 description: BackgroundChildren and youth with intellectual disabilities (IDs) are at risk of falls due to balance problems.ObjectiveThis study was conducted to assess the effects of six weeks of core stability exercises on balance in this population.MethodsThirty-five participants with IDs from a special school were selected. Static and dynamic balance were assessed by the one-legged stance test (OLS) and lower quarter Y balance test (YBT-LQ), respectively.ResultsCore stability exercises significantly improved static balance with eyes opened (EO) on firm (FI) ground (t = −5.269, P < 0.001) and dynamic balance in all three directions (left leg: anterior: t = −3.197, P = 0.005; posteromedial: t =  − 4.608, P < 0.001; posterolateral: t = −4.706, P < 0.001; right leg: anterior: t = −3.324, P = 0.004; posteromedial: t = −5.614, P < 0.001; posterolateral: t = −5.905, P < 0.001).ConclusionsSix weeks of core stability exercises significantly improved the static balance of children and youth with IDs under EO and FI conditions, as well as all three directions of dynamic balance. Future studies with multiple measurement points are warranted to examine the long-term effectiveness of this training on balance in this population. creator: Jing Qi creator: Yecheng Zhong creator: Junjie Zhou creator: Niuniu Li creator: Yuhang Han creator: Zehua Dong creator: Yan Li creator: Wenhong Xu uri: https://doi.org/10.7717/peerj.20454 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Qi et al. title: Single-cell RNA-seq reveals breast cancer heterogeneity and identifies TCP1 as a therapeutic target in breast cancer link: https://peerj.com/articles/20451 last-modified: 2025-12-09 description: Breast cancer is composed of diverse cell populations, and this intratumoral heterogeneity profoundly affects clinical behavior. Here, we leveraged single cell RNA sequencing (scRNA-seq) of 68 breast cancer specimens to dissect tumor heterogeneity at high resolution. Unsupervised clustering identified all major cell types of the tumor microenvironment (TME)—including malignant epithelial cells, fibroblasts, T cells, macrophages, endothelial cells, and others—with striking variability in their proportions across molecular subtypes. For example, a BRCA1-mutant triple-negative breast cancer (TNBC) sample showed dense immune infiltration, whereas an estrogen receptor (ER)-positive tumor was mostly epithelial, consistent with known subtype differences in immunogenicity. We applied inference of copy number variations (inferCNV) to distinguish malignant epithelial cells, identifying ~90,000 tumor cells with significant copy-number aberrations enriched for cancer hallmark pathways. Re-clustering of these malignant cells revealed five discrete subpopulations. Notably, a KRT17-positive subcluster displayed the highest stemness score and a distinctive ETS-family transcription factor (ERG) regulon, suggesting a stem-like phenotype. Using The Cancer Genome Atlas (TCGA) cohort, we found that genes upregulated in this KRT17+ subpopulation, particularly NFKBIA, PDLIM4, and TCP1 stratified patient survival. An 8-gene risk signature derived from the KRT17 program segregated patients into high- and low-risk groups with markedly different outcomes. High-risk tumors were characterized by an immunosuppressive TME enriched in M2-like macrophages, whereas low-risk tumors more often harbored lymphocyte-predominant infiltrates. Focusing on TCP1, a chaperonin subunit upregulated in high-risk tumors, we demonstrate that TCP1 knockdown in breast cancer cell lines substantially impairs cell migration (~50% reduction in wound closure) and invasion (P < 0.01). These findings reveal functionally distinct malignant cell states within breast cancer and identify TCP1 as a promising therapeutic target to disrupt aggressive, stem-like tumor cell programs, ultimately guiding more personalized treatment strategies. creator: Houman Wu creator: Haiyang Du creator: Gao Si creator: Xuejie Song creator: Fuchun Si uri: https://doi.org/10.7717/peerj.20451 license: https://creativecommons.org/licenses/by-nc/4.0 rights: © 2025 Wu et al.