PeerJ
type: channel
link: https://peerj.com/articles/
description: Articles published in PeerJ
publisher: PeerJ Inc.
publication name: PeerJ
issn: 2167-8359
items: Analysis of molecular subtypes and prognostic signature of senescence-associated secretory phenotype in pancreatic cancer
items: A new species of aposematic grasshopper of the genus Pseudoutanacris (Acrididae: Gomphocerinae) from the Andean cloud forest of the Ecuadorian Amazon basin
items: Cholesterol and steroid synthesis pathways may be involved in the inhibition of osteosarcoma cell viability by calcium-sensing receptor antagonism
items: The impact of physical activity on social anxiety among college students: an analysis of the chain mediation effect of family support and self-efficacy
items: Development and validation of a risk prediction model for overall survival in cervical cancer patients under 50: a prospective cohort study in southwest China
items: Improving taxonomic resolution, biomass and abundance assessments of aquatic invertebrates by combining imaging and DNA megabarcoding
items: The petrosal and bony labyrinth of extinct horses (Perissodactyla, Equidae) and their implications for perissodactyl evolution
items: Feeding ecology of scolopendromorphs: integrating a global literature review with Japanese citizen-sourced data
items: Bacterial diversity in the jelly of shark Ampullae of Lorenzini: a holobiont perspective
items: Evaluating portable EEG: a comparison between two wireless systems (EPOC Flex and LiveAmp) and the wired BrainAmp system

Analysis of molecular subtypes and prognostic signature of senescence-associated secretory phenotype in pancreatic cancer
type: item
type: AcademicArticle
description: Background Pancreatic cancer (PC) exhibits an extremely poor prognosis due to its high heterogeneity. The senescence-associated secretory phenotype (SASP), a distinct secretory profile displayed by senescent cells, has been increasingly studied. However, the role of SASP in PC prognosis and treatment remains unclear. Methods Transcriptomic sequencing data from PC patients were analyzed using consensus clustering based on SASP genes. A prognostic signature was subsequently constructed via Least Absolute Shrinkage and Selection Operator (LASSO) regression using survival-related SASP genes. Pathway enrichment analysis for distinct subgroups was performed using Gene Set Variation Analysis (GSVA). Comprehensive analyses of mutational landscapes and tumor immune microenvironments were conducted across risk-stratified PC samples. Results Consensus clustering based on SASP genes identified two SASP-associated clusters (SASPclusters), with cluster B demonstrating significantly worse prognosis than cluster A. Thirty-three SASP genes showed significant associations with PC prognosis, and a 7-gene SASP-based prognostic signature was established. High-risk patients exhibited significantly higher mutation rates. Distinct immune cell infiltration patterns, immune functions, checkpoint expression levels, and chemosensitivity profiles were observed between risk groups. Besides, we found that ANGPTL4 could promote PC cell proliferation, migration, and invasion. Conclusion Molecular subtyping and risk stratification based on SASP genes effectively predict PC prognosis and reveal heterogeneity in mutational burden, immune microenvironment, and therapeutic sensitivity. These computational findings deepen our understanding of potential role of SASP in PC and provide a theoretical foundation for personalized treatment strategies.
format: application/pdf
format: text/html
creator: Yuewen Kuang
creator: Mingkun Jia
creator: Yuming Zhu
creator: Zhiyong Xiang
subject: Bioinformatics
subject: Computational Biology
subject: Gastroenterology and Hepatology
subject: Oncology
subject: Data Mining and Machine Learning
description: doi:10.7717/peerj.20476
publisher: PeerJ Inc.
rights: © 2026 Kuang et al.
abstract: Background Pancreatic cancer (PC) exhibits an extremely poor prognosis due to its high heterogeneity. The senescence-associated secretory phenotype (SASP), a distinct secretory profile displayed by senescent cells, has been increasingly studied. However, the role of SASP in PC prognosis and treatment remains unclear. Methods Transcriptomic sequencing data from PC patients were analyzed using consensus clustering based on SASP genes. A prognostic signature was subsequently constructed via Least Absolute Shrinkage and Selection Operator (LASSO) regression using survival-related SASP genes. Pathway enrichment analysis for distinct subgroups was performed using Gene Set Variation Analysis (GSVA). Comprehensive analyses of mutational landscapes and tumor immune microenvironments were conducted across risk-stratified PC samples. Results Consensus clustering based on SASP genes identified two SASP-associated clusters (SASPclusters), with cluster B demonstrating significantly worse prognosis than cluster A. Thirty-three SASP genes showed significant associations with PC prognosis, and a 7-gene SASP-based prognostic signature was established. High-risk patients exhibited significantly higher mutation rates. Distinct immune cell infiltration patterns, immune functions, checkpoint expression levels, and chemosensitivity profiles were observed between risk groups. Besides, we found that ANGPTL4 could promote PC cell proliferation, migration, and invasion. Conclusion Molecular subtyping and risk stratification based on SASP genes effectively predict PC prognosis and reveal heterogeneity in mutational burden, immune microenvironment, and therapeutic sensitivity. These computational findings deepen our understanding of potential role of SASP in PC and provide a theoretical foundation for personalized treatment strategies.
bibliographic citation: Kuang et al. (2026) Analysis of molecular subtypes and prognostic signature of senescence-associated secretory phenotype in pancreatic cancer. PeerJ 14:e20476 https://doi.org/10.7717/peerj.20476
date submitted: 2025-06-05
date accepted: 2025-11-04
issued: 2026-01-06
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Kuang
  given name: Yuewen
author list: Agent
  family name: Jia
  given name: Mingkun
author list: Agent
  family name: Zhu
  given name: Yuming
author list: Agent
  family name: Xiang
  given name: Zhiyong
doi: 10.7717/peerj.20476
volume: 14
issn: 2167-8359
publication name: PeerJ
publication date: 2026-01-06
copyright: ©2026 Kuang et al.
attribution name: Kuang et al.

A new species of aposematic grasshopper of the genus Pseudoutanacris (Acrididae: Gomphocerinae) from the Andean cloud forest of the Ecuadorian Amazon basin
type: item
type: AcademicArticle
description: We have identified a new grasshopper species belonging to the genus Pseudoutanacris Jago, 1971, in the montane forests of the eastern Andes in Ecuador. This discovery expands the known distribution of the genus, previously limited to a single species in the Bolivian tropics, by over 2,000 kilometers. For the first time, a female of the genus is described, and notes on the ecology and natural history of the species are presented. We also provide the first barcodes of the genus Pseudoutanacris Jago, 1971. The males of a newly described species, Pseudoutanacris grilla sp. nov. shares a striking coloration pattern with their Bolivian congener, Pseudoutanacris chromobapta Jago, 1971, setting them apart from other members of the tribe Amblytropidiini. However, the females maintain a cryptic coloration pattern, similar to that of the tribe members, and display different behavior from the males. During our study, we also observed Ps. grilla sp. nov. on the same plant as Megacheilacris graminicola (Descamps & Amédégnato, 1971) (Bactrophorinae: Romaleidae), a species with similar chromatic characteristics. This finding also marks the first formal documentation of the new geographical records of M. graminicola (Descamps & Amédégnato, 1971) in Ecuador.
format: application/pdf
format: text/html
creator: Felipe Campos-Yánez
creator: Ana B. García-Ruilova
creator: Diego J. Inclán
subject: Biodiversity
subject: Entomology
description: doi:10.7717/peerj.20376
publisher: PeerJ Inc.
rights: © 2026 Campos-Yánez et al.
abstract: We have identified a new grasshopper species belonging to the genus Pseudoutanacris Jago, 1971, in the montane forests of the eastern Andes in Ecuador. This discovery expands the known distribution of the genus, previously limited to a single species in the Bolivian tropics, by over 2,000 kilometers. For the first time, a female of the genus is described, and notes on the ecology and natural history of the species are presented. We also provide the first barcodes of the genus Pseudoutanacris Jago, 1971. The males of a newly described species, Pseudoutanacris grilla sp. nov. shares a striking coloration pattern with their Bolivian congener, Pseudoutanacris chromobapta Jago, 1971, setting them apart from other members of the tribe Amblytropidiini. However, the females maintain a cryptic coloration pattern, similar to that of the tribe members, and display different behavior from the males. During our study, we also observed Ps. grilla sp. nov. on the same plant as Megacheilacris graminicola (Descamps & Amédégnato, 1971) (Bactrophorinae: Romaleidae), a species with similar chromatic characteristics. This finding also marks the first formal documentation of the new geographical records of M. graminicola (Descamps & Amédégnato, 1971) in Ecuador.
bibliographic citation: Campos-Yánez et al. (2026) A new species of aposematic grasshopper of the genus Pseudoutanacris (Acrididae: Gomphocerinae) from the Andean cloud forest of the Ecuadorian Amazon basin. PeerJ 14:e20376 https://doi.org/10.7717/peerj.20376
date submitted: 2025-04-17
date accepted: 2025-10-20
issued: 2026-01-06
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Campos-Yánez
  given name: Felipe
author list: Agent
  family name: García-Ruilova
  given name: Ana B.
author list: Agent
  family name: Inclán
  given name: Diego J.
doi: 10.7717/peerj.20376
volume: 14
issn: 2167-8359
publication name: PeerJ
publication date: 2026-01-06
copyright: ©2026 Campos-Yánez et al.
attribution name: Campos-Yánez et al.

Cholesterol and steroid synthesis pathways may be involved in the inhibition of osteosarcoma cell viability by calcium-sensing receptor antagonism
type: item
type: AcademicArticle
description: Background This study examined the effect of calcium-sensing receptor (CaSR) antagonism on human osteosarcoma cells and investigated the underlying molecular mechanisms of this effect through transcriptome sequencing. Methods Human osteosarcoma cell lines MG-63 and Saos-2 were treated with different concentrations (0.1–10 µM) of the CaSR antagonist NPS-2143. Cell Counting Kit-8 (CCK-8) assays were used to detect the effect of CaSR antagonism on the viability of the cells. RNA sequencing was performed on cells treated with five µM NPS-2143 for 24 hours, followed by bioinformatic analysis to identify differentially expressed genes and enriched pathways. qRT-PCR was conducted to validate key genes. Results CCK-8 assays showed that at low concentrations (0.1 and one µM), NPS-2143 had no significant effect on MG-63 and Saos-2 cell viability. At higher concentrations (five µM and 10 µM), the viability of MG-63 and Saos-2 cells was significantly reduced. Five µM was therefore selected for subsequent experiments. RNA sequencing revealed distinct gene expression profiles in NPS-2143–treated cells compared to controls. A total of 927 differentially expressed genes (DEGs) were identified in Saos-2 cells (378 upregulated, 549 downregulated), and 59 DEGs were identified in MG-63 cells (33 upregulated, 26 downregulated). Reactome and KEGG pathway enrichment analyses indicated significant enrichment of cholesterol and steroid biosynthesis–related pathways. Transcriptome sequencing showed that NPS-2143 modulated the expression of genes in cholesterol and steroid synthesis pathways. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) confirmed that NPS-2143 promoted the expression of the cholesterol and steroid synthesis pathway genes, CYP51A1, DHCR24, LSS, and MSMO1 in MG-63 and Saos-2 cells. Discussion The inhibitory effect of NPS-2143 on MG-63 and Saos-2 osteosarcoma tumor cell viability was confirmed. CaSR antagonism significantly up-regulated genes …
format: application/pdf
format: text/html
creator: Luchuan Wang
creator: Jianfa Wang
creator: Xinjie Chu
creator: Yao Liu
creator: Yanping Fan
creator: Xunzhong Qi
creator: Jin Guo
creator: Shuqiu Wang
subject: Bioinformatics
subject: Cell Biology
subject: Genomics
description: doi:10.7717/peerj.20546
publisher: PeerJ Inc.
rights: © 2026 Wang et al.
abstract: Background This study examined the effect of calcium-sensing receptor (CaSR) antagonism on human osteosarcoma cells and investigated the underlying molecular mechanisms of this effect through transcriptome sequencing. Methods Human osteosarcoma cell lines MG-63 and Saos-2 were treated with different concentrations (0.1–10 µM) of the CaSR antagonist NPS-2143. Cell Counting Kit-8 (CCK-8) assays were used to detect the effect of CaSR antagonism on the viability of the cells. RNA sequencing was performed on cells treated with five µM NPS-2143 for 24 hours, followed by bioinformatic analysis to identify differentially expressed genes and enriched pathways. qRT-PCR was conducted to validate key genes. Results CCK-8 assays showed that at low concentrations (0.1 and one µM), NPS-2143 had no significant effect on MG-63 and Saos-2 cell viability. At higher concentrations (five µM and 10 µM), the viability of MG-63 and Saos-2 cells was significantly reduced. Five µM was therefore selected for subsequent experiments. RNA sequencing revealed distinct gene expression profiles in NPS-2143–treated cells compared to controls. A total of 927 differentially expressed genes (DEGs) were identified in Saos-2 cells (378 upregulated, 549 downregulated), and 59 DEGs were identified in MG-63 cells (33 upregulated, 26 downregulated). Reactome and KEGG pathway enrichment analyses indicated significant enrichment of cholesterol and steroid biosynthesis–related pathways. Transcriptome sequencing showed that NPS-2143 modulated the expression of genes in cholesterol and steroid synthesis pathways. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) confirmed that NPS-2143 promoted the expression of the cholesterol and steroid synthesis pathway genes, CYP51A1, DHCR24, LSS, and MSMO1 in MG-63 and Saos-2 cells. Discussion The inhibitory effect of NPS-2143 on MG-63 and Saos-2 osteosarcoma tumor cell viability was confirmed. CaSR antagonism significantly up-regulated genes …
bibliographic citation: Wang et al. (2026) Cholesterol and steroid synthesis pathways may be involved in the inhibition of osteosarcoma cell viability by calcium-sensing receptor antagonism. PeerJ 14:e20546 https://doi.org/10.7717/peerj.20546
date submitted: 2025-04-04
date accepted: 2025-11-17
issued: 2026-01-05
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Wang
  given name: Luchuan
author list: Agent
  family name: Wang
  given name: Jianfa
author list: Agent
  family name: Chu
  given name: Xinjie
author list: Agent
  family name: Liu
  given name: Yao
author list: Agent
  family name: Fan
  given name: Yanping
author list: Agent
  family name: Qi
  given name: Xunzhong
author list: Agent
  family name: Guo
  given name: Jin
author list: Agent
  family name: Wang
  given name: Shuqiu
doi: 10.7717/peerj.20546
volume: 14
issn: 2167-8359
publication name: PeerJ
publication date: 2026-01-05
copyright: ©2026 Wang et al.
attribution name: Wang et al.

The impact of physical activity on social anxiety among college students: an analysis of the chain mediation effect of family support and self-efficacy
type: item
type: AcademicArticle
description: Background This study aimed to explore the mechanisms through which physical activity affects social anxiety in college students, with a specific focus on the sequential mediating roles of family support and self-efficacy. Methods A total of 391 valid responses were analyzed using the Physical Activity Rating Scale (PARS-3), the Interaction Anxiousness Scale (IAS). Family Support Scale (PSS-Fa), and the General Self-Efficacy Scale (GSES). Mediation analyses were conducted with structural equation modeling (SEM) and bootstrapping procedures (5,000 resamples). Results Physical activity significantly predicted lower social anxiety (β = − 0.187, p < .001). Both family support (β = − 0.309, p < .001) and self-efficacy (β = − 0.390, p < .001) mediated this association, with the sequential pathway (β = − 0.073, p < .001) accounting for 13.35% of the total effect. Conclusion Physical activity was associated with lower social anxiety indirectly via higher family support and self-efficacy, while the direct effect was not statistically significant in the full mediation model. These findings provide empirical support for incorporating physical activity into university-based mental health strategies aimed at alleviating social anxiety.
format: application/pdf
format: text/html
creator: Baiyi Yang
creator: Xiaodi Yang
creator: Zhengyang Fan
creator: Chang Liu
creator: Zhanfei Zheng
subject: Psychiatry and Psychology
subject: Mental Health
subject: Sports Medicine
description: doi:10.7717/peerj.20511
publisher: PeerJ Inc.
rights: © 2026 Yang et al.
abstract: Background This study aimed to explore the mechanisms through which physical activity affects social anxiety in college students, with a specific focus on the sequential mediating roles of family support and self-efficacy. Methods A total of 391 valid responses were analyzed using the Physical Activity Rating Scale (PARS-3), the Interaction Anxiousness Scale (IAS). Family Support Scale (PSS-Fa), and the General Self-Efficacy Scale (GSES). Mediation analyses were conducted with structural equation modeling (SEM) and bootstrapping procedures (5,000 resamples). Results Physical activity significantly predicted lower social anxiety (β = − 0.187, p < .001). Both family support (β = − 0.309, p < .001) and self-efficacy (β = − 0.390, p < .001) mediated this association, with the sequential pathway (β = − 0.073, p < .001) accounting for 13.35% of the total effect. Conclusion Physical activity was associated with lower social anxiety indirectly via higher family support and self-efficacy, while the direct effect was not statistically significant in the full mediation model. These findings provide empirical support for incorporating physical activity into university-based mental health strategies aimed at alleviating social anxiety.
bibliographic citation: Yang et al. (2026) The impact of physical activity on social anxiety among college students: an analysis of the chain mediation effect of family support and self-efficacy. PeerJ 14:e20511 https://doi.org/10.7717/peerj.20511
date submitted: 2025-07-18
date accepted: 2025-11-11
issued: 2026-01-05
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Yang
  given name: Baiyi
author list: Agent
  family name: Yang
  given name: Xiaodi
author list: Agent
  family name: Fan
  given name: Zhengyang
author list: Agent
  family name: Liu
  given name: Chang
author list: Agent
  family name: Zheng
  given name: Zhanfei
doi: 10.7717/peerj.20511
volume: 14
issn: 2167-8359
publication name: PeerJ
publication date: 2026-01-05
copyright: ©2026 Yang et al.
attribution name: Yang et al.

Development and validation of a risk prediction model for overall survival in cervical cancer patients under 50: a prospective cohort study in southwest China
type: item
type: AcademicArticle
description: Objective Accurately predicting the prognosis of cervical cancer in younger patients is increasingly important due to the rising incidence of the disease in China and the growing number of cases among individuals under 50. This study aimed to develop a nomogram to predict overall survival (OS) in cervical cancer patients under 50 in southwest China. Methods Clinicopathological and follow-up data for cervical cancer patients under 50 were prospectively collected as part of an ongoing longitudinal cohort study at Chongqing University Cancer Hospital between January 1, 2015, and May 31, 2019. A training cohort (n = 703) and a validation cohort (n = 301) were randomly selected. Variables associated with OS were assessed using a Cox regression model. Multivariate analysis was used to construct the nomogram and identify independent prognostic factors. The model’s performance was evaluated using decision curve analysis (DCA), calibration curves, area under the receiver operating characteristic curve (AUC-ROC), and the concordance index. Results The final model identified pathology, International Federation of Gynecology and Obstetrics (FIGO) staging, treatment, β2-microglobulin, neutrophil-lymphocyte ratio (NLR), and albumin as independent risk factors for OS in patients under 50. The concordance index for OS was 0.818 in the training cohort and 0.747 in the validation cohort. Calibration curves in both cohorts showed strong agreement between predicted and observed survival probabilities. In the training cohort, AUCs for 1-, 3-, and 5-year OS were 0.851, 0.847, and 0.816, respectively; in the validation cohort, they were 0.810, 0.733, and 0.730. Compared to the FIGO staging system, the nomogram demonstrated superior predictive accuracy and net benefit, as shown by the net reclassification index (NRI) and DCA. Conclusion The nomogram provides a reliable tool for predicting overall survival in cervical cancer patients under 50, supporting more personalized treatment planning…
format: application/pdf
format: text/html
creator: Li Yuan
creator: Baogang Wen
creator: Xiuying Li
creator: Fangrong Liu
creator: Haike Lei
creator: Qi Zhou
subject: Epidemiology
subject: Gynecology and Obstetrics
subject: Oncology
subject: Public Health
subject: Women’s Health
description: doi:10.7717/peerj.20509
publisher: PeerJ Inc.
rights: © 2026 Yuan et al.
abstract: Objective Accurately predicting the prognosis of cervical cancer in younger patients is increasingly important due to the rising incidence of the disease in China and the growing number of cases among individuals under 50. This study aimed to develop a nomogram to predict overall survival (OS) in cervical cancer patients under 50 in southwest China. Methods Clinicopathological and follow-up data for cervical cancer patients under 50 were prospectively collected as part of an ongoing longitudinal cohort study at Chongqing University Cancer Hospital between January 1, 2015, and May 31, 2019. A training cohort (n = 703) and a validation cohort (n = 301) were randomly selected. Variables associated with OS were assessed using a Cox regression model. Multivariate analysis was used to construct the nomogram and identify independent prognostic factors. The model’s performance was evaluated using decision curve analysis (DCA), calibration curves, area under the receiver operating characteristic curve (AUC-ROC), and the concordance index. Results The final model identified pathology, International Federation of Gynecology and Obstetrics (FIGO) staging, treatment, β2-microglobulin, neutrophil-lymphocyte ratio (NLR), and albumin as independent risk factors for OS in patients under 50. The concordance index for OS was 0.818 in the training cohort and 0.747 in the validation cohort. Calibration curves in both cohorts showed strong agreement between predicted and observed survival probabilities. In the training cohort, AUCs for 1-, 3-, and 5-year OS were 0.851, 0.847, and 0.816, respectively; in the validation cohort, they were 0.810, 0.733, and 0.730. Compared to the FIGO staging system, the nomogram demonstrated superior predictive accuracy and net benefit, as shown by the net reclassification index (NRI) and DCA. Conclusion The nomogram provides a reliable tool for predicting overall survival in cervical cancer patients under 50, supporting more personalized treatment planning…
bibliographic citation: Yuan et al. (2026) Development and validation of a risk prediction model for overall survival in cervical cancer patients under 50: a prospective cohort study in southwest China. PeerJ 14:e20509 https://doi.org/10.7717/peerj.20509
date submitted: 2025-01-13
date accepted: 2025-11-10
issued: 2026-01-05
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Yuan
  given name: Li
author list: Agent
  family name: Wen
  given name: Baogang
author list: Agent
  family name: Li
  given name: Xiuying
author list: Agent
  family name: Liu
  given name: Fangrong
author list: Agent
  family name: Lei
  given name: Haike
author list: Agent
  family name: Zhou
  given name: Qi
doi: 10.7717/peerj.20509
volume: 14
issn: 2167-8359
publication name: PeerJ
publication date: 2026-01-05
copyright: ©2026 Yuan et al.
attribution name: Yuan et al.

Improving taxonomic resolution, biomass and abundance assessments of aquatic invertebrates by combining imaging and DNA megabarcoding
type: item
type: AcademicArticle
description: Understanding biodiversity change requires a comprehensive assessment of not only the identity of species inhabiting an ecosystem but also their biomass and abundance. However, assessing biodiversity on the species level with precise biomass information is a time-consuming process and thus rarely applied. While DNA-based approaches like DNA barcoding offer precise species identification, they lack information on specimen size and biomass. In contrast, high-throughput imaging techniques enable rapid measurements of a specimen’s size and morphological features but may have low taxonomic resolution. In this study, we combined DNA megabarcoding, i.e., high-throughput barcoding of single specimens, with semi-automated imaging and deep neural networks to produce accurate taxonomic identifications, abundance, and biomass estimations for insects. In a multiple stressor field experiment, we collected a dataset of 743 specimens from 14 species of the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT), which are routinely used as aquatic biological quality indicator taxa. Each specimen was imaged, weighed, and megabarcoded using the COI barcode gene. From the images captured using the semi-automated imaging device BIODISCOVER, we curated a final dataset of 146,439 images taken from two perpendicular cameras. We trained convolutional neural networks (CNNs) with these pictures for species identification and biomass estimation and evaluated their performance. In addition, we investigated whether models pre-trained for species identification perform better on the biomass estimation task, compared to models trained solely for biomass estimation, thus potentially reducing the need for extensive labelled data in future studies. Our findings demonstrate that combining DNA megabarcoding with automated imaging and deep neural networks enables fast, reliable, but also comprehensive assessment of species composition and biomass on the specimen level, contributing to the urgently need…
format: application/pdf
format: text/html
creator: Philipp M. Rehsen
creator: Mia S. Honka
creator: Mikko Impiö
creator: Iris Madge Pimentel
creator: Florian Leese
creator: Arne J. Beermann
subject: Biodiversity
subject: Molecular Biology
subject: Taxonomy
subject: Data Mining and Machine Learning
subject: Freshwater Biology
description: doi:10.7717/peerj.20501
publisher: PeerJ Inc.
rights: © 2026 Rehsen et al.
abstract: Understanding biodiversity change requires a comprehensive assessment of not only the identity of species inhabiting an ecosystem but also their biomass and abundance. However, assessing biodiversity on the species level with precise biomass information is a time-consuming process and thus rarely applied. While DNA-based approaches like DNA barcoding offer precise species identification, they lack information on specimen size and biomass. In contrast, high-throughput imaging techniques enable rapid measurements of a specimen’s size and morphological features but may have low taxonomic resolution. In this study, we combined DNA megabarcoding, i.e., high-throughput barcoding of single specimens, with semi-automated imaging and deep neural networks to produce accurate taxonomic identifications, abundance, and biomass estimations for insects. In a multiple stressor field experiment, we collected a dataset of 743 specimens from 14 species of the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT), which are routinely used as aquatic biological quality indicator taxa. Each specimen was imaged, weighed, and megabarcoded using the COI barcode gene. From the images captured using the semi-automated imaging device BIODISCOVER, we curated a final dataset of 146,439 images taken from two perpendicular cameras. We trained convolutional neural networks (CNNs) with these pictures for species identification and biomass estimation and evaluated their performance. In addition, we investigated whether models pre-trained for species identification perform better on the biomass estimation task, compared to models trained solely for biomass estimation, thus potentially reducing the need for extensive labelled data in future studies. Our findings demonstrate that combining DNA megabarcoding with automated imaging and deep neural networks enables fast, reliable, but also comprehensive assessment of species composition and biomass on the specimen level, contributing to the urgently need…
bibliographic citation: Rehsen et al. (2026) Improving taxonomic resolution, biomass and abundance assessments of aquatic invertebrates by combining imaging and DNA megabarcoding. PeerJ 14:e20501 https://doi.org/10.7717/peerj.20501
date submitted: 2025-08-14
date accepted: 2025-11-10
issued: 2026-01-05
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Rehsen
  given name: Philipp M.
author list: Agent
  family name: Honka
  given name: Mia S.
author list: Agent
  family name: Impiö
  given name: Mikko
author list: Agent
  family name: Madge Pimentel
  given name: Iris
author list: Agent
  family name: Leese
  given name: Florian
author list: Agent
  family name: Beermann
  given name: Arne J.
doi: 10.7717/peerj.20501
volume: 14
issn: 2167-8359
publication name: PeerJ
publication date: 2026-01-05
copyright: ©2026 Rehsen et al.
attribution name: Rehsen et al.

The petrosal and bony labyrinth of extinct horses (Perissodactyla, Equidae) and their implications for perissodactyl evolution
type: item
type: AcademicArticle
description: Perissodactyla, or odd-toed ungulates, are represented today by 16 species of rhinoceroses, tapirs, and horses. Perissodactyls were much more diverse in the past, having a rich fossil record spanning from the earliest Eocene (~56 Ma) to recent, including a myriad of extinct lineages. Despite over a century of study, the inter-relationships of some extinct perissodactyl families remain poorly resolved. New morphological characters are needed to help solve this issue. Recent studies suggest that the ear region, i.e., the petrosal and the bony labyrinth of the inner ear, is a valuable source of morphological characters for mammalian phylogenetic analyses. The petrosal is the bony structure protecting the inner ear, the organs of hearing and balance in mammals. However, perissodactyl petrosals are poorly documented and have not been used in such a phylogenetic framework. In this study, we describe the petrosals and inner ears of five European fossil equid taxa and perform a preliminary phylogenetic analysis. Despite its small sample size, our phylogenetic analysis recovers important groupings, which suggests the petrosal is phylogenetically informative in equids. This study supports the relevance of the ear region for phylogenetic inference and its potential to better resolve long-contentious relationships within Perissodactyla.
format: application/pdf
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creator: Owen Axel Goodchild
creator: Sydney Nicole Rosen
creator: Bastien Mennecart
creator: Jin Meng
creator: Jérémy Tissier
subject: Evolutionary Studies
subject: Paleontology
subject: Zoology
description: doi:10.7717/peerj.20484
publisher: PeerJ Inc.
rights: © 2026 Goodchild et al.
abstract: Perissodactyla, or odd-toed ungulates, are represented today by 16 species of rhinoceroses, tapirs, and horses. Perissodactyls were much more diverse in the past, having a rich fossil record spanning from the earliest Eocene (~56 Ma) to recent, including a myriad of extinct lineages. Despite over a century of study, the inter-relationships of some extinct perissodactyl families remain poorly resolved. New morphological characters are needed to help solve this issue. Recent studies suggest that the ear region, i.e., the petrosal and the bony labyrinth of the inner ear, is a valuable source of morphological characters for mammalian phylogenetic analyses. The petrosal is the bony structure protecting the inner ear, the organs of hearing and balance in mammals. However, perissodactyl petrosals are poorly documented and have not been used in such a phylogenetic framework. In this study, we describe the petrosals and inner ears of five European fossil equid taxa and perform a preliminary phylogenetic analysis. Despite its small sample size, our phylogenetic analysis recovers important groupings, which suggests the petrosal is phylogenetically informative in equids. This study supports the relevance of the ear region for phylogenetic inference and its potential to better resolve long-contentious relationships within Perissodactyla.
bibliographic citation: Goodchild et al. (2026) The petrosal and bony labyrinth of extinct horses (Perissodactyla, Equidae) and their implications for perissodactyl evolution. PeerJ 14:e20484 https://doi.org/10.7717/peerj.20484
date submitted: 2025-04-28
date accepted: 2025-11-06
issued: 2026-01-05
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Goodchild
  given name: Owen Axel
author list: Agent
  family name: Rosen
  given name: Sydney Nicole
author list: Agent
  family name: Mennecart
  given name: Bastien
author list: Agent
  family name: Meng
  given name: Jin
author list: Agent
  family name: Tissier
  given name: Jérémy
doi: 10.7717/peerj.20484
volume: 14
issn: 2167-8359
publication name: PeerJ
publication date: 2026-01-05
copyright: © 2026 Goodchild et al.
attribution name: Goodchild et al.

Feeding ecology of scolopendromorphs: integrating a global literature review with Japanese citizen-sourced data
type: item
type: AcademicArticle
description: Knowledge of food habits is essential for ecological research, yet those are often assessed based on general assumptions rather than evidence, especially in secretive animals that are difficult to observe in the wild, such as centipedes. This leads to underestimation and mischaracterisation of their ecological roles. To address this problem, the present study evaluates the trophic interactions of scolopendromorphs by a dual approach, which integrates a global literature review with analysis of Japanese citizen-sourced data to examine the diets of scolopendromorphs. A total of 76 publications were systematically reviewed, and 102 reported predation events were analysed to assess publication trends and predator–prey size ratios. Concurrently, 8,684 entries from social media and citizen science platforms were mined, yielding 1,130 predation records that were used to construct a detailed prey inventory for Japanese scolopendromorphs. The literature review revealed that scolopendromorphs consume small prey when targeting mammals and amphibians but are capable of preying on large reptiles comparable to themselves, at least regarding body length. Despite the increase in recent publications, it is highly probable that available reports are biased towards vertebrate prey. In contrast, although the citizen-sourced data lacked quantitative metrics such as body size, they encompassed a much broader array of trophic interactions, including the consumption of animals, both alive and dead, and plant material, many of which are not covered in the literature. The citizen-sourced data revealed ecologically notable interactions including cross predation, foraging on spider webs, and ingestion of venomous animals. Collectively, these findings highlight the remarkably broad foraging versatility of scolopendromorphs and ascertain a potential risk of drawing ecological inferences from unverified assumptions or a biased subset of evidence. By integrating a traditional literature review wit…
format: application/pdf
format: text/html
creator: Ryosuke Uno
subject: Animal Behavior
subject: Ecology
subject: Entomology
subject: Zoology
subject: Data Science
description: doi:10.7717/peerj.20482
publisher: PeerJ Inc.
rights: © 2026 Uno
abstract: Knowledge of food habits is essential for ecological research, yet those are often assessed based on general assumptions rather than evidence, especially in secretive animals that are difficult to observe in the wild, such as centipedes. This leads to underestimation and mischaracterisation of their ecological roles. To address this problem, the present study evaluates the trophic interactions of scolopendromorphs by a dual approach, which integrates a global literature review with analysis of Japanese citizen-sourced data to examine the diets of scolopendromorphs. A total of 76 publications were systematically reviewed, and 102 reported predation events were analysed to assess publication trends and predator–prey size ratios. Concurrently, 8,684 entries from social media and citizen science platforms were mined, yielding 1,130 predation records that were used to construct a detailed prey inventory for Japanese scolopendromorphs. The literature review revealed that scolopendromorphs consume small prey when targeting mammals and amphibians but are capable of preying on large reptiles comparable to themselves, at least regarding body length. Despite the increase in recent publications, it is highly probable that available reports are biased towards vertebrate prey. In contrast, although the citizen-sourced data lacked quantitative metrics such as body size, they encompassed a much broader array of trophic interactions, including the consumption of animals, both alive and dead, and plant material, many of which are not covered in the literature. The citizen-sourced data revealed ecologically notable interactions including cross predation, foraging on spider webs, and ingestion of venomous animals. Collectively, these findings highlight the remarkably broad foraging versatility of scolopendromorphs and ascertain a potential risk of drawing ecological inferences from unverified assumptions or a biased subset of evidence. By integrating a traditional literature review wit…
bibliographic citation: Uno (2026) Feeding ecology of scolopendromorphs: integrating a global literature review with Japanese citizen-sourced data. PeerJ 14:e20482 https://doi.org/10.7717/peerj.20482
date submitted: 2025-08-06
date accepted: 2025-11-06
issued: 2026-01-05
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Uno
  given name: Ryosuke
doi: 10.7717/peerj.20482
volume: 14
issn: 2167-8359
publication name: PeerJ
publication date: 2026-01-05
copyright: © 2026 Uno
attribution name: Uno

Bacterial diversity in the jelly of shark Ampullae of Lorenzini: a holobiont perspective
type: item
type: AcademicArticle
description: The Ampullae of Lorenzini (AoL) are specialized electrosensory organs found in sharks and other chondrichthyans. They allow the detection of electric fields, temperature changes, and salinity variations. These organs contain a jelly composed of mucopolysaccharides, proteins, and ions, whose microbiota had not been previously characterized. In this study, we investigated and described the presence of bacteria associated with the AoL jelly in seven shark species from the Mexican coast, including three species from the family Sphyrnidae and four from the family Carcharhinidae. Bacteria present in the AoL jelly were cultured on selective media and characterized through 16S rRNA gene sequencing and phylogenetic analysis. We identified bacterial species belonging to the families Staphylococcaceae, Micrococcaceae, Bacillaceae, Vibrionaceae, Aeromonadaceae, and Microbacteriaceae. Additionally, we performed whole-genome sequencing of a subset of these bacterial isolates using the Illumina platform to identify genes related to AoL colonization and potential biological functions. We propose that the bacteria found in the jelly may be regular inhabitants of the AoL, as it provides the nutrients necessary for their persistence. This study represents the first report of bacteria associated with the AoL jelly in sharks, offering new insights into the microbiota of these organs and their potential influence on electrosensory function.
format: application/pdf
format: text/html
creator: Nataly Bolaño-Martínez
creator: Benjamín Cristian Corona-Comunidad
creator: Oscar Uriel Mendoza-Vargas
creator: Luis E. Eguiarte
creator: Valeria Souza
subject: Aquaculture, Fisheries and Fish Science
subject: Ecology
subject: Ecosystem Science
subject: Marine Biology
subject: Microbiology
description: doi:10.7717/peerj.20461
publisher: PeerJ Inc.
rights: © 2026 Bolaño-Martínez et al.
abstract: The Ampullae of Lorenzini (AoL) are specialized electrosensory organs found in sharks and other chondrichthyans. They allow the detection of electric fields, temperature changes, and salinity variations. These organs contain a jelly composed of mucopolysaccharides, proteins, and ions, whose microbiota had not been previously characterized. In this study, we investigated and described the presence of bacteria associated with the AoL jelly in seven shark species from the Mexican coast, including three species from the family Sphyrnidae and four from the family Carcharhinidae. Bacteria present in the AoL jelly were cultured on selective media and characterized through 16S rRNA gene sequencing and phylogenetic analysis. We identified bacterial species belonging to the families Staphylococcaceae, Micrococcaceae, Bacillaceae, Vibrionaceae, Aeromonadaceae, and Microbacteriaceae. Additionally, we performed whole-genome sequencing of a subset of these bacterial isolates using the Illumina platform to identify genes related to AoL colonization and potential biological functions. We propose that the bacteria found in the jelly may be regular inhabitants of the AoL, as it provides the nutrients necessary for their persistence. This study represents the first report of bacteria associated with the AoL jelly in sharks, offering new insights into the microbiota of these organs and their potential influence on electrosensory function.
bibliographic citation: Bolaño-Martínez et al. (2026) Bacterial diversity in the jelly of shark Ampullae of Lorenzini: a holobiont perspective. PeerJ 14:e20461 https://doi.org/10.7717/peerj.20461
date submitted: 2024-07-15
date accepted: 2025-11-03
issued: 2026-01-05
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Bolaño-Martínez
  given name: Nataly
author list: Agent
  family name: Corona-Comunidad
  given name: Benjamín Cristian
author list: Agent
  family name: Mendoza-Vargas
  given name: Oscar Uriel
author list: Agent
  family name: Eguiarte
  given name: Luis E.
author list: Agent
  family name: Souza
  given name: Valeria
doi: 10.7717/peerj.20461
volume: 14
issn: 2167-8359
publication name: PeerJ
publication date: 2026-01-05
copyright: © 2026 Bolaño-Martínez et al.
attribution name: Bolaño-Martínez et al.

Evaluating portable EEG: a comparison between two wireless systems (EPOC Flex and LiveAmp) and the wired BrainAmp system
type: item
type: AcademicArticle
description: Background Recent advances in equipment miniaturization have led to low-cost, portable electroencephalography (EEG) systems that facilitate data collection in real-world settings and with larger samples. Although wireless EEG systems were originally developed for non-research applications, recent studies have provided valuable information to help researchers make informed choices, particularly about participant comfort, mobility during recordings, and data validity. This study aimed to assess the impact of portability by comparing the performance of portable consumer- and research-grade systems (EPOC Saline Flex, EM; LiveAmp, LA) with fixed research-grade systems (BrainAmp, BA). Method Continuous EEG was recorded with each system in healthy adults performing five benchmark tasks in fundamental and clinical cognitive neuroscience. Mental states (alpha power variations in open/closed eyes) and unconscious perception (steady-state visual evoked potential, SSVEP) were analyzed through time/frequency methods, while active (N200 and P300 components during active listening and N170 component during face recognition) and passive cognitive processes (Mismatch negativity, MMN component during passive listening) were examined using time/amplitude analyses (event-related potential, ERPs). Our analyses compared system efficiency at native and equalized sampling rates and examined 100%, 75%, and 50% of the datasets to determine the required trial number for satisfactory signal quality. Results Despite the smaller amount of signal retained for EM, all systems recorded the expected resting state alpha power decrease and SSVEP responses, with EM showing lower spectral effects ([EM < (LA≈BA)]). ERPs for active (N170, N200, P300) and passive (MMN) processes emerged across all systems, with EM and LA showing lower amplitudes only for N170 compared to BA. Furthermore, the dataset reduction resulted in a decreased N170 at P7 only for EM ([EM < LA < BA]). EM also exhibited shorter latenci…
format: application/pdf
format: text/html
creator: Justine Epinat-Duclos
creator: Antoine Rossignon
creator: Jérôme Prado
creator: Jean-Baptiste Van der Henst
creator: Yves Paulignan
creator: Maude Beaudoin-Gobert
creator: Françoise Lecaignard
creator: Nathalie Bedoin
subject: Neuroscience
subject: Psychiatry and Psychology
description: doi:10.7717/peerj.20416
publisher: PeerJ Inc.
rights: © 2026 Epinat-Duclos et al.
abstract: Background Recent advances in equipment miniaturization have led to low-cost, portable electroencephalography (EEG) systems that facilitate data collection in real-world settings and with larger samples. Although wireless EEG systems were originally developed for non-research applications, recent studies have provided valuable information to help researchers make informed choices, particularly about participant comfort, mobility during recordings, and data validity. This study aimed to assess the impact of portability by comparing the performance of portable consumer- and research-grade systems (EPOC Saline Flex, EM; LiveAmp, LA) with fixed research-grade systems (BrainAmp, BA). Method Continuous EEG was recorded with each system in healthy adults performing five benchmark tasks in fundamental and clinical cognitive neuroscience. Mental states (alpha power variations in open/closed eyes) and unconscious perception (steady-state visual evoked potential, SSVEP) were analyzed through time/frequency methods, while active (N200 and P300 components during active listening and N170 component during face recognition) and passive cognitive processes (Mismatch negativity, MMN component during passive listening) were examined using time/amplitude analyses (event-related potential, ERPs). Our analyses compared system efficiency at native and equalized sampling rates and examined 100%, 75%, and 50% of the datasets to determine the required trial number for satisfactory signal quality. Results Despite the smaller amount of signal retained for EM, all systems recorded the expected resting state alpha power decrease and SSVEP responses, with EM showing lower spectral effects ([EM < (LA≈BA)]). ERPs for active (N170, N200, P300) and passive (MMN) processes emerged across all systems, with EM and LA showing lower amplitudes only for N170 compared to BA. Furthermore, the dataset reduction resulted in a decreased N170 at P7 only for EM ([EM < LA < BA]). EM also exhibited shorter latenci…
bibliographic citation: Epinat-Duclos et al. (2026) Evaluating portable EEG: a comparison between two wireless systems (EPOC Flex and LiveAmp) and the wired BrainAmp system. PeerJ 14:e20416 https://doi.org/10.7717/peerj.20416
date submitted: 2024-12-10
date accepted: 2025-10-28
issued: 2026-01-05
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Epinat-Duclos
  given name: Justine
author list: Agent
  family name: Rossignon
  given name: Antoine
author list: Agent
  family name: Prado
  given name: Jérôme
author list: Agent
  family name: Van der Henst
  given name: Jean-Baptiste
author list: Agent
  family name: Paulignan
  given name: Yves
author list: Agent
  family name: Beaudoin-Gobert
  given name: Maude
author list: Agent
  family name: Lecaignard
  given name: Françoise
author list: Agent
  family name: Bedoin
  given name: Nathalie
doi: 10.7717/peerj.20416
volume: 14
issn: 2167-8359
publication name: PeerJ
publication date: 2026-01-05
copyright: © 2026 Epinat-Duclos et al.
attribution name: Epinat-Duclos et al.

PeerJ
type: Periodical
uri: PeerJ
issn: 2167-8359