title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=116 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Propofol-based deep sedation for colonoscopy: does sufentanil, alfentanil or ketamine help? A propensity score weighted retrospective study link: https://peerj.com/articles/19146 last-modified: 2025-03-10 description: IntroductionGastrointestinal endoscopy is a frequent procedure for diagnosing and following up on various digestive disorders. It is often conducted under propofol sedation. The aim of this work is, first, to determine whether the addition of sufentanil, alfentanil, or ketamine to propofol has a propofol-sparing effect and, secondarily, how these drugs affect the patients’ hemodynamic parameters and oxygenation as well as the duration of the procedure.MethodsData from patients who underwent colonoscopy were extracted from the anesthesia records database and divided into four groups. Patients received either propofol or a combination of propofol and sufentanil, alfentanil, or ketamine. After inverse propensity weighting, we determined the average treatment effects for each group for the primary and secondary endpoints.ResultsSufentanil was associated with a less than 10% decrease in propofol consumption. Alfentanil and ketamine showed no propofol-sparing effect. Sufentanil was associated with 2 min shorter procedures. Alfentanil was associated with more patients presenting hypoxemia and had no propofol-sparing effect.ConclusionShould a balanced sedation technique be chosen, sufentanil appears to be the adjuvant of choice, given its propofol-sparing effect and the absence of induced hypoxemia. A further prospective study is necessary to explain the lack of propofol-sparing effect of ketamine and alfentanil and confirm and explain the negative impact of alfentanil on patients’ oxygenation. creator: Michele Fostier creator: Quentin Delhez creator: Gintare Januleviciute creator: Laurent Bairy uri: https://doi.org/10.7717/peerj.19146 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2025 Fostier et al. title: The impact of long COVID on quality of life and work performance among healthcare workers in Portugal link: https://peerj.com/articles/19089 last-modified: 2025-03-10 description: BackgroundCoronavirus disease 2019 (COVID-19) is a multisystem infectious disease which affected 5.7 million people in Portugal. A subgroup of patients experienced long-term effects from the infection, now referred to as long COVID. Long COVID can considerably reduce the quality of life (QoL) of affected patients. This study aimed to evaluate the impact of long COVID on QoL and work performance among healthcare workers (HCWs) in Portugal.MethodsA cross-sectional correlational survey was performed in 348 HCWs employed either in hospitals, or non-hospital health facilities in Portugal. Participants completed an online survey using Google Forms between May and June 2024, which consisted of multiple-choice questions and took less than 10 min to fill out. Long COVID was considered present if the defined symptoms started at least 3 months after the primary infection of COVID-19, and persisted for at least 2 months. The outcome measures were performance at work and QoL. Performance at work was measured using a seven-point Likert scale and QoL was evaluated using the Satisfaction with Life Scale (SWLS). Data was analyzed using SPSS.ResultsA total of 277 participants (79.6%) had history of SARS-CoV-2 infection, and 223 participants (64.1%) reported a history of long COVID. Extreme fatigue was reported by 158 participants (57.0%), cognitive dysfunction by 118 participants (42.6%), shortness of breath by 76 participants (27.4%), and persistent cough by 168 participants (60.6%). In the multivariate analysis, long COVID was significantly associated with lower SWLS scores indicating that long COVID negatively impacted QoL. Having two or more chronic diseases showed a trend towards lower performance, and extreme fatigue and cognitive dysfunction showed strong negative associations with performance.DiscussionBased on a national sample of HCWs (348 individuals), a high percentage of participants (64.1%) reported a history of long COVID. These results suggest that HCWs in Portugal have a prevalence of the disease similar to that of the worldwide population. Concerning performance at work, having two or more chronic diseases showed a trend towards lower performance, as well as extreme fatigue and cognitive dysfunction. Interestingly, we found a negative association between being a clinical secretary and SWLS. This might be explained by the specific challenges or stressors faced by clinical secretaries, which could negatively impact their QoL. In conclusion, long COVID was prevalent in the studied sample of HCWs and had a negative impact on their QoL. Extreme fatigue and cognitive dysfunction were strongly negatively associated with performance. This suggests the need for targeted care for HCWs as a group. The results of this study can guide healthcare authorities in addressing important long-term consequences that should be considered in rehabilitation programs for post-COVID-19 recovery. creator: Filipe Prazeres creator: Ana Paula Romualdo creator: Inês Campos Pinto creator: Joana Silva creator: Andreia M. Oliveira uri: https://doi.org/10.7717/peerj.19089 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2025 Prazeres et al. title: Exploring the classical and numerical Delboeuf illusion: the impact of transcranial alternating current stimulation on magnitude processing link: https://peerj.com/articles/19064 last-modified: 2025-03-10 description: Understanding cognitive and neural mechanisms underlying quantity processing is crucial for unraveling human cognition. The existence of a single magnitude system, encompassing non-symbolic number estimation alongside other magnitudes like time and space, is still highly debated since clear evidence is limited. Recent research examined whether spatial biases also influence numerosity judgments, using visual illusions like the Delboeuf illusion. While findings support a generalized magnitude system, direct comparisons of spatial and numerical Delboeuf illusions are missing. This study explored whether perceptual biases similarly affect different magnitude processing and whether transcranial alternating current stimulation (tACS) modulates these processes. Participants underwent three tACS conditions (seven Hz, 18 Hz, placebo) while performing tasks involving the classic and numerical Delboeuf illusions. We hypothesized that theta-frequency tACS (seven Hz) would enhance visual integration and illusion strength, while beta tACS (18 Hz) would reduce it by promoting visual segregation. Results indicated higher discrimination accuracy in area-based tasks than numerical judgments. Nonetheless, a significant correlation between performances in spatial and numerical illusions supported the existence of a shared mechanism for magnitude processing. Contrary to expectations, seven Hz tACS reduced the perceptual illusion’s strength. No significant interaction emerged between tACS frequency and discrimination abilities. These findings deepen our understanding of the cognitive processes involved in magnitude perception, potentially supporting the hypothesis of a generalized magnitude system. They also highlight the potential and limitations of non-invasive brain stimulation techniques, such as tACS, in modulating perceptual processes, offering insights into the neural underpinnings of quantity perception. creator: Maria Santacà creator: Francesco Carabba creator: Achini Mihindukulasooriya Fernando creator: Enrico Pitocco creator: Luca Battaglini creator: Umberto Granziol uri: https://doi.org/10.7717/peerj.19064 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Santacà et al. title: Effectiveness of FIFA injury prevention programs in reducing ankle injuries among football players: a systematic review link: https://peerj.com/articles/18910 last-modified: 2025-03-10 description: BackgroundAnkle injuries are some of the most common injuries among footballers and can prevent players from participating in sport. The Fédération Internationale de Football Association (FIFA) developed FIFA injury prevention programs to reduce overall football injuries, but their effectiveness on a particular joint, such as the ankle, was not assessed. Therefore, this project aims to investigate if these FIFA injury prevention programs are particularly effective in reducing ankle injuries.MethodA systematic review was conducted with the following criteria for study selection: Randomized controlled trials (RTCs) comparing the FIFA programs (FIFA 11 the old version and FIFA 11+) with the usual training for the teams. Other studies that included the number or percentage of ankle injuries as an outcome. Sample: Male and female footballers aged between 13 and 40 years old and without any restriction on particular skill levels. The Physiotherapy Evidence Database scale (PEDro) was used to assess the methodological quality of the included studies.ResultsThe search strategy identified five RCTs that used the FIFA programs. The included studies had a good-to-excellent methodological quality according to the PEDro scale (ranging from 5 to 7 out of 10). The pooled data from all the included studies indicated that the FIFA 11 and FIFA 11+ programs were effective in reducing the ankle injury rate by 14%, while pooled results from the studies that used the FIFA 11+ program significantly reduced ankle injury rate by 32%. However, the FIFA 11 program was not effective in reducing the ankle injury rate.ConclusionThe FIFA programs, and especially the FIFA 11+ program, appear to be more effective than the usual training in preventing ankle injuries among footballers. creator: Mohammad Alhazmi creator: Emad Alhazmi creator: Wael Abdulghani Alghamdi creator: Mohammed Zalah creator: Shadab Uddin creator: Moattar Raza Rizvi creator: Fuzail Ahmad uri: https://doi.org/10.7717/peerj.18910 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Alhazmi et al. title: Mapping desert shrub aboveground biomass in the Junggar Basin, Xinjiang, China using quantile regression forest (QRF) link: https://peerj.com/articles/19099 last-modified: 2025-03-07 description: Haloxylon ammodendron is an essential species within the Central Asian desert ecosystem, with its aboveground biomass (AGB) serving as a crucial marker of ecosystem health and desertification levels. Precise and effective methods for predicting AGB are vital for understanding the spatial distributions and ecological roles of desert regions. However, the low vegetation cover in these areas poses significant challenges for satellite-based research. In this study, aboveground biomass training and validation datasets were gathered using UAV LiDAR, covering an area of 50 square kilometers. These datasets were integrated with high-resolution, multi-temporal satellite images from Sentinel-1 (S1) and Sentinel-2 (S2). This study applied a spatial cross-validation method to develop a quantile regression forest (QRF) prediction model. This model was used to predict the AGB of Haloxylon ammodendron forest across a study area of 14,000 square kilometers. The findings suggest that, when supported by ground data, multi-source remote sensing technology can estimate the AGB distribution of Haloxylon ammodendron over large areas. Significant uncertainty exists within the model due to the low vegetation cover characteristic of arid regions and the uneven distribution of sampling points. This uncertainty can be reduced by using area of applicability (AOA) and uncertainty maps, which identify the regions where the model’s predictions are most accurate and guide further data collection to enhance precision. This study provides improved insight into the spatial distribution and extent of Haloxylon ammodendron AGB in the research area and offers essential geospatial information for ecosystem conservation strategies. The results also contribute to the understanding of how desert vegetation growth and carbon cycling respond to environmental changes, and for forecasting future vegetation dynamics in arid regions. creator: XueFeng Yang uri: https://doi.org/10.7717/peerj.19099 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Yang title: Self-reported history of head injury is associated with cognitive impulsivity on a delay discounting task link: https://peerj.com/articles/19057 last-modified: 2025-03-07 description: BackgroundHead injuries are a major health care concern that can produce many long lasting cognitive, mental, and physical problems. An emerging literature indicates increased impulsivity in patients with a history of traumatic brain injury (TBI). In a recent study, Veterans with clinically-assessed history of mild TBI had increased cognitive, but not motor, impulsivity. Cognitive impulsivity refers to a preference for smaller immediate rewards (i.e., less willing to wait for larger rewards) while motor impulsivity refers to difficulty inhibiting a motor response. This study extended this work to investigating cognitive and motor impulsivity in a non-clinical sample of putatively healthy undergraduates self-reporting a history of head injury.MethodsOne hundred and sixteen undergraduates, fifty reporting a history of head injury (HI+) and sixty-six reporting no head injury (HI-), participated in an online study via Qualtrics. They completed a series of demographic questionnaires, the UPPS Impulsive Behavior Scale, a computer-based Go/No-go task to assess motor impulsivity, and a computer-based version of the Monetary Choice Questionnaire (MCQ) to assess cognitive impulsivity.ResultsHI+ individuals exhibited cognitive impulsivity, measured as a reduced willingness to wait for a larger delayed reward in the MCQ, as compared to HI- individuals. There were no significant differences in performance on the Go/No-go task between the HI+ and HI- groups. Overall, these findings that a self-reported history of head injury in a non-clinical sample are related to cognitive impulsivity, but not motor impulsivity, are consistent with findings from Veterans with clinically-assessed mild TBI. Future work should assess more details on head injuries to further explore how a head injury relates to cognitive impulsivity. creator: M. Todd Allen creator: Alejandro Interian creator: Vibha Reddy creator: Kailyn Rodriguez creator: Catherine E. Myers uri: https://doi.org/10.7717/peerj.19057 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Allen et al. title: Changes in tooth size of Otaria byronia: an indicator of density-dependent effects? link: https://peerj.com/articles/18963 last-modified: 2025-03-07 description: Teeth provide valuable information about an individual’s life cycle and serve as a powerful tool for visualizing population-level changes associated with density-dependent processes. In pinnipeds, teeth are used to estimate the age of individuals based on the count of growth layer groups (GLG) in the dentine. In this study, we analyzed changes in tooth size and GLG widths in the canines of Otaria byronia throughout the past 100 years, linking these to fluctuations in population abundance. A total of 76 male individuals from Patagonia were analyzed, classified into two periods: harvest and postharvest. The length and diameter of each tooth were measured prior to sagittal sectioning. Only for the postharvest period body length was recorded. Longitudinal sections of the upper canine were prepared, age was determined and the width of each GLG was measured in the resulting half-tooth. Results indicated a positive correlation (F = 62.90; p < 0.001; n = 50; r2 = 0.59) between body length and tooth length in postharvest individuals, suggesting that tooth growth is a reliable indicator of body growth. Individuals from the harvest period had narrower GLGs (t = 3.75; p < 0.001) and smaller tooth size (t = 3.48; p < 0.001) compared to those from the postharvest period. These results indicate that somatic growth of individuals may vary with population numbers and resources available. Also, hard structures like teeth are excellent tools for visualizing density-dependence effects. creator: Ailin Sosa Drouville creator: Federico Heredia creator: Mariano A. Coscarella creator: Enrique Crespo creator: María Florencia Grandi uri: https://doi.org/10.7717/peerj.18963 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2025 Sosa Drouville et al. title: Effects of 440-Hz vs. 432-Hz preferred music frequencies, during warm-up, on intermittent anaerobic speed test performance in men and women kickboxers: a double-blind crossover study link: https://peerj.com/articles/19084 last-modified: 2025-03-06 description: BackgroundPreferred music has been shown to enhance psychological and physiological parameters in order to increase physical performance in high intensity exercises. However, the effects of preferred music are less conclusive with different frequencies. The present study assessed the effects of listening to preferred music during warm-up at different frequencies on physical performance and psychophysiological responses specific in male and female kickboxers.MethodsIn a double-blind crossover study design, fifteen men and thirteen women kickboxers randomly performed the intermittent kickboxing anaerobic speed test (IKAST) after listening to preferred music around 440 Hz (PM44Hz), or 432 Hz (PM432Hz) frequencies or no music during warm-up. Physical performance indices, heart rate, blood lactate, rating of perceived exertion (RPE) and feeling scale (FS) were measured.ResultsWarm-up with PM440 Hz significantly improved IKAST performance indices with the highest impact velocity and FS, lowest mean heart rate and RPE, followed by PM432 Hz for both sexes compared to the control condition. For sex interaction, men had lower heart rate with PM440Hz, women the lowest with PM432Hz. In addition, women had higher positive feeling scale with PM440Hz, while men did not experience any significant change between the two musical conditions.ConclusionPM440Hz during warm-up was found to be more effective in improving specific performance, positive mood with a potential dissociation from discomfort during the test. Also, women were more affected by the music frequency difference compared to men. creator: Nidhal Jebabli creator: Manar Boujabli creator: Mariem Khlifi creator: Nejmeddine Ouerghi creator: Anissa Bouassida creator: Abderraouf Ben Abderrahman creator: Roland van den Tillaar uri: https://doi.org/10.7717/peerj.19084 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Jebabli et al. title: Factors associated with post-stroke fatigue among stroke survivors: a cross-sectional study link: https://peerj.com/articles/19052 last-modified: 2025-03-06 description: BackgroundPost-stroke fatigue (PSF) is a common complication experienced by stroke survivors. These individuals often confront psychological challenges such as depression and anxiety, along with significant obstacles like reduced quality of life (QoL) and limitations in activities of daily living (ADLs). Such challenges can profoundly affect their overall recovery and well-being. Despite its prevalence, the associated factors contributing to PSF remain poorly understood. This study aims to primarily investigate these associated factors, while also examining the interrelationships among PSF, depression level, QoL, and ADLs, highlighting the need for a better understanding of these complex interactions.MethodsThis cross-sectional study involved 271 stroke survivors and was conducted at the Department of Neurology, Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, China, from September 2023 to January 2024. Participants independently completed the Fatigue Severity Scale (FSS), Patient Health Questionnaire-9 (PHQ-9), and the Short Version of the Stroke-Specific Quality of Life Scale (SV-SS-QoL) as part of a convenience sampling method, while medical professionals assessed the Barthel Index (BI) using the same sampling framework. Multivariable linear regression analyses were employed to determine the factors associated with the persistence of PSF.ResultsThe mean FSS score was 35.04 ± 11.60, while the average score for the SV-SS-QoL was 34.28 ± 9.51, and the BI score averaged 77.79 ± 25.90. Approximately 45.8% of participants (n = 124) experienced PSF. The mean score on the PHQ-9 was 7.63 ± 6.13. A significant negative correlation was identified between fatigue and both QoL and ADLs (P < 0.01). Furthermore, multiple linear regression analyses revealed that age, gender, income level, depression level, QoL, and ADLs were associated factors of fatigue severity among stroke survivors, all showing statistically significant differences (P < 0.01).ConclusionThis study emphasizes the critical factors associated with PSF and highlights the necessity of developing targeted interventions, such as depression management, QoL enhancement, and ADLs restoration, to alleviate fatigue in stroke survivors. Future research should focus on evaluating the effectiveness of these interventions to optimize rehabilitation outcomes and improve survivors’ overall recovery and well-being. creator: Yuan Dong creator: Linxi Tang creator: Salwismawati Badrin creator: Salziyan Badrin creator: Jiarun Wu uri: https://doi.org/10.7717/peerj.19052 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2025 Dong et al. title: Investigating passive eDNA samplers and submergence times for marine surveillance link: https://peerj.com/articles/19043 last-modified: 2025-03-06 description: Passive environmental DNA (eDNA) samplers offer a cost-effective and scalable approach to marine biodiversity monitoring, potentially aiding detections of non-indigenous species. This study explored the efficiency of passive eDNA samplers to detect a variety of globally problematic marine invasive species in field conditions: Sabella spallanzanii, Styela clava, Bugula neritina and Undaria pinnatifida. Four passive sampler substrates, nylon filters, positively charged nylon discs, nylon mesh, and artificial sponges, were tested across six submergence times, ranging from 10 to 720 min, against standard filtration-based approaches. Our results demonstrated that passive samplers could achieve comparable or even higher eDNA yields than traditional active filtration methods, indicating their potential for biosecurity surveillance. Species-specific droplet-digital PCR (ddPCR) assays provided sensitive and quantifiable eDNA signals, though assay validation remains crucial to avoid false negatives. Significant variation in eDNA signal detection highlighted the importance of considering both material selection and submersion time, depending on the targeted organisms. Furthermore, 18S rRNA metabarcoding was undertaken to assess how the overall detected biodiversity might interfere with species-specific detections. Certain sessile organisms, such as ascidians and polychaetes, dominated early representation on the passive filters but did not interfere with species-specific detection. By optimizing material selection, submersion time, and assay validation, passive eDNA sampling can enhance the sensitivity and reliability of eDNA-based monitoring, contributing to improved marine biosecurity and conservation efforts. creator: Ulla von Ammon creator: Gert-Jan Jeunen creator: Olivier Laroche creator: Xavier Pochon creator: Neil J. Gemmell creator: Jo-Ann L. Stanton creator: Anastasija Zaiko uri: https://doi.org/10.7717/peerj.19043 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2025 von Ammon et al.