title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=653 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Simulating physiological flexibility in the acute glucocorticoid response to stressors reveals limitations of current empirical approaches link: https://peerj.com/articles/14039 last-modified: 2022-09-16 description: Wild animals often experience unpredictable challenges that demand rapid and flexible responses. The glucocorticoid mediated stress response is one of the major systems that allows vertebrates to rapidly adjust their physiology and behavior. Given its role in responding to challenges, evolutionary physiologists have focused on the consequences of between-individual and, more recently, within-individual variation in the acute glucocorticoid response. However, empirical studies of physiological flexibility are severely limited by the logistical challenges of measuring the same animal multiple times. Data simulation is a powerful approach when empirical data are limited, but has not been adopted to date in studies of physiological flexibility. In this article, I develop a simulation that can generate realistic acute glucocorticoid response data with user specified characteristics. Simulated animals can be sampled continuously through an acute response and across as many separate responses as desired, while varying key parameters. Using the simulation, I develop several scenarios that address key questions in physiological flexibility. These scenarios demonstrate the conditions under which a single glucocorticoid trait can be accurately assessed with typical experimental designs, the consequences of covariation between different components of the acute stress response, and the way that context specific differences in variability of acute responses can influence the power to detect relationships between the strength of the acute stress response and fitness. I also describe how to use the simulation tools to aid in the design and evaluation of empirical studies of physiological flexibility. creator: Conor Taff uri: https://doi.org/10.7717/peerj.14039 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Taff title: Sophocarpine inhibits tumor progression by antagonizing the PI3K/AKT/mTOR signaling pathway in castration-resistant prostate cancer link: https://peerj.com/articles/14042 last-modified: 2022-09-16 description: ObjectiveThe objective of this study was to investigate the inhibitory effect of sophocarpine on the progression of castration-resistant prostate cancer (CRPC) and the underlying molecular mechanism.MethodsDU145 and PC3 cells (two CRPC cell lines), incubated with different concentrations of sophocarpine, were used. Cell Counting Kit-8 assay, real-time cellular analysis, and colony formation assay were conducted to evaluate the proliferation of CRPC cells. Cytometry flow analysis was performed to evaluate the apoptosis rate of CRPC cells. Wound healing and Transwell invasion assays were performed and the levels of the epithelial-mesenchymal transition (EMT)-related proteins were determined to analyze cell migration and invasion abilities. A xenografted tumor model of nude mice was used to examine the anti-cancer effect of sophocarpine on CRPC. Western blotting was performed to evaluate the activities of the PI3K/AKT/mTOR signaling pathway both in cells and tumor tissues.ResultsIn vitro tests showed that sophocarpine suppressed the proliferation of CRPC cells, reduced the migration and invasion abilities, and increased the apoptosis rate. In vivo, sophocarpine decreased the weight and volume of tumor tissues. Mechanically, sophocarpine exerted its anti-cancer effects by inactivating PI3K/AKT/mTOR signaling.ConclusionSophocarpine inhibited the progression of CRPC by downregulating the PI3K/AKT/mTOR signaling pathway and showed a potential to be an anti-cancer agent against CRPC. creator: Min Weng creator: Chenghao Shi creator: Hui Han creator: Hengyue Zhu creator: Yanyi Xiao creator: Hangcheng Guo creator: Zhixian Yu creator: Cunzao Wu uri: https://doi.org/10.7717/peerj.14042 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Weng et al. title: Bombardier beetles repel invasive bullfrogs link: https://peerj.com/articles/13805 last-modified: 2022-09-15 description: Invasive non-native predators negatively affect native species; however, some native species can survive the predation pressures of invasive species by using pre-existing antipredator strategies or evolving defenses against invasive predators. The American bullfrog Lithobates catesbeianus (Anura: Ranidae) has been intentionally introduced to many countries and regions, and has impacted native animals through direct predation. Bombardier beetles (Coleoptera: Carabidae: Brachininae: Brachinini) discharge chemicals at a temperature of approximately 100 °C from the tip of the abdomen when they are attacked by predators. This “bombing” can successfully repel predators. However, adults of a native bombardier beetle Pheropsophus (Stenaptinus) occipitalis jessoensis have been reportedly found in the gut contents of the introduced bullfrog L. catesbeianus in Japan. These records suggest that the invasive bullfrog L. catesbeianus attacks the native bombardier beetle P. occipitalis jessoensis under field conditions in Japan; however, the effectiveness of the bombing defense against invasive bullfrogs is unclear. To test the effectiveness of the bombing defense against bullfrogs, we investigated the behavioral responses of L. catesbeianus juveniles to P. occipitalis jessoensis adults under laboratory conditions. Contrary to previous gut content results, almost all the bullfrogs (96.3%) rejected bombardier beetles before swallowing them; 88.9% rejected the beetles after being bombed, and 7.4% stopped attacking the beetles before being bombed. Only 3.7% successfully swallowed and digested the beetle. All of the beetles collected from non-bullfrog-invaded sites could deter bullfrogs, suggesting that the pre-existing defenses of bombardier beetles played an essential role in repelling bullfrogs. When treated beetles that were unable to discharge hot chemicals were provided, 77.8% of bullfrogs successfully swallowed and digested the treated beetles. These results indicate that bombing is important for the successful defense of P. occipitalis jessoensis against invasive bullfrogs. Although invasive bullfrogs have reportedly impacted native insect species, P. occipitalis jessoensis has an existing defense mechanism strong enough to repel the invasive predators. creator: Shinji Sugiura creator: Tomoki Date uri: https://doi.org/10.7717/peerj.13805 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Sugiura and Date title: The backbone symptoms of depression: a network analysis after the initial wave of the COVID-19 pandemic in Macao link: https://peerj.com/articles/13840 last-modified: 2022-09-15 description: BackgroundThe coronavirus disease 2019 (COVID-19) pandemic disrupted the working lives of Macau residents, possibly leading to mental health issues such as depression. The pandemic served as the context for this investigation of the network structure of depressive symptoms in a community sample. This study aimed to identify the backbone symptoms of depression and to propose an intervention target.MethodsThis study recruited a convenience sample of 975 Macao residents between 20th August and 9th November 2020. In an electronic survey, depressive symptoms were assessed with the Patient Health Questionnaire-9 (PHQ-9). Symptom relationships and centrality indices were identified using directed and undirected network estimation methods. The undirected network was constructed using the extended Bayesian information criterion (EBIC) model, and the directed network was constructed using the Triangulated Maximally Filtered Graph (TMFG) method. The stability of the centrality indices was evaluated by a case-dropping bootstrap procedure. Wilcoxon signed rank tests of the centrality indices were used to assess whether the network structure was invariant between age and gender groups.ResultsLoss of energy, psychomotor problems, and guilt feelings were the symptoms with the highest centrality indices, indicating that these three symptoms were backbone symptoms of depression. The directed graph showed that loss of energy had the highest number of outward projections to other symptoms. The network structure remained stable after randomly dropping 50% of the study sample, and the network structure was invariant by age and gender groups.ConclusionLoss of energy, psychomotor problems and guilt feelings constituted the three backbone symptoms during the pandemic. Based on centrality and relative influence, loss of energy could be targeted by increasing opportunities for physical activity. creator: Yan-Jie Zhao creator: Wei Bai creator: Hong Cai creator: Sha Sha creator: Qinge Zhang creator: Si Man Lei creator: Ka-In Lok creator: Ines Hang Iao Chow creator: Teris Cheung creator: Zhaohui Su creator: Lloyd Balbuena creator: Yu-Tao Xiang uri: https://doi.org/10.7717/peerj.13840 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Zhao et al. title: On the move: spatial ecology and habitat use of red fox in the Trans-Himalayan cold desert link: https://peerj.com/articles/13967 last-modified: 2022-09-15 description: Red fox (Vulpes vulpes) is the most widespread wild carnivore globally, occupying diverse habitats. The species is known for its adaptability to survive in dynamic anthropogenic landscapes. Despite being one of the most extensively studied carnivores, there is a dearth of information on red fox from the Trans-Himalayan region. We studied the home range sizes of red fox using the different estimation methods: minimum convex polygon (MCP), kernel density estimator (KDE), local convex hull (LoCoH) and Brownian-bridge movement model (BBMM). We analysed the daily movement and assessed the habitat selection with respect to topographic factors (ruggedness, elevation and slope), environmental factor (distance to water) and anthropogenic factors (distance to road and human settlements). We captured and GPS-collared six red fox individuals (three males and three females) from Chiktan and one female from Hemis National Park, Ladakh, India. The collars were programmed to record GPS fixes every 15-min. The average BBMM home range estimate (95% contour) was 22.40 ± 12.12 SD km2 (range 3.81–32.93 km2) and the average core area (50% contour) was 1.87 ± 0.86 SD km2 (range 0.55–2.69 km2). The estimated average daily movement of red fox was 17.76 ± 8.45 SD km/d (range 10.91–34.22 km/d). Red fox significantly selected lower elevations with less rugged terrain and were positively associated with water. This is the first study in the Trans-Himalayan landscape which aims to understand the daily movement of red fox at a fine temporal scale. Studying the movement and home range sizes helps understand the daily energetics and nutritional requirements of red fox. Movement information of a species is important for the prioritisation of areas for conservation and can aid in understanding ecosystem functioning and landscape management. creator: Hussain S. Reshamwala creator: Pankaj Raina creator: Zehidul Hussain creator: Shaheer Khan creator: Rodolfo Dirzo creator: Bilal Habib uri: https://doi.org/10.7717/peerj.13967 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Reshamwala et al. title: Transcriptomic analysis and physiological characteristics of exogenous naphthylacetic acid application to regulate the healing process of oriental melon grafted onto squash link: https://peerj.com/articles/13980 last-modified: 2022-09-15 description: The plant graft healing process is an intricate development influenced by numerous endogenous and environmental factors. This process involves the histological changes, physiological and biochemical reactions, signal transduction, and hormone exchanges in the grafting junction. Studies have shown that applying exogenous plant growth regulators can effectively promote the graft healing process and improve the quality of grafted plantlets. However, the physiological and molecular mechanism of graft healing formation remains unclear. In our present study, transcriptome changes in the melon and cucurbita genomes were analyzed between control and NAA treatment, and we provided the first view of complex networks to regulate graft healing under exogenous NAA application. The results showed that the exogenous NAA application could accelerate the graft healing process of oriental melon scion grafted onto squash rootstock through histological observation, increase the SOD, POD, PAL, and PPO activities during graft union development and enhance the contents of IAA, GA3, and ZR except for the IL stage. The DEGs were identified in the plant hormone signal-transduction, phenylpropanoid biosynthesis, and phenylalanine metabolism through transcriptome analysis of CK vs. NAA at the IL, CA, and VB stage by KEGG pathway enrichment analysis. Moreover, the exogenous NAA application significantly promoted the expression of genes involved in the hormone signal-transduction pathway, ROS scavenging system, and vascular bundle formation. creator: Chuanqiang Xu creator: Fang Wu creator: Jieying Guo creator: Shuan Hou creator: Xiaofang Wu creator: Ying Xin uri: https://doi.org/10.7717/peerj.13980 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Xu et al. title: Interactions of semiconductor Cd-based quantum dots and Cd2+ with gut bacteria isolated from wild Salmo trutta fry link: https://peerj.com/articles/14025 last-modified: 2022-09-15 description: BackgroundWith the rapid development of nanotechnology, more and more nanoproducts are being released into the environment where they may both pose ecological risks and be toxic to living organisms. The ecotoxicological impact of quantum dots (QDs), a class of nanoparticles (NPs), on aquatic organisms is becoming an emerging issue, this due to their nano-specific properties, to the physico-chemical transformation in the environment and to the possible release of toxic metals from their structure such as Cd.MethodsIn this work, (i) spectroscopic measurements of commercially available Cd-based QDs (CdSe/ZnS-COOH) were made at various pH values (5.0 and 7.0) to study their interactions (at a concentration of 4 nm) with various strains of Gram-positive and Gram-negative gut bacteria after short-term exposure and (ii) the antibacterial efficacy of QDs and Cd2+ (at a concentration 0.09–3.56 mM) against gut bacteria isolated from wild freshwater Salmo trutta fry was studied at different temperatures (15 °C and 25 °C) and pH values (5.0 and 7.0) by applying a well-established disc diffusion assay.ResultsTwenty-six gut bacterial isolates from wild Salmo trutta fry were identified as Aeromonas spp., A. popoffii, A. salmonicida, A. sobria, Carnobacterium maltaromaticum, Buttiauxella sp., Listeria sp., Microbacterium sp., Shewanella putrefaciens and Serratia sp. Cd-based (CdSe/ZnS-COOH) QDs at a concentration of 4 nm were found to be stable in aqueous media (with pH 7.0) or starting to form aggregates (at pH 5.0), thus, apparently, did not release heavy metals (HMs) into the media over 48 h in conditions of light or dark and did not show antibacterial efficacy on the gut bacteria isolated from wild Salmo trutta fry after short-term (9 h and 48 h) incubations. Cd2+ was found to produce significant dose-dependent toxic effects on bacterial growth, and the size of the inhibition zones on some of the tested strains significantly correlated with temperature. The most sensitive and the most resistant to Cd2+ were the Gram-positive bacteria, for which the minimum inhibitory concentration (MIC) values of Cd2+ were 0.09–0.27 mM and 3.11–3.29 mM respectively and varied significantly between the tested temperatures (15 °C and 25 °C). The MIC values of Cd2+ for the Gram-negative bacteria (18 out of 22 strains) ranged from 0.44 to 0.71 mM and did not differ significantly between the tested temperatures. Among the selected Gram-positive and Gram-negative strains, those with the higher sensitivity towards Cd2+ also revealed relatively stronger signals of QDs photoluminescence (PL) when transferred after incubation into fresh medium without QDs. In addition, the formation of endogenous metalloporphyrins observed spectroscopically in some bacterial strains indicates certain differences in metabolic activity that may play a protective role against potential oxidative damage. creator: Renata Butrimienė creator: Agnė Kalnaitytė creator: Emilija Januškaitė creator: Saulius Bagdonas creator: Živilė Jurgelėnė creator: Dalius Butkauskas creator: Tomas Virbickas creator: Danguolė Montvydienė creator: Nijolė Kazlauskienė creator: Vesta Skrodenytė-Arbačiauskienė uri: https://doi.org/10.7717/peerj.14025 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Butrimienė et al. title: CAV1 alleviated CaOx stones formation via suppressing autophagy-dependent ferroptosis link: https://peerj.com/articles/14033 last-modified: 2022-09-15 description: BackgroundCalcium oxalate (CaOx) is the most common type of kidney stone, but the mechanism of CaOx stones formation remains unclear. The injury of renal cells such as ferroptosis and autophagy has been considered a basis for stones formation.MethodsWe conducted transmission electron microscope (TEM), reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), and C11-BODIPY analysis to explore whether CaOx could induce autophagy-dependent ferroptosis in vivo and in vitro. To explore the possible mechanism, we conducted bioinformatic analysis of patients with or without CaOx stones, Western blot and qPCR were used to identify the different genes we found in bioinformatic analysis.ResultsIn our study, we found that CaOx could induce autophagy-dependent ferroptosis no matter in vivo or in vitro, which might finally lead to urolithiasis. Bioinformatic analysis of the GSE73680 dataset indicated that the expression of caveolin-1 (CAV1) was higher in control patients than CaOx stone patients, the STRING database indicated that CAV1 might interact with low density lipoprotein receptro-related protein 6 (LRP6), Gene Set Enrichment Analysis (GSEA) showed that the WNT pathway positively associated with the control group while negatively related to the stone group, and LRP6 was the core gene of the WNT pathway. Western blot found that CAV1, LRP6, and Wnt/β-Catenin were decreased in Human Kidney2 (HK2) cells stimulated with CaOx. Furthermore, the WNT pathway was considered to be involved in autophagy and ferroptosis.ConclusionsWe presumed that CAV1 could ameliorate autophagy-dependent ferroptosis through the LRP6/Wnt/β-Catenin axis, and finally alleviate CaOx stone formation. creator: Yuanyuan Yang creator: Senyuan Hong creator: Yuchao Lu creator: Qing Wang creator: Shaogang Wang creator: Yang Xun uri: https://doi.org/10.7717/peerj.14033 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Yang et al. title: Analysis of road traffic injuries and casualties in China: a ten-year nationwide longitudinal study link: https://peerj.com/articles/14046 last-modified: 2022-09-15 description: BackgroundRoad traffic injuries (RTIs) are a serious global problem, and a huge challenge for both economic development and public health.MethodsThis longitudinal study was based on the national data from Chinese authorities. Descriptive analysis was utilized to analyze the prevalence and trend of RTIs among different types, groups and regions. In addition, ridge regression or/and curve regression were also used to explore the relationship between those possible influencing factors and RTIs.ResultsFrom 2010 to 2019, the death toll from motor vehicle accidents (MVAs) decreased firstly and then increased, while the death toll from non-MVAs continued to rise since 2012, and the death toll from pedestrian and occupant accidents fluctuated only a little. The mortality rate of MVA was relatively stable from 2010 to 2012, and declined from 2013. The mortality rate of motor vehicle accidents was higher in rural than urban, the same to male compared with female. The results of ridge regression showed that gross domestic product (GDP)-per-capita, total population, number of health personnel and car ownership were positively correlated with the death toll of non-MVAs (P < 0.05). Additionally, the results of curve regression suggested that the quadratic or cubic relationship between each factor and the number of MVAs was well fitted, while only partially fitted in fatalities.ConclusionsIn recent years, RTIs in China show different trends, and the problem of non-motor vehicle traffic injuries has been neglected which should be paid more attention. Moreover, according to the new trends and traffic conditions in RTIs revealed in this study, it is necessary to formulate targeted intervention measures establish a multi-faceted comprehensive safety system to reduce the disease burden of RTIs as well as the total injuries. creator: Miao Qi creator: Xiuli Hu creator: Xiahong Li creator: Xue Wang creator: Xiuquan Shi uri: https://doi.org/10.7717/peerj.14046 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Qi et al. title: Correlation and agreement of regional cerebral oxygen saturation measured from sensor sites at frontal and temporal areas in adult patients undergoing cardiovascular anesthesia link: https://peerj.com/articles/14058 last-modified: 2022-09-15 description: BackgroundThe function and viability of the brain depend on adequate oxygen supply. A decrease in cerebral blood supply causing cerebral desaturation may lead to many neurological complications. Direct measurement of regional cerebral oxygen saturation (rScO2) assists in early detection and management. Near-infrared spectroscopy (NIRS) has been introduced for measuring rScO2. A pair of sensors are attached to the right and left forehead. However, there are some situations where the forehead of the patient is not accessible for sensor attachment (e.g., neurosurgery involving the frontal area; a bispectral index (BIS) sensor already attached, or a wound to the forehead); therefore, alternate sites for sensor attachment are required. The temporal area was proposed as an alternate site. The objective of this study was to assess the correlation and agreement of rScO2 measured at the forehead vs. the temporal area.MethodsAdult patients undergoing cardiothoracic or vascular surgery were monitored for rScO2 using two pairs of ForeSight sensors. The first pair (A1 and A2) were attached to the right and left forehead, while the second pair (B1 and B2) were attached to the right and left temporal area. The rScO2 values measured from A1 vs. B1 and A2 vs. B2 were assessed for correlation and agreement using the Bland-Altman analysis.ResultsData from 19 patients with 14,364 sets of data were analyzed. The data from A1 vs. B1 and A2 vs. B2 showed moderate positive correlation (r = 0.627; P < 0.0001 and r = 0.548; P < 0.0001). The biases of A1 vs. B1 and A2 vs. B2 were −2.3% (95% CI [−2.5 to −2.2]; P < 0.0001) and 0.7% (95% CI [0.6–0.8]; P < 0.0001). The lower and upper limits of agreement of A1 vs. B1 were −17.5% (95% CI [−17.7 to −17.3]) and 12.8% (95% CI [12.6–13.0]). The lower and upper limits of agreement of A2 vs. B2 were −14.6% (95% CI [−14.8 to −14.4]) and 16.0% (95% [CI 15.8–16.3]).ConclusionsThe rScO2 values measured from sensors at the frontal and temporal areas show a moderate correlation with sufficiently good agreement. The temporal area may be an alternative to the frontal area for cerebral oximetry monitoring. creator: Sirirat Tribuddharat creator: Kriangsak Ngamsaengsirisup creator: Phatcharakamon Mahothorn creator: Thepakorn Sathitkarnmanee uri: https://doi.org/10.7717/peerj.14058 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Tribuddharat et al.