title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=607 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Symbiotic association of microalgae and plants in a deep water culture system link: https://peerj.com/articles/14536 last-modified: 2022-12-07 description: In this study, microalgae culture (Chlorella vulgaris) and mint seedlings (Mentha spp.) were combined in a hydroponic system to improve plant growth. Mint seedlings were grown both in microalgae-containing and in microalgae-free trial groups, and both groups were subjected to aerated and non-aerated conditions to show the effect of aeration and microalgae co-cultivation on the mint weight and height. The plant quality was also determined with color measurements of the mint leaves. The increase in the weight of the plants was the highest in microalgae-containing and aerated group (0.47 g) and the lowest in microalgae-free and non-aerated group (0.22 g). On the other hand, the variation in the plant height was not significant between the groups, the growth was lateral. The best quality mint leaves were also produced in microalgae-containing and aerated group. Our results have revealed the symbiotic life of the mint plant placed in the hydroponic system with microalgae and demonstrated improved mint growth and quality. This co-cultivation system is also potentially more environmentally friendly compared to growing microalgae and mint independently because of lower cost of aeration and mixing for microalgae cultivation, higher nutrient consumption efficiency, and reduced nutrient outflow. creator: Gülsüm Ebru Özer Uyar creator: Nurdan Mısmıl uri: https://doi.org/10.7717/peerj.14536 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Özer Uyar and Mısmıl title: N-mixture model-based estimate of relative abundance of sloth bear (Melursus ursinus) in response to biotic and abiotic factors in a human-dominated landscape of central India link: https://peerj.com/articles/13649 last-modified: 2022-12-06 description: Reliable estimation of abundance is a prerequisite for a species’ conservation planning in human-dominated landscapes, especially if the species is elusive and involved in conflicts. As a means of population estimation, the importance of camera traps has been recognized globally, although estimating the abundance of unmarked, cryptic species has always been a challenge to conservation biologists. This study explores the use of the N-mixture model with three probability distributions, i.e., Poisson, negative binomial (NB) and zero-inflated Poisson (ZIP), to estimate the relative abundance of sloth bears (Melursus ursinus) based on a camera trapping exercise in Sanjay Tiger Reserve, Madhya Pradesh from December 2016 to April 2017. We used environmental and anthropogenic covariates to model the variation in the abundance of sloth bears. We also compared null model estimates (mean site abundance) obtained from the N-mixture model to those of the Royle-Nichols abundance-induced heterogeneity model (RN model) to assess the application of similar site-structured models. Models with Poisson distributions produced ecologically realistic and more precise estimates of mean site abundance (λ = 2.60 ± 0.64) compared with other distributions, despite the relatively high Akaike Information Criterion value. Area of mixed and sal forest, the photographic capture rate of humans and distance to the nearest village predicted a higher relative abundance of sloth bears. Mean site abundance estimates of sloth bears obtained from the N-mixture model (Poisson distribution) and the RN model were comparable, indicating the overall utility of these models in this field. However, density estimates of sloth bears based on spatially explicit methods are essential for evaluating the efficacy of the relatively more cost-effective N-mixture model. Compared to commonly used index/encounter-based methods, the N-mixture model equipped with knowledge on governing biotic and abiotic factors provides better relative abundance estimates for a species like the sloth bear. In the absence of absolute abundance estimates, the present study could be insightful for the long-term conservation and management of sloth bears. creator: Sankarshan Chaudhuri creator: Rajasekar Rajaraman creator: Sankar Kalyanasundaram creator: Sambandam Sathyakumar creator: Ramesh Krishnamurthy uri: https://doi.org/10.7717/peerj.13649 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Chaudhuri et al. title: Hypoxia-induced factor and its role in liver fibrosis link: https://peerj.com/articles/14299 last-modified: 2022-12-06 description: Liver fibrosis develops as a result of severe liver damage and is considered a major clinical concern throughout the world. Many factors are crucial for liver fibrosis progression. While advancements have been made to understand this disease, no effective pharmacological drug and treatment strategies have been established that can effectively prevent liver fibrosis or even could halt the fibrotic process. Most of those advances in curing liver fibrosis have been aimed towards mitigating the causes of fibrosis, including the development of potent antivirals to inhibit the hepatitis virus. It is not practicable for many individuals; however, a liver transplant becomes the only suitable alternative. A liver transplant is an expensive procedure. Thus, there is a significant need to identify potential targets of liver fibrosis and the development of such agents that can effectively treat or reverse liver fibrosis by targeting them. Researchers have identified hypoxia-inducible factors (HIFs) in the last 16 years as important transcription factors driving several facets of liver fibrosis, making them possible therapeutic targets. The latest knowledge on HIFs and their possible role in liver fibrosis, along with the cell-specific activities of such transcription factors that how they play role in liver fibrosis progression, is discussed in this review. creator: Jan Mohammad Omar creator: Yang Hai creator: Shizhu Jin uri: https://doi.org/10.7717/peerj.14299 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Mohammad Omar et al. title: Stiffness and thickness of the upper trapezius muscle increase after repeated climbing bouts in male climbers link: https://peerj.com/articles/14409 last-modified: 2022-12-06 description: BackgroundIndoor climbing involves overloading the shoulder girdle, including the rotator cuff and upper trapezius muscles. This on the field study aimed to investigate the effects of repeated climbing bouts on morphological and mechanical measures of the upper trapezius muscle.Materials and MethodsFifteen experienced male climbers participated in the study. Rate of perceived exertion (RPE), blood lactate concentration ([La−]b), and stiffness and thickness over four points of the upper trapezius were assessed before and after a repeated climbing exercise. The procedure for the climbing exercise consisted of five climbs for a total time of 5-minutes per climb, followed by a 5-minute rest.ResultsThe analysis showed an increase from baseline to after the 3rd climb (p ≤ 0.01) for RPE and after the 5th climb for [La−]b (p ≤ 0.001). Muscle stiffness and thickness increased at all points (1–2–3–4) after the 5th climb (p ≤ 0.01). We found spatial heterogeneity in muscle stiffness and thickness; muscle stiffness was the highest at Point 4 (p ≤ 0.01), while muscle thickness reached the highest values at points 1–2 (both p ≤ 0.01). Moreover, the analysis between the dominant and non-dominant shoulder showed greater stiffness after the 1st climb at Point 1 (p = 0.004) and after the 5th climb at Point 4 (p ≤ 0.001).ConclusionsFor muscle thickness, the analysis showed significant changes in time and location between the dominant and the non-dominant shoulder. Bilateral increases in upper trapezius muscle stiffness and thickness, with simultaneous increases in RPE and blood lactate in response to consecutive climbs eliciting fatigue. creator: Sebastian Klich creator: Adam Kawczyński creator: Klaudia Sommer creator: Natalia Danek creator: César Fernández-de-las-Peñas creator: Lori A. Michener creator: Pascal Madeleine uri: https://doi.org/10.7717/peerj.14409 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Klich et al. title: Multi-dimensional feature recognition model based on capsule network for ubiquitination site prediction link: https://peerj.com/articles/14427 last-modified: 2022-12-06 description: Ubiquitination is an important post-translational modification of proteins that regulates many cellular activities. Traditional experimental methods for identification are costly and time-consuming, so many researchers have proposed computational methods for ubiquitination site prediction in recent years. However, traditional machine learning methods focus on feature engineering and are not suitable for large-scale proteomic data. In addition, deep learning methods are mostly based on convolutional neural networks and fuse multiple coding approaches to achieve classification prediction. This cannot effectively identify potential fine-grained features of the input data and has limitations in the representation of dependencies between low-level features and high-level features. A multi-dimensional feature recognition model based on a capsule network (MDCapsUbi) was proposed to predict protein ubiquitination sites. The proposed module consisting of convolution operations and channel attention was used to recognize coarse-grained features in the sequence dimension and the feature map dimension. The capsule network module consisting of capsule vectors was used to identify fine-grained features and classify ubiquitinated sites. With ten-fold cross-validation, the MDCapsUbi achieved 91.82% accuracy, 91.39% sensitivity, 92.24% specificity, 0.837 MCC, 0.918 F-Score and 0.97 AUC. Experimental results indicated that the proposed method outperformed other ubiquitination site prediction technologies. creator: Weimin Li creator: Jie Wang creator: Yin Luo creator: Tsigabu Teame Bezabih uri: https://doi.org/10.7717/peerj.14427 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Li et al. title: Mitochondrial genomes assembled from non-invasive eDNA metagenomic scat samples in the endangered Amur tiger Panthera tigris altaica link: https://peerj.com/articles/14428 last-modified: 2022-12-06 description: The Amur or Siberian tiger Panthera tigris altaica (Temminck, 1844) is currently restricted to a small region of its original geographical range in northwestern Asia and is considered ‘endangered’ by the IUCN Red List of Threatened Species. This solitary, territorial, and large top predator is in major need of genomic resources to inform conservation management strategies. This study formally tested if complete mitochondrial genomes of P. tigris altaica can be assembled from non-enriched metagenomic libraries generated from scat eDNA samples using the Illumina sequencing platform and open-access bioinformatics pipelines. The mitogenome of P. tigris altaica was assembled and circularized using the pipeline GetOrganelle with a coverage ranging from 322.7x to 17.6x in four different scat eDNA samples. A nearly complete mitochondrial genome (101x) was retrieved from a fifth scat eDNA sample. The complete or nearly complete mitochondrial genomes of P. tigris altaica were AT-rich and composed of 13 protein coding genes (PCGs), 22 transfer RNA genes, two ribosomal RNA genes, and a putative control region. Synteny observed in all assembled mitogenomes was identical to that reported before for P. tigris altaica and other felids. A phylogenomic analysis based on all PCGs demonstrated that the mitochondrial genomes assembled from scat eDNA reliably identify the sequenced samples as belonging to P. tigris and distinguished the same samples from closely and distantly related congeneric species. This study demonstrates that it is viable to retrieve accurate whole and nearly complete mitochondrial genomes of P. tigris altaica (and probably other felids) from scat eDNA samples without library enrichment protocols and using open-access bioinformatics workflows. This new genomic resource represents a new tool to support conservation strategies (bio-prospecting and bio-monitoring) in this iconic cat. creator: J. Antonio Baeza uri: https://doi.org/10.7717/peerj.14428 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Baeza title: Prediction of individual mortality risk among patients with chronic obstructive pulmonary disease: a convenient, online, individualized, predictive mortality risk tool based on a retrospective cohort study link: https://peerj.com/articles/14457 last-modified: 2022-12-06 description: BackgroundChronic obstructive pulmonary disease (COPD) is a serious condition with a poor prognosis. No clinical study has reported an individual-level mortality risk curve for patients with COPD. As such, the present study aimed to construct a prognostic model for predicting individual mortality risk among patients with COPD, and to provide an online predictive tool to more easily predict individual mortality risk in this patient population.Patients and methodsThe current study retrospectively included data from 1,255 patients with COPD. Random survival forest plots and Cox proportional hazards regression were used to screen for independent risk factors in patients with COPD. A prognostic model for predicting mortality risk was constructed using eight risk factors.ResultsCox proportional hazards regression analysis identified eight independent risk factors among COPD patients: B-type natriuretic peptide (hazard ratio [HR] 1.248 [95% confidence interval (CI) 1.155–1.348]); albumin (HR 0.952 [95% CI 0.931–0.974); age (HR 1.033 [95% CI 1.022–1.044]); globulin (HR 1.057 [95% CI 1.038–1.077]); smoking years (HR 1.011 [95% CI 1.006–1.015]); partial pressure of arterial carbon dioxide (HR 1.012 [95% CI 1.007–1.017]); granulocyte ratio (HR 1.018 [95% CI 1.010–1.026]); and blood urea nitrogen (HR 1.041 [95% CI 1.017–1.066]). A prognostic model for predicting risk for death was constructed using these eight risk factors. The areas under the time-dependent receiver operating characteristic curves for 1, 3, and 5 years were 0.784, 0.801, and 0.806 in the model cohort, respectively. Furthermore, an online predictive tool, the “Survival Curve Prediction System for COPD patients”, was developed, providing an individual mortality risk predictive curve, and predicted mortality rate and 95% CI at a specific time.ConclusionThe current study constructed a prognostic model for predicting an individual mortality risk curve for COPD patients after discharge and provides a convenient online predictive tool for this patient population. This predictive tool may provide valuable prognostic information for clinical treatment decision making during hospitalization and health management after discharge (https://zhangzhiqiao15.shinyapps.io/Smart_survival_predictive_system_for_COPD/). creator: Shubiao Lu creator: Yuwen Zhou creator: Xuejuan Huang creator: Jinsong Lin creator: Yingyu Wu creator: Zhiqiao Zhang uri: https://doi.org/10.7717/peerj.14457 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Lu et al. title: LncRNA RP11-551L14.4 suppresses breast cancer development by inhibiting the expression of miR-4472 link: https://peerj.com/articles/14482 last-modified: 2022-12-06 description: BackgroundPrevious studies have been reported that long non-coding RNA (lncRNA) can regulate the expression of genes which are involved in many important cellular processes The potential role of lncRNA RP11-551L14.4 in the development of breast cancer and the possible regulatory mechanisms was investigated.MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) was conducted to analyze RP11-551L14.4 expression in 36 paired breast cancer tissues and adjacent tissues. The expression of RP11-551L14.4 in multiple breast cancer cell lines was detected by qRT-PCR. Meanwhile, overexpression of RP11-551L14.4 models was established using lentivirus in BT474 and T47D breast cancer cells. Cell counting kit-8 (CCK-8), cell colony formation and cell cycle assays were performed to detect the effects of RP11-551L14.4 on the biological function of breast cancer cells. Besides, bioinformatics techniques, dual luciferase reporter gene assay and rescue experiments were used to investigate the potential mechanisms.ResultsRP11-551L14.4 expression was negatively associated with the advanced tumor stage. Breast cancer patients with low RP11-551L14.4 expression manifested a poorer prognosis. The results of qRT-PCR showed that RP11-551L14.4 expression in breast cancer tissues was significantly lower than in adjacent tissues. Meanwhile, overexpression of RP11-551L14.4 significantly decreased the cell proliferation and cell cycle. Bioinformatics technology showed that RP11-551L14.4 could complementarily bind to miR-4472. qRT-PCR results indicated that the expression levels of miR-4472 and RP11-551L14.4 in breast cancer were negatively correlated. Luciferase reporter gene assay showed that miR-4472 remarkably decreased the relative luciferase activity of the wild-type RP11-551L14.4 vector. miR-4472 is a direct target gene of RP11-551L14.4. miR-4472 levels were reduced, and repulsive guidance molecule A (RGMA) mRNA or protein levels were increased after overexpression of RP11-551L14.4 in the breast cancer cells. miR-4472 reversed the effects caused by RP11-551L14.4 in breast cancer cells.ConclusionRP11-551L14.4 expression was remarkably decreased in breast cancer tissues and cells. RP11-551L14.4 may inhibit the malignant progression of breast cancer by regulating miR-4472 expression. creator: Bin Wang creator: Hang Chen creator: Rui Yang creator: Lei Xing creator: Chuan Chen creator: Junxia Chen uri: https://doi.org/10.7717/peerj.14482 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Wang et al. title: A pipeline for assembling low copy nuclear markers from plant genome skimming data for phylogenetic use link: https://peerj.com/articles/14525 last-modified: 2022-12-06 description: BackgroundGenome skimming is a popular method in plant phylogenomics that do not include a biased enrichment step, relying on random shallow sequencing of total genomic DNA. From these data the plastome is usually readily assembled and constitutes the bulk of phylogenetic information generated in these studies. Despite a few attempts to use genome skims to recover low copy nuclear loci for direct phylogenetic use, such endeavor remains neglected. Causes might include the trade-off between libraries with few reads and species with large genomes (i.e., missing data caused by low coverage), but also might relate to the lack of pipelines for data assembling.MethodsA pipeline and its companion R package designed to automate the recovery of low copy nuclear markers from genome skimming libraries are presented. Additionally, a series of analyses aiming to evaluate the impact of key assembling parameters, reference selection and missing data are presented.ResultsA substantial amount of putative low copy nuclear loci was assembled and proved useful to base phylogenetic inference across the libraries tested (4 to 11 times more data than previously assembled plastomes from the same libraries).DiscussionCritical aspects of assembling low copy nuclear markers from genome skims include the minimum coverage and depth of a sequence to be used. More stringent values of these parameters reduces the amount of assembled data and increases the relative amount of missing data, which can compromise phylogenetic inference, in turn relaxing the same parameters might increase sequence error. These issues are discussed in the text, and parameter tuning through multiple comparisons tracking their effects on support and congruence is highly recommended when using this pipeline. The skimmingLoci pipeline (https://github.com/mreginato/skimmingLoci) might stimulate the use of genome skims to recover nuclear loci for direct phylogenetic use, increasing the power of genome skimming data to resolve phylogenetic relationships, while reducing the amount of sequenced DNA that is commonly wasted. creator: Marcelo Reginato uri: https://doi.org/10.7717/peerj.14525 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Reginato title: Cryptic population structure at the northern range margin of the service tree Sorbus domestica link: https://peerj.com/articles/14397 last-modified: 2022-12-05 description: Climate change has aroused interest in planting warm- and drought-adapted trees in managed forests and urban areas. An option is to focus on tree species that occur naturally, but have centers of distribution in warmer and drier areas. However, in order to protect the species pool of genetic diversity, efforts of planting and promotion should be informed by knowledge on the local genetic diversity. Here, we studied the macro- and micro-scale population genetic structure of the rare European fruit tree Sorbus domestica at its northern range margin, in western Switzerland. New microsatellite data were combined with published data from across the European distribution of the species. Analyses revealed the presence of mainly one of two species-wide ancestral clusters, i.e., the western European cluster, with evidence that it consists of two cryptic sub-clusters. Average pairwise FST of 0.118 was low across the range, and only allelic richness was reduced in the northern margin compared to more southern and southeastern areas of Europe. Based on our finding of considerable genetic diversity of the species in western and northern Switzerland, we suggest that a national propagation program should focus on collecting seeds from natural, high-density tree stands and propagate locally. More generally, our study shows that rare tree species in marginal areas of their distributions do not necessarily have low genetic diversity or heightened levels of inbreeding, and in those cases probably need no assisted migration in efforts to propagate them. creator: Georg F.J. Armbruster creator: Kay Lucek creator: Yvonne Willi uri: https://doi.org/10.7717/peerj.14397 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Armbruster et al.