title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=1062 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Seasonal variations in leaf and branch trace elements and the influence of a 3-yr 100% rainfall exclusion on Pinus massoniana Lamb link: https://peerj.com/articles/9935 last-modified: 2020-09-16 description: BackgroundTrace elements are essential for the growth and survival of plants, and their concentrations and distributions in plants are effective reflections of ecological adaptation strategies. However, this aspect has seldom been addressed.MethodChanges in the leaf and branch trace elements of Pinus massoniana Lamb, induced by seasonal dynamics and in response to a 3-yr 100% rainfall exclusion, were evaluated.ResultsThe results showed that the concentrations of Fe, Cu, Zn, Cd, Ni and Cr in leaves of P. massoniana in the control group had high seasonal resolution. There were three groups according to their patterns over the growing season: (1) nutrient elements (Cu, Zn, Ni and Cd), which continuously decreased in concentration during the growing season, with the highest concentration in spring and the lowest in autumn; (2) accumulating element (Cr), which increased in concentration from spring to autumn; and (3) indifferent element (Fe), which increased in concentration from spring to summer and decreased in concentration from summer to autumn. The concentrations of trace elements in leaves and branches showed no significant differences with mild drought stress, except for Fe and Cr in leaves and Cr in branches, which significantly increased (p < 0.05) under the result of self-selection under mild drought stress. Therefore, the resultant seasonal and drought effects on trace element cycling in P. massoniana could provide theoretical support to respond to future climate change. creator: Tian Lin creator: Xuanmei Zheng creator: Huaizhou Zheng uri: https://doi.org/10.7717/peerj.9935 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 Lin et al. title: Nitrogen form plays an important role in the growth of moso bamboo (Phyllostachys edulis) seedlings link: https://peerj.com/articles/9938 last-modified: 2020-09-16 description: BackgroundThis study aimed to gain an understanding of the growth response of Phyllostachys edulis (moso bamboo) seedlings to nitrogen (N) and potassium (K) to benefit nutrient management practices and the design of proper fertilizer in nursery cultivation.MethodsAn orthogonal array L8(4×24) was used to study the effects of N forms (NH4+, NO3−), N concentrations (8, 32 mmol/L), and K+concentrations (0, 0.5, 1.5, 3 mmol/L) on seedling height, leaf number, chlorophyll content (SPAD value), biomass, root systems, and N content of P. edulis seedlings. Plants were grown in vermiculite under controlled greenhouse conditions.ResultsOur study showed that N form played a significant role in the overall performance of P. edulis seedlings, followed by the effect of N and K+ concentrations. Among the N forms, NH4+ significantly improved the growth of P. edulis seedlings compared with NO3−. Seedling height, leaf number, chlorophyll SPAD value, biomass, and root system architecture (root length, root surface area, root volume, and root tips) were greater with 8 mmol/L of NH4+ treatments than with 32 mmol/L of NH4+treatments, whereas root diameter and N content of P. edulis seedlings were higher with 32 mmol/L of NH4+ than with 8 mmol/L of NH4+. K displayed inconsistent effects on the growth of P. edulis seedlings. Specifically, seedling height, leaf number, biomass and root volume increased when the K+ concentration was increased from 0 to 0.5 mmol/L, followed by a decrease when the K+ concentration was further increased from 0.5 to 3 mmol/L. Root average diameter of the seedlings was the highest with a K+ concentration of 1.5 mmol/L, and K had some inhibitory effects on the chlorophyll SPAD value of the seedlings. P. edulis seedlings performed well with 8 mmol/L NH4+and further tolerated a higher concentration of both NH4+ and NO3−, although excessive N could inhibit seedling growth. A lower concertation of K (≤ 0.5 mmol/L) promoted seedling growth and increasing K+ concentration in the nutrient solution did not alleviate the inhibitory effect of high N on the growth of P. edulis seedlings. Therefore, NH4+nitrogen as the main form of N fertilizer, together with a low concertation of K+, should be supplied in the cultivation and nutrient management practices of moso bamboo. creator: Na Zou creator: Ling Huang creator: Huijing Chen creator: Xiaofeng Huang creator: Qingni Song creator: Qingpei Yang creator: Tianchi Wang uri: https://doi.org/10.7717/peerj.9938 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 Zou et al. title: An empirical examination of sample size effects on population demographic estimates in birds using single nucleotide polymorphism (SNP) data link: https://peerj.com/articles/9939 last-modified: 2020-09-16 description: Sample size is a critical aspect of study design in population genomics research, yet few empirical studies have examined the impacts of small sample sizes. We used datasets from eight diverging bird lineages to make pairwise comparisons at different levels of taxonomic divergence (populations, subspecies, and species). Our data are from loci linked to ultraconserved elements and our analyses used one single nucleotide polymorphism per locus. All individuals were genotyped at all loci, effectively doubling sample size for coalescent analyses. We estimated population demographic parameters (effective population size, migration rate, and time since divergence) in a coalescent framework using Diffusion Approximation for Demographic Inference, an allele frequency spectrum method. Using divergence-with-gene-flow models optimized with full datasets, we subsampled at sequentially smaller sample sizes from full datasets of 6–8 diploid individuals per population (with both alleles called) down to 1:1, and then we compared estimates and their changes in accuracy. Accuracy was strongly affected by sample size, with considerable differences among estimated parameters and among lineages. Effective population size parameters (ν) tended to be underestimated at low sample sizes (fewer than three diploid individuals per population, or 6:6 haplotypes in coalescent terms). Migration (m) was fairly consistently estimated until <2 individuals per population, and no consistent trend of over-or underestimation was found in either time since divergence (T) or theta (Θ = 4Nrefμ). Lineages that were taxonomically recognized above the population level (subspecies and species pairs; that is, deeper divergences) tended to have lower variation in scaled root mean square error of parameter estimation at smaller sample sizes than population-level divergences, and many parameters were estimated accurately down to three diploid individuals per population. Shallower divergence levels (i.e., populations) often required at least five individuals per population for reliable demographic inferences using this approach. Although divergence levels might be unknown at the outset of study design, our results provide a framework for planning appropriate sampling and for interpreting results if smaller sample sizes must be used. creator: Jessica F. McLaughlin creator: Kevin Winker uri: https://doi.org/10.7717/peerj.9939 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2020 McLaughlin and Winker title: Galectin-3 not Galectin-9 as a candidate prognosis marker for hepatocellular carcinoma link: https://peerj.com/articles/9949 last-modified: 2020-09-16 description: BackgroundGalectins (Gal) are a family of protein that bind to the β-galactoside of glycoproteins. It modulates a variety of biological functions, such as tumor growth, angiogenesis and tumor metastasis. A series of experimental and clinical evidences have been reported to support a correlation between galectin expressions and neoplastic transformation, progression and prognosis. The objective of this study was to estimate the expression of Gal-3 and Gal-9 in order to evaluate their relation to hepatocellular carcinoma (HCC) -related clinical features and their prognostic values.MethodsWe evaluated Gal-3 and Gal-9 expression in 247 HCC patients by a tissue microarray immunohistochemistry method, then analyzed the relationship between expression levels of Gal-3 and Gal-9 protein and tumor parameters or clinical outcomes.ResultsThe Gal-3 expression was significantly higher in tumor tissues compared with adjacent non-tumor tissues (P < 0.001), while no significant differences of Gal-9 was detected (P = 0.222). A higher Gal-3 expression was significantly associated with lymph-vascular invasion (P = 0.049), poor histological differentiation (P = 0.016), and no cirrhosis (P = 0.040). In contrast, a lower Gal-9 expression was related to lymph-vascular invasion (P = 0.012) and poor histological differentiation (P = 0.002). Survival analysis showed that patients with higher Gal-3 expression had worse overall survival (P = 0.012) , however no correlation was found between Gal-9 expression and survival (P = 0.185). Multivariate analysis showed that multiple tumor (HR = 1.94, 95% CI [1.36–2.78]), tumor size ≥ 5 cm (HR = 1.51, 95% CI [1.07–2.12]), Lymph-vascular invasion (HR = 1.45, 95% CI [1.00–2.10]) and Gal-3 expression (HR = 1.57, 95% CI [1.06–2.33]) were independent influencing factors of prognosis in patients with hepatocellular carcinoma.ConclusionGal-3 was expected to serve as a novel prognostic marker of hepatocellular carcinoma, while Gal-9 expression was only related to tumor progression. creator: Fei Kong creator: Meishan Jin creator: Donghui Cao creator: Zhifang Jia creator: Yawen Liu creator: Jing Jiang uri: https://doi.org/10.7717/peerj.9949 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 Kong et al. title: Effect of concurrent training on trainability performance factors in youth elite golf players link: https://peerj.com/articles/9963 last-modified: 2020-09-16 description: BackgroundDue to the early specialization of golf players, examining the within session sequence of training should be considered to enhance performance and prevent injury risk. The present study analyzed the effects of an 18-week concurrent training developed before or after a specific golf session in adolescence elite golfers on several performance factors.MethodsSixteen right-handed male golfers, were randomly divided into two groups: after golf specific training (AG) (n = 8, age: 16.77 ± 0.58 years) and before golf specific training (BG) (n = 8, age: 16.93 ± 0.59 years). AG and BG players followed a concurrent physical conditioning program (CT) after or before the golf specific training, respectively. Body mass, body fat, muscle mass, jumping ability (CMJ), ball speed (Sball), golf movements screens (GMS), power in a golf swing-specific cable woodchop (Wmax) and the perceived training load (TL) in golf specific training (TL-G) and TL in CT (TL-CT) were measured on three separate occasions.ResultsBG demonstrates a lower TL-CT than AG (p < .001, ${\eta }_{p}^{2}=0.90$ηp2=0.90) along the training program without effects on TL-G, achieving significant percentage of change on CMJ (9.38%; p = .165; d = 0.73), GMS (50.52%; p = .41, d = 0.91), Wmax (16.93%; p = .001; d = 2.02) and Sball (1.82%; p = .018; d = 0.92) without interaction effects on anthropometric measures.ConclusionsPerforming CT sessions before the regular golf training can improve specific performance factors with a lower perceived TL than the same training carried out after the regular golf training. creator: Juan Carlos Redondo creator: Ana María de Benito creator: José María Izquierdo uri: https://doi.org/10.7717/peerj.9963 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 Redondo et al. title: Assessing turbine passage effects on internal fish injury and delayed mortality using X-ray imaging link: https://peerj.com/articles/9977 last-modified: 2020-09-16 description: Knowledge on the extent and mechanisms of fish damage caused by hydropower facilities is important for the conservation of fish populations. Herein, we assessed the effects of hydropower turbine passage on internal fish injuries using X-ray technology. A total of 902 specimens from seven native European fish species were screened for 36 types of internal injuries and 86 external injuries evaluated with a previously published protocol. The applied systematic visual evaluation of X-ray images successfully detected skeletal injuries, swim bladder anomalies, emphysema, free intraperitoneal gas and hemorrhages. Injuries related to handling and to impacts of different parts of the hydropower structure could be clearly distinguished applying multivariate statistics and the data often explained delayed mortality within 96 h after turbine passage. The internal injuries could clearly be assigned to specific physical impacts resulting from turbine passage such as swim bladder rupture due to abrupt pressure change or fractures of skeletal parts due to blade-strike, fluid shear or severe turbulence. Generally, internal injuries were rarely depicted by external evaluation. For example, 29% of individuals with vertebral fractures did not present externally visible signs of severe injury. A combination of the external and internal injury evaluation allows quantifying and comparing fish injuries across sites, and can help to identify the technologies and operational procedures which minimize harm to fish in the context of assessing hydropower-related fish injuries as well as in assessing fish welfare. creator: Melanie Mueller creator: Katharina Sternecker creator: Stefan Milz creator: Juergen Geist uri: https://doi.org/10.7717/peerj.9977 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2020 Mueller et al. title: Enrichment in conservative amino acid changes among fixed and standing missense variations in slowly evolving proteins link: https://peerj.com/articles/9983 last-modified: 2020-09-16 description: The process of molecular evolution has many elements that are not yet fully understood. Evolutionary rates are known to vary among protein coding and noncoding DNAs, and most of the observed changes in amino acid or nucleotide sequences are assumed to be non-adaptive by the neutral theory of molecular evolution. However, it remains unclear whether fixed and standing missense changes in slowly evolving proteins are more or less neutral compared to those in fast evolving genes. Here, based on the evolutionary rates as inferred from identity scores between orthologs in human and Rhesus Macaques (Macaca mulatta), we found that the fraction of conservative substitutions between species was significantly higher in their slowly evolving proteins. Similar results were obtained by using four different methods of scoring conservative substitutions, including three that remove the impact of substitution probability, where conservative changes require fewer mutations. We also examined the single nucleotide polymorphisms (SNPs) by using the 1000 Genomes Project data and found that missense SNPs in slowly evolving proteins also had a higher fraction of conservative changes, especially for common SNPs, consistent with more non-conservative substitutions and hence stronger natural selection for SNPs, particularly rare ones, in fast evolving proteins. These results suggest that fixed and standing missense variants in slowly evolving proteins are more likely to be neutral. creator: Mingrui Wang creator: Dapeng Wang creator: Jun Yu creator: Shi Huang uri: https://doi.org/10.7717/peerj.9983 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 Wang et al. title: Interdependency of regulatory effects of iron and riboflavin in the foodborne pathogen Shigella flexneri determined by integral transcriptomics link: https://peerj.com/articles/9553 last-modified: 2020-09-15 description: Shigella flexneri is the causative agent of dysentery. For pathogens, iron is a critical micronutrient as its bioavailability is usually low in bacterial niches. This metal is involved in critical physiological processes mainly as a component of important metabolic molecules involved in redox reactions. Usually bacteria respond to fluctuations in iron availability to regulate iron acquisition and other iron-related functions. Recently the close metabolic feedback between iron and riboflavin, another pivotal biological redox agent, began to draw attention in bacteria. This is a widespread biological phenomenon, partly characterized by the coordination of regulatory responses to iron and riboflavin, probably owed to the involvement of these cofactors in common processes. Nonetheless, no systematic analyses to determine the extent of this regulatory effect have been performed in any species. Here, the transcriptomics responses to iron, riboflavin, iron in the presence of riboflavin and riboflavin in the presence of iron were assessed and compared in S. flexneri. The riboflavin regulon had a 43% overlap with the iron regulon. Notably, the presence of riboflavin highly increased the number of iron-responsive genes. Reciprocally, iron drastically changed the pool of riboflavin-responsive genes. Gene ontology (GO) functional terms enrichment analysis showed that biological processes were distinctively enriched for each subgroup of responsive genes. Among the biological processes regulated by iron and riboflavin were iron uptake, amino acids metabolism and electron transfer for ATP synthesis. Thus, iron and riboflavin highly affect the transcriptomics responses induced by each other in S. flexneri. GO terms analysis suggests that iron and riboflavin coordinately regulate specific physiological functions involving redox metabolism. creator: Luis Fernando Lozano Aguirre creator: Juan Carlos Salazar creator: José Ignacio Vásquez creator: Víctor Antonio García-Angulo uri: https://doi.org/10.7717/peerj.9553 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 Lozano Aguirre et al. title: Differences in the support needs of children with developmental disabilities among groups of medical and behavioral needs link: https://peerj.com/articles/9557 last-modified: 2020-09-15 description: Background/AimsMedical and behavioral needs are relevant in organizing and providing support strategies that improve the quality of life for children, along with their families. The present study aims to examine the impact of medical and behavioral needs on the need for support of children with disabilities.MethodsHealth and education professionals were interviewed using the Supports Intensity Scale-Children’s version to estimate the support needs of 911 children and adolescents (5–16 years) with an intellectual disability, including 55.32% with an additional disability. For data analysis, a model for measuring support needs was specified, consisting of seven support needs factors and three method factors. In estimating the model, four groups of medical and behavioral needs were considered. The factor scores’ means of the groups were compared through t-tests.ResultsMedical and behavioral needs had an impact on overall support needs. Differences were found in all support domains for medical needs. The greatest influence of behavioral needs was found in the Social and School participation areas but was indistinguishable between the mild and moderate levels of needs.ConclusionsMedical and behavioral needs greatly affect the need for support in a child’s daily life, so they need to be considered a priority for support services. The importance of standardized assessments is emphasized to help develop support strategies. creator: Victor B. Arias creator: Virginia Aguayo creator: Miguel A. Verdugo creator: Antonio M. Amor uri: https://doi.org/10.7717/peerj.9557 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 Arias et al. title: A prognostic long non-coding RNA-associated competing endogenous RNA network in head and neck squamous cell carcinoma link: https://peerj.com/articles/9701 last-modified: 2020-09-15 description: BackgroundThis study aimed to develop multi-RNA-based models using a competing endogenous RNA (ceRNA) regulatory network to provide survival risk prediction in head and neck squamous cell carcinoma (HNSCC).MethodsAll long non-coding RNA (lncRNA), microRNA (miRNA), and mRNA expression data and clinicopathological features related to HNSCC were derived from The Cancer Genome Atlas. Differentially expressed RNAs were calculated using R. Prognostic factors were identified using univariate Cox regression analysis. Functional analysis was performed using GO, KEGG pathways, and PPI network. Based on the results, we derived a risk signature and compared high- and low-risk subgroups using LASSO regression analysis. Survival analysis and the relationship between risk signature and clinicopathological features were performed using log-rank tests and Cox regression analysis. A ceRNA regulatory network was constructed, and prognostic lncRNAs and miRNA expression levels were validated in vitro and in vivo.ResultsA list of 207 lncRNAs, 18 miRNAs and 362 mRNAs related to overall survival was established. Five lncRNAs (HOTTIP, LINC00460, RMST, SFTA1P, and TM4SF19-AS1), one miRNA (hsa-miR-206), and one mRNA (STC2) were used to construct the ceRNA network. Three prognostic models contained 13 lncRNAs, eight miRNAs, and 17 mRNAs, which correlated with the patient status, disease-free survival (DFS), stage, grade, T stage, N stage, TP53 mutation status, angiolymphatic invasion, HPV status, and extracapsular spread. KEGG pathway analysis revealed significant enrichment of “Transcriptional misregulation in cancer” and “Neuroactive ligand-receptor interaction.” In addition, HOTTIP, LINC00460, miR-206 and STC2 were validated in GTEx data, GEO microarrays and six HNSCC cell lines.ConclusionsOur findings clarify the interaction of ceRNA regulatory networks and crucial clinicopathological features. These results show that prognostic biomarkers can be identified by constructing multi-RNA-based prognostic models, which can be used for survival risk prediction in patients with HNSCC. creator: Chengyao Zhang creator: Wei Cao creator: Jiawu Wang creator: Jiannan Liu creator: Jialiang Liu creator: Hao Wu creator: Siyi Li creator: Chenping Zhang uri: https://doi.org/10.7717/peerj.9701 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 Zhang et al.