title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=1275 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Transcriptome association studies of neuropsychiatric traits in African Americans implicate PRMT7 in schizophrenia link: https://peerj.com/articles/7778 last-modified: 2019-09-26 description: In the past 15 years, genome-wide association studies (GWAS) have provided novel insight into the genetic architecture of various complex traits; however, this insight has been primarily focused on populations of European descent. This emphasis on European populations has led to individuals of recent African descent being grossly underrepresented in the study of genetics. With African Americans making up less than 2% of participants in neuropsychiatric GWAS, this discrepancy is magnified in diseases such as schizophrenia and bipolar disorder. In this study, we performed GWAS and the gene-based association method PrediXcan for schizophrenia (n = 2,256) and bipolar disorder (n = 1,019) in African American cohorts. In our PrediXcan analyses, we identified PRMT7 (P = 5.5 × 10−6, local false sign rate = 0.12) as significantly associated with schizophrenia following an adaptive shrinkage multiple testing adjustment. This association with schizophrenia was confirmed in the much larger, predominantly European, Psychiatric Genomics Consortium. In addition to the PRMT7 association with schizophrenia, we identified rs10168049 (P = 1.0 × 10−6) as a potential candidate locus for bipolar disorder with highly divergent allele frequencies across populations, highlighting the need for diversity in genetic studies. creator: Peter N. Fiorica creator: Heather E. Wheeler uri: https://doi.org/10.7717/peerj.7778 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2019 Fiorica and Wheeler title: Comprehensive evaluation of fluroxypyr herbicide on physiological parameters of spring hybrid millet link: https://peerj.com/articles/7794 last-modified: 2019-09-26 description: Foxtail millet (Setaria italic L.) is an important food and fodder crop that is cultivated worldwide. Quantifying the effects of herbicides on foxtail millet is critical for safe herbicide application. In this study, we analyzed the effects of different fluroxypyr dosages on the growth parameters and physiological parametric of foxtail millet, that is, peroxidation characteristics, photosynthetic characteristics, and endogenous hormone production, by using multivariate statistical analysis. Indicators were screened via Fisher discriminant analysis, and the growth parameters, peroxidation characteristics, photosynthesis characteristics and endogenous hormones of foxtail millet at different fluroxypyr dosages were comprehensively evaluated by principal component analysis. On the basis of the results of principal component analysis, the cumulative contribution rate of the first two principal component factors was 93.72%. The first principal component, which explained 59.23% of total variance, was selected to represent the photosynthetic characteristics and endogenous hormones of foxtail millet. The second principal component, which explained 34.49% of total variance, represented the growth parameters of foxtail millet. According to the principal component analysis, the indexes were simplified into comprehensive index Z, and the mathematical model of comprehensive index Z was set as F = 0.592Z1 + 0.345Z2. The results showed that the comprehensive evaluation score of fluroxypyr at moderate concentrations was higher than at high concentrations. Consequently, one L (active ingredient, ai) ha−1 fluroxypyr exerted minimal effects on growth parameters, oxidase activity, photosynthetic activity, and endogenous hormones, and had highest value of comprehensive evaluation, which had efficient and safe benefits in foxtail millet field. creator: Meijun Guo creator: Jie Shen creator: Xi-e Song creator: Shuqi Dong creator: Yinyuan Wen creator: Xiangyang Yuan creator: Pingyi Guo uri: https://doi.org/10.7717/peerj.7794 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2019 Guo et al. title: The rediscovery of the rare Vietnamese endemic Eriophorum scabriculme redefines generic limits in the Scirpo-Caricoid Clade (Cyperaceae) link: https://peerj.com/articles/7538 last-modified: 2019-09-25 description: For those familiar with boreal bogs and wet tundra, species of Eriophorum (“the cotton grasses”) will undoubtedly represent some of the most striking and memorable taxa they have encountered. This small genus of 20 Holarctic sedge species (Cyperaceae) is remarkable because its inflorescences produce large, brilliantly white to rusty-red cottony masses when its flowers develop a perianth of highly elongated bristles after anthesis. In this study, we document the rediscovery of Eriophorum scabriculme, a narrow Vietnamese endemic known from only two collections made approximately 7 km apart near Sa Pa in Lào Cai Province over 75 years ago. Using plastid DNA sequences (matK, ndhF), embryology, and morphology, we test whether E. scabriculme is aligned within the Scirpo-Caricoid Clade (genus Khaosokia and tribes Cariceae, Dulichieae, Scirpeae, and Sumatroscirpeae) or the Ficinia Clade (Cypereae), and we determine whether its unique character combinations (≥10 elongated bristles, reduced sheathing basal leaves, 1–4 spikelets) could be evidence for a new genus or simply mark it as an unusual species within currently recognised genera. In addition, we document the discovery of seven new populations, and we extend its range westward to Lai Châu Province and southward in Lào Cai Province by more than 47 km. Our results demonstrate that Eriophorum scabriculme is best treated in the genus Trichophorum, thus re-circumscribing both genera and their limits with Scirpus s.str. In addition, we emend the description of Trichophorum scabriculme (Beetle) J.R.Starr, Lév.-Bourret & B.A. Ford, provide the first pictures and accurate illustration of the species, and assess its conservation status in Vietnam (VU, Vulnerable). Our study corroborates the fact that in such a diverse and taxonomically difficult family like the sedges, conspicuous characters like highly elongated bristles may be useful for dividing diversity, but they are no guarantee that the groups they mark are natural. creator: Julian R. Starr creator: Étienne Léveillé-Bourret creator: Vũ Anh Tài creator: Nguyê˜n Thị Kim Thanh creator: Bruce A. Ford uri: https://doi.org/10.7717/peerj.7538 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2019 Starr et al. title: Cellular accumulation and cytotoxic effects of zinc oxide nanoparticles in microalga Haematococcus pluvialis link: https://peerj.com/articles/7582 last-modified: 2019-09-25 description: BackgroundZinc oxide nanoparticles (ZnO NPs) are widely used in household and cosmetic products which imply an increased releasing of these particles into the environment, especially aquatic ecosystems, resulting in the need of assessing the potential toxic effects of ZnO NPS on the aquatic organisms, particularly on microalgae which form the base for food chain of aquatic biota. The present study has investigated the dose- and time-dependent cellular accumulation and the corresponding cytotoxic effects of increasing concentrations of ZnO NPs from 10–200 μg/mL on microalga Haematococcus pluvialis at an interval of 24 h for 96 h.MethodsThe scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) was used to qualitatively detect the cellular accumulation of ZnO NPs in algal cells, while inductively coupled plasma optical emission spectrometry (ICP OES) was performed to quantify the cell associated-zinc in algal cells. The percentage of cell death, reduction in algal biomass, and loss in photosynthetic pigments were measured to investigate the cytotoxic effects of ZnO NPs on H. pluvialis. Extracellular and intracellular changes in algal cells resulted from the treatment of ZnO NPs were demonstrated through optical, scanning, and transmission electron microscopic studies.ResultsSEM-EDX spectrum evidenced the accumulation of ZnO NPs in algal biomass and ICP OES results reported a significant (p < 0.05) dose- and time-dependent accumulation of zinc in algal cells from 24 h for all the tested concentrations of ZnO NPs (10–200 μg/mL). Further, the study showed a significant (p < 0.05) dose- and time-dependent growth inhibition of H. pluvialis from 72 h at 10–200 μg/mL of ZnO NPs. The morphological examinations revealed substantial surface and intracellular damages in algal cells due to the treatment of ZnO NPs.DiscussionThe present study reported the significant cellular accumulation of ZnO NPs in algal cells and the corresponding cytotoxic effects of ZnO NPs on H. pluvialis through the considerable reduction in algal cell viability, biomass, and photosynthetic pigments together with surface and intracellular damages. creator: Sinouvassane Djearamane creator: Yang Mooi Lim creator: Ling Shing Wong creator: Poh Foong Lee uri: https://doi.org/10.7717/peerj.7582 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2019 Djearamane et al. title: The effects of growth rate and biomechanical loading on bone laminarity within the emu skeleton link: https://peerj.com/articles/7616 last-modified: 2019-09-25 description: The orientation of vascular canals in primary bone may reflect differences in growth rate and/or adaptation to biomechanical loads. Previous studies link specific canal orientations to bone growth rates, but results between different taxa are contradictory. Circumferential vascular canals (forming laminar bone) have been hypothesized to reflect either (or both) rapid growth rate or locomotion-induced torsional loading. Previous work on the hindlimb biomechanics in the emu shows that the femur and tibiotarsus experience large shear strains, likely resulting from torsional loads that increase through ontogeny. Here, we test how growth rate and biomechanical loading affect bone laminarity in wing and hindlimb elements from growing emu (2–60 wks). If laminar bone is an adaptation to torsion-induced shear strains, it should increase from juveniles to adults. Alternatively, if bone laminarity reflects rapid growth, as has been shown previously in emu, it should be abundant in fast-growing juveniles and decrease with age. Transverse mid-shaft histological sections from the limb bones (femur, tibiotarsus, humerus, ulna, and radius) were prepared and imaged. Growth rates were measured using fluorescent bone labels. Vascular canal orientation was quantified using laminarity index (proportion of circumferential canals). Principal components analysis was performed to convert highly correlated variables (i.e., mass, age, growth rate, and shear strain) into principal components. Random-intercept beta regression modeling determined which principal components best explained laminarity. The fastest growth rates were found in young individuals for all five skeletal elements. Maximum growth rate did not coincide with peak laminarity. Instead, in the femur and tibiotarsus, elevated laminarity is strongly correlated with adult features such as large size, old age, and modest growth rate. This result is contrary to predictions made based on a previous study of emu but is consistent with results observed in some other avian species (penguin, chicken). Shear strain in the caudal octant of the femur and tibiotarsus is positively correlated with laminarity but has a weaker effect on laminarity relative to mass, age, and growth rate. Laminarity in the wing elements is variable and does not correlate with ontogenetic factors (including mass, age, and growth rate). Its presence may relate to relaxed developmental canalization or a retained ancestral feature. In conclusion, ontogeny (including growth rate) is the dominant influence on vascular canal orientation at least in the hindlimb of the emu. creator: Amanda L. Kuehn creator: Andrew H. Lee creator: Russell P. Main creator: Erin L.R. Simons uri: https://doi.org/10.7717/peerj.7616 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2019 Kuehn et al. title: Bar-HRM: a reliable and fast method for species identification of ginseng (Panax ginseng, Panax notoginseng, Talinum paniculatum and Phytolacca Americana) link: https://peerj.com/articles/7660 last-modified: 2019-09-25 description: BackgroundKorean ginseng has long been famous and is one of the most well known forms of ginseng. The root of plants in the genus Panax is commonly recognized as ginseng. Different Panax species of ginseng root have been used as treatments. Although many other herbs are called ginseng, they do not contain the active compounds of ginsenosides. In Thailand, we have Thai ginseng which is of course not one of Panax species. Thai ginseng is the root from Talinum paniculatum and, due to its morphological root similarity, it is almost impossible to differentiate between them. Also, another plant species, Phytollacca americana, has significantly similar root morphology to real ginseng but its seeds and root are poisonous. Misunderstanding what true ginseng is compared to others could endanger lives and cause financial loss by buying inferior products.MethodsDNA barcoding combination with High Resolution Melting (called Bar-HRM) was used for species discrimination of the Panax ginseng and others. Five regions included ITS2, matK, psbA-trnH and rbcL were evaluated in the analyses.ResultsThe ITS2 region was found to be the most suitable primers for the analysis. The melting profile from the HRM analyses using the chosen ITS2 primers showed that Korean ginseng (Panax ginseng) could be discriminated from other Penax species. Also, other ginseng species with morphological similarity could be easily distinguished from the true ginseng. The developed Bar-HRM method poses a great potential in ginseng species discrimination and thus could be also useful in ginseng authentication. creator: Maslin Osathanunkul creator: Panagiotis Madesis uri: https://doi.org/10.7717/peerj.7660 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2019 Osathanunkul and Madesis title: Effect of reduced pH on physiology and shell integrity of juvenile Haliotis iris (pāua) from New Zealand link: https://peerj.com/articles/7670 last-modified: 2019-09-25 description: The New Zealand pāua or black footed abalone, Haliotis iris, is one of many mollusc species at potential risk from ocean acidification and warming. To investigate possible impacts, juvenile pāua (~24 mm shell length) were grown for 4 months in seawater pH/pCO2 conditions projected for 2100. End of century seawater projections (pHT 7.66/pCO2 ~1,000 μatm) were contrasted with local ambient conditions (pHT 8.00/pCO2 ~400 μatm) at two typical temperatures (13 and 15 °C). We used a combination of methods (morphometric, scanning electron microscopy, X-ray diffraction) to investigate effects on juvenile survival and growth, as well as shell mineralogy and integrity. Lowered pH did not affect survival, growth rate or condition, but animals grew significantly faster at the higher temperature. Juvenile pāua were able to biomineralise their inner nacreous aragonite layer and their outer prismatic calcite layer under end-of-century pH conditions, at both temperatures, and carbonate composition was not affected. There was some thickening of the nacre layer in the newly deposited shell with reduced pH and also at the higher temperature. Most obvious was post-depositional alteration of the shell under lowered pH: the prismatic calcite layer was thinner, and there was greater etching of the external shell surface; this dissolution was greater at the higher temperature. These results demonstrate the importance of even a small (2 °C) difference in temperature on growth and shell characteristics, and on modifying the effects at lowered pH. Projected CO2-related changes may affect shell quality of this iconic New Zealand mollusc through etching (dissolution) and thinning, with potential implications for resilience to physical stresses such as predation and wave action. creator: Vonda J. Cummings creator: Abigail M. Smith creator: Peter M. Marriott creator: Bryce A. Peebles creator: N. Jane Halliday uri: https://doi.org/10.7717/peerj.7670 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2019 Cummings et al. title: Cloning of a new HSP70 gene from western flowerthrips, Frankliniella occidentalis, and expression patterns during thermal stress link: https://peerj.com/articles/7687 last-modified: 2019-09-25 description: Frankliniella occidentalis (Pergande) is an invasive pest that endangers a wide variety of horticultural and agronomic crops. HSP70 is the most important member of the heat shock protein (HSP) family and plays an important role in insect thermal tolerance. In this study, a new gene encoding HSP70 from F. occidentalis, Fohsp706, was selected from the F. occidentalis transcriptome exposed to thermal stress (40 °C) and cloned by RT-PCR and RACE. Further characterization indicated that Fohsp706 localizes to the cytoplasm and does not contain introns. Quantitative real-time reverse transcriptase PCR indicated that Fohsp706 expression was significantly up-regulated by thermal stress; furthermore, there were significant differences in Fohsp706 expression in adults and second instar nymphs after heat stress. Our results indicated that Fohsp706 contributes to thermotolerance in F. occidentalis and provides another example of how this pest adapts to unfavorable environmental conditions. creator: Xiao-xiang Zhang creator: Jing Qin creator: Jia-Wen Yuan creator: Ming-Xing Lu creator: Yu-Zhou Du uri: https://doi.org/10.7717/peerj.7687 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2019 Zhang et al. title: The interplay between cognitive tasks and vision for upright posture balance in adolescents link: https://peerj.com/articles/7693 last-modified: 2019-09-25 description: BackgroundThe control of an upright stance in humans is important in medicine, psychology, and physiology. The maintenance of upright stance balance depends not only on sensory information from proprioceptive, vestibular, cutaneous, and visual sources but also on cognitive resources. The present study investigated the effects of cognitive tasks while standing with eyes open on upright stance balance in adolescents. We hypothesized that performing a cognitive task while standing with eyes open would increase body sway among these adolescents and that the upright posture would thus become less stable.MethodsA static balance assessment system comprising a force platform connected to a computer was used to evaluate the stability of the upright stance among 21 healthy adolescents under six conditions: no cognitive task, a relatively easy cognitive task, or the same cognitive task made more difficult, with each task being performed while the eyes were open and again while the eyes were closed. The participants performed mental calculations as fast as possible by subtracting either 3 or 18 from a random three-digit number continuously, for the simple cognitive task or the difficult cognitive task, respectively. Each calculation was completed within 10 s. The evaluation indexes used to measure upright posture stability were the root mean square (RMS) of the total body sway in the mediolateral and anteroposterior directions, the mean velocity (MV) value of the total body sway, and the Romberg quotient (RQ) of these values.ResultsThe RMS (p < 0.01) and MV (p < 0.01) values of the upright posture sway were lower when participants performed no cognitive task and their eyes were open than when their eyes were closed. When their eyes were open, compared with no cognitive task, the values of the measures evaluating upright posture sway were higher, meaning the stance was less stable, while performing either the simple or the more difficult cognitive task (RMS: simple task, p < 0.01; difficult task, p < 0.05; MV: simple task, p < 0.01; difficult task, p < 0.01) although no significant differences were detected for the RMS or MV values between the simple and more difficult cognitive tasks. The RQs for both the RMS and the total MV values of the upright posture sway during performance of the difficult cognitive task were significantly lower than when the participants performed no task.ConclusionPerformance of a cognitive task significantly reduced the upright posture balance in adolescents during eyes open although increased task difficulty did not show a greater effect. The interference between the performance of a cognitive task and the visual control of an upright stance may be attributable in part to cognitive and visual processing streams competing for common central resources, consistent with the Multiple Resource Theory of information processing. creator: Hai-Jiang Meng creator: Shan-Shan Luo creator: Yuan-Gang Wang uri: https://doi.org/10.7717/peerj.7693 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2019 Meng et al. title: Soil warming increases soil temperature sensitivity in subtropical Forests of SW China link: https://peerj.com/articles/7721 last-modified: 2019-09-25 description: BackgroundSoil respiration (RS) plays an important role in the concentration of atmospheric CO2 and thus in global climate patterns. Due to the feedback between RS and climate, it is important to investigate RS responses to climate warming.MethodsA soil warming experiment was conducted to explore RS responses and temperature sensitivity (Q10) to climate warming in subtropical forests in Southwestern China, and infrared radiators were used to simulate climate warming.ResultsWarming treatment increased the soil temperature and RS value by 1.4 °C and 7.3%, respectively, and decreased the soil water level by 4.2% (%/%). Both one- and two-factor regressions showed that warming increased the Q10 values by 89.1% and 67.4%, respectively. The effects of water on Q10show a parabolic relationship to the soil water sensitivity coefficient. Both RS and Q10 show no acclimation to climate warming, suggesting that global warming will accelerate soil carbon release. creator: Chaoxiang Yuan creator: Guiqing Zhu creator: Shuangna Yang creator: Gang Xu creator: Yingyun Li creator: Hede Gong creator: Chuansheng Wu uri: https://doi.org/10.7717/peerj.7721 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2019 Yuan et al.