PeerJ
type: channel
link: https://peerj.com/articles/
description: Articles published in PeerJ
publisher: PeerJ Inc.
publication name: PeerJ
issn: 2167-8359
items: Physiological responses of hydroponically-grown Japanese mint under nutrient deficiency
items: Simulated manned Mars exploration: effects of dietary and diurnal cycle variations on the gut microbiome of crew members in a controlled ecological life support system
items: The relationships between bilingual learning, willingness to study abroad and convergent creativity
items: Transcriptome association studies of neuropsychiatric traits in African Americans implicate PRMT7 in schizophrenia
items: Comprehensive evaluation of fluroxypyr herbicide on physiological parameters of spring hybrid millet
items: The rediscovery of the rare Vietnamese endemic Eriophorum scabriculme redefines generic limits in the Scirpo-Caricoid Clade (Cyperaceae)
items: Cellular accumulation and cytotoxic effects of zinc oxide nanoparticles in microalga Haematococcus pluvialis
items: The effects of growth rate and biomechanical loading on bone laminarity within the emu skeleton
items: Bar-HRM: a reliable and fast method for species identification of ginseng (Panax ginseng, Panax notoginseng, Talinum paniculatum and Phytolacca Americana)
items: Effect of reduced pH on physiology and shell integrity of juvenile Haliotis iris (pāua) from New Zealand

Physiological responses of hydroponically-grown Japanese mint under nutrient deficiency
type: item
type: AcademicArticle
description: This research aims to determine growth and deficiency patterns as well as antioxidative potentials of Japanese mint (Mentha arvensis) hydroponically grown under limited macronutrients and micronutrients. The experiment was conducted for 60 days after transplanting in an evaporative greenhouse (avg temp = 28–30 °C, 60–65 %RH), using deep water culture technique. Plants were grown in nutrient solution consisting of complete Hoagland’s solution (CTRL), and nutrient solutions lacking one of the following macronutrients and micronutrients: nitrogen (-N), phosphorus (-P), potassium (-K), iron (-Fe), manganese (-Mn), and copper (-Cu). The deficiency symptoms, growth patterns, and stress response mechanism were followed. All treatments except for the CTRL induced deficiency symptoms and physiological changes. Macronutrient deprivation reduced growth determined by the morphological parameters while micronutrient omission had no effect except for no iron treatment. The result showed that potassium and iron deficiencies had foremost adversely effect on growth of Japanese mint. Under nutrient stress conditions, plant only gave antioxidative responses to phosphorus and potassium deficiencies. However, the negative plant-stress relationship was found for no iron treatment indicating the detoxification mode of plant for lacking of micronutrient.
format: application/pdf
format: text/html
creator: Chananchida Janpen
creator: Naruemon Kanthawang
creator: Chaiartid Inkham
creator: Fui Ying Tsan
creator: Sarana Rose Sommano
subject: Agricultural Science
subject: Plant Science
description: doi:10.7717/peerj.7751
publisher: PeerJ Inc.
rights: © 2019 Janpen et al.
abstract: This research aims to determine growth and deficiency patterns as well as antioxidative potentials of Japanese mint (Mentha arvensis) hydroponically grown under limited macronutrients and micronutrients. The experiment was conducted for 60 days after transplanting in an evaporative greenhouse (avg temp = 28–30 °C, 60–65 %RH), using deep water culture technique. Plants were grown in nutrient solution consisting of complete Hoagland’s solution (CTRL), and nutrient solutions lacking one of the following macronutrients and micronutrients: nitrogen (-N), phosphorus (-P), potassium (-K), iron (-Fe), manganese (-Mn), and copper (-Cu). The deficiency symptoms, growth patterns, and stress response mechanism were followed. All treatments except for the CTRL induced deficiency symptoms and physiological changes. Macronutrient deprivation reduced growth determined by the morphological parameters while micronutrient omission had no effect except for no iron treatment. The result showed that potassium and iron deficiencies had foremost adversely effect on growth of Japanese mint. Under nutrient stress conditions, plant only gave antioxidative responses to phosphorus and potassium deficiencies. However, the negative plant-stress relationship was found for no iron treatment indicating the detoxification mode of plant for lacking of micronutrient.
bibliographic citation: Janpen et al. (2019) Physiological responses of hydroponically-grown Japanese mint under nutrient deficiency. PeerJ 7:e7751 https://doi.org/10.7717/peerj.7751
date submitted: 2019-06-05
date accepted: 2019-08-25
issued: 2019-09-26
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Janpen
  given name: Chananchida
author list: Agent
  family name: Kanthawang
  given name: Naruemon
author list: Agent
  family name: Inkham
  given name: Chaiartid
author list: Agent
  family name: Tsan
  given name: Fui Ying
author list: Agent
  family name: Sommano
  given name: Sarana Rose
doi: 10.7717/peerj.7751
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-09-26
copyright: ©2019 Janpen et al.
attribution name: Janpen et al.

Simulated manned Mars exploration: effects of dietary and diurnal cycle variations on the gut microbiome of crew members in a controlled ecological life support system
type: item
type: AcademicArticle
description: Background Changes in gut microbiome are closely related to dietary and environment variations, and diurnal circle interventions impact on human metabolism and the microbiome. Changes in human gut microbiome and serum biochemical parameters during long-term isolation in a controlled ecological life support system (CELSS) are of great significance for maintaining the health of crewmembers. The Green Star 180 project performed an integrated study involving a four-person, 180-day duration assessment in a CELSS, during which variations in gut microbiome and the concentration of serum 25-hydroxyvitamin D, α-tocopherol, retinol and folic acid from the crewmembers were determined. Results Energy intake and body mass index decreased during the experiment. A trade-off between Firmicutes and Bacteroidetes during the study period was observed. Dynamic variations in the two dominant genus Bacteroides and Prevotella indicated a variation of enterotypes. Both the evenness and richness of the fecal microbiome decreased during the isolation in the CELSS. Transition of diurnal circle from Earth to Mars increased the abundance of Fusobacteria phylum and decreased alpha diversity of the fecal microbiome. The levels of serum 25-hydroxyvitamin D in the CELSS were significantly lower than those outside the CELSS. Conclusions The unique isolation process in the CELSS led to a loss of alpha diversity and a transition of enterotypes between Bacteroides and Prevotella. Attention should therefore be paid to the transition of the diurnal circle and its effects on the gut microbiome during manned Mars explorations. In particular, serum 25-hydroxyvitamin D levels require monitoring under artificial light environments and during long-term space flight. Large-scale studies are required to further consolidate our findings.
format: application/pdf
format: text/html
creator: Hai-Sheng Dong
creator: Pu Chen
creator: Yan-Bo Yu
creator: Peng Zang
creator: Zhao Wei
subject: Biodiversity
subject: Bioinformatics
subject: Ecology
subject: Genomics
subject: Microbiology
description: doi:10.7717/peerj.7762
publisher: PeerJ Inc.
rights: © 2019 Dong et al.
abstract: Background Changes in gut microbiome are closely related to dietary and environment variations, and diurnal circle interventions impact on human metabolism and the microbiome. Changes in human gut microbiome and serum biochemical parameters during long-term isolation in a controlled ecological life support system (CELSS) are of great significance for maintaining the health of crewmembers. The Green Star 180 project performed an integrated study involving a four-person, 180-day duration assessment in a CELSS, during which variations in gut microbiome and the concentration of serum 25-hydroxyvitamin D, α-tocopherol, retinol and folic acid from the crewmembers were determined. Results Energy intake and body mass index decreased during the experiment. A trade-off between Firmicutes and Bacteroidetes during the study period was observed. Dynamic variations in the two dominant genus Bacteroides and Prevotella indicated a variation of enterotypes. Both the evenness and richness of the fecal microbiome decreased during the isolation in the CELSS. Transition of diurnal circle from Earth to Mars increased the abundance of Fusobacteria phylum and decreased alpha diversity of the fecal microbiome. The levels of serum 25-hydroxyvitamin D in the CELSS were significantly lower than those outside the CELSS. Conclusions The unique isolation process in the CELSS led to a loss of alpha diversity and a transition of enterotypes between Bacteroides and Prevotella. Attention should therefore be paid to the transition of the diurnal circle and its effects on the gut microbiome during manned Mars explorations. In particular, serum 25-hydroxyvitamin D levels require monitoring under artificial light environments and during long-term space flight. Large-scale studies are required to further consolidate our findings.
bibliographic citation: Dong et al. (2019) Simulated manned Mars exploration: effects of dietary and diurnal cycle variations on the gut microbiome of crew members in a controlled ecological life support system. PeerJ 7:e7762 https://doi.org/10.7717/peerj.7762
date submitted: 2019-03-08
date accepted: 2019-08-26
issued: 2019-09-26
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Dong
  given name: Hai-Sheng
author list: Agent
  family name: Chen
  given name: Pu
author list: Agent
  family name: Yu
  given name: Yan-Bo
author list: Agent
  family name: Zang
  given name: Peng
author list: Agent
  family name: Wei
  given name: Zhao
doi: 10.7717/peerj.7762
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-09-26
copyright: © 2019 Dong et al.
attribution name: Dong et al.

The relationships between bilingual learning, willingness to study abroad and convergent creativity
type: item
type: AcademicArticle
description: Convergent creativity is a form of creative thinking that uses existing knowledge or traditional methods to analyze available information and generate an appropriate solution. The differences in the performance of participants in convergent creativity caused by bilingual learning is a popular research area in creativity. A final sample of 68 participants was asked to complete the remote associates test (RAT). The results indicate that a moderate positive correlation exists between bilingual learning and convergent creativity. Students who want to study abroad perform better on the RAT than those who do not, and this effect is mediated by second language proficiency. These findings suggest that improving students’ English proficiency and increasing their opportunities to study abroad may be effective ways to promoting convergent creativity.
format: application/pdf
format: text/html
creator: Yuan Zhao
creator: Yuan Yuan
creator: Wangbing Shen
creator: Chuanlin Zhu
creator: Dianzhi Liu
subject: Psychiatry and Psychology
subject: Science and Medical Education
description: doi:10.7717/peerj.7776
publisher: PeerJ Inc.
rights: © 2019 Zhao et al.
abstract: Convergent creativity is a form of creative thinking that uses existing knowledge or traditional methods to analyze available information and generate an appropriate solution. The differences in the performance of participants in convergent creativity caused by bilingual learning is a popular research area in creativity. A final sample of 68 participants was asked to complete the remote associates test (RAT). The results indicate that a moderate positive correlation exists between bilingual learning and convergent creativity. Students who want to study abroad perform better on the RAT than those who do not, and this effect is mediated by second language proficiency. These findings suggest that improving students’ English proficiency and increasing their opportunities to study abroad may be effective ways to promoting convergent creativity.
bibliographic citation: Zhao et al. (2019) The relationships between bilingual learning, willingness to study abroad and convergent creativity. PeerJ 7:e7776 https://doi.org/10.7717/peerj.7776
date submitted: 2019-05-03
date accepted: 2019-08-27
issued: 2019-09-26
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Zhao
  given name: Yuan
author list: Agent
  family name: Yuan
  given name: Yuan
author list: Agent
  family name: Shen
  given name: Wangbing
author list: Agent
  family name: Zhu
  given name: Chuanlin
author list: Agent
  family name: Liu
  given name: Dianzhi
doi: 10.7717/peerj.7776
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-09-26
copyright: ©2019 Zhao et al.
attribution name: Zhao et al.

Transcriptome association studies of neuropsychiatric traits in African Americans implicate PRMT7 in schizophrenia
type: item
type: AcademicArticle
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.
format: application/pdf
format: text/html
creator: Peter N. Fiorica
creator: Heather E. Wheeler
subject: Genetics
subject: Genomics
subject: Psychiatry and Psychology
description: doi:10.7717/peerj.7778
publisher: PeerJ Inc.
rights: © 2019 Fiorica and Wheeler
abstract: 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.
bibliographic citation: Fiorica et al. (2019) Transcriptome association studies of neuropsychiatric traits in African Americans implicate PRMT7 in schizophrenia. PeerJ 7:e7778 https://doi.org/10.7717/peerj.7778
date submitted: 2019-05-13
date accepted: 2019-08-27
issued: 2019-09-26
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Fiorica
  given name: Peter N.
author list: Agent
  family name: Wheeler
  given name: Heather E.
doi: 10.7717/peerj.7778
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-09-26
copyright: © 2019 Fiorica and Wheeler
attribution name: Fiorica and Wheeler

Comprehensive evaluation of fluroxypyr herbicide on physiological parameters of spring hybrid millet
type: item
type: AcademicArticle
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.
format: application/pdf
format: text/html
creator: Meijun Guo
creator: Jie Shen
creator: Xi-e Song
creator: Shuqi Dong
creator: Yinyuan Wen
creator: Xiangyang Yuan
creator: Pingyi Guo
subject: Agricultural Science
subject: Plant Science
description: doi:10.7717/peerj.7794
publisher: PeerJ Inc.
rights: © 2019 Guo et al.
abstract: 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.
bibliographic citation: Guo et al. (2019) Comprehensive evaluation of fluroxypyr herbicide on physiological parameters of spring hybrid millet. PeerJ 7:e7794 https://doi.org/10.7717/peerj.7794
date submitted: 2019-03-18
date accepted: 2019-08-29
issued: 2019-09-26
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Guo
  given name: Meijun
author list: Agent
  family name: Shen
  given name: Jie
author list: Agent
  family name: Song
  given name: Xi-e
author list: Agent
  family name: Dong
  given name: Shuqi
author list: Agent
  family name: Wen
  given name: Yinyuan
author list: Agent
  family name: Yuan
  given name: Xiangyang
author list: Agent
  family name: Guo
  given name: Pingyi
doi: 10.7717/peerj.7794
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-09-26
copyright: © 2019 Guo et al.
attribution name: Guo et al.

The rediscovery of the rare Vietnamese endemic Eriophorum scabriculme redefines generic limits in the Scirpo-Caricoid Clade (Cyperaceae)
type: item
type: AcademicArticle
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.
format: application/pdf
format: text/html
creator: Julian R. Starr
creator: Étienne Léveillé-Bourret
creator: Vũ Anh Tài
creator: Nguyê˜n Thị Kim Thanh
creator: Bruce A. Ford
subject: Biodiversity
subject: Conservation Biology
subject: Plant Science
subject: Taxonomy
description: doi:10.7717/peerj.7538
publisher: PeerJ Inc.
rights: © 2019 Starr et al.
abstract: 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.
bibliographic citation: Starr et al. (2019) The rediscovery of the rare Vietnamese endemic Eriophorum scabriculme redefines generic limits in the Scirpo-Caricoid Clade (Cyperaceae). PeerJ 7:e7538 https://doi.org/10.7717/peerj.7538
date submitted: 2019-04-23
date accepted: 2019-07-23
issued: 2019-09-25
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Starr
  given name: Julian R.
author list: Agent
  family name: Léveillé-Bourret
  given name: Étienne
author list: Agent
  family name: Tài
  given name: Vũ Anh
author list: Agent
  family name: Thị Kim Thanh
  given name: Nguyê˜n
author list: Agent
  family name: Ford
  given name: Bruce A.
doi: 10.7717/peerj.7538
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-09-25
copyright: ©2019 Starr et al.
attribution name: Starr et al.

Cellular accumulation and cytotoxic effects of zinc oxide nanoparticles in microalga Haematococcus pluvialis
type: item
type: AcademicArticle
description: Background Zinc 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. Methods The 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. Results SEM-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. Discussion The present study reported the significant cellular accumulation of ZnO NPs in algal cells and the corresponding cytotoxic effects…
format: application/pdf
format: text/html
creator: Sinouvassane Djearamane
creator: Yang Mooi Lim
creator: Ling Shing Wong
creator: Poh Foong Lee
subject: Biochemistry
subject: Cell Biology
subject: Ecotoxicology
description: doi:10.7717/peerj.7582
publisher: PeerJ Inc.
rights: © 2019 Djearamane et al.
abstract: Background Zinc 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. Methods The 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. Results SEM-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. Discussion The present study reported the significant cellular accumulation of ZnO NPs in algal cells and the corresponding cytotoxic effects…
bibliographic citation: Djearamane et al. (2019) Cellular accumulation and cytotoxic effects of zinc oxide nanoparticles in microalga Haematococcus pluvialis. PeerJ 7:e7582 https://doi.org/10.7717/peerj.7582
date submitted: 2019-05-21
date accepted: 2019-07-29
issued: 2019-09-25
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Djearamane
  given name: Sinouvassane
author list: Agent
  family name: Lim
  given name: Yang Mooi
author list: Agent
  family name: Wong
  given name: Ling Shing
author list: Agent
  family name: Lee
  given name: Poh Foong
doi: 10.7717/peerj.7582
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-09-25
copyright: © 2019 Djearamane et al.
attribution name: Djearamane et al.

The effects of growth rate and biomechanical loading on bone laminarity within the emu skeleton
type: item
type: AcademicArticle
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 …
format: application/pdf
format: text/html
creator: Amanda L. Kuehn
creator: Andrew H. Lee
creator: Russell P. Main
creator: Erin L.R. Simons
subject: Developmental Biology
subject: Evolutionary Studies
subject: Histology
description: doi:10.7717/peerj.7616
publisher: PeerJ Inc.
rights: © 2019 Kuehn et al.
abstract: 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 …
bibliographic citation: Kuehn et al. (2019) The effects of growth rate and biomechanical loading on bone laminarity within the emu skeleton. PeerJ 7:e7616 https://doi.org/10.7717/peerj.7616
date submitted: 2018-05-08
date accepted: 2019-08-05
issued: 2019-09-25
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Kuehn
  given name: Amanda L.
author list: Agent
  family name: Lee
  given name: Andrew H.
author list: Agent
  family name: Main
  given name: Russell P.
author list: Agent
  family name: Simons
  given name: Erin L.R.
doi: 10.7717/peerj.7616
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-09-25
copyright: ©2019 Kuehn et al.
attribution name: Kuehn et al.

Bar-HRM: a reliable and fast method for species identification of ginseng (Panax ginseng, Panax notoginseng, Talinum paniculatum and Phytolacca Americana)
type: item
type: AcademicArticle
description: Background Korean 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. Methods DNA 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. Results The 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.
format: application/pdf
format: text/html
creator: Maslin Osathanunkul
creator: Panagiotis Madesis
subject: Agricultural Science
subject: Genetics
subject: Molecular Biology
subject: Plant Science
description: doi:10.7717/peerj.7660
publisher: PeerJ Inc.
rights: © 2019 Osathanunkul and Madesis
abstract: Background Korean 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. Methods DNA 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. Results The 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.
bibliographic citation: Osathanunkul et al. (2019) Bar-HRM: a reliable and fast method for species identification of ginseng (Panax ginseng, Panax notoginseng, Talinum paniculatum and Phytolacca Americana). PeerJ 7:e7660 https://doi.org/10.7717/peerj.7660
date submitted: 2019-05-14
date accepted: 2019-08-12
issued: 2019-09-25
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Osathanunkul
  given name: Maslin
author list: Agent
  family name: Madesis
  given name: Panagiotis
doi: 10.7717/peerj.7660
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-09-25
copyright: ©2019 Osathanunkul and Madesis
attribution name: Osathanunkul and Madesis

Effect of reduced pH on physiology and shell integrity of juvenile Haliotis iris (pāua) from New Zealand
type: item
type: AcademicArticle
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.
format: application/pdf
format: text/html
creator: Vonda J. Cummings
creator: Abigail M. Smith
creator: Peter M. Marriott
creator: Bryce A. Peebles
creator: N. Jane Halliday
subject: Ecology
subject: Marine Biology
subject: Climate Change Biology
subject: Biogeochemistry
description: doi:10.7717/peerj.7670
publisher: PeerJ Inc.
rights: © 2019 Cummings et al.
abstract: 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.
bibliographic citation: Cummings et al. (2019) Effect of reduced pH on physiology and shell integrity of juvenile Haliotis iris (pāua) from New Zealand. PeerJ 7:e7670 https://doi.org/10.7717/peerj.7670
date submitted: 2019-01-07
date accepted: 2019-08-13
issued: 2019-09-25
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Cummings
  given name: Vonda J.
author list: Agent
  family name: Smith
  given name: Abigail M.
author list: Agent
  family name: Marriott
  given name: Peter M.
author list: Agent
  family name: Peebles
  given name: Bryce A.
author list: Agent
  family name: Halliday
  given name: N. Jane
doi: 10.7717/peerj.7670
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-09-25
copyright: © 2019 Cummings et al.
attribution name: Cummings et al.

PeerJ
type: Periodical
uri: PeerJ
issn: 2167-8359