PeerJ
type: channel
link: https://peerj.com/articles/
description: Articles published in PeerJ
publisher: PeerJ Inc.
publication name: PeerJ
issn: 2167-8359
items: Extinction and the U.S. Endangered Species Act
items: eHealth adoption and use among healthcare professionals in a tertiary hospital in Sub-Saharan Africa: a Qmethodology study
items: Rapid ecological specialization despite constant population sizes
items: Ability emotional intelligence in young people and older adults with and without depressive symptoms, considering gender and educational level
items: The newly described Araguaian river dolphins, Inia araguaiaensis (Cetartiodactyla, Iniidae), produce a diverse repertoire of acoustic signals
items: Physiological responses of Oxyrrhis marina to a diet of virally infected Emiliania huxleyi
items: Modulation of biochemical and physiological parameters in Hordeum vulgare L. seedlings under the influence of benzyl-butyl phthalate
items: Effect of irradiance on the emission of short-lived halocarbons from three common tropical marine microalgae
items: An affordable and automated imaging approach to acquire highly resolved individual data—an example of copepod growth in response to multiple stressors
items: Using Ipomoea aquatic as an environmental-friendly alternative to Elodea nuttallii for the aquaculture of Chinese mitten crab

Extinction and the U.S. Endangered Species Act
type: item
type: AcademicArticle
description: The U.S. Endangered Species Act is one of the strongest laws of any nation for preventing species extinction, but quantifying the Act’s effectiveness has proven difficult. To provide one measure of effectiveness, we identified listed species that have gone extinct and used previously developed methods to update an estimate of the number of species extinctions prevented by the Act. To date, only four species have been confirmed extinct with another 22 possibly extinct following protection. Another 71 listed species are extinct or possibly extinct, but were last seen before protections were enacted, meaning the Act’s protections never had the opportunity to save these species. In contrast, a total of 39 species have been fully recovered, including 23 in the last 10 years. We estimate the Endangered Species Act has prevented the extinction of roughly 291 species since passage in 1973, and has to date saved more than 99% of species under its protection.
format: application/pdf
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creator: Noah Greenwald
creator: Kieran F. Suckling
creator: Brett Hartl
creator: Loyal A. Mehrhoff
subject: Biodiversity
subject: Conservation Biology
subject: Science Policy
description: doi:10.7717/peerj.6803
publisher: PeerJ Inc.
rights: © 2019 Greenwald et al.
abstract: The U.S. Endangered Species Act is one of the strongest laws of any nation for preventing species extinction, but quantifying the Act’s effectiveness has proven difficult. To provide one measure of effectiveness, we identified listed species that have gone extinct and used previously developed methods to update an estimate of the number of species extinctions prevented by the Act. To date, only four species have been confirmed extinct with another 22 possibly extinct following protection. Another 71 listed species are extinct or possibly extinct, but were last seen before protections were enacted, meaning the Act’s protections never had the opportunity to save these species. In contrast, a total of 39 species have been fully recovered, including 23 in the last 10 years. We estimate the Endangered Species Act has prevented the extinction of roughly 291 species since passage in 1973, and has to date saved more than 99% of species under its protection.
bibliographic citation: Greenwald et al. (2019) Extinction and the U.S. Endangered Species Act. PeerJ 7:e6803 https://doi.org/10.7717/peerj.6803
date submitted: 2019-01-07
date accepted: 2019-03-16
issued: 2019-04-22
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Greenwald
  given name: Noah
author list: Agent
  family name: Suckling
  given name: Kieran F.
author list: Agent
  family name: Hartl
  given name: Brett
author list: Agent
  family name: A. Mehrhoff
  given name: Loyal
doi: 10.7717/peerj.6803
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-04-22
copyright: © 2019 Greenwald et al.
attribution name: Greenwald et al.

eHealth adoption and use among healthcare professionals in a tertiary hospital in Sub-Saharan Africa: a Qmethodology study
type: item
type: AcademicArticle
description: Background The aim of the study was to explore the viewpoints of healthcare professionals (HCPs) on the adoption and use of eHealth in clinical practice in sub-Saharan Africa (SSA). Information and communication technologies (ICTs) including eHealth provide HCPs the opportunity to provide quality healthcare to their patients while also improving their own clinical practices. Despite this, previous research has identified these technologies have their associated challenges when adopting them for clinical practice. But more research is needed to identify how these eHealth resources influence clinical practice. In addition, there is still little information about adoption and use of these technologies by HCPs inclinical practice in Sub-Saharan Africa. Method An exploratory descriptive design was adopted for this study. Thirty-six (36) HCPs (18 nurses and 18 physicians) working in the clinical area in a tertiary health institution in SSA participated in this study. Using Qmethodology, study participants rank-ordered forty-six statementsin relation to their adoption and use of eHealth within their clinical practice.This was analysed using by-person factor analysis and complemented with audio-taped interviews. Results The analysis yielded four factors i.e., distinct viewpoints the HCPs hold about adoption and use of eHealth within their clinical practice. These factors include: “Patient-focused eHealth advocates” who use the eHealth because they are motivated by patients and their families preferences; “Task-focused eHealth advocates” use eHealth because it helps them complete clinical tasks; “Traditionalistic-pragmatists” recognise contributions eHealth makes in clinical practice but separate from their routine clinical activities; and the “Tech-focused eHealth advocates” who use the eHealth because they are motivated by the technology itself. Conclusion The study shows the equivocal viewpoints that HCPs have about eHealth within their clinical practice. This, in additio…
format: application/pdf
format: text/html
creator: Muhammad Awwal Ladan
creator: Heather Wharrad
creator: Richard Windle
subject: Nursing
subject: Human–Computer Interaction
description: doi:10.7717/peerj.6326
publisher: PeerJ Inc.
rights: © 2019 Ladan et al.
abstract: Background The aim of the study was to explore the viewpoints of healthcare professionals (HCPs) on the adoption and use of eHealth in clinical practice in sub-Saharan Africa (SSA). Information and communication technologies (ICTs) including eHealth provide HCPs the opportunity to provide quality healthcare to their patients while also improving their own clinical practices. Despite this, previous research has identified these technologies have their associated challenges when adopting them for clinical practice. But more research is needed to identify how these eHealth resources influence clinical practice. In addition, there is still little information about adoption and use of these technologies by HCPs inclinical practice in Sub-Saharan Africa. Method An exploratory descriptive design was adopted for this study. Thirty-six (36) HCPs (18 nurses and 18 physicians) working in the clinical area in a tertiary health institution in SSA participated in this study. Using Qmethodology, study participants rank-ordered forty-six statementsin relation to their adoption and use of eHealth within their clinical practice.This was analysed using by-person factor analysis and complemented with audio-taped interviews. Results The analysis yielded four factors i.e., distinct viewpoints the HCPs hold about adoption and use of eHealth within their clinical practice. These factors include: “Patient-focused eHealth advocates” who use the eHealth because they are motivated by patients and their families preferences; “Task-focused eHealth advocates” use eHealth because it helps them complete clinical tasks; “Traditionalistic-pragmatists” recognise contributions eHealth makes in clinical practice but separate from their routine clinical activities; and the “Tech-focused eHealth advocates” who use the eHealth because they are motivated by the technology itself. Conclusion The study shows the equivocal viewpoints that HCPs have about eHealth within their clinical practice. This, in additio…
bibliographic citation: Ladan et al. (2019) eHealth adoption and use among healthcare professionals in a tertiary hospital in Sub-Saharan Africa: a Qmethodology study. PeerJ 7:e6326 https://doi.org/10.7717/peerj.6326
date submitted: 2018-10-12
date accepted: 2018-12-20
issued: 2019-04-19
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Ladan
  given name: Muhammad Awwal
author list: Agent
  family name: Wharrad
  given name: Heather
author list: Agent
  family name: Windle
  given name: Richard
doi: 10.7717/peerj.6326
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-04-19
copyright: ©2019 Ladan et al.
attribution name: Ladan et al.

Rapid ecological specialization despite constant population sizes
type: item
type: AcademicArticle
description: Background The bushbuck, Tragelaphus scriptus, is a widespread and ecologically diverse ungulate species complex within the spiral-horned antelopes. This species was recently found to consist of two genetically divergent but monophyletic lineages, which are paraphyletic at mitochondrial (mt)DNA owing to an ancient interspecific hybridization event. The Scriptus lineage (T. s. scriptus) inhabits the north-western half of the African continent while Sylvaticus (T. s. sylvaticus) is found in the south-eastern half. Here we test hypotheses of historical demography and adaptation in bushbuck using a higher-resolution framework, with four nuclear (MGF, PRKCI, SPTBN, and THY) and three new mitochondrial markers (cytochrome b, 12S rRNA, and 16S rRNA). Methods Genealogies were reconstructed for the mitochondrial and nuclear data sets, with the latter dated using fossil calibration points. We also inferred the demographic history of Scriptus and Sylvaticus using coalescent-based methods. To obtain an overview of the origins and ancestral colonisation routes of ancestral bushbuck sequences across geographic space, we conducted discrete Bayesian phylogeographic and statistical dispersal-vicariance analyses on our nuclear DNA data set. Results Both nuclear DNA and mtDNA support previous findings of two genetically divergent Sylvaticus and Scriptus lineages. The three mtDNA loci confirmed 15 of the previously defined haplogroups, including those with convergent phenotypes. However, the nuclear tree showed less phylogenetic resolution at the more derived parts of the genealogy, possibly due to incomplete lineage sorting of the slower evolving nuclear genome. The only exception to this was the montane Menelik’s bushbuck (Sylvaticus) of the Ethiopian highlands, which formed a monophyletic group at three of four nuclear DNA loci. We dated the coalescence of the two lineages to a common ancestor ∼2.54 million years ago. Both marker sets revealed similar demographic histories of consta…
format: application/pdf
format: text/html
creator: Andrinajoro R. Rakotoarivelo
creator: Paul O’Donoghue
creator: Michael W. Bruford
creator: Yoshan Moodley
subject: Biodiversity
subject: Biogeography
subject: Conservation Biology
subject: Genetics
subject: Zoology
description: doi:10.7717/peerj.6476
publisher: PeerJ Inc.
rights: © 2019 Rakotoarivelo et al.
abstract: Background The bushbuck, Tragelaphus scriptus, is a widespread and ecologically diverse ungulate species complex within the spiral-horned antelopes. This species was recently found to consist of two genetically divergent but monophyletic lineages, which are paraphyletic at mitochondrial (mt)DNA owing to an ancient interspecific hybridization event. The Scriptus lineage (T. s. scriptus) inhabits the north-western half of the African continent while Sylvaticus (T. s. sylvaticus) is found in the south-eastern half. Here we test hypotheses of historical demography and adaptation in bushbuck using a higher-resolution framework, with four nuclear (MGF, PRKCI, SPTBN, and THY) and three new mitochondrial markers (cytochrome b, 12S rRNA, and 16S rRNA). Methods Genealogies were reconstructed for the mitochondrial and nuclear data sets, with the latter dated using fossil calibration points. We also inferred the demographic history of Scriptus and Sylvaticus using coalescent-based methods. To obtain an overview of the origins and ancestral colonisation routes of ancestral bushbuck sequences across geographic space, we conducted discrete Bayesian phylogeographic and statistical dispersal-vicariance analyses on our nuclear DNA data set. Results Both nuclear DNA and mtDNA support previous findings of two genetically divergent Sylvaticus and Scriptus lineages. The three mtDNA loci confirmed 15 of the previously defined haplogroups, including those with convergent phenotypes. However, the nuclear tree showed less phylogenetic resolution at the more derived parts of the genealogy, possibly due to incomplete lineage sorting of the slower evolving nuclear genome. The only exception to this was the montane Menelik’s bushbuck (Sylvaticus) of the Ethiopian highlands, which formed a monophyletic group at three of four nuclear DNA loci. We dated the coalescence of the two lineages to a common ancestor ∼2.54 million years ago. Both marker sets revealed similar demographic histories of consta…
bibliographic citation: Rakotoarivelo et al. (2019) Rapid ecological specialization despite constant population sizes. PeerJ 7:e6476 https://doi.org/10.7717/peerj.6476
date submitted: 2018-07-27
date accepted: 2019-01-17
issued: 2019-04-19
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Rakotoarivelo
  given name: Andrinajoro R.
author list: Agent
  family name: O’Donoghue
  given name: Paul
author list: Agent
  family name: Bruford
  given name: Michael W.
author list: Agent
  family name: Moodley
  given name: Yoshan
doi: 10.7717/peerj.6476
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-04-19
copyright: ©2019 Rakotoarivelo et al.
attribution name: Rakotoarivelo et al.

Ability emotional intelligence in young people and older adults with and without depressive symptoms, considering gender and educational level
type: item
type: AcademicArticle
description: Background There is little research on differences in Emotional Intelligence (EI) ability at different stages of adult development. The few published studies tend not to use older adult samples. Previous studies on EI ability and age have shown contradictory results. Our main objective was to evaluate results in EI ability across different stages of adult development, taking into account gender, depressive symptoms, and educational level. Methods We interviewed 166 participants (108 women), 66 of whom were aged 18–30 years, 53 aged 31–60 years, and 40 aged 61–76 years. All were either working or enrolled in colleges at the time of the study. The assessment tools used were the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT), a test that assesses performance-based EI, and the Centre for Epidemiologic Studies-Depression (CES-D) scale, a tool to evaluate depressive symptoms. Results Young people, women, and participants with a higher educational level achieved higher scores on the MSCEIT. Additionally, depressive symptomatology was only partially associated with the MSCEIT (i.e., with the using emotions branch). However, a subsequent joint analysis of the independent effects of variables age, gender, educational level, and depressive symptomatology and their interactions on MSCEIT total suggests that only educational level and depressive symptomatology were associated with EI ability, with the direct relationship between age and gender with MSCEIT disappearing. Additionally, our study indicated an interaction effect between age and depressive symptoms, showing that participants in age cohorts 18–30 and 31–60 and without depressive symptoms have a higher EI ability. Discussion Our study suggests that the direct effects of age and gender on EI ability across adult development, using a wide age range, can change or disappear when effects of educational level and depressive symptomatology, and their interactions, are controlled for. Our results also suggest that E…
format: application/pdf
format: text/html
creator: Beatriz Navarro-Bravo
creator: José M. Latorre
creator: Ana Jiménez
creator: Rosario Cabello
creator: Pablo Fernández-Berrocal
subject: Geriatrics
subject: Psychiatry and Psychology
description: doi:10.7717/peerj.6595
publisher: PeerJ Inc.
rights: © 2019 Navarro-Bravo et al.
abstract: Background There is little research on differences in Emotional Intelligence (EI) ability at different stages of adult development. The few published studies tend not to use older adult samples. Previous studies on EI ability and age have shown contradictory results. Our main objective was to evaluate results in EI ability across different stages of adult development, taking into account gender, depressive symptoms, and educational level. Methods We interviewed 166 participants (108 women), 66 of whom were aged 18–30 years, 53 aged 31–60 years, and 40 aged 61–76 years. All were either working or enrolled in colleges at the time of the study. The assessment tools used were the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT), a test that assesses performance-based EI, and the Centre for Epidemiologic Studies-Depression (CES-D) scale, a tool to evaluate depressive symptoms. Results Young people, women, and participants with a higher educational level achieved higher scores on the MSCEIT. Additionally, depressive symptomatology was only partially associated with the MSCEIT (i.e., with the using emotions branch). However, a subsequent joint analysis of the independent effects of variables age, gender, educational level, and depressive symptomatology and their interactions on MSCEIT total suggests that only educational level and depressive symptomatology were associated with EI ability, with the direct relationship between age and gender with MSCEIT disappearing. Additionally, our study indicated an interaction effect between age and depressive symptoms, showing that participants in age cohorts 18–30 and 31–60 and without depressive symptoms have a higher EI ability. Discussion Our study suggests that the direct effects of age and gender on EI ability across adult development, using a wide age range, can change or disappear when effects of educational level and depressive symptomatology, and their interactions, are controlled for. Our results also suggest that E…
bibliographic citation: Navarro-Bravo et al. (2019) Ability emotional intelligence in young people and older adults with and without depressive symptoms, considering gender and educational level. PeerJ 7:e6595 https://doi.org/10.7717/peerj.6595
date submitted: 2018-07-31
date accepted: 2019-02-09
issued: 2019-04-19
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Navarro-Bravo
  given name: Beatriz
author list: Agent
  family name: Latorre
  given name: José M.
author list: Agent
  family name: Jiménez
  given name: Ana
author list: Agent
  family name: Cabello
  given name: Rosario
author list: Agent
  family name: Fernández-Berrocal
  given name: Pablo
doi: 10.7717/peerj.6595
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-04-19
copyright: ©2019 Navarro-Bravo et al.
attribution name: Navarro-Bravo et al.

The newly described Araguaian river dolphins, Inia araguaiaensis (Cetartiodactyla, Iniidae), produce a diverse repertoire of acoustic signals
type: item
type: AcademicArticle
description: The recent discovery of the Araguaian river dolphin (Inia araguaiaensis) highlights how little we know about the diversity and biology of river dolphins. In this study, we described the acoustic repertoire of this newly discovered species in concert with their behaviour. We analysed frequency contours of 727 signals (sampled at 10 ms temporal resolution). These contours were analyzed using an adaptive resonance theory neural network combined with dynamic time-warping (ARTwarp). Using a critical similarity value of 96%, frequency contours were categorized into 237 sound-types. The most common types were emitted when calves were present suggesting a key role in mother-calf communication. Our findings show that the acoustic repertoire of river dolphins is far from simple. Furthermore, the calls described here are similar in acoustic structure to those produced by social delphinids, such as orcas and pilot whales. Uncovering the context in which these signals are produced may help understand the social structure of this species and contribute to our understanding of the evolution of acoustic communication in whales.
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creator: Gabriel Melo-Santos
creator: Angélica Lúcia Figueiredo Rodrigues
creator: Rodrigo Hipólito Tardin
creator: Israel de Sá Maciel
creator: Miriam Marmontel
creator: Maria Luisa Da Silva
creator: Laura Johanna May-Collado
subject: Animal Behavior
subject: Biodiversity
subject: Ecology
subject: Zoology
subject: Freshwater Biology
description: doi:10.7717/peerj.6670
publisher: PeerJ Inc.
rights: © 2019 Melo-Santos et al.
abstract: The recent discovery of the Araguaian river dolphin (Inia araguaiaensis) highlights how little we know about the diversity and biology of river dolphins. In this study, we described the acoustic repertoire of this newly discovered species in concert with their behaviour. We analysed frequency contours of 727 signals (sampled at 10 ms temporal resolution). These contours were analyzed using an adaptive resonance theory neural network combined with dynamic time-warping (ARTwarp). Using a critical similarity value of 96%, frequency contours were categorized into 237 sound-types. The most common types were emitted when calves were present suggesting a key role in mother-calf communication. Our findings show that the acoustic repertoire of river dolphins is far from simple. Furthermore, the calls described here are similar in acoustic structure to those produced by social delphinids, such as orcas and pilot whales. Uncovering the context in which these signals are produced may help understand the social structure of this species and contribute to our understanding of the evolution of acoustic communication in whales.
bibliographic citation: Melo-Santos et al. (2019) The newly described Araguaian river dolphins, Inia araguaiaensis (Cetartiodactyla, Iniidae), produce a diverse repertoire of acoustic signals. PeerJ 7:e6670 https://doi.org/10.7717/peerj.6670
date submitted: 2018-06-07
date accepted: 2019-02-22
issued: 2019-04-19
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Melo-Santos
  given name: Gabriel
author list: Agent
  family name: Figueiredo Rodrigues
  given name: Angélica Lúcia
author list: Agent
  family name: Tardin
  given name: Rodrigo Hipólito
author list: Agent
  family name: de Sá Maciel
  given name: Israel
author list: Agent
  family name: Marmontel
  given name: Miriam
author list: Agent
  family name: Da Silva
  given name: Maria Luisa
author list: Agent
  family name: May-Collado
  given name: Laura Johanna
doi: 10.7717/peerj.6670
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-04-19
copyright: ©2019 Melo-Santos et al.
attribution name: Melo-Santos et al.

Physiological responses of Oxyrrhis marina to a diet of virally infected Emiliania huxleyi
type: item
type: AcademicArticle
description: The coccolithophore Emiliania huxleyi forms some of the largest phytoplankton blooms in the ocean. The rapid demise of these blooms has been linked to viral infections. E. huxleyi abundance, distribution, and nutritional status make them an important food source for the heterotrophic protists which are classified as microzooplankton in marine food webs. In this study we investigated the fate of E. huxleyi (CCMP 374) infected with virus strain EhV-86 in a simple predator-prey interaction. The ingestion rates of Oxyrrhis marina were significantly lower (between 26.9 and 50.4%) when fed virus-infected E. huxleyi cells compared to non-infected cells. Despite the lower ingestion rates, O. marina showed significantly higher growth rates (between 30 and 91.3%) when fed infected E. huxleyi cells, suggesting higher nutritional value and/or greater assimilation of infected E. huxleyi cells. No significant differences were found in O. marina cell volumes or fatty acids profiles. These results show that virally infected E. huxleyi support higher growth rates of single celled heterotrophs and in addition to the “viral shunt” hypothesis, viral infections may also divert more carbon to mesozooplankton grazers.
format: application/pdf
format: text/html
creator: Andrew G. Goode
creator: David M. Fields
creator: Stephen D. Archer
creator: Joaquín Martínez Martínez
subject: Marine Biology
subject: Microbiology
subject: Virology
subject: Biological Oceanography
description: doi:10.7717/peerj.6722
publisher: PeerJ Inc.
rights: © 2019 Goode et al.
abstract: The coccolithophore Emiliania huxleyi forms some of the largest phytoplankton blooms in the ocean. The rapid demise of these blooms has been linked to viral infections. E. huxleyi abundance, distribution, and nutritional status make them an important food source for the heterotrophic protists which are classified as microzooplankton in marine food webs. In this study we investigated the fate of E. huxleyi (CCMP 374) infected with virus strain EhV-86 in a simple predator-prey interaction. The ingestion rates of Oxyrrhis marina were significantly lower (between 26.9 and 50.4%) when fed virus-infected E. huxleyi cells compared to non-infected cells. Despite the lower ingestion rates, O. marina showed significantly higher growth rates (between 30 and 91.3%) when fed infected E. huxleyi cells, suggesting higher nutritional value and/or greater assimilation of infected E. huxleyi cells. No significant differences were found in O. marina cell volumes or fatty acids profiles. These results show that virally infected E. huxleyi support higher growth rates of single celled heterotrophs and in addition to the “viral shunt” hypothesis, viral infections may also divert more carbon to mesozooplankton grazers.
bibliographic citation: Goode et al. (2019) Physiological responses of Oxyrrhis marina to a diet of virally infected Emiliania huxleyi. PeerJ 7:e6722 https://doi.org/10.7717/peerj.6722
date submitted: 2018-04-09
date accepted: 2019-03-05
issued: 2019-04-19
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Goode
  given name: Andrew G.
author list: Agent
  family name: Fields
  given name: David M.
author list: Agent
  family name: Archer
  given name: Stephen D.
author list: Agent
  family name: Martínez Martínez
  given name: Joaquín
doi: 10.7717/peerj.6722
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-04-19
copyright: ©2019 Goode et al.
attribution name: Goode et al.

Modulation of biochemical and physiological parameters in Hordeum vulgare L. seedlings under the influence of benzyl-butyl phthalate
type: item
type: AcademicArticle
description: Background Phthalates are man-made chemical compounds with numerous applications especially known for their use as plasticizers. They have weak bonding to the polymeric matrix or products in which they are used. Owing to this reason, they are readily released into the environment which makes them ubiquitous. The agricultural soils are also reported to be polluted with phthalates up to a considerable extent which causes adverse effects on flora and fauna. A few studies have been conducted on phthalate-induced phytotoxicity, which has revealed that phthalates affect the quality and yield of edible plants. In the last decades, some crops were analyzed for phthalate-induced adversities; among them, barley was the least explored. Methods The present study has investigated the impact of benzyl-butyl phthalate (BBP) on barley (Hordeum vulgare L.) seedlings to address the biochemical, physiological consequences, and toxicological implications. After the exogenous exposure of BBP (viz. 0, 25, 50, 100, 200, 400, 800, 1,600 mg/L) for 7 days, barley seedlings were analyzed for different indices. Results The exposure of BBP mediated a significant (p ≤ 0.05, 0.01) overall elevation in the contents of pigment, proline, soluble protein, carbohydrate, hydrogen peroxide (H2O2), and malondialdehyde (MDA) in shoots and roots of barley seedlings. The activities of superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) were also stimulated significantly in shoots and roots of seedlings against BBP stress except for SOD activity which declined in the roots. The polyphenols (non-enzymatic antioxidants) content was also altered in all the treated concentrations as compared to the control. Furthermore, BBP caused stomatal abnormalities, induced cytotoxicity, and loss of plasma membrane integrity. Conclusions BBP disturbed the normal physiology of barley which could also affect the yield of the crop under field conditi…
format: application/pdf
format: text/html
creator: Arpna Kumari
creator: Rajinder Kaur
subject: Agricultural Science
subject: Plant Science
subject: Ecotoxicology
description: doi:10.7717/peerj.6742
publisher: PeerJ Inc.
rights: © 2019 Kumari and Kaur
abstract: Background Phthalates are man-made chemical compounds with numerous applications especially known for their use as plasticizers. They have weak bonding to the polymeric matrix or products in which they are used. Owing to this reason, they are readily released into the environment which makes them ubiquitous. The agricultural soils are also reported to be polluted with phthalates up to a considerable extent which causes adverse effects on flora and fauna. A few studies have been conducted on phthalate-induced phytotoxicity, which has revealed that phthalates affect the quality and yield of edible plants. In the last decades, some crops were analyzed for phthalate-induced adversities; among them, barley was the least explored. Methods The present study has investigated the impact of benzyl-butyl phthalate (BBP) on barley (Hordeum vulgare L.) seedlings to address the biochemical, physiological consequences, and toxicological implications. After the exogenous exposure of BBP (viz. 0, 25, 50, 100, 200, 400, 800, 1,600 mg/L) for 7 days, barley seedlings were analyzed for different indices. Results The exposure of BBP mediated a significant (p ≤ 0.05, 0.01) overall elevation in the contents of pigment, proline, soluble protein, carbohydrate, hydrogen peroxide (H2O2), and malondialdehyde (MDA) in shoots and roots of barley seedlings. The activities of superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) were also stimulated significantly in shoots and roots of seedlings against BBP stress except for SOD activity which declined in the roots. The polyphenols (non-enzymatic antioxidants) content was also altered in all the treated concentrations as compared to the control. Furthermore, BBP caused stomatal abnormalities, induced cytotoxicity, and loss of plasma membrane integrity. Conclusions BBP disturbed the normal physiology of barley which could also affect the yield of the crop under field conditi…
bibliographic citation: Kumari et al. (2019) Modulation of biochemical and physiological parameters in Hordeum vulgare L. seedlings under the influence of benzyl-butyl phthalate. PeerJ 7:e6742 https://doi.org/10.7717/peerj.6742
date submitted: 2018-11-02
date accepted: 2019-03-06
issued: 2019-04-19
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Kumari
  given name: Arpna
author list: Agent
  family name: Kaur
  given name: Rajinder
doi: 10.7717/peerj.6742
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-04-19
copyright: ©2019 Kumari and Kaur
attribution name: Kumari and Kaur

Effect of irradiance on the emission of short-lived halocarbons from three common tropical marine microalgae
type: item
type: AcademicArticle
description: Marine algae have been reported as important sources of biogenic volatile halocarbons that are emitted into the atmosphere. These compounds are linked to destruction of the ozone layer, thus contributing to climate change. There may be mutual interactions between the halocarbon emission and the environment. In this study, the effect of irradiance on the emission of halocarbons from selected microalgae was investigated. Using controlled laboratory experiments, three tropical marine microalgae cultures, Synechococcus sp. UMACC 371 (cyanophyte), Parachlorella sp. UMACC 245 (chlorophyte) and Amphora sp. UMACC 370 (diatom) were exposed to irradiance of 0, 40 and 120 µmol photons m−2s−1. Stress in the microalgal cultures was indicated by the photosynthetic performance (Fv/Fm, maximum quantum yield). An increase in halocarbon emissions was observed at 120 µmol photons m−2s−1, together with a decrease in Fv/Fm. This was most evident in the release of CH3I by Amphora sp. Synechococcus sp. was observed to be the most affected by irradiance as shown by the increase in emissions of most halocarbons except for CHBr3 and CHBr2Cl. High positive correlation between Fv/Fm and halocarbon emission rates was observed in Synechococcus sp. for CH2Br2. No clear trends in correlation could be observed for the other halocarbons in the other two microalgal species. This suggests that other mechanisms like mitochondria respiration may contribute to halocarbon production, in addition to photosynthetic performance.
format: application/pdf
format: text/html
creator: Yong-Kian Lim
creator: Fiona Seh-Lin Keng
creator: Siew-Moi Phang
creator: William T. Sturges
creator: Gill Malin
creator: Noorsaadah Abd Rahman
subject: Marine Biology
subject: Biosphere Interactions
subject: Climate Change Biology
subject: Biogeochemistry
subject: Environmental Impacts
description: doi:10.7717/peerj.6758
publisher: PeerJ Inc.
rights: © 2019 Lim et al.
abstract: Marine algae have been reported as important sources of biogenic volatile halocarbons that are emitted into the atmosphere. These compounds are linked to destruction of the ozone layer, thus contributing to climate change. There may be mutual interactions between the halocarbon emission and the environment. In this study, the effect of irradiance on the emission of halocarbons from selected microalgae was investigated. Using controlled laboratory experiments, three tropical marine microalgae cultures, Synechococcus sp. UMACC 371 (cyanophyte), Parachlorella sp. UMACC 245 (chlorophyte) and Amphora sp. UMACC 370 (diatom) were exposed to irradiance of 0, 40 and 120 µmol photons m−2s−1. Stress in the microalgal cultures was indicated by the photosynthetic performance (Fv/Fm, maximum quantum yield). An increase in halocarbon emissions was observed at 120 µmol photons m−2s−1, together with a decrease in Fv/Fm. This was most evident in the release of CH3I by Amphora sp. Synechococcus sp. was observed to be the most affected by irradiance as shown by the increase in emissions of most halocarbons except for CHBr3 and CHBr2Cl. High positive correlation between Fv/Fm and halocarbon emission rates was observed in Synechococcus sp. for CH2Br2. No clear trends in correlation could be observed for the other halocarbons in the other two microalgal species. This suggests that other mechanisms like mitochondria respiration may contribute to halocarbon production, in addition to photosynthetic performance.
bibliographic citation: Lim et al. (2019) Effect of irradiance on the emission of short-lived halocarbons from three common tropical marine microalgae. PeerJ 7:e6758 https://doi.org/10.7717/peerj.6758
date submitted: 2018-09-11
date accepted: 2019-03-09
issued: 2019-04-19
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Lim
  given name: Yong-Kian
author list: Agent
  family name: Keng
  given name: Fiona Seh-Lin
author list: Agent
  family name: Phang
  given name: Siew-Moi
author list: Agent
  family name: Sturges
  given name: William T.
author list: Agent
  family name: Malin
  given name: Gill
author list: Agent
  family name: Abd Rahman
  given name: Noorsaadah
doi: 10.7717/peerj.6758
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-04-19
copyright: ©2019 Lim et al.
attribution name: Lim et al.

An affordable and automated imaging approach to acquire highly resolved individual data—an example of copepod growth in response to multiple stressors
type: item
type: AcademicArticle
description: Individual trait variation is essential for populations to cope with multiple stressors and continuously changing environments. The immense number of possible stressor combinations and the influence of phenotypic variation makes experimental testing for effects on organisms challenging. The acquisition of such data requires many replicates and is notoriously laborious. It is further complicated when responses occur over short time periods. To overcome such challenges, we developed an automated imaging platform to acquire temporally highly resolved individual data. We tested this platform by exposing copepods to a combination of a biotic stressor (predator cues) and a toxicant (copper) and measured the growth response of individual copepods. We tested the automatically acquired data against published manually acquired data with much lower temporal resolution. We find the same general potentiating effects of predator cues on the adverse effects of copper, and the influence of an individual’s clutch identity on its ability to resist stress, between the data obtained from low and high temporal resolution. However, when using the high temporal resolution, we also uncovered effects of clutch ID on the timing and duration of stage transitions, which highlights the importance of considering phenotypic variation in ecotoxicological testing. Phenotypic variation is usually not acknowledged in ecotoxicological testing. Our approach is scalable, affordable, and adjustable to accommodate both aquatic and terrestrial organisms, and a wide range of visually detectable endpoints. We discuss future extensions that would further widen its applicability.
format: application/pdf
format: text/html
creator: Jan Heuschele
creator: Torben Lode
creator: Tom Andersen
creator: Katrine Borgå
creator: Josefin Titelman
subject: Marine Biology
subject: Toxicology
subject: Ecotoxicology
description: doi:10.7717/peerj.6776
publisher: PeerJ Inc.
rights: © 2019 Heuschele et al.
abstract: Individual trait variation is essential for populations to cope with multiple stressors and continuously changing environments. The immense number of possible stressor combinations and the influence of phenotypic variation makes experimental testing for effects on organisms challenging. The acquisition of such data requires many replicates and is notoriously laborious. It is further complicated when responses occur over short time periods. To overcome such challenges, we developed an automated imaging platform to acquire temporally highly resolved individual data. We tested this platform by exposing copepods to a combination of a biotic stressor (predator cues) and a toxicant (copper) and measured the growth response of individual copepods. We tested the automatically acquired data against published manually acquired data with much lower temporal resolution. We find the same general potentiating effects of predator cues on the adverse effects of copper, and the influence of an individual’s clutch identity on its ability to resist stress, between the data obtained from low and high temporal resolution. However, when using the high temporal resolution, we also uncovered effects of clutch ID on the timing and duration of stage transitions, which highlights the importance of considering phenotypic variation in ecotoxicological testing. Phenotypic variation is usually not acknowledged in ecotoxicological testing. Our approach is scalable, affordable, and adjustable to accommodate both aquatic and terrestrial organisms, and a wide range of visually detectable endpoints. We discuss future extensions that would further widen its applicability.
bibliographic citation: Heuschele et al. (2019) An affordable and automated imaging approach to acquire highly resolved individual data—an example of copepod growth in response to multiple stressors. PeerJ 7:e6776 https://doi.org/10.7717/peerj.6776
date submitted: 2018-11-28
date accepted: 2019-03-12
issued: 2019-04-19
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Heuschele
  given name: Jan
author list: Agent
  family name: Lode
  given name: Torben
author list: Agent
  family name: Andersen
  given name: Tom
author list: Agent
  family name: Borgå
  given name: Katrine
author list: Agent
  family name: Titelman
  given name: Josefin
doi: 10.7717/peerj.6776
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-04-19
copyright: © 2019 Heuschele et al.
attribution name: Heuschele et al.

Using Ipomoea aquatic as an environmental-friendly alternative to Elodea nuttallii for the aquaculture of Chinese mitten crab
type: item
type: AcademicArticle
description: Elodea nuttallii is widely used in Chinese mitten crab (CMC) rearing practice, but it is not a native aquatic plant and cannot endure high temperature. Thus, large E. nuttallii mortality and water deterioration events could occur during high-temperature seasons. The aim of this study was to identify the use of local macrophytes in CMC rearing practice, including Ipomoea aquatic and Oryza sativa. A completely randomized field experiment was conducted to investigate the crab yield, water quality, bacterioplankton community and functions in the three different systems (E. nuttallii, I. aquatic, and O. sativa). Average crab yields in the different macrophyte systems did not differ significantly. The I. aquatic and O. sativa systems significantly decreased the total nitrogen and nitrate-N quantities in the outflow waters during the rearing period compared to the E. nuttallii system, and the I. aquatic and O. sativa plants assimilated more nitrogen than the E. nuttallii plant. Moreover, the significant changes of bacterioplankton abundances and biodiversity in the three systems implied that cleanliness of rearing waters was concomitantly attributed to the differential microbial community and functions. In addition, principle component analysis successfully differentiated the bacterioplankton communities of the three macrophytes systems. Environmental factor fitting and the co-occurrence network analyses indicated that pH was the driver of bacterioplankton community structure. Functional predictions using PICRUSt (v.1.1.3) software based on evolutionary modeling indicated a higher potential for microbial denitrification in the I. aquatic and O. sativa systems. Notably, the O. sativa plants stopped growing in the middle of the rearing period. Thus, the I. aquatic system rather than the O. sativa system could be a feasible and environmental-friendly alternative to the E. nuttallii system in CMC rearing practice.
format: application/pdf
format: text/html
creator: Linlin Shi
creator: Meijuan Jin
creator: Mingxing Shen
creator: Changying Lu
creator: Haihou Wang
creator: Xingwei Zhou
creator: Lijuan Mei
creator: Shixue Yin
subject: Agricultural Science
subject: Aquaculture, Fisheries and Fish Science
subject: Microbiology
subject: Freshwater Biology
subject: Environmental Contamination and Remediation
description: doi:10.7717/peerj.6785
publisher: PeerJ Inc.
rights: © 2019 Shi et al.
abstract: Elodea nuttallii is widely used in Chinese mitten crab (CMC) rearing practice, but it is not a native aquatic plant and cannot endure high temperature. Thus, large E. nuttallii mortality and water deterioration events could occur during high-temperature seasons. The aim of this study was to identify the use of local macrophytes in CMC rearing practice, including Ipomoea aquatic and Oryza sativa. A completely randomized field experiment was conducted to investigate the crab yield, water quality, bacterioplankton community and functions in the three different systems (E. nuttallii, I. aquatic, and O. sativa). Average crab yields in the different macrophyte systems did not differ significantly. The I. aquatic and O. sativa systems significantly decreased the total nitrogen and nitrate-N quantities in the outflow waters during the rearing period compared to the E. nuttallii system, and the I. aquatic and O. sativa plants assimilated more nitrogen than the E. nuttallii plant. Moreover, the significant changes of bacterioplankton abundances and biodiversity in the three systems implied that cleanliness of rearing waters was concomitantly attributed to the differential microbial community and functions. In addition, principle component analysis successfully differentiated the bacterioplankton communities of the three macrophytes systems. Environmental factor fitting and the co-occurrence network analyses indicated that pH was the driver of bacterioplankton community structure. Functional predictions using PICRUSt (v.1.1.3) software based on evolutionary modeling indicated a higher potential for microbial denitrification in the I. aquatic and O. sativa systems. Notably, the O. sativa plants stopped growing in the middle of the rearing period. Thus, the I. aquatic system rather than the O. sativa system could be a feasible and environmental-friendly alternative to the E. nuttallii system in CMC rearing practice.
bibliographic citation: Shi et al. (2019) Using Ipomoea aquatic as an environmental-friendly alternative to Elodea nuttallii for the aquaculture of Chinese mitten crab. PeerJ 7:e6785 https://doi.org/10.7717/peerj.6785
date submitted: 2018-11-20
date accepted: 2019-03-14
issued: 2019-04-19
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Shi
  given name: Linlin
author list: Agent
  family name: Jin
  given name: Meijuan
author list: Agent
  family name: Shen
  given name: Mingxing
author list: Agent
  family name: Lu
  given name: Changying
author list: Agent
  family name: Wang
  given name: Haihou
author list: Agent
  family name: Zhou
  given name: Xingwei
author list: Agent
  family name: Mei
  given name: Lijuan
author list: Agent
  family name: Yin
  given name: Shixue
doi: 10.7717/peerj.6785
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-04-19
copyright: © 2019 Shi et al.
attribution name: Shi et al.

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