PeerJ
type: channel
link: https://peerj.com/articles/
description: Articles published in PeerJ
publisher: PeerJ Inc.
publication name: PeerJ
issn: 2167-8359
items: Aspergillus terreus obtained from mangrove exhibits antagonistic activities against Pythium aphanidermatum-induced damping-off of cucumber
items: Threshold-like associations as a function of disturbance
items: RNA-seq transcriptome profiling of porcine lung from two pig breeds in response to Mycoplasma hyopneumoniae infection
items: Classification of RNA backbone conformations into rotamers using 13C′ chemical shifts: exploring how far we can go
items: A new small device made of glass for separating microplastics from marine and freshwater sediments
items: https://peerj.com/articles/7919
items: Effects of the loss of estrogen on the heart’s hypertrophic response to chronic left ventricle volume overload in rats
items: Spatio-temporal patterns of the oceanic conditions and nearshore marine community in the Mid-Atlantic Bight (New Jersey, USA)
items: The distribution and mitochondrial genotype of the hydroid Aglaophenia latecarinata is correlated with its pelagic Sargassum substrate type in the tropical and subtropical western Atlantic Ocean
items: Determining the optimal maximal and submaximal voluntary contraction tests for normalizing the erector spinae muscles

Aspergillus terreus obtained from mangrove exhibits antagonistic activities against Pythium aphanidermatum-induced damping-off of cucumber
type: item
type: AcademicArticle
description: A study was conducted to investigate the potential of Aspergillus terreus obtained from Avicennia marina mangrove roots in inhibiting Pythium aphanidermatum and damping-off disease of cucumber. Aspergillus terreus exhibited in vitro inhibition of Pythium aphanidermatum growth. Electron microscope examination revealed that the antagonistic fungal isolate resulted in shrinking and groves in Pythium hypha. When Aspergillus terreus culture filtrate was added to Pythium aphanidermatum, it resulted in a significant increase (by 73%) in electrolyte leakage from Pythium hypha compared to the control, as well as significant reduction (by 71%) in oospore production. The Aspergillus terreus culture was also found to produce a cellulase enzyme, which is suggested to be involved in the antagonism against Pythium aphanidermatum. Adding Aspergillus terreus to soil infested with Pythium aphanidermatum significantly reduced percent mortality in cucumber seedlings by 70%. Aspergillus terreus, when applied alone on cucumber seedlings, did not show any suppressive effects on cucumber growth (length and fresh and dry weight). This appears to be the first report of isolation from mangrove of Aspergillus terreus with antagonistic activity against Pythium aphanidermatum-induced damping-off of cucumber. The study indicates that fungal isolates obtained from marine environments may serve as potential biocontrol agents against some plant pathogens.
format: application/pdf
format: text/html
creator: Hanaa Al-Shibli
creator: Sergey Dobretsov
creator: Abdulrahman Al-Nabhani
creator: Sajeewa S.N. Maharachchikumbura
creator: Velazhahan Rethinasamy
creator: Abdullah M. Al-Sadi
subject: Agricultural Science
subject: Microbiology
subject: Plant Science
description: doi:10.7717/peerj.7884
publisher: PeerJ Inc.
rights: © 2019 Al-Shibli et al.
abstract: A study was conducted to investigate the potential of Aspergillus terreus obtained from Avicennia marina mangrove roots in inhibiting Pythium aphanidermatum and damping-off disease of cucumber. Aspergillus terreus exhibited in vitro inhibition of Pythium aphanidermatum growth. Electron microscope examination revealed that the antagonistic fungal isolate resulted in shrinking and groves in Pythium hypha. When Aspergillus terreus culture filtrate was added to Pythium aphanidermatum, it resulted in a significant increase (by 73%) in electrolyte leakage from Pythium hypha compared to the control, as well as significant reduction (by 71%) in oospore production. The Aspergillus terreus culture was also found to produce a cellulase enzyme, which is suggested to be involved in the antagonism against Pythium aphanidermatum. Adding Aspergillus terreus to soil infested with Pythium aphanidermatum significantly reduced percent mortality in cucumber seedlings by 70%. Aspergillus terreus, when applied alone on cucumber seedlings, did not show any suppressive effects on cucumber growth (length and fresh and dry weight). This appears to be the first report of isolation from mangrove of Aspergillus terreus with antagonistic activity against Pythium aphanidermatum-induced damping-off of cucumber. The study indicates that fungal isolates obtained from marine environments may serve as potential biocontrol agents against some plant pathogens.
bibliographic citation: Al-Shibli et al. (2019) Aspergillus terreus obtained from mangrove exhibits antagonistic activities against Pythium aphanidermatum-induced damping-off of cucumber. PeerJ 7:e7884 https://doi.org/10.7717/peerj.7884
date submitted: 2019-04-27
date accepted: 2019-09-12
issued: 2019-10-21
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Al-Shibli
  given name: Hanaa
author list: Agent
  family name: Dobretsov
  given name: Sergey
author list: Agent
  family name: Al-Nabhani
  given name: Abdulrahman
author list: Agent
  family name: Maharachchikumbura
  given name: Sajeewa S.N.
author list: Agent
  family name: Rethinasamy
  given name: Velazhahan
author list: Agent
  family name: Al-Sadi
  given name: Abdullah M.
doi: 10.7717/peerj.7884
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-10-21
copyright: © 2019 Al-Shibli et al.
attribution name: Al-Shibli et al.

Threshold-like associations as a function of disturbance
type: item
type: AcademicArticle
description: According to the intelligence-creativity threshold hypothesis, there should be a positive association between intelligence and creative potential up to a certain point, the threshold, after which a further increase in intelligence should have no association with creativity. In the present simulation study, the measured intelligence and creativity of virtual subjects were affected by their true abilities as well as a disturbance factor that varied in magnitude between subjects. The results indicate that the hypothesized threshold-like association could be due to some disturbing factor, for example, low motivation, illness, or linguistic confusion, that varies between individuals and that affects both measured intelligence and measured creativity, especially if the actual association between intelligence and creativity is weak. This, together with previous negative findings, calls the validity of the intelligence-creativity threshold hypothesis into question.
format: application/pdf
format: text/html
creator: Kimmo Sorjonen
creator: Michael Ingre
creator: Bo Melin
subject: Neuroscience
subject: Psychiatry and Psychology
subject: Statistics
description: doi:10.7717/peerj.7891
publisher: PeerJ Inc.
rights: © 2019 Sorjonen et al.
abstract: According to the intelligence-creativity threshold hypothesis, there should be a positive association between intelligence and creative potential up to a certain point, the threshold, after which a further increase in intelligence should have no association with creativity. In the present simulation study, the measured intelligence and creativity of virtual subjects were affected by their true abilities as well as a disturbance factor that varied in magnitude between subjects. The results indicate that the hypothesized threshold-like association could be due to some disturbing factor, for example, low motivation, illness, or linguistic confusion, that varies between individuals and that affects both measured intelligence and measured creativity, especially if the actual association between intelligence and creativity is weak. This, together with previous negative findings, calls the validity of the intelligence-creativity threshold hypothesis into question.
bibliographic citation: Sorjonen et al. (2019) Threshold-like associations as a function of disturbance. PeerJ 7:e7891 https://doi.org/10.7717/peerj.7891
date submitted: 2019-06-16
date accepted: 2019-09-13
issued: 2019-10-21
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Sorjonen
  given name: Kimmo
author list: Agent
  family name: Ingre
  given name: Michael
author list: Agent
  family name: Melin
  given name: Bo
doi: 10.7717/peerj.7891
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-10-21
copyright: © 2019 Sorjonen et al.
attribution name: Sorjonen et al.

RNA-seq transcriptome profiling of porcine lung from two pig breeds in response to Mycoplasma hyopneumoniae infection
type: item
type: AcademicArticle
description: Background Mycoplasma hyopneumoniae (Mhp) is the main pathogen causing respiratory disease in the swine industry. Mhp infection rates differ across pig breeds, with Chinese native pig breeds that exhibit high fecundity (e.g., Jiangquhai, Meishan, Erhualian) more sensitive than Duroc, Landrace, and other imported pig breeds. However, the genetic basis of the immune response to Mhp infection in different pig breeds is largely unknown. Aims The aims of this study were to determine the relative Mhp susceptibility of the Chinese native Jiangquhai breed compared to the Duroc breed, and identify molecular mechanisms of differentially expressed genes (DEGs) using an RNA-sequencing (RNA-seq) approach. Methods Jiangquhai and Duroc pigs were artificially infected with the same Mhp dose. The entire experiment lasted 28 days. Daily weight gain, Mhp-specific antibody levels, and lung lesion scores were measured to evaluate the Mhp infection susceptibility of different breeds. Experimental pigs were slaughtered on the 28th day. Lung tissues were collected for total RNA extraction. RNA-seq was performed to identify DEGs, which were enriched by gene ontology (GO) and the Kyoto Encyclopedia annotation of Genes and Genomes (KEGG) databases. DEGs were validated with real-time quantitative polymerase chain reaction (RT-qPCR). Results Infection with the same Mhp dose produced a more serious condition in Jiangquhai pigs than in Duroc pigs. Jiangquhai pigs showed poorer growth, higher Mhp antibody levels, and more serious lung lesions compared with Duroc pigs. RNA-seq identified 2,250 and 3,526 DEGs in lung tissue from Jiangquhai and Duroc pigs, respectively. The two breeds shared 1,669 DEGs, which were involved in immune-relevant pathways including cytokine-cytokine receptor interaction, PI3K-Akt signaling pathway, and chemokine signaling pathway. Compared to Jiangquhai pigs, more chemokines, interferon response factors, and interleukins were specifically activated in Duroc pigs; CXCL10, …
format: application/pdf
format: text/html
creator: Ligang Ni
creator: Chengyi Song
creator: Xinsheng Wu
creator: Xuting Zhao
creator: Xiaoyan Wang
creator: Bichun Li
creator: Yuan Gan
subject: Biotechnology
subject: Genomics
subject: Veterinary Medicine
description: doi:10.7717/peerj.7900
publisher: PeerJ Inc.
rights: © 2019 Ni et al.
abstract: Background Mycoplasma hyopneumoniae (Mhp) is the main pathogen causing respiratory disease in the swine industry. Mhp infection rates differ across pig breeds, with Chinese native pig breeds that exhibit high fecundity (e.g., Jiangquhai, Meishan, Erhualian) more sensitive than Duroc, Landrace, and other imported pig breeds. However, the genetic basis of the immune response to Mhp infection in different pig breeds is largely unknown. Aims The aims of this study were to determine the relative Mhp susceptibility of the Chinese native Jiangquhai breed compared to the Duroc breed, and identify molecular mechanisms of differentially expressed genes (DEGs) using an RNA-sequencing (RNA-seq) approach. Methods Jiangquhai and Duroc pigs were artificially infected with the same Mhp dose. The entire experiment lasted 28 days. Daily weight gain, Mhp-specific antibody levels, and lung lesion scores were measured to evaluate the Mhp infection susceptibility of different breeds. Experimental pigs were slaughtered on the 28th day. Lung tissues were collected for total RNA extraction. RNA-seq was performed to identify DEGs, which were enriched by gene ontology (GO) and the Kyoto Encyclopedia annotation of Genes and Genomes (KEGG) databases. DEGs were validated with real-time quantitative polymerase chain reaction (RT-qPCR). Results Infection with the same Mhp dose produced a more serious condition in Jiangquhai pigs than in Duroc pigs. Jiangquhai pigs showed poorer growth, higher Mhp antibody levels, and more serious lung lesions compared with Duroc pigs. RNA-seq identified 2,250 and 3,526 DEGs in lung tissue from Jiangquhai and Duroc pigs, respectively. The two breeds shared 1,669 DEGs, which were involved in immune-relevant pathways including cytokine-cytokine receptor interaction, PI3K-Akt signaling pathway, and chemokine signaling pathway. Compared to Jiangquhai pigs, more chemokines, interferon response factors, and interleukins were specifically activated in Duroc pigs; CXCL10, …
bibliographic citation: Ni et al. (2019) RNA-seq transcriptome profiling of porcine lung from two pig breeds in response to Mycoplasma hyopneumoniae infection. PeerJ 7:e7900 https://doi.org/10.7717/peerj.7900
date submitted: 2019-05-24
date accepted: 2019-09-16
issued: 2019-10-21
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Ni
  given name: Ligang
author list: Agent
  family name: Song
  given name: Chengyi
author list: Agent
  family name: Wu
  given name: Xinsheng
author list: Agent
  family name: Zhao
  given name: Xuting
author list: Agent
  family name: Wang
  given name: Xiaoyan
author list: Agent
  family name: Li
  given name: Bichun
author list: Agent
  family name: Gan
  given name: Yuan
doi: 10.7717/peerj.7900
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-10-21
copyright: ©2019 Ni et al.
attribution name: Ni et al.

Classification of RNA backbone conformations into rotamers using 13C′ chemical shifts: exploring how far we can go
type: item
type: AcademicArticle
description: The conformational space of the ribose-phosphate backbone is very complex as it is defined in terms of six torsional angles. To help delimit the RNA backbone conformational preferences, 46 rotamers have been defined in terms of these torsional angles. In the present work, we use the ribose experimental and theoretical 13C′ chemical shifts data and machine learning methods to classify RNA backbone conformations into rotamers and families of rotamers. We show to what extent the experimental 13C′ chemical shifts can be used to identify rotamers and discuss some problem with the theoretical computations of 13C′ chemical shifts.
format: application/pdf
format: text/html
creator: Alejandro A. Icazatti
creator: Juan M. Loyola
creator: Igal Szleifer
creator: Jorge A. Vila
creator: Osvaldo A. Martin
subject: Biochemistry
subject: Bioinformatics
subject: Computational Biology
description: doi:10.7717/peerj.7904
publisher: PeerJ Inc.
rights: © 2019 Icazatti et al.
abstract: The conformational space of the ribose-phosphate backbone is very complex as it is defined in terms of six torsional angles. To help delimit the RNA backbone conformational preferences, 46 rotamers have been defined in terms of these torsional angles. In the present work, we use the ribose experimental and theoretical 13C′ chemical shifts data and machine learning methods to classify RNA backbone conformations into rotamers and families of rotamers. We show to what extent the experimental 13C′ chemical shifts can be used to identify rotamers and discuss some problem with the theoretical computations of 13C′ chemical shifts.
bibliographic citation: Icazatti et al. (2019) Classification of RNA backbone conformations into rotamers using 13C′ chemical shifts: exploring how far we can go. PeerJ 7:e7904 https://doi.org/10.7717/peerj.7904
date submitted: 2019-06-03
date accepted: 2019-09-16
issued: 2019-10-21
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Icazatti
  given name: Alejandro A.
author list: Agent
  family name: Loyola
  given name: Juan M.
author list: Agent
  family name: Szleifer
  given name: Igal
author list: Agent
  family name: Vila
  given name: Jorge A.
author list: Agent
  family name: Martin
  given name: Osvaldo A.
doi: 10.7717/peerj.7904
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-10-21
copyright: ©2019 Icazatti et al.
attribution name: Icazatti et al.

A new small device made of glass for separating microplastics from marine and freshwater sediments
type: item
type: AcademicArticle
description: Separating microplastics from marine and freshwater sediments is challenging, but necessary to determine their distribution, mass, and ecological impacts in benthic environments. Density separation is commonly used to extract microplastics from sediments by using heavy salt solutions, such as zinc chloride and sodium iodide. However, current devices/apparatus used for density separation, including glass beakers, funnels, upside-down funnel-shaped separators with a shut-off valve, etc., possess various shortcomings in terms of recovery rate, time consumption, and/or usability. In evaluating existing microplastic extraction methods using density separation, we identified the need for a device that allows rapid, simple, and efficient extraction of microplastics from a range of sediment types. We have developed a small glass separator, without a valve, taking a hint from an Utermöhl chamber. This new device is easy to clean and portable, yet enables rapid separation of microplastics from sediments. With this simple device, we recovered 94–98% of <1,000 µm microplastics (polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, and polystyrene). Overall, the device is efficient for various sizes, polymer types, and sediment types. Also, microplastics collected with this glass-made device remain chemically uncontaminated, and can, therefore, be used for further analysis of adsorbing contaminants and additives on/to microplastics.
format: application/pdf
format: text/html
creator: Ryota Nakajima
creator: Masashi Tsuchiya
creator: Dhugal J. Lindsay
creator: Tomo Kitahashi
creator: Katsunori Fujikura
creator: Tomohiko Fukushima
subject: Environmental Contamination and Remediation
subject: Environmental Impacts
description: doi:10.7717/peerj.7915
publisher: PeerJ Inc.
rights: © 2019 Nakajima et al.
abstract: Separating microplastics from marine and freshwater sediments is challenging, but necessary to determine their distribution, mass, and ecological impacts in benthic environments. Density separation is commonly used to extract microplastics from sediments by using heavy salt solutions, such as zinc chloride and sodium iodide. However, current devices/apparatus used for density separation, including glass beakers, funnels, upside-down funnel-shaped separators with a shut-off valve, etc., possess various shortcomings in terms of recovery rate, time consumption, and/or usability. In evaluating existing microplastic extraction methods using density separation, we identified the need for a device that allows rapid, simple, and efficient extraction of microplastics from a range of sediment types. We have developed a small glass separator, without a valve, taking a hint from an Utermöhl chamber. This new device is easy to clean and portable, yet enables rapid separation of microplastics from sediments. With this simple device, we recovered 94–98% of <1,000 µm microplastics (polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, and polystyrene). Overall, the device is efficient for various sizes, polymer types, and sediment types. Also, microplastics collected with this glass-made device remain chemically uncontaminated, and can, therefore, be used for further analysis of adsorbing contaminants and additives on/to microplastics.
bibliographic citation: Nakajima et al. (2019) A new small device made of glass for separating microplastics from marine and freshwater sediments. PeerJ 7:e7915 https://doi.org/10.7717/peerj.7915
date submitted: 2019-06-10
date accepted: 2019-09-17
issued: 2019-10-21
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Nakajima
  given name: Ryota
author list: Agent
  family name: Tsuchiya
  given name: Masashi
author list: Agent
  family name: Lindsay
  given name: Dhugal J.
author list: Agent
  family name: Kitahashi
  given name: Tomo
author list: Agent
  family name: Fujikura
  given name: Katsunori
author list: Agent
  family name: Fukushima
  given name: Tomohiko
doi: 10.7717/peerj.7915
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-10-21
copyright: © 2019 Nakajima et al.
attribution name: Nakajima et al.

https://peerj.com/articles/7919
type: item
type: AcademicArticle
title: Mercuric pollution of surface water, superficial sediments, Nile tilapia (Oreochromis nilotica Linnaeus 1758 [Cichlidae]) and yams (Dioscorea alata) in auriferous areas of Namukombe stream, Syanyonja, Busia, Uganda
description: The mercury content and the contamination characteristics of water, sediments, edible muscles of a non-piscivorous fish (Oreochromis nilotica Linnaeus 1758 [Cichlidae]) and yams (Dioscorea alata) from Namukombe stream in Busia gold district of Uganda were evaluated. Human health risk assessment from consumption of contaminated fish and yams as well as contact with contaminated sediments from the stream were performed. Forty-eight (48) samples of water (n = 12), sediments (n = 12), fish (n = 12) and yams (n = 12) were taken at intervals of 10 m from three gold recovery sites located at up, middle and down sluices of the stream and analyzed for total mercury (THg) using US EPA method 1631. Results (presented as means ± standard deviations) showed that water in the stream is polluted with mercury in the range of < detection limit to 1.21 ± 0.040 mg/L while sediments contain mean THg from < detection limit to 0.14 ± 0.040 ugg−1. Mean THg content of the edible muscles of O. nilotica ranged from < detection limit to 0.11 ± 0.014 ugg−1while D. alata contained from < detection limit to 0.30 ± 0.173 ugg−1mean THg. The estimated daily intake ranged from 0.0049 ugg−1day−1 to 0.0183 ugg−1day−1 and 0.0200 ugg−1day−1 to 0.0730 ugg−1day−1 for fish consumed by adults and children respectively. The corresponding health risk indices ranged from 0.0123 to 0.0458 and 0.0500 to 0.1830. Estimated daily intake was from 0.0042 ugg−1day−1 to 0.1279 ugg−1day−1 and 0.0130 ugg−1day−1 to 0.3940 ugg−1day−1 for D. alata consumed by adults and children respectively. The health risk indices recorded were from 0.011 to 0.320 and 0.033 to 0.985 for adults and children respectively. The mean THg content of the sediments, edible muscles of O. nilotica and D. alata were within acceptable WHO/US EPA limits. About 91.7% of the water samples had mean THg above US EPA maximum permissible limit for mercury in drinking water. Consumption of D. alata grown within 5 m radius up sluice of Namukombe stream may po…
format: application/pdf
format: text/html
creator: Timothy Omara
creator: Shakilah Karungi
creator: Raymond Kalukusu
creator: BrendaVictoria Nakabuye
creator: Sarah Kagoya
creator: Bashir Musau
subject: Aquaculture, Fisheries and Fish Science
subject: Toxicology
subject: Aquatic and Marine Chemistry
description: doi:10.7717/peerj.7919
publisher: PeerJ Inc.
rights: © 2019 Omara et al.
abstract: The mercury content and the contamination characteristics of water, sediments, edible muscles of a non-piscivorous fish (Oreochromis nilotica Linnaeus 1758 [Cichlidae]) and yams (Dioscorea alata) from Namukombe stream in Busia gold district of Uganda were evaluated. Human health risk assessment from consumption of contaminated fish and yams as well as contact with contaminated sediments from the stream were performed. Forty-eight (48) samples of water (n = 12), sediments (n = 12), fish (n = 12) and yams (n = 12) were taken at intervals of 10 m from three gold recovery sites located at up, middle and down sluices of the stream and analyzed for total mercury (THg) using US EPA method 1631. Results (presented as means ± standard deviations) showed that water in the stream is polluted with mercury in the range of < detection limit to 1.21 ± 0.040 mg/L while sediments contain mean THg from < detection limit to 0.14 ± 0.040 ugg−1. Mean THg content of the edible muscles of O. nilotica ranged from < detection limit to 0.11 ± 0.014 ugg−1while D. alata contained from < detection limit to 0.30 ± 0.173 ugg−1mean THg. The estimated daily intake ranged from 0.0049 ugg−1day−1 to 0.0183 ugg−1day−1 and 0.0200 ugg−1day−1 to 0.0730 ugg−1day−1 for fish consumed by adults and children respectively. The corresponding health risk indices ranged from 0.0123 to 0.0458 and 0.0500 to 0.1830. Estimated daily intake was from 0.0042 ugg−1day−1 to 0.1279 ugg−1day−1 and 0.0130 ugg−1day−1 to 0.3940 ugg−1day−1 for D. alata consumed by adults and children respectively. The health risk indices recorded were from 0.011 to 0.320 and 0.033 to 0.985 for adults and children respectively. The mean THg content of the sediments, edible muscles of O. nilotica and D. alata were within acceptable WHO/US EPA limits. About 91.7% of the water samples had mean THg above US EPA maximum permissible limit for mercury in drinking water. Consumption of D. alata grown within 5 m radius up sluice of Namukombe stream may po…
bibliographic citation: Omara et al. (2019) Mercuric pollution of surface water, superficial sediments, Nile tilapia (Oreochromis nilotica Linnaeus 1758 [Cichlidae]) and yams (Dioscorea alata) in auriferous areas of Namukombe stream, Syanyonja, Busia, Uganda. PeerJ 7:e7919 https://doi.org/10.7717/peerj.7919
date submitted: 2019-07-04
date accepted: 2019-09-18
issued: 2019-10-21
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Omara
  given name: Timothy
author list: Agent
  family name: Karungi
  given name: Shakilah
author list: Agent
  family name: Kalukusu
  given name: Raymond
author list: Agent
  family name: Nakabuye
  given name: BrendaVictoria
author list: Agent
  family name: Kagoya
  given name: Sarah
author list: Agent
  family name: Musau
  given name: Bashir
doi: 10.7717/peerj.7919
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-10-21
copyright: ©2019 Omara et al.
attribution name: Omara et al.

Effects of the loss of estrogen on the heart’s hypertrophic response to chronic left ventricle volume overload in rats
type: item
type: AcademicArticle
description: Aortic valve regurgitation (AR) can result in heart failure from chronic overloading of the left ventricle (LV). Little is known of the role of estrogens in the LV responses to this condition. The aim of the study was to compare LV remodeling in female rats with severe AR in absence of estrogens by ovariectomy (Ovx). In a first study, we investigated over 6 months the development of hypertrophy in four groups of female Wistar rats: AR or sham-operated (sham) and Ovx or not. Ovx reduced normal heart growth. As expected, volume overload (VO) from AR resulted in significant LV dilation (42% and 32% increase LV end-diastolic diameter in intact and Ovx groups vs. their respective sham group; p < 0.0001). LV weight was also significantly and similarly increased in both AR groups (non-Ovx and Ovx). Increase in stroke volume or cardiac output and loss of systolic function were similar between AR intact and AR Ovx groups compared to sham. We then investigated what were the effects of 17beta-estradiol (E2; 0.03 mg/kg/day) treatment on the parameters studied in Ovx rats. Ovx reduced uterus weight by 85% and E2 treatment restored up to 65% of the normal weight. E2 also helped normalize heart size to normal values. On the other hand, it did not influence the extent of the hypertrophic response to AR. In fact, E2 treatment further reduced LV hypertrophy in AR Ovx rats (41% over Sham Ovx + E2). Systolic and diastolic functions parameters in AR Ovx + E2 were similar to intact AR animals. Ovx in sham rats had a significant effect on the LV gene expression of several hypertrophy markers. Atrial natriuretic peptide (Nppa) gene expression was reduced by Ovx in sham-operated females whereas brain natriuretic peptide (Nppb) expression was increased. Alpha (Myh6) and beta (Myh7) myosin heavy chain genes were also significantly modulated by Ovx in sham females. In AR rats, LV expression of both Nppa and Nppb genes were increased as expected. Ovx further increased it of AR rats for Nppa and…
format: application/pdf
format: text/html
creator: Elisabeth Walsh-Wilkinson
creator: Catherine Beaumont
creator: Marie-Claude Drolet
creator: Ève-Marie Roy
creator: Charlie Le Houillier
creator: Jonathan Beaudoin
creator: Marie Arsenault
creator: Jacques Couet
subject: Cardiology
subject: Diabetes and Endocrinology
description: doi:10.7717/peerj.7924
publisher: PeerJ Inc.
rights: © 2019 Walsh-Wilkinson et al.
abstract: Aortic valve regurgitation (AR) can result in heart failure from chronic overloading of the left ventricle (LV). Little is known of the role of estrogens in the LV responses to this condition. The aim of the study was to compare LV remodeling in female rats with severe AR in absence of estrogens by ovariectomy (Ovx). In a first study, we investigated over 6 months the development of hypertrophy in four groups of female Wistar rats: AR or sham-operated (sham) and Ovx or not. Ovx reduced normal heart growth. As expected, volume overload (VO) from AR resulted in significant LV dilation (42% and 32% increase LV end-diastolic diameter in intact and Ovx groups vs. their respective sham group; p < 0.0001). LV weight was also significantly and similarly increased in both AR groups (non-Ovx and Ovx). Increase in stroke volume or cardiac output and loss of systolic function were similar between AR intact and AR Ovx groups compared to sham. We then investigated what were the effects of 17beta-estradiol (E2; 0.03 mg/kg/day) treatment on the parameters studied in Ovx rats. Ovx reduced uterus weight by 85% and E2 treatment restored up to 65% of the normal weight. E2 also helped normalize heart size to normal values. On the other hand, it did not influence the extent of the hypertrophic response to AR. In fact, E2 treatment further reduced LV hypertrophy in AR Ovx rats (41% over Sham Ovx + E2). Systolic and diastolic functions parameters in AR Ovx + E2 were similar to intact AR animals. Ovx in sham rats had a significant effect on the LV gene expression of several hypertrophy markers. Atrial natriuretic peptide (Nppa) gene expression was reduced by Ovx in sham-operated females whereas brain natriuretic peptide (Nppb) expression was increased. Alpha (Myh6) and beta (Myh7) myosin heavy chain genes were also significantly modulated by Ovx in sham females. In AR rats, LV expression of both Nppa and Nppb genes were increased as expected. Ovx further increased it of AR rats for Nppa and…
bibliographic citation: Walsh-Wilkinson et al. (2019) Effects of the loss of estrogen on the heart’s hypertrophic response to chronic left ventricle volume overload in rats. PeerJ 7:e7924 https://doi.org/10.7717/peerj.7924
date submitted: 2019-07-09
date accepted: 2019-09-20
issued: 2019-10-21
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Walsh-Wilkinson
  given name: Elisabeth
author list: Agent
  family name: Beaumont
  given name: Catherine
author list: Agent
  family name: Drolet
  given name: Marie-Claude
author list: Agent
  family name: Roy
  given name: Ève-Marie
author list: Agent
  family name: Le Houillier
  given name: Charlie
author list: Agent
  family name: Beaudoin
  given name: Jonathan
author list: Agent
  family name: Arsenault
  given name: Marie
author list: Agent
  family name: Couet
  given name: Jacques
doi: 10.7717/peerj.7924
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-10-21
copyright: ©2019 Walsh-Wilkinson et al.
attribution name: Walsh-Wilkinson et al.

Spatio-temporal patterns of the oceanic conditions and nearshore marine community in the Mid-Atlantic Bight (New Jersey, USA)
type: item
type: AcademicArticle
description: Oceanic environmental conditions influence, shape, and control the geographical range, spatial distribution, abundance, and size composition of marine fauna. Water temperature, salinity, dissolved oxygen, depth, and sediment type influence select fish life-history characteristics and community structure. Marine communities are vulnerable to major changes in environmental conditions, but the response and severity depends on various biological or ecological factors, such as resilience to stress or adaptation. Researchers around the world have predicted and documented numerous alterations in fish communities caused by ongoing significant physicochemical shifts associated with natural and potentially unnatural sources, but published studies describing the historical conditions are lacking for most regions around the world, including the coastal waters off New Jersey. Given the need to understand these processes, a multifaceted investigation was undertaken to describe, evaluate, and compare the oceanic conditions and nearshore marine fauna community off New Jersey during 1988 through 2015. Findings showed the oceanic conditions varied over time and space. Mean surface water temperature increased significantly about 0.6 °C per decade, mean salinity decreased about 1.3 psu per decade, and dissolved oxygen increased 0.09 mg/l per decade. Over 20.4 million fish and invertebrates (1,338.3 mt) representing 214 (water temperature preference classified) species (not including unidentified species) were collected within 15 strata (areas: 12−26) off the coast of New Jersey from 1988 to 2015. Three marine fauna water temperature preference groups (coldwater-adapted, warmwater-adapted, and subtropic-adapted) were identified in the study area. The main coldwater-adapted species collected were longfin squid (Loligo pealei) (n = 2, 225, 975), Atlantic herring (Clupea harengus) (n = 544, 032), and little skate (Leucoraja erinacea) (n = 316, 356), while Atlantic butterfish (Peprilus tria…
format: application/pdf
format: text/html
creator: Juan C. Levesque
subject: Aquaculture, Fisheries and Fish Science
subject: Biodiversity
subject: Ecology
subject: Marine Biology
subject: Climate Change Biology
description: doi:10.7717/peerj.7927
publisher: PeerJ Inc.
rights: © 2019 Levesque
abstract: Oceanic environmental conditions influence, shape, and control the geographical range, spatial distribution, abundance, and size composition of marine fauna. Water temperature, salinity, dissolved oxygen, depth, and sediment type influence select fish life-history characteristics and community structure. Marine communities are vulnerable to major changes in environmental conditions, but the response and severity depends on various biological or ecological factors, such as resilience to stress or adaptation. Researchers around the world have predicted and documented numerous alterations in fish communities caused by ongoing significant physicochemical shifts associated with natural and potentially unnatural sources, but published studies describing the historical conditions are lacking for most regions around the world, including the coastal waters off New Jersey. Given the need to understand these processes, a multifaceted investigation was undertaken to describe, evaluate, and compare the oceanic conditions and nearshore marine fauna community off New Jersey during 1988 through 2015. Findings showed the oceanic conditions varied over time and space. Mean surface water temperature increased significantly about 0.6 °C per decade, mean salinity decreased about 1.3 psu per decade, and dissolved oxygen increased 0.09 mg/l per decade. Over 20.4 million fish and invertebrates (1,338.3 mt) representing 214 (water temperature preference classified) species (not including unidentified species) were collected within 15 strata (areas: 12−26) off the coast of New Jersey from 1988 to 2015. Three marine fauna water temperature preference groups (coldwater-adapted, warmwater-adapted, and subtropic-adapted) were identified in the study area. The main coldwater-adapted species collected were longfin squid (Loligo pealei) (n = 2, 225, 975), Atlantic herring (Clupea harengus) (n = 544, 032), and little skate (Leucoraja erinacea) (n = 316, 356), while Atlantic butterfish (Peprilus tria…
bibliographic citation: Levesque (2019) Spatio-temporal patterns of the oceanic conditions and nearshore marine community in the Mid-Atlantic Bight (New Jersey, USA). PeerJ 7:e7927 https://doi.org/10.7717/peerj.7927
date submitted: 2019-06-07
date accepted: 2019-09-20
issued: 2019-10-21
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Levesque
  given name: Juan C.
doi: 10.7717/peerj.7927
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-10-21
copyright: ©2019 Levesque
attribution name: Levesque

The distribution and mitochondrial genotype of the hydroid Aglaophenia latecarinata is correlated with its pelagic Sargassum substrate type in the tropical and subtropical western Atlantic Ocean
type: item
type: AcademicArticle
description: The pelagic brown macroalga Sargassum supports rich biological communities in the tropical and subtropical Atlantic region, including a variety of epiphytic invertebrates that grow on the Sargassum itself. The thecate hydroid Aglaophenia latecarinata is commonly found growing on some, but not all, Sargassum forms. In this study, we examined the relationship between A. latecarinata and its pelagic Sargassum substrate across a broad geographic area over the course of 4 years (2015–2018). The distribution of the most common Sargassum forms that we observed (Sargassum fluitans III and S. natans VIII) was consistent with the existence of distinct source regions for each. We found that A. latecarinata hydroids were abundant on both S. natans VIII and S. fluitans III, and also noted a rare observation of A. latecarinata on S. natans I. For the hydroids on S. natans VIII and S. fluitans III, hydroid mitochondrial genotype was strongly correlated with the Sargassum substrate form. We found significant population genetic structure in the hydroids, which was also consistent with the distributional patterns of the Sargassum forms. These results suggest that hydroid settlement on the Sargassum occurs in type-specific Sargassum source regions. Hydroid species identification is challenging and cryptic speciation is common in the Aglaopheniidae. Therefore, to confirm our identification of A. latecarinata, we conducted a phylogenetic analysis that showed that while the genus Aglaophenia was not monophyletic, all A. latecarinata haplotypes associated with pelagic Sargassum belonged to the same clade and were likely the same species as previously published sequences from Florida, Central America, and one location in Brazil (São Sebastião). A nominal A. latecarinata sequence from a second Brazilian location (Alagoas) likely belongs to a different species.
format: application/pdf
format: text/html
creator: Annette F. Govindarajan
creator: Laura Cooney
creator: Kerry Whittaker
creator: Dana Bloch
creator: Rachel M. Burdorf
creator: Shalagh Canning
creator: Caroline Carter
creator: Shannon M. Cellan
creator: Fredrik A.A. Eriksson
creator: Hannah Freyer
creator: Grayson Huston
creator: Sabrina Hutchinson
creator: Kathleen McKeegan
creator: Megha Malpani
creator: Alex Merkle-Raymond
creator: Kendra Ouellette
creator: Robin Petersen-Rockney
creator: Maggie Schultz
creator: Amy N.S. Siuda
subject: Biogeography
subject: Marine Biology
subject: Biological Oceanography
description: doi:10.7717/peerj.7814
publisher: PeerJ Inc.
rights: © 2019 Govindarajan et al.
abstract: The pelagic brown macroalga Sargassum supports rich biological communities in the tropical and subtropical Atlantic region, including a variety of epiphytic invertebrates that grow on the Sargassum itself. The thecate hydroid Aglaophenia latecarinata is commonly found growing on some, but not all, Sargassum forms. In this study, we examined the relationship between A. latecarinata and its pelagic Sargassum substrate across a broad geographic area over the course of 4 years (2015–2018). The distribution of the most common Sargassum forms that we observed (Sargassum fluitans III and S. natans VIII) was consistent with the existence of distinct source regions for each. We found that A. latecarinata hydroids were abundant on both S. natans VIII and S. fluitans III, and also noted a rare observation of A. latecarinata on S. natans I. For the hydroids on S. natans VIII and S. fluitans III, hydroid mitochondrial genotype was strongly correlated with the Sargassum substrate form. We found significant population genetic structure in the hydroids, which was also consistent with the distributional patterns of the Sargassum forms. These results suggest that hydroid settlement on the Sargassum occurs in type-specific Sargassum source regions. Hydroid species identification is challenging and cryptic speciation is common in the Aglaopheniidae. Therefore, to confirm our identification of A. latecarinata, we conducted a phylogenetic analysis that showed that while the genus Aglaophenia was not monophyletic, all A. latecarinata haplotypes associated with pelagic Sargassum belonged to the same clade and were likely the same species as previously published sequences from Florida, Central America, and one location in Brazil (São Sebastião). A nominal A. latecarinata sequence from a second Brazilian location (Alagoas) likely belongs to a different species.
bibliographic citation: Govindarajan et al. (2019) The distribution and mitochondrial genotype of the hydroid Aglaophenia latecarinata is correlated with its pelagic Sargassum substrate type in the tropical and subtropical western Atlantic Ocean. PeerJ 7:e7814 https://doi.org/10.7717/peerj.7814
date submitted: 2019-05-12
date accepted: 2019-09-02
issued: 2019-10-18
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Govindarajan
  given name: Annette F.
author list: Agent
  family name: Cooney
  given name: Laura
author list: Agent
  family name: Whittaker
  given name: Kerry
author list: Agent
  family name: Bloch
  given name: Dana
author list: Agent
  family name: Burdorf
  given name: Rachel M.
author list: Agent
  family name: Canning
  given name: Shalagh
author list: Agent
  family name: Carter
  given name: Caroline
author list: Agent
  family name: Cellan
  given name: Shannon M.
author list: Agent
  family name: Eriksson
  given name: Fredrik A.A.
author list: Agent
  family name: Freyer
  given name: Hannah
author list: Agent
  family name: Huston
  given name: Grayson
author list: Agent
  family name: Hutchinson
  given name: Sabrina
author list: Agent
  family name: McKeegan
  given name: Kathleen
author list: Agent
  family name: Malpani
  given name: Megha
author list: Agent
  family name: Merkle-Raymond
  given name: Alex
author list: Agent
  family name: Ouellette
  given name: Kendra
author list: Agent
  family name: Petersen-Rockney
  given name: Robin
author list: Agent
  family name: Schultz
  given name: Maggie
author list: Agent
  family name: Siuda
  given name: Amy N.S.
doi: 10.7717/peerj.7814
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-10-18
copyright: © 2019 Govindarajan et al.
attribution name: Govindarajan et al.

Determining the optimal maximal and submaximal voluntary contraction tests for normalizing the erector spinae muscles
type: item
type: AcademicArticle
description: Background This study aimed to identify which maximum voluntary isometric contraction (MVIC) and sub-MVIC tests produce the highest activation of the erector spinae muscles and the greatest reduction in inter-individual variability, to put them forward as reference normalization maneuvers for future studies. Methods Erector spinae EMG activity was recorded in 38 healthy women during five submaximal and three maximal exercises. Results None of the three MVIC tests generated the maximal activation level in all the participants. The maximal activation level was achieved in 68.4% of cases with the test performed on the roman chair in the horizontal position (96.3 ± 7.3; p < 0.01). Of the five submaximal maneuvers, the one in the horizontal position on the roman chair produced the highest percentage of activation (61.1 ± 16.7; p < 0.01), and one of the lowest inter-individual variability values in the normalized signal of a trunk flexion-extension task. Conclusions A modified Sorensen MVIC test in a horizontal position on a roman chair and against resistance produced the highest erector spinae activation, but not in 100% of participants, so the execution of several normalization maneuvers with the trunk at different inclinations should be considered to normalize the erector spinae EMG signal. A modified Sorensen test in a horizontal position without resistance is the submaximal maneuver that produces the highest muscle activation and the greatest reduction in inter-individual variability, and could be considered a good reference test for normalization.
format: application/pdf
format: text/html
creator: Gemma Biviá-Roig
creator: Juan Francisco Lisón
creator: Daniel Sánchez-Zuriaga
subject: Anatomy and Physiology
subject: Kinesiology
subject: Orthopedics
description: doi:10.7717/peerj.7824
publisher: PeerJ Inc.
rights: © 2019 Biviá-Roig et al.
abstract: Background This study aimed to identify which maximum voluntary isometric contraction (MVIC) and sub-MVIC tests produce the highest activation of the erector spinae muscles and the greatest reduction in inter-individual variability, to put them forward as reference normalization maneuvers for future studies. Methods Erector spinae EMG activity was recorded in 38 healthy women during five submaximal and three maximal exercises. Results None of the three MVIC tests generated the maximal activation level in all the participants. The maximal activation level was achieved in 68.4% of cases with the test performed on the roman chair in the horizontal position (96.3 ± 7.3; p < 0.01). Of the five submaximal maneuvers, the one in the horizontal position on the roman chair produced the highest percentage of activation (61.1 ± 16.7; p < 0.01), and one of the lowest inter-individual variability values in the normalized signal of a trunk flexion-extension task. Conclusions A modified Sorensen MVIC test in a horizontal position on a roman chair and against resistance produced the highest erector spinae activation, but not in 100% of participants, so the execution of several normalization maneuvers with the trunk at different inclinations should be considered to normalize the erector spinae EMG signal. A modified Sorensen test in a horizontal position without resistance is the submaximal maneuver that produces the highest muscle activation and the greatest reduction in inter-individual variability, and could be considered a good reference test for normalization.
bibliographic citation: Biviá-Roig et al. (2019) Determining the optimal maximal and submaximal voluntary contraction tests for normalizing the erector spinae muscles. PeerJ 7:e7824 https://doi.org/10.7717/peerj.7824
date submitted: 2019-05-31
date accepted: 2019-09-03
issued: 2019-10-18
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Biviá-Roig
  given name: Gemma
author list: Agent
  family name: Lisón
  given name: Juan Francisco
author list: Agent
  family name: Sánchez-Zuriaga
  given name: Daniel
doi: 10.7717/peerj.7824
volume: 7
issn: 2167-8359
publication name: PeerJ
publication date: 2019-10-18
copyright: ©2019 Biviá-Roig et al.
attribution name: Biviá-Roig et al.

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