title: PeerJ
description:  Articles published in PeerJ
link: https://peerj.com/articles/index.rss3?journal=peerj&page=800
creator: info@peerj.com PeerJ
errorsTo: info@peerj.com PeerJ
language: en

title: Dinophiliformia early neurogenesis suggests the evolution of conservative neural structures across the Annelida phylogenetic tree
link: https://peerj.com/articles/12386
last-modified: 2021-12-08
description: Despite the increasing data concerning the structure of the adult nervous system in various Lophotrochozoa groups, the early events during the neurogenesis of rare and unique groups need clarification. Annelida are a diverse clade of Lophotrochozoa, and their representatives demonstrate a variety of body plans, lifestyles, and life cycles. Comparative data about the early development are available for Errantia, Sedentaria, Sipuncula, and Palaeoannelida; however, our knowledge of Dinophiliformia is currently scarce. Representatives of Dinophiliformia are small interstitial worms combining unique morphological features of different Lophotrochozoan taxa and expressing paedomorphic traits. We describe in detail the early neurogenesis of two related species: Dimorphilus gyrociliatus and Dinophilus vorticoides, from the appearance of first nerve cells until the formation of an adult body plan. In both species, the first cells were detected at the anterior and posterior regions at the early trochophore stage and demonstrated positive reactions with pan-neuronal marker anti-acetylated tubulin only. Long fibers of early cells grow towards each other and form longitudinal bundles along which differentiating neurons later appear and send their processes. We propose that these early cells serve as pioneer neurons, forming a layout of the adult nervous system. The early anterior cell of D. vorticoides is transient and present during the short embryonic period, while early anterior and posterior cells in D. gyrociliatus are maintained throughout the whole lifespan of the species. During development, the growing processes of early cells form compact brain neuropile, paired ventral and lateral longitudinal bundles; unpaired medial longitudinal bundle; and commissures in the ventral hyposphere. Specific 5-HT- and FMRFa-immunopositive neurons differentiate adjacent to the ventral bundles and brain neuropile in the middle trochophore and late trochophore stages, i.e. after the main structures of the nervous system have already been established. Processes of 5-HT- and FMRFa-positive cells constitute a small proportion of the tubulin-immunopositive brain neuropile, ventral cords, and commissures in all developmental stages. No 5-HT- and FMRFa-positive cells similar to apical sensory cells of other Lophotrochozoa were detected. We conclude that: (i) like in Errantia and Sedentaria, Dinophiliformia neurogenesis starts from the peripheral cells, whose processes prefigure the forming adult nervous system, (ii) Dinophiliformia early cells are negative to 5-HT and FMRFa antibodies like Sedentaria pioneer cells.
creator: Elizaveta Fofanova
creator: Tatiana D. Mayorova
creator: Elena E. Voronezhskaya
uri: https://doi.org/10.7717/peerj.12386
license: https://creativecommons.org/licenses/by/4.0/
rights: © 2021 Fofanova et al.

title: Effects of fallow tillage on winter wheat yield and predictions under different precipitation types
link: https://peerj.com/articles/12602
last-modified: 2021-12-08
description: In northern China, precipitation that is primarily concentrated during the fallow period is insufficient for the growth stage, creates a moisture shortage, and leads to low, unstable yields. Yield prediction in the early growth stages significantly informs field management decisions for winter wheat (Triticum aestivum L.). A 10-year field experiment carried out in the Loess Plateau area tested how three tillage practices (deep ploughing (DP), subsoiling (SS), and no tillage (NT)) influenced cultivation and yield across different fallow periods. The experiment used the random forest (RF) algorithm to construct a prediction model of yields and yield components. Our results revealed that tillage during the fallow period was more effective than NT in improving yield in dryland wheat. Under drought condition, DP during the fallow period achieved a higher yield than SS, especially in drought years; DP was 16% higher than SS. RF was deemed fit for yield prediction across different precipitation years. An RF model was developed using meteorological factors for fixed variables and soil water storage after tillage during a fallow period for a control variable. Small error values existed in the prediction yield, spike number, and grains number per spike. Additionally, the relative error of crop yield under fallow tillage (5.24%) was smaller than that of NT (6.49%). The prediction error of relative meteorological yield was minimum and optimal, indicating that the model is suitable to explain the influence of meteorological factors on yield.
creator: Yu Feng
creator: Wen Lin
creator: Shaobo Yu
creator: Aixia Ren
creator: Qiang Wang
creator: Hafeez Noor
creator: Jianfu Xue
creator: Zhenping Yang
creator: Min Sun
creator: Zhiqiang Gao
uri: https://doi.org/10.7717/peerj.12602
license: https://creativecommons.org/licenses/by/4.0/
rights: © 2021 Feng et al.

title: A short scale for measuring attitudes towards the doctor-patient relationship: psychometric properties and measurement invariance of the German Patient-Practitioner-Orientation Scale (PPOS-D6)
link: https://peerj.com/articles/12604
last-modified: 2021-12-08
description: BackgroundThe Patient-Practitioner Orientation Scale (PPOS) was originally developed to compare doctor’s and patient’s consensus regarding patient centeredness. Research assumed PPOS measurements to be comparable across different groups of participants, however, without assessing the actual validity of this assumption. In this study, we investigate the psychometric properties and measurement invariance of a short version of the German translation of the PPOS.MethodsBased on a cross-sectional survey of N = 332 medical students, we present a short version of the German Patient-Practitioner-Orientation Scale (PPOS-D6) and examine its psychometric properties as well as measurement invariance across participants with varying levels of medical experience and gender using multigroup confirmatory factor analyses.ResultsResults indicate that PPOS-D6 provides valid and reliable measurements of patient-centeredness that are invariant across participants with different medical experience. Preliminary results also suggest invariance across gender.ConclusionPPOS-D6 is a suitable and efficient measure to compare group-specific attitudes towards the doctor-patient interaction. Additional research on convergent and discriminant validity and divergent study samples is advised.
creator: Roman Pauli
creator: Saskia Wilhelmy
uri: https://doi.org/10.7717/peerj.12604
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2021 Pauli and Wilhelmy

title: The cost of a meal: factors influencing prey profitability in Australian fur seals
link: https://peerj.com/articles/12608
last-modified: 2021-12-08
description: Knowledge of the factors shaping the foraging behaviour of species is central to understanding their ecosystem role and predicting their response to environmental variability. To maximise survival and reproduction, foraging strategies must balance the costs and benefits related to energy needed to pursue, manipulate, and consume prey with the nutritional reward obtained. While such information is vital for understanding how changes in prey assemblages may affect predators, determining these components is inherently difficult in cryptic predators. The present study used animal-borne video data loggers to investigate the costs and benefits related to different prey types for female Australian fur seals (Arctocephalus pusillus doriferus), a primarily benthic foraging species in the low productivity Bass Strait, south-eastern Australia. A total of 1,263 prey captures, resulting from 2,027 prey detections, were observed in 84.5 h of video recordings from 23 individuals. Substantial differences in prey pursuit and handling times, gross energy gain and total energy expenditure were observed between prey types. Importantly, the profitability of prey was not significantly different between prey types, with the exception of elasmobranchs. This study highlights the benefit of animal-borne video data loggers for understanding the factors that influence foraging decisions in predators. Further studies incorporating search times for different prey types would further elucidate how profitability differs with prey type.
creator: Nelle Meyers
creator: Cassie N. Speakman
creator: Nicole A.S.-Y. Dorville
creator: Mark A. Hindell
creator: Jayson M. Semmens
creator: Jacquomo Monk
creator: Alistair M.M. Baylis
creator: Daniel Ierodiaconou
creator: Andrew J. Hoskins
creator: Greg J. Marshall
creator: Kyler Abernathy
creator: John P.Y. Arnould
uri: https://doi.org/10.7717/peerj.12608
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2021 Meyers et al.

title: First report of the genus Bicorniphontodes (Copepoda, Harpacticoida, Ancorabolidae) in South Korea, with descriptions of three new species
link: https://peerj.com/articles/12530
last-modified: 2021-12-07
description: We report the occurrence of the genus Bicorniphontodes George, Glatzel & Schröder, 2019 in Korean waters, with descriptions of three new species: Bicorniphontodes lacuna sp. nov., B. comptus sp. nov., and B. huysi sp. nov. Morphology analysis was carried out to reconstruct the phylogenetic relationships of Bicorniphontodes species, including the three new species. Parsimony analysis based on 41 characters revealed that the three new species are clustered together as a monophyletic clade, of which B. horstgeorgei (George & Gheerardyn, 2015) is a sister species. The monophyletic status of three new species was supported by five synapomorphies, such as the micro-morphological conditions of the exopodal segments of the first leg, coxae of the second to fourth legs, exopod of the fifth leg in the female and baseoendopod of the fifth leg in the male, and the maxillular endopod represented by two setae. These three species can be easily distinguished based on the morphology of the rostrum, cephalothoracic processes, female genital double-somite, caudal rami, and second endopodal segment of the third leg in the male. The taxonomic position of B. bicornis sensuKim, 2013 in Korean fauna was reevaluated based on the newly collected material from Udo Islet near Jeju Island; this resulted in a synonym of B. huysi sp. nov.
creator: Jong Guk Kim
creator: Jimin Lee
creator: Kyuhee Cho
uri: https://doi.org/10.7717/peerj.12530
license: https://creativecommons.org/licenses/by/4.0/
rights: © 2021 Kim et al.

title: The determination of thiocyanate in the blood plasma and holding water of Amphiprion clarkii after exposure to cyanide
link: https://peerj.com/articles/12409
last-modified: 2021-12-07
description: The illegal practice of cyanide fishing continues throughout the Indo-Pacific. To combat this destructive fishing method, a reliable test to detect whether a fish has been captured using cyanide (CN) is needed. We report on the toxicokinetics of acute, pulsed CN exposure and chronic thiocyanate (SCN) exposure, the major metabolite of CN, in the clownfish species, Amphiprion clarkii. Fish were pulse exposed to 50 ppm CN for 20 or 45 s or chronically exposed to 100 ppm SCN for 12 days and blood plasma levels of SCN were measured. SCN blood plasma levels reached a maximum concentration (301–468 ppb) 0.13–0.17 days after exposure to CN and had a 0.1 to 1.2 day half-life. The half-life of blood plasma SCN after chronic exposure to SCN was found to be 0.13 days. Interestingly, we observed that when a fish, with no previous CN or SCN exposure, was placed in holding water spiked to 20 ppb SCN, there was a steady decrease in the SCN concentration in the holding water until it could no longer be detected at 24 hrs. Under chronic exposure conditions (100 ppm, 12 days), trace levels of SCN (∼40 ppb) were detected in the holding water during depuration but decreased to below detection within the first 24 hrs. Our holding water experiments demonstrate that low levels of SCN in the holding water of A. clarkii will not persist, but rather will quickly and steadily decrease to below detection limits refuting several publications. After CN exposure, A. clarkii exhibits a classic two compartment model where SCN is eliminated from the blood plasma and is likely distributed throughout the body. Similar studies of other species must be examined to continue to develop our understanding of CN metabolism in marine fish before a reliable cyanide detection test can be developed.
creator: J. Alexander Bonanno
creator: Nancy E. Breen
creator: Michael F. Tlusty
creator: Lawrence Andrade
creator: Andrew L. Rhyne
uri: https://doi.org/10.7717/peerj.12409
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2021 Bonanno et al.

title: Macrobenthic community responses to multiple environmental stressors in a subtropical estuary
link: https://peerj.com/articles/12427
last-modified: 2021-12-07
description: We assessed how multi- and univariate models reflect marine environmental health based on macrobenthic community responses to three environmental stressor categories: hydrodynamics, organic enrichment and metal contamination. We then compared the models with the benthic index AMBI (AZTI Marine Biotic Index). Macrobenthic community and physicochemical variables were sampled at 35 sites along Babitonga Bay, a subtropical estuary in Southern Brazil. Distance-based linear modelling identified depth, grain size and organic matter as well as Cu and Zn as key stressors affecting the macrobenthos. Using canonical analysis of principal coordinates (CAP), we developed three multivariate models based on the variability in community composition, creating stress gradients. The metal gradient showed better correlation with the benthic community. Sediment quality indices (Geoaccumulation Index and Contamination Factor) showed a low to moderate contamination status, with higher concentrations for Cr, Ni and Zn at the inner areas of the bay. According to AMBI, Babitonga Bay has a “good” environmental health status, and the AMBI values show stronger correlations with the hydrodynamic and organic enrichment gradients (r = 0.50 and r = 0.47) rather than the metal gradient (r = 0.29). Lumbrineridae polychaetes (not included in the AMBI list) and Scoloplos sp. were negatively related to the metal contamination gradient and were considered sensitive, while Sigambra sp., Magelona papillicornis, the gastropod Heleobia australis and species of the crustacean order Mysida were positively related to the gradient and considered tolerant to higher concentrations of metals in the sediment. Despite the inconsistency in the ecological classification provided by AMBI and its relationship with the metal gradient, our results suggest that the environmental quality was satisfactory for the studied gradients. The metal gradient showed the weakest correlation to AMBI. In such cases, the ecological classification of taxa by the index should be evaluated under the perspective of the action of inorganic genotoxic contaminants represented by metals.
creator: Fernanda M. Souza
creator: Eliandro R. Gilbert
creator: Kalina M. Brauko
creator: Luciano Lorenzi
creator: Eunice Machado
creator: Mauricio G. Camargo
uri: https://doi.org/10.7717/peerj.12427
license: https://creativecommons.org/licenses/by/4.0/
rights: © 2021 Souza et al.

title: Mitochondrial sequence diversity reveals the hybrid origin of invasive gibel carp (Carassius gibelio) populations in Hungary
link: https://peerj.com/articles/12441
last-modified: 2021-12-07
description: BackgroundInvasive gibel carp, Carassius gibelio (Bloch, 1782) has become well-established in the Hungarian waters and now are spreading in the European waters. On major concern now is the potential hybridization between gibel carp and the other invasive species in the Carassius auratus complex (CAC), which may further accelerate the spread of the whole invasive species complex. The identification of gibel carp and their hybrids is difficult because of its morphological similarity to the other species in CAC. Here we carry out a genomic assessment to understand the history of gibel carp invasion and its phylogenetic relationship with the other species in CAC. Three loci of the mitochondrial genome (D-loop, CoI, Cytb) were used to determine the phylogenetic origin of individuals and relarionship among six gibel carp populations and the other species in the CAC.MethodolgyA total of 132 gibel carp samples from six locations in Southern Transdanubia (Hungary) were collected after phenotypic identification to measure the genetic diversity within and among gibel carp populations of Southern Transdanubia (Hungary). The genetic background was examined by the sequences of the mitochondrial genome: D-loop, Cytochrome c oxidase I (CoI) and Cytochrome b (Cytb). Mitochondrial genetic markers are excellent tools for phylogenetic studies because they are maternally inherited. Successfully identified haplotypes were aligned and with reference sequences in nucleotide databases (i.e., NCBI-BLAST: National Centre for Biotechnology Information and BOLD: Barcode of Life Data System). The phylogenetic relationships among gibel carp populations were then analyzed together with the reference sequences to understand the relationship and the level of hybridization with the species in CAC.ResultsAmong the 132 aligned D-loop sequences 22 haplotypes were identified. Further examination of representative individuals of the 22 haplotypes, six Cytb and four CoI sequences were detected. The largest number of haplotypes of all three loci were found in Lake Balaton, the largest shallow lake in Central Europe. Based on the NCBI-BLAST alignment of the D-loop, haplotypes of Carassius auratus auratus and Carassius a. buergeri in CAC were identified in the C. gibelio samples. Further analysis of haplotypes with the other two mitochondrial markers confirmed the occurrence of intragenus hybridization of C. gibelio in the Hungarian waters.ConclusionBy using three mitochondrial markers (D-loop, Cytb, CoI), we genomically characterized a gibel carp-complex in Hungarian waters and assessed the C. gibelio phylogenetic status between them. Hybrid origin of locally invasive Carassius taxon was detected in Hungary. It points out that invasive species are not only present in Hungary but reproduce with each other in the waters, further accelerating their spread.
creator: Szilvia Keszte
creator: Arpad Ferincz
creator: Katalin Tóth-Ihász
creator: Réka Enikő Balogh
creator: Ádám Staszny
creator: Árpád Hegyi
creator: Péter Takács
creator: Bela Urbanyi
creator: Balázs Kovács
uri: https://doi.org/10.7717/peerj.12441
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2021 Keszte et al.

title: A cross-sectional study for the mental health status and sleep quality among college students in Macao during the COVID-19 pandemic
link: https://peerj.com/articles/12520
last-modified: 2021-12-07
description: ObjectivesThe main focus of this study was to investigate the effect of the coronavirus disease (COVID-19) pandemic on the mental health condition and sleep quality of college students in Macao. In addition, the students’ behaviours during the pandemic, such as drinking alcohol, taking sleeping pills, and seeking psychological counselling were analyzed.MethodA cross-sectional survey of mental health and sleep quality status, as well as the possible behavioral risk factors, was conducted among the college students of Macao in August, 2020 during the COVID-19 pandemic. An online self-report questionnaire survey method was applied to assess the general demographics and related lifestyle behaviors of students. The general mental health condition and sleep quality were evaluated through the General Health Questionnaire (GHQ-12) and Pittsburgh Sleep Quality Index (PSQI) questionnaires, respectively. The main statistical methods included the Chi-square test, Bonferroni correction, and Pearson correlation. Data analysis was performed using SPSS Version 24.0.ResultsA total of 980 students were investigated in the study, of which 977 completed the survey. During the COVID-19 pandemic period, overall college students in Macao were psychologically well adjusted and reported good quality of sleep. However, female students were in poorer psychological condition than males (P < 0.05). Moreover, the students over 20 years of age had poorer sleep quality than students aged less than or equal to 20 (P < 0.05). The significant differences were found among the students in different study majors for the mental health status and sleep quality (both P < 0.05), which were associated with certain behaviors, such as drinking alcohol, taking sleeping pills, and seeking for help in psychological counselling during the COVID-19 pandemic period.ConclusionsPoor mental health status could be either the consequence or cause of sleep disturbance, which might further affected physical health. Therefore, regular assessment of mental health condition and sleep quality of college students is particularly necessary during public health emergencies, such as the COVID-19 pandemic, and appropriate intervention should be provided to the students.
creator: Xiaoyu Tao
creator: Dong Chen
creator: Yawen Fan
creator: Lanxin Zhang
creator: Houqian Shan
creator: Yi Wei
creator: Xi Yu
creator: Tian Zhong
creator: Ling Wang
creator: Sookja Kim Chung
creator: Yaqin Yu
creator: Ying Xiao
uri: https://doi.org/10.7717/peerj.12520
license: https://creativecommons.org/licenses/by/4.0/
rights: © 2021 Tao et al.

title: Factors associated with psychosocial problems in Korean nursing and non-nursing students during the COVID-19 pandemic
link: https://peerj.com/articles/12541
last-modified: 2021-12-07
description: BackgroundThe coronavirus disease 2019 (COVID-19) pandemic has changed our lives in many ways, including school closures and social distancing practices. These abrupt life changes may have led to psychosocial problems in college students. This study aimed to identify the factors associated with psychosocial problems in South Korean nursing and non-nursing students.MethodsThis descriptive cross-sectional survey was conducted with 139 nursing and 147 non-nursing students (N = 286) between August 6 and October 30, 2020. We investigated participants’ general characteristics (that is, sociodemographic and health-promoting behaviors), sensitivity to COVID-19 infection, COVID-19 pandemic response indicators, and psychosocial problems. The factors associated with psychosocial problems were determined using multiple regression analysis.ResultsAmong the COVID-19 pandemic response indicators, perceived health status during the COVID-19 pandemic was verified as a factor associated with psychosocial problems in nursing (β =  − 5.831, p < .001) and non-nursing students (β =  − 8.513, p < .001). Perceived stress (β = 1.263, p = .045), trust in policy (β = .892, p < .001), and religion (β =  − 1.424, p = .004) were verified as correlates of psychosocial problems in non-nursing students.ConclusionAs the COVID-19 pandemic continues, the stakeholders can use our study results to identify students experiencing psychosocial problems and subsequently as a theoretical background for developing intervention programs for those at a high risk of psychosocial problems. Additionally, it can be used as primary data for future research and practice regarding COVID-19 guidelines among students.
creator: Jeongmin Ha
creator: Dahye Park
uri: https://doi.org/10.7717/peerj.12541
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2021 Ha and Park