title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=1523 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Cytotoxicity and antimicrobial action of selected phytochemicals against planktonic and sessile Streptococcus mutans link: https://peerj.com/articles/4872 last-modified: 2018-06-04 description: BackgroundDental caries remains the most prevalent and costly oral infectious disease worldwide, encouraging the search for new and more effective antimicrobials. Therefore, the aim of this work was to study the antimicrobial action of selected phytochemicals (eugenol, citronellol, sabinene hydrate, trans-cinnamaldehyde, terpineol and cinnamic acid) against Streptococcus mutans in planktonic and biofilm states as well as the cytotoxicity of these compounds.MethodsThe antibacterial activity of the selected compounds was evaluated by the determination of the minimal bactericidal concentration. The resazurin assay was used to assess the metabolic activity of sessile S. mutans. The cytotoxicity was determined using a fibroblast cell line.ResultsAmong the tested phytochemicals, citronellol, cinnamic acid and trans-cinnamaldehyde were the most effective against both planktonic and sessile S. mutans, an effect apparently related to their hydrophobic character. Additionally, these three compounds did not compromise fibroblasts cell viability.DiscussionCitronellol, cinnamic acid and trans-cinnamaldehyde demonstrated significant antimicrobial activity and low cytotoxicity proposing their potential as a novel group of therapeutic compounds to control oral infectious diseases. Moreover, their effects are particularly relevant when benchmarked against eugenol, a phytochemical commonly used for prosthodontic applications in dentistry. creator: Marta Ribeiro creator: Joana Malheiro creator: Liliana Grenho creator: Maria Helena Fernandes creator: Manuel Simões uri: https://doi.org/10.7717/peerj.4872 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Ribeiro et al. title: Bullying victimization and child sexual abuse among left-behind and non-left-behind children in China link: https://peerj.com/articles/4865 last-modified: 2018-06-04 description: BackgroundBullying is one of the most important factors associated with child abuse. However, robust tests supporting the assumption that being bullied can contribute to child sexual abuse (CSA) among left-behind children (LBC) remain sparse. This study aims to investigate the association of bullying victimization with CSA among LBC in China.MethodsA cross-sectional study was conducted in six middle schools of Sichuan and Anhui province in 2015. The bullying victimization was assessed by seven items from the Revised Olweus Bully/Victim Questionnaire. The experience of CSA was measured by ten items CSA scale with good consistency.ResultsA total of 1,030 children met the sampling criteria, including 284 LBC and 746 non-LBC. The prevalence of CSA was 22.89% in LBC and 20.19% in non-LBC (p > 0.05). Bullying victimization was related to CSA among both LBC (adjusted Odds Ratio [aOR] = 2.52, 95% CI [1.34–4.73]) and non-LBC (aOR = 2.35, 95% CI [1.58–3.53]). The association between bullying victimization and CSA was much higher among left-behind girls (left-behind girls: aOR = 7.36, 95% CI [2.16–24.99]; non-left-behind girls: aOR = 2.38, 95% CI [1.08–5.27]). Also, LBC of a young age (11–15), children with siblings, living in rural areas and non-traditional family structure who were bullied were more likely to suffer CSA than their non-LBC peers.ConclusionsBullying victimization is associated with a significant increase in CSA among both LBC and non-LBC. Anti-bullying programs should target vulnerable populations including female LBC and LBC with siblings to reduce the risk of CSA. creator: Li Yan creator: Qianqian Zhu creator: Xiaowen Tu creator: Xiayun Zuo creator: Chunyan Yu creator: Chaohua Lou creator: Qiguo Lian uri: https://doi.org/10.7717/peerj.4865 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Yan et al. title: Seasonal fluctuation of oribatid mite communities in forest microhabitats link: https://peerj.com/articles/4863 last-modified: 2018-06-04 description: Oribatid mites are abundant and diverse decomposers in almost all terrestrial microhabitats, especially in temperate forests. Although their functional importance in the decomposition system in these forests has been investigated, spatio-temporal patterns of oribatid mite communities inhabiting different microhabitats have largely been neglected. Therefore, we (i) investigated seasonal fluctuation (monthly over one year) in oribatid-mite community structure and specificity to three microhabitats (moss, dead wood and litter) and (ii) analyzed the influence of air temperature and overall air humidity on seasonal community changes. In total, 57,398 adult oribatid mite individuals were collected. Total abundance, species richness and diversity differed among microhabitats. Seasonal changes were most pronounced in moss and least in litter. While overall air humidity had no influence on species distribution and community changes, air temperature positively influenced species richness and diversity, again most pronounced in moss. The calculated environmental temperature occurrence niche showed that 35% of adult oribatid mite species occurred at higher air temperatures. Furthermore, interaction/bipartite networks were more generalized—i.e., species were more equally distributed among moss, dead wood and litter—when ambient air temperatures were higher. This pattern is probably due to the dispersal ability of adult oribatid mites, i.e., species enter a dispersal mode only at higher air temperatures. creator: Katja Wehner creator: Michael Heethoff creator: Adrian Brückner uri: https://doi.org/10.7717/peerj.4863 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Wehner et al. title: Combined therapy of pulsed radiofrequency and nerve block in postherpetic neuralgia patients: a randomized clinical trial link: https://peerj.com/articles/4852 last-modified: 2018-06-04 description: Caused by viral infection, postherpetic neuralgia (PHN) is the most common chronic neuropathic pain. Various treatment modalities such as early use of nerve block therapy (NBT) and pulsed radiofrequency (PRF) have been studied in reducing pain, however, no consistent success was achieved in all the patients treated with single regimen. The combined therapy of PRF and NBT with different targeting mechanism are of interest and remains to be determined. Here we investigated the combined effects of pulsed radiofrequency (PRF) with nerve block therapy (NBT) in PHN patients in a prospective randomized clinical trial. Sixty PHN patients were divided into four groups (n = 15 each): the conventional puncture group (group CP), the nerve block therapy group (group NB), the PRF group (group PRF), and the combined treatment group (PRF combined with nerve block therapy (group CT). To evaluate the extent of remission of hyperalgesia, we recorded the visual analogue scale (VAS) scores during cotton swab reaction before and after treatment and in the resting and active pain states. In addition, blood samples were collected and plasma cytokine and neuropeptides such as interleukin-6 (IL-6), substance P (SP), and β-endorphin (β-EP) were measured by enzyme-linked immunosorbent assay (ELISA) at the admission (basic state), before the operation, and at 12 h postoperatively. The number of adverse events (nausea, vomiting, constipation, puncture point hemorrhage, swelling and redness) within 12 h of the treatment were also documented. Our results showed that VAS scores during cotton swab reaction decreased after treatment in all patients (p < 0.05). Compared to group CP, plasma IL-6 and SP levels decreased (p < 0.05) and β-EP levels increased (p < 0.05) in groups NB, PRF, and CT. There were no significant differences in adverse events among groups (p > 0.05). We found that PRF in combination with NBT increased β-EP levels and decreased plasma IL-6 and SP, thereby alleviating pain and hyperalgesia in PHN patients. Taken together, our data suggest combined therapy of PRF and NBT is effective and safe for PHN patients. creator: Dan Li creator: Guohua Sun creator: Hanzhe Sun creator: Yanjuan Wang creator: Zhiping Wang creator: Jianping Yang uri: https://doi.org/10.7717/peerj.4852 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Li et al. title: Exploring constructs of well-being, happiness and quality of life link: https://peerj.com/articles/4903 last-modified: 2018-06-01 description: BackgroundExisting definitions of happiness, subjective well-being, and quality of life suggest conceptual overlap between these constructs. This study explored the relationship between these well-being constructs by applying widely used measures with satisfactory psychometric properties.Materials and MethodsUniversity students (n = 180) completed widely used well-being measures including the Oxford Happiness Questionnaire (OHQ), the World Health Organization Quality of Life Questionnaire, the Satisfaction with Life Scale, and the Positive and Negative Affect Scale. We analyzed the data using correlation, regression, and exploratory factor analysis.ResultsAll included well-being measures demonstrated high loadings on the global well-being construct that explains about 80% of the variance in the OHQ, the psychological domain of Quality of Life and subjective well-being. The results show high positive correlations between happiness, psychological and health domains of quality of life, life satisfaction, and positive affect. Social and environmental domains of quality of life were poor predictors of happiness and subjective well-being after controlling for psychological quality of life.ConclusionTogether, these data provide support for a global well-being dimension and interchangeable use of terms happiness, subjective well-being, and psychological quality of life with the current sample and measures. Further investigation with larger heterogeneous samples and other well-being measures is warranted. creator: Oleg N. Medvedev creator: C. Erik Landhuis uri: https://doi.org/10.7717/peerj.4903 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2018 Medvedev and Landhuis title: N-acetylcysteine protects against motor, optomotor and morphological deficits induced by 6-OHDA in zebrafish larvae link: https://peerj.com/articles/4957 last-modified: 2018-06-01 description: BackgroundParkinson’s disease (PD) is the second most common neurodegenerative disorder. In addition to its highly debilitating motor symptoms, non-motor symptoms may precede their motor counterparts by many years, which may characterize a prodromal phase of PD. A potential pharmacological strategy is to introduce neuroprotective agents at an earlier stage in order to prevent further neuronal death. N-acetylcysteine (NAC) has been used against paracetamol overdose hepatotoxicity by restoring hepatic concentrations of glutathione (GSH), and as a mucolytic in chronic obstructive pulmonary disease by reducing disulfide bonds in mucoproteins. It has been shown to be safe for humans at high doses. More recently, several studies have evidenced that NAC has a multifaceted mechanism of action, presenting indirect antioxidant effect by acting as a GSH precursor, besides its anti-inflammatory and neurotrophic effects. Moreover, NAC modulates glutamate release through activation of the cystine-glutamate antiporter in extra-synaptic astrocytes. Its therapeutic benefits have been demonstrated in clinical trials for several neuropsychiatric conditions but has not been tested in PD models yet.MethodsIn this study, we evaluated the potential of NAC to prevent the damage induced by 6-hydroxydopamine (6-OHDA) on motor, optomotor and morphological parameters in a PD model in larval zebrafish.ResultsNAC was able to prevent the motor deficits (total distance, mean speed, maximum acceleration, absolute turn angle and immobility time), optomotor response impairment and morphological alterations (total length and head length) caused by exposure to 6-OHDA, which reinforce and broaden the relevance of its neuroprotective effects.DiscussionNAC acts in different targets relevant to PD pathophysiology. Further studies and clinical trials are needed to assess this agent as a candidate for prevention and adjunctive treatment of PD. creator: Radharani Benvenutti creator: Matheus Marcon creator: Carlos G. Reis creator: Laura R. Nery creator: Camila Miguel creator: Ana P. Herrmann creator: Monica R.M. Vianna creator: Angelo Piato uri: https://doi.org/10.7717/peerj.4957 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2018 Benvenutti et al. title: Occupational health and safety characteristics of agricultural workers in Adana, Turkey: a cross-sectional study link: https://peerj.com/articles/4952 last-modified: 2018-06-01 description: BackgroundAmong agricultural workers, especially in the seasonal migratory ones, housing and hygiene related issues, occupational accidents, low levels of education, poverty and absence of social security problems emerge as significant public health problems. This study aims to compare migrant-seasonal workers (MSWs) and resident agricultural workers (RAWs) in terms of socio-demographic characteristics and occupational health and safety in Adana, one of Turkey’s most important agricultural cities.MethodsThis cross-sectional study was conducted on RAWs and MSWs, aged 15–65, operating in the province of Adana. The calculated sample sizes for both MSWs and RAWs were distributed using stratified simple random sampling to five districts of Adana.ResultsThe mean age of the 798 participating agricultural workers was 34.6 ± 14.2. Of the RAWs, 78.8% and of the MSWs 57.0% were male; 5.8% of RAWs and 32.8% of MSWs were illiterate. The mean number of people in the households of the participating workers was 5.1 for RAWs and 6.6 for MSWs. Of the RAWs, 20.5% were not covered by any social security scheme while this percentage was 35.1% in MSWs. RAWs worked 9.9 h a day while MSWs worked 10.9 h a day. Of the agricultural workers, 12.9% had injuries caused by occupational accidents.DiscussionAgricultural workers, who are a large part of Turkey’s economically active population, do not have healthy and safe working conditions. New regulations in the fields of social security, record keeping, monitoring, supervision, education and occupational health have been implemented recently to solve these problems. Despite the recent improvements there are still some problematic issues in the auditing of the necessary practices. creator: Ramazan Azim Okyay creator: Ferdi Tanır creator: Pelin Mutlu Ağaoğlu uri: https://doi.org/10.7717/peerj.4952 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2018 Okyay et al. title: Understanding the cone scale in Cupressaceae: insights from seed-cone teratology in Glyptostrobus pensilis link: https://peerj.com/articles/4948 last-modified: 2018-06-01 description: Both wild-type and teratological seed cones are described in the monoecious conifer Glyptostrobus pensilis and compared with those of other Cupressaceae sensu lato and other conifers. Some Cupressaceae apparently possess a proliferation of axillary structures in their cone scales. In our interpretation, in Glyptostrobus each bract of both typical and atypical seed cones bears two descending accessory shoots, interpreted here as seed scales (ovuliferous scales). The primary seed scale is fertile and forms the ovules, the second is sterile and forms characteristic tooth-like structures. The bract and the two axillary seed scales are each supplied with a single distinct vascular bundle that enters the cone axis as a separate strand; this vasculature also characterises the descending accessory short shoots in the vegetative parts of the crown. In wild-type seed cones, the fertile seed scale is reduced to its ovules, and the ovules are always axillary. In contrast, the ovules of some of the teratological seed cones examined were located at the centre of the cone scale. An additional tissue found on the upper surface of the sterile lower seed scale is here interpreted as the axis of the fertile seed scale. Thus, the central position of the ovules can be explained by recaulescent fusion of the upper fertile and lower sterile seed scales. In several teratological cone scales, the ovules were enveloped by an additional sterile tissue that is uniseriate and represents an epidermal outgrowth of the fertile seed scale. Close to the ovules, the epidermis was detached from lower tissue and surrounded the ovule completely, except at the micropyle. These teratological features are potentially significant in understanding seed-cone homologies among extant conifers. creator: Veit Martin Dörken creator: Paula J. Rudall uri: https://doi.org/10.7717/peerj.4948 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2018 Dörken and Rudall title: Some maternal lineages of domestic horses may have origins in East Asia revealed with further evidence of mitochondrial genomes and HVR-1 sequences link: https://peerj.com/articles/4896 last-modified: 2018-06-01 description: ObjectivesThere are large populations of indigenous horse (Equus caballus) in China and some other parts of East Asia. However, their matrilineal genetic diversity and origin remained poorly understood. Using a combination of mitochondrial DNA (mtDNA) and hypervariable region (HVR-1) sequences, we aim to investigate the origin of matrilineal inheritance in these domestic horses.MethodsTo investigate patterns of matrilineal inheritance in domestic horses, we conducted a phylogenetic study using 31 de novo mtDNA genomes together with 317 others from the GenBank. In terms of the updated phylogeny, a total of 5,180 horse mitochondrial HVR-1 sequences were analyzed.ResultsEightteen haplogroups (Aw-Rw) were uncovered from the analysis of the whole mitochondrial genomes. Most of which have a divergence time before the earliest domestication of wild horses (about 5,800 years ago) and during the Upper Paleolithic (35–10 KYA). The distribution of some haplogroups shows geographic patterns. The Lw haplogroup contained a significantly higher proportion of European horses than the horses from other regions, while haplogroups Jw, Rw, and some maternal lineages of Cw, have a higher frequency in the horses from East Asia. The 5,180 sequences of horse mitochondrial HVR-1 form nine major haplogroups (A-I). We revealed a corresponding relationship between the haplotypes of HVR-1 and those of whole mitochondrial DNA sequences. The data of the HVR-1 sequences also suggests that Jw, Rw, and some haplotypes of Cw may have originated in East Asia while Lw probably formed in Europe.ConclusionsOur study supports the hypothesis of the multiple origins of the maternal lineage of domestic horses and some maternal lineages of domestic horses may have originated from East Asia. creator: Hongying Ma creator: Yajiang Wu creator: Hai Xiang creator: Yunzhou Yang creator: Min Wang creator: Chunjiang Zhao creator: Changxin Wu uri: https://doi.org/10.7717/peerj.4896 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Ma et al. title: Cranial anatomy of Bellusaurus sui (Dinosauria: Eusauropoda) from the Middle-Late Jurassic Shishugou Formation of northwest China and a review of sauropod cranial ontogeny link: https://peerj.com/articles/4881 last-modified: 2018-06-01 description: Bellusaurus sui is an enigmatic sauropod dinosaur from the Middle-Late Jurassic Shishugou Formation of northwest China. Bellusaurus is known from a monospecific bonebed preserving elements from more than a dozen juvenile individuals, including numerous bones of the skull, providing rare insight into the cranial anatomy of juvenile sauropods. Here, we present a comprehensive description of the cranial anatomy of Bellusaurus, supplementing the holotypic cranial material with additional elements recovered from recent joint Sino-American field expeditions. Bellusaurus is diagnosed by several unique autapomorphies, including a neurovascular foramen piercing the ascending process of the maxilla at midheight, the frontal process of the nasal extending farther posteriorly onto the frontal than the prefrontal, and U-shaped medial and lateral notches in the posterior margin of the ventral process of the squamosal. Several features identified here, including a preantorbital opening in the maxilla, a stepped dorsal margin of the vomerine process of the pterygoid, and the partitioning of the dorsal midline endocranial fossae associated with the dural venous sinuses into anterior and posterior components by a transverse ridge of the parietal, are consistent with recent phylogenetic hypotheses that recover Bellusaurus as a basal macronarian or close relative of Neosauropoda. We review the current state of knowledge of sauropod cranial ontogeny, placing several aspects of the cranial anatomy of Bellusaurus in an ontogenetic context and providing explicit hypotheses of ontogenetic transformations that can be tested by future discoveries of ontogenetic variants of sauropod skulls. While scoring ontogenetically variable characters as unknown may help to alleviate the biasing effects of ontogeny on the phylogenetic position of juvenile specimens, we caution that this approach may remove phylogenetically informative character information, and argue that inference methods that are known to be less sensitive to homoplasy than equal weights parsimony (i.e., implied weights parsimony; Bayesian approaches) should also be employed. creator: Andrew J. Moore creator: Jinyou Mo creator: James M. Clark creator: Xing Xu uri: https://doi.org/10.7717/peerj.4881 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2018 Moore et al.