title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=903 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Nicotine smoking is associated with impaired cognitive performance in Pakistani young people link: https://peerj.com/articles/11470 last-modified: 2021-06-02 description: Nicotine smoking is the most common mode of tobacco smoking among young people. It affects the areas of the brain associated with memory, attention, and learning. This study has investigated the effect of nicotine smoking on cognitive performance. One hundred male volunteers (50 nicotine smokers and 50 nonsmokers) aged 18–30 years with similar socioeconomic backgrounds were recruited for this study. Clinical history of participants was obtained using a questionnaire. Their brain health and handedness were determined using the Mini Mental State Examination (MMSE) and the Edinburgh Handedness Inventory (EHI), respectively. The dependent variables examined in the study were attention-switching tasks (AST), pattern recognition memory (PRM), and choice reaction time (CRT). These parameters were assessed using the Cambridge Neuropsychological Automated Battery (CANTAB). The average ages of participating smokers and nonsmokers were 24.02 ± 3.41 years (mean ± standard deviation) and 22.68 ± 1.87 years, respectively. MMSE and EHI scores of smokers were 28.42 ± 1.09 and 99.75 ± 1.77, respectively; for nonsmokers, these scores were 28.54 ± 1.34 and 98 ± 1.91, respectively. The mean score for AST correct latency/delay was significantly higher (p = 0.050) in smokers (620.26 ± 142.03) than in nonsmokers (570.11 ± 108.39). The percentage of correct AST trials was significantly higher (p = 0.000) in nonsmokers (96.95 ± 2.18) than in smokers (83.75 ± 11.22). The PRM percent correct were significantly higher (p = 0.000) of nonsmokers (93.42 ± 8.34) than of smokers (79.75 ± 13.44). The mean correct latency for CRT was significantly higher (p = 0.009) in smokers (509.87 ± 129.83) than in nonsmokers (455.20 ± 65.73). From this data, it can be concluded that nicotine smoking is linked with impaired cognitive functions in smokers. creator: Tuba Riaz creator: Ghulam Murtaza creator: Areej Arif creator: Shahid Mahmood creator: Razia Sultana creator: Fawaz Al-Hussain creator: Shahid Bashir uri: https://doi.org/10.7717/peerj.11470 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2021 Riaz et al. title: Involvement of plasminogen activator inhibitor-1 and its related molecules in atrial fibrosis in patients with atrial fibrillation link: https://peerj.com/articles/11488 last-modified: 2021-06-02 description: Atrial fibrillation is the most common form of cardiac arrhythmia. Atrial fibrosis is a significant feature of atrial fibrillation though its mechanism is not well understood. We searched the Gene Expression Omnibus database to compare mRNA expression patterns between atrial fibrillation and sinus rhythm samples; one hundred and forty eight differentially expressed genes were identified. Most of these genes were significantly enriched in the extracellular matrix organization process and collagen-activated tyrosine kinase receptor signaling pathway. To screen hub genes involved in atrial fibrosis, we constructed a protein-protein interaction network and found that three hub genes (SERPINE1/plasminogen activator inhibitor-1/PAI-1, TIMP Metallopeptidase Inhibitor 3/TIMP3 and decorin/DCN) play vital roles in atrial fibrosis, especially plasminogen activator inhibitor-1. Elevated plasminogen activator inhibitor-1 expression was positively correlated with the p53 signaling pathway. Plasminogen activator inhibitor-1 and p53 protein expression levels were verified in patients with sinus rhythm and atrial fibrillation by Western blot analysis. Compared with the sinus rhythm controls, p53 and plasminogen activator inhibitor-1 protein expressions were upregulated in the atrial tissues of patients with atrial fibrillation. p53 was also found to regulate plasminogen activator inhibitor-1 based on the results of cellular and molecular experiments. Thus, the p53/plasminogen activator inhibitor-1 signaling axis may participate in the pathophysiological processes of atrial fibrillation, and plasminogen activator inhibitor-1 may serve as a new therapeutic biomarker in atrial fibrillation. creator: Qiaoqiao Li creator: Yingyu Lai creator: Xiaoyan Gao creator: Xin Li creator: Chun-Yu Deng creator: Huiming Guo creator: Junfei Zhao creator: Hui Yang creator: Yuwen Xu creator: Shulin Wu creator: Yumei Xue creator: Fang Rao uri: https://doi.org/10.7717/peerj.11488 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2021 Li et al. title: The gut microbiome of the Sunda pangolin (Manis javanica) reveals its adaptation to specialized myrmecophagy link: https://peerj.com/articles/11490 last-modified: 2021-06-02 description: BackgroundThe gut microbiomes of mammals are closely related to the diets of their hosts. The Sunda pangolin (Manis javanica) is a specialized myrmecophage, but its gut microbiome has rarely been studied.MethodsUsing high-throughput Illumina barcoded 16S rRNA amplicons of nine fecal samples from nine captive Sunda pangolins, we investigated their gut microbiomes.ResultsThe detected bacteria were classified into 14 phyla, 24 classes, 48 orders, 97 families, and 271 genera. The main bacterial phyla were Firmicutes (73.71%), Proteobacteria (18.42%), Actinobacteria (3.44%), and Bacteroidetes (0.51%). In the PCoA and neighbor-net network (PERMANOVA: pangolins vs. other diets, weighted UniFrac distance p < 0.01, unweighted UniFrac distance p < 0.001), the gut microbiomes of the Sunda pangolins were distinct from those of mammals with different diets, but were much closer to other myrmecophages, and to carnivores, while distant from herbivores. We identified some gut microbiomes related to the digestion of chitin, including Lactococcus, Bacteroides, Bacillus, and Staphylococcus species, which confirms that the gut microbiome of pangolins may help them to digest chitin.SignificanceThe results will aid studies of extreme dietary adaption and the mechanisms of diet differentiation in mammals, as well as metagenomic studies, captive breeding, and ex situ conservation of pangolins. creator: Fuhua Zhang creator: Na Xu creator: Wenhua Wang creator: Yishuang Yu creator: Shibao Wu uri: https://doi.org/10.7717/peerj.11490 license: https://creativecommons.org/licenses/by-nc/4.0 rights: ©2021 Zhang et al. title: Reliability of hip muscle strength measured in principal and intermediate planes of movement link: https://peerj.com/articles/11521 last-modified: 2021-06-02 description: BackgroundMuscle strength testing is widely used in clinical and athletic populations. Commercially available dynamometers are designed to assess strength in three principal planes (sagittal, transverse, frontal). However, the anatomy of the hip suggests muscles may only be recruited submaximally during tasks performed in these principal planes.ObjectiveTo evaluate the inter-session reliability of maximal isometric hip strength in the principal planes and three intermediate planes.MethodsTwenty participants (26.1 ± 2.7 years, 50% female) attended two testing sessions 6.2 ± 1.8 days apart. Participants completed 3-5 maximal voluntary isometric contractions for hip abduction, adduction, flexion, extension, and internal and external rotation measured using a fixed uniaxial load cell (custom rig) and commercial dynamometer (Biodex). Three intermediate hip actions were also tested using the custom rig: extension with abduction, extension with external rotation, and extension with both abduction and external rotation.ResultsModerate-to-excellent intraclass correlation coefficients were observed for all principal and intermediate muscle actions using the custom rig (0.72–0.95) and the Biodex (0.85–0.95). The minimum detectable change was also similar between devices (custom rig = 11–31%; Biodex = 9–20%). Bland-Altman analysis revealed poor agreement between devices (range between upper and lower limits of agreement = 77–131%).ConclusionsAlthough the custom rig and Biodex showed similar reliability, both devices may lack the sensitivity to detect small changes in hip strength commonly observed following intervention. creator: Basilio A.M. Goncalves creator: David J. Saxby creator: Adam Kositsky creator: Rod S. Barrett creator: Laura E. Diamond uri: https://doi.org/10.7717/peerj.11521 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2021 Goncalves et al. title: Effects of thiourea on the skull of Triturus newts during ontogeny link: https://peerj.com/articles/11535 last-modified: 2021-06-02 description: BackgroundIn amphibians, thyroid hormone (TH) has a profound role in cranial development, especially in ossification of the late-appearing bones and remodeling of the skull. In the present study, we explored the influence of TH deficiency on bone ossification and resulting skull shape during the ontogeny of Triturus newt hybrid larvae obtained from interspecific crosses between T. ivanbureschi and T. macedonicus.MethodsLarvae were treated with two concentrations of thiourea (an endocrine disruptor that chemically inhibits synthesis of TH) during the midlarval and late larval periods. Morphological differences of the cranium were assessed at the end of the midlarval period (ontogenetic stage 62) and the metamorphic stage after treatment during the late larval period.ResultsThere was no difference in the ossification level and shape of the skull between the experimental groups (control and two treatment concentrations) at stage 62. During the late larval period and metamorphosis, TH deficit had a significant impact on the level of bone ossification and skull shape with no differences between the two treatment concentrations of thiourea. The most pronounced differences in bone development were: the palatopterygoid failed to disintegrate into the palatal and pterygoid portions, retardation was observed in development of the maxilla, nasal and prefrontal bones and larval organization of the vomer was retained in thiourea-treated larvae.ConclusionsThis implies that deficiency of TH caused retardation in development and arrested metamorphic cranium skeletal reorganization, which resulted in divergent cranial shape compared to the control group. Our results confirmed that skull remodeling and ossification of late-appearing bones is TH–dependent, as in other studied Urodela species. Also, our results indicate that TH plays an important role in the establishment of skull shape during the ontogeny of Triturus newts, especially during the late larval period and metamorphosis, when TH concentrations reach their maximum. creator: Maja Ajduković creator: Tijana Vučić creator: Milena Cvijanović uri: https://doi.org/10.7717/peerj.11535 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2021 Ajduković et al. title: Dynamic residue interaction network analysis of the oseltamivir binding site of N1 neuraminidase and its H274Y mutation site conferring drug resistance in influenza A virus link: https://peerj.com/articles/11552 last-modified: 2021-06-02 description: BackgroundOseltamivir (OTV)-resistant influenza virus exhibits His-to-Tyr mutation at residue 274 (H274Y) in N1 neuraminidase (NA). However, the molecular mechanisms by which the H274Y mutation in NA reduces its binding affinity to OTV have not been fully elucidated.MethodsIn this study, we used dynamic residue interaction network (dRIN) analysis based on molecular dynamics simulation to investigate the correlation between the OTV binding site of NA and its H274Y mutation site.ResultsdRIN analysis revealed that the OTV binding site and H274Y mutation site of NA interact via the three interface residues connecting them. H274Y mutation significantly enhanced the interaction between residue 274 and the three interface residues in NA, thereby significantly decreasing the interaction between OTV and its surrounding loop 150 residues. Thus, we concluded that such changes in residue interactions could reduce the binding affinity of OTV to NA, resulting in drug resistant influenza viruses. Using dRIN analysis, we succeeded in understanding the characteristic changes in residue interactions due to H274Y mutation, which can elucidate the molecular mechanism of reduction in OTV binding affinity to influenza NA. Finally, the dRIN analysis used in this study can be widely applied to various systems such as individual proteins, protein-ligand complexes, and protein-protein complexes, to characterize the dynamic aspects of the interactions. creator: Mohini Yadav creator: Manabu Igarashi creator: Norifumi Yamamoto uri: https://doi.org/10.7717/peerj.11552 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2021 Yadav et al. title: Alien plants of Europe: introduction pathways, gateways and time trends link: https://peerj.com/articles/11270 last-modified: 2021-06-01 description: The Convention on Biological Diversity (CBD) pathways classification framework used in the implementation of the European Union’s (EU) Regulation 1143/2014 on invasive alien species (IAS Regulation) has recently been adopted by the European Alien Species Information Network (EASIN), the official information system supporting the implementation of the IAS Regulation. In the current paper, the result of an alignment of the primary introduction pathways of all alien plants in Europe included in the EASIN catalogue is presented, based on the CBD framework. In total, 6,250 alien plant taxa (marine plants excluded), both alien to Europe (native range outside Europe) and alien in Europe (native range partially in Europe) are reported. Altogether 5,175 plant taxa had their primary introduction pathway aligned based on the CBD framework, while for the rest the pathway remains unknown. In addition, the taxonomy, year and country of its first record in the wild are provided for each taxon. Our analyses reveal that the main primary introduction pathways of alien plants into Europe are linked to accidental escapes from ornamental and horticultural activities. Northwestern European countries seem to act as the main gateway areas of alien plants into Europe. Recent first observations of new alien taxa growing spontaneously exhibit a contemporary accelerating trend for plants alien to Europe, particularly linked to ornamental and horticultural activities. On the other hand, the number of new plants alien in Europe seems to have stabilized over the last few decades. The present work can assist in the prioritization of introduction pathways control, with the target of slowing down the rate of alien plants introductions into Europe, following also the requirements of the IAS Regulation. creator: Margarita Arianoutsou creator: Ioannis Bazos creator: Anastasia Christopoulou creator: Yannis Kokkoris creator: Andreas Zikos creator: Sevasti Zervou creator: Pinelopi Delipetrou creator: Ana Cristina Cardoso creator: Ivan Deriu creator: Eugenio Gervasini creator: Konstantinos Tsiamis uri: https://doi.org/10.7717/peerj.11270 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2021 Arianoutsou et al. title: A new pterosaur tracksite from the Lower Cretaceous of Wuerho, Junggar Basin, China: inferring the first putative pterosaur trackmaker link: https://peerj.com/articles/11361 last-modified: 2021-06-01 description: We report the discovery of 114 small pterosaur footprints preserved in a greyish-green fine sandstone slab comprising 57 manus imprints and 57 pes imprints. Due to the chaotic distribution of footprints, the trackways are difficult to recognize. The pes imprints are sub-triangular and enlongate, the metatarsal part is roughly subequal to the digital part. The manus imprints are asymmetrical, longer than wide, and the lengths of digits I–III gradually increase. According to the diagnostic features of the Wuerho small pterosaur tracks, the present set was classified as Pteraichnus and is different from the nine reported valid ichnospecies of Pteraichnus. We therefore propose a new ichnospecies, Pteraichnus wuerhoensis isp. nov. The description is based on the anatomical characteristics (lengths of digits I–IV, length of digital part, length of metatarsal part) extracted from the pes imprints and comparisons with the pes bone fossils of Noripterus complicidens. We infer that the footprints were probably left by N. complicidens and the total width of the wings was presumably 2–2.3 m. In addition, the high density (365 per square meter) and varied sizes of the Wuerho small pterosaur tracks suggest that many pterosaurs of different ages lived in Huangyangquan Reservoir tracksite 1 area. Thus the trackmakers may have had gregarious behavior. creator: Yang Li creator: Xiaolin Wang creator: Shunxing Jiang uri: https://doi.org/10.7717/peerj.11361 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2021 Li et al. title: Early maternal separation is not associated with changes in telomere length in domestic kittens (Felis catus) link: https://peerj.com/articles/11394 last-modified: 2021-06-01 description: ObjectiveStudies of multiple species have found that adverse early life experiences, including childhood trauma and maternal separation, can result in accelerated telomere shortening. The objective of this study was to determine if premature separation from the mother affected telomere length in domestic kittens (Felis catus). Subjects were 42 orphaned kittens and 10 mother-reared kittens from local animal rescue groups and shelters. DNA was extracted from whole blood collected from kittens at approximately 1 week and 2 months of age. Telomere length was assessed by qPCR (quantitative polymerase chain reaction) from a total of 86 samples and expressed as a ratio of telomere PCR relative to a single copy gene PCR (T/S).ResultsA generalized linear mixed model found there were no detectable differences in telomere length based on survival (F1, 76.2 = 3.35, p = 0.07), orphan status (F1, 56.5 = 0.44, p = 0.51), time point (F1, 43.5 = 0.19, p = 0.67), or the interaction between orphan status and time (F1, 43.5 = 0.86, p = 0.36). Although in other species telomere shortening is commonly associated with aging, even early in life, we did not find evidence for telomere shortening by two months of age. Our results suggest that the experience of early maternal separation in domestic cats who are subsequently hand-reared by humans does not accelerate telomere shortening compared to mother-reared kittens, at least in the first few months of life. creator: Mikel Delgado creator: C.A. Tony Buffington creator: Melissa Bain creator: Dana L. Smith creator: Karen Vernau uri: https://doi.org/10.7717/peerj.11394 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2021 Delgado et al. title: Guiclupea superstes, gen. et sp. nov., the youngest ellimmichthyiform (clupeomorph) fish to date from the Oligocene of South China link: https://peerj.com/articles/11418 last-modified: 2021-06-01 description: A new ellimmichthyiform, Guiclupea superstes, gen. et sp. nov., from the Oligocene Ningming Formation of Ningming Basin, Guangxi Zhuang Autonomous Region, South China is described herein. With relatively large body size, parietals meeting at the midline, anterior ceratohyal with a beryciform foramen in the center, a complete predorsal scutes series of very high number and about equally-size scutes with radiating ridges on dorsal surface, first preural centrum unfused with first uroneural but fused with the parhypural, and first ural centrum of roughly the same size as the preural centrum, Guiclupea superstes cannot be assigned to the order Clupeiformes. The phylogenetic analyses using parsimony and Bayesian inference methods with Chanos/Elops as outgroup respectively suggests that the new form is closer to ellimmichthyiform genus Diplomystus than to any other fishes, although there are some discrepancies between the two criteria and different outgroups used. It shares with Diplomystus the high supraoccipital crest, pelvic-fin insertion in advance of dorsal fin origin, and the number of predorsal scutes more than 20. The new form represents the youngest ellimmichthyiform fish record in the world. Its discovery indicates that the members of the Ellimmichthyiformes had a wider distribution range and a longer evolutional history than previously known. creator: Gengjiao Chen creator: Mee-mann Chang creator: Feixiang Wu creator: Xiaowen Liao uri: https://doi.org/10.7717/peerj.11418 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2021 Chen et al.