Ontogenetic moulting behavior of the Cambrian oryctocephalid trilobite Arthricocephalites xinzhaiheensis
Moulting behaviors in trilobites are a crucial strategy during development. Previous studies have demonstrated inter-and intraspecific variability of moulting behavior in trilobites. Currently, ecdysial motifs for trilobites are considered not stable even within species and fewer detailed studies dealt with moulting behaviors in a single species of trilobite during development. Here a large sample of meraspid to holaspid exuviae of Arthricocephalites xinzhaiheensis (131 specimens) from the Cambrian Balang Formation of South China has allowed description of the reasonably complete ontogenic moulting sequence. Both ontogenetic stage and body size reveal gradual transition of configuration from Somersault configuration to Henningsmoen’s configuration during development. Somersault configuration is exclusive till meraspid degree five and exists in subsequent growth stages. This suggests that opening of the facial and rostral sutures allowing the emergence forward of the post-ecdysial trilobite was prevalent in early growth stages. In later development, Henningsmoen’s configuration (showing disarticulation of the cranidium) became more dominant. This study indicates that gradual transition of ontogenetic moulting behavior occurred in oryctocephalid trilobites in the early Cambrian.
Wang et al. (2021) Ontogenetic moulting behavior of the Cambrian oryctocephalid trilobite Arthricocephalites xinzhaiheensis. PeerJ 9:e12217 https://doi.org/10.7717/peerj.12217
Large-scale differences in diversity and functional adaptations of prokaryotic communities from conserved and anthropogenically impacted mangrove sediments in a tropical estuary
Mangroves are tropical ecosystems with strategic importance for climate change mitigation on local and global scales. They are also under considerable threat due to fragmentation degradation and urbanization. However, a complete understanding of how anthropogenic actions can affect microbial biodiversity and functional adaptations is still lacking. In this study, we carried out 16S rRNA gene sequencing analysis using sediment samples from two distinct mangrove areas located within the Serinhaém Estuary, Brazil. The first sampling area was located around the urban area of Ituberá, impacted by domestic sewage and urban runoff, while the second was an environmentally conserved site. Our results show significant changes in the structure of the communities between impacted and conserved sites. Biodiversity, along with functional potentials for the cycling of carbon, nitrogen, phosphorus and sulfur, were significantly increased in the urban area. We found that the environmental factors of organic matter, temperature and copper were significantly correlated with the observed shifts in the communities. Contributions of specific taxa to the functional potentials were negatively correlated with biodiversity, such that fewer numbers of taxa in the conserved area contributed to the majority of the metabolic potential. The results suggest that the contamination by urban runoff may have generated a different environment that led to the extinction of some taxa observed at the conserved site. In their place we found that the impacted site is enriched in prokaryotic families that are known human and animal pathogens, a clear negative effect of the urbanization process.
De Santana et al. (2021) Large-scale differences in diversity and functional adaptations of prokaryotic communities from conserved and anthropogenically impacted mangrove sediments in a tropical estuary. PeerJ 9:e12229 https://doi.org/10.7717/peerj.12229
Reliability of the weight-bearing ankle dorsiflexion range of motion measurement using a smartphone goniometer application
Background Weight-bearing ankle dorsiflexion range of motion measurement (weight-bearing lunge test) is gaining in popularity because it mimics lower extremity function in daily physical activities. The purpose of the study is to assess the intra-rater and the inter-rater reliability of the weight-bearing ankle dorsiflexion range of motion measurement with a flexed knee using a smartphone application Spirit Level Plus installed on an Android smartphone. Methods Thirty-two young, healthy subjects participated in the study and were measured in four sessions by two examiners. One measurement was taken on each ankle in every session. Eight measurements were taken from each participant. A total of 256 were taken from all the participants. The measurements for the individual subject were repeated no sooner than 24 hours after the first session. In order to assess the reliability, intraclass correlation coefficients (ICC), standard error measurements (SEM) and minimal detectable change (MDC) at the 95% confidence interval were calculated. Results Statistical data analysis revealed moderate intra-rater reliability for the right ankle (ICC = 0.72, 95% CI [0.49–0.85]) and good intra-rater reliability for the left ankle (ICC = 0.82, 95% CI [0.66–0.91]). Inter-rater reliability is moderate for the right (ICC = 0.73, 95% CI [0.52–0.86]) and the left ankle (ICC = 0.65, 95% CI [0.39–0.81]). Conclusion The observed method is moderately reliable and appropriate when the main objective is to assess ankle dorsiflexion mobility in weight-bearing when weight-bearing is not contraindicated. The concurrent validity of the Spirit Level Plus application is excellent.
Zunko et al. (2021) Reliability of the weight-bearing ankle dorsiflexion range of motion measurement using a smartphone goniometer application. PeerJ 9:e11977 https://doi.org/10.7717/peerj.11977
Transcriptome and structure analysis in root of Casuarina equisetifolia under NaCl treatment
Background High soil salinity seriously affects plant growth and development. Excessive salt ions mainly cause damage by inducing osmotic stress, ion toxicity, and oxidation stress. Casuarina equisetifolia is a highly salt-tolerant plant, commonly grown as wind belts in coastal areas with sandy soils. However, little is known about its physiology and the molecular mechanism of its response to salt stress. Results Eight-week-old C. equisetifolia seedlings grown from rooted cuttings were exposed to salt stress for varying durations (0, 1, 6, 24, and 168 h under 200 mM NaCl) and their ion contents, cellular structure, and transcriptomes were analyzed. Potassium concentration decreased slowly between 1 h and 24 h after initiation of salt treatment, while the content of potassium was significantly lower after 168 h of salt treatment. Root epidermal cells were shed and a more compact layer of cells formed as the treatment duration increased. Salt stress led to deformation of cells and damage to mitochondria in the epidermis and endodermis, whereas stele cells suffered less damage. Transcriptome analysis identified 10,378 differentially expressed genes (DEGs), with more genes showing differential expression after 24 h and 168 h of exposure than after shorter durations of exposure to salinity. Signal transduction and ion transport genes such as HKT and CHX were enriched among DEGs in the early stages (1 h or 6 h) of salt stress, while expression of genes involved in programmed cell death was significantly upregulated at 168 h, corresponding to changes in ion contents and cell structure of roots. Oxidative stress and detoxification genes were also expressed differentially and were enriched among DEGs at different stages. Conclusions These results not only elucidate the mechanism and the molecular pathway governing salt tolerance, but also serve as a basis for identifying gene function related to salt stress in C. equisetifolia.
Wang et al. (2021) Transcriptome and structure analysis in root of Casuarina equisetifolia under NaCl treatment. PeerJ 9:e12133 https://doi.org/10.7717/peerj.12133
Detection of syrup adulterants in manuka and jarrah honey using HPTLC-multivariate data analysis
High-Performance Thin-Layer Chromatography (HPTLC) was used in a chemometric investigation of the derived sugar and organic extract profiles of two different honeys (Manuka and Jarrah) with adulterants. Each honey was adulterated with one of six different sugar syrups (rice, corn, golden, treacle, glucose and maple syrups) in five different concentrations (10%, 20%, 30%, 40%, and 50% w/w). The chemometric analysis was based on the combined sugar and organic extract profiles’ datasets. To obtain the respective sugar profiles, the amount of fructose, glucose, maltose, and sucrose present in the honey was quantified and for the organic extract profile, the honey’s dichloromethane extract was investigated at 254 and 366 nm, as well as at T (Transmittance) white light and at 366 nm after derivatisation. The presence of sugar syrups, even at a concentration of only 10%, significantly influenced the honeys’ sugar and organic extract profiles and multivariate data analysis of these profiles, in particular cluster analysis (CA), principal component analysis (PCA), principal component regression (PCR), partial least-squares regression (PLSR) and Machine Learning using an artificial neural network (ANN), were able to detect post-harvest syrup adulterations and to discriminate between neat and adulterated honey samples. Cluster analysis and principal component analysis, for instance, could easily differentiate between neat and adulterated honeys through the use of CA or PCA plots. In particular the presence of excess amounts of maltose and sucrose allowed for the detection of sugar adulterants and adulterated honeys by HPTLC-multivariate data analysis. Partial least-squares regression and artificial neural networking were employed, with augmented datasets, to develop optimal calibration for the adulterated honeys and to predict those accurately, which suggests a good predictive capacity of the developed model.
Islam et al. (2021) Detection of syrup adulterants in manuka and jarrah honey using HPTLC-multivariate data analysis. PeerJ 9:e12186 https://doi.org/10.7717/peerj.12186
Microbial growth in biobeds for treatment of residual pesticide in banana plantations
Background High doses of ethylenebisdithiocarbamate (EBDC) are used in banana production, and unused pesticide mixture (solution) is often disposed of improperly. This can result in soil and water contamination and present an undue risk to rural communities and the environment. An alternative to reduce the environmental impacts caused by pesticide residues is the biobeds treatment. It is necessary to establish if the composition of the proposed biomixtures supports microbial activity to degrade pesticides in biobeds. This research aimed to evaluate the EBDC effect on the distribution and abundance of microbial populations in polluted biomixtures . Methods For this purpose, a biomixture based on banana stem, mulch, and Fluvisol soil (50:25:25% v/v) was prepared and polluted with 1,000 mg L−1 EBDC. The response variables kinetics were determined every 14 days for three months, such as pH, organic matter, moisture, cation exchange capacity, microbial colonies, and cell counts at three depths within the experimental units. Results EBDC reduced the number of microbial colonies by 72%. Bacterial cells rapidly decreased by 69% and fungi 89% on the surface, while the decrease was gradual and steady at the middle and bottom of the biobed. The microbial populations stabilized at day 42, and the bacteria showed a total recovery on day 84, but the fungi slightly less. At the end of the experiment, the concentration of EBDC in the biomixture was 1.3–4.1 mg L−1. A correlation was found between fungal count (colonies and cells) with EBDC concentration. A replacement of the biomixture is suggested if the bacterial population becomes less than 40 × 106 CFU mL−1 and the fungal population less than 8 × 104 CFU mL−1 or if the direct cell count becomes lower than 50 × 104 cells mL−1 in bacteria and 8 × 102 cells mL−1 in fungi. Conclusion The biomixture based on banana stem supports the microbial activity necessary for the degradation of the EBDC pesticide. It was found that fungi could be used as indicators of the pollutant degradation process in the biomixtures. Microbial counts were useful to establish the mobility and degradation time of the pesticide and the effectiveness of the biomixture. Based on the results, it is appropriate to include the quantification of microbial populations to assess the effectiveness of pesticide degradation and the maturity level of the biomixture.
Domínguez-Rodríguez et al. (2021) Microbial growth in biobeds for treatment of residual pesticide in banana plantations. PeerJ 9:e12200 https://doi.org/10.7717/peerj.12200
Chimpanzee facial gestures and the implications for the evolution of language
Great ape manual gestures are described as communicative, flexible, intentional, and goal-oriented. These gestures are thought to be an evolutionary pre-cursor to human language. Conversely, facial expressions are thought to be inflexible, automatic, and derived from emotion. However, great apes can make a wide range of movements with their faces, and they may possess the control needed to gesture with their faces as well as their hands. We examined whether chimpanzee facial expressions possess the four important gesture properties and how they compare to manual gestures. To do this, we quantified variables that have been previously described through largely qualitative means. Chimpanzee facial expressions met all four gesture criteria and performed remarkably similar to manual gestures. Facial gestures have implications for the evolution of language. If other mammals also show facial gestures, then the gestural origins of language may be much older than the human/great ape lineage.
Florkiewicz et al. (2021) Chimpanzee facial gestures and the implications for the evolution of language. PeerJ 9:e12237 https://doi.org/10.7717/peerj.12237
Fungi in soil and understory have coupled distribution patterns
Ecological processes that control fungal distribution are not well understood because many fungi can persist in a wide variety of dissimilar habitats which are seldom sampled simultaneously. Geographic range size is reflective of species’ resource usage, and for plants and animals, there is a robust positive correlation between niche-breadth and range-size. It remains unknown whether this pattern is true for fungi. To investigate the fungal niche breadth–range size relationship we identified habitat specialists and generalists from two habitats (plant leaves and soil) and asked whether habitat specialization influenced fungal biogeography. We sampled fungi from the soil and phylloplane of tropical forests in Vanuatu and used DNA metabarcoding of the fungal ITS1 region to examine rarity, range size, and habitat connectivity. Fungal communities from the soil and phylloplane are spatially autocorrelated and the spatial distribution of individual fungal OTU are coupled between habitats. Habitat breadth (generalist fungi) did not result in larger range sizes but did correlate positively with occurrence frequency. Fungi that were frequently found were also found in high abundance, a common observation in similar studies of plants and animals. Fungal abundance-occupancy relationships differed by habitat and habitat-specificity. Soil specialists were found to be locally abundant but restricted geographically. In contrast, phylloplane generalists were found to be abundant over a large range in multiple habitats. These results are discussed in the context of differences between habitat characteristics, stability and spatial distribution. Identifying factors that drive spatial variation is key to understanding the mechanisms that maintain biodiversity in forests.
Boraks et al. (2021) Fungi in soil and understory have coupled distribution patterns. PeerJ 9:e11915 https://doi.org/10.7717/peerj.11915
Who’s who in Magelona: phylogenetic hypotheses under Magelonidae Cunningham & Ramage, 1888 (Annelida: Polychaeta)
Known as shovel head worms, members of Magelonidae comprise a group of polychaetes readily recognised by the uniquely shaped, dorso-ventrally flattened prostomium and paired ventro-laterally inserted papillated palps. The present study is the first published account of inferences of phylogenetic hypotheses within Magelonidae. Members of 72 species of Magelona and two species of Octomagelona were included, with outgroups including members of one species of Chaetopteridae and four of Spionidae. The phylogenetic inferences were performed to causally account for 176 characters distributed among 79 subjects, and produced 2,417,600 cladograms, each with 404 steps. A formal definition of Magelonidae is provided, represented by a composite phylogenetic hypothesis explaining seven synapomorphies: shovel-shaped prostomium, prostomial ridges, absence of nuchal organs, ventral insertion of palps and their papillation, presence of a burrowing organ, and unique body regionation. Octomagelona is synonymised with Magelona due to the latter being paraphyletic relative to the former. The consequence is that Magelonidae is monotypic, such that Magelona cannot be formally defined as associated with any phylogenetic hypotheses. As such, the latter name is an empirically empty placeholder, but because of the binomial name requirement mandated by the International Code of Zoological Nomenclature, the definition is identical to that of Magelonidae. Several key features for future descriptions are suggested: prostomial dimensions, presence/absence of prostomial horns, morphology of anterior lamellae, presence/absence of specialised chaetae, and lateral abdominal pouches. Additionally, great care must be taken to fully describe and illustrate all thoracic chaetigers in descriptions.
Mortimer et al. (2021) Who’s who in Magelona: phylogenetic hypotheses under Magelonidae Cunningham & Ramage, 1888 (Annelida: Polychaeta). PeerJ 9:e11993 https://doi.org/10.7717/peerj.11993
The syndemic condition of psychosocial problems related to depression among sexually transmitted infections patients
Background The prevalence of depression in sexually transmitted infections (STIs) patients is much higher than general public. However, studies focusing on comprehensive psychosocial effects on depression among STIs patients are limited. This study aimed to examine association of multiple psychosocial syndemic conditions with depression among STIs patients in Shanghai, China. Methods We conducted a cross-sectional study and recruited 910 STIs patients from Shanghai Skin Disease Hospital. Participants self-reported their demographics and themselves completed the scales of depression, self-esteem, loneliness, social support, entrapment, defeat and interpersonal needs. Logistic regressions were performed to detect the possible contributing psychosocial factors for depression and to verify the syndemic conditions of psychosocial problems. Results Of the STIs patient sample, the prevalence of depression was 17.9%. Multivariable analysis showed low-level self-esteem (odds ratio [ORm]: 2.18, 95% CI [1.19–4.00]) and social support (ORm: 2.18, 95% CI [1.37–3.46]), high-level entrapment (ORm: 6.31, 95% CI [3.75–10.62]) and defeat (ORm: 2.60, 95% CI [1.51–4.48]) increased the risk of depression. Psychosocial syndemic conditions magnified effect in fusing depression (adjusted odds ratio [AOR]: 11.94, 95% CI [7.70–18.53]). Participants with more than 4 psychosocial problems were about 22 times more likely to have depression (AOR: 22.12, 95% CI [13.19–37.09]). Conclusions The psychosocial problems syndemic magnifying the risk of depression was confirmed and psychosocial interventions to prevent depression is needed among STIs patients.
Xu et al. (2021) The syndemic condition of psychosocial problems related to depression among sexually transmitted infections patients. PeerJ 9:e12022 https://doi.org/10.7717/peerj.12022