Three new species of subterranean amphipods (Pseudocrangonyctidae: Pseudocrangonyx) from limestone caves in South Korea
Pseudocrangonyx Akatsuka & Komai, 1922 is the most diverse group of subterranean amphipods in the groundwater communities of Far East Asia. In Korea, the diversity of the group has been underestimated due to the records of morphological variants of Pseudocrangonyx asiaticus Uéno, 1934. To estimate the species diversity, we analyzed the morphological characteristics and conducted molecular analyses of specimens collected from Korean caves that we treated as morphological variants of P. asiaticus. We described three new subterranean pseudocrangonyctid amphipod species, P. deureunensis sp. nov., P. kwangcheonseonensis sp. nov., and P. hwanseonensis sp. nov., from the groundwater of limestone caves in South Korea. Additionally, we determined sequences of the nuclear large subunit ribosomal RNA and the mitochondrial cytochrome c oxidase subunit I gene of the new species for molecular analyses. Molecular phylogenetic analyses revealed that the three new species formed a monophylum together with P. joolaei Lee et al., 2020 and P. wonkimi Lee, Tomikawa & Min, 2020, which are species that are endemic to Korean caves.
Lee et al. (2021) Three new species of subterranean amphipods (Pseudocrangonyctidae: Pseudocrangonyx) from limestone caves in South Korea. PeerJ 9:e10786 https://doi.org/10.7717/peerj.10786
Comparing impacts of metal contamination on macroinvertebrate and fish assemblages in a northern Japanese river
Researchers have long assessed the ecological impacts of metals in running waters, but few such studies investigated multiple biological groups. Our goals in this study were to assess the ecological impacts of metal contamination on macroinvertebrates and fishes in a northern Japanese river receiving treated mine discharge and to evaluate whether there was any difference between the metrics based on macroinvertebrates and those based on fishes in assessing these impacts. Macroinvertebrate communities and fish populations were little affected at the downstream contaminated sites where concentrations of Cu, Zn, Pb, and Cd were 0.1–1.5 times higher than water-quality criteria established by the U.S. Environmental Protection Agency. We detected a significant reduction in a few macroinvertebrate metrics such as mayfly abundance and the abundance of heptageniid mayflies at the two most upstream contaminated sites with metal concentrations 0.8–3.7 times higher than the water-quality criteria. There were, however, no remarkable effects on the abundance or condition factor of the four dominant fishes, including masu salmon (Oncorhynchus masou). These results suggest that the richness and abundance of macroinvertebrates are more sensitive to metal contamination than abundance and condition factor of fishes in the studied river. Because the sensitivity to metal contamination can depend on the biological metrics used, and fish-based metrics in this study were limited, it would be valuable to accumulate empirical evidence for ecological indicators sensitive to metal contamination within and among biological groups to help in choosing which groups to survey for general environmental impact assessments in metal-contaminated rivers.
Environmental Contamination and Remediation
Namba et al. (2021) Comparing impacts of metal contamination on macroinvertebrate and fish assemblages in a northern Japanese river. PeerJ 9:e10808 https://doi.org/10.7717/peerj.10808
Flower visitors of Streptocarpus teitensis: implications for conservation of a critically endangered African violet species in Kenya
Background The African violets are endangered plant species restricted mainly to the Eastern Arc Mountains biodiversity hotspots in Kenya and Tanzania. These plants grow well in shaded environments with high humidity. Given their restricted geographical range and published evidence of dependance on insect vectors to facilitate sexual reproduction, understanding their pollination biology is vital for their survival. Methods We conducted an empirical study using flower visitor observations, pan trapping and bagging experiments to establish the role of flower visitors in the fruit set of a locally endemic and critically endangered species of African violet in Taita Hills, Kenya, Streptocarpus teitensis. Results The study found that fruit set is increased by 47.8% in S. teitensis when flowers are visited by insects. However, it is important to note the presence of putative autogamy suggesting S. teitensis could have a mixed breeding system involving self-pollination and cross-pollination since bagged flowers produced 26.9% fruit set. Conclusions Insects appear to be essential flower visitors necessary for increased fruit set in S. teitensis. However, there is evidence of a mixed breeding system involving putative self-pollination and cross-pollination suggesting that S. teitensis is somewhat shielded from the negative effects of pollinator losses. Consequently, S. teitensis appears to be protected to a degree from the risks such as reproduction failure associated with pollinator losses by the presence of a safety net in putative self-pollination.
Otieno et al. (2021) Flower visitors of Streptocarpus teitensis: implications for conservation of a critically endangered African violet species in Kenya. PeerJ 9:e10473 https://doi.org/10.7717/peerj.10473
Can valence and origin of emotional words influence the assessments of ambiguous stimuli in terms of warmth or competence?
People tend to think that emotions influence the way they think in a spectacular way. We wanted to determine whether it is possible to prime the assessments of ambiguous stimuli by presenting emotion-laden words. We did not expect the differences in assessments that depend only on the emotional factors to be particularly large. Participants were presented with words differing in valence and origin of an affective state, but aligned for arousal, concreteness, length and frequency of use. Their first task was to remember a word. While keeping the word in mind, their second task was to guess by intuition whether the symbol was related to certain traits. Participants assessed objects represented by coding symbols on the scales of warmth or competence. We expected positive valence and automatic origin to promote higher ratings in terms of warmth and reflective origin to promote higher ratings in terms of competence. Positive valence appeared to boost assessments in terms of both warmth and competence, while the origin effect was found to be dissociative: automatic origin promoted intensity of warmth assessments and reflective origin intensity of competence assessments. The study showed an existing relation between emotional and social aspects of the mind, and therefore supports the conclusion that both domains may result from dual processes of a more general character.
Imbir et al. (2021) Can valence and origin of emotional words influence the assessments of ambiguous stimuli in terms of warmth or competence?. PeerJ 9:e10488 https://doi.org/10.7717/peerj.10488
A novel IMU-based clinical assessment protocol for Axial Spondyloarthritis: a protocol validation study
Clinical assessment of spinal impairment in Axial Spondyloarthritis is currently performed using the Bath Ankylosing Spondylitis Metrological Index (BASMI). Despite being appreciated for its simplicity, the BASMI index lacks sensitivity and specificity of spinal changes, demonstrating poor association with radiographical range of motion (ROM). Inertial measurement units (IMUs) have shown promising results as a cost-effective method to quantitatively examine movement of the human body, however errors due to sensor angular drift have limited their application to a clinical space. Therefore, this article presents a wearable sensor protocol that facilitates unrestrained orientation measurements in space while limiting sensor angular drift through a novel constraint-based approach. Eleven healthy male participants performed five BASMI-inspired functional movements where spinal ROM and continuous kinematics were calculated for five spine segments and four spinal joint levels (lumbar, lower thoracic, upper thoracic and cervical). A Bland–Altman analysis was used to assess the level of agreement on range of motion measurements, whilst intraclass correlation coefficient (ICC), standardised error measurement, and minimum detectable change (MDC) to assess relative and absolute reliability. Continuous kinematics error was investigated through root mean square error (RMSE), maximum absolute error (MAE) and Spearman correlation coefficient (ρ). The overall error in the measurement of continuous kinematic measures was low in both the sagittal (RMSE = 2.1°), and frontal plane (RMSE = 2.3°). ROM limits of agreement (LoA) and minimum detectable change were excellent for the sagittal plane (maximum value LoA 1.9° and MDC 2.4°) and fair for lateral flexion (overall value LoA 4.8° and MDC 5.7°). The reliability analysis showed excellent level of agreement (ICC > 0.9) for both segment and joint ROM across all movements. The results from this study demonstrated better or equivalent accuracy than previous studies and were considered acceptable for application in a clinical setting. The protocol has shown to be a valuable tool for the assessment of spinal ROM and kinematics, but a clinical validation study on Axial Spondyloarthritis patients is required for the development and testing of a novel mobility index.
Franco et al. (2021) A novel IMU-based clinical assessment protocol for Axial Spondyloarthritis: a protocol validation study. PeerJ 9:e10623 https://doi.org/10.7717/peerj.10623
A trace fossil made by a walking crayfish or crayfish-like arthropod from the Lower Jurassic Moenave Formation of southwestern Utah, USA
New invertebrate trace fossils from the Lower Jurassic Moenave Formation at the St. George Dinosaur Discovery Site at Johnson Farm (SGDS) continue to expand the ichnofauna at the site. A previously unstudied arthropod locomotory trace, SGDS 1290, comprises two widely spaced, thick, gently undulating paramedial impressions flanked externally by small, tapered to elongate tracks with a staggered to alternating arrangement. The specimen is not a variant of any existing ichnospecies, but bears a striking resemblance to modern, experimentally generated crayfish walking traces, suggesting a crayfish or crayfish-like maker for the fossil. Because of its uniqueness, we place it in a new ichnospecies, Siskemia eurypyge. It is the first fossil crayfish or crayfish-like locomotion trace ever recorded.
Rose et al. (2021) A trace fossil made by a walking crayfish or crayfish-like arthropod from the Lower Jurassic Moenave Formation of southwestern Utah, USA. PeerJ 9:e10640 https://doi.org/10.7717/peerj.10640
Rocks of different mineralogy show different temperature characteristics: implications for biodiversity on rocky seashores
As some intertidal biota presently live near their upper tolerable thermal limits when emersed, predicted hotter temperatures and an increased frequency of extreme-heat events associated with global climate change may challenge the survival and persistence of such species. To predict the biological ramifications of climate change on rocky seashores, ecologists have collected baseline rock temperature data, which has shown substrate temperature is heterogenous in the rocky intertidal zone. A multitude of factors may affect rock temperature, although the potential roles of boulder surface (upper versus lower), lithology (rock type) and minerology have been largely neglected to date. Consequently, a common-garden experiment using intertidal boulders of six rock types tested whether temperature characteristics differed among rock types, boulder surfaces, and whether temperature characteristics were associated with rock mineralogy. The temperature of the upper and lower surfaces of all six rock types was heterogeneous at the millimetre to centimetre scale. Three qualitative patterns of temperature difference were identified on boulder surfaces: gradients; mosaics; and limited heterogeneity. The frequency of occurrence of these temperature patterns was heavily influenced by cloud cover. Upper surfaces were generally hotter than lower surfaces, plus purple siltstone and grey siltstone consistently had the hottest temperatures and white limestone and quartzite the coolest. Each rock type had unique mineralogy, with maximum temperatures correlated with the highest metallic oxide and trace metal content of rocks. These baseline data show that rock type, boulder surface and mineralogy all contribute to patterns of heterogenous substrate temperature, with the geological history of rocky seashores potentially influencing the future fate of species and populations under various climate change scenarios.
Janetzki et al. (2021) Rocks of different mineralogy show different temperature characteristics: implications for biodiversity on rocky seashores. PeerJ 9:e10712 https://doi.org/10.7717/peerj.10712
Delimiting the genera of the Ficinia Clade (Cypereae, Cyperaceae) based on molecular phylogenetic data
Generic delimitations in the Ficinia Clade of tribe Cypereae are revisited. In particular, we aim to establish the placement of annual species currently included in Isolepis of which the phylogenetic position is uncertain. Phylogenetic inference is based on two nuclear markers (ETS, ITS) and five plastid markers (the genes matK, ndhF, rbcL and rps16, the trnL intron and trnL-F spacer) data, analyzed using model based methods. Topologies based on nuclear and plastid data show incongruence at the backbone. Therefore, the results are presented separately. The monophyly of the smaller genera (Afroscirpoides, Dracoscirpoides, Erioscirpus, Hellmuthia, Scirpoides) is confirmed. However, Isolepis is paraphyletic as Ficinia is retrieved as one of its clades. Furthermore, Ficinia is paraphyletic if I. marginata and allies are excluded. We take a pragmatic approach based on the nuclear topology, driven by a desire to minimize taxonomic changes, to recircumscribe Ficinia to include the annual Isolepis species characterized by cartilaginous glumes and formally include all the Isolepis species inferred outside the core Isolepis clade. Consequently, the circumscription of Isolepis is narrowed to encompass only those species retrieved as part of the core Isolepis clade. Five new combinations are made (Ficinia neocapensis, Ficinia hemiuncialis, Ficinia incomtula, Ficinia leucoloma, Ficinia minuta). We present nomenclatural summary at genus level, identification keys and diagnostic features.
Muasya et al. (2021) Delimiting the genera of the Ficinia Clade (Cypereae, Cyperaceae) based on molecular phylogenetic data. PeerJ 9:e10737 https://doi.org/10.7717/peerj.10737
Age-related abnormalities of thalamic shape and dynamic functional connectivity after three hours of sleep restriction
Background Previous neuroimaging studies have detected abnormal activation and intrinsic functional connectivity of the thalamus after total sleep deprivation. However, very few studies have investigated age-related changes in the dynamic functional connectivity of the thalamus and the abnormalities in the thalamic shape following partial sleep deprivation. Methods Fifty-five participants consisting of 23 old adults (mean age: 68.8 years) and 32 young adults (mean age: 23.5 years) were included in current study. A vertex-based shape analysis and a dynamic functional connectivity analysis were used to evaluate the age-dependent structural and functional abnormalities after three hours of sleep restriction. Results Shape analysis revealed the significant main effect of deprivation with local atrophy in the left thalamus. In addition, we observed a significant age deprivation interaction effect with reduced variability of functional connectivity between the left thalamus and the left superior parietal cortex following sleep restriction. This reduction was found only in young adults. Moreover, a significantly negative linear correlation was observed between the insomnia severity index and the changes of variability (post-deprivation minus pre-deprivation) in the functional connectivity of the left thalamus with the left superior parietal cortex. Conclusions The results indicated that three hours of sleep restriction could affect both the thalamic structure and its functional dynamics. They also highlighted the role of age in studies of sleep deprivation.
Long et al. (2021) Age-related abnormalities of thalamic shape and dynamic functional connectivity after three hours of sleep restriction. PeerJ 9:e10751 https://doi.org/10.7717/peerj.10751
Description and rediagnosis of the crested hadrosaurid (Ornithopoda) dinosaur Parasaurolophus cyrtocristatus on the basis of new cranial remains
For nearly 60 years, skulls of Parasaurolophus species have been differentiated primarily on the basis of crest shape rather than on unique morphologic characters of other cranial elements. Complicating matters is the fact that crests dramatically change shape throughout ontogeny. Without a complete growth series, it has become difficult to assess the taxonomic distinctness of each species through the lens of allometric growth. Parasaurolophus cyrtocristatus has proven to be especially troublesome to assess because of the poorly preserved nature of the type and only skull. A new, partial skull from the Fossil Forest Member of the Fruitland Formation—the same geologic unit as the type specimen—is the first opportunity to re-diagnose this species as well as redefine the genus with many new traits. An undescribed, short-crested subadult skull from the Kaiparowits Formation of Utah previously assigned to cf. P. cyrtocristatus allows detailed comparisons to be made between the unnamed Utah taxon and the material of this species from the type locality. We find that several characteristics of the squamosal, supraoccipital, and premaxilla shared between the referred skull and the type skull are unique to P. cyrtocristatus (senso stricto) within the genus, irrespective of the overall crest shape. A phylogenetic analysis that includes six new characters posits that P. cyrtocristatus and P. tubicen are sister taxa, and that the latter does not share a closest common ancestor with the long-crested P. walkeri as previously hypothesized. This result helps to explain why both taxa are found in northeastern New Mexico, USA and in sequential geologic units (Fruitland Formation and Kirtland Formation, respectively). Additionally, the exquisitely preserved new skull provides the first opportunity to unequivocally identify the osteological make-up of the Parasaurolophus cranial crest. Unlike in previous reconstructions, the crest composition in Parasaurolophus follows what is seen in other lambeosaurines such as Corythosaurus, where the dorsal process of the premaxilla dominates the crest, with the nasal forming 80% of the ventral paired tubes, and the lateral premaxillary process acting a lateral cover between the dorsal and ventral tubes. The skull of P. cyrtocristatus is still incompletely known, so more complete material will likely reveal new features that further differentiate this species and aid in determining the pace of ornamental crest evolution.
Gates et al. (2021) Description and rediagnosis of the crested hadrosaurid (Ornithopoda) dinosaur Parasaurolophus cyrtocristatus on the basis of new cranial remains. PeerJ 9:e10669 https://doi.org/10.7717/peerj.10669