Assessing the difference of tolerance and phytoremediation potential in mercury contaminated soil of a non-food energy crop, Helianthus tuberosus L. (Jerusalem artichoke)
This study was conducted to evaluate the effects of mercury stress on growth, photosynthesis and mercury accumulation in different cultivars of a non-food energy crop, Jerusalem artichoke, and to screen appropriate cultivars for their efficacy in the phytoremediation of mercury (Hg2+) contaminated soil. Cultivars LZJ033 (high above-ground biomass and nutrient content, and strongly sexual reproduction) and LZJ119 (a long period of vegetative growth) exhibited more tolerance to mercury stress than LZJ047 (the highest tuber yield and total sugar content). The lines LZJ119 and LZJ047 showed delays in emergence time of about four weeks, and LZJ047 exhibited the highest mortality rate, 85.19%, under treatment with 10 mg kg-1 mercury. The MDA (malondialdehyde) content increased whereas and the Pn (net photosynthetic rate), Fv∕Fm (the maximum quantum yield of PSII photochemistry) and chlorophyll content decreased in response to mercury stress. The stem diameter, stem biomass and photosynthetic rate of Jerusalem artichoke showed some modest increases in response to mercury stress and exhibited hormesis at least 1 mg kg-1 mercury treatment. Overall, LZJ119 produced more biomass under mercury stress, whereas LZJ033 exhibited a greater capacity for mercury bioaccumulation. Accordingly, LZJ119 may be a good candidate cultivar for use in cases of moderate—low mercury contamination, whereas LZJ033 may be a better candidate under conditions of high mercury contamination. When Jerusalem artichoke was cultivated in mercury contaminated soil, it not only removed the mercury from soil but also produced large amounts of tubers and shoots which could be used as feedstock for the production of bioethanol.
Environmental Contamination and Remediation
Lv et al. (2018) Assessing the difference of tolerance and phytoremediation potential in mercury contaminated soil of a non-food energy crop, Helianthus tuberosus L. (Jerusalem artichoke). PeerJ 6:e4325 https://doi.org/10.7717/peerj.4325
A quasi-randomised, controlled, feasibility trial of GLITtER (Green Light Imaging Interpretation to Enhance Recovery)—a psychoeducational intervention for adults with low back pain attending secondary care
Background Although it is broadly accepted that clinicians should endeavour to reassure patients with low back pain, to do so can present a significant clinical challenge. Guidance for how to provide effective reassurance is scarce and there may be a need to counter patient concerns arising from misinterpretation of spinal imaging findings. ‘GLITtER’ (Green Light Imaging Intervention to Enhance Recovery) was developed as a standardised method of communicating imaging findings in a manner that is reassuring and promotes engagement in an active recovery. This feasibility study is an important step towards definitive testing of its effect. Methods This feasibility study was a prospective, quasi-randomised, parallel trial with longitudinal follow-up, involving sampling of patients attending a spinal outpatient clinic at a metropolitan hospital. English speaking adults (18–75 years) presenting to the clinic with low back pain and prior spinal imaging were considered for inclusion. Eligible patients were allocated to receive a GLITtER consultation or a standard consultation (as determined by appointment scheduling and clinician availability), and were blinded to their allocation. Full details of the GLITtER intervention are described in accordance with the Tidier template.Follow-up data were collected after 1 and 3 months. The primary outcome of this study was the fulfillment of specific feasibility criteria which were established a priori. Determination of a sample size for a definitive randomised controlled trial was a secondary objective. Results Two hundred seventy-six patients underwent preliminary screening and 31 patients met the final eligibility criteria for study inclusion. Seventeen participants were allocated to the intervention group and 14 were allocated to the control group. Three month follow-up data were available from 42% of the 31 enrolled participants (N = 13, six intervention, seven control). Feasibility indicators for consent, resource burden and acceptability of the GLITtER intervention were met, however participant recruitment was slower than anticipated and an acceptable follow-up rate was not achieved. Conclusions Failure to achieve pre-specified recruitment and follow-up rates were important outcomes of this feasibility study. We attribute failure to issues that are likely to be relevant for other clinical trials with this population. It is realistic to consider that these challenges can be overcome through careful strategy, ample funding and continued partnership with health care providers. Trial registration The trial was registered on the Australian and New Zealand Clinical Trials Registry on 28/2/2017 (ACTRN12617000317392).
Karran et al. (2018) A quasi-randomised, controlled, feasibility trial of GLITtER (Green Light Imaging Interpretation to Enhance Recovery)—a psychoeducational intervention for adults with low back pain attending secondary care. PeerJ 6:e4301 https://doi.org/10.7717/peerj.4301
Spatial and temporal patterns of human Puumala virus (PUUV) infections in Germany
Background Worldwide, the number of recorded human hantavirus infections as well as the number of affected countries is on the rise. In Europe, most human hantavirus infections are caused by the Puumala virus (PUUV), with bank voles (Myodes glareolus) as reservoir hosts. Generally, infection outbreaks have been related to environmental conditions, particularly climatic conditions, food supply for the reservoir species and land use. However, although attempts have been made, the insufficient availability of environmental data is often hampering accurate temporal and spatially explicit models of human hantavirus infections. Methods In the present study, dynamics of human PUUV infections between 2001 and 2015 were explored using ArcGIS in order to identify spatio-temporal patterns. Results Percentage cover of forest area was identified as an important factor for the spatial pattern, whereas beech mast was found explaining temporal patterns of human PUUV infections in Germany. High numbers of infections were recorded in 2007, 2010 and 2012 and areas with highest records were located in Baden-Wuerttemberg (southwest Germany) and North Rhine-Westphalia (western Germany). Conclusion More reliable data on reservoir host distribution, pathogen verification as well as an increased awareness of physicians are some of the factors that should improve future human infection risk assessments in Germany.
Cunze et al. (2018) Spatial and temporal patterns of human Puumala virus (PUUV) infections in Germany. PeerJ 6:e4255 https://doi.org/10.7717/peerj.4255
On the morphological variability of Ichniotherium tracks and evolution of locomotion in the sistergroup of amniotes
Ichniotherium tracks with a relatively short pedal digit V (digit length ratio V/IV < 0.6) form the majority of yet described Late Carboniferous to Early Permian diadectomorph tracks and can be related to a certain diadectid clade with corresponding phalangeal reduction that includes Diadectes and its close relatives. Here we document the variation of digit proportions and trackway parameters in 25 trackways (69 step cycles) from nine localities and seven further specimens with incomplete step cycles from the type locality of Ichniotherium cottae (Gottlob quarry) in order to find out whether this type of Ichniotherium tracks represents a homogeneous group or an assemblage of distinct morphotypes and includes variability indicative for evolutionary change in trackmaker locomotion. According to our results, the largest sample of tracks from three Lower Permian sites of the Thuringian Forest, commonly referred to I. cottae, is not homogeneous but shows a clear distinction in pace length, pace angulation, apparent trunk length and toe proportions between tracks from Bromacker quarry and those from the stratigraphically older sites Birkheide and Gottlob quarry. Three Late Carboniferous trackways of Ichniotherium with relatively short pedal digit V from Haine’s Farm, Ohio, and Alveley near Birmingham, United Kingdom, that have been referred to the ichnotaxa “Baropus hainesi,” “Megabaropus hainesi” and “Ichniotherium willsi,” respectively, share a marked outward rotation of foot imprints with respect to walking direction. Apart from this feature they are in many aspects similar to the Birkheide and Gottlob records of I. cottae. With the possible exception of the Maroon Formation (Early Permian, Colorado) sample, Early Permian Ichniotherium trackways with a relatively short pedal digit V fall into the morphological spectrum of the three well defined “Hainesi–Willsi,” “Birkheide–Gottlob” and “Bromacker” morphotypes. With their more obtuse pace angulations and higher body-size-normalized pace and stride lengths the Bromacker type tracks imply higher walking speeds of their trackmakers compared to all other Ichniotherium tracks. More generally, a trend towards higher locomotion capability from the last common ancestor of all Ichniotherium producers to the last common ancestor of all “Ichniotherium with relatively short pedal digit V” and from the latter to the trackmakers of the mid-Early Permian Bromacker type can be deduced—with the reservation that overall sample size is relatively small, making this scenario a preliminary assessment. Whether the presumed advancements represent a more general pattern within diadectomorphs remains open until the non-European Ichniotherium trackway record improves. Ichnotaxonomic implications are discussed.
Buchwitz et al. (2018) On the morphological variability of Ichniotherium tracks and evolution of locomotion in the sistergroup of amniotes. PeerJ 6:e4346 https://doi.org/10.7717/peerj.4346
A review of bottom-up vs. top-down control of sponges on Caribbean fore-reefs: what’s old, what’s new, and future directions
Interest in the ecology of sponges on coral reefs has grown in recent years with mounting evidence that sponges are becoming dominant members of reef communities, particularly in the Caribbean. New estimates of water column processing by sponge pumping activities combined with discoveries related to carbon and nutrient cycling have led to novel hypotheses about the role of sponges in reef ecosystem function. Among these developments, a debate has emerged about the relative effects of bottom-up (food availability) and top-down (predation) control on the community of sponges on Caribbean fore-reefs. In this review, we evaluate the impact of the latest findings on the debate, as well as provide new insights based on older citations. Recent studies that employed different research methods have demonstrated that dissolved organic carbon (DOC) and detritus are the principal sources of food for a growing list of sponge species, challenging the idea that the relative availability of living picoplankton is the sole proxy for sponge growth or abundance. New reports have confirmed earlier findings that reef macroalgae release labile DOC available for sponge nutrition. Evidence for top-down control of sponge community structure by fish predation is further supported by gut content studies and historical population estimates of hawksbill turtles, which likely had a much greater impact on relative sponge abundances on Caribbean reefs of the past. Implicit to investigations designed to address the bottom-up vs. top-down debate are appropriate studies of Caribbean fore-reef environments, where benthic communities are relatively homogeneous and terrestrial influences and abiotic effects are minimized. One recent study designed to test both aspects of the debate did so using experiments conducted entirely in shallow lagoonal habitats dominated by mangroves and seagrass beds. The top-down results from this study are reinterpreted as supporting past research demonstrating predator preferences for sponge species that are abundant in these lagoonal habitats, but grazed away in fore-reef habitats. We conclude that sponge communities on Caribbean fore-reefs of the past and present are largely structured by predation, and offer new directions for research, such as determining the environmental conditions under which sponges may be food-limited (e.g., deep sea, lagoonal habitats) and monitoring changes in sponge community structure as populations of hawksbill turtles rebound.
Pawlik et al. (2018) A review of bottom-up vs. top-down control of sponges on Caribbean fore-reefs: what’s old, what’s new, and future directions. PeerJ 6:e4343 https://doi.org/10.7717/peerj.4343
The association between chronic bullying victimization with weight status and body self-image: a cross-national study in 39 countries
Background Childhood obesity and school bullying are pervasive public health issues and known to co-occur in adolescents. However, the association between underweight or thinness and chronic bullying victimization is unclear. The current study examined whether chronic bullying victimization is associated with weight status and body self-image. Methods A school-based, cross-sectional study in 39 North American and European countries and regions was conducted. A total of 213,595 adolescents aged 11, 13, and 15 years were surveyed in 2009/10. Chronic bullying victimization was identified using the Revised Olweus Bully/Victim Questionnaire. Weight status was determined using self-reported height and weight and the body mass index (BMI), and body self-image was based on perceived weight. We tested associations between underweight and bullying victimization using three-level logistic regression models. Results Of the 213,595 adolescents investigated, 11.28% adolescents reported chronic bullying victimization, 14.80% were classified as overweight/obese according to age- and sex-specific BMI criteria, 12.97% were underweight, and 28.36% considered themselves a little bit fat or too fat, 14.57% were too thin. Bullying victimization was less common in older adolescent boys and girls. Weight status was associated with chronic bullying victimization (adjusted ORunderweight = 1.10, 95% CI = 1.05–1.16, p = 0.002; adjusted ORoverweight = 1.40, 95% CI = 1.32–1.49, p < 0.0001; adjusted ORobese = 1.91, 95% CI = 1.71–2.14, p < 0.0001). Body self-image also related to chronic bullying victimization (adjusted ORtoo thin = 1.42, 95% CI = 1.36–1.49, p < 0.0001; adjusted ORa little bit fat = 1.54, 95% CI = 1.48–1.61, p < 0.0001; adjusted ORtoo fat = 3.30, 95% CI = 2.96–3.68, p < 0.0001). Conclusion Both perceived weight and self-rated overweight are associated with chronic bullying victimization. Both overweight and underweight children are at risk of being chronically bullied.
Lian et al. (2018) The association between chronic bullying victimization with weight status and body self-image: a cross-national study in 39 countries. PeerJ 6:e4330 https://doi.org/10.7717/peerj.4330
The role of awareness of repetition during the development of automaticity in a dot-counting task
This study examined whether being aware of the repetition of stimuli in a simple numerosity task could aid the development of automaticity. The numerosity task used in this study was a simple counting task. Thirty-four participants were divided into two groups. One group was instructed that the stimuli would repeat many times throughout the experiment. The results showed no significant differences in the way automatic processing developed between the groups. Similarly, there was no correlation between the point at which automatic processing developed and the point at which participants felt they benefitted from the repetition of stimuli. These results suggest that extra-trial features of a task may have no effect on the development of automaticity, a finding consistent with the instance theory of automatisation.
Speelman et al. (2018) The role of awareness of repetition during the development of automaticity in a dot-counting task. PeerJ 6:e4329 https://doi.org/10.7717/peerj.4329
Evidence for widespread dysregulation of circadian clock progression in human cancer
The ubiquitous daily rhythms in mammalian physiology are guided by progression of the circadian clock. In mice, systemic disruption of the clock can promote tumor growth. In vitro, multiple oncogenes can disrupt the clock. However, due to the difficulties of studying circadian rhythms in solid tissues in humans, whether the clock is disrupted within human tumors has remained unknown. We sought to determine the state of the circadian clock in human cancer using publicly available transcriptome data. We developed a method, called the clock correlation distance (CCD), to infer circadian clock progression in a group of samples based on the co-expression of 12 clock genes. Our method can be applied to modestly sized datasets in which samples are not labeled with time of day and coverage of the circadian cycle is incomplete. We used the method to define a signature of clock gene co-expression in healthy mouse organs, then validated the signature in healthy human tissues. By then comparing human tumor and non-tumor samples from twenty datasets of a range of cancer types, we discovered that clock gene co-expression in tumors is consistently perturbed. Subsequent analysis of data from clock gene knockouts in mice suggested that perturbed clock gene co-expression in human cancer is not caused solely by the inactivation of clock genes. Furthermore, focusing on lung cancer, we found that human lung tumors showed systematic changes in expression in a large set of genes previously inferred to be rhythmic in healthy lung. Our findings suggest that clock progression is dysregulated in many solid human cancers and that this dysregulation could have broad effects on circadian physiology within tumors. In addition, our approach opens the door to using publicly available data to infer circadian clock progression in a multitude of human phenotypes.
Shilts et al. (2018) Evidence for widespread dysregulation of circadian clock progression in human cancer. PeerJ 6:e4327 https://doi.org/10.7717/peerj.4327
Evaluating the adaptive evolutionary convergence of carnivorous plant taxa through functional genomics
Carnivorous plants are striking examples of evolutionary convergence, displaying complex and often highly similar adaptations despite lack of shared ancestry. Using available carnivorous plant genomes along with non-carnivorous reference taxa, this study examines the convergence of functional overrepresentation of genes previously implicated in plant carnivory. Gene Ontology (GO) coding was used to quantitatively score functional representation in these taxa, in terms of proportion of carnivory-associated functions relative to all functional sequence. Statistical analysis revealed that, in carnivorous plants as a group, only two of the 24 functions tested showed a signal of substantial overrepresentation. However, when the four carnivorous taxa were analyzed individually, 11 functions were found to be significant in at least one taxon. Though carnivorous plants collectively may show overrepresentation in functions from the predicted set, the specific functions that are overrepresented vary substantially from taxon to taxon. While it is possible that some functions serve a similar practical purpose such that one taxon does not need to utilize both to achieve the same result, it appears that there are multiple approaches for the evolution of carnivorous function in plant genomes. Our approach could be applied to tests of functional convergence in other systems provided on the availability of genomes and annotation data for a group.
Wheeler et al. (2018) Evaluating the adaptive evolutionary convergence of carnivorous plant taxa through functional genomics. PeerJ 6:e4322 https://doi.org/10.7717/peerj.4322
Detours in long-distance migration across the Qinghai-Tibetan Plateau: individual consistency and habitat associations
Migratory birds often follow detours when confronted with ecological barriers, and understanding the extent and the underlying drivers of such detours can provide important insights into the associated cost to the annual energy budget and the migration strategies. The Qinghai-Tibetan Plateau is the most daunting geographical barrier for migratory birds because the partial pressure of oxygen is dramatically reduced and flight costs greatly increase. We analyzed the repeated migration detours and habitat associations of four Pallas’s Gulls Larus ichthyaetus across the Qinghai-Tibetan Plateau over 22 migration seasons. Gulls exhibited notable detours, with the maximum distance being more than double that of the expected shortest route, that extended rather than reduced the passage across the plateau. The extent of longitudinal detours significantly increased with latitude, and detours were longer in autumn than in spring. Compared with the expected shortest routes, proximity to water bodies increased along autumn migration routes, but detour-habitat associations were weak along spring migration routes. Thus, habitat availability was likely one, but not the only, factor shaping the extent of detours, and migration routes were determined by different mechanisms between seasons. Significant between-individual variation but high individual consistency in migration timing and routes were revealed in both seasons, indicating a stronger influence of endogenous schedules than local environmental conditions. Gulls may benefit from repeated use of familiar routes and stopover sites, which may be particularly significant in the challenging environment of the Qinghai-Tibetan Plateau.
Liu et al. (2018) Detours in long-distance migration across the Qinghai-Tibetan Plateau: individual consistency and habitat associations. PeerJ 6:e4304 https://doi.org/10.7717/peerj.4304