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Revealing the transfer pathways of cyanobacterial-fixed N into the boreal forest through the feather-moss microbiome
Get PDFBiological N fixation in feather-mosses is one of the largest inputs of new nitrogen (N) to boreal forest ecosystems; however, revealing the fate of newly fixed N within the bryosphere (i.e. bryophytes and their associated organisms) remains uncertain. Herein, we combined N tracers, high resolution secondary ion mass-spectrometry (NanoSIMS) and a molecular survey of bacterial, fungal and diazotrophic communities, to determine the origin and transfer pathways of newly fixed N within feather-moss ( ) and its associated microbiome. NanoSIMS images reveal that newly fixed N , derived from cyanobacteria, is incorporated into moss tissues and associated bacteria, fungi and micro-algae. These images demonstrate that previous assumptions that newly fixed N is sequestered into moss tissue and only released by decomposition are not correct. We provide the first empirical evidence of new pathways for N fixed in feather-mosses to enter the boreal forest ecosystem (i.e. through its microbiome) and discuss the implications for wider ecosystem function. [Abstract copyright: Copyright © 2022 Arróniz-Crespo, Bougoure, Murphy, Cutler, Souza-Egipsy, Chaput, Jones, Ostle, Wade, Clode and DeLuca.
Climatic similarity and genomic background shape the extent of parallel adaptation in Timema stick insects
Get PDFEvolution can repeat itself, resulting in parallel adaptations in independent lineages occupying similar environments. Moreover, parallel evolution sometimes, but not always, uses the same genes. Two main hypotheses have been put forth to explain the probability and extent of parallel evolution. First, parallel evolution is more likely when shared ecologies result in similar patterns of natural selection in different taxa. Second, parallelism is more likely when genomes are similar because of shared standing variation and similar mutational effects in closely related genomes. Here we combine ecological, genomic, experimental and phenotypic data with Bayesian modelling and randomization tests to quantify the degree of parallelism and its relationship with ecology and genetics. Our results show that the extent to which genomic regions associated with climate are parallel among species of Timema stick insects is shaped collectively by shared ecology and genomic background. Specifically, the extent of genomic parallelism decays with divergence in climatic conditions (that is, habitat or ecological similarity) and genomic similarity. Moreover, we find that climate-associated loci are likely subject to selection in a field experiment, overlap with genetic regions associated with cuticular hydrocarbon traits and are not strongly shaped by introgression between species. Our findings shed light on when evolution is most expected to repeat itself.</p
Metacognition during unfamiliar face matching
Get PDFKruger and Dunning (1999) described a metacognitive bias in which insight into performance is linked to competence: poorer performers are less aware of their mistakes than better performers. Competence-based insight has been argued to apply generally across task domains, including a recent report investigating social cognition using a variety of face-matching tasks. Problematically, serious statistical and methodological criticisms have been directed against the traditional method of analysis used by researchers in this field. Here, we further illustrate these issues and investigate new sources of insight within unfamiliar face matching. Over two experiments (total N = 1077), where Experiment 2 was a preregistered replication of the key findings from Experiment 1, we found that insight into performance was multi-faceted. Participants demonstrated insight which was not based on competence, in the form of accurate updating of estimated performance. We also found evidence of insight which was based on competence: the difference in confidence on correct versus incorrect trials increased with competence. By providing ways that we can move beyond problematic, traditional approaches, we have begun to reveal a more realistic story regarding the nature of insight into face perception
Tidal water exchange drives fish and crustacean abundances in salt marshes
Get PDFCoastal salt marshes provide important habitat for fishes and crustaceans, including species of commercial value that feed or take refuge in the marsh. Yet population abundances vary considerably between sites, often without clear explanation. We hypothesised that faunal abundance and mean size would be positively related to 2 physical properties that govern marsh accessibility to water-dependent species, as has been found on the southeastern coast of the USA: (1) the volume of water exchanged by tidal flooding, which gives access to the marsh, and (2) edge amount, the length of the water-vegetation borderline per unit area where species can take refuge and feed. Digital terrain models and tidal information were used to select 5 marshes in Wales, UK, that differed in edge amount and water exchange (52°N, 4°W). Fishes and crustaceans were sampled using baited traps, fyke nets and seine nets. In total, 15 species were caught, including commercially valuable brown shrimp, European eel and sea bass. We found water exchange volume, but not edge amount, boosted fish and crustacean abundances. Crab and sea bass sizes were both negatively affected by water exchange, while shrimp and fish sizes were unaffected. Our findings show how the mechanisms that drive fish and crustacean abundances and sizes vary between geographical regions. Feasibly, fisheries associations with marsh hydrogeomorphology might operate differently as well
Non‐native plant invasion can accelerate global climate change by increasing wetland methane and terrestrial nitrous oxide emissions
Get PDFApproximately 17% of the land worldwide is considered highly vulnerable to non-native plant invasion, which can dramatically alter nutrient cycles and influence greenhouse gas (GHG) emissions in terrestrial and wetland ecosystems. However, a systematic investigation of the impact of non-native plant invasion on GHG dynamics at a global scale has not yet been conducted, making it impossible to predict the exact biological feedback of non-native plant invasion to global climate change. Here, we compiled 273 paired observational cases from 94 peer-reviewed articles to evaluate the effects of plant invasion on GHG emissions and to identify the associated key drivers. Non-native plant invasion significantly increased methane (CH4) emissions from 129 kg CH4 ha−1 year−1 in natural wetlands to 217 kg CH4 ha−1 year−1 in invaded wetlands. Plant invasion showed a significant tendency to increase CH4 uptakes from 2.95 to 3.64 kg CH4 ha−1 year−1 in terrestrial ecosystems. Invasive plant species also significantly increased nitrous oxide (N2O) emissions in grasslands from an average of 0.76 kg N2O ha−1 year−1 in native sites to 1.35 kg N2O ha−1 year−1 but did not affect N2O emissions in forests or wetlands. Soil organic carbon, mean annual air temperature (MAT), and nitrogenous deposition (N_DEP) were the key factors responsible for the changes in wetland CH4 emissions due to plant invasion. The responses of terrestrial CH4 uptake rates to plant invasion were mainly driven by MAT, soil NH4+, and soil moisture. Soil NO3−, mean annual precipitation, and N_DEP affected terrestrial N2O emissions in response to plant invasion. Our meta-analysis not only sheds light on the stimulatory effects of plant invasion on GHG emissions from wetland and terrestrial ecosystems but also improves our current understanding of the mechanisms underlying the responses of GHG emissions to plant invasion
Temporal and spectral electrooculographic features in an aiming task
Get PDFElectrooculogram (EOG) studies in sport have focused on temporal oculomotor features such as the quiet eye (QE) period – the duration of the final fixation on the action’s visual target. On the one hand, it is unclear whether EOG can provide valid QE measurements due to its poor spatial resolution relative to the eye tracker (ET). On the other hand, EOG’s high temporal resolution facilitates extraction of time-frequency content through spectral decomposition. In this study, we aimed to (1) examine which EOG signal processing options and algorithms (eye position or velocity) yield the most valid QE measurements, (2) introduce a novel method—the EOG spectrogram—that describes both temporal and spectral oculomotor features, and (3) rank the utility of four oculomotor measures (QE-ET, QEEOG-pos, QE-EOG-vel, EOG spectrogram) for predicting motor performance on unseen data. We co-recorded EOG and ET while 16 participants of varying expertise putted golf balls to a 4-m distance target on a flat surface. Concurrent validity and temporal discrepancy analyses revealed that QE-EOG-pos and QE-EOG-vel are valid and accurate for certain processing options (channel, filter, thresholds). The EOG spectrogram—obtained through multi-taper Fast-Fourier-Transform— distinguished activity in lower frequencies (saccades) and higher frequencies (fixational activity) before and during movement execution. Nested cross-validation indicated that the EOG spectrogram yielded the lowest generalizability error and the greatest stability on unseen data, followed by a tie between QE-ET and QE-EOG-vel, and then by QE-EOGpos. Correlational analyses suggested a monotonic association between better motor performance and greater EOG high-frequency fixational activity (> 25 Hz) during movement execution
Vitamin D metabolites are associated with physical performance in young healthy adults
Get PDFPurpose This study aimed to determine vitamin D metabolites and vitamin D receptor (VDR) single-nucleotide polymorphism (SNP) relationships with physical performance. Methods In 1205 men and 322 women (94.8% White Caucasian, 22.0 ± 2.8 yr) commencing military training, we measured serum vitamin D metabolites (25-hydroxyvitamin D (25(OH)D) and 24,25-dihydroxyvitamin D (24,25(OH)2D) by high-performance liquid chromatography tandem mass spectrophotometry and 1,25-dihydroxyvitamin D (1,25(OH)2D) by immunoassay), VDR SNPs (rs2228570, rs4516035, and rs7139166 by polymerase chain reaction genotyping), and endurance performance by 2.4-km run, muscle strength by maximal dynamic lift, and muscle power by maximal vertical jump. Results Serum 25(OH)D was negatively associated with 2.4-km run time and positively associated with muscle power (β = −12.0 and 90.1), 1,25(OH)2D was positively associated with run time and negatively associated with strength and muscle power (β = 5.6, −1.06, and −38.4), and 24,25(OH)2D was negatively associated with run time (β = −8.9; P < 0.01), after controlling for age, sex, smoking, alcohol, physical activity, time outdoors, season, and body mass index. Vitamin D metabolites (25(OH)D, 1,25(OH)2D, and 24,25(OH)2D) together explained variances of 5.0% in run time, 0.7% in strength, and 0.9% in muscle power (ΔF P < 0.001). All performance measures were superior with low 1,25(OH)2D:24,25(OH)2D ratio (P < 0.05). VDR SNPs were not associated with physical performance (ΔFP ≥ 0.306). Conclusions Vitamin D metabolites accounted for a small portion of variance in physical performance. Associations between vitamin D metabolites and run time were the most consistent. VDR SNPs explained no variance in performance. Greater conversion of 25(OH)D to 24,25(OH)2D, relative to 1,25(OH)2D (i.e., low 1,25(OH)2D:24,25(OH)2D ratio), was favorable for performance, indicating 24,25(OH)2D may have a role in optimizing physical performance
Signature of CEF-phonon coupling in Kondo lattice system CeCuGa3
Get PDFWe present the results of inelastic neutron scattering (INS) measurements on Kondo lattice heavy fermion CeCuGa3. The low-temperature magnetic susceptibility exhibits an anomaly near 2.6 K associated with an antiferromagnetic transition which is further confirmed by the heat capacity measurement. The analysis of magnetic heat capacity Cmag (T) based on the crystal electric field (CEF) model reveals an overall CEF splitting of ∼ 21 meV. The INS data reveal two strong magnetic excitations near 4.5 and 6.9 meV, which, however failed to reproduce the observed Cmag (T). We therefore analyze the INS data by a model based on magneto-elastic (i.e. CEF-phonon) coupling which suggests that the excitations observed near 4.5 and 6.9 meV originate from the CEF-phonon coupling as observed in CeCuAl3 and CeAuAl3
Pre-competitive anxiety and autonomic responses in professional U-20 futsal players: Effect of the competition phase and game location
Get PDFThe study examined whether pre-competition anxiety and autonomic responses in elite futsal players change across the playoffs at away vs home venues. Heart rate variability, somatic and cognitive anxiety and self-confidence (by CSAI-2R questionnaire) were evaluated in nine male futsal players from a professional U-20 team, before competitive matches at the quarter-final, semi-final and final stages played at home and away venues. Two-way ANOVA for repeated measures was used, considering factor one the game location and factor two the playoff stage, with significance set at p<0.05. Significant effects of the playoff stage were demonstrated in the Mean of HR (F = 4.643; p = 0.014) and SD2 index (F = 14.83; p=<0.001)(quarter versus final). No difference was found for somatic and cognitive anxiety and self-confidence between the two factors. The results suggest that play at the final stage of the playoff, regardless of the game location, may cause higher physiological stress, demonstrated by elevated HR and decrease of SD2 index
Spotlight on coarse sediments: comparative characterization of a poorly investigated seafloor biotope in the German Bight (SE North Sea)
Get PDFExtensive marine benthos surveys have resulted in a solid understanding of the broad distribution pattern of seafloor biotopes in the southeastern North Sea (temperate northeast Atlantic region). However, due to the low spatial resolution of large-scale surveys, specific smaller-scale biotopes with scattered distribution have been insufficiently captured. Consequently, knowledge regarding the environmental characteristics and species inventories of some specific biotopes is still limited. We investigated the habitat characteristics and the macro-infauna (i.e., organisms in samples collected by a sediment grab and retained in a sieve with a mesh size of 1000 µm) of a spatially restricted, patchy coarse sediment (i.e., grain size fraction > 500 µm accounting for ≥ 60 % of the total sample mass) biotope in the German Bight over three consecutive years. Habitat and faunal characteristics were contrasted with four other benthic biotopes sampled at the same time to allow for a comparative evaluation. Our study revealed considerable fluctuations in grain size distribution among samples of the coarse sediment, potentially resulting from a frequent redistribution of sediments. A total number of 243 infauna taxa were identified at the 66 stations sampled over three consecutive years (16-33 stations per year) with a considerable proportion of endangered and rare species. The results highlight that previous studies have underestimated the species richness of the biotope. The focus on this previously poorly studied biotope type allowed us to detect species in the study region that were formerly unreported. The macro-infauna in the coarse sediments was characterized by comparatively high abundance and biomass, which may provide a rich food resource for organisms from higher trophic levels. Therefore, coarse sediments likely are an ecologically valuable seafloor biotope despite its limited coverage