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Aim: This study characterised the decoupling of internal-to-external workload in marathon running and investigated whether decoupling magnitude and onset could improve predictions of marathon performance. Methods: The decoupling of internal-to-external workload was calculated in 82,303 marathon runners (13,125 female). Internal workload was determined as a percentage of maximum heart rate, and external workload as speed relative to estimated critical speed (CS). Decoupling magnitude (i.e., decoupling in the 35–40 km segment relative to the 5–10 km segment) was classified as low (< 1.1), moderate (≥ 1.1 but < 1.2) or high (≥ 1.2). Decoupling onset was calculated when decoupling exceeded 1.025. Results: The overall internal-to-external workload decoupling experienced was 1.16 ± 0.22, first detected 25.2 ± 9.9 km into marathon running. The low decoupling group (34.5% of runners) completed the marathon at a faster relative speed (88 ± 6% CS), had better marathon performance (217.3 ± 33.1 min), and first experienced decoupling later in the marathon (33.4 ± 9.0 km) compared to those in the moderate (32.7% of runners, 86 ± 6% CS, 224.9 ± 31.7 min, and 22.6 ± 7.7 km), and high decoupling groups (32.8% runners, 82 ± 7% CS, 238.5 ± 30.7 min, and 19.1 ± 6.8 km; all p < 0.01). Compared to females, males' decoupling magnitude was greater (1.17 ± 0.22 vs. 1.12 ± 0.16; p < 0.01) and occurred earlier (25.0 ± 9.8 vs. 26.3 ± 10.6 km; p < 0.01). Marathon performance was associated with the magnitude and onset of decoupling, and when included in marathon performance models utilising CS and the curvature constant, prediction error was reduced from 6.45 to 5.16%. Conclusion: Durability characteristics, assessed as internal-to-external workload ratio, show considerable inter-individual variability, and both its magnitude and onset are associated with marathon performance. [ABSTRACT FROM AUTHOR]

This letter to the editor responds to a paper that compares different mathematical models for describing the relationship between exercise intensity and duration before task failure. The authors argue that a power law model is a better fit for a wide range of intensities and durations compared to the commonly used hyperbolic model. However, they also acknowledge that the hyperbolic model has physiological significance, particularly in terms of the critical power (CP) and work prime (W') parameters. The authors suggest that incorporating durability as a parameter may improve the accuracy of mathematical models for endurance performance. Overall, the letter emphasizes the importance of considering the physiological significance of parameters when choosing a mathematical model. [Extracted from the article]

Dear Editor, We appreciate the opportunity to reply to the letter by Yentes et al. regarding our publication, "A non-linear analysis of running in the heavy and severe intensity domains" (Hunter et al. [2]). Figure 1 shows power spectrum density plots for a participant for hip, knee, and ankle flexion/extension prior to smoothing of marker coordinates. 1 Power spectral density plots of the ankle, knee and hip joint of a trial from a single participant representative of the group mean prior to smoothing. [Extracted from the article]

Purpose: Altered movement complexity, indicative of system dysfunction, has been demonstrated with increased running velocity and neuromuscular fatigue. The critical velocity (CV) denotes a metabolic and neuromuscular fatigue threshold. It remains unclear whether changes to complexity during running are coupled with the exercise intensity domain in which it is performed. The purpose of this study was to examine whether movement variability and complexity differ exclusively above the CV intensity during running. Methods: Ten endurance-trained participants ran at 95%, 100%, 105% and 115% CV for 20 min or to task failure, whichever occurred first. Movement at the hip, knee, and ankle were sampled throughout using 3D motion analysis. Complexity of kinematics in the first and last 30 s were quantified using sample entropy (SampEn) and detrended fluctuation analysis (DFA-α). Variability was determined using standard deviation (SD). Results: SampEn decreased during all trials in knee flexion/extension and it increased in hip internal/external rotation, whilst DFA-α increased in knee internal/external rotation. SD of ankle plantar/dorsiflexion and inversion/eversion, knee internal/external rotation, and hip flexion/extension and abduction/adduction increased during trials. Hip flexion/extension SampEn values were lowest below CV. DFA-α was lower at higher velocities compared to velocities below CV in ankle plantar/dorsiflexion, hip flexion/extension, hip adduction/abduction, hip internal/external rotation. In hip flexion/extension SD was highest at 115% CV. Conclusions: Changes to kinematic complexity over time are consistent between heavy and severe intensity domains. The findings suggest running above CV results in increased movement complexity and variability, particularly at the hip, during treadmill running. [ABSTRACT FROM AUTHOR]

Polyploidization is frequently associated with increased transposable element (TE) content. However, what drives TE dynamics following whole genome duplication (WGD) and the evolutionary implications remain unclear. Here, we leverage whole-genome resequencing data available for ~300 individuals of Arabidopsis arenosa, a well characterized natural diploid-autotetraploid plant species, to address these questions. Based on 43,176 TE insertions we detect in these genomes, we demonstrate that relaxed purifying selection rather than transposition bursts is the main driver of TE over-accumulation after WGD. Furthermore, the increased pool of TE insertions in tetraploids is especially enriched within or near environmentally responsive genes. Notably, we show that the major flowering-time repressor gene FLC is disrupted by a TE insertion specifically in the rapid-cycling tetraploid lineage that colonized mainland railways. Together, our findings indicate that tetrasomy leads to an enhanced accumulation of genic TE insertions, some of which likely contribute to local adaptation. Why transposable elements (TEs) accumulate in polyploids and the evolutionary implications remain unclear. Here, the authors show that following whole genome duplication, relaxed purifying selection is the main driver of TE over-accumulation, which provides variants for rapid local adaptation. [ABSTRACT FROM AUTHOR]

A correction to this paper has been published: https://doi.org/10.1007/s00421-021-04671-y [ABSTRACT FROM AUTHOR]

The affiliation of Malin Jonell with Beijer Institute of Ecological Economics, The Royal Swedish Academy of Sciences, Stockholm, Sweden was inadvertently omitted. The original version of this Article contained errors in the author affiliations. The affiliation of Malin Jonell and Beatrice Crona with Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden was inadvertently omitted. [Extracted from the article]

Numerous studies have focused on the need to expand production of 'blue foods', defined as aquatic foods captured or cultivated in marine and freshwater systems, to meet rising population- and income-driven demand. Here we analyze the roles of economic, demographic, and geographic factors and preferences in shaping blue food demand, using secondary data from FAO and The World Bank, parameters from published models, and case studies at national to sub-national scales. Our results show a weak cross-sectional relationship between per capita income and consumption globally when using an aggregate fish metric. Disaggregation by fish species group reveals distinct geographic patterns; for example, high consumption of freshwater fish in China and pelagic fish in Ghana and Peru where these fish are widely available, affordable, and traditionally eaten. We project a near doubling of global fish demand by mid-century assuming continued growth in aquaculture production and constant real prices for fish. Our study concludes that nutritional and environmental consequences of rising demand will depend on substitution among fish groups and other animal source foods in national diets. Global demand for "blue food" is growing. In this quantitative synthesis, the authors analyse global seafood demand and project trends to 2050, finding considerable regional variation in the relationship between wealth and consumption. [ABSTRACT FROM AUTHOR]

Understanding how to take into account the breadth of considerations required by third-wave HCI remains a challenge when designing technologies. This requires an understanding of what embodiment means, and in particular, a collective notion of embodiment. Within the field of digital musical instrument (DMI) design, the need for a DMI to support musical agency has been recognised along with a view of the inter-relationship between musician, instrument, context and audience as an ecology has been developed. These considerations are consonant with an understanding of embodiment within this field. In this paper we describe a project in which a digital musical instrument was designed and developed adopting an approach informed by participatory design where musicians became integral to the design process. Through this process a practical understanding of the nature of musical agency and this ecology was developed. This understanding provides insights into the nature of embodiment and meaning making within a creative and performative practice, and is informative to the wider field of HCI as it seeks to understand considerations of embodiment. [ABSTRACT FROM AUTHOR]

Diverse adaptive visual processing mechanisms allow us to complete visual search tasks in a wide visual photopic range (>0.6 cd/m2). Whether search strategies or mechanisms known from this range extend below, in the mesopic and scotopic luminance spectra (<0.6 cd/m2), has yet to be addressed. Based on a study that addressed simple target discrimination in luminance environments using contrast-dependent behavioral efficiency functions, we assessed visual search in more complex-feature and conjunction-search paradigms. The results verify the previously reported deficiency windows defined by an interaction of base luminance and luminance contrast for more complex visual-search tasks. Based on significant regression analyses, a more precise definition of the magnitude of contribution of different contrast parameters. Characterized feature search patterns had approximately a 2.5:1 ratio of contribution from the Michelson contrast property relative to Weber contrast, whereas the ratio was approximately 1:1 in a serial-search condition. The results implicate near-complete magnocellular isolation in a visual-search paradigm that has yet to be demonstrated. Our analyses provide a new method of characterizing visual search and the first insight in its underlying mechanisms in luminance environments in the low mesopic and scotopic spectra. [ABSTRACT FROM AUTHOR]