This is a two-part study to determine one or more reliable physiological anchors for perception of effort. The purpose of Study 1 was to compare ratings of perceived exertion (RPE) at the ventilatory ...threshold (VT) in running, cycling, and upper body exercise with the premise that if RPE at VT did not differ across exercise modes, VT might provide a unique set of physiological inputs for perception of effort. For 27 participants, values for VT and for RPE at VT (Borg 6 to 20 scale) averaged 9.4 km⋅h−1 (SD = 0.7) and 11.9 km⋅h−1 (SD = 1.4) respectively in running, 135 W (SD = 24) and 12.1 W (SD = 1.6) in cycling, and 46 W (SD = 5) and 12.0 W (SD = 1.7) in upper body exercise. RPE did not differ, suggesting that VT may anchor effort perception. In Study 2, 10 participants performed cycle ergometer exercise for 30 minutes at their VT (M = 101 W, SD = 21), at their maximal lactate steady state (M = 143 W, SD = 22), and at their critical power (CP; M = 167 W, SD = 23). Mean end-exercise RPE were 12.1 (SD = 2.1), 15.0 (SD = 1.9), and 19.0 (SD = 0.5), respectively. The very close clustering of RPE during exercise at CP hints that the confluence of physiological responses at CP may (also) serve as a determinant in perception of effort.
In order to understand the social impact of digital platforms, we need to examine the ways in which they reconfigure space – not only through critique of that reconfiguring but also examination of ...the conditions within the spaces it forms. This article offers a typology of the injuries enacted by platform logistics, taking online retail as its focus and using Amazon as an exemplar. Cognitive Injury occurs when platforms act to conceal their operation from the awareness of users. Hidden Injury is enacted on the invisible labour that sustains platform functionality, a precarious workforce that labours under harsh conditions and within hostile spaces, somewhere below the cognisance of the user. Moral Injury speaks of the way that platform logistics, in concealing from awareness the conditions that sustain its operation, attacks the ability of users, or of a society at large, to act with responsibility. These injuries are shown to be at play in the processes that facilitate buying online and order fulfilment. It is argued that the speed of purchasing and delivery enacts an unconscious consumption, which dislocates users from the labour that delivers the goods, creating a kind of perceptual pollution that diminishes a sense of moral responsibility.
To (1) determine if wearing a cloth face mask significantly affected exercise performance and associated physiological responses, and (2) describe perceptual measures of effort and participants' ...experiences while wearing a face mask during a maximal treadmill test.
Randomised controlled trial of healthy adults aged 18-29 years. Participants completed two (with and without a cloth face mask) maximal cardiopulmonary exercise tests (CPETs) on a treadmill following the Bruce protocol. Blood pressure, heart rate, oxygen saturation, exertion and shortness of breath were measured. Descriptive data and physical activity history were collected pretrial; perceptions of wearing face masks and experiential data were gathered immediately following the masked trial.
The final sample included 31 adults (age=23.2±3.1 years; 14 women/17 men). Data indicated that wearing a cloth face mask led to a significant reduction in exercise time (-01:39±01:19 min/sec, p<0.001), maximal oxygen consumption (VO
max) (-818±552 mL/min, p<0.001), minute ventilation (-45.2±20.3 L/min), maximal heart rate (-8.4±17.0 beats per minute, p<0.01) and increased dyspnoea (1.7±2.9, p<0.001). Our data also suggest that differences in SpO
and rating of perceived exertion existed between the different stages of the CPET as participant's exercise intensity increased. No significant differences were found between conditions after the 7-minute recovery period.
Cloth face masks led to a 14% reduction in exercise time and 29% decrease in VO
max, attributed to perceived discomfort associated with mask-wearing. Compared with no mask, participants reported feeling increasingly short of breath and claustrophobic at higher exercise intensities while wearing a cloth face mask. Coaches, trainers and athletes should consider modifying the frequency, intensity, time and type of exercise when wearing a cloth face mask.
Higher scores on the personality trait of neuroticism, the tendency to experience negative emotions, are associated with worse mental and physical health. Studies examining links between neuroticism ...and health typically operationalize neuroticism by summing the items from a neuroticism scale. However, neuroticism is made up of multiple heterogeneous facets, each contributing to the effect of neuroticism as a whole. A recent study showed that a 12-item neuroticism scale described one broad trait of general neuroticism and two special factors, one characterizing the extent to which people worry and feel vulnerable, and the other characterizing the extent to which people are anxious and tense. This study also found that, although individuals who were higher on general neuroticism lived shorter lives, individuals whose neuroticism was characterized by worry and vulnerability lived longer lives. Here, we examine the genetic contributions to the two special factors of neuroticism-anxiety/tension and worry/vulnerability-and how they contrast with that of general neuroticism. First, we show that, whereas the polygenic load for neuroticism is associated with the genetic risk of coronary artery disease, lower intelligence, lower socioeconomic status (SES), and poorer self-rated health, the genetic variants associated with high levels of anxiety/tension, and high levels of worry/vulnerability are associated with genetic variants linked to higher SES, higher intelligence, better self-rated health, and longer life. Second, we identify genetic variants that are uniquely associated with these protective aspects of neuroticism. Finally, we show that different neurological pathways are linked to each of these neuroticism phenotypes.
Nitrogen is a key regulator of primary productivity in many terrestrial ecosystems. Historically, only inorganic N (NH(4)(+) and NO(3)(-)) and L-amino acids have been considered to be important to ...the N nutrition of terrestrial plants. However, amino acids are also present in soil as small peptides and in D-enantiomeric form. We compared the uptake and assimilation of N as free amino acid and short homopeptide in both L- and D-enantiomeric forms. Sterile roots of wheat (Triticum aestivum L.) plants were exposed to solutions containing either (14)C-labelled L-alanine, D-alanine, L-trialanine or D-trialanine at a concentration likely to be found in soil solution (10 µM). Over 5 h, plants took up L-alanine, D-alanine and L-trialanine at rates of 0.9±0.3, 0.3±0.06 and 0.3±0.04 µmol g(-1) root DW h(-1), respectively. The rate of N uptake as L-trialanine was the same as that as L-alanine. Plants lost ca.60% of amino acid C taken up in respiration, regardless of the enantiomeric form, but more (ca.80%) of the L-trialanine C than amino acid C was respired. When supplied in solutions of mixed N form, N uptake as D-alanine was ca.5-fold faster than as NO(3)(-), but slower than as L-alanine, L-trialanine and NH(4)(+). Plants showed a limited capacity to take up D-trialanine (0.04±0.03 µmol g(-1) root DW h(-1)), but did not appear to be able to metabolise it. We conclude that wheat is able to utilise L-peptide and D-amino acid N at rates comparable to those of N forms of acknowledged importance, namely L-amino acids and inorganic N. This is true even when solutes are supplied at realistic soil concentrations and when other forms of N are available. We suggest that it may be necessary to reconsider which forms of soil N are important in the terrestrial N cycle.
Individuals with lower socio-economic status (SES) are at increased risk of physical and mental illnesses and tend to die at an earlier age 1–3. Explanations for the association between SES and ...health typically focus on factors that are environmental in origin 4. However, common SNPs have been found collectively to explain around 18% of the phenotypic variance of an area-based social deprivation measure of SES 5. Molecular genetic studies have also shown that common physical and psychiatric diseases are partly heritable 6. It is possible that phenotypic associations between SES and health arise partly due to a shared genetic etiology. We conducted a genome-wide association study (GWAS) on social deprivation and on household income using 112,151 participants of UK Biobank. We find that common SNPs explain 21% of the variation in social deprivation and 11% of household income. Two independent loci attained genome-wide significance for household income, with the most significant SNP in each of these loci being rs187848990 on chromosome 2 and rs8100891 on chromosome 19. Genes in the regions of these SNPs have been associated with intellectual disabilities, schizophrenia, and synaptic plasticity. Extensive genetic correlations were found between both measures of SES and illnesses, anthropometric variables, psychiatric disorders, and cognitive ability. These findings suggest that some SNPs associated with SES are involved in the brain and central nervous system. The genetic associations with SES obviously do not reflect direct causal effects and are probably mediated via other partly heritable variables, including cognitive ability, personality, and health.
•Common SNPs explain 21% of social deprivation and 11% of household income•Two loci attained genome-wide significance for household income•Genes in these loci have been linked to synaptic plasticity•Genetic correlations were found between both measures of SES and many other traits
Individuals with lower socio-economic status (SES) are at increased risk of physical and mental illnesses. Hill et al. find extensive genetic correlations between SES and health, psychiatric, and cognitive traits. This suggests that the link between SES and health is driven, in part, by a shared genetic association.
Genetic correlations estimated from genome-wide association studies (GWASs) reveal pervasive pleiotropy across a wide variety of phenotypes. We introduce genomic structural equation modelling ...(genomic SEM): a multivariate method for analysing the joint genetic architecture of complex traits. Genomic SEM synthesizes genetic correlations and single-nucleotide polymorphism heritabilities inferred from GWAS summary statistics of individual traits from samples with varying and unknown degrees of overlap. Genomic SEM can be used to model multivariate genetic associations among phenotypes, identify variants with effects on general dimensions of cross-trait liability, calculate more predictive polygenic scores and identify loci that cause divergence between traits. We demonstrate several applications of genomic SEM, including a joint analysis of summary statistics from five psychiatric traits. We identify 27 independent single-nucleotide polymorphisms not previously identified in the contributing univariate GWASs. Polygenic scores from genomic SEM consistently outperform those from univariate GWASs. Genomic SEM is flexible and open ended, and allows for continuous innovation in multivariate genetic analysis.
Often, the glycolytic contribution in a bout of heavy or severe intensity exercise is estimated by multiplying the increase in blood lactate concentration above resting levels that is engendered by ...the exercise (in mM) by 3.3 (or 3) mL·kg
per mM. Our purpose was to verify the value of this conversion factor, using methods that were completely different from those of the original studies.
Six women (mean ± SD), age, 23 ± 1 year; VO
, 46 ± 4 mL·kg
·min
) and three men (23 ± 0 years; 54 ± 8 mL·kg
·min
) completed 6 min of heavy intensity exercise in conditions of normoxia and hypoxia (F
O
, ∼12%). VO
was measured throughout the exercise and 7 min of recovery. The increase in glycolytic contribution was estimated as the reduction in aerobic contribution in hypoxia, after correction for the effects of hypoxia on the oxygen demand and on the contribution from phosphocreatine. The peak post-exercise blood lactate concentration was measured in fingerstick blood samples.
The ratio between the increase in estimated glycolytic contribution (in mL·kg
) in hypoxia and the increase in peak blood lactate concentration (in mM) yielded an oxygen equivalent of 3.4 ± 0.4 mL·kg
per mM (range, 2.6 mL·kg
per mM to 4.0 mL·kg
1 per mM) for cycle ergometer exercise.
These results generally support the use of a common conversion factor to calculate the glycolytic contribution from post-exercise blood lactate concentrations. However, there is some inter-individual variability in the conversion factor.
1 Tissue Engineering and Reparative Dentistry, School of Dentistry, Cardiff University, Heath Park, Cardiff CF14 4XY, UK
2 School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3US, UK
...3 School of Medicine, University of West Virginia, Morgantown, WV 26506, USA
Biofilms provide a reservoir of potentially infectious micro-organisms that are resistant to antimicrobial agents, and their importance in the failure of medical devices and chronic inflammatory conditions is increasingly being recognized. Particular research interest exists in the association of biofilms with wound infection and non-healing, i.e. chronic wounds. In this study, fluorescent in situ hybridization (FISH) was used in combination with confocal laser scanning microscopy (CLSM) to detect and characterize the spatial distribution of biofilm-forming bacteria which predominate within human chronic skin wounds ( Pseudomonas aeruginosa , Staphylococcus aureus , Streptococcus sp. and Micrococcus sp.). In vitro biofilms were prepared using a constant-depth film fermenter and a reconstituted human epidermis model. In vivo biofilms were also studied using biopsy samples from non-infected chronic venous leg ulcers. The specificity of peptide nucleic acid (PNA) probes for the target organisms was confirmed using mixed preparations of planktonic bacteria and multiplex PNA probing. Identification and location of individual bacterial species within multi-species biofilms demonstrated that P. aeruginosa was predominant. CLSM revealed clustering of individual species within mixed-species biofilms. FISH analysis of archive chronic wound biopsy sections showed bacterial presence and allowed bacterial load to be determined. The application of this standardized procedure makes available an assay for identification of single- or multi-species bacterial populations in tissue biopsies. The technique provides a reliable tool to study bacterial biofilm formation and offers an approach to assess targeted biofilm disruption strategies in vivo .
Correspondence Sladjana Malic malics{at}cardiff.ac.uk
Abbreviations: CLSM, confocal laser scanning microscopy; CDFF, constant-depth film fermenter; CVLU, chronic venous leg ulcer; FISH, fluorescent in situ hybridization; PNA, peptide nucleic acid; RHE, reconstituted human epidermis
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