Switching modalities in a sentence verification task: ERP evidence for embodied language processing

In an event related potential (ERP) experiment using written language materials only, we investigated a potential modulation of the N400 by the modality switch effect. The modality switch effect occurs when a first sentence, describing a fact grounded in one modality, is followed by a second sentence describing a second fact grounded in a different modality. For example, "A cellar is dark" (visual), was preceded by either another visual property "Ham is pink" or by a tactile property "A mitten is soft." We also investigated whether the modality switch effect occurs for false sentences ("A cellar is light"). We found that, for true sentences, the ERP at the critical word "dark" elicited a significantly greater frontal, early N400-like effect (270370 ms) when there was a modality mismatch than when there was a modality-match. This pattern was not found for the critical word "light" in false sentences. Results similar to the frontal negativity were obtained in a late time window (500700 ms). The obtained ERP effect is similar to one previously obtained for pictures. We conclude that in this paradigm we obtained fast access to conceptual properties for modality-matched pairs, which leads to embodiment effects similar to those previously obtained with pictorial stimuli

Copyright and cultural work: an exploration

This article first discusses the contemporary debate on cultural “creativity” and the economy. Second, it considers the current state of UK copyright law and how it relates to cultural work. Third, based on empirical research on British dancers and musicians, an analysis of precarious cultural work is presented. A major focus is how those who follow their art by way of “portfolio” work handle their rights in ways that diverge significantly from the current simplistic assumptions of law and cultural policy. Our conclusions underline the distance between present top-down conceptions of what drives production in the cultural field and the actual practice of dancers and musicians

Epidemic malaria and warmer temperatures in recent decades in an East African highland

Climate change impacts on malaria are typically assessed with scenarios for the long-term future. Here we focus instead on the recent past (1970–2003) to address whether warmer temperatures have already increased the incidence of malaria in a highland region of East Africa. Our analyses rely on a new coupled mosquito–human model of malaria, which we use to compare projected disease levels with and without the observed temperature trend. Predicted malaria cases exhibit a highly nonlinear response to warming, with a significant increase from the 1970s to the 1990s, although typical epidemic sizes are below those observed. These findings suggest that climate change has already played an important role in the exacerbation of malaria in this region. As the observed changes in malaria are even larger than those predicted by our model, other factors previously suggested to explain all of the increase in malaria may be enhancing the impact of climate change

Novel dimeric β-helical model of an ice nucleation protein with bridged active sites

<p>Abstract</p> <p>Background</p> <p>Ice nucleation proteins (INPs) allow water to freeze at high subzero temperatures. Due to their large size (>120 kDa), membrane association, and tendency to aggregate, an experimentally-determined tertiary structure of an INP has yet to be reported. How they function at the molecular level therefore remains unknown.</p> <p>Results</p> <p>Here we have predicted a novel β-helical fold for the INP produced by the bacterium <it>Pseudomonas borealis</it>. The protein uses internal serine and glutamine ladders for stabilization and is predicted to dimerize via the burying of a solvent-exposed tyrosine ladder to make an intimate hydrophobic contact along the dimerization interface. The manner in which <it>Pb</it>INP dimerizes also allows for its multimerization, which could explain the aggregation-dependence of INP activity. Both sides of the <it>Pb</it>INP structure have tandem arrays of amino acids that can organize waters into the ice-like clathrate structures seen on antifreeze proteins.</p> <p>Conclusions</p> <p>Dimerization dramatically increases the 'ice-active' surface area of the protein by doubling its width, increasing its length, and presenting identical ice-forming surfaces on both sides of the protein. We suggest that this allows sufficient anchored clathrate waters to align on the INP surface to nucleate freezing. As <it>Pb</it>INP is highly similar to all known bacterial INPs, we predict its fold and mechanism of action will apply to these other INPs.</p

Effect of ageing and exercise training on myokine expression responses to acute exercise

Age-related muscle loss is a major contributor to falls, fraility and mortality. It has been widely suggested that chronic, age-related inflammation contributes to the gradual loss of skeletal muscle mass that occurs with ageing. Indeed, ageing is associated with elevations in a number of circulating inflammatory proteins, many of which have detrimental effects on skeletal muscle growth and protein balance. Exercise training has been shown to reduce chronic inflammation and, therefore, may represent an appropriate means to reduce age-related inflammation and counteract sarcopenia. Yet few studies have evaluated the effect of aging on skeletal muscle expression of inflammatory proteins and the effect of acute and repeated exercise on these factors. The aim of the current study was to determine the effect of 12 weeks of resistance exercise training on the levels of myokines within skeletal muscle, both at rest and following an acute bout of exercise and to examine how these responses may vary in young and older subjects, thus evaluating the potential for exercise to reduce age-related muscle inflammation. Six healthy young (aged 18-25 years) and 8 healthy older men (aged 60-75 years) completed 12 weeks of resistance exercise training. Muscle biopsies were collected before and 2 h after an acute exercise bout at the beginning and the end of the 12 week training period. Muscle tissue was analyzed for the expression of key inflammatory (MCP-1, IL-8, IL-6 and TNF-α) and anti-inflammatory cytokines (IL-10, IL-13 and IL-4) via bead-based multiplex analysis. Acute exercise increased the expression of inflammatory myokines, while anti-inflammatory myokines remained unchanged. In contrast to the hypothesis for this study, neither age nor training had a significant effect on the expression of myokines within skeletal muscle either in the resting state or 2 hours following exercise. However, older individuals displayed an increased inflammatory response to exercise prior to training when compared to younger individuals. Twelve weeks of resistance exercise training appeared to normalize this difference. Given the variability in myokine levels between individuals and the small subject number in the current study, further research is required to confirm this findin

Ageing has no effect on the regulation of the ubiquitin proteasome-related genes and proteins following resistance exercise

Skeletal muscle atrophy is a critical component of the ageing process. Age-related muscle wasting is due to disrupted muscle protein turnover, a process mediated in part by the ubiquitin proteasome pathway (UPP). Additionally, older subjects have been observed to have an attenuated anabolic response, at both the molecular and physiological levels, following a single-bout of resistance exercise (RE). We investigated the expression levels of the UPP-related genes and proteins involved in muscle protein degradation in 10 older (60-75 years) versus 10 younger (18-30 years) healthy male subjects at basal as well as 2 hours after a single-bout of RE. MURF1, atrogin-1 and FBXO40, their substrate targets PKM2, myogenin, MYOD, MHC and EIF3F as well as MURF1 and atrogin-1 transcriptional regulators FOXO1 and FOXO3 gene and/or protein expression levels were measured via real time PCR and western blotting, respectively. At basal, no age-related difference was observed in the gene/protein levels of atrogin-1, MURF1, myogenin, MYOD and FOXO1/3. However, a decrease in FBXO40 mRNA and protein levels was observed in older subjects, while PKM2 protein was increased in older subjects. In response to RE, MURF1, atrogin-1 and FBXO40 mRNA were upregulated in both the younger and older subjects, with changes observed in protein levels. In conclusion, UPP-related gene/protein expression is comparably regulated in healthy young and old male subjects at basal and following RE. These findings suggest that UPP signalling plays a limited role in the process of age-related muscle wasting. Future studies are required to investigate additional proteolytic mechanisms in conjunction with skeletal muscle protein breakdown measurements following RE in older versus younger subjects

Identification of MicroRNAs Linked to Regulators of Muscle Protein Synthesis and Regeneration in Young and Old Skeletal Muscle

Over the course of ageing there is a natural and progressive loss of skeletal muscle mass. The onset and progression of age-related muscle wasting is associated with an attenuated activation of Akt-mTOR signalling and muscle protein synthesis in response to anabolic stimuli such as resistance exercise. MicroRNAs (miRNAs) are novel and important post-transcriptional regulators of numerous cellular processes. The role of miRNAs in the regulation of muscle protein synthesis following resistance exercise is poorly understood. This study investigated the changes in skeletal muscle miRNA expression following an acute bout of resistance exercise in young and old subjects with a focus on the miRNA species predicted to target Akt-mTOR signalling

Enhanced skeletal muscle ribosome biogenesis, yet attenuated mTORC1 and ribosome biogenesis-related signalling, following short-term concurrent versus single-mode resistance training

Combining endurance training with resistance training (RT) may attenuate skeletal muscle hypertrophic adaptation versus RT alone; however, the underlying mechanisms are unclear. We investigated changes in markers of ribosome biogenesis, a process linked with skeletal muscle hypertrophy, following concurrent training versus RT alone. Twenty-three males underwent eight weeks of RT, either performed alone (RT group, n = 8), or combined with either high-intensity interval training (HIT+RT group, n = 8), or moderate-intensity continuous training (MICT+RT group, n = 7). Muscle samples (vastus lateralis) were obtained before training, and immediately before, 1 h and 3 h after the final training session. Training-induced changes in basal expression of the 45S ribosomal RNA (rRNA) precursor (45S pre-rRNA), and 5.8S and 28S mature rRNAs, were greater with concurrent training versus RT. However, during the final training session, RT further increased both mTORC1 (p70S6K1 and rps6 phosphorylation) and 45S pre-rRNA transcription-related signalling (TIF-1A and UBF phosphorylation) versus concurrent training. These data suggest that when performed in a training-accustomed state, RT induces further increases mTORC1 and ribosome biogenesis-related signalling in human skeletal muscle versus concurrent training; however, changes in ribosome biogenesis markers were more favourable following a period of short-term concurrent training versus RT performed alon